A satellite receiver includes: demultiplexing units each demultiplexing, into subchannel signals of a predetermined band, a digital reception signal obtained by converting a calibration signal received by a corresponding one of receiving antenna elements into a digital signal; excitation coefficient multiplication units multiplying the subchannel signals by an excitation coefficient; a complex adder adding the subchannel signals multiplied by the excitation coefficient together for each subchannel signal of the same band; a correlation detection unit calculating, with the use of one demultiplexing unit as a reference demultiplexing unit, a cross-correlation value for each subchannel signal output from each demultiplexing unit different from the reference demultiplexing unit with respect to a subchannel signal of a same band output from the reference demultiplexing unit; and an excitation coefficient generation unit generating a corrected excitation coefficient based on a cross-correlation value and an excitation coefficient created in advance.

The embodiments herein provide a system and method for integrated optimization of design and performance of satellite constellations. The present disclosure provides a method for optimization of design and performance of satellite constellation to provide internet connectivity at preset geographic regions. In current methods, the optimizations of subsystems are performed independently and the results are combined, resulting in a loss of overall optimality. The present disclosure defines the relationships between subsystems such that integrity of complete design is tested with fewer complexities and provides an integrated optimization framework, in which every subsystem is optimized individually and collectively. The present disclosure provides a method for optimization of power subsystem of satellites by determining the pattern of payload operation and need for peak power. The present disclosure also provides a method to minimize the number of satellites required in constellations by carefully regulating spot beams formed by individual satellites in constellations.

This application provides a communication method and apparatus. The method includes: A terminal device receives first information sent by a first base station, where the first information includes a first timing advance of a second base station, or the first information includes a parameter used by the terminal device to obtain the first timing advance of the second base station, and the first timing advance is a timing advance used in a process of data transmission with the second base station; and the terminal device obtains the first timing advance of the second base station based on the first information.

A satellite receiver for wireless signals having carrier frequencies in the V or the W band of frequencies is described. The satellite receiver may receive the wireless signals at high elevation angles, such as greater than 62° . This high elevation angle may reduce losses, which may allow the satellite receiver to communicate at a data rate of at least 50 Mbps. In order to accommodate these system requirements, the one or more satellites that provide the wireless signals may have eccentric geosynchronous or near-geosynchronous orbits that are inclined relative to an equatorial plane of the Earth, such as an eccentricity between 0.12 and 0.3. Moreover, the one or more satellites may have ground tracks substantially along one or more continents, and may be in view of dense population regions in the one or more continents with a higher frequency than low-density population regions in the one or more continents.

A satellite receiver with a switchable array of antenna elements for receiving wireless signals from at least a satellite is described. The antenna elements may be dynamically selected based at least in part on a location and motion of the satellite receiver, and a location and a motion of at least the satellite that provides wireless signals. Moreover, the antenna elements may also be dynamically selected based at least in part on utilization and/or availability of a terrestrial wireless communication network that communicates with the satellite receiver. The satellite receiver may predict availability of communication with at least the satellite. Furthermore, the array of antenna elements may provide improved power efficiency, pointing accuracy and/or isotropic gain relative to an array of antenna elements without switched antenna elements, such as for carrier frequencies in the V or the W band of frequencies.

Systems and method for supporting a fractionated satellite constellation are disclosed. A gateway satellite may route communications to and from auxiliary satellites using a first communication protocol. The auxiliary satellites may be orbitally-coupled with the gateway satellite and may be equipped with respective payload types that provide respective functionalities. The auxiliary satellites may also use respective communications protocols that are different than one another and the first communication protocol. Routing communications to and from auxiliary satellites may include relaying a communication between multiple auxiliary satellites. Routing communications between auxiliary satellites may include relaying a communication between multiple gateway satellites. Routing communications to and from auxiliary satellites may also include relaying communications between commercial satellites and auxiliary satellites.

In one example, an antenna system is described. The antenna system includes a primary antenna on an aircraft. The primary antenna is mechanically steerable and has an asymmetric antenna beam pattern with a narrow beamwidth axis and a wide beamwidth axis at boresight. The antenna system also includes a secondary antenna on the aircraft, the secondary antenna including an array of antenna elements. The antenna system also includes an antenna selection system to control communication of a signal between the aircraft and a target satellite via the primary antenna and the secondary antenna. The antenna selection system switches communication of the signal from the primary antenna to the secondary antenna when a performance characteristic for communication with the target satellite satisfies a threshold due to a position of the aircraft relative to the target satellite.

The present disclosure relates to a maritime communication system based on low earth orbit satellites and an unmanned aerial vehicle. The maritime communication system according to one embodiment may include one or more maritime users, one or more satellites connected to a network operator, and an unmanned aerial vehicle (UAV) for relaying communication between the maritime users and the satellites.

A signal processing apparatus and method provides the ability to dynamically select a subset of subcarriers from a received frequency division multiplex (FDM), select which subsets of subcarriers are coherently combined per satellite, and translate the selected subcarriers into a FDM having a smaller bandwidth. There are at least two first phase aligners, a digital cross-connect, and at least two second phase aligners. The first and second phase aligners are configured to receive a pair of in-phase and quadrature pairs and provide automatic gain control and coherent combing of the pairs. The digital cross-connect is configured to receive the in-phase and quadrature pairs from the two phase aligners and associate any in-phase and quadrature pair with another. Preferably, the apparatus further includes dual front-end digital channelizers configured to convert signals into an in-phase and quadrature pairs which are input to the first phase aligners.

Embodiments of this application provide a timing offset parameter update method, a device, and a system, and relate to the field of communication technologies, to help reduce signaling overheads generated when a network device updates a value of a timing offset parameter. The method includes: A terminal device obtains first information that includes a first reference value and first indication information, where the first indication information indicates an update rule of a timing offset parameter, and the first reference value is an initial value of the timing offset parameter. The terminal device updates a value of the timing offset parameter based on the first information and a timing offset variation, to obtain an updated value of the timing offset parameter, where an absolute value of the timing offset variation is equal to an absolute value of a difference between any two consecutively updated values of the timing offset parameter.