Abstract: A satellite communication system with software defined network orchestration. Implementations include a route management function (RMF) that receives link status from the satellites and determines simple routing tables which are uploaded to the satellites. The routing tables allow the satellites to route data based on a satellite ID placed in a data header to reduce the memory and computing load on satellite resources. Further, implementations include secure user terminal (UT) to UT IP routing in the constellation for direct UT to UT communication. The satellite communication system may combine the benefits of Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellite systems into an MEO-LEO satellite system.

Abstract: A satellite communication system that combines the benefits of Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellite systems into an MEO-LEO satellite system. The MEO-LEO system includes an LEO constellation combined with a MEO constellation where the LEO constellation may provide global coverage with broad average capacity and may support ‘hot spot’ coverage where desired. The MEO constellation may provide unique advantages including backhaul to ground in remote areas, higher traffic density for key locations, and a secure global backhaul for key customers. Data may be routed over optical inter-satellite links using Software Defined Networking concepts to provide MEO-LEO (backhaul and ground access), LEO-LEO (upstream & downstream); and (3) MEO-MEO (crosslinks & downlinks). Further, implementations described herein include secure user terminal (UT) to UT IP routing in the constellation for direct UT to UT communication.

Abstract: An adaptive transmit power control process enables the uplink transmit power of a user terminal to be adjusted based on a scan angle of the antenna for the user terminal. The antenna periodically reports the scan angle to the user terminal, and a current maximum transmit power for the user terminal is determined based on the scan angle. The current maximum transmit power is then used as the basis for determining an allocation of resources to the user terminal. The transmit power control process enables resources to be assigned as needed across multiple carriers and enables a power spectral density of a user terminal to be adjusted based on nominal and offset transmit power parameters.

Abstract: MAC layer enhancements in protocol stacks of a user terminal of a satellite communication system such as a 5G based system. The MAC layer may include a scheduler that allows resource aggregation by allocating additional radio resources to users on one beam using carriers allocated to an adjacent beam. The MAC layer enhancements may also provide user terminals the ability to report their battery status to the scheduler which can then send signals to the user terminal that allow the terminal to shut down electronics to conserve power resources based on the battery status.

Abstract: A satellite communication system which provides interference mitigation across multiple constellations. The satellite communication system provides interference mitigation when an in-line event occurs where a main lobe of a satellite of the first constellation and a main lobe of a user terminal communicating with the satellite of the second satellite constellation intersect sufficiently to cause significant interference on a common frequency band of the satellite and the user terminal.

Abstract: A satellite communication system with software defined network orchestration. Implementations include a route management function (RMF) that receives link status from the satellites and determines simple routing tables which are uploaded to the satellites. The routing tables allow the satellites to route data based on a satellite ID placed in a data header to reduce the memory and computing load on satellite resources. Further, implementations include secure user terminal (UT) to UT IP routing in the constellation for direct UT to UT communication. The satellite communication system may combine the benefits of Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellite systems into an MEO-LEO satellite system.

Abstract: A satellite communication system that combines the benefits of Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellite systems into an MEO-LEO satellite system. The MEO-LEO system includes an LEO constellation combined with a MEO constellation where the LEO constellation may provide global coverage with broad average capacity and may support ‘hot spot’ coverage where desired. The MEO constellation may provide unique advantages including backhaul to ground in remote areas, higher traffic density for key locations, and a secure global backhaul for key customers. Data may be routed over optical inter-satellite links using Software Defined Networking concepts to provide MEO-LEO (backhaul and ground access), LEO-LEO (upstream & downstream); and (3) MEO-MEO (crosslinks & downlinks). Further, implementations described herein include secure user terminal (UT) to UT IP routing in the constellation for direct UT to UT communication.

Abstract: An improved air interface for satellite systems such as a 5G-based non-geostationary (NGSO) satellite system. The air interface includes an improved physical interface for efficient operation over NGSO satellite systems. The air interface includes an improved forward link for communicating from the satellite gateway to the user terminal and a return link for communicating from the user terminal to the satellite gateway.

Abstract: A transition satellite system which includes a legacy satellite system and a new satellite system that incorporates gateway level transition, satellite level transition and carrier level transition. The transition satellite system allows new satellite systems with user terminals, satellites and gateways to be able to coexist with existing legacy systems allowing a gradual phase-out of legacy user terminals and systems.

Abstract: A method for iterative estimation of a set of unknown channel parameters in a beamforming network including determining a first order estimate of offsets at measurement nodes and an estimate of the confidence in the initial estimate of the measurement nodes' offsets, and iterating, until a desired estimation accuracy is obtained, determining an improved estimate of a parameter set, and the confidence in the estimates, using the prior estimate of the offsets at the measurement nodes and determining an improved estimate of the offsets at the measurement nodes and the associated confidence values using the prior estimate of the parameter set and the corresponding confidence values.

Abstract: A method for iterative estimation of a set of unknown channel parameters in a beamforming network including determining a first order estimate of offsets at measurement nodes and an estimate of the confidence in the initial estimate of the measurement nodes' offsets, and iterating, until a desired estimation accuracy is obtained, determining an improved estimate of a parameter set, and the confidence in the estimates, using the prior estimate of the offsets at the measurement nodes and determining an improved estimate of the offsets at the measurement nodes and the associated confidence values using the prior estimate of the parameter set and the corresponding confidence values.

Abstract: A radio, and related methods of radio communication, consisting of a multi-modulation modem, wherein the multi-modulation modem that modulates and demodulates signals using a plurality of modulations. The radio also comprises a frequency converter coupled to the multi-modulation modem for converting the signals to a radio frequency and a transceiver unit including an antenna coupled to the frequency converter for transmitting the signals over a radio communications link. The multi-modulation modem includes a modulator that includes a modulation selector unit that selects respective ones of the plurality of modulations to modulate the signals. The multi-modulation modem also includes a demodulator for demodulating the signals having been modulated using the plurality of modulations.

Abstract: A radio, and related methods of radio communication, consisting of one or more signal formatters, wherein the one or more signal formatters format signals for transmission through the radio and the signals comprise a plurality of transport mode signals. The radio also includes a modem coupled to the one or more signal formatters for modulating the signals, a frequency converter coupled to the modem for upconverting the signals having been modulated to a radio frequency, and a transceiver unit coupled to the frequency converter for transmitting the signals having been upconverted over a radio communications link.

Abstract: A method and apparatus for performing fractional minimum shift key modulation for a very small aperture terminal. A signal with a fractional modulation which appears to be frequency shift key is generated in the indoor unit. The outdoor unit employs a novel multiplication method to translate this signal to a minimum shift key modulated signal for satellite transmission.

Abstract: A method and apparatus for performing fractional minimum shift key modulation for a very small aperture terminal. A signal with a fractional modulation which appears to be frequency shift key is generated in the indoor unit. The outdoor unit employs a novel multiplication method to translate this signal to a minimum shift key modulated signal for satellite transmission.

Abstract: A frequency generation device for a satellite communication system composed of a central hub station and a number of remote units. The remote units contain a single synthesizer located in an indoor unit. In this invention, the indoor-located synthesizer is a direct digital synthesizer which modulates the baseband signal and conveys the modulated signal to an outdoor unit for communication between the remote unit and the central hub. In the outdoor unit, the signal is converted directly by a fixed number to a Ku band frequency and transmitted to the central hub.

Abstract: A remote ground terminal transmitter for transmitting a modulated data signal having a constant envelope amplitude. The remote ground terminal transmitter comprises a source of data signals, a modulator for providing a carrier signal, receiving a data signal from the source of data signals, and modulating the carrier signal with the received data signal so as to produce a constant envelope minimum shift key modulation signal. The transmitter further comprises a power amplifier which operates in the saturation mode to amplify the modulated carrier signal produced by the modulator to the desired power level.

Abstract: A multisubscriber unit is disclosed for use of in a digital cellular communication system to communicate with a base transceiver station and eventually to switched telephone network. The multisubscriber unit connects to a plurality of individual subscriber telephones. It includes a plurality of upconverters, modulators, downconverters, demodulators speech compressors, speech decompressors, and voice activity detectors that are assigned to a subscriber telephone upon detection of an off hook signal from the telephone. Preferably, upon the detection of data to be transmitted, to channel allocation is requested from a pool of time division multiple access channels in a digital speech interpolation pool.

Abstract: A remote ground terminal for transmitting a modulated data signal to a satellite. The remote ground terminal comprises a source of data signals, a demodulator for receiving a data signal and coupling the data signal to a transmitter, and for producing a power control signal during the period the data signal is present at an input of the demodulator. The power control signal is coupled to the transmitter and controls the operation of the transmitter such that the transmitter only receives power when the demodulator produces the power control signal. During the period the transmitter receives power, it functions to provide and modulate a carrier signal in accordance with the data signal received from the source of data signals.

Abstract: A digital cellular communication system in which fixed subscribers and mobile subscribers share base transceiver stations, base station controllers and mobile switching centers to communicate with the switched telephone network. Mobile subscribers communicate using any cellular radio protocol, while the fixed subscribers communicate via a multi-subscriber unit (MSU) using the inventive air interface. The MSU system uses digital speech interpolation to transmit speech spurts between subscribers and the switched telephone network. Preferably, time division multiple access channels in a digital speech interpolation pool are allocated and deallocated on a speech spurt basis.