Research On Detection Algorithms Of Spatial Multiplexing Signal In Cooperative MIMO System

In future wireless communications, it is severe frequency-selective fading channel to support high data rate; meanwhile the available bandwidth becomes limited. To improve the spectrum-efficiency, one of the promising techniques is multiple input multiple output (MIMO) technique. Without additional consumption of bandwidth, MIMO technique can effectively improve the data transmission rate and capacity of the system.However, using MIMO technique in the current cellular mobile communication terminals will be subject to many restrictions, due to the requirement of almost irrelevant subchannels between antennas, making it difficult to install two or more antennas on mobile terminal. This has seriously affected the development of MIMO technique. Thus, cooperative communication is proposed, to achieve diversity and multiplexing gain via different user terminals, and greatly improving the reliability and validity of the system.In this paper, we first introduced the basic characteristics of MIMO channel, and simulated the Rayleigh and Rice channel models, then introduced the MIMO diversity technologies. According these, we proposed to apply cyclic delay transmit diversity (CDTD) technique to cooperative MIMO multi-code CDMA system. The computer simulation results showed that CDTD can improve BER performance of the cooperative multi-code CDMA system, but the inter-chip interference (ICI), making the system overall performance degrade as the number of code multiplexing order increasing.So in the last chapter, we proposed a frequency-domain iterative inter-chip interference (ICI) combined with parallel interference cancellation (PIC) technology (ICP), which makes it possible to eliminate the interference between antennas and the residual inter-chip interference between chips. From the simulation results, it is derived that compared to the traditional frequency-domain iterative PIC the proposed method ICP improves BER performance and the throughput of the system significantly and has faster convergence speed and better detection performance.