Noise reduction algorithm for LS channel estimation in OFDM system

Abstract

Wireless communication system incorporating coherent OFDM requires the estimation and tracking of the channel Impulse Response (CIR) for accurate demodulation of data at the receiver. In pilot-symbol-aided OFDM system, Minimum Mean Square Error (MMSE) estimator performs better than Least Square (LS) estimator; however, computational complexity associated with the MMSE method is relatively higher than the LS. Although, the LS estimator has lower complexity and requires minimum knowledge the channel state information, the estimator suffers from inherent additive Gaussian noise and Inter Carrier Interference (ICI). Following that, in this study an efficient and improved channel estimation technique is proposed based on the LS algorithm. Simulation results show that the proposed method performs considerably better than the conventional LS method for a range of Signal to Noise Ratios (SNRs). In addition, the performance of the proposed method is found to be almost equal, if compared with the MMSE estimator. Despite the proposed method experiences relatively higher computational complexity than the LS, the complexity is yet to be achieved about 40 % lower than the MMSE.