8 results about "Satellite transmitter" patented technology

In a non-geostationary orbit (NGSO) satellite mobile communication system, a communication device receives a synchronization signal block (SSB), which is subjected to partial pre-compensation, from an NGSO satellite transmitter through a downlink (DL) beam, and then transmits the received synchronization signal block (SSB) to the NGSO satellite transmitter through the downlink (DL) beam. And realizing cell synchronization with the NGSO satellite transmitter by using the SSB subjected to partial pre-compensation. A center frequency of a primary synchronization signal and a center frequency of a secondary synchronization signal within the partially pre-compensated SSB are pre-offset by the NGSO satellite transmitter by an integer number of subcarriers relative to a center frequency of the partially pre-compensated SSB to achieve a correlation with movement of the NGSO satellite transmitter relative to the coverage on the earth of the DL beam According to the method, partial pre-compensation of Doppler shift (DS) is carried out. Even if Doppler frequency offset is large due to high mobility of an NGSO satellite, cell synchronization can be simplified.

This invention discloses a method for establishing satellite-to-ground QKD links in a low-Earth orbit quantum satellite network, belonging to the field of quantum communication technology. The invention includes: maintaining satellite-to-ground QKD links established in the previous time window with a real-time key generation rate higher than a threshold within the current time window; screening candidate satellite-to-ground QKD links based on visibility information, achievable key generation rate, and the number of idle QKD transceivers; determining and establishing the optimal satellite-to-ground QKD link based on a comparison of the number of idle quantum satellite transmitters with the number of candidate links, combined with the number of quantum satellites visible to each ground station within the current time window and the achievable key quantity of each candidate satellite-to-ground QKD link. This invention, by comprehensively considering link quality, equipment resource constraints, the number of quantum satellites visible to each ground station, and the achievable key quantity of each link, achieves dynamic and intelligent establishment of satellite-to-ground QKD links, effectively improving key production efficiency and key distribution balance, while reducing system overhead caused by frequent link switching.

The application relates to a pseudo-satellite ephemeris parameter design method based on Kalman filtering. The method comprises the following steps: a pseudo-satellite transmitter acquires a real-time position of the pseudo-satellite, a pre-set cruise standard route, and a standard cruise speed and a standard position of the pseudo-satellite on the cruise standard route, calculates a difference value between the real-time position at a signal transmission moment and the standard position, obtains a first difference value, performs Kalman filtering on the first difference value, fits to obtain ephemeris parameters, and broadcasts the ephemeris parameters to a user receiver through a pseudo-satellite signal; the user receiver receives the pseudo-satellite signal, obtains Kalman gain according to a maneuvering frequency of a pseudo-satellite motion model, obtains a second difference value according to the Kalman gain and the first difference value, and obtains a predicted position of the pseudo-satellite at a signal receiving moment according to the second difference value, the standard position and the standard cruise speed. The method can accurately represent the real-time position of the pseudo-satellite in the case that there is a difference between the real-time position of the pseudo-satellite and the standard cruise route.

The present invention discloses a two-way radio, typically a marine VHF radio, integrating a satellite distress alert transmitter, sharing much of the radio hardware with the satellite transmitter, while enabling good functionality of both, for search and rescue of people in distress.

The present disclosure relates to a satellite deployer (100) made of a high performance polymer (HPP), said deployer (100) comprising an outer structure (102), a lid (104), and at least one access panel (106), wherein at least one satellite (108) is configured within the outer structure (102), said at least one satellite (108) being operatively coupled with an ejector plate (110) to enable said at least one satellite (108) to be launched from said deployer (100). The satellite deployer of the present disclosure has lighter weight, cost effective and a long shelf life.

The application relates to a pseudo-satellite ephemeris parameter design method based on a motion model. The method comprises the following steps: a pseudo-satellite transmitter acquires real-time position, real-time cruise speed, real-time cruise acceleration, a cruise standard route, a standard cruise speed and a standard position of the pseudo-satellite on the cruise standard route, calculates a difference value between the real-time position at a signal transmission moment and the standard position, obtains a first difference value, fits ephemeris parameters according to a history speed and acceleration of the pseudo-satellite in real-time cruise before the signal transmission moment, and broadcasts the ephemeris parameters to a user receiver through a pseudo-satellite signal; the user receiver receives the pseudo-satellite signal, obtains a second difference value according to the first difference value, a difference speed and a difference acceleration; and a predicted position of the pseudo-satellite at a signal receiving moment is obtained according to the second difference value, the standard position and the standard cruise speed. The method can calculate the position of the pseudo-satellite while fully considering the motion of the pseudo-satellite.

This application relates to the field of satellite optical communication and remote sensing data transmission technology, and discloses a satellite non-domain remote sensing data backhaul method based on single-photon detection. This method generates a two-dimensional spatially encoded signal light field and an orthogonally polarized point-source reference pilot light field based on binary data at the satellite transmitter. These two fields are spatiotemporally combined and transmitted to a scattering channel. At the ground receiver, the light field is separated according to polarization state, and photons are collected using a single-photon array. An asymmetric time window is set based on the time statistics of the reference light field to filter the photon-generated signal and the reference speckle image. The channel point spread function is estimated using the reference speckle, and a deconvolution operation is performed on the signal speckle in the frequency domain to reconstruct the spatial pattern. The data is then demodulated by correlation matching with a standard basis pattern. This invention effectively suppresses diffuse noise and eliminates channel ambiguity through orthogonal pilot co-path transmission and time-domain gating, achieving highly robust data backhaul under strong scattering environments.

The application discloses a large-scale constellation network low-overhead space vector segmentation routing method, and mainly solves the problems of high routing overhead and reduced network performance in the prior art, and the scheme is as follows: inter-satellite and cross-layer links of different constellations are respectively established; the earth surface is divided into regions, and the satellite constellations are grouped according to the regions; in the same group, a medium-orbit satellite is taken as a controller of a low-orbit satellite, and is responsible for routing control and management of the low-orbit satellite; the low-orbit satellite checks the inter-satellite link with a neighbor satellite and the queue length of the inter-satellite transmitter of the low-orbit satellite; the medium-orbit satellite receives the link fault feedback information and the queue information report of the low-orbit satellite in the management range of the medium-orbit satellite, obtains regional topological state information, and calculates three routing tables of a single-layer region, an inter-region and a multi-layer inter-layer; the low-orbit satellite utilizes the three routing tables to perform different on-satellite routing forwarding according to the position relationship of a source satellite and a destination satellite. The application reduces routing overhead, improves network performance, and can be used for a large-scale constellation network.