||A Low-Complexity LS Turbo Channel Estimation Technique for MU-MIMO Systems
Takano, YasuhiroSu, Hsuan-Jung
IEEE Signal Processing Letters
714 , 2018-05 , Institute of Electrical and Electronics Engineers (IEEE)
Turbo channel estimation algorithms can improve estimation accuracy in multiuser (MU)-multi-input multi-output (MIMO) systems. However, the conventional least squares (LS) turbo channel estimation technique based on the maximum likelihood (ML) approach is difficult to be performed in large MU-MIMO systems since it requires a cubic complexity order O(κ3 NT3 NR3) for a system constant κ and numbers of NT-transmit and NR-receive antennas. This is because the conventional technique computes inversion of a covariance matrix whose size is proportional to κNTNR. We propose a new low-complexity LS estimation technique that requires a complexity order O(κ3 NT3) only by utilizing algebraic property on the covariance matrix. Simulation results shown in this letter verify that the proposed technique significantly reduces processing time without sacrificing the estimation performance.