CDMA信号时差频差联合估计算法研究

针对CDMA信号时域频域同时重叠的特征,分析了不同用户的时差分布对互模糊函数计算的影响,总结了直接互模糊相关法的不足之处。在此基础上,提出了一种解扩后互模糊相关算法,并将其与直接互模糊相关算法进行性能比较,推导了解扩后互模糊相关对信噪比的改善值。仿真结果验证了解扩后互模糊相关算法具有抑制其他用户干扰和改善输出信噪比的优点。

Research on TDOA/FDOA Joint Estimation Algorithm for CDMA Signals

Focusing on the overlap in both time domain and frequency domain of CDMA signals,the paper first analyses the effect of different user's TDOA distribution on cross-ambiguity function computation,and summarizes its disadvantages,then proposes a new algorithm called de-spreaded cross-ambiguity correlation,and makes a performance comparison with direct cross-ambiguity correlation.The paper also derives the improvement of correlation SNR achieved by the new algorithm.The results of simulation verify the new algorithms advantages in restraining other users' interference and improving the output SNR over direct cross-ambiguity correlation.