A General Analysis and Optimization Framework of Time Index Modulation for Integrated Data and Energy Transfer

Integrated data and energy transfer (IDET) has been considered as a key technology to tackle the energy shortage in the densely connected wireless networks. In this paper, a novel time index modulation (TIM) assisted IDET system is studied, where data information is delivered not only by the conventional modulation scheme, but also by the time index of the activated symbol durations for either wireless data transfer (WDT) or wireless energy transfer (WET). With the aid of theoretical analysis, the average energy harvesting performance as well as the achievable data rate between the transmitter and the receiver are both derived in the semi-closed form. Further, a population-based optimizer is conceived to obtain the power allocation of WDT and WET signals, in order to maximize the energy harvesting performance by satisfying the constraints of the achievable data rate. Simulation results validate our theoretical analysis, while they also demonstrate that the TIM assisted system can substantially increase the IDET performance.