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Ítem SNR estimation for on body communications in MB OFDM Ultra Wide Band communications(Ieee Computer Society, 2010-04-12) Navarro Cadavid, AndrésIn this paper a new signal to noise ratio estimator algorithm based on the moments of the received signal is presented. The novel algorithm has been designed for Ultra Wide Band communications based on Multi Band Orthogonal Frequency Division Multiplexing (MB-OFDM) communication systems. In this proposal, we analyze the behavior of ultra wide band channels when the time and frequency fading have fast changes. Hence, different time coherence values were considered and all the frequency fading models are based in real measurements made in an anechoic chamber. It is remarkable that all the measurement campaigns were focused on body communications. We conclude that the proposed model can be used for SNR estimation in adaptive modulation and channel estimation and link quality control in MB OFDM systems. The performance of the proposed SNR estimation algorithm and its comparison with other SNR estimators was achieved through simulations based on real channel measurements.Ítem A statistical channel model for on body Area networks in Ultra Wide Band Communications(IEEE, 2009-09-10) Cardona, NarcisThis paper presents a novel statistical channel model for Ultra Wide Band Communications when On Body Area Networks Environments are considered. Results and Analysis of frequency measurements from 1GHz to 12GHz for body area networks are described. We propose a modified Saleh-Valenzuela statistical channel model considering different assumptions for small scale statistics in the model. Results show that the small scale amplitude follows a log normal distribution, the inter arrival times between multi path components are poisson process; the decay factor, the number of paths and clusters follow exponential distributions. The proposed model can be used for realistic simulations for on body communications in Ultra Wide Band systems. © 2009 IEEE.