From the beginning of the project until the end of the reporting period, the APOLLO project pursued a comprehensive and interdisciplinary investigation of wireless powered communications (WPC), spanning theoretical foundations, algorithm and system design, and experimental validation.
The work progressed in a coherent manner across the technical work packages, following a bottom-up, cross-layer methodology that links circuit modeling, information theory, signal processing, system-level analysis, and prototyping.
At the theoretical level, the project established realistic yet tractable models for RF energy harvesting and rectification, characterized fundamental information–energy trade-offs, and derived capacity limits and optimal designs for a wide range of communication scenarios.
Building on these foundations, advanced WPC/SWIPT techniques were developed at the link and system levels, including novel waveforms, modulation schemes, precoding strategies, receiver architectures, and resource-allocation mechanisms, explicitly accounting for hardware non-linearities, safety constraints, and large-scale network effects. The project further extended WPC concepts to 5G/B5G networks, machine-type communications, passive IoT, edge computing, fluid-antenna systems, intelligent reflecting surfaces, and emerging quantum-enabled communication paradigms.
In parallel with the theoretical work, APOLLO developed significant experimental and implementation capabilities. Several key techniques were validated using software-defined radio (SDR) platforms, WPT hardware, and realistic circuit-level simulations, including frequency-domain SWIPT waveforms, tone-index multisine modulation,
chirp-based designs, and integrated receiver prototypes. These activities bridged the gap between theory and practice and reinforced the practical relevance of the project’s results.
The project produced a large body of high-quality scientific outputs, including publications in leading IEEE journals and conferences (143 publications), and significantly enhanced the international visibility and leadership of the research group. Beyond dissemination through publications, invited talks, and editorial activities, the results demonstrated strong industrial and exploitation potential, leading to two ERC Proof of Concept grants and national funding for the development of proof-of-concept implementations.
Overall, APOLLO has delivered substantial scientific advances, established lasting research capacity, trained a new generation of researchers, and laid the foundations for future academic, industrial, and societal impact in energy-sustainable wireless communications.
