Measurement and control signal rapid capturing method and device for Doppler frequency hierarchical search

Abstract

The invention provides a measurement and control signal rapid capturing method and device for Doppler frequency hierarchical search, and belongs to the technical field of satellite measurement and control, and the method comprises the steps: determining a plurality of search frequency points of a first level from a Doppler frequency uncertain range based on a Doppler search interval of the first level; searching all the search frequency points of the first level to obtain the detection quantity of the first level; if the detection quantity is not smaller than the reference threshold, taking a Doppler frequency value corresponding to a search frequency point corresponding to the detection quantity as an initial Doppler estimation frequency; determining a local verification frequency range based on the initial Doppler estimation frequency and the Doppler search interval of the first level; searching in the local verification frequency range based on the local fixed search interval to obtain a target Doppler frequency estimated value, judging that the signal is successfully captured and outputting the target Doppler frequency estimated value; the local fixed search interval is determined according to the target search precision. The satellite measurement and control signal capturing efficiency can be improved.

Description

Technical Field

[0001] This application belongs to the field of satellite telemetry, tracking and command technology, and more specifically, it relates to a method and apparatus for rapid acquisition of telemetry and command signals using Doppler frequency hierarchical search. Background Technology

[0002] In satellite telemetry, tracking, and command (TT&C) systems, direct-sequence spread spectrum (DSSS) signals are widely used due to their excellent anti-interference capabilities. However, on the one hand, the complex space environment and variable transmission paths during signal transmission result in a wide range of carrier-to-noise ratios (CNR) for the received signal; on the other hand, the high-speed relative motion between the transmitter and receiver of the DSS signal leads to a large range of Doppler frequency uncertainty. This poses a significant challenge to signal acquisition in onboard TT&C transponders.

[0003] Conventional signal acquisition methods set a fixed Doppler frequency search interval based on the lowest operating carrier-to-noise ratio (CNR). In scenarios with a large range of uncertain Doppler frequencies in the received signal, the fixed Doppler search interval method results in a large number of search units, high computational cost, and long acquisition time. When the received signal CNR is higher than the lowest operating CNR, there is room for further performance improvement. In particular, when the actual received signal CNR is higher than the lowest operating CNR, a larger search interval could have been used to reduce computational cost; however, the fixed Doppler search method still uses a fine interval designed for the worst-case scenario, resulting in a significant waste of computational resources.

[0004] In contrast, fast signal acquisition methods that adjust the Doppler frequency search interval based on real-time carrier-to-noise ratio (CNR) prior information can effectively reduce the computational complexity of signal acquisition methods based on fixed Doppler search intervals. Existing technology includes a frequency search method that adaptively adjusts the search interval based on real-time CNR, avoiding the resource waste of setting the search interval based on the lowest CNR. However, the performance of this method depends on the accuracy of the CNR prior information. In actual signal acquisition processes, accurate CNR prior information is difficult to obtain, which leads to a decrease in the performance of this method.

[0005] In summary, given the need for rapid acquisition in satellite telemetry and control where the Doppler frequency uncertainty of the received signal is large and the prior information on the carrier-to-noise ratio is insufficient, there is an urgent need for a rapid acquisition method that can adapt to changes in the carrier-to-noise ratio of the received signal, and can ensure the acquisition performance of signals with different carrier-to-noise ratios without requiring accurate prior information on the carrier-to-noise ratio, while significantly reducing the acquisition time and computational load. Summary of the Invention

[0006] The purpose of this application is to provide a method and apparatus for rapid acquisition of telemetry and control signals using Doppler frequency hierarchical search, thereby improving the efficiency of satellite telemetry and control signal acquisition. To achieve the above objective, the technical solution provided by this application is as follows: Firstly, a method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search is provided, including: Multiple search frequencies at the first level are determined from the Doppler frequency uncertainty range based on the first-level Doppler search interval; each search frequency corresponds to a Doppler frequency value. Search all search frequency points in the first level to obtain the detection volume of the first level; If the detected quantity is not less than the reference threshold, the Doppler frequency value corresponding to the search frequency point of the detected quantity is used as the initial Doppler estimation frequency; the local verification frequency range is determined based on the initial Doppler estimation frequency and the first-level Doppler search interval; the target Doppler frequency estimate is obtained by searching within the local verification frequency range based on the local fixed search interval, the signal acquisition is determined to be successful, and the target Doppler frequency estimate is output; the local fixed search interval is determined according to the target search accuracy. If the detected quantity is less than the reference threshold, the search continues to the next level until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of layers in the hierarchical search.

[0007] Secondly, a device for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search is provided, comprising: The first-level search range determination module is used to determine multiple search frequency points of the first level from the Doppler frequency uncertainty range based on the first-level Doppler search interval; each search frequency point corresponds to a Doppler frequency value; The first-level search module is used to search all search frequency points in the first level to obtain the detection volume of the first level. The local search verification module is used to determine the local verification frequency range based on the initial Doppler frequency value corresponding to the search frequency point of the detected quantity if the detected quantity is not less than the reference threshold; determine the local verification frequency range based on the initial Doppler estimation frequency and the first-level Doppler search interval; search within the local verification frequency range based on the local fixed search interval to obtain the target Doppler frequency estimate, determine that the signal acquisition is successful, and output the target Doppler frequency estimate; the local fixed search interval is determined according to the target search accuracy. The hierarchical search module is used to perform the next level of search if the detected quantity is less than the reference threshold, until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of hierarchical search levels.

[0008] Thirdly, embodiments of this application also provide an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the Doppler frequency hierarchical search measurement and control signal rapid acquisition method provided by any possible implementation of the first aspect.

[0009] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the Doppler frequency hierarchical search method for rapid acquisition of measurement and control signals provided by any possible implementation of the first aspect.

[0010] The beneficial effects of the technical solution provided in this application are as follows: The Doppler frequency layer search method and apparatus for rapid acquisition of measurement and control signals provided in this application, compared with related technologies, are as follows: The embodiments of this application solve the technical problems of large carrier-to-noise ratio range and large Doppler frequency uncertainty range in direct spread spectrum signal acquisition in satellite telemetry and control systems. At the same time, they overcome the defects of waste of computational resources in traditional fixed interval search methods and reliance on prior information of carrier-to-noise ratio in existing adaptive search methods, thereby improving the signal acquisition performance of onboard telemetry and control transponders.

[0011] To address the issue of redundant computational resources caused by the use of fine intervals throughout the fixed-interval search method, this application's embodiment starts from the uncertainty range of the maximum Doppler frequency determination. It first uses the first-level search interval to coarsely determine the initial Doppler estimation frequency, and then performs fine verification with fixed intervals only in a small area near the signal. This eliminates the need for fine searching across the entire range, significantly reducing the number of search units, lowering the computational load and acquisition time, and avoiding wasted computational resources.

[0012] To address the issue that existing adaptive search methods rely on accurate prior information about the carrier-to-noise ratio (CNR) and suffer from performance degradation in real-world scenarios, this application's embodiments do not require prior CNR information. Through a hierarchical strategy of coarse-search localization and local fine-search, it adapts to changes in the CNR of the received signal, ensuring the effectiveness and accuracy of signal acquisition under varying CNR conditions. Furthermore, the local fixed search interval in this application's embodiments is set according to the target search accuracy. This improves acquisition efficiency while ensuring that the accuracy of the Doppler frequency estimation meets the practical application requirements of satellite telemetry and control, balancing signal acquisition speed and accuracy, and adapting to the computing power and real-time requirements of onboard equipment, thus demonstrating strong engineering practicality. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below.

[0014] Figure 1 A flowchart illustrating the rapid acquisition method for measurement and control signals using Doppler frequency layer search provided in this application embodiment; Figure 2 A flowchart illustrating another method for rapid acquisition of measurement and control signals using Doppler frequency layer search, provided in an embodiment of this application; Figure 3This is a structural block diagram of the Doppler frequency hierarchical search measurement and control signal rapid acquisition device provided in the embodiments of this application; Figure 4 A schematic block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0015] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0016] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the terms “comprising” and “including” as used in embodiments of this application mean that the corresponding feature can be implemented as the presented feature, information, data, step, operation, element, and / or component, but do not exclude implementation as other features, information, data, step, operation, element, component, and / or combinations thereof supported by the art. It should be understood that when we say that an element is “connected” or “coupled” to another element, the one element can be directly connected or coupled to the other element, or it can mean that the one element and the other element establish a connection relationship through an intermediate element. Furthermore, “connected” or “coupled” as used herein can include wireless connection or wireless coupling. The term “and / or” as used herein indicates at least one of the items defined by the term; for example, “A and / or B” can be implemented as “A,” or as “B,” or as “A and B.” When describing multiple (two or more) items, if the relationship between the multiple items is not explicitly defined, the relationship between the multiple items can refer to one, several or all of the multiple items. For example, the description of "parameter A includes A1, A2, A3" can be implemented as parameter A includes A1 or A2 or A3, or it can be implemented as parameter A includes at least two of the three items A1, A2 and A3.

[0017] It is understood that in the embodiments of this application, data such as user information are involved. When the embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with relevant laws, regulations and standards.

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0019] This application aims to address the problems of existing fixed-search-interval acquisition methods, such as numerous search units, long acquisition times, and redundant computational resources, when the received signal carrier-to-noise ratio varies greatly and the Doppler frequency uncertainty range is large. This application proposes a fast direct-sequence spread spectrum (DSSS) signal acquisition method based on Doppler Frequency Hierarchical Search (DFHS). This method rapidly determines the signal's hierarchical level through multi-level variable-interval search and combines this with local fixed-interval verification to achieve fast and high-precision signal acquisition.

[0020] This application provides a method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search. This method can be executed by electronic devices, such as... Figure 1 and Figure 2 As shown, the method may include: S101: Based on the first-level Doppler search interval, determine multiple search frequency points of the first level from the Doppler frequency uncertainty range; each search frequency point corresponds to a Doppler frequency value.

[0021] In this embodiment, before determining the multiple search frequencies of the first level and the frequencies corresponding to each of the multiple search frequencies from the Doppler frequency uncertainty range based on the first level Doppler search interval, the method further includes: determining the Doppler search interval of multiple levels; and determining the Doppler frequency uncertainty range based on the maximum Doppler frequency of the received signal.

[0022] In this embodiment, the Doppler search interval refers to the fixed step size for traversing the Doppler frequency search. The interval varies at different levels, with the first level having the largest interval, for example, 400Hz. The Doppler frequency uncertainty range refers to all possible values ​​of the actual Doppler frequency of the received signal, for example, -6kHz to +6kHz. The search frequency point refers to the frequency search position selected within the uncertainty range according to the search interval, such as discrete positions like -6kHz and -5.6kHz. The Doppler frequency value refers to the actual physical frequency corresponding to each search frequency point, measured in Hertz (Hz). For example, search frequency point 2 corresponds to a frequency value of -5.6kHz. The maximum Doppler frequency refers to the extreme value of the Doppler frequency of the received signal, determined by the satellite-to-ground relative motion parameters, for example, 6kHz.

[0023] For example, this embodiment first initializes the relevant parameters of the hierarchical search method. Specifically, this embodiment can define... and These are the index and total number of the hierarchical search levels, respectively. At the beginning of the search . No. The Doppler search interval at each level is , For The first unit normalized Layer search interval, where, The coherent integration time of the direct-sequence spread spectrum (DSSS) signal is preset by the satellite telemetry and control system's acquisition parameters. Generally, to prevent symbol polarity reversal during the coherent integration time, which would prevent effective signal energy accumulation, the maximum coherent integration time is equal to the duration of a single symbol bit. Since a smaller layer number results in a larger search interval, therefore... .

[0024] To achieve the reuse of Doppler search frequencies between layers, this embodiment can store the Doppler search frequencies during large-interval searches in real time. When there are duplicate elements between the frequency set of small-interval searches and the frequency set of large-interval searches, duplicate calculations in the corresponding search units can be avoided. Since the Doppler frequency uncertainty range is the same across different layer searches, and the search frequencies are uniformly distributed, the first... Layer search interval Search interval with layer 1 The relationship between them is: .

[0025] For example, in the practical application of rapid acquisition of telemetry and control signals by Doppler frequency hierarchical search, this embodiment can determine the Doppler search intervals of multiple levels. Combining the acquisition indicators of the satellite telemetry and control system, the computing power level of the onboard equipment, and the Doppler frequency characteristics of the actual telemetry and control scenario, the total number of hierarchical search levels is preset. Based on the principle that the smaller the number of levels, the larger the interval, the Doppler search interval of each level is determined. The first level adopts the maximum interval adapted to the coarse search requirements, and the intervals of the remaining levels decrease sequentially according to the level. The interval values ​​are determined by the simulation of the telemetry and control scenario and the calibration of measured data to adapt to the acquisition requirements of signals with different carrier-to-noise ratios.

[0026] This embodiment can obtain the maximum Doppler frequency of the received signal by combining satellite orbit prediction data, relative velocity between the satellite and the ground, and carrier frequency of telemetry and control signals with physical calculation methods of Doppler frequency. Then, using this value as the upper and lower boundaries, a continuous interval from the negative maximum Doppler frequency to the positive maximum Doppler frequency is determined, which is the Doppler frequency uncertainty range. This ensures that the range completely covers all possible values ​​of the actual Doppler frequency of the received signal.

[0027] This embodiment can determine multiple search frequency points in the first level from the Doppler frequency uncertainty range based on the first level Doppler search interval. Taking the lower limit of the Doppler frequency uncertainty range as the starting position and the first level Doppler search interval as the fixed step size, discrete frequency positions are selected sequentially in the entire uncertainty range. During the selection process, it is ensured that the entire interval is continuously covered without any position omissions or repetitions. Each selected discrete position is a search frequency point in the first level.

[0028] This embodiment can match the corresponding Doppler frequency value for each search frequency point in the first level. The Doppler frequency value is the actual physical frequency corresponding to each search frequency point on the frequency coordinate axis, forming a one-to-one mapping relationship with the search frequency point. The Doppler frequency values ​​corresponding to the search frequency points selected according to the step size are distributed at equal intervals, and finally a complete set of search frequency points and corresponding Doppler frequency values ​​in the first level is formed, which provides a specific and clear execution basis for subsequent first-level frequency search operations and ensures the engineering implementation of the search operation.

[0029] This embodiment lays the foundation for hierarchical searching by pre-determining multi-level Doppler search intervals. The first level employs a large interval design, which significantly reduces the number of search frequencies, thereby lowering computational load and acquisition time. Based on the uncertainty range determined by the maximum Doppler frequency, it can completely cover the possible values ​​of actual Doppler frequencies, avoiding signal omissions. Simultaneously, the search frequencies determined according to the intervals correspond one-to-one with their corresponding frequency values, providing accurate basis for subsequent searches. This eliminates the need to rely on prior carrier-to-noise ratio information, adapting to the complex real-world scenarios of satellite telemetry and control, and improving the practicality and adaptability of the method.

[0030] S102: Search all search frequency points of the first level to obtain the detection quantity of the first level.

[0031] In this embodiment, a search is performed on all search frequency points of the first level to obtain the detection quantity of the first level, including: For each search frequency point in the first level: The peak-to-average power ratio (PAPR) of the received signal at the search frequency is calculated based on the frequency corresponding to the search frequency. PAPR is the ratio of the peak power to the average power of the signal. The maximum peak-to-average power ratio (PAPR) is determined from the PAPRs of all search frequency points in the first level and used as the detection quantity for the first level.

[0032] In this embodiment, calculating the peak-to-average power ratio (PAPR) of the received signal based on the frequency corresponding to the search frequency point includes: performing frequency compensation and coherent accumulation on the received signal based on the frequency corresponding to the search frequency point to obtain a coherently accumulated signal; and calculating the PAPR of the coherently accumulated signal as the PAPR of the received signal corresponding to the search frequency point.

[0033] In this embodiment, the detection quantity is the core indicator characterizing the matching degree of the hierarchical search signal, with the maximum peak-to-average power ratio (PAPR) as the value, for example, 85. PAPR is the ratio of the peak power to the average power of the received signal, quantifying the signal energy characteristics, for example, 72. Peak power is the maximum power value of the signal during the coherent accumulation period, for example, 1000 milliwatts. Average power is the average power of the signal during the coherent accumulation period. Frequency compensation is the operation of calibrating the Doppler frequency offset of the received signal to achieve alignment with the reference frequency. Coherent accumulation refers to the energy superposition process of the frequency-aligned signal, for example, an accumulation time of 20 milliseconds. The coherently accumulated signal refers to the signal obtained after frequency compensation and coherent accumulation, and is the basis for PAPR calculation.

[0034] For example, the multi-level variable interval search in this embodiment specifically includes: No. Layer search frequency point confirmation. Starting from layer 1, at search intervals... Perform a Doppler frequency search. Let the maximum Doppler frequency of the received signal be denoted as . The Doppler frequency uncertainty range is: The initial search frequency is ,in This indicates rounding up. Therefore, the number of frequency points to be searched in the first layer is... ; The frequency corresponding to the frequency point to be searched in the first layer is: ; In the When performing a layer search, it is necessary to avoid searching for previously searched frequency points. The number of frequency points that need to be searched in the layer is ; No. The frequencies corresponding to the frequency points that the layer needs to search for are:

[0035] Search by frequency point Layer. Starting from the first layer, the search is performed traversally within the Doppler frequency uncertainty range at the set search interval until all Doppler frequency points within the current layer are searched. The peak-to-average power ratio (PAPR) of all search frequency points in the current layer is calculated, and the maximum PAPR is used as the detection metric for detection decision.

[0036] For example, in the practical application of rapid acquisition of measurement and control signals by Doppler frequency hierarchical search, the search and acquisition of detection quantities for all search frequencies in the first level need to be performed according to the logic of processing each frequency point and summarizing the results across all levels. The specific technical implementation steps are as follows: This embodiment can process each search frequency point in the first level independently. First, the Doppler frequency value corresponding to the search frequency point is retrieved. Using this as a reference, frequency compensation is performed on the original telemetry and control signal received by the satellite transponder. Digital signal processing is used to calibrate the Doppler frequency offset of the received signal caused by the relative motion between the satellite and the ground, so that the carrier frequency of the received signal is precisely aligned with the frequency corresponding to the search frequency point, eliminating the signal energy loss caused by frequency deviation. After frequency compensation, this embodiment can perform coherent accumulation processing on the compensated signal. According to the acquisition index of the satellite telemetry and control system, a fixed accumulation time is preset. The signal within this time period is continuously superimposed to highlight the energy characteristics of the effective signal, while suppressing the interference of random noise, to obtain the coherent accumulated signal corresponding to the search frequency point, providing a clean signal object for subsequent peak-to-average power ratio calculation.

[0037] For the obtained coherent accumulated signal, the peak-to-average power ratio (PAPR) is calculated. This embodiment first extracts the peak power of the signal during the accumulation period, i.e., the maximum value during signal power fluctuation. Then, it calculates the average power of the signal during the same period, i.e., the arithmetic mean of all power samples. The ratio of the peak power to the average power is then calculated, and the result is the PAPR of the received signal corresponding to the search frequency point, completing the feature value extraction for a single search frequency point. After the PAPR calculation for all search frequency points in the first level is completed, this embodiment performs a full summary and comparison of the PAPR values ​​for all frequency points. The maximum PAPR is selected through numerical traversal and directly determined as the detection quantity for the first level. This detection quantity directly reflects the degree of matching between the received signal and all search frequency points in the first level, providing a core quantitative basis for subsequent detection success determination.

[0038] This embodiment effectively calibrates the Doppler frequency shift and superimposes signal energy by performing frequency compensation and coherent accumulation at each frequency point, improving the distinction between effective signals and noise and ensuring the accuracy of the signal peak-to-average power ratio (PAPR) calculation. Using the ratio of peak power to average power as the PAPR allows for precise quantification of the signal matching degree at each frequency point. Selecting the maximum PAPR as the detection quantity directly reflects the optimal signal matching result at the first level, providing a reliable quantitative basis for subsequent detection and judgment. Furthermore, this processing method does not rely on prior carrier-to-noise ratio (CNR) information, making it suitable for complex measurement and control scenarios and improving the effectiveness of hierarchical search.

[0039] S103: If the detected quantity is not less than the reference threshold, the Doppler frequency value corresponding to the search frequency point of the detected quantity is used as the initial Doppler estimated frequency; the local verification frequency range is determined based on the initial Doppler estimated frequency and the first-level Doppler search interval; the target Doppler frequency estimate is obtained by searching within the local verification frequency range based on the local fixed search interval, the signal acquisition is determined to be successful, and the target Doppler frequency estimate is output; the local fixed search interval is determined according to the target search accuracy.

[0040] In this embodiment, the local verification frequency range is determined based on the initial Doppler estimation frequency and the first-level Doppler search interval, including: The normalized Doppler frequency difference is determined based on the initial Doppler estimated frequency and the first-level Doppler search interval; The normalized Doppler frequency difference is divided into value intervals and the interval index of each value interval is determined; Determine the normalized frequency difference value corresponding to each interval index, and filter the target interval index of the value interval where the initial Doppler estimated frequency is located based on the normalized frequency difference value corresponding to all interval indices; The local verification frequency range is determined based on the normalized frequency difference value corresponding to the target interval index and the Doppler search interval of the first level.

[0041] In this embodiment, a search is performed within a local verification frequency range based on a local fixed search interval to obtain the target Doppler frequency estimate, including: Based on a local fixed search interval, multiple local search frequency points are determined in the local verification frequency range, and the peak-to-average power ratio of the signal corresponding to each of the multiple local search frequency points is calculated. The local maximum peak-to-average ratio (PAR) is determined from the signal PARs corresponding to multiple local search frequency points, and the search cell corresponding to the local maximum PAR is taken as the target cell; the search cell is a search frequency point. The target Doppler frequency estimate is obtained based on the target cell.

[0042] In this embodiment, the reference threshold refers to the quantization critical value used to determine whether signal detection is successful, determined by the measurement and control system indicators and noise characteristics, for example, 60; the initial Doppler estimation frequency refers to the Doppler frequency value corresponding to the first-level detection quantity, which is the result of coarse signal search and localization, for example, -4000Hz; the local verification frequency range refers to the fine search interval defined around the initial estimation frequency, for example, -4200Hz to -3800Hz; the local fixed search interval refers to the fine search step size set to ensure acquisition accuracy, determined by the target search accuracy, for example, 50Hz; the target Doppler frequency estimate refers to the precise Doppler frequency obtained from the local fine search, which is the final... The capture result is, for example, -4050Hz; the normalized Doppler frequency difference refers to the value of the actual frequency difference after dimensionless processing according to the search interval, for example, 0.8; the interval index refers to the digital identifier of the normalized frequency difference value interval, for example, 1, 2; the target interval index refers to the value interval index to which the initial estimated frequency belongs, for example, 1; the local search frequency point refers to the fine search position selected at fixed intervals within the local verification range, for example, -4200Hz, -4150Hz; the local maximum peak-to-average ratio refers to the maximum signal peak-to-average ratio among the local search frequency points, for example, 92; the target cell refers to the local search frequency point corresponding to the local maximum peak-to-average ratio, which is the optimal position for fine search.

[0043] For example, this embodiment can determine whether the detection was successful. The obtained detection quantity is compared with a reference threshold. If it is not less than the reference threshold, local fixed-interval verification is performed. Specifically, at the hierarchical level... If a frequency point is found to be successfully detected, its corresponding frequency is denoted as . Normalized Doppler frequency difference is ,Right now .

[0044] Based on the set search interval Divide the possible normalized Doppler frequency difference values ​​into intervals, and denote the index of each interval as . , ; in, This indicates rounding down to the nearest integer. (Note: The original text contains some formatting errors and inconsistencies. A more accurate translation would require the full text.) , .

[0045] The index of the value range is hour, The value of for ; Doppler frequency estimation The search frequency point corresponding to the maximum peak-to-average ratio at the current level, therefore The corresponding cumulative loss should be minimized.

[0046] make , The corresponding value range index is ; remember for hour The set of possible values ​​for is expressed as: ; The index of the value range is hour, The value of for ; No. The local verification scope of the layer is ; Set the Doppler frequency search range during local verification to... The Doppler frequency search interval during local verification is set to a fixed value. Calculate the peak-to-average power ratio (PAPR) of each frequency point within the local validation range, and use the search cell corresponding to the maximum PAPR as the target cell. Declare successful capture, output the estimation result, and end the search.

[0047] For example, in the practical application of rapid acquisition of measurement and control signals by Doppler frequency layer search, after completing the calculation of the first level of detection quantity, this embodiment can first compare the detection quantity with a preset reference threshold. If the detection quantity is not less than the reference threshold, the subsequent local fine verification operation is immediately carried out. The specific technical implementation steps are as follows: This embodiment can extract the search frequency point corresponding to the detected quantity and determine its corresponding Doppler frequency value as the initial Doppler estimation frequency. This frequency is the coarse search and localization result of the signal, serving as the core benchmark for local fine verification. This embodiment can determine the local verification frequency range based on the initial Doppler estimation frequency and the first-level Doppler search interval. First, the normalized Doppler frequency difference is calculated by combining the two, and the computational complexity of subsequent interval division is simplified through dimensionless processing. This embodiment can divide all possible values ​​of the normalized Doppler frequency difference into continuous intervals, assigning a unique interval index to each interval, forming a correspondence between the index and the interval. This embodiment can clarify the specific value range of the normalized frequency difference corresponding to each interval index, and filter out the value interval to which the initial Doppler estimation frequency belongs through numerical matching, determining the index of this interval as the target interval index. This embodiment can combine the normalized frequency difference value corresponding to the target interval index and the first-level Doppler search interval to restore the normalized interval to a frequency interval with physical units. This interval is the local verification frequency range, ensuring that the range accurately covers the actual frequency of the signal.

[0048] This embodiment determines a local fixed search interval, which is set entirely based on the target search accuracy of the satellite telemetry and control system. Higher accuracy requirements result in a smaller interval, providing a fixed step size for subsequent fine-grained searches. Based on this local fixed search interval, starting from the lower limit of the local verification frequency range, discrete frequency positions are sequentially selected within the range at a fixed step size. Each position is a local search frequency point. The selection process ensures continuous coverage of the entire local verification frequency range without any omissions or repetitions. After determining the local search frequency points, the peak-to-average power ratio (PAPR) is calculated sequentially for each local search frequency point. The calculation process uses frequency compensation, coherent accumulation, and then calculating the peak power to average power ratio to obtain the PAPR corresponding to each local search frequency point.

[0049] After the peak-to-average power ratio (PAPR) of all local search frequency points is calculated, this embodiment can perform a full summary and comparison of all values, filter out the local PAPR with the largest PAPR, and determine the local search frequency point corresponding to the local PAPR as the target cell. This embodiment can extract the Doppler frequency value corresponding to the target cell and determine it as the target Doppler frequency estimate. At this point, the signal acquisition is directly determined to be successful, and the target Doppler frequency estimate is output as the final result, completing the entire acquisition process of the measurement and control signal.

[0050] This embodiment uses the comparison between the detected value and the reference threshold as the judgment criterion, which can accurately identify whether the coarse search for signal localization is effective. This embodiment defines a local verification range around the initial Doppler estimation frequency, avoiding a full-range fine search and reducing computational load and acquisition time. This embodiment determines the verification range by normalizing the frequency difference and dividing the interval, ensuring the scientific and accurate nature of the range definition. This embodiment sets a fixed local search interval according to the target accuracy and combines the peak-to-average power ratio to filter target cells, achieving high-precision signal acquisition. The final output target Doppler frequency estimate meets the accuracy requirements of the measurement and control system, balancing acquisition efficiency and accuracy.

[0051] S104: If the detected quantity is less than the reference threshold, proceed to the next level of search until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of layers for hierarchical search.

[0052] In this embodiment, the next level of search refers to a finer Doppler frequency search with smaller intervals, such as a second-level search, a third-level search, etc. The total number of hierarchical search levels is a preset maximum number of search levels, determined by the capture requirements, for example, 4 levels.

[0053] For example, when comparing the obtained detection count with a reference threshold, if it is less than the reference threshold, it is determined whether all levels of search have been completed. Search layer index. ,like If the multi-level variable interval search of this embodiment is executed repeatedly, then the capture failure is declared and the search ends.

[0054] For example, in the practical application of rapid acquisition of measurement and control signals using Doppler frequency layer search, after calculating the detection quantity of the first level, this embodiment can compare the detection quantity with a preset reference threshold of the system to determine whether a valid signal has been detected in the first level. If the detection quantity is less than the reference threshold, it is determined that no valid signal has been detected in the first level, and the search operation of the next level is immediately started. In this embodiment, the preset Doppler search interval of the level can be retrieved first, which is smaller than that of the previous level. Then, based on the determined Doppler frequency uncertainty range, deduplication is performed in combination with the set of searched frequency points reused between levels to determine the unique search frequency point and corresponding frequency value of this level.

[0055] This embodiment performs frequency compensation, coherent accumulation, and peak-to-average power ratio (PAPR) calculation on each search frequency point at this level, extracts the maximum PAPR at this level as the detection quantity, and compares the detection quantity with the reference threshold again. If the detection quantity is still less than the reference threshold, the search continues at the next level, repeating the level search, detection quantity calculation, and threshold comparison operations.

[0056] After each level of search is completed, a threshold determination is performed until the detection quantity at a certain level is not less than the reference threshold. Local fixed-interval verification is then carried out to obtain the target Doppler frequency estimate. If the search continues until the preset total number of levels is reached and the detection quantity at all levels is less than the reference threshold, the search is terminated and the signal acquisition is determined to have failed.

[0057] This embodiment achieves a progressive search from coarse to fine by successively comparing the level detection quantity with the reference threshold. When no signal is detected, it automatically moves to the next level, ensuring progressively accurate signal localization. By limiting the search boundary through a preset total number of layers, it avoids wasting computing power due to unlimited searching, balancing the comprehensiveness and efficiency of the acquisition, and adapting to the acquisition needs of measurement and control signals with different carrier-to-noise ratios.

[0058] Based on the same principle as the Doppler frequency hierarchical search method for rapid acquisition of measurement and control signals provided in the embodiments of this application, the embodiments of this application also provide a Doppler frequency hierarchical search device for rapid acquisition of measurement and control signals, such as... Figure 3 As shown, the Doppler frequency hierarchical search measurement and control signal rapid acquisition device 20 may specifically include: a first-level search range determination module 21, a first-level search module 22, a local search verification module 23, and a hierarchical search module 24. The first-level search range determination module 21 is used to determine multiple search frequency points of the first level from the Doppler frequency uncertainty range based on the first-level Doppler search interval; each search frequency point corresponds to a Doppler frequency value. The first-level search module 22 is used to search all search frequency points in the first level to obtain the detection quantity of the first level; The local search verification module 23 is used to: if the detected quantity is not less than the reference threshold, use the Doppler frequency value corresponding to the search frequency point of the detected quantity as the initial Doppler estimated frequency; determine the local verification frequency range based on the initial Doppler estimated frequency and the first-level Doppler search interval; search within the local verification frequency range based on the local fixed search interval to obtain the target Doppler frequency estimate, determine that the signal acquisition is successful, and output the target Doppler frequency estimate; the local fixed search interval is determined according to the target search accuracy. The hierarchical search module 24 is used to perform the next level of search if the detected quantity is less than the reference threshold, until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of hierarchical search levels.

[0059] In one embodiment of this application, the Doppler frequency hierarchical search measurement and control signal rapid acquisition device 20 further includes a hierarchical search parameter acquisition module, used to: determine the Doppler search interval of multiple levels; and determine the Doppler frequency uncertainty range based on the maximum Doppler frequency of the received signal.

[0060] In one embodiment of this application, the first-level search module 22 is specifically used for: searching each search frequency point in the first level: The peak-to-average power ratio (PAPR) of the received signal at the search frequency is calculated based on the frequency corresponding to the search frequency. PAPR is the ratio of the peak power to the average power of the signal. The maximum peak-to-average power ratio (PAPR) is determined from the PAPRs of all search frequency points in the first level and used as the detection quantity for the first level.

[0061] In one embodiment of this application, the first-level search module 22 is further configured to: perform frequency compensation and coherent accumulation on the received signal based on the frequency corresponding to the search frequency point to obtain a coherently accumulated signal; and calculate the peak-to-average power ratio (PAPR) of the coherently accumulated signal as the PAPR of the received signal corresponding to the search frequency point.

[0062] In one embodiment of this application, the local search verification module 23 is specifically used to: determine the normalized Doppler frequency difference based on the initial Doppler estimated frequency and the first-level Doppler search interval; The normalized Doppler frequency difference is divided into value intervals and the interval index of each value interval is determined; Determine the normalized frequency difference value corresponding to each interval index, and filter the target interval index of the value interval where the initial Doppler estimated frequency is located based on the normalized frequency difference value corresponding to all interval indices; The local verification frequency range is determined based on the normalized frequency difference value corresponding to the target interval index and the Doppler search interval of the first level.

[0063] In one embodiment of this application, the local search verification module 23 is further configured to: determine multiple local search frequency points in the local verification frequency range based on a local fixed search interval, and calculate the signal peak-to-average power ratio corresponding to each of the multiple local search frequency points; The local maximum peak-to-average ratio (PAR) is determined from the signal PARs corresponding to multiple local search frequency points, and the search cell corresponding to the local maximum PAR is taken as the target cell; the search cell is a search frequency point. The target Doppler frequency estimate is obtained based on the target cell.

[0064] In one embodiment of this application, the first Hierarchical Doppler search interval Doppler search interval of the first level The relationship between them is: .

[0065] The apparatus of this application embodiment can execute the method provided in this application embodiment. The implementation principle is similar. The actions performed by each module in the apparatus of each embodiment of this application correspond to the steps in the method of each embodiment of this application. For detailed functional descriptions of each module of the apparatus, please refer to the descriptions in the corresponding methods shown above, which will not be repeated here.

[0066] Figure 4 A schematic diagram of the structure of an electronic device to which this application embodiment applies is shown, such as... Figure 4 As shown, the electronic device can be used to implement the methods provided in any embodiment of this application.

[0067] like Figure 4 As shown, the electronic device 300 may primarily include at least one processor 301. Figure 4 The diagram shows components such as a memory 302, a communication module 303, and an input / output interface 304. Optionally, these components can be connected and communicate with each other via a bus 305. It should be noted that... Figure 4 The structure of the electronic device 300 shown is merely illustrative and does not constitute a limitation on the electronic devices to which the methods provided in the embodiments of this application are applicable.

[0068] The memory 302 can be used to store operating systems and applications, etc. The applications can include computer programs that implement the methods shown in the embodiments of this application when invoked by the processor 301, and can also include programs for implementing other functions or services. The memory 302 can be ROM (Read Only Memory) or other types of static storage devices that can store static information and instructions, RAM (Random Access Memory) or other types of dynamic storage devices that can store information and computer programs, or it can be EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.

[0069] Processor 301 is connected to memory 302 via bus 305 and implements corresponding functions by calling the application programs stored in memory 302. Processor 301 can be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 301 can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0070] Electronic device 300 can connect to a network via communication module 303 (which may include, but is not limited to, components such as a network interface) to communicate with other devices (such as user terminals or servers) through the network and achieve data interaction, such as sending data to or receiving data from other devices. Communication module 303 may include wired network interfaces and / or wireless network interfaces, meaning the communication module may include at least one of wired or wireless communication modules.

[0071] The electronic device 300 can connect to necessary input / output devices, such as a keyboard and display device, via the input / output interface 304. The electronic device 300 itself may have a display device, and other display devices can also be connected externally via the interface 304. Optionally, a storage device, such as a hard drive, can also be connected via the interface 304 to store data from the electronic device 300, retrieve data from the storage device, or store data from the storage device in the memory 302. It is understood that the input / output interface 304 can be a wired interface or a wireless interface. Depending on the actual application scenario, the device connected to the input / output interface 304 can be a component of the electronic device 300 or an external device connected to the electronic device 300 when needed.

[0072] The bus 305 used to connect the components may include a path for transmitting information between the components. The bus 305 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Depending on its function, the bus 305 may be divided into an address bus, a data bus, a control bus, etc.

[0073] Optionally, for the solution provided in the embodiments of this application, the memory 302 can be used to store a computer program that executes the solution of this application, and the processor 301 runs the computer program. When the processor 301 runs the computer program, it implements the operation of the method or apparatus provided in the embodiments of this application.

[0074] Based on the same principle as the method provided in the embodiments of this application, the embodiments of this application provide a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it can implement the corresponding content of the aforementioned method embodiments.

[0075] It should be noted that the terms "first," "second," "third," "fourth," "1," "2," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in a sequence other than that shown in the figures or text.

[0076] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0077] It should be understood that although arrows indicate various operation steps in the flowcharts of this application's embodiments, the order in which these steps are implemented is not limited to the order indicated by the arrows. Unless explicitly stated herein, in some implementation scenarios of this application's embodiments, the implementation steps in each flowchart can be executed in other orders as required. Furthermore, some or all steps in each flowchart, based on the actual implementation scenario, may include multiple sub-steps or multiple stages. Some or all of these sub-steps or stages can be executed at the same time, and each sub-step or stage can also be executed at different times. In scenarios where execution times differ, the execution order of these sub-steps or stages can be flexibly configured according to requirements, and this application's embodiments do not limit this.

[0078] The above description is only an optional implementation method for some implementation scenarios of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application without departing from the technical concept of this application also fall within the protection scope of the embodiments of this application.

Claims

1. A method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search, characterized in that, include: Multiple search frequencies at the first level are determined from the Doppler frequency uncertainty range based on the first-level Doppler search interval; each search frequency corresponds to a Doppler frequency value. Search all search frequency points in the first level to obtain the detection volume of the first level; If the detected quantity is not less than the reference threshold, the Doppler frequency value corresponding to the search frequency point of the detected quantity is used as the initial Doppler estimation frequency; a local verification frequency range is determined based on the initial Doppler estimation frequency and the first-level Doppler search interval; a search is performed in the local verification frequency range based on the local fixed search interval to obtain the target Doppler frequency estimate, the signal acquisition is determined to be successful, and the target Doppler frequency estimate is output; the local fixed search interval is determined according to the target search accuracy; If the detected quantity is less than the reference threshold, the next level of search is performed until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of the hierarchical search.

2. The method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search as described in claim 1, characterized in that, Before determining the multiple search frequencies of the first level and the frequencies corresponding to each of the multiple search frequencies from the Doppler frequency uncertainty range based on the first-level Doppler search interval, the method further includes: Determine the Doppler search intervals at multiple levels; The Doppler frequency uncertainty range is determined based on the maximum Doppler frequency of the received signal.

3. The method for rapid acquisition of measurement and control signals using Doppler frequency layer search as described in claim 1, characterized in that, The step of searching all search frequency points of the first level to obtain the detection quantity of the first level includes: For each search frequency point in the first level: The peak-to-average power ratio (PAPR) of the received signal corresponding to the search frequency point is calculated based on the frequency corresponding to the search frequency point; the PAPR is the ratio of the peak power to the average power of the signal. The maximum peak-to-average power ratio (PAPR) is determined from the PAPRs of all search frequency points in the first level and used as the detection quantity for the first level.

4. The method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search as described in claim 3, characterized in that, The calculation of the peak-to-average power ratio (PAPR) of the received signal corresponding to the search frequency point based on the frequency corresponding to the search frequency point includes: Based on the frequency corresponding to the search frequency point, the received signal is frequency compensated and coherently accumulated to obtain a coherently accumulated signal; The peak-to-average power ratio (PAPR) of the coherent accumulated signal is calculated as the PAPR of the received signal corresponding to the search frequency point.

5. The method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search as described in claim 1, characterized in that, The step of determining the local verification frequency range based on the initial Doppler estimation frequency and the Doppler search interval of the first level includes: The normalized Doppler frequency difference is determined based on the initial Doppler estimated frequency and the Doppler search interval of the first level; The normalized Doppler frequency difference is divided into value intervals, and the interval index of each value interval is determined; Determine the normalized frequency difference value corresponding to each interval index, and filter the target interval index of the value interval where the initial Doppler estimated frequency is located based on the normalized frequency difference values ​​corresponding to all interval indices; The local verification frequency range is determined based on the normalized frequency difference value corresponding to the target interval index and the Doppler search interval of the first level.

6. The method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search as described in claim 5, characterized in that, The step of searching within the local verification frequency range based on a local fixed search interval to obtain the target Doppler frequency estimate includes: Based on a local fixed search interval, multiple local search frequency points are determined in the local verification frequency range, and the peak-to-average power ratio of the signal corresponding to each of the multiple local search frequency points is calculated. The local maximum peak-to-average ratio is determined from the signal peak-to-average ratios corresponding to the plurality of local search frequency points, and the search unit corresponding to the local maximum peak-to-average ratio is taken as the target cell; the search unit is a search frequency point. The target Doppler frequency estimate is obtained based on the target cell.

7. The method for rapid acquisition of measurement and control signals using Doppler frequency hierarchical search as described in claim 1, characterized in that, No. Hierarchical Doppler search interval Doppler search interval of the first level The relationship between them is: .

8. A rapid acquisition device for measurement and control signals using Doppler frequency hierarchical search, characterized in that, include: The first-level search range determination module is used to determine multiple search frequency points of the first level from the Doppler frequency uncertainty range based on the first-level Doppler search interval; each search frequency point corresponds to a Doppler frequency value; The first-level search module is used to search all search frequency points in the first level to obtain the detection quantity of the first level. A local search verification module is used to: if the detected quantity is not less than a reference threshold, use the Doppler frequency value corresponding to the search frequency point of the detected quantity as the initial Doppler estimation frequency; determine a local verification frequency range based on the initial Doppler estimation frequency and the first-level Doppler search interval; search within the local verification frequency range based on a local fixed search interval to obtain the target Doppler frequency estimate, determine that the signal acquisition is successful, and output the target Doppler frequency estimate; the local fixed search interval is determined according to the target search accuracy. The hierarchical search module is used to perform the next level of search if the detected quantity is less than the reference threshold, until the target Doppler frequency estimate is obtained or the number of search levels reaches the total number of hierarchical search levels.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and the processor executes the Doppler frequency hierarchical search method for rapid acquisition of measurement and control signals as described in any one of claims 1 to 7 when running the computer program.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the rapid acquisition method for measurement and control signals using Doppler frequency hierarchical search as described in any one of claims 1 to 7.

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