A system for doppler profile presetting of baseband uplink signals

Abstract

The application provides a system for Doppler file presetting of a baseband uplink signal, comprising: a frequency scanning module, which performs Doppler file presetting by using a frequency scanning mode; a parameter pre-reading module, which performs timing pre-reading on parameters in the Doppler file; a parameter distribution module, which distributes time of a frequency point at a preset time to a time coincidence judgment module, and simultaneously distributes a frequency value to the frequency scanning module as a scanning start frequency of the frequency scanning module when presetting a first point; a parameter conversion module, which converts preset frequency and time parameters by using frequency relationship and time relationship of previous and subsequent preset frequency points in the Doppler file to obtain a frequency change rate and a time interval of frequency change; a time coincidence judgment module, which performs synchronous reading and configuration on each frequency scanning parameter by using a time coincidence judgment mode; and a ping-pong switching timing module, which performs timeout protection on work of the frequency scanning module based on a time interval between previous and subsequent preset points.

Description

Technical Field

[0001] This invention relates to the field of deep space telemetry and control technology for aircraft, and more specifically, to a system for presetting Doppler files using baseband uplink signals. Background Technology

[0002] Uplink Doppler presets are widely used in deep space telemetry and communication applications. Conventional uplink Doppler presets are typically implemented using direct presets or multi-point interpolation. The direct preset method involves calculating the required frequency control word based on the desired preset frequency, and then directly configuring the calculated frequency control word to the DDS module to output the specified frequency. The multi-point interpolation method involves calculating two frequency interpolations based on the frequencies of the current preset point and the next preset point, then calculating the frequency of each interpolation point based on the required number of interpolation points, and calculating the corresponding frequency control word based on the obtained interpolation point frequencies. Finally, the frequency control word for each interpolation point is sequentially output to the DDS module to output the frequencies of the preset points and the interpolation points. For general applications, the above implementation methods are sufficient. However, for deep space tracking and control applications with high precision requirements, the small intervals between preset frequency changes necessitate high preset accuracy. Multi-point interpolation can only address frequency abrupt changes caused by direct presets, but it still suffers from frequency steps. Furthermore, the precision is limited by the platform's hardware performance, and performing a large number of interpolation points to meet accuracy requirements results in a large computational load, consuming significant CPU resources and computation time. This poses a significant challenge to deep space tracking and control scenarios that demand high preset accuracy and stability. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the prior art, namely, low preset accuracy, insufficient smoothness of frequency changes, and large resource consumption.

[0004] Therefore, the present invention provides a system for presetting Doppler files using baseband uplink signals.

[0005] This invention provides a system for presetting Doppler files using baseband uplink signals, comprising:

[0006] The frequency scanning module uses frequency scanning to preset the Doppler file.

[0007] The parameter pre-reading module performs timed pre-reading of parameters in the Doppler file;

[0008] The parameter distribution module distributes the time of the preset frequency point to the time conformity decision module. When the first point is preset, the frequency value is also distributed to the frequency scanning module as the starting frequency for scanning.

[0009] The parameter conversion module uses the frequency and time relationships between preset frequency points in the Doppler file to convert the preset frequency and time parameters to obtain the rate of change of frequency and the time interval of frequency change.

[0010] The parameter cache RAM caches the frequency scan parameters and time parameters after the parameter conversion is completed.

[0011] The time conformity decision module uses the time conformity decision method to synchronously read and configure the parameters for each frequency scan, so that the time conformity decisions of two adjacent preset times do not affect each other.

[0012] The ping-pong switching timing module provides timeout protection for the operation of the frequency scanning module based on the time interval between two preset points, ensuring that the timeout protections of two adjacent points are independent of each other.

[0013] The frequency scanning module is equipped with a timed reset logic to clear the residual accumulated phase after each scan segment ends, thereby eliminating the cumulative error caused by phase accumulation.

[0014] A system for presetting Doppler files using baseband uplink signals according to the above-described technical solution of the present invention may further have the following additional technical features:

[0015] In the above technical solution, the frequency scanning module is used to preset the Doppler file by scanning from one frequency point to the next.

[0016] In the above technical solution, the parameter pre-reading module pre-reads the preset parameters in the Doppler file before each preset, based on the Doppler file and preset time. The preset is started from the parameter in the file that is closest to the current time. The frequency points of the two preset times in the file that are closest to the current time are read and sent to the parameter conversion module. The parameters of two points are pre-read each time, namely the frequency and time of the current preset point and the frequency and time of the next preset point.

[0017] In the above technical solution, after receiving the preset point information transmitted by the parameter pre-reading module, the parameter conversion module calculates the frequency change rate and the time interval of the frequency change segment from preset point 1 to preset point 2 based on the frequency and preset time of the input preset point 1 and preset point 2.

[0018] In the above technical solution, the frequency scan parameters and time parameters after parameter conversion cached in the parameter cache RAM are used for subsequent frequency scans.

[0019] In the above technical solution, when each preset moment arrives, the time-to-be-released pulse of the time-matching judgment module goes high. The frequency change rate and time interval of the preset point 1 to preset point 2 are read out synchronously from the parameter cache RAM using the time-to-be-released pulse. The frequency change rate parameter and the direction of change are latched and set to the frequency scanning module using the time-to-be-released pulse. The time interval parameter is latched and set to the ping-pong switching timing module.

[0020] In the above technical solution, the time conformity decision module includes three independent time conformity decision units.

[0021] In the above technical solution, after the ping-pong switching timing module receives the new time interval parameter, it pulls up the working pulse of the timer to enable the operation of the frequency scanning module, drives the frequency scanning module to start working, and starts timing at the same time. When the time interval expires, it pulls down the working pulse of the timer to stop the operation of the frequency scanning module synchronously, so that the frequency scanning module stops at the preset point 2.

[0022] In the above technical solution, the ping-pong switching timing module includes two timers capable of switching between ping-pong games.

[0023] In the above technical solution, a timed reset logic is designed in the frequency scanning module to detect whether it is a new frequency change rate parameter. If it is a new frequency change rate parameter, the residual phase of the phase accumulator of the frequency change rate is cleared to ensure that the change rate of the next frequency change rate is uniform.

[0024] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0025] Resource-saving, this invention only occupies a small amount of logic and storage resources of the chip.

[0026] The frequency change is smooth. Since the frequency scanning method is used to realize the change from the current preset point to the next preset point, the frequency change is at the system clock level. For example, if the system clock is 60MHz, whenever the preset frequency changes by 1Hz, the actual output frequency change using the method of this invention is 1 / 60e6, and the change interval is very small. Since the frequency is quantized by the system clock, the smoothness of the frequency change is much higher than that of the multi-point interpolation method.

[0027] The preset accuracy is high. For the preset time, a time-matching design is adopted, that is, the preset time is set as a time-matching time, and the preset time is compared with the B-code time. When the time arrives, the preset is performed immediately. Since the time comparison algorithm of this invention is applied at the chip level, the chip's operating clock frequency is high, making the determination of the preset time more accurate. Therefore, compared with the timing preset of the multi-point interpolation method, the preset time accuracy of this invention is higher. For the preset frequency, since the system clock is used to quantize the preset frequency, every 1Hz change can be quantized by the system clock. Compared with the multi-point interpolation method, the preset frequency accuracy is higher, the computational load is smaller, and the implementation method is simpler.

[0028] It has strong scalability and is simple to implement. It can be applied to the file preset design for independent uplink Doppler compensation for two or more targets. It can be used for uplink Doppler preset and downlink Doppler compensation. It has wide applicability and strong scalability.

[0029] Highly efficient and stable, this invention employs a timer-based approach, using a timer to enable frequency variation segments and enter a timeout protection state after compensation is completed. This ensures that the frequency compensation module stops at the corresponding frequency point after a preset time, without any scanning out-of-bounds issues, effectively guaranteeing the stability of the preset uplink Doppler compensation file.

[0030] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0031] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0032] Figure 1 This is a circuit block diagram of a system for presetting Doppler files using baseband uplink signals according to an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the principle and input / output interface of the parameter conversion module in a system for presetting Doppler files using baseband uplink signals, according to an embodiment of the present invention.

[0034] Figure 3 This is a timing diagram of a system parameter caching design for Doppler file preset of baseband uplink signal according to an embodiment of the present invention;

[0035] Figure 4 This is an example diagram of a system parameter cache RAM for Doppler file preset of baseband uplink signal according to an embodiment of the present invention;

[0036] Figure 5 This is a design diagram of a time conformity decision device in a system for presetting Doppler files using baseband uplink signals, according to an embodiment of the present invention.

[0037] Figure 6 This is a design diagram of a ping-pong switching timing module in a system for presetting Doppler files of baseband uplink signals according to an embodiment of the present invention;

[0038] Figure 7 This is a design diagram of a frequency scanning module in a system for presetting Doppler files of baseband uplink signals according to an embodiment of the present invention. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] The following reference Figures 1 to 7 This describes a system for presetting Doppler files using baseband uplink signals, provided by some embodiments of the present invention.

[0042] Some embodiments of this application provide a system for presetting Doppler files using baseband uplink signals.

[0043] like Figures 1 to 7 As shown, the first embodiment of the present invention proposes a system for presetting Doppler files for baseband uplink signals, comprising:

[0044] The frequency scanning module uses a frequency scanning method to preset Doppler files; it uses a high-precision and smooth frequency scanning method to replace the traditional direct preset method or multi-point interpolation method for Doppler file preset.

[0045] The frequency scanning module is used to preset the Doppler file by scanning from one frequency point to the next.

[0046] The parameter pre-reading module performs timed pre-reading of parameters in the Doppler file;

[0047] The parameter pre-reading module pre-reads the preset parameters in the Doppler file before each preset, based on the Doppler file and preset time. It starts the preset from the parameter in the file that is closest to the current time. It reads the frequency points of the two preset times in the file that are closest to the current time and sends them to the parameter conversion module. Each time, it pre-reads the parameters of two points, namely the frequency and time of the current preset point and the frequency and time of the next preset point.

[0048] The parameter distribution module distributes the time of the preset frequency point to the time conformity decision module. When the first point is preset, the frequency value is also distributed to the frequency scanning module as the starting frequency for scanning.

[0049] The parameter conversion module uses the frequency and time relationships between preset frequency points in the Doppler file to convert the preset frequency and time parameters to obtain the rate of change of frequency and the time interval of frequency change.

[0050] After receiving the preset point information from the parameter pre-reading module, the parameter conversion module calculates the frequency change rate and the time interval of the frequency change segment from preset point 1 to preset point 2 based on the frequency and preset time of preset point 1 and preset point 2.

[0051] The parameter cache RAM caches the frequency scan parameters and time parameters after the parameter conversion is completed.

[0052] The frequency scan parameters and time parameters after parameter conversion, which are cached in the parameter cache RAM, are used for subsequent frequency scans.

[0053] The time conformity decision module uses the time conformity decision method to synchronously read and configure the parameters for each frequency scan, so that the time conformity decisions of two adjacent preset times do not affect each other.

[0054] When each preset moment arrives, the time-to-be-defined pulse of the time-matching judgment module goes high. The time-to-be-defined pulse is used to synchronously read out the frequency change rate and the time interval between preset point 1 and preset point 2 cached in the parameter cache RAM. The time-to-be-defined pulse is used to latch and set the frequency change rate parameter and the direction of change to the frequency scanning module, and the time interval parameter is latched and set to the ping-pong switching timing module.

[0055] The time compliance decision module includes three independent time compliance decision units.

[0056] The ping-pong switching timing module provides timeout protection for the operation of the frequency scanning module based on the time interval between two preset points, ensuring that the timeout protections of two adjacent points are independent of each other.

[0057] After receiving the new time interval parameter, the ping-pong switching timing module pulls the timer's working pulse high, uses the working pulse to enable the frequency scanning module to work, drives the frequency scanning module to start working, and starts timing at the same time. When the time interval expires, it pulls the timer's working pulse low, synchronously stops the frequency scanning module, and makes the frequency scanning module stop at the preset point 2.

[0058] The ping-pong switching timing module includes two timers capable of switching between ping-pong games.

[0059] The frequency scanning module is equipped with a timed reset logic to clear the residual accumulated phase after each scan segment, eliminating the cumulative error caused by phase accumulation. The timed reset logic in the frequency scanning module detects whether there is a new frequency change rate parameter. If it is, the residual phase of the frequency change rate phase accumulator is cleared to ensure that the rate of change of the next frequency change is uniform.

[0060] The second embodiment of this invention proposes a system for presetting Doppler files from baseband uplink signals. Based on the first embodiment, it includes a parameter pre-reading module, a parameter distribution module, a parameter conversion module, a write control logic module, a parameter cache RAM, time conformity decision units 1-3, a read control logic module, a ping-pong switching circuit, two timers, an enable output circuit, and a frequency scanning module. An externally input Doppler file contains preset frequency points and times.

[0061] See Figure 1 Once the preset process begins, the parameter pre-reading module periodically reads the time parameters from the Doppler file. The preset parameters stored in the Doppler file are in the format of [preset time, preset frequency point], for example, 2020-02-01 14:00:00, 16000.01Hz. It checks the current system time against the time of each set of parameters in the Doppler file, and starts the preset process from the nearest upcoming preset time, pre-reading two sets of preset parameters each time.

[0062] See Figure 2 The parameter conversion module calculates the frequency change rate and time interval between two preset points based on the frequency and time parameters of the two preset points passed in by the parameter pre-reading module. For example, if the two preset sets of parameters are (f1, t1) and (f2, t2), the frequency change is Δf = f2 - f1, the time interval between the two preset times is Δt = t2 - t1, and the frequency change rate is v = Δf / Δt. When the frequency change rate is greater than 0, the frequency change direction Direct = 0; when the frequency change rate is less than 0, Direct = 1.

[0063] See Figure 3The write control logic module calculates the frequency change rate, frequency change direction, and time interval of the current preset segment and assembles them into a data block according to a one-to-one correspondence before caching it. For example, if the frequency parameters to be stored, after being processed by the parameter conversion module, are the frequency change rate v, the frequency change direction Direct, and the frequency change time interval Δt, then according to the bit-by-bit processing, the resulting data block parameter BlockPara = {frequency change rate v, frequency change direction Direct, frequency change time interval Δt}, after being assembled into a parameter block, the frequency scan parameters are cached into the parameter cache RAM under the drive of the system clock, with one data point corresponding to one data point. See the interface diagram of the parameter cache RAM for details. Figure 4 In practice, it is implemented as a readable and writable FIFO.

[0064] See Figure 1 The parameter distribution module distributes the time of the frequency point to be preset to the preset time conformity decision module. When presetting the first point, it simultaneously distributes the frequency value to the frequency scanning module as the starting frequency for scanning. The preset time is then set to the time conformity decision unit.

[0065] See Figure 5 The time conformance decision unit is responsible for making an accurate judgment on the arrival of the preset time. It compares the current B time code time with the preset time. The time conformance decision unit module consists of three parts: a time comparator above the second, a time comparator below the second, and an AND gate logic. When the time comparator above the second detects that the current B time code time is equal to the time above the second of the preset time, and the time comparator below the second detects that the current B time code time is equal to the time below the second of the preset time, it is considered that the preset time has arrived, the time arrival pulse is pulled high, and the preset parameter reading control logic is triggered.

[0066] See Figure 1 The read control logic module reads the previously cached parameter block (including frequency change rate, frequency change direction, and time interval) synchronously according to the edge pulse at the preset time. It sets the frequency change rate to the frequency scanning module and synchronously sets the time interval to the timer module. After setting, the time pulse is delayed by 1 beat and sent to the ping-pong switching timing module to start the timer. The ping-pong switching timing module includes a ping-pong switching circuit and two timers.

[0067] See Figure 6After receiving the timing interval parameter from the read control logic, the timer's delta_s starts working upon detecting the start pulse at the tim_start port. The timer outputs a high-level signal. The timer consists of three parts: a second timer, a second counter, and a comparator. The second timer accurately counts seconds according to the system clock's counting method. Upon completion, it outputs a second timing pulse. The second counter detects this pulse and increments the count. When the count reaches the set time interval delta_s, it pulls the timer's indicator level low, indicating the timing is complete. The accumulator remains in its current state, and the timer enters a timeout protection state. During the timer's operation, the timer's indicator level synchronously drives the frequency scanning module's scan enable.

[0068] See Figure 7 The frequency scanning module consists of three parts: residual phase clearing, frequency linear fitting compensation, and a scan rate frequency control word accumulator. Its working mechanism is as follows: driven by the scan enable `work_en`, the scan rate frequency control word accumulator accumulates based on the scan rate frequency control word, detecting changes in the most significant bit. Each time a carry-over from a high-order bit is completed, a frequency linear fitting compensation refresh enable is provided. The frequency linear fitting compensation module, based on the refresh enable and the input scan start frequency, performs a linear fit on the preset frequency control word according to the scan direction. For example, when the scan direction `Direct` is 0 (the frequency change direction is positive),... The preset frequency control word is incremented once under the refresh enable drive. When the scan direction Direct is 1 (frequency change direction is negative), the preset frequency control word is decremented under the refresh enable drive. Then, driven by the system clock, the preset frequency control word is output in real time, with residual phase clearing logic. The frequency control word for the current scan rate is cached each time. Upon receiving new parameters, the frequency control word for the current scan rate is compared with the frequency control word for the previous preset scan rate. If they are not equal, the residual phase of the scan rate frequency control word accumulator is cleared; otherwise, it is not cleared. The main process of the frequency scanning module is as follows: Based on the set frequency change rate, frequency change direction, and time interval, when the scan enable is high, the frequency scanning module performs a frequency scan according to the set frequency change rate and frequency change direction. After scanning to the specified time interval, it reaches the specified frequency point. If there are no new parameters or scan enable drive subsequently, the frequency value output by the frequency scanning module will remain. When new parameters and scan enable drive are available, the frequency segmented timed scanning process will be repeated according to the aforementioned process.

[0069] Specifically, this invention uses Doppler data to preset the frequency of the uplink baseband signal. Before presetting, the time parameters in the Doppler data are read periodically, starting from the nearest upcoming preset time. Two sets of preset parameters are read each time. The frequency change rate and time interval between each two points are calculated based on the frequency and time parameters of the preset point. The calculated frequency change rate and time interval are cached. The preset time is set to the time conformity decision unit. The frequency scanning module and the timer are triggered by the time conformity decision unit. When the preset time arrives, the previously cached parameters (including the scan rate and time interval) are read synchronously according to the edge pulse of the preset time. The scan rate is set to the frequency scanning module, and the time interval is synchronously set to the ping-pong switching timing module. The timer starts working and outputs a high level. When the timer completes the specified timing, it pulls the timing indicator low. The working indicator level of the timer drives the scanning enable of the frequency scanning module, so that the frequency scanning module scans at a specified time and at a specified scanning rate. After scanning for a specified time, it reaches the specified frequency point. If there are no new parameters or scanning enable driving, the frequency value output by the frequency scanning module will remain. When there are new parameters and scanning enable driving, the frequency segmentation and timing scanning process will be repeated again according to the above process to achieve the function of high accuracy and high flexibility of uplink frequency preset.

[0070] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A system for presetting Doppler files using baseband uplink signals, characterized in that, include: The frequency scanning module uses frequency scanning to preset the Doppler file. The parameter pre-reading module performs timed pre-reading of parameters in the Doppler file; The parameter distribution module distributes the time of the preset frequency point to the time conformity decision module. When the first point is preset, the frequency value is also distributed to the frequency scanning module as the starting frequency for scanning. The parameter conversion module uses the frequency and time relationships between preset frequency points in the Doppler file to convert the preset frequency and time parameters to obtain the rate of change of frequency and the time interval of frequency change. The parameter cache RAM caches the frequency scan parameters and time parameters after the parameter conversion is completed. The time conformity decision module uses the time conformity decision method to synchronously read and configure the parameters for each frequency scan, so that the time conformity decisions of two adjacent preset times do not affect each other. The ping-pong switching timing module provides timeout protection for the operation of the frequency scanning module based on the time interval between two preset points, ensuring that the timeout protections of two adjacent points are independent of each other. The frequency scanning module is equipped with a timed reset logic to clear the residual accumulated phase after each scan segment ends, thereby eliminating the cumulative error caused by phase accumulation.

2. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, The frequency scanning module is used to preset the Doppler file by scanning from one frequency point to the next.

3. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, The parameter pre-reading module pre-reads the preset parameters in the Doppler file before each preset, based on the Doppler file and preset time. It starts the preset from the parameter in the file that is closest to the current time. It reads the frequency points of the two preset times in the file that are closest to the current time and sends them to the parameter conversion module. Each time, it pre-reads the parameters of two points, namely the frequency and time of the current preset point and the frequency and time of the next preset point.

4. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, After receiving the preset point information from the parameter pre-reading module, the parameter conversion module calculates the frequency change rate and the time interval of the frequency change segment from preset point 1 to preset point 2 based on the frequency and preset time of preset point 1 and preset point 2.

5. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, The frequency scan parameters and time parameters after parameter conversion, which are cached in the parameter cache RAM, are used for subsequent frequency scans.

6. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, When each preset moment arrives, the time-to-be-defined pulse of the time-matching judgment module goes high. The time-to-be-defined pulse is used to synchronously read out the frequency change rate and the time interval between preset point 1 and preset point 2 cached in the parameter cache RAM. The time-to-be-defined pulse is used to latch and set the frequency change rate parameter and the direction of change to the frequency scanning module, and the time interval parameter is latched and set to the ping-pong switching timing module.

7. The system for presetting Doppler files for baseband uplink signals according to claim 6, characterized in that, The time compliance decision module includes three independent time compliance decision units.

8. The system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, After receiving the new time interval parameter, the ping-pong switching timing module pulls the timer's working pulse high, uses the working pulse to enable the frequency scanning module to work, drives the frequency scanning module to start working, and starts timing at the same time. When the time interval expires, it pulls the timer's working pulse low, synchronously stops the frequency scanning module, and makes the frequency scanning module stop at the preset point 2.

9. A system for presetting Doppler files for baseband uplink signals according to claim 8, characterized in that, The ping-pong switching timing module includes two timers capable of switching between ping-pong games.

10. A system for presetting Doppler files for baseband uplink signals according to claim 1, characterized in that, The frequency scanning module is designed with a timed reset logic to detect whether it is a new frequency change rate parameter. If it is a new frequency change rate parameter, the residual phase of the phase accumulator of the frequency change rate is cleared to ensure that the change rate of the next frequency change rate is uniform.

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