Abstract:
A hybrid broadcast receiver (20) and method (300) of operating a memory (28) in the receiver (20). The memory (28) is used to store received data being processed in the receiver (20). The receiver (20) is configured to receive both a terrestrial signal (12) broadcast by a terrestrial transmitter (14) and a satellite signal (16) broadcast by a satellite transmitter (18). Terrestrial data from the terrestrial signal (12) is stored in a terrestrial portion (30) of the memory (28) that includes a top end (36) or first location (52) of the memory (28). Satellite data from the satellite signal (16) is stored in a satellite portion (32) of the memory (28) that includes a bottom end (38) or last location of the memory (28).
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 terrestrial receiver (58) and method for recovering universal services in a spot beam satellite radio transmission system (46) including at least two discrete signal sources (48 and 50) producing first and second adjacent or overlapping spot beam loci (52 and 54) within a coverage area (42), wherein the signals (60 and 62) forming the spot beams (52 and 54) each contain repeating time aligned universal services having a master synchronizing frame, at least one common channel, and at least one spot specific channel with differing frequency and/or polarization. The receiver (58) switches among a plurality of antenna elements (12) to receive a signal. At least a portion of plurality of antenna elements (12) 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 (14) is in communication with the plurality of antenna elements (12), and switches among single antenna elements (12) to receive the transmitted signal. A controller (16) is in communication with the switching device (14), and commands the switching device (14) to select each of the antenna elements (12) separately in predetermined periods of time based upon the predetermined time intervals of each of the master synchronizing frames. 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 (16) commands the switching device (14) to switch to an antenna element (12) based upon the determined power level.
Abstract:
A receiver system (10) and method (100) of receiving signals is provided. The receiver system (10) includes a plurality of antennas that receive signals and are proximate to one another, a plurality of tuners, a signal combiner (20), and a symbol timing combiner (22). The plurality of tuners are in communication with the plurality of antennas. The signal combiner (20) is in communication with the plurality of tuners, and combines an output of each of the plurality of tuners. The symbol timing combiner (22) is in communication with the signal combiner (20) and the plurality of tuners, wherein an output of the signal combiner (20) and outputs from each of the tuners are received by the symbol timing combiner (22), and the symbol timing combiner (22) emits a combined symbol timing output that is received by each of the tuners. The plurality of tuners process the signals communicated from the plurality of antennas based upon the combined symbol timing output.
Abstract:
A terrestrial receiver (58) and method for recovering universal services in a spot beam satellite radio transmission system (46) including at least two discrete signal sources (48 and 50) producing first and second adjacent or overlapping spot beam loci (52 and 54) within a coverage area (42), wherein the signals (60 and 62) forming the spot beams (52 and 54) each contain repeating time aligned universal services having a master synchronizing frame, at least one common channel, and at least one spot specific channel with differing frequency and/or polarization. The receiver (58) switches among a plurality of antenna elements (12) to receive a signal. At least a portion of plurality of antenna elements (12) 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 (14) is in communication with the plurality of antenna elements (12), and switches among single antenna elements (12) to receive the transmitted signal. A controller (16) is in communication with the switching device (14), and commands the switching device (14) to select each of the antenna elements (12) separately in predetermined periods of time based upon the predetermined time intervals of each of the master synchronizing frames. 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 (16) commands the switching device (14) to switch to an antenna element (12) based upon the determined power level.
Abstract:
The present invention generally relates to the transmission of digital data, and more particularly, to the transmission of digital data in a satellite digital audio radio ("SDAR") system. In the SDAR system, there may be different types of required services. Some of these services may be considered high priority and others may be of a lower priority. Current SDAR systems have the same performance on all user data. Therefore, there is a need to vary the performance of different services. The present invention provides a method and apparatus for optimizing the throughput (i.e. information) in a digital transmission system by transmitting the different services with different performance levels. The present invention addresses the need in the art to vary the performance of different services (i.e., levels of data). Because the performance of the primary level of data will not be equal to the performance of the secondary level of data, the primary level will need to be further protected. The primary level data may be streaming data. The secondary level data does not need as much protection because it may be rebroadcast repeatedly. The easiest and most cost effective solution is to integrate multiple symbols for a secondary level bit. The present invention provides a method and apparatus in which the power level for the data levels can be set within each data packet using a message header providing the different services with different levels of performance.