摘要： 面对无线电监测或电子对抗等非协作电子环境,在低信噪比情况下对截获信号载波频偏进行估计时存在估计范围和估计精度不平衡的问题。为此,提出一种改进的无数据辅助频偏估计算法。对Q倍的归一化基带信号做自相关函数的差分运算,消除最大相关间隔对估计范围的影响,并通过对差分后相位的加权求和得到有效的频偏估计值。仿真结果表明,即使在信噪比低至－15 dB时,该算法仍然可以达到近似10-4的估计误差精度,能够满足实际监测要求。

关键词: 频偏估计, 估计精度, 最大相关间隙, 加权平均, 无数据辅助

Abstract: In order to solve the problem of imbalance between the estimation accuracy and estimation range of the intercepted signal with low Signal-to-Noise Ratio(SNR) in electronic environment,such as radio monitoring and electronic warfare and other non-cooperation communications,this paper proposes an improved Non-Data-Aided(NDA) frequency shift estimation algorithm.The influence of the maximum correlation interval to estimation range is removed through the difference function of the self-correlation of Q times of the normalized baseband signal.Then an effective estimation value is accomplished by the weighted summation of the difference phase.Simulation results show that the proposed algorithm can obtain the estimation accuracy of almost 10-4 even if the SNR is low to-15 dB,which could meet the requirements of the actual monitoring.

Key words: frequency shift estimation, estimation accuracy, maximum correlation interval, weighted average, Non-Data-Aided(NDA)

中图分类号: 

• TN91