基于MUD/SD的认知无线电系统遍历容量研究

摘要

This paper proposed a new multi-user diversity spectrum-sharing cognitive radio system model based on multiple antennas switch diversity receiver. Compared with traditional multi-user diversity spectrum-sharing system model, this model improved cognitive user system channel ergodic capacity because of valid multiple antennas switch diversity gain in cognitive receiver. Utilizing the derived cumulative distribution function and probability density function of the cognitive received signal-to-noise ratio( SNR) , it investigated the channel ergodic capacity of cognitive users system. For the case of unlimited cognitive user transmit power, it also derived the closed-form expression for the ergodic capacity.%提出了基于多天线选择分集接收的多用户分集认知无线电系统模型.该系统模型由于在认知接收端采用了多天线选择分集接收,相比传统多用户分集认知无线电系统采用的单天线接收,能够进一步提高认知用户系统信道遍历容量.推导并给出了认知接收端信噪比的概率密度函数与累积分布函数,分析了多天线数目与认知用户数对系统信道遍历容量的影响,同时给出了不考虑认知用户发送功率约束条件下的认知用户系统信道遍历容量的解析表达式.