Abstract
Narrowband interference (NBI) suppression plays an important role in the performance of a direct-sequence code-division multiple-access (DS-CDMA) system. Although it is well known that a CDMA system possesses the feature of resistance to narrowband interference to some extent, it has been shown that employing interference suppression filters prior to signal despreading can further enhance the performance of a DS-CDMA system. Over the past two decades, there have been many researches concerned with the development of techniques for active NBI suppression. But, most of the NBI suppression techniques were not considered for near-far environments. In this thesis, we propose an enhanced offset predictor for NBI suppression in a near-far situation. The proposed scheme has better performance than the previous techniques. Finally, we discuss a combination of NBI suppression and multiuser detection, where turbo partial parallel interference cancellation is considered for combining with the proposed NBI suppression scheme. From simulation results, it is shown that the proposed NBI suppression method is essential for improving the performance of a CDMA system.