Minimizing Sum-MSE Implies Identical Downlink and Dual Uplink Power Allocations

—Minimizing the sum of mean squared errors using linear transceivers under a sum power constraint in the multiuser downlink is a non-convex problem. Existing algorithms exploit an uplink-downlink duality and transform the solution of a convex problem in the virtual uplink back to the downlink. In this letter, we analyze the optimality criteria for the power allocation subproblem in the virtual uplink, and demonstrate that the optimal solution leads to identical power allocations in the downlink and virtual uplink, thus extending the known duality results and permitting a reduction in the computational complexity of existing algorithms.

• Type: Journal
• Year: 2011
• Where: TCOM
• Authors: Adam J. Tenenbaum, Raviraj S. Adve
• Keywords: Downlink, Power Allocations, TCOM 2011, Virtual Uplink