Research On Space Time Coding Technology Of MIMO-PLC System

Multiple-Input Multiple-Output Power Line Communication(MIMO-PLC)can effectively combat the problem of multipath fading of traditional PLC channels,but PLC has great challenges in terms of reliability and channel capacity.Potentially effective means of reliability and channel capacity are receiving increasing attention.Many problems need to be solved to adapt MIMO technology to power line media.Both the physical characteristics of electromagnetic transmission and the optimization of signal processing strategies must be considered.Space-time coding,as a coding technology capable of implementing parallel multiplex transmission,can cause the transmission signal to generate correlations in space and time domain between each transmission port and transmission cycle.It is this correlation that can effectively solve and overcome the fading of the MIMO channel,and can also reduce transmission errors.Therefore,this paper will focus on the application of space-time coding in MIMO-PLC systems,and analyze the anti-error performance of these coding methods combined with simulation.First of all,this paper establishes a PLC channel model and an impulse noise model,and analyzes the capacity of traditional PLC channels and the capacity of MIMO-PLC channels.Then,the design principles of space-time coding are analyzed theoretically,and the coding and decoding schemes of space-time block codes,layered space-time codes,and space-time trellis codes in MIMO-PLC systems are introduced.Finally,Matlab simulation results show that the introduction of space-time coding scheme can overcome the influence of channel fading,achieve transmit diversity gain without sacrificing bandwidth,and improve the system’s anti-error performance.Based on Orthogonal Frequency Division Multiplexing(OFDM)technology,it has the advantages of anti-multipath delay,high frequency band utilization,and the ability to effectively overcome frequency selective fading.This paper discusses the basic model of MIMO-OFDM system,and establishes a space-time coding transmission scheme suitable for MIMO-OFDM system transmission.Simulation results prove that the introduction of OFDM brings significant performance improvements.On the basis of theoretical analysis,in order to further improve system performance,this paper selects Turbo codes as the channel coding technology,and designs a MIMO-OFDM-PLC iterative cascade system that jointly encodes space-time block codes and Turbo codes.Obtaining the diversity gain brought by space-time coding,and also ensuring the coding gain brought by the superior error correction ability of the Turbo code,thereby improving the overall system performance.