الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Next generation communication systems are challenged by the fast growing demand on higher-speed higher-quality services. Advanced signal processing techniques, developed modulation and coding techniques, different multiple-access transmissions, and various types of diversity supported the system evolution toward the next generation requirements. Unfortunately, these advanced techniques are incapable of solving the limited resources of the wireless networks. In the last few years a new transmission concept was highlighted and intensively exploited that is; the cooperative transmissions. The new paradigm provides two important factors; transmit diversity and a smart utilization of the network resource allocation in wireless networks. Consequently, it serves to virtually expand the wireless networks resources and enhance the system performance as well as the quality of service.
On the other hand, systems applying code-division-multiple-access are seeking for codes with optimal correlation properties with impulsive autocorrelation function and orhtogonality between different codes. Various communication systems are used to apply multiple spreading using families such as the M-sequences and Gold codes combined with Walsh codes to fulfill these correlation requirements. While these systems insist to use single codes in the spreading operations, some code sets were satisfying the recommended correlation properties. Such as the orthogonal complementary code sets that possess the optimal correlation properties.
This thesis reaches for a practical implementation of a half-duplex decode-and-forward algorithm based on the use of orthogonal complementary code sets in a multi-user CDMA transmission framework. The performance analysis of the proposed cooperative algorithm is shown to provide a probability of error performance adjacent to the theoretical performance, and illustrates a remarkable enhancement compared to the case of non¬cooperative transmissions. Next, the decode-and-forward receiver model is carefully observed and a channel blind A-combiner is suggested instead of the sub-optimum A-MRC. The proposed combiner adopts a new dynamic-blind estimation of the combiner’s weight A. The performance observation illustrates the efficiency of the combiner’s weight estimation and the promising performance resulting by applying the blind combiner. Finally, a cooperative resource allocation strategy is proposed to networks supporting terminals with multi-rate requirements in order to enhance the network quality of service. The proposed strategy is shown to have a noticeable impact on the system performance.