Modulation in the Air: Backscatter Communication Over Ambient OFDM Carrier
By Gang Yang, Ying-Chang Liang, Rui Zhang, Yiyang Pei. IEEE Transactions on Communications, 2017
307 citations recorded by the source corpus.
Ambient backscatter communication (AmBC) enables radio-frequency (RF) powered backscatter devices (BDs) (e.g., sensors and tags) to modulate their information bits over ambient RF carriers in an over-the-air manner. This technology, also called “modulation in the air,” has emerged as a promising solution to achieve green communication for future Internet of Things. This paper studies an AmBC system by leveraging the ambient orthogonal frequency division multiplexing (OFDM) modulated signals in the air. We first model such AmBC system from a spread-spectrum communication perspective, upon which a novel joint design for BD waveform and receiver detector is proposed. The BD symbol period is designed as an integer multiplication of the OFDM symbol period, and the waveform for BD bit “0” maintains the same state within the BD symbol period, while the waveform for BD bit “1” has a state transition in the middle of each OFDM symbol period within the BD symbol period. In the receiver detector design, we construct the test statistic that cancels out the direct-link interference by exploiting the repeating structure of the ambient OFDM signals due to the use of cyclic prefix. For the system with a single-antenna receiver, the maximum-likelihood detector is proposed to recover the BD bits, for which the optimal threshold is obtained in closed-form expression. For the system with a multi-antenna receiver, we propose a new test statistic which is a linear combination of the per-antenna test statistics and derive the corresponding optimal detector. The proposed optimal detectors require only knowing the strength of the backscatter channel, thus simplifying their implementation. Moreover, practical timing synchronization algorithms are proposed for the designed AmBC system, and we also analyze the effect of various system parameters on the transmission rate and detection performance. Finally, extensive numerical results are provided to verify that the proposed transceiver design can improve the system bit-error-rate performance and the operating range significantly and achieve much higher data rate, as compared with the conventional design.
Subfields: Electrical and Electronic Engineering
View Paper: https://www.semanticscholar.org/paper/b84aab9f1ae3e26c6718ad4a44448c6d206b3771
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In Electrical and Electronic Engineering
Citations in the corpus
- Ambient Backscatter Communications: A Contemporary Survey (2017, background): “[144] extend the work in [143] by considering”
- Large Intelligent Surface/Antennas (LISA): Making Reflective Radios Smart (2019, background): “Nevertheless, due to the lack of cooperation with the primary system, AmBC suffers from severe direct-link interference (DLI), and the coverage range and transmission rate of AmBC are limited [10]–[12].”
- Symbiotic Radio: A New Communication Paradigm for Passive Internet of Things (2018, methodology): “in [20], a novel BD waveform is designed to support clever interference cancellation by exploiting the cyclic prefix property of the ambient orthogonal frequency division multiplexing”
- Cooperative Ambient Backscatter Communications for Green Internet-of-Things (2018, methodology): “We assume that the ABD can align the transmission of its own symbol c(n) with its received OFDM symbol,3 since the A-BD can estimate the arrival time of OFDM signal by some methods like the scheme that utilizes the repeating structure of CP in OFDM singals [5].”
- Intelligent Reflecting Surface: A Programmable Wireless Environment for Physical Layer Security (2019, background): “Compared with the existing related techniques, i.e., traditional reflecting surfaces [7], amplify-and-forward (AF) relay [8], active intelligent surface [9], and backscatter communication [10]–[12], IRS has the following advantages [13], [14].”