SWIPT transceiver design for broadband wireless systems

Future networks are envisioned to host enormous amount of wirelessly connected devices that could possibly harvest energy too. This dual demand led researchers to propose a new concept: simultaneous wireless information and power transfer (SWIPT), which allows WPT and WIT to coexist in the same system using the same resources. In the first part of the thesis, we propose a novel waveform design where the power signal is composed of a high peak modulated rectangular pulse sent during the cyclic prefix (CP) of the cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM) system. We investigate through theoretical analysis, simulations and real measurements the interference caused by the channel dispersion as well as the energy harvesting performance. In the second part, we investigate the possibility of maximizing the harvested energy when the time-domain phases are optimized adapting to the channel. We formulated the optimization problem using the nonlinearity model of the rectifier. In the third part, we use stochastic geometry (SG) to analyze the interference coming from multiple transceivers coexisting in the same propagation environment considering an indoor environment. We study the impact of potential desynchronization errors, the rate-energy trade-off as function of the nodes density, and the influence of frequency selective channels. In the last part, we propose a new setup using a Gabor expansion to create a time-frequency lattice, enabling to assign dynamically the resources. We investigate a frequency domain interference analysis theoretically and using simulations.
(SC - Sciences) -- UCL, 2021