Abstract: Power spectral density in an aeronautical satellite communication system is controlled through the use of adaptive inroute selection and spreading. Once a communication session has been established between the aircraft and the satellite, environmental conditions and aircraft conditions are monitored to detect events capable of affecting transmit/receive properties during the communication session. A maximum allowable transmission output is determined based, at least in part, on governmental regulations and the conditions being monitored. One or more transmit parameters are adjusted in order to maintain transmission output power of the aircraft terminal below the maximum allowable transmission output power.

Abstract: An approach for improved compensation for nonlinear distortion in multicarrier satellite systems is provided. Source reflecting encoded and modulated sequences of source data symbols are received. Each source signal is predistorted, and a transmit filter is applied to each predistorted source signal. Each filtered signal is translated to a carrier frequency, and the translated signals are combined into a composite signal for transmission via a multicarrier transponder. The final predistorted version of each source signal is generated via an iterative process of a number of stages, wherein, for a given stage and for each source signal, the process comprises: receiving a prior predistorted version of each source signal from a preceding stage; processing each prior predistorted source signal based on all of the received prior predistorted source signals, wherein the processing is performed based on a characterization of one or more characteristics of the multicarrier satellite transponder.

Abstract: A single or multistage signal predistorter includes an input coupled to receive an information signal comprising input samples and an output coupled to the high power amplifier, the signal predistorter configured to receive an input sample, generate a distortion sample based on an estimate of nonlinearity of the high power amplifier at an operating saturation level, modify the input sample with a correction term to generate a predistortion signal, wherein the correction term is proportional to the distortion sample, and further wherein the predistortion signal comprises the information signal modified to account for nonlinearities in the high power amplifier.

Abstract: An apparatus for PLL bandwidth expansion including a compensation filter and a phase locked loop, where the compensation filter is programmed with a compensation function derived based on programmable coefficients and parameters of a transmitting device, a frequency response of the phase locked loop, and a wanted frequency response.

Abstract: A method and a satellite gateway for minimizing an impact of a noise floor variation in a spot beam satellite system. A demodulator processes digitized signals from multiple channels. Digitized signals are automatically gain controlled by respective automatic gain control components associated with respective channels. Automatic gain controlled digitized signals are downconverted and provided to a burst processor. The burst processor processes each downconverted signal and provides, with respect to each downconverted signal, an automatic gain control estimate, a code rate, and an inroute number to a processor component. The processor component determines an average automatic gain control value for each inroute, provides automatic gain control references to the respective automatic gain control components, and periodically sends noise map information to satellite terminals served by the satellite gateway. In some embodiments, the automatic gain control values are biased according to corresponding code rates.

Abstract: A method and a satellite communication system are provided. At least one satellite gateway earth station receives at least one multicast stream from an external network. In a static forwarding mode, the at least one satellite gateway earth station replicates and forwards traffic from the at least one multicast stream over at least one first respective outroute carrier of at least one first respective spot beam of a satellite regardless of whether any terminal is arranged to actively receive any of the at least one multicast stream. In a dynamic forwarding mode, the at least one satellite gateway earth station replicates and forwards second traffic from any of the at least one multicast stream over at least one second respective outroute carrier of at least one second respective spot beam only when at least one respective terminal is arranged to actively receive the any of the at least one multicast stream.

Abstract: A single or multistage signal predistorter includes an input coupled to receive an information signal comprising input samples and an output coupled to the high power amplifier, the signal predistorter configured to receive an input sample, generate a distortion sample based on an estimate of nonlinearity of the high power amplifier at an operating saturation level, modify the input sample with a correction term to generate a predistortion signal, wherein the correction term is proportional to the distortion sample, and further wherein the predistortion signal comprises the information signal modified to account for nonlinearities in the high power amplifier.

Abstract: A method and a satellite terminal are provided. The satellite terminal may range over multiple frequencies and may receive, from a satellite gateway, a signal quality indicator with respect to each of the ranged multiple frequencies. Noise and interference for a corresponding frequency are estimated based on at least one of the received signal quality indicators for the corresponding frequency. Path loss is estimated based on multiple received signal quality indicators, each of which is received in response to the satellite terminal transmitting a signal while not performing the ranging process. A transmit power level of the satellite terminal is adjusted for the corresponding frequency based on the estimated path loss and the estimated noise and interference for the corresponding frequency.

Abstract: An apparatus for inline monitoring of transmit signals is disclosed. The apparatus includes a processor, and one or more fiber optic lines for supplying a transmit signal to/from a remote transmission station. The processor is configured to receive input for selecting one or more fiber optic lines for examination, determine at least one property of the transmit signal to be monitored, and retrieve information corresponding to the at least one property for a predetermined period of time. The processor is further configured to output a visual representation of the retrieved information, perform an analysis of the retrieved information and the visual representation, and facilitate identification of at least one status associated with the transmit signal based, at least in part, on the analysis.

Abstract: A satellite modem, a GPS device, and a method are provided. The satellite modem requests current location information from a GPS device and waits no more than a preconfigured amount of time to receive the current location information. When the satellite modem receives the current location information, the satellite modem determines whether the current location information indicates a location in which the satellite modem is authorized to operate. When the satellite modem determines that the current location information indicates a location in which the satellite modem is not authorized to operate, the satellite modem performs at least one action from a group of actions including preventing the satellite modem from operating normally, permitting the satellite modem to operate with a reduced functionality, and transmitting a message to a network management center indicating that the satellite modem is not located at an authorized location.

Abstract: Systems and methods are provided for separating the uplink signal from the downlink signal in a satellite communication system. A communication terminal for satellite communications is provided, comprising a reflector having a prime focus; a first feed located at the prime focus of the reflector and in optical communication with the reflector; a frequency-selective surface module having a reflected focus and located at a point along a communication path between the main reflector and the first feed; and a second feed located at the reflected focus of the frequency-selective surface module and in optical communication with the frequency-selective surface module.

Abstract: Systems and methods for peer group diagnosis detection are disclosed. In an example embodiment, a beam profile including a plurality of satellite beam characteristics is determined. A peer group of satellite terminals is determined. Terminal profiles with terminal characteristics for the satellite terminals in the peer group are determined. A normalized baseline profile including normalized terminal characteristics for the peer group is determined. Measured operational statistics of the satellite terminals in the peer group are received and converted into normalized operation statistics using the terminal profiles and the normalized baseline profile. Normalized peer group operational statistics including a mean and a standard deviation of normalized operational statistics are determined. A normalized deviation of the normalized operational statistics is determined for each satellite terminal. The normalized deviations for each satellite terminal are compared to a threshold deviation.

Abstract: Methods and systems for providing sourcing Internet access requests from ISP subscribers serviced by a gateway not physically located near the subscribers. As the localization needs of all subscribers are not necessarily the same, the gateway determines an appropriate source IP address to use to ensure that the IP protocol localization features work efficiently. In addition, the gateway can help enforce rules related to the governing law of the geographic area of the subscriber and/or rules based on the content providers licensing. Through determination of the context of a request, the gateway may also determine whether localized sourcing of a request is necessary based on the type of content being requested.

Abstract: A method and a satellite communication system are provided. At least one satellite gateway earth station receives at least one multicast stream from an external network. In a static forwarding mode, the at least one satellite gateway earth station replicates and forwards traffic from the at least one multicast stream over at least one first respective outroute carrier of at least one first respective spot beam of a satellite regardless of whether any terminal is arranged to actively receive any of the at least one multicast stream. In a dynamic forwarding mode, the at least one satellite gateway earth station replicates and forwards second traffic from any of the at least one multicast stream over at least one second respective outroute carrier of at least one second respective spot beam only when at least one respective terminal is arranged to actively receive the any of the at least one multicast stream.

Abstract: Systems and methods provide a receiver design capable of both wideband (high symbol rate) and narrowband (low symbol rate) operations requirements without compromising narrowband performance. Moreover, such a receiver design can be very low cost, and eschewing the need for any expensive and/or specialized elements. A receiver configured in accordance with various embodiments utilizes a fully integrated tuner in which narrowband filters are configured to be bypassable when in wideband (high symbol rate) mode in favor of fixed wideband filters. Additionally, an analog-to-digital converter (ADC) can be implemented with digital gain for wideband operation, as well as digital data bit mapping to accommodate industry standard application-specific integrated circuits (ASICs) interfaces, such as from a 12 bit ADC core to an 8 bit digital interface.

Abstract: A signal transmission approach comprises encoding a source signal (comprising source symbols) to generate a corresponding encoded signal. The encoded signal is modulated by mapping each source symbol to a respective signal constellation point of an applied signal constellation to generate a modulated signal. The modulated signal is pre-distorted based on a distortion estimate to generate a pre-distorted signal. The pre-distorted signal is filtered to generate a filtered signal. The filtered signal is frequency translated and amplified to generate a transmission signal for transmission via an uplink channel of a satellite communications system. To increase throughput, the source signal is processed through the apparatus and the resulting transmission signal is generated at a Faster-than-Nyquist (FTN) symbol rate and with a tight frequency roll-off. The modulated signal is pre-distorted based on a distortion estimate relating to the nonlinearity and the filters applied before and/or after the pre-distorter.

Abstract: A very small aperture terminal (VSAT) installation tool is provided having the ability to measure cable loss along an interfacility link (IFL) between an outdoor unit and an indoor unit of the VSAT. Radio frequency (RF) signals can be transmitted from the indoor unit to the outdoor unit, where the RF signals are intercepted along the IFL prior to reaching the outdoor unit, and the output power is determined. The determined output power is compared to an expected output power at the indoor unit. The delta between the determined output power and the expected output power can be used to adjust the power of the indoor unit such that the outdoor unit can operate without reaching its compression point.

Abstract: A method and apparatus for providing half-duplex communications for a Very Small Aperture Terminal (VSAT) operating on a continuous received stream is disclosed. The method includes: decoding the continuous received stream to establish synchronization with the continuous received stream; locating, in the continuous received stream, a time plan including a receiving timeslot and a transmitting timeslot; demodulating the continuous received stream by adapting to a timing and frequency variation of the continuous received stream in the receiving timeslot, freewheeling the adapting of the continuous received stream during the transmitting timeslot, and resuming the adapting of the continuous received stream when the transmitting timeslot ends; stopping a receiving of the continuous received stream during the transmitting timeslot; and transmitting from the VSAT during the transmitting timeslot.

Abstract: A split gateway hub for a bent-leg communication system is disclosed. The gateway hub includes: a modulator to modulate a bit stream into a signal to be transmitted to a remote terminal via a radio frequency (RF) signal; a Time Synchronization Application (TSA), geographically co-located with the modulator, to provide timing reference and synchronization to the remote terminal; a network access component to provide traffic for the bit stream; and an Inroute Group Manager (IGM) to manage the traffic to and from the remote terminal. In the split gateway hub, the IGM is disposed geographically remote from either the TSA or from the network access component, and the bent-leg communication system uses a satellite or a High Attitude Platform (HAP) for relaying the RF signal.

Abstract: It is determined, e.g., in a communications terminal, that a test triggering event has occurred. A test is initiated based on the determination that the test triggering event has occurred. One or more transmissions are transmitted at one or more respective specified power levels. Measurement data is received from a remote measurement unit indicating respective received power levels of the one or more transmissions by the remote measurement unit. Based on the measurement data, a maximum transmit power level is determined.