A DTMB signal monitoring device and method with sweep frequency and frequency point program monitoring functions

Abstract

The application discloses a DTMB signal monitoring device and method with sweep frequency and frequency point program monitoring functions, and belongs to the technical field of digital television broadcast monitoring, Internet of Things and embedded system. The device comprises an ARM processor, a DTMB demodulation unit, an MQTT module and an RTMP module. Sweep frequency and frequency point monitoring dual modes are supported. In the sweep frequency mode, the ARM receives sweep frequency instructions through the MQTT, controls the sweep frequency of the demodulation unit through the USB, and reports the result through the MQTT. In the frequency point monitoring mode, the ARM receives instructions containing target frequency points through the MQTT, controls the demodulation of the demodulation unit through the USB, transmits the video stream to the ARM through the USB, pushes the decoded stream to the server through the RTMP, and simultaneously transmits indicators such as CNR, BER, quality and strength to the ARM through the UART and reports the indicators through the MQTT. The application adopts a cooperative architecture of ARM master control and DTMB slave demodulation, combines MQTT remote interaction, RTMP video pushing and USB+UART dual-channel separation, realizes remote multi-dimensional monitoring of DTMB signals, and is suitable for unattended signal quality monitoring of broadcast television transmitting stations and key areas.

Description

Technical Field

[0001] This invention belongs to the fields of digital television broadcast monitoring, Internet of Things and embedded systems technology, and specifically relates to a DTMB signal monitoring device and method with frequency sweeping and frequency point program monitoring functions. Background Technology

[0002] DTMB (Digital Television Terrestrial Multimedia Broadcasting) is China's national standard for digital terrestrial television broadcasting. To ensure the coverage quality of broadcast television signals, signal monitoring equipment needs to be deployed at transmitting stations, relay stations, and key areas to monitor the frequency sweep results, program playback quality, and various signal indicators of the DTMB signal in real time.

[0003] Existing DTMB signal monitoring technologies have the following main shortcomings:

[0004] Limited monitoring methods: Some existing equipment can only monitor single indicators such as signal level and BER, lacking the ability to comprehensively monitor multi-dimensional signal parameters such as CNR and quality, and cannot obtain video footage of frequency programs in real time to verify broadcast effects.

[0005] Limited remote interaction capabilities: Most existing devices are for local display and local operation, lacking remote command issuance and data feedback mechanisms based on IoT protocols. Although a few devices have GPRS communication modules, their functions are limited to periodically transmitting a few parameters such as level values ​​and BER, and they cannot support bidirectional, real-time command interaction and flexible reporting of multi-dimensional monitoring data.

[0006] Insufficient separation of signal acquisition and processing: In existing technologies, DTMB demodulation chips are usually used as the main control chip of the system, integrating multiple functions such as audio and video decoding and graphics processing. This results in a fragmented processing capability, making it difficult to fully expose the demodulated raw TS stream data to a higher-performance processor for in-depth analysis.

[0007] Lack of remote video stream monitoring capability: Existing DTMB monitoring equipment generally lacks the ability to convert demodulated program video streams into standard streaming media network transmission protocols (such as RTMP) in real time and push them to streaming media servers. Maintenance personnel cannot remotely view program images of each frequency point in real time, making it difficult to intuitively judge the broadcast quality.

[0008] Mixed control and data channels: In existing solutions, control commands and monitoring data are often transmitted through the same channel, which leads to problems such as command response delay and low data transmission efficiency, especially in high bit rate TS streaming scenarios.

[0009] Therefore, there is an urgent need for a DTMB signal monitoring device that can simultaneously support both frequency sweep monitoring and frequency point program indicator monitoring modes, and has remote two-way interaction and real-time video push capabilities. Summary of the Invention

[0010] The present invention aims to provide a DTMB signal monitoring device and method with frequency sweeping and frequency point program monitoring functions, so as to solve the technical problems in the prior art such as single monitoring methods, limited remote interaction capabilities, and lack of remote video stream monitoring capabilities.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A DTMB signal monitoring device with frequency sweeping and frequency point program monitoring functions includes:

[0013] The ARM processor serves as the main control unit.

[0014] The DTMB demodulation unit is connected to the ARM processor and is used to demodulate the DTMB signal;

[0015] The Internet of Things (IoT) communication module is connected to the ARM processor and supports the MQTT protocol for bidirectional interaction of commands and data with external callers.

[0016] The streaming media push module, connected to the ARM processor, supports the RTMP protocol and is used to push the decoded video stream to an external streaming media server.

[0017] The device supports two working modes: frequency sweep mode and frequency point program index monitoring mode.

[0018] Frequency sweep mode: The ARM processor receives external frequency sweep instructions via the MQTT protocol and sends the frequency sweep instructions to the DTMB demodulation unit via the first data interface; after the DTMB demodulation unit performs the frequency sweep, it sends back the frequency sweep result data via the first data interface; the ARM processor processes the frequency sweep result data and sends it to the external caller via the MQTT protocol.

[0019] Frequency point program indicator monitoring mode: The ARM processor receives a monitoring command containing the target frequency point via the MQTT protocol and sends a frequency point program playback command to the DTMB demodulation unit via the first data interface; after demodulating the target frequency point, the DTMB demodulation unit transmits the program video stream to the ARM processor via the first data interface, and simultaneously transmits the signal indicator data to the ARM processor via the second data interface; the ARM processor decodes the video stream and encodes it into RTMP format and pushes it to the external streaming media server, while simultaneously sending the signal indicator data to the external caller via the MQTT protocol.

[0020] Furthermore, the signal performance data includes CNR (carrier-to-noise ratio), BER (bit error rate), quality, and strength. The definitions and typical monitoring ranges of each parameter are shown in Table 1.

[0021] Table 1. Definitions and Monitoring Range of Signal Indicator Parameters

[0022] Furthermore, the first data interface is a USB interface, and the second data interface is a UART serial port.

[0023] Furthermore, the ARM processor uses the RK3588 SoC, and the DTMB demodulation unit uses the Hi2318M chip.

[0024] Furthermore, the ARM processor runs an embedded Linux operating system with a built-in MQTT client and RTMP streaming client.

[0025] The present invention also provides a DTMB signal monitoring method with frequency sweeping and frequency point program monitoring functions, including specific steps of frequency sweeping mode and frequency point program index monitoring mode.

[0026] The frequency sweep mode includes the following steps:

[0027] Step A1: The ARM processor receives the frequency sweep command issued by the external caller via the MQTT protocol;

[0028] Step A2: The ARM processor parses the frequency sweep instruction and sends it to the DTMB demodulation unit through the first data interface;

[0029] Step A3: The DTMB demodulation unit performs real-time scanning of the DTMB signal frequency points;

[0030] Step A4: The DTMB demodulation unit transmits the frequency sweep result data back to the ARM processor through the first data interface;

[0031] Step A5: The ARM processor processes the frequency sweep result data and sends it to the external caller via the MQTT protocol;

[0032] The frequency point program indicator monitoring mode includes the following steps:

[0033] Step B1: The ARM processor receives a frequency point program indicator monitoring instruction from an external caller via the MQTT protocol. The instruction contains target frequency point information (see Table 5 for the specific format).

[0034] Step B2: The ARM processor parses the monitoring instructions and sends the frequency point program playback instructions to the DTMB demodulation unit through the first data interface;

[0035] Step B3: The DTMB demodulation unit demodulates the DTMB signal at the target frequency.

[0036] Step B4: The DTMB demodulation unit transmits the demodulated program video stream to the ARM processor through the first data interface;

[0037] Step B5: The DTMB demodulation unit transmits the signal index data of the target frequency to the ARM processor through the second data interface;

[0038] Step B6: The ARM processor decodes the received video stream data and encodes it into RTMP streaming media format, then publishes it to an external streaming media server;

[0039] Step B7: The ARM processor processes the received signal indicator data and sends it to the external caller via the MQTT protocol.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] Dual-mode monitoring capability: This invention supports both frequency sweep mode and frequency point program indicator monitoring mode, which can quickly obtain the signal distribution of the entire frequency band, and also deeply monitor the program content and signal indicators of specific frequency points, meeting the monitoring needs of different scenarios.

[0042] MQTT-based IoT remote interaction: The MQTT protocol is used as the communication protocol between the device and the external caller, supporting bidirectional real-time command issuance and data reporting, realizing remote unattended operation and unified access management of the device.

[0043] USB + Serial Port Dual-Channel Collaborative Architecture: The USB interface is used for control command issuance and high-speed data (video stream / sweep results) transmission, while the serial port is used for signal indicator data transmission. This achieves the separation of control flow, high-speed data flow and low-speed data flow, avoiding congestion and delay caused by mixed transmission of multiple types of data.

[0044] RTMP Real-time Video Stream Push: The demodulated program video stream is decoded, encoded into RTMP format, and pushed to the streaming media server. Maintenance personnel can remotely view the program images of each frequency point in real time through any player that supports RTMP, and intuitively judge the broadcast quality.

[0045] High-performance main controller + specialized slave architecture: The ARM processor is used as the main controller and the DTMB demodulation unit is used as the slave. The two work together, and the overall system performance is better than that of a single chip solution.

[0046] Multi-dimensional signal indicator monitoring: Monitors multiple signal indicators such as CNR, BER, quality, and strength to provide more comprehensive data support for signal quality assessment.

[0047] Table 2 shows a comparison of the key indicators of the present invention with those of existing technologies.

[0048] Table 2 Comparison of key indicators between the present invention and existing technologies Attached Figure Description

[0049] Figure 1 This is a block diagram of the overall hardware structure of an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram of control commands and data stream transmission according to an embodiment of the present invention.

[0051] Figure 3 This is a flowchart of the frequency sweep mode method according to an embodiment of the present invention.

[0052] Figure 4 This is a flowchart of the frequency point program index monitoring mode method according to an embodiment of the present invention. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0054] Example 1: Hardware Architecture

[0055] like Figure 1 As shown, the DTMB signal monitoring device in this embodiment includes:

[0056] ARM Processor: The main control processor is the Rockchip RK3588 SoC. This chip uses an octa-core architecture (quad-core Cortex-A76 + quad-core Cortex-A55), with a main frequency of 2.4GHz. It integrates a 6 TOPS NPU, a high-performance GPU, and an 8K video codec, and runs an embedded Linux operating system. The ARM processor has a built-in Ethernet controller and supports 4G / 5G module expansion.

[0057] DTMB Demodulation Unit: Utilizing the Hi2318M chip manufactured by Beijing Haier Integrated Circuit Design Co., Ltd. This chip integrates a complete DTMB demodulation unit and a 32-bit MCU, supports USB 2.0 OTG interface and UART serial port, and fully complies with the DTMB (GB20600-2006) national standard. In this solution, the Hi2318M is used only as a DTMB demodulation slave device; its internal audio / video decoding, JPEG decoding, and other functions are not enabled.

[0058] Interface connection:

[0059] The ARM processor is connected to the DTMB demodulation unit via a USB 2.0 interface (first data interface) for sending frequency sweep commands, sending frequency point program playback commands, transmitting frequency sweep result data back, and transmitting program video streams.

[0060] The ARM processor and the DTMB demodulation unit are connected via a UART serial port (second data interface) for the transmission of signal indicators such as CNR, BER, quality, and strength.

[0061] Communication module: The ARM processor has a built-in MQTT client that connects to the MQTT Broker via Ethernet or 4G network for bidirectional communication with external callers; it also has a built-in RTMP streaming client that connects to the streaming media server via Ethernet.

[0062] Example 2: Application of the MQTT Internet of Things Communication Protocol

[0063] This invention fully adopts the MQTT protocol as the communication protocol between the device and external callers. The program information in the monitoring command can be obtained in advance through frequency scanning. Specific implementation details are shown in Tables 3-5.

[0064] Table 3 MQTT Topic Definition Table

[0065] Table 4. Examples of JSON format for frequency sweep commands

[0066] Table 5. Example of JSON format for frequency point program indicator monitoring instructions.

[0067] QoS mechanism: Critical instructions (such as frequency point program monitoring instructions) are transmitted at QoS level 1 (at least once) to ensure reliable transmission; monitoring data reporting is transmitted at QoS level 0 to reduce network overhead.

[0068] Heartbeat and Device Status: The device periodically sends heartbeat messages to the MQTT Broker, which include information such as device ID, online status, and current working mode, so that external callers can keep track of the device's operating status in real time.

[0069] Example 3: Frequency Sweep Mode Workflow

[0070] like Figure 3 As shown, the workflow in frequency sweep mode is as follows:

[0071] Step S301: The external caller (such as the monitoring center server) sends a frequency sweep command to the device through the MQTT protocol. The command content includes parameters such as the frequency band range (e.g., 470MHz~862MHz) and the frequency sweep step size.

[0072] Step S302: After receiving the instruction, the MQTT client on the ARM processor parses the instruction content and sends the formatted frequency sweep instruction to the Hi2318M chip via the USB protocol.

[0073] Step S303: After receiving the frequency sweep command, the Hi2318M chip's internal DTMB demodulation unit begins to scan each frequency point in the frequency band in real time according to the specified step size, and detects whether there is a DTMB signal and its basic parameters at each frequency point.

[0074] Step S304: The Hi2318M chip packages the frequency sweep result data (including the frequency, program number, program name, video encoding, audio encoding, etc. of each frequency point) and sends it back to the ARM processor via USB protocol. Among them, the program information is obtained by quickly parsing the TS stream of the locked frequency point.

[0075] Step S305: The ARM processor processes the frequency sweep result data (including data parsing, format conversion, noise reduction filtering, etc.), encapsulates the processed data into JSON format, and publishes it to the topic subscribed by the external caller via the MQTT protocol.

[0076] The performance test results of the frequency sweep mode are shown in Table 6.

[0077] Table 6 Performance test results of frequency sweep mode

[0078] Example 4: Workflow of Frequency Point Program Index Monitoring Mode

[0079] like Figure 4 As shown, the workflow under the frequency point program index monitoring mode is as follows:

[0080] Step S401: The external caller sends a frequency point program indicator monitoring command to the device via the MQTT protocol. The command includes target frequency point information, program number, program name, video encoding, audio encoding, and optional monitoring duration (see Table 5).

[0081] Step S402: After receiving the instruction, the MQTT client on the ARM processor parses the instruction content and sends a frequency point program playback instruction to the Hi2318M chip via the USB protocol, requesting it to lock the target frequency point and start demodulation.

[0082] Step S403: After receiving the instruction, the Hi2318M chip's internal DTMB demodulation unit locks the target frequency, demodulates the DTMB signal, and generates the original program transport stream (TS stream).

[0083] Step S404: The Hi2318M chip transmits the demodulated program TS stream to the ARM processor in real time via the USB interface. The ARM processor uses DMA mode to receive the data, ensuring no packet loss in high-bitrate data.

[0084] Step S405: Simultaneously, the Hi2318M chip transmits the signal indicator data of the target frequency point—including CNR (carrier-to-noise ratio), BER (bit error rate), quality, and strength—to the ARM processor in real time via the UART serial port. The transmission of the signal indicator data uses a serial port protocol with a baud rate set to 115200bps.

[0085] Step S406: After receiving the TS stream, the ARM processor calls the RK3588's software decoding library (supporting formats such as H.264 / AVS+) to decode the TS stream in real time and extract the program video data. Subsequently, the ARM processor calls an RTMP streaming client to encode the decoded video data into RTMP streaming media format and publish it to a designated external streaming media server via Ethernet. Maintenance personnel can remotely view the program on that frequency in real time using a player that supports the RTMP protocol (such as VLC, FFplay, etc.).

[0086] Step S407: The ARM processor simultaneously processes and stores the received signal indicators such as CNR, BER, quality, and strength, and encapsulates them into JSON format via the MQTT protocol and sends them to the external caller in real time.

[0087] The performance test results of the frequency point program index monitoring mode are shown in Table 7.

[0088] Table 7 Performance Test Results of Frequency Point Program Index Monitoring Mode

[0089] Example 5: Control and Data Separation Channel Design

[0090] One of the core innovations of this invention lies in the separate channel design for control commands, high-speed data, and low-speed data, such as... Figure 2 As shown:

[0091] USB Channel (First Data Interface): Carries three types of data transmission: ARM processor → DTMB demodulation unit control commands (sweep commands, frequency point program playback commands, etc.); DTMB demodulation unit → ARM processor sweep result data (sweep mode); DTMB demodulation unit → ARM processor program video stream (TS) data (frequency point program index monitoring mode). The theoretical transmission rate of the USB 2.0 interface is up to 480Mbps, which can fully meet the real-time transmission requirements of TS streams (usually several Mbps to tens of Mbps).

[0092] Serial port channel (second data interface, UART): Only carries the transmission of signal indicator data (CNR, BER, quality, strength). These data are small in volume and have high real-time requirements, so 115200bps serial port transmission is sufficient. Separating the transmission of signal indicator data from video stream data avoids data loss or delay caused by the indicator data competing for bandwidth with the high-speed TS stream on the USB channel.

[0093] This dual-channel design, which uses USB for control and serial port for high-speed data and serial port for low-speed indicators, is not publicly available in existing DTMB monitoring technologies and is highly original.

[0094] In summary, this invention, by employing a master-slave collaborative architecture of an ARM processor and a DTMB demodulation unit, combined with bidirectional remote interaction of the MQTT IoT protocol, real-time video stream push via RTMP, and a dual-channel design with separate USB and serial ports, achieves dual-mode functionality for frequency sweeping and frequency point program indicator monitoring. It effectively solves the problems of existing DTMB monitoring equipment, such as limited monitoring methods, limited remote interaction capabilities, and lack of remote video stream monitoring. It boasts outstanding advantages such as novel architecture, comprehensive functions, remote controllability, and strong scalability, making it suitable for unattended signal quality monitoring in broadcast television transmission stations and key areas.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A DTMB signal monitoring device with frequency sweeping and frequency point program monitoring functions, characterized in that, include: The ARM processor serves as the main control unit. The DTMB demodulation unit is connected to the ARM processor and is used to demodulate the DTMB signal; The Internet of Things (IoT) communication module is connected to the ARM processor and supports the MQTT protocol for bidirectional interaction of commands and data with external callers. The streaming media push module is connected to the ARM processor, supports the RTMP protocol, and is used to push the decoded video stream to an external streaming media server; The device supports two operating modes: frequency sweep mode and frequency point program indicator monitoring mode. In frequency sweep mode, the ARM processor receives external frequency sweep commands via the MQTT protocol and sends the commands to the DTMB demodulation unit via the first data interface. After performing the frequency sweep, the DTMB demodulation unit sends back the sweep result data via the first data interface. The ARM processor processes the sweep result data and sends it to the external caller via the MQTT protocol. In frequency point program indicator monitoring mode, the ARM processor receives monitoring commands containing the target frequency via the MQTT protocol and sends a frequency point program playback command to the DTMB demodulation unit via the first data interface. After demodulating the target frequency, the DTMB demodulation unit transmits the program video stream to the ARM processor via the first data interface and simultaneously transmits the signal indicator data to the ARM processor via the second data interface. The ARM processor decodes and encodes the video stream into RTMP format and pushes it to the external streaming media server. Simultaneously, it sends the signal indicator data to the external caller via the MQTT protocol.

2. The DTMB signal monitoring device with frequency sweeping and frequency point program monitoring functions according to claim 1, characterized in that, The signal metrics data include CNR (carrier-to-noise ratio), BER (bit error rate), quality, and strength.

3. The DTMB signal monitoring device with frequency sweeping and frequency point program monitoring functions according to claim 1, characterized in that, The first data interface is a USB interface, and the second data interface is a UART serial port; the ARM processor uses an RK3588 SoC, and the DTMB demodulation unit uses a Hi2318M chip; the ARM processor runs an embedded Linux operating system and has a built-in MQTT client and RTMP streaming client; the ARM processor is also connected to an Ethernet controller and / or a 4G / 5G module.

4. A method for monitoring DTMB signals based on the device according to any one of claims 1 to 3, characterized in that, The system includes a frequency sweep mode and a frequency point program indicator monitoring mode. The frequency sweep mode includes the following steps: Step A1: The ARM processor receives a frequency sweep command from an external caller via the MQTT protocol; Step A2: The ARM processor parses the frequency sweep command and sends it to the DTMB demodulation unit via the first data interface; Step A3: The DTMB demodulation unit performs real-time scanning of the DTMB signal frequencies; Step A4: The DTMB demodulation unit transmits the frequency sweep result data back to the ARM processor via the first data interface; Step A5: The ARM processor processes the frequency sweep result data and sends it to the external caller via the MQTT protocol. The frequency point program indicator monitoring mode includes the following steps: Step B1: The ARM processor receives a frequency point program indicator monitoring command from an external caller via the MQTT protocol. The instruction includes target frequency information; Step B2: The ARM processor parses the monitoring instruction and sends the frequency program playback instruction to the DTMB demodulation unit through the first data interface; Step B3: The DTMB demodulation unit demodulates the DTMB signal of the target frequency; Step B4: The DTMB demodulation unit transmits the demodulated program video stream to the ARM processor through the first data interface; Step B5: The DTMB demodulation unit transmits the signal indicator data of the target frequency to the ARM processor through the second data interface; Step B6: The ARM processor decodes the received video stream data, encodes it into RTMP streaming media format, and publishes it to an external streaming media server; Step B7: The ARM processor processes the received signal indicator data and sends it to the external caller through the MQTT protocol.

5. The DTMB signal monitoring method according to claim 4, characterized in that, The first data interface is a USB interface, and the second data interface is a UART serial port. The ARM processor uses DMA to receive the frequency sweep result data and video stream data through the USB interface.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method described in any one of claims 4 to 5.

Images