CN211015523U

CN211015523U - Ultrahigh frequency tag decoding device supporting error correction

Info

Publication number: CN211015523U
Application number: CN201921509724.3U
Authority: CN
Inventors: 孙晓霞; 张建伟
Original assignee: Shanghai Mingsi Microelectronics Co ltd
Current assignee: Shanghai Mingsi Microelectronics Co ltd
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2020-07-14
Anticipated expiration: 2029-09-12

Abstract

The utility model provides a support hyperfrequency label decoding device of error correction, a serial communication port contains: ternary counter, carry counter, PIE counter, error correction symbol decision device. When the PIE symbol is received, the ternary counter and the PIE counter start counting, and when the count value of the ternary counter is 2, the carry counter is increased by 1. And after the PIE symbol is finished, the error correction symbol decision device performs error correction according to the count values of the ternary counter, the carry counter and the PIE counter, and decides whether the current PIE symbol is 0 or 1 according to the corrected value. The beneficial effects of the utility model are that, when the clock frequency ratio of decoding is lower, and when Tari length ratio was short, can solve the problem of the misjudgement of traditional decoding method.

Description

Ultrahigh frequency tag decoding device supporting error correction

Technical Field

The utility model belongs to the integrated circuit design field particularly, belongs to the technical field that hyperfrequency RFID label chip decoded.

Background

Rfid (radio Frequency identification), i.e. radio Frequency identification technology. A radio frequency identification system generally comprises a reader-writer, an electronic tag and a back-end data processing platform.

According to the frequency of the radio signal sent by the reader-writer, the RFID system can be divided into four types, i.e., low frequency, high frequency, ultra-high frequency, and microwave. The working frequency of the ultra-high frequency RFID system based on the EPC Class1 Gen2 protocol is 860MHz-960MHz, and the ultra-high frequency RFID system is applied to scenes with longer read-write distance and higher read-write speed.

The EPC Class1 Gen2 protocol specifies that PIE encoding is adopted for data sent to a tag by a card reader, and how to reduce the clock frequency of decoding and reduce the possibility of misjudgment during decoding is always a hot point of research.

As shown in fig. 1, according to the protocol, the PIE symbol length of logic 0 is equal to 1 Tari, the PIE symbol length of logic 1 is equal to or greater than 1.5Tari, and is equal to or less than 2Tari, the PIE symbol length of rtca L is equal to or greater than 2.5Tari, and is equal to or less than 3Tari, the PIE symbol length of trca L is equal to or greater than 2.75Tari, and is equal to or less than 9 Tari.

The current hot method for PIE coding and decoding mainly counts Tari and RTCA L sent by a card reader as a whole, after the count value is divided by 3, the result of rounding is recorded as N, then the length of a subsequent PIE symbol is counted, when the length of a symbol behind RTCA L is greater than 2N, the symbol is judged to be TRCA L, when the length of the symbol is greater than or equal to N, the symbol is judged to be logic 1, and when the length of the symbol is less than N, the symbol is judged to be logic 0.

Disclosure of Invention

In order to overcome the defects of the prior art, the utility model provides a support hyperfrequency label decoding device that error correction. Characterized in that it comprises: ternary counter, carry counter, PIE counter, error correction symbol decision device.

The main function of the ternary counter is to count according to the ternary rule, and the counter returns to 0 value to start counting again each time when counting to 2. The input of the ternary counter is connected with the output data demodulated by the analog module, and the output of the ternary counter is connected with the input of the carry counter.

The main function of the carry counter is to increment the carry counter by 1 each time the ternary counter counts to 2. The input of the carry counter is connected with the output of the ternary counter, and the output of the carry counter is connected with the input of the error correction symbol decision device.

The main function of the PIE counter is to count the length of each PIE symbol and register the final count value. The input of the PIE counter is connected with the output data demodulated by the analog module, and the output of the PIE counter is connected with the input of the error correction symbol decision device.

The main function of the error correction symbol decision device is to perform error correction on the count values of the ternary counter and the carry counter, then compare the corrected value with the value of the PIE counter, and judge whether the current PIE symbol is 0 or 1. When a PIE symbol ends, the error correction symbol determiner will first compare the value of the PIE counter to the value of the carry counter. When the value of the PIE counter is greater than the value of the carry counter, the PIE symbol is decided to be 1. When the value of the PIE counter is smaller than the value of the carry counter, the PIE symbol is decided as 0. When the value of the PIE counter is equal to the value of the carry counter, correction needs to be carried out according to the value of the ternary counter, when the value of the ternary counter is 2, the PIE symbol is judged to be 1, and when the value of the ternary counter is 0 or 1, the PIE symbol is judged to be 0. The input of the error correction symbol decision device is divided into three paths, one path of input is the output of a ternary counter, one path of input is the output of a carry counter, and the other path of input is the output of a PIE counter. The output is decoded output data and is output to other functional modules for use.

Use the beneficial effects of the utility model are that, when decoding clock frequency ratio lower, and when Tari length ratio was short-term, use this device to decode the problem that the erroneous judgement that can effectual solution use traditional approach to cause was decided.

Drawings

Fig. 1 shows the PIE encoding format specified by the protocol.

Fig. 2 is the utility model provides a support hyperfrequency label decoding device of error correction.

Detailed Description

Preferred embodiments of the present apparatus will be described in detail below with reference to the accompanying drawings.

As shown in fig. 2, the uhf tag decoding apparatus supporting error correction is characterized by comprising: ternary counter, carry counter, PIE counter, error correction symbol decision device.

And the input of the ternary counter is connected with the demodulated output data of the RF circuit, and the output of the ternary counter is connected with the input of the carry counter and the error correction symbol decision device. The ternary counter performs ternary counting, and when the ternary counter counts to 2, the value of the counter clears 0, and the accumulation counting is restarted. When a PIE symbol ends, the ternary counter registers its current count value.

And the input of the carry counter is connected with the output of the ternary counter, and the output of the carry counter is connected with the input of the error correction symbol decision device. The carry counter is incremented by 1 each time the ternary counter counts to 2. When a PIE symbol ends, the carry counter registers its current count value.

And the input of the PIE counter is connected with the RF demodulation output data, and the output of the PIE counter is connected with the input of the error correction symbol decision device. The PIE counter starts counting each time a PIE symbol is received, and registers its current count value when a PIE symbol ends.

And the input of the error correction symbol decision device is respectively connected with the output of the ternary counter, the output of the carry counter and the output of the PIE counter, and the output of the error correction symbol decision device is decision output data. When a PIE symbol ends, the error correction symbol determiner will first compare the value of the PIE counter to the value of the carry counter. When the value of the PIE counter is greater than the value of the carry counter, the PIE symbol is decided to be 1. When the value of the PIE counter is smaller than the value of the carry counter, the PIE symbol is decided as 0. When the value of the PIE counter is equal to the value of the carry counter, correction needs to be carried out according to the value of the ternary counter, when the value of the ternary counter is 2, the PIE symbol is judged to be 1, and when the value of the ternary counter is 0 or 1, the PIE symbol is judged to be 0.

Can see through above embodiment, the beneficial effects of the utility model are that, the frequency ratio when the clock of decoding is lower, and when Tari's length ratio was short, adopt traditional rounding method to cause the misjudgment very probably, nevertheless adopt the utility model discloses can carry out effectual error correction, avoid the emergence of misjudgment.

Although the present invention has been described in detail with respect to the preferred embodiments, various modifications and alterations will become apparent to those skilled in the art upon reading the foregoing description. The above description and drawings are only examples of the practice of the invention, and it should be understood that the above description should not be taken as limiting the invention.

Claims

1. An apparatus for decoding an ultra-high frequency tag supporting error correction, comprising: a ternary counter, a carry counter, a PIE counter and an error correction symbol decision device; the ternary counter is used for counting input demodulation signals, the input of the ternary counter is connected with demodulation output signals of the analog circuit, and the output of the ternary counter is connected with the carry counter and the error correction symbol decision device; the carry counter is used for recording the times counted by the ternary counter to 2, the input of the carry counter is connected with the ternary counter, and the output of the carry counter is connected with the error correction symbol decision device; the PIE counter is used for counting PIE symbols, the input of the PIE counter is connected with a demodulation output signal of the analog circuit, and the output of the PIE counter is connected with the error correction symbol decision device; the error correction symbol decision device is used for correcting according to the values of the ternary counter, the carry counter and the PIE counter, the input of the error correction symbol decision device is connected with the ternary counter, the carry counter and the PIE counter, and the error correction symbol decision device outputs the decoding result of the current PIE code.