Research On Parameter Extraction And Feature Evaluation Methods For Wireless Channel

With the development of technology,wireless communication has become more and more important in life,and wireless communication systems are becoming more and more complicated.Wireless communication systems are diverse,and it is impossible to conduct actual measurement experiments for each communication environment.Therefore,various communication models need to be established to meet the needs of simulation experiments.In wireless communication,wireless channel has been the focus of research as a measure of communication quality.In this thesis,firstly,single-input single-output(SISO)channel models are established by using the shaping filter method,which mainly include Rayleigh fading channel and Rician fading channel.For the two basic fading channels,the first-order statistical characteristics and the second-order statistical characteristics are extracted respectively.For the first-order statistical characteristics,a K-S test method for evaluating the channel is proposed,and the feasibility of the scheme is verified.The simulation results show that when the sample length is 128000 and the significance level is less than 0.01,the correct recognition probability of this scheme is over 95%,which has high performance and can be used as an important basis for the standardized evaluation of Rayleigh and Rician fading channels.Secondly,the SISO channel is used to generate a multiple-input multiple-output(MIMO)channel according to the correlation matrix method,and the first-order statistical characteristics and second-order statistical characteristics of the MIMO channel are extracted.Each path of the MIMO channel satisfies the statistical characteristics of the specific SISO channel,and the irrelevance is satisfied between the different paths.The K-S test is used to verify the MIMO channel paths.The simulation results show that the MIMO channel has good first-order statistical properties.Finally,the pilot-based channel estimation methods for MIMO-OFDM system are introduced.Based on this,an improved DFT channel estimation method is proposed.The simulation and analysis are carried out.The simulation results show that the improved method can further improve the accuracy of DFT channel estimation.Under the same mean square error,the improved method has a performance gain of about 9 dB SNR compared with the LS estimation method.At the same bit error rate,the improved method has a performance gain of about 3 dB SNR compared to the LS estimation method.