An enhanced channel estimation technique with adaptive pilot spacing for OFDM system

In this paper, we propose a novel method for channel estimation based on adaptive pilot spacing using low complexity with least-square (LS) channel estimation. Many channel estimation method uses LS or MMSE (Minimum Mean Square Error) channel estimator. The MMSE channel estimation technique suffers from a high computational complexity with an order of O(N - P
₃
) operations ((N - P) represents the total number pilot in one OFDM symbol) due to an inversion matrix operation. However LS presents low complexity. MMSE have good results in low SNR (Signal to Noise Ratio), but with high SNR, LS estimator is more efficient. So, we are interested in LS estimator with adaptive pilot arrangement in order to have a minimal complexity and better results for low and high SNR. MATLAB Monte-Carlo simulations are used to evaluate the performance of the proposed estimator.