In the high orbit space, the visibility of GPS main lobe signal is poor due to the earth's occlusion and the increase in signal transmission distance. Therefore, the side lobe signals are essential for navigation mission, which puts forward higher requirements for the sensitivity of the receiver. In addition, the cross-correlation interference (CCI) caused by the large power difference between the main and side lobe signals is serious and results in the false acquisition of the side lobe signals. To improve the acquisition sensitivity and stability of the receiver, we designed a GPS signal acquisition algorithm for the high orbit space. The characteristics of high orbit GPS signal are analyzed according to the propagation process of GPS signal link. The influence of CCI on the acquisition performance of the side lobe signals is explored. Based on the parallel code phase search method, the coherent accumulation and incoherent accumulation are combined to improve the acquisition sensitivity. At the same time, according to the different probability distribution characteristics of autocorrelation peak and cross-correlation peaks in the correlator output, CCI is detected by means of hypothesis testing. The strong signals are reconstructed by using the amplitudes, code phases and Doppler shifts provided by the tracking loop. The CCIs are estimated by correlating the reconstructed strong signals with the local duplicated signals and eliminated from the correlation results of the side lobe signals to obtain the correct acquisition results. Simulation results show that the proposed algorithm can eliminate the CCIs in the high orbit space and improve the acquisition sensitivity of the receiver. Moreover, the CCIs under different Doppler shift differences of the main and side lobe signals can be effectively eliminated.

在高轨道空间中，由于地球的遮挡和信号传输距离的增加，GPS主瓣信号的可见性很差。因此，旁瓣信号对于导航任务是必不可少的，这对接收机的灵敏度提出了更高的要求。另外，由主瓣信号和旁瓣信号之间的大功率差引起的互相关干扰（CCI）严重，并且导致对旁瓣信号的错误获取。为了提高接收器的采集灵敏度和稳定性，我们针对高轨道空间设计了GPS信号采集算法。根据GPS信号链路的传播过程，对高轨道GPS信号的特性进行了分析。探讨了CCI对旁瓣信号采集性能的影响。基于并行码相位搜索方法，相干累加和非相干累加相结合以提高捕获灵敏度。同时，根据相关器输出中自相关峰和互相关峰的概率分布特征，通过假设检验检测CCI。通过使用跟踪环路提供的幅度，代码相位和多普勒频移来重构强信号。通过将重构的强信号与本地重复信号相关联来估计CCI，并从旁瓣信号的相关结果中消除CCI，以获得正确的采集结果。仿真结果表明，该算法可以消除高轨道空间中的CCI，提高接收机的捕获灵敏度。此外，可以有效消除主瓣和旁瓣信号在不同多普勒频移差异下的CCI。