Adaptive, Low Complexity and Efficient Channel Estimation Algorithm for OFDM System Using Iterative Decoder

Orthogonal frequency division multiplexing (OFDM) provides an effective and low complexity means of eliminating inter symbol interference for transmission over frequency selective fading channels. In OFDM systems, channel estimation is very crucial to demodulate the data coherently. For good channel estimation, spectral efficiency and lower computational complexity are two important points to be considered. In this paper, we explore Iterative channel estimation based on Least Square (LS) and Minimum Mean Square Error (MMSE) methods in order to improve Mean Square Error (MSE) by applying the Iteration. Using the appropriate adaptive algorithm, it is shown that with adequate number of iteration, channel estimation can be improved by reducing computational complexity. It has been shown that MSE improves if the initial estimate is better than primary LS or MMSE estimate.