Simultaneous Wireless Information and Power Transfer for the MISO Interference Channel: Gain from Decoding Interferences

We study a simultaneous wireless information and power transfer (SWIPT) setup for the K-user multiple-input single-output (MISO) interference channel Each transmitter can either send a private or a common message, and each receiver uses a power splitting method that divides the received signal into two parts for information decoding and energy harvesting. The private message is recovered by the destination receiver only while the common message is recovered by all the receivers. While satisfying individual rate and energy harvesting constraints, our goal is to minimize the total transmit power by properly selecting the message types, designing the beamforming vectors at transmitters, and adjusting the power splitting parameters at receivers. To optimize the parameters of our proposed scheme, we first formulate the problem in terms of a semidefinite programming (SDP) and further relax the formulation to propose low complexity algorithms for numerical optimization. In numerical results, it is shown that the required transmit power of the proposed scheme is much lower than that of the conventional scheme based on transmitting private messages only, especially when the required harvesting energy is high or the channel gains of the cross-links are strong.