Label signal decoding method, label decoding device and label reader

Abstract

The invention relates to the technical field of RFID radio frequency, and mainly relates to a label signal decoding method, a label decoding device and a label reader. The label signal decoding methodcomprises a data sampling step, a frame header detection steps and a data decoding step. In the frame head detection step, a matching degree of a frame head template sequence and a label data signalsequence is measured by using related coefficients, and a frame header is accurately found in a waveform comparison mode; in the data decoding step, data sequences within a bit period are extracted according to a sampling multiplier N and a level skip condition of a data part, and the problem of decoding failure caused by frequency offset of a certain degree can be processed; and the computation amount of determining the data bit according to an accumulated value is small, the judgment result is reliable, and certain fault tolerance is available.

Description

technical field

[0001] The invention relates to the field of RFID radio frequency technology, and mainly relates to a tag signal decoding method, a tag decoding device and a tag reader. Background technique

[0002] RFID (Radio Frequency Identification) technology refers to an automatic identification technology that uses induction, radio waves or microwaves for non-contact two-way communication for the purpose of identification and data exchange. This technology can be used to track and manage all physical objects. The quality of RFID tag signal decoding directly affects the sensitivity and throughput of the reader, and becomes an important indicator for evaluating the performance of the reader.

[0003] According to the GB29768 standard, the tag signal returned by the RFID tag to the RFID reader is in the FM0 encoding format. The tag signal includes a frame header part and a data part.

[0004] The characteristic of FM0 encoding is: the change of the level is used to rep...

Examples

Embodiment 1

[0052] A tag signal decoding method, comprising steps:

[0053] one. data sampling

[0054] Sampling the received tag analog signal at N times the sampling rate (in this embodiment, 8 times the sampling rate is used as an example, that is, N=8) to obtain the original tag digital signal sequence. The specific steps include:

[0055] 1. Perform high-speed digital sampling on the received tag analog signal at N times the sampling rate to obtain the original tag digital signal sequence.

[0056] 2. Perform digital filtering on the original tag digital signal sequence obtained by high-speed digital sampling to filter out high-frequency signals in the original tag digital signal, which can effectively remove noise signals.

[0057] 3. Distinguish between high and low levels of the filtered original label digital signal: sampling points above the zero-crossing detection threshold are considered high level "1", and sampling points below a certain threshold are considered low level" ...

Embodiment 2

[0076] Such as Figure 4 Shown is a label decoding device for implementing the label decoding method of the present invention, which can be used to implement the decoding method in Embodiment 1. The label decoding device includes:

[0077] 1. Data sampling module

[0078]The received tag analog signal is sampled at an N-fold sampling rate (in this embodiment, an 8-fold sampling rate is used as an example for description, that is, N=8) to obtain an original tag digital signal sequence. Specifically include:

[0079] The AD sampling unit performs high-speed digital sampling on the received tag analog signal at an N-fold sampling rate to obtain the original tag digital signal sequence.

[0080] The FIR filtering unit performs digital filtering on the original tag digital signal sequence obtained by high-speed digital sampling to filter out high-frequency signals in the original tag digital signal, which can effectively remove noise signals.

[0081] The zero-crossing detectio...

Embodiment 3

[0100] A label reader includes the label decoding device described in the second embodiment. Ability to identify and decode tag signals sent by tags based on FMO encoding.

technical field

[0001] The invention relates to the field of RFID radio frequency technology, and mainly relates to a tag signal decoding method, a tag decoding device and a tag reader. Background technique

[0002] RFID (Radio Frequency Identification) technology refers to an automatic identification technology that uses induction, radio waves or microwaves for non-contact two-way communication for the purpose of identification and data exchange. This technology can be used to track and manage all physical objects. The quality of RFID tag signal decoding directly affects the sensitivity and throughput of the reader, and becomes an important indicator for evaluating the performance of the reader.

[0003] According to the GB29768 standard, the tag signal returned by the RFID tag to the RFID reader is in the FM0 encoding format. The tag signal includes a frame header part and a data part.

[0004] The characteristic of FM0 encoding is: the change of the level is used to rep...

Examples

Embodiment 1

[0052] A tag signal decoding method, comprising steps:

[0053] one. data sampling

[0054] Sampling the received tag analog signal at N times the sampling rate (in this embodiment, 8 times the sampling rate is used as an example, that is, N=8) to obtain the original tag digital signal sequence. The specific steps include:

[0055] 1. Perform high-speed digital sampling on the received tag analog signal at N times the sampling rate to obtain the original tag digital signal sequence.

[0056] 2. Perform digital filtering on the original tag digital signal sequence obtained by high-speed digital sampling to filter out high-frequency signals in the original tag digital signal, which can effectively remove noise signals.

[0057] 3. Distinguish between high and low levels of the filtered original label digital signal: sampling points above the zero-crossing detection threshold are considered high level "1", and sampling points below a certain threshold are considered low level" ...

Embodiment 2

[0076] Such as Figure 4 Shown is a label decoding device for implementing the label decoding method of the present invention, which can be used to implement the decoding method in Embodiment 1. The label decoding device includes:

[0077] 1. Data sampling module

[0078]The received tag analog signal is sampled at an N-fold sampling rate (in this embodiment, an 8-fold sampling rate is used as an example for description, that is, N=8) to obtain an original tag digital signal sequence. Specifically include:

[0079] The AD sampling unit performs high-speed digital sampling on the received tag analog signal at an N-fold sampling rate to obtain the original tag digital signal sequence.

[0080] The FIR filtering unit performs digital filtering on the original tag digital signal sequence obtained by high-speed digital sampling to filter out high-frequency signals in the original tag digital signal, which can effectively remove noise signals.

[0081] The zero-crossing detectio...

Embodiment 3

[0100] A label reader includes the label decoding device described in the second embodiment. Ability to identify and decode tag signals sent by tags based on FMO encoding.

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