采用有效的窄带干扰抑制技术,可极大地改善扩频通信系统的性能.首先详细介绍了频域干扰抑制算法的基本思想,给出了算法实现的模块框图;其次具体分析了算法实现的关键技术:重叠加窗,背景噪声估计,干扰门限确定及干扰消除策略;最后以误码率作为干扰消除算法性能的评判标准,仿真分析了频域窄带干扰抑制技术中干扰强度、干扰频带宽度、干扰频率位置、干扰消除门限、陷幅值、加窗重叠度等因素对系统误码率的影响,为在不同条件下算法最佳参数的选取提供了依据.仿真结果表明:当干扰消除门限值取4aF,陷幅值取2σF~6σF,加窗重叠度为50%时,该算法可获得最佳抗干扰性能.
Narrow-band interference suppression can be used to greatly improve the performance of spread spectrum communication systems. Following introduction of the basic idea of frequency domain interference suppression algorithm, the paper gives a block diagram for algorithm implementation. Key technologies for implementation of the algorithm, overlapping windows, estimation of background noise, interference threshold determination and interference cancellation strategies, are analyzed. Taking BER (Bit Error Rate) as the evaluation criteria for the perform- ance of the interference cancellation algorithm, simulation is done on factors of influence on system BER in narrowband interference suppression technologies in the frequency domain, including interference intensity, interference bandwidth, interference frequency, interference cancellation threshold, trap amplitude and windowed overlapping. The result provides a basis for selection of the best parameters for the algorithm under different conditions. Simulation shows that the algorithm reaches the optimal performance of antPinterference ability when the interference cancellation threshold is s 4au , trap amplitude is between 2σF to 6σF , and windowed overlapping degree is 50%.