Comparison of Single-Carrier and Multi-Carrier QAMSystem Performance in the Presence of Carrier Phase Jitter

Abstract

In this contribution, we investigate how the carrier phase jitter of a phase-locked oscillator for IF-to-baseband conversion affects the performance of single-carrier QAM (SC-QAM) and multi-carrier QAM (MC-QAM); the considered multi-carrier system is of the OFDM (orthogonal frequency-division multiplexed) type. This phase jitter reduces the signal-to-noise ratio (SNR) at the input of the decision device, and therefore gives rise to an increase of the bit error rate. We show that, for a given jitter variance, SC-QAM and MC-QAM yield the same SNR degradation. However, when the synchronization for MC-QAM is derived from a pilot tone, we point out that the resulting jitter variance is considerably larger than for SC-QAM, in which case MC-QAM is degraded much more than SC-QAM.