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In this work, we study the design of a precoder on the user downlink of a multibeam satellite channel. The variations in channel due to phase noise introduced by on-board oscillators and the long round trip delay result in outdated channel information at the transmitter. The phase uncertainty is modelled and a robust design framework is formulated based on(More)
—A main challenge towards realizing the next generation Terabit/s broadband satellite communications (SatCom) is the limited spectrum available in the Ka band. An attractive solution is to move the feeder link to the higher Q/V band, where more spectrum is available. When utilizing the Q/V band, due to heavy rain attenuation, gateway diversity is considered(More)
In this paper we study Perfectly Secure Message Transmission (PSMT) between a sender S and a receiver R, connected in a directed synchronous network through multiple parallel edges (called wires), each of which are directed from S to R or vice-versa. The un-reliability of the network is modeled by an Byzantine adversary with infinite power. Thus the(More)
In the <i>unconditionally reliable message transmission</i> (URMT) problem, two non-faulty players, the <i>sender</i> <b>S</b> and the <i>receiver</i> <b>R</b> are part of a synchronous network modeled as a directed graph. <b>S</b> has a message that he wishes to send to <b>R</b>; the challenge is to design a protocol such that after exchanging messages as(More)
—A class of infinite impulse response (IIR) perfect reconstruction (PR) filterbank is obtained with an allpass delay chain and finite impulse response (FIR) matrices at the analysis side. Such a formulation leads to a filterbank that can be optimized to any desired response. For a first-order allpass, the synthesis bank becomes FIR. Design examples showing(More)
We consider the problem of detecting a sparse random signal from the compressive measurements without reconstructing the signal. Using a subspace model for the sparse signal where the signal parameters are drawn according to Gaussian law, we obtain the detector based on Neyman-Pearson criterion and analytically determine its operating characteristics when(More)
—Design of high bandwidth and reliable feeder links is central towards provisioning new services on the user link of a multibeam satellite communication (SatCom) system. Towards this, utilization of the Q/V band and an exploitation of multiple gateways (GW) as a transmit diversity measure for overcoming severe propagation effects are being considered. In(More)
—Exploiting transmit diversity amid a high number of multiple gateways (GW) is a new research challenge in Q/V band satellite communication providing data rates of hundreds of Gbit/s. In this paper, we propose a practical switching strategy in a scenario with N +P GWs (N active and P redundant GWs) towards achieving GW transmit diversity. Differently from(More)