Acta Metallurgica Sinica(English letters) ›› 2010, Vol. 17 ›› Issue (1): 56-61.doi: 10.1016/S1005-8885(09)60424-6

• Wireless • Previous Articles     Next Articles

Improving amplify-and-forward relay
selection algorithm based on partial relay link

WANG Fei-fei, LIU Yuan-an, LIN Xiao-feng, XIE Gang   

  1. Key Laboraty of Universal Wireless Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China
  • Received:2008-11-26 Revised:1900-01-01 Online:2010-02-28
  • Contact: WANG Fei-fei

Abstract:

This article addresses the design problem of selecting an appropriate relay in amplify-and-forward (AF) cooperative diversity systems. In this regard, this article focuses on relay selection based on partial channel knowledge only across the source and relay links. In particular, the two fundamental questions will be answered, that is, whether to cooperate and whom to cooperate with. Through answering these two questions, an improved relay selection strategy based on partial relay link, which emphasizes that cooperation happens when necessary, is proposed to aim at maximizing the average mutual information. Then a joint optimization, in terms of power allocation and relay selection, is employed to guarantee a robust performance for relay selection based on partial relay link. Optimum power is allocated between the source and the selected relay to maximize the output signal-to-noise (SNR) at the destination. Simulation results turn out that the improved scheme can achieve better performance than previous work and the robust performance can be guaranteed by employing joint optimization.

Key words:

cooperative diversity;amplify-and-forward relay;relay selection;average mutual information