Comprssive Sensing Based Channel Estimation For Wideband Millimeter Wave Massive MIMO Systems

In millimeter communication system,massive array and wideband can be used to improve the efficiency of data transmission.However,in this communication system,it will not only lead to phase difference of each path on the base station antenna,but also lead to pulse response delay under wideband,which is called spatial wideband effect.This paper focuses on the spatial wideband effect caused by millimeter wave wideband,and discusses the channel estimation and hybrid precoding in the millimeter wave massive multiple input multiple output(MIMO)system in this state.In this system,orthogonal frequency division multiplexing(OFDM)is used to modulate the signal.The contents are as follows:(1)The wideband millimeter wave OFDM uplink transmission system is studied.The signal is received at the receiver by using a hybrid architecture.The spectral efficiency of the system is analyzed by considering the spatial wideband effect and the frequency wideband effect in the channel model.The analysis and simulation results show that the wideband causes the beam squint.In addition,the influence of bandwidth and number of subcarriers on beam squint effect is also revealed.(2)Considering the frequency-spatial wideband effect,a channel estimation scheme based on subcarrier grouping and compressed sensing is proposed.In addition,we calculate the complexity of each step of the carrier grouping algorithm proposed in this paper,and also calculate the complexity of each step of the comparison algorithm,and the results show that the grouping algorithm proposed in this paper has a low complexity.The normalized mean square error corresponding to Cramer Rao bound is analyzed,and the spectral efficiency is also analyzed.The simulation results show that the performance of the proposed grouping algorithms is better than the existing methods.(3)Considering the frequency-spatial wideband effect,a codebook design algorithm based on orthogonal matching pursuit algorithm is proposed.The algorithm considers the beam squint effect caused by wideband,and designs a corresponding codebook for each subcarrier.Simulation results show that the codebook design algorithm proposed in this paper has better performance in this communication system.