Antenna side Beidou signal conversion system based on passive mixing technology

Abstract

This invention relates to an antenna-side BeiDou signal conversion system based on passive mixing technology, belonging to the field of satellite navigation signal processing technology. The system includes: a passive mixing and matching unit for BeiDou bands, which acquires multi-band BeiDou signals from the antenna side, identifies frequency band characteristics, adjusts the mixing method, and generates a standardized signal through adaptive matching conversion; a processing device and collaborative protection and control unit monitors interference signals, dynamically adjusts the receiving and verification methods, and activates interference protection and temperature control mechanisms; a mixing and processing closed-loop collaborative control unit realizes signal detection, feature feedback, and dynamic parameter adjustment, forming a collaborative solution in weak signal scenarios; and a BeiDou signal anti-interference distortion compensation unit suppresses non-BeiDou band interference, detects signal distortion, and dynamically compensates for it. This system integrates accurate conversion of BeiDou multi-band signals, secure protection of the processing device, efficient processing of weak signals, and anti-interference distortion compensation, improving signal conversion accuracy and system stability.

Description

Technical Field

[0001] This invention belongs to the field of satellite navigation signal processing technology, specifically relating to an antenna-side BeiDou signal conversion system based on passive mixing technology. Background Technology

[0002] As application scenarios continue to expand, users' demands for navigation and positioning accuracy are shifting from traditional meter-level to centimeter-level and millimeter-level. As the first gate for receiving and initially processing BeiDou signals, the antenna side's signal conversion efficiency, multi-band adaptability, and the operational safety of the calculation device directly determine the reliability of subsequent navigation data, making it a core link in ensuring the implementation of high-precision applications.

[0003] However, in the current field of satellite navigation signal processing, antenna-side BeiDou signal conversion technology still faces many prominent bottlenecks, making it difficult to meet the high-precision requirements in complex scenarios: First, the adaptability of multi-band signal conversion is insufficient. The BeiDou system covers multiple frequency bands, and the frequency characteristics and amplitude ranges of each frequency band are different. Existing mixing and conversion technologies mostly adopt fixed modes to adapt to a single frequency band, or use simple parameter adjustments to be compatible with multiple frequency bands. They lack a targeted adaptive matching mechanism, making it difficult to achieve accurate matching and conversion of signals in each frequency band. This can easily lead to problems such as large conversion loss and signal distortion, and cannot meet the antenna side's requirements for integrated processing of multi-band signals.

[0004] Secondly, the protection of the calculation device lacks coordination with signal processing. As the core computing component after signal conversion, the calculation device is responsible for decoding BeiDou signals, calculating positioning data, and extracting navigation information. It is a key link in realizing signal conversion to applications. However, its existing protection methods are mostly independent shielding shells or fixed threshold protection, which are not deeply coordinated with the mixing and conversion process. Electromagnetic interference and heat generated during the mixing process can easily directly penetrate the calculation device, leading to data verification errors, reduced calculation accuracy, and even component damage, affecting the overall stability of the system.

[0005] Third, the weak signal processing capability is weak; the antenna side often faces scenarios such as signal blockage and long-distance transmission attenuation, resulting in insufficient BeiDou signal strength. Existing technologies mostly optimize the mixing gain or the solution algorithm separately, lacking a coordinated control mechanism between the two. It is difficult to balance the conversion effect and the solution accuracy in weak signal scenarios, and it is easy to cause signal loss or excessive solution error, which restricts the application of BeiDou technology in weak signal scenarios such as outdoor monitoring and underground engineering.

[0006] Fourth, the anti-interference and distortion compensation methods are limited; the electromagnetic environment on the antenna side is complex, and non-BeiDou frequency band interference signals such as industrial equipment radiation and adjacent channel signals can easily intrude into the transmission link. Existing anti-interference technologies mostly only set up filtering mechanisms in a single link of the mixing link or the solution link, lacking a two-way linkage suppression effect; at the same time, distortion problems such as phase shift and amplitude fluctuation in the signal mixing and conversion process mostly rely on back-end amplification compensation, which has poor compensation timeliness and further affects the accuracy of the solution data.

[0007] The aforementioned technical deficiencies make it difficult for existing antenna-side BeiDou signal conversion systems to meet the high-precision requirements of complex application scenarios, thus restricting the large-scale application of BeiDou navigation technology in antenna-limited scenarios such as portable devices, vehicle terminals, and outdoor monitoring. Summary of the Invention

[0008] To address the aforementioned problems in the existing technology, this invention provides an antenna-side BeiDou signal conversion system based on passive mixing technology. The objective of this invention can be achieved through the following technical solution: include: The passive mixing and matching unit of the BeiDou band acquires BeiDou multi-band signals from the antenna side, identifies the signal characteristics of each band, and adjusts the mixing and conversion method; it generates standardized BeiDou signals by adaptively matching and mixing and converting signals of each band through band-adaptive matching. The calculation device, in collaboration with the protection and control unit, acquires the characteristics of interference signals generated by mixing in real time, analyzes the range of interference impact, and dynamically adjusts the signal reception and data verification methods of the calculation device. When the interference exceeds the preset safety range, it automatically activates data storage and shielding protection, and resumes calculation operation after the interference is eliminated. It also synchronously conducts the heat generated by mixing and calculation, and provides feedback to adjust and control the temperature rise. The frequency mixing and solving closed-loop collaborative control unit detects the BeiDou signal transmission status and quality in real time, extracts key signal features and feeds them back to the frequency mixing link, and dynamically adjusts the frequency mixing conversion parameters based on the feedback features. When the signal strength is lower than the preset threshold range, the frequency mixing gain adjustment and the solution processing method are optimized simultaneously to form a collaborative scheme for conversion and solution. The BeiDou signal anti-interference distortion compensation unit, based on the aforementioned conversion and decomposition collaborative scheme, uses a mixing link to selectively suppress non-BeiDou frequency band interference signals, synchronously and in real-time detect phase and amplitude changes during signal transmission, and dynamically adjust the mixing matching parameters; the decomposition link analyzes the interference components in the mixing output signal in real-time, extracts interference signal features, and feeds them back to the mixing link.

[0009] Specifically, the process of identifying the signal characteristics of each frequency band and adjusting the mixing conversion method is as follows: acquiring the BeiDou multi-band signals received by the antenna side, and extracting features from each signal one by one; constructing feature vectors from the extracted features, comparing them with the standard vectors of the inherent characteristics of each frequency band of the BeiDou system, and confirming the frequency band to which each signal belongs through vector similarity; and adjusting the bias state of the mixer diode, the parameter combination of the impedance matching network, and the matching mode of the signal transmission path in a targeted manner according to the feature differences of signals in different frequency bands.

[0010] Specifically, the process of converting signals of each frequency band by adaptive matching mixing is as follows: based on historical conversion data, a mapping relationship between the signal characteristics of each frequency band and the mixing parameters is constructed, and the mixing parameters of the corresponding frequency band are automatically retrieved through feature matching; the deviation between the output signal and the standard signal is compared in real time, and the mixing parameters are dynamically calibrated by gradient adjustment method to optimize the matching coefficient of the signal coupler.

[0011] Specifically, the process of dynamically adjusting the signal reception and data verification method of the solving device is as follows: Based on the characteristic information and influence range of the interference signal, the gain level of the calculation device is adjusted. Synchronously optimize data verification rules, increase verification dimensions, and first coarsely screen the received data to remove obvious outliers, and then finely screen and verify key features. Valid data is retained according to preset standards, and abnormal data that are distorted due to interference are marked and removed.

[0012] Specifically, the automatic data storage and shielding protection process is as follows: continuously monitor the intensity changes of interference signals; when the monitored value exceeds the preset safety range, fully store the raw data, intermediate calculation results, and related operating parameters that have not yet been calculated; at the same time, activate the electromagnetic shielding switch to cut off the transmission path of interference signals into the core calculation link of the calculation device; set data access permissions, activate the isolation circuit at the hardware level, and build a double protection barrier to block the propagation of interference.

[0013] Specifically, the feedback adjustment and control of the temperature rise is as follows: deploy a temperature sensor to acquire the temperature data of the mixing link and the solving device in real time during operation; when the temperature data approaches the upper limit of the preset temperature range, adjust the mixing operation parameters to reduce the conversion power consumption of the invalid frequency band; at the same time, optimize the heat dissipation conduction path, widen the heat dissipation channel, and control the temperature rise through multi-stage coordinated operation to maintain the equipment operating environment temperature within the preset temperature range.

[0014] Specifically, the process of real-time detection of BeiDou signal transmission status and quality in the solution link is as follows: The link starts a continuous monitoring mechanism, and uses time series analysis to track the stability of signal transmission, analyze amplitude consistency and verify integrity; Calculate the percentage of valid data in the total data after removing signal interruption periods, and count the frequency and interval of signal interruptions; Establish benchmark ranges for various monitoring indicators based on historical normal operation data, and compare the current monitoring results to determine the signal transmission status and quality.

[0015] Specifically, the process of extracting key signal features and feeding them back to the mixing link is as follows: from the detected BeiDou signal, relevant key features are selected according to their weight in terms of their impact on the conversion effect; the selected feature information is classified and organized, the data format is unified and the feature values ​​are normalized, and the data is integrated into standardized feedback data according to a preset format; the standardized feedback data is transmitted to the mixing link, and the integrity of the data is verified by comparing the check codes.

[0016] Specifically, the process of forming the conversion and resolution collaborative scheme is as follows: continuously monitor signal strength changes, and when the detected value is lower than a preset threshold, the mixing link receives the feedback signal characteristics; adjust the gain adjustment parameters according to the degree of signal attenuation to optimize the coupling matching details in the signal conversion process; the resolution link synchronously adjusts the filtering coefficient of the weak signal noise reduction algorithm to optimize the data fusion logic; set the linkage trigger threshold between the mixing parameters and the resolution algorithm, and confirm the timing sequence of parameter adjustment and the time nodes of process connection.

[0017] Specifically, the process by which the mixing link selectively suppresses non-BeiDou frequency band interference signals in advance is as follows: the frequency range and characteristic parameters of each frequency band of the BeiDou system are pre-set, and a frequency band identification standard library is established; the mixing link starts a frequency band identification mechanism based on a frequency spectrum analysis algorithm to screen all received signals one by one; first, a coarse screening is performed according to the frequency range, and then a fine screening is performed by comparing the characteristic parameters to determine whether the signal conforms to or does not conform to the BeiDou frequency band standard; the transmission channel is opened for signals that conform to the standard, and for interference signals of non-BeiDou frequency bands, the frequency band selection switch is controlled to disconnect their path into the subsequent transmission and processing link.

[0018] Specifically, the process of real-time detection of phase and amplitude changes during signal transmission is as follows: a detection module is integrated into the mixing link, and the detection module continuously tracks the signal transmission process after it is started; the phase offset and amplitude fluctuation status are acquired, and various change data are recorded in real time in chronological order; the recorded change data are analyzed in real time, compared with the normal fluctuation range standard, and the current change is compared with the preset reasonable range.

[0019] Specifically, the process of real-time analysis of interference components in the mixed output signal by the solution link is as follows: after receiving the mixed output signal, the solution link decomposes the signal step by step according to the frequency band and amplitude range; extracts feature information in each level through a signal feature extraction algorithm; compares the extracted feature information with the standard BeiDou signal features in multiple dimensions, analyzes the differences, and identifies interference components based on the differences; further analyzes the composition characteristics of the interference components to determine the type and intensity of the interference.

[0020] The beneficial effects of this invention are as follows: (1) By setting up a passive mixing matching unit and a mixing solution closed-loop collaborative control unit for the BeiDou frequency band, the signals of each BeiDou frequency band are first accurately identified by feature vector comparison, and parameters such as the bias state of the mixing diode and the impedance matching network are adjusted in a targeted manner. The mixing parameters are automatically retrieved by combining the mapping relationship and dynamically calibrated by the gradient adjustment method to generate standardized BeiDou signals. Then, the signal status and quality are continuously monitored by the solution link, key features are screened and standardized and fed back to the mixing link. In the weak signal scenario, the mixing gain and the solution noise reduction algorithm are adjusted in stages, and the linkage threshold and connection node are clarified, which effectively improves the accuracy and continuity of multi-band signal conversion and strengthens the conversion and solution collaborative effect in the weak signal scenario. (2) By setting up a solution device collaborative protection and control unit and a Beidou signal anti-interference distortion compensation unit, the gain level of the solution device is first adjusted based on the characteristics of the interference signal, the verification rules are optimized and abnormal data is removed by coarse and fine screening. When the interference exceeds the standard, data temporary storage and electromagnetic shielding and circuit isolation are activated for dual protection. At the same time, temperature control is coordinated by temperature sensor monitoring, power consumption adjustment and heat dissipation optimization. Then, non-Beidou frequency band interference is screened and blocked by frequency spectrum analysis algorithm, signal phase and amplitude changes are detected in real time, the solution link is decomposed and the interference components are identified by multi-dimensional comparison, and the mixing parameters are adjusted in feedback to fully ensure the stable operation of the solution device and significantly improve the system's anti-interference capability and signal transmission fidelity. Attached Figure Description

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a system architecture diagram of the antenna-side BeiDou signal conversion system based on passive mixing technology of the present invention; Figure 2 This is a data flow diagram of the antenna-side BeiDou signal conversion system based on passive mixing technology of the present invention. Detailed Implementation

[0023] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0024] Please see Figures 1-2 An antenna-side BeiDou signal conversion system based on passive mixing technology; include: The passive mixing and matching unit of the BeiDou band acquires BeiDou multi-band signals from the antenna side, identifies the signal characteristics of each band, and adjusts the mixing and conversion method; it generates standardized BeiDou signals by adaptively matching and mixing and converting signals of each band through band-adaptive matching. The calculation device, in collaboration with the protection and control unit, acquires the characteristics of interference signals generated by mixing in real time, analyzes the range of interference impact, and dynamically adjusts the signal reception and data verification methods of the calculation device. When the interference exceeds the preset safety range, it automatically activates data storage and shielding protection, and resumes calculation operation after the interference is eliminated. It also synchronously conducts the heat generated by mixing and calculation, and provides feedback to adjust and control the temperature rise. The frequency mixing and solving closed-loop collaborative control unit detects the BeiDou signal transmission status and quality in real time, extracts key signal features and feeds them back to the frequency mixing link, and dynamically adjusts the frequency mixing conversion parameters based on the feedback features. When the signal strength is lower than the preset threshold range, the frequency mixing gain adjustment and the solution processing method are optimized simultaneously to form a collaborative scheme for conversion and solution. The BeiDou signal anti-interference distortion compensation unit, based on the aforementioned conversion and decomposition collaborative scheme, uses a mixing link to selectively suppress non-BeiDou frequency band interference signals, synchronously and in real-time detect phase and amplitude changes during signal transmission, and dynamically adjust the mixing matching parameters; the decomposition link analyzes the interference components in the mixing output signal in real-time, extracts interference signal features, and feeds them back to the mixing link.

[0025] In this embodiment, the BeiDou signal anti-interference distortion compensation unit, based on the frequency band selective suppression of non-BeiDou frequency band interference signals, adds a targeted suppression step for frequency-shifting BeiDou signal leakage in indoor passive DAS combining scenarios: a frequency feature library of frequency-shifting BeiDou signals is established in advance, recording the frequency range, amplitude characteristics, and transmission patterns of common frequency-shifting BeiDou signals; the mixing link screens the received signals through a frequency spectrum analysis algorithm, identifying frequency-shifting BeiDou leakage signals that match the feature library as interference signals, and controlling the frequency band selection switch to cut off the transmission path of such signals; at the same time, for low-power frequency-shifting BeiDou leakage signals, a narrowband filter component is used to accurately intercept them, ensuring that the leakage signals cannot enter the subsequent mixing and solving links, thus avoiding interference of frequency-shifting signal leakage to the original BeiDou signal.

[0026] In this embodiment, the BeiDou multi-band signal on the antenna side refers to the multi-band radio frequency signal directly received by the antenna in this invention from the BeiDou satellite navigation system, covering various working frequency band signals planned by the BeiDou system (excluding specific frequency band numbers); the signal carrier is a high-frequency electromagnetic wave, containing the carrier wave broadcast by the satellite and modulation data (such as navigation messages, pseudorange codes, etc.), and has the exclusive frequency characteristics, amplitude range and phase characteristics of each frequency band, which is the original input signal for subsequent mixing conversion and decoding processing.

[0027] In this embodiment, the characteristics of the interference signal refer to the inherent attributes and related information of non-BeiDou useful signals intruding into the antenna-side environment. Specifically, these include the frequency range, amplitude intensity, phase change pattern, duration of the interference signal, and the range of impact of the interference signal on the BeiDou signal transmission link and the operation of the calculation device (such as the affected signal frequency band and the degree of interference to the calculation data). This is the core basis for the system to dynamically adjust the protection strategy and optimize the anti-interference mechanism.

[0028] In this embodiment, key signal features refer to the core signal attributes that play a decisive role in the conversion accuracy and solution accuracy of BeiDou signals. These specifically include: frequency deviation, amplitude fluctuation, signal-to-noise ratio, phase consistency, transmission stability, data integrity, and signal attenuation in weak signal scenarios. These features directly reflect signal quality and transmission status, and are crucial references for adjusting mixing link parameters and optimizing link algorithms.

[0029] In this embodiment, the mixing matching parameters refer to the core control parameters that ensure accurate adaptation between the mixing conversion process and the characteristics of the BeiDou signal. Specifically, these include: the bias state of the mixing diodes, the parameter combination of the impedance matching network, the matching coefficient of the signal coupler, the mixing gain adjustment parameters, and the phase and amplitude calibration parameters used to compensate for signal distortion. These parameters are dynamically adjusted to ensure efficient conversion of multi-band signals, enhancement of weak signals, and correction of signal distortion, generating a standardized signal that meets the computational requirements.

[0030] Specifically, the process of identifying the signal characteristics of each frequency band and adjusting the mixing conversion method is as follows: acquiring the BeiDou multi-band signals received by the antenna side, and extracting features from each signal one by one; constructing feature vectors from the extracted features, comparing them with the standard vectors of the inherent characteristics of each frequency band of the BeiDou system, and confirming the frequency band to which each signal belongs through vector similarity; and adjusting the bias state of the mixer diode, the parameter combination of the impedance matching network, and the matching mode of the signal transmission path in a targeted manner according to the feature differences of signals in different frequency bands.

[0031] Specifically, the process of converting signals of each frequency band by adaptive matching mixing is as follows: based on historical conversion data, a mapping relationship between the signal characteristics of each frequency band and the mixing parameters is constructed, and the mixing parameters of the corresponding frequency band are automatically retrieved through feature matching; the deviation between the output signal and the standard signal is compared in real time, and the mixing parameters are dynamically calibrated by gradient adjustment method to optimize the matching coefficient of the signal coupler.

[0032] Specifically, the process of dynamically adjusting the signal reception and data verification method of the solving device is as follows: Based on the characteristic information and influence range of the interference signal, the gain level of the calculation device is adjusted. Synchronously optimize data verification rules, increase verification dimensions, and first coarsely screen the received data to remove obvious outliers, and then finely screen and verify key features. Valid data is retained according to preset standards, and abnormal data that are distorted due to interference are marked and removed.

[0033] Specifically, the automatic data storage and shielding protection process is as follows: continuously monitor the intensity changes of interference signals; when the monitored value exceeds the preset safety range, fully store the raw data, intermediate calculation results, and related operating parameters that have not yet been calculated; at the same time, activate the electromagnetic shielding switch to cut off the transmission path of interference signals into the core calculation link of the calculation device; set data access permissions, activate the isolation circuit at the hardware level, and build a double protection barrier to block the propagation of interference.

[0034] Specifically, the feedback adjustment and control of the temperature rise is as follows: deploy a temperature sensor to acquire the temperature data of the mixing link and the solving device in real time during operation; when the temperature data approaches the upper limit of the preset temperature range, adjust the mixing operation parameters to reduce the conversion power consumption of the invalid frequency band; at the same time, optimize the heat dissipation conduction path, widen the heat dissipation channel, and control the temperature rise through multi-stage coordinated operation to maintain the equipment operating environment temperature within the preset temperature range.

[0035] Specifically, the process of real-time detection of BeiDou signal transmission status and quality in the solution link is as follows: The link starts a continuous monitoring mechanism, and uses time series analysis to track the stability of signal transmission, analyze amplitude consistency and verify integrity; Calculate the percentage of valid data in the total data after removing signal interruption periods, and count the frequency and interval of signal interruptions; Establish benchmark ranges for various monitoring indicators based on historical normal operation data, and compare the current monitoring results to determine the signal transmission status and quality.

[0036] Specifically, the process of extracting key signal features and feeding them back to the mixing link is as follows: from the detected BeiDou signal, relevant key features are selected according to their weight in terms of their impact on the conversion effect; the selected feature information is classified and organized, the data format is unified and the feature values ​​are normalized, and the data is integrated into standardized feedback data according to a preset format; the standardized feedback data is transmitted to the mixing link, and the integrity of the data is verified by comparing the check codes.

[0037] Specifically, the process of forming the conversion and resolution collaborative scheme is as follows: continuously monitor signal strength changes, and when the detected value is lower than a preset threshold, the mixing link receives the feedback signal characteristics; adjust the gain adjustment parameters according to the degree of signal attenuation to optimize the coupling matching details in the signal conversion process; the resolution link synchronously adjusts the filtering coefficient of the weak signal noise reduction algorithm to optimize the data fusion logic; set the linkage trigger threshold between the mixing parameters and the resolution algorithm, and confirm the timing sequence of parameter adjustment and the time nodes of process connection.

[0038] Specifically, the process by which the mixing link selectively suppresses non-BeiDou frequency band interference signals in advance is as follows: the frequency range and characteristic parameters of each frequency band of the BeiDou system are pre-set, and a frequency band identification standard library is established; the mixing link starts a frequency band identification mechanism based on a frequency spectrum analysis algorithm to screen all received signals one by one; first, a coarse screening is performed according to the frequency range, and then a fine screening is performed by comparing the characteristic parameters to determine whether the signal conforms to or does not conform to the BeiDou frequency band standard; the transmission channel is opened for signals that conform to the standard, and for interference signals of non-BeiDou frequency bands, the frequency band selection switch is controlled to disconnect their path into the subsequent transmission and processing link.

[0039] Specifically, the process of real-time detection of phase and amplitude changes during signal transmission is as follows: a detection module is integrated into the mixing link, and the detection module continuously tracks the signal transmission process after it is started; the phase offset and amplitude fluctuation status are acquired, and various change data are recorded in real time in chronological order; the recorded change data are analyzed in real time, compared with the normal fluctuation range standard, and the current change is compared with the preset reasonable range.

[0040] Specifically, the process of real-time analysis of interference components in the mixed output signal by the solution link is as follows: after receiving the mixed output signal, the solution link decomposes the signal step by step according to the frequency band and amplitude range; extracts feature information in each level through a signal feature extraction algorithm; compares the extracted feature information with the standard BeiDou signal features in multiple dimensions, analyzes the differences, and identifies interference components based on the differences; further analyzes the composition characteristics of the interference components to determine the type and intensity of the interference.

[0041] In this embodiment, the frequency band identification and mixing parameter adjustment of the passive mixing matching unit of the BeiDou frequency band are specifically implemented as follows: After the antenna receives BeiDou multi-frequency band signals, it extracts features from each signal one by one, extracts information such as frequency spectrum lines and amplitude fluctuation period, and constructs feature vectors; the vector is imported into the comparison module with the pre-stored standard feature vectors of each BeiDou frequency band, and the matching degree is calculated by the cosine similarity algorithm to confirm the frequency band to which each signal belongs; for the differences of signals in different frequency bands, the bias voltage level of the mixing diode is actually adjusted (three adjustable ranges are set according to the frequency band characteristics), and the parameter combination of capacitors and inductors in the impedance matching network is matched. At the same time, the adaptation interface of the signal transmission path is switched to ensure that the link and frequency band features are matched; a feature-parameter mapping table is constructed based on historical conversion data, the corresponding mixing parameters are automatically retrieved, the amplitude and phase deviations of the output signal and the standard signal are compared in real time, the mixing parameters are calibrated every 10ms using the gradient descent method, the matching coefficient of the signal coupler is optimized, and finally a standardized BeiDou signal is generated.

[0042] In this embodiment, the weak signal coordination scheme of the mixing and solving closed-loop coordinated control unit is implemented as follows: The solving link continuously monitors the signal transmission status through the timing analysis module, and collects signal strength data every 5ms. When the detected value is lower than the preset threshold, the coordination mechanism is triggered immediately. The mixing link receives key features such as signal attenuation and signal-to-noise ratio from the solving link, and classifies them into three levels according to the attenuation level: mild, moderate, and severe. The amplification factor parameters of the gain adjustment module are adjusted accordingly. At the same time, the coupling depth of the signal coupler is optimized to reduce weak signal loss. The solving link synchronously adjusts the filtering coefficient of the weak signal noise reduction algorithm to broaden the effective signal frequency bandwidth, optimize the data fusion logic, and improve the weak signal resolution capability. The linkage trigger threshold between the mixing parameter adjustment and the solving algorithm optimization is preset, and the timing order of adjusting the mixing gain first and then optimizing the solving algorithm is clearly defined. A process connection interval of 20ms is set to ensure that the two coordinate without delay.

[0043] In this embodiment, the interference protection and data protection of the coordinating protection and control unit of the calculation device are implemented as follows: The interference detection module collects the interference signal in the mixing process in real time, extracts its frequency, amplitude, phase characteristics and influence range, and adjusts the gain level of the signal amplification module of the calculation device based on the feature data to weaken the influence of the interference signal; the data verification rules are optimized, and two verification dimensions, phase consistency and amplitude stability, are added. The received data is first coarsely screened by threshold screening to remove obvious abnormal values, and then finely screened by feature comparison to verify key information, and abnormal data with feature distortion are marked and removed; when the interference intensity monitoring value exceeds the safe range, the non-volatile storage unit is triggered to completely store the current original data, intermediate calculation results and running parameters; at the same time, the electromagnetic shielding switch is activated to cut off the interference conduction path, exclusive data access permissions are set at the software level, and the isolation circuit is activated at the hardware level to build dual protection; after the interference monitoring value returns to normal, the calculation operation is restarted through the parameter recovery module.

[0044] In this embodiment, the frequency band selective anti-interference of the BeiDou signal anti-interference distortion compensation unit is implemented as follows: The frequency range and characteristic parameters of each BeiDou frequency band are pre-stored in the system to establish a frequency band identification standard library; the mixing link starts a frequency spectrum analysis algorithm to screen all received signals one by one: first, a coarse screening is performed according to the frequency range to remove signals that clearly exceed the BeiDou frequency band; then, the characteristic parameters of the remaining signals are extracted and compared with the standard library data to complete the fine screening; the transmission channel is opened for signals that meet the standard, and for interference signals from non-BeiDou frequency bands, the frequency band selection switch is controlled to disconnect their path into the subsequent link, suppressing interference from the source; simultaneously, the phase detection sensor and amplitude acquisition unit in the mixing link acquire signal data every 2ms, recording the phase offset angle and amplitude fluctuation value, and analyzing the change pattern through a trend fitting algorithm to dynamically adjust the impedance matching network parameters and gain adjustment value to compensate for signal distortion.

[0045] In this embodiment, the antenna-side BeiDou signal conversion system based on passive mixing technology can serve as the front-end signal processing unit for BeiDou indoor positioning, seamlessly connecting with the passive DAS system and the indoor distributed communication network. The specific connection logic is as follows: After generating a standardized BeiDou signal, the passive mixing and matching unit of this system adjusts the signal's frequency, amplitude, and transmission rate to ensure that the parameters of the standardized BeiDou signal are consistent with the combiner access standard of the passive DAS / communication indoor distributed transmission network. The frequency parameters match the network's idle frequency band range, and the amplitude parameters are controlled within the network's allowed input power range. A standardized signal interface is set at the system output end to directly connect to the signal input port of the passive DAS / communication indoor distributed transmission network without the need for additional adapter hardware. The system's mixing and solving closed-loop collaborative control unit establishes data interaction with the channel state monitoring module of the passive DAS / communication indoor distributed transmission network, acquiring real-time channel attenuation and interference level data. Based on this data, the mixing and conversion parameters are dynamically adjusted to ensure that the standardized BeiDou signal output by the system always adapts to the network's transmission status, achieving efficient connection with the passive DAS / communication indoor distributed transmission network and providing a standardized BeiDou signal source for subsequent signal combining and transmission.

[0046] In this embodiment, taking an outdoor surveying team conducting BeiDou high-precision positioning surveying in an industrial area on the outskirts of a city as an example, the surrounding environment of the work area is complex, including electromagnetic radiation from factory equipment and obstruction from multiple buildings. The antenna is prone to receiving multi-band BeiDou signals and also faces problems such as interference signal intrusion, weak signal transmission, and equipment overheating. The specific implementation process is as follows: The passive mixing and matching unit of the Beidou frequency band starts signal conversion: After the system antenna receives multi-frequency signals from Beidou satellites, it immediately extracts features from each signal, sorts out core information such as frequency spectrum lines and amplitude fluctuation period, and constructs feature vectors. These feature vectors are then compared with the pre-stored standard feature vectors of each Beidou frequency band using a cosine similarity algorithm. A similarity threshold s1 (s1=0.85) is set to quickly confirm the frequency band to which each signal belongs. To address the differences in signal characteristics across different frequency bands, the system automatically adjusts the bias voltage of the mixer diodes to the m level (m=3), and, in conjunction with the parameter combinations of capacitors and inductors in the impedance matching network, switches the adapter interface for the signal transmission path. Simultaneously, based on a feature-parameter mapping table constructed from historical conversion data, it retrieves the corresponding frequency band mixing parameters, compares the amplitude and phase deviations of the output signal with the standard signal every t1 ms (t1=10), dynamically calibrates the parameters using the gradient descent method, optimizes the matching coefficient of the signal coupler to k1 (k1=0.92), and finally generates a standardized BeiDou signal and transmits it to the processing device. The calculation device works in conjunction with the protection and control unit to carry out protection and safeguards: During the mixing and conversion process, the system collects interference signals in real time through the interference detection module, extracts their frequency, amplitude, phase characteristics and range of influence. When the interference amplitude exceeds the threshold i1 (i1=0.3V), the system adjusts the gain level of the signal amplification module of the calculation device to g1 (g1=2) based on these data to weaken the interference effect. Meanwhile, the data verification rules were optimized, and two verification dimensions, phase consistency and amplitude stability, were added. A phase deviation threshold p1 (p1=5°) and an amplitude fluctuation threshold a1 (a1=0.1dB) were set. The received data was first screened by thresholds to remove obvious outliers, and then key information was verified by feature comparison. Abnormal data with feature distortion was marked and removed. During operation, when the electromagnetic interference intensity of the factory exceeds the safe range i2 (i2=0.5V / m), the system immediately triggers the non-volatile storage unit to completely store the current raw data, intermediate calculation results and operating parameters; activates the electromagnetic shielding switch to cut off the interference conduction path; sets exclusive data access permissions at the software level; and starts the isolation circuit at the hardware level to build dual protection. In addition, the temperature sensor of the mixing link and the solution device collects temperature data every t2 ms (t2=5). When the temperature approaches the upper limit of the preset range tmax (tmax=60℃), the system adjusts the mixing operation parameters, reduces the power consumption of the invalid frequency band conversion to below w1 (w1=15W), and starts the micro cooling fan, adjusting the speed to v1 (v1=3000r / min) to optimize the heat conduction path and ensure that the equipment temperature is maintained within the safe range. The mixed-frequency calculation closed-loop collaborative control unit optimizes weak signal processing: Due to building obstruction in the work area, some BeiDou signals are attenuated during transmission. The calculation link collects signal strength data every t3 ms (t3=5) through the time sequence analysis module. When the detected value is lower than the preset threshold smin (smin=20dBm), key features such as signal attenuation degree and signal-to-noise ratio are immediately extracted. The data format is unified and the feature values ​​are normalized to form standardized feedback data, which is transmitted to the mixed-frequency link through a dedicated high-speed data bus. After the data integrity is confirmed by check code comparison, the mixed-frequency link is divided into three levels according to the attenuation degree: mild (20dBm-15dBm), moderate (15dBm-10dBm), and severe (<10dBm). The amplification factor of the gain adjustment module is adjusted to g2 (g2=3 / 5 / 8) accordingly, and the coupling depth of the signal coupler is optimized to k2 (k2=0.85 / 0.90 / 0.95). The filtering coefficients of the weak signal noise reduction algorithm are adjusted to f1 (f1=0.12) in the synchronous calculation link, the effective signal frequency bandwidth is widened to b1 (b1=2MHz), and the data fusion logic is optimized. The mixing gain is adjusted first and the calculation algorithm is optimized according to the preset rules, with t4 ms (t4=20) as the process connection interval, forming a mixing-calculation collaborative scheme to improve the accuracy of weak signal resolution. The BeiDou signal anti-interference distortion compensation unit enhances signal fidelity: Based on the aforementioned conversion and solution collaborative scheme, the mixing link initiates a frequency spectrum analysis algorithm, with the preset BeiDou frequency band range being fmin-fmax (fmin=1.1GHz, fmax=1.6GHz). All received signals are screened one by one: first, a coarse screening is performed according to this frequency range to remove interference signals that are significantly outside the range; then, the characteristic parameters of the remaining signals are extracted, compared with the standard library data, and a matching threshold s2 (s2=0.9) is set to complete the fine screening. Only signals that meet the standard are allowed to pass through the transmission channel. For interference signals that are not in the BeiDou frequency band, the frequency band selection switch is controlled to disconnect their subsequent transmission path. Meanwhile, the phase detection sensor and amplitude acquisition unit in the mixing link collect signal data every t5 ms (t5=2), recording the phase offset angle and amplitude fluctuation value. When the phase offset exceeds p2 (p2=8°) and the amplitude fluctuation exceeds a2 (a2=0.2dB), the trend fitting algorithm is used to analyze the change pattern and dynamically adjust the impedance matching network parameters and gain adjustment value to compensate for signal distortion. After the solution link receives the mixing output signal, it decomposes the signal according to frequency band and amplitude interval, extracts the feature information of each level and compares it with the standard Beidou signal in multiple dimensions, analyzes the differences and identifies the interference components, determines the interference type and intensity and feeds it back to the mixing link, further optimizing the filtering parameters to f2 (f2=0.15) to ensure the accuracy of the final solution data and provide high-precision positioning support for outdoor surveying.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An antenna-side BeiDou signal conversion system based on passive mixing technology, characterized in that, include: The passive mixing and matching unit of the BeiDou band acquires BeiDou multi-band signals from the antenna side, identifies the signal characteristics of each band, and adjusts the mixing and conversion method; it generates standardized BeiDou signals by adaptively matching and mixing and converting signals of each band through band-adaptive matching. The calculation device, in collaboration with the protection and control unit, acquires the characteristics of interference signals generated by mixing in real time, analyzes the range of interference impact, and dynamically adjusts the signal reception and data verification methods of the calculation device. When interference exceeds the preset safety range, data storage and shielding protection are automatically activated. The calculation operation resumes after the interference is eliminated. The heat generated by mixing and calculation is synchronously conducted, and the temperature rise is controlled by feedback adjustment. The frequency mixing and solving closed-loop collaborative control unit detects the BeiDou signal transmission status and quality in real time, extracts key signal features and feeds them back to the frequency mixing link, and dynamically adjusts the frequency mixing conversion parameters based on the feedback features. When the signal strength is lower than the preset threshold range, the frequency mixing gain adjustment and the solution processing method are optimized simultaneously to form a collaborative scheme for conversion and solution. The BeiDou signal anti-interference distortion compensation unit, based on the aforementioned conversion and decomposition collaborative scheme, uses a mixing link to selectively suppress non-BeiDou frequency band interference signals, synchronously and in real-time detect phase and amplitude changes during signal transmission, and dynamically adjust the mixing matching parameters; the decomposition link analyzes the interference components in the mixing output signal in real-time, extracts interference signal features, and feeds them back to the mixing link.

2. The system according to claim 1, characterized in that, The specific process of identifying the signal characteristics of each frequency band and adjusting the mixing conversion method is as follows: acquire the BeiDou multi-band signals received by the antenna side, and extract features from each signal one by one; construct feature vectors from the extracted features, compare them with the standard vectors of the inherent characteristics of each frequency band of the BeiDou system, and confirm the frequency band to which each signal belongs through vector similarity; and adjust the bias state of the mixer diode, the parameter combination of the impedance matching network, and the matching mode of the signal transmission path in a targeted manner according to the feature differences of signals in different frequency bands.

3. The system according to claim 1, characterized in that, The specific process of frequency band adaptive matching mixing conversion of signals in each frequency band is as follows: based on historical conversion data, a mapping relationship between the signal characteristics of each frequency band and the mixing parameters is constructed, and the mixing parameters of the corresponding frequency band are automatically retrieved through feature matching; the deviation between the output signal and the standard signal is compared in real time, and the mixing parameters are dynamically calibrated by gradient adjustment method to optimize the matching coefficient of the signal coupler.

4. The system according to claim 1, characterized in that, The specific process of dynamically adjusting the signal reception and data verification method of the solution device is as follows: Based on the characteristic information and influence range of the interference signal, the gain level of the calculation device is adjusted. Synchronously optimize data verification rules, increase verification dimensions, and first coarsely screen the received data to remove obvious outliers, and then finely screen and verify key features. Valid data is retained according to preset standards, and abnormal data that are distorted due to interference are marked and removed.

5. The system according to claim 1, characterized in that, The specific process of automatically starting data storage and shielding protection is as follows: continuously monitor the intensity change of interference signals, and when the monitored value exceeds the preset safety range, fully store the raw data, intermediate calculation results and related operating parameters that have not yet been solved; at the same time, activate the electromagnetic shielding switch to cut off the transmission path of interference signals into the core calculation link of the solution device; set data access permissions, activate the isolation circuit at the hardware level, and build a double protection barrier to block the propagation of interference.

6. The system according to claim 1, characterized in that, The specific process of the feedback adjustment and control of the temperature rise is as follows: deploy temperature sensors to acquire temperature data of the mixing link and the solving device in real time during operation; when the temperature data approaches the upper limit of the preset temperature range, adjust the mixing operation parameters to reduce the conversion power consumption of the invalid frequency band; at the same time, optimize the heat dissipation conduction path, widen the heat dissipation channel, and control the temperature rise through multi-stage coordinated operation to maintain the operating environment temperature of the equipment within the preset temperature range.

7. The system according to claim 1, characterized in that, The specific process of real-time detection of BeiDou signal transmission status and quality in the solution link is as follows: The link starts a continuous monitoring mechanism, and uses time series analysis to track the stability of signal transmission, analyze amplitude consistency and verify integrity; Calculate the percentage of valid data in the total data after removing signal interruption periods, and count the frequency and interval of signal interruptions; Establish benchmark ranges for various monitoring indicators based on historical normal operation data, and compare the current monitoring results to determine the signal transmission status and quality.

8. The system according to claim 1, characterized in that, The specific process of extracting key signal features and feeding them back to the mixing link is as follows: from the detected BeiDou signals, relevant key features are selected according to their weight in relation to the conversion effect; The selected feature information is classified and organized, the data format is unified and the feature values ​​are normalized, and the standardized feedback data is integrated according to the preset format. The standardized feedback data is transmitted to the mixing link and the integrity of the data is verified by comparing the check code.

9. The system according to claim 1, characterized in that, The specific process of forming the conversion and solution collaborative scheme is as follows: continuously monitor signal strength changes, and when the detected value is lower than the preset threshold, the mixing link receives the feedback signal characteristics; adjust the gain adjustment parameters according to the degree of signal attenuation to optimize the coupling matching details in the signal conversion process; the solution link synchronously adjusts the filtering coefficient of the weak signal noise reduction algorithm to optimize the data fusion logic; set the linkage trigger threshold between the mixing parameters and the solution algorithm, and confirm the timing sequence of parameter adjustment and the time nodes of process connection.

10. The system according to claim 1, characterized in that, The specific process of the mixing link selectively suppressing non-BeiDou frequency band interference signals in advance is as follows: the frequency range and characteristic parameters of each frequency band of the BeiDou system are pre-set, and a frequency band identification standard library is established; the mixing link starts a frequency band identification mechanism based on frequency spectrum analysis algorithm to screen all received signals one by one; first, a coarse screening is performed according to the frequency range, and then a fine screening is performed by comparing the characteristic parameters to determine whether the signal conforms to or does not conform to the BeiDou frequency band standard; the transmission channel is opened for signals that conform to the standard, and for interference signals of non-BeiDou frequency bands, the frequency band selection switch is controlled to disconnect their path into the subsequent transmission and resolution link.

11. The system according to claim 1, characterized in that, The specific process of detecting phase and amplitude changes during real-time signal transmission is as follows: a detection module is integrated into the mixing link, and the detection module continuously tracks the signal transmission process after it is started; the phase offset and amplitude fluctuation status are acquired, and various change data are recorded in real time in chronological order; the recorded change data are analyzed in real time, compared with the normal fluctuation range standard, and the current change is compared with the preset reasonable range.

12. The system according to claim 1, characterized in that, The specific process of the real-time analysis of interference components in the mixed output signal by the solution link is as follows: After receiving the mixed output signal, the solution link decomposes the signal step by step according to the frequency band and amplitude range; extracts the feature information in each level through the signal feature extraction algorithm; compares the extracted feature information with the standard Beidou signal features in multiple dimensions, analyzes the differences, and identifies the interference components based on the differences; further analyzes the composition characteristics of the interference components to determine the type and intensity of the interference.

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