基于BSS方法的卫星信号高精度快速捕获

High-accuracy Fast Acquisition of Satellite Signal based on Blind Signal Separation

卫星信号的捕获速度和精度直接影响到软件接收机的工作性能。针对现有卫星信号的捕获方法无法实现对全球定位系统(GPS)卫星信号快速精确捕获的问题,文章提出一种基于盲信号分离(BSS)方法的GPS卫星信号高精度快速捕获方法。采用小波阈值降噪法对混叠的GPS卫星信号进行降噪处理,提高卫星信号的信噪比,利用提出的基于子空间估计算法的卫星信号BSS方法求解GPS卫星信号的多普勒频率和码相位,从而恢复出不可观测的各个源信号。实验结果表明,该算法能够对真实卫星信号实现快速精确捕获;对比传统算法,文章所提的捕获算法更加适用于对弱信号的捕获需求,该算法具有较好的工程应用价值。

Acquisition speed and accuracy of satellite signal directly affect the working performance of software Global Positioning System(GPS)receiver.Aiming at the problem that the existing acquisition methods of satellite signals cannot achieve fast and accurate acquisition of GPS signals,the paper proposes a high-precision and fast acquisition method of GPS satellite signals based on blind separation.Firstly,the wavelet threshold algorithm is used to denoise the original signal of GPS satellite in order to improve the signal-to-noise ratio of satellite signal.Then the doppler effect frequency and phase of GPS satellite signal are solved by the proposed blind separation method based on subspace estimation algorithm to recover the unobserved source signals.Experimental results show that the proposed algorithm could accurately capture real satellite signals.Simulation results indicate that compared with the traditional algorithm,the acquisition algorithm in this paper is more suitable for the acquisition of weak signals,which shows that the algorithm has a better engineering application value.