Abstract:

An optimal resource allocation scheme for an orthogonal frequency-division multiple (OFDM) two-way relay network with physical network coding is constructed. Considering the total transmit power and user rate constraints, a sub-optimal resource allocation scheme is proposed to maximize the achievable sum rate of the terminals with low complexity. Using convex optimization techniques, a closed-form solution for power allocation among relay node and two terminals is derived. Thereafter, the variable dimensionality of the objective function is reduced from 3 to 1 that can dramatically decrease the complexity of the solution. Simulation shows that the proposed approach achieves the optimal sum rate and is better than that of the traditional resource assignment method but with less computational load in various scenarios.

Key words: resource allocation, power control, two-way relay, network coding, orthogonal frequency division multiple)