中文摘要：

为了减小基于时域线性预测干扰估计的DSSS系统窄带干扰抑制技术对有用信号产生的损伤,根据干扰环境下接收信号的循环平稳特性,提出了一种利用频移滤波器对干扰进行估计并将干扰抵消的DSSS系统窄带干扰抑制方法.该方法在对干扰进行估计时,既利用了干扰的时域相关性,又利用了干扰的频域相关性.理论分析和仿真结果表明,在强干扰环境下,接收信号的循环平稳性主要由强干扰决定.与传统时域线性预测方法相比,该方法对干扰估计的时平均均方误差更小,能够更精确地估计和消除频谱相关的干扰,减轻对有用信号的损伤,进一步降低系统的误比特率,因而具有更加优良的干扰抑制性能,特别在干扰较强或干扰频带较宽时,优势更加明显.

英文摘要：

To mitigate the impairment to the desired signal caused by the conventional narrow-band interference （NBI） suppression technique based on interference estimations by linear predictions in time domain in direct sequence spread spectrum （DSSS） systems, an approach of suppressing NBI in DSSS systems using a frequency-shift （FRESH） filter to estimate the NBI is proposed based on the cyclostationary characteristics of the received signal in the environment of the interference, which can use the correlation of the interference not only in time domain but also in frequency domain for the interference estimation. The results from theoretical analysis and simulations indicate that the cyclostationary characteristics of the strong interference in the received signal is exhibited mainly in the environment of the strong interference. Compared with the traditional techniques based on linear pre- dictions in time domain, smaller time average-mean square errors can be achieved, the spectrum-correlated interference can be estimated and eliminated more exactly, and the impairment to the desired signal is mitigated. The bit error rate of the system is reduced further, so better interference suppression performance can be achieved. The advantage is more evident especially when the interference is stronger or the frequency band of the interference is wider.