# CRC-Based Reliable WiFi Backscatter Communication for Supply Chain Management  
[PERSON]  
1 School of Computer Science and Technology, University of Science and Technology of China,  
Hefei 230026, China 1  
[PERSON]  
2 Business School, China University of Political Science and Law, Beijing 102249, China 2  
[PERSON]  
1 School of Computer Science and Technology, University of Science and Technology of China,  
[PERSON]  
3 School of Computer Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China 3  
[PERSON]  
3 School of Computer Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China 3  
[PERSON]  
1 School of Computer Science and Technology, University of Science and Technology of China,  
Hefei 230026, China 1  
Footnote 1: [[https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci)]([https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci))  
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Footnote 7: [[https://www.mdpi](https://www.mdpi)]([https://www.mdpi](https://www.mdpi)). LoRa [27], and Bluetooth [28; 29; 30; 31]. However, traditional backscatter systems require specialized hardware to achieve backscatter communication. For instance, WiFi backscatter [32] requires a power supply to connect to the network, and BackFi [33] uses customized full-duplex hardware. Passive WiFi [34] needs a dedicated continuous wave signal generator as the excitation signal source. These hardware requirements limit the application scenarios of backscatter systems. HitchHike [35] achieves backscatter communication by commodity devices and introduces the idea of codeword translation, which allows a backscatter tag to embed its information on standard 802.11b packets. Codeword translation has been extended to Bluetooth, ZigBee, and LoRa by FreeRider [36] and LoRa Backscatter [37]. In HitchHike, one more access point is deployed to demodulate excitation signals, enabling the system to decode tag data via a simple and efficient XOR decoder. In addition, ambient backscatter communication and antenna selection methods are also used to improve the technology [38; 39; 40]. We can categorize backscatter systems into two modes, as shown in Figure 1. In mode A, the backscatter communication system uses a controlled excitation source for backscattering and decoding. This mode has additional requirements on the excitation source. The pre-defined excitation packet does not carry valid information, and the excitation signal may cause interference with other devices on the same communication channel. In mode B, the system employs an additional AP to receive excitation signals, and it decodes tag data through backscatter data and original data. Compared to active communication infrastructure, both modes of backscatter systems require additional hardware at the transmitter or receiver, which leads to extra costs and may present challenges in large-scale deployment on the current WiFi infrastructure. Inspired by these observations, this paper focuses on single-AP decoding with ambient WiFi signals. The main contributions in this work are summarized as follows.