中文摘要：

在感知中继网络中，为实现授权频带在主次用户间的高效利用，提出一种基于检测结果的频谱共享机制，允许次用户根据频谱检测的结果自适应地选择传输方式．并在该机制下，考虑主次用户间的干扰情况，进而根据信干噪比（SINR）推导出次用户网络的中断概率和符号错误概率的闭式表达式．仿真结果表明，本机制与传统的频谱共享机制相比，能在保证主用户通信的前提下，使次用户网络获得较高的性能增益．

英文摘要：

A spectrum sharing scheme is proposed that allows the cognitive users to select either direct transmission or cooperative underlay transmission adaptively according to the spectrum detection in cogni- tive relay networks. Moreover, analysis on the cognitive network with this scheme is presented. Based on signal-to-interference and noise ratio （SINR） , the closed-form expressions of outage probability and the symbol error probability are derived. Simulation shows that this scheme can achieve better performance than the traditional overlay scheme and underlay scheme in guaranteeing the primary link and enhancing the performance of the cognitive network.