中文摘要：

研究了underlay频谱共享模式下认知中继网络的中断性能,推导出独立非同分布Rayleigh衰落信道下次用户中断概率精确解的闭合表达式。通过对具有不同分布参数的Rayleigh衰落信道下系统性能进行MonteCarlo仿真,验证了理论推导的正确性。仿真结果表明,次用户发射机与中继之间（S_T→S_R）的中继链路以及次用户发射机与主用户接收机之间（ST→PD）的干扰链路——这两种链路的信道状态是影响认知中继网络中断性能的主要因素。

英文摘要：

The outage performance of the secondary user is investigated for cognitive relay networks with underlay spectrum sharing model. An exact closed-form of outage probability is derived over independent but non-identically distributed（ non-i. d.） Rayleigh fading channels. The derived formula is verified by Monte-Carlo simulations and is served as an effective tool to evaluate the outage performance under different channel parameters. Simulation results show that the channel state of the relaying link（ S_T→ S_R）and the interference link（ S_T→ P_D） dominate the outage performance in cognitive relay networks.