Abstract: A method for air to ground communication interference mitigation within an aircraft equipped with a multi-beam array antenna includes adjusting a modulation symbol interleaving and/or forward error correction of an aircraft receiver interface in response to detected interference from an interferer. The method further includes reducing a data rate of the aircraft receiver interface when the adjusting of the modulation symbol interleaving and/or forward error correction does not mitigate the detected interference. Another method for interference mitigation may include performing antenna beam-steering away from a geographic (GEO) arc during an aircraft turn. This method further includes reducing an aircraft transmitter transmit power when a signal quality of a forward link is within a predetermined range of a signal quality threshold.

Abstract: Techniques are provided which may be implemented in various methods, apparatuses, and/or articles of manufacture for use by a device that is operable in a plurality of modes, including “higher power mode” and a “lower power mode”. A timing circuit may be set based, at least in part, on a phase value obtained from a signal from a ground-based transmitter, and operation of the device may be selectively transitioned to a lower power mode wherein the device uses the timing circuit. In certain example implementations, operation of the device to the lower power mode may be selectively transition and based, at least in part, on a determination that one or more attribute values satisfy a profile test indicating that the electronic device is likely to be within a characterized environment, and/or a determination that the electronic device is likely to be in a constrained motion state.

Abstract: Techniques are provided which may be implemented in various methods, apparatuses, and/or articles of manufacture for use in and/or with an electronic device that is operable in a plurality of selectable power modes, including at least a “higher power mode” and a “lower power mode”. In an example implementation, with an electronic device operating in a higher power mode may selectively transition to a lower power mode based, at least in part, on at least phase value obtained from a signal acquired from a ground-based transmitter. Further techniques are provided which may be implemented to allow electronic device to selectively transition from a lower power mode to one or more other selectable power modes, e.g., including various “medium power modes”, and various “higher power modes”.

Abstract: Aeronautical broadband communication is enhanced by providing an apparatus having a first antenna configured to communicate using a signal orientation corresponding to a first polarization, and a second antenna configured to communicate using a signal orientation corresponding to a second polarization, where the second polarization has at least one characteristic difference from the first polarization. Additional antennas may be used, where multiple antennas share one polarization, and multiple other antennas share a different polarization, and signals from like-polarized antennas are combined for beam-formation.

Abstract: Apparatus and method are disclosed for digital authentication and verification. In one embodiment, authentication involves storing a cryptographic key and a look up table (LUT), generating an access code using the cryptographic key; generating multiple parallel BPSK symbols based upon the access code; converting the BPSK symbols into multiple tones encoded with the access code using the LUT; and outputting the multiple tones encoded with the access code for authentication. In another embodiment, verification involves receiving multiple tones encoded with an access code; generating multiple parallel BPSK symbols from the multiple tones; converting the BPSK symbols into an encoded interleaved bit stream of the access code; de-interleaving the encoded interleaved bit stream; and recovering the access code from the encoded de-interleaved bit stream.

Abstract: An air to ground communication system provides internet access to aircraft from ground based stations. The air to ground system shares spectrum with uplink portions of a satellite communication spectrum. Interference mitigation techniques are employed to avoid interference between the ground based communications and satellite communications. Fade mitigation techniques are employed to provide communication to aircraft at low angles of elevation in the presence of rain.

Abstract: An OCDMA transmission arrangement involves encoding both first and second nominally orthogonal polarization signals with a same long code, and transmitting the long-encoded first and second nominally orthogonal polarization signals from respective first and second transmission sources to at least one destination. A corresponding OCDMA demodulating arrangement demodulates the first and second nominally orthogonal polarization signals that were transmitted from respective first and second transmission sources after having been encoded with the same long code. The demodulation arrangement involves receiving the encoded first and second nominally orthogonal polarization signals, and applying the same long code to the received encoded first and second nominally orthogonal polarization signals.

Abstract: A novel MAC algorithm is disclosed having various features for a modern CDMA interference-shared reverse link, including (a) link quality assurance, (b) individual congestion control, (c) variable data rate transition policy, and/or (d) reverse link partitioning. Link quality assurance is provided by monitoring transmission feedback information (ACK/NACK) to indirectly determine the quality of a communication link. Wireless devices are individually targeted to perform congestion control of the reverse link. Variable data transmission rates and discontinuous transmissions are achieved by individual wireless devices that autonomously adjust their transmission rate and transmit power. The reverse link can also be partitioned among the different wireless devices by individually controlling the transmit power of the wireless devices operating on the reverse link.

Abstract: A ground station antenna array includes a first array of antenna elements. A second array of antenna elements are vertically aligned with the first array of antenna elements. The first array of antenna elements and the second array of antenna elements are coupled to the digital beam forming circuitry and each cover a same sector of azimuth; the first array of antenna elements only covering a first elevation; the second array of antenna elements only covering a second lower elevation. The digital beam forming circuitry directs a radiation pattern of the first array of antenna elements in a first range of elevation angles, and directs a radiation pattern of the second array of antenna elements in a second range of elevation angles. The second array of antenna elements has higher gain than the first array. A respective transceiver is coupled to respective antenna elements of the first and second arrays.

Abstract: A method for real-time calibration of an air to ground two-way communication system. The method includes calibrating a ground base station antenna array according to forward link calibration coefficients received from an aircraft as part of a communication signaling protocol during operation of the air to ground two-way communication system. The method may also includes communicating between the ground base station antenna array and the aircraft over a narrow beam.

Abstract: A method for ground to air communication includes receiving a first pilot signal on a first wide beam from a first ground base station by a first antenna element covering a first range of azimuth angles from an aircraft. Data is received on a directed data beam from the first ground base station by the first antenna element. A second pilot signal is received on a second wide beam from a second ground base station by a second antenna element covering a second range of azimuth angles different than the first range of azimuth angles. A signal strength of the second pilot signal is compared with a signal strength of the first pilot signal. Data reception is switched from the first antenna element to the second antenna element if the signal strength of the second pilot signal is greater than the signal strength of the first pilot signal.

Abstract: Transmitter and receiver units for use in an OFDM communications system and configurable to support multiple types of services. The transmitter unit includes one or more encoders, a symbol mapping element, and a modulator. Each encoder receives and codes a respective channel data stream to generate a corresponding coded data stream. The symbol mapping element receives and maps data from the coded data streams to generate modulation symbol vectors, with each modulation symbol vector including a set of data values used to modulate a set of tones to generate an OFDM symbol. The modulator modulates the modulation symbol vectors to provide a modulated signal suitable for transmission. The data from each coded data stream is mapped to a respective set of one or more “circuits”. Each circuit can be defined to include a number of tones from a number of OFDM symbols, a number of tones from a single OFDM symbol, all tones from one or more OFDM symbols, or some other combination of tones.

Abstract: Techniques to process data for transmission in a time division duplexed (TDD) communication system. In one aspect, the frequency response of a forward link is estimated at a base station based on reverse link transmissions (e.g., pilots) from a terminal. Prior to a data transmission on the forward link, the base station determines a reverse transfer function based on the pilots transmitted by the terminal, “calibrates” the reverse transfer function with a calibration function to derive an estimate of a forward transfer function, and preconditions modulation symbols based on weights derived from the forward transfer function. In another aspect, the terminal estimates the “quality” of the forward link and provides this information to the base station. The base station then uses the information to properly code and modulate data prior to transmission such that the transmitted data can be received by the terminal at the desired level of performance.

Abstract: A hybrid satellite-mesh network including a ground segment, a mobile segment and a satellite segment provides high bandwidth communication between mobile platforms and the Internet. The satellite segment is used only when mesh network communication links between mobile segment nodes and ground segment nodes are unavailable. Mobile segment nodes can function in either an access terminal mode or an access point mode to communicate with other mobile segment nodes according to a routing algorithm in a mesh portion of the network. Mobile segment nodes employ adaptive frequency reuse, link level date rate adaptation, link level power control and adaptive beam forming antennas.

Abstract: Reverse link data rate indications in wireless communication systems are defined with low identification overhead. Existence of a pilot signal is leveraged in order to reduce the overhead for identifying and selecting the reverse link data rate. At least two distinguishable pilot signals are defined, in which, based on the particular pilot signal present in the transmitted frame, at least one rate set from the multiple available rate sets can be determined. Reverse rate information in the transmitted frame is then used to identify which specific data rate within the determined rate set is used. Based on the identified data rate, the receiver may then decode the payload data in the transmitted frame.

Abstract: In a synchronous application to control forward link (FL) data rates in a satellite system, user equipment (UE) repeatedly transmits a quality control measurement (QCM) index during a QCM period. During this QCM period, the data rate cannot change. The associated satellite transmits at a new rate corresponding to the QCM index. The UE knows that it will begin receiving new data at the new rate after a QCM delay. In an asynchronous application, a satellite transmits a rate change signal over a FL rate indication channel (RICH). A UE monitors the FL RICH for this signal. When the signal quality is to be low, the satellite sends only a single bit of the QCM index over a first orthogonal channel. When the signal quality is not low, the satellite transmits each bit of the QCM index in a separate orthogonal channel of the FL RICH.

Abstract: Methods and apparatus are disclosed to provide orthogonal multiple access communication in a return link of a satellite communication system. In one embodiment, a closed loop control of a transmit parameter associated with transmission of signals may be performed. In addition, changes in motion of a terminal are monitored such that an open loop control of the transmit parameter is performed, if the detected change meets a certain threshold. For example, an open control is performed if an abrupt or sudden motion is detected.

Abstract: Techniques for efficiently transmitting various types of signaling on the forward and reverse links in an OFDM-based system are described. Instead of specifically allocating subbands to individual signaling channels, signaling data for a signaling channel on a given link is sent as “underlay” to other transmissions that may be sent on the same link. Each wireless terminal is assigned a different PN code. The signaling data for each terminal is spectrally spread over all or a portion of the system bandwidth using the assigned PN code. For the reverse link, a wireless terminal may transmit signaling on all N usable subbands and may transmit traffic data on L subbands assigned for data transmission, which may be a subset of the N usable subbands. For the forward link, a base station may transmit signaling and traffic data for all terminals on the N usable subbands.

Abstract: Aspects describe utilizing the Internet capability in mobile devices/networks to deliver broadcast multimedia to a device. The broadcast can be video, audio, and so forth. Initially the broadcast multimedia is transmitted at high data rates (and in unicast mode) in order for a buffer associated with mobile device to be built to a very long buffer length. When the long buffer length is reached, the multimedia can be delivered at real-time rates. The multimedia delivered at real times rates can be unicast mode or in multicast mode. If the buffer is depleted, a mobile device that is part of a multicast group can autonomously disassociated from the group until the buffer length is restored.

Abstract: A method for detecting a plurality of navigation beacon signals by using either two antennas or a synthetic aperture antenna for receiving a plurality of distinct measurements, and combining the plurality of distinct measurements using a plurality of antenna weight components to form an interference cancellation beam. In one embodiment, the plurality of antenna weight components is determined by eigenvalue processing. In another embodiment, the plurality of antenna weight components is determined by simplified processing. In another aspect, a single antenna is used for receiving an originally received measurement. A copy of the originally received measurement is made and processed to achieve the proper time delay to emulate spatial diversity. The originally received measurement and the processed copy are combined to form an interference cancellation beam.