In this letter, we consider the problem of channel estimation for large intelligent metasurface (LIM) assisted massive multiple-input multiple-output (MIMO) systems. The main challenge of this problem is that the LIM integrated with a large number of low-cost metamaterial antennas can only passively reflect the incident signal by a certain phase shift, and does not have any signal processing capability. To deal with this, we introduce a general framework for the estimation of the transmitter-LIM and LIM-receiver cascaded channel, and propose a two-stage algorithm that includes a sparse matrix factorization stage and a matrix completion stage. Simulation results illustrate that the proposed method can achieve accurate channel estimation for LIM-assisted massive MIMO systems.
@article{arxiv.1905.07948,
title = {Cascaded Channel Estimation for Large Intelligent Metasurface Assisted Massive MIMO},
author = {Zhen-Qing He and Xiaojun Yuan},
journal= {arXiv preprint arXiv:1905.07948},
year = {2019}
}