Improved pilot-based LS and MMSE channel estimation using DFT for DVB-T OFDM systems

Abstract

In this paper channel estimation techniques for Digital Video Broadcasting Terrestrial (DVB-T) based OFDM transmission and reception are investigated. Channel estimation based on comb type pilot arrangement is studied through Discrete Fourier Transform (DFT) algorithm. The estimation of channel at pilot frequencies is based on Least Squares (LS) and Minimum Mean Square Error (MMSE) estimators while interpolation is done using linear and spline cubic interpolation. Existing channel estimation usually addresses the scattered and continual pilot arrangement for DVB-T based OFDM systems. Pilot based channel estimator presented here differs from previous methods in a way that it is based on comb type pilot arrangement, which accurately estimates the MSE in the presence of COST 207 Typical Urban Reception (TU6) channel model. This paper shows that DFT-based algorithm can improved the MSE of conventional LS and MMSE estimators by removing the impact of noise outside the maximum channel delay length.