Research And Design Of Channel Estimation Algorithm For Millimeter Wave Relay System

Millimeter wave communication technology can overcome all kinds of problems existing in wireless communication,because of its wavelength and wide frequency band.As one of the key technologies in 5G communication,millimeter wave communication has a wide application prospect,but the problem of short transmission distance limits its development.The relay system can expand the cell coverage,extend the communication transmission distance and improve the system channel capacity,so it has become one of the hot research directions.Millimeter wave communication technology combined with relay system can solve the problem of short transmission distance.Accurate channel state information can greatly improve the system performance.In millimeter wave relay system,the channel has become more and more complex.Based on this situation,this thesis mainly studies the channel estimation algorithm in millimeter wave relay system.1.Aiming at the problem of channel estimation in one-way double hop relay system,a channel estimation method based on the Tensor Train decomposition model is proposed.The channel state information of two hop link is estimated in parallel by using the characteristic that the received signal conforms to the high-order tensor model.Simulation results show that the proposed channel estimation method improves the performance of channel estimation.What's more,the proposed method reduces the computational complexity compared with other channel estimation methods.2.Aiming at the channel estimation problem of millimeter wave one-way multi hop relay system,a channel estimation method based on the PARATUCK decomposition model is proposed.This method only needs a small number of pilot sequences to reduce the pilot overhead.Taking advantage of the high-order tensor form of the received signal,the channel matrices of base station relay,relay relay and relay user are estimated in parallel.The simulation results show that the proposed method is effective The effectiveness of the channel estimation method is proposed.3.Aiming at the problem of channel estimation in two-way relay system,a channel estimation method based on the nested PARAFAC decomposition model is proposed.Bi-ALS algorithm is used to estimate the segmented channel state information in parallel.The proposed channel estimation method reduces the pilot design requirements,and the simulation results show the effectiveness of the proposed method.