为了提高认知系统的性能,提出一种混合中继选择协议(HPRS).通过判断中继是否能正确解码源信号来决定中继采用何种协议转发数据,最终选取其中信噪比最大的中继作为最优中继,并推导了HPRS在高信噪比下中断概率的近似表达式及分集度.理论和仿真结果表明,放大转发中继选择(SAF)、解码转发中继选择(SDF)协议和HPRS均可获得空间满分集度,而HPRS的中断性能要优于SAF和SDF协议.
A hybrid protocol with relay selection (HPRS) is derived to improve the cognitive performance. What a cooperative protocol is chosed is rest with the the source signal relay decoding. The relay with the highest relay-destination signal-to-noise ratio is selected to forward the data. The approximated outage probability formulation and diversity for HPRS is given. Simulation shows that amplify-and-forward with relay selection (SAF), decode-and-forward with relay selection (SDF) protocol and HPRS can achieve full space diversities, but the HPRS is better than that of both SAF and SDF in outage performance.