基于过时信道状态信息的机会协作性能研究

Performance of opportunistic cooperative communication with outdated CSI

机会中继是协作通信系统中提高频谱效率和节省功率消耗的常用方法。在通信过程中,信道估计时刻和实际中继传输信息时刻存在一定的延时,其产生的过时信道状态信息(Outdated CSI)会严重地影响协作通信系统的性能。分别从考虑直传链路和不考虑直传链路两方面,分析了过时信道状态信息对机会协作分集系统中断概率的影响。仿真结果表明,系统性能随着相关系数ρ的减小而变差,并且随着中继节点数目的增加而提高。

The opportunistic relay selection （ORS） is a common method of cooperative communication system for spectral efficiency and power saving. However, there may exist a delay between channel estimation and actual data transmission during the communication processing. Consequently, this delay causes outdated channel state information （CSI） and the performance of the cooperative communication will be affected. This paper presents the effect of outdated CSI on the outage probability of an ORS system by deriving the mathematical expression of outage probability in considering direct link and not considering direct link. The result of theoretical analysis and computer simulation show that system performance deteriorates with decreasing correlation coefficient p, and increases with the increase in the number of relay nodes.