Information transmission method in radio frequency recognition system

A radio frequency identification system and information transmission technology, which is applied in the field of wireless communication, can solve the problems of DC imbalance, the number of high and low levels of frame synchronization codes, etc., and achieve the effect of improving autocorrelation performance and reducing the probability of false synchronization

CN101425121BInactive Publication Date: 2011-04-20ZTE CORP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2011-04-20
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses an information transmission method in a radio frequency identification system. After a label receives the command from a reader, the label encodes and modulates the information to be transmitted into a modulation signal and transmits the modulation signal to the reader; the frame format of the modulation signal includes a frame synchronization code; in the frame synchronization code, the quantity of high electric levels is the same as that of low electric levels, and four sequential electric levels with the same polarity are included in a codon. The technical scheme ofthe invention improves the autocorrelation of the frame synchronization code and meanwhile solves the problem of direct current unbalancing caused by different quantities of the high and the lower electric levels of the frame synchronization code.
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Description

technical field

[0001] The invention relates to a wireless communication technology, in particular to an information transmission method in a radio frequency identification system. Background technique

[0002] A radio frequency identification (RFID, Radio Frequency Identify) system includes a tag and a reader. It is a non-contact automatic identification technology. It automatically identifies the target object and obtains relevant data through radio frequency signals. The identification work does not require manual intervention and can work in various harsh environments. RFID technology can identify high-speed moving objects and can identify multiple tags at the same time, and the operation is fast and convenient.

[0003] The radio frequency identification system includes passive radio frequency identification and active radio frequency identification, and the essential difference between the two lies in the label side. The former tag obtains energy from the waveform tr...

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Embodiment Construction

[0043] The invention improves the autocorrelation performance of the frame synchronization code by modifying the frame synchronization code of the frame format in the tag modulation signal.

[0044] Below in conjunction with accompanying drawing, the implementation of technical scheme is described in further detail:

[0045] refer to Figure 7 As shown, the frame format of the modulated signal in the RFID system adopted by the present invention consists of five parts, including: frame start bit, bit synchronization code, frame synchronization code, data information and check code. The structure of the frame synchronization code determines whether the starting moment of a frame of data can be correctly parsed.

[0046] With reference to shown in Fig. 8, be the frame synchronous code 1 that the present invention proposes, it is a 12 frame synchronous codes, represented by M1, M2, ..., M12 successively, and its two polarities are represented by V1 and V2 respectively . The cod...