Modified decision feedback methods for OFDM channel tracking

In an orthogonal frequency division multiplexing (OFDM) system, part of bandwidth is occupied by pilot symbols for time-varying channel estimation. In order to reduce the period of the training sequence while improving bandwidth efficiency, we study new time-domain channel tracking algorithms with a modified decision feedback loop. In company with the channel tracking algorithms, some decision error detectors and error concealment methods are proposed to reduce the error probability for avoiding decision error propagation. In our simulations, we compare the performance of the proposed decision error detectors and error concealment methods to show the efficiency of the proposed algorithms in time-varying channels.