Low-complexity channel and frequency offset estimation in MIMO systems
A low-complexity approach to the joint estimation of frequency offset and channel matrix in a MIMO flat-fading channel using a training sequence is presented. The frequency offsets for all transmit antennas are assumed to be equal. The proposed algorithm first computes an initial estimation. This estimation is good enough for most applications. To increase the accuracy of the estimation, approximation of ML function around its maximum point and finding the maximum point analytically is suggested. Simulation results are performed for a 4×4 MIMO system to show the effectiveness of the algorithm.