Wireless communication technology has become very important in today's IoT with the increasing size of devices and connections. One of them, something called ambient backscatter technology has a great future in IoT as it is not only low cost but also power efficient. However, one problem with existing ambient backscatter systems is that two commercial receivers are required to decode the data transmitted by the backscatter tags, which makes the system very complex and increases the cost of both software and hardware. To solve this problem, our paper published in IEEE/ACM IWQoS 2023 proposes a new system, Twoferscatter, which is a simplified version of the ambient backscatter system for IoT communications. Twoferscatter requires only one common commercial receiver to decode data transmitted by the backscatter tags, thus simplifying the configuration and reduces cost. To achieve this goal, we propose a method called "nomination-verification decoding strategy" that utilizes the backscatter data to decode the tag data.
Figure 1: An Overview of the system.
Imagine our Twoferscatter system as a pair of backscattering partners. First, we have a mischievous backscatter tag, which plays a game of backscatter using WiFi signals in the environment and transmits tag data in the process. Next, we have an awesome backscatter receiver, which is a commercial receiver that can decode WiFi. Our system has a key technology! We use a brilliant method called the "Nomination-Verification Decoding Strategy", which nominates all possible tags from the backscatter data and verifies them one by one. Using this method, we can decode the tag data from the backscattered data with only one receiver, which acts as a super detective to decode the tag data from the backscattered WiFi signals without the help of another receiver. Oh, one more little tidbit! We have also developed a block-level modulation method that allows the Twoferscatter system to tackle large-scale multiple-input multiple-output (MIMO) challenges, making it even more versatile and powerful. In short, our Twoferscatter system is a pair of partners who work together to achieve simple and efficient tag data transmission through backscattering and clever decoding strategies. And, with our innovative modulation methods, the Twoferscatter system can handle even more complex communication scenarios.
We didn't just talk about it, we conducted a series of experiments to verify the awesomeness of Twoferscatter! Our system smoothly decoded tag data with a single AP, proving its usefulness and efficiency. Did you know. The receiver we used was even an unmodified network interface card (NIC). Nevertheless, we still achieved an amazing tag data throughput of 5.62 kilobits per second! Furthermore, we managed to achieve communication distances of up to 12 meters between the tag and the receiver. These results reveal the potential of Twoferscatter for passive IoT applications.
In short, we have not only talked about the theory, but we have also demonstrated the reliability of Twoferscatter through our experiments. Both in terms of rate and distance, we achieved marvelous results!