CN108449742B - Auxiliary demodulation system and method for near field communication - Google Patents

Abstract

Translated fromChinese

本发明提供一种近场通信的辅助解调系统和方法，在该系统中设置频率计和辅助信号生成模块；通过频率计提取数据信号的载波的频率值，并将载波的频率值发送至辅助信号生成模块，数据信号为近场通信设备的射频天线接收的信号幅度大于第一预设值的通信信号；再通过辅助信号生成模块生成与载波同频率的辅助信号，并将辅助信号发送至近场通信设备的解调模块，以供解调模块根据辅助信号对通信信号进行解调；从而在近场通信设备之间的一次交互期间，使近场通信设备的解调模块能持续接收到与载波同频率信号，并依据该信号进行解调，避免了目前的在解调过程中由于通信信号不连续而需要多次重复提取载波的情况，保证了数据传输的完整性。

The invention provides an auxiliary demodulation system and method for near field communication. A frequency meter and an auxiliary signal generating module are set in the system; the frequency value of the carrier wave of the data signal is extracted by the frequency meter, and the frequency value of the carrier wave is sent to the auxiliary A signal generation module, where the data signal is a communication signal with a signal amplitude greater than the first preset value received by the radio frequency antenna of the near field communication device; and then generates an auxiliary signal with the same frequency as the carrier through the auxiliary signal generation module, and sends the auxiliary signal to the near field The demodulation module of the communication device is used for the demodulation module to demodulate the communication signal according to the auxiliary signal; so that during an interaction between the near field communication devices, the demodulation module of the near field communication device can continue to receive and The same frequency signal is obtained, and demodulation is performed according to the signal, which avoids the current situation of repeatedly extracting the carrier wave due to discontinuous communication signals in the demodulation process, and ensures the integrity of data transmission.

Description

Auxiliary demodulation system and method for near field communication

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: afrequency meter 11 and an auxiliarysignal generation module 12; thefrequency meter 11 is connected with an auxiliarysignal generating module 12; thefrequency 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 auxiliarysignal 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 auxiliarysignal 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 afrequency 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 thefrequency 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, thefrequency meter 11 sends the frequency value to the auxiliarysignal generation module 12 of the auxiliary demodulation system, the auxiliarysignal 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 auxiliarysignal 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)

Translated fromChinese

1.一种近场通信的辅助解调系统，其特征在于，包括：频率计和辅助信号生成模块；1. an auxiliary demodulation system of near field communication, is characterized in that, comprises: frequency meter and auxiliary signal generation module;所述频率计连接所述辅助信号生成模块；the frequency meter is connected to the auxiliary signal generating module;所述频率计，用于提取数据信号的载波的频率值，并将所述载波的频率值发送至所述辅助信号生成模块，所述数据信号为近场通信设备的射频天线接收的信号幅度大于第一预设值的通信信号；The frequency meter is used to extract the frequency value of the carrier wave of the data signal, and send the frequency value of the carrier wave to the auxiliary signal generation module, and the data signal is that the amplitude of the signal received by the radio frequency antenna of the near field communication device is greater than the communication signal of the first preset value;所述辅助信号生成模块，用于生成与所述载波同频率的辅助信号，并将所述辅助信号发送至所述近场通信设备的解调模块，以供所述解调模块根据所述辅助信号对所述通信信号进行解调；The auxiliary signal generation module is configured to generate an auxiliary signal with the same frequency as the carrier, and send the auxiliary signal to the demodulation module of the near field communication device, so that the demodulation module can use the auxiliary signal according to the auxiliary signal. the signal demodulates the communication signal;所述辅助信号生成模块包括晶体振荡器和时钟倍频/分频电路；The auxiliary signal generating module includes a crystal oscillator and a clock frequency multiplying/dividing circuit;所述晶体振荡器，用于生成固定频率的脉冲信号；The crystal oscillator is used to generate a fixed frequency pulse signal;所述时钟倍频/分频电路，用于将固定频率的脉冲信号转换成与所述载波同频率的脉冲信号。The clock frequency multiplying/dividing circuit is used to convert a fixed frequency pulse signal into a pulse signal of the same frequency as the carrier wave.2.根据权利要求1所述的系统，其特征在于，所述系统还包括：信号检测模块；2. The system according to claim 1, wherein the system further comprises: a signal detection module;所述信号检测模块连接所述辅助信号生成模块；The signal detection module is connected to the auxiliary signal generation module;所述信号检测模块，用于检测所述通信信号的信号幅度，在确定所述通信信号的信号幅度小于第二预设值时，向所述辅助信号生成模块发送传输指令；The signal detection module is configured to detect the signal amplitude of the communication signal, and when it is determined that the signal amplitude of the communication signal is less than a second preset value, send a transmission instruction to the auxiliary signal generation module;相应地，所述辅助信号生成模块，用于在接收到所述传输指令后，将所述辅助信号发送至所述近场通信设备的解调模块。Correspondingly, the auxiliary signal generation module is configured to send the auxiliary signal to the demodulation module of the near field communication device after receiving the transmission instruction.3.根据权利要求1所述的系统，其特征在于，所述辅助信号生成模块还包括波形变换电路；3. The system according to claim 1, wherein the auxiliary signal generating module further comprises a waveform transformation circuit;所述波形变换电路，用于将与所述载波同频率的脉冲信号转换成与所述载波同频率的预设波形的信号。The waveform conversion circuit is used for converting the pulse signal of the same frequency as the carrier into a signal of preset waveform with the same frequency as the carrier.4.根据权利要求1所述的系统，其特征在于，所述系统还包括：复位模块；4. The system according to claim 1, wherein the system further comprises: a reset module;所述复位模块连接所述频率计和所述辅助信号生成模块；The reset module is connected to the frequency meter and the auxiliary signal generation module;所述复位模块，用于产生复位信号，通过所述复位信号重置所述频率计或者所述辅助信号生成模块的工作状态。The reset module is configured to generate a reset signal, and reset the working state of the frequency counter or the auxiliary signal generating module through the reset signal.5.根据权利要求1所述的系统，其特征在于，所述系统还包括：运算放大器电路；5. The system of claim 1, wherein the system further comprises: an operational amplifier circuit;所述运算放大器电路连接所述频率计；the operational amplifier circuit is connected to the frequency meter;所述运算放大器电路，用于将所述数据信号的信号幅度调整到第三预设值以下。The operational amplifier circuit is used to adjust the signal amplitude of the data signal to be below a third preset value.6.根据权利要求1所述的系统，其特征在于，所述系统还包括：与门电路；6. The system according to claim 1, wherein the system further comprises: an AND gate circuit;所述与门电路连接所述频率计；the AND gate circuit is connected to the frequency meter;所述与门电路，用于将所述数据信号的波形转换为方波。The AND gate circuit is used to convert the waveform of the data signal into a square wave.7.一种近场通信的辅助解调方法，其特征在于，包括：7. An auxiliary demodulation method for near field communication, characterized in that, comprising:利用频率计提取数据信号的载波的频率值，并将所述载波的频率值发送至辅助信号生成模块，所述数据信号为近场通信设备的射频天线接收的信号幅度大于第一预设值的通信信号；The frequency value of the carrier wave of the data signal is extracted by a frequency meter, and the frequency value of the carrier wave is sent to the auxiliary signal generation module, where the data signal is the signal amplitude received by the radio frequency antenna of the near field communication device greater than the first preset value. communication signal;利用所述辅助信号生成模块中的晶体振荡器生成固定频率的脉冲信号，再利用所述辅助信号生成模块中的时钟倍频/分频电路将固定频率的脉冲信号转换成与所述载波同频率的辅助信号；并将所述辅助信号发送至所述近场通信设备的解调模块，以供所述解调模块根据所述辅助信号对所述通信信号进行解调。The crystal oscillator in the auxiliary signal generation module is used to generate a fixed frequency pulse signal, and then the clock frequency multiplication/frequency division circuit in the auxiliary signal generation module is used to convert the fixed frequency pulse signal into the same frequency as the carrier wave and send the auxiliary signal to the demodulation module of the near field communication device, so that the demodulation module can demodulate the communication signal according to the auxiliary signal.8.根据权利要求7所述的方法，其特征在于，所述将固定频率的脉冲信号转换成与所述载波同频率的辅助信号之后，还包括：检测所述通信信号的信号幅度，判断所述通信信号的信号幅度是否小于第二预设值；8 . The method according to claim 7 , wherein after converting the fixed-frequency pulse signal into an auxiliary signal having the same frequency as the carrier wave, the method further comprises: detecting the signal amplitude of the communication signal, and determining the signal amplitude of the communication signal. 9 . whether the signal amplitude of the communication signal is less than the second preset value;相应地，所述将所述辅助信号发送至所述近场通信设备的解调模块，包括：在确定所述通信信号的信号幅度小于第二预设值后，将所述辅助信号发送至所述近场通信设备的解调模块。Correspondingly, the sending the auxiliary signal to the demodulation module of the near field communication device includes: after determining that the signal amplitude of the communication signal is less than a second preset value, sending the auxiliary signal to the near-field communication device. The demodulation module of the near field communication device.

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