一种认知无线电系统双门限频谱分配算法

摘要

Based on the spectrum allocation of Underlay model in cognitive radio systems,a double-threshold based spectrum allocation algorithm was proposed.Two signal-to-noise radio (SNR) thresholds were also given.If SNR is less than the small threshold,aiming to maximize the channel capacity of the primary users,some second users are chosen to cooperate with primary users to communicate data.If SNR is larger than the big threshold,considering to maximize the number of the second users accessing the spectrum,some second users are allowed to use the occupied spectrum with low power.If SNR is between the two thresholds,primary users occupy the spectrum alone.Simulation and numerical results illustrate the reliability of the theoretical analysis.%基于认知无线电系统中Underlay频谱共享模型,提出了一种双门限频谱分配算法.给定两个信噪比门限,当信噪比低于较小的门限时,系统选择认知用户做中继协助授权用户进行数据传输,以授权用户信道容量最大化为优化目标进行频谱分配；当信噪比大于较大的门限时,系统允许认知用户之间进行低功率数据传输,以认知用户接入数量最大化为优化目标进行频谱分配；当信噪比介于两门限之间时,由授权用户单独进行数据传输.理论分析和仿真表明,当授权用户信噪比低于较小门限时,所提方法能提高授权用户的信道容量；当授权用户信噪比大于较大门限时,所提方法可以提高认知用户的接入数量.