Location method and device of wireless radio frequency identification system

Abstract

The invention belongs to the technical field of wireless communication, and in particular discloses a location method and a device of wireless radio frequency identification system; wherein, a carrier wave is generated from a radio frequency identification reader of the system and modulated by a pseudorandom sequence; the modulation depth of the modulated carrier wave is small and has little influence on the normal work of label; the detection label of the reader returns modulation signals and restores pseudorandom sequence synchronously; the restored and sent pseudorandom sequences are interrelated by the reader to obtain the signal of TOA and the distance between the label and the reader is calculated; one or a plurality of reference label verification can remove signal treatment delay and system error and improve location precision; multi readers can obtain multi distances; if the readers are taken as centers of circles and correspondent distances are taken as radii, then the pointof intersection of the circles is the estimation location of the detected labels. The invention has high location precision and is affected little by the environment.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a positioning method and device for a radio frequency identification (RFID) system. Background technique [0002] With the wide application of radio frequency identification (Radio Frequency Identification) technology, people's demand for RFID real-time data is growing rapidly, so there is an urgent need for an RFID system that can provide real-time data and location information, which has led to the development of RFID real-time positioning systems. research and development. [0003] However, in the RFID system, in order to reduce costs, the tags cannot be made very complicated, so it is impossible to send and receive complex modulation signals like the GPS positioning system. In order to realize the tracking and positioning of RFID tags, the existing readers can only be improved to achieve this goal. The dual requirements of real-time and positionin...

AI Technical Summary

Problems solved by technology

The ranging-based positioning technology calculates the node position by measuring the distance and angle information from the reader to the tag, using trilateration, triangulation or maximum likelihood estimation (multilateration) positioning methods; no need for ranging positioning The technology does not need to measure distance and angle information, and only determines whether the tag is in a certain area based on information such as network connectivity, so the cost is low and the implementation and deployment are simple; but its application range and positioning accuracy are very limited

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