Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNRS), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BERL, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNRS), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BERL, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.

Abstract: A communications system (10) and method of operating the communications system includes a first stratospheric platform generating a second beam having a frequency the same as a satellite beam to the same service area. User terminals are configured to receive the first beam or the second beam.

Abstract: A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNRS), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BERL, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: Devices and methods are disclosed for reducing power control cushion of a user terminal configured to communicate with a satellite and a gateway station. The present invention provides a power control algorithm implemented in a user terminal that is designed to operate in a satellite communication system. The power control algorithm can recursively calculate a returnlink power to reduce a power control cushion so that an extra link margin is available to the satellite communication system. The present invention also provides a source coding technique that provides an accurate feedback signal for the user terminal. The average metric of input signal frames is coded in a sequence of bits that are carried by contiguous output signal frames.

Abstract: A method and apparatus for transmitting and receiving a coded signal having an upper layer signal and a lower layer signal is disclosed. The method comprises the steps of combining the upper layer signal and the lower layer signal, encoding the combined upper layer signal and lower layer signal, delaying the upper layer signal, modulating the delayed upper layer signal, modulating the lower layer signal, transmitting the delayed upper layer signal and transmitting the lower layer signal. The apparatus comprises an encoder, for encoding a combined upper layer signal and lower layer signal, a delay, communicatively coupled to the encoder, for delaying the upper layer signal, a first modulator, for modulating the delayed upper layer signal, a second modulator, for modulating the lower layer signal, a transmitter, communicatively coupled to the first modulator, for transmitting the delayed upper layer signal, and a second transmitter, communicatively coupled to the second modulator.

Abstract: A method for communicating and a communications system apparatus are disclosed. The apparatus comprises a communications platform and a gateway communicatively coupleable with a terrestrially-based network. The communications platform is disposed in a stratospheric location and transponds information between at least one of a plurality of user terminals and the gateway in essentially a bent pipe fashion. The method comprises the steps of receiving a first signal from the user terminal having an antenna in a stratospherically-based communication platform that maintains an apparent position relative to the user terminal within a beamwidth of a user terminal antenna and transponding the first signal from the stratospherically based communications platform to a gateway ground station.

Abstract: A system and method for tracking a user. The system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells. In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub.

Abstract: A method for integrating coverage areas of multiple transponder platforms includes the step of arranging a plurality of coverage areas in a cluster wherein each of the plurality of coverage areas is assigned a color that differs from that of every other coverage area in a same cluster and wherein each of the plurality of coverage areas overlaps at least one other coverage area in the same cluster for maximizing utilization of multiple system resources.

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a pseudo-training sequence including an idealized input signal, and generating equalizer parameters from the pseudo-training sequence. The apparatus comprises a demodulator for demodulating an input signal to produce a data output, a modulator, communicatively coupled to the demodulator, for remodulating the data output to produce a pseudo-training sequence including an idealized input signal, and a parameter generation module, communicatively coupled to the modulator for generating equalizer parameters from the pseudo-training sequence.

Abstract: A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Abstract: A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNRS), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BERL, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.

Abstract: A method for beamforming signals for an array of receiving or transmitting elements includes the steps of selecting a beam elevation and azimuth and grouping elements of an antenna array into element ensembles that are substantially aligned with a wavefront projection on the antenna array corresponding to the selected beam elevation and azimuth.

Abstract: A communication system including a first transceiver located on a first platform at a predetermined altitude. A first antenna is located on the first platform and connected to the first transceiver. A second antenna is connected to the other end of the first transceiver. A second transceiver is located on a ground hub physically and independent of the first platform. A third antenna is located on the ground hub and connected to the second transceiver. The third antenna is adapted to communicate with the second antenna. The first platform is maintained in a stratospheric orbit. A beamforming system is connected to the second transceiver and mounted on the ground hub. The beamforming system provides a beamformed signal from the second transceiver to the first transceiver effective to drive the first array antenna to radiate multiple beams to a surface, whereby the multiple beams create time varying and dissimilar footprints thereon.

Abstract: A communication system has a high altitude communication device generating a plurality of user link beams having a first communication characteristic and a feeder link having a first communication characteristic. A gateway terminal receives the user link beam. A user terminal receives at least one of the user link beams. The plurality of user link beams comprises a first user link beam within a first cell and a first isolation zone outside the first cell. The plurality of user link beams comprises a second user link beam having the first communication characteristic and positioned within a second cell and a second isolation zone outside said second cell. The second isolation zone overlaps the first isolation zone. The feeder link is positioned within the first isolation zone and the second isolation zone. The feeder link has the first communication characteristic.