Abstract
Ambient backscatter communication (AmBC) is an emerging communication technology enabling green Internet of Things deployments. The widespread acceptance of this paradigm is limited by the low signal-to-interference-plus-noise ratio (SINR) of the signal impinging on the receiver antenna due to the strong direct path interference and unknown ambient signal. The adverse impact of these two factors can be mitigated by using noncoherent multiantenna receivers, which are known to require a higher SINR to reach the bit-error-rate (BER) performance of coherent receivers. However, considering the unknown ambient signal, unknown location of AmBC tags, and varying channel conditions, coherent receivers for AmBC systems are rarely studied in the literature. In this article, a coherent multiantenna receiver, which requires no prior information of the ambient signal for decoding the binary-phase-shift-keying (BPSK) modulated signal, is presented. The performance of the proposed receiver is compared with an ideal coherent receiver that has perfect phase information, and also with the performance of a noncoherent receiver, which assumes distributions for ambient signal and phase offset caused by the excess length of the backscatter path. Comparative simulation results show the designed receiver can achieve the same BER performance of the ideal coherent receiver with 1-dB more SINR, which corresponds to 5-dB or more gain with respect to noncoherent reception of on-off-keying modulated signals. Variation in the detection performance with the tag location shows that the coverage area is in the close vicinity of the transmitter and a larger region around the receiver, which is consistent with the theoretical results.
Highlights
Recent advances in computing and communication technologies have enabled data exchanges among different devices without human intervention, known as Internet-ofThings (IoT)
The results indicate that acceptable performance is achieved when the SNR of the legacy system is high and/or when the tag is in a close vicinity of the transmitter or in a large region (∼ 20 wavelengths) around the receiver excluding the null beam of the receiver antenna array
The receiver utilizes multiple antennas to mitigate the strong Direct Path Interference (DPI) and the rapidly varying ambient signal, and uses logistic regression algorithm to tackle the challenging phase offset caused by the excess length of backscatter path
Summary
Recent advances in computing and communication technologies have enabled data exchanges among different devices without human intervention, known as Internet-ofThings (IoT). The recently emerging Ambient Backscatter Communication (AmBC) paradigm efficiently handles both limitations while traditional communication technologies fall short for massive IoT deployments [1], [2]. Significant bandwidth efficiency enhancement can be obtained by using the spectrum allocated for a legacy system [4] Possessing these features, AmBC is becoming a promising component for realizing a sustainable IoT ecosystem. For traditional bi-static backscatter systems, receivers have been widely studied to increase the communication range [14]–[17]. The non-coherent receiver [16] and the coherent receiver [17] are designed for the OOK-modulated and frequency shift keying (FSK)modulated tag signal, respectively These detectors cannot be applied directly to the AmBC systems as an AmBC system uses the unknown modulated signal of a legacy system as its source signal. It is one major factor that hampers detection performance
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
