关键词: SFM干扰, 联合, 伪码复合, 能量重心校正, 功率谱累积平均

Abstract: Aiming at the difficulties and low sensitivity of joint capture of multiple DBOC signals in general sinusoidal frequency modulation (SFM) interference and dynamic environments, an improved discrete sinusoidal frequency modulation transform (DSFMT) interference suppression algorithm is proposed. On the basis of partial match filter-fractional Fourier transform (PMF-FRFT) combined with pseudocode composite, a joint capture algorithm combining energy center of gravity correction, periodic graph method, and power spectrum cumulative average is proposed. Firstly, improve the received signal in DSFMT and perform interference zeroing; Then, perform PMF-FRFT on the time-domain signal after interference suppression and the local composite pseudocode; Reuse the energy center of gravity correction to highlight the captured peak, and use the periodic graph method to calculate the power spectrum; Finally, the power spectrum cumulative average algorithm is used to smooth out noise. The simulation results show that the proposed algorithm can effectively suppress interference while preserving the original signal well. And after accumulating 20 times, it is possible to simultaneously capture three DBOC signals with a signal-to-noise ratio of -24 dB.

Key words: sinusoidal frequency modulation (SFM) interference, union, pseudo code composite, energy center of gravity correction, power spectrum cumulative average