CAI Rong-wen (蔡融文), SUN En-chang (孙恩昌), ZHANG Yan-hua (张延华)
(College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124, China)
Abstract： Cooperative relaying has played an important role in rapid evolution of wireless communications. The cooperative performance strongly depends on the selected relays. In this paper, we concentrate on relay selection in amplify-and-forward (AF) cooperative communication system, and an optimal multi-relay selection scheme is put forward to minimize the average symbol error rate(SER) of the system. Firstly, for the minimum average SER, on the basis of the statistic channel information, we define a parameter named equivalent channel gain which describes the channel status of two phases in the cooperative process. Then, under the constraint of equal power allocation, an optimal relay selection scheme is proposed in ascending order of equivalent channel gain (ECG). The scheme implies that the suitable number of relay nodes should be selected under the different signal-to-noise ratio (SNR) ranges to minimize the average SER. Computer simulation results show that the average SER rate of the proposed scheme is lower than these of the other schemes.
Key words： cooperative relaying; amplify-and-forward (AF); symbol error rate(SER); equal power allocation; multi-relay selection
CLD number： TN925 Document code： A
Article ID： 1674-8042(2013)04-0365-05 doi： 10.3969/j.issn.1674-8042.2013.04.014
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