分数多普勒OTFS系统护域限扰导频信道估计OA

The fractional Doppler OTFS system has some problems such as low spectrum utilization and poor channel estimation performance due to different pilot pattern settings and corresponding channel estimation algorithms.Aiming at this problem,a pilot structure of guard-domain limiting interference was proposed.The receiver combined the direction of arrival estimation method in array signal processing to estimate the channel parameters,which can estimate the channel parameters without being limited by the channel matrix.Firstly,the guard interval area of the pilot symbol was determined according to the dispersion range of the fractional Doppler in the delay-doppler domain.Secondly,the multipath fading signal at the receiver was modeled and analyzed.The covariance matrix of the received signal was decoherently processed by spatial smoothing(SS)technology.Finally,the Doppler value was estimated by multiple signal classification(MUSIC)method,and parameter such as delay and channel gain were calculated according to the estimation results.The simulation results show that the combination of this pilot structure and SS-MUSIC method can effectively solve the channel parameter estimation problem of fractional Doppler OTFS system.The spectral efficiency of this pilot structure is improved by about 10.3%compared with the full guard interval pilot structure,and it shows better NMSE performance in the high SNR region.