Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A signal attenuator is configured to selectively attenuate the one or more unwanted inband signals to form a modified received signal that includes the desired communication signal and the attenuated inband signals. A signal separator processes the modified received signal to form an estimate of the desired communication signal and an estimate of the inband signals.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A signal attenuator is configured to selectively attenuate the one or more unwanted inband signals to form a modified received signal that includes the desired communication signal and the attenuated inband signals. A signal separator processes the modified received signal to form an estimate of the desired communication signal and an estimate of the inband signals.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A receiver receives a communication signal, the received communication signal including the desired communication signal and one or more inband signals. A signal separator processes the received signal to form an estimate of the desired communication signal and an estimate of the inband signals. A performance improver processes the received signal and the estimate of the one or more inband signals to form an improved estimate of the desired communication signal and an improved estimate of the inband signals.

Abstract: A method of and system for determining cross-polarization isolation is described. In one embodiment, a modulated signal is obtained from a communication link. The modulated signal includes a modulated co-polarized signal component and a modulated cross-polarized signal component. Cross-polarization isolation is determined using the modulated co-polarized signal component and the modulated cross-polarized signal component. The determined cross-polarization isolation can be used to adjust an antenna.

Abstract: The present invention provides a method and apparatus for determining the transmit location of an emitter using a single geostationary satellite. In an embodiment, a signal is received at a ground station from the emitter and relayed by the geostationary satellite. The signal is received at the ground station at a plurality of time instances and has a plurality of observed frequencies, one for each time instance. A plurality of lines of position are determining based on the plurality of observed frequencies. The transmit location of the emitter is determined based on at least one intersection among the plurality of lines of position.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A receiver receives a communication signal, the received communication signal including the desired communication signal and one or more inband signals. A signal processor processes the received signal to form an estimate of the desired communication signal and an estimate of the inband signals. The estimate of the inband signals is thereby removed from the received signal. The estimate of the desired communication signal and the estimate of the inband signals are formed without prior knowledge of characteristics of the inband signals and without obtaining a copy of any of the inband signals from any source other than the received signal.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A receiver receives a communication signal, the received communication signal including the desired communication signal and one or more inband signals. A signal processor processes the received signal to form an estimate of the desired communication signal and an estimate of the inband signals. The estimate of the inband signals is thereby removed from the received signal. The estimate of the desired communication signal and the estimate of the inband signals are formed without prior knowledge of characteristics of the inband signals and without obtaining a copy of any of the inband signals from any source other than the received signal.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: A system for and method of detecting interference in a communication system. In an embodiment, a receiver acquires a communication signal, the communication signal comprising a carrier signal and an in-band interference signal. A signal processor conditions the communication signal and extracts the in-band interference signal without interrupting the carrier signal to form an error signal. The error signal is representative of the in-band interference signal. The signal processor is further configured to process the error signal to obtain one or more spectral properties of the error signal in a manner suitable for display.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth based on weighted least-squares estimation based on two TDOA and two FDOA measurements, none of which need to be acquired at the same time. The four TDOA and FDOA measurements and the errors in each of the measurements are determined. Weights for the errors in the TDOA and FDOA measurements are determined, and the weights are applied in a weighted errors function. The weights account for the errors in the measurements and the errors in the satellite positions and velocities, and are dependent on the localization geometry. The weighted errors function is minimized to determine the location estimate of the unknown emitter.

Abstract: A method and system for measuring noise and or interference in a communications signal without taking the signal out of service. In the present invention the communications signal is converted from an RF signal into an IF signal. The IF signal is then digitized and stored. The stored signal is processed to determine the interference signal. The interference signal is calculated from an error vector produced by a blind equalizer demodulator. The interference signal is extracted and presented to a user.

Abstract: The invention is a signal processing system and method having increased bandwidth. An embodiment of the invention is a method of processing an analog input signal. The analog input signal is split into a first set of signals. The first set of signals are filtered. The first set of signals are digitized to form a second set of signals. The second set of signals are filtered to form a third set of signals. The third set of signals are combined to form a combined signal by adding the signals in the third set signals together to form a digital version of the analog input signal.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth based on weighted least-squares estimation based on two TDOA and two FDOA measurements, none of which need to be acquired at the same time. The four TDOA and FDOA measurements and the errors in each of the measurements are determined. Weights for the errors in the TDOA and FDOA measurements are determined, and the weights are applied in a weighted errors function. The weights account for the errors in the measurements and the errors in the satellite positions and velocities, and are dependent on the localization geometry. The weighted errors function is minimized to determine the location estimate of the unknown emitter.

Abstract: A method for providing power control to a uplink signal, comprising an uplink station transmitting an uplink signal to a satellite. The satellite also transmits a loopback signal representing the received uplink signal back to the uplink station. The satellite also transmits a beacon signal to the uplink station. The uplink station adjusts the power of the uplink signal based on measurements of the beacon signal and the uplink signal.

Abstract: A method for providing power control to a uplink signal, comprising an uplink station transmitting an uplink signal to a satellite. The satellite also transmits a loopback signal representing the received uplink signal back to the uplink station. The satellite also transmits a beacon signal to the uplink station. The uplink station adjusts the power of the uplink signal based on measurements of the beacon signal and the uplink signal.

Abstract: A method and system for measuring noise and or interference in a communications signal without taking the signal out of service. In the present invention the communications signal is converted from an RF signal into an IF signal. The IF signal is then digitized and stored. The stored signal is processed to determine the interference signal. The interference signal is calculated from an error vector produced by a blind equalizer demodulator. The interference signal is extracted and presented to a user.

Abstract: A method and apparatus for monitoring and controlling the operating point of a satellite transponder amplifier. In one aspect of the invention, a time domain signal received at a ground station is digitally sampled. Then, a histogram of the received signal is computed. To form the histogram, the digital samples are categorized according to which of a plurality of amplitude ranges each sample falls within. When plotted as a graph, the number of occurrences within each amplitude range forms the histogram. Under low compression levels, the histogram generally appears as an approximately bell-shaped curve. However, under higher compression levels, the bell-shaped curve becomes distorted. By correlating the acquired histogram to a template histogram, an amount of compression can be determined. This amount of compression indicates the operating point of the transponder amplifiers.