The Power Allocation for SWIPT-based Cognitive Two-Way Relay Networks with Rate Fairness Consideration

This paper investigates the power allocation under power control for simultaneously wireless information and power transfer (SWIPT) based cognitive two-way relay network. Aiming at maximizing the minimum transmission rates of the cognitive users, an optimization work which aims to optimize the user transmission power allocation is proposed. To ensure the primary work performance, the transmission power of each cognitive nodes is set not to exceed the primary user interference threshold. On this power control basis, the closed form of power allocation ratio for each cognitive node are derived. Numerical results verify the derived power allocation scheme and reveal that the proposed scheme outperforms the traditional schemes with transmission fairness.