CN108449742B - Auxiliary demodulation system and method for near field communication - Google Patents
Auxiliary demodulation system and method for near field communication Download PDFInfo
- Publication number
- CN108449742B CN108449742B CN201810205454.0A CN201810205454A CN108449742B CN 108449742 B CN108449742 B CN 108449742B CN 201810205454 A CN201810205454 A CN 201810205454A CN 108449742 B CN108449742 B CN 108449742B
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- auxiliary
- module
- near field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/80—Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/14—Demodulator circuits; Receiver circuits
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Near-Field Transmission Systems (AREA)
Abstract
The invention provides an auxiliary demodulation system and method of near field communication, a frequency meter and an auxiliary signal generating module are arranged in the system; extracting a frequency value of a carrier of a data signal through a frequency meter, and sending the frequency value of the carrier to an auxiliary signal generation module, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of the near field communication equipment is larger than a first preset value; generating an auxiliary signal with the same frequency as the carrier wave through an auxiliary signal generating module, and sending the auxiliary signal to a demodulation module of the near field communication equipment so that the demodulation module demodulates the communication signal according to the auxiliary signal; therefore, during one-time interaction between the near field communication devices, the demodulation module of the near field communication device can continuously receive the signal with the same frequency as the carrier wave and demodulate according to the signal, thereby avoiding the situation that the carrier wave needs to be repeatedly extracted for many times due to the discontinuity of the communication signal in the current demodulation process and ensuring the integrity of data transmission.
Description
Technical Field
The present invention relates to the field of communications technologies, and in particular, to an auxiliary demodulation system and method for near field communication.
Background
Near Field Communication (NFC), also known as short-range wireless Communication, allows electronic devices to perform contactless point-to-point data transmission with each other. The NFC equipment comprises a reader (PCD) and a proximity card (PICC), wherein the reader can continuously transmit sine wave signals (electromagnetic waves) all the time, and when the proximity card is in a signal interference range, the proximity card acquires energy in a coupling mode and feeds back different signals (electromagnetic waves) to the reader. After confirming the proximity card in the proximity field, the reader encodes and modulates data to be transmitted onto a high-frequency carrier wave and transmits the data to the outside through a radio frequency antenna, the proximity card receives a signal sent by the reader through inductive coupling of the radio frequency antenna, the signal is demodulated to obtain a command, then the information of the proximity card is encoded and modulated according to the command and then fed back to the reader, and the reader decodes the information fed back by the proximity card.
The reader and the proximity card realize information interaction through an ISO/IEC 14443 protocol, the protocol specifies that the carrier frequency of a radio-frequency signal on a radio-frequency antenna is 12.56MHz to 14.56MHz, the reader or the proximity card can demodulate the signal only by utilizing the carrier signal, and the carrier frequency of the radio-frequency signal on the radio-frequency antenna is a range value, so the reader or the proximity card needs to extract the carrier before demodulating the received signal and then demodulate the signal according to the carrier.
However, since the proximity card is coupled to obtain energy and then feed back a signal, a situation that there is no electromagnetic field may occur during one interaction between the reader and the proximity card, and the communication signal is discontinuous.
Disclosure of Invention
To overcome or at least partially solve the above problems, the present invention provides a system and method for assisted demodulation of near field communication.
According to an aspect of the present invention, there is provided an auxiliary demodulation system for near field communication, comprising: a frequency meter and an auxiliary signal generation module; the frequency meter is connected with the auxiliary signal generating module; the frequency meter is used for extracting the frequency value of the carrier of the data signal and sending the frequency value of the carrier to the auxiliary signal generation module, and the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of the near field communication equipment is larger than a first preset value; and the auxiliary signal generating module is used for generating an auxiliary signal with the same frequency as the carrier wave and sending the auxiliary signal to the demodulating module of the near field communication equipment so that the demodulating module demodulates the communication signal according to the auxiliary signal.
Wherein, this system still includes: a signal detection module; the signal detection module is connected with the auxiliary signal generation module; the signal detection module is used for detecting the signal amplitude of the communication signal and sending a transmission instruction to the auxiliary signal generation module when the signal amplitude of the communication signal is determined to be smaller than a second preset value; correspondingly, the auxiliary signal generating module is configured to send the auxiliary signal to the demodulation module of the near field communication device after receiving the transmission instruction.
The auxiliary signal generation module comprises a crystal oscillator and a clock frequency multiplication/division circuit; a crystal oscillator for generating a pulse signal of a fixed frequency; and the clock frequency doubling/dividing circuit is used for converting the pulse signal with the fixed frequency into the pulse signal with the same frequency as the carrier wave.
The auxiliary signal generation module also comprises a waveform conversion circuit; and the waveform conversion circuit is used for converting the pulse signal with the same frequency as the carrier wave into a signal with a preset waveform with the same frequency as the carrier wave.
Wherein, this system still includes: a reset module; the reset module is connected with the frequency meter and the auxiliary signal generation module; and the reset module is used for generating a reset signal and resetting the working state of the frequency meter or the auxiliary signal generation module through the reset signal.
Wherein, this system still includes: an operational amplifier circuit; the operational amplifier circuit is connected with the frequency meter; and the operational amplifier circuit is used for adjusting the signal amplitude of the data signal to be below a third preset value.
Wherein, this system still includes: an AND gate circuit; the AND gate circuit is connected with the frequency meter; and the AND gate circuit is used for converting the waveform of the data signal into a square wave.
In another aspect of the present invention, an auxiliary demodulation method for near field communication is provided, including: extracting a frequency value of a carrier wave of a data signal, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of the near field communication equipment is larger than a first preset value; generating an auxiliary signal with the same frequency as the carrier according to the frequency value of the carrier; and sending the auxiliary signal to a demodulation module of the near field communication equipment so that the demodulation module demodulates the communication signal according to the auxiliary signal.
Wherein, after generating the auxiliary signal with the same frequency as the carrier according to the frequency value of the carrier, the method further comprises: detecting the signal amplitude of the communication signal, and judging whether the signal amplitude of the communication signal is smaller than a second preset value; accordingly, the transmission of the auxiliary signal to the demodulation module of the near field communication device comprises: and after determining that the signal amplitude of the communication signal is smaller than the second preset value, sending the auxiliary signal to a demodulation module of the near field communication equipment.
The invention provides an auxiliary demodulation system and method for near field communication, wherein a frequency meter and an auxiliary signal generation module are arranged in the system; extracting a frequency value of a carrier of a data signal through a frequency meter, and sending the frequency value of the carrier to an auxiliary signal generation module, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of the near field communication equipment is larger than a first preset value; generating an auxiliary signal with the same frequency as the carrier wave through an auxiliary signal generating module, and sending the auxiliary signal to a demodulation module of the near field communication equipment so that the demodulation module demodulates the communication signal according to the auxiliary signal; therefore, during one-time interaction between the near field communication devices, the demodulation module of the near field communication device can continuously receive the signal with the same frequency as the carrier wave and demodulate according to the signal, thereby avoiding the situation that the carrier wave needs to be repeatedly extracted for many times due to the discontinuity of the communication signal in the current demodulation process and ensuring the integrity of data transmission.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is a schematic diagram of an auxiliary demodulation system for near field communication according to an embodiment of the present invention;
fig. 2 is a flowchart of an auxiliary demodulation method for near field communication according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In one embodiment of the present invention, referring to fig. 1, there is provided an auxiliary demodulation system for near field communication, including: a frequency meter 11 and an auxiliary signal generation module 12; the frequency meter 11 is connected with an auxiliary signal generating module 12; the frequency meter 11 is configured to extract a frequency value of a carrier of a data signal, and send the frequency value of the carrier to the auxiliary signal generation module 12, where the data signal is a communication signal whose signal amplitude received by a radio frequency antenna of the near field communication device is greater than a first preset value; and the auxiliary signal generating module 12 is configured to generate an auxiliary signal having the same frequency as the carrier, and send the auxiliary signal to a demodulation module of the near field communication device, so that the demodulation module demodulates the communication signal according to the auxiliary signal.
Specifically, the proximity card acquires energy in a coupling manner and feeds back a signal, which causes the situation that no electromagnetic field exists during one interaction between the reader and the proximity card, the communication signal is intermittently transmitted and received, a demodulation module of the near field communication device needs to extract a carrier wave according to the communication signal when demodulating the communication signal, the demodulation module cannot continuously extract the carrier wave during the intermittent period of the communication signal, and the carrier wave needs to be extracted again after the communication signal reappears, which may cause incomplete data transmission. The present embodiment provides an auxiliary demodulation system, which includes a frequency meter 11, which is also called a frequency counter, and is an electronic measurement instrument specially used for measuring the frequency of a measured signal. In the embodiment, a communication signal received by a radio frequency antenna of near field communication equipment is taken as a detected signal, and a carrier wave of the communication signal is extracted; since the communication signal is intermittently received, when the frequency meter 11 extracts the frequency value of the carrier of the communication signal, there is a certain requirement for the intensity of the communication signal, that is, the communication signal whose signal amplitude is greater than the first preset value.
After extracting the frequency value of the carrier of the communication signal, the frequency meter 11 sends the frequency value to the auxiliary signal generation module 12 of the auxiliary demodulation system, the auxiliary signal generation module 12 continuously generates an auxiliary signal having the same frequency as the carrier, and continuously sends the auxiliary signal to the demodulation module of the near field communication device during the interaction between the near field communication devices, and the demodulation module demodulates the communication signal according to the auxiliary signal. Although the auxiliary signal generated by the auxiliary signal generating module 12 may not coincide with the phase of the carrier in the communication signal, it is insensitive to the phase of the signal during demodulation and does not affect the result of demodulation.
The auxiliary demodulation system of the embodiment can be arranged at the reader end, can also be arranged on a proximity card, and can achieve the auxiliary demodulation function.
In the embodiment, a frequency value of a carrier of a data signal is extracted through a frequency meter, and the frequency value of the carrier is sent to an auxiliary signal generation module, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of near field communication equipment is greater than a first preset value; generating an auxiliary signal with the same frequency as the carrier wave through an auxiliary signal generating module, and sending the auxiliary signal to a demodulation module of the near field communication equipment so that the demodulation module demodulates the communication signal according to the auxiliary signal; therefore, during one-time interaction between the near field communication devices, the demodulation module of the near field communication device can continuously receive the signal with the same frequency as the carrier wave and demodulate according to the signal, thereby avoiding the situation that the carrier wave needs to be repeatedly extracted for many times due to the discontinuity of the communication signal in the current demodulation process and ensuring the integrity of data transmission.
Based on the above embodiment, the system further includes: a signal detection module; the signal detection module is connected with the auxiliary signal generation module; the signal detection module is used for detecting the signal amplitude of the communication signal and sending a transmission instruction to the auxiliary signal generation module when the signal amplitude of the communication signal is determined to be smaller than a second preset value; correspondingly, the auxiliary signal generating module is configured to send the auxiliary signal to the demodulation module of the near field communication device after receiving the transmission instruction.
Specifically, the demodulation module extracts the carrier of the communication signal, the intensity of the communication signal is required to meet a certain condition, and the carrier cannot be extracted and demodulated if the intensity of the communication signal is too small; the present embodiment uses the intensity of the communication signal as a condition for sending the auxiliary signal to the demodulation module, and when the communication signal is continuous in one interaction, the auxiliary signal does not need to be sent, so as to save energy consumption. The embodiment provides a signal detection module, configured to detect a signal amplitude of a communication signal, and instruct an auxiliary signal generation module to send the auxiliary signal to a demodulation module when it is determined that the signal amplitude of the communication signal is smaller than a second preset value.
Based on the above embodiment, the auxiliary signal generation module includes a crystal oscillator and a clock frequency multiplication/division circuit; a crystal oscillator for generating a pulse signal of a fixed frequency; and the clock frequency doubling/dividing circuit is used for converting the pulse signal with the fixed frequency into the pulse signal with the same frequency as the carrier wave.
Specifically, a crystal oscillator is an oscillation circuit formed by cutting a thin piece (simply referred to as a wafer) from a quartz crystal at a certain azimuth angle and packaging the cut piece, and adding an integrated circuit inside the package. The crystal oscillator can generate a pulse signal with stable frequency, for example, an on-board crystal oscillator of an FPGA belongs to the crystal oscillator, and the frequency of the on-board crystal oscillator is 100 MHz. In this embodiment, the auxiliary signal generating module includes, in addition to the crystal oscillator, a clock frequency doubling/dividing circuit that can double and reduce the frequency of the input signal and output the signal, and the clock frequency doubling/dividing circuit can adjust the fixed-frequency pulse signal generated by the crystal oscillator to a pulse signal having the same frequency as the carrier wave to generate the auxiliary signal.
Based on the above embodiment, the auxiliary signal generating module further includes a waveform converting circuit; and the waveform conversion circuit is used for converting the pulse signal with the same frequency as the carrier wave into a signal with a preset waveform with the same frequency as the carrier wave.
In particular, when the auxiliary signal generated by modulation only by the crystal oscillator and the clock frequency doubling/dividing circuit is used for demodulation, the effect may not be the best, and in the present embodiment, a waveform converting circuit is further provided in the auxiliary signal generating module, and converts the waveform of the signal generated by modulation by the crystal oscillator and the clock frequency doubling/dividing circuit into a waveform more suitable for demodulation, such as a square wave.
Based on the above embodiment, the system further includes: a reset module; the reset module is connected with the frequency meter and the auxiliary signal generation module; and the reset module is used for generating a reset signal and resetting the working state of the frequency meter or the auxiliary signal generation module through the reset signal.
Specifically, the frequency meter or the auxiliary signal generation module may have a condition that an operating state needs to be reset in a communication process, and needs to be reset after the communication is completed.
Based on the above embodiment, the system further includes: an operational amplifier circuit; the operational amplifier circuit is connected with the frequency meter; and the operational amplifier circuit is used for adjusting the signal amplitude of the data signal to be below a third preset value.
Specifically, in order to avoid that the power of the communication signal is too large, which may cause the frequency meter to fail to work normally or even damage the frequency meter, the present embodiment provides an operational amplifier circuit in the auxiliary demodulation system, which adjusts the amplitude of the communication signal below a third preset value (e.g., 5V).
Based on the above embodiment, the system further includes: an AND gate circuit; the AND gate circuit is connected with the frequency meter; and the AND gate circuit is used for converting the waveform of the data signal into a square wave.
Specifically, the and gate circuit provided in the auxiliary demodulation system of this embodiment converts the waveform of the communication signal into a square wave, so that the communication signal can be processed by a digital signal after entering the frequency meter, thereby improving the statistical accuracy of the frequency meter on the number of cycles of the measured signal in a specific time period.
As another embodiment of the present invention, referring to fig. 2, there is provided an auxiliary demodulation method for near field communication, including: s21, extracting the frequency value of the carrier wave of the data signal, wherein the data signal is a communication signal of which the signal amplitude received by the radio frequency antenna of the near field communication equipment is larger than a first preset value; s22, generating an auxiliary signal with the same frequency as the carrier wave according to the frequency value of the carrier wave; s23, sending the auxiliary signal to a demodulation module of the near field communication device, so that the demodulation module demodulates the communication signal according to the auxiliary signal.
Specifically, a frequency value of a carrier of the data signal is extracted; because the communication signal is received discontinuously, when the frequency of the carrier wave of the communication signal is extracted, certain requirements are required on the intensity of the communication signal, namely the communication signal with the signal amplitude larger than the first preset value is used as the data signal.
After the frequency value of the carrier of the data signal is extracted, an auxiliary signal with the same frequency as the carrier is continuously generated according to the frequency value of the carrier, the auxiliary signal is continuously sent to a demodulation module of the near field communication equipment during the interaction period between the near field communication equipment, and the demodulation module demodulates the communication signal according to the auxiliary signal.
In the embodiment, an auxiliary signal having the same frequency as the carrier wave is generated by extracting the frequency value of the carrier wave of the data signal and according to the frequency value of the carrier wave; sending the auxiliary signal to a demodulation module of the near field communication device, so that the demodulation module demodulates the communication signal according to the auxiliary signal; therefore, during one-time interaction between the near field communication devices, the demodulation module of the near field communication device can continuously receive the signal with the same frequency as the carrier wave and demodulate according to the signal, thereby avoiding the situation that the carrier wave needs to be repeatedly extracted for many times due to the discontinuity of the communication signal in the current demodulation process and ensuring the integrity of data transmission.
Based on the above embodiment, after generating the auxiliary signal having the same frequency as the carrier according to the frequency value of the carrier, the method further includes: detecting the signal amplitude of the communication signal, and judging whether the signal amplitude of the communication signal is smaller than a second preset value; accordingly, the transmission of the auxiliary signal to the demodulation module of the near field communication device comprises: and after determining that the signal amplitude of the communication signal is smaller than the second preset value, sending the auxiliary signal to a demodulation module of the near field communication equipment.
Specifically, the present embodiment uses the intensity of the communication signal as a condition for sending the auxiliary signal to the demodulation module, and when the communication signal is continuous in one interaction, the auxiliary signal does not need to be sent, so as to save energy consumption, and the auxiliary signal is sent only under the condition that the communication signal is interrupted; that is, the signal amplitude of the communication signal is detected, and when the signal amplitude of the communication signal is determined to be smaller than the second preset value, the auxiliary signal is sent to the demodulation module.
Finally, the description is as follows: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. An assisted demodulation system for near field communication, comprising: a frequency meter and an auxiliary signal generation module;
the frequency meter is connected with the auxiliary signal generation module;
the frequency meter is used for extracting a frequency value of a carrier of a data signal and sending the frequency value of the carrier to the auxiliary signal generation module, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of the near field communication equipment is larger than a first preset value;
the auxiliary signal generation module is configured to generate an auxiliary signal having the same frequency as the carrier, and send the auxiliary signal to a demodulation module of the near field communication device, so that the demodulation module demodulates the communication signal according to the auxiliary signal;
the auxiliary signal generation module comprises a crystal oscillator and a clock frequency multiplication/division circuit;
the crystal oscillator is used for generating a pulse signal with a fixed frequency;
and the clock frequency doubling/dividing circuit is used for converting the pulse signal with fixed frequency into the pulse signal with the same frequency as the carrier wave.
2. The system of claim 1, further comprising: a signal detection module;
the signal detection module is connected with the auxiliary signal generation module;
the signal detection module is used for detecting the signal amplitude of the communication signal and sending a transmission instruction to the auxiliary signal generation module when the signal amplitude of the communication signal is determined to be smaller than a second preset value;
correspondingly, the auxiliary signal generating module is configured to send the auxiliary signal to the demodulation module of the near field communication device after receiving the transmission instruction.
3. The system of claim 1, wherein the auxiliary signal generation module further comprises a waveform transformation circuit;
the waveform conversion circuit is used for converting the pulse signal with the same frequency as the carrier wave into a signal with a preset waveform with the same frequency as the carrier wave.
4. The system of claim 1, further comprising: a reset module;
the reset module is connected with the frequency meter and the auxiliary signal generation module;
the reset module is used for generating a reset signal and resetting the working state of the frequency meter or the auxiliary signal generation module through the reset signal.
5. The system of claim 1, further comprising: an operational amplifier circuit;
the operational amplifier circuit is connected with the frequency meter;
the operational amplifier circuit is used for adjusting the signal amplitude of the data signal to be below a third preset value.
6. The system of claim 1, further comprising: an AND gate circuit;
the AND gate circuit is connected with the frequency meter;
and the AND gate circuit is used for converting the waveform of the data signal into a square wave.
7. A method for assisted demodulation for near field communication, comprising:
extracting a frequency value of a carrier wave of a data signal by using a frequency meter, and sending the frequency value of the carrier wave to an auxiliary signal generation module, wherein the data signal is a communication signal of which the signal amplitude received by a radio frequency antenna of near field communication equipment is larger than a first preset value;
generating a pulse signal with a fixed frequency by using a crystal oscillator in the auxiliary signal generation module, and converting the pulse signal with the fixed frequency into an auxiliary signal with the same frequency as the carrier by using a clock frequency doubling/dividing circuit in the auxiliary signal generation module; and sending the auxiliary signal to a demodulation module of the near field communication device for the demodulation module to demodulate the communication signal according to the auxiliary signal.
8. The method of claim 7, wherein after converting the fixed frequency pulse signal into the auxiliary signal having the same frequency as the carrier, further comprising: detecting the signal amplitude of the communication signal, and judging whether the signal amplitude of the communication signal is smaller than a second preset value;
accordingly, the sending the auxiliary signal to the demodulation module of the near field communication device comprises: and after the signal amplitude of the communication signal is determined to be smaller than a second preset value, the auxiliary signal is sent to a demodulation module of the near field communication equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810205454.0A CN108449742B (en) | 2018-03-13 | 2018-03-13 | Auxiliary demodulation system and method for near field communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810205454.0A CN108449742B (en) | 2018-03-13 | 2018-03-13 | Auxiliary demodulation system and method for near field communication |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108449742A CN108449742A (en) | 2018-08-24 |
| CN108449742B true CN108449742B (en) | 2020-05-19 |
Family
ID=63194949
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810205454.0A Active CN108449742B (en) | 2018-03-13 | 2018-03-13 | Auxiliary demodulation system and method for near field communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108449742B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113115296B (en) * | 2021-04-25 | 2022-10-18 | Oppo广东移动通信有限公司 | Near field communication method and related device |
| CN115333579B (en) * | 2021-05-11 | 2024-01-23 | 意法半导体(鲁塞)公司 | Near field communication device |
| CN116366077B (en) * | 2023-06-02 | 2023-07-28 | 北京安天网络安全技术有限公司 | Control method, device, equipment and medium of software defined radio equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102739590A (en) * | 2011-04-14 | 2012-10-17 | 苏州东奇信息科技有限公司 | CP-EBPSK communication system for pseudorandom sequence phase modulation and communication method thereof |
| CN104883249A (en) * | 2015-06-16 | 2015-09-02 | 桂林电子科技大学 | Time synchronization relay system and method based on wireless communication |
| CN106992818A (en) * | 2017-06-05 | 2017-07-28 | 吉林大学 | A kind of phase generated carrier demodulation device and method program control based on phase |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6018046A (en) * | 1983-07-12 | 1985-01-30 | Clarion Co Ltd | Psk demodulator |
| JP2948479B2 (en) * | 1994-07-15 | 1999-09-13 | エヌ・ティ・ティ移動通信網株式会社 | Mobile radio |
| DE69839396T2 (en) * | 1997-06-13 | 2009-05-07 | Kabushiki Kaisha Kenwood | CIRCUIT FOR RECOVERY TIMING |
| CN101344933A (en) * | 2008-09-04 | 2009-01-14 | 复旦大学 | Active radio frequency identification tag |
| CN101369319A (en) * | 2008-10-14 | 2009-02-18 | 复旦大学 | Active radio frequency identification tag |
| CN201328110Y (en) * | 2008-11-10 | 2009-10-14 | 石强 | Phase-locking frequency tracking device |
| CN101420399B (en) * | 2008-12-12 | 2011-09-07 | 中国电子科技集团公司第七研究所 | Receiver, BPSK demodulation circuit and BPSK demodulation method |
-
2018
- 2018-03-13 CN CN201810205454.0A patent/CN108449742B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102739590A (en) * | 2011-04-14 | 2012-10-17 | 苏州东奇信息科技有限公司 | CP-EBPSK communication system for pseudorandom sequence phase modulation and communication method thereof |
| CN104883249A (en) * | 2015-06-16 | 2015-09-02 | 桂林电子科技大学 | Time synchronization relay system and method based on wireless communication |
| CN106992818A (en) * | 2017-06-05 | 2017-07-28 | 吉林大学 | A kind of phase generated carrier demodulation device and method program control based on phase |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108449742A (en) | 2018-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108449742B (en) | Auxiliary demodulation system and method for near field communication | |
| US8914061B2 (en) | Contactless integrated circuit having NFC and UHF operating modes | |
| EP2267646B1 (en) | Signal enhancer chip for radio frequency identification system and signal enhancer | |
| JP2008061218A (en) | Semiconductor integrated circuit device and receiving device | |
| US20050168324A1 (en) | Method and circuit arrangement for wireless data transmission | |
| US8971802B2 (en) | Near field communication apparatus | |
| US9686041B2 (en) | End of communication detection | |
| JP2008122255A (en) | Distance measuring device | |
| CN102306266B (en) | Simulator for radio frequency identification | |
| US8923383B2 (en) | Transmitter and transmitting method using delay locked loop | |
| RU2565527C1 (en) | Method of transmitting data through air gap and device therefor | |
| US20230385594A1 (en) | System for pairing an item of data of a uwb transmitter device and a tag comprising a graphic code | |
| RU2517372C2 (en) | Multi-frequency label and method and system for dynamic adjustment of radiofrequency parameters of multi-frequency label | |
| KR100836469B1 (en) | Rfid reader and rfid system | |
| US7760073B2 (en) | RFID tag modification for full depth backscatter modulation | |
| FI116650B (en) | Procedure for improving the power of a remote identifier | |
| CN113255388B (en) | Card reader and card reading method without communication with NFC module of mobile phone | |
| EP4092913B1 (en) | Transmitter with a frequency measurement stage | |
| EP4092916A1 (en) | Transmitter with a wave shape measurement stage | |
| EP2555422A1 (en) | Receiver device and remote control system | |
| CN116415614A (en) | Frequency shift backscatter tag system capable of reducing tag unit power consumption | |
| KR20070084860A (en) | Reader for rfid system | |
| JPH06103878B2 (en) | Data communication device | |
| Lee et al. | Low Power RF Interface of the Near-field Communications Tag IC for Sensors | |
| CN104980149A (en) | Self-calibration oscillator applied to non-contact smart IC (Integrated Circuit) card |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |