| Summary: | 碩士 === 國立臺北科技大學 === 電機工程系所 === 98 === Multiple access interference (MAI) is one major factor that degrades communication quality of a spreading spectrum communication system. To overcome this problem, an orthogonal complementary code (OCC)-based multi-carrier code division multiple access (MC-CDMA) system is presented in this study. While OCC demonstrates its well performance over AWGN channel, it performance over frequency-selective fading channel is not satisfactorily. To address this difficulty, a two-stage multi-user detector that consists of parallel interference cancellation (PIC) and hybrid optimization algorithm is suggested in this study, in which the PIC aims to reduce MAI to help successive multi-user detection performed by a hybrid optimization algorithm that combines particle swarm optimization (PSO) with Nelder-Mead (NM) simplex algorithm. Furthermore, the proposed optimization algorithm is used to adjust the weights of partial parallel interference cancellation (PPIC) to improve system performance. Experimental result demonstrates the effectiveness of the proposed approach on multi-user detector in the MC-CDMA system.
|
|---|
