矩形二进相移键控窄带干扰抑制技术

Interference Rejection Based on Spectral Correlation in DSSS Communication Systems

对矩形二进相移键控(BPSK)窄带干扰以较高的扩频信号码片率进行采样,保留干扰的谱冗余,进一步建立了干扰的循环平稳模型,采用频移(FRESH)滤波器同时利用时域相关性和频域相关性来抑制窄带干扰.仿真实验表明,采用FRESH滤波器,相对于传统横向滤波器而言能够显著提高直接序列扩频通信系统抗窄带干扰性能.

The periodical characteristic of chips makes rectangular binary phase shift keying (BPSK) narrowband interference not stationary but cyclostationary and cyclostationary signal. As the chip rate of spread spectrum (SS) signal is much high than the baud rate of the interference, the baud rate correlated spectral correlation of the interference can be preserved. The narrowband interference was modeled as cyclostationary. Compared with the stationary model, this can preserve more information. Based on the cyclostationary model, FRESH filter was introduced and it can make use of the correlation in time and frequency domain. The computer simulation shows that FRESH filter can improve the system performance.