一种改进的北斗卫星信号并行捕获方法

An Improved Parallel Acquisition Method for BDS Signals

为了提高全并行捕获方式下北斗卫星信号的发现概率,提出了一种改进的并行捕获算法。相对于传统的检测方法,该算法每次搜索需要存储少量的候选值,采用多次观测并统计候选值来完成信号检测。虽然增加了少量存储空间和运算,但是其利用了更多的观测信息,因此有利于提高弱信号下的发现概率。该方法不需要实时统计噪声分布,从而避免了噪声波动对于门限的影响。在高斯白噪声模型下给出了系统发现概率和虚警率的定量评估。理论分析和仿真结果表明该方法可以有效改善北斗弱信号的发现概率,相对于传统判决方法可以提高捕获灵敏度达3-4dB。

A modified parallel acquisition method for improving detection probability of BDS（ Beidou Satellite Navigation System） signal is proposed in this paper. Relative to the traditional detection,little amount of candidate observations need to be stored during every search round. Signal detection can be achieved by means of repetitive observations and statistics of these values. In spite of less increase in memory and operation,this approach contributes to the improvement of weak signal detection probability due to the utilization of more observation information. The influence of noise fluctuation on threshold can be avoid without noise distribution analyzed in real time. System detection probability and false alarm probability are given based on the white Gaussian noise model. Analytical and simulation results demonstrate the effectiveness of this approach for BDS weak signal acquisition. As a result,this approach yields higher acquisition sensitivity up to 3 - 4dB compared with the traditional method.