Iterative Channel Estimation in LTE Uplink

Abstract: An algorithm for iterative channel estimation using soft feedback for LTE uplink is proposed. The algorithm has low complexity compared to MMSE estimation and does not require knowledge of the channel statistics. A simple polynomial model is used for noise suppression across OFDM symbols and a DCT-based filter is used for noise suppression across subcarriers. The algorithm has been tested on several channel models and has been shown to provide a gain of about 0:5 dB with two estimation stages, compared to the no-feedback case. Further, the algorithm has been applied to a MIMO case. A comparison has been made between the proposed algorithm and turbo equalization.