认知中继网络中基于频谱感知的自适应功率控制策略

摘要

针对采用联合overlay和underlay频谱共享模式的认知中继网络,基于频谱感知结果和干扰信道条件,提出了自适应功率控制策略,从理论上分析了次用户的中断概率.通过Monte-Carlo仿真,与单一overlay或underlay频谱共享模式和固定功率控制方案下次用户的中断性能进行了比较.仿真结果表明,采用自适应功率控制方案,在相同中断概率条件下,次用户对主用户的干扰概率降低了70％～80％;在相同干扰概率条件下,次用户的中断概率降低了1～2个数量级,频谱共享性能得到了有效提高.%An adaptive power control scheme is proposed for the cognitive relay networks with joint overlay and underlay spectrum sharing model.The transmit power of the secondary user is adjusted adaptively according to the spectrum sensing results and the interference channel condition.The outage probability of the secondary user is compared by Monte-Carlo simulations between the fixed power control scheme and pure overlay or underlay spectrum sharing schemes.The results show that,by employing the adaptive power control strategy,the interference probability of the secondary user to the primary user is decreased by 70％ ～80％ under the same outage probability.Also,the outage probability of the secondary user is reduced by 1 ～ 2 orders of magnitude under the same interference probability.Thus,the performance of the spectrum sharing is improved effectively.