基于循环统计量检测的QAM信号多普勒参数盲估计

针对动中通卫星通信系统中QAM信号多普勒参数盲估计难的问题,提出了一种基于循环统计量检测的盲估计算法。算法无需同步和匹配滤波等预处理,通过检测QAM信号四倍频偏处的循环频率来估计多普勒频偏,并利用数据分段求频率的方法计算变化率。仿真结果表明,在低信噪比的高斯噪声信道和多径衰落信道下,算法均可以准确而有效地实现QAM信号多普勒参数的盲估计。

Blind Doppler parameters estimation of QAM signals based on cyclic-statistical tests

Aiming at the difficulties of blind Doppler parameters estimation for QAM signals in SCOTM(Satellite Communication on-the-move),a blind estimation algorithm based on cyclic-statistical tests is proposed.The algorithm obviates the need for preprocessing tasks,such as symbol timing recovery and matched filtering.By detecting one of the cyclic frequencies of QAM signals,located at the quartic frequency offset,Doppler frequency is effectively estimated,meanwhile,the data division method is exploited to calculate the Doppler-rate.Experimental results indicate that the novel algorithm can accomplish blind Doppler parameters estimation effectively and accurately in AWGN channel and fading channel under low SNRs.