CN-122026999-A - Satellite internet of things intelligent access device based on orbit prediction and multi-satellite cooperation

CN122026999ACN 122026999 ACN122026999 ACN 122026999ACN-122026999-A

Abstract

The invention discloses an intelligent access device of a satellite Internet of things based on orbit prediction and multi-satellite cooperation, which belongs to the field of low orbit satellite Internet of things communication and comprises a main control and calculation unit, a multi-satellite access and radio frequency unit, an ephemeris storage and orbit prediction unit, a positioning and time service unit and a data buffering and service adaptation unit. The multi-satellite access and radio frequency unit integrates at least two independent radio frequency front-end channels to support parallel processing of a plurality of satellite signals, and the ephemeris storage and orbit prediction unit is used for calculating accurate orbit parameters of future visible satellites. The device is characterized in that a main control and calculation unit can actively generate an access and switching plan according to a track prediction result and service requirements, and control a plurality of radio frequency channels to cooperatively work in a main-standby or load balancing mode. The method and the system fundamentally solve the problem of unstable connection of the low-orbit satellite Internet of things terminal caused by high-speed movement of the satellite, and remarkably improve communication continuity, reliability and system efficiency.

Inventors

LV QIANG
LIANG JUNMIN
TANG YAO
SONG BO
SONG PENGPENG
LIU JINQUAN
FENG SHIGANG

Assignees

北京国电高科科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260310

Claims (10)

1. Satellite internet of things intelligent access device based on orbit prediction and multi-satellite cooperation is characterized by comprising: The main control and calculation unit is used for executing central control and decision; The ephemeris storage and orbit prediction unit is used for predicting orbit parameters and visible time windows of future visible satellites based on real-time position and time information of the device and stored satellite orbit data; The positioning and timing unit is used for providing real-time self geographic position information and a high-precision time reference; the data buffering and service adapting unit is used for buffering, classifying and marking priority of the data to be transmitted; the multi-satellite access and radio frequency unit comprises at least two independent radio frequency front-end channels and is used for establishing and maintaining physical layer connection with a plurality of satellites; The main control and calculation unit generates a predictive satellite access and switching plan based on the prediction data from the ephemeris storage and orbit prediction unit, the space-time information of the positioning and time service unit, the service data information of the data buffering and service adapting unit and the real-time link state of the multi-satellite access and radio frequency unit; and controlling the multi-star access and radio frequency unit to execute multi-star cooperative access operation or seamless switching operation based on prediction according to the access and switching plan.
2. The apparatus of claim 1, wherein the ephemeris storage and orbit prediction unit is configured to: receiving device longitude, latitude and altitude coordinates and coordinated world time from the positioning and time service unit, and acquiring a stored satellite orbit number; Based on the device position, time and orbit number, an orbit model is run to calculate and output an elevation sequence, an azimuth sequence, a range rate sequence and a visible time window for each visible satellite over a period of time in the future.
3. The apparatus of claim 2, wherein the ephemeris storage and orbit prediction unit is further configured to: And calculating a corresponding Doppler frequency shift estimated value sequence according to the calculated distance change rate sequence, the preset carrier frequency and the light speed.
4. The apparatus of claim 1, wherein each set of independent radio frequency front end channels in the multi-star access and radio frequency unit comprises: the receiving link is used for receiving satellite signals and at least comprises a low noise amplifier, a down converter and an analog-to-digital converter which are connected in sequence, and the local oscillation frequency of the down converter is controlled by the main control and calculation unit; A transmit chain for transmitting signals to satellites includes at least a digital-to-analog converter, an up-converter, and a power amplifier.
5. The apparatus of claim 1, wherein the master and computing unit is configured to, prior to performing satellite access or handoff: based on the ephemeris storage and Doppler frequency shift estimated value of the target satellite at the access time provided by the orbit prediction unit, controlling the target radio frequency front-end channel to execute two-stage frequency precompensation, wherein the operations comprise: the first stage, the frequency coarse adjustment is carried out in the analog domain by adjusting the local oscillation frequencies of a down converter and an up converter in the target radio frequency front-end channel; And the second stage, which performs frequency fine tuning in the digital domain by configuring the phase increment of a digitally controlled oscillator of a corresponding channel in the digital signal processor.
6. The apparatus of claim 1, wherein the multi-star cooperative access operation performed by the master and computing unit control comprises two modes: A main and standby mode, wherein one radio frequency front end channel is controlled to be used as a main service channel to be connected with one satellite, and at least one other radio frequency front end channel is controlled to be used as a standby channel to be kept synchronous with the other satellite and maintained in a link, and the service is switched to the standby channel when the quality of the main channel is deteriorated; and in a load balancing mode, controlling a plurality of radio frequency front-end channels to be simultaneously accessed into different visible satellites, and dividing a data stream to be transmitted into substreams to be transmitted in parallel through the channels.
7. The apparatus of claim 1, wherein the predictive based seamless handover operation performed by the master and computing unit control comprises: Starting an idle radio frequency front-end channel to pre-synchronize with a target satellite at a preset time before the end time of a current service satellite visible window determined based on prediction; In the presynchronization process, doppler frequency shift precompensation is carried out on the signals of the target satellite; At a switching point where the connection of the current service satellite is terminated or determined according to the link quality, migrating the service data stream from the radio frequency front-end channel serving the current satellite to the radio frequency front-end channel serving the target satellite after the presynchronization is completed; and after the migration is completed, releasing the connection with the original current service satellite and related resources.
8. The apparatus of claim 1, wherein the master and computing unit is configured to generate the access and handover plan by executing a decision algorithm comprising: inputting visible satellite parameters, current link state and service information to be transmitted; Scoring each candidate satellite based on a weighted scoring function, wherein the function comprehensively considers elevation angle, residual visible time, doppler frequency shift and predicted signal-to-noise factors; And selecting a target satellite according to the grading result, and generating a control instruction set containing the identification, the presynchronization starting time and the required Doppler precompensation value.
9. The apparatus of claim 1, wherein the positioning and timing unit comprises: A multimode satellite positioning receiver for acquiring a geographic location of the device; the high-stability clock source is used for providing a high-stability clock signal to serve as a unified clock reference of the whole device radio frequency system and the digital sampling system.
10. The apparatus of claim 1, wherein the multi-star access and radio frequency unit further comprises a multi-channel digital signal processor for performing parallel digital down-conversion, synchronization and demodulation operations on digital intermediate frequency signals from the at least two sets of radio frequency front-end channels.

Description

Satellite internet of things intelligent access device based on orbit prediction and multi-satellite cooperation Technical Field The invention belongs to the field of low orbit satellite Internet of things communication, and particularly relates to an intelligent access device of a satellite Internet of things based on orbit prediction and multi-satellite cooperation. Background With the intensive deployment of low orbit satellite constellations, the satellite Internet of things has great potential in realizing wide-area and real-time data acquisition and transmission, and greatly expands the coverage of a ground cellular network. However, the high speed mobility of low orbit satellites relative to ground terminals presents a fundamental challenge for the continuity and stability of the communication connection. The traditional technical architecture of the ground Internet of things terminal is difficult to directly adapt to the dynamic space-sky network environment. At present, the terminal device of the Internet of things facing the low-orbit satellite mostly adopts a simplified single-channel design and a passive response strategy, and has the key technical defects that firstly, the terminal normally passively searches and switches to the next satellite after the current satellite signal is deteriorated or lost, and the communication interruption time is long due to the 'break-before-make' mode, so that the service requirement on high continuity requirement cannot be met. And secondly, the terminal is usually connected with a single star with the strongest signal, and cannot cooperatively utilize a plurality of satellite resources visible at the same moment, so that uneven network load is caused, and reliability cannot be improved through link redundancy. Moreover, the terminal lacks the capability of predicting satellite orbits, can not plan switching time in advance, and can not predict and compensate the obvious Doppler frequency shift caused by high-speed satellite motion, so that the initial access and switching synchronization process is slow, and the overall transmission efficiency is low. Disclosure of Invention In order to solve the technical problems, the invention provides an intelligent access device of a satellite Internet of things based on orbit prediction and multi-satellite cooperation, which comprises: The main control and calculation unit is used for executing central control and decision; The ephemeris storage and orbit prediction unit is used for predicting orbit parameters and visible time windows of future visible satellites based on real-time position and time information of the device and stored satellite orbit data; The positioning and timing unit is used for providing real-time self geographic position information and a high-precision time reference; the data buffering and service adapting unit is used for buffering, classifying and marking priority of the data to be transmitted; the multi-satellite access and radio frequency unit comprises at least two independent radio frequency front-end channels and is used for establishing and maintaining physical layer connection with a plurality of satellites; The main control and calculation unit generates a predictive satellite access and switching plan based on the prediction data from the ephemeris storage and orbit prediction unit, the space-time information of the positioning and time service unit, the service data information of the data buffering and service adapting unit and the real-time link state of the multi-satellite access and radio frequency unit; and controlling the multi-star access and radio frequency unit to execute multi-star cooperative access operation or seamless switching operation based on prediction according to the access and switching plan. Optionally, the ephemeris storage and orbit prediction unit is configured to: receiving device longitude, latitude and altitude coordinates and coordinated world time from the positioning and time service unit, and acquiring a stored satellite orbit number; Based on the device position, time and orbit number, an orbit model is run to calculate and output an elevation sequence, an azimuth sequence, a range rate sequence and a visible time window for each visible satellite over a period of time in the future. Optionally, the ephemeris storage and orbit prediction unit is further configured to: And calculating a corresponding Doppler frequency shift estimated value sequence according to the calculated distance change rate sequence, the preset carrier frequency and the light speed. Optionally, each set of independent radio frequency front end channels in the multi-star access and radio frequency unit includes: the receiving link is used for receiving satellite signals and at least comprises a low noise amplifier, a down converter and an analog-to-digital converter which are connected in sequence, and the local oscillation frequency of the down converter is controlled by the ma