CHAPTER 3 – COOPERATIVE COMMUNICATION
We have introduced a new form of diversity for the concept of mobile communications system of cooperation. Cooperation by mobile phone users for each user is assigned. Cooperation can be considered as a new form of space diversity, antenna diversity in the transmission process, however, and other complications, Intermobiles noisy channels, each phone has sent a separate message. (W. Yu and T. Lan, 2007, pp. 2646–2660) According to A. Goldsmith (2005), wireless communications technology is asking as functions of mobile access. Since its inception, it has gone through several stages of development. Its wide range of applications to meet growing demand. (A. Goldsmith, 2005) Multipath fading radio channel, the path loss and shadow effects, causing major find possible solutions for wireless communications in the history of the greatest challenges. According to D. Tse and P. Viswanath (2005) effects caused by random changes in time, the channel quality, frequency and space, the power of traditional communication technology are difficult to use in a wireless environment. (D. Tse and P. Viswanath, 2005) Despite the many proposed solutions, high efficiency of the method is not performed until the technology over the past two decades, the diversity of the proposal. (D. Tse and P. Viswanath, 2005) According to Fitzek (2006), multi-hop communication of information theory can be traced to the relay channel model. Relay channel model, including the origin, destination and relay, which are used to facilitate the process as a source of information about the destination. (E. Erkip, A. Sendonaris and Fitzek, 2006) According to Liu (2009), communication is based on the collaborative nature of the spread of wireless communications, indicating that the source and destination of the transmission of signals between the leaves of adjacent nodes. (Liu, 2009) The aim of the cooperation and exchange is that the diversity of destinations to create a listening space for processing and transmission of information, resulting in increased speed and reliability. (Chandrasekaran, 2005) According to Chandrasekaran (2005), the cooperation on the basic idea is the model of the relay channel of communication, collaborative communication channels is different. The recent evolution is the diversity of motivations, rather than fading concept of channel capacity. (Chandrasekaran, 2005) In most cases, the target system cannot process signals from multi-hop relay and the relay is designed to assist the main channel. In the communication of collaboration across system resources as a source of information as well as two relays and the destination process and relay the signal source. Therefore, the recent emphasis on cooperation is a little different. (Anghel and M. Kaveh, 2004, pp. 1416-1421)
According to Fitzek (2006), network of multi-hop communications links between the source and destination using the relay. The nature of the expansion of wireless networks can make the relay transmission. Relay transmitted to the destination, in accordance with the appropriate technology is not the same. Then the information received. (E. Erkip, A. Sendonaris and Fitzek, 2006) According to the outreach program, a combination of the power transmission and retransmission, the target cannot go beyond the transmission of a single jump. The main advantage is obtained without using any serial device diversity antenna fading. (Hunter, 2006, pp. 375–391) According to W. Yu and T. Lan (2007), use of a high degree of diversity techniques to improve the performance of wireless communications, because it makes the signal during the course of the single-elimination. It is using different channels, such as time, frequency and space diversity, and diversifies income. (W. Yu and T. Lan, 2007) In particular, data from more multiple output (MIMO) systems theory, provided that the requirements of multiple wireless...
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