基于变换域方法抑制线性调频干扰的GPS接收机设计

Design of a GPS Receiver for Suppressing Linear Frequency Modulation Interference based on the Transform Domain

GPS接收机的信号通常很微弱,很容易受到有意或无意的干扰。对于线性调频干扰,在GPS接收机中很难用单一的时域或频域方法消除,因为线性调频干扰不同于一般的宽带或窄带干扰。另外线性调频干扰在变换域有不同于GPS C/A码的显著特征,基于此特点设计了一种在变换域抑制线性调频干扰的GPS接收机。分析了线性调频干扰在变换域的特征,仿真结果验证了这种设计方法的可行性。

The GPS signals are usually very weak and easily interfered. Additionally, in the GPS signals, it is difficult to mitigate the linear frequency modulation （LFM） interfer- ences only in the time or frequency domain. The LFM interference is different from the nor- mal wideband and narrowband interferences. It has obvious time-frequency signature that is distinct from the GPS coarse/acquisition （C/A） spread spectrum code. In this paper, a new GPS receiver is proposed to mitigate the LFM interferences based on the fractional Fourier transform （FRFT） in the transform domain. The simulation results show that this method is valid.