认知无线电中移动认知用户功率控制方法

The power control algorithm of mobile cognitive users in cognitive radio

传统认知无线电中的功率控制问题都是基于认知用户位置不变的情况,本文针对可移动认知用户的功率控制问题进行深入研究.首先对不同通信场景进行分析和归一化整理,建立通用通信模型,极大的简化了干扰估计和功率控制算法;其次根据认知用户的可移动性,推导出授权用户所受干扰与认知用户移动距离和运动矢量方向的函数表达式,实现了认知用户对授权用户干扰的实时预测;根据预测结果采用最小发射功率准则实现认知用户的功率控制.仿真结果表明,本文方法能够实时、高效的对认知用户进行功率控制,与采用固定步长的功率控制算法相比能够节约功耗20%.

The traditional power control problems of cognitive radio are based on the situation that the position of cognitive user is unchanged. This paper has done a lot of work on the power control problems of mobile CR users. First of all, we analyze various communication situation and sort with normalization, establish general communication model which highly simplifies the interference estimation and power control algorithm; Secondly, according to the mobility of the CR users, the function expression of the interference of PR user, moving distance and the vector direction of CR user which realized the real-time prediction of interference from CR to PR users is deduced. Finally the power control of the cognitive users is realized according to the prediction result by minimum transmission power norm. The simulation result Shows that the algorithm can control the transmitting power of CR users timely and efficiently which can save 20% for the power consumption compared with the fixed step power control algorithm.