无线协作网络中存在干扰时的中继选择协议

针对无线协作网络中共道干扰影响中继选择的问题,提出一种存在干扰的中继选择协议(RSI).该协议以最小化系统中断概率为目标,选择具有最大瞬时端到端信干比的中继节点转发源节点信息,并且在考虑直接传输时,目的节点采用选择合并策略合并直接传输和中继传输,从而充分利用空间分集增益,降低了系统的中断概率.RSI协议不需要中继节点之间交互信息,通过竞争的方式完成数据传输,节省了系统开销,具有较好的实用性.仿真结果表明,在瑞利信道中,当中继节点个数为4、中断概率为10-2时,与最大最小中继选择协议相比,RSI协议能够取得约3~4 dB的信噪比增益.

Relay Selection Protocol for Cooperative Wireless Networks with Interference

A relay selection protocol with interference (RSI) is proposed to solve the problem that co-channel interferences affect the relay selection in cooperative wireless networks. The protocol minimizes the system outage probability, and selects the relay with maximum instantaneous end-to-end signal to interference and noise ratio to forward the source message. Moreover, the selec-tion combining scheme is deployed at the destination to combine the direct transmission and relay transmission when the direct transmission is taken into account. This strategy can make full use of space diversity and decrease the system outage probability. Compared with the existing relay selection protocols, the proposed protocol does not need any information exchange between any two relays, and the data transmission is completed by competition. Thus, the proposed protocol has a low system cost and good practicability. Simulation results and comparisons with the max-min relay selection protocol show that when the number of relays is 4 and the outage probability is 10~(-2), the proposed protocol achieves about 3～4 dB signal to noise ratio gain in Rayleigh fading channels.