Sending Gaussian multiterminal sources over the Gaussian MAC with bandwidth expansion

In this work, we investigate the minimum power of transmitting Gaussian multiterminal sources over the Gaussian multiple access channel (MAC) with bandwidth expansion. Distributed encoders observe the individual components of the multiterminal sources and attempt to describe them to a central decoder. Instead of assuming the sources and the channel have matched bandwidth, we consider the scenario when the transmission is subject to a bandwidth constraint in terms of the number of channel uses per source sample. We study the minimum transmission power such that the decoder can reconstruct the individual sources and meet the mean squared error (MSE) constraints on them. For any given bandwidth and distortion constraints, we optimize uncoded transmission to obtain an upper bound on the minimum transmission power. A hybrid coding scheme is then proposed to obtain a tighter upper bound.