低信噪比信号时变相位差的估计性能分析  

Estimation Performance Analysis of Time-varying Phase Difference with Low SNR Signal

作　　者：吕宗申[1] 于宏毅[1] 沈彩耀[1] 

机构地区：[1]解放军信息工程大学信息工程学院,郑州450002

出　　处：《计算机工程》2012年第17期70-72,76,共4页Computer Engineering

摘　　要：在信号合成系统中,信号间的频率差估计存在不可忽略的误差,因此会降低相位差的估计精度,影响合成信号的质量。为解决该问题,利用某采样点前后各L/2点数据估计补偿该点的相位差,并逐点依次运行,从而避免相位差的时变性所产生的补偿偏差。通过理论推导分析残留频率差Δf对相位差估计精度的影响,当互相关数据长度L与归一化频率差Δf/fs的乘积约为0.37时,估计精度最高,在实际应用中对L的选取有一定指导意义。At the system of signal combining, the frequency difference between the signal error can not be ignored, and it reduces the estimated accuracy of the phase difference, affects the quality of the synthesized signal. So this paper uses a sampling point before and after L/2 data to estimate the compensation that point out of phase, and point by point in order to run, avoids the deviation of the phase difference time-varying compensation. Analysis through the derivation of the residual frequency difference Afphase estimation accuracy when the product of the length L of the cross-correlation data and the normalized frequency difference △flfs approximately 0.37, it is estimated that the highest accuracy. In the practical application of the selection of L there is certain guiding significance.

关 键 词：信号合成 互相关 时变相位差 信噪比增益 克拉美-罗下界 频率估计 

分 类 号：TN927[电子电信—通信与信息系统]