Fractionally Spaced Frequency Equalization Method for Orthogonal Frequency Division Multiplexing (OFDM) Jointing with Modified Pilot Sequences

Abstract

In order to obtain accurate and high-speed data transmission, the orthogonal frequency division multiplexing(OFDM) technology is introduced and it is a kind of a multi-carriers modulation technology with high efficiency in the use of frequency band and characteristics of strong anti-interference ability. The fractionally spaced OFDM frequency domain equalization algorithm based on modified pilot sequences is proposed. In this proposed algorithm, one-dimensional linear interpolation method is used to estimate the frequency domain response of all subcarriers by part of the subcarriers’ frequency domain response with reducing the number of transmitted pilot sequences, and received signals are oversampled to acquire more detailed channel information. The computer simulations in underwater acoustic channel show that the performance of proposed method outperforms the single-carrier system and traditional OFDM system.