WLCp2-01: Frequency Domain Equalization With Tomlinson-Harashima Precoding for Single Carrier Broadband Wireless Communications

As an alternative to orthogonal frequency-division multiplexing (OFDM) to deal with the detrimental effects of multipath fading, single carrier frequency domain equalization (SC-FDE) has been recently receiving much attention. Most of the existing FDE structures focused on the signal processing at the receiver. In this paper, a new FDE structure, which consists of a Tomlinson-Harashima Precoder (THP) at the transmitter and an FDE at the receiver, is proposed based on the minimum mean square error (MMSE) criterion. Since the feedback processing is performed at the transmitter, no error propagation problem exists in the proposed THP-FDE scheme. Numerical results will demonstrate the improved performance of our proposed scheme compared to the conventional FDE schemes. We will analyze the error probability, and investigate the channel estimation errors and channel variation effects on the proposed THP-FDE system as well. It will be shown that by applying channel prediction and THP compensation techniques such detrimental effects of wireless links can be greatly reduced.