一种直扩系统窄带干扰抑制技术研究

Research on Narrowband Interference Suppression in DSSS System

直扩系统具有功率谱密度低、信号隐蔽性好、多址通信能力强,抗噪声/干扰能力强等特点,在航天测控系统中得到广泛应用,但其自身抗干扰能力有限,需开展直扩测控系统中窄带干扰抑制技术的研究。本文介绍了基于变换域的FFT变换干扰抑制算法和SVD奇异值分解干扰抑制算法,并对FFT变换干扰抑制算法进行了加窗处理和重叠变换改进设计与仿真。通过仿真对比,改进设计后干扰的频谱泄露大为降低,同时减小对有用信号的损伤。该方法在数字电路中易于实现,对数字接收机的设计具有较大的参考价值。

Direct spread sequence spectrum(DSSS)technology has become the most popular communication mechanism in modern TT&C system because of its low power spectrum density,well-concealed signals,high range resolution,strong capacity of multi-address communication,as well as remarkable anti-jamming and anti-noise abilities.However,its anti-anti-jamming ability is limited,it is necessary to carry out the research on the narrowband interference(NBI)suppression technique in the DSSS system.In this paper,SVD singular value decomposition interference suppression algorithm and FFT transform interference suppression algorithm that based on transform domain are introduced.The windowed processing and overlapping transformation are used to improve the design of the latter,and the simulation work is done at the same time.Through the simulation comparison,the spectrum leakage of the interference is greatly reduced and the damage to the useful signal is reduced after the improved design.This method is easy to realize in digital circuit and has great reference value for the design of digital receiver.