Enhanced equalization in OFDM systems using cyclic prefix

Abstract

Orthogonal frequency division multiplexing (OFDM) is a modulation technique that provides high achievable data rates in wireless environment by combating multipath effects and has relatively simple implementation. In this paper, it is demonstrated that how the cyclic prefix can be used to enhance the operation of an OFDM equalizer when the channel is perfectly known at the receiver or is obtained through training. This method relies on transforming the OFDM channel into two subchannels (circular and linear) that share the same input and are characterized by the same channel parameters. Conventionally, data is recovered by utilizing only the circular subchannel while in this method, both the circular and linear subchannels are used to recover the data. The improved performance of the proposed method is demonstrated with the help of simulations for constant modulus as well as non-constant modulus data.