WO2009093815A1 - Appareil de réception de données et son procédé de réception - Google Patents

Appareil de réception de données et son procédé de réception Download PDF

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Publication number
WO2009093815A1
WO2009093815A1 PCT/KR2008/007772 KR2008007772W WO2009093815A1 WO 2009093815 A1 WO2009093815 A1 WO 2009093815A1 KR 2008007772 W KR2008007772 W KR 2008007772W WO 2009093815 A1 WO2009093815 A1 WO 2009093815A1
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WIPO (PCT)
Prior art keywords
digital
digital data
data
signals
signal
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PCT/KR2008/007772
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English (en)
Inventor
Yang-Hun Choi
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Wicomm Technology Co., Ltd.
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Publication of WO2009093815A1 publication Critical patent/WO2009093815A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
    • H04B5/77—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes for interrogation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
    • G06K7/10297—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/40—Near-field transmission systems, e.g. inductive or capacitive transmission systems characterised by components specially adapted for near-field transmission
    • H04B5/48—Transceivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0045—Arrangements at the receiver end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0078—Avoidance of errors by organising the transmitted data in a format specifically designed to deal with errors, e.g. location
    • H04L1/0083—Formatting with frames or packets; Protocol or part of protocol for error control

Definitions

  • the present invention relates, in general, to a data receiving apparatus used in a
  • Radio-Frequency IDentification (RFID) system and a data receiving method therefor, and, more particularly, to a data receiving apparatus and a data receiving method therefor which receive and decode communication signals transmitted by a tag.
  • RFID Radio-Frequency IDentification
  • An RFID system 10 generally refers to a data recognition system which is capable of reading data stored in the chip of an RFID tag at the request of an RFID reader.
  • the RFID system 10, as shown in FIG. 1, includes an RFID tag 100 for storing unique information, an RFID reader 110 for performing reading and decryption functions, a host computer 120 for processing data read from the RFID tag, application software, and a network.
  • the RFID tag 100 is also referred to as a transponder which is the compound word of a transmitter and a responder, and is configured to include an IC chip and an antenna circuit. Communication is performed through wireless access by the antenna and an RF module between the RFID tag and the RFID reader.
  • the RFID reader 110 is also referred to as an interrogator, and is configured to include a separate data receiving apparatus and a separate data transmitting apparatus. A direction in which data is transmitted from the data transmitting apparatus of the RFID reader to the RFID tag is called an uplink, and a direction in which data is received from the RFID tag to the data receiving apparatus of the RFID reader is called a downlink.
  • the data receiving apparatus of the RFID reader must have improved decoding accuracy in order to stably restore data received from the RFID tag.
  • the data receiving apparatus of the RFID reader uses an additional sampling correction module before decoding is performed.
  • this method produces a delay time depending on sampling correction because decoding is performed after the sampling correction is completed, thereby resulting in the reception apparatus processing slowly.
  • an object of the present invention is to provide a data receiving apparatus and a data receiving method therefor which are capable of increasing the accuracy of decoding and also correcting sampling error without the need to change or use the hardware of a data receiving apparatus in order to increase a sampling frequency.
  • a data receiving apparatus including a reception unit for receiving and demodulating signals; an Analog/Digital (A/D) conversion unit for sampling the signals, demodulated by the reception unit, using a preset sampling frequency, converting the sampled signals into digital signals, and outputting the digital signals; and a signal processing unit for comparing each of the digital signals, received from the A/D conversion unit, with a preset reference value, changing the input digital signal to digital data according to a result of the comparison, and decoding the digital data by comparing the changed digital data with previously defined protocol code; wherein, if, as a result of the comparison, the digital signal is greater than the reference value, the signal processing unit changes the digital signal to digital data which has a positive sign (+) and corresponds to the digital signal, and, if, as a result of the comparison, the digital signal is smaller than the reference value, the signal processing unit changes the digital signal to digital data which has a negative sign (-
  • the reception unit receives and demodulates RFID signals coded using
  • the signal processing unit may include a change module for changing the input digital signal to the digital data, and the change module may change the input digital signal to the digital data by subtracting the reference value from the input digital signal.
  • the data receiving further includes a memory unit for storing data, and the signal processing unit sequentially stores the digital data in the memory unit according to data size corresponding to the protocol code.
  • the signal processing unit includes a decoding module for decoding the stored digital data.
  • the decoding module reads digital data which was stored in the memory unit and corresponds to the data size, calculates a comparison value by comparing the read digital data set having the data size with the protocol code, and detects and co rrects sampling error of the digital data set generated during the sampling of the A/D conversion unit using the calculated comparison value and simultaneously outputs a result of decoding.
  • the decoding module of the signal processing unit may calculate the comparison value by multiplying the read digital data set by the data set of the protocol code in corresponding digit positions and adding values obtained through the multiplication in corresponding digit positions.
  • the decoding module of the signal processing unit may determine whether sampling error has been generated by determining whether the comparison value falls within a preset error range, and, if, as a result of the determination, the sampling error is determined to have occurred, corrects the sampling error using digital data which was stored before or after the digital data set and belongs to the data stored in the memory unit.
  • the decoding module of the signal processing unit may shift the digital data set to the left by one digital data unit and then fill the lowest digit position of the digital data set with digital data which belongs to the data stored in the memory unit and was stored after the digital data set.
  • the decoding module of the signal processing unit may shift the digital data set to the right by one digital data unit and then fill a highest digit position of the digital data set with digital data which belongs to the data stored in the memory unit and was stored before the digital data set.
  • the reception unit receives and demodulates Radio-Frequency IDen- tification (RFID) communication signals using Miller code having a symbol duration M of 4, the sampling frequency is set to a value four times greater than a frequency of the demodulated signals, the A/D conversion unit converts each of the signals demodulated by the reception unit into a 8 -bit digital signal and outputs the converted 8-bit digital signal, and the decoding module of the signal processing unit sets a size of the digital data set to a value 16 times greater than the size of the digital data.
  • RFID Radio-Frequency IDen- tification
  • a data receiving method for a data receiving apparatus including the steps of (a) demodulating received signals; (b) sampling the demodulated signals using a preset sampling frequency, converting the sampled signals into digital signals, and outputting the digital signals; (c) comparing each of the output digital signals with a preset reference value, and if, as a result of the comparison, the output digital signal is greater than the reference value, changing the digital signal to digital data which has a positive sign (+) and corresponds to the digital signal, and if, as a result of the comparison, the output digital signal is smaller than the reference value, changing the digital signal to digital data which has a negative sign (-) and corresponds to the digital signal; (d) sequentially storing the digital data changed at the step (c) according to data size corresponding to previously defined protocol code; and (e) decoding the digital data by comparing the changed digital data with the protocol code.
  • the decoding step (e) includes the steps of (el) reading the stored digital data having the data size, and calculating a comparison value by comparing the read digital data set having the data size with a data set of the protocol code; (e2) determining whether the comparison value calculated at the step (el) falls within an error range corresponding to sampling error generated at the step (b); (e3) if, as a result of the determination at the step (e2), the comparison value is determined to fall within the error range, correcting the sampling error for the digital data set and returning to the step (el); and (e4) if, as a result of the determination at the step (e2), the comparison value is determined not to fall within the error range, outputting a result of decoding corresponding to the digital data set based on the comparison value calculated at the step (el).
  • input digital signals are changed to signals having a positive sign (+) or a negative sign (-) and are then decoded, so that the accuracy of decoding can be improved.
  • the operation of the data receiving apparatus and the receiving method therefor according to the present invention are performed through a simple subtraction operation and are performed while digital signals are being input from the A/D conversion unit, so that performance time can be reduced.
  • decoding is not performed after a sampling correction procedure has been completed, but the sampling correction is performed simultaneously with the decoding process, so that performance time can be reduced.
  • the data receiving apparatus and the receiving method therefor according to the present invention can increase a sampling frequency without changing the hardware design, so that the accuracy of decoding can be improved and the performance time of the overall reception procedure can be reduced at low cost.
  • FIG. 1 is a block diagram of a conventional data receiving apparatus
  • FIG. 2 is a block diagram of a data receiving apparatus according to a first embodiment of the present invention
  • FIG. 3 is a diagram showing the waveforms of Miller codes used in embodiments of the present invention
  • FIG. 4 shows a digital signal obtained through the conversion of an Analog/Digital
  • FIG. 5 shows digital data obtained through the change of a signal processing unit according to the first embodiment of the present invention
  • FIG. 6 is a block diagram of a data receiving apparatus according to a second embodiment of the present invention
  • FIG. 7 is a diagram illustrating a decoding operation according to the second embodiment of the present invention
  • FIG. 8 is a diagram illustrating the correction module of a signal processing unit according to the second embodiment of the present invention
  • FIG. 9 is a flowchart showing the control flow of the signal processing unit according to the second embodiment of the present invention.
  • FIG. 2 is a block diagram of a data receiving apparatus according to a first embodiment of the present invention.
  • the data receiving apparatus 200 according to the first embodiment of the present invention includes a reception unit 210, an A/D conversion unit
  • the reception unit 210 receives and demodulates a communication signal.
  • the A/D conversion unit 220 samples the signal demodulated by the reception unit 210 using a preset sampling frequency, converts the sampled signal into a digital signal, and then outputs the digital signal.
  • the signal processing unit 230 compares the input digital signal, received from the A/D conversion unit 220, with a preset reference value, changes the digital signal to digital data, and decodes the digital data by comparing the digital data with protocol code defined in a protocol.
  • the protocol code used in the embodiments of the present invention is a Miller code having a symbol duration (M) of 4, as shown in FIG. 3.
  • the protocol code is one of the codes used in RFID wireless communication.
  • the Miller code 0 shown in FIG. 3 may be represented by 16 data sets ⁇ +1,+ 1,-1,-1,+1,+1,-1,-1,+1,+ 1,-1,-1,+1,+1,-1,-1 ⁇ , such as MO shown in FIG. 7 (a).
  • the Miller code 1 shown in FIG. 3 may be represented by 16 data sets ⁇ +l,+l,-l,-l,+l,+l,-l,-l,-l,+l,+l,-l,-l,+l,+l,-l,-l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l,+l
  • Modulation 0 FMO
  • Manchester code The method may be selected depending on the purpose of the RFID system.
  • the reception unit 210 may include a reception port 211 for receiving communication signals and a demodulation module 212 for demodulating the communication signals received from the reception port 211. Since the construction of the reception unit 210 is known in the art, it will be described in brief.
  • the reception port 211 may be formed of an antenna or a cable network port for receiving communication signals.
  • the communication signals are defined according to a communication protocol.
  • the reception port 211 is formed of an antenna for receiving communication signals in a pertinent frequency band.
  • the demodulation module 212 restores the original signals (baseband signals) prior to their modulation by demodulating the communication signals received from the reception port 211.
  • the demodulation module 212 may demodulate the received communication signals using a heterodyne system.
  • the demodulated signals are coded baseband signals, such as Miller codes shown in FIG. 3.
  • the symbol duration M may be 2 or 8.
  • the A/D conversion unit 220 converts the signals demodulated by the demodulation module 212 of the reception unit 210 into digital signals. This conversion is performed through sampling and quantization.
  • a sampling frequency used in the sampling is preferably set to at least a frequency two times greater than the frequency of a normal demodulation signal.
  • the frequency of signals actually received and demodulated by the reception unit 210 may be higher or lower than that of a normal demodulation signal due to disturbance, etc. Accordingly, the sampling frequency is set on the basis of the frequency of a normal demodulation signal.
  • the sampling frequency is set to a value four times greater than that of a normal demodulation signal. That is, if the frequency of the normal demodulation signal is 100 kHz, the sampling frequency is set to 400 kHz. In the present embodiment, this sampling and quantization process is known in the art, so that a detailed description thereof is omitted.
  • the A/D conversion unit 220 used in the first embodiment converts the signal demodulated by the demodulation module 212 of the reception unit 210 into 8 -bit digital signals for each sampling.
  • the digital signal converted by the A/D conversion unit 220 may be represented as shown in FIG. 4.
  • FIG. 4 shows a digital signal corresponding to 16th sampling in the form of a decimal numerical value.
  • the 220 may convert a demodulation signal having a '0' value into a digital signal '0' and a demodulation signal having a T value into a digital signal '255'.
  • the signal processing unit 230 compares the digital signal received from the A/D conversion unit 220 with a preset reference value. If, as a result of the comparison, the input digital signal is greater than the reference value, the signal processing unit 230 changes the input digital signal to digital data which has a positive sign (+) and corresponds to the input digital signal. In contrast, if, as a result of the comparison, the input digital signal is smaller than the reference value, the signal processing unit 230 changes the input digital signal to digital data which has a negative sign (-) and corresponds to the input digital signal.
  • the signal processing unit 230 compares the changed digital data with a protocol code defined according to a protocol, and decodes the digital data.
  • decoding may be performed using one of various known methods.
  • the signal processing unit 230 as shown in FIG. 1, may include a change module
  • the change module 231 sets a reference value to '127', and subtracts the reference value '127' from an 8-bit digital signal that is received from the A/D conversion unit 220 and is similar to that shown in FIG. 4.
  • the reference value corresponds to an intermediate value between digital signals '0' and '255' obtained by the A/D conversion unit 220.
  • the reference value may vary depending on the type of protocol code or the form of a digital signal output from the A/D conversion unit 220.
  • the reference value is set such that a digital signal output from the A/D conversion unit 220 has appropriate negative (-) or positive (+) digital data corresponding to the value of the digital signal.
  • the signal processing unit 230 uses the correlation-type decoding method, the result value of a correlation operation for decoding does not become '0'. Accordingly, the inaccuracy in the performance of decoding, which is generated because the result value of a correlation operation for decoding before the performance of the change module 231 becomes '0' can be reduced.
  • the change module 231 of the signal processing unit 230 can perform its operation through a simple subtraction operation. Since this subtraction operation can be performed while a digital signal is received from the A/D conversion unit 220, the delay of performance time is rarely generated.
  • a data receiving apparatus 300 includes, as shown in FIG. 6, a reception unit 310, an A/D conversion unit 320, a memory unit 325, and a signal processing unit 330.
  • the reception unit 310 receives and demodulates a communication signal.
  • the A/D conversion unit 320 samples the demodulation signal demodulated by the reception unit 310 using a preset sampling frequency, converts the sampled signal into a digital signal, and outputs the digital signal.
  • the signal processing unit 330 compares the digital signal received from the A/ D conversion unit 320 with a preset reference value, and changes the digital signal to digital data.
  • the signal processing unit 330 sequentially stores the changed digital data in the memory unit 325 according to data size corresponding to protocol code defined in a protocol.
  • the signal processing unit 330 detects and corrects sampling error, which is generated when the A/D conversion unit 320 performs sampling, while reading and decoding the digital data stored in the memory unit 325.
  • Respective elements of the second embodiment will be described in detail below with reference to FIG. 6.
  • the second embodiment is implemented by adding a function of detecting and correcting sampling error to the decoding process of the first embodiment.
  • the description overlapping that of the first embodiment is omitted here.
  • a Miller code having a symbol duration M of 4 shown in FIG. 3 will be described using an example, as in the first embodiment.
  • the data receiving apparatus 300 of the second embodiment further includes the memory unit 325 for storing data, unlike that of the first embodiment.
  • the memory unit 325 sequentially stores digital data, changed by a change module
  • the size of data is 16 times greater than the size of digital data in accordance with the Miller code having a symbol duration M of 4 in the protocol code. That is, in the case where the size of the digital data is 8 bits, the size of the data is '8 bits x 16', as shown in FIG. 5.
  • the size of the data may vary depending on the protocol code. That is, in the case where a Miller code having a symbol duration M of 2 or 8 is used, when the size of digital data is 8 bits, the size of data is '8 bits x 8' or '8 bits x 32'.
  • the signal processing unit 330 may be divided into the change module 331, a storage module 332, and a decoding module 333, as shown in FIG. 6.
  • the change module 331 compares the digital signal obtained by the A/D conversion unit 320 with a preset reference value. If, as a result of the comparison, the digital signal is greater than the reference value, the change module 331 changes the digital signal to digital data having a positive sign (+). If, as a result of the comparison, the digital signal is smaller than the reference value, the change module 331 changes the digital signal to digital data having a negative sign (-). Since the detailed description thereof has been given in connection with the first embodiment, it is omitted here. That is, the changed digital data is the same as shown in FIG. 5.
  • the storage module 332 sequentially stores the digital data, changed by the change module 331, in the memory unit 325 according to the data size corresponding to the protocol code defined in the protocol.
  • the digital data is sequentially stored in the memory unit 325 from the left side in a fashion similar to that shown in FIG. 5.
  • the leftmost side of FIG. 5 corresponds to the position of the most significant digital data
  • the rightmost side of FIG. 5 corresponds to the position of the least significant digital data.
  • the decoding module 333 reads the digital data which was stored in the memory unit
  • the decoding module 333 will be described in detail below with reference to FIG. 7.
  • the decoding module 333 multiplies the digital data set read from the memory unit 325 by the data set MO corresponding to the Miller code 0 in corresponding digit positions and adds the values multiplied in corresponding digit positions, thereby calculating a comparison value. As shown in FIG. 7(b), a comparison value is then calculated using the read digital data set and the data set Ml corresponding to the Miller code 1. In the case where as shown in FIG. 7, the comparison value corresponding to the Miller code 0 is '2040' and the comparison value corresponding to the Miller code 1 is '0', the decoding module 333 outputs decoding result '0' corresponding to the read digital data set according to the correlation-type decoding method.
  • the decoding module 333 may include a comparison value calculation module 333a for reading the digital data which was stored in the memory unit 325 and has a size corresponding to the protocol code, and calculating a comparison value by comparing the read digital data set with the data set corresponding to the protocol code.
  • the error detection module 333b determines whether sampling error has occurred in the A/D conversion unit 320 based on the calculated comparison value. If, as a result of the determination in the error detection module 333b, sampling error is determined to have occurred, the correction module 333c corrects the sampling error. If, as a result of the determination in the error detection module 333b, sampling error is determined not to have occurred, the result output module 333d outputs the decoding result of the read digital data set based on the calculated comparison value.
  • the comparison value calculation module 333a reads the digital data which was stored in the storage module 332 and has a size corresponding to a protocol code, and calculates a comparison value by comparing the read digital data set with the data set corresponding to the protocol code.
  • FIG. 8(a) shows the waveform of the Miller code 0, which is a protocol code and has a symbol duration M of 4, and FIGS. 8(b) and 8(c) show the waveforms of digital data sets read from the memory unit 325.
  • the waveform of FIG. 8(b) lags behind the waveform of FIG. 8 (a) in phase by 45°
  • the waveform of FIG. 8(c) leads the waveform of FIG. 8 (a) in phase by 45°.
  • the waveform shown in FIG. 8(d) is the results of multiplication of the values of FIGS. 8 (a) and 8(b) in corresponding digit positions, and the value of addition of the results obtained through the multiplication in corresponding digit positions corresponds to the comparison value calculated in the comparison value calculation module 333a.
  • the calculated comparison value is '+135'.
  • FIG. 8(e) shows the results of multiplication of the values of FIGS. 8 (a) and 8(c) in corresponding digit positions, and a comparison value corresponding to the value of addition of the multiplication results is '+135' in the same manner as described above.
  • the error detection module 333b determines that sampling error exists in the A/D conversion unit 320 and instructs the correction module 333b to perform its operation.
  • the error range may be set depending on the type of a protocol code, the size of digital data and the size of a digital data set. In a condition, such as that shown in FIG. 7, the error range may be set to a range from '-520' to '+520'.
  • the error detection module 333b determines that the comparison value falls within the set error range, thereby determining that sampling error exists. If the error detection module 333b has determined that there is sampling error, the correction module 333c performs its operation.
  • the correction module 333c corrects the sampling error of the digital data set using digital data stored in the memory unit 325 before or after the digital data set.
  • the correction module 333c will be described in greater detail with reference to the frequency of the signal demodulated in the reception unit 310.
  • the correction module 333c shifts the read digital data set to the left by one digital data unit and then fills the lowest digit position of the digital data set with digital data which belongs to the data stored in the memory unit 325 and was stored after the digital data set.
  • the correction module 333c shifts the read digital data set to the right by one digital data unit and then fills the highest digit position of the digital data set with digital data which belongs to the data stored in the memory unit 325 and was stored before the digital data set.
  • correction module 333c will be described using an example with reference to FIG. 8.
  • FIG. 8(a) shows the waveform of Miller code 0, which is a protocol code and has a symbol duration M of 4
  • FIGS. 8(b) and 8(c) show the waveforms of digital data sets read from the memory unit 325.
  • the waveform of FIG. 8(b) lags behind that of FIG. 8 (a) in phase by 45
  • the waveform of FIG. 8(c) leads that of FIG. 8 (a) in phase by 45.
  • the phases of digital data sets such as those shown in FIGS. 8(b) and 8(c), need correction.
  • the correction module 333c shifts the read digital data set (refers to the waveform of FIG. 8(b)) to the left by one byte, deletes a digital data value in the highest digit position, empties the lowest digit position, and fills the emptied lowest digit position with digital data which was stored in the memory unit 325 after the read digital data set. Accordingly, sampling correction is performed. This approximately corresponds to the case where the waveform of FIG. 8(b) is made to coincide with the waveform of FIG. 8 (a) by shifting the waveform of FIG. 8(b) to the left.
  • the correction module 333c shifts the read digital data set (refer to the waveform of FIG. 8(c)) to the right by one byte, deletes a digital data value in the lowest digit position, empties the highest digit position, and fills the emptied highest digital position with digital data which was stored in the memory unit 325 before the read digital data set. Accordingly, sampling correction is performed. This approximately corresponds to the case where the waveform of FIG. 8(c) is made to coincide with the waveform of FIG. 8 (a) by shifting the waveform of FIG. 8(c) to the right.
  • the operation of the correction module 333c can be performed within the decoding process because it is performed while the read digital data is compared with the protocol code. Furthermore, since decoding can be immediately performed when sampling correction is not necessary, the time delay, which is generated because a sampling correction process must be performed before a decoding process as in the conventional data receiving apparatus, is not generated.
  • the signal processing unit 330 first controls the reception unit 310 so that the reception unit 310 receives and demodulates the communication signals at step S310. Thereafter, the signal processing unit 330 controls the A/D conversion unit 320 so that the A/D conversion unit 320 samples the signals, demodulated at step S310, using a preset sampling frequency, converts the sampled signal into a digital signal, and outputs the digital signal at step S320.
  • the signal processing unit 330 compares the digital signal output at S320 with a preset reference value. If the digital signal is greater than the reference value, the signal processing unit 330 changes the output digital signal to digital data which has a positive sign (+) and corresponds to the output digital signal. In contrast, if the digital signal is smaller than the reference value, the signal processing unit 330 changes the output digital signal to digital data which has a negative sign (-) and corresponds to the output digital signal at step S330.
  • the step S330 is performed by subtracting '127' from a value corresponding to the result of sampling of the digital signal. The changed digital data corresponds to that shown in FIG. 5.
  • the signal processing unit 330 sequentially stores the digital data changed at step S330 in the memory unit 325 according to the data size corresponding to the protocol code defined in the communication protocol at step S340.
  • the signal processing unit 330 reads the digital data which was stored at step S340 and has the data size, compares the digital data set with the data set of the protocol code, and performs decoding based on the result of the comparison at step S350. In this case, sampling error generated during the step S320 can be detected and corrected during the performance of decoding at step S350.
  • the step S350 refers to the decoding step of the signal processing unit 330 according to the second embodiment, and may include four steps as shown in FIG. 9(b).
  • the signal processing unit 330 reads the digital data which was stored at step
  • the comparison value is calculated by multiplying the read digital data set by the data set of the protocol code in corresponding digit positions and then adding the results of the multiplication. That is, the results of multiplication of the sets of FIGS. 8 (a) and 8(b) in corresponding digit positions correspond to those shown in FIG. 8(d), and the comparison value is '+135'. The results of multiplication of the sets of FIGS. 8 (a) and 8(c) in corresponding digit positions correspond to those shown in FIG. 8(e), and the sampling error value corresponds to '+135'.
  • the signal processing unit 330 determines whether the comparison value calculated at step S351 falls within an error range corresponding to the sampling error at step S352.
  • the signal processing unit 330 corrects the sampling error for the digital data set and proceeds to the step S351, at step S353.
  • the signal processing unit 330 corrects the sampling error for the read digital data using digital data stored before or after the read digital data set.
  • step S353 may vary depending on the frequency of the signal demodulated at step S310.
  • step S350 may be performed in such a manner that the waveform of FIG. 8(b) is made to coincide with the waveform of FIG. 8 (a) by shifting the waveform of FIG. 8(b) to the left.
  • step S350 may be performed in such a manner that the waveform of FIG. 8(c) is made to coincide with the waveform of FIG. 8 (a) by shifting the waveform of FIG. 8(c) to the right.
  • the signal processing unit 330 outputs the result of the decoding using the comparison value calculated at step S350, at step S354.
  • the signal processing unit 330 can perform sampling error, generated in the A/D conversion unit 320, during a decoding process and can also immediately perform decoding without performing a sampling correction procedure when sampling correction is not necessary. Accordingly, the time delay, which is generated because the sampling correction procedure is inevitably performed before the decoding procedure as in a conventional data receiving apparatus, is not generated.
  • the data receiving apparatus can be used in the data receiving apparatus (RFID reader) of an RFID system in which the problem of in- consistency in phase and synchronization frequently occurs due to distance, reflection, etc. because the data receiving apparatus is based on wireless communication.

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Abstract

La présente invention concerne un appareil de réception de données et un procédé de réception de données correspondant. L'appareil de réception de données comporte une unité de réception, une unité de conversion analogique/numérique, et une unité de traitement de signaux. L'unité de réception reçoit et démodule des signaux. L'unité de conversion analogique/numérique prélève, convertit numériquement et émet en sortie les signaux. L'unité de traitement de signaux compare chaque signal numérique avec une valeur de référence prédéterminée, transforme le signal numérique d'entrée en signal de données selon un résultat de comparaison, et décode les données numériques en comparant les données numériques transformées avec un code de protocole défini précédemment. Si le signal numérique est supérieur à la valeur de référence, l'unité de traitement de signaux transforme le signal numérique en données numériques correspondantes ayant un signe positif (+). Par contre, si le signal numérique est inférieur à la valeur de référence, l'unité de traitement de signaux transforme le signal numérique en données numériques correspondantes ayant un signe négatif (-).
PCT/KR2008/007772 2008-01-24 2008-12-30 Appareil de réception de données et son procédé de réception WO2009093815A1 (fr)

Applications Claiming Priority (2)

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KR1020080007682A KR100940830B1 (ko) 2008-01-24 2008-01-24 데이터수신장치와 이의 수신방법
KR10-2008-0007682 2008-01-24

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KR101772475B1 (ko) 2015-11-23 2017-08-29 엔비노드 주식회사 광대역 ｒｆ 신호 디지털 저장 장치 및 방법

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7049964B2 (en) * 2004-08-10 2006-05-23 Impinj, Inc. RFID readers and tags transmitting and receiving waveform segment with ending-triggering transition
US20060186995A1 (en) * 2005-02-22 2006-08-24 Jiangfeng Wu Multi-protocol radio frequency identification reader tranceiver
US20070025475A1 (en) * 2005-07-28 2007-02-01 Symbol Technologies, Inc. Method and apparatus for data signal processing in wireless RFID systems
KR20070056816A (ko) * 2005-11-30 2007-06-04 주식회사 유컴테크놀러지 무선주파수인식 시스템

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7049964B2 (en) * 2004-08-10 2006-05-23 Impinj, Inc. RFID readers and tags transmitting and receiving waveform segment with ending-triggering transition
US20060186995A1 (en) * 2005-02-22 2006-08-24 Jiangfeng Wu Multi-protocol radio frequency identification reader tranceiver
US20070025475A1 (en) * 2005-07-28 2007-02-01 Symbol Technologies, Inc. Method and apparatus for data signal processing in wireless RFID systems
KR20070056816A (ko) * 2005-11-30 2007-06-04 주식회사 유컴테크놀러지 무선주파수인식 시스템

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KR100940830B1 (ko) 2010-02-04

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