Channel Information Access And Feedback Strategy Research On Broadband Wireless Multimedia

Recently Boardband Trunking Communication System has been widely developed and applied in modern society.B-TrunC physical layer Based on Time Division Duplex Long Term Evolution is an important development branch of it.This paper studies the the access to channel information,feedback strategy and implementation on broadband wireless multimedia experimental machine in B-TrunC system based on TD-LTE.Paper studies B-TrunC system physical protocol based on TD-LTE standard,organizes overall process of the downlink and uplink data shared channel,designes the overall framework of B-TrunC system.Based on TD-LTE,thesis sets up B-TrunC system basic link on Matlab simulation platform and analyses the performance of shared channel under the circumstance of additive white Gaussian noise.By regarding Rice channel as typical channel,paper researches on channel estimation technology in B-TrunC system,including the method of moment estimation,K-S estimation and maximum likelihood estimation technology.Former two methods only use the envelope of signal,while maximum likelihood method makes full use of envelope and phase,thus it achieves the optimal performance.However,complexity is rather high for maximum,the method of moment estimation can achieve good tradeoff between performance and complexity.Paper studies least squares estimation algorithm and linear minimum mean square error estimation algorithm in Rice channel,and puts forward an optimization algorithm of weighted and deviation correction,theoretically analyses and simulation to show that they can enhance the noise suppression,and the greater Rice factor brings stronger noise suppression ability,which results in more precision in estimation.Paper studies the estimation technology of Signal to Interference plus Noise Ratio(SINR)in B-TrunC system,including alogorithms based on cyclic prefix,empty subcarrier and interference offset respectively.After estimating the noise variance,paper considers SINR measurement alogorithm based on equilibrium data when system contains antenna interference,and then analyses the mapping method of SINR to measure the overall performance of link.By comparing performance of typical algorithms theoretically,paper gives digital simulation on Matlab and analyses the applicability of SINR algorithms on experimental machine.Paper studies the adaptive modulation and coding technology of B-TrunC system,mainly focus on channel parameters feedback algorithm of downlink,analyses the mapping method from SINR to channel quality indication.Paper researches rank indication algorithms based on channel correlation matrix or capacity and precoding matrix indication algorithms based on the decomposition of channel matrix or mutual information respectively.At last,paper gives digital simulation on Matlab and analyses the performance of adaptive modulation and coding technology on experimental machine.Thesis finally summarizes research results of the full text and points out the research direction in future.