2014/01/09 by Rania Morsi, Morsi, Rania, Diomidis S. Michalopoulos +4
Engineering · #Energy Harvesting in Wireless Networks #Advanced MIMO Systems Optimization #Wireless Power Transfer Systems
paper · pdf · doi:10.48550/arxiv.1401.1943
In this paper, we study downlink multi-user scheduling for a time-slotted\nsystem with simultaneous wireless information and power transfer. In\nparticular, in each time slot, a single user is scheduled to receive\ninformation, while the remaining users opportunistically harvest the ambient\nradio frequency energy. We devise novel online scheduling schemes in which the\ntradeoff between the users' ergodic rates and their average amount of harvested\nenergy can be controlled. In particular, we modify the well-known maximum\nsignal-to-noise ratio (SNR) and maximum normalized-SNR (N-SNR) schedulers by\nscheduling the user whose SNR/N-SNR has a certain ascending order (selection\norder) rather than the maximum one. We refer to these new schemes as\norder-based SNR/N-SNR scheduling and show that the lower the selection order,\nthe higher the average amount of harvested energy in the system at the expense\nof a reduced ergodic sum rate. The order-based N-SNR scheduling scheme provides\nproportional fairness among the users in terms of both the ergodic achievable\nrate and the average harvested energy. Furthermore, we propose an order-based\nequal throughput (ET) fair scheduler, which schedules the user having the\nminimum moving average throughput out of the users whose N-SNR orders fall into\na given set of allowed orders. We show that this scheme provides the users with\nproportionally fair average harvested energies. In this context, we also derive\nfeasibility conditions for achieving ET with the order-based ET scheduler.\nUsing the theory of order statistics, the average per-user harvested energy and\nergodic achievable rate of all proposed scheduling schemes are analyzed and\nobtained in closed form for independent and non-identically distributed\nRayleigh, Ricean, Nakagami-m, and Weibull fading channels. Our closed-form\nanalytical results are corroborated by simulations.\n