We present DanBlue, a commodity Bluetooth backscatter system that can take multi-frequency signals as excitations. Unlike all prior systems, DanBlue leverages ambient Bluetooth signals of various frequencies to backscatter in the standard Bluetooth-hopping way. To do so, we first introduce an edge proxy to identify uncontrolled ambient Bluetooth signals. Then, we design a wideband channel hopping to enable fast frequency shifts for low-power tags, empowering backscatter hopping much like active Bluetooth hopping. We prototype the DanBlue tag using off-the-shelf FPGAs and the DanBlue edge with commercial off-the-shelf (COTS) chips. Through comprehensive field studies, we show that DanBlue supports hopping from any-frequency Bluetooth excitations to any-frequency Bluetooth channels. Furthermore, the accuracy of frequency identification is as high as 99% with less than 7.1 ms latency. For the first time, we demonstrate DanBlue can emulate the Bluetooth protocol stack and seamlessly build connectivity with multiple active Bluetooth radios. We believe DanBlue is taking a crucial step forward on fully functioning battery-free Bluetooth. 

Dances with Blues: Harnessing Multi-Frequency Carriers for Commodity Bluetooth Backscatter

Ambient backscatter is one of the most promising wireless communication techniques that can accommodate the ever-growing scale of IoT devices and connections. The state-of-the-art ambient backscatter systems, however, have to employ two commodity receivers for tag-data demodulation, resulting in additional software and hardware overhead. Using off-the-shelf ambient WiFi signals and a single AP to achieve backscatter communication has seldom been studied before. In this paper, we introduce Twoferscatter, an innovative ambient backscatter system that uses a single commodity AP to decode tag data alone. We propose a nomination-verification decoding strategy to achieve tag-data decoding with the backscatter data. We also develope a block-level modulation method that extends our system to massive MIMO excitation. Our experiments demonstrate that Twoferscatter can successfully demodulate tag data with a single AP. It can deliver up to 5.62 kbps tag-data goodput and work at tag-Rx distances of up to 12 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$m$</tex> using an unmodified NIC receiver. We believe Twoferscatter has a bright future in passive IoT applications since it is the first ambient backscatter that uses ambient WiFi as excitation and requires only a single AP for demodulation. 

Ambient Backscatter with a Single Commodity AP

In the past decade, backscatter communications have drawn significant attention as they are an ultra-low-power solution to transmit IoT sensor data, including video and audio. However, most of the state-of-the-art backscatter systems that are fully compatible with commodity radios suffer from poor synchronization accuracy and low throughput, being unable to support various multimedia sensors. In this paper, we propose Bitalign, a Bluetooth backscatter system that can make use of uncontrolled ambient signals as excitations and deliver high throughput for multimedia streaming applications. To do so, we identify several backscatter bottlenecks and employ a set of techniques to considerably boost backscatter throughput. In particular, we introduce an identification-based synchronization method that can efficiently distinguish various ambient signals and accurately decide where to modulate. We further propose a matching-based synchronization method with higher synchronization accuracy. In addition, we propose header reconstruction to make Bitalign truly compatible with commercial Bluetooth devices. Finally, we implement a tag prototype using FPGAs and conduct extensive experiments. Results show that the minimum bit error rate of Bitalign is 0.5%, which is 60 times better than that of FreeRider, a state-of-the-art Bluetooth system that features uncontrolled excitors. The maximal theoretical throughput of Bitalign is 1.98 Mbps.

Bitalign: Bit Alignment for Bluetooth Backscatter Communication

This paper proposes a new cooperative offloading protocol termed "user reciprocity" for backscatter communication (BackCom)-aided mobile edge computing (MEC) systems, whose quintessence is that each user can switch alternately between the active or the BackCom mode in different slots, and one user works in the active mode and the other user works in the BackCom mode in each time slot. Specifically, the user in the BackCom mode can always use the signal transmitted by the user in the active mode for more data transmission in a spectrum-sharing manner. To evaluate the proposed protocol, a computation efficiency (CE) maximization-based optimization problem is formulated by jointly power control, time scheduling, power reflection coefficient (RC) adjustment, and computing frequency allocation, while adhering to constraints on energy budgets, computing frequency thresholds, minimum computed bits, and harvested energy. To solve this non-convex problem, Dinkelbach's method and quadratic transform are first employed to transform the complex fractional forms into linear ones. Then, an iterative algorithm is designed by decomposing the resulting problem to obtain the suboptimal solution. For analytical insights, we not only provide some closed-form solutions, but also derive the analytical performance gain with reciprocal mode. Simulation results demonstrate that the proposed scheme outperforms benchmark schemes regarding the CE. 

Computation-Efficient Backscatter-Blessed MEC with User Reciprocity

This letter proposes a new user cooperative offloading protocol called user reciprocity in backscatter communication (BackCom)-aided mobile edge computing systems with efficient computation, whose quintessence is that each user can switch alternately between the active or the BackCom mode in different slots, and one user works in the active mode and the other user works in the BackCom mode in each time slot. In particular, the user in the BackCom mode can always use the signal transmitted by the user in the active mode for more data transmission in a spectrum-sharing manner. To evaluate the proposed protocol, a computation efficiency (CE) maximization-based optimization problem is formulated by jointly power control, time scheduling, reflection coefficient adjustment, and computing frequency allocation, while satisfying various physical constraints on the maximum energy budget, the computing frequency threshold, the minimum computed bits, and harvested energy threshold. To solve this non-convex problem, Dinkelbach's method and quadratic transform are first employed to transform the complex fractional forms into linear ones. Then, an iterative algorithm is designed by decomposing the resulting problem to obtain the suboptimal solution. The closed-form solutions for the transmit power, the RC, and the local computing frequency are provided for more insights. Besides, the analytical performance gain with the reciprocal mode is also derived. Simulation results demonstrate that the proposed scheme outperforms benchmark schemes regarding the CE.

pdf/computation-efficient-backscatter-blessed-mec-with-user-31y2nfi0.pdf

Bidirectional links are widely adopted in many active radios to provide efficient data exchanges, e.g., WiFi and Bluetooth. However, they are underexplored for general-purpose backscatter communications. The downlinks of state-of-the-art Bluetooth backscatter systems are based on packet length modulation, which is inefficient and unreliable. In this paper, we propose BiBlue, a bidirectional Bluetooth backscatter system that uses an edge server to enable fast and reliable downlinks. Specifically, our edge server acts like a bridge that can translate commercial Bluetooth signals to Amplitude Shift Keying (ASK) signals. In addition, we design a reliable edge-to-tag link that adaptively decodes ASK signal under variance. Finally, we propose a low-power uplink design that enables connection-based bidirectional communication with commodity devices. We prototype BiBlue using FPGA and Software Defined Radio (SDR). Extensive experimental results demonstrate that BiBlue achieves more than 62x downlink throughput gains over FreeRider and meanwhile supports an 80 cm communication range of edge-to-tag with BER at around 1%. 

Bidirectional Bluetooth Backscatter with Edges

Recently, backscatter technology has attracted much interest in wireless communication due to its novel low-cost and battery-free design. Since Bluetooth Low Energy (BLE) was born to be low energy consumption, great efforts have been made in BLE-based backscatter systems, like FreeRider, RBLE. In this paper, we present BonusBlue, a BLE backscatter system that enables high-goodput communication with commercial BLE devices. BonusBlue tag generates BLE packets by modulating data on excitation signals and set up a data connection with BLE receiver using a state machine, thus achieving a high-goodput communication link. We present this state machine design and build a prototype of our tag using an FPGA, and evaluate its performance with BLE devices. Our evaluation shows that the backscatter tag can build a robust data connection link with commodity BLE device in the guidance of our state machine and transmit tag data on this link. Experimental results show that our backscatter system can achieve a goodput of up to 16.9 kbps.

Enabling High-Goodput Backscatter Communication with Commodity BLE

This paper presents a novel method of determining the overlapping area in advance to accelerate the SIFT (Scale Invariant Feature Transformation) algorithm. The SIFT algorithm can achieve high accuracy in image matching, however, it can be time-consuming when processing large images. The proposed method in this paper pre-selects the overlapping area of input images to speed up the feature extraction of SIFT. This improvement of SIFT can greatly reduce the
processing time without affecting the accuracy.

/pdf/region-based-pre-selection-of-overlapping-area-for-the-sift-2puldpgosi.pdf

Region-based Pre-selection of Overlapping Area for the SIFT Algorithm

Traditional LTE backscatter devices continuously reflect signals as long as they have sufficient energy, which results in wasted energy and transmission failure since LTE receivers operate in a low duty cycle manner. We present EPScatter, which utilizes standards-compliant paging to allow tags and receivers to maintain consistent sleep and wake schedules. In particular, EPScatter uses a low-power state machine to adapt to the different transmission stages of the receiver. For example, when the receiver goes to sleep, the tag also goes to sleep for energy saving and efficient transmission. 

Poster: Duty-Cycled Paging for LTE Backscatter

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Maoran Jiang

Author Tools

Chat about Author