Utilizing Interference by Network Coding for Simultaneous Wireless Information and Power Transfer

This letter puts forth a novel way to manage interference in simultaneous wireless information and power transfer (SWIPT) systems by utilizing physical-layer network coding (PNC). We consider multi-user multiple-input single-output (MU-MISO) broadcast channels. Unlike the conventional zero-forcing scheme, the PNC-SWIPT scheme introduced in this letter does not eliminate the interfering signals at the receivers. The PNC-SWIPT scheme cancels out the undesired messages over a finite field during PNC demodulation for information decoding (ID). It preserves the interfering signals which are beneficial energy sources for energy harvesting (EH). Simulation results show that the PNC-SWIPT scheme achieves superior EH performance than conventional interference mitigation schemes, such as zero-forcing (ZF) and maximizing EH precoding (Max EH), while maintaining the same ID performance. The performance improvement of the PNC-SWIPT scheme mainly comes from canceling out the interference at the receivers from the aspect of data by PNC, without eliminating the interfering signals which are beneficial energy sources.