Gabor Expansion for Simultaneous Wireless Power and Information Transfer (SWIPT): Interference Analysis

Kassab, Hussein [UCL] Louveaux, Jérôme [UCL]

Wireless power transfer (WPT) has recently appealed the research community. One application for such technology is powering up future IoT devices and sensors. This article proposes a setup where both WPT and information transfer (IT) coexist sharing the same time and frequency resources in a flexible manner while keeping the interference at a low level. The interference of WPT on IT is analyzed as a performance metric for the proposed scheme. In particular, the influence of WPT side lobes on the main lobes of the information signal is computed to assess its impact on the performance of IT. The proposed scheme uses a Gabor expansion to create both power and information signals. This structure enables to assign resources for energy and information dynamically on the time-frequency lattice providing a high flexibility in the system. We propose to use the Gaussian basis functions to create the WPT signal since they are well localized both in time and in frequency, therefore creating the lowest possible interference on the nearby subcarriers. Hence, any multi-carrier system with different modulation schemes can be used for IT in the allowed time-frequency grid such as CP-OFDM and FBMC-OQAM. The expressions of interference are computed and simulation results show the low level of interference created by the power signal on the information signals which validates the possible coexistence of both systems.