传统的接收机码环环路中,对伪码相位的估计受到非相干附带的均值非零噪声的影响,而且具有延时误差和延迟效应。针对这样的问题,为了提高接收机码相位估计精度,文中基于极大似然估计法,提出了一种改进的基于极大似然估计的码鉴相器跟踪环路算法。仿真实验表明,伪码估计误差降低了0.15个码片左右,码相位估计精度得到了提升,且在一定程度上提高了环路的稳定性。

In the code ring circuit of traditional receiver, the estimation of PN code phase was influenced by incoherent additive mean nonzero noise, and it had delay error and delay effect. Based on the Maximum Likelihood Estimate (MLE) algorithm, an modified code discriminator tracking loop algorithm based on maximum likelihood estimation was proposed to improve code phase estimation precision. Simulation experiments indicated that the PN code estimating error reduced 0. 15 chips. The code phase estimation accuracy had been promoted, and to some extent, the stability of the loop had been improved.