Analysis And Research On Space-time Block Coding In MIMO System

An important breakthrough in the field of wireless communication-the multiple input multiple output (MIMO) technology which use multiple transmit and receive antennas method in the radio link has much improved the system capacity, effectively resist multi-path fading in the channel. Space-time coding is a coding technology based on this MIMO system. It utilize the transmit diversity of MIMO adequately, and this coding technology can effectively enhance the profitability of frequency, also it can greatly improve the quality of communication service. Space-time block code as one kind of space-time coding obtains much more attention, because of its low coding and decoding complexity.This article mainly analyses and researches the Space-time coding technology through the method of theory deduction combined system imitation. Primarily included:1,Introduces the conception and classification of diversity, presents the MIMO capacity with the influence factors on flat fading channels, which provides the correlation theory to the method on how to increase the channel capacity.2,Elaborates design criteria and performance parameter, besides introduces some important kinds of Space-time coding, analyses their merits and defects respectively.3,Analyses the Space-time block code (STBC) in detail, including the orthogonal design for Space-time block code and Quasi-Orthogonal Space-time block code, discusses their fundamental principle, characteristics, coding and decoding algorithm, performance imitation roundly. Proposes a scheme based on orthogonal design for space-time block code. This algorithm is on the condition of knowing channel state information at transmitter, which not only enhances the system performance, but also constructs full data rate and complex orthogonal design STBC with more than 2 transmit antennas. The method breaks through the limitation of complex orthogonal STBC with full data rate only exists in 2 transmit antennas.4,Primarily studies iterative soft-decision algorithm of concatenated code. This concatenated code combines the good error corrected channel code with advanced near Shannon limit—Low-Density Parity-Check Code and Space-time code. This concatenated scheme improves the performance in vast scale. This paper presents concatenated scheme and concrete iterative algorithm of the concatenated code. In addition, the improved STBC knowing channel state information at transmitter is made as a concatenated code, and gives the analysis of system imitation results. The method overcomes the drawback of complex orthogonal STBC getting non 1 data rate and can provide more coding gains through concatenated coding.