A simple channel shortening equalizer for wireless TDD-OFDM systems

Abstract

In a Orthogonal Frequency Division Multiplexing (OFDM) system, a channel shortening equalizer (CSE) combats multipath interferences by shortening the channel delay spread to the desired length. In this paper, a simple and efficient channel shortening pre-equalizer for a wireless OFDM system is proposed. The equalizer takes advantages of the characteristics of a wireless channel which can be represented as a finite impulse response (FIR) filter and is an all zero system. It eliminates the zeros of FIR to effectively reduce the length of channel impulse response. The proposed equalizer simplifies wireless OFDM transceivers. The simulation results show the validity of the proposed preequalizer.