Intersatellite data communication system
By employing two phased array antennas and a time-division multiplexing strategy in the inter-satellite communication system, combined with a link adaptive estimation method, and dynamically adjusting the communication rate, the problems of susceptibility to interference and insufficient coverage in inter-satellite communication were solved, and stable and reliable multi-angle communication was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-31
AI Technical Summary
In existing technologies, inter-satellite communication is susceptible to interference from ground-based telemetry and control systems, resulting in poor communication stability and reliability. Furthermore, narrow-beam antennas have insufficient coverage, making it difficult to meet the needs of multi-angle and multi-directional communication, and they cannot adapt to the requirements of different communication distances.
Employing two phased array antennas and a time-division multiplexing strategy, combined with a link adaptive estimation method, the communication rate is dynamically adjusted, making it suitable for inter-satellite data communication in small satellite constellations.
It achieves quasi-omnidirectional communication, improves anti-interference capability and coverage, adapts to the needs of different communication distances, and ensures the stability and reliability of communication.
Smart Images
Figure CN121770588A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an inter-satellite data communication system, belonging to the field of satellite communication technology. Background Technology
[0002] Currently, inter-satellite communication typically employs wide-beam passive antennas in the S-band for interconnection between constellations. To achieve quasi-omnidirectional inter-satellite communication, at least four passive antennas are usually required in an array. However, ground-based telemetry and control systems also use the S-band for communication. When ground-based telemetry and control systems send high-power uplink signals, they can easily interfere with inter-satellite communication constellations passing overhead, leading to transmission failures or data loss, severely impacting communication stability and reliability. To address these issues, the communication frequency of the inter-satellite communication constellation must avoid the S-band used by ground-based telemetry and control. Furthermore, the existing wide-beam communication antennas must be replaced with narrow-beam antennas to improve communication directionality and anti-interference capabilities. In addition, the narrow-beam antenna must have sufficient coverage to meet the multi-angle and multi-directional requirements of inter-satellite communication. Simultaneously, to adapt to diverse operating conditions with inter-satellite communication distances ranging from tens to thousands of kilometers, the system must also support communication modes under both strong and weak signal conditions to ensure communication stability and reliability. Summary of the Invention
[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a satellite inter-satellite data communication system that uses two phased array antennas for communication, adopts a time division multiplexing strategy, and combines a link adaptive estimation method to dynamically adjust the communication rate, which is suitable for small satellites.
[0004] The technical solution of the present invention is: an inter-satellite data communication system, comprising an inter-satellite communication unit, an inter-satellite microwave component, and an inter-satellite phased array antenna; The inter-satellite communication unit includes a protocol processing module, a baseband signal transmission module, a baseband signal receiving module, and a radio frequency transceiver module. The protocol processing module receives inter-satellite data sent by an external satellite service subsystem, encapsulates it into data service frames, and outputs them to the baseband signal transmission module during the data transmission time slot according to time-division multiplexing. Simultaneously, the protocol processing module frames local time data, encapsulates it into synchronization service frames, and outputs them to the baseband signal transmission module during the time synchronization time slot according to time-division multiplexing. The protocol processing module receives data service frames and synchronization service frames sent by the baseband signal receiving module. It also parses the synchronization service frames to obtain time synchronization data, which serves as a time reference. It then parses the data service frames and sends the inter-satellite data to the satellite service subsystem. The baseband signal transmission module receives the synchronization service frames sent by the protocol processing module, performs Reed-Muller code encoding, serial-to-parallel conversion, and spread spectrum processing on the transmission format indicator information, stores it, and then transmits the baseband signal according to the transmission format indicator information. The MAC frames sent by the signal transmission module undergo low-density parity-check encoding, rate matching, serial-to-parallel conversion, and spread spectrum processing, and the data is stored. Additionally, the baseband signal transmission module generates a synchronization header sequence and a training sequence, which are then merged with the spread service data frame and the synchronization service frame to output two data streams. These are modulated to an intermediate frequency (IF) to obtain IF modulated data, which is then sent to the radio frequency transceiver module. The baseband signal receiving module receives the IF data sent by the radio frequency transceiver module, performs AD sampling, down-conversion, signal acquisition, tracking, despreading, demodulation, rate matching, and decoding to obtain data service frames and synchronization service frames, which are then sent to the protocol processing module. The radio frequency transceiver module receives the IF modulated data output by the baseband signal transmission module, up-converts and amplifies it, and outputs two Ka-band radio frequency signals to the inter-satellite microwave component. The inter-satellite communication unit receives command data sent by the satellite service subsystem, performs parsing and control, and simultaneously sends its own telemetry information to the satellite service subsystem. The inter-satellite microwave component receives two Ka-band radio frequency signals sent by the inter-satellite communication unit, and after impedance matching and mixing, outputs them to the inter-satellite phased array antenna respectively. The inter-satellite phased array antenna receives satellite position data, attitude data, and time data sent by the satellite service subsystem, calculates the pointing angle of the phased array antenna, and drives the phased array antenna radio frequency component to radiate the two radio frequency signals sent by the inter-satellite microwave component. The inter-satellite phased array antenna receives command data sent by the satellite service subsystem, performs analysis and control, and simultaneously sends its own telemetry information to the satellite service subsystem.
[0005] Furthermore, the inter-satellite phased array antenna is provided in two sets, and the inter-satellite communication unit includes a primary device and a backup device. Both the primary device and the backup device transmit two radio frequency signals, which are output to the two inter-satellite phased array antennas respectively. The two inter-satellite phased array antennas are in the same state and operate in hot backup mode.
[0006] Furthermore, the inter-satellite communication unit receives OC commands sent by the satellite service subsystem for switching between primary and backup equipment; the inter-satellite communication unit receives primary power from the power supply subsystem for powering the equipment; the inter-satellite communication unit includes primary and backup equipment, and performs cold backup operation; the inter-satellite phased array antenna receives primary power from the power supply subsystem for powering the equipment.
[0007] Furthermore, the inter-satellite communication unit and the inter-satellite phased array antenna communicate in the Ka band, and the communication method adopts time-division multiplexing with the transmission and reception at the same frequency.
[0008] Furthermore, the networking communication mode of the inter-satellite communication unit dynamically supports a number of inter-satellite communication units.
[0009] Furthermore, the number of inter-satellite communication units is not less than 9.
[0010] Furthermore, the inter-satellite phased array antenna receives satellite broadcast time, broadcast position data, and broadcast attitude data, extrapolates them to the real-time position data and real-time attitude data corresponding to the local time, and realizes that the inter-satellite phased array antenna accurately points to the communication target satellite.
[0011] Furthermore, the communication rate between the inter-satellite communication unit and other inter-satellite communication unit nodes within the satellite constellation is dynamically adjusted.
[0012] Furthermore, the inter-satellite communication unit dynamically adjusts the communication rate based on the link estimated energy. When the link carrier-to-noise ratio is between [47~53) dBHz, the communication rate is at level one, 4kbps; when the link carrier-to-noise ratio is between [53~59) dBHz, the communication rate is at level two, 16kbps; and when the link carrier-to-noise ratio is greater than 59dBHz, the communication rate is at level three, 64kbps.
[0013] Furthermore, the protocol processing module receives the second pulse and time data output by the external GNSS receiver, generates time synchronization data, and encapsulates it into a synchronization service frame for maintaining the local time.
[0014] The advantages of this invention compared to the prior art are: (1) The present invention adopts a time division multiplexing strategy to support the dynamic change of the number of communication terminals in the satellite constellation, and uses two phased array antennas for communication to achieve quasi-omnidirectional communication.
[0015] (2) The present invention adopts the link adaptive estimation method to dynamically adjust the satellite communication rate to meet the needs of inter-satellite communication distances from tens of kilometers to 3,000 kilometers. Attached Figure Description
[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram illustrating the principle of the present invention. Detailed Implementation
[0017] To better understand the above technical solutions, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present invention, rather than limitations on the technical solutions of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.
[0018] The following description, in conjunction with the accompanying drawings, provides a more detailed account of an inter-satellite data communication system provided by an embodiment of the present invention. Figure 1 Specific implementation methods may include: inter-satellite communication unit, inter-satellite microwave component and inter-satellite phased array antenna; The inter-satellite communication unit includes a protocol processing module, a baseband signal transmission module, a baseband signal receiving module, and a radio frequency transceiver module. The protocol processing module receives inter-satellite data sent by an external satellite service subsystem, encapsulates it into data service frames, and outputs them to the baseband signal transmission module during the data transmission time slot according to time-division multiplexing. Simultaneously, the protocol processing module frames local time data, encapsulates it into synchronization service frames, and outputs them to the baseband signal transmission module during the time synchronization time slot according to time-division multiplexing. The protocol processing module receives data service frames and synchronization service frames sent by the baseband signal receiving module. It also parses the synchronization service frames to obtain time synchronization data, which serves as a time reference. It then parses the data service frames and sends the inter-satellite data to the satellite service subsystem. The baseband signal transmission module receives the synchronization service frames sent by the protocol processing module, performs Reed-Muller code encoding, serial-to-parallel conversion, and spread spectrum processing on the transmission format indicator information, stores it, and then transmits the baseband signal according to the transmission format indicator information. The MAC frames sent by the signal transmission module undergo low-density parity-check encoding, rate matching, serial-to-parallel conversion, and spread spectrum processing, and the data is stored. Additionally, the baseband signal transmission module generates a synchronization header sequence and a training sequence, which are then merged with the spread service data frame and the synchronization service frame to output two data streams. These are modulated to an intermediate frequency (IF) to obtain IF modulated data, which is then sent to the radio frequency transceiver module. The baseband signal receiving module receives the IF data sent by the radio frequency transceiver module, performs AD sampling, down-conversion, signal acquisition, tracking, despreading, demodulation, rate matching, and decoding to obtain data service frames and synchronization service frames, which are then sent to the protocol processing module. The radio frequency transceiver module receives the IF modulated data output by the baseband signal transmission module, up-converts and amplifies it, and outputs two Ka-band radio frequency signals to the inter-satellite microwave component. The inter-satellite communication unit receives command data sent by the satellite service subsystem, performs parsing and control, and simultaneously sends its own telemetry information to the satellite service subsystem. The inter-satellite microwave component receives two Ka-band radio frequency signals sent by the inter-satellite communication unit, and after impedance matching and mixing, outputs them to the inter-satellite phased array antenna. The inter-satellite phased array antenna receives satellite position data, attitude data, and time data sent by the satellite service subsystem, calculates the pointing angle of the phased array antenna, and drives the phased array antenna radio frequency component to radiate the two radio frequency signals sent by the inter-satellite microwave component. The inter-satellite phased array antenna receives command data sent by the satellite service subsystem, performs analysis and control, and simultaneously sends its own telemetry information to the satellite service subsystem.
[0019] In the solutions provided in the embodiments of the present invention, such as Figure 1As shown, an inter-satellite data communication system includes: an inter-satellite communication unit, an inter-satellite microwave component, a first inter-satellite phased array antenna, and a second inter-satellite phased array antenna. The inter-satellite communication unit includes a protocol processing module, a baseband signal transmission module, a baseband signal reception module, and a radio frequency transceiver module. The protocol processing module receives inter-satellite data transmitted by the satellite service subsystem, encapsulates it into data service frames, and outputs them to the baseband signal transmission module in the data transmission time slot according to time-division multiplexing. Simultaneously, the protocol processing module receives second pulses and time data output from the GNSS receiver, generates time synchronization data, encapsulates it into synchronization service frames, and outputs them to the baseband signal transmission module in the time synchronization time slot according to time-division multiplexing. The protocol processing module receives the data service frames and synchronization service frames transmitted by the baseband signal reception module. Simultaneously, it parses the synchronization service frames to obtain time synchronization data as a time reference; and parses the data service frames to transmit the inter-satellite data to the satellite service subsystem. The baseband signal transmitting module receives the synchronization service frames sent by the protocol processing module, performs RM (Reed-Muller Code) encoding, serial-to-parallel conversion, and spread spectrum processing on the TFI (Transport Format Indicator) information, and stores it. Based on the TFI information, it performs LDPC (Low-Density Parity-Check) encoding, rate matching, serial-to-parallel conversion, and spread spectrum processing on the MAC frames sent by the baseband signal transmitting module, and stores the data. Furthermore, the baseband signal transmitting module generates a synchronization header sequence and a training sequence, merges them with the spread service data frames and synchronization service frames to output I and Q data, modulates them to an intermediate frequency (IF), obtains IF modulated data, and sends it to the radio frequency transceiver module. The baseband signal receiving module receives the IF data sent by the radio frequency transceiver module, performs AD sampling, down-conversion, signal acquisition, tracking, despreading, demodulation, rate matching, and decoding to obtain data service frames and synchronization service frames, and sends them to the protocol processing module. The RF transceiver module receives intermediate frequency modulated data output from the baseband signal transmitting module, up-converts and amplifies it, and outputs two Ka-band RF signals to the inter-satellite microwave component. The inter-satellite communication unit receives command data sent by the satellite service subsystem via the CAN interface, performs parsing and control, and simultaneously sends its own telemetry information to the satellite service subsystem via the CAN interface. The inter-satellite communication unit receives OC commands from the satellite service subsystem for switching between primary and backup equipment. The inter-satellite communication unit receives primary power from the power supply subsystem for equipment power supply. The inter-satellite communication unit includes primary and backup equipment, operating under cold backup conditions.
[0020] The inter-satellite microwave unit receives two Ka-band radio frequency signals transmitted from the primary equipment of the inter-satellite communication unit. After impedance matching and mixing, the first Ka-band radio frequency signal is output to the first inter-satellite phased array antenna, and the second Ka-band radio frequency signal is output to the second inter-satellite phased array antenna. Similarly, the inter-satellite microwave unit receives two Ka-band radio frequency signals transmitted from the backup equipment of the inter-satellite communication unit. After impedance matching and mixing, the first Ka-band radio frequency signal is output to the first inter-satellite phased array antenna, and the second Ka-band radio frequency signal is output to the second inter-satellite phased array antenna.
[0021] The first inter-satellite phased array antenna receives satellite position, attitude, and time data from the satellite service subsystem via a CAN interface. It then calculates the antenna's pointing angle and drives the phased array antenna's RF components to radiate the two RF signals transmitted by the inter-satellite microwave components. The first inter-satellite phased array antenna also receives command data from the satellite service subsystem via the CAN interface, performs analysis and control, and simultaneously transmits its own telemetry information to the satellite service subsystem via the CAN interface. The first inter-satellite phased array antenna receives primary power from the power supply subsystem for equipment power. Similarly, the second inter-satellite phased array antenna operates in the same state as the first, with both antennas performing hot backup.
[0022] Two inter-satellite phased array antennas are provided. The inter-satellite communication unit includes a primary device and a backup device. Both the primary device and the backup device transmit two radio frequency signals, which are output to the two inter-satellite phased array antennas respectively. The two inter-satellite phased array antennas are in the same state and operate in hot backup mode.
[0023] The inter-satellite communication unit receives OC commands from the satellite service subsystem for switching between primary and backup equipment; the inter-satellite communication unit receives primary power from the power supply subsystem for powering the equipment; the inter-satellite communication unit includes primary and backup equipment and performs cold backup operation; the inter-satellite phased array antenna receives primary power from the power supply subsystem for powering the equipment.
[0024] The inter-satellite communication unit and the inter-satellite phased array antenna communicate in the Ka band, and the communication method adopts time-division multiplexing with the same frequency for transmission and reception.
[0025] The networking communication mode of the inter-satellite communication unit can dynamically support 1 to N inter-satellite communication units, where N≥9.
[0026] The inter-satellite phased array antenna receives satellite broadcast time, broadcast position data, and broadcast attitude data, extrapolates them to the real-time position data and real-time attitude data corresponding to the local time, and enables the inter-satellite phased array antenna to accurately point to the communication target satellite.
[0027] The communication rate between the inter-satellite communication unit and other inter-satellite communication unit nodes within the satellite constellation can be dynamically adjusted. The inter-satellite communication unit dynamically adjusts the communication rate based on the estimated link energy. When the link carrier-to-noise ratio (CNR) is between [47~53) dBHz, the communication rate is at level one, 4 kbps; when the CNR is between [53~59) dBHz, the communication rate is at level two, 16 kbps; and when the CNR is greater than 59 dBHz, the communication rate is at level three, 64 kbps.
[0028] The protocol processing module receives the second pulse and time data output from an external GNSS receiver, generates time synchronization data, and encapsulates it into a synchronization service frame for maintaining local time.
[0029] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
[0030] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.
[0031] The contents not described in detail in this specification are common knowledge to those skilled in the art.
Claims
1. A satellite inter-satellite data communication system, characterized by The inter-satellite communication unit comprises an inter-satellite communication unit, an inter-satellite microwave assembly and an inter-satellite phased array antenna. The inter-satellite communication unit comprises a protocol processing module, a baseband signal transmitting module, a baseband signal receiving module and a radio frequency transceiver module; the protocol processing module receives inter-satellite data transmitted by an external satellite service subsystem, encapsulates the data into a data service frame, and outputs the data to the baseband signal transmitting module in a time division multiplexing time slot during a data transmission time slot; simultaneously, the protocol processing module frames local time data, encapsulates the data into a synchronization service frame, and outputs the data to the baseband signal transmitting module in a time synchronization time slot according to the time division multiplexing time slot; the protocol processing module receives data service frames and synchronization service frames transmitted by the baseband signal receiving module, simultaneously analyzes the synchronization service frames to obtain time synchronization data as a time reference, and analyzes the data service frames to transmit the inter-satellite data to the satellite service subsystem; the baseband signal transmitting module receives the synchronization service frames transmitted by the protocol processing module, Reed-Muller code encodes, serial-to-parallel converts, and spread spectrum processes transmission format indicator information, and stores the information; then, according to the transmission format indicator information, the baseband signal transmitting module low-density parity check encodes and rate matches MAC frames transmitted by the baseband signal transmitting module, serial-to-parallel converts, spread spectrum processes, and stores the data; in addition, the baseband signal transmitting module generates a synchronization header sequence and a training sequence, merges the spread spectrum processed service data frames and synchronization service frames, and outputs two-way data, which is modulated to an intermediate frequency to obtain intermediate frequency modulation data, and transmitted to the radio frequency transceiver module; The baseband signal receiving module receives intermediate frequency data transmitted by the radio frequency transceiver module, performs AD sampling, frequency down conversion, signal capture, tracking, despreading, demodulation, de-rate matching and decoding to obtain data service frames and synchronization service frames, and transmits the data service frames and the synchronization service frames to the protocol processing module; the radio frequency transceiver module receives intermediate frequency modulation data output by the baseband signal transmitting module, performs frequency up conversion and amplification, and outputs two-way Ka frequency band radio frequency signals to the inter-satellite microwave assembly; the inter-satellite communication unit receives instruction data transmitted by the satellite service subsystem, analyzes and controls the data, and simultaneously transmits telemetry information of the inter-satellite communication unit to the satellite service subsystem; The inter-satellite microwave assembly receives two-way Ka frequency band radio frequency signals transmitted by the inter-satellite communication unit, performs impedance matching and mixing, and outputs the signals to the inter-satellite phased array antenna; The inter-satellite phased array antenna receives satellite position data, attitude data and time data transmitted by the satellite service subsystem, performs phased array antenna pointing angle calculation, and drives the phased array antenna radio frequency assembly to radiate two-way radio frequency signals transmitted by the inter-satellite microwave assembly; The inter-satellite phased array antenna receives instruction data transmitted by the satellite service subsystem, analyzes and controls the data, and simultaneously transmits telemetry information of the inter-satellite phased array antenna to the satellite service subsystem.
2. A satellite inter-satellite data communication system according to claim 1, characterised in that, The inter-satellite phased array antenna is provided with two sets, the inter-satellite communication unit comprises a main device and a backup device, the main device and the backup device both transmit two-way radio frequency signals, and the two-way radio frequency signals are output to the two sets of inter-satellite phased array antennas respectively; The two sets of inter-satellite phased array antennas are in consistent state and work in hot backup mode.
3. A satellite inter-satellite data communication system according to claim 1, characterised in that, The inter-satellite communication unit receives OC instructions sent by the satellite service subsystem, and is used for switching of the main device and the backup device; the inter-satellite communication unit receives primary power provided by the power subsystem, and is used for device power supply; the inter-satellite communication unit comprises the main device and the backup device, and works in a cold backup mode; the inter-satellite phased array antenna receives primary power provided by the power subsystem, and is used for device power supply.
4. A satellite inter-satellite data communication system according to claim 1, characterised in that, The inter-satellite communication unit and the inter-satellite phased array antenna have a Ka frequency band, and adopt a time division multiplexing mode of the same frequency point for transmission and reception.
5. A satellite inter-satellite data communication system according to claim 1, wherein, The networking communication mode of the inter-satellite communication unit dynamically supports a plurality of inter-satellite communication unit numbers.
6. A satellite inter-satellite data communication system as claimed in claim 5, characterized in that The number of the inter-satellite communication unit is not less than 9.
7. A satellite inter-satellite data communication system according to claim 1, wherein, The inter-satellite phased array antenna receives satellite broadcast time, broadcast position data and broadcast attitude data, extrapolates real-time position data and real-time attitude data corresponding to the local time, and realizes accurate pointing of the inter-satellite phased array antenna to a communication target satellite.
8. A satellite inter-satellite data communication system according to claim 1, wherein, The communication rate between the inter-satellite communication unit and other inter-satellite communication unit nodes in the satellite constellation is dynamically adjusted.
9. A satellite inter-satellite data communication system as claimed in claim 8, characterized in that The inter-satellite communication unit dynamically adjusts the communication rate according to link estimation energy; when the link carrier-to-noise ratio is between [47-53) dBHz, the communication rate is one grade, 4 kbps; when the link carrier-to-noise ratio is between [53-59) dBHz, the communication rate is two grades, 16 kbps; and when the link carrier-to-noise ratio is greater than 59 dBHz, the communication rate is three grades, 64 kbps.
10. A satellite inter-satellite data communication system according to claim 1, wherein, The protocol processing module receives second pulses and time data output by an external GNSS receiver, generates time synchronization data, and encapsulates the time synchronization data into a synchronization service frame, which is used for maintaining local time.