认知无线电具有时延约束的干扰功率分析

Interference Power Analyses of Delay-Constrained Cognitive Radio Systems

为量化认知无线电队列时延与干扰功率之间的关系,提出一种功率分配方案.此方案以最小化主用户接收端平均干扰功率为目标,受限于次用户时延服务质量约束.推导非对称Nakagami-m衰落信道平均干扰功率闭合解.仿真结果表明,干扰功率与时延约束之间存在折中.当时延约束较严格时,认知无线电系统通过天线分集可显著降低次用户对主用户的干扰.

To quantify the relationships between the queuing-delay bound at the secondary user and the interference power to the primary receiver caused by the secondary user,a power allocation scheme was proposed for cognitive radio systems. The scheme aims at minimizing an average interference power subject to a delay-bound quality-of-service（ Qo S） constraint. The closed-form expression for an average interference power was obtained in asymmetric Nakagami-m fading channels. Simulations show that there exists a tradeoff between interference power and the delay-bound constraint. It is also shown that diversitybased cognitive radio systems can significantly reduce the interference power,especially under stringent delay-bound constraint.