Design Of Indoor High-Speed Wireless Transmission System For FPGA Implementation

Information interaction is an important part of human life.With the development of modern communication technology,new concepts and technologies gradually emerge,people’s demand for multimedia information interaction has become more and more urgent,indoor environment video wireless interaction has been a hot topic in the communication industry in recent years.How to avoid ISI or ICI in complex indoor channel environments,and how to obtain more efficient and reliable transmission performance,will continue to be an exploration of wireless communication systems direction for improvement.The realization of high-speed,low-latency,large-capacity,and high-reliability indoor wireless communication systems is inseparable from MIMO technology and OFDM technology.Therefore,it is of great significance to study the transmitter modulation scheme design of MIMO-OFDM system and the key time-frequency synchronization technology of receiver for complex indoor channel environment,especially in the theoretical analysis and engineering application of realizing high-speed and reliable wireless communication system.First of all,this thesis introduces the research background and significance,and summarizes the research status of indoor wireless communication at home and abroad.This thesis also briefly explains the theoretical basis,advantages and problems of MIMO-OFDM system transmission,and studies the impact of time-frequency synchronization in wireless communication systems.This thesis explains the theoretical basis and advantages of MIMOOFDM system transmission,analyzes the influence of time-frequency synchronization errors in wireless communication systems,and studies the basic transceiver structure of modern indoor wireless communication systems and the difficulty of time-frequency synchronization of system receivers in complex indoor channel environments.Based on the research and analysis,this thesis designs the modulation and demodulation process and signal frame format of the indoor wireless transmission transceiver system,and briefly describes the channel model used in the system simulation.Secondly,aiming at the specific research on the design of the MIMO-OFDM system modulator,this thesis analyzes the wireless transmission performance indicators,determines the overall structure and process of the system transmitter modulation,and designs each specific modulation process,including both adaptive coding and MIMO-OFDM modulates.Thirdly,aiming at the problem of efficient wireless transmission in indoor complex environment,this thesis deeply studies the time-frequency synchronization algorithm of the system receiver.The demodulation of the system receiver starts with frame synchronization.According to the analysis and design,the frame synchronization and coarse frequency synchronization are combined,and the phase information obtained from the frame synchronization correlation operation is used to estimate the coarse frequency offset,thus realizing the joint time-frequency coarse synchronization design.Then,this thesis simulates and analyzes the existing precise timing synchronization algorithm based on training sequence.The following problems exist in the existing precise timing correlation algorithms:multi-peak issues due to design limitations,offsets and continuous spikes caused by multipath effects,the problem that the decision amplitude is not obvious,algorithmic complexity and other issues.In order to effectively improve the demodulation performance and the precision of the fine timing synchronization algorithm,a cross-stacking crosscorrelation precise timing synchronization algorithm and “inverse shift peak elimination”processing is proposed in this thesis.The algorithm avoids the multi-peak problem by crossstacking cross-correlation,and eliminates the influence of multi-path continuous spikes by inverse shift peak-cutting processing.The algorithm balances the complexity and improves the overall performance of precise timing synchronization while ensuring that the decision variable produces an obvious peak value.For fine carrier frequency synchronization,an improved algorithm is proposed in this thesis,which ensures the accuracy of frequency offset estimation and balances the computational complexity of the system.Finally,based on FPGA,the architecture design and performance analysis of the system implementation are carried out.According to the above-mentioned theoretical scheme and algorithm,the complete system circuit implementation structure and the circuit implementation structure of transmitter modulator and receiver time-frequency synchronization module are designed.The circuit structure analysis and timing design simulation are carried out for the realization of specific functional modules,and the circuit ports of the modules are given.Combined with system static timing analysis,logic circuit simulation and MATLAB system scheme comparison simulation,the feasibility of the design scheme and the performance of the system are verified.