A dual-engine multi-beam tracking method applied to Beidou communication baseband chip

Abstract

The present invention belongs to the technical field of Beidou communication receiver baseband chips, and more particularly relates to a dual-engine multi-beam tracking method applied to Beidou communication baseband chips. The method comprises: a Beidou receiver receives satellite signals and preprocesses them to obtain Beidou satellite intermediate frequency (IF) signals; an analog-to-digital conversion module converts the IF signals into digital signals and divides them into 21 parallel beam channels; and a capture engine performs a two-dimensional time-frequency search on the digital signals of the 21 beam channels to obtain the carrier phases of the first through twenty-first beams. By utilizing a master-slave engine collaborative working mechanism, a dynamic parameter compensation strategy, and sensor fusion technology, the present invention aims to effectively reduce hardware overhead while significantly improving the robustness and positioning accuracy of multi-beam tracking, meeting the requirements of low-power terminal devices and enhancing positioning performance in complex environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of Beidou communication receiver baseband chips, and in particular relates to a dual-engine multi-beam tracking method applied to Beidou communication baseband chips. Background Art

[0002] In the design architecture of the Beidou receiver baseband chip, such as Figure 2 As shown, the analog-to-digital conversion module is closely connected to the capture engine, which in turn is connected to 21 independent tracking channel engines. These tracking channel engines are each connected to 21 beam-local carrier generators to achieve accurate tracking of the carrier phase and Doppler frequency shift of all Beidou satellite beams. However, traditional solutions using this approach have obvious shortcomings: each tracking channel engine is equipped with complex components such as a carrier digitally controlled oscillator and loop filter. This not only causes the 21 parallel tracking channels to occupy a large amount of FPGA logic resources, but also leads to a significant increase in chip area and power consumption, making it difficult to meet the requirements of low-power terminal devices.

[0003] More critically, each tracking channel operates independently and lacks the necessary parameter correlation modeling. When the Doppler frequency shift changes suddenly (for example, in high-speed motion scenarios), this independence can easily lead to tracking loss, requiring the signal to be recaptured, which poses a threat to the continuity of positioning. In addition, existing solutions fail to fully explore and utilize the time-varying correlation between the carrier phase difference between beams and the Doppler frequency shift, which not only causes unnecessary repeated calculations but also may lead to error accumulation. Especially in complex electromagnetic environments, this accumulated error is more easily amplified, thereby adversely affecting positioning accuracy. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] In order to overcome the technical problems existing in the design of existing Beidou receiver baseband chips, such as large hardware resource consumption, poor adaptability to dynamic environments, computational redundancy, and positioning accuracy being easily affected by complex electromagnetic environments, the present invention provides a dual-engine multi-beam tracking method applied to Beidou communication baseband chips. The method aims to effectively reduce hardware overhead while significantly improving the robustness and positioning accuracy of multi-beam tracking through a master-slave engine collaborative working mechanism, a dynamic parameter compensation strategy, and sensor fusion technology, so as to meet the needs of low-power terminal devices and enhance positioning performance in complex environments.

[0006] (2) Technical solution

[0007] The present invention is implemented through the following technical solution: The present invention proposes a dual-engine multi-beam tracking method applied to a Beidou communication baseband chip, the method is implemented based on dual-engine multi-beam tracking, and the dual-engine multi-beam tracking includes a Beidou receiver, a radio frequency front-end module connected to the Beidou receiver, an analog-to-digital conversion module connected to the radio frequency front-end module, a capture engine connected to the analog-to-digital conversion module, a first tracking channel engine connected to the capture engine, a second tracking channel engine connected to a signal selector, a signal selector connected to the capture engine, a beam setter connected to the second tracking channel engine, a difference calculation unit connected to the second tracking channel engine and the signal selector, a difference updater connected to the difference calculation unit, a gyroscope connected to the difference updater, and a first beam local carrier generator connected to the first tracking channel engine. The tracking channel engine is implemented by a second tracking channel engine and a second beam local carrier generator, a third beam local carrier generator, a fourth beam local carrier generator, a fifth beam local carrier generator, a sixth beam local carrier generator, a seventh beam local carrier generator, an eighth beam local carrier generator, a ninth beam local carrier generator, a tenth beam local carrier generator, an eleventh beam local carrier generator, a twelfth beam local carrier generator, a thirteenth beam local carrier generator, a fourteenth beam local carrier generator, a fifteenth beam local carrier generator, a sixteenth beam local carrier generator, a seventeenth beam local carrier generator, an eighteenth beam local carrier generator, a nineteenth beam local carrier generator, a twentieth beam local carrier generator, and a twenty-first beam local carrier generator, which are respectively connected to the second tracking channel engine;

[0008] The method comprises:

[0009] (1) The Beidou receiver receives satellite signals and pre-processes them to obtain Beidou satellite intermediate frequency signals f m , generally set to 15.75MHz; pre-processing is: using the RF front-end module to receive satellite signals and perform down-conversion and filtering processing to output Beidou satellite intermediate frequency signals;

[0010] (2) converting the intermediate frequency signal into a digital signal through an analog-to-digital conversion module and dividing it into 21 parallel beam channels;

[0011] (3) The capture engine performs a two-dimensional time-frequency search on the digital signals of the 21 beam channels, and obtains the carrier phases of the first beam to the twenty-first beam (the first beam to the twenty-first beam include the first beam, the second beam, the third beam, the fourth beam, the fifth beam, the sixth beam, the seventh beam, the eighth beam, the ninth beam, the tenth beam, the eleventh beam, the twelfth beam, the thirteenth beam, the fourteenth beam, the fifteenth beam, the sixteenth beam, the seventeenth beam, the eighteenth beam, the nineteenth beam, the twentieth beam, and the twenty-first beam) respectively. and Doppler frequency ;in, k =1, 2, ..., 21;

[0012] (IV) The first tracking channel engine locks and tracks the carrier phase of the first beam and Doppler frequency and generating a corresponding local carrier signal through a first beam local carrier generator;

[0013] (5) The signal selector selects the input mode according to the power-on status of the Beidou receiver, including:

[0014] If it is the first time to start up, change the carrier phase from the first beam to the twenty-first beam captured in step (3) and Doppler frequency Direct input to the second tracking channel engine;

[0015] If it is not the first time to start the machine, the carrier phase difference output by the difference calculation unit and input to the second tracking channel engine;

[0016] (6) The beam setter controls the second tracking channel engine to track the carrier phase of the second beam to the twenty-first beam in a polling manner. and Doppler frequency ;

[0017] (7) The difference calculation unit calculates the carrier phase difference between the first beam and the second to twenty-first beams and Doppler frequency difference ;

[0018] (8) Due to the fact that geostationary satellites are stationary relative to the Earth's reference frame, the relative motion between the satellite receiver and the satellite is equivalent to the motion of the satellite receiver relative to the Earth's reference frame. Therefore, the Doppler variation caused by the relative motion between the satellite receiver and the satellite can be measured and predicted using a gyroscope. The gyroscope is used to calculate the motion state of the satellite receiver and output real-time acceleration that changes with time. a ( t ), Doppler prediction is performed for beams that are not in the tracking channel engine calculation;

[0019] That is, the difference updater is based on the real-time acceleration output by the gyroscope a ( t ), the Doppler frequencies of the second to twenty-first beams are updated by the formula:

[0020] ;in, is the center frequency of the satellite signal, which is generally 2491.75MHz, c is the speed of light, which is generally 299792458m / s, and t is time;

[0021] (IX) Update the carrier phase and Doppler frequency The signals are input to the second beam local carrier generator to the twenty-first beam local carrier generator to generate corresponding local carrier signals to achieve real-time tracking of the first to twenty-first beams.

[0022] Preferably, the signal output by the first beam local carrier generator is: ,in, is the BeiDou satellite intermediate frequency signal frequency in step (1), and t is the time.

[0023] Preferably, the signals output by the second beam local carrier generator to the twenty-first beam local carrier generator (the second beam local carrier generator to the twenty-first beam local carrier generator include the second beam local carrier generator, the third beam local carrier generator, the fourth beam local carrier generator, the fifth beam local carrier generator, the sixth beam local carrier generator, the seventh beam local carrier generator, the eighth beam local carrier generator, the ninth beam local carrier generator, the tenth beam local carrier generator, the eleventh beam local carrier generator, the twelfth beam local carrier generator, the thirteenth beam local carrier generator, the fourteenth beam local carrier generator, the fifteenth beam local carrier generator, the sixteenth beam local carrier generator, the seventeenth beam local carrier generator, the eighteenth beam local carrier generator, the nineteenth beam local carrier generator, the twentieth beam local carrier generator, and the twenty-first beam local carrier generator) are: .

[0024] (3) Beneficial effects

[0025] The present invention aims to effectively reduce hardware overhead through the master-slave engine collaborative working mechanism, dynamic parameter compensation strategy and sensor fusion technology, while significantly improving the robustness and positioning accuracy of multi-beam tracking to meet the needs of low-power terminal devices and enhance positioning performance in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0027] Figure 1 This is a system block diagram of the present invention.

[0028] Figure 2A system block diagram of the prior art. DETAILED DESCRIPTION

[0029] To overcome the drawbacks of traditional Beidou baseband chips, which require 21 independent tracking channel engines, each containing modules such as a carrier numerically controlled oscillator (NCO) and a loop filter, resulting in high hardware complexity and power consumption, this paper proposes a dual-engine multi-beam tracking method for Beidou communication baseband chips. This method uses a dual-engine architecture (the master engine locks the main beam, while the slave engines dynamically poll the remaining beams) to reduce the number of hardware channels from 21 to two core engines, significantly reducing FPGA logic resource usage (by approximately 60%), while also reducing chip area and power consumption, making it suitable for low-power scenarios such as IoT terminals.

[0030] The above-mentioned specific implementations include: the method is implemented based on dual-engine multi-beam tracking, and the dual-engine multi-beam tracking includes a Beidou receiver, a radio frequency front-end module connected to the Beidou receiver, an analog-to-digital conversion module connected to the radio frequency front-end module, a capture engine connected to the analog-to-digital conversion module, a first tracking channel engine connected to the capture engine, a second tracking channel engine connected to a signal selector, a signal selector connected to the capture engine, a beam setter connected to the second tracking channel engine, a difference calculation unit connected to the second tracking channel engine and the signal selector, a difference updater connected to the difference calculation unit, a gyroscope connected to the difference updater, a first beam local carrier generator connected to the first tracking channel engine, and a second local carrier generator connected to the second tracking channel engine respectively. Beam local carrier generator, third beam local carrier generator, fourth beam local carrier generator, fifth beam local carrier generator, sixth beam local carrier generator, seventh beam local carrier generator, eighth beam local carrier generator, ninth beam local carrier generator, tenth beam local carrier generator, eleventh beam local carrier generator, twelfth beam local carrier generator, thirteenth beam local carrier generator, fourteenth beam local carrier generator, fifteenth beam local carrier generator, sixteenth beam local carrier generator, seventeenth beam local carrier generator, eighteenth beam local carrier generator, nineteenth beam local carrier generator, twentieth beam local carrier generator and twenty-first beam local carrier generator are implemented (refer to Figure 1 shown);

[0031] In the traditional solution, when the Doppler frequency shift changes suddenly (such as high-speed movement), it is easy to lose lock due to the independent operation of the channel, and the signal needs to be recaptured, resulting in positioning interruption. Therefore, the present invention introduces the difference calculation unit and the gyroscope sensor fusion technology, which calculates the carrier phase difference between the main beam and the remaining beams in real time. and Doppler frequency difference , and combined with the acceleration output by the gyroscope a (t ) Dynamically update the prediction model ( ), thereby achieving Doppler frequency shift pre-compensation for non-tracking beams, effectively avoiding loss of lock problems, and improving continuous positioning capabilities in high-speed scenarios;

[0032] Furthermore, traditional methods require 21 engines to independently resolve the same satellite constellation signal, resulting in repeated calculations (such as Doppler prediction and loop filtering) and error accumulation. The present invention utilizes a master-slave engine collaborative mechanism. The master engine (the first tracking channel engine) continuously locks onto the first beam and generates a reference local carrier signal. The slave engine (the second tracking channel engine) dynamically generates local carrier signals for the remaining beams based on the difference calculation results. The present invention eliminates redundant calculations through parameter correlation modeling and utilizes gyroscope data to suppress Doppler frequency shift errors caused by motion, thereby improving positioning accuracy (the measured error is reduced by approximately 30%).

[0033] In addition, traditional hardware has a fixed number of 21 channels and cannot allocate resources on demand. This invention uses a beam setter to control the slave engine to track the second to 21st beams in a polling manner. It supports dynamic adjustment of tracking priority (for example, prioritizing tracking of high-elevation-angle satellites) and can adapt to future satellites or frequency points (such as the B3 band) through software configuration, reducing hardware upgrade costs.

[0034] The specific implementations of the above are:

[0035] The method comprises:

[0036] (1) The Beidou receiver receives satellite signals and pre-processes them to obtain Beidou satellite intermediate frequency signals f m , generally set to 15.75MHz; pre-processing is: using the RF front-end module to receive satellite signals and perform down-conversion and filtering processing to output Beidou satellite intermediate frequency signals;

[0037] (2) converting the intermediate frequency signal into a digital signal through an analog-to-digital conversion module and dividing it into 21 parallel beam channels;

[0038] (3) The capture engine performs a two-dimensional time-frequency search on the digital signals of the 21 beam channels, and obtains the carrier phases of the first beam to the twenty-first beam (the first beam to the twenty-first beam include the first beam, the second beam, the third beam, the fourth beam, the fifth beam, the sixth beam, the seventh beam, the eighth beam, the ninth beam, the tenth beam, the eleventh beam, the twelfth beam, the thirteenth beam, the fourteenth beam, the fifteenth beam, the sixteenth beam, the seventeenth beam, the eighteenth beam, the nineteenth beam, the twentieth beam, and the twenty-first beam) respectively. and Doppler frequency ;in, k =1, 2, ..., 21;

[0039] (IV) The first tracking channel engine locks and tracks the carrier phase of the first beam and Doppler frequency The first tracking channel engine is set as the main engine, and the carrier phase of the first beam is fixedly locked. and Doppler frequency , generate a reference signal as the reference source for all beam tracking;

[0040] The second tracking channel engine is set as a slave engine, and receives the original parameters of the first startup or the difference parameters of the non-first startup through the signal selector. Combined with the polling instructions of the beam setter, it generates the local carrier signals of the remaining 20 beams in sequence. In addition, the dynamic switching logic is set. That is, when it is first started, the slave engine directly uses the carrier phase output by the capture engine. and Doppler frequency ; When it is not the first time to start up, based on the carrier phase difference and Doppler frequency difference Update parameters to reduce the amount of real-time computation, specifically steps (5) and (6), as follows:

[0041] (5) The signal selector selects the input mode according to the power-on status of the Beidou receiver, including:

[0042] If it is the first time to start up, change the carrier phase from the first beam to the twenty-first beam captured in step (3) and Doppler frequency Direct input to the second tracking channel engine;

[0043] If it is not the first time to start the machine, the carrier phase difference output by the difference calculation unit and input to the second tracking channel engine;

[0044] (6) The beam setter controls the second tracking channel engine to track the carrier phase of the second beam to the twenty-first beam in a polling manner. and Doppler frequency ;

[0045] (7) The difference calculation unit calculates the carrier phase difference between the first beam and the second to twenty-first beams (reflecting the phase offset of adjacent beams, used to eliminate common errors such as ionospheric delay) and Doppler frequency difference ;

[0046] (8) Due to the fact that geostationary satellites are stationary relative to the Earth's reference frame, the relative motion between the satellite receiver and the satellite is equivalent to the motion of the satellite receiver relative to the Earth's reference frame. Therefore, the Doppler variation caused by the relative motion between the satellite receiver and the satellite can be measured and predicted using a gyroscope. The gyroscope is used to calculate the motion state of the satellite receiver and output real-time acceleration that changes with time. a ( t ), Doppler prediction is performed for beams that are not in the tracking channel engine calculation;

[0047] That is, the difference updater is based on the real-time acceleration output by the gyroscope a ( t ), update the Doppler frequencies of the second to twenty-first beams through the formula (acceleration output by the gyroscope a ( t ) integral prediction of Doppler changes caused by receiver motion to achieve dynamic frequency offset compensation. In addition, acceleration a ( t ) is incorporated into the Doppler prediction model to overcome the limitation of traditional solutions that rely on satellite signal parameters and ignore local dynamic changes. The formula is:

[0048] ;in, is the center frequency of the satellite signal, which is generally 2491.75MHz, c is the speed of light, which is generally 299792458m / s, and t is time;

[0049] The above setting is a closed-loop update mechanism, and the difference updater adjusts in real time based on the gyroscope data. , ensuring that the local carrier signal generated from the engine remains synchronized with the satellite signal to avoid tracking loss due to sudden changes in motion;

[0050] (IX) Update the carrier phase and Doppler frequency input to the local carrier generators of the second to twenty-first beams to generate corresponding local carrier signals to achieve real-time tracking of the first to twenty-first beams;

[0051] The signal output by the first beam local carrier generator is: ,in, is the BeiDou satellite intermediate frequency signal frequency in step (1), and t is the time;

[0052] The signals output by the second to twenty-first beam local carrier generators (the second to twenty-first beam local carrier generators include the second beam local carrier generator, the third beam local carrier generator, the fourth beam local carrier generator, the fifth beam local carrier generator, the sixth beam local carrier generator, the seventh beam local carrier generator, the eighth beam local carrier generator, the ninth beam local carrier generator, the tenth beam local carrier generator, the eleventh beam local carrier generator, the twelfth beam local carrier generator, the thirteenth beam local carrier generator, the fourteenth beam local carrier generator, the fifteenth beam local carrier generator, the sixteenth beam local carrier generator, the seventeenth beam local carrier generator, the eighteenth beam local carrier generator, the nineteenth beam local carrier generator, the twentieth beam local carrier generator, and the twenty-first beam local carrier generator) are: .

[0053] The comparison table between the present invention (dual engines) and the traditional solution (21 channels) is shown in the following table:

[0054]

[0055] The present invention realizes hardware resource reuse through a dual-engine architecture, improves tracking robustness through differential dynamic compensation, and enhances dynamic adaptability through sensor fusion, providing new innovations for the efficient and low-consumption design of Beidou baseband chips.

Claims

1. A dual-engine multi-beam tracking method applied to a Beidou communication baseband chip, the method comprising: (1) The Beidou receiver receives and pre-processes satellite signals to obtain Beidou satellite intermediate frequency signals; (2) converting the intermediate frequency signal into a digital signal through an analog-to-digital conversion module and dividing it into 21 parallel beam channels; (3) The capture engine performs a two-dimensional time-frequency search on the digital signals of the 21 beam channels, and obtains the carrier phases of the first beam to the twenty-first beam respectively. and Doppler frequency ;in, k =1, 2, ... ..., 21; It is characterized in that: it also includes the following steps: (IV) The first tracking channel engine locks and tracks the carrier phase of the first beam and Doppler frequency and generating a corresponding local carrier signal through a first beam local carrier generator; (5) The signal selector selects the input mode according to the power-on status of the Beidou receiver, including: If it is the first time to start up, change the carrier phase from the first beam to the twenty-first beam captured in step (3) and Doppler frequency Direct input to the second tracking channel engine; If it is not the first time to start the machine, the carrier phase difference output by the difference calculation unit and input to the second tracking channel engine; (6) The beam setter controls the second tracking channel engine to track the carrier phase of the second beam to the twenty-first beam in a polling manner. and Doppler frequency ; (7) The difference calculation unit calculates the carrier phase difference between the first beam and the second to twenty-first beams and Doppler frequency difference ; (8) The difference updater is based on the real-time acceleration output by the gyroscope a ( t ), the Doppler frequency difference from the second beam to the twenty-first beam after the update is as follows: ； in, is the center frequency of the satellite signal, c is the speed of light, and t is the time; (IX) Update the carrier phase and Doppler frequency difference The signals are input to the second beam local carrier generator to the twenty-first beam local carrier generator to generate corresponding local carrier signals to achieve real-time tracking of the first to twenty-first beams.

2. The dual-engine multi-beam tracking method for a Beidou communication baseband chip according to claim 1, characterized in that: The signal output by the first beam local carrier generator is: ,in, is the BeiDou satellite intermediate frequency signal frequency in step (1), and t is the time.

3. The dual-engine multi-beam tracking method for Beidou communication baseband chip according to claim 1, characterized in that: The signals output by the second beam local carrier generator to the twenty-first beam local carrier generator are: ,in, is the BeiDou satellite intermediate frequency signal frequency in step (1).

4. The dual-engine multi-beam tracking method for Beidou communication baseband chip according to claim 1, characterized in that: The Beidou receiver is also connected to a radio frequency front-end module for receiving satellite signals and performing down-conversion and filtering processing to output Beidou satellite intermediate frequency signals.

5. The dual-engine multi-beam tracking method for Beidou communication baseband chip according to claim 1, characterized in that: In the step (eight), f 0=2491.75MHz.

6. The dual-engine multi-beam tracking method for Beidou communication baseband chip according to claim 1, characterized in that: In the step (eight), c =299792458m / s.

7. The dual-engine multi-beam tracking method for Beidou communication baseband chip according to claim 2 or 3, characterized in that: <h2 style=";text-align:left;direction:ltr"> f <h2 style=";text-align:left;direction:ltr"> m <h2 style=";text-align:left;direction:ltr"> =15.75MHz.

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