A novel power allocation scheme for multi-user single-DF-relay networks

In multi-user single-DF-relay cooperative networks, where the relay is shared by multiple users and its transmit power is constrained, power allocation scheme affects the performance of whole communication system. In this paper, the power allocation problem of this type system is investigated. Firstly, two theorems and a lemma are presented for different constraint conditions. Then, based on the proposed theorems and lemma, optimal power allocation schemes to minimize sum-system-power consumption and maximize system achievable sum-rate are derived, respectively. And the corresponding exact closed form expressions to allocate power optimally are obtained as well. Numerical simulations are also supplemented to verify the optimality of the proposed solutions. (C) 2019 Elsevier B.V. All rights reserved.