高阶QAM实时多域分析联合载波同步算法研究  

Jointed carrier recovery algorithm for high-order QAMreal-time multi-domain analysis

作　　者：阎啸[1] 王茜[2] 秦开宇[2] 

机构地区：[1]电子科技大学自动化工程学院,成都610054 [2]电子科技大学空天科学技术研究院,成都610054

出　　处：《仪器仪表学报》2010年第4期923-928,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(60672029)资助项目

摘　　要：在宽带通信信号实时多域分析通用架构基础上,针对宽带高阶QAM通信信号实时多域分析,提出了一种面向测试的高精度快速联合载波同步算法。该算法采用基于离散傅里叶变换(DFT)的载波频偏盲估计算法和改进的双模载波同步环路,并引入频谱滑动平均、输出跟踪保持和环路参数自动调节等处理机制,可在极大频偏条件下快速实现载波相位精确跟踪。研究表明:在实时分析带宽为20MHz的条件下,采用该算法对码率为6.4MSps的宽带256QAM信号进行实时多域分析。载波同步的最大频偏捕获范围能够达到±10MHz;载波频偏盲估计精度较以前算法提高了5倍;载波恢复环路能够在大约1800个符号周期内锁定,并实现载波相位精确同步。Based on common real-time multi-domain signal analysis architecture for high-order QAM communication, a novel high-precision non-data-aided jointed carrier recovery algorithm for high-order QAM analysis and specification measurement is presented. The proposed two-step solution is composed of an innovative blind carrier frequency offset estimator based on discrete fourier transform （DFT） and an improved dual-mode carrier recovery loop. Combined with spectrum moving average, output track ＆ hold and online loop coefficient adjustment, the proposed algo- rithm can realize high-precision carrier synchronization at fast speed in the presence of large frequency offset. Experiment results show that the maximum frequency acquisition range is within ＋ 10 MHz for 256QAM signal with symbol rate of 6.4 MSps, when the real-time analysis span is set to 20 MHz. Compared with previous algorithm, the accuracy of the blind carrier frequency offset estimation algorithm is improved by 5 times. The carrier can be recovered within about 1 800 symbol periods.

关 键 词：正交幅度调制 实时多域分析 载波同步 离散傅里叶变换 

分 类 号：TM932[电气工程—电力电子与电力传动]