DAS-based audio data acquisition method and system, electronic equipment and storage medium

Abstract

The invention relates to the field of optical fiber sensing, in particular to a DAS-based audio data acquisition method and system, electronic equipment and a storage medium. Acquiring real-time audio data and real-time energy of the to-be-measured optical cable at the current sampling time point; updating the reference noise threshold value through the reference energy in the real-time audio data; acquiring a starting point of an effective signal in the real-time audio data according to the real-time energy and the updated reference noise threshold value, and amplifying the real-time audio data collected behind the starting point; and taking the amplified real-time audio data as effective audio data. Compared with the prior art, the method has the advantages that the reference noise threshold value containing the system noise is obtained, the reference energy containing the external noise is used for updating the reference noise threshold value, then the effective signal can be obtained based on the updated reference noise threshold value and the real-time energy, calculation is simple, and no complex algorithm or extra hardware is needed.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing, and more particularly, to a method, system, electronic device, and storage medium for acquiring audio data based on DAS. Background Art

[0002] Distributed Acoustic Sensing (DAS) is a sensing technology that uses the interference effect of fiber backscattering to achieve continuous distributed detection of acoustic signals, and it has broad application prospects in fields such as perimeter security, pipeline monitoring, and seismic exploration. The signal-to-noise ratio of the audio data in the DAS system is affected by multiple factors, including internal system noise and external environmental noise. Too low signal-to-noise ratio makes it difficult to identify the audio data, thus affecting the analysis of the DAS system. In the existing DAS systems, techniques such as filtering and noise reduction are usually used to improve the signal-to-noise ratio, but these methods often require complex algorithms and hardware support, and it is difficult to adapt to complex and changing environments. Summary of the Invention

[0003] The present invention aims to overcome at least one defect of the above-mentioned prior art, and provides a method, system, electronic device, and storage medium for acquiring audio data based on DAS, which is used to effectively improve the signal-to-noise ratio of audio data acquisition through simple hardware and algorithms.

[0004] The technical solution adopted by the present invention is as follows: According to a first aspect of the present invention, there is provided a method for acquiring audio data based on DAS, and the acquisition method includes: Obtaining a reference noise threshold of the DAS system in the optical cable to be measured; Collecting real-time audio data of the current sampling time point of the optical cable to be measured through the DAS system, and obtaining the real-time energy of the current sampling time point according to the real-time audio data; Obtaining the reference energy corresponding to the real-time audio data; the reference energy is the audio energy value within a period of time before the current sampling time point; Updating the reference noise threshold according to the reference energy; Judging whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; If there is a valid signal, taking the current sampling time point as the starting point of the valid signal, and amplifying the real-time audio data collected after the starting point; Taking the amplified real-time audio data as valid audio data.

[0005] By pre-collecting the reference noise threshold of the DAS system when there is no valid signal in the optical cable to be measured, it serves as one of the judgment criteria for whether the audio data obtained in the optical cable to be measured is a valid signal; then, by obtaining the real-time audio data of the optical cable to be measured and calculating the real-time energy and reference energy of the real-time audio data, where the reference energy is the audio energy value within a period of time before the current sampling time point, reflecting the audio energy and noise situation in the optical cable to be measured before the current sampling time point; therefore, the reference noise threshold is updated by the reference energy, enabling the reference noise threshold to be adjusted based on the actual noise situation, and thus better realizing the judgment of the valid signal; at the same time, after determining the starting point of the valid signal, the valid signal is amplified. When the valid signal is amplified while the system noise remains unchanged, the signal-to-noise ratio of the real-time audio data increases. Since the calculation operation of the present invention is simple, there is no need to adopt complex algorithms, nor is it necessary to use additional hardware to improve the signal-to-noise ratio of the audio data.

[0006] Further, the obtaining of the reference noise threshold of the DAS system in the optical cable to be measured specifically includes: Collecting the reference audio data of the optical cable to be measured through the DAS system; the reference audio data is the audio data when there is no valid signal in the optical cable to be measured; According to a preset first data window, obtaining the first window audio data within a preset first time range from the reference audio data; Obtaining the noise energy of the first window audio data according to the mean square deviation of the first window audio data; Obtaining the reference noise threshold according to the noise energy.

[0007] The reference audio data is collected through the first data window. By setting the size of the first data window and the collection position of the first data window in the reference audio data, the first window audio data can be flexibly and accurately obtained in the reference audio data, enabling the first window audio data to more accurately represent the noise energy of the system.

[0008] Further, the obtaining of the reference energy corresponding to the real-time audio data specifically includes: According to a preset second data window, obtaining the second window audio data within a second time range from the audio data before the current sampling time point; Calculating the mean square deviation of the second window audio data, and obtaining the reference energy corresponding to the real-time audio data according to the mean square deviation of the second window audio data.

[0009] By setting the second data window, audio data before the current sampling time point is collected, and based on the mean square error of the audio data in the second window collected, the reference energy corresponding to the real-time audio data is obtained, enabling the reference energy to effectively reflect the noise and audio energy conditions in the audio data before the current sampling time point. Furthermore, based on the reference energy, the adjustment of the reference noise threshold can be better achieved.

[0010] Further, the updating of the reference noise threshold according to the reference energy specifically includes: Compare the reference energy with the reference noise threshold; If the reference energy is less than the reference noise threshold, set the reference noise threshold to be equal to the reference energy; If the reference energy is greater than or equal to the reference noise threshold, keep the reference noise threshold unchanged.

[0011] By updating the reference noise threshold through the reference energy, the reference noise threshold can change with the change of the reference energy, and further, the judgment of the effective signal can be realized more accurately.

[0012] Further, the judgment of whether there is an effective signal in the real-time audio data according to the real-time energy and the updated reference noise threshold specifically includes: When the real-time energy is greater than the updated reference noise threshold, it is determined that there is an effective signal in the real-time audio data; When the real-time energy is less than or equal to the updated reference noise threshold, it is determined that there is no effective signal in the real-time audio data.

[0013] Further, the amplification of the real-time audio data collected after the starting point is specifically: Amplify the audio data collected after the starting point according to a preset magnification factor.

[0014] Further, after the amplification of the real-time audio data collected after the starting point, it further includes: Continue to collect the real-time audio data after the starting point, and obtain the corresponding reference energy according to the real-time audio data after the starting point; Further update the updated reference noise threshold according to the reference energy after the starting point; Judge whether there is an effective signal in the real-time audio data after the starting point according to the real-time energy and the further updated reference noise threshold; If there is no valid signal, use the sampling time point corresponding to the real-time audio data after the starting point as the end point of the valid signal, and stop amplifying the real-time audio data collected after the end point.

[0015] According to the second aspect of the present invention, the present invention also provides an audio data acquisition system based on DAS, and the acquisition system includes: A reference threshold acquisition module, configured to acquire the reference noise threshold of the DAS system in the optical cable to be measured; An audio data acquisition module, configured to collect real-time audio data of the current sampling time point of the optical cable to be measured through the DAS system, and acquire the real-time energy of the current sampling time point according to the real-time audio data; An audio energy calculation module, configured to acquire the reference energy corresponding to the real-time audio data; the reference energy is the audio energy value within a period of time before the current sampling time point; A noise threshold update module, configured to update the reference noise threshold according to the reference energy; A valid signal confirmation module, configured to determine whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; if there is a valid signal, use the current sampling time point as the starting point of the valid signal, amplify the real-time audio data collected after the starting point; and use the amplified real-time audio data as valid audio data.

[0016] According to the third aspect of the present invention, the present invention also provides an electronic device, including a memory and a processor, where a computer-readable instruction is stored on the memory, and the processor executes the computer-readable instruction to implement the method for acquiring audio data based on DAS described in the first aspect above. According to the fourth aspect of the present invention, the present invention also provides a computer storage medium, on which a computer-readable instruction is stored, and when the computer-readable instruction is executed, the method for acquiring audio data based on DAS described in the first aspect above is implemented.

[0017] Compared with the prior art, the beneficial effects of the present invention are: The present invention pre-collects a reference noise threshold of a DAS system in the optical cable to be measured, and the reference noise threshold reflects the system noise of the DAS system. Therefore, the reference noise threshold can be used as one of the judgment criteria for whether the audio data obtained in the optical cable to be measured is a valid signal. Then, by obtaining the real-time audio data at the current sampling time point in the optical cable to be measured and calculating the reference energy, the reference energy reflects the audio energy situation before the current sampling time point. The reference noise threshold is updated by the reference energy, so that the reference noise threshold can be adaptively adjusted according to the actual audio energy situation, and thus the acquisition of valid signals can be better realized. Finally, the obtained valid signal is amplified. When the valid signal is amplified and the system noise remains unchanged, the signal-to-noise ratio of the real-time audio data increases. Since the calculation operation of the present invention is simple, complex algorithms do not need to be adopted, and additional hardware is not needed to improve the signal-to-noise ratio of audio data either. Description of the Drawings

[0018] Figure 1 It is a flowchart of the steps of the acquisition method of the present invention.

[0019] Figure 2 It is a flowchart of the steps of obtaining the reference noise threshold of the present invention.

[0020] Figure 3 It is a flowchart of the steps of obtaining the reference energy of the present invention.

[0021] Figure 4 It is a flowchart of the steps of updating the reference noise threshold of the present invention.

[0022] Figure 5 It is a flowchart of the steps of judging the valid signal of the present invention.

[0023] Figure 6 It is a system structure diagram of the acquisition system of the present invention.

[0024] Figure 7 It is a device structure diagram of the electronic device of the present invention.

[0025] Annotation of the attached drawings: Reference threshold acquisition module 11, audio data acquisition module 12, audio energy calculation module 13, noise threshold update module 14, valid signal confirmation module 15, memory 21, processor 22, bus 23, communication interface 24. Detailed Embodiments

[0026] The accompanying drawings of the present invention are only for illustrative purposes and should not be construed as limiting the present invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0027] Embodiment 1 Distributed fiber optic acoustic sensing technology (DAS technology) is a sensing technology that uses the interference effect of fiber optic backscattered Rayleigh scattering to achieve continuous distributed detection of acoustic signals. When sound or vibration causes a linear change in the interference light phase at a certain position on the optical fiber, by extracting the interference signals at different times at that position and performing demodulation, quantitative measurement of external sound or vibration can be achieved. Therefore, DAS technology has broad application prospects in fields such as perimeter security, pipeline monitoring, and seismic exploration.

[0028] However, in practical applications, the monitoring of DAS systems is affected by the signal-to-noise ratio of the audio data obtained by demodulating the interference signals. The signal-to-noise ratio refers to the ratio of the power of the effective signal to the noise power. Therefore, the lower the signal-to-noise ratio, the more difficult it is for DAS devices to identify the audio data; the signal-to-noise ratio of the audio data of DAS systems is affected by multiple factors, mainly including internal system noise and external environmental noise.

[0029] Internal system noise can include many factors such as the line width and power stability of the laser. System noise is mostly fixed noise, and even if there is no effective signal in the corresponding optical fiber, the system noise will still exist; external environmental noise can include the acoustic waves and vibration effects generated by various external environmental changes. External environmental noise is dynamic and will change to a certain extent with the change of the environment. Therefore, corresponding methods are needed to improve the signal-to-noise ratio of the audio data.

[0030] Existing DAS systems usually use technologies such as filtering and noise reduction to improve the signal-to-noise ratio, but these methods often require complex algorithms and hardware support. At the same time, due to the need for corresponding algorithms and hardware to support these methods, it is difficult to expand their applications to adapt to complex and changeable environments.

[0031] Therefore, developing a simple, effective, easy-to-implement and highly adaptable method for improving the signal-to-noise ratio of DAS audio data is of great significance for improving the audio restoration effect of DAS devices.

[0032] This embodiment provides a technical solution that can solve the above-mentioned problems of the prior art, which will be described in detail below with reference to the accompanying drawings.

[0033] As Figure 1 shown, this embodiment provides a method for obtaining audio data based on DAS. The obtaining method may specifically include: S1: Obtain the reference noise threshold of the DAS system in the optical cable to be measured; In this embodiment, the DAS system is mainly used to collect the acoustic wave influence on the optical cable to be measured. Therefore, the effective signal in this embodiment mainly refers to the acoustic wave signal received by the optical cable to be measured. In order to effectively extract the effective signal from the optical cable to be measured, it is necessary to exclude the noise from various signals received by the optical cable to be measured.

[0034] In this embodiment, the reference noise threshold is the noise condition of the DAS system in the optical cable to be measured; it can be understood that the reference noise threshold represents the system noise condition generated by the DAS system itself after the DAS system is connected to the optical cable to be measured without the interference of other external factors.

[0035] Specifically, in this embodiment, obtaining the reference noise threshold of the DAS system according to the first window audio data, as Figure 2 shown, specifically may include: S11: Collect the reference audio data of the optical cable to be measured through the DAS system; In this embodiment, the reference audio data is the audio data when there is no effective signal in the optical cable to be measured; that is, as described above, after the DAS system is connected to the optical cable to be measured, the audio data collected without the interference of other external factors. Preferably, in order to ensure the reliability of the data, the reference audio data can collect the audio data within a relatively long time range.

[0036] As described above, the reference noise threshold represents the noise condition generated inside the DAS system without the interference of other external factors. Therefore, the reference noise threshold can be obtained through the reference audio data when the optical cable to be measured does not contain effective signals.

[0037] S12: According to the preset first data window, obtain the first window audio data within the preset first time range from the reference audio data; Specifically, in this step, the reference audio data does not contain effective signals. Therefore, theoretically, the noise energy in the reference audio data is relatively balanced. Therefore, the first data window can be a fixed time window, and only the first window audio data needs to be collected once.

[0038] S13: Obtain the noise energy of the first window audio data according to the mean square deviation of the first window audio data; By calculating the mean square deviation of the first-window audio data, the positive and negative nature of the signals in the first-window audio data can be eliminated, and then the first-window audio data can be centralized to calculate the average value, which can effectively reflect the average energy level of the first-window audio data. At the same time, the mean square deviation has a certain robustness to the noise and outliers in the first-window audio data, and thus can effectively integrate the noise therein to reflect the overall energy level of the first-window audio data.

[0039] S14: Obtain the reference noise threshold according to the noise energy.

[0040] Preferably, in this embodiment, the reference noise threshold can be set to twice the noise energy.

[0041] S2: Collect the real-time audio data of the to-be-detected optical cable at the current sampling time point through the DAS system, and obtain the real-time energy of the current sampling time point according to the real-time audio data. The DAS system collects the audio data by collecting a small segment of audio data within a certain time range each time, and then splicing the audio data collected in each time range. Among them, the small time range corresponds to a sampling time point. The sampling time point is affected by the sampling accuracy of the DAS system and also needs to be set according to the actual application scenario. The shorter the sampling time point, the higher the bandwidth of the DAS system, the wider the frequency range that can be measured, and the more scenarios that can be applied. However, this will also increase the system noise and the complexity of data processing. Therefore, the specific sampling time point needs to be set according to the actual application scenario. In this embodiment, the sampling time point can be set to the millisecond level or even the microsecond level.

[0042] In this embodiment, the real-time energy of the current sampling time point can be understood as the energy situation of the real-time audio data collected at the current sampling time point in the to-be-detected optical cable. Specifically, for the acquisition of the real-time energy, the steps for obtaining the above-mentioned reference noise threshold can be referred to. Specifically, it can include calculating the mean square deviation of the real-time audio data at the current sampling time point, and obtaining the real-time energy of the real-time audio data according to the mean square deviation of the real-time audio data.

[0043] At the same time, it can be understood that there may be valid signals in the real-time audio data. Therefore, in this embodiment, the valid signals in the real-time audio data need to be identified. S3: Obtain the reference energy corresponding to the real-time audio data. In this embodiment, the reference energy is the audio energy value within a certain period of time before the current sampling time point. Therefore, as Figure 3As described above, the acquisition of the reference energy may include the following steps: S31: According to a preset second data window, obtain second-window audio data within a second time range from the audio data before the current sampling time point; In a specific implementation manner of this embodiment, since the real-time audio data can be regarded as the real-time audio data within a certain time range in the optical cable to be measured, the width of the second data window can be set according to the interval between sampling time points. Then, in the form of a sliding window, with one sampling time point as the step size, as the real-time audio data is continuously acquired, it slides in the real-time audio data until before the current sampling time point. Each time it slides, the real-time audio data contained in the second data window is intercepted to obtain the second-window audio data corresponding to the sampling time point, ensuring that the second-window audio data contains the latest audio data information.

[0044] Meanwhile, in a specific implementation manner, a sampling processing period can be set. In each sampling processing period, the second-window audio data collected each time by window sliding is cached, and the second-window audio data is processed in the buffer area. Then, after the processing of the second-window audio data in the current sampling processing period is completed, the second-window audio data in the current sampling processing period is released, and the second-window audio data in the next sampling processing period is acquired for caching processing, and so on, so that the second-window audio data in each real-time sampling processing period can be processed in a timely manner, while ensuring parallel processing of data and improving processing efficiency.

[0045] S32: Calculate the mean square error of the second-window audio data, and obtain the reference energy corresponding to the real-time audio data according to the mean square error of the second-window audio data.

[0046] As described above, the mean square error can effectively integrate the noise in the audio data. Since the second-window audio data is the same as the real-time audio data, it contains both internal system noise and external environmental noise. Therefore, by calculating the mean square error of the second-window audio data, the system noise and environmental noise in the second-window audio data can be effectively integrated, and then the overall energy level of the second-window audio data can be obtained.

[0047] Preferably, in this embodiment, obtaining the reference energy corresponding to the real-time audio data according to the mean square error of the second-window audio data may specifically be taking twice the mean square error of the second-window audio data as the reference energy of the real-time audio data.

[0048] S4: Update the reference noise threshold according to the reference energy; It can be understood that the external environmental noise in the real-time audio data is dynamic and will change with the environment. Then, in the actual application process, in order to better eliminate the influence of the noise in the real-time audio data, it is necessary to update the reference noise threshold and introduce the influence of the environmental noise into the reference noise threshold.

[0049] Therefore, in this step, as Figure 4 shown, the update of the reference noise threshold can specifically include: S41: Compare the reference energy with the reference noise threshold; S42: If the reference energy is less than the reference noise threshold, set the reference noise threshold to be equal to the reference energy; In this embodiment, the original reference noise threshold represents the internal system noise obtained in the absence of an effective signal, and the reference energy is obtained by calculating the mean square error of the second window audio data, which integrates the overall situation of the internal system noise, external environmental noise, and audio energy before the current sampling time point. Therefore, when the reference energy is less than the reference noise threshold, it means that the real-time audio data before the current sampling time point does not contain external environmental noise and audio energy and is mainly affected by environmental noise. So, the reference noise threshold is updated to be equal to the reference energy to comprehensively consider the influence of the environmental noise and internal noise.

[0050] In this step, by continuously updating the reference noise threshold, the reference noise threshold can reflect the influence of both the internal system noise and external environmental noise, enabling it to match according to the actual environmental noise and the energy situation of the effective signal, and thus being able to more accurately determine whether an effective signal appears.

[0051] S43: If the reference energy is greater than or equal to the reference noise threshold, keep the reference noise threshold unchanged.

[0052] In step S42, the reference noise threshold is updated so that the reference noise threshold can effectively reflect the situation of the internal system noise and external environmental noise. Therefore, when the reference energy is greater than or equal to the reference noise threshold, it can be understood that an effective signal may start to appear in the audio data at the previous sampling time point.

[0053] It should be noted that the reference noise threshold is equivalent to a global variable, which will be updated as time progresses, that is, with the update of the sampling time point. And the reference energy and the real-time energy are real-time variables. Therefore, through the settings of the above steps S42 and S43, the sampling time of the reference energy is matched with the reference noise threshold, which is conducive to better capturing the time when the valid signal appears and disappears.

[0054] S5: Determine whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; Specifically, in this embodiment, as Figure 5 shown, the determination of the valid signal may specifically include: S51: When the real-time energy is greater than the updated reference noise threshold, it is determined that there is a valid signal in the real-time audio data; S52: When the real-time energy is less than or equal to the updated reference noise threshold, it is determined that there is no valid signal in the real-time audio data.

[0055] As described above, the updated reference noise threshold comprehensively considers the influences of environmental noise and internal noise. Therefore, when the real-time energy at the current sampling time point is greater than the updated reference noise threshold, it can be considered that in addition to environmental noise and internal noise, the real-time energy contains a valid signal; otherwise, it can be considered that the real-time energy does not contain a valid signal.

[0056] S6: If there is a valid signal, use the current sampling time point as the starting point of the valid signal, and amplify the real-time audio data collected after the starting point; Specifically, in this embodiment, the amplification of the real-time audio data collected after the starting point may specifically include: Amplify the audio data collected after the starting point according to a preset magnification. It can be understood that when the power of the audio data is amplified while the environmental noise remains unchanged, it is equivalent to an increase in the signal-to-noise ratio of the valid signal. Preferably, in this embodiment, the preset magnification can be set to 10 times; by amplifying the valid signal by 10 times, it is equivalent to an increase in the signal-to-noise ratio of 20*lg(10)=20dB.

[0057] It can be understood that in the optical cable to be measured, valid signals may not be collected at each sampling time point, or the signal intensity of the collected valid signals is too low to be effectively analyzed.

[0058] Therefore, in this embodiment, after amplifying the real-time audio data, it may further include: Continue to collect the real-time audio data after the starting point, and obtain the corresponding reference energy according to the real-time audio data after the starting point; Further update the updated reference noise threshold according to the reference energy after the starting point; According to the real-time energy and the further updated reference noise threshold, determine whether there is a valid signal in the real-time audio data after the starting point; If there is no valid signal, use the sampling time point corresponding to the real-time audio data after the starting point as the end point of the valid signal, and stop amplifying the real-time audio data collected after the end point. Among them, the acquisition of the reference energy and the update of the reference noise threshold can be obtained respectively with reference to the descriptions of steps S31 - S32 and steps S41 - S43 above; in addition, the judgment of the end point of the valid signal can be referred to the judgment in step S52 above, that is, when the real-time energy after the starting point is less than or equal to the further updated reference noise threshold, at this time there is no valid signal in the real-time audio data after the starting point, then use the corresponding sampling time point as the end point of the valid signal.

[0059] It should be noted that in this embodiment, the amplification of the real-time audio data is actually the amplification of the valid signal, and the real-time audio data is continuously acquired. Therefore, during the acquisition of the real-time audio data, multiple segments of valid signals may be acquired, that is, the audio data between a starting point and a corresponding end point.

[0060] Therefore, stopping the amplification of the real-time audio data collected after the end point does not mean stopping the acquisition of the real-time audio data. On the contrary, it is necessary to continue to collect the real-time audio data, and continuously obtain the starting point and end point of the valid signal according to the real-time audio data, and amplify the real-time audio data between the starting point and the end point to achieve the amplification of all valid signals.

[0061] S7: Use the amplified real-time audio data as the valid audio data.

[0062] As described above, the amplified real-time audio data corresponds to the amplified valid signal. By amplifying the valid signal, the signal-to-noise ratio of the audio data is effectively improved. Further, by extracting the amplified real-time audio data as the valid audio data, the signal-to-noise ratio of the audio data is further improved.

[0063] In this embodiment, the reference noise threshold of the DAS system when there is no valid signal is collected in advance to determine whether the audio data in the optical cable to be measured is a valid signal; then, the real-time audio data containing the valid signal is collected, the real-time energy and the reference energy of the real-time audio data are calculated, and the reference noise threshold is updated by using the reference energy, so that the reference noise threshold can include the external noise and the internal noise at the previous sampling time point, and can better compare with the reference noise threshold through the real-time energy to obtain the valid signal and the starting point of the valid signal; and by amplifying the valid signal, the signal-to-noise ratio is improved without changing the system noise. This method is simple to calculate and does not require complex algorithms or additional hardware.

[0064] Embodiment 2 Based on the same inventive concept as the embodiment, as Figure 6 shown, this embodiment provides an audio data acquisition system based on DAS. The acquisition system may specifically include: A reference threshold acquisition module 11, configured to acquire the reference noise threshold of the DAS system in the optical cable to be measured; In this embodiment, the DAS system is mainly used to collect and obtain the influence of the sound waves received by the optical cable to be measured. Therefore, the valid signal in this embodiment mainly refers to the sound wave signal received by the optical cable to be measured. In order to effectively extract the valid signal from the optical cable to be measured, it is necessary to exclude the noise from various signals received by the optical cable to be measured.

[0065] In this embodiment, the reference noise threshold is the noise condition of the DAS system in the optical cable to be measured; it can be understood that the reference noise threshold represents the system noise condition generated by the DAS system itself after the DAS system is connected to the optical cable to be measured without the interference of other external factors.

[0066] Specifically, in this embodiment, the acquiring the reference noise threshold of the DAS system according to the first window audio data may specifically include: First, the reference audio data of the optical cable to be measured is collected by the DAS system; In this embodiment, the reference audio data is the audio data when there is no valid signal in the optical cable to be measured; that is, as described above, the audio data collected after the DAS system is connected to the optical cable to be measured without the interference of other external factors. Preferably, in order to ensure the reliability of the data, the reference audio data may collect the audio data within a relatively long time range.

[0067] As described above, the reference noise threshold represents the noise condition generated inside the DAS system without the interference of other external factors. Therefore, the reference noise threshold can be obtained through the reference audio data when there is no valid signal in the optical cable to be measured.

[0068] Next, according to a preset first data window, obtain first window audio data within a preset first time range from the reference audio data; Specifically, since there is no valid signal in the reference audio data, theoretically, the noise energy in the reference audio data is relatively balanced. Therefore, the first data window can be a fixed time window, and only the first window audio data needs to be collected once.

[0069] Then, obtain the noise energy of the first window audio data according to the mean square error of the first window audio data; By calculating the mean square error of the first window audio data, the positive and negative nature of the signal in the first window audio data can be eliminated, and then the first window audio data can be centralized to calculate the average value, which can effectively reflect the average energy level of the first window audio data; at the same time, the mean square error has a certain robustness to the noise and outliers in the first window audio data, and can effectively integrate the noise therein to reflect the overall energy level of the first window audio data.

[0070] Finally, obtain the reference noise threshold according to the noise energy.

[0071] Preferably, in this embodiment, the reference noise threshold can be set to twice the noise energy.

[0072] The audio data acquisition module 12 is configured to collect real-time audio data of the to-be-tested optical cable at the current sampling time point through a DAS system, and obtain the real-time energy at the current sampling time point according to the real-time audio data; The DAS system acquires the audio data by collecting a small segment of audio data within a time range each time, and then splicing the audio data collected in each time range; wherein, the small time range corresponds to a sampling time point. The sampling time point is affected by the sampling accuracy of the DAS system and also needs to be set according to the actual application scenario; the shorter the sampling time point, the higher the bandwidth of the DAS system, the wider the frequency range that can be measured, and the more scenarios that can be applied, but this will also increase the system noise and the complexity of data processing. Therefore, the specific sampling time point needs to be set according to the actual application scenario; in this embodiment, the sampling time point can be set to the millisecond level or even the microsecond level.

[0073] In this embodiment, the real-time energy at the current sampling time point can be understood as the energy situation of the real-time audio data collected at the current sampling time point in the optical cable to be measured. Specifically, for the acquisition of the real-time energy, reference can be made to the acquisition of the above-mentioned reference noise threshold. Specifically, it may include calculating the mean square error of the real-time audio data at the current sampling time point, and obtaining the real-time energy of the real-time audio data according to the mean square error of the real-time audio data.

[0074] Meanwhile, it can be understood that the real-time audio data may contain valid signals. Therefore, in this embodiment, it is necessary to identify the valid signals in the real-time audio data.

[0075] The audio energy calculation module 13 is used to obtain the reference energy corresponding to the real-time audio data. In this embodiment, the reference energy is the audio energy value within a period of time before the current sampling time point. Therefore, the acquisition of the reference energy may include: First, according to a preset second data window, second-window audio data within a second time range is obtained from the audio data before the current sampling time point. In a specific implementation manner of this embodiment, since the real-time audio data can be regarded as the real-time audio data within a certain time range in the optical cable to be measured, the width of the second data window can be set according to the interval between sampling time points. Then, in the form of a sliding window, with one sampling time point as the step size, as the real-time audio data is continuously acquired, it slides in the real-time audio data until before the current sampling time point. Each time it slides, the real-time audio data contained in the second data window is intercepted to obtain the second-window audio data corresponding to the corresponding sampling time point, ensuring that the second-window audio data contains the latest audio data information.

[0076] Meanwhile, in a specific implementation manner, a sampling processing period can be set. In each sampling processing period, the second-window audio data collected each time by window sliding is cached, and the second-window audio data is processed in the buffer area. Then, after the processing of the second-window audio data in the current sampling processing period is completed, the second-window audio data in the current sampling processing period is released, and the second-window audio data in the next sampling processing period is obtained for caching processing, and so on, so that the second-window audio data in each real-time sampling processing period can be processed in a timely manner, while ensuring parallel processing of data and improving processing efficiency.

[0077] Then, calculate the mean square error of the second-window audio data, and obtain the reference energy corresponding to the real-time audio data according to the mean square error of the second-window audio data.

[0078] As described above, the mean square error can effectively integrate the noise in the audio data. Since the second window audio data is the same as the real-time audio data, which contains both internal system noise and external environmental noise, by calculating the mean square error of the second window audio data, the system noise and environmental noise in the second window audio data can be effectively integrated, and then the overall energy level of the second window audio data can be obtained.

[0079] Preferably, in this embodiment, obtaining the reference energy corresponding to the real-time audio data according to the mean square error of the second window audio data may specifically be taking twice the mean square error of the second window audio data as the reference energy of the real-time audio data.

[0080] The noise threshold update module 14 is used to update the reference noise threshold according to the reference energy; It can be understood that the external environmental noise in the real-time audio data is dynamic and will change with the environment. Then, in the actual application process, in order to better eliminate the influence of the noise in the real-time audio data, it is necessary to update the reference noise threshold and introduce the influence of the environmental noise into the reference noise threshold.

[0081] Therefore, the update of the reference noise threshold may specifically include: Comparing the reference energy with the reference noise threshold; If the reference energy is less than the reference noise threshold, set the reference noise threshold to be equal to the reference energy; In this embodiment, the original reference noise threshold represents the internal system noise situation obtained without an effective signal, and the reference energy is obtained by calculating the mean square error of the second window audio data, which integrates the overall situation of the internal system noise, external environmental noise, and audio energy before the current sampling time point. Therefore, when the reference energy is less than the reference noise threshold, it means that the real-time audio data before the current sampling time point does not contain external environmental noise and audio energy and is mainly affected by environmental noise. So, the reference noise threshold is updated to be equal to the reference energy to comprehensively consider the influence of environmental noise and internal noise.

[0082] Specifically, by continuously updating the reference noise threshold, the reference noise threshold can reflect the influence of both internal system noise and external environmental noise, enabling it to match according to the actual environmental noise and the energy situation of the effective signal, and thus being able to more accurately be used to judge whether an effective signal appears.

[0083] Next, if the reference energy is greater than or equal to the reference noise threshold, the reference noise threshold remains unchanged.

[0084] Specifically, the update of the reference noise threshold enables the reference noise threshold to effectively reflect the internal system noise and external environmental noise. Therefore, when the reference energy is greater than or equal to the reference noise threshold, it can be understood that an effective signal may start to appear in the audio data at the previous sampling time point.

[0085] The effective signal confirmation module 15 is configured to determine whether there is an effective signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; Specifically, in this embodiment, the determination of the effective signal may specifically include: When the real-time energy is greater than the updated reference noise threshold, it is determined that there is an effective signal in the real-time audio data; When the real-time energy is less than or equal to the updated reference noise threshold, it is determined that there is no effective signal in the real-time audio data.

[0086] As described above, the updated reference noise threshold incorporates the effects of environmental noise and internal noise. Therefore, when the real-time energy at the current sampling time point is greater than the updated reference noise threshold, it can be considered that in addition to environmental noise and internal noise, the real-time energy contains an effective signal; otherwise, it can be considered that the real-time energy does not contain an effective signal.

[0087] If there is an effective signal, the current sampling time point is used as the starting point of the effective signal, and the real-time audio data collected after the starting point is amplified; Specifically, in this embodiment, the amplification of the real-time audio data collected after the starting point may specifically include: The audio data collected after the starting point is amplified according to a preset magnification factor. It can be understood that when the power of the audio data is amplified while the environmental noise remains unchanged, it is equivalent to an increase in the signal-to-noise ratio of the effective signal. Preferably, in this embodiment, the preset magnification factor can be set to 10 times; by amplifying the effective signal by 10 times, it is equivalent to increasing the signal-to-noise ratio by 20*lg(10)=20dB.

[0088] It can be understood that in the optical cable to be measured, an effective signal may not necessarily be collected at each sampling time point, or the signal intensity of the collected effective signal is too low to be effectively analyzed.

[0089] Therefore, in this embodiment, after amplifying the real-time audio data, it may further include: Continue to collect the real-time audio data after the starting point, and obtain the corresponding reference energy according to the real-time audio data after the starting point; Further update the updated reference noise threshold according to the reference energy after the starting point; According to the real-time energy and the further updated reference noise threshold, determine whether there is a valid signal in the real-time audio data after the starting point; If there is no valid signal, use the sampling time point corresponding to the real-time audio data after the starting point as the end point of the valid signal, and stop amplifying the real-time audio data collected after the end point. Among them, the acquisition of the reference energy can be implemented by the above-mentioned audio energy calculation module 13, and the update of the reference noise threshold can be implemented by the above-mentioned noise threshold update module 14; and the judgment of the valid signal can be implemented by the above-mentioned valid signal confirmation module 15. The judgment of the end point of the valid signal can be: when the real-time energy is less than or equal to the updated reference noise threshold, there is no valid signal in the real-time audio data at this time, and the corresponding sampling time point is used as the end point of the valid signal.

[0090] It should be noted that in this embodiment, the amplification of the real-time audio data is actually the amplification of the valid signal. The real-time audio data is continuously acquired. Therefore, during the acquisition of the real-time audio data, multiple segments of valid signals may be acquired, that is, the audio data between a starting point and the corresponding end point.

[0091] Therefore, stopping the amplification of the real-time audio data collected after the end point does not stop the acquisition of the real-time audio data. On the contrary, it is necessary to continue to collect the real-time audio data, and continuously obtain the starting point and end point of the valid signal according to the real-time audio data, and amplify the real-time audio data between the starting point and the end point to achieve the amplification of all valid signals.

[0092] The valid signal confirmation module 15 is further configured to use the amplified real-time audio data as valid audio data; As described above, the amplified real-time audio data corresponds to the amplified valid signal. By amplifying the valid signal, the signal-to-noise ratio of the audio data is effectively improved. Further, by extracting the amplified real-time audio data as valid audio data, the signal-to-noise ratio of the audio data is further improved.

[0093] Embodiment 3 Based on the same inventive concept as in Embodiment 1, as Figure 7As shown, this embodiment provides an electronic device, including a memory 21 and a processor 22. The memory 21 stores computer-readable instructions, and the processor 22 executes the computer-readable instructions to implement the method for obtaining audio data based on DAS in this embodiment.

[0094] Preferably, the electronic device further includes a bus 23 and a communication interface 24. The processor 22, the communication interface 24, and the memory 21 are connected through the bus 23.

[0095] Among them, the memory 21 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory. The communication connection between this system network element and at least one other network element is realized through at least one communication interface 24 (which can be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. can be used. The bus 23 can be an ISA bus, a PCI bus, an EISA bus, etc. The bus 23 can be divided into an address bus, a data bus, a control bus, etc. (not fully drawn in the figure).

[0096] The processor 22 may be an integrated circuit chip with the ability to process signals. In a specific implementation process, each step in the embodiments of the above method may be completed by the integrated logic circuit of the hardware in the processor 22 or the instructions in the form of software. The above-mentioned processor 22 may be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it may also be a digital signal processor (DSP for short), an application specific integrated circuit (ASIC for short), a field-programmable gate array (FPGA for short), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, which can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor 22 may also be any conventional processor 22, etc. The steps of the method disclosed in combination with the embodiments of the present invention may be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by the combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 21, and the processor 22 reads the information in the memory 21 and combines its hardware to complete the steps of the method in the foregoing embodiments.

[0097] The embodiments of the present invention also provide a computer-readable storage medium. The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by the processor 22, the computer-executable instructions cause the processor 22 to implement the above-mentioned method for obtaining audio data based on DAS. For the specific implementation, reference may be made to the embodiments, which will not be elaborated here.

[0098] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0099] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the technical solutions of the present invention, rather than limitations on the specific implementation manners of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An audio data acquisition method based on DAS, characterized in that The acquisition method includes: Obtaining the reference noise threshold of the DAS system in the optical cable to be measured; Collecting the real-time audio data of the optical cable to be measured at the current sampling time point through the DAS system, and obtaining the real-time energy at the current sampling time point according to the real-time audio data; Obtaining the reference energy corresponding to the real-time audio data; the reference energy is the audio energy value within a period of time before the current sampling time point; Updating the reference noise threshold according to the reference energy; Judging whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; If there is a valid signal, taking the current sampling time point as the starting point of the valid signal, and amplifying the real-time audio data collected after the starting point; Taking the amplified real-time audio data as valid audio data.

2. The audio data acquisition method based on DAS according to claim 1, wherein The obtaining of the reference noise threshold of the DAS system in the optical cable to be measured specifically includes: Collecting the reference audio data of the optical cable to be measured through the DAS system; the reference audio data is the audio data when there is no valid signal in the optical cable to be measured; Obtaining the first window audio data within a preset first time range from the reference audio data according to a preset first data window; Obtaining the noise energy of the first window audio data according to the mean square error of the first window audio data; Obtaining the reference noise threshold according to the noise energy.

3. The audio data acquisition method based on DAS according to claim 1, wherein The obtaining of the reference energy corresponding to the real-time audio data specifically includes: Obtaining the second window audio data within a second time range from the audio data before the current sampling time point according to a preset second data window; Calculating the mean square error of the second window audio data, and obtaining the reference energy corresponding to the real-time audio data according to the mean square error of the second window audio data.

4. The audio data acquisition method based on DAS according to claim 1, wherein The updating of the reference noise threshold according to the reference energy specifically includes: Comparing the reference energy with the reference noise threshold; If the reference energy is less than the reference noise threshold, setting the reference noise threshold to be equal to the reference energy; If the reference energy is greater than or equal to the reference noise threshold, keeping the reference noise threshold unchanged.

5. The audio data acquisition method based on DAS according to claim 1, wherein The judging of whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold specifically includes: When the real-time energy is greater than the updated reference noise threshold, determining that there is a valid signal in the real-time audio data; When the real-time energy is less than or equal to the updated reference noise threshold, determining that there is no valid signal in the real-time audio data.

6. The method for obtaining audio data based on DAS according to any one of claims 1-5, characterized in that The amplifying of the real-time audio data collected after the starting point specifically is: Amplifying the audio data collected after the starting point according to a preset magnification factor.

7. The method for acquiring audio data based on DAS according to any one of claims 1-5, characterized in that, After the amplifying of the real-time audio data collected after the starting point, it further includes: Continuing to collect the real-time audio data after the starting point, and obtaining the corresponding reference energy according to the real-time audio data after the starting point; Further update the updated reference noise threshold according to the reference energy after the starting point; Judge whether there is a valid signal in the real-time audio data after the starting point according to the real-time energy and the further updated reference noise threshold; If there is no valid signal, use the sampling time point corresponding to the real-time audio data after the starting point as the end point of the valid signal, and stop amplifying the real-time audio data collected after the end point.

8. An audio data acquisition system based on DAS, characterized in that, The acquisition system includes: A reference threshold acquisition module, configured to acquire the reference noise threshold of the DAS system in the optical cable to be measured; An audio data acquisition module, configured to acquire the real-time audio data of the current sampling time point of the optical cable to be measured through the DAS system, and acquire the real-time energy of the current sampling time point according to the real-time audio data; An audio energy calculation module, configured to acquire the reference energy corresponding to the real-time audio data; the reference energy is the audio energy value within a period of time before the current sampling time point; A noise threshold update module, configured to update the reference noise threshold according to the reference energy; A valid signal confirmation module, configured to judge whether there is a valid signal in the real-time audio data according to the real-time energy and the updated reference noise threshold; if there is a valid signal, use the current sampling time point as the starting point of the valid signal, amplify the real-time audio data collected after the starting point; and use the amplified real-time audio data as valid audio data.

9. An electronic device, comprising a memory and a processor, characterized in that, The computer-readable instructions are stored on the memory, and the processor executes the computer-readable instructions to implement the DAS-based audio data acquisition method according to any one of claims 1-7 above.

10. A computer storage medium, characterized in that, The computer-readable instructions are stored thereon, and when the computer-readable instructions are executed, the DAS-based audio data acquisition method according to any one of claims 1-7 above is implemented.

Images