Interference has destructive impacts on all signals, but due to the weakness of the global positioning system (GPS) signals, even low-power interference has a significant destructive effect. Mitigation of that effect is a challenging issue for GPS receivers. We investigate the performance of the acquisition in the presence of the most effective and common interferences in use, such as single-tone continuous wave interference (CWI), multi-tone CWI, and chirp jamming. Our purpose is not to mitigate or completely remove the interference signal, but by using a signal processing method after the correlation, a receiver can acquire weak signals in the presence of interference with a jammer-to-signal ratio up to 60 dB. The main idea is derived from image processing filters so that by applying proper filters to the values of the cross-ambiguity function in the search space, the interference signal contribution decreases without any need for prior knowledge of its specific characteristics. Accordingly, even weak GPS signals can be easily acquired, and the number of acquired satellites increases significantly compared to the usual anti-jamming methods. Moreover, signals can be acquired even at twice the normal decision threshold value.

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GPS接收机的新的后相关抗干扰技术

干扰对所有信号都具有破坏性影响，但是由于全球定位系统（GPS）信号较弱，即使是低功率干扰也具有明显的破坏性影响。对于GPS接收机而言，减轻这种影响是一个具有挑战性的问题。我们在使用最有效和常见干扰的情况下（例如单音连续波干扰（CWI），多音CWI和chi声干扰）下调查采集性能。我们的目的不是减轻或完全消除干扰信号，而是通过在相关之后使用信号处理方法，接收机可以在存在干扰的情况下以高达60 dB的干扰信号比获取微弱的信号。主要思想源自图像处理滤波器，因此，通过对搜索空间中的交叉歧义函数的值应用适当的滤波器，可以减少干扰信号的贡献，而无需事先了解其特定特性。因此，即使是微弱的GPS信号也能够容易地获取，并且与通常的抗干扰方法相比，获取的卫星的数量显着增加。此外，即使是正常判定阈值的两倍，也可以获取信号。