On use of the MM algorithm for channel estimation in MIMO OFDM

In this paper, the general channel estimator for MIMO OFDM is derived and MM algorithms are used to reduce computational complexity. The first M of MM stands for majorization (minorization) and the second M stands for minimization (maximization). It´s well known that EM algorithms are powerful tools for channel estimation using iterative calculation. Indeed, every EM-type algorithm is a special case of the more general class of MM algorithms. To construct an EM-type algorithm is skillful and complicated. In contrast, the MM algorithms are easier to be understood and applied. In addition to constructing channel estimation algorithms based on the MM principle we also analyze the convergence property of the MM-type algorithms. Finally, the simulation results demonstrate the performance of MM-type channel estimation algorithms.