ROBUST CHANNEL ESTIMATION AND INTERPOLATION

摘要

Present robust 2D MMSE or minimax approach assumes significant time and frequency selectivity due to which it has a poor MSE performance for RBs with low/ moderate frequency and/or time selectivity. Further a filter cannot be designed assuming low frequency and/or time selectivity and use that for all channel models. The instant invention proposes Robust Adaptive (RA) MMSE filter that can bridge the gap between a robust 2D MMSE/minimax and the optimal MMSE approach. Further the RA MMSE filter smoothens the filter coefficients of the robust 2D MMSE filter with the degree of smoothing adaptively changing with amount of frequency and time selectivity within a RB. Further the method uses multiple hypothesis tests on the maximum likelihood CFR estimates at the pilots. Further the RA MMSE filter solves the minimax estimation problem with additional constraints on the autocorrelation sequence corresponding to the channel frequency response.