Research And Implementation Of SC-FDE System Based On MIMO

Wireless channels are the main transmission carriers of information in wireless communication systems.However,its propagation characteristics can have certain effects on the transmitted information.In particular,the multipath effect in wireless channels can make the communication system less reliable and effective.Therefore,it is especially critical to solve the problems caused by multipath effect in wireless communication systems.In the prior art,orthogonal frequency division multiplexing(OFDM)and single carrier frequency domain equalization(SC-FDE)can effectively solve a series of problems caused by multipath effects.The communication system composed by both technologies has the same processing performance and computational complexity.In the engineering implementation of LTE system,SC-FDE is often applied in the uplink of LTE due to its relatively low peakto-average power characteristics.The multiple-input multiple-output technology(MIMO)is fully utilizing the abundant space resources,so it greatly improves the transmission efficiency and quality of wireless communication system.This paper focuses on the research and implementation of SC-FDE communication system based on MIMO technology,which works as follows:Firstly,this paper studies and analyzes the characteristics and theoretical models of wireless channels;discusses the basic principles of SC-FDE technology and MIMO technology,including the composition and modeling of SC-FDE system,diversity and multiplexing techniques in MIMO technology and STBC block coding.Secondly,the key technologies in the MIMO-SC-FDE system are studied and discussed,and the corresponding key technologies are selected to build the whole system design scheme.For the design of the transmitter side of the system,this paper focuses on the selection of the guide frequency,the insertion method of the guide frequency,and the design of the frame structure.In terms of frame structure design,two frame structures are proposed as alternatives in this paper.Since the complexity of engineering implementation is taken into account,the frame structure based on the guide frequency crossover is finally chosen in this paper.For the design of the receiver side of the system,this paper focuses on four aspects:timing synchronization,frequency synchronization,channel estimation,and frequency domain equalization,which are studied and discussed and the corresponding techniques are selected.In terms of channel estimation,the DFT transform domain-based LS channel estimation method is chosen as the channel estimation method for this system due to its excellent noise immunity and low algorithmic complexity.In terms of frequency domain equalization,the MMSE equalization technique is finally chosen in this paper due to the consideration of the anti-noise performance of the system equalization stage.Finally,the physical layer is implemented in FPGA+DSP architecture according to the overall design plan of the system.The main implementation tasks on the FPGA side are:overall implementation on the transmitter side,timing synchronization on the receiver side,frequency synchronization,channel estimation,and FPGA and DSP data communication interface implementation.Finally,the hardware system is tested by adjustable attenuator test and channel emulator test.According to the test results,the MIMO-SC-FDE hardware communication system designed in this paper works well,and all the indicators satisfied the expected requirements.