Multi-Dimensional Sparse-Coded Ambient Backscatter Communication for Massive IoT Networks

In this paper, we propose a multi-dimensional sparse-coded ambient backscatter communication (MSC-AmBC) system for long-range and high-rate massive Internet of things (IoT) networks. We utilize the characteristics of the ambient sources employing orthogonal frequency division multiplexing (OFDM) modulation to mitigate strong direct-link interference and improve signal detection of AmBC at the reader. Also, utilization of the sparsity originated from the duty-cycling operation of batteryless RF tags is proposed to increase the dimension of signal space of backscatter signals to achieve either diversity or multiplexing gains in AmBC. We propose optimal constellation mapping and reflection coefficient projection and expansion methods to effectively construct multi-dimensional constellation for high-order backscatter modulation while guaranteeing sufficient energy harvesting opportunities at these tags. Simulation results confirm the feasibility of the long-range and high-rate AmBC in massive IoT networks where a huge number of active ambient sources and passive RF tags coexist.

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Signal Detection for Ambient Backscatter Communication with OFDM Carriers

Sensors ◽

10.3390/s19030517 ◽

2019 ◽

Vol 19 (3) ◽

pp. 517 ◽

Cited By ~ 4

Author(s):

Thu Nguyen ◽

Yoan Shin ◽

Jin Kim ◽

Dong Kim

Keyword(s):

Orthogonal Frequency Division Multiplexing ◽

Low Cost ◽

Detection Threshold ◽

Energy Detector ◽

Test Statistic ◽

Significance Level ◽

Backscatter Communication ◽

Optimal Power ◽

Energy Detectors ◽

Ambient Backscatter

Ambient backscatter communication (AmBC) is considered as a promising future emerging technology. Several works on AmBC have been proposed thanks to its convenience and low cost property. This paper focuses on finding the optimal energy detector at the receiver side and estimating the corresponding bit error rate for the communication system utilizing the AmBC. Through theoretical and numerical analyses, we present two important results. First, we improve the existing energy detector by calculating the optimal averaging power orders. Second, we take advantage of the early work on orthogonal frequency division multiplexing (OFDM), where the repeating structure of ambient OFDM signals is exploited to cancel out the direct-link interference by using a cyclic prefix, then provide a test statistic in which optimal detection threshold and optimal power order are derived accordingly. The study reveals the inherent limitation of AmBC energy detectors and provides a guidance for achieving optimal power order for a given significance level.

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Optimum MCS for high-throughput long-range ambient backscatter communication networks

2017 IEEE 18th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC) ◽

10.1109/spawc.2017.8227716 ◽

2017 ◽

Author(s):

Tae Yeong Kim ◽

Dong In Kim

Keyword(s):

Long Range ◽

Communication Networks ◽

High Throughput ◽

Backscatter Communication ◽

Ambient Backscatter

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A Physical Layer Security Enhancement Scheme under the Ambient Backscatter System

Symmetry ◽

10.3390/sym13010005 ◽

2020 ◽

Vol 13 (1) ◽

pp. 5

Author(s):

Pengfei Hou ◽

Jianping Gong ◽

Jumin Zhao

Keyword(s):

Radio Frequency ◽

Radio Frequency Identification ◽

Physical Layer Security ◽

Physical Layer ◽

Artificial Noise ◽

Identification System ◽

Secrecy Rate ◽

Channel Quality ◽

Backscatter Communication ◽

Ambient Backscatter

In this paper, we proposed a scheme that Injects artificial noise from the tag end (IANT) to enhance the physical layer security of the ambient backscatter communication (ABC) system. The difference between the ABC system and the traditional radio frequency identification system is whether it uses the radio frequency (RF) signals in the environment to supply energy and modulation information for passive tags. In the IANT scheme, we select the best tag to communicate with the reader according to the channel quality between tags and reader, and at the same time select another tag to generate artificial noise that affects the receiving effect of the eavesdropper. This paper uses the method of generating noise copies in the reader to reduce the interference of artificial noise on the signal received by the reader. The simulation results show that with the increase in channel quality between tags and reader and the increase in the number of tags, the proposed IANT scheme is significantly superior to the contrast scheme in terms of system achievable secrecy rate, effectively enhancing the physical layer security of the ABC system.

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