No abstract

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

WOSInternational audienceWe derive a lower bound on the capacity of discrete-time Rician-fading channels that are selective both in time and frequency. The noncoherent setting is considered, where neither the transmitter nor the receiver knows a priori the actual channel realization. Single-input single-output communications subject to both average and peak power constraints are investigated. The lower bound assumes independent and identically distributed input data and is expressed as a difference between two terms. The first term is the information rate of the coherent channel with a weighted signal-to-noise ratio that results from the peak-power limitation. The second term is a penalty term, explicit in the Doppler spectrum of the channel, that captures the effect of the channel uncertainty induced by the noncoherent setting. The impact of channel selectivity and power constraints are discussed, and numerical applications on an experimental Rician channel surveyed in an underwater acoustic environment are also provided

No abstract

In order to provide a concise time-varying SISO channel model, the principle of maximum entropy is applied to scattering function derivation. The resulting model is driven by few parameters that are expressed as moments such as the channel average power or the Doppler spread. Physical interpretations of the model outputs are discussed. In particular, it is shown that common Doppler spectra such as the flat or the Jakes spectrum fit well into the maximum entropy framework.

No abstract

No abstract

No abstract