Gaussian multiple-access channels under received-power constraints

Performance limits for multiple-access channels are well known as long as the messages of different nodes are independent. Considerable research efforts have been devoted to the problem when the source information is dependent across nodes, revealing capacities for certain special cases. This work presents a new scenario for which conclusive results can be established: The additive white Gaussian multiple-access channel under a constraint on the power at the receiver. The results of this paper have natural applications to sensor networks. By contrast to recent scaling-law results, this paper establishes coinciding upper and lower bounds, and hence, the exact performance limits, for some scenarios of interest.