Surface acoustic wave positioning system and method fusing intensity and phase information

Abstract

The invention discloses a surface acoustic wave positioning system and method fusing intensity and phase information. The surface acoustic wave label is of a double-frequency double-channel structure,and the center distance from the reflecting gratings of the two propagation channels to the interdigital transducer is inversely proportional to the center frequency of the interdigital transducer. The reader is connected with three reader antennas through a one-to-three switch, and the three reader antennas are respectively located at three fixed positions. Before system positioning, a positioning area is divided into a plurality of sub-areas without a phase ambiguity problem, fingerprint points are arranged in geometric centroids of the sub-areas to establish a fingerprint library, the characteristic value of each fingerprint point comprises 12 characteristic values including echo signal intensity and phase, and then the sub-area where a positioning target is located is determined by adopting a fingerprint positioning algorithm. And finally, the unambiguous phase difference of the echo signal is taken as distance measurement information, and thus obtaining a two-dimensional coordinate of the positioning target through a trilateral positioning algorithm. The invention has the characteristics of high positioning precision and low system cost, and not only solves the problem of phase ambiguity, but also eliminates the temperature influence.

Description

Technical field: [0001] The invention relates to a surface acoustic wave positioning system and a positioning method that integrates intensity and phase information, and belongs to the field of radio frequency identification positioning. Background technique: [0002] In recent years, the rapid development of positioning technology has been driven by the growing demand for location-based services. Radio Frequency Identification (RFID) technology has been widely used in the field of positioning due to its simple system structure and non-contact transmission mode. 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, in recent years, RFID positioning technology based on received signal phase (Received Signal Phase, RSP) has gradually developed. On the basis of th...

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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

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