中文摘要：

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。

英文摘要：

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.