CDMA信号的时频差高精度估计算法

A high precision TDOA and FDOA estimation method for CDMA signals

针对多用户CDMA信号的时频域重叠特征,提出了一种新颖的时频差高精度估计方法。该方法结合扩频信号的捕获和解扩操作,以较短的信号样本和较低的计算量,仅两次时间-频率分维迭代实现了用户信号分离和时频差估计,再通过时域和频域内插进一步提高估计精度。仿真结果表明,与直接互模糊函数相关法相比,该方法能够有效提高CDMA信号时频差估计精度,降低计算量。

Given the overlap in time-frequency domain of code division multiple access （CDMA） multi-user signals, we propose a novel estimation method for time difference of arrival （TDOA） and frequency difference of arrival （FDOA）. Based on the acquiring and dispreading of spread spectrum signals, with short-term signal samples and limited computation, the method adopts only two iterations of time-frequency searching to separate signals and estimate time frequency difference, and then uses the time domain and frequency domain interpolation to further improve estimation accuracy. Simulation re- sults show that the presented algorithm can effectively improve the estimation accuracy of time-frequency difference of CDMA signals and lower the computational complexity in comparison with the cross ambi- guity function correlation method.