Common-mode interference resistant active pen and touch screen interaction system and signal demodulation method

Abstract

The invention discloses an active pen and touch screen interaction system resistant to common-mode interference and a signal demodulation method. The system comprises a signal receiving terminal and a signal transmitting terminal. The signal transmitting terminal modulates data to be transmitted by adopting a differential binary phase shift keying modulation method, and transmits a generated modulation signal to the signal receiving terminal; the analog front-end receiving module is coupled with the signal transmitting terminal, receives the modulation signal and outputs a digital square wave signal after fidelity extraction processing; and the digital demodulation processing module performs differential coherent digital demodulation on the digital square wave signal based on the prior characteristics of the modulation signal, inhibits residual noise and recovers data to be sent. The analog front end focuses strong common-mode noise suppression and analog filtering, the digital demodulation algorithm performs secondary digital purification by using signal time sequence characteristics, and the two constructs an efficient anti-interference pipeline. Meanwhile, the regular square wave signals can be directly processed through differential coherent demodulation, and the requirements for performance and power consumption of a rear-end processor are lowered.

Description

Technical Field

[0001] This invention relates to the field of data communication technology, and in particular to an active pen and touchscreen interaction system and signal demodulation method that resists common-mode interference. Background Technology

[0002] Existing terminal interaction systems typically include a signal transmitting terminal and a signal receiving terminal. In complex electromagnetic environments and due to noise interference from the receiving terminal itself, the signal-to-noise ratio of the received signal is extremely low, posing a significant challenge to stable demodulation. Conventional demodulation schemes have limited anti-interference capabilities and are prone to misjudgment due to noise, affecting the accuracy and stability of communication interaction. Summary of the Invention

[0003] This invention provides an active pen and touch screen interaction system and signal demodulation method that resists common-mode interference. Without increasing the complexity of analog circuits, it improves the demodulation accuracy and robustness of the system in low signal-to-noise ratio environments, and achieves reliable terminal communication interaction.

[0004] This invention provides an active pen and touchscreen interaction system with anti-common-mode interference, comprising: a signal receiving terminal; The signal transmitting terminal is configured to modulate the data to be transmitted using differential binary phase shift keying modulation and send the generated modulated signal to the signal receiving terminal. An analog front-end receiving module, coupled to the signal transmitting terminal, is configured to receive the modulated signal, perform fidelity extraction processing on the modulated signal, and output a digital square wave signal. The digital demodulation processing module is configured to perform differential coherent digital demodulation processing on the digital square wave signal based on the prior features of the modulated signal, so as to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

[0005] Furthermore, the analog front-end receiving module includes a charge transporter, a transimpedance amplifier, a capacitively coupled amplifier, and a comparator connected in sequence; The charge transporter is configured to convert a charge signal on a coupling element disposed between the signal transmitting terminal and the analog front-end receiving module into a current signal. The transimpedance amplifier is configured to convert the current signal into a first voltage signal; The capacitively coupled amplifier is configured to process the first voltage signal to obtain a second voltage signal. The comparator is configured to output the digital square wave signal based on the comparison result between the second voltage signal and the reference voltage.

[0006] Furthermore, the digital demodulation processing module includes a symbol delay unit, a differential detection unit, a statistical processing unit, and a decision unit connected in sequence; The symbol delay unit is configured to delay the digital square wave signal by a preset time to obtain a delayed signal; The differential detection unit is configured to generate a bipolar signal based on the phase relationship between the digital square wave signal and the delayed signal; The statistical processing unit is configured to perform statistical processing on the bipolar signal within a preset time window to obtain statistical results; The decision unit is configured to output a corresponding logical value based on the comparison result between the statistical result and the set threshold.

[0007] Furthermore, the differential detection unit; The differential detection unit is configured to multiply the digital square wave signal with the delayed signal to output a bipolar signal.

[0008] Furthermore, the statistical processing unit includes an accumulator; The accumulator is configured to integrate and accumulate the bipolar signal to obtain an accumulated value.

[0009] Furthermore, the decision unit includes a decision processor; The decision unit is configured to compare the accumulated value with the set threshold within a preset time window and output the demodulated logical value.

[0010] On the other hand, the present invention also discloses a signal modulation method for an active pen and a touch screen to resist common-mode interference, the method comprising: Differential binary phase shift keying modulation is used to modulate the data to be transmitted to obtain the modulated signal; After performing fidelity extraction processing on the modulated signal, a digital square wave signal is output. Based on the prior characteristics of the modulation signal, differential coherent digital demodulation is performed on the digital square wave signal to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

[0011] Furthermore, the modulation signal is processed to output a digital square wave signal, including: The modulation signal is converted into a current signal; The current signal is converted into a first voltage signal; The first voltage signal is processed to obtain the second voltage signal; Based on the comparison result between the second voltage signal and the reference voltage, the digital square wave signal is output.

[0012] Furthermore, after performing fidelity extraction processing on the modulated signal, the output digital square wave signal includes: Convert external input signals into current signals; The current signal is converted into a first voltage signal; The first voltage signal is processed to obtain the second voltage signal; Based on the comparison result between the second voltage signal and the reference voltage, the digital square wave signal is output.

[0013] Furthermore, the differential coherent digital demodulation processing of the digital square wave signal includes: The digital square wave signal is delayed by a preset time to obtain a delayed signal; A bipolar signal is generated based on the phase relationship between the digital square wave signal and the delayed signal; The bipolar signal is statistically processed within a preset time window to obtain statistical results; Based on the comparison between the statistical results and the set threshold, the corresponding logical value is output.

[0014] Furthermore, based on the phase relationship between the digital square wave signal and the delayed signal, a bipolar signal is generated; statistical processing is performed on the bipolar signal within a preset time window to obtain statistical results; based on the comparison between the statistical results and a set threshold, the corresponding logical value is output, including: Differential detection is performed on the digital square wave signal and the delayed signal. When the two signals are in the same phase, a first polarity signal is output, and when the two signals are out of phase, a second polarity signal is output, thus obtaining a bipolar signal. The bipolar signal is integrated and accumulated within a preset time window to obtain the accumulated result; The accumulated result is judged, and when the accumulated result is greater than a set threshold, it is determined as a first logic signal, and when the accumulated result is less than the set threshold, it is determined as a second logic signal.

[0015] Compared with the prior art, the present invention has at least the following technical effects: A complete anti-interference architecture is constructed through the coordinated operation of the analog front-end receiving module and the digital demodulation processing module. Specifically, the analog front-end receiving module is used to extract the modulated signal with high fidelity; the digital demodulation processing module fully utilizes the timing characteristics of the modulated signal to perform secondary digital purification, further suppressing residual noise in the analog front-end output signal, significantly improving the demodulation accuracy and robustness of the system in low signal-to-noise ratio environments. Furthermore, the differential coherent demodulation algorithm disclosed in this embodiment can directly process the regular square wave signal output by the analog front-end without relying on a high-precision analog-to-digital converter or complex digital filters, effectively reducing the performance and power consumption requirements of the back-end processor and achieving efficient matching between the algorithm and hardware. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the active pen and touch screen interaction system with anti-common-mode interference in Embodiment 1 of the present invention; Figure 2 These are simulation waveforms of each signal in the differential coherent digital demodulation process in Embodiment 1 of the present invention. Figure 3 This is a simplified flowchart illustrating the signal adjustment method for the active pen and touchscreen in Embodiment 2 of the present invention to resist common-mode interference. Detailed Implementation

[0017] The following description, with reference to schematic diagrams, illustrates an active pen and touchscreen interaction system and signal demodulation method for resisting common-mode interference according to the present invention. Preferred embodiments of the invention are shown. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0018] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0019] Example 1 Please refer to Figure 1 This embodiment discloses an active pen and touchscreen interaction system with anti-common-mode interference, comprising: A signal receiving terminal and a signal transmitting terminal are configured to modulate the data to be transmitted using phase shift keying modulation and transmit the generated modulated signal to the signal receiving terminal. An analog front-end receiving module, coupled to the signal transmitting terminal, is configured to receive the modulated signal, perform fidelity extraction processing on the modulated signal, and output a digital square wave signal. A digital demodulation processing module is configured to perform differential coherent digital demodulation processing on the digital square wave signal based on the prior features of the modulated signal to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

[0020] In this embodiment, a complete anti-interference architecture is constructed through the collaborative operation of the analog front-end receiving module and the digital demodulation processing module. Specifically, the analog front-end receiving module is used to extract the modulated signal with high fidelity; the digital demodulation processing module fully utilizes the timing characteristics of the modulated signal to perform secondary digital purification, further suppressing residual noise in the analog front-end output signal, significantly improving the demodulation accuracy and robustness of the system in low signal-to-noise ratio environments. Furthermore, the differential coherent demodulation algorithm disclosed in this embodiment directly processes the regular square wave signal output by the analog front-end, without relying on a high-precision analog-to-digital converter or complex digital filters, effectively reducing the performance and power consumption requirements of the back-end processor and achieving efficient matching between the algorithm and hardware.

[0021] In this embodiment, the signal receiving terminal includes, but is not limited to, interactive devices with signal receiving capabilities such as touchscreens, touchpads, and capacitive sensing panels. The signal transmitting terminal includes, but is not limited to, interactive devices with signal transmitting capabilities such as active pens, styluses, and capacitive pens.

[0022] In this embodiment, the phase shift keying modulation method is differential binary phase shift keying modulation. Differential binary phase shift keying modulation is a phase modulation technique that encodes the data to be transmitted into the relative phase changes of adjacent symbols, rather than absolute phase values. The advantage of using differential coding is that the receiver does not need to perform absolute recovery of the carrier phase; demodulation can be completed simply by detecting the phase changes between adjacent symbols. This simplifies the receiver design complexity and enhances the system's tolerance to carrier phase drift.

[0023] Specifically, the signal transmitting terminal transmits a high-voltage square wave signal at a specific frequency (e.g., frequency f0), with an amplitude reaching the level of 10V. In this modulation method, the data to be transmitted is differentially encoded according to the following rules: when the data to be transmitted is logic "1", the phase of the current symbol remains unchanged relative to the phase of the previous symbol, that is, the phase change is 0 degrees; when the data to be transmitted is logic "0", the phase of the current symbol is flipped relative to the phase of the previous symbol, that is, the phase change is 180 degrees.

[0024] In this embodiment, the analog front-end receiving module includes a charge transporter, a transimpedance amplifier, a capacitively coupled amplifier, and a comparator connected in sequence.

[0025] The charge transporter is configured to convert a charge signal on a coupling element between the signal transmitting terminal and the analog front-end receiving module into a current signal. The transimpedance amplifier is configured to convert the current signal into a first voltage signal. The capacitively coupled amplifier is configured to process the first voltage signal to obtain a second voltage signal. The comparator is configured to output the digital square wave signal based on a comparison between the second voltage signal and a reference voltage.

[0026] In this embodiment, the coupling element is a coupling capacitor Cf.

[0027] Understandably, during signal transmission, the modulated signal couples to the self-capacitance of the signal receiving terminal via the parasitic capacitance Cs between the transmitting end of the signal transmitting terminal and the sensing electrodes of the signal receiving terminal. Taking touch applications as an example, the typical value of the parasitic capacitance between the pen tip and the screen sensing electrodes is about a few picofarads, while the typical value of the self-capacitance of the touch screen is about 600 picofarads. Due to the huge difference in capacitance between the two, the amplitude of the signal coupled to the receiving end is attenuated to the microvolt level, resulting in an extremely weak signal.

[0028] For the aforementioned weak signal, the analog front-end receiving module is responsible for high-fidelity extraction. In this module, a transimpedance amplifier performs current-to-voltage conversion while simultaneously implementing low-pass filtering to obtain the first voltage signal. A capacitively coupled amplifier then amplifies and high-pass filters the first voltage signal to obtain the second voltage signal. Together, these two components form a bandpass filter, effectively filtering out out-of-band noise and common-mode interference. Finally, a comparator converts the filtered analog signal into a regular digital square wave signal. This digital square wave signal is synchronized with the transmitter's transmission frequency, providing a high-quality input signal for subsequent digital demodulation processing.

[0029] Furthermore, in this embodiment, the digital demodulation processing module includes a symbol delay unit, a differential detection unit, a statistical processing unit, and a decision unit connected in sequence.

[0030] The symbol delay unit is configured to delay the digital square wave signal by a preset time to obtain a delayed signal. The differential detection unit is configured to generate a bipolar signal based on the phase relationship between the digital square wave signal and the delayed signal. The statistical processing unit is configured to perform statistical processing on the bipolar signal within a preset time window to obtain a statistical result. The decision unit is configured to output a corresponding logical value based on a comparison between the statistical result and a set threshold.

[0031] In this embodiment, even when there is slight distortion or jitter in the analog front-end output, the integration and accumulation stage in digital demodulation can provide sufficient noise margin, thereby improving the stability of subsequent decision-making and ultimately enhancing the reliability of the system in harsh electromagnetic environments.

[0032] In a specific example, both the preset duration and the preset time window are set to one symbol period. Setting the delay duration to one symbol period allows the differential detection operation to accurately compare the phase relationship between two adjacent symbols; setting the statistical time window to one symbol period allows for real-time demodulation while maximizing the use of all signal energy within a single symbol for noise suppression, thus achieving optimal signal-to-noise ratio improvement.

[0033] In this embodiment, the differential detection unit includes a multiplier.

[0034] Specifically, the multiplier is configured to multiply the digital square wave signal with the delayed signal and output a bipolar signal.

[0035] In this embodiment, the differential detection unit is configured to multiply the digital square wave signal with the delayed signal to output a bipolar signal.

[0036] In this embodiment, the decision unit includes a decision maker.

[0037] Specifically, the decision maker is configured to compare the accumulated value with the set threshold within a preset time window and output the demodulated logical value.

[0038] The following details the working principle of the digital demodulation processing module: First, the symbol delay unit delays the digital square wave signal by one symbol period to obtain the delayed signal. This symbol period is strictly aligned with the data bits of the differential binary phase shift keying modulation, ensuring that the delayed signal corresponds exactly to the phase state of the previous symbol.

[0039] According to the differential binary phase shift keying (DPS) coding rules, data information is carried in the relative phase changes of adjacent symbols. To detect this phase difference, the differential detection unit performs a differential detection operation on the digital square wave signal and the delayed signal. Specifically, the differential detection unit multiplies the digital square wave signal and the delayed signal, outputting a bipolar signal. When the digital square wave signal and the delayed signal are in phase, the multiplication operation output is positive; when their phases are opposite, the multiplication operation output is negative. Through this step, phase information is successfully converted into amplitude information.

[0040] Subsequently, the statistical processing unit samples the bipolar signal using a sampling clock synchronized with the symbol period, and integrates and accumulates the sampled values ​​over a complete symbol period to obtain the accumulated result t for that period. The isomorphic accumulator integrates and accumulates the bipolar signal to obtain the accumulated value.

[0041] Finally, the decision unit makes a final decision based on the accumulated result. Specifically, the decision unit is configured to compare the accumulated value with the set threshold and output the demodulated logic value. According to the working principle of the multiplier, when adjacent symbols are in phase, the accumulated result is positive; when adjacent symbols are in opposite phases, the accumulated result is negative. Therefore, zero can be used as the natural threshold for decision: if the accumulated result is greater than zero, it is determined that adjacent symbols are in phase, and the demodulated output is logic "1"; if the accumulated result is less than zero, it is determined that adjacent symbols are in opposite phases, and the demodulated output is logic "0". This decision logic is clear and is the optimal decision criterion, without the need for a complex threshold calibration process.

[0042] In one specific example, the digital demodulation processing module further includes a data recovery unit. The data recovery unit is configured to buffer multiple consecutively output logical values, convert the buffered logical values ​​from serial to parallel according to a preset data frame format to form a data frame, and parse the data frame to recover the data to be sent.

[0043] Please refer to Figure 2 The Figure 2 The simulation waveforms for digital signal processing illustrate the signals at each stage of the differential coherent digital demodulation process.

[0044] The first row shows the waveform of the clock enable signal VIN_PEN; the second row shows the waveform of the digital square wave signal VOUT; the third row shows the waveform of the delayed signal delayed_out; the fourth row shows the waveform of the bipolar signal mult_out; the fifth row shows the symbol period synchronization signal Sample_pulse set in the accumulator, which is used to divide the symbol period boundary and control the accumulator to output the accumulated result and clear it to zero at the end of each symbol period; the sixth row shows the waveform of the accumulated value Accum_out output by the accumulator; and the seventh row shows the waveform of the decision unit output signal Out_phase_diff.

[0045] Therefore, the anti-common-mode interference terminal communication system disclosed in this embodiment, through differential coherent digital demodulation module performing delay, differential detection, integration accumulation, and decision processing on the digital square wave signal, can effectively suppress residual common-mode noise interference in the signal and achieve accurate recovery of the original modulated data. Simulation results show that the output signal waveform of the decision unit is clear and stable, verifying that the system has good anti-interference performance and reliable data demodulation capability in a common-mode interference environment.

[0046] Example 2 Please refer to Figure 3 Based on the same inventive concept, this embodiment discloses a signal adjustment method for an active pen and touchscreen that resists common-mode interference. It is implemented using the active pen and touchscreen interaction system for resisting common-mode interference disclosed in Embodiment 1. The method includes: S1. Differential binary phase shift keying modulation is used to modulate the data to be transmitted to generate a modulated signal; S2. After performing fidelity extraction processing on the modulated signal, output a digital square wave signal; S4. Based on the prior characteristics of the modulation signal, differential coherent digital demodulation is performed on the digital square wave signal to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

[0047] Specifically, step S1 includes: S21. Convert the modulation signal into a current signal; S22. Convert the current signal into a first voltage signal; S23. Perform signal processing on the first voltage signal to obtain a second voltage signal; S24. Based on the comparison result between the second voltage signal and the reference voltage, output the digital square wave signal.

[0048] More specifically, step S3 includes: S31. Delay the digital square wave signal by a preset time to obtain a delayed signal; S32. Generate a bipolar signal based on the phase relationship between the digital square wave signal and the delayed signal; S33. Perform statistical processing on the bipolar signal within a preset time window to obtain statistical results; S34. Based on the comparison between the statistical results and the set threshold, output the corresponding logical value.

[0049] Specifically, a bipolar signal is generated based on the phase relationship between the digital square wave signal and the delayed signal; statistical processing is performed on the bipolar signal within a preset time window to obtain statistical results; and a corresponding logical value is output based on a comparison between the statistical results and a set threshold, including: S320. Perform differential detection on the digital square wave signal and the delayed signal, output a first polarity signal when the two are in the same phase, and output a second polarity signal when the two are in opposite phases, to obtain a bipolar signal; S330. Integrate and accumulate the bipolar signal within a preset time window to obtain the accumulated result; S340. The accumulated result is judged, and when the accumulated result is greater than a set threshold, it is determined as a first logic signal, and when the accumulated result is less than the set threshold, it is determined as a second logic signal.

[0050] In a specific example, the first polarity signal is "+1", the second polarity signal is "-1"; the first logic signal is logic "1", the second logic signal is logic "0"; and the set threshold is zero.

[0051] It is understood that the above-mentioned signal adjustment method for the active pen and touch screen that resists common-mode interference is based on the same technical design principle as the active pen and touch screen interaction system that resists common-mode interference disclosed in Embodiment 1. Both can achieve the same technical purpose. The effect that the active pen and touch screen interaction system that resists common-mode interference can achieve has been described in detail in Embodiment 1, so it will not be repeated here.

[0052] Various modifications and variations are possible without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. An active pen and touchscreen interaction system with anti-common-mode interference, characterized in that, include: Signal receiving terminal; The signal transmitting terminal is configured to modulate the data to be transmitted using differential binary phase shift keying modulation and send the generated modulated signal to the signal receiving terminal. An analog front-end receiving module, coupled to the signal transmitting terminal, is configured to receive the modulated signal, perform fidelity extraction processing on the modulated signal, and output a digital square wave signal. The digital demodulation processing module is configured to perform differential coherent digital demodulation processing on the digital square wave signal based on the prior features of the modulated signal, so as to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

2. The active pen and touchscreen interaction system with anti-common-mode interference as described in claim 1, characterized in that, The analog front-end receiving module includes a charge transporter, a transimpedance amplifier, a capacitively coupled amplifier, and a comparator connected in sequence. The charge transporter is configured to convert a charge signal on a coupling element disposed between the signal transmitting terminal and the analog front-end receiving module into a current signal. The transimpedance amplifier is configured to convert the current signal into a first voltage signal; The capacitively coupled amplifier is configured to process the first voltage signal to obtain a second voltage signal. The comparator is configured to output the digital square wave signal based on the comparison result between the second voltage signal and the reference voltage.

3. The active pen and touchscreen interaction system with anti-common-mode interference as described in claim 1, characterized in that, The digital demodulation processing module includes a symbol delay unit, a differential detection unit, a statistical processing unit, and a decision unit connected in sequence. The symbol delay unit is configured to delay the digital square wave signal by a preset time to obtain a delayed signal; The differential detection unit is configured to generate a bipolar signal based on the phase relationship between the digital square wave signal and the delayed signal; The statistical processing unit is configured to perform statistical processing on the bipolar signal within a preset time window to obtain statistical results; The decision unit is configured to output a corresponding logical value based on the comparison result between the statistical result and the set threshold.

4. The active pen and touchscreen interaction system with anti-common-mode interference as described in claim 3, characterized in that, The differential detection unit; The differential detection unit is configured to multiply the digital square wave signal with the delayed signal to output a bipolar signal.

5. The active pen and touchscreen interaction system with anti-common-mode interference as described in claim 4, characterized in that, The statistical processing unit includes an accumulator; The accumulator is configured to integrate and accumulate the bipolar signal to obtain an accumulated value.

6. The active pen and touchscreen interaction system with anti-common-mode interference as described in claim 5, characterized in that, The decision unit includes a decision-making device; The decision unit is configured to compare the accumulated value with the set threshold within a preset time window and output the demodulated logical value.

7. A signal modulation method for an active stylus and touchscreen to resist common-mode interference, characterized in that, The method includes: Differential binary phase shift keying modulation is used to modulate the data to be transmitted to generate a modulated signal; After performing fidelity extraction processing on the modulated signal, a digital square wave signal is output. Based on the prior characteristics of the modulation signal, differential coherent digital demodulation is performed on the digital square wave signal to suppress residual noise in the digital square wave signal and recover the data to be transmitted.

8. The signal modulation method for active stylus and touchscreen against common-mode interference as described in claim 7, characterized in that, After performing fidelity extraction processing on the modulated signal, the output digital square wave signal includes: The modulation signal is converted into a current signal; The current signal is converted into a first voltage signal; The first voltage signal is processed to obtain the second voltage signal; Based on the comparison result between the second voltage signal and the reference voltage, the digital square wave signal is output.

9. The signal modulation method for active stylus and touchscreen against common-mode interference as described in claim 8, characterized in that, Differential coherent digital demodulation processing of the digital square wave signal includes: The digital square wave signal is delayed by a preset time to obtain a delayed signal; A bipolar signal is generated based on the phase relationship between the digital square wave signal and the delayed signal; The bipolar signal is statistically processed within a preset time window to obtain statistical results; Based on the comparison between the statistical results and the set threshold, the corresponding logical value is output.

10. The signal modulation method for active pen and touch screen against common-mode interference as described in claim 9, characterized in that, A bipolar signal is generated based on the phase relationship between the digital square wave signal and the delayed signal; Within a preset time window, statistical processing is performed on the bipolar signal to obtain statistical results. Based on the comparison between the statistical results and a set threshold, corresponding logical values ​​are output, including: Differential detection is performed on the digital square wave signal and the delayed signal. When the two signals are in the same phase, a first polarity signal is output, and when the two signals are out of phase, a second polarity signal is output, thus obtaining a bipolar signal. The bipolar signal is integrated and accumulated within a preset time window to obtain the accumulated result; The accumulated result is judged, and when the accumulated result is greater than a set threshold, it is determined as a first logic signal, and when the accumulated result is less than the set threshold, it is determined as a second logic signal.

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