基于FFT频谱校正的全数字QAM解调法  

A fully digitalized QAM demodulation scheme based on correcting FFT spectrum

作　　者：黄翔东[1] 王兆华[1] 崔海涛[1] 

机构地区：[1]天津大学电子信息工程学院,天津300072

出　　处：《电子技术应用》2010年第12期103-106,110,共5页Application of Electronic Technique

基　　金：国家自然科学基金资助项目(60802048);天津市应用基础与前沿技术研究计划重点项目(10JCZDJC16100)

摘　　要：针对QAM相干解调法需严格载波同步的不足,提出一种新的基于FFT频谱校正的全数字QAM解调方案,此方案采用了软件无线电的处理思想,直接在载波频段对QAM信号进行采样,采用FFT频谱校正估计出各码元周期内的载波幅值和初相位来实现信息比特解码。仿真实验证明,此方案方法简单,不仅降低了同步机制要求,而且在FFT长度为8时即可获得接近于传统相干解调法理论下限的误比特率性能。To overcome the drawback of coherent QAM demodulation method in strict carrier synchronization, this paper proposes a novel fully digitalized demodulation scheme based on correcting FFT spectrum, which incorporates the idea of software-defined radio. Through directly sampling the QAM signal in carder frequency band and then correcting the FFT spectrum, the carrier＇s amplitudes and original phases in individual symbol durations can be estimated that the information bits can be decoded. Simulation proves that the proposed scheme is simple, and not only does it reduce the demand of synchronization but also its bit error performance approximates to that of conventional coherent demodulation when FFT length is set as ‘8＇.

关 键 词：QAM 软件无线电 FFT频谱校正 同步 

分 类 号：TN911.72[电子电信—通信与信息系统] TN763[电子电信—信息与通信工程]