Analysis of the effects of Nyquist pulse‐shaping on the performance of OFDM systems with carrier frequency offset

Abstract

Abstract An exact method for calculating the bit error rate (BER) of an uncoded orthogonal frequency‐division multiplexing (OFDM) system with transmitter Nyquist pulse‐shaping over AWGN channels in the presence of frequency offset is derived. This method represents a unified way to calculate the BER of this system with different one‐ and two‐dimensional subcarrier modulation formats. The precise BER expressions are obtained using a characteristic function method. The effects of several widely referenced Nyquist pulse‐shapings, including the Franks pulse, the raised‐cosine pulse, the ‘better than’ raised‐cosine (BTRC) pulse, the second‐order continuous window (SOCW), the double‐jump pulse and the polynomial pulse on intercarrier interference (ICI) reduction and BER improvement of the system with carrier frequency offset are examined in the AWGN channel. The dependence of the BER on the roll‐off factor of the pulse employed for a specific system in the presence of frequency offset is investigated. Analysis and numerical results show that the Franks pulse exhibits the best performance among the Nyquist pulses considered in most cases. Copyright © 2008 John Wiley & Sons, Ltd.