Cooperative wireless energy harvesting and information transfer in stochastic networks

Abstract

In this paper, we consider a large-scale wireless ad hoc network with multiple source-destination communication pairs, where the sources operate with wireless energy harvesting. Before data transmission, each source should first harvest the radio frequency energy transferred from its corresponding destination. Since the source-destination distance is long, the efficiency of wireless energy transfer is very low. As a result, the transmission power of the source is weak, which is detrimental to the successful data transmissions. Instead, we introduce a relay in-between each source and destination for the wireless energy transfer and data transmission. The close distance between the relay and the source can improve the energy harvesting efficiency and the data relaying can improve the link robustness. With the assistance from the relay, the area spectrum efficiency is significantly enhanced compared with the non-cooperative system. A series of discrete power levels is defined for the sources and the probability of choosing each power level is analyzed by averaging over the random channel fading. We analyze the data success probabilities through averaging over the uncertain interference caused by the random locations of users, the channel fadings, and the various source transmission powers. The upper and lower approximations of data success probabilities are derived using the stochastic geometry theory for the cooperative energy and data transfer system. The optimal time allocation between the wireless energy transfer and the data transmission is investigated to maximize the system area throughput. Numerical and simulation results are provided to validate our theoretical analysis and show the dependence of system performance on various parameter settings. The results can provide the guidelines for the deployment of the energy harvesting cooperative communication system.

Sum-Rate Enhancement in Multiuser MIMO Decode-and-Forward Relay Broadcasting Channel With Energy Harvesting Relays

“…In the simulations, we assume that all the relays are equidistant from the source, as well as all the destinations. As shown in [23], [24], the wireless energy transfer is limited by the distance between the transmitter and the receiver. Thus, in our simulations, we are limited to cases of short distances, in order of meters.…”

Time and Power Allocation for Energy Efficiency Maximization in Wireless-Powered Full-Duplex Relay Systems

“…For the TS protocol [5,6], the energy and information signals are transmitted through different time slots. The data source first collects energy from the power signal and then uses the collected energy to transmit the information signal [7]. For the PS architecture [8,9], the receiver divides the received power between energy harvesting and information processing.…”

Simultaneous wireless energy transfer and spectrum sharing with primary data relaying in cognitive radio networks

“…For the large-scale network, Krikidis studied the cooperative relay protocol to show the tradeoff between the outage performance and the wireless energy transfer (WET) [3]. For the stochastic networks, the cooperative energy transfer and data relaying protocol was proposed by properly modeling the locations of users as Poisson point process [16]. Rubio et al analyzed the tradeoff between the sum-rate and the energy constraints in the multiuser multiple-input multiple-output (MIMO) system [17].…”