Joint Wireless Information and Energy Transfer in a Two-User MIMO Interference Channel

Abstract

Recently, joint wireless information and energy transfer (JWIET) methods have been proposed to relieve the battery limitation of wireless devices. However, the JWIET in a general K-user MIMO interference channel (IFC) has been unexplored so far. In this paper, we investigate for the first time the JWIET in K-user MIMO IFC, in which receivers either decode the incoming information data (information decoding, ID) or harvest the RF energy (energy harvesting, EH). In the K-user IFC, we consider three different scenarios according to the receiver mode -i) multiple EH receivers and a single ID receiver, ii) multiple IDs and a single EH, and iii) multiple IDs and multiple EHs. For all scenarios, we have found a common necessary condition of the optimal transmission strategy and, accordingly, developed the transmission strategy that satisfies the common necessary condition, in which all the transmitters transferring energy exploit a rank-one energy beamforming. Furthermore, we have also proposed an iterative algorithm to optimize the covariance matrices of the transmitters that transfer information and the powers of the energy beamforming transmitters simultaneously, and identified the corresponding achievable rate-energy tradeoff region. Finally, we have shown that by selecting EH receivers according to their signal-to-leakage-and-harvested energy-ratio (SLER), we can improve the achievable rate-energy region further. Index TermsJoint wireless information and energy transfer, K-user MIMO interference channel, Rank-one beamforming

Joint Wireless Information and Energy Transfer with Reduced Feedback in MIMO Interference Channels

“…We note that, to the best of the authors' knowledge, it is the first time that the partial CSIT is treated in MIMO IFC accounting for JWIET. Interestingly, we can prove that our proposed non-cooperative strategy with partial CSIT is optimal, contrary to the one currently known in the literature [12] that are suboptimal 2 . Because the pseudo-random chaotic waves can be utilized to increase the energy harvesting efficiency [17], the interference from EAP is assumed not decodable at the ID MS as in [12].…”

“…Interestingly, we can prove that our proposed non-cooperative strategy with partial CSIT is optimal, contrary to the one currently known in the literature [12] that are suboptimal 2 . Because the pseudo-random chaotic waves can be utilized to increase the energy harvesting efficiency [17], the interference from EAP is assumed not decodable at the ID MS as in [12]. Then, the EAP may create a rank-one beam with the aim to either maximize the energy harvested at the EH MS (maximum energy beamforming, MEB) or minimize the interference at the ID MS (minimum leakage beamforming, MLB).…”

Wireless information and power transfer: from scientific hypothesis to engineering practice

“…For example, Xu et al in [12] considered the energy beamforming concept in the context of a multiple-input single-output (MISO) downlink system. Furthermore, Park and Clerckx in [13] designed a beamforming-aided solution for a Kuser interference-limited system relying on multiple transmitter and receiver pairs, while Li et al in [14] considered a collaborative energy beamforming design using multiple transmitter and receiver pairs. The beneficial impact of large-scale/massive MIMOs was studied in [15].…”

“…As a result, a conventionally harmful secondary transmission becomes potentially useful in the context of a SWIPT system. In this case, the underlying interference model is of paramount importance, where in a pair of primary and secondary links, four potential operation combinations are feasible at the respective receivers of the primary and secondary links, as detailed in [13]. This naturally necessitates further game theoretical and information theoretical insights.…”

SWIPT techniques for multiuser MIMO broadcast systems

“…The BD technique allows for a simple solution but wastes some degrees of freedom and, thus, degrades the overall performance. Paper [7], considered a MIMO network consisting of k transmitter-receiver pairs with co-channel interference. In [8], authors considered a MIMO system with single-stream transmission.…”