An OFDM receiver with decision-directed channel estimation for the scattered pilot scheme in fast fading environments

This paper proposes a new OFDM receiver employing a Decision-Directed Channel Estimator (DDCE) that can effectively track carrier fluctuation in the fast fading environments. The receiver is applied to the scattered pilot scheme. The channel estimator consists of (i) an initial channel estimator using the MMSE-based channel estimation and (ii) DDCE employing the Recursive Least Squares algorithm. The receiver can improve the tracking performance by iterating the channel estimation and decoding. Computer simulations with the digital terrestrial television broadcasting standard demonstrate that the BER performance of the coherent detection with DDCE is superior to that of the differential detection, and can achieve an excellent BER performance in the 16QAM modulation scheme.