Research On Space-time Coding And Pre-coding For MIMO Communication Systems

MIMO (Multiple-Input Multiple-OutPut) system is one of the key technologies in the future of broadband wireless mobile communication, it use the multiple antenna technology to inhibit the fading, the system's communication capacity improved greatly by the MIMO technology, spectrum efficiency can be increased exponentially without increasing the bandwidth and antenna transmit power, it also can improve the reliability of the channel and reduce the error rate, therefore, MIMO technology has been focused in a wide range.Space-time coding technology is a feasible and effective method to achieve the capacity of MIMO radio channel, which includes space-time codes and spatial multiplexing that based on transmit diversity. The multiple access interference and multipath fading of MIMO system can cause the distortion and distortion of signal, we need to come up with effective space-time signal processing program to solve this problem. Signal detection technology is an effective method which solve multi-user interference from the receiver side. the Pre-coding technology of MIMO systems pretreatment the transmit signals to reduce inter-symbol interference, use the feedback information form the channel to improve performances of the system.This article describes the basic principle of MIMO system, fading channel models and diversity techniques, then introduces the multi-user detection techniques in MIMO system, and at last introduced the principles and design criteria of space-time coding, analysis the Advantages and disadvantages between different space-time coding, introduce the design criteria by the example of STBC(Space-time Block Code) decoding, and analysis the performance of different number of antennas of STBC scheme.Finally, the system focused on the Space-Time Coding MIMO pre-coding technique, designed pre-coded scheme with feedback, analysis the design criterion of statistical information based on the optimal channel precoding, and compared the simulation result of the number of MIMO space-time pre-coding scheme with different antenna. The Simulation results show that the space-time multiuser detection algorithm based on minimum mean square error making a better performance of pre-coded technology for space-time coding in a MIMO system.