A surface acoustic wave localization system and localization method integrating intensity and phase information

Abstract

The invention discloses a surface acoustic wave positioning system and a positioning method integrating intensity and phase information. The surface acoustic wave tag is a dual-frequency dual-channel structure, and the center distance from the reflection grating of the two propagation channels to the interdigital transducer is inversely proportional to its center frequency. The reader is connected to three reader antennas through a one-to-three switch, and the three reader antennas are located at three fixed positions respectively. Before the system positioning, the positioning area is divided into several sub-areas without phase ambiguity problem, and fingerprint points are set at the geometric centroid of the sub-area to establish a fingerprint database. The eigenvalues ​​of each fingerprint point include echo signal strength and phase. A total of 12 Then, the fingerprint positioning algorithm is used to determine the sub-region where the positioning target is located. Finally, the unambiguous phase difference of the echo signal is used as the ranging information, and the two-dimensional coordinates of the positioning target are obtained through the trilateral positioning algorithm. The invention has the characteristics of high positioning accuracy and low system cost, which not only solves the problem of phase ambiguity, but also eliminates the influence of temperature.

Description

Technical field: [0001] The invention relates to a surface acoustic wave positioning system and a positioning method integrating intensity and phase information, and belongs to the field of radio frequency identification positioning. Background technique: [0002] In recent years, the growing demand for location services has driven the rapid development of location technology. Radio Frequency Identification (RFID) technology has been widely used in the field of positioning due to its simple system structure and non-contact transmission. According to the different ranging methods in the positioning process, RFID positioning technology is mainly divided into methods based on Received Signal Strength Indicator (RSSI) and Time Of Arrival (TOA). Due to the corresponding relationship between phase and time, RFID positioning technology based on Received Signal Phase (RSP) has been gradually developed in recent years. On the basis of the above ranging method, the positioning algor...

AI Technical Summary

Problems solved by technology

[0008] Aiming at the problems existing in the existing surface acoustic wave positioning technology, the present invention proposes a surface acoustic wave positioning system and positioning method that integrates intensity and phase information. The reader is connected to three reader antennas through a one-to-three switch. First, set fingerprint points offline and build a fingerprint library according to the sub-areas in the positioning area where there is no phase ambiguity problem. Then use the fingerprint positioning algorithm to determine the sub-area where the positioning target is located. Finally Obtain the precise two-dimensional coordinates of the positioning target through the trilateral positioning algorithm

Images