Noise Power and SNR Estimation Based on the Preamble in Tri-Sectored OFDM Systems

This paper describes the signal-to-noise ratio (SNR) estimation based on the preamble in tri-sectored OFDM systems. Several SNR estimators from previous literature suffer degradation in several important fading channel models. This paper proposes an estimation method that takes advantage of the fact that the preamble sequence symbols are assigned to every third subcarrier for each BS sector. Typically the closer the MS is to the BS, the more corrupted the noise power estimate is due to the higher signal power term in the estimator. The proposed method lowers the noise estimate by exploiting the differences in the powers of the orthogonal preambles received from the three spatially separated BS sectors. The simulation results show that the performance of our estimator improves as the power received from the two non-serving sectors decreases relative to the received power of the serving sector.