Front-end estimation of Noise Power and SNR in OFDM systems

In this paper a front-end noise power and SNR estimation method based on one OFDM preamble is proposed and compared with previously published SNR estimators - none of which are front-end estimator. The estimator makes use of two identical halves property of time synchronization preamble used in OFDM systems and relies on autocorrelation of the same. The current estimator is compared with two existing SNR estimators, the Reddy estimator and Subspace based estimator in terms of normalized mean square error (NMSE) and estimated SNR. It is observed that current estimator gives SNR estimates better than Reddy and subspace estimators. The estimator performs SNR estimation at front-end of the receiver unlike all other estimators which perform SNR estimation at back-end of the receiver.