Narrow-Band Interference suppression in transform domain based on Difference-Cluster-Threshold algorithm

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.