Orthogonal-Time-Frequency-Space Signal Design for Integrated Data and Energy Transfer: Benefits from Doppler Offsets

TL;DR

This paper introduces an OTFS-based integrated data and energy transfer system that effectively counters Doppler effects in high-mobility scenarios, outperforming traditional OFDM approaches in energy harvesting efficiency.

Contribution

It proposes a novel OTFS waveform design for IDET that mitigates Doppler offsets, with an optimized power-splitting receiver and a geometric programming solution for enhanced high-mobility performance.

Findings

OTFS-IDET achieves higher energy harvesting than OFDM-IDET in simulations.

The system effectively counters Doppler offsets in high-mobility scenarios.

Optimization via geometric programming improves overall IDET performance.

Abstract

Integrated data and energy transfer (IDET) is an advanced technology for enabling energy sustainability for massively deployed low-power electronic consumption components. However, the existing work of IDET using the orthogonal-frequency-division-multiplexing (OFDM) waveforms is designed for static scenarios, which would be severely affected by the destructive Doppler offset in high-mobility scenarios. Therefore, we proposed an IDET system based on orthogonal-time-frequency-space (OTFS) waveforms with the imperfect channel assumption, which is capable of counteracting the Doppler offset in high-mobility scenarios. At the transmitter, the OTFS-IDET system superimposes the random data signals and deterministic energy signals in the delay-Doppler (DD) domain with optimally designed amplitudes. The receiver optimally splits the received signal in the power domain for achieving the best IDET performance. After formulating a non-convex optimisation problem, it is transformed into a geometric programming (GP) problem through inequality relaxations to obtain the optimal solution. The simulation demonstrates that a higher amount of energy can be harvested when employing our proposed OTFS-IDET waveforms than the conventional OFDM-IDET ones in high mobility scenarios.