Research On Channel Estimation And Adaptive Equalization For Logging Data Transmission Cable

With the rapidly development of information society,the demand of the oil resources as important energy is sharply rising.The advanced imaging logging technology is used in petroleum industry to get more various physical properties in logging and adjust processing.The transmission characteristic of logging cable is not very well,which causes the inter-symbol interference and increases the error rates of system.In order to solve those problems,we can use equalizer to compensate the attenuation characteristic of the cable and improve the transmission rate of the cable.First of all,this thesis analysis the cable transmission characteristics and completes the cable model for providing the design of the adaptive equalizer channel;Secondly this thesis studies the principles of equalizer and the algorithms of adaptive RLS?LMS and variable step size LMS.The performance of algorithms is analyzed and compared by MATLAB.Then the thesis proposes a new variable step size LMS algorithm from convergence rate and steady state.In order to determine parameters and prove performance of adaptive equalizer in system,a complete OFDM system is established by MATLAB.Finally,a LMS adaptive equalizer is designed by Verilog and validated by Modelsim.The results show that the equalizer can effectively compensate the channel attenuation and improve the performance of the system.