A Novel Continuous Wave Interference Detectable Adaptive Notch Filter for GPS Receivers

In this paper, we propose an interference detectable adaptive notch filter (ANF) for GPS receivers. The proposed ANF can estimate the existence of continuous wave interference (CWI) and its power, by exploiting the statistic value within an adaptive second-order infinite impulse response (IIR) filter. Moreover, our ANF is modulized, which allows more modules can be included to deal with multiple CWIs. We also design an adaptation algorithm for each ANF module and prove that the ANF module can adaptively notch the strongest CWI at its input, and this merit enables us to notch the primary CWIs with a limited number of ANF modules. Simulation results show that the adaption of the ANF modules converges in four iterations, and the signal to interference plus noise ratio (SINR) improvements can reach 21 dB.