Islam Is The Third And Newest Religion Of Abrahamic Faiths

1a. Islam (5) You often hear that Islam is the third and newest religion of the Abrahamic faiths (after Judaism and Christianity). However, you have read and heard that Islam does not understand itself as a â€Å"new† religion. Please describe how Islam understands itself as a continuation of monotheism and a correction of Judaism and Christianity. You can make reference to certain Qur’anic ideas which we discussed in class and include considerations of historical objects like the Kaaba in your answer. You are also welcome to use ideas found in the readings. Word Limit: 100 – 150 Firstly, the word Islam literally means â€Å"one who surrenders† [to Allah], in Arabic (http://muslimvoices.org/word-islam-meaning/). This directly and instantaneously expresses the direct continuation of monotheism that Islam understands itself as. For example the Qur’an describes the Kaaba, the most sacred place in the Islamic world, to have been built by the recognized father of Judaism and Christianity, Abraham. Islam recognizes itself not only as the continuation of the monotheism spoken by Judaism and Christianity but also as the correction of it. The Islamic belief is that Judaism and Christianity originally taught the word of God, but eventually corrupted it. While Islam recognizes Judaism and Christianity as religions originating from the same God as it does, Muslims believe that Islam supersedes Judaism and Christianity; the Qur’an is the final, undivided word of God and Muhammad is the last of the

A Study of Water Quality Near to a Coral Reef Site in the...

Canadian Journal on Chemical Engineering Technology Vol. 3 No. 3, April 2012 A Study of Water Quality Near to a Coral Reef Site in the Region of Dubai, United Arab Emirates Rami El Khatib, Adnan Falah, Golaleh Tavakoli, Christine D cruz and Jasmine Pereira Abstract — The water quality near to a coral reef site in Jebel Ali, Dubai, United Arab Emirates (UAE) was studied. Many Physico-Chemical parameters for water samples taken at two different depths (0.5 m and 1.0 m) parallel to a coral reef site were measured and analyzed. The data showed that the pH is equal to 6.4, 6.1 respectively which indicates an acidic environment. The average of total dissolved solids (TDS) is approximately equal to 43,600 mg/L and 43,200†¦show more content†¦Coastal engineering, land reclamation and dredging have also caused severe damage to corals along the mainland coast, especially in UAE and Bahrain. -Authors: Rami El Khatib (Correspondence), Adnan Falah, Golaleh Tavakoli, Christine D cruz and Jasmine Pereira, School of Environment and Health Sciences, Canadian University of Dubai, Dubai, UAE. 54 Canadian Journal on Chemical Engineering Technology Vol. 3 No. 3, April 2012 II. MATERIALS AND METHODS Chemicals, reagents used for water analysis experiment were of Hana, HPLC grade and were stored under dry conditions. HANA Spectroquant tests Kits are used to measure the concentration of inorganic species in water spectrophotometrically. Instruments, HI 83200 Multiparameter Bench Photometer was used to measure the concentration of inorganic species in water at specific wavelength (ÃŽ »nm), using appropriate reagents HANA Spectroquant test Kits plus spectrometer in the wavelength range 190 – 1100 nm using 1 cm matched quartz cells. Sample collection, sea water samples were collected from six points parallel to the coral reef. Three samples were taken 8m from the shore at a depth of 0.5 m and three samples were taken 15m from the shore at a depth of 1.0 m (Fig. 3). Samples were then analyzed within one week from the time of collection. Water samples collected were subjected to: Fig.1 United ArabShow MoreRelatedBurj Al Arab4747 Words   |  19 PagesKsenia Kozlova European University Burj Al Arab - Dubai, United Arab Emirates Reasons for the choice I have chosen the Burj al Arab hotel for the following reasons: first of all I have been twice in Dubai, and I have really enjoyed it, then it has been my dream for the last two years to come back to the UAE and to spend at least one night in this wonderful hotel. I hope my dream will come true this year. I am planning to visit this country this September, that’s why I’veRead MoreDevelopment and Globalisation Essay7740 Words   |  31 PagesDevelopment and Globalisation Development A process of social and economic advancement in terms of the quality of human life. Development can involve can involve economic, demographic, social political and cultural changes. Development is a term that can be used in many different contexts whether it is social, economical, political etc. However generally development refers to an improvement in certain areas: †¢ Economic o An increase in the country’s economy with

Global Climate Change Essay Example For Students

Global Climate Change Essay Climate change is not a new concept; in fact there is evidence of major climate changes throughout the earths history. However since the industrial revolution and especially since world war two, there has been an unprecedented change in the earths atmosphere (Gates 4). As of March 1999, scientists reported the construction of a thousand-year record of the average temperature on earth. The results of their study concluded that a nine hundred-year cooling trend has been decisively reversed within the last fifty years (Bell and Strieber 9-10). The effects of these rapid atmospheric changes are seen in increased storm intensity, rising seas, drier cropland, dying forests and coral reefs, proliferating diseases, floods, droughts, fires, and heat waves (Gates 2). These effects have hit home for many in the United States already with the intense flooding of the southeast coast that came with hurricane Opal in 1995 and the extensive flooding of the southeast Florida coast from hurricane Hugo in 1998 (Read 68). These storms are causing increasing amounts of damage due to their growing sizes. In June of 1999, a tornado struck the Midwest with record-breaking winds reaching up to three hundred and thirteen miles per hour (Bell and Strieber 126). #Also in 1999, hurricane Floyd set a record by reaching the size of Texas at its strongest point. Increasing numbers of forest fires spread throughout the southwestern regions of the United States every year. By June of 1998, after a great period of drought, giant fires in Texas together with fires in Mexico and Guatemala created a cloud of smoke thousands of miles long and thick enough to block the suns light at noon in the worst places. This was the second worst fire outbreak ever recorded in human history (Bell and Strieber). It is clear that our temperatures are rising around the globe, but by how much, and how fast? While some scientists disagree about the cause or rate at which the earth is warming, scientific research leads us to believe that the temperature rise is real (Verma 125-127). The global average temperature is predicted to rise somewhere between 1 and 3.5 Celsius degrees by 2100, according to the rate of carbon emissions and other greenhouse gasses that continue to be emitted (Flavin and Dunn 6). In 1998 the global average temperature exceeded even the most radical global warming models whose predictions were as recent as 1995. 1998 ended up as the warmest year recorded in history until 1999, when it became clear that temperatures were rising much faster than ever expected (Bell and Streiber). Contrary to popular belief the greenhouse effect is not a bad thing. It is completely natural and it is in fact vital to our survival on earth. Without the greenhouse effect, the world would actually be about 33 degrees Celsius colder (Read 28). In recent years however, we have been experiencing too much of a good thing. Greenhouse gasses prevent the suns heat from escaping the earths atmosphere after it enters, making the temperature rise. We base our global warming models on the amount of carbon dioxide and other greenhouse gasses humankind is releasing into the air (Bell and Strieber 197). The acceleration of global warming can be linked to an increase in industry, forest destruction, and agriculture, which are major producers of greenhouse gasses such as carbon dioxide and methane (Gates 1). In the last 160,000 years before the industrial revolution the concentration of carbon dioxide, the most prevalent of the greenhouse gasses in the atmosphere, never exceeded about 280 parts per million. Since then, carbon dioxide has risen to about 360 parts per million and continues to rise (Read 39-40). The major cause of the increase in carbon dioxide in the atmosphere is the burning of fossil fuels like, coal and petroleum (Budyko 185-186). Methane, another greenhouse gas, is 70 times more effective at trapping heat than carbon dioxide. Methane is increasing by about 1% every year, which is twice as fast as carbon dioxide. .u86e92a8c408ec1cf1406578a6124ad55 , .u86e92a8c408ec1cf1406578a6124ad55 .postImageUrl , .u86e92a8c408ec1cf1406578a6124ad55 .centered-text-area { min-height: 80px; position: relative; } .u86e92a8c408ec1cf1406578a6124ad55 , .u86e92a8c408ec1cf1406578a6124ad55:hover , .u86e92a8c408ec1cf1406578a6124ad55:visited , .u86e92a8c408ec1cf1406578a6124ad55:active { border:0!important; } .u86e92a8c408ec1cf1406578a6124ad55 .clearfix:after { content: ""; display: table; clear: both; } .u86e92a8c408ec1cf1406578a6124ad55 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u86e92a8c408ec1cf1406578a6124ad55:active , .u86e92a8c408ec1cf1406578a6124ad55:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u86e92a8c408ec1cf1406578a6124ad55 .centered-text-area { width: 100%; position: relative ; } .u86e92a8c408ec1cf1406578a6124ad55 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u86e92a8c408ec1cf1406578a6124ad55 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u86e92a8c408ec1cf1406578a6124ad55 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u86e92a8c408ec1cf1406578a6124ad55:hover .ctaButton { background-color: #34495E!important; } .u86e92a8c408ec1cf1406578a6124ad55 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u86e92a8c408ec1cf1406578a6124ad55 .u86e92a8c408ec1cf1406578a6124ad55-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u86e92a8c408ec1cf1406578a6124ad55:after { content: ""; display: block; clear: both; } READ: Bioethics Essay However, methane levels in our atmosphere are much lower than carbon dioxide levels. Some major sources of methane include the anaerobic decomposition of organic material such as cattle manure and rice paddies; the extraction, refining, and distribution of .

The Worn Path free essay sample

With her long dress and unlaced shoes, Phoenix Jackson the protagonist of the story lets nothing stop her on her journey in the frigid December weather. In Eudora Welty’s â€Å"A Worn Path,† Phoenix Jackson is an unpredictable old Negro woman who is determined to acquire the medication for her â€Å"ill†grandson, and through all of the tough obstacles she somehow pulls through and reaches her goal, aside from her thoughts that ties into the story. It seems like she is living in denial and as if she has walked this whole â€Å"worn path† only to compensate herself and make herself feel better about the true situation she is in after the loss of her grandson. In â€Å"A Worn Path,† Eudora Welty portrays Phoenix as a very old and small Negro woman who may seem ready to pass through anything that is thrown her way, but the descriptions of some events contain psychological connection to the story line. We will write a custom essay sample on The Worn Path or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The story itself is quite simple but the way Welty uses metaphors and irony is how the psychological connection comes into play. Phoenix may always seem to know what exactly is going on around her, but the way she describes certain events can lead us to believe she’s not exactly in the right state of mind. Her denial thoughts leave us to not know any of her upcoming reactions. First, Phoenix shows she is experiencing some Denial hallucinations such as when she describes the little boy bringing her a piece of marble cake and when she reaches out to take it from his hand Welty explains, â€Å"But when she went to take it there was just her hand in the air. † The dark setting of this story shows she may be feeling quite lonely and that is why she may have thought she saw a little boy. This little boy may have just been a past thought of her young grandson. Also, Welty wrote in her story that Phoenix later went through a â€Å"corn maze† when really there was no path at all, but it led her to a scarecrow that Phoenix thought was a ghost. She asked the â€Å"ghost† a few simple questions, but when she got no answer that is when she realized it was just a scarecrow, yet she still talked to him as if he were a real person and she says, â€Å"My senses is gone I too old. I the oldest people I ever know. Dance, old scarecrow† She said, â€Å"while I dancing with you. †(Welty). Next, Phoenix shows some different acts of denial when she comes about the scarecrow she seems as if she is a bit relieved when she realizes that it was not a ghost like she thought. We know she seems relieved because after seeing it was not a ghost Welty describes Phoenix’s face as, â€Å"Her face lighted†. When being relieved that the scarecrow was not a ghost, but then not being scared at all when the hunter later pointed his gun right at her face. She seems to not stick with just one sense in her personality Phoenix shows moments when she is aware of the truth and other when she’s in denial. The scarecrow for instance could have also reminded her of her grandson in the sense that she thought it was a ghost and when the hunter pointed the gun to her face maybe she was not afraid because she knows that her grandson is not just ill, but he has already passed on so she misses him enough to not care if she would be shot to death and later be reunited with him in heaven. According to Frauds theory Psychoanalytical Criticism he argues that ‘we develop defenses: selective perception, selective memory, denial, displacement, projection, regression, fear of intimacy, and fear of death, among others. Later, towards the ending of the story, Welty portrays Phoenix as being confused as well. As Phoenix is sitting in the doctor’s office she says nothing back to the nurse who is asking her questions, she just sits upright in her chair with a straight look on her face. The nurse asks a few questions, but one question really triggers Phoenix and she finally answers back. The nurse asked, â€Å"Tell us quickly about your grandson, and get it over. He isnt dead, is he? † and that is when Phoenix replies, â€Å"My grandson. It was my memory had left me. There I sat and forgot why I made my long trip. † The whole time in the doctor’s office she acts as if she is confused and has lost all parts to her memory. This also could be because she does not want to admit that her grandson has passed away, therefor Phoenix is in denial and does not even know what’s real or fake anymore and is in a state of confusion. â€Å"The Worn Path† by Eudora Welty is about an African American that uses her determination to head into town for Medicine for her grandson. This is where Jackson faces most of her obstacles during the journey, but she fears nothing because of the state of denial she is in. Phoenix is showing signs of not knowing what’s going on in true reality compared to what she wants to be true, however this is where is think the denial comes into play. She’s in denial that her grandson is dead, and when she encounters the hunter, scarecrow that is the reason we get two different reactions because she is a state of denial that she doesn’t know what real anymore. Therefore, we as readers are left in a state questioning ourselves whether or not Phoenix’s grandson is dead or alive.

Inetrview with a person from a controlled environment essays

Inetrview with a person from a controlled environment essays What controlled environment did you spend time in? How long? When I graduated from High School I entered into the Merchant Marine Academy at Fort Schuyler in New York. From then until I was in my mid thirties I was involved with ocean liners, tankers and ships. For periods of one year at a time I would be on a ship traveling the world, making shipments and patrolling the seas. The controlled environment was both on the ship and in the academy. Once on the ship I had to obey the rules and morals taught to us in the academy. Was there an effort to separate you from your former identity? No not really. Contrary to the NAVY, ARMY or Marines our boot camp was less severe and did not include such physical conditioning. Our personalities were not changed because we were not in combat and did not have to learn to be a killing machine. What were the most important rules you had to follow? Besides not falling in the water, we had to obey almost everything our captain told us. Our captain was like our parents his wishes were our commands. The captain set the standards and the rules for us to follow. What were the least and less important rules you had to follow? There was a uniform but it was not very important that we followed it. As an officer we had to look respectable but usually the uniform requirements were not met. We also had a curfew but that was rarely followed and it was rare for a person to get into any trouble for breaking curfew. What were some of the make-dos the inmates made up for their deprivations with? Since there was no T.V. almost every night after dinner we held chess and checkers tournament. The games were fast paced and mostly just for fun, no money was ever wagered. We also drank a lot of beer when we were at sea for extended amounts of time. Which were accepted by the authorities and which were not? Well the chess tournaments everyone enjoyed and we ...

French Prepositions with Geographical Names

French Prepositions with Geographical Names Deciding which French  preposition  to use with countries, cities, and other  geographical names  can be somewhat confusing, at least until now! This lesson will explain which prepositions to use and why. Gendered Nouns Like all French  nouns, geographical names like countries, states, and provinces have a  gender. Knowing the gender of each geographical name is the first step in determining which preposition to use. As a general guideline, geographical names which end in  e  are  feminine, while those that end in any other letter are masculine. There are, of course, exceptions which simply have to be memorized. See the individual lessons for explanations of the gender of each geographical name. Examples In English, we use three different prepositions with geographical names, depending on what we are trying to say. Je vais  en  FranceIm going  to  FranceJe suis  en  FranceIm  in  FranceJe suis  de  FranceIm  from  France However, in French numbers 1 and 2 take the  same  preposition. Whether you are going  to France or you are  in  France, the same preposition is used. Thus in French there are only two prepositions to choose from for each type of geographical name. The difficulty lies in knowing which preposition to use for a city vs a state vs a country.

Critical analysis do not go gentle into that good night by dylan Essay

Critical analysis do not go gentle into that good night by dylan thomas - Essay Example Like many other poets, life and death and the new life binding new generations also attracted him. His poem, Do not go gentle into that night has very much attracted the readers with various factors. BBC writes, â€Å"Perhaps the most striking thing about Do Not Go Gentle is the contrast between its form, which is strict, regular and controlled, and its message, which incites the man to "rage against the dying of the light† (BBC Wales arts). The poem has been written in the villanelle style through which the poet could create a wonderful impact among the readers. The critical analysis of the poem is conducted on the grounds that the poem discloses his thoughts and experiences of death. Analysing the theme of the poem one can see the poet addressing his father, the retired military man, who is approaching death. For the poet one should be very vigilant when approaching death. He insists, "Do not go Gentle into that Good Night." Here the poet differs from other poets who exhort to face death gently. ‘Good Night’ here stands for death or the last night for which one waits for. This is to be noted that the poem presents the various perspectives of death from different people who all demonstrated one common struggle to hold on to life (123helpme.com). The second and the third line of the poem make clear theme of the poem when he writes, â€Å"Old age should burn and rage at close of day/Rage, rage against the dying of the light† (Line 2-3). For the poet, when one reaches in his/her old age, one should burn with burn with emotion at ‘close of day,’ that is, against the all powerful death. The poet stresses burning and raging in the third line which is used as a refrain and the repetition of the word ‘rage.’ The following stanzas of the poem clearly indicate how the wise men, good men, wild men and grave men react to the call of death. The poet presents these men in order to make clear the fact that death is unavoid able and it is the natural tendency of man to fight against or using his all weapons to prevent it. Very often, it may not be for their own sake, but for assuring their close ones security and hope that they will be there forever. Addressing his father, the poet reveals the general truth and as a supporting factor, he produces the examples of wise men, good men, wild men and grave men, that is, they are regretted in leaving this world. Though it is difficult for one to identify these elements directly from the poem except in the line, ‘Curse, bless me now with your fierce tears, I pray’ (Line17). Therefore, it is evident of the poet’s understanding of people’s attitude to life and death. The poet persuades his father, who was a militant man, to â€Å"rage against the dying of the light† through the examples of the wise, good, wild and grave men. The unwillingness of the wise men is suggestive of the unwillingness of man to accept death easily. Whene ver man feels that he has not accomplished all his desires—which one can never attain in one’s life, he hesitant to receive death. Thus, one can infer that the poet was trying to affirm man’s unwillingness to accept the imminent death. The poet has also used various poetic devices and symbolisms to make his propositions more effective. The use of the literary device villanelle with the rhyme scheme alternating between ‘night’ and ‘day’ really enhances the beauty of the poem. The use of the complex style

Multilingualism in new york Essay Example | Topics and Well Written Essays - 500 words

Multilingualism in new york - Essay Example If these current trends are not reversed, then the endangered languages are soon going to be extinct within the next century (Welcher). Attempts to prevent the extinction of endangered language have resulted to the formation of the Endangered Language Alliance. Therefore, a student at The City University of New York with basic linguistic fieldwork who wills to take part in documenting the endangered language should join the group and together with the members. The student should also develop an interest in learning those languages that are almost facing extinction. Grenoble & Lindsay (85) asserts that vast knowledge of the endangered language will act as a security incase the language becomes extinct. This will ensure that all facts regarding the language do not disappear all at once. Secondly, the student may visit the speakers of the endangered languages and conduct interviews. While conducting the interviews, the student is expected to make audio tapes and videotapes, as well as make written records of the endangered languages used in informal and informal settings (Davis 76). The translations of the endangered language are also included in the recordings so as to preserve the data in the best appropriate manner to avoid confusion in the future. Analysis of the vocabulary and rules of the endangered language is an initiative that helps significantly preserve the endangered languages. In addition to that, the student should write grammars and dictionaries of these languages that they wish to preserve (Grenoble & Lindsay 45). Working hand in hand with other linguists’, the student should visit neighboring communities within the city of New York to meet speakers who are willing to preserve their language. While visiting the endangered language speakers, the student should offer practical and technical help with language maintenance, teaching and revival. The assistance comes about while working on the grammars and

Classical conditioning Essay Example for Free

Classical conditioning Essay Classical conditioning is a form of basic learning the body automatically responds to a stimulus. One stimulus takes on the properties of another. The Russian physiologist Ivan Pavlov (1849-1936) is credited for discovering the basic principles of classical conditioning whilst he was studying digestion in dogs. He developed a technique for collecting dog’s salivary secretions. Pavlov (cited in Eysneck M.W 2009) noticed that the dogs would often start salivating before they were given any food or saw the feeding bucket or even when they heard the footstep of the laboratory assistant coming to feed them. Quite by accident Pavlov had discovered that the environmental control of behaviour can be changed as a result of two stimuli becoming associated with each other. These observations led to what’s now called classical conditioning. A neutral stimulus (such as a bell) which normally wouldn’t produce a response (such a salivating) eventually becomes paired with another stimulus (such as the food) this is referred to an unconditional response. When the bell and food (unconditional stimulus) are paired often enough the dogs start to salivate as soon as they hear the bell and before the food is served. When this occurs conditioning has taken place. (Cited in Burns 1995) Pavlov argued that if dogs could be conditioned to salivate then it is possible to apply the process to bodily process that effect illness and mental health disorders. Nowadays classical conditioning is applied in the treatment of phobias and in aversion therapies.(Cited in Burns 1995). Operant conditioning Operant conditioning is the process of a behaviour in which the likelihood of a specific behaviour is increased or decreased through positive or negative reinforcement. The theory is based on Thorndike (1993) law of effects which state that behaviour is a function of its consequences (cited in O’ Brien 2009). Skinner used observation as a leading approach to operate conditioning. A key principle of operant conditioning was that where behaviour is reinforced (that is where people are rewarded when they behave in a particular way). It will tend to be repeated under particular circumstances. (Cited in Gross R 2010). For example a mother picking up a crying infant and if the baby stops crying when picked up, the probablility of the mother repeating the same behaviour increases since the cessation of the baby’s crying is a reinforced.(Gerry, K et alt page45) . Reinforcers can also be primary or secondary. Primary reinforcers are our basic needs like food, water and shelter. Secondary reinforcers are events that have become rewarded through their association. For example money, because money can satisfy people needs it takes on reinforcing characteristics of its own. Operant conditioning can be used in behaviour management and in education, for example children are rewarded when they do well in school and punished if they fail, if they see someone getting rewarded they are more likely to copy the good behaviour. Operant conditioning can also be used to help people with addictions along with classical conditioning,for example in alcohol and drug addiction. Operant conditioning is also used in pain management and in social skills training. It has also been used to reward schizophrenic patients for good behaviour. For example given them tokens in exchange for sweet when they behave well in hospital.(Aylon Azrin,1968,cited in Eysenck 2009). Social Learning The social learning theory proposed by Albert Bandura (1965), has become the most influential theory of learning and development. Bandura argued that direct reinforcement could not account for all types of learning. He argued that people could learn new information by observing other people this type of learning can be used to explain a wide variety of behaviours.(Cited in Eysenck, M 2009) for example Teenagers wanting to be thin like the models that they observe on the television or on the computer. Bandura (1965) Three groups of young children watched a film about adults behaving aggressively towards inflatable Bobo dolls. In one of the films it showed adults being rewarded for aggressive behaviour. The second group were scolded and the third group were neither rewarded or punished. All children showed increased aggression if offered a reward for what they learnt, and the behaviour decreases if they are punished. (Cited in Gross 2009). for example social learning can be learnt thro ugh the media. Pop stars are often seen as role models, and children of smokers are more likely to smoke when they are adults. Phobic patient benefit more from watching fearful patients gradually overcome their fears. (Cited in Gerry,K.et alt 1996) There are three core concepts in social learning, first learning through observation, mental state is essential part of the process and the theory also recognises that just because something is learnt doesn’t mean it will result in a change in behaviour.(cited in Burns 1995)Positive reinforcement is far more effective than negative reinforcement. Bandura believed that observation and direct reinforcement could account for all types of learning. He argued that emotional behaviour could be switched off through modelling procedure. Learning need not necessarily be correct. Through learning human behaviour can be modified. Learning is very important when working in social care, helpers need to know how to modify client’s attitude toward their illness so the helper can work with them to recover.(cited in Burns 2005)

Romeo and Juliet by William Shakespeare as a Tragedy Essay -- Papers

Romeo and Juliet by William Shakespeare as a Tragedy "Romeo and Juliet" is considered by most people to be Shakespeare's most tragic work. Two young people die for their love for each other - what can be more purer, romantic and tragic than that. But is it as simple as that? What does actually make the play so tragic? Before we can discuss the tragic aspects of Romeo and Juliet, we must first understand the meaning of the term 'tragedy'. The Chambers Dictionary defines tragedy as" a type of drama dealing with tragic events and often involving the fall of an honourable, worthy and important protagonist, often with elevated action and language; a play of this type; the art of such drama; any piece of literature, music, etc ending with disaster for the protagonist; a disaster, any sad story or turn of events; any event involving killing". Romeo and Juliet is a tragedy by the definition in the dictionary. Both lead roles, Romeo and Juliet, die in the play, therefore making it tragic. However there are many more factors which are typical of Shakespeare' tragedies which occur, and some factors which make the play less tragic. Juliet is a more tragic figure because she has no real control over her life at all. The arrival of Romeo and their subsequent love affair gives her an alternative to a life controlled by her father and his choice of husband for her - she could run away and live a romantic life with Romeo. At the end both Romeo and Paris are dead so even if she survived there would be no future for Juliet. Main characters in Shakespeare's plays are often quite innocent and are swept along by other events happening at the time, for e... ...nciliation with her father. Her union with Romeo has lost Juliet her family whatever the outcome. 'Romeo and Juliet' was written as a tragedy, and is still seen as such over four hundred years later. A modern day audience may react differently to some aspects of the play - the treatment of women and the age of Juliet, for example. In our society, Juliet would still be considered a child and Romeo would be in as much trouble for his marriage to underage Juliet as he would be for the murder of Tybalt. Yet, despite that, our sympathies are with the young couple who were not responsible for the feud between their parents but who had to suffer the consequences. The tragedy is inevitable from the beginning. From the moment Romeo first sees Juliet and they share their first kiss they hurtle headlong towards their death.

Aquinas Epistemology and God Essay

Introduction:The scientific developments of the renaissance were powerful and they stimulate new ways of thought that one can be tempted to disregard any role medieval thinking plays in the general development of both renaissance and post renaissance philosophy up till today. It would be a mistake to take it that Descartes, Locke achieved a total radical break from the past and inaugurated a completely new philosophical era. One cannot understand scholars like Descartes or Locke without having some real knowledge of medieval thinking. Thus, in this essay, I wish to show that Aquinas, a thinker of the middle ages, thought on knowledge is of permanent value and that it deserves respect and due consideration for today’s discourse of philosophy. Aquinas Theory on Knowledge: His philosophy is based on the premise that knowledge and being are correlates. â€Å"In so far a thing is, it is knowable and in this resides its ontological truth. † Thus, the Thomistic theory of knowledge is a realist theory. It plays an integral part in his metaphysics and philosophy of being. Aquinas is not interested in the problem of objective as we have it in modern thinking and today rather, he is much more interested in how we acquire our knowledge and put them to use. Simply put, he investigates the process of knowledge. He identified three levels of acquiring knowledge namely: sense-experience, imaginations or ideations and intellection. Aquinas thus made an important contribution to epistemology, recognising the central part played by sense perception in human cognition. It is through the senses that we first become acquainted with existent, material things. Sense experience is contact with material things through the senses which supplies materials for the formation of ideas in imagination upon which understanding climbs to contemplate. It is thus a misconception to suppose that the fundamental role of sense perception was a discovery of the classical British empiricist. It is a synthesis of Aquinas’ Aristotelian view of knowledge. As a matter of fact, Aquinas laid more stress on sense perception as the first and unique source of knowledge than the British empiricist because he identified sense perception as the initial source of knowledge than reflection and introspection. â€Å"For a man perceives that he has a soul, and lives and exists by the fact that he perceives by the senses†. This source of knowledge for Aquinas is responsible for his five ways that he uses to prove God’s existence from the material world. He did not accept Anselm’s ontological proof because, he argues that self evident truths, such as God’s existence in which its attributes belong necessarily to the subject , may not be fruits of experience but experience makes man to be conscious of them. That is another reason where he differs from radical British empiricist. He argues based on his arguments for God that â€Å"in as far as God is manifested in and through the beings of the sensible world, as the necessary source,†¦ the embodied human intellect is capable of proceeding beyond sense to know the source of a non-dependent, non-conditioned absolute being called God. † He sees the intellect as capable of penetrating through the unanalysed superficiality of sensation. Agreeing with Aristotle, he admits that knowledge is obtained through two stages of operation, sensitive and intellective, which are intimately related to one another. The intellect does attain ideas from the material that is presented to it by the senses to extend beyond the world of the senses. The two cognitive faculties, the sense and intellect, are naturally capable of acquiring knowledge proper to them. Thus, for Aquinas, it is man’s initiative to know through his makeup although such make up is sustained by God. This sustenance by God makes him to make the proper distinction between faith and reason as sources of knowledge. Truths of faith are revealed truth such as trinity and truths of the scripture. But truths of reason must be perceived and abstracted upon. St. Thomas insistently repeats â€Å"reason gathers truth on the ground of intrinsic evidence, while faith accepts truths based on the authority of the word of God. Therefore, there are two types of wisdom namely philosophical –highest activity of man’s intellect and theological- super science or revealed truth. This distinction is essential to today’s view or tension between science and religion. According to Paul Tillich, â€Å"neither scientific nor historical truth can affirm or negate the truth of faith. The truth of faith can not negate nor affirm scientific or historical truth too†. This is because, their objects are different. Truths of faith are revealed and not available to the senses while that of science is purely experiential based. Thus, they do not contradict each other. Nonetheless, both faith and reason can assist each other. According to Aquinas, faith can act as organ which helps reason to reach its final direction, the supreme truth which is God, â€Å"because God is in the highest degree of immateriality, he occupies the highest place in knowledge†. This led him to explain the value of knowledge and its truth, which is the ultimate goal of the intellect in perceiving and abstracting ideas. He noted that the intellect through a vigilant control of the senses can guarantee the formation of the sense representations. The intellect acquires truth when it gives value to the representations and ideas it forms in phantasm. â€Å"For Aquinas all the data of sense knowledge and all intelligible things are essentially true. † Truth consists in the equality of the intellect with its object, and such concordance is always found, both in sensitive cognition and in the idea. Error may exist in the judgment, since it can happen that a predicate may be attributed to a subject to which it does not really belong. Besides the faculty of judgment, Aquinas also admits the faculty of discursive reasoning, which consists in the derivation of the knowledge of particulars from the universal. Deductive, syllogistic demonstration must be carried out according to the logical relationships which exist between two judgments. In this process consists the science which the human intellect can construct by itself, without recourse either to innate ideas or to any particular illumination. This error free judgment for Aquinas, is proper to the being which is the supreme fundamental and greatest perfection permeating all things and giving them consistency and reality. Thus, each thing exists in its participation in Being. The true representation is received when the intellect gathers the Being of beings. Meanwhile, some truth can be received although not perfect, when the data is abstracted by the intellect. The dilemma of knowledge search today is explained by Thomistic epistemology recourse to revealed truth. Thomas claimed that human reason is naturally led to knowledge – from sense experience through phantasm to intellection- to knowing truth and know all truths, whether it is the material world, spiritual world, speculative, practical, political, moral or educational truth etc. But it meets with difficulties which include passions, sentiments, complexity of objects etc. This obstacle is more serious in terms of religious or moral truths because of their abstract nature. Nonetheless, reason has the ability to reach higher grounds to know God – the supreme truth- his attributes, existence but these obstacles are removed by God’s assistance or intervention to furnish human reason with a clearer manifestation of his being. The ultimate threshold of knowledge alone can give light to the mind to reach him. Thus, he introduces faith in his epistemology though at the end. The ordinary organ of knowledge is reason enabled through immediate evidence of experience but faith comes in when there are obstacles to assist reason to reach quickly as possible its final threshold, supreme truth. â€Å"Faith will tell us Christ is present when our human senses fail†. Conclusion: The limitation Aquinas placed on reason due to obstacles in which it needs to be helped by God makes the whole idea of his epistemology a movement to faith. It seems to many that Aquinas argues to God and not for truth in its own sake. Hegel for instance argues that he treated philosophy according to the categories of theology. Bertrand Russell. A Thomism which limits itself to the consideration of material substance as the start of all knowledge proves itself inadequate in age where everything seems beyond our sensual grasp. Again, Thomism didn’t relinquish heritage of truth for the sake of new sides but a one way drive of reason Nonetheless, Aquinas’ epistemology is vital for us because it has consequences for philosophy generally especially in relation to theology. ——————————————– [ 2 ]. Aquinas copplestton [ 4 ]. Aquinas copleston [ 6 ]. Age of belif p 150 [ 7 ]. Baptissta mondin p. 306 [ 8 ]. Yeager Hudson p. 12 [ 9 ]. P. 73 yeager hudson [ 11 ]. Benediction hymn composed by Aquinas for the feast of corpus Christi {cf. [ 12 ]. Marin j. walsh.

Computers help in agriculture?

Agriculture Computers help in agriculture? It can't sow seeds or harvest crops or irrigate fields. But it can definitely help the farmers and the agricultural scientist in various stages of farming. And why haven't we used computers in agriculture till date? Just one reason, farmers are not comfortable with computers. And since there's no market for such a technology, the industry never bothered to consider that field for making any software.Countries like USA and Australia use software in their day to day farming activity. It helps them choose the right crop for their field, track the growth and accounting after harvesting. Clearly such technology is useless for Indian agriculture scenario because most farmers in India cannot effectively use it and only a few would be willing to invest in such a tool. So can computer technology really help Indian or other countries agriculture? And my answer is a big yes.It has a bigger role to play in Indian agriculture than in any other countries. Indian agriculture systems have a symbiosis between farmers and agriculture scientists. Scientists need input from farmers about their experience, to come up with new strategies for farmers. If we can somehow avail all the necessary data to scientist, they can for sure come up with better strategies. And if we can aid in their strategy planning by providing tools to do that, scientists will be able to compare different strategies.Having leveraged the scientists to come up various farming strategies, the next obvious step is to enforce these strategies through farmers by letting them choose the one which suits their land the best. Imagine software, which can predict the soil fertility of a land after harvesting a particular crop, provided we have the soil fertility information of the land and the crop to be harvested now. Well if you can predict the fertility of the soil after a particular crop harvest, it lets you decide what's the other crops can be cultivated later and helps deci de the best crop rotation policy.This would guarantee the highest yield all the time. We are not in an ideal world where everyone is a computer wizard. In such a non-ideal world, what good would it bring if given to farmers? How many farmers are out there who can efficiently use such a tool? How to make software that is so easy to use even for farmers? On the other hand, if we give this tool to scientist or government officials, they can help farmers choose the best crop for their lands.

Bill Gates before Microsoft

Bill Gates before Microsoft I selected Bill Gates because he is a very important person today, and I didn't know much about him other than he was the richest man in the world. I wanted to know how or why he became so successful. Also, I wanted to know why he is such a controversial person.Facts in BriefBirth: October 28th, 1955 in Seattle WashingtonParents: William H. and Mary GatesEducation: Lakeside, a private high school, and a major of Prelaw at HarvardChildhoodBill was the second of three children. His father was a lawyer. His mother was very active in business, education, public service, and was on the board of United Way. Growing up, school was very easy for him and he learned very quickly. Most people who knew him say that it was impossible to win an argument against him because he knew so much. Socially, he was an outcast; his interests were very different from others.Bill Gates at the World Economic Forum ,2007.SchoolBy 1970, he was sent to a private school in Seattle called Lakeside because he was gi fted. There he discovered computers and fell in love with them. His school bought computer time for a year, but he used it up in a week. He was addicted.He became good friends with Paul Allen, another computer whiz. Pretty soon, they became very good programmers. To learn more about computers, they would sometimes climb into trash bins of local computer companies to find programmers' old notes.Finally, he got a job working out computer bugs. Soon, Paul and he also organized a company called the Traf-o-data; it recorded traffic data for his town and it was very profitable. He also developed some programs for his school. One kept track of pay roll, and the other kept track of class scheduling; it also put...

How to Further Your Writing Name

How to Further Your Writing Name Its simple. Each and every single day you promote yourself. For instance: 1) Write a guest blog post and pitch it. 2) Leave deep, well-written, intelligent replies on other blogs demonstrating who you are and how personable you are. 3) Do a signing anywhere (if you write books). 4) Post on social media something related to your brand or writing. 5) Find mentors on social media and connect with a post. 6) Send review copies (if you write books). 7) Connect with a local bookstore (if you write books). 8) Connect with a library. Join the Friends of the Library. 9) Attend a library event. 10) Volunteer an event at the library (regardless what you write). 11) Attend someone elses signing and give them (just them, not the audience) your book or business card. 12) Join the Chamber of Commerce and send them an ad. 13) Attend a writers group. 14) Attend a Chamber or public event and give out your card. 15) Start a biweekly or monthly newsletter. 16) Create an email signature block about your writing. 17) Host a book party at your home. 18) Connect with an area book club and send a copy of your book. 19) Write a feature for the local paper. 20) Write a feature and pitch it to a local magazine. 21) Write reviews for other authors, emailing them with a copy of the review and a thank-you for writing the book. 22) Attend a writers conference and connect with ten authors. 23) Never leave home without your business cards. Give one out per day. 24) Ask a school if you can make a presentation. 25) Contact your local community center and ask about making a presentation. 26) Send postcards to your community make them simple and professional. 27) Send a press release to your local television station  to the specific journalist who does human interest pieces. Make the press release about a topic other than the fact you write or have a book. 28) Be seen writing. 29) Write AUTHOR in any place that asks for your profession. 30) Tell someone you are an author, and have answers for those standard questions of What do you write?, Where can I buy your books?, and How can I become published, too? Do not waffle. Own being an expert. Keep a calendar. Each day you promote yourself in any way, cross it off with a big red X. Be honest. And when you dont, leave it blatantly blank. Develop the habit of self-promotion. The point is to become that person everyone recognizes as that writer, not just someone who sometimes writes.

Interior Design Assignment Example | Topics and Well Written Essays - 500 words

Interior Design - Assignment Example With the fascinating variety of experiences, but textural and cultural to dip into, there has never been a better time to be an interior designer, or interior architects as we are often known as. The first and most noticeable challenge that our profession faces is control over the gradual but inexorable dominance of technology. The curricula in colleges are software specific, to the extent that in cases the act of design itself is limited by what can be designed then displayed with the available software. Design firms use colleges like training grounds for their own recruitment, by encouraging instruction in software and technology used by their firm. The use of technology in all its forms is a boon without a doubt, but the challenge is the need to propagate the use of technology as a tool, rather than as a set of design-defining parameters. Another challenge that is faced by the field of interior design is the corporatization of the field, where a relatively small group of design firms amass the resources and the means to dominate every aspect of the profession.. To deal with this, Interior designers have to redefine themselves and the way they project their skills and their profession, so as to enable their potential clients to see the innate value in personal interaction.

Artist and manager Essay Example | Topics and Well Written Essays - 2000 words

Artist and manager - Essay Example A year later, he worked in partnership with rapper B.o.B on Nothin’ on You and core-wrote Travis McCoy’s Billionaire. These two debut hit songs were Top Ten hits. Bruno turned this impetus in his favor launching a solo profession with his debut album, Doo-Wops & Hooligans. I met Bruno Mars by booking a hotel room where the he was staying (Bruno Mars 1). Being a musician tremendous, it is virtually felony that people are permitted to ply music for a living. But like felony, music does not normally pay. To get the gigs that pay, and keep getting them, musicians require to exude a high level of professionalism that is frequently a lot less alluring than the sexy life of a celebrity. Bruno Mars follows directions well Since most musicians make a living playing music for other people, they have to excel at what those individuals want. Whether the artist is hired to play a wedding, be studio musician, they have to excel at taking directions. More often than not, those directi ons are defectively communicated by individuals that do not understand music, but an expert musician understands how to translate any sort of instruction rapidly, without getting frustrated, and make the patron satisfied and happy. Bruno Mars is well organized In a nutshell, a professional musician keeps a calendar and learns how to tell time. There is nothing more annoying that tardiness. Furthermore, an artist possibly needs to keep track of huge quantity of material. Many sidemen play in manifold bands and have to learn unique music by song-composers than hire them, and cover for concerts. Bruno Mars has good communication skills When handling with individuals that do not understand anything about music and not much about the trade, an artist should be capable to lead most of the conversation. Offers recommendations, draw up contracts, and understand how to say what they want without coming off as impatient or greedy (Allen 13-21) SWOT analysis for music industry The beginning of just about every marketing strategy is history begins with what is understood s a SWOT Analysis. Even if I don’t always do it properly, a SWOT analysis is the best way to deal with Bruno Mars’ current status in a market and what the next steps must be. Having one in handle will assist me to establish what the steps of my client’s marketing plan must be and how best to approach the 2-3 months of marketing for Mars’ brand. SWOT analyses are separated into two classifications: internal and external. The strengths and weakness of Bruno Mars brand are things the band can regulate and the chances and threats are things that are outside my control. It is essential to acknowledge this fact when attempting to decide which steps to take moving forward. As Bruno Mar’s manager I like to utilize the SWOT analysis to take a hard look at a band’s present status. The analysis does not to have to be long, but I want to understand that real strengths, weakne sses, opportunities, and threats the musician has. This specific SWOT analysis is done based on Bruno Mars’ new album release (Macy 23-45). Strengths Twitter following: 17, 374, 406 YouTube view count of 100, 000 views each video release for the last 2 months Local press has positively covered the artist in the past Weaknesses The artist has not tour sponsors Not sufficient money to pay for national publicity campaign Live performances have not been set up in a touring route. This makes

Carrie Fisher - Bipolar Disorder Research Paper Example | Topics and Well Written Essays - 750 words

Carrie Fisher - Bipolar Disorder - Research Paper Example Bipolar Disorder is one that has been affecting so many lives until now. To be able to understand this better, Bipolar Disorder is commonly known as manic-depressive illness which is one kind of brain disorder that causes one to have an extreme change of mood, energy, and activity levels that prevents one to carry out a day to day task. Though the symptoms are not easily seen as a mental disorder, it is usually severe (NIMH Â · Bipolar Disorder., n.d.). As opposed to mood swings that could be affected by menstrual cycle, a sudden change or turnaround of circumstances, bipolar disorder is a continuous cycle that cannot be controlled. It can result to inconsistency, poor performance at work, or even suicide. However, what is great to know is that this can be cured through a series of rehabilitation programs. One of the most famous cases of Bipolar disorder would be that of Carrie Fisher. She is an American actress, novelist, and a screen writer that no doubt put most of her life in th e spotlight. However, things started getting a bit blurry when Carrie started not being able to sleep or stop talking which she thought was just part of being in Hollywood. According to one article, she immediately resorted to trips to rehabilitation centers as she abruptly realized it was nothing but depression that was causing her to act a certain way (Carrie Fisher and her life with Bipolar Disorder | bphope., n.d.). This presentation of Bipolar Disorder is inconsistent as this certain disorder is believed through study and experience as one that is not easily spotted when it starts. The symptoms are always considered as the effects of another problem and never considered the main problem. For a lot of people, they suffer for years first before they realize they are suffering from bipolar disorder. In the article I am citing on Carrie Fisher’s battle with Bipolar Disorder, the author pointed out that Carrie started acting out extreme emotions when she was in her adult year s, while she was on top of her game. Well, this is a consistent fact about Bipolar Disorder as it is one that usually develops in one’s late teens or early adult years though almost half of all cases start before the age 25 (NIMH Â · Bipolar Disorder., n.d.). Another interesting fact about how the author foretold the case of Carrie is that, finally, when Carrie Fisher was able to learn about her Bipolar disease, she did not hide it from the public or seen it as something that needed hiding. Instead, she chose to make her battle against it part of her public persona by even speaking about it in public to help others who are suffering from the same illness overcome it. This is consistent with the reality of the disease as Bipolar Disorder is a long-term illness that cannot be cured by one time intake of medicine but is something that could be defeated through a step by step effort everyday, all throughout a person’s life. With this inspiring story that is shared to us u ntil today through the life of Carrie Fisher, we all must know that mental diseases are something that we must take seriously. This is because of the number of families today that cease to

Radio Resource Management in OFDMA Networks

Radio Resource Management in OFDMA Networks 1 Introduction The convenience and popularity of wireless technology has now extended into multimedia communications, where it poses a unique challenge for transmitting high rate voice, image, and data signals simultaneously, synchronously, and virtually error-free. That challenge is currently being met through Orthogonal Frequency Division Multiplexing (OFDM), an interface protocol that divides incoming data streams into sub-streams with overlapping frequencies that can then be transmitted in parallel over orthogonal subcarriers [2,3]. To allow multiple accesses in OFDM , Orthogonal Frequency Division Multiple Access (OFDMA) was introduced. Relaying techniques, along with OFDMA, are used to achieve high data rate and high spectral efficiency. 1.1 Orthogonal Frequency Division Multiple Access OFDMA, an interface protocol combining features of OFDM and frequency division multiple access (FDMA)., was developed to move OFDM technology from a fixed-access wireless system to a true cellular system with mobility with same underlying technology, but more flexibility was defined in the operation of the system [1,8]. In OFDMA, subcarriers are grouped into larger units, referred to as sub-channels, and these sub-channels are further grouped into bursts which can be allocated to wireless users [4]. 1.2 Relay-Enhanced Networks In cellular systems, a way to achieve remarkable increase in data rate, but without claiming for more bandwidth, is to shrink cell sizes, however, with smaller cells more base stations (BSs) are needed to cover a same area due to which deployment and networking of new BSs acquire significant costs [5]. An alternative solution to this problem is to deploy smart relay stations (RSs), which can communication with each other and with BSs through wireless connections reducing systems cost. A relay station (RS), also called repeater or multi-hop station, is a radio system that helps to improve coverage and capacity of a base station (BS) and the resulting networks employing relay stations are sometimes called cooperative networks [6]. 1.3 Technological Requirement The continuously evolving wireless multimedia services push the telecommunication industries to set a very high data rate requirement for next generation mobile communication systems. As spectrum resource becomes very scarce and expensive, how to utilize this resource wisely to fulfil high quality user experiences is a very challenging research topic. Orthogonal frequency-division multiple access (OFDMA)-based RRM schemes together with relaying techniques allocate different portions of radio resources to different users in both the frequency and time domains and offers a promising technology for providing ubiquitous high-data-rate coverage with comparatively low cost than deploying multiple base stations [5]. Although wireless services are the demand of future due to their mobility and low cost infrastructure but along with this they suffer serious channel impairments. In particular, the channel suffers from frequency selective fading and distance dependent fading (i.e., large-scale fading) [1, 8]. While frequency selective fading results in inter-symbol-interference (ISI), large-scale fading attenuates the transmitted signal below a level at which it can be correctly decoded. Orthogonal Frequency-Division Multiple Access (OFDMA) relay-enhanced cellular network, the integration of multi-hop relaying with OFDMA infrastructure, has become one of the most promising solutions for next-generation wireless communications. 1.3.1 Frequency Selective Fading In wireless communications, the transmitted signal is typically reaching the receiver through multiple propagation paths (reflections from buildings, etc.), each having a different relative delay and amplitude. This is called multipath propagation and causes different parts of the transmitted signal spectrum to be attenuated differently, which is known as frequency-selective fading. In addition to this, due to the mobility of transmitter and/or receiver or some other time-varying characteristics of the transmission environment, the principal characteristics of the wireless channel change in time which results in time-varying fading of the received signal [9]. 1.3.2 Large Scale Fading Large scale fading is explained by the gradual loss of received signal power (since it propagates in all directions) with transmitter-receiver (T-R) separation distance. These phenomenonss cause attenuation in the signal and decrease in its power. To overcome this we use diversity and multi-hop relaying. 1.3.3 Diversity Diversity refers to a method for improving the reliability of a message signal by using two or morecommunication channelswith different characteristics. Diversity plays an important role in combatingfadingandco-channel interferenceand avoidingerror bursts. It is based on the fact that individual channels experience different levels of fading and interference. Multiple versions of the same signal may be transmitted and/or received and combined in the receiver [10]. 1.4 Proposed Simulation Model We developed a simulation model in which each user-pair is allocated dynamically a pair of relay and subcarrier in order to maximize its achievable sum-rate while satisfying the minimum rate requirement. The algorithm and the results of the simulation model are given in chapter 4. 1.5 Objectives The objective of our project is to have a detail overview of the literature regarding Orthogonal Frequency Division Multiple Access (OFDMA), Radio Resource Management (RRM) and Relaying techniques. After literature review we developed a simulation framework in which we will try to use minimum resources to get maximum throughput by using dynamic resource allocation. 1.6 Tools For the design and implementation of proposed Algorithm, we have used the following tools MATLAB Smart Draw Corel Draw 1.7 Overview Chapter 2 contains the literature review. It explains the basic principles of OFDMA, Radio Resource Management (RRM) and the relaying techniques. Chapter 3 explains the implementation of OFDM generation and reception that how an OFDM signal is generated and transmitted through the channel and how it is recovered at the receiver. Chapter 4 could be considered as the main part of thesis. It focuses on the simulation framework and the code. We have followed the paper â€Å"Subcarrier Allocation for multiuser two-way OFDMA Relay networks with Fairness Constraints†. In this section we have tried to implement the Dynamic Resource Allocation algorithm in order to achieve the maximum sum rate. Results are also discussed at the end of the end of the chapter. 2 Literature Review Introduction: First section of this Chapter gives a brief overview about OFDMA.OFDMA basically is the combination of Orthogonal Frequency Division Multiplexing (OFDM) and Frequency Division Multiplexing Access (FDMA).OFDMA provides high data rates even through multipath fading channels. In order to understand OFDMA, we must have brief introduction to Modulation, Multiple Access, Propagation mechanisms, its effects and its impairments while using OFDMA. 2.1 Modulation Modulation is the method of mapping data with change in carrier phase, amplitude, frequency or the combination [11]. There are two types of modulation techniques named as Single Carrier Modulation (SCM) Transmission Technique or Multicarrier Modulation (MCM) Transmission Technique. [12] Single Carrier Modulation (SCM) In single carrier transmission modulation (SCM) transmission, information is modulated using adjustment of frequency, phase and amplitude of a single carrier [12]. Multi Carrier Modulation (MCM) In multicarrier modulation transmission, input bit stream is split into several parallel bit streams then each bit stream simultaneously modulates with several sub-carriers (SCs) [12]. 2.2 Multiplexing Multiplexing is the method of sharing bandwidth and resources with other data channels. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end [13]. 2.2.1 Analog Transmission In analog transmission, signals are multiplexed using frequency division multiplexing (FDM), in which the carrier bandwidth is divided into sub channels of different frequency widths,and each signal is carried at the same time in parallel. 2.2.2 Digital Transmission In digital transmission, signals are commonly multiplexed using time-division multiplexing (TDM), in which the multiple signals are carried over the same channel in alternating time slots. 2.2.3 Need for OFDMA General wireless cellular systems are multi-users systems. We have limited radio resources as limited bandwidth and limited number of channels. The radio resources must be shared among multiple users. So OFDM is a better choice in this case. OFDM is the combination of modulation and multiplexing. It may be a modulation technique if we analyze the relation between input and output signals. It may be a multiplexing technique if we analyze the output signal which is the linear sum of modulated signal. In OFDM the signal is firstly split into sub channels, modulated and then re-multiplexed to create OFDM carrier. The spacing between carriers is such that they are orthogonal to one another. Therefore there is no need of guard band between carriers. In this way we are saving the bandwidth and utilizing our resources efficiently. 2.3 Radio Propagation Mechanisms There are 3 propagation mechanisms: Reflection, Diffraction and Scattering. These 3 phenomenon cause distortion in radio signal which give rise to propagation losses and fading in signals [14]. 2.3.1 Reflection Reflection occurs when a propagating Electro-Magnetic (EM) wave impinges upon an object which has very large dimensions as compared to the wavelength of the propagating wave. Reflections occur from the surface of the earth and from buildings and walls. 2.3.2 Diffraction When the radio path between the transmitter and receiver is obstructed by a surface that has sharp irregularities (edges), diffraction occurs. The secondary waves resulting from the obstructing surface are present throughout the space and even behind the obstacle, giving rise to a bending of waves around the obstacle, even when a line-of-sight path does not exist between transmitter and receiver. At high frequencies, diffraction, like reflection, depends on the geometry of the object, as well as the amplitude, phase and polarization of the incident wave at the point of diffraction. 2.3.3 Scattering When the medium through which the wave travels consists of objects with dimensions that are small compared to the wavelength, and where the number of obstacles per unit volume is large. Scattered waves are produced by rough surfaces, small objects or by other irregularities in the channel. In practice, foliage, street signs and lamp posts produce scattering in a mobile radio communications system. 2.4 Effects of Radio Propagation Mechanisms The three basic propagation mechanisms namely reflection, diffraction and scattering as we have explained above affect on the signal as it passes through the channel. These three radio propagation phenomena can usually be distinguished as large-scale path loss, shadowing and multipath fading [14][15]. 2.4.1 Path Loss Path Lossis the attenuation occurring by an electromagnetic wave in transit from a transmitter to a receiver in a telecommunication system. In simple words, it governs the deterministic attenuation power depending only upon the distance between two communicating entities. It is considered as large scale fading because it does not change rapidly. 2.4.2 Shadowing Shadowingis the result of movement of transmitter, receiver or any channel component referred to as (obstacles). Shadowing is a statistical parameter. Shadowing follows a log-normal distribution about the values governed by path loss. Although shadowing depends heavily upon the channel conditions and density of obstacles in the channel, it is also normally considered a large scale fading component alongside path loss. 2.4.3 Multipath Fading Multipath Fadingis the result of multiple propagation paths which are created by reflection, diffraction and scattering. When channel has multiple paths. Each of the paths created due to these mechanisms may have its characteristic power, delay and phase. So receiver will be receiving a large number of replicas of initially transmitted signal at each instant of time. The summation of these signals at receiver may cause constructive or destructive interferences depending upon the delays and phases of multiple signals. Due to its fast characteristic nature, multipath fading is called small scale fading. 2.5 Orthogonal Frequency Division Multiplexing (OFDM) Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multicarrier modulation that is robust to multi-path radio channel impairments [15]. Now-a-days it is widely accepted that OFDM is the most promising scheme in future high data-rate broadband wireless communication systems. OFDM is a special case of MCM transmission. In OFDM, high data rate input bit stream or data is first converted into several parallel bit stream, than each low rate bit stream is modulated with subcarrier. The several subcarriers are closely spaced. However being orthogonal they do not interfere with each other. 2.5.1 Orthognality Signals are orthogonal if they are mutually independent of each other. Orthogonality is a property that allows multiple information signals to be transmitted perfectly over a common channel and detected, without interference. Loss of orthogonality results in blurring between these information signals and degradation in communications. Many common multiplexing schemes are inherently orthogonal. The term OFDM has been reserved for a special form of FDM. The subcarriers in an OFDM signal are spaced as close as is theoretically possible while maintain orthogonality between them.In FDM there needs a guard band between channels to avoid interference between channels. The addition of guard band between channels greatly reduces the spectral efficiency. In OFDM, it was required to arrange sub carriers in such a way that the side band of each sub carrier overlap and signal is received without interference. The sub-carriers (SCs) must be orthogonal to each other, which eliminates the guard band and improves the spectral efficiency . 2.5.2 Conditions of orthogonality 2.5.2.1 Orthogonal Vectors Vectors A and B are two different vectors, they are said to be orthogonal if their dot product is zero 2.6 OFDM GENERATION AND RECEPTION OFDM signals are typically generated digitally due to the complexity of implementation in the analog domain. The transmission side is used to transmit digital data by mapping the subcarrier amplitude and phase. It then transforms this spectral representation of the data into the time domain using an Inverse Discrete Fourier Transform (IDFT) but due to much more computational efficiency in Inverse Fast Fourier Transform (IFFT), IFFT is used in all practical systems. The receiver side performs the reverse operations of the transmission side, mixing the RF signal to base band for processing, and then a Fast Fourier Transform (FFT) is employed to analyze the signal in the frequency domain. The demodulation of the frequency domain signal is then performed in order to obtain the transmitted digital data. The IFFT and the FFT are complementary function and the most suitable term depends on whether the signal is being recovered or transmitted but the cases where the signal is independent of this distinction then these terms can be used interchangeably [15]. 2.6.1 OFDM Block Diagram 2.6.2 Implementation of OFDM Block Diagram 2.6.2.1 Serial to Parallel Conversion: In an OFDM system, each channel can be broken down into number of sub-carriers. The use of sub-carriers can help to increase the spectral efficiency but requires additional processing by the transmitter and receiver which is necessary to convert a serial bit stream into several parallel bit streams to be divided among the individual carriers. This makes the processing faster as well as is used for mapping symbols on sub-carriers. 2.6.2.2 Modulation of Data: Once the bit stream has been divided among the individual sub-carriers by the use of serial to parallel converter, each sub-carrier is modulated using 16 QAM scheme as if it was an individual channel before all channels are combined back together and transmitted as a whole. 2.6.2.3 Inverse Fourier Transform: The role of the IFFT is to modulate each sub-channel onto the appropriate carrier thus after the required spectrum is worked out, an inverse Fourier transform is used to find the corresponding time domain waveform. 2.6.2.4 Parallel to Serial Conversion: Once the inverse Fourier transform has been done each symbol must be combined together and then transmitted as one signal. Thus, the parallel to serial conversion stage is the process of summing all sub-carriers and combining them into one signal 2.6.2.5 Channel: The OFDM signal is then transmitted over a channel with AWGN having SNR of 10 dB. 2.6.2.6 Receiver: The receiver basically does the reverse operations to the transmitter. The FFT of each symbol is taken to find the original transmitted spectrum. The phase angle of each transmission carrier is then evaluated and converted back to the data word by demodulating the received phase. The data words are then combined back to the same word size as the original data. 2.7 OFDMA in a broader perspective OFDM is a modulation scheme that allows digital data to be efficiently and reliably transmitted over a radio channel, even in multipath environments [17]. OFDM transmits data by using a large number of narrow bandwidth carriers. These carriers are regularly spaced in frequency, forming a block of spectrum. The frequency spacing and time synchronization of the carriers is chosen in such a way that the carriers are orthogonal, meaning that they do not interfere with each other. This is despite the carriers overlapping each other in the frequency domain [18]. The name ‘OFDM is derived from the fact that the digital data is sent using many carriers, each of a different frequency (Frequency Division Multiplexing) and these carriers are orthogonal to each other [19]. 2.7.1 History of OFDMA The origins of OFDM development started in the late 1950s with the introduction of Frequency Division Multiplexing (FDM) for data communications. In 1966 Chang patented the structure of OFDM and published the concept of using orthogonal overlapping multi-tone signals for data communications. In 1971 Weinstein introduced the idea of using a Discrete Fourier Transform (DFT) for Implementation of the generation and reception of OFDM signals, eliminating the requirement for banks of analog subcarrier oscillators. This presented an opportunity for an easy implementation of OFDM, especially with the use of Fast Fourier Transforms (FFT), which are an efficient implementation of the DFT. This suggested that the easiest implementation of OFDM is with the use of Digital Signal Processing (DSP), which can implement FFT algorithms. It is only recently that the advances in integrated circuit technology have made the implementation of OFDM cost effective. The reliance on DSP prevented the wide spread use of OFDM during the early development of OFDM. It wasnt until the late 1980s that work began on the development of OFDM for commercial use, with the introduction of the Digital Audio Broadcasting (DAB) system. 2.7.2 Advantages using OFDMA There are some advantages using OFDMA. OFDM is a highly bandwidth efficient scheme because different sub-carriers are orthogonal but they are overlapping. Flexible and can be made adaptive; different modulation schemes for subcarriers, bit loading, adaptable bandwidth/data rates possible. Has excellent ICI performance because of addition of cyclic prefix. In OFDM equalization is performed in frequency domain which becomes very easy as compared to the time domain equalization. Very good at mitigating the effects of delay spread. Due to the use of many sub-carriers, the symbol duration on the sub-carriers is increased, relative to delay spread. ISI is avoided through the use of guard interval. Resistant to frequency selective fading as compared to single carrier system. Used for high data rate transmission. OFDMA provides flexibility of deployment across a variety of frequency bands with little need for modification is of paramount importance. A single frequency network can be used to provide excellent coverage and good frequency re-use. OFDMA offers frequency diversity by spreading the carriers all over the used spectrum. 2.7.3 Challenges using OFDMA These are the difficulties we have to face while using OFDMA [20][21][22], The OFDM signal suffers from a very high peak to average power ratio (PAPR) therefore it requires transmitter RF power amplifiers to be sufficiently linear in the range of high input power. Sensitive to carrier frequency offset, needs frequency offset correction in the receiver. Sensitive to oscillator phase noise, clean and stable oscillator required. The use of guard interval to mitigate ISI affects the bandwidth efficiency. OFDM is sensitive to Doppler shift frequency errors offset the receiver and if not corrected the orthogonality between the carriers is degraded. If only a few carriers are assigned to each user the resistance to selective fading will be degraded or lost. It has a relatively high sensitivity to frequency offsets as this degrades the orthogonality between the carriers. It is sensitive to phase noise on the oscillators as this degrades the orthogonaility between the carriers. 2.7.4 Comparison with CDMA in terms of benefits 2.7.4.2 CDMA Advantages: CDMA has some advantages over OFDMA [22], Not as complicated to implement as OFDM based systems. As CDMA has a wide bandwidth, it is difficult to equalise the overall spectrum significant levels of processing would be needed for this as it consists of a continuous signal and not discrete carriers. Not as easy to aggregate spectrum as for OFDM. 2.7.5 OFDMA in the Real World: UMTS, the European standard for the 3G cellular mobile communications, and IEEE 802.16, a broadband wireless access standard for metropolitan area networks (MAN), are two live examples for industrial support of OFDMA. Table 1 shows the basic parameters of these two systems. Table 1. OFDMA system parameters in the UMTS and IEEE 802.16 standards 2.8 Radio Resource Management In second section of this chapter we will discuss radio resource management schemes, why we need them and how they improve the efficiency of the network. Radio resource management is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems. Radio resource management involves algorithms and strategies for controlling parameters such as Transmit power Sub carrier allocation Data rates Handover criteria Modulation scheme Error coding scheme, etc 2.8.1 Study of Radio Resource Management End-to-end reconfigurability has a strong impact on all aspects of the system, ranging from the terminal, to the air interface, up to the network side. Future network architectures must be flexible enough to support scalability as well as reconfigurable network elements, in order to provide the best possible resource management solutions in hand with cost effective network deployment. The ultimate aim is to increase spectrum efficiency through the use of more flexible spectrum allocation and radio resource management schemes, although suitable load balancing mechanisms are also desirable to maximize system capacity, to optimize QoS provision, and to increase spectrum efficiency. Once in place, mobile users will benefit from this by being able to access required services when and where needed, at an affordable cost. From an engineering point of view, the best possible solution can only be achieved when elements of the radio network are properly configured and suitable radio resource m anagement approaches/algorithms are applied. In other words, the efficient management of the whole reconfiguration decision process is necessary, in order to exploit the advantages provided by reconfigurability. For this purpose, future mobile radio networks must meet the challenge of providing higher quality of service through supporting increased mobility and throughput of multimedia services, even considering scarcity of spectrum resources. Although the size of frequency spectrum physically limits the capacity of radio networks, effective solutions to increase spectrum efficiency can optimize usage of available capacity. Through inspecting the needs of relevant participants in a mobile communication system, i.e., the Terminal, User, Service and Network, effective solutions can be used to define the communication configuration between the Terminal and Network, dependent on the requirements of Services demanded by Users. In other words, it is necessary to identify proper communications mechanisms between communications apparatus, based on the characteristics of users and their services. This raises further questions about how to manage traffic in heterogeneous networks in an efficient way. 2.8.2 Methods of RRM 2.8.2.1 Network based functions Admission control (AC) Load control (LC) Packet scheduler (PS) Resource Manager (RM) Admission control In the decision procedure AC will use threshold form network planning and from Interference measurements. The new connection should not impact the planned coverage and quality of existing Connections. (During the whole connection time.) AC estimates the UL and DL load increase which new connection would produce. AC uses load information from LC and PC. Load change depends on attributes of RAB: traffic and quality parameters. If UL or DL limit threshold is exceeded the RAB is not admitted. AC derives the transmitted bit rate, processing gain, Radio link initial quality parameters, target BER, BLER, Eb/No, SIR target. AC manages the bearer mapping The L1 parameters to be used during the call. AC initiates the forced call release, forced inter-frequency or intersystem handover. Load control Reason of load control Optimize the capacity of a cell and prevent overload The interference main resource criteria. LC measures continuously UL and DL interference. RRM acts based on the measurements and parameters from planning Preventive load control In normal conditions LC takes care that the network is not overloaded and remains Stable. Overload condition . LC is responsible for reducing the load and bringing the network back into operating area. Fast LC actions in BTS Lower SIR target for the uplink inner-loop PC. LC actions located in the RNC. Interact with PS and throttle back packet data traffic. Lower bit rates of RT users.(speech service or CS data). WCDMA interfrequency or GSM intersystem handover. Drop single calls in a controlled manner. 2.8.2.3 Connection based functions Handover Control (HC) Power Control (PC) Power control Uplink open loop power control. Downlink open loop power control. Power in downlink common channels. Uplink inner (closed) loop power control. Downlink inner (closed) loop power control. Outer loop power control. Power control in compressed mode. Handover Intersystem handover. Intrafrequency handover. Interfrequency handover. Intersystem handover. Hard handover (HHO). All the old radio links of an MS are released before the new radio links are established. Soft handover (SHO) SMS is simultaneously controlled by two or more cells belonging to different BTS of the same RNC or to different RNC. MS is controlled by at least two cells under one BTS. Mobile evaluated handover (MEHO) The UE mai Radio Resource Management in OFDMA Networks Radio Resource Management in OFDMA Networks 1 Introduction The convenience and popularity of wireless technology has now extended into multimedia communications, where it poses a unique challenge for transmitting high rate voice, image, and data signals simultaneously, synchronously, and virtually error-free. That challenge is currently being met through Orthogonal Frequency Division Multiplexing (OFDM), an interface protocol that divides incoming data streams into sub-streams with overlapping frequencies that can then be transmitted in parallel over orthogonal subcarriers [2,3]. To allow multiple accesses in OFDM , Orthogonal Frequency Division Multiple Access (OFDMA) was introduced. Relaying techniques, along with OFDMA, are used to achieve high data rate and high spectral efficiency. 1.1 Orthogonal Frequency Division Multiple Access OFDMA, an interface protocol combining features of OFDM and frequency division multiple access (FDMA)., was developed to move OFDM technology from a fixed-access wireless system to a true cellular system with mobility with same underlying technology, but more flexibility was defined in the operation of the system [1,8]. In OFDMA, subcarriers are grouped into larger units, referred to as sub-channels, and these sub-channels are further grouped into bursts which can be allocated to wireless users [4]. 1.2 Relay-Enhanced Networks In cellular systems, a way to achieve remarkable increase in data rate, but without claiming for more bandwidth, is to shrink cell sizes, however, with smaller cells more base stations (BSs) are needed to cover a same area due to which deployment and networking of new BSs acquire significant costs [5]. An alternative solution to this problem is to deploy smart relay stations (RSs), which can communication with each other and with BSs through wireless connections reducing systems cost. A relay station (RS), also called repeater or multi-hop station, is a radio system that helps to improve coverage and capacity of a base station (BS) and the resulting networks employing relay stations are sometimes called cooperative networks [6]. 1.3 Technological Requirement The continuously evolving wireless multimedia services push the telecommunication industries to set a very high data rate requirement for next generation mobile communication systems. As spectrum resource becomes very scarce and expensive, how to utilize this resource wisely to fulfil high quality user experiences is a very challenging research topic. Orthogonal frequency-division multiple access (OFDMA)-based RRM schemes together with relaying techniques allocate different portions of radio resources to different users in both the frequency and time domains and offers a promising technology for providing ubiquitous high-data-rate coverage with comparatively low cost than deploying multiple base stations [5]. Although wireless services are the demand of future due to their mobility and low cost infrastructure but along with this they suffer serious channel impairments. In particular, the channel suffers from frequency selective fading and distance dependent fading (i.e., large-scale fading) [1, 8]. While frequency selective fading results in inter-symbol-interference (ISI), large-scale fading attenuates the transmitted signal below a level at which it can be correctly decoded. Orthogonal Frequency-Division Multiple Access (OFDMA) relay-enhanced cellular network, the integration of multi-hop relaying with OFDMA infrastructure, has become one of the most promising solutions for next-generation wireless communications. 1.3.1 Frequency Selective Fading In wireless communications, the transmitted signal is typically reaching the receiver through multiple propagation paths (reflections from buildings, etc.), each having a different relative delay and amplitude. This is called multipath propagation and causes different parts of the transmitted signal spectrum to be attenuated differently, which is known as frequency-selective fading. In addition to this, due to the mobility of transmitter and/or receiver or some other time-varying characteristics of the transmission environment, the principal characteristics of the wireless channel change in time which results in time-varying fading of the received signal [9]. 1.3.2 Large Scale Fading Large scale fading is explained by the gradual loss of received signal power (since it propagates in all directions) with transmitter-receiver (T-R) separation distance. These phenomenonss cause attenuation in the signal and decrease in its power. To overcome this we use diversity and multi-hop relaying. 1.3.3 Diversity Diversity refers to a method for improving the reliability of a message signal by using two or morecommunication channelswith different characteristics. Diversity plays an important role in combatingfadingandco-channel interferenceand avoidingerror bursts. It is based on the fact that individual channels experience different levels of fading and interference. Multiple versions of the same signal may be transmitted and/or received and combined in the receiver [10]. 1.4 Proposed Simulation Model We developed a simulation model in which each user-pair is allocated dynamically a pair of relay and subcarrier in order to maximize its achievable sum-rate while satisfying the minimum rate requirement. The algorithm and the results of the simulation model are given in chapter 4. 1.5 Objectives The objective of our project is to have a detail overview of the literature regarding Orthogonal Frequency Division Multiple Access (OFDMA), Radio Resource Management (RRM) and Relaying techniques. After literature review we developed a simulation framework in which we will try to use minimum resources to get maximum throughput by using dynamic resource allocation. 1.6 Tools For the design and implementation of proposed Algorithm, we have used the following tools MATLAB Smart Draw Corel Draw 1.7 Overview Chapter 2 contains the literature review. It explains the basic principles of OFDMA, Radio Resource Management (RRM) and the relaying techniques. Chapter 3 explains the implementation of OFDM generation and reception that how an OFDM signal is generated and transmitted through the channel and how it is recovered at the receiver. Chapter 4 could be considered as the main part of thesis. It focuses on the simulation framework and the code. We have followed the paper â€Å"Subcarrier Allocation for multiuser two-way OFDMA Relay networks with Fairness Constraints†. In this section we have tried to implement the Dynamic Resource Allocation algorithm in order to achieve the maximum sum rate. Results are also discussed at the end of the end of the chapter. 2 Literature Review Introduction: First section of this Chapter gives a brief overview about OFDMA.OFDMA basically is the combination of Orthogonal Frequency Division Multiplexing (OFDM) and Frequency Division Multiplexing Access (FDMA).OFDMA provides high data rates even through multipath fading channels. In order to understand OFDMA, we must have brief introduction to Modulation, Multiple Access, Propagation mechanisms, its effects and its impairments while using OFDMA. 2.1 Modulation Modulation is the method of mapping data with change in carrier phase, amplitude, frequency or the combination [11]. There are two types of modulation techniques named as Single Carrier Modulation (SCM) Transmission Technique or Multicarrier Modulation (MCM) Transmission Technique. [12] Single Carrier Modulation (SCM) In single carrier transmission modulation (SCM) transmission, information is modulated using adjustment of frequency, phase and amplitude of a single carrier [12]. Multi Carrier Modulation (MCM) In multicarrier modulation transmission, input bit stream is split into several parallel bit streams then each bit stream simultaneously modulates with several sub-carriers (SCs) [12]. 2.2 Multiplexing Multiplexing is the method of sharing bandwidth and resources with other data channels. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end [13]. 2.2.1 Analog Transmission In analog transmission, signals are multiplexed using frequency division multiplexing (FDM), in which the carrier bandwidth is divided into sub channels of different frequency widths,and each signal is carried at the same time in parallel. 2.2.2 Digital Transmission In digital transmission, signals are commonly multiplexed using time-division multiplexing (TDM), in which the multiple signals are carried over the same channel in alternating time slots. 2.2.3 Need for OFDMA General wireless cellular systems are multi-users systems. We have limited radio resources as limited bandwidth and limited number of channels. The radio resources must be shared among multiple users. So OFDM is a better choice in this case. OFDM is the combination of modulation and multiplexing. It may be a modulation technique if we analyze the relation between input and output signals. It may be a multiplexing technique if we analyze the output signal which is the linear sum of modulated signal. In OFDM the signal is firstly split into sub channels, modulated and then re-multiplexed to create OFDM carrier. The spacing between carriers is such that they are orthogonal to one another. Therefore there is no need of guard band between carriers. In this way we are saving the bandwidth and utilizing our resources efficiently. 2.3 Radio Propagation Mechanisms There are 3 propagation mechanisms: Reflection, Diffraction and Scattering. These 3 phenomenon cause distortion in radio signal which give rise to propagation losses and fading in signals [14]. 2.3.1 Reflection Reflection occurs when a propagating Electro-Magnetic (EM) wave impinges upon an object which has very large dimensions as compared to the wavelength of the propagating wave. Reflections occur from the surface of the earth and from buildings and walls. 2.3.2 Diffraction When the radio path between the transmitter and receiver is obstructed by a surface that has sharp irregularities (edges), diffraction occurs. The secondary waves resulting from the obstructing surface are present throughout the space and even behind the obstacle, giving rise to a bending of waves around the obstacle, even when a line-of-sight path does not exist between transmitter and receiver. At high frequencies, diffraction, like reflection, depends on the geometry of the object, as well as the amplitude, phase and polarization of the incident wave at the point of diffraction. 2.3.3 Scattering When the medium through which the wave travels consists of objects with dimensions that are small compared to the wavelength, and where the number of obstacles per unit volume is large. Scattered waves are produced by rough surfaces, small objects or by other irregularities in the channel. In practice, foliage, street signs and lamp posts produce scattering in a mobile radio communications system. 2.4 Effects of Radio Propagation Mechanisms The three basic propagation mechanisms namely reflection, diffraction and scattering as we have explained above affect on the signal as it passes through the channel. These three radio propagation phenomena can usually be distinguished as large-scale path loss, shadowing and multipath fading [14][15]. 2.4.1 Path Loss Path Lossis the attenuation occurring by an electromagnetic wave in transit from a transmitter to a receiver in a telecommunication system. In simple words, it governs the deterministic attenuation power depending only upon the distance between two communicating entities. It is considered as large scale fading because it does not change rapidly. 2.4.2 Shadowing Shadowingis the result of movement of transmitter, receiver or any channel component referred to as (obstacles). Shadowing is a statistical parameter. Shadowing follows a log-normal distribution about the values governed by path loss. Although shadowing depends heavily upon the channel conditions and density of obstacles in the channel, it is also normally considered a large scale fading component alongside path loss. 2.4.3 Multipath Fading Multipath Fadingis the result of multiple propagation paths which are created by reflection, diffraction and scattering. When channel has multiple paths. Each of the paths created due to these mechanisms may have its characteristic power, delay and phase. So receiver will be receiving a large number of replicas of initially transmitted signal at each instant of time. The summation of these signals at receiver may cause constructive or destructive interferences depending upon the delays and phases of multiple signals. Due to its fast characteristic nature, multipath fading is called small scale fading. 2.5 Orthogonal Frequency Division Multiplexing (OFDM) Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multicarrier modulation that is robust to multi-path radio channel impairments [15]. Now-a-days it is widely accepted that OFDM is the most promising scheme in future high data-rate broadband wireless communication systems. OFDM is a special case of MCM transmission. In OFDM, high data rate input bit stream or data is first converted into several parallel bit stream, than each low rate bit stream is modulated with subcarrier. The several subcarriers are closely spaced. However being orthogonal they do not interfere with each other. 2.5.1 Orthognality Signals are orthogonal if they are mutually independent of each other. Orthogonality is a property that allows multiple information signals to be transmitted perfectly over a common channel and detected, without interference. Loss of orthogonality results in blurring between these information signals and degradation in communications. Many common multiplexing schemes are inherently orthogonal. The term OFDM has been reserved for a special form of FDM. The subcarriers in an OFDM signal are spaced as close as is theoretically possible while maintain orthogonality between them.In FDM there needs a guard band between channels to avoid interference between channels. The addition of guard band between channels greatly reduces the spectral efficiency. In OFDM, it was required to arrange sub carriers in such a way that the side band of each sub carrier overlap and signal is received without interference. The sub-carriers (SCs) must be orthogonal to each other, which eliminates the guard band and improves the spectral efficiency . 2.5.2 Conditions of orthogonality 2.5.2.1 Orthogonal Vectors Vectors A and B are two different vectors, they are said to be orthogonal if their dot product is zero 2.6 OFDM GENERATION AND RECEPTION OFDM signals are typically generated digitally due to the complexity of implementation in the analog domain. The transmission side is used to transmit digital data by mapping the subcarrier amplitude and phase. It then transforms this spectral representation of the data into the time domain using an Inverse Discrete Fourier Transform (IDFT) but due to much more computational efficiency in Inverse Fast Fourier Transform (IFFT), IFFT is used in all practical systems. The receiver side performs the reverse operations of the transmission side, mixing the RF signal to base band for processing, and then a Fast Fourier Transform (FFT) is employed to analyze the signal in the frequency domain. The demodulation of the frequency domain signal is then performed in order to obtain the transmitted digital data. The IFFT and the FFT are complementary function and the most suitable term depends on whether the signal is being recovered or transmitted but the cases where the signal is independent of this distinction then these terms can be used interchangeably [15]. 2.6.1 OFDM Block Diagram 2.6.2 Implementation of OFDM Block Diagram 2.6.2.1 Serial to Parallel Conversion: In an OFDM system, each channel can be broken down into number of sub-carriers. The use of sub-carriers can help to increase the spectral efficiency but requires additional processing by the transmitter and receiver which is necessary to convert a serial bit stream into several parallel bit streams to be divided among the individual carriers. This makes the processing faster as well as is used for mapping symbols on sub-carriers. 2.6.2.2 Modulation of Data: Once the bit stream has been divided among the individual sub-carriers by the use of serial to parallel converter, each sub-carrier is modulated using 16 QAM scheme as if it was an individual channel before all channels are combined back together and transmitted as a whole. 2.6.2.3 Inverse Fourier Transform: The role of the IFFT is to modulate each sub-channel onto the appropriate carrier thus after the required spectrum is worked out, an inverse Fourier transform is used to find the corresponding time domain waveform. 2.6.2.4 Parallel to Serial Conversion: Once the inverse Fourier transform has been done each symbol must be combined together and then transmitted as one signal. Thus, the parallel to serial conversion stage is the process of summing all sub-carriers and combining them into one signal 2.6.2.5 Channel: The OFDM signal is then transmitted over a channel with AWGN having SNR of 10 dB. 2.6.2.6 Receiver: The receiver basically does the reverse operations to the transmitter. The FFT of each symbol is taken to find the original transmitted spectrum. The phase angle of each transmission carrier is then evaluated and converted back to the data word by demodulating the received phase. The data words are then combined back to the same word size as the original data. 2.7 OFDMA in a broader perspective OFDM is a modulation scheme that allows digital data to be efficiently and reliably transmitted over a radio channel, even in multipath environments [17]. OFDM transmits data by using a large number of narrow bandwidth carriers. These carriers are regularly spaced in frequency, forming a block of spectrum. The frequency spacing and time synchronization of the carriers is chosen in such a way that the carriers are orthogonal, meaning that they do not interfere with each other. This is despite the carriers overlapping each other in the frequency domain [18]. The name ‘OFDM is derived from the fact that the digital data is sent using many carriers, each of a different frequency (Frequency Division Multiplexing) and these carriers are orthogonal to each other [19]. 2.7.1 History of OFDMA The origins of OFDM development started in the late 1950s with the introduction of Frequency Division Multiplexing (FDM) for data communications. In 1966 Chang patented the structure of OFDM and published the concept of using orthogonal overlapping multi-tone signals for data communications. In 1971 Weinstein introduced the idea of using a Discrete Fourier Transform (DFT) for Implementation of the generation and reception of OFDM signals, eliminating the requirement for banks of analog subcarrier oscillators. This presented an opportunity for an easy implementation of OFDM, especially with the use of Fast Fourier Transforms (FFT), which are an efficient implementation of the DFT. This suggested that the easiest implementation of OFDM is with the use of Digital Signal Processing (DSP), which can implement FFT algorithms. It is only recently that the advances in integrated circuit technology have made the implementation of OFDM cost effective. The reliance on DSP prevented the wide spread use of OFDM during the early development of OFDM. It wasnt until the late 1980s that work began on the development of OFDM for commercial use, with the introduction of the Digital Audio Broadcasting (DAB) system. 2.7.2 Advantages using OFDMA There are some advantages using OFDMA. OFDM is a highly bandwidth efficient scheme because different sub-carriers are orthogonal but they are overlapping. Flexible and can be made adaptive; different modulation schemes for subcarriers, bit loading, adaptable bandwidth/data rates possible. Has excellent ICI performance because of addition of cyclic prefix. In OFDM equalization is performed in frequency domain which becomes very easy as compared to the time domain equalization. Very good at mitigating the effects of delay spread. Due to the use of many sub-carriers, the symbol duration on the sub-carriers is increased, relative to delay spread. ISI is avoided through the use of guard interval. Resistant to frequency selective fading as compared to single carrier system. Used for high data rate transmission. OFDMA provides flexibility of deployment across a variety of frequency bands with little need for modification is of paramount importance. A single frequency network can be used to provide excellent coverage and good frequency re-use. OFDMA offers frequency diversity by spreading the carriers all over the used spectrum. 2.7.3 Challenges using OFDMA These are the difficulties we have to face while using OFDMA [20][21][22], The OFDM signal suffers from a very high peak to average power ratio (PAPR) therefore it requires transmitter RF power amplifiers to be sufficiently linear in the range of high input power. Sensitive to carrier frequency offset, needs frequency offset correction in the receiver. Sensitive to oscillator phase noise, clean and stable oscillator required. The use of guard interval to mitigate ISI affects the bandwidth efficiency. OFDM is sensitive to Doppler shift frequency errors offset the receiver and if not corrected the orthogonality between the carriers is degraded. If only a few carriers are assigned to each user the resistance to selective fading will be degraded or lost. It has a relatively high sensitivity to frequency offsets as this degrades the orthogonality between the carriers. It is sensitive to phase noise on the oscillators as this degrades the orthogonaility between the carriers. 2.7.4 Comparison with CDMA in terms of benefits 2.7.4.2 CDMA Advantages: CDMA has some advantages over OFDMA [22], Not as complicated to implement as OFDM based systems. As CDMA has a wide bandwidth, it is difficult to equalise the overall spectrum significant levels of processing would be needed for this as it consists of a continuous signal and not discrete carriers. Not as easy to aggregate spectrum as for OFDM. 2.7.5 OFDMA in the Real World: UMTS, the European standard for the 3G cellular mobile communications, and IEEE 802.16, a broadband wireless access standard for metropolitan area networks (MAN), are two live examples for industrial support of OFDMA. Table 1 shows the basic parameters of these two systems. Table 1. OFDMA system parameters in the UMTS and IEEE 802.16 standards 2.8 Radio Resource Management In second section of this chapter we will discuss radio resource management schemes, why we need them and how they improve the efficiency of the network. Radio resource management is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems. Radio resource management involves algorithms and strategies for controlling parameters such as Transmit power Sub carrier allocation Data rates Handover criteria Modulation scheme Error coding scheme, etc 2.8.1 Study of Radio Resource Management End-to-end reconfigurability has a strong impact on all aspects of the system, ranging from the terminal, to the air interface, up to the network side. Future network architectures must be flexible enough to support scalability as well as reconfigurable network elements, in order to provide the best possible resource management solutions in hand with cost effective network deployment. The ultimate aim is to increase spectrum efficiency through the use of more flexible spectrum allocation and radio resource management schemes, although suitable load balancing mechanisms are also desirable to maximize system capacity, to optimize QoS provision, and to increase spectrum efficiency. Once in place, mobile users will benefit from this by being able to access required services when and where needed, at an affordable cost. From an engineering point of view, the best possible solution can only be achieved when elements of the radio network are properly configured and suitable radio resource m anagement approaches/algorithms are applied. In other words, the efficient management of the whole reconfiguration decision process is necessary, in order to exploit the advantages provided by reconfigurability. For this purpose, future mobile radio networks must meet the challenge of providing higher quality of service through supporting increased mobility and throughput of multimedia services, even considering scarcity of spectrum resources. Although the size of frequency spectrum physically limits the capacity of radio networks, effective solutions to increase spectrum efficiency can optimize usage of available capacity. Through inspecting the needs of relevant participants in a mobile communication system, i.e., the Terminal, User, Service and Network, effective solutions can be used to define the communication configuration between the Terminal and Network, dependent on the requirements of Services demanded by Users. In other words, it is necessary to identify proper communications mechanisms between communications apparatus, based on the characteristics of users and their services. This raises further questions about how to manage traffic in heterogeneous networks in an efficient way. 2.8.2 Methods of RRM 2.8.2.1 Network based functions Admission control (AC) Load control (LC) Packet scheduler (PS) Resource Manager (RM) Admission control In the decision procedure AC will use threshold form network planning and from Interference measurements. The new connection should not impact the planned coverage and quality of existing Connections. (During the whole connection time.) AC estimates the UL and DL load increase which new connection would produce. AC uses load information from LC and PC. Load change depends on attributes of RAB: traffic and quality parameters. If UL or DL limit threshold is exceeded the RAB is not admitted. AC derives the transmitted bit rate, processing gain, Radio link initial quality parameters, target BER, BLER, Eb/No, SIR target. AC manages the bearer mapping The L1 parameters to be used during the call. AC initiates the forced call release, forced inter-frequency or intersystem handover. Load control Reason of load control Optimize the capacity of a cell and prevent overload The interference main resource criteria. LC measures continuously UL and DL interference. RRM acts based on the measurements and parameters from planning Preventive load control In normal conditions LC takes care that the network is not overloaded and remains Stable. Overload condition . LC is responsible for reducing the load and bringing the network back into operating area. Fast LC actions in BTS Lower SIR target for the uplink inner-loop PC. LC actions located in the RNC. Interact with PS and throttle back packet data traffic. Lower bit rates of RT users.(speech service or CS data). WCDMA interfrequency or GSM intersystem handover. Drop single calls in a controlled manner. 2.8.2.3 Connection based functions Handover Control (HC) Power Control (PC) Power control Uplink open loop power control. Downlink open loop power control. Power in downlink common channels. Uplink inner (closed) loop power control. Downlink inner (closed) loop power control. Outer loop power control. Power control in compressed mode. Handover Intersystem handover. Intrafrequency handover. Interfrequency handover. Intersystem handover. Hard handover (HHO). All the old radio links of an MS are released before the new radio links are established. Soft handover (SHO) SMS is simultaneously controlled by two or more cells belonging to different BTS of the same RNC or to different RNC. MS is controlled by at least two cells under one BTS. Mobile evaluated handover (MEHO) The UE mai