الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Multiuser detection and turbo coding are two of the most powerful techniques for enhancing the performance of next-generation wideband code-division multiple-access (CDMA) systems. Wideband code-division multiple - access (CDMA) has been adopted by industry as a key technology for the next generation wireless communication systems - due to the time variation and frequency selectivity of wireless multipath channels, the presence of time variant fading, intersymbol interference (ISI), and multiple access interferece (MAI) constitute major impediments to reliable communication in CDMA systems, also fading in wireless environments is a major obstacle to reliable communications. In order to mitigate the effects of fading, channel coding is often employed. In this thesis, the performance and design of turbo-coded DS/CDMA is examined over Rayleigh fading channels using a MATLAB computer simulation programs performed, showing the main parameters which affect the performance such as the number of iterations used in decoding process, the code rate, the frame size of input data, and the generator polynomials used in the component codes and finally the number of users in the system.
The thesis considers coherent BPSK signaling over both time-correlated and fully-interleaved Rayleigh (Uncorrelated). Slow-fading channels with additive noise. The MAP algorithm is discussed as an optimal decoding algorithm. Also, the feedback decoder used in decoding turbo codes is discussed by means of two MAP decoders with iterative process.