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.