A method performed on-board by a satellite for processing a signal received from a terminal during a current time interval, includes receiving, during the current time interval, a main signal containing a message from a terminal, each message having a priority level; sampling the main signal to obtain samples; storing the obtained samples into the satellite memory; first demodulating the messages corresponding to the current time interval contained in the samples stored in memory; when the satellite is in the range of a ground station, transmitting to the ground station the content of the memory. The first demodulating includes, for each message of the messages contained in the samples and by priority order: demodulating and decoding the message; forwarding, using direct link or inter-satellite-link, the demodulated message to a ground station; estimating the number of remaining non-demodulated messages in the samples stored in the memory.

A satellite communications system is disclosed, the system comprising a ground controller, a decode-and-forward (DF) satellite transponder, and a digital high-power amplifier (HPA). The DF is further comprised of a transponder front end including a digital channelizer and a predistorter. The ground controller is configured to transmit multiple-access frequency-division-multiplexed signals to the DF, where the DF is configured to down-convert the signals received at the transponder front end. The digital channelizer is configured to convert the signals received into a single sample steam and feed the stream through the predistorter into the single digital HPA, wherein the HPA is configured to amplify each input sample of the stream in sample-by-sample fashion and generates a discrete output. The DF is further configured to convert the output of the digital HPA to a continuous time signal and up-convert the output with a main carrier frequency for down-link transmission to multiple-access ground users.

A satellite communications system is disclosed, the system comprising a ground controller, a decode-and-forward (DF) satellite transponder, and a digital high-power amplifier (HPA). The DF is further comprised of a transponder front end including a digital channelizer and a predistorter. The ground controller is configured to transmit multiple-access frequency-division-multiplexed signals to the DF, where the DF is configured to down-convert the signals received at the transponder front end. The digital channelizer is configured to convert the signals received into a single sample steam and feed the stream through the predistorter into the single digital HPA, wherein the HPA is configured to amplify each input sample of the stream in sample-by-sample fashion and generates a discrete output. The DF is further configured to convert the output of the digital HPA to a continuous time signal and up-convert the output with a main carrier frequency for down-link transmission to multiple-access ground users.

Disclosed embodiments relate satellites using a Software-Defined Radio (“SDR”) system. In one example, a geostationary (GEO) satellite includes an antenna system including multiple antennas, each configured to provide a spot beam having an adjustable throughput for a terrestrial coverage area while the antenna is in an active state and the satellite is in orbit above the Earth, a front-end subsystem communicatively coupled to the antenna system having an input side including an input filter and an analog-to-digital converter, and an output side including an output filter and a digital-to-analog converter, and a software defined radio (“SDR”) communicatively coupled to the antenna system via the front-end subsystem. The SDR, in response to a surge modification request, modifies a throughput of each active antenna by increasing or decreasing a share of a satellite power budget allotted to the antenna by deactivating or activating a previously active or previously inactive antenna, respectively.

Disclosed embodiments relate satellites using a Software-Defined Radio (“SDR”) system. In one example, a geostationary (GEO) satellite includes an antenna system including multiple antennas, each configured to provide a spot beam having an adjustable throughput for a terrestrial coverage area while the antenna is in an active state and the satellite is in orbit above the Earth, a front-end subsystem communicatively coupled to the antenna system having an input side including an input filter and an analog-to-digital converter, and an output side including an output filter and a digital-to-analog converter, and a software defined radio (“SDR”) communicatively coupled to the antenna system via the front-end subsystem. The SDR, in response to a surge modification request, modifies a throughput of each active antenna by increasing or decreasing a share of a satellite power budget allotted to the antenna by deactivating or activating a previously active or previously inactive antenna, respectively.

A satellite communications system is disclosed, the system comprising a ground controller, a decode-and-forward (DF) satellite transponder, and a digital high-power amplifier (HPA). The DF is further comprised of a transponder front end including a digital channelizer and a predistorter. The ground controller is configured to transmit multiple-access frequency-division-multiplexed signals to the DF, where the DF is configured to down-convert the signals received at the transponder front end. The digital channelizer is configured to convert the signals received into a single sample steam and feed the stream through the predistorter into the single digital HPA, wherein the HPA is configured to amplify each input sample of the stream in sample-by-sample fashion and generates a discrete output. The DF is further configured to convert the output of the digital HPA to a continuous time signal and up-convert the output with a main carrier frequency for down-link transmission to multiple-access ground users.

A satellite communications system is disclosed, the system comprising a ground controller, a decode-and-forward (DF) satellite transponder, and a digital high-power amplifier (HPA). The DF is further comprised of a transponder front end including a digital channelizer and a predistorter. The ground controller is configured to transmit multiple-access frequency-division-multiplexed signals to the DF, where the DF is configured to down-convert the signals received at the transponder front end. The digital channelizer is configured to convert the signals received into a single sample steam and feed the stream through the predistorter into the single digital HPA, wherein the HPA is configured to amplify each input sample of the stream in sample-by-sample fashion and generates a discrete output. The DF is further configured to convert the output of the digital HPA to a continuous time signal and up-convert the output with a main carrier frequency for down-link transmission to multiple-access ground users.

Disclosed embodiments relate to modular antenna systems. In one example, an antenna system includes M user terminal elements, each being application-agnostic and including an antenna either to generate an incoming signal in response to incident satellite radio waves or to transmit an outgoing signal, and an active circuit to process the incoming and outgoing signals, a control circuit to control the processing performed by the M active circuits, and N user terminal modules (UTM) each including a daisy-chain of O of the M active circuits, each UTM further including a buffer placed after every P active circuits in order to correct any degradation that has occurred in the daisy-chain, and wherein M can be adjusted so that an antenna area and a corresponding throughput and bandwidth available to an application are adjustable and scalable.

A system to reduce a count of satellite gateways is disclosed. The system includes: a feeder link capacity of a satellite; a spectrum ranging from 26.5 GHz to 75 GHz; a gateway feeder link capacity that is an aggregate of capacities of channels defined in the spectrum; and RF gateways communicating with the satellite via the channels, wherein the count of the satellite gateways is less than or equal to a rounded-up integer of the feeder link capacity divided by the gateway feeder link capacity, and the satellite is a geosynchronous orbit satellite.

A system to reduce a count of satellite gateways is disclosed. The system includes: a feeder link capacity of a satellite; a spectrum ranging from 26.5 GHz to 75 GHz; a gateway feeder link capacity that is an aggregate of capacities of channels defined in the spectrum; and RF gateways communicating with the satellite via the channels, wherein the count of the satellite gateways is less than or equal to a rounded-up integer of the feeder link capacity divided by the gateway feeder link capacity, and the satellite is a geosynchronous orbit satellite.