Survey on Symbiotic Radio: A Paradigm Shift in Spectrum Sharing and Coexistence

Abstract

of mobile communication aims to connect this world digitally through green communication networks that provide secure, ubiquitous, and unlimited connectivity in an attempt to improve the overall quality of life. The driving force behind the development of these networks is the rapid evolution of Internet-of-Things (IoT), which has stimulated the proliferation of wireless applications in health, education, agriculture, utilities, etc. However, these applications are accompanied by the deployment of a massive number of IoT devices that require a significant radio spectrum for wireless connectivity. IoT devices usually have low data rate requirements and limited power provision but desirably a long life. Recently, the development of passive radio systems has opened new paradigms of spectrum sharing and coexistence. These systems utilize the radio resources and infrastructure of the active radio systems to perform their functionalities. By enabling the dependent coexistence, a new technology named symbiotic radio (SRad) enables the symbiotic relationships between the different radio systems ranging from mutual benefits or competition in terms of sharing the resources, in particular for IoT devices. This survey first provides the motivation for dependent coexistence and background of spectrum sharing through coexistence along with existing literature. Then, it describes the active and passive radio systems definition and a brief overview. Afterward, the history of symbiosis and the role of SRad technology in spectrum sharing and coexistence are defined while focusing on symbiotic communication. Lastly, we discuss research challenges, future directions, and applications scenarios.

Multi-BD Symbiotic Radio-Aided 6G IoT Network: Energy Consumption Optimization with QoS Constraint Approach

“…Wireless energy harvesting benefits from active and passive technologies developed for telecommunication systems and networks, such as wireless powered communication networks (WPCN) [17], simultaneous wireless information and power transfer (SWIPT) [18], reconfigurable intelligent surface (RIS), bistatic and ambient backscatter communication (AmBC) [19] and SR [20].…”

Characterizing the Energy-Efficiency Region of Symbiotic Radio Communications

“…Such results demonstrate that there exists a nontrivial trade-off between maximizing EE P T and EE RIS−BD . To investigate such a trade-off, we will characterize the EE region of the considered RIS-BD based SR system as defined in (9). But before we do that, we will analyze the asymptotic performance of this SR system to get more insights.…”

“…By contrast, in CSR, the symbol duration of the passive BD signal spans multiple PT symbol durations, which may contribute additional multipath signal components to enhance the active primary transmission [5]. SR communication is expected to find a wide range of applications, such as E-health, wearable devices, environmental monitoring, vehicle-to-everything (V2E), and smart city [9]. Significant research efforts have been recently devoted to the study of SR communications, e.g., in terms of theoretical analysis [10] and performance optimization to maximize the achievable rate [11], channel capacity [12] and EE [13].…”

Characterizing the Energy-Efficiency Region of Symbiotic Radio Communications

“…By contrast, in CSR, the BD symbol duration is much longer than that of the PT, so that it may contribute additional multipath signal component to enhance the active primary transmission [1]. SR communication is anticipated to find a wide range of applications, such as E-health, wearable devices, manufacturing, and vehicle-to-everything [6].…”