Abstract-This letter deals with the problem of non data aided (NDA) signal to noise ratio (SNR) estimation of OFDM signals transmitted through unknown multipath fading channel. Most of existing OFDM SNR estimators are based on the knowledge of pilot sequences which is not applicable in some contexts such as cognitive radio for instance. We show that it is possible to take advantage of the periodic redundancy induced by the cyclic prefix to get an accurate NDA SNR estimator. Numerical simulations highlight the benefit of the proposed method compared with the state of the art.

International audienceWatermark is a freely available benchmark for physical-layer schemes for underwater acoustic communications. It allows researchers to test and compare algorithms for the physical layer under realistic and reproducible conditions. The benchmark is a shell around the validated FFI channel simulator Mime, which is driven by at-sea measurements of the time-varying impulse response. The first release of Watermark is issued with a library of channels measured in Norway (two sites), France, and Hawaii, offering three frequency bands (4-8, 10-18, and 32.5-37.5 kHz), single-hydrophone and array receivers, and play times varying from 33 seconds to 33 minutes