An Efficient Two-Step Power Allocation Method for OFDM-Based Two-Way Full-Duplex Links

An efficient two-step method to allocate power for orthogonal frequency division multiplexing-based full-duplex (FD) two-way communication links is proposed in this letter. We try to maximize sum data rate of the two-way link by allocating available power over each subcarrier at both FD transceivers with imperfect self-interference cancellation. This sum-rate optimization problem is formulated under total power constraint. In order to solve this problem, we first consider a one-subcarrier problem and derive the closed-form solution for power allocation. Based on this result, the multi-carrier optimization problem can be solved by our proposed two-step method. First, we allocate total power to each subcarrier optimally, and then we solve the power allocation problem for each subcarrier. Compared with direct dual decomposition method, numerical results indicate that our two-step method can obtain the same two-way link performance, however, with much lower computational complexity.