Wireless energy and information transfer in WBAN: A comprehensive state-of-the-art review

Wireless energy and information transfer have been effectively employed to facilitate reliable operation and communication among sensor nodes of wireless body area networks (WBANs). This work, therefore, presents the recent advances related to wireless power transfer (WPT)/simultaneous wireless information and power transfer (SWIPT) applied in WBAN composed of on-/in-body sensors for healthcare monitoring. A comprehensive overview of WPT/SWIPT-enabled WBANs was provided by characterizing them regarding the system requirements, network architecture, device design, and channel modeling. Considering the system requirements, optimization and performance analysis are identified as major tools to enhance and quantify the system's efficiency. Given the power scarcity issue, it is also imperative to ensure robust, user-friendly, and long-term WBAN operation; accordingly, existing battery-assisted and battery-free device designs are discussed. Furthermore, different network topologies, varying from single-input-single-output to multiple-input-multiple-output, are required to maintain WBAN applications. Therefore, this survey includes the network architecture as an important classification category requiring close attention. Additionally, understanding propagation models is indispensable to building competent WBAN. This review describes channel modeling from the perspective of stochastic and deterministic environments. In summary, this paper aims to serve as a comprehensive reference, providing readers with an insightful exploration of WPT/SWIPT-enabled WBANs, addressing their both advantages and limitations.