基于自适应中继的认知协作网络功率分配

摘要

在中继系统中基于译码转发(DF)的功率分配算法会由于译码错误造成误差变大,而基于放大转发(AF)的功率分配算法会引起噪声放大.针对上述问题,提出一种基于自适应中继的多载波正交频分复用认知协作功率分配算法.根据传输信号的信噪比自适应选择合适的转发算法分配功率,保证主要用户的干扰温度保持在合理限度内,并最大化系统的信道容量.仿真结果表明,与DF算法、AF算法相比,该自适应算法在低信噪比区域与高信噪比区域均能获得较高的信道容量.%In relayed transmission systems,power allocation algorithm based on Decode and Forward(DF) increases error in case of incorrect decoding of the information symbols,and the one based on Amplify Forward(AF) amplifies the noise.In order to solve the problem,a Cognitive Radio(CR) Orthogonal Frequency Division Multiplexing(OFDM) power allocation algorithm based on Adaptive Relay(AR) is proposed in this paper.The proposed algorithm adaptively selects proper relayed forward scheme according to the Signal Noise Ratio(SNR) to allocate power.The objective is to maximize the system capacity while the interference introduced to the Primary Users(PU) is below the tolerated limit.Simulation results show the proposed AR algorithm achieve higher capacity compared with DF and AF,whenever in low SNR areas or in high SNR areas.