机会接入CR中采用自适应MQAM的性能分析  

PERFORMANCE ANALYSIS OF ADAPTIVE MQAM FOR COGNITIVE RADIO WITH OPPORTUNISTIC ACCESS

作　　者：张金艳[1] 

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018

出　　处：《南阳理工学院学报》2013年第3期34-37,共4页Journal of Nanyang Institute of Technology

摘　　要：研究Nakagami衰落信道上机会接入认知无线电中次用户采用接收最大比分集合并自适应M进制正交幅度调制的性能,推导次用户链路采用恒定功率变速率自适应连续或离散速率M进制正交幅度调制时的平均频谱利用率的闭合表达式,并给出数值计算和仿真结果。数值计算和仿真结果表明:频谱感知会恶化SU链路平均频谱利用率性能,SU链路分集可以改善其平均频谱利用率的性能。The spectral efficiency performance of adaptive M-ary quadrature amplitude modulation(MQAM)for cognitive radio(CR)with opportunistic access when maximal ratio combining(MRC) is employed over Nakagami fading channels is analyzed.The closed-form expressions of secondary user(SU) link's average spectral efficiency of constant-power variable-rate(VR) adaptive continuous-rate(ACR) and adaptive discrete-rate(ADR) MQAM are derived.Numerical calculation and simulation results show that the spectrum sensing greatly influences the spectral efficiency performance and the ASE performance is improved when MRC is adopted by SU.

关 键 词：认知无线电 自适应调制 正交幅度调制 最大比合并 频谱效率 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术] TN9[电子电信—信息与通信工程]