Cascade Channel Estimation for IRS-assisted Millimeter-wave Multi-user Systems
In intelligent reflecting surface(IRS)-assisted millimeter-wave multi-user systems,in order to solve the problem of performance degradation caused by incomplete sparsity of the traditional channel estimation scheme,a three-stage joint estimation scheme based on multi-user common sparse structure is proposed.In this scheme,the common parameters based on the completely sparse structure are used as the prior information,and the performance is improved through user joint estimation.Specifically,in the first stage the user's commonality is used to estimate the common parameter information of the specific structure of the cascade channel.In the second stage,an improved orthogonal matching pursuit(OMP)algorithm is proposed to estimate the user's unique parameter information as the initial value of joint estimation,the secondary screening of the support set atoms is introduced to ensure that the support set used for estimation is optimal.In the third stage,the joint estimation of the user cascading channel is carried out according to the prior information and the initial value.The simulation results show that the proposed scheme can significantly reduce the redundant pilot consumption compared with the existing structured sparse scheme,and the estimation accuracy can be increased by 3～4 dB at the maximum under the same pilot overhead.
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维普
