Phase based SNR estimation in OFDM over the medium voltage network

Abstract

Modern digital communications over the aggressive medium voltage network (MVN) channel are based on reliable signal to noise ratio (SNR) estimation. In this work, a novel phase based SNR estimation method for Orthogonal Frequency Division Multiplexing (OFDM) systems transmitting over the MVN is proposed. By exploiting the fact that under additive white Gaussian noise (AWGN) conditions the phase errors at the receiver are normally distributed when the real SNR is over 10dB, the method estimates the SNR by only making use of the signal's phase samples. The knowledge of the current channel's transfer function as well as the current transmission power is not necessary for the SNR estimation, which simplifies the calculations and increases the method's applicability in practical systems communicating within the MVN environment. Immunity against constant phase errors and phase jitter caused by noise, the MVN channel or/and realistic OFDM synchronization count to further beneficial properties of the proposed estimator.