中文摘要：

针对直接序列扩频通信系统中窄带干扰抑制问题，该文提出一种基于门限抑制窄带干扰的新算法。新算法利用接收信号频谱包络的差分值找到非干扰信号频谱分段，然后将非干扰信号频谱分段谱线最大幅度模值作为门限，从而实现干扰抑制。仿真统计分析表明，该算法的乘法次数约为自适应多门限算法的1/5.4，加法次数分别约为自适应多门限的1/4和双门限前向连续均值切除（Double Threshold Forward Consecutive Mean Excision, DT-FCME）算法的1/5，降低了运算复杂度。仿真实验结果表明，该算法的仿真时间仅为自适应多门限算法的1/3和DT-FCME算法的1/4，且误码率性能与自适应多门限和DT-FCME算法相当。

英文摘要：

In order to mitigate the Narrow-Band Interference （NBI） signal in Direct Sequence Spread Spectrum （DSSS） system, a Difference-Cluster-Threshold （D-CT） narrowband interference suppression algorithm based on threshold detection in transform domain is proposed. The D-CT algorithm takes advantage of the difference values of the spectrum envelope of the received signal to find the non-interference signal spectrum segments, and thus it can suppress the NBI signals by using the maximum amplitude modulus value of the spectrum segment as the threshold. Statistical analysis shows that the number of multiplications of the adaptive multi-threshold algorithm is about 5.4 times that of the D-CT algorithm. The number of additions of the D-CT is only about one fourth that of the adaptive multi-threshold and one fifth that of the Double Threshold Forward Consecutive Mean Excision （DT-FCME） respectively. Simulation results indicate that the simulation time of the D-CT algorithm is approximately one third that of the adaptive multi-threshold algorithm and one fourth that of the DT-FCME algorithm respectively without losing the BER performance.