Study Of Space-time Multi-user Detection Correlative Technology

The Smart Antenna technique is the combination of adaptive antenna array with Space-Time Processing, which can deal with signal in space area and time area. Its basic thought is that we can receive and transmit a lot of different user' s signal on the same way without interference by the different space characteristic of the every mobile user. In reality it make correspond by letter the resources to no longer limit at time area(TDMA), frequency area(FDMA) or code area(CDMA) but expanded to the space area, belongs to space division(SDMA) system. We can not only improve the base antenna coverage, system capacity and service quality, but also reduce the inter-symbol interfere, multi- access interfere and transmitting power by the use of the Smart Antenna technique in wireless communication .Space-time processing is not only the core of the Smart Antenna technique, but also the key of signal processing in the third generation of wireless communication system. It has been the present focuses in signal processing and communication field.Introduing space-time MMSE algorithm, in order to reduce algorithm complexity, proposing a space-time MMSE Multi-user Detection algorithm of low complexity, the optimal factor is achieved by using a steepest descent algorithm, The new algorithm reduces the complexitv remarkably compared with the conventional space-time MMSE algorithm, Simulatiom results illustrate that the new algorithm can offer stable convergence and good detection performance.This thesis is dedicated to the application of modernistic optimum algorithms to solve the difficult issue of MUD design. researching tabu search algorithm,proposing a space-time multi-user Detection algorithm based on tabu search algorithm. This new algorithm has lower complexity and lower BER, and is prone to project implement.Therefore , the main content of this paper is that researching the method of restraining the so-called multiple access inteuference (MAI) to reach low bit error rate(BER) with acceptable computation complexity. Our attention is focusing on the sub-optimal MUD algorithm.