Passive Internet of Things: Background, Concept, Challenges and Progress

ZHENG Liming; LIU Peiguo; WANG Hongyi; WU Jianfei

doi:10.11999/JEIT221219

Volume 45 Issue 7

Jul. 2023

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ZHENG Liming, LIU Peiguo, WANG Hongyi, WU Jianfei. Passive Internet of Things: Background, Concept, Challenges and Progress[J]. Journal of Electronics & Information Technology, 2023, 45(7): 2293-2310. doi: 10.11999/JEIT221219

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ZHENG Liming, LIU Peiguo, WANG Hongyi, WU Jianfei. Passive Internet of Things: Background, Concept, Challenges and Progress[J]. Journal of Electronics & Information Technology, 2023, 45(7): 2293-2310. doi: 10.11999/JEIT221219

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Passive Internet of Things: Background, Concept, Challenges and Progress

doi: 10.11999/JEIT221219

College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China

Funds: The National Natural Science Foundation of China (52101391)

Received Date: 2022-09-19
Rev Recd Date: 2023-02-17

Available Online: 2023-02-21

Publish Date: 2023-07-10

Abstract

Abstract

In the past decades, the scope of Internet of Things (IoT) is expanded continuously. With hundreds of billions of smart devices connect to IoT, huge challenges are arisen from several aspects such as device cost, connectivity capability, and power supplies. Fortunately, the new paradigm - passive IoT is coming which is one of the effective solutions for these challenges. Some related concepts are analyzed and the definition of passive IoT is proposed. For the first time, the four challenges faced by passive IoT, such as low energy density, low conversion efficiency, limited distance of backscatter communication, and difficulty in transmission of power and information simultaneous, are studied. The problems are analyzed in deeply and the research progress are surveyed. For the challenge of low energy density, the research progress is reviewed from three aspects: beamforming, antenna design for energy harvesting, and intelligent reflecting surface. For the challenge of low energy conversion efficiency, from receiver architecture optimization, waveform design, impedance matching, rectifier optimization. For the challenge of limited distance of backscatter communication, the research progress is reviewed from seven aspects: new modulation scheme, new frequency-shifted backscattering scheme, MIMO, new channel coding scheme, new signal detection method, intelligent reflecting surface enhancing, and semi-active mode. Considering the difficulty in transmission of power and information simultaneous, the research progress is reviewed from two aspects: optimization of the receiver architecture and the energy information compatible signal coding scheme. For each aspect, the advantages and disadvantages of various methods are analyzed and the future research directions are pointed out.

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