Abstract: An avionics system comprises a plurality of avionics components; at least one OFDM transmitter coupled to a respective one or more of the plurality of avionics components and configured to transmit a wireless OFDM signal comprising a plurality of sub-bands; at least one OFDM receiver coupled to a respective one or more of the plurality of avionics components and configured to receive the wireless OFDM signal transmitted by the OFDM transmitter; and a radio altimeter configured to transmit a signal tone that sweeps a frequency spectrum allocated to the radio altimeter at a predefined rate and periodicity. The at least one OFDM transmitter is configured to transmit the wireless OFDM signal in the frequency spectrum allocated to the radio altimeter and to sequentially turn off respective subsets of the plurality of sub-bands in synchronization with the predefined rate and periodicity of the signal tone frequency sweep.

Abstract: A method of estimating Doppler shift for air to ground communications comprises obtaining an initial position of an aircraft during flight, wherein the aircraft includes an onboard database with stored positions for a plurality of ground station towers; when a subsequent position of the aircraft nears a stored position of a closest ground station tower, requesting a Doppler shift estimation for the closest ground station tower; obtaining a current position of the aircraft when requesting the Doppler shift estimation; defining an aircraft position vector from the initial position to the current position; defining a tower position vector from the initial position to the stored position; subtracting the aircraft position vector from the tower position vector to determine an aircraft to tower position vector; differentiating the aircraft to tower position vector with respect to time to determine a velocity magnitude to the closest ground station tower; and calculating a Doppler shift.

Abstract: An avionics system comprises a plurality of avionics components; at least one OFDM transmitter coupled to a respective one or more of the plurality of avionics components and configured to transmit a wireless OFDM signal comprising a plurality of sub-bands; at least one OFDM receiver coupled to a respective one or more of the plurality of avionics components and configured to receive the wireless OFDM signal transmitted by the OFDM transmitter; and a radio altimeter configured to transmit a signal tone that sweeps a frequency spectrum allocated to the radio altimeter at a predefined rate and periodicity. The at least one OFDM transmitter is configured to transmit the wireless OFDM signal in the frequency spectrum allocated to the radio altimeter and to sequentially turn off respective subsets of the plurality of sub-bands in synchronization with the predefined rate and periodicity of the signal tone frequency sweep.

Abstract: One embodiment is directed to an aircraft position report system. The system comprises a satellite, an aircraft position reporting receiver mounted on the satellite, an antenna element mounted on the satellite, and an antenna interface mounted on the satellite. The aircraft position reporting receiver receives aircraft position reports through the antenna element by associating a spot beam with a narrow coverage area. The aircraft position reports are derived from a signal produced by the antenna element. The antenna interface changes the narrow coverage area associated with the spot beam to receive aircraft position reports from a wide coverage region within a reporting period. In one exemplary embodiment, the antenna interface mechanically steers the spot beam for each receiver to one of the narrow coverage areas. In another exemplary embodiment, the antenna interface electronically steers the spot beam for each receiver to one of the narrow coverage areas.

Abstract: A method, system, and apparatus for communicating data with a seismic sensor are provided. The method comprises identifying data to be transmitted and one or more seismic events that correspond to the data to be transmitted. One or more seismic events are created that are distinguishable into binary code from one or more seismic sensors within the array. Seismic events can be distinguished by their pattern or frequency. A first frequency can be assigned as a first binary code and a second frequency can be assigned as a second binary code. Likewise, different patterns of acoustic energy can designate different binary codes. Combinations of patterns and frequencies can be used together to create distinct distinguishable seismic events.

Abstract: A method for maintaining a nominal decoder time phase alignment through a data drop-out period is provided. The method includes determining if a search window is open. A search-window width of the search window is an initial search-window width. The initial search-window width is larger than the width of the frame synchronization pattern. The method also includes determining if a bit clock rising edge is detected and searching for the frame synchronization pattern on a bit level when the search window is open and the bit clock rising edge is detected. If the frame synchronization pattern is not found responsive to the searching, the method also includes determining if a receipt time of the bit received when the bit clock rising edge was detected is coincident with an expected start time of the frame synchronization pattern.

Abstract: A method for maintaining a nominal decoder time phase alignment through a data drop-out period is provided. The method includes determining if a search window is open. A search-window width of the search window is an initial search-window width. The initial search-window width is larger than the width of the frame synchronization pattern. The method also includes determining if a bit clock rising edge is detected and searching for the frame synchronization pattern on a bit level when the search window is open and the bit clock rising edge is detected. If the frame synchronization pattern is not found responsive to the searching, the method also includes determining if a receipt time of the bit received when the bit clock rising edge was detected is coincident with an expected start time of the frame synchronization pattern.

Abstract: One embodiment is directed towards an RF receiver for receiving a pulse-position modulated signal transmitted with a 1090 MHz ADS-B transmitter, wherein the pulse-position modulated signal is preceded by a preamble of 4 pulses that conform to an ADS-B protocol. The receiver can filter a digital sample stream with a filter matched to pulses in an earlier half of an expected preamble sequence to produce a first matched filter output sample stream. The receiver can also filter the digital sample stream with a filter matched to a pulses in a latter half of the expected preamble sequence to produce a second matched filter output sample stream. The receiver can determine that a sequence of pulses match the expected preamble sequence based on when the first matched filter output sample stream and the second matched filter output sample stream are above a minimum trigger level at the same time.

Abstract: One embodiment is directed towards an RF receiver for receiving a pulse-position modulated signal transmitted with a 1090 MHz ADS-B transmitter, wherein the pulse-position modulated signal is preceded by a preamble of 4 pulses that conform to an ADS-B protocol. The receiver can filter a digital sample stream with a filter matched to pulses in an earlier half of an expected preamble sequence to produce a first matched filter output sample stream. The receiver can also filter the digital sample stream with a filter matched to a pulses in a latter half of the expected preamble sequence to produce a second matched filter output sample stream. The receiver can determine that a sequence of pulses match the expected preamble sequence based on when the first matched filter output sample stream and the second matched filter output sample stream are above a minimum trigger level at the same time.

Abstract: A system comprises an outer shell having an inner spherical cavity and an inner sphere located in the spherical cavity. The inner sphere comprises a sensor; at least one transmit antenna; and at least one transmitter coupled to the sensor and to a respective one of the at least one transmit antenna. The system also comprises a first receive antenna located in the spherical cavity; a second receive antenna located in the spherical cavity; and a receiver located outside of the outer shell. The receiver is configured to determine the signal to noise ratio of a first signal received at the first receive antenna and the signal to noise ratio of a second signal received at the second receive antenna; and to combine the first and second signals based on the respective signal to noise ratios such that interference due to multi-path signals in the spherical cavity is reduced.

Abstract: A method for synchronizing frames when a frame synchronization pattern is lost is provided. The method includes forcing a frame state machine to an operate mode following an initial synchronization, searching for the frame synchronization pattern on a bit level while running the frame state machine in the operate mode, and correcting for synchronization on the bit level while running the frame state machine in the operate mode when synchronization is lost. The initial synchronization includes a search mode.

Abstract: One embodiment is directed to an aircraft position report system. The system comprises a satellite, an aircraft position reporting receiver mounted on the satellite, an antenna element mounted on the satellite, and an antenna interface mounted on the satellite. The aircraft position reporting receiver receives aircraft position reports through the antenna element by associating a spot beam with a narrow coverage area. The aircraft position reports are derived from a signal produced by the antenna element. The antenna interface changes the narrow coverage area associated with the spot beam to receive aircraft position reports from a wide coverage region within a reporting period. In one exemplary embodiment, the antenna interface mechanically steers the spot beam for each receiver to one of the narrow coverage areas. In another exemplary embodiment, the antenna interface electronically steers the spot beam for each receiver to one of the narrow coverage areas.

Abstract: Systems and methods of providing error tolerant robust simplex wireless data for systems employing time correlated data transfer are provided. In one embodiment, a system comprises: sensors that produce samples of time correlated data; and a node coupled to the sensors by a wireless link. The link comprises a primary stream for simplex transmission of data packets, and a secondary stream for simplex transmission of delayed data packets, the delayed data packets a delayed retransmission of the time correlated data. When the node receives a first data packet from a first sensor via the primary stream, the data receiving node check validity. When the first data packet is corrupted, the node validity checks a second data packet received via the secondary stream. When both packets contain corrupted data, the node builds a reconstructed plurality of sequential time correlated data samples based on non-corrupted data samples from within the data packets.

Abstract: A method for synchronizing frames when a frame synchronization pattern is lost is provided. The method includes forcing a frame state machine to an operate mode following an initial synchronization, searching for the frame synchronization pattern on a bit level while running the frame state machine in the operate mode, and correcting for synchronization on the bit level while running the frame state machine in the operate mode when synchronization is lost. The initial synchronization includes a search mode.

Abstract: A system comprises an outer shell having an inner spherical cavity and an inner sphere located in the spherical cavity. The inner sphere comprises a sensor; at least three transmit antennas; and at least three transmitters each coupled to the sensor and to a respective one of the at least three transmit antennas. The system comprises at least three receive antennas each located in the spherical cavity, wherein each of the at least three receive antennas is frequency matched to a transmit frequency of a respective one of the at least one transmit antennas. The system also comprises at least three receivers each coupled to a respective one of the at least three receive antennas and a data selection logic circuit configured to select at least one signal from the signals received from each of the at least three receivers based on the respective signal quality of the received signals.

Abstract: A system comprises an outer shell having an inner spherical cavity and an inner sphere located in the spherical cavity. The inner sphere comprises a sensor; at least one transmit antenna; and at least one transmitter coupled to the sensor and to a respective one of the at least one transmit antenna. The system also comprises a first receive antenna located in the spherical cavity; a second receive antenna located in the spherical cavity; and a receiver located outside of the outer shell. The receiver is configured to determine the signal to noise ratio of a first signal received at the first receive antenna and the signal to noise ratio of a second signal received at the second receive antenna; and to combine the first and second signals based on the respective signal to noise ratios such that interference due to multi-path signals in the spherical cavity is reduced.

Abstract: Systems and methods of providing error tolerant robust simplex wireless data for systems employing time correlated data transfer are provided. In one embodiment, a system comprises: sensors that produce samples of time correlated data; and a node coupled to the sensors by a wireless link. The link comprises a primary stream for simplex transmission of data packets, and a secondary stream for simplex transmission of delayed data packets, the delayed data packets a delayed retransmission of the time correlated data. When the node receives a first data packet from a first sensor via the primary stream, the data receiving node check validity. When the first data packet is corrupted, the node validity checks a second data packet received via the secondary stream. When both packets contain corrupted data, the node builds a reconstructed plurality of sequential time correlated data samples based on non-corrupted data samples from within the data packets.

Abstract: An electronic device includes a communication bus having a physical layer for interacting with a peripheral device. The physical layer is configured to be adjacent to a link layer on the peripheral device. The electronic device further includes a connector at a junction of the physical layer and the link layer. Communication through the communication bus is maintained through the physical layer when the link layer of the peripheral device is disconnected from the physical layer at the connector.

Abstract: A network system for inter-component communications in an electronic device is disclosed. The system comprises a plurality of components for an electronic device, where each of the components communicates with at least one other component over a communications medium for a wireless mesh network. Each of the components comprises a communications transceiver operable to determine network traffic load levels for an exchange of communication data between the components, and allocate the network traffic between at least one pair of the components over a plurality of wireless links within the wireless mesh network based on potential-field based measurements at each of the components. In addition, each of the communications transceivers share the exchange of the communication data between the components based on a prescribed priority level for allocation of the network traffic.

Abstract: An apparatus and method for connectivity in networks configured for non-disruptive disconnection of one or more peripheral devices are disclosed. The apparatus includes a first logical layer associated with a first peripheral device, the first peripheral device arranged in a network configured for non-disruptive disconnection of at least one peripheral device, at least a second logical layer associated with at least a second peripheral device, the at least a second peripheral device arranged in the network configured for non-disruptive disconnection of at least one peripheral device, at least one power source associated with the first logical layer and the at least a second logical layer, and a first electrically conductive link coupled to the first logical layer, the at least a second logical layer, and the at least one power source associated with the first logical layer and the at least a second logical layer.