Wireless Information and Power Transfer: A Dynamic Power Splitting Approach

Abstract

Energy harvesting is a promising solution to prolong the operation time of energy-constrained wireless networks. In particular, scavenging energy from ambient radio signals, namely wireless energy harvesting (WEH), has recently drawn significant attention. In this paper, we consider a point-to-point wireless link over the flat-fading channel, where the receiver has no fixed power supplies and thus needs to replenish energy via WEH from the signals sent by the transmitter. We first consider a SISO (single-input single-output) system where the singleantenna receiver cannot decode information and harvest energy independently from the same signal received. Under this practical constraint, we propose a dynamic power splitting (DPS) scheme, where the received signal is split into two streams with adjustable power levels for information decoding and energy harvesting separately based on the instantaneous channel condition that is assumed to be known at the receiver. We derive the optimal power splitting rule at the receiver to achieve various trade-offs between the maximum ergodic capacity for information transfer and the maximum average harvested energy for power transfer, which are characterized by the boundary of a so-called "rateenergy" region. Moreover, for the case when the channel state information is also known at the transmitter, we investigate the joint optimization of transmitter power control and receiver power splitting. The achievable rate-energy (R-E) region by the proposed DPS scheme is compared against that by the existing time switching scheme as well as a performance upper bound by ignoring the practical receiver constraint. Finally, we extend the result for DPS to the SIMO (single-input multiple-output) system where the receiver is equipped with multiple antennas. In particular, we investigate a low-complexity power splitting scheme, namely antenna switching, which can be practically implemented to achieve the near-optimal rate-energy trade-offs as compared to the optimal DPS.

Secrecy Performance of Wirelessly Powered Wiretap Channels

“…Motivated by this, we now look into the asymptotic regime, where simple expressions can be obtained. 3 For the asymptotic high SNR regime, we assume that λ M → ∞ with an arbitrary λ W . Such a scenario has been widely adopted in the literature, see for instance [27]- [30].…”

Power Allocation and Splitting Algorithm for SWIPT in Energy Harvesting Networks with Channel Estimation Error

“…Transfer, SWIPT)을 위한 방안에 대한 연구 역시 활발 히 수행되고 있다 [4][5][6][7]. [4,5]에서는 수학적 모델링을 통해 SWIPT의 이론적인 성능 한계를 도출하였다.…”

“…[4,5]에서는 수학적 모델링을 통해 SWIPT의 이론적인 성능 한계를 도출하였다. [6] 에서는 순간적인 채널 상황을 고려하여 효율적인 SWIPT를 위한 최적의 파워 분할 (Power splitting) 기법 을 제안하였다. 또한, [7]에서는 OFDMA (Orthogonal 도로 사용할 수 있다 [7].…”

Precoding Design and Power Allocation in Two-User MU-MIMO Wireless Ad Hoc Networks

“…These models demonstrate that wireless communication systems can effectively support EH [5,6]. Since radio frequency (RF) signals can transmit information and energy simultaneously, a joint investigation of SWIPT has recently drawn significant attention [7], and various models for different SWIPT systems have been considered to characterize the performance trade-off between wireless energy transfer (WET) and wireless information transfer (WIT) in the same transmitted signal [8][9][10]. Furthermore, one key issue in implementing SWIPT is the practical limitation that existing energy harvesting circuits cannot be used to decode and harvest the RF signals concurrently [11], to solve this problem, PS designs have been proposed for SWIPT, with PS, the received signal is split into two parts, with one part used for ID and the other part for EH [12].…”