Research On Signal Design Processing Method Of ISAC Based On Pilot And Data

The integration of sensing and communication(IS AC)has gradually become a research hotspot in the field of sensing and communication due to its high frequency spectrum utilization and the saving of hardware equipment.The ISAC technology is applied to the internet of vehicles,unmanned aerial vehicle clusters,smart city and other scenarios to improve the performance of communication and sensing.Phase coding has the characteristics of improving signal correlation and reducing peak to average power ratio,so it is used to optimize the ISAC signal.Starting from the development history of ISAC,this thesis investigates the current development status and key problems of the ISAC technology.Then,we analyze the performance of orthogonal frequency division multiplexing(OFDM)signal based on phase coding.A high accuracy sensing signal processing method,based on joint pilot and data,is proposed based on the signal.In order to improve the communication reliability and sensing accuracy,a precoding method for the multiple in multiple out-orthogonal time frequency space(MIMO-OTFS)system is proposed.The main contributions of the thesis are as follows:(1)This thesis introduces a design scheme of OFDM signal based on phase coding,and deduces the ambiguity function of the signal and the Cramer-Rao Lower Bound of distance and velocity sensing through theoretical analysis.Then the performance improvement of the phase coding technology is demonstrated to the ISAC signal.The sensing performance of phase-coding OFDM ISAC signal is verified by simulation.(2)Aiming at reducing the quantization error of traditional sensing methods,a high accuracy sensing method based on iterative method is proposed,which simultaneously calls the pilot and the data part of the signal.The sensing scenarios divided into short distance sensing and long distance sensing.Different sensing methods are designed respectively.Finally,the performance of the proposed methods is verified by simulation.(3)For the MIMO-OTFS system with high communication capacity and strong resistance to Doppler shift,this thesis designs a precoding method to optimize the communication reliability and sensing accuracy of the ISAC signal.The performance of the proposed precoding scheme is verified by simulation.