Near field communication optimization method in highway engineering environment

Abstract

The invention discloses a near field communication optimization method in a highway engineering environment, and relates to the field of highway engineering communication.The near field communication optimization method comprises the steps that in a networking limited tunnel in the highway engineering environment, a loudspeaker processes audio data and sends the audio data to a sending end; the sending end outputs audio data to two adjacent receiving ends; the receiving end processes the audio data and plays the audio data on the loudspeaker; wherein one receiving end exchanges delay information with the sending end through a timestamp synchronization mechanism, and the loudspeaker of the same receiving end processes the delay information and plays audio after being adjusted according to self delay; and the other receiving end obtains the predicted audio frame through an audio prediction algorithm, and the loudspeaker of the same receiving end processes the predicted audio frame and plays the audio according to self delay adjustment. According to the method, the prediction frame is matched with the timestamp synchronization technology, accurate and efficient transmission of near-field data is achieved, the one-to-one effective transmission range of near-field communication is exceeded, and data information can be completely transmitted without errors.

Description

Technical Field

[0001] The present invention relates to the field of highway engineering communications, and in particular to a near field communication optimization method in a highway engineering environment. Background Art

[0002] In highway engineering projects, near-field communications are involved in confidential spaces such as tunnels and air-raid shelters. Data transmission is limited because the project location and distance do not meet the networking requirements in terms of hardware conditions. The long distance of near-field communications leads to low data transmission efficiency, easy packet loss and poor data consistency. Summary of the invention

[0003] The present invention provides a near field communication optimization method in a highway engineering environment to solve the problems of the prior art.

[0004] In a first aspect, the present invention provides a near field communication optimization method in a highway engineering environment, comprising: In networked constrained tunnels in highway engineering environments, including: The speaker processes the audio data to the sender; The transmitting end outputs audio data to two adjacent receiving ends; The receiving end processes the audio data and plays it on the speaker; Among them, a receiving end exchanges delay information with the sending end through a timestamp synchronization mechanism, and the speaker of the same receiving end processes the delay information and plays the audio after adjusting it according to its own delay; Among them, another receiving end obtains the predicted audio frame through the audio prediction algorithm, and the speaker of the same receiving end processes the predicted audio frame and plays the audio after adjusting it according to its own delay.

[0005] Furthermore, every three near-field communication devices form a communication optimization group, wherein one transmitting end corresponds to two adjacent receiving ends, one of the receiving ends is converted into a transmitting end through a switching switch after receiving the audio data, and sends the audio data to the two adjacent receiving ends, one of the receiving ends being the initial transmitting end.

[0006] Furthermore, the other receiving end obtains the predicted audio frame through the audio prediction algorithm, and the speaker of the same receiving end processes the predicted audio frame and plays the audio after adjusting the delay thereof, including: The received audio data is weighted linearly combined to obtain the approximate current value. The formula is as follows: in, a k are the predictor coefficients, determined by minimizing the squared difference between the actual audio data and the predicted samples; : represents the predicted value of the current sampling point; x [ n ]: represents the true value of the current sampling point; x[n−k] : represents the true value of the kth historical sampling point; : represents the kth LPC coefficient, which is used to weight the historical sampling points; e [ n ]: represents the prediction error, that is, the difference between the true value and the predicted value; P : Represents the order of the predictor, that is, the number of historical sampling points used to predict the current value.

[0007] Furthermore, the one receiving end exchanges delay information with the transmitting end through a timestamp synchronization mechanism, and the speaker of the same receiving end processes the delay information and plays the audio after adjusting its own delay, including: The receiving end receives the timestamp of the synchronous packaging of the audio data packet, parses the timestamp of the audio data packet and compares it with the local time of the near field communication device where the receiving end is located, and calculates the transmission delay of the audio data; Perform data correction.

[0008] Furthermore, the data correction includes: Based on the calculated delay, the buffer size of the audio data is dynamically adjusted, and the audio alignment algorithm is connected to synchronize the audio data.

[0009] Furthermore, the receiver periodically exchanges delay information with the transmitter and synchronously performs a timestamp calibration step periodically to adapt to the device's drift.

[0010] Furthermore, when the audio data packet synchronously transmits the data text, the display screen corresponding to the speaker performs text transcription, and the receiving end receives the transcribed text, and corrects the audio data according to the transcribed text, specifically including: Acoustic feature extraction: Call the Wav2Vec2 model to extract the acoustic features of audio data; Generate frame-level label probabilities: Calculate the label category probability for each audio frame; Generate Grid Matrix: Create a matrix representing the probability of labels being aligned at time steps; Find the most likely path: Use a dynamic programming algorithm to find the most likely alignment path; Merge segments into words: Merge segments into words and calculate the alignment time for each word; The playback delay of the audio data in the audio data packet is adjusted according to the alignment path, so that the audio data acquired in the speaker is aligned in time with the text on the display screen.

[0011] Furthermore, the LPC order P It is determined by the number of resonance peaks, where one resonance peak corresponds to a pair of poles.

[0012] Further, when the switch is switched so that the current receiving end becomes the sending end to transmit audio data externally, the original initial sending end becomes the receiving end and synchronously receives the delay information or the predicted audio frame; When the delay information is sent, the receiving end where the original initial sending end is located removes the delay of the near field communication device in the delay information, and then plays the audio after adjusting according to its own delay; When the predicted audio frame is sent, the receiving end where the original initial sending end is located directly loads the adjustment data of the predicted audio frame and then plays the audio.

[0013] Furthermore, when each receiving end switches the switch to send out the received audio data, the received delay information or predicted audio frame sent by the original sending end is consistent. Each group of three near-field communication devices in the communication optimization group includes two cycles of delay information correction and one cycle of audio frame correction, or includes one cycle of delay information correction and two cycles of audio frame correction.

[0014] In a second aspect, the present invention provides a near field communication optimization system in a highway engineering environment, comprising at least one communication optimization group, each communication optimization group comprising three near field communication devices, each near field communication device comprising a switching switch, a transmitting end, i.e., a receiving end, a display screen, a speaker, and an audio collector; cooperated to implement any method as in the first aspect; Among them, the switching switch switches the transmitting end to the receiving end, and switches the receiving end to the transmitting end; The multiple communication optimization groups overlap two adjacent near field communication devices, and each near field communication device forwards the audio data to the original sending end for audio data verification.

[0015] The present invention provides a near-field communication optimization method in a highway engineering environment, which uses prediction frames in conjunction with timestamp synchronization technology to achieve accurate and efficient transmission of near-field data, and exceeds the one-to-one effective transmission range of near-field communication, and can transmit data information completely and accurately.

[0016] The communication optimization group developed by the present invention reduces communication costs and improves the efficiency of highway engineering operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 A flow chart of a near field communication optimization method in a highway engineering environment provided by an exemplary embodiment of the present invention.

[0018] Figure 2 A framework diagram of a near field communication optimization system in a highway engineering environment provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0019] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0020] First, the terms involved in the present invention are explained: Bluetooth is a short-range wireless communication technology that operates in the 2.4GHz ISM band and uses frequency hopping spread spectrum technology to achieve short-range communication between devices. Bluetooth devices connect to each other by establishing a pairing relationship. The pairing process includes steps such as device discovery, connection establishment, authentication, and encryption to ensure the security and reliability of communication.

[0021] In a two-way Bluetooth connection, each device is equipped with a microphone and a speaker. When one party speaks, the microphone converts the sound signal into an electrical signal, which is converted into a digital signal by an analog-to-digital converter (ADC).

[0022] The digital signal is pre-processed by the signal processing module, such as noise reduction, gain control, etc., to improve the voice quality. Then, the signal is encoded by the audio codec (such as SBC, AAC, etc.) in the Bluetooth protocol stack to compress the digital signal into a format suitable for wireless transmission.

[0023] However, due to the problems of Bluetooth connection efficiency and connection sequence, near-field communication leads to inconsistent data transmission, and is prone to packet loss and Bluetooth disconnection. This is because the communication signal is poor and there is no basic equipment to realize the Internet. Therefore, it is considered to use near-field Bluetooth communication plus data processing to sort the Bluetooth interconnection and then transmit the data signal, so that each Bluetooth sub-device is a near-field "gateway" and acts as a data hub to transmit data.

[0024] The present invention provides a near field communication optimization method in a highway engineering environment, aiming to solve the above technical problems in the prior art.

[0025] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0026] Embodiment 1: This embodiment provides a near field communication optimization method in a highway engineering environment, which specifically includes the following steps in a network-restricted tunnel in a highway engineering environment: Figure 1 As shown: Step a, the speaker processes the audio data to the transmitting end; Step b, the transmitting end outputs audio data to two adjacent receiving ends; Step c1, a receiving end exchanges delay information with a sending end through a timestamp synchronization mechanism, and a speaker at the same receiving end processes the delay information and plays audio after adjusting its own delay; Step c2: another receiving end obtains a predicted audio frame through an audio prediction algorithm, and a speaker at the same receiving end processes the predicted audio frame and plays the audio after adjusting the delay thereof; Step d, after receiving the audio data, a receiving end is converted into a transmitting end by switching a switch, and sends the audio data to two adjacent receiving ends, one of which is the initial transmitting end; Step e: repeat steps c1, c2, and d until all receiving ends receive the audio data.

[0027] Wherein, for step c2, LPC is used to determine the predictor coefficient by minimizing the prediction error, and the audio sample data is predicted. The predictor coefficient is solved by using the Yule-Walker equation based on the autocorrelation function of the audio signal, and the Levinson-Durbin algorithm is used to solve the Yule-Walker equation. The specific example is as follows: Read an audio file: Use MATLAB's audioread function to read the audio file.

[0028] Convert audio signals to mono for processing Windowing: The audio signal is windowed to reduce spectral leakage.

[0029] Window the audio frame using a Hamming window or other window function.

[0030] Calculate the LPC coefficients: Use MATLAB's lpc function to calculate the LPC coefficients. The basic syntax of the lpc function is lpc(x, p), where x is the input signal, P is the order of the predictor.

[0031] The choice of predictor order has an important impact on the prediction results and usually needs to be adjusted according to the specific application.

[0032] Generation of prediction signal: Using the calculated LPC coefficients, a prediction signal is generated through a filter.

[0033] Use the filter function to generate prediction signals.

[0034] Calculation of prediction error: The difference between the original audio signal and the predicted signal is calculated to obtain the prediction error.

[0035] The prediction error can be used to evaluate the performance of the predictor.

[0036] The code example is as follows: [x, fs] = audioread('1.wav'); % Read audio file x1 = x(:,1); % Convert to mono n = 200; % frame length p0 = 50; % overlap length xx = buffer(x1, n, p0); % Frame processing m = 8; % Select the 8th frame y = xx((m-1)*n+1:m*n); % Extract one frame of data p = 12; % predictor order ar = lpc(y, p); % Calculate LPC coefficients est_x = filter([0 -ar(2:end)], 1, y); % Generate prediction signal err = y - est_x; % Calculate the prediction error % Drawing results figure; plot(x1); title('Original signal'); figure; subplot(2,2,1); plot(y, 'r'); title('Original frame'); subplot(2,2,2); plot(est_x); title('A frame predicted by LPC'); subplot(2,2,3); plot(err, 'r'); title('Residual signal'); like Figure 2 As shown, this embodiment 2 provides a system to implement the multi-method operation as in embodiment 1, specifically including: inside a section of a mountain, five near-field communication devices with a long distance between them are arranged, the five near-field communication devices are three groups of communication optimization groups, each communication optimization group includes three adjacent near-field communication devices, each near-field communication device includes a switching switch, a transmitting end, i.e., a receiving end, a display screen, a speaker and an audio collector; due to poor network communication in the mountain, near-field communication devices are used for data transmission, from which it can be seen that dotted lines are exchanged to predict audio frames, and delay information is exchanged between each interval of near-field communication devices, and near-field low-latency communication is achieved between each interval of near-field communication devices, and the delay is lower than human body induction, therefore, it is equivalent to no delay, and the original near-field communication between two near-field communication devices with a long distance between them cannot achieve the effect of the present invention due to delay, electromagnetic shielding, interference and other factors, wherein the switching switch switches the transmitting end to the receiving end, and switches the receiving end to the transmitting end.

[0037] In the several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0038] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0039] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0040] Those skilled in the art will appreciate that the embodiments of the present invention may be provided as methods or systems. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects.

[0041] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0042] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

[0043] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only, and the true scope and spirit of the present invention is indicated by the claims above.

[0044] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A near field communication optimization method in a highway engineering environment, characterized in that: In networked constrained tunnels in highway engineering environments, including: The speaker processes the audio data to the sender; The transmitting end outputs audio data to two adjacent receiving ends; The receiving end processes the audio data and plays it on the speaker; Among them, a receiving end exchanges delay information with the sending end through a timestamp synchronization mechanism, and the speaker of the same receiving end processes the delay information and plays the audio after adjusting it according to its own delay; Among them, another receiving end obtains the predicted audio frame through the audio prediction algorithm, and the speaker of the same receiving end processes the predicted audio frame and plays the audio after adjusting it according to its own delay.

2. The near field communication optimization method in a highway engineering environment according to claim 1 is characterized in that: Every three near-field communication devices form a communication optimization group, in which one transmitter corresponds to two adjacent receivers, one of which is converted into a transmitter through a switching switch after receiving audio data, and sends audio data to the two adjacent receivers, one of which is the initial transmitter.

3. The near field communication optimization method in a highway engineering environment according to claim 2 is characterized in that: The other receiving end obtains the predicted audio frame through the audio prediction algorithm, and the speaker of the same receiving end processes the predicted audio frame and plays the audio after adjusting the delay thereof, including: The received audio data is weighted linearly combined to obtain the approximate current value. The formula is as follows: in, a k are the predictor coefficients, determined by minimizing the squared difference between the actual audio data and the predicted samples; : represents the predicted value of the current sampling point; x [ n ]: represents the true value of the current sampling point; x[n−k] : represents the true value of the kth historical sampling point; : represents the kth LPC coefficient, which is used to weight the historical sampling points; e [ n ]: represents the prediction error, that is, the difference between the true value and the predicted value; P : Represents the order of the predictor, that is, the number of historical sampling points used to predict the current value.

4. The near field communication optimization method in a highway engineering environment according to claim 2 is characterized in that: The receiving end exchanges delay information with the transmitting end through a timestamp synchronization mechanism, and the speaker of the same receiving end processes the delay information and plays the audio after adjusting the delay according to its own delay, including: The receiving end receives the timestamp of the synchronous packaging of the audio data packet, parses the timestamp of the audio data packet and compares it with the local time of the near field communication device where the receiving end is located, and calculates the transmission delay of the audio data; Perform data correction.

5. The near field communication optimization method in a highway engineering environment according to claim 4 is characterized in that: The data correction comprises: Based on the calculated delay, the buffer size of the audio data is dynamically adjusted, and the audio alignment algorithm is connected to synchronize the audio data.

6. The near field communication optimization method in a highway engineering environment according to claim 4, characterized in that: The receiver periodically exchanges delay information with the sender and synchronously performs the timestamp calibration step periodically.

7. The near field communication optimization method in a highway engineering environment according to claim 5, characterized in that: When the audio data packet transmits the data text synchronously, the display screen corresponding to the speaker performs text transcription, and the receiving end receives the transcribed text and corrects the audio data according to the transcribed text, specifically including: Acoustic feature extraction: Call the Wav2Vec2 model to extract the acoustic features of audio data; Generate frame-level label probabilities: Calculate the label category probability for each audio frame; Generate Grid Matrix: Create a matrix representing the probability of labels being aligned at time steps; Find the most likely path: Use a dynamic programming algorithm to find the most likely alignment path; Merge segments into words: Merge segments into words and calculate the alignment time for each word; The playback delay of the audio data in the audio data packet is adjusted according to the alignment path, so that the audio data acquired in the speaker is aligned in time with the text on the display screen.

8. The near field communication optimization method in a highway engineering environment according to claim 3 is characterized in that: in, LPC order P It is determined by the number of resonance peaks, where one resonance peak corresponds to a pair of poles.

9. The near field communication optimization method in a highway engineering environment according to claim 2, characterized in that: When the switch is switched from the current receiving end to the sending end to transmit audio data outward, the original initial sending end becomes the receiving end and synchronously receives the delay information or the predicted audio frame; When the delay information is sent, the receiving end where the original initial sending end is located removes the delay of the near field communication device in the delay information, and then plays the audio after adjusting according to its own delay; When the predicted audio frame is sent, the receiving end where the original initial sending end is located directly loads the adjustment data of the predicted audio frame and then plays the audio.

10. The near field communication optimization method in a highway engineering environment according to claim 9, characterized in that: When each receiving end switches the switch to send out the received audio data, the received delay information or predicted audio frame sent by the original sending end is consistent. Each group of three near-field communication devices in the communication optimization group includes two cycles of delay information correction and one cycle of audio frame correction, or one cycle of delay information correction and two cycles of audio frame correction.

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