Abstract: A new dual-hop communication scheme is proposed and analyzed for a cognitive cooperative system where multiple primary-user receivers coexist. In this proposed scheme, both source and relay are equipped with a single antenna, but multiple receive antennas are equipped at the destination. Maximum ratio combining is adopted to improve the system performance. Moreover, the outage probability performance is investigated over Rayleigh fading channels and the exact closed-form expression is derived, then an asymptotic expression for the outage probability is obtained at high signal-to-noise ratio. Simulation results are presented to verify the theoretical analysis.

Key words: cognitive cooperative communication, maximum ratio combining, outage probability

摘要： 在多个主用户同时存在的情境下，提出了一种新的两跳认知协作通信系统，并对该系统进行了性能分析。该系统的信源和中继均只具有单个天线，而在信宿处配置了多根接收天线并使用了最大比合并技术来进行信号的接收。此外，对该认知协作通信系统在瑞利衰落信道下的中断概率性能进行了研究，推导得到了中断概率的准确闭合表达式，以及在高信噪比时的渐进表达式。通过利用计算机仿真验证了理论分析的正确性。

关键词: 认知协作通信, 最大比合并, 中断概率