OFDM vs. Single-Carrier Modulation: A New View on the PAR Behavior

Abstract:
Since many years, the peak-to-average power ratio (PAR) behavior of single- and multi-carrier signals is controversially discussed in the literature. Thereby, the inferiority of multi-carrier transmission, in particular orthogonal frequency-division multiplexing (OFDM), was often stated. However, the generality of this assertion has to be doubted, as advanced single-carrier techniques have been ignored. In this paper, efficient approaches for the assessment of the PAR behavior for both modulation strategies are presented. In the single-carrier case, the impact of signal shaping on the constellation is assessed. On this basis, a meaningful comparison with OFDM based on identical spectral shapes is given, which enables a new point of view on the PAR performance of single- and multi-carrier schemes.