Research on Optimal Relay Location with Power Assignment over Fading Channels
| Autor: | Wei-Chen Chao, 趙偉丞 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 In recent years, cooperative communication has become an indispensable communication technology. By cooperative communication, not only can effectively combat channel fading, but also can improve the system capacity, coverage, and ultimately makes the system performance significantly improved. General speaking, in order to reduce the complexity of the performance analyses, we usually assume the channel state information is perfectly known by the communication node for the assignment of transmission power or the adjustment of relay position. However, in the actual communication transmission, the channel state information is not easy to know in advance. Although, we can estimate the channel state by channel estimation, it will increase the complexity of communications systems. Further discussion of this paper, under the condition of being random variables about the channel state information, and by the statistical properties of the channel state, we explore the performance of cooperative communications systems from the viewpoint of probability and statistics. This thesis is mainly divided into two parts. Primarily, for the channel state information being under known condition, we explore two kinds of optimization problems: the first one is, examine how to assign the transmission power and the relay position to reach the maximum system channel capacity; and, the second one is to investigate the maximum transmission distance of the source node through the assignment of transmission power and the adjustment of relay position, under the condition of error-free transmission at a given data rate. The second part is to investigate the above two optimization problems under the condition of being random variables about the channel state information. In response to these optimization problems, we first construct a mathematical model for each problem with the related constrained conditions. According to the constrained conditions and its physical meaning, we can analyze and simplify the mathematical expressions. Finally corroborated through numerical simulation, we can appropriately solve the above optimization problems using the derived mathematical expressions. Keywords: Cooperative Communications、Channel State Information、Optimization problems、Channel Capacity、Power Assignment |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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