Adaptive two-stage filter bank based narrowband interference suppression in DSSS systems

In this paper, we propose a cost efficient approach for narrowband interference suppression in direct sequence spread spectrum systems. Our proposed approach takes advantage of the multirate property by using cosine- and sine- modulated perfect reconstruction filter bank blocks of small size to form an adaptive two-stage tree-structured filter bank. In the first stage, an efficient complex modulated critical sampled filter bank is built to split the complex input signal into 2M real low-rate subchannel signals. The detected interfered subchannel signals are further decomposed by the second staged filter banks for narrowband interference suppression in DSSS systems. The proposed structure is cost efficient in terms of computation and storage. Simulation results demonstrate that our approach also effectively enhances the systempsilas performance.