62 results about "Satellite downlink" patented technology

The invention relates to the technical field of low earth orbit satellites, and discloses a method and equipment for improving the signal-to-noise ratio of a low earth orbit satellite signal, and the method comprises the steps: carrying out the multi-dimensional signal collection and processing of a received signal of a low earth orbit satellite downlink, and obtaining a signal tensor model; executing structured decomposition based on the signal tensor model to obtain a channel factor matrix group; performing multi-stage sequential processing according to the channel factor matrix group to obtain low-orbit satellite channel state information; inputting the low-orbit satellite channel state information into an interference identification module for feature extraction and interference type analysis to obtain an interference type and probability distribution thereof; performing multi-dimensional adaptive filtering on the received signal to obtain a target signal; and performing modulation coding and beam forming parameter joint optimization on the target signal and the low-earth-orbit satellite channel state information to obtain a low-earth-orbit satellite communication link, thereby solving the problem of large fluctuation of the signal-to-noise ratio in a satellite rapid moving scene, and realizing balance of power efficiency and anti-interference performance at the same time.

The invention discloses a method for aggregating ocean buoy data, which comprises the following steps of: establishing a space-time correlation model according to the spatial distribution density of buoy clusters and the dynamic characteristics of an ocean environment, and adaptively dividing buoy groups with a data compression cooperative relationship; performing a data-related compression operation within the buoy group; constructing a transmission priority dynamic sorting engine, and calculating a dynamic weight coefficient; performing hierarchical packaging processing on the differential coding data, distributing enhanced forward error correction coding resources for high-priority data, and reserving redundant transmission time slots; the method comprises the following steps: receiving a hierarchical data packet through a low-orbit satellite and executing on-satellite preprocessing, reconstructing an original data stream by using a distributed decoder, and meanwhile, fusing multi-dimensional space-time related data to generate an aggregated data product; and finally, the aggregated data product is transmitted to a ground data center through a satellite downlink. According to the invention, uplink data volume is reduced, disaster monitoring timeliness is improved, ground station processing load is reduced, and system environment adaptability is enhanced.

A satellite adaptive modulation method based on deep reinforcement learning: 1) Perform initialization operations; initialize the state space, action space, and greedy parameter; 2) The signal receiving end on the ground receives the signal from the satellite downlink and extracts the pilot information in the current frame for signal-to-noise ratio (SNR) estimation. After the receiving end calculates the SNR estimation result, it is transmitted to the ground sending end through the ground feedback link; 3) The sending end translates the selected action into the corresponding modulation method and coding rate; 4) Determine whether the current iteration number is an integer multiple of the preset network update step number. If so, go to step 5) for network update; if not, update the SNR state and return to 2) to enter the next round of iteration; 5) Introduce the concept of a dual network and improve the learning effect and accelerate the convergence of the results by optimizing the structure of the neural network. 6) Update the SNR state, increment the greedy parameter, and return to 2) for the next round of iteration.

A method for calibrating a PCO and a hardware delay of a downlink navigation antenna of an LEO satellite Ls includes: calculating, by using a precise orbit determination and timing result and ground calibrations, a ground calibrated phase center orbit initial value of the downlink navigation antenna and a ground calibrated satellite clock bias initial value; calculating, based on the ground calibrated phase center orbit initial value and the ground calibrated satellite clock bias initial value, a correction amount of the downlink navigation antenna by separating or combining GNSS signals and LEO satellite downlink navigation signals; and correcting, based on the correction amount of the downlink navigation antenna, the PCO of the downlink navigation antenna and the hardware delay of the downlink navigation antenna, so as to realize in-orbit calibration of the PCO of the downlink navigation antenna and the hardware delay of the downlink navigation antenna.

The invention provides a low earth orbit satellite signal capturing method based on PMF-FFT. The low earth orbit satellite signal capturing method comprises the steps that firstly, low earth orbit satellite downlink signals are received and frequency mixing is carried out; carrying out adjustable parameter window adding processing on the frequency-mixed signal; inputting the windowed signal into a PMF module, and carrying out correlation calculation on the windowed signal and a local pseudo code to obtain PMF module output; carrying out adjustable parameter window adding processing on the output of each segmented matched filter in the PMF module; performing N-point FFT on the output result of the segmented matched filter; performing normalization processing on the FFT result of the # imgabs0 # point to obtain a normalized amplitude-frequency response; and performing threshold judgment according to the normalized amplitude-frequency response to realize capture. The method not only solves the problems of difficulty in broadband capture, long capture time and poor anti-Doppler effect of the traditional signal capture method, but also solves the problem that the traditional PMF-FFT method cannot break through a preset capture threshold and misses capture due to the fact that the normalized power spectral density at the target Doppler frequency shift is reduced due to energy loss under the condition of low signal-to-noise ratio. Therefore, the low-orbit satellite navigation signal can be quickly captured.

The invention provides a low-orbit navigation enhanced satellite orbit and clock error integrated determination method, which comprises the following steps that: a low-orbit navigation enhanced satellite carries a GNSS (Global Navigation Satellite System) receiver, can receive a multi-system GNSS satellite navigation signal and can issue a navigation enhanced signal at the same time, a downlink signal and a satellite-borne GNSS receiver clock share the same source, and a deviation exists between the clock error and the clock error of the satellite-borne receiver; the satellite-borne observation data of the low-orbit satellite, the GNSS of the ground station and the observation data of the low-orbit satellite are fused, an observation model for fusion processing is given, and the orbit of the low-orbit navigation enhanced satellite, the receiver clock error and the downlink signal time delay deviation are integrally determined. Unified adjustment and parameter joint calculation of satellite-borne and downlink observation values of the low earth orbit satellite are realized.

The invention discloses a multi-mode joint information source channel coding system for satellite-ground semantic communication. The multi-mode joint information source channel coding system comprises a joint information source channel coder and a decoder, the encoder is used for sequentially performing feature extraction, feature fusion, data cutting and phase modulation operation on input multi-modal data to generate a transmitting signal, and transmitting the transmitting signal to a ground base station through a channel; and the decoder is used for sequentially performing real and virtual part separation, data expansion, feature extraction and modal data recovery operation on the received signal so as to reconstruct multi-modal data. According to the system, public semantic information among multi-modal data can be mined, the time-varying low-signal-to-noise-ratio channel characteristics of a satellite downlink are combined, the information bottleneck theory highly related to data reconstruction quality is used as guidance to optimize a coding space, complex field transmission signals with the high compression ratio are generated in a self-adaptive mode, and the multi-modal multi-domain transmission signals are obtained. The reconstruction quality of the multi-modal data can be ensured, and the bandwidth and the energy consumption overhead of satellite communication can be remarkably reduced.

The invention belongs to the technical field of low earth orbit satellite communication, and particularly relates to a low earth orbit satellite large-scale hopping beam efficient scheduling method and system based on an interference approximation model. According to the method, downlink beam resources of a multi-beam low-orbit satellite are used as research objects, and the problems that in existing large-scale and long-period beam scheduling, the performance evaluation complexity of a beam scheduling strategy is high, and the complexity of a beam scheduling algorithm is rapidly increased along with the increase of variable dimensions are solved. The invention provides low-complexity design and application based on an inter-beam interference approximation model, the inter-beam interference approximation model is introduced from a probability perspective, a rapid performance evaluation method is designed, and a low-complexity scheduling method is designed for two typical low-orbit satellite beam scheduling problems by utilizing an introduced beam activation intensity concept.

The invention discloses a Starlink satellite downlink signal timing synchronization method based on deep learning, and the method comprises the steps: firstly carrying out the segmentation cross-correlation preprocessing of a received signal, and generating a two-dimensional real number feature map with significant spectral line features; then, an improved SS-YOLOv9 network model is constructed and trained, according to the model, in a YOLOv9 infrastructure, a lightweight SimAM saliency attention module is embedded into a backbone network to enhance feature separability, an FAF adaptive feature fusion module is introduced into a path aggregation structure of a neck network to optimize multi-scale feature fusion, and the feature fusion is optimized; precise positioning is realized by adopting a decoupling detection head and a coordinate attention mechanism; and finally decoding bounding box coordinates output by the network into timing synchronization points in original signals. According to the method, the problem that the performance of a traditional method is sharply deteriorated in a severe channel environment is effectively solved, and the method has high precision, high robustness and excellent environmental adaptability.

The present invention belongs to the field of satellite communication technology, and specifically relates to a low-orbit satellite communication system energy efficiency optimization method based on imperfect CSI. The method comprises: establishing a multi-user multi-beam low-orbit satellite downlink transmission system; constructing a maximization minimum system user energy efficiency optimization model based on the multi-user multi-beam low-orbit satellite downlink transmission system; constructing a Gaussian channel uncertainty model according to the imperfect CSI; constructing a robust resource allocation model based on maximization minimum system user energy efficiency according to the maximization minimum system user energy efficiency optimization model and the Gaussian channel uncertainty model; solving the robust resource allocation model to obtain a robust resource allocation scheme; and the system performing resource allocation according to the robust resource allocation scheme to obtain optimal system energy efficiency. The present invention improves the energy efficiency and robustness of users of the low-orbit satellite communication system and reduces the interruption probability of system users.

The application provides a satellite-under device random access method, a satellite, a terminal device and an electronic device. The method comprises the following steps: the satellite respectively sends a power allocation range to at least one terminal device; the terminal device receives the power allocation range sent by the satellite; a check value is determined according to any uplink transmission power in the power allocation range and a current access frequency initiated by the terminal device; the check value is sent to the satellite; the satellite receives the check value respectively sent by at least one terminal device; a device access table is determined according to at least one check value; the device access table is respectively sent to at least one terminal device; the terminal device receives the device access table sent by the satellite; whether the terminal device accesses the satellite is determined according to the device access table. The method can effectively prevent a malicious terminal from forging a legal identity to initiate a random access with multiple frequencies, improve the access rate of a legal terminal, and improve the security performance of satellite-under device random access.

The invention provides a high-mobility platform random access method and system for a low-orbit satellite data chain, and the method comprises the steps: taking a satellite ephemeris and platform navigation information as initial guidance, receiving and analyzing a satellite downlink signal, and carrying out the joint estimation to obtain a space-time frequency parameter; based on the estimated timestamp as a time reference of a frequency hopping pattern, driving a local frequency hopping sequence generator, predicting and verifying the current frequency hopping pattern, and performing frequency offset correction according to the estimated Doppler frequency offset; and in response to successful verification of the frequency hopping pattern, constructing a pre-compensated uplink and starting a frequency hopping pattern tracking loop for fine tuning of the time-space-frequency parameter and the frequency hopping pattern phase, so that the user accesses the low-orbit satellite data link at random and enters steady-state communication. The time-space-frequency alignment problem and the time-varying frequency hopping pattern capturing and tracking problem are synchronously solved, and rapid, reliable and anti-interference random access of the high-mobility platform is achieved.

The invention discloses a monopulse phase comparison tracking signal processing method based on a digital beacon receiver, and relates to the technical field of radio orientation, and the method comprises the steps: carrying out the antenna pointing deviation analysis of a shipborne communication-in-motion antenna according to the predicted ship attitude information in a preset time window, and obtaining a predicted pointing deviation angle sequence; carrying out feature extraction to obtain a directional deviation trend feature, and determining the resolving complexity of four paths of radio frequency signals of the shipborne communication-in-motion antenna; dynamically configuring the phase comparison algorithm processing precision, the filtering processing mode and the signal compensation mechanism of the digital beacon receiver, and generating an adaptive signal resolving process; and according to an adaptive signal resolving process, resolving the continuous wave satellite downlink beacon signal in the preset time window through a digital beacon receiver to obtain a monopulse phase comparison tracking signal, and regulating and controlling the orientation and pitching of the shipborne communication-in-motion antenna in real time. According to the invention, the technical problem of poor radio orientation effect in the prior art is solved.

The invention discloses a hidden measurement and control device and method based on distributed cooperative beam forming, and belongs to the technical field of satellite hidden measurement and control, and the device comprises a demodulation receiving unit of a measurement and control terminal, a measurement and control service function unit, an inter-satellite link unit, a modulation transmitting unit, a decision scheduling unit, a service flow selection unit and a parameter design unit. According to the method, the inherent advantages of the distributed satellite array are utilized for cooperation, the beam forming technology is utilized from the airspace angle to achieve radiation capability enhancement in the legal measurement and control station direction, energy blanking is achieved in the enemy reconnaissance system direction, artificial noise is introduced into a beam forming vector, the concealment performance of the system is further enhanced, and the system performance is improved. The threat that a satellite downlink measurement and control system is easily interfered and intercepted is solved, and the safety of a measurement and control link is ensured.

The application provides a satellite navigation signal abnormal reason analysis method, establishes a satellite signal transmission channel combination distortion model, generates an ideal signal, and constitutes a combination distortion distortion model library; collects measured satellite downlink signal data to obtain a measured signal quality evaluation result, compares and analyzes the measured signal quality evaluation result with a set evaluation index, finds out a group of the most matched evaluation result data and pre-stored data in the distortion model library; and according to the best matching relationship between the measured satellite signal evaluation result and the distortion model library data, obtains the corresponding satellite signal transmission channel distortion condition. The application can efficiently and credibly give an abnormal signal specific reason analysis result, helps a navigation system to quickly lock the signal abnormal reason, and provides valuable reference and important support for channel distortion compensation and stable operation of the system.

The application discloses a low-orbit satellite navigation enhancement and ground CORS cooperative system and relates to the technical field of satellite navigation positioning, which comprises a space segment, a ground segment and a user segment; the space segment comprises a low-orbit satellite and is used for broadcasting navigation enhancement signals; the ground segment comprises an enhanced CORS network and a star-ground cooperative control center; each ground reference station simultaneously receives GNSS signals and navigation enhancement signals and generates observation data; the star-ground cooperative control center performs precise orbit determination based on low-orbit satellite downlink data and observation data, and uploads star-ground calculation results to the low-orbit satellite to update the generation parameters of the navigation enhancement signals; the user segment comprises a hybrid enhancement receiver, which is used for receiving GNSS signals, navigation enhancement signals and differential data and performing multi-source fusion positioning calculation. The application can improve the low-orbit satellite orbit determination precision, shorten the user initialization time, expand the service coverage, reduce the system construction cost and enhance the integrity guarantee capability.

Embodiments of the present disclosure are directed to systems and methods for enhanced multi-satellite downlink connectivity. Each of two or more extraterrestrial base stations communicate data in a downlink to a single user equipment (UE). Encoding each downlink with a different and orthogonal code permits the re-use of at least partially overlapping frequency resources without intra-channel interference. The separated data streams can be used either to provide additional redundancy when the same data is communicated on each stream or to increase throughput when at least partially different data is communicated on each stream.

A computing system includes a processor configured to receive packet preamble binary data and packet header binary data associated with a satellite. The processor may generate an analog signal encoding the packet preamble binary data and the packet header binary data. The processor may receive a satellite downlink signal. Within each of a plurality of sampling intervals of the satellite downlink signal, the processor may calculate a respective association between the satellite downlink signal and at least a portion of the analog signal. The processor may select an identified sampling interval of the plurality of sampling intervals based at least in part on the plurality of associations. The processor may decode the binary satellite signal data based at least in part on the identified samples of the satellite downlink signal. The processor may output the binary satellite signal data.

The application provides a navigation satellite on-orbit operation main and backup clock frequency drift rate optimal transfer method, comprising: combining satellite-ground two-way ranging observation data, using satellite-ground two-way comparison method to calculate a plurality of main clock difference parameters; through on-orbit navigation satellite downlink engineering telemetry data, obtaining the clock difference parameters of the hot backup clock relative to the main clock; calculating a plurality of hot backup clock difference parameters; in the main and backup clock following state, the phase and frequency of the hot backup clock are equal to the phase and frequency of the main clock and change synchronously with time; after the on-orbit navigation satellite is stably operated, the frequency drift rate of the satellite clock difference data is a constant, the hot backup clock difference parameters are uploaded to the on-orbit navigation satellite storage; when the on-orbit navigation satellite autonomously monitors that the main clock and the hot backup clock are switched, the stored hot backup clock difference parameters are directly and autonomously called to replace the main clock difference parameters as the satellite clock difference data, the satellite clock difference data after switching is compensated, and the frequency drift rate of the satellite clock difference data is corrected.

The application discloses a satellite downlink wireless transmission method, device and equipment and a storage medium, and belongs to the technical field of wireless communication. The method comprises the following steps: acquiring target statistical channel state information between a satellite and a user terminal; determining a target problem by using the target statistical channel state information, wherein the target problem is to maximize the ergodic achievable rate of the user terminal under the constraints of satellite transmission power and unmanned aerial vehicle relay power; updating a transmission covariance matrix and a relay amplification matrix by using an alternating optimization algorithm on the basis of the target problem, so as to obtain an optimized transmission covariance matrix and an optimized relay amplification matrix; and transmitting a signal to the user terminal through the unmanned aerial vehicle relay based on the optimized transmission covariance matrix and the optimized relay amplification matrix. The technical scheme provided by the application can realize downlink wireless transmission in an unmanned aerial vehicle assisted satellite communication system by using statistical channel state information.

This invention relates to the field of satellite navigation system technology and proposes a method for monitoring the integrity of a satellite navigation system. The method involves the satellite navigation system performing the following actions: receiving bidirectional measurement data from an inter-satellite link and correcting errors; using predicted orbit and predicted clock bias parameters to reduce the bidirectional observation data of the inter-satellite link to determine a first inter-satellite geometric distance and a first relative clock bias; calculating a second inter-satellite geometric distance and a second relative clock bias based on satellite navigation messages; subtracting the second inter-satellite geometric distance and the second relative clock bias from the first inter-satellite geometric distance and the first relative clock bias, respectively, to determine geometric distance residuals and relative clock bias residuals; receiving pseudorange data and phase data of the satellite downlink navigation signal from a ground monitoring station and correcting errors; using satellite navigation messages to calculate the equivalent distance error of the navigation satellite; and determining the integrity status of the satellite payload based on the geometric distance residuals, relative clock bias residuals, and the equivalent distance error of the navigation satellite.

A base station including an electronic processor configured to: receive a first signal from a primary satellite, the first signal including a plurality of raw signals from a first user equipment camped on a downlink of the primary satellite; receive a second signal from a diversity satellite, the second signal including at least one of the plurality of raw signals from the first user equipment; store, in a signal sample memory, a copy of the first signal and a copy of the second signal; estimate a bipolar delay for the user equipment; synchronize the copy of the first signal and the copy of the second signal by applying the bipolar delay to the copy of the second signal; and combine the synchronized copies of the first and second signals to generate a plurality of synchronized raw signals for the first user equipment.

The invention relates to a high-efficiency high-capacity space-based Internet of Things access method, which comprises the following steps of: firstly, assisting a user terminal to perceive a link state by using an on-satellite demodulator, and then dynamically broadcasting the working state of an uplink demodulator through a satellite downlink modulator, so that the link throughput rate of uplink random access is improved. According to the invention, the global terminal position management characteristic of the service operation center of the constellation system is utilized to form the dynamic terminal random sending probability parameter under the coverage of the satellite beam, and the dynamic terminal random sending probability parameter is broadcasted to the user terminal in real time through the satellite, so that the data sending probability parameter of the terminal is dynamically changed, and the throughput rate of user link random access is optimized from the system level.

The invention relates to the technical field of wireless communication, and discloses a single-antenna terminal time-varying arrival angle prediction method based on equivalent and prior information, which comprises the following steps: establishing a motion model of a satellite relative to a terminal, and determining model parameters to be estimated; on the basis of displacement equivalence, signals sent by a satellite at different moments and different positions and received by a fixed single-antenna terminal are equivalent to signals sent by the satellite at the same moment and received by a virtual array antenna terminal, and a single-antenna equivalent array manifold matrix is constructed; according to the constructed equivalent array popular matrix, processing a received signal by using a MUSIC algorithm to obtain signal arrival angle information; performing model fitting on the estimation results of the plurality of different moments and an undetermined satellite motion model through a least square fitting algorithm to obtain a final satellite motion model, and retaining or updating the arrival angle prediction model to obtain a new prediction model of a satellite service period; according to the method, the arrival angle estimation capability of the single-antenna Internet of Things terminal on the high-dynamic satellite downlink signal is improved.

The invention provides a satellite downlink hidden transmission method based on an MIMO (Multiple Input Multiple Output) technology. According to the method, satellite hidden transmission in a mobile scene is supported, the processing complexity of a multi-layer weighted fractional order Fourier transform modulation signal method is reduced, and the real-time performance of synchronous distribution is improved; according to the scheme of the invention, a satellite counts state information by using a slowly varying channel between the satellite and a ground station, dynamically calculates a hidden processing matrix according to a minimum mean square error criterion, and pre-processes to-be-transmitted data in real time, so that the anti-interception and anti-cracking capability of downlink transmission data is improved; a hidden processing matrix is introduced into a satellite transmitting end, mass data are mapped to multiple antennas in parallel to be transmitted out at the same time after space-time hidden processing, and the transmission rate of a system and the anti-interception capability of the data are improved by utilizing spatial multiplexing gain provided by an MIMO technology under the condition that the frequency is the same and the transmitting power is not increased.

A non-terrestrial radio network node may determine a count, or a number, of user equipment being served by, or that are connected to, the node via at least one non-terrestrial beam. The node may analyze the count, or number, with respect to at least one power increase criterion or at least one power decrease criterion. With respect to a baseline / default power allocation, the node may increase or decrease transmission power allocated to a particular non-terrestrial beam if the beam is determined to serve a number of user equipment that exceeds a configured power increase criterion or that is less than a configured power decrease criterion, respectively. The node may increase or decrease transmission power allocated to a non-terrestrial beam according to a configured power change step value. Based on counts of user equipment served by different beams, the node may determine to allocate different transmission power amounts to different beams.

The application relates to a kind of on-orbit calibration methods of low-orbit communication satellite downlink phased array antenna based on CDM, belonging to the field of satellite testing technology.The method takes the pointing measurement and calibration of low-orbit communication satellite downlink phased array antenna as input, and realizes the measurement and calibration of the beam pointing of the downlink phased array antenna through the test and data processing of multiple beams EIRP of the downlink phased array antenna.The method has the functions of calibration signal generation, beam EIRP test, beam three-dimensional directional diagram reconstruction, pointing deviation measurement and beam pointing adjustment.Simulation experiments show that the calibration method designed by the application can effectively reduce the beam pointing deviation of low-orbit communication satellite downlink phased array antenna.

The present invention proposes a method for capturing low-earth orbit satellite signals based on PMF-FFT. First, the downlink signals of low-earth orbit satellites are received and mixed; the mixed signals are processed with an adjustable parameter window; the windowed signals are input into the PMF module to calculate the correlation with the local pseudo-code to obtain the output of the PMF module; each segmented matched filter output in the PMF module is processed with an adjustable parameter window; an N-point FFT is performed on the output results of the segmented matched filters; the N-point FFT results are normalized to obtain the normalized amplitude-frequency response; threshold judgment is performed based on the normalized amplitude-frequency response to achieve capture. The present invention not only solves the problems existing in traditional signal capture methods, such as difficult capture of wide frequency bands, long capture time, and poor anti-Doppler effect, but also overcomes the problem that in the case of low signal-to-noise ratio, the normalized power spectral density at the target Doppler frequency shift decreases due to energy loss in the traditional PMF-FFT method, and it is impossible to break through the preset capture threshold and cause missed capture, realizing the rapid capture of low-earth orbit satellite navigation signals.

The invention discloses a communication and navigation integrated implementation system and method of a low earth orbit satellite Internet of Things system. The system comprises a low earth orbit satellite module, a ground terminal receiving module, a positioning and parameter calculation module, an access control and compensation module and an uplink communication link establishment module. A positioning measurement signal is introduced into a satellite downlink NB-IoT (Narrow Band Internet of Things) or eMTC (Enhanced Machine Type Communication) signal, so that a ground terminal can simultaneously complete positioning data acquisition, optimal satellite selection and time and frequency compensation of an uplink signal, thereby effectively solving the problems of low access efficiency and difficulty in synchronization and compensation in the prior art. According to the invention, deep fusion of communication and navigation is realized, the access speed and reliability of the low-orbit satellite Internet of Things system are improved, and the method has good application prospect and popularization value.