Atomic norm denoising-based channel estimation for massive multiuser MIMO systems

In this paper, we propose a novel channel estimation method for massive multiple-input multiple-output (MIMO) systems operating in time-division duplexing (TDD) mode. By exploiting the fact that the degrees of freedom of the physical channel matrix are smaller than the number of free parameters, the channel estimation is formulated as an atomic norm denoising problem and solved efficiently via the alternating direction method of multipliers (ADMM). Both theoretical analysis and numerical simulations demonstrate that our proposed method outperforms existing ones in terms of the channel estimation performance.