基于DPSCT和频谱校正的窄带干扰CBOC信号捕获算法

针对窄带干扰环境下组合二进制偏移载波(combined binary offset carrier, CBOC)信号难以被准确捕获的问题,提出了一种基于频域双相移组合陷波器(dual phase shift combination trap, DPSCT)结合批处理、频谱校正的捕获算法。该算法首先用陷波器对任意频点的窄带干扰进行抑制,再通过批处理提高处理速度,最后针对快速傅里叶变换(fast Fourier transform, FFT)过程中扇贝损失易导致捕获概率降低的问题,提出了基于部分匹配滤波器(partially matched filter, PMF)结合相位差+单点傅里叶变换频谱校正的捕获方法。仿真结果表明,该算法对在窄带干扰抑制后波形恢复和捕获概率等方面均有良好的性能,当信干比(signal to interference ratio, SIR)为-37 dB时,该算法较未校正之前捕获概率有4 dB的提高,并有效缩短了捕获时间。

Acquisition algorithm of narrowband interference CBOC signal based on DPSCT and spectrum correction

For the problem of difficulty in accurate acquisition of combined binary offset carrier (CBOC) signals under the narrowband interference environment, a acquisition algorithm is proposed based on frequency domain dual phase shift combination trap (DPSCT) combined with batch processing and spectrum correction. Firstly, the trap is used to suppress narrowband interference at any frequency. Secondly, the processing speed is increased through batch processing. Finally, for the problem that the scallop loss is easy to cause the detection probability to decrease in the process of fast Fourier transform (FFT), a acquisition method based on partially matched filter (PMF) combined with phase difference plus single-point Fourier transform (FT) spectrum correction is proposed.The simulation results show that the algorithm has good performance in waveform recovery and acquisition probability after narrowband interference suppression. When the signal to interference ratio (SIR) is -37 dB, the proposed algorithm has an improvement of 4 dB over the acquisition probability before correction, reducing the acquisition time effectively.