AST & Science, LLC

Phased arrays on satellites that approximate/emulate the shape of a rounded triangle such that elliptical apertures can be generated in any desired direction while requiring the minimum possible phased array area. The common shapes for phased arrays are circular, square, or hexagonal, with circular phased arrays often being viewed as the preferred shape. However, it is shown here that rounded triangular phased arrays can be generated to accommodate elliptical apertures as necessary to serve the field of view beneath a satellite and do so with fewer antennas than their circular counterparts. For applications where elliptical apertures are desirable, such as satellite-to-Earth communications, the rounded triangular model for phased arrays is demonstrably more efficient than the circular model.

An array of antenna assemblies each generate solar power and utilize the generated solar power at that antenna assembly, which enables large amounts of power to be generated. An antenna assembly having a flat antenna layer forming a first outer surface of said antenna assembly, a flat solar layer forming a second outer surface of said antenna assembly, and a flat structural layer having a flat support structure sandwiched between the antenna layer and the solar layer. The antenna layer has a flat antenna plate with one or more antennas at the first outer surface of the antenna assembly to communicate with Earth. The solar layer has a flat solar plate with one or more solar cells at the second outer surface of the antenna assembly to receive solar energy and generate power.

Aspects of the technology involve a satellite communication system comprising a base station that communicates with standard compliant user equipment (UE) via a satellite having a field of view. The base station includes a processing device configured to generate a satellite beam at the satellite having a first transmission protocol or a second transmission protocol. The processing device is able to selectively switch between the first transmission protocol and the second transmission protocol based on an actual amount of data traffic by the UE in the field of view or an expected amount of data traffic by the UE in the field of view.

A LEO satellite communication system is in communication with a first setting satellite having a first field of view including a first plurality of cells, and a second rising satellite having a second field of view including a second plurality of cells. The first and second satellites have an overlapping field of view having an overlapping plurality of cells located therein. A first processing device has a first communication port communicating with a first cell of the first plurality of cells via said first antenna over a first beam, and a second communication port communicating with an overlapping cell of the overlapping plurality of cells via said second antenna over a second beam. Said first processing device switches from said first communication port to said second communication port in response to the first cell of the first plurality of cells moving into the overlapping field of view.

A ground station processes downlink signals received from respective satellites. The ground station has a plurality of signal conditioning devices each receiving a respective one of the downlink signals and providing a conditioned downlink signal. A plurality of Doppler and/or Delay compensator devices each receive a respective conditioned downlink signal from a respective one of the plurality of signal conditioning devices. The compensator devices conduct Doppler and/or Delay compensation on the received conditioned downlink signal, and provide a compensated downlink signal output. A selector or diversity combiner receives the compensated downlink signal from each of the plurality of Doppler and/or Delay compensators. The selector or diversity combiner selects one of the received compensated downlink signals based on received signal strength of each received compensated downlink signal to provide a selected downlink signal, or diversity combines all of the received compensated downlink signals to provide a diversity combined signal. The selector or diversity combiner provides the selected downlink signal or the diversity combined signal to an eNodeB.

The technology employs a polarization switching technique in a satellite-based cellular communication system, in order to prevent dropped connections when communicating with client communication devices. The polarization switching is implementable without requiring additional antenna elements on the satellite(s), while enabling the satellites(s) to be agnostic to the polarization transmitted by user equipment. The dwell time is selected so that the polarization switching is transparent to the users of the client computing devices. In one configuration, certain antenna elements can be set to handle a vertically polarized downlink and a horizontally polarized uplink, while other elements are set to handle a vertically polarized uplink and a horizontally polarized downlink, although other polarization configurations may be employed. A digital switch with a general purpose I/O (GPIO) controller may be employed for switching according to the dwell time.

The technology provides a gateway system that enables satellite communication with user equipment (UE). A system includes multiple gateways, where each gateway includes processing devices, baseband units, a gateway channel routing block, and a set of antennas for communicating with a constellation of orbiting satellites. The gateways include a primary gateway and a diversity gateway. A set of communication links operatively connects the gateways together. A diversity combiner may be operatively coupled to the gateways via one or more of the communication links. The diversity combiner is configured to receive and combine signals from at least two of the gateways. The system is configured to determine when to switch a satellite communication link from the primary gateway to the diversity gateway according to a threshold level of communication requirement based on a status condition of the primary gateway and a status condition of the diversity gateway.

The technology relates to a Common Public Radio Interface (CPRI) satellite communication system and corresponding method. The satellite communication system has, in one arrangement, a base station configured to communicate with standard compliant user equipment (UE) via a satellite having a field of view. The base station includes a plurality of base band units and a base station memory configured to store control information, downlink signal information and uplink signal information associated with a cell in the field of view. The system also includes a processing device configured to cause the satellite to generate a satellite beam in accordance with the control information, downlink signal information and uplink signal information stored in the base station memory.

Aspects of the technology involve a satellite communication system comprising a base station that communicates with standard compliant user equipment (UE) via a satellite having a field of view. The base station includes a processing device configured to generate a satellite beam at the satellite having a first transmission protocol or a second transmission protocol. The processing device is able to selectively switch between the first transmission protocol and the second transmission protocol based on an actual amount of data traffic by the UE in the field of view or an expected amount of data traffic by the UE in the field of view.

OFDM-BPSK symbol sequences are used for mutual-coupling based phase array calibration. Such substitution allows phase to be estimated more accurately using a given estimation duration without compromising other estimates' (amplitude and group delay) accuracies.