Power allocation of two-way full-duplex AF relay under residual self-interference

This paper investigates the power allocation scheme to maximize the sum-rate of a two-way full-duplex (FD) AF relay system under residual self-interference. The variance of self-interference is proportional to the λth power of transmitted power (λ denotes the self-interference level and 0 ≤ λ ≤ 1). The optimization problem under joint power constraint is proved to be quasi-concave and we convert it to a quasi-convex problem with its convenient derivation. The closed-form expressions of optimal power allocation factor are intractable with the exponent λ. Thus, we take two sub-optimal schemes into consideration in the sense of asymmetric and symmetric two-way structure. Bisection is introduced to allocate power when 0 <; λ <; 1. All the simulation results have demonstrated that the performance of proposed schemes outperforms the uniform power allocation scheme.