Research On 5G Pusch Channel Estimation And Equalization Technology Under High-speed Movement

The rapid change of channels in high-speed mobile scenarios will further increase the requirements for channel estimation and channel equalization techniques.At the same time,as a key technology in the R16 enhanced high-speed mobile scenario of the 5G system,the channel estimation and equalization technology of multiple transmission points(Multi-TRP)in the highspeed rail scenario is facing greater difficulties and challenge.This dissertation is mainly based on the research of high-speed rail 5G mobile communication and Multi-TRP,and at the same time uses orthogonal frequency division multiplexing(OFDM)and multiple-input multipleoutput as key technologies.In the high-speed rail mobile scenarios,a series of researches are carried out on the channel estimation and equalization technology of 5G physical uplink shared channel(PUSCH).In the PUSCH uplink,the demodulation reference signal(DMRS)is used as a pilot and the PUSCH data symbols are jointly transmitted in the form of an OFDM resource grid,and the receiver uses the pilot-assisted channel estimation,channel interpolation and channel equalization and other technologies complete the restoration of the transmitted signal.At the same time,in order to restore the high-speed rail mobile scene to the greatest extent,the dissertation establishes a simulated channel model from the aspects of channel delay and Doppler frequency offset,so as to provide a more accurate and reasonable channel scene for the research work of the dissertation.In addition,in order to better evaluate the performance of different channel estimation and equalization techniques and PUSCH receivers under high-speed mobile,the dissertation selects mean squared error(MSE),bit error rate(BER)and spectrum efficiency as an objective criterion for performance.On the one hand,while researching and optimizing the performance of PUSCH channel estimation and equalization algorithm under high-speed mobile,the specific impact of Doppler frequency offset interference on the time domain interpolation algorithm is further explored,on the other hand,by introducing the Multi-TRP system and taking the number of TRPs at the base station side in the system as a variable,the performance of the PUSCH receiver in different high-speed mobile scenarios is evaluated and analyzed.The simulation results show that among the series of channel estimation methods used in the dissertation,the linear minimum mean square error(LMMSE)algorithm at the pilot and the frequency domain Wiener interpolation algorithm at the non-pilot are relatively better.At the same time,the resistance of time-domain Wiener interpolation to Doppler frequency offset is higher than that of linear interpolation in high-speed moving scenarios.Considering the complexity of the algorithm and the performance advantages,the minimum mean square error(MMSE)equalization algorithm is more cost-effective.Furthermore,by combining the MultiTRP system and the PUSCH link,the more the number of TRPs on the base station side in the Multi-TRP system,the better the reception performance of the corresponding PUSCH in the Multi-TRP system due to the mutual cooperation between different TRPs.The above series of simulation analysis not only optimizes the channel estimation and equalization performance under high-speed movement,but also confirms the applicability and performance superiority of Multi-TRP technology in PUSCH link transmission.