Study On Partner Selection Problem In Cooperative Diversity Networks

Mobile communications has been extensive research in recent decades, and has made a great contribution to the development and progress of human society. But electromagnetic waves are faced with more complex propagation environment. Multi-path fading effect limits the quality of wireless communications. Diversity technique can separate the independent fading signals at the receiver in order to combat channel fading. MIMO (Multiple Input Multiple Output) technique which was proposed in recent years forms a spatial diversity by placing the multi-antenna in the transmitter and receiver to increase system capacity and reliability. However, in practical applications, the physical conditions in the mobile terminals limit the application of spatial diversity techniques.Sendonaris proposed the concept of cooperative diversity due to the lack of MIMO technique. It makes single-antenna users to communicate through a cooperative way to create virtual MIMIO system to improve system performance. The existing literature focused more on the cooperative diversity performance analysis, while the partner selection to achieve cooperative diversity as an important step in the cooperative diversity should not be ignored. In this paper, we summarize the existing partner selection algorithm, and then we introduce two traditional resource allocation strategies named Max-Min algorithm and Nash bargaining solution (NBS) algorithm into cooperative networks based on IDMA superposition modulation, which has a special restriction that every two cooperative nodes have to be mutual partners. Considering this restriction, we introduce the New Max-Min algorithm considers the fairness among users in the networks, and the New NBS algorithm considers the tradeoff between system efficiency and fairness among users. Simulation results show that the New Max-Min algorithm can archive higher fairness with the concern of Jain's fairness index, and the New NBS algorithm can archive more fairness within reducing some system-level performance.