Three-User Gaussian Multiple Access Channel With Partially Cooperating Encoders

A three-user Gaussian Multiple Access Channel (MAC) with encoders partially cooperating over a ring of finite-capacity uni-directional links is studied. The model is a simple extension of the classical two-user MAC with conferencing encoders. Upper and lower bounds on the maximum achievable common rate are derived. The lower bound is attained via a novel multi-layer cooperative strategy. The bounds are tight for a certain range of values of the inter-user link capacity. Numerical results are provided to corroborate the analysis. Complex networks in which terminals are potentially connected via a number of different radio interfaces or wired links are becoming increasingly appropriate models for current and future communication scenarios.