| High reliability, high speed, high stability is the long development goals of wirelesscommunication system. For the increasingly complex electromagnetic environment and themore dense of the user group, how to reduce the bit error rate of the system, improve thechannel capacity, and reduce the influence of signal decline become serious problems.This paper combineS the channel coding-LDPC code, MIMO technology and the OFDMtechnology that can effectively restrain the frequency selective decline to establish theLDPC-MIMO-OFDM communication system model. Promoted by the influence of the Turboiterative thought and technology, this paper focus on the soft input soft output algorithm toresearch the LDPC code decoding and space-time decoding with combined iteration detectionmechanism, so as to further improve the system reliability, provide the references forLDPC-MIMO-OFDM system in wireless communication application.Firstly, the paper tracks the development trend of LDPC code, MIMO and iterativeinspection receiving technology, summarizes the research achievements and the existingproblems. Secondly, Combined with the multiple-input multiple-output (MIMO) systemmodel and the OFDM technology, therefore the MIMO-OFDM cascade system has beenresearched. To improve the communication system reliability, the LDPC code is introduced.Based on the LDPC code, the SISO decoding algorithm is analyzed, whose complexity andreliability are compared, determined the LDPC-space-time code SISO scheme. Mainly to thespace-time code SISO detection algorithm, the iterative algorithm based on MMSEinterference detection is used as the detection scheme. Furthermore, the LDPC code combinedwith SISO establishes the iteration detection mechanism, which share information through thecycle feedback to correction the error. Finally, in order to improve the system reliability,promote the speed of data transmission and control the frequency selective decline,LDPC-MIMO-OFDM system is designed combine with MIMO-OFDM system andLDPC-space-time code system.LDPC-MIMO-OFDM system simulation platform is established, make a simulation forthe various factors that can impact the LDPC-MIMO-OFDM system performance. Thesimulation result is compared, which measure the reliability, efficiency, real-time, complexityand feasibility comprehensively, and determined the eclectic parameters the combinationscheme. It lays the foundation for the subsequent hardware design and application popularize,and provides a reference design scheme for future wireless communication system. |
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