Performance detection system for vehicle-mounted short-wave communication system

Abstract

The invention provides a vehicle-mounted short-wave communication system performance detection system. The system adopts a modular design and mainly comprises a radio frequency power detection module, a spectrum analysis module and an industrial digital processor module. The radio frequency power detection module generates an initial signal through direct digital frequency synthesis, the initial signal enters the frequency division and phase discrimination controller after being processed by the low-pass filter, and frequency synthesis is completed through the voltage-controlled oscillator. And the spectrum analysis module realizes digital signal processing of the high-speed synchronous radio frequency signal. The industrial digital processor module is responsible for overall control and data processing, and supports a wireless communication technology to realize efficient data interaction. The system integrates a multifunctional radio frequency standard signal source and provides support of various modulation modes. The system solves the problems of poor portability, low detection precision, weak anti-interference capability and the like in the prior art, provides a high-precision and high-reliability detection tool for fault diagnosis and performance optimization of a vehicle-mounted short-wave communication system, and has remarkable technical advancement and market application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of shortwave communication, and particularly relates to a performance detection system for a vehicle-mounted shortwave communication system. Background Art

[0002] With the transformation of the shortwave communication system from the traditional point-to-point dedicated mode to the digital access network mode, the optimization of the vehicle-mounted shortwave communication system has become a key challenge in the field. Due to the limitations of the vehicle volume and load capacity, it is difficult to install a high-performance long antenna on the vehicle-mounted system, resulting in its radiation performance being significantly lower than that of the fixed shortwave communication system. To overcome this problem, the research focus is on optimizing the antenna design and erection position, and using the vehicle body reflection effect to increase the effective electrical length of the antenna.

[0003] In practical applications, building a shortwave access network based on the vehicle-mounted shortwave communication system faces worldwide problems in planning and optimization. The primary task is to improve the comprehensive performance detection ability of the vehicle-mounted shortwave communication system, including but not limited to key parameters such as transceiver performance, spectrum analysis, power intensity measurement, signal field time-domain distribution, coverage range assessment, and interference source analysis. Currently, although the widely used VOPCAP software in the world can predict the signal landing level after ionospheric reflection by pre-inputting antenna parameters, due to the lack of electromagnetic interference assessment in the vehicle-mounted environment, there are large deviations in its prediction results.

[0004] As a widely used detection method, the antenna comparison method evaluates the performance by comparing the coverage effects of different shortwave communication systems in the same area. However, the antenna comparison method mainly provides a theoretical performance evaluation and cannot fully reflect the complex situation of the vehicle-mounted shortwave communication system in practical applications. In addition, the existing detection methods are difficult to achieve portability. These traditional means are difficult to meet the requirements of rapid and flexible deployment in diverse field environments due to their dependence on relatively large equipment and complex operation processes, thus restricting their wide popularization and convenient use in practical applications.

[0005] In addition, vehicle-mounted shortwave radios enhance the overall anti-interference ability of the system by means of fixed-frequency, adaptive, and frequency-hopping wireless communication technologies. However, in a complex wireless environment, these technologies are difficult to meet the precise detection requirements for the comprehensive performance of shortwave communication systems. Under complex working conditions, when crosstalk signals generated by the coupling of radio frequency signals and wireless electromagnetic fields undergo time-frequency conversion through high-speed sampling and fast Fourier transform (FFT), the bit error rate of the digital system increases significantly due to rate mismatches. The main solution on the market currently is to use orthogonal frequency division multiplexing (OFDM) technology to alleviate the high bit error rate problem caused by interference. Although OFDM technology is quite mature in implementation and can effectively suppress or reduce bit error phenomena caused by electromagnetic interference in complex environments as a cost-effective solution, it cannot fundamentally solve the problems of crosstalk and high bit error rate caused by interference at the hardware level.

[0006] Therefore, it is particularly urgent to develop a portable comprehensive detection device for the performance of vehicle-mounted shortwave communication systems in order to more accurately meet the needs of vehicle-mounted shortwave communication systems in network optimization. Such a device will help to achieve accurate performance evaluation of vehicle-mounted shortwave communication systems under real operating conditions, thus promoting the further development of this field. Summary of the Invention

[0007] The purpose of the embodiments of the present invention is to provide a performance detection system for vehicle-mounted shortwave communication systems, which solves the deficiencies of existing detection methods in terms of portability, real-time performance, and accuracy, and realizes comprehensive, flexible, and accurate performance evaluation of vehicle-mounted shortwave communication systems in actual application scenarios.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is a performance detection system for vehicle-mounted shortwave communication systems, including:

[0009] A radio frequency power detection module, which is used to detect the radio frequency signal power of the vehicle-mounted shortwave communication system and is signal-connected to the industrial digital processor module;

[0010] An industrial digital processor module, which integrates an operation control unit, memory, and communication interface; is used to control the operation of each module of the system, process detection data, and execute frequency synthesis control; a storage module is also integrated in the industrial digital processor module, and the industrial digital processor module is signal-connected to the data communication module, which is used to realize wireless control instruction interaction and detection data transmission with the vehicle-mounted shortwave radio;

[0011] An antenna feeder detection module, which is used to evaluate the standing wave ratio, return loss, cable loss, and fault point location of the vehicle-mounted shortwave antenna, and measure by comparing the coverage ranges of the calibrated magnetic field antenna and the shortwave antenna; and is signal-connected to the industrial digital processor module;

[0012] The spectrum analysis module obtains the radio frequency signals of the vehicle-mounted short-wave communication system by connecting a calibrated short-wave antenna, performs spectrum analysis on the received short-wave radio frequency signals, generates a spectrum heat map and a chromatogram, and analyzes the signal interference sources and spectrum statistical characteristics; it is signal-connected to the industrial digital processor module;

[0013] The RTK differential multi-frequency positioning module is used to associate detection data with geographical location information and is signal-connected to the industrial digital processor module;

[0014] The PMU power management module provides a multi-level regulated power supply and is cable-connected to the industrial digital processor module.

[0015] Further, the radio frequency power detection module includes three-stage low-noise current amplifiers to amplify weak radio frequency signals step by step to reduce the noise coefficient, and a high-speed analog-to-digital converter is used to achieve high-resolution signal sampling.

[0016] Further, the radio frequency power detection module synthesizes the DDS and PLL frequencies in the radio frequency power detection module according to the instructions sent by the industrial digital processor module.

[0017] Further, the detection system further includes a calibrated magnetic field antenna, a short-wave antenna, and a multi-functional radio frequency standard signal source;

[0018] The calibrated magnetic field antenna and the short-wave antenna obtain the working parameters of the short-wave radio frequency signals of the detection object and provide the required radio frequency signal channel parameters for each detection module; the calibrated magnetic field antenna and the short-wave antenna are signal-connected to the radio frequency power detection module and the spectrum analysis module through coaxial cables;

[0019] The multi-functional radio frequency standard signal source is used to provide a standard reference signal source for spectrum analysis and is signal-connected to the industrial digital processor module.

[0020] Further, the radio frequency power detection module includes a DDS generator, a voltage-controlled oscillator, a low-pass filter, a band-pass filter, a frequency division and phase discrimination controller;

[0021] The industrial digital processor includes a synchronous controller and a hardware watchdog;

[0022] The specific process of the DDS and PLL frequency synthesis is as follows: the DDS generator generates an initial short-wave coupling frequency signal; this signal is filtered by a low-pass filter; the filtered signal enters the frequency division and phase discrimination controller, and the parameters are processed according to the different frequency domain DDS and PLL frequency synthesis synchronous control methods of the industrial digital processor module, and feedback control and dual-mode frequency division counting are provided through the voltage-controlled oscillator; the output signal of the voltage-controlled oscillator is frequency-synthesized with the output signal of the filtered DDS generator.

[0023] Further, before the output of the frequency division and phase discrimination controller provides feedback control and dual-mode frequency division counting through the voltage-controlled oscillator, it is filtered through a low-pass filter.

[0024] Further, the specific method for synchronously controlling the different frequency domain DDS and PLL frequency syntheses is as follows:

[0025] S1. Initialize the industrial digital processor module and the DDS generator:

[0026] Set the frequency control word F of the DDS word ; set the frequency division ratios R and N of the frequency division and phase discrimination controller, where R is the frequency division ratio of the prescaler and N is the frequency division ratio of the feedback frequency divider;

[0027] S2. Under normal circumstances when writing the DDS frequency word and control word, the synchronization controller embedded in the industrial digital processor module sets the frequency division parameters and the synchronization control word, and then the industrial digital processor module sets the working parameters for the frequency division and phase discrimination controller in the radio frequency power detection module. If any abnormality is found during the whole process, it is reset by the hardware watchdog. Under normal circumstances, the frequency synthesis start signal can be sent to start the frequency syntheses of the DDS and PLL; if not normal, return to S1 for re-initialization.

[0028] Further, the specific process of the industrial digital processor module setting the working parameters for the frequency division and phase discrimination controller is as follows:

[0029] S201. Set the input frequency of the frequency division and phase discrimination controller to f in_DDS , and the output frequency to f out_VCO ;

[0030] Among them, f in_DDS is equal to the output frequency of the DDS generator:

[0031]

[0032] Among them, F word is the clock frequency, and n is the number of bits of the phase accumulator in the DDS generator;

[0033] The output frequency of the frequency division and phase discrimination controller is

[0034] S202. Adjust the frequency division ratio N of the PLL through the synchronization control algorithm; make f out_VCO equal to the target frequency f target .

[0035] Further, the specific synchronization control algorithm is as follows:

[0036] S2021. Calculate the error signal e(t) = f target - fout_VCO ;

[0037] S2022. Adjust the frequency division ratio N of the frequency division and phase discrimination controller according to the error signal:

[0038]

[0039] where f ref is the reference frequency;

[0040] When e(t)≠0, adjust the frequency division ratio N to make the system reach a steady state.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] The performance detection system of the vehicle-mounted short-wave communication system proposed by the present invention realizes low spurious signal level, high switching speed and excellent phase noise performance by adopting the in-loop frequency synthesis technology of direct digital frequency synthesis (DDS) exciting phase-locked loop (PLL) combined with the synchronous control algorithm, significantly improving the purity of the radio frequency signal and the system stability; uses highly sensitive calibrated magnetic field antennas and short-wave antennas to accurately measure the performance of the antenna feeder, and integrates a multi-functional radio frequency standard signal source to support multiple modulation methods, expanding the application range. The system is designed compactly and modularly, which is convenient for carrying and deployment. At the same time, the introduction of wireless communication technology improves the test flexibility. The high-performance industrial digital processor module ensures the real-time and accurate data processing. The user-friendly interface and the support for automatic and manual mode switching improve the operation convenience. In addition, by effectively suppressing spurious signals, the hardware design is simplified, the cost is reduced and the maintenance is facilitated. In summary, the present invention greatly improves the detection accuracy, portability and practicability of the system, and has important promotion value and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Figure 1 is the module diagram of the detection system of this embodiment;

[0045] Figure 2 is the block diagram of the in-loop frequency synthesis technology of DDS exciting PLL of this embodiment;

[0046] Figure 3 is the system initialization work flow chart of the synchronous frequency synthesis technology of this embodiment;

[0047] Figure 4 It is the connection block diagram of the comprehensive performance detection work of the vehicle-mounted short-wave communication system in this embodiment;

[0048] Figure 5 It is the block diagram of the implementation of the antenna-feeder and spectrum analysis technology of the vehicle-mounted short-wave communication system in this embodiment. Specific embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] This embodiment provides a performance detection system for a vehicle-mounted short-wave communication system, which mainly detects the comprehensive performance parameters of the short-wave transceiver and signal spectrum detection and analysis, power intensity detection and analysis, signal field time-domain distribution, signal coverage detection, and interference source detection and analysis of the vehicle-mounted short-wave communication system in actual use scenarios. It provides quantitative parameters and a basis for the access network planning and optimization of the vehicle-mounted short-wave communication system.

[0051] Such as Figure 1 , the detection system described in this embodiment specifically includes a radio frequency power detection module, a waveform display button module, a PMU power management module, a storage module, an industrial digital processor module, a data communication module, an antenna-feeder detection module, a spectrum analysis module, an RTK differential multi-frequency positioning module, a calibrated magnetic field antenna and a short-wave antenna, and a multi-functional radio frequency standard signal source.

[0052] In some specific embodiments, the industrial digital processor module is the main control and operation core of the entire detection system; it specifically realizes detection control, detection data operation and processing, detection waveform and data display, detection data storage, and data communication. According to the detection task, it is responsible for starting different detection modules. The detection modules transmit the detection data to the industrial digital processor module through the internal data bus of the device. The industrial digital processor module presents the processed results in a human-computer interaction manner according to the data operation and processing process, and stores and transmits the detection results to the remote terminal.

[0053] In some possible embodiments, the industrial digital processor module uses the Shenwei H8000 processor and its SW64 instruction set as the main operation control unit. The industrial digital processor is configured with 64GB of DDR4 dynamic random access memory (DRAM) and is equipped with an externally hot-pluggable 1TB NVMe interface solid-state drive (SSD) as a storage module to expand the storage capacity. In terms of communication interfaces, this module integrates a gigabit Ethernet interface and a 5G wireless communication module that support the MQTT protocol, thus realizing efficient data transmission and remote connection functions.

[0054] In some possible embodiments, the initialization detection of the detection system is triggered and started by the industrial digital processor module through the human-machine interface (HMI). After startup, the physical magnetic field environment and the short-wave antenna are calibrated by a multifunctional radio frequency standard signal source to ensure accurate measurement of the physical magnetic field environment and the performance of the short-wave antenna. After the radio frequency power detection module receives the wirelessly coupled digital signal and transmits it to the industrial digital processing module, frequency synthesis, time-frequency domain transformation, interference processing, spectrum analysis, etc. are performed. The intermediate data and results during the processing are temporarily stored or stored in the storage module, and detection location information is added. Finally, the detection results are presented to the operator in the form of a waterfall heat map through the waveform display module. At the same time, the detection data can be sent to local and remote servers through the data port for further data analysis and management.

[0055] In some specific embodiments, the data communication module, the RTK differential multi-frequency positioning module, and the waveform display button module are connected through the AXI (Advanced eXtensible Interface) bus and the APB (Advanced Peripheral Bus) bus inside the industrial digital processor module H8000. The AXI bus is used for high-speed data transmission and is suitable for applications that require high bandwidth, such as storage and data communication; while the APB bus is used for low-speed peripheral control, such as differential multi-frequency positioning and waveform display buttons.

[0056] In some specific embodiments, the PMU power management module is connected to the industrial digital processor module through a 12V / 5A NPC (Non-Planar Configuration) structure to ensure stable and reliable power supply for the system.

[0057] In some specific embodiments, the spectrum analysis module is an independent hardware carrier. The spectrum analysis module is connected to the industrial digital processor module through the AXI high-speed bus to meet the requirements of high-speed data transmission and complex spectrum analysis operations.

[0058] In some specific embodiments, the multifunctional radio frequency standard signal source is used to provide an accurate standard reference signal source for spectrum analysis and is signal-connected to the industrial digital processor module.

[0059] Other detection modules are connected to the industrial digital processor module through standard coaxial cables to achieve reliable data transmission.

[0060] In some specific embodiments, the radio frequency power detection module performs radio frequency power detection on the short-wave radio frequency signal received by the calibrated standard magnetic field antenna and provides three working modes: broadband power meter, narrowband power meter, and through-type power meter. It can support radio frequency signal frequencies from 9K to 6GHz at most, and the maximum level range reaches 125W to meet the coverage range of vehicle-mounted short-wave signals.

[0061] In some possible embodiments, the radio frequency power detection module uses the model MM30D, with the core using AD8371. The frequency detection range is 1 to 1000Mhz. As a radio frequency power detection purpose, it has strong anti-interference ability and high sensitivity. In this embodiment, the dynamic range requirement of the input signal of the radio frequency power detection module reaches -65dbm to +10dbm. Integratability and low power consumption are also one of the core selection indicators of the radio frequency power detection module in this embodiment. The specific size cannot exceed 100mm * 100mm, and the integrated interface uses a standard differential coaxial connection method. In the low-power part, the peak power of the entire module during maximum power detection cannot exceed 25 watts.

[0062] In some specific embodiments, the waveform display key module mainly provides a man-machine interaction interface for the detection process, presenting detection results, detection data, and detection process control. In this embodiment, the display screen resolution is 1280 * 800. The waveform display key module uses a serial communication screen and internally integrates a touch and key control integrated module, with the model OCM1280800T-2D. The waveform display module is only connected and communicates with the industrial digital processor module through the QSPI high-speed interface, mainly providing key control for the detection process and presenting detection data graphics, etc., to provide a customized HMI man-machine interface for the detection.

[0063] In some specific embodiments, the PMU power management module provides power supply for the vehicle-mounted short-wave communication system comprehensive performance detection equipment, including the ACDC unit, DCDC unit, lithium battery pack, and power supply management for each module, providing a stable and reliable working power supply for each module during the equipment detection process.

[0064] In this embodiment, the PMU power management module is specifically [module name not provided in the original], and is wire-connected to other modules; the specific devices used by the PMU power management module can be selected according to needs, as long as they are all within the scope disclosed in this embodiment. In some possible embodiments, the PMU power management module uses the ADP5320 of ADI to implement power supply and power management for the detection device. In this embodiment, the PMU power management module ensures that the AC ripple voltage in the DC power supply system does not exceed 15 millivolts (mV).

[0065] In some specific embodiments, the storage module is mainly used to store detection results, detection reports, detection records, operation logs, system maintenance, and updated firmware, facilitating the detection personnel to query the detection results and perform device updates and maintenance. In some specific embodiments, the storage module is divided into two types. One is an expandable DDR4 memory with ECC check, with a frequency of 2666 MHz, integrated on the industrial digital processor module motherboard through a dedicated memory slot SIMM interface. The second is an external large data storage hard drive using a 1T NVME solid-state drive, integrated through the standard M.2 interface on the industrial digital processor module motherboard, and supports hot plugging.

[0066] In some specific embodiments, the data communication module is used to handshake with the vehicle-mounted shortwave communication system to send the standard signal to be detected and the control signal of the vehicle-mounted shortwave transmitter.

[0067] In some possible embodiments, the data communication module uses an adaptive gigabit Ethernet PHY based on YT8531 and a 5G wireless module model E27V with a 10Mbps QSPI interface. The hardware module design mainly considers anti-interference, and is specifically implemented using a shielding layer.

[0068] In some specific embodiments, the antenna-feeder detection module is used to detect the performance of the vehicle-mounted short-wave communication system antenna or feeder. The model of the antenna-feeder detection module is PW-47D. In this embodiment, the physical performance detection of the antenna-feeder adopts the comparison method of a calibrated magnetic field antenna and a calibrated short-wave antenna for measurement. A highly sensitive calibrated magnetic field probe is selected to detect the coverage range of the antenna-feeder. It is mainly considered that the short-wave signal range to be detected is 30 - 300 MHz. Therefore, the selected model of the magnetic field probe for calibration can be 2 - 3 times within the detection frequency range, and the specific model is SSPF-800. At the same time, the calibrated short-wave antenna is used to detect the coverage range of the antenna-feeder again. The industrial digital processor module calibrates the overlapping area of the two coverage ranges. The purpose of calibration is to improve the detection error of the target to be measured. After calibration, the performance attenuation or difference value of the vehicle-mounted short-wave communication system antenna or feeder is obtained. In addition to the antenna-feeder coverage range, the specific antenna-feeder performance indicators include detection contents such as standing wave ratio measurement (SWR), return loss (RL), cable loss (LOSS), and fault point distance positioning (DTF). In this embodiment, the overall performance indicators of the vehicle-mounted short-wave communication system antenna-feeder are evaluated through comprehensive analysis of the above detection data and compared with the factory-set antenna-feeder technical indicators, and finally maintenance suggestions for the vehicle-mounted short-wave radio antenna-feeder are given.

[0069] In some specific embodiments, the spectrum analysis module obtains the radio frequency signals of the vehicle-mounted short-wave communication system by connecting to a calibrated short-wave antenna, and analyzes the spectrum, chromatogram, and spectrum heat map of these signals to provide analysis of short-wave signal frequency interference, radio frequency emission leakage, and spectrum statistical characteristics for the vehicle-mounted short-wave communication system in practical applications, so as to assist maintenance and repair personnel to more accurately locate faults and provide solutions.

[0070] In some specific embodiments, the spectrum analysis module adopts a spectrum analysis module based on the xilinx Kintex high-end series XC7K325T chip, and the module model is GGFW-K7325T. The spectrum analysis module is used for digital signal processing after high-speed synchronous radio frequency coupling, and the parallel processing speed fundamental frequency is not lower than 1.6 GHz. Specifically, the industrial digital processor module issues control instructions to the spectrum analysis module according to the detection task requirements, including spectrum analysis range setting (such as frequency band selection, resolution bandwidth adjustment), signal capture trigger condition configuration (such as threshold level, trigger mode), and analysis mode selection (such as real-time spectrum analysis, peak hold analysis, etc.). The spectrum analysis module performs corresponding signal acquisition and preprocessing operations according to the instructions.

[0071] In some specific embodiments, the RTK differential multi-frequency positioning module is used to provide high-precision positioning services for the application environment of the vehicle-mounted short-wave communication system, that is, to associate detection data with geographical location information, so that maintenance personnel can accurately and quickly lock other external short-wave interference radio frequency signal sources. In some possible embodiments, the model of the RTK differential multi-frequency positioning module is RTK3288F, and the RTK differential multi-frequency positioning module provides an I2C communication interface for positioning data communication with the industrial digital processor module.

[0072] In some specific embodiments, the calibrated magnetic field antenna and short-wave antenna are used to provide a radio frequency signal coupling device for the vehicle-mounted short-wave communication system for short-wave signal antenna feeder detection, radio frequency power detection, radio frequency frequency detection, and spectrum analysis detection. The purpose is to highly sensitively obtain the working parameters of the short-wave radio frequency signal of the detection object and provide the channel parameters of the detected short-wave radio frequency signal for each detection module. The calibrated magnetic field antenna and the calibrated short-wave antenna are mainly used to reduce the radio frequency signal coupling error in the radio spectrum overlapping area during the detection process. Improve the detection accuracy, otherwise the detection faces a complex electromagnetic environment, such as geomagnetic or other air radio frequency interference, which leads to a decrease in detection accuracy. In this embodiment, the calibration of the magnetic field antenna and the short-wave antenna is based on the international standard IEC60228, and the calibration standard of the short-wave antenna is GY / T5057-2020.

[0073] In some specific embodiments, the multi-functional standard radio frequency signal source is used to provide a standard reference signal source for spectrum analysis of the short-wave radio frequency signal of the detection object. Whether the standard radio frequency signal source is accurate directly determines the spectrum analysis detection accuracy. In some possible embodiments, the multi-functional standard radio frequency signal source is PF0438-20Z of the 41st Research Institute of CETC. Frequency range: 0 - 1000Mhz.

[0074] This embodiment solves the problems of a wide variety of domestic vehicle-mounted short-wave radio detection equipment, poor generality, insufficient subsequent expandability, and lack of comprehensive performance test capabilities in various working condition wireless environments through high-integration multi-module coordinated detection and analog-to-digital signal processing.

[0075] In this embodiment, the radio frequency power detection module synthesizes signals according to the instructions sent by the industrial digital processor module through the synchronous control technology of direct digital frequency synthesis (DDS) and phase-locked loop (PLL). After synthesis, the detection frequency is higher, reaching more than 300Mhz, and it can provide high-resolution and stable high-frequency signals for the transceiver channels of high-speed short-wave communication.

[0076] In some specific embodiments, during the frequency synthesis process, the industrial digital processor module coordinates the cooperation between the spectrum analysis module and the RF power detection module through a synchronization control algorithm. For example, when a specific modulation signal needs to be generated, the processor module synchronously configures the output frequency of the DDS (Direct Digital Synthesizer) and the frequency division parameter of the PLL (Phase Locked Loop). The spectrum analysis module real-time feedbacks signal quality indicators (such as phase noise, spurious rejection ratio) for the processor module to dynamically optimize the frequency synthesis strategy.

[0077] Existing frequency synthesis technologies are mainly divided into three categories: direct frequency synthesis (DFS), phase-locked frequency synthesis (PLLS), and direct digital frequency synthesis (DDS). The principle of DFS is simple, easy to implement, and has a short frequency conversion time. However, its frequency range is limited, and the output spectrum quality is poor. PLL has a wide output frequency band, high operating frequency, and excellent spectrum quality. However, its frequency resolution and conversion speed are relatively low. DDS is known for its high frequency resolution, fast conversion time, high frequency stability, and low phase noise. However, it has limitations in realizing high-bandwidth spectra and is accompanied by relatively large spectral clutter.

[0078] In this embodiment, the frequencies of the RF power detection module DDS and PLL are synthesized. Specifically, the DDS in the RF detection module is used as the direct excitation source of the PLL in the digital processor online. The frequency synthesis process control adopts a synchronization control algorithm to ensure coupling between different frequency domain systems. The DDS and PLL frequency synthesis technology under the synchronization control algorithm of this embodiment overcomes the disadvantages of the low output frequency of DDS and the low frequency resolution of PLL in this detection system. By designing a matching loop low-pass filter, phase noise, and externally adapted circuits for loop stability, etc., the frequency synthesis performance is greatly improved, and filtering measures are taken for the system power supply to improve spurious rejection. Finally, a method different from the existing general DDS and PLL simple frequency synthesis method is determined to meet the requirements of the detection technology of this embodiment.

[0079] The system implementation block diagram of the synchronization control method for DDS and PLL frequency synthesis in different frequency domains in this embodiment is as Figure 2Shown as follows: In this embodiment, an in-loop frequency synthesis technology of a phase-locked loop (PLL) based on direct digital synthesis (DDS) excitation is adopted. The short-wave coupling frequency is generated by a MAX038 high-precision DDS generator embedded in the radio frequency power detection module, and its phase and frequency parameters are configured by an industrial digital processing module (model: H8000). The generated signal is filtered by a low-pass filter (LPF1) and then enters an ADF4106 high-precision frequency division and phase discrimination controller (PLL) for further processing. ADF4106 operates in the frequency division ratio and frequency divider mode configured by the industrial digital processing module, and provides synchronous control and dual-mode frequency division counting through the feedback of a voltage-controlled oscillator (VCO). The output of ADF4106 is filtered by an LPF2 low-pass filter and then processed by a voltage-controlled oscillator (VCO). Subsequently, this signal and the filtered DDS output signal perform frequency synthesis through a synchronous control method. Finally, the synthesized signal is processed by a band-pass filter to obtain an output signal that meets the requirements of the detection modulation frequency. The short-wave synchronous control frequency synthesis technology based on the above technology can achieve a low spurious signal level, a high switching speed, and excellent phase noise performance, and at the same time supports frequency modulation and phase modulation functions. In addition, the different frequency domain DDS and PLL frequency synthesis synchronous control method of this embodiment effectively suppresses spurious signals, reduces the filtering difficulty, simplifies the hardware design, and provides a reliable guarantee for the linear frequency modulation continuous short-wave comprehensive performance detection of the short-wave communication system.

[0080] In some specific embodiments, the low-pass filter, the band-pass filter, and the frequency division and phase discrimination controller are all integrated in the radio frequency power detection module.

[0081] In some specific embodiments, such as Figure 3 , the different frequency domain DDS and PLL frequency synthesis control method is specifically as follows:

[0082] S1. Initialize the industrial digital processor module and the DDS generator (radio frequency power detection module): Set the frequency control word F of the DDS word ; Set the frequency division ratio R and N of the PLL (frequency division and phase discrimination controller), where R is the frequency division ratio of the prescaler and N is the frequency division ratio of the feedback frequency divider;

[0083] S2. When writing the DDS frequency word and control word, under normal circumstances, the synchronous controller embedded in the industrial digital processor module sets the frequency division parameters and the synchronous control word, and then the industrial digital processor module sets the working parameters for the ADF4106 in the radio frequency power detection module. If an abnormality is found during the whole process, it is reset by the hardware watchdog. Under normal circumstances, the frequency synthesis start signal can be sent to start the frequency synthesis of DDS and PLL. If it is not normal, return to S1 to re-initialize (such as Figure 3 ).

[0084] In some specific embodiments, the process of the industrial digital processor module setting working parameters for the frequency division and phase discrimination controller is as follows:

[0085] S201. Set the input frequency of the frequency division and phase discrimination controller to f in_DDS , and the output frequency to f out_VCO .

[0086] Among them, f in_DDS is equal to the output frequency of the DDS:

[0087]

[0088] Among them, F word is the clock frequency, and n is the number of bits of the phase accumulator in the DDS generator;

[0089] The output frequency of the frequency division and phase discrimination controller is

[0090] S202. Adjust the frequency division ratio N of the PLL through the synchronization control algorithm; make f out_VCO equal to the target frequency f target .

[0091] In some specific embodiments, the synchronization control algorithm is specifically as follows:

[0092] S2021. Calculate the error signal e(t) = f target - f out_VCO ;

[0093] S2022. Adjust the frequency division ratio N of the frequency division and phase discrimination controller according to the error signal:

[0094]

[0095] Among them, f ref is the reference frequency;

[0096] When e(t) ≠ 0, adjust the frequency division ratio N; make the system stable.

[0097] If e(t) is not 0 for a long time, it indicates that the system is unlocked or there is a hardware fault, and the hardware watchdog will force a reset to restore stable operation.

[0098] In some specific embodiments, the hardware watchdog is integrated in the industrial digital processor module.

[0099] This embodiment can generate a continuous, stable, and reliable coupled digital signal in the 30 - 300 MHz frequency band according to the frequency band of the radio station under test, and it is the core digital signal source for the subsequent processor module to perform spectrum analysis. The digital signal processing technology and high - speed spectrum analysis technology built into the industrial digital processor module achieve digital measurement below the intermediate frequency, greatly improving the resolution and test accuracy of the short - wave communication transceiver system, including the detection accuracy and speed of comprehensive performance indicators such as the antenna - feeder system, transceiver, channel, and anti - interference ability.

[0100] Because the white noise of the current mainstream power amplifier itself and the resolution problem of the high - speed analog - to - digital conversion device itself affect the system detection accuracy, the conventional method is to perform noise filtering first and then high - speed digital - to - analog conversion, but it cannot completely solve the system noise. In this embodiment, both the radio - frequency power detection module and the antenna - feeder detection module adopt a three - stage power amplification technology and a high - speed analog - to - digital converter.

[0101] In some possible embodiments, the power amplifier in the radio - frequency power detection module and the antenna - feeder detection module of this embodiment uses an SR570 low - noise current amplifier as the core component. The first - stage SR570 preliminarily amplifies the received weak radio - frequency signal and outputs it as the input of the second - stage SR570; the second - stage SR570 further amplifies the signal and transmits it to the third - stage SR570. Through this step - by - step amplification method, while maintaining signal integrity, the introduction and amplification of noise can be minimized. The three - stage amplification structure of this embodiment can effectively reduce the noise coefficient at each stage, thereby improving the overall signal - to - noise ratio (SNR) and ensuring that the signals for subsequent processing have high quality.

[0102] In some possible embodiments, the high - speed analog - to - digital converter selects a high - resolution, high - sampling - rate high - speed ADC chip, such as AD9680. The high - speed ADC samples the analog signal at an extremely high sampling rate to ensure that all details of the signal are captured. The sampled signal is quantized into a digital signal, usually with a resolution of 12 bits or higher, to ensure the accuracy of signal conversion. The digital signal is converted into digital components after modulation and demodulation and temporarily stored in the RAM.

[0103] The radio - frequency power detection module and the antenna - feeder detection module adopt a front - mid - position configuration method, that is, the power amplifier and the high - speed ADC are arranged as close as possible. This layout can significantly shorten the hardware connection path, reduce the noise interference that may be introduced during signal transmission, and thus improve the integrity and stability of the signal.

[0104] In this embodiment, the anti-interference ability of the hardware circuit is improved by optimizing the layout and wiring design. Specifically, power devices and digital-analog hybrid devices are arranged in independent isolated areas to reduce mutual interference. The wiring adopts a four-layer structure, where the power supply and ground wires are each independent layers, ensuring power supply stability and reducing noise. The digital signal lines are wired using differential equal-length and equal-impedance strategies to improve signal integrity and anti-interference performance. In addition, for devices with a working frequency exceeding 100 MHz, this embodiment uses a dedicated custom shielding layer for isolation, further enhancing the anti-interference ability of the system. Through these comprehensive hardware circuit design measures, the reliability and stability of the overall system are significantly improved.

[0105] In this embodiment, the main PCB material is selected as a composite FR4 material with high anti-interference performance. The detection antenna part uses a shielded type 1 flexible coaxial cable to connect the detection antenna to the main PCB, and a customized connector after gold plating impedance adaptation is used. For device layout and wiring, a simulation model is first established. Through the simulation model, a failure analysis model after the system layout is constructed. Through the analysis of the implementation model, optimization is carried out to finally determine the layout and wiring. Finally, after the hardware board is installed, anti-interference and signal integrity analysis and optimization are carried out, and finally the technical requirements achieved by this embodiment are realized. Moreover, the radio frequency power detection module can be configured in two working states: automatic mode or manual mode. In the automatic mode, it can provide the coupling power level for the antenna feeder detection module, ensuring the measurement accuracy and efficiency of the core antenna feeder in the short-wave communication system. The radio frequency power detection module not only provides the high-precision coupling power of the measured antenna system, but also provides the necessary input signal for the antenna feeder detection module. At the same time, it also provides the basic direction angle of the measured short-wave antenna for the antenna feeder system, supporting that the maximum output power of the short-wave transceiver can reach 100 W when it is used independently as a wireless communication device. Moreover, the radio frequency power detection module is configured with a power amplifier and a high-speed ADC, effectively improving the detection accuracy and speed of the comprehensive performance of the short-wave communication system. The system prototype test of this embodiment is 2 orders of magnitude higher than that of existing similar products.

[0106] As Figure 4 , this embodiment abandons the traditional electrical cable connection method and instead adopts wireless communication technology. Specifically, a dedicated data communication module is installed inside the vehicle short-wave communication system. This module uses a data communication antenna in the 2.4 GHz frequency band to establish a wireless data link with the vehicle short-wave radio equipment. The main function of this link is to achieve precise control and data interaction with the vehicle short-wave radio during the test process, thereby improving the flexibility and convenience of the test process.

[0107] Based on the comprehensive performance detection requirements of the vehicle-mounted short-wave communication system, in this embodiment, control instructions are sent to the vehicle-mounted short-wave radio through the data communication module. After receiving the instructions, the vehicle-mounted short-wave radio emits short-wave radio frequency signals of a specific frequency according to the instruction requirements, and the signals are broadcast and transmitted through the vehicle-mounted short-wave antenna. The calibrated short-wave antenna can couple and receive the test frequency signals emitted by the vehicle-mounted short-wave radio. By performing operations such as radio frequency power detection, frequency detection, antenna-feeder performance evaluation, and spectrum analysis on the received signals, key parameters of the vehicle-mounted short-wave radio frequency signal channel can be obtained. These data provide support for maintenance personnel to troubleshoot interference sources, perform spectrum scanning and monitoring, measure radio frequency signals and frequency bands, and locate system faults, thereby improving the reliability and maintenance efficiency of the system.

[0108] The radio frequency power and frequency detection of the short-wave signal are realized by performing spectrum analysis on the coupled short-wave signal received by the system in this embodiment. Specifically, the radio frequency power is obtained through integral operation between two test cursor points in the spectrum analysis. Spectrum analysis can display all the short-wave signal frequencies existing in the electromagnetic environment. By locking the transmission frequency of the transmitter, it can be verified whether the received radio frequency conforms to the application requirements of the vehicle-mounted short-wave radio. According to the signal characteristics of the short-wave radio under test, the radio frequency power detection supports three types of power measurements: broadband power, narrowband power, and through-power detection.

[0109] The antenna-feeder performance detection in this embodiment includes standing wave ratio measurement (SWR), return loss (RL), cable loss (LOSS), distance-to-fault location (DTF), etc., and can also provide antenna-feeder coverage range detection. The antenna-feeder detection module is built-in with a tracking signal generator, and cooperating with the return loss test bridge of the equipment accessories, it can detect the return loss and cable loss of the antenna-feeder of the short-wave signal emitted by the vehicle-mounted short-wave radio coupled by the detection equipment. For the antenna coverage range detection in this patented technology, the comparison method of a calibrated high-sensitivity standard magnetic field antenna and a calibrated short-wave antenna is used for measurement. The calibrated standard magnetic field antenna can be deployed around the detection equipment. The vehicle-mounted short-wave communication system can move flexibly during the detection process. The moving range of the vehicle-mounted radio is obtained through the RTK differential positioning system, and the coverage range of the vehicle-mounted short-wave antenna-feeder is detected by comparing with the calibrated short-wave antenna integrated on the detection equipment.

[0110] This embodiment integrates a calibrated short-wave antenna, which is used to capture the radio frequency signals of the vehicle-mounted short-wave communication system, and through spectrum analysis, chromatogram analysis, and spectrum heat map analysis, it provides a detailed evaluation of short-wave signal frequency interference, radio frequency emission leakage, and spectrum statistical characteristics.

[0111] Such as Figure 5, in this embodiment, the vehicle-mounted short-wave antenna transmits radio frequency signals according to the requirements of the detection content. The radio frequency signals pass through the calibrated short-wave coupling antenna to generate simulated signals to be detected. The analog signals are converted into digital signals after passing through the high-precision ADC / DAC unit. The digital signals are converted into digital components after modulation and demodulation. The digital components are temporarily stored in the RAM. The industrial digital processor module performs FFT transformation on the digital components in the RAM through the arithmetic unit, extracts the spectral characteristic values for display, and provides spectral data support for the required detection items.

[0112] The system of this embodiment is mainly applied to the comprehensive performance detection of portable short-wave communication systems, including communication bit error rate, standing wave ratio, antenna direction angle, antenna transmission power, radio station positioning, etc.

[0113] Compare the system of this embodiment with the mainstream products ZP-300 and EPS8400. The main parameters are shown in Table 1:

[0114]

[0115]

[0116] Each embodiment in this specification is described in a related manner. For the same and similar parts between each embodiment, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the related parts, reference can be made to the partial description of the method embodiment.

[0117] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A vehicle-mounted shortwave communication system performance detection system, characterized in that: include: The radio frequency power detection module is used to detect the radio frequency signal power of the vehicle-mounted short-wave communication system and is connected to the industrial digital processor module signal; An industrial digital processor module integrates an operation control unit, a memory, and a communication interface; it is used to control the operation of each module of the system, process detection data, and perform frequency synthesis control; the industrial digital processor module also integrates a storage module, and the industrial digital processor module is connected to the data communication module by signal, so as to realize wireless control instruction interaction with the vehicle-mounted shortwave radio station and detect data transmission; Antenna and feeder detection module, used to evaluate the standing wave ratio, return loss, cable loss and fault location of the vehicle-mounted shortwave antenna, and to measure by comparing the coverage of the calibrated magnetic field antenna and the shortwave antenna; connected to the industrial digital processor module signal; The spectrum analysis module obtains the radio frequency signal of the vehicle-mounted shortwave communication system by connecting to a calibrated shortwave antenna, performs spectrum analysis on the received shortwave radio frequency signal, generates spectrum heat map and chromatogram, and analyzes the signal interference source and spectrum statistical characteristics; it is connected to the industrial digital processor module signal; RTK differential multi-frequency positioning module, used to associate detection data with geographic location information, and connected to the industrial digital processor module signal; The PMU power management module provides a multi-level regulated power supply and is connected to the industrial digital processor module cable.

2. A vehicle-mounted shortwave communication system performance detection system according to claim 1, characterized in that: The radio frequency power detection module includes three-stage low-noise current amplifiers, which amplify weak radio frequency signals step by step to reduce the noise coefficient, and use a high-speed analog-to-digital converter to achieve high-resolution signal sampling.

3. A vehicle-mounted shortwave communication system performance detection system according to claim 1, characterized in that: The radio frequency power detection module performs frequency synthesis on the DDS and PLL frequencies in the radio frequency power detection module according to the instruction sent by the industrial digital processor module.

4. A vehicle-mounted shortwave communication system performance detection system according to claim 1, characterized in that: The detection system also includes a calibrated magnetic field antenna and shortwave antenna, and a multifunctional radio frequency standard signal source; The calibrated magnetic field antenna and shortwave antenna obtain the working parameters of the shortwave radio frequency signal of the detection object, and provide the required radio frequency signal channel parameters for each detection module; the calibrated magnetic field antenna and shortwave antenna are connected to the radio frequency power detection module and the spectrum analysis module through coaxial cable signals; The multifunctional radio frequency standard signal source is used to provide a standard reference signal source for spectrum analysis and is connected to the industrial digital processor module signal.

5. A vehicle-mounted shortwave communication system performance detection system according to claim 3, characterized in that: The radio frequency power detection module includes a DDS generator, a voltage-controlled oscillator, a low-pass filter, a band-pass filter, a frequency division and phase detection controller; The industrial digital processor includes a synchronous controller and a hardware watchdog; The DDS and PLL frequency synthesis process is specifically as follows: the DDS generator generates an initial short-wave coupling frequency signal; the signal is filtered through a low-pass filter; the filtered signal enters the frequency division and phase detection controller, and the parameters are processed according to the DDS and PLL frequency synthesis synchronization control method in different frequency domains of the industrial digital processor module, and feedback control and dual-mode frequency division counting are provided through the voltage-controlled oscillator; the output signal of the voltage-controlled oscillator is frequency synthesized with the signal output by the filtered DDS generator.

6. A vehicle-mounted shortwave communication system performance detection system according to claim 5, characterized in that: The frequency division and phase detection controller output is filtered through a low pass filter before providing feedback control and dual-mode frequency division counting through a voltage controlled oscillator.

7. A vehicle-mounted shortwave communication system performance detection system according to claim 5, characterized in that: The method for synchronous control of frequency synthesis of DDS and PLL in different frequency domains is specifically as follows: S1. Initialize the industrial digital processor module and DDS generator: Set the frequency control word F of DDS word ; Set the frequency division ratios R and N of the frequency division and phase detector controller, where R is the frequency division ratio of the pre-divider and N is the frequency division ratio of the feedback divider; S2, DDS frequency word and control word are written normally. The synchronous controller embedded in the industrial digital processor module sets the frequency division parameters and synchronous control words. Then the industrial digital processor module sets the working parameters for the frequency division and phase detection controller in the RF power detection module. If any abnormality is found during the whole process, the hardware watchdog will reset it. Under normal circumstances, the frequency synthesis start signal can be sent to start the DDS and PLL to perform frequency synthesis. If it is abnormal, it will return to S1 to reinitialize.

8. A vehicle-mounted shortwave communication system performance detection system according to claim 7, characterized in that: The process of setting working parameters for the frequency division and phase detection controller by the industrial digital processor module is as follows: S201, set the input frequency of the frequency division and phase detection controller to f in_DDS , the output frequency is f out_VCO ; Among them, f in_DDS Equal to the output frequency of the DDS generator: where F word is the clock frequency, n is the number of bits of the phase accumulator in the DDS generator; The output frequency of the frequency division and phase detection controller is S202, adjusting the frequency division ratio N of the PLL through a synchronous control algorithm; making f out_VCO Equal to the target frequency f target .

9. A vehicle-mounted shortwave communication system performance detection system according to claim 8, characterized in that: The synchronization control algorithm is specifically: S2021, calculate error signal e(t)=f target -f out_VCO ; S2022, adjusting the frequency division ratio N of the frequency division and phase detection controller according to the error signal: where f ref is the reference frequency; When e(t)≠0, adjust the frequency division ratio N to make the system stable.

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