Digital or analog private network communication early warning equipment special for railway

Abstract

The invention provides digital or analog private network communication early warning equipment special for a railway. The digital or analog private network communication early warning equipment comprises a radio frequency receiving module, an analog signal processing module, a digital signal processing module, a signal feature detection module, a main control module and a man-machine interaction module, the man-machine interaction module is used for setting the same working frequency and signaling as the railway special interphone; the radio frequency receiving module is used for receiving an analog signal of the railway special interphone in an analog system and a digital signal of the railway special interphone in a digital system; and the signal feature detection module is used for judging the call validity through carrier waves and subaudio frequencies in an analog system and judging the call validity through carrier waves, color codes and ID verification in a digital system so as to monitor the use condition of the special interphone for the railway. Through the receiving function of the digital or analog interphone special for the railway, the use condition of the railway safety officer talkback equipment can be indirectly monitored, and the safety of a railway wireless communication network and the reliability of dispatching and commanding are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of railway early warning equipment, and in particular to a railway-specific digital or analog private network communication early warning equipment. Background Art

[0002] Railway-specific wireless communication systems, as a core component of railway transportation dispatching and command, undertake crucial communication tasks such as train operation control, station-department intercommunication, and emergency command. Traditional railway-specific intercom systems coexist with analog formats (such as FM frequency modulation + CTCSS sub-audio) and digital formats (such as the DMR protocol). Existing communication monitoring equipment typically utilizes a single-format processing architecture, which suffers from the following technical drawbacks: 1) Dual-mode signal processing is incompatible, requiring two independent systems to monitor analog and digital communications, resulting in equipment redundancy and increased costs; 2) Signal validity is judged using a single dimension: analog formats rely solely on carrier detection, susceptible to co-channel interference, while digital formats lack multi-level verification using color codes and IDs, posing the risk of false triggering; 3) The lack of intelligent call feature extraction and identity recognition mechanisms makes it difficult to promptly detect unauthorized terminal access or illegal communication behavior. These issues directly impact the security of railway wireless communication networks and the reliability of dispatching and command. Summary of the Invention

[0003] In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a railway-specific digital or analog private network communication early warning device to overcome the defects in the prior art.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a railway-specific digital or analog private network communication early warning device, including a radio frequency receiving module, an analog signal processing module, a digital signal processing module, a signal feature detection module, a main control module and a human-computer interaction module; wherein the radio frequency receiving module is electrically connected and signal-connected to the main control module, the main control module is electrically connected and signal-connected to the human-computer interaction module, and the human-computer interaction module is used to set the operating frequency and signaling of the radio frequency receiving module, and the operating frequency and signaling are the same as those of the railway-specific intercom, so that the radio frequency receiving module can receive the analog signal of the railway-specific intercom in the analog format and the digital signal in the digital format, and output the corresponding baseband audio signal or digital intermediate frequency signal; the analog signal processing module is electrically connected and signal-connected to the radio frequency receiving module The analog signal processing module is connected, and is used to perform carrier detection and sub-audio decoding on the analog signal from the RF receiving module; the digital signal processing module is electrically connected and signal-connected with the RF receiving module, and is used to perform carrier detection, color code decoding and ID verification on the digital signal from the RF receiving module; the signal feature detection module is electrically connected and signal-connected with the analog signal processing module, the digital signal processing module and the main control module respectively, and the signal feature detection module is used to determine the validity of the call through the carrier and sub-audio in the analog format, and determine the validity of the call through the carrier, color code and ID verification in the digital format, and when the call is valid, sends a confirmation signal containing the ID of the railway-specific intercom to the main control module to realize the monitoring of the usage of the railway-specific intercom.

[0005] The above technical solution, through the collaborative design of the RF receiving module and the human-computer interaction module, supports adaptive reception of analog / digital dual-mode signals, covering the full operating frequency band of railway-specific walkie-talkies, significantly reducing the complexity of equipment deployment. The system automatically identifies the signal format and switches to the corresponding processing channel, with a processing delay of less than 50ms. In the analog format, a dual-factor verification of carrier and sub-audio is adopted, and in the digital format, a three-level verification system of carrier, color code, and ID is constructed. Through the reception function of railway-specific digital or analog walkie-talkies, the use of railway safety personnel's intercom equipment can be indirectly monitored, illegal terminal access or illegal communication behavior can be promptly detected, and the security of the railway wireless communication network and the reliability of dispatching and command can be improved.

[0006] As a further explanation of the railway-specific digital or analog private network communication warning device described in the present invention, preferably, it also includes a timer module and an alarm output module; wherein the timer module is electrically connected and signal-connected to the main control module, and the human-computer interaction module is also used to set the timing warning cycle of the timer module, so that when the main control module receives a confirmation signal from the signal feature detection module, the timer module is controlled to start timing, and after the railway-specific intercom stops calling, the timer module is controlled to reset the warning cycle to re-time, and the timer module sends an interrupt signal to the main control module when the timing reaches a set threshold; the alarm output module is electrically connected and signal-connected to the main control module, and the alarm output module is used to emit a warning prompt sound, vibration, and light prompt when the timing reaches the set threshold and no call is received from the railway-specific intercom.

[0007] Through the above technical solution, a configurable monitoring cycle is set through the timer module. When the railway safety officer initiates a call using the intercom, the early warning device can simultaneously receive the call from the intercom, thereby monitoring the use of the safety officer's intercom device. When the intercom device stops calling, the early warning device will reset the warning time and then restart the timing to reduce the false alarm rate and improve the reliability of the early warning. When the early warning device reaches the set time and has not received a call from the intercom device, the early warning device will issue an early warning prompt sound, vibration, and light prompt. At this time, the safety officer perceives the prompt of the early warning device through sound / light reminder / vibration, which plays a role in periodically judging the safety officer's work status and avoiding the risk of communication loss due to human negligence or equipment failure. The alarm output module supports multi-mode alarms of sound, light and vibration, adapting to the complex environment of the railway site and ensuring that the safety officer can perceive abnormal conditions in a timely manner.

[0008] As a further explanation of the railway-specific digital or analog private network communication warning equipment described in the present invention, preferably, the RF receiving module includes a tunable bandpass filter and a dual-mode RF chip; wherein, the tunable bandpass filter is located between the antenna and the RF input end of the dual-mode RF chip, the tunable bandpass filter is electrically and signal-connected to the main control module, and the center frequency of the tunable bandpass filter is dynamically adjusted by the tuning voltage output by the main control module to suppress out-of-band interference and improve the signal-to-noise ratio of the target frequency band; the dual-mode RF chip is respectively connected to the main control module, the analog signal processing module and the digital signal processing module, the dual-mode RF chip is used to receive the RF signal preprocessed by the tunable bandpass filter, and analyze the duty cycle and spectral characteristics of the RF signal by sampling the signal envelope through the built-in ADC, output the baseband audio signal to the analog signal processing module, and output the digital intermediate frequency signal to the digital signal processing module.

[0009] Through this technical solution, the tunable bandpass filter dynamically adjusts its center frequency based on the tuning voltage output by the main control module, precisely matching the operating frequency band of railway-specific intercoms and improving signal acquisition stability in complex electromagnetic environments. The dual-mode RF chip uses its built-in ADC to sample the RF signal envelope in real time, automatically analyzing the duty cycle to determine digital / analog format and spectral characteristics to determine bandwidth and modulation method, enabling switching between digital and analog intercom signals for railway-specific intercoms.

[0010] As a further illustration of the railway-specific digital or analog private network communication warning device described in the present invention, preferably, the analog signal processing module includes an analog signal carrier detection unit and a sub-audio decoding unit, the analog signal carrier detection unit is electrically and signal-connected to the sub-audio decoding unit, and the carrier detection unit and the sub-audio decoding unit are respectively electrically and signal-connected to the signal feature detection module; wherein the analog signal carrier detection unit is configured as an envelope detector, a bandpass filter and a comparator connected in sequence, for extracting the envelope waveform of the signal amplitude from the baseband audio signal through the envelope detector, filtering out the out-of-band noise through the bandpass filter and outputting a pure carrier signal, and comparing the filtered carrier signal with a preset voltage threshold through the comparator to generate a carrier presence flag signal; the sub-audio decoding unit is configured as a cascaded programmable low-pass filter and a sub-audio decoder, for separating the sub-audio component from the baseband audio signal through the programmable low-pass filter, decoding the sub-audio component through the sub-audio decoder, and outputting a sub-audio code value; so that the analog signal carrier detection unit transmits the signal strength, carrier frequency and carrier presence flag signal of the carrier, and the sub-audio decoding unit transmits the sub-audio code value to the signal feature detection module.

[0011] Through this technical solution, the analog signal carrier detection unit in the analog signal processing module uses a cascaded architecture of an envelope detector, a bandpass filter, and a comparator to extract the carrier envelope waveform from the baseband audio. It dynamically determines the presence of the carrier using a preset voltage threshold, effectively avoiding carrier misjudgments caused by signal attenuation or sudden noise. The sub-audio decoding unit uses a programmable low-pass filter to filter out speech and high-frequency noise, accurately separating the sub-audio signal and ensuring reliable sub-audio identification even in strong background noise.

[0012] As a further explanation of the railway-specific digital or analog private network communication warning equipment described in the present invention, preferably, the digital signal processing module includes a digital carrier detection unit, a color code decoding unit and an ID verification unit, the digital carrier detection unit is electrically connected and signal-connected to the color code decoding unit and the ID verification unit respectively, and the digital carrier detection unit, the color code decoding unit and the ID verification unit are electrically connected and signal-connected to the signal feature detection module respectively; wherein the digital carrier detection unit is configured as a digital down converter, a digital bandpass filter and a power detector, and is used to perform orthogonal demodulation on the digital intermediate frequency signal through the digital down converter to generate a baseband I / Q data stream, filter out-of-band noise and extract effective digital signals through the digital bandpass filter, and judge the carrier through the power detector. Existence and signal strength; the color code decoding unit is configured as a synchronization header detector and a color code extractor, which is used to match the frame synchronization sequence in the digital signal through the synchronization header detector, determine the time slot boundary and frame structure, and parse the color code field from the synchronized data frame through the color code extractor, and convert it into a color code number; the ID verification unit is configured as an ID parser and a pre-stored ID matcher, which is used to extract the sender ID information from the address field of the data frame through the ID parser, compare the extracted ID with the legal ID list preset by the main control module through the pre-stored ID matcher, and output the verification result; so that the digital carrier detection unit transmits the carrier signal strength and existence flag, the color code decoding unit transmits the color code number, and the ID verification unit transmits the ID verification result to the signal feature detection module.

[0013] Through this technical solution, the digital carrier detection unit employs orthogonal demodulation and digital bandpass filtering to effectively suppress adjacent-channel interference and phase noise. The color code decoding unit rapidly locks time slot boundaries through frame synchronization sequence matching. The color code extractor uses a cyclic redundancy check (CRC) error correction mechanism to parse the color code field, improving decoding accuracy and preventing signal crosstalk between adjacent railway communication groups, ensuring intra-group privacy. The ID verification unit extracts the sender ID from the data frame and performs a hash match against the master control module's pre-set database of legitimate IDs, effectively blocking unauthorized device access risks.

[0014] As a further explanation of the railway-specific digital or analog private network communication warning device described in the present invention, preferably, the signal feature detection module includes an analog validity judgment unit, a digital validity judgment unit and a logic arbitration unit, the analog validity judgment unit and the digital validity judgment unit are electrically and signal-connected to the logic arbitration unit respectively, and the logic arbitration unit is electrically and signal-connected to the main control module; wherein, the analog validity judgment unit is used to receive the carrier signal strength and existence flag from the analog signal processing module, generate a carrier valid flag by comparing the carrier strength with a preset threshold and verifying whether the carrier frequency is within the railway-specific frequency band, and receive the sub-audio coding value from the analog signal processing module, match it with the legal sub-audio list preset by the main control module, and generate a sub-audio valid flag; and when the carrier valid flag and the sub-audio valid flag are established at the same time, the analog validity judgment unit sends an analog format valid signal to the logic arbitration unit; the digital validity judgment unit is used to receive The digital signal processing module receives the carrier signal strength and existence flag from the digital signal processing module, generates a digital carrier valid flag by judging whether the carrier strength continuously exceeds the threshold value and the carrier duty cycle complies with the digital protocol specification, receives the color code number from the digital signal processing module, compares it with the legal color code list preset by the main control module, generates a color code valid flag, and receives the ID verification result from the digital signal processing module, generates an ID valid flag by verifying the format validity and authority level of the ID; and the digital validity judgment unit sends a digital standard valid signal to the logic arbitration unit when the carrier valid flag, color code valid flag and ID valid flag are established at the same time; the logic arbitration unit is used to select the analog standard valid signal or the digital standard valid signal as the current valid judgment result according to the standard priority strategy configured by the main control module, and generate a confirmation signal containing the corresponding railway dedicated walkie-talkie ID, standard type and timestamp according to the current valid judgment result, and transmit it to the main control module.

[0015] Through the above technical solution, the analog validity judgment unit implements double verification through hardware comparators and matchers to ensure the legitimacy of analog calls. The analog validity judgment unit simultaneously verifies the carrier strength, carrier frequency band and sub-audio coding. The three criteria are combined to take effect, and the illegal analog signal interception rate is ≥99.8%. The digital validity judgment unit ensures the compliance of digital communications through multi-level verification logic of carrier stability, color code matching, and ID authority. The digital validity judgment unit integrates carrier duty cycle, color code and ID authority verification, with a 100% blocking rate for unauthorized digital signals, eliminating the risk of counterfeit device access. The logic arbitration unit supports dynamic configuration priority of the main control module to resolve conflicts when dual-mode signals coexist and ensure the uniqueness of the judgment result.

[0016] As a further explanation of the railway-specific digital or analog private network communication warning device described in the present invention, preferably, the timer module includes a clock source unit, a timing control unit, a threshold comparison unit and an interrupt trigger unit, the clock source unit is electrically connected and signal-connected to the timing control unit, the timing control unit is electrically connected and signal-connected to the threshold comparison unit, the threshold comparison unit is electrically connected and signal-connected to the interrupt trigger unit, the interrupt trigger unit is electrically connected and signal-connected to the main control module, and the timing control unit, the threshold comparison unit and the interrupt trigger unit are respectively electrically connected and signal-connected to the main control module; wherein, the clock source unit is used to generate a reference clock signal and output a timing drive pulse; the timing control unit is used to receive the timing drive pulse, and accumulate the count when receiving the timing instruction sent by the main control module, and clear it when the reset instruction sent by the main control module; the threshold comparison unit is used to store the count value threshold corresponding to the timing warning cycle time set by the main control module through the human-computer interaction module, and compare the current count value of the timing control unit with the count value threshold in real time, and send a timeout flag to the interrupt trigger unit when the two are equal; the interrupt trigger unit is used to generate a high-level interrupt request signal after receiving the timeout flag, and transmit it to the main control module.

[0017] Through the above technical solution, the timer module realizes precise periodic control of railway safety officers' communication behavior through multi-unit collaborative timing and interrupt triggering mechanism.

[0018] As a further explanation of the railway-specific digital or analog private network communication early warning equipment described in the present invention, preferably, the alarm output module includes an sound and light alarm unit and a vibration motor unit, and the sound and light alarm unit and the vibration motor unit are respectively electrically connected and signal-connected to the main control module. The sound and light alarm unit is used to output sound pressure and three-color LED strobe indication according to the control signal of the main control module, and the vibration motor unit is used to generate vibration according to the control signal of the main control module.

[0019] Through the above technical solution, the multi-dimensional alarm fusion of sound, light and vibration has solved the perception limitations of a single mode in complex railway scenarios, ensuring that safety officers can respond to communication anomalies immediately under any working conditions.

[0020] The beneficial effects of the present invention are as follows: The present invention supports adaptive reception of analog / digital dual-mode signals through the collaborative design of the radio frequency receiving module and the human-computer interaction module, can cover the full-standard working frequency band of railway-specific intercoms (such as the 400MHz analog / digital frequency band), and significantly reduces the complexity of equipment deployment. The system automatically identifies the signal format and switches to the corresponding processing channel, and the processing delay is less than 50ms. Under the analog format, a dual-factor verification of carrier and sub-audio is adopted, and a three-level verification system of carrier, color code and ID is constructed under the digital format. Through the receiving function of railway-specific digital or analog intercoms, the use of railway safety personnel's intercom equipment can be indirectly monitored, illegal terminal access or illegal communication behavior can be discovered in time, and the security of the railway wireless communication network and the reliability of dispatching and command can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram of the architecture of the railway-specific digital or analog private network communication warning equipment and the railway-specific intercom of the present invention;

[0022] Figure 2 This is a structural block diagram of the railway-specific digital or analog private network communication early warning device of the present invention;

[0023] Figure 3 It is a structural block diagram of the radio frequency receiving module of the present invention;

[0024] Figure 4 is a structural block diagram of the analog signal processing module of the present invention;

[0025] Figure 5 is a structural block diagram of a digital signal processing module of the present invention;

[0026] Figure 6 It is a structural block diagram of the signal feature detection module of the present invention;

[0027] Figure 7 This is a structural block diagram of the timer module and alarm output module of the present invention. DETAILED DESCRIPTION

[0028] In order to further understand the structure, features and other purposes of the present invention, the following detailed description is given in conjunction with the attached preferred embodiments and the accompanying drawings. The embodiments described in the drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention.

[0029] As a first embodiment of the present invention, Figure 2 As shown, the present invention provides a railway-specific digital or analog private network communication warning device, including a radio frequency receiving module 1, an analog signal processing module 2, a digital signal processing module 3, a signal feature detection module 4, a main control module 5 and a human-computer interaction module 8.

[0030] The RF receiving module 1 is electrically connected and signal-connected to the main control module 5, and the main control module 5 is electrically connected and signal-connected to the human-computer interaction module 8. The human-computer interaction module 8 is used to set the operating frequency and signaling of the RF receiving module 1. The operating frequency and signaling are the same as those of the railway-specific intercom, so that the RF receiving module 1 can receive the analog signal of the railway-specific intercom in the analog format and the digital signal in the digital format, and output the corresponding baseband audio signal or digital intermediate frequency signal, such as Figure 1 shown.

[0031] The analog signal processing module 2 is electrically and signal-connected to the RF receiving module 1 and is configured to perform carrier detection and sub-audio decoding on the analog signal from the RF receiving module 1. The digital signal processing module 3 is electrically and signal-connected to the RF receiving module 1 and is configured to perform carrier detection, color code decoding, and ID verification on the digital signal from the RF receiving module 1.

[0032] The signal feature detection module 4 is electrically and signal-connected to the analog signal processing module 2, the digital signal processing module 3 and the main control module 5 respectively. The signal feature detection module 4 is used to determine the validity of the call through the carrier and sub-audio in the analog format, and to determine the validity of the call through the carrier, color code and ID verification in the digital format. When the call is valid, a confirmation signal containing the ID of the railway-specific intercom is sent to the main control module 5 to monitor the usage of the railway-specific intercom.

[0033] This implementation method supports adaptive reception of analog / digital dual-mode signals through the collaborative design of the RF receiving module and the human-computer interaction module, and can cover the full operating frequency band of railway-specific walkie-talkies (such as the 400MHz analog / digital band), significantly reducing the complexity of equipment deployment. The system automatically identifies the signal format and switches to the corresponding processing channel, with a processing delay of less than 50ms. In the analog format, a dual-factor verification of carrier and sub-audio is adopted, and a three-level verification system of carrier, color code and ID is constructed in the digital format. Through the receiving function of railway-specific digital or analog walkie-talkies, the use of railway safety personnel's intercom equipment can be indirectly monitored, illegal terminal access or illegal communication behavior can be discovered in a timely manner, and the security of the railway wireless communication network and the reliability of dispatching and command can be improved.

[0034] As a second embodiment of the present invention, based on the first embodiment, it further includes a timer module 6 and an alarm output module 7. Figure 1As shown, the timer module 6 is electrically and signal-connected to the main control module 5. The human-computer interaction module 8 is also used to set the timer module 6's timer warning cycle time, so that when the main control module 5 receives a confirmation signal from the signal feature detection module 4, the timer module 6 is controlled to start timing, and after the railway-specific intercom stops calling, the timer module 6 is controlled to reset the warning cycle time to restart timing, and the timer module 6 sends an interrupt signal to the main control module 5 when the timing reaches a set threshold. The alarm output module 7 is electrically and signal-connected to the main control module 5. The alarm output module 7 is used to emit a warning tone, vibration, or light prompt when the timing reaches a set threshold and no call is received from the railway-specific intercom.

[0035] This embodiment sets a configurable monitoring period (such as 1-10 minutes adjustable) through the timer module 6. When the railway safety officer uses the intercom to initiate a call, the early warning device can simultaneously receive the call from the intercom, thereby monitoring the use of the safety officer's intercom device. When the intercom device stops calling, the early warning device will reset the early warning time and then restart the timing to reduce the false alarm rate and improve the reliability of the early warning. When the early warning device timing reaches the set time and no call from the intercom device is received, the early warning device will issue an early warning prompt sound, vibration, and light prompt. At this time, the safety officer perceives the prompt of the early warning device through sound / light reminder / vibration, which plays a role in periodically judging the work status of the safety officer and avoiding the risk of communication loss due to human negligence or equipment failure. The alarm output module 7 supports multi-mode alarms of sound, light and vibration, adapting to the complex environment of the railway site (such as high noise and low light scenes), ensuring that the safety officer can perceive abnormal conditions in time.

[0036] As a third embodiment of the present invention, Figure 3 As shown, the RF receiving module 1 includes a tunable bandpass filter 11 and a dual-mode RF chip 12. The tunable bandpass filter 11 is located between the antenna and the RF input of the dual-mode RF chip 12. The tunable bandpass filter 11 is electrically and signal-connected to the main control module 5. The center frequency of the tunable bandpass filter 11 is dynamically adjusted by the tuning voltage output by the main control module 5 to suppress out-of-band interference and improve the signal-to-noise ratio in the target frequency band.

[0037] The dual-mode RF chip 12 is connected to the main control module 5, the analog signal processing module 2, and the digital signal processing module 3. The dual-mode RF chip 12 (e.g., AT1846S) receives the RF signal preprocessed by the tunable bandpass filter 11, samples the signal envelope using a built-in ADC, analyzes the RF signal's duty cycle and spectral characteristics, and outputs a baseband audio signal to the analog signal processing module 2 and a digital intermediate frequency signal to the digital signal processing module 3. The main control module 5 connects to the dual-mode RF chip 12 via an SPI interface, configuring its operating mode parameters in real time. These include the squelch threshold and sub-audio CTCSS frequency in analog mode, and the color code range and TDMA time slot parameters in digital mode.

[0038] In this embodiment, the tunable bandpass filter 11 dynamically adjusts its center frequency based on the tuning voltage output by the main control module 5, accurately matching the operating frequency band of the railway-specific intercom (e.g., UHF 400-470MHz), thereby improving signal capture stability in complex electromagnetic environments. The dual-mode RF chip 12 (e.g., AT1846S) samples the RF signal envelope in real time through a built-in ADC, automatically analyzes the duty cycle to determine the digital / analog format, and analyzes the spectrum characteristics to determine, for example, bandwidth and modulation mode, thereby achieving switching response to the intercom signal under the digital / analog format of the railway-specific intercom.

[0039] As a fourth embodiment of the present invention, Figure 4 As shown, the analog signal processing module 2 includes an analog signal carrier detection unit 21 and a sub-audio decoding unit 22. The analog signal carrier detection unit 21 is electrically connected and signal-connected to the sub-audio decoding unit 22, and the carrier detection unit 21 and the sub-audio decoding unit 22 are electrically connected and signal-connected to the signal feature detection module 4 respectively.

[0040] The analog signal carrier detection unit 21 is configured as an envelope detector, a bandpass filter, and a comparator connected in sequence. The envelope detector extracts the signal amplitude envelope waveform from the baseband audio signal, filters out-of-band noise with the bandpass filter, and outputs a pure carrier signal. The comparator compares the filtered carrier signal with a preset voltage threshold to generate a carrier presence flag signal. Using a cascaded architecture of an envelope detector, a bandpass filter, and a comparator, the analog signal carrier detection unit 21 extracts the carrier envelope waveform from the baseband audio signal and dynamically determines carrier presence (e.g., CTCSS / DCS enable status) using a preset voltage threshold, effectively avoiding carrier misjudgments caused by signal attenuation or sudden noise.

[0041] The sub-audio decoding unit 22 is configured as a cascaded programmable low-pass filter and a sub-audio decoder. It uses the programmable low-pass filter to separate the sub-audio component from the baseband audio signal, decodes the sub-audio component through the sub-audio decoder, and outputs a sub-audio code value. The sub-audio decoding unit 22 uses a programmable low-pass filter (with an adjustable cutoff frequency, such as 67-250Hz) to filter out speech and high-frequency noise, accurately separating the sub-audio signal and ensuring reliable resolution of the sub-audio identity even in strong background noise.

[0042] The analog signal carrier detection unit 21 transmits the signal strength, carrier frequency and carrier existence flag signal of the carrier, and the sub-audio code value of the sub-audio decoding unit 22 to the signal feature detection module 4 .

[0043] The analog signal processing module 2 of this embodiment collaboratively analyzes the carrier and sub-audio through the analog signal carrier detection unit 21 and the sub-audio decoding unit 22, which solves the limitation of traditional analog signal monitoring equipment relying on a single criterion (such as only detecting the carrier), and provides dual technical verification for the compliance use of railway safety officers' analog walkie-talkies, further enhancing the reliability and authority of the communication early warning system.

[0044] As a fifth embodiment of the present invention, Figure 5 As shown, the digital signal processing module 3 includes a digital carrier detection unit 31, a color code decoding unit 32 and an ID verification unit 33. The digital carrier detection unit 31 is electrically connected and signal-connected to the color code decoding unit 32 and the ID verification unit 33 respectively, and the digital carrier detection unit 31, the color code decoding unit 32 and the ID verification unit 33 are electrically connected and signal-connected to the signal feature detection module 4 respectively.

[0045] The digital carrier detection unit 31 is configured as a digital down-converter, a digital band-pass filter, and a power detector. It is used to perform orthogonal demodulation on the digital intermediate frequency signal through the digital down-converter to generate a baseband I / Q data stream, filter out-of-band noise and extract the valid digital signal through the digital band-pass filter, and determine the presence of the carrier and the signal strength through the power detector. For digital modulated signals (such as DMR), it is necessary to extract the baseband signal through digital down-conversion and filtering, and power detection determines the validity of the carrier. It is adapted to common frequency bands of railway digital private networks (such as 400MHz UHF) to avoid adjacent channel interference. The digital carrier detection unit 31 uses orthogonal demodulation (I / Q demodulation) and digital band-pass filtering technology to effectively suppress adjacent channel interference and phase noise.

[0046] The color code decoding unit 32 is configured as a synchronization header detector and a color code extractor. The synchronization header detector matches the frame synchronization sequence in the digital signal to determine time slot boundaries and frame structure. The color code extractor parses the color code field from the synchronized data frame and converts it into a color code number. Railway digital private networks (such as DMR) rely on color codes to distinguish logical channels, requiring synchronization and color code extraction to ensure channel legitimacy. The color code decoding unit 32 quickly locks to time slot boundaries by matching the frame synchronization sequence (such as the DMR time slot synchronization header). The color code extractor parses the color code field (0-15) based on a cyclic redundancy check (CRC) error correction mechanism, improving decoding accuracy, avoiding signal crosstalk between adjacent railway communication groups (same frequency, different color codes), and ensuring the privacy of intra-group communications.

[0047] The ID verification unit 33 is configured as an ID parser and a pre-stored ID matcher. It extracts the sender ID information from the address field of the data frame through the ID parser, compares the extracted ID with the list of legal IDs preset by the main control module 5 through the pre-stored ID matcher, and outputs the verification result. By comparing the pre-stored ID list (such as the railway dispatcher's authorized ID), the legitimacy of the call identity is verified, meeting the authority management requirements of railway on-site personnel. The ID verification unit 33 extracts the sender ID from the data frame and performs a hash match with the legal ID database preset by the main control module 5, blocking the risk of unauthorized device access at the source.

[0048] The digital carrier detection unit 31 transmits the carrier signal strength and existence flag, the color code decoding unit 32 transmits the color code number, and the ID verification unit 33 transmits the ID verification result to the signal feature detection module 4 .

[0049] In this embodiment, the digital signal processing module 3 implements multi-level collaborative processing of carrier detection, color code decoding and ID verification through the digital carrier detection unit 31, color code decoding unit 32 and ID verification unit 33, thereby achieving high-reliability analysis and security management of digital signals.

[0050] As a sixth embodiment of the present invention, Figure 6 As shown, the signal feature detection module 4 includes an analog validity judgment unit 41, a digital validity judgment unit 42 and a logic arbitration unit 43. The analog validity judgment unit 41 and the digital validity judgment unit 42 are electrically connected and signal-connected to the logic arbitration unit 43 respectively, and the logic arbitration unit 43 is electrically connected and signal-connected to the main control module 5.

[0051] The simulation validity judgment unit 41 receives the carrier signal strength and existence flag from the simulation signal processing module 2, and generates a carrier validity flag by comparing the carrier strength with the preset threshold and verifying whether the carrier frequency is within the railway-specific frequency band. The simulation validity judgment unit 41 receives the sub-audio code value from the simulation signal processing module 2, matches it with the legal sub-audio list preset by the main control module 5, and generates a sub-audio validity flag. When the carrier validity flag and the sub-audio validity flag are established at the same time, the simulation validity judgment unit 41 sends a simulation format validity signal to the logic arbitration unit 43. The simulation validity judgment unit 41 implements double verification through a hardware comparator and a matcher to ensure the legitimacy of the simulation call. The simulation validity judgment unit 41 synchronously checks the carrier strength (≥preset threshold), the carrier frequency band (railway-specific range) and the sub-audio code (matching the whitelist). The three criteria are combined to take effect, and the illegal simulation signal interception rate is ≥99.8%.

[0052] The digital validity judgment unit 42 receives the carrier signal strength and presence flag from the digital signal processing module 3. It generates a digital carrier validity flag by determining whether the carrier strength continuously exceeds the threshold and whether the carrier duty cycle complies with the digital protocol specification. The digital validity judgment unit 42 receives the color code number from the digital signal processing module 3, compares it with the list of legal color codes preset by the main control module 5, and generates a color code validity flag. The digital validity judgment unit 42 receives the ID verification result from the digital signal processing module 3 and generates an ID validity flag by verifying the format validity and permission level of the ID. When the carrier validity flag, color code validity flag, and ID validity flag are all present, the digital validity judgment unit 42 sends a digital format validity signal to the logic arbitration unit 43. The digital validity judgment unit 42 ensures the compliance of digital communications through multi-level verification logic based on carrier stability, color code matching, and ID permission. The digital validity judgment unit 42 integrates carrier duty cycle (such as DMR 30%-70%), color code (0-15 legal group number) and ID authority (dispatcher / inspector classification) verification, with a 100% blocking rate for unauthorized digital signals, eliminating the risk of counterfeit device access.

[0053] The logic arbitration unit 43 is used to select either the analog or digital valid signal as the current valid determination result based on the system priority strategy configured by the main control module 5. Based on the current valid determination result, it generates a confirmation signal containing the corresponding railway-specific intercom ID, system type, and timestamp, and transmits it to the main control module 5. The logic arbitration unit 43 supports dynamic priority configuration by the main control module, resolving conflicts when dual-mode signals coexist, and ensuring unique determination results. The logic arbitration unit 43 can be implemented using the SN74LS148 8-line to 3-line priority encoder.

[0054] The signal feature detection module 4 of this embodiment performs analog and digital dual-channel validity judgment and intelligent arbitration mechanism through the analog validity judgment unit 41, the digital validity judgment unit 42 and the logic arbitration unit 43 to achieve full-dimensional security management and control of railway communication signals.

[0055] As a seventh embodiment of the present invention, Figure 7 As shown, the timer module 6 includes a clock source unit 61, a timing control unit 62, a threshold comparison unit 63 and an interrupt trigger unit 64. The clock source unit 61 is electrically connected and signal-connected to the timing control unit 62, the timing control unit 62 is electrically connected and signal-connected to the threshold comparison unit 63, the threshold comparison unit 63 is electrically connected and signal-connected to the interrupt trigger unit 64, the interrupt trigger unit 64 is electrically connected and signal-connected to the main control module 5, and the timing control unit 62, the threshold comparison unit 63 and the interrupt trigger unit 64 are respectively electrically connected and signal-connected to the main control module 5.

[0056] The clock source unit 61 is used to generate a reference clock signal and output a timing drive pulse. The timing control unit 62 is used to receive the timing drive pulse, and to perform cumulative counting when receiving the timing instruction sent by the main control module 5, and to clear it when the main control module 5 sends a reset instruction. The threshold comparison unit 63 is used to store the count value threshold corresponding to the timing warning cycle time set by the main control module 5 through the human-computer interaction module 8, and to compare the current count value of the timing control unit 62 with the count value threshold in real time, and to send a timeout flag to the interrupt trigger unit 64 when the two are equal. The interrupt trigger unit 64 is used to generate a high-level interrupt request signal after receiving the timeout flag, and transmit it to the main control module 5. The timer module of this embodiment realizes precise periodic control of the communication behavior of railway safety officers through a multi-unit collaborative timing and interrupt triggering mechanism.

[0057] As an eighth embodiment of the present invention, Figure 7 As shown, the alarm output module 7 includes an audio-visual alarm unit 71 and a vibration motor unit 72. The audio-visual alarm unit 71 and the vibration motor unit 72 are respectively electrically and signal-connected to the main control module 5. The audio-visual alarm unit 71 is used to output sound pressure in conjunction with a three-color LED strobe indication according to the control signal of the main control module 5, and the vibration motor unit 72 is used to generate vibration according to the control signal of the main control module 5. This embodiment overcomes the perception limitations of a single mode in complex railway scenarios by integrating multi-dimensional alarms of sound, light, and vibration, ensuring that safety officers can respond immediately to communication anomalies under any working conditions.

[0058] In addition, the human-computer interaction module 8 is connected to the 2The C bus is electrically and signal-connected to the main control module 5. The human-computer interaction module 8 may include a function button group and a liquid crystal display. The function button group includes a frequency setting key, a timing adjustment key, and an early warning reset key, which are used for manual operation through the function button group. The liquid crystal display is used to display the usage status, remaining early warning time and alarm status of each railway-specific walkie-talkie in real time.

[0059] The above-mentioned railway-specific digital or analog private network communication warning equipment has the receiving function of railway-specific digital or analog walkie-talkies, and can indirectly monitor the use of railway safety officers' walkie-talkie equipment. The specific operating process of this warning device is as follows: first, the operating frequency and signaling are preset to be the same as those of the railway-specific equipment, and a timed warning cycle time of 1 to 10 minutes is set, which is implemented through the human-computer interaction module 8. Railway-specific walkie-talkies are divided into analog and digital formats. When the railway-specific walkie-talkie uses the analog format, the warning device's RF receiving module 1, analog signal processing module 2, and signal feature detection module 4 identify the railway walkie-talkie's call status by determining the same carrier and sub-audio frequency. When the railway-specific walkie-talkie uses the digital format, the warning device uses the RF receiving module 1, digital signal processing module 3, and signal feature detection module 4 to determine whether the railway walkie-talkie is transmitting by determining the carrier, color code, and ID.

[0060] When the security officer initiates a call using the intercom device, the early warning device can simultaneously receive the call from the intercom, which is achieved through the radio frequency receiving module 1, and the timer module 6 starts timing. When the intercom device stops calling, the timer module 6 of the early warning device will reset the early warning time and then restart the timing. When the early warning device reaches the set time and has not received a call from the intercom device, the alarm output module 7 of the early warning device will emit an early warning prompt sound, vibration, and light prompt. At this time, the security officer perceives the prompt of the early warning device through sound / light reminder / vibration, which plays a role in periodically judging the work status of the security officer. The security officer can reset the early warning time through a dedicated button.

[0061] By utilizing the receiving function of railway-specific digital or analog intercoms, the present invention can indirectly monitor the usage of railway safety officers' intercom equipment, periodically judge the work status of safety officers, promptly discover illegal terminal access or illegal communication behavior, and improve the security of the railway wireless communication network and the reliability of dispatching and command.

[0062] It should be noted that the above summary of the invention and specific embodiments are intended to demonstrate the practical application of the technical solutions provided by the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art will readily make various modifications, equivalent substitutions, or improvements within the spirit and principles of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A railway-specific digital or analog private network communication early warning device, characterized in that: It comprises a radio frequency receiving module (1), an analog signal processing module (2), a digital signal processing module (3), a signal feature detection module (4), a main control module (5) and a human-computer interaction module (8); wherein, The radio frequency receiving module (1) is electrically connected to the main control module (5) and is signal-connected thereto. The main control module (5) is electrically connected to the human-machine interaction module (8) and is signal-connected thereto. The human-machine interaction module (8) is used to set the operating frequency and signaling of the radio frequency receiving module (1). The operating frequency and signaling are the same as those of the railway dedicated intercom, so that the radio frequency receiving module (1) can receive analog signals in an analog format and digital signals in a digital format from the railway dedicated intercom, and output corresponding baseband audio signals or digital intermediate frequency signals. The analog signal processing module (2) is electrically and signal-connected to the radio frequency receiving module (1), and the analog signal processing module (2) is used to perform carrier detection and sub-audio decoding on the analog signal from the radio frequency receiving module (1); The digital signal processing module (3) is electrically and signal-connected to the radio frequency receiving module (1), and the digital signal processing module (3) is used to perform carrier detection, color code decoding, and ID verification on the digital signal from the radio frequency receiving module (1); The signal feature detection module (4) is electrically connected and signal-connected to the analog signal processing module (2), the digital signal processing module (3) and the main control module (5). The signal feature detection module (4) is used to determine the validity of a call through carrier and sub-audio in an analog format, and to determine the validity of a call through carrier, color code and ID verification in a digital format. When the call is valid, the module sends a confirmation signal containing the ID of the railway dedicated intercom to the main control module (5), thereby realizing monitoring of the use of the railway dedicated intercom.

2. The railway-specific digital or analog private network communication early warning device according to claim 1, characterized in that: It also includes a timer module (6) and an alarm output module (7); wherein, The timer module (6) is electrically and signal-connected to the main control module (5). The human-computer interaction module (8) is further used to set a timing warning cycle time of the timer module (6), so that when the main control module (5) receives a confirmation signal from the signal feature detection module (4), the timer module (6) is controlled to start timing, and after the railway dedicated intercom stops calling, the timer module (6) is controlled to reset the warning cycle time to restart timing, and the timer module (6) sends an interrupt signal to the main control module (5) when the timing reaches a set threshold. The alarm output module (7) is electrically and signal-connected to the main control module (5). The alarm output module (7) is used to issue an early warning tone, vibration, or light prompt when a call from the railway dedicated intercom is not received when the timing reaches a set threshold.

3. The railway-specific digital or analog private network communication early warning device according to claim 1, characterized in that: The radio frequency receiving module (1) comprises a tunable bandpass filter (11) and a dual-mode radio frequency chip (12); wherein, The tunable bandpass filter (11) is located between the antenna and the radio frequency input end of the dual-mode radio frequency chip (11). The tunable bandpass filter (11) is electrically connected and signal-connected to the main control module (5). The center frequency of the tunable bandpass filter (11) is dynamically adjusted by a tuning voltage output by the main control module (5) to suppress out-of-band interference and improve the signal-to-noise ratio of the target frequency band. The dual-mode radio frequency chip (12) is respectively connected to the main control module (5), the analog signal processing module (2) and the digital signal processing module (3). The dual-mode radio frequency chip (12) is used to receive the radio frequency signal pre-processed by the tunable bandpass filter (11), and analyze the duty cycle and spectrum characteristics of the radio frequency signal by sampling the signal envelope through the built-in ADC, output the baseband audio signal to the analog signal processing module (2), and output the digital intermediate frequency signal to the digital signal processing module (3).

4. The railway-specific digital or analog private network communication early warning device according to claim 1, characterized in that: The analog signal processing module (2) includes an analog signal carrier detection unit (21) and a sub-audio decoding unit (22), the analog signal carrier detection unit (21) and the sub-audio decoding unit (22) are electrically connected and signal-connected, and the carrier detection unit (21) and the sub-audio decoding unit (22) are respectively electrically connected and signal-connected to the signal feature detection module (4); wherein, The analog signal carrier detection unit (21) is configured as an envelope detector, a bandpass filter and a comparator connected in sequence, and is used to extract the envelope waveform of the signal amplitude from the baseband audio signal through the envelope detector, filter out-of-band noise through the bandpass filter and output a pure carrier signal, and compare the filtered carrier signal with a preset voltage threshold through the comparator to generate a carrier existence flag signal; The sub-audio decoding unit (22) is configured as a cascaded programmable low-pass filter and a sub-audio decoder, and is used to separate the sub-audio component from the baseband audio signal through the programmable low-pass filter, decode the sub-audio component through the sub-audio decoder, and output a sub-audio code value; The analog signal carrier detection unit (21) transmits the signal strength, carrier frequency and carrier existence flag signal of the carrier, and the sub-audio decoding unit (22) transmits the sub-audio coding value to the signal feature detection module (4).

5. The railway-specific digital or analog private network communication early warning device according to claim 1, characterized in that: The digital signal processing module (3) includes a digital carrier detection unit (31), a color code decoding unit (32) and an ID verification unit (33), the digital carrier detection unit (31) is electrically connected to the color code decoding unit (32) and the ID verification unit (33) and the digital carrier detection unit (31), the color code decoding unit (32) and the ID verification unit (33) are electrically connected to the signal feature detection module (4) and the digital signal processing module ... The digital carrier detection unit (31) is configured as a digital down-converter, a digital band-pass filter and a power detector, and is used to perform orthogonal demodulation on the digital intermediate frequency signal through the digital down-converter to generate a baseband I / Q data stream, filter out-of-band noise through the digital band-pass filter and extract the effective digital signal, and determine the presence of the carrier and the signal strength through the power detector; The color code decoding unit (32) is configured as a synchronization header detector and a color code extractor, and is used to match the frame synchronization sequence in the digital signal through the synchronization header detector to determine the time slot boundary and frame structure, and to parse the color code field from the synchronized data frame through the color code extractor and convert it into a color code number; The ID verification unit (33) is configured as an ID parser and a pre-stored ID matcher, and is used to extract the sender ID information from the address field of the data frame through the ID parser, compare the extracted ID with the legal ID list preset by the main control module (5) through the pre-stored ID matcher, and output a verification result; The digital carrier detection unit (31) transmits the carrier signal strength and existence mark, the color code decoding unit (32) transmits the color code number, and the ID verification unit (33) transmits the ID verification result to the signal feature detection module (4).

6. The railway-specific digital or analog private network communication early warning device according to claim 1, characterized in that: The signal feature detection module (4) includes an analog validity judgment unit (41), a digital validity judgment unit (42) and a logic arbitration unit (43), wherein the analog validity judgment unit (41) and the digital validity judgment unit (42) are respectively electrically connected and signal-connected to the logic arbitration unit (43), and the logic arbitration unit (43) is electrically connected and signal-connected to the main control module (5); wherein, The analog validity judgment unit (41) is used to receive the carrier signal strength and existence flag from the analog signal processing module (2), generate a carrier validity flag by comparing the carrier strength with a preset threshold and verifying whether the carrier frequency is within the railway dedicated frequency band, and receive the sub-audio code value from the analog signal processing module (2), match it with the legal sub-audio list preset by the main control module (5), and generate a sub-audio validity flag; and when the carrier validity flag and the sub-audio validity flag are both established, the analog validity judgment unit (41) sends an analog format validity signal to the logic arbitration unit (43); The digital validity judgment unit (42) is used to receive the carrier signal strength and existence flag from the digital signal processing module (3), generate a digital carrier validity flag by judging whether the carrier strength continuously exceeds the threshold value and the carrier duty cycle complies with the digital protocol specification, receive the color code number from the digital signal processing module (3), compare it with the legal color code list preset by the main control module (5), generate a color code validity flag, and receive the ID verification result from the digital signal processing module (3), generate an ID validity flag by verifying the format validity and authority level of the ID; and when the carrier validity flag, the color code validity flag and the ID validity flag are simultaneously established, the digital validity judgment unit (42) sends a digital format validity signal to the logic arbitration unit (43); The logic arbitration unit (43) is used to select an analog format valid signal or a digital format valid signal as a current valid determination result according to the format priority strategy configured by the main control module (5), and to generate a confirmation signal including a corresponding railway dedicated intercom ID, format type and timestamp according to the current valid determination result, and transmit the confirmation signal to the main control module (5).

7. The railway-specific digital or analog private network communication early warning device according to claim 2, characterized in that: The timer module (6) includes a clock source unit (61), a timing control unit (62), a threshold comparison unit (63) and an interrupt trigger unit (64); the clock source unit (61) is electrically connected and signal-connected to the timing control unit (62); the timing control unit (62) is electrically connected and signal-connected to the threshold comparison unit (63); the threshold comparison unit (63) is electrically connected and signal-connected to the interrupt trigger unit (64); the interrupt trigger unit (64) is electrically connected and signal-connected to the main control module (5); and the timing control unit (62), the threshold comparison unit (63) and the interrupt trigger unit (64) are respectively electrically connected and signal-connected to the main control module (5); wherein, The clock source unit (61) is used to generate a reference clock signal and output a timing drive pulse; The timing control unit (62) is used to receive the timing drive pulse, and to perform cumulative counting when receiving the timing instruction sent by the main control module (5), and to reset the count when receiving the reset instruction sent by the main control module (5); The threshold comparison unit (63) is used to store the count value threshold corresponding to the timing warning cycle time set by the main control module (5) through the human-computer interaction module (8), and compare the current count value of the timing control unit (62) with the count value threshold in real time, and send a timeout flag to the interrupt trigger unit (64) when the two are equal; The interrupt trigger unit (64) is used to generate a high-level interrupt request signal after receiving the timeout flag, and transmit it to the main control module (5).

8. The railway-specific digital or analog private network communication early warning device according to claim 2, characterized in that: The alarm output module (7) includes an audible and visual alarm unit (71) and a vibration motor unit (72). The audible and visual alarm unit (71) and the vibration motor unit (72) are respectively electrically connected and signal-connected to the main control module (5). The audible and visual alarm unit (71) is used to output sound pressure in conjunction with a three-color LED strobe indication according to a control signal of the main control module (5). The vibration motor unit (72) is used to generate vibration according to the control signal of the main control module (5).

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