无先验参数条件下直扩信号时差估计研究

Time Difference Estimation of Direct Sequence Spread Spectrum Signal Without Priori Knowledge

周期谱相关具有较强的抑制噪声和抗干扰的能力,适应于低信噪比时差估计的情况,但其抗噪声和干扰能力完全在于循环频率的选择。目前关于直扩信号时差估计的研究都是建立在循环频率已知的前提下进行的。运用直扩信号的周期谱特性,可在无先验参数条件下确定其循环频率,对时差进行估计,大大降低了谱相关时差估计算法的计算量。仿真结果表明,该方法是切实可行的。

Time difference estimation （TDE） based on cyclic spectral correlation is more robust against noise and interference than the conventional generalized cross correlation methods, which can work in the environment of low SNR. However the study on TDE of direct sequeme spread（DSSS） signal is built on the priori knowledge of cyclic frequency now. The method of chosing cycle frequency proposed in this paper is without priori knowledg of cyclic frequeny, which reduces calculation of TDE based on cycle spectral correlation. The simulation results indicate that it is feasible.