A system of architecture, apparatus and calibration method is invented for high-power flexible-polarization payload for satellite communications. The system comprises onboard phase-tracked apparatus, flexible polarization mechanism, and in-orbit calibration method. The power combining and polarization performance of the phase-tracked payload is monitored on ground by measuring the cross-polarization discrimination (XPD) and/or axial ratio (AR). The high performance over the life is achieved by optimization of the XPD or AR on ground and adjusting complex gain of the transponders. The high-power flexible-polarization in-orbit-calibration payload may be applied but not limited to UHF, L, S, C, X, Ku and Ka-band high power satellite systems.

A wireless communication network such as a 5G communication network can use MIMO technologies to enhance bandwidth between a wireless communications base station and one or more user equipment devices within a service area of the base station. RF signal repeaters can be utilized to provide one or more additional physical channels for communication between the MIMO base station and the MIMO user equipment. These RF signal repeaters can be regarded as increasing the MIMO channel diversity within the ambient environment.

Satellites provide communication between devices such as user terminals (UTs) and ground stations that are connected to points-of-presence (PoP) connected to other networks, such as the Internet. The PoP accepts downstream data addressed to the UT. A representation of the communication resources that are expected to be used to pass the downstream data from the PoP to the UT is determined and executed on one or more processors. The representations may include representations of traffic shapers, modems, and so forth at different points in the network. The representations may consider real-world and simulated feedback data. Within the representation, traffic shaping is employed to determine preshaped data that includes resource metadata designating the communication resources to be used. The preshaped data is passed along to the actual communication resources for subsequent delivery. The preshaping substantially improves performance of constrained communication resources. The preshaped data may be reshaped as real-world conditions change.

Systems and methods are described for robust scheduling of beam switching patterns in satellite communications systems. Embodiments operate in context of a hub-spoke satellite communications architecture having a number of gateway terminals servicing large numbers of user terminals over a number of spot beams. The satellite includes switching subsystems that distribute capacity to the user beams from multiple of the gateway terminals in a shared manner according to a beam group switching pattern. The beam group switching pattern is robustly formulated to continue distributing capacity during gateway outages (e.g., when one or two gateway terminals are temporarily non-operational due to rain fade, equipment failure, etc.). For example, the beam group switching pattern can be formulated to minimize worst-case degradation of capacity across user beams, to prioritize certain beams or beam groups, etc.

The present disclosure describes methods and systems applicable to multi-branch non-orthogonal (NOMA) wireless communication. The described methods and systems include a base station (120) determining (705) a first plurality of multiple access resources and an order of the first plurality of multiple access resources. The base station (120) transmits (710), to a user equipment (110), a message that includes the determined first plurality of multiple access resources and the determined order of the first plurality of multiple access resources. The user equipment (110) transmits, to the base station (120), a multi-branch data stream using a second plurality of multiple access resources that is determined from the first plurality of multiple access resources, after which the base station (120) decodes (730) data from the multi-branch data stream by combining the second plurality of multiple access resources in accordance with the determined order of the first plurality of multiple access resources.

An orbiting multiple access transceiver communicates with terrestrial mobile stations which are also capable of communicating with terrestrial base stations. The multiple access transceiver is configured to sample a signal when a terrestrial mobile station of interest is not transmitting to produce a sample signal. The sample signal may be processed to produce an out-of-phase signal that may be applied to a signal when the terrestrial mobile station of interest is transmitting to produce a clearer signal from the terrestrial mobile station of interest.

A space-air-ground integrated UAV-assisted IoT data collection method based on AoI comprises: constructing a UAV-assisted space-air-ground integrated IoT system, constructing a UAV channel model and an AoI model, establishing an AoI-based UAV-assisted space-air-ground integrated IoT data collection model, transforming a problem into a Markov problem, introducing a neural network to solve a high-dimensional state problem, introducing a deep reinforcement learning algorithm to train UAVs to find optimal collection points, and introducing a matching theory to match the UAVs and IoT devices. To meet the requirement for the timeliness of information collection, the invention finds the optimal configuration of flight parameters of UAVs and deduces the restrictive relation between performance indicators such as AoI, system capacity and energy utilization rate, thus effectively improving the timeliness of information collection, reducing the management and control complexity of the system, and improving the application level of AI in the IoT field.

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.

A user terminal and a method of using the user terminal disclosed. The method may comprise: storing, at a user terminal (UT), a dataset that comprises a plurality of elements, wherein each of the plurality of elements is associated with a unique predetermined terrestrial location; using the dataset, determining an element (E.sub.k) from among the plurality of elements based on a proximity of the UT to the respective unique, predetermined terrestrial location of the element (E.sub.k); and then determining one of the plurality of satellite beams with which to utilize satellite communication.

Methods and apparatus relating to use of actual and/or virtual beacons are described. Virtual beacons are virtual in that an actual beacon need not be transmitted but a rather a virtual beacon transmitter at a desired location maybe considered to transmit virtual beacons. In some embodiments a set of beacon transmitter information for one or more beacons is supplied to devices in a communications system. The beacon transmitter information indicates transmission power and location of actual and virtual beacon transmitters as well as information to be communicated by virtual beacons. Devices with access to beacon information can determine based on the location of a wireless terminal whether the wireless terminal is within coverage area of a virtual beacon and report reception of the virtual beacon to the wireless terminal or a component of the wireless terminal which acts upon receiving an indication of beacon reception.