Abstract
In this thesis, the recently proposed highly efficient receiver called the RAKE with bi-direction decision feedback (RAKE-BDDF) receiver [6] is investigated for Direct-Sequence M-ary Bi-orthogonal Keying (DS-MBOK) system. The proposed receiver is designed to cancel all the post- and the pre- intersymbol interferences as well as multi-code interference at symbol rate by using a novel bi-directional decision feedback structure. For multiuser DS-MBOK uplink system, the spreading codes used by different users may lose their low cross-correlation property when passing through multipath channel, and incurs severe multiple access interference (MAI) in receiver. In this thesis, we propose two new multiuser detectors for DS-MBOK system which are called RAKE-BDDF-PIC detector and RAKE-BDDF-SIC detector. The proposed MUD scheme combine the BDDF structure and parallel or successive interference cancellation scheme to eliminate all the intersymbol interference (ISI), multi-code interference (MCI) and multiple access interference (MAI) terms. Finally, the simulation results show that the MUD receivers can significantly improve the performance and approximately attain single-user matched filter bound (MFB) without any costly matrix-inversion or trellis-searching.