Gaussian multiple-access channels with weighted energy constraint

The Gaussian multiple-access channel with weighted energy constraint E¯_sum=Σ_kE_k/|d_k| ² models the situation in cellular multiuser communication more accurately than the standard approach with d_k=1,∀k. The minimum weighted sum energy E¯_sum is shown to be only achievable at a unique energy tupel (E₁, ..., E_K), if all weights differ in amplitude. Moreover, the theory is generalized to a multiple receiver system describing cellular communication systems with optimum multiple cell-site processing. While for single-receiver systems the optimum energy tupel is a vertex of the allowed energy region, i.e. successive cancellation is possible, for a multi-receiver system this does not hold in general