The Research For The MIMO Channel Performance And Beaforming System

Although it is long been known that wireless communication system is a SI SO system (Single Input Single Output). But with wireless products showed exponential growth trend, the scarcity of frequency resources has become a significant barrier to prevent improvement of wireless communication system. The experts suggested many solutions to improve the efficiency of frequency, and they considered that MIMO system (Multiple Input Multiple Output) is a valid approach. In stark contrast to the traditional SISO system, both receiver and transmitter contains enough wires in MIMO system. The researchers named E.Telatar and J.Foshini from Bell Laboratory verified independently that MIMO system could acquire considerable information and breakthrough the blockage of traditional channel capacity, and it is a promotion of C.E.Shannon channel capacity.This passage firstly introduce the background and conception of MIMO and analyze its features, process and some problems to be solved.Secondly, the passage discuss the influence of MIMO system parameter (eg. array shape, antenna spacing, distribution of signal energy. and angle spread etc.) to MIMO system. Besides. it explicit a high-efficiency approximation algorithm to increase the efficiency of calculation. It also discuss the three-dimensional model of spatial correlation with taking into the factor of EOA(elevation-of-arrival). And then, analyze the connection between spatial correlation and relevant factors (such as system capacity, bit error rate etc.) Except that, comparison between beamforming system of cellular system and MIMO system is an important part of this passage, with the study of outage capacity, outage probability, cumulative distribution function and other parameters, identify the compromise between beamforming system and diversity system, then analyze the performance of the two systems with handoff and without it to find out a compromise between them. Lastly, I make a conclusion of the main research and indicate the future of MIMO system skill.