Systems, methods, and apparatus for a virtual transponder utilizing inband telemetry are disclosed. A disclosed method for a virtual transponder utilizing inband telemetry comprises transmitting, by a hosted payload (HoP) operation center (HOC), encrypted hosted commands to a host spacecraft operations center (SOC). The method further comprises transmitting, by the host SOC, encrypted host commands and encrypted hosted commands to a vehicle. Also, the method comprises reconfiguring a payload on the vehicle according to unencrypted host commands and/or unencrypted hosted commands. In addition, the method comprises transmitting payload data to a host receiving antenna and/or a hosted receiving antenna. Also, the method comprises transmitting encrypted host telemetry to the host SOC. In addition, the method comprises transmitting encrypted hosted telemetry to the hosted receiving antenna. Further, the method comprises transmitting, by the hosted receiving antenna, the encrypted hosted telemetry to the HOC.

A solid state power amplifier uses a Doherty power amplifier that can be implemented as a monolithic microwave integrated circuit. By adjusting the DC bias of the amplifying stages in each branch of the Doherty amplifier, the output power, linearity, and DC power can be adjusted to provide a specified output, where the specification for the output can include the maintaining of desired DC power and linearity. The Doherty power amplifier can be used in a satellite payload or other application utilizing solid state power amplifiers, while providing the proper amount of RF output power and DC power. A single amplifier can have its bias levels adjusted for different output levels, helping to minimize the number of designs that are required for a given satellite payload, reducing the variety of parts in a satellite payload.

An electromagnetic pulse (EMP) resistant telecommunications system includes core components mounted within and shielded by a Faraday cage. The components include a data source or storage device. An ethernet switch selectively connects the data source or storage device to a primary satellite router and a post-EMP satellite router. Telecommunications signals are output from and input to the core components via low noise blocks (LNBs) and block upconverters (BUCs). A method of resisting EMP interference for a telecommunications system includes the steps of enclosing and shielding core components in a Faraday cage and providing output via LNBs and BUCs to an antenna subsystem.

A system and method for transmitting packets from a transceiver to a repeater in the presence of relative motion between the transceiver and the repeater. In some embodiments, the method includes: adjusting a plurality of transmission times; transmitting each of a plurality of packets, at a respective adjusted transmission time, from the transceiver to the repeater; and retransmitting, by the repeater, each of the packets, at a respective retransmission time, each of the retransmission times being, as a result of the adjusting, more nearly the same as it would have been, in the absence of: the relative motion, and the adjusting.

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.

The present invention relates to a satellite communications system comprising a satellite with a spatial digital modulator for transmitting an incoming bit stream in multiple beams, wherein the spatial digital modulator configured to generate transmit symbols by dividing the incoming bit stream into symbols of a symbol alphabet and to allocate each transmit symbol to a specific beam. The invention further relates to a method for transmitting a bit stream by such a satellite communications system.

A method for receiving an ADS-B message is disclosed including a synchronisation phase for detecting the start of the message and a decoding phase for recovering a bit stream corresponding to a block of data in the message. The synchronisation phase is based on determining a sequence of log-likelihood ratios having the greatest likelihood of corresponding to a sequence of symbols expected from a preamble of the message. Each log-likelihood ratio corresponds to a ratio between the respective probabilities that a symbol of the signal received corresponds to one of two possible values for a symbol. The decoding phase applies a belief propagation algorithm to a sequence of log-likelihood ratios respectively associated with the symbols in the block of data in the message, with an optimised parity matrix of the cyclic redundancy code of the message.

Disclosed are a calibration system and method for correction of tracking drifts in the output section of a satellite payload and a beamforming network. The disclosed technique exploits characterisation of path gain and phase tracking drifts as deterministic errors that can be measured over spacecraft lifetime without statistical approximations, and thereafter predicted for in-orbit daily temperature variations. Also disclosed is a satellite payload for transmitting test signals to the calibration system.

Various arrangements for performing transmodulation of a forward feeder link are presented. A first data stream and a second data stream can be modulated into a higher-order modulation forward feeder link having a higher-order digital modulation scheme. A satellite can receive the higher-order modulation forward feeder link. The satellite can demodulate the higher-order modulator forward feeder link into a bit stream. This bit stream may then be remodulated and retransmitted as multiple forward user links.

Various arrangements for a satellite-based forward link overlay are presented herein. In some embodiments, broadband data is modulated at a particular frequency, phase, and/or timing to create a broadband data signal. The frequency, phase, and/or timing are used to modulate a low-bandwidth data signal. The low-bandwidth data signal can then be combined with the broadband data signal and transmitted via satellite to a geographic region. A low-bandwidth receiver unit may determine the frequency, phase, and/or timing from the embedded broadband signal and use such information to demodulate and despread the low-bandwidth data signal.