MIMO Channel Estimation by QR Decomposition and LMS Adaptive Filter

Channel estimation is one of the most decisive factors in evaluating performance of the MIMO systems. There are different methods for estimation of MIMO systems, that, adaptive algorithm is which. Among adaptive algorithms, Least Mean Square (LMS) algorithm is the most popular because it has the features of a proper filter including simplicity in applying and no complexity in using. In the other hand, some of important detectors in MIMO systems use QR decomposition for signal extraction, which is of a higher level of complexity. In this paper, a new method for MIMO channel QR estimation is proposed and instead of estimating the channel matrix H and them decomposing QR in detector, from the beginning, Q and R estimated directly actually, channel matrix is detained through the estimation of Q and R. according to MATLAB simulation applying LMS algorithm and QR decomposition in channel estimation with iteratively and/or SNR increment will result in the error reduction.