Abstract: A printed circuit board includes a substrate having a plurality of stacked circuit board layers. The substrate has a top surface and a bottom surface. The printed circuit board includes a signal contact on the substrate. The signal contact has a signal via and a signal trace extending from the signal via. The signal via extends between the top surface and the bottom surface along a via axis. The printed circuit board includes an anti-pad around the signal via extending through the substrate along the via axis. The anti-pad extends between the top surface and the bottom surface. The anti-pad has a first width at the top surface and the lower anti-pad has a second width at the bottom surface different than the first width.

Abstract: A printed circuit board includes a substrate having a plurality of stacked circuit board layers. The substrate has a top surface and a bottom surface. The printed circuit board includes a signal contact on the substrate. The signal contact has a signal via and a signal trace extending from the signal via. The signal via extends between the top surface and the bottom surface along a via axis. The printed circuit board includes an anti-pad around the signal via extending through the substrate along the via axis. The anti-pad extends between the top surface and the bottom surface. The anti-pad has a first width at the top surface and the lower anti-pad has a second width at the bottom surface different than the first width.

Abstract: A communication system includes a satellite and a ground station. The satellite is configured to preferentially receive signals from each of a plurality of sub-regions within a region of communication of the satellite. The ground station is configured to determine a location of the ground station, determine in which of the sub-regions that the ground station resides based on the location, and transmit a signal to the satellite during a time-interval assigned to the sub-region. The ground stations time-multiplex the transmission of signals from various ground stations to the satellite based on which sub-region of the larger region (e.g. the continental United States or CONUS) that the ground station resides. The time multiplexing is such that ground stations in one region are not transmitting signals to the satellite during the same time interval as ground stations in adjacent sub-regions.

Abstract: A satellite communication system using hierarchical modulation to transmit a plurality of modulated signals to sub-regions within a region. Each modulated signal includes high priority content and low priority content. The system includes a satellite equipped with a plurality of satellite transmitters coupled to a plurality of antenna elements, e.g. a phased array of antenna elements. The antenna elements are utilized selectively to direct a modulated signal from a satellite transmitter to a distinct sub-region. The satellite transmitters and antenna also cooperate to broadcast the high-priority content to the region such that a ground receiver traveling from a first sub-region to an adjacent second sub-region adjacent will not experience a loss of high-priority content. First low-priority content of a first modulated signal directed to the first sub-region is independent of second low-priority content of a second modulated signal directed to the second sub-region.

Abstract: A satellite communication system using hierarchical modulation to transmit a plurality of modulated signals to sub-regions within a region. Each modulated signal includes high priority content and low priority content. The system includes a satellite equipped with a plurality of satellite transmitters coupled to a plurality of antenna elements, e.g. a phased array of antenna elements. The antenna elements are utilized selectively to direct a modulated signal from a satellite transmitter to a distinct sub-region. The satellite transmitters and antenna also cooperate to broadcast the high-priority content to the region such that a ground receiver traveling from a first sub-region to an adjacent second sub-region adjacent will not experience a loss of high-priority content. First low-priority content of a first modulated signal directed to the first sub-region is independent of second low-priority content of a second modulated signal directed to the second sub-region.

Abstract: A method is presented to extend a frequency lock range of a received RF signal in a satellite receiver. One step in the method includes analyzing data information of a preamble associated with the received satellite RF signal. Another step includes determining an estimated frequency value that is a function of the analyzed data information that further includes at least a portion of the frequency error formed therein. A further step includes comparing the determined estimated frequency value to a predetermined threshold value. Another step includes using the determined estimated frequency value when the determined frequency value is greater than the predetermined threshold value to operatively control tracking mode electronic circuitry disposed in the satellite receiver to attain frequency lock on the received satellite RF signal.

Abstract: A hybrid broadcast receiver and method of operating a memory in the receiver. The memory is used to store received data being processed in the receiver. The receiver is configured to receive both a terrestrial signal broadcast by a terrestrial transmitter and a satellite signal broadcast by a satellite transmitter. Terrestrial data from the terrestrial signal is stored in a terrestrial portion of the memory that includes a top end or first location of the memory. Satellite data from the satellite signal is stored in a satellite portion of the memory that includes a bottom end or last location of the memory.

Abstract: A method is presented to extend a frequency lock range of a received RF signal in a satellite receiver. One step in the method includes analyzing data information of a preamble associated with the received satellite RF signal. Another step includes determining an estimated frequency value that is a function of the analyzed data information that further includes at least a portion of the frequency error formed therein. A further step includes comparing the determined estimated frequency value to a predetermined threshold value. Another step includes using the determined estimated frequency value when the determined frequency value is greater than the predetermined threshold value to operatively control tracking mode electronic circuitry disposed in the satellite receiver to attain frequency lock on the received satellite RF signal.

Abstract: Long time interleaver and listenable audio performance enhancements for a satellite receiver are presented. One enhancement includes comparing a correlation and a predetermined threshold value and blocking satellite signal data transmission from entry into long time interleaver (LTI) device circuitry and forward error correction (FEC) circuitry when the correlation value is the same as, or less than the predetermined threshold value. Another enhancement includes using Reed-Solomon codeword error checking to prevent erroneous baseband signal data from being accepted as good baseband signal data. A further enhancement includes storing symbol timing and frequency data during a strong signal condition of the satellite receiver and using this stored data when the satellite receiver encounters a weak signal condition. Another enhancement includes mitigating DC offset noise in a satellite receiver having a zero-IF tuner.

Abstract: Long time interleaver and listenable audio performance enhancements for a satellite receiver are presented. One enhancement includes comparing a correlation and a predetermined threshold value and blocking satellite signal data transmission from entry into long time interleaver (LTI) device circuitry and forward error correction (FEC) circuitry when the correlation value is the same as, or less than the predetermined threshold value. Another enhancement includes using Reed-Solomon codeword error checking to prevent erroneous baseband signal data from being accepted as good baseband signal data. A further enhancement includes storing symbol timing and frequency data during a strong signal condition of the satellite receiver and using this stored data when the satellite receiver encounters a weak signal condition. Another enhancement includes mitigating DC offset noise in a satellite receiver having a zero-IF tuner.

Abstract: A system and method of communicating signals is provided. The system includes a plurality of satellites, at least one receiver, and at least one satellite uplink station. The plurality of satellites include at least one active satellite. The at least one receiver is in communication with the plurality of satellites, and receives a signal from the at least one active satellite. The at least one satellite uplink station is in communication with the plurality of satellites, and transmits the signal and alters a frequency of the signal based upon a location of the at least one active satellite to reduce a Doppler frequency shift when activating and deactivating the plurality of satellites.

Abstract: A system and method of multi-source communications, including a source provider, a transmitter, a receiver, a summing device, a plurality of delay devices, and a switch. The source provider provides a signal including a first and second signal. The transmitter is in communication with the source provider and the receiver. The receiver is in communication with the transmitter. The summing device combines the first and second signals received by the receiver. The delay device delays at least one of the first and second signals. The switch forms a bypass, such that at least one of the first and second signals bypasses one of the plurality of delay devices.

Abstract: A system and method of communicating sub-synchronization information into a transmitted digital audio stream and extracting sub-synchronization information from a received digital audio stream is provided. The method includes the steps of having a transmitter introduce sub-synchronization information into a data stream at a period less than that of existing transmitter pre-amble signals, and transmitting that data to a receiver. The method further includes the steps of receiving the transmitted data stream in the receiver circuitry, extracting the synchronization information, and using the synchronization information to accurately decode the received audio data.

Abstract: A receiver system and method for switching among a plurality of antenna elements to receive a signal. At least a portion of plurality of antenna elements receive a transmitted signal, such that the transmitted signal includes a plurality of sub-channels that are transmitted in predetermined time intervals. A switching device is in communication with the plurality of antenna elements, and switches among single antenna elements to receive the transmitted signal. A controller is in communication with the switching device, and commands the switching device to select each of the antenna elements separately in predetermined periods of time based upon the predetermined time intervals of each of the sub-channels. A power level of the transmitted signal is determined during the predetermined period of time that corresponds to the predetermined time intervals, and the controller commands the switching device to switch to an antenna element based upon the determined power level.

Abstract: High priority data and low priority digital data are transmitted as primary and secondary data in hierarchically modulated, orthogonal frequency division multiplexing (OFDM) from an earth-orbiting satellite. To enable the transmitter amplifier to be operated with less back-off from saturation without clipping, the low priority OFDM symbols have fewer samples than the high priority OFDM symbols, and the high priority samples on which the low priority samples are superimposed are selected according to a first deterministic rule using sample power comparisons of the high priority samples to concentrate the low priority samples on those high priority samples having lower (optimally, the lowest) sample power. The low priority samples are distributed on the selected high priority samples according to a second deterministic rule relating the original low priority sample order to the original high priority sample order.

Abstract: A communication system and method of communicating signals to a plurality of different types of receivers is provided. At least one transmitter transmits hierarchically modulated high priority and low priority signals as a single frequency network. At least one satellite re-transmits the high priority signal in a first circularly polarized direction and the low priority signal in a second circularly polarized direction. At least one of a first receiver having a single antenna is configured to receive the high priority signal in the first circularly polarized direction and switched to receive the low priority signal in the second circularly polarized direction, and a second receiver having a first antenna is configured to receive the high priority signal in the first circularly polarized direction, and a second antenna is configured to receive the low priority signal in the second circularly polarized direction substantially simultaneously.

Abstract: A communication system and method of communicating signals to a plurality of different types of receivers is provided. The communication system includes at least one transmitter that transmits a high priority signal and a low priority signal that are hierarchically modulated and transmitted as a single frequency network. At least one satellite receives and re-transmits at least one of the high priority and low priority signals. At least one of the plurality of receivers include a processor that performs the steps of storing the hierarchically modulated signal, demodulating the high priority signal from the hierarchically modulated signal, decoding the demodulated high priority signal, re-encoding the high priority signal, and processing the stored hierarchically modulated signal based upon the re-encoded high priority signal.

Abstract: The present invention provides a method to minimize degradation in a D-MPSK hierarchical modulation system by adding additional data throughput (i.e., secondary information) as an offset to the primary signal transmitted by a SDARS terrestrial repeater. The present invention provides techniques for adding the additional throughput as Level 2 data by transmitting offset phase and/or amplitude information across adjacent OFDM symbols and/or adjacent frequency subcarriers.

Abstract: Additional data may be added to the current SDARS satellite signals as a phase and/or amplitude offset from the legacy quadrature phase shift keying (QPSK) modulated data and transmitted by the SDAR terrestrial repeaters. However, in the case where a legacy receiver architecture for a differential modulation system outputs angular/phase differences between carriers, the phase and/or amplitude information appears as distortion to the legacy receiver. The present invention provides a method for optimizing the SDARS infrastructure more efficiently by allowing independent adjustment of the phase and/or amplitude offset (610) at each terrestrial site. The present invention provides a method for adjusting the performance of each signal together or separately as needed.

Abstract: Where the additional data throughput is added using an amplitude offset or a combination of phase and amplitude offset, the legacy differential demodulator does not recover the amplitude information. The present invention provides a method for demodulating amplitude offsets in a differential modulation system in order to recover the amplitude information. The demodulated amplitude information may be used to recover the additional Level 2 data transmitted as an amplitude offset or combination phase and amplitude offset in a differential multiple phase shift keying (D-MPSK) transmission, such as across adjacent OFDM symbols and/or adjacent frequency subcarriers.