A reconfigurable modular based space-borne GNSS receiver

Abstract

A kind of based on reconfigurable modularization satellite-borne GNSS receiver, modularization design is adopted, including radio frequency module, navigation module, control module and bottom plate;Wherein, radio frequency module, navigation module, control module adopt standardization structure design, reconfigurable combination between modules, can support multiple antenna input, multiple machine redundancy backup and be applicable to satellite-borne scene.Radio frequency module receives multiple antenna GNSS radio frequency signal input, and completes amplification, combination and power division processing;Navigation module is based on integrated navigation chip and completes GNSS signal acquisition, tracking and positioning;Control module is based on main control CPU and completes communication with on-board subsystem, control instruction receiving and execution etc.;Bottom plate is used to provide interconnection between modules, external interface and basic power supply.The application is applicable to complex satellite-borne scene, has reconfigurable characteristics, has flexibility, universality and reliability, can greatly reduce design cost, realizes batch production capacity.

Description

TECHNICAL FIELD

[0001] The application relates to a reconfigurable modularized satellite-borne GNSS receiver, and belongs to the field of satellite navigation. BACKGROUND

[0002] With the rapid development of commercial aerospace, microsatellites have developed rapidly in the fields of broadband communication, electronic reconnaissance, remote sensing observation and the like due to the advantages of small size, high maneuverability, fast construction speed and low-orbit operation, and present a large-scale networking trend, and the construction demand is large. The satellite-borne GNSS receiver, as one of the core components, provides high-precision position, speed and time information for the satellite. Unlike the ground scene, the satellite-borne scene is complex, the satellite moves at a high speed and has different attitude adjustments, the signal Doppler shift is large, the visible star switching speed is fast, and the like, which puts forward very high requirements on the performance and reliability of the satellite-borne GNSS receiver. The traditional satellite-borne GNSS receiver is still mainly in the form of a subsystem or a large single machine, and the single-board design of FPGA+DSP and RF+special baseband is used to ensure the performance and reliability, and the miniaturization and low power consumption are very limited. In recent years, some domestic satellites have begun to select ordinary ground commercial small GNSS receivers as on-board orbit determination equipment, but the space adaptability and reliability cannot meet the long-term on-orbit work requirements. In addition, due to the different functions and structural definitions of satellite models and constellations, generalization cannot be realized, and most of the existing satellite-borne GNSS receivers are realized by using a customized scheme, so that the design, production cost and cycle are difficult to compress, and batch production capacity cannot be formed. SUMMARY

[0003] The technical problem to be solved by the application is to overcome the shortcomings of the prior art and provide a reconfigurable modularized satellite-borne GNSS receiver. The reconfigurable modularized satellite-borne GNSS receiver adopts a modular design and comprises a radio frequency module, a navigation module, a control module and a bottom plate. The radio frequency module, the navigation module and the control module adopt a standardized structure design, and the modules can be reconfigurably combined, can support multiple antenna inputs, multiple machine redundancy backup and are suitable for satellite-borne scenes. The radio frequency module receives multiple antenna GNSS radio frequency signal inputs and completes amplification, combination and power division processing. The navigation module completes GNSS signal acquisition, tracking and positioning based on an integrated navigation chip. The control module completes communication with satellite subsystems, control instruction reception and execution and the like based on a master control CPU. The bottom plate is used for providing interconnection between the modules, external interfaces and basic power supply. The application is suitable for complex satellite-borne scenes, has a reconfigurable characteristic, has flexibility, universality and reliability, can greatly reduce the design cost and realize batch production capacity.

[0004] The object of the application is achieved by the following technical solutions.

[0005] A kind of based on reconfigurable modularization's spaceborne GNSS receiver, including radio frequency module, navigation module, control module, bottom plate;

[0006] Radio frequency module is used to receive GNSS radio frequency signal, then carries out first-order filter amplification, combination and power division processing, outputs multiple radio frequency signals;Each radio frequency signal input is input to a navigation module;

[0007] Navigation module includes radio frequency front-end circuit, integrated navigation chip;Radio frequency front-end circuit is used to receive and process radio frequency signal;Integrated navigation chip is used to complete GNSS signal acquisition, tracking and positioning, and outputs positioning result, observation data to control module, while receiving control module instruction;

[0008] Control module receives the data output by navigation module and carries out packing, completes data communication with on-board subsystem, and control module receives instruction and controls the working mode and state of navigation module;

[0009] Bottom plate is used to provide interconnection between modules, external interface, debugging interface and power supply.

[0010] Further, radio frequency module receives multiple antenna radio frequency signal inputs, and after first-order filter amplification is completed for each radio frequency signal, in turn passes through multi-combination combiner and one-to-many power divider, and outputs multiple radio frequency signals;Radio frequency module supports up to 4 radio frequency inputs, up to 3 radio frequency signal outputs, and the gain control is in the range of 14-16dB.

[0011] Further, the radio frequency front-end circuit of navigation module receives single radio frequency signal output by radio frequency module, and in turn outputs 3 differential radio frequency signals after passing through amplifier, power divider, filter and single-ended to differential balun, and the 3 differential radio frequency signals are respectively 1.5G frequency band, 1.2G frequency band and 1.1G frequency band;Single radio link gain should be controlled in 35-40dB.

[0012] Further, 3 differential radio frequency signals are simultaneously input to integrated navigation chip of navigation module;Integrated navigation chip completes down-conversion and analog-to-digital conversion of 3 differential radio frequency signals, and outputs digital intermediate frequency signals of different frequency points, and completes acquisition, tracking and positioning of multi-mode multi-frequency GNSS signals for 3 digital intermediate frequency signals.

[0013] Further, the communication interface of integrated navigation chip and control module is UART;Integrated navigation chip also reserves 1-way UART interface as backup.

[0014] Further, the bottom plate has four SMA connectors, receives up to four GNSS antenna radio frequency signals, and outputs to radio frequency module through micro inter-board connector.

[0015] Further, the radio frequency module is provided with at most four radio frequency signal inputs, three radio frequency signal outputs, and an antenna feed ANTVCC is reserved.

[0016] Further, the inter-board connector pin definition of the navigation module defines, in addition to the power supply VCC, GND, UART, 1PPS, JTAG, and reset signals, the integrated navigation chip analog intermediate frequency output, integrated navigation chip internal radio frequency chip configuration interface SPI, integrated navigation chip internal radio frequency chip sampling clock for integrated navigation chip testing and debugging requirements, and defines IIC and GPIO interfaces for communication interface expansion, improving the versatility of the navigation module and reducing subsequent design changes.

[0017] Further, the inter-board connector pin definition of the control module adopts a unified standard, in addition to the power supply signal, reset signal, and JTAG, a series of communication interfaces and debugging interfaces are provided; wherein, the communication interface between the control module and the on-board subsystem includes CAN, IIC, RS422, and SPI, supporting one or more options.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] (1) The present application adopts modular design, the function and interface definition of each module are clear and standardized structure design is adopted, which can reduce the design and production cost.

[0020] (2) Under the requirement of standardized structure design, the present application forms a plurality of pluggable and replaceable radio frequency modules by selecting different combiners and power dividers, supports multiple antenna signal input and radio frequency signal output at the same time, and improves the spatial applicability of the satellite-borne GNSS receiver.

[0021] (3) The present application can realize multiple machine redundancy backup by combining a plurality of radio frequency modules, navigation modules, control modules and a bottom plate, and improve the reliability of the satellite-borne GNSS receiver.

[0022] (4) The navigation module of the present application is realized based on an integrated navigation chip, has high function density, supports multi-mode and multi-frequency GNSS signal positioning at the same time, has small size, low power consumption and high reliability, and can meet the application requirements of microsatellites. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the basic principle block diagram of the satellite-borne GNSS receiver embodiment 1 of the present application;

[0024] Figure 2 is the basic principle block diagram of the radio frequency module of the embodiment 1 of the present application;

[0025] Figure 3 is the basic principle block diagram of the navigation module of the embodiment 1 of the present application;

[0026] Figure 4 is a basic principle block diagram of the control module of the embodiment 1 of the application;

[0027] Figure 5 is a basic principle block diagram of the satellite-borne GNSS receiver of the embodiment 2 of the application. DETAILED DESCRIPTION

[0028] In order to make the object, technical scheme and advantages of the application more clear, the embodiments of the application will be further described in detail below with reference to the drawings.

[0029] Embodiment 1

[0030] The application provides a satellite-borne GNSS receiver based on reconfigurable modularization, as shown in the figure, which mainly comprises a radio frequency module, a navigation module, a control module and a bottom plate. The navigation module A and the navigation module B are the same type of navigation modules, which can be cold backup for each other, and can also work simultaneously. The control module A and the control module B are the same type of control modules, which can be cold backup for each other, and can also work simultaneously. Figure 1

[0031] The radio frequency module, the navigation module and the control module all adopt standardized structure design, the size of a single radio frequency module is 40x20mm, the size of a single navigation module is 40x40mm, and the size of a single control module is 40x40mm.

[0032] The bottom plate is used for providing interconnection between modules, external interface, debugging interface and basic power supply; the radio frequency module, the navigation module, the control module and the bottom plate are connected through a micro interboard connector.

[0033] The bottom plate has four SMA connectors, which receive at most four GNSS antenna radio frequency signals. In this embodiment, two of the SMA connectors are used to receive two GNSS antenna radio frequency signals, and the signals are input to the radio frequency module through the micro interboard connector.

[0034] The radio frequency module outputs multiple radio frequency signals to the navigation module through a filter, an amplifier, a combiner and a power divider.

[0035] The navigation module amplifies, divides power, filters and processes the input single radio frequency signal, forms three differential radio frequency signals, completes radio frequency signal down-conversion, analog-to-digital conversion, digital intermediate frequency processing, capture, tracking, navigation positioning solution and the like based on an integrated navigation chip, and outputs positioning result data and the like to the control module through a UART.

[0036] ​The control module receives data input by the navigation module through UART and performs packaging processing. Standard interfaces, including CAN, IIC, RS422, and SPI, are adopted to support one or more data communications with the on-board subsystems. The control module receives control instructions from the on-board subsystems and forwards them to the navigation module to control the switching of the working mode of the navigation module.

[0037] (1) RF module

[0038] As shown in FIG. 1, the RF module receives double-channel GNSS antenna RF signal input, and uses a filter and a low-noise amplifier to perform one-stage filtering and amplification on each channel of the RF signal. Then, the RF signal sequentially passes through a two-in-one combiner and a one-to-two power divider, and outputs double-channel RF signal. The overall gain of the RF module is controlled within 14-16 dB. Figure 2 In addition, according to the design requirements of the on-board GNSS receiver, different port numbers of combiners and power dividers can be selected inside the RF module while maintaining the standard structure design and pin definition, so as to realize the reception of multi-channel antenna signals and the output of multi-channel RF signals. For example, a three-in-one combiner and a two-in-one power divider can be used to realize three-channel GNSS antenna signal input and double-channel RF signal output.

[0039] However, it is necessary to ensure that the RF module formed after selecting different combiners and power dividers conforms to the standard structure design, and the pin definition of the inter-board connector uses the same standard, so as to realize the plug-in replacement of different types of RF modules. Since multi-channel combining and power dividing will cause attenuation, and considering the volume limitation of the RF module, in addition to the fixed basic power supply VCC and GND pins, at most four RF signal inputs and three RF signal outputs are provided, and an antenna feed ANTVCC is reserved to improve the applicability and compatibility. The RF module selects the corresponding RF signal input and output pins according to the input port of the internal combiner and the output port of the power divider.

[0040] Each channel of the RF signal output by the RF module is input to a navigation module for processing.

[0041] (2) Navigation module

[0042] As shown in FIG. 2, each channel of the RF signal output by the RF module is input to a navigation module.

[0043] Figure 3 The navigation module mainly consists of a RF front-end circuit and an integrated navigation chip. The RF signal sequentially passes through a low-noise amplifier, a power divider, a surface acoustic wave filter, and a single-ended-to-differential balun, and outputs three channels of differential RF signals, which support 1.5G frequency band, 1.2G frequency band, and 1.1G frequency band, respectively. The gain of a single RF link is controlled within 35-40 dB.

[0044] The navigation module mainly consists of a RF front-end circuit and an integrated navigation chip. The RF signal sequentially passes through a low-noise amplifier, a power divider, a surface acoustic wave filter, and a single-ended-to-differential balun, and outputs three channels of differential RF signals, which support 1.5G frequency band, 1.2G frequency band, and 1.1G frequency band, respectively. The gain of a single RF link is controlled within 35-40 dB.

[0045] ​The three differential radio frequency signals are input to the integrated navigation chip of the navigation module.

[0046] The integrated navigation chip is internally integrated with a radio frequency chip, a digital baseband chip, a Flash and a power supply, has high functional density ratio and low power consumption, and supports GPS L1 / L2 / L5, BDS B1 / B2 / B3 and GLONASS L1 / L2 three-mode eight-frequency signals. The radio frequency chip integrated in the integrated navigation chip supports simultaneous input of three differential radio frequency signals, completes secondary down-conversion, amplifiers, filters and the like. The digital baseband chip configures parameters for the radio frequency chip, completes down-conversion and analog-to-digital conversion of the three differential radio frequency signals, and outputs three digital intermediate frequency signals of different frequencies. The digital baseband chip integrated in the integrated navigation chip supports processing of three digital intermediate frequency signals, and completes three-mode eight-frequency GNSS signal acquisition, tracking and positioning through software algorithm design. Positioning results, observation data and the like are output from a UART interface of the integrated navigation chip to the control module. Meanwhile, one UART interface is reserved as a backup.

[0047] The pin definitions of the inter-board connector of the navigation module are fixed for basic signals such as power supply VCC, GND, UART, 1PPS, JTAG and reset signals, and part of the interfaces are defined for the test and debugging requirements of the integrated navigation chip, including: integrated navigation chip analog intermediate frequency output, integrated navigation chip internal radio frequency chip configuration interface SPI, integrated navigation chip internal radio frequency chip sampling clock and the like. Meanwhile, IIC and GPIO interfaces are defined for communication interface expansion, improvement of the universality of the navigation module and reduction of subsequent design changes.

[0048] (3) Control module

[0049] As shown in Figure 4 , the control module mainly consists of a main control CPU, an interface circuit, a power supply and a storage unit. The data output from the navigation module is received through the UART, and is packaged according to the data agreement. The data packaging is completed by software algorithm. The pin definitions of the inter-board connector of the control module adopt a unified standard, and a series of communication interfaces and debugging interfaces are provided in addition to the fixed definitions of basic signals such as power supply signals, reset signals and JTAG. The communication interfaces of the control module and the on-board subsystems include CAN, IIC, RS422 and SPI, and support one or more optional interfaces.

[0050] The CAN bus interface is realized by a CAN transceiver and peripheral circuits, and the IIC bus interface mainly includes an IIC repeater and peripheral circuits. The control module sends the packaged data to the outside through the above interfaces in a timely manner, and can also send data through a specific interface according to specific design requirements.

[0051] In addition, the control module receives polling instructions sent by the subsystem on the satellite through a CAN or IIC bus interface, and sends specified data according to the polling instructions. Meanwhile, the control module receives control instructions sent by the subsystem on the satellite, and forwards the control instructions to the navigation module, which completes mode switching and the like based on the control instructions.

[0052] The power supply part of the control module mainly completes 5V power supply and internal required 3.3V, 1.8V and 1.2V power conversion and control. The storage unit mainly includes a Flash required for storing programs.

[0053] Embodiment 2

[0054] The present embodiment is as shown in Figure 5

[0055] (1) One radio frequency module, two navigation modules and two control modules and a bottom plate are selected to realize the design of the satellite-borne GNSS receiver.

[0056] (2) The radio frequency module supports three-way GNSS antenna input, and outputs two-way radio frequency signals by sequentially selecting a filter, a low-noise amplifier, a three-in-one combiner and a one-to-two power divider.

[0057] (3) Two navigation modules and two control modules are selected respectively, and the design in Embodiment 1 is followed, and double-machine cold backup is adopted to improve the space applicability and reliability.

[0058] (4) The radio frequency module, the navigation module and the control module all adopt standardized structure design and pin definition, the size of a single radio frequency module is 40*20mm, the size of a single navigation module is 40*40mm, and the size of a single control module is 40*40mm.

[0059] (5) The bottom plate follows the design in Embodiment 1, and three-way SMA connectors are used to support three-way GNSS antenna input.

[0060] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

[0061] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not depart from the technical solutions of the present application, all belong to the protection scope of the technical solutions of the present application.​

Claims

1. A reconfigurable modular based space-borne GNSS receiver characterized in that, The RF module, the navigation module, the control module, and the bottom plate are included. The RF module is used for receiving GNSS RF signals, and then performing first-stage filtering and amplification, combining and power splitting processing, and outputting multiple RF signals. Each RF signal is input to one navigation module. The navigation module includes a RF front-end circuit and an integrated navigation chip. The RF front-end circuit is used for receiving and processing RF signals. The integrated navigation chip is used for completing GNSS signal acquisition, tracking and positioning, and outputting positioning results and observation data to the control module. The control module receives data output by the navigation module, and performs packaging to complete data communication with on-board subsystems. The control module receives instructions and controls the working mode and state of the navigation module. The bottom plate is used for providing interconnection between modules, external interfaces, debugging interfaces, and power supply. The RF module, the navigation module, and the control module all adopt standardized structure design. The size of a single RF module is 40*20mm, the size of a single navigation module is 40*40mm, and the size of a single control module is 40*40mm. Pin definitions of inter-board connectors of the RF module, the navigation module, and the control module adopt the same standard, so as to realize plug-in replacement of different types of RF modules. The RF module receives multiple antenna RF signal inputs, and after first-stage filtering and amplification of each RF signal, sequentially passes through a multi-combining combiner and a one-to-many power splitter, and outputs multiple RF signals. The RF module supports up to 4 RF inputs and up to 3 RF signal outputs, and the gain control is within the range of 14-16dB. The RF module is provided with up to four RF signal inputs and three RF signal outputs, and an antenna feed ANTVCC is reserved. The integrated navigation chip internally integrates a RF chip, a digital baseband chip, a Flash, and a power supply. In addition to power supply VCC, GND, UART, 1PPS, JTAG, and reset signals, the pin definition of the inter-board connector of the navigation module also defines an integrated navigation chip analog intermediate frequency output, an integrated navigation chip internal RF chip configuration interface SPI, and an integrated navigation chip internal RF chip sampling clock. IIC and GPIO interfaces are defined for communication interface expansion, improving the versatility of the navigation module and reducing subsequent design changes. The pin definition of the inter-board connector of the control module adopts a unified standard. In addition to power supply signals, reset signals, and JTAG, a series of communication interfaces and debugging interfaces are provided. The communication interfaces between the control module and the on-board subsystems include CAN, IIC, RS422, and SPI, and support one or more of them. The RF front-end circuit of the navigation module receives single RF signal output by the RF module, sequentially passes through an amplifier, a power splitter, a filter, and a single-ended to differential balun, and outputs three differential RF signals, i.e., 1.5G frequency band, 1.2G frequency band, and 1.1G frequency band. The gain of a single RF link should be controlled within 35-40dB. The control module is composed of a main control CPU, an interface circuit, a power supply, and a storage unit. The control module receives data output by the navigation module through UART, and performs packaging processing according to data agreement. The data packaging is completed by software algorithm.

2. The space-borne GNSS receiver of claim 1, wherein The three differential radio frequency signals are simultaneously input to an integrated navigation chip of the navigation module; the integrated navigation chip completes down-conversion and analog-digital conversion of the three differential radio frequency signals, outputs digital intermediate frequency signals of different frequencies, and completes acquisition, tracking and positioning of multi-mode and multi-frequency GNSS signals on the three digital intermediate frequency signals.

3. The space-borne GNSS receiver of claim 2, wherein, The communication interface between the integrated navigation chip and the control module is UART; the integrated navigation chip also reserves one UART interface as a backup.

4. The space-borne GNSS receiver according to any one of claims 1 to 3, characterized in that, The bottom plate is provided with four SMA connectors, which receive up to four GNSS antenna radio frequency signals and output to the radio frequency module through a micro inter-board connector.

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