Open Access

OFDM versus Single Carrier: A Realistic Multi-Antenna Comparison

  • Jan Tubbax1Email author,
  • Liesbet Van der Perre1,
  • Marc Engels1,
  • Hugo De Man1 and
  • Marc Moonen2
EURASIP Journal on Advances in Signal Processing20042004:320840

https://doi.org/10.1155/S1110865704402315

Received: 20 June 2003

Published: 19 August 2004

Abstract

There is an ongoing discussion in the broadband wireless world about the respective benefits of orthogonal frequency division multiplexing (OFDM) and single carrier with frequency domain equalization (SC-FD). SC-FD allows for more relaxed front-end requirements, of which the power amplifier efficiency is very important for battery-driven terminals. OFDM, on the other hand, can yield improved BER performance at low complexity. Both schemes have extensions to multiple antennas to enhance the spectral efficiency and/or the link reliability. Moreover, both schemes have nonlinear versions using decision feedback equalization (DFE) to further improve performance of the linear equalizers. In this paper, we compare these high-performance OFDM and SC-FD schemes using multiple antennas and DFE, while also accounting for the power amplifier efficiency. To make a realistic comparison, we also consider most important digital imperfections, such as channel and noise estimation, transmit and receive filtering, clipping and quantization, as well as link layer impact. Our analysis shows that for frequency-selective channels the relative performance impact of the power amplifier is negligible compared to the frequency diversity impact. The higher frequency diversity exploitation of SC-FD allows it to outperform OFDM in most cases. Therefore, SC-FD is a suitable candidate for broadband wireless communication.

Keywords

single carrierOFDMmulti-antennapower amplifierdecision feedback equalization