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CN-121978654-A - Signal-to-noise ratio enhancement method, balance detection method and circuit

CN121978654ACN 121978654 ACN121978654 ACN 121978654ACN-121978654-A

Abstract

The invention discloses a signal-to-noise ratio enhancement method, a balance detection method and a circuit, wherein gain and reference threshold voltage are regulated according to an output signal of an analog-to-digital converter, so that the average value of the threshold voltage is closest to the average value of a signal after gain processing, and the peak-to-peak value of the signal after gain processing is larger than the difference value of the threshold voltage.

Inventors

  • WU KENAN

Assignees

  • 黄山学院

Dates

Publication Date
20260505
Application Date
20251216

Claims (10)

  1. 1. A signal-to-noise ratio enhancement method, comprising: gain processing is carried out on the wind measuring laser radio frequency signal at the current moment; Generating a new threshold voltage according to the reference threshold voltage, the signal-to-noise ratio enhanced stochastic resonance signal obtained at the previous moment and a preset fixed relation, and comparing the signal subjected to gain processing at the current moment with the new threshold voltage to obtain the signal-to-noise ratio enhanced stochastic resonance signal at the current moment; the wind-measuring laser radio frequency signal is an output signal of an amplifying and filtering module of the balance detector, and the new threshold voltage is a high threshold voltage or a low threshold voltage; the gain and the reference threshold voltage are regulated according to the output signal of the analog-to-digital converter, the target of regulating the reference threshold voltage comprises enabling the average value of the threshold voltage to be closest to the average value of the signal after gain processing, the target of regulating the gain comprises enabling the peak-to-peak value of the signal after gain processing to be larger than the difference value of the threshold voltage, the average value of the threshold voltage is the average value of the high threshold voltage and the low threshold voltage, and the difference value of the threshold voltage is the difference value of the high threshold voltage and the low threshold voltage.
  2. 2. The method of claim 1, wherein adjusting the gain further comprises adjusting the ratio of the root mean square of the noise in the gain-processed signal to the threshold voltage difference to be within a pre-calibrated optimal proportional relationship.
  3. 3. The method of claim 1 or 2, wherein adjusting the gain based on the analog-to-digital converter output signal comprises: counting the hopping frequency of the output signal of the analog-to-digital converter, if the hopping frequency is lower than the pre-calibrated optimal frequency range, increasing the gain, if the hopping frequency is higher than the pre-calibrated optimal frequency range, reducing the gain, and if the hopping frequency is in the pre-calibrated optimal frequency range, keeping the gain unchanged.
  4. 4. The method of claim 1, wherein adjusting the reference threshold voltage based on the analog-to-digital converter output signal comprises: And calculating the average value of the output signals of the analog-to-digital converter, if the average value is larger than 0.5, reducing the reference threshold voltage, and if the average value is smaller than 0.5, increasing the reference threshold voltage.
  5. 5. A signal-to-noise ratio enhancing circuit, which is characterized by comprising a gain module and a Schmitt trigger; The input end of the gain module is connected with the amplifying and filtering module of the balance detector, the first input end and the second input end of the Schmitt trigger are respectively connected with the output end of the gain module and the processor of the balance detector, and the output end of the Schmitt trigger is connected with the analog-to-digital converter of the balance detector; the gain module is used for carrying out gain processing on the wind measuring laser radio frequency signal at the current moment; The Schmitt trigger is used for generating a new threshold voltage according to a reference threshold voltage, a stochastic resonance signal with enhanced signal-to-noise ratio obtained at the last moment and a preset fixed relation, comparing a signal subjected to gain processing at the current moment with the new threshold voltage to obtain the stochastic resonance signal with enhanced signal-to-noise ratio at the current moment, wherein the new threshold voltage is a high threshold voltage or a low threshold voltage; The processor is used for generating gain and reference threshold voltage according to the output signal of the analog-to-digital converter and respectively transmitting the generated gain and the generated reference threshold voltage to the gain module and the Schmitt trigger; The method comprises the steps that a processor generates a reference threshold voltage, wherein the processor generates a target of the reference threshold voltage comprises enabling a threshold voltage average value to be closest to a signal average value after gain processing, the processor generates a target of the gain comprises enabling a peak-to-peak value of the signal after gain processing to be larger than a threshold voltage difference value, the threshold voltage average value is the average value of a high threshold voltage and a low threshold voltage, and the threshold voltage difference value is the difference value of the high threshold voltage and the low threshold voltage.
  6. 6. The circuit of claim 5 wherein the processor generating the target of gain further comprises causing a ratio between a root mean square of noise in the gain processed signal and a threshold voltage difference to be within a pre-calibrated optimal proportional relationship.
  7. 7. The circuit of claim 5 or 6, wherein the processor generates the gain from the analog-to-digital converter output signal, comprising: counting the hopping frequency of the output signal of the analog-to-digital converter, if the hopping frequency is lower than the pre-calibrated optimal frequency range, increasing the gain, if the hopping frequency is higher than the pre-calibrated optimal frequency range, reducing the gain, and if the hopping frequency is in the pre-calibrated optimal frequency range, keeping the gain unchanged.
  8. 8. The circuit of claim 5, wherein the processor generates the reference threshold voltage from the analog-to-digital converter output signal, comprising: And calculating the average value of the output signals of the analog-to-digital converter, if the average value is larger than 0.5, reducing the reference threshold voltage, and if the average value is smaller than 0.5, increasing the reference threshold voltage.
  9. 9. A balance detection method, comprising the method of any one of claims 1-4.
  10. 10. A balance detection circuit comprising the circuit of any one of claims 5 to 8.

Description

Signal-to-noise ratio enhancement method, balance detection method and circuit Technical Field The invention relates to a signal-to-noise ratio enhancement method, a balance detection method and a circuit, and belongs to the field of coherent wind lidar. Background In the field of coherent wind-measuring laser radar, a balance detector is generally required to convert an optical signal into an electrical signal, specifically, after the wind-measuring laser signal is converted into a wind-measuring optical signal through a photoelectric detector connected with a cathode and an anode, the electrical signal is amplified and filtered through an amplifying and filtering module (namely, the electrical signal is amplified and filtered in sequence) to obtain a wind-measuring laser radio frequency signal with the frequency of MHz, then an analog-to-digital converter is used for sampling the radio frequency signal to obtain sampling data, and a processor is used for analyzing and processing the sampling data. Because the anemometry signal is very weak, the radio frequency signal obtained by the balanced detection technology is usually submerged in noise, and the signal-to-noise ratio is low. In order to increase the detection distance of the coherent wind lidar, the signal to noise ratio is enhanced before the radio frequency signal is sampled. The traditional enhancement method is to filter the radio frequency signal and filter noise outside the interested frequency range as much as possible, however, the method has limited effect on improving the signal-to-noise ratio. Disclosure of Invention The invention provides a signal-to-noise ratio enhancement method, a balance detection method and a circuit, which solve the problems disclosed in the background technology. According to one aspect of the present application, there is provided a signal-to-noise ratio enhancement method, including: gain processing is carried out on the wind measuring laser radio frequency signal at the current moment; Generating a new threshold voltage according to the reference threshold voltage, the stochastic resonance signal obtained at the previous moment and subjected to signal-to-noise ratio enhancement and a preset fixed relation; Comparing the signal subjected to gain processing at the current moment with a new threshold voltage to obtain a stochastic resonance signal with enhanced signal-to-noise ratio at the current moment; the wind-measuring laser radio frequency signal is an output signal of an amplifying and filtering module of the balance detector, and the new threshold voltage is a high threshold voltage or a low threshold voltage; the gain and the reference threshold voltage are regulated according to the output signal of the analog-to-digital converter, the target of regulating the reference threshold voltage comprises enabling the average value of the threshold voltage to be closest to the average value of the signal after gain processing, the target of regulating the gain comprises enabling the peak-to-peak value of the signal after gain processing to be larger than the difference value of the threshold voltage, the average value of the threshold voltage is the average value of the high threshold voltage and the low threshold voltage, and the difference value of the threshold voltage is the difference value of the high threshold voltage and the low threshold voltage. Further, the gain adjustment target further comprises that the ratio between the root mean square of noise in the signal after gain processing and the threshold voltage difference value is in a pre-calibrated optimal proportional relation range. Further, adjusting the gain based on the analog-to-digital converter output signal includes: counting the hopping frequency of the output signal of the analog-to-digital converter, if the hopping frequency is lower than the pre-calibrated optimal frequency range, increasing the gain, if the hopping frequency is higher than the pre-calibrated optimal frequency range, reducing the gain, and if the hopping frequency is in the pre-calibrated optimal frequency range, keeping the gain unchanged. Further, adjusting the reference threshold voltage according to the analog-to-digital converter output signal includes: And calculating the average value of the output signals of the analog-to-digital converter, if the average value is larger than 0.5, reducing the reference threshold voltage, and if the average value is smaller than 0.5, increasing the reference threshold voltage. According to another aspect of the present application, there is provided a signal-to-noise ratio enhancement circuit comprising a gain module and a schmitt trigger; The input end of the gain module is connected with the amplifying and filtering module of the balance detector, the first input end and the second input end of the Schmitt trigger are respectively connected with the output end of the gain module and the processor of the balance detector, and the