Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream and improving the synchronization of the received signal in which an overlay layer frame is synchronized to a base layer frame. The base layer frame includes additional data that is used to synchronize the receivers to demodulate and decode the overlay layer and the base layer. The additional data is modulated using a technique that aids the receiver in synchronizing the received signal that is different from the overlay layer.

Abstract: Systems and methods for increasing bandwidth for digital content delivery are presented. A content delivery method and system split a digitally encoded content file (e.g., song, television show, movie, podcast, or other audio or video content file) to be delivered to receivers into at least two files with a first file being stored at a receiver in advance of receiving the second file. The first file generally includes a majority of the information in the content file but is denatured and cannot be decoded by a receiver or media player to produce even a portion of the original content file without the second file. The second file includes information derived from the original content file that is not contained in the first file. Upon receiving the transmitted second file, a receiver combines and processes both files to recover the original content file wholly or substantially for playback.

Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream to increase the amount of data transmitted in the SDARS system. Using improved (next generation) receiver designs, additional services can be provided to users while existing legacy receivers can continue to receive the services broadcast on the base layer modulated data stream in the legacy system.

Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream and improving the synchronization of the received signal in which an overlay layer frame is synchronized to a base layer frame. The base layer frame includes additional data that is used to synchronize the receivers to demodulate and decode the overlay layer and the base layer. The additional data is modulated using a technique that aids the receiver in synchronizing the received signal that is different from the overlay layer.

Abstract: A communication system (10) using hierarchical modulation includes at least one satellite (12 & 13) transmitting a data stream and a hierarchical modulated data stream, and at least one terrestrial station (16) transmitting the data stream and the hierarchical modulated data stream. The communication system can further include at least one receiver (18) for demodulating and combining the data stream from at least one satellite and from at least one terrestrial station and for hierarchically demodulating and combining the hierarchical modulated data stream from at least one satellite and the hierarchical modulated data stream from at least one terrestrial station. The terrestrial station can be a terrestrial repeater repeating the data stream and the hierarchical data stream from at least one satellite. The system can also include an uplink (11) having a hierarchical modulator for modulating both the data stream and the hierarchical data stream.

Abstract: A system (100) for combining satellite and terrestrial signals from spatially diverse antennas (102 and 104) includes a tuner (101) and at least first and second analog to digital converters (103, 105) for converting at least two among the plurality of satellite signals and the terrestrial signal to a first digital stream and a second digital stream. A switch arrangement (106, 102 126) selectively switches among the first digital stream and the second digital stream before demodulating the digital streams using a plurality of algorithms (112, 122, 130) that selectively uses respectively demodulated signals of the first digital stream and the second digital stream to control (114, 124, 132) the switch arrangement to provide a plurality of multiplexed signals (161, 162, 163) that are combined (134) to form a combined signal (170). The combined signal can then be forward error corrected (136).

Abstract: A method (500) for timing recovery in an orthogonal frequency division multiplexing (OFDM) system includes the steps of detecting (502) a lack of a synchronization symbol and determining (504) a timing offset from calculating the average group delay across the subcarriers over multiple OFDM symbols. The timing offset is fed back (506) to a demodulator and the symbol timing is adjusted (508) based on the Average Group Delay phasor fed back to the demodulator.

Abstract: A communication system (10) using hierarchical modulation includes at least one satellite (12 & 13) transmitting a data stream and a hierarchical modulated data stream, and at least one terrestrial station (16) transmitting the data stream and the hierarchical modulated data stream. The communication system can further include at least one receiver (18) for demodulating and combining the data stream from at least one satellite and from at least one terrestrial station and for hierarchically demodulating and combining the hierarchical modulated data stream from at least one satellite and the hierarchical modulated data stream from at least one terrestrial station. The terrestrial station can be a terrestrial repeater repeating the data stream and the hierarchical data stream from at least one satellite. The system can also include an uplink (11) having a hierarchical modulator for modulating both the data stream and the hierarchical data stream.

Abstract: A system (10) for converting streaming digital data to frequency modulated data includes a digital decoder (12) providing content and associated data, a system controller (14) for formatting the associated data into frequency modulated sub-carrier data, and a frequency modulator (20) for modulating (24) the content and combining (25) the modulated content with a buffered version of the frequency modulated sub-carrier data. The streaming digital data can come from a satellite digital audio radio system receiver and the associated data can include at least one among a channel name, a channel number, an artist name, a song title, and traffic information. The system controller can format the associated data into an RDS Message format. The frequency modulator can include an RDS physical layer (32) and an RDS data link layer (30) that can generate a checksum. The frequency modulator can also include a register or buffer (28).

Abstract: A system (100) for combining satellite and terrestrial signals from spatially diverse antennas (102 and 104) includes a tuner (101) and at least first and second analog to digital converters (103, 105) for converting at least two among the plurality of satellite signals and the terrestrial signal to a first digital stream and a second digital stream. A switch arrangement (106, 102 126) selectively switches among the first digital stream and the second digital stream before demodulating the digital streams using a plurality of algorithms (112, 122, 130) that selectively uses respectively demodulated signals of the first digital stream and the second digital stream to control (114, 124, 132) the switch arrangement to provide a plurality of multiplexed signals (161, 162, 163) that are combined (134) to form a combined signal (170). The combined signal can then be forward error corrected (136).

Abstract: A method (500) for timing recovery in an orthogonal frequency division multiplexing (OFDM) system includes the steps of detecting (502) a lack of a synchronization symbol and determining (504) a timing offset from calculating the average group delay across the subcarriers over multiple OFDM symbols. The timing offset is fed back (506) to a demodulator and the symbol timing is adjusted (508) based on the Average Group Delay phasor fed back to the demodulator.

Abstract: Apparatus and method of achieving diversity in reception of plural digital broadcast signals. A stream of a complete set of code bits is generated from one or more sources of data bits. A first Critical Subset of code bits is chosen or selected for a first channel (e.g. a specified puncturing pattern is applied to the stream of a complete set of code sets). A second (e.g. alternative) Critical Subset of code bits is chosen or selected for a second channel (e.g. a second or alternative puncturing pattern is chosen for the second channel). Further alternative Critical Subsets may be chosen for any additional channels. All the channels are transmitters, some can incorporate time delay to achieve temporal diversity. Moreover, the order of transmitting the code bits on each channel can be different (for example, the interleaving depths can be different).

Abstract: Most cable television systems in the United States (over 75% as of this application) are structured for one-way only service between the cable headend and the user. With more and more services being introduced that require a two-way connection with the user (e.g. impulse-pay-per-view, home shopping, Internet access), it has become necessary for more and more cable systems to upgrade to a two-way capability at considerable cost and over a fairly long period of time. The typical short-term solution to the lack of two-way capability is to send request backlinks over he user's telephone line. The problem with this solution is that when used, it ties up the telephone line and requires an additional telephone connection to be located near the cable set-top-box or modem. A more practical solution is the hub centered backhaul invention described herein. With this invention, users can operate their cable systems as if they were two-way systems, with all available interactive capabilities available.

Abstract: Most cable television systems in the United States (over 75% as of this application) are structured for one-way only service between the cable headend and the user. With more and more services being introduced that require a two-way connection with the user (e.g. impulse-pay-per-view, home shopping, Internet access), it has become necessary for more and more cable systems to upgrade to a two-way capability at considerable cost and over a fairly long period of time. The typical short-term solution to the lack of two-way capability is to send request backlinks over he user's telephone line. The problem with this solution is that when used, it ties up the telephone line and requires an additional telephone connection to be located near the cable set-top-box or modem. A more practical solution is the hub centered backhaul invention described herein. With this invention, users can operate their cable systems as if they were two-way systems, with all available interactive capabilities available.

Abstract: Apparatus and method of achieving diversity in reception of plural digital broadcast signals. A stream of a complete set of code bits is generated from one or more sources of data bits. A first Critical Subset of code bits is chosen or selected for a first channel (e.g. a specified puncturing pattern is applied to the stream of a complete set of code sets). A second (e.g. alternative) Critical Subset of code bits is chosen or selected for a second channel (e.g. a second or alternative puncturing pattern is chosen for the second channel). Further alternative Critical Subsets may be chosen for any additional channels. All the channels are transmitters, some can incorporate time delay to achieve temporal diversity. Moreover, the order of transmitting the code bits on each channel can be different (for example, the interleaving depths can be different).

Abstract: Apparatus and method of achieving diversity in reception of plural digital broadcast signals. A stream of a complete set of code bits is generated from one or more sources of data bits. A first Critical Subset of code bits is chosen or selected for a first channel (e.g. a specified puncturing pattern is applied to the stream of a complete set of code sets). A second (e.g. alternative) Critical Subset of code bits is chosen or selected for a second channel (e.g. a second or alternative puncturing pattern is chosen for the second channel). Further alternative Critical Subsets may be chosen for any additional channels. All the channels are transmitters, some can incorporate time delay to achieve temporal diversity. Moreover, the order of transmitting the code bits on each channel can be it different (for example, the interleaving depths can be different).

Abstract: An information broadcast system having a broadband broadcast system selected from cable and satellite for broadcasting requested information from a selected information source, including the Internet, to one or more selected subscriber stations includes an independent backhaul channel for communicating information request signals from a subscriber station to one or more central processing stations. The system includes a data broadcast station for transmitting requested data from the selected data source and central station via the data broadcast station to the one or more selected subscriber stations. The high-data rate broadcast station forwards requested data from a data source to the data broadcast station. A backhaul satellite communication system, independent of the broadband broadcast system, has a backhaul satellite ground terminal for coupling information request signals from backhaul satellite communication system to high data broadcast station terminal.

Abstract: Interactive internet activities are a very popular means for gathering information for business, personal, medical, entertainment and other purposes. Most internet interaction is asymmetrical in nature in that a client's requests for information are much smaller (in data size) than the resulting information delivered by the server. Although the client/internet link is inherently asymmetrical, there remains a great deal of interaction and overhead required between the client and the server that increases the bandwidth needs for the client's upstream request channel. There are many advantages to reducing this upstream traffic volume and thereby making the internet interaction even more asymmetrical. Such compression of request data could allow more clients to utilize a single upstream data path instead of separate paths.

Abstract: A universal interactive control system for the downloading and playback of information and entertainment services from one or more network distribution centers, said one or more network distribution centers providing information and entertainment signals selected from video and audio programs, video catalogs, and data files, said universal interactive control system. The interactive control system includes: a controller circuit, a data distribution circuit controlled by the controller circuit, a data processor circuit controlled by the controller circuit, and a first plurality of interface connector circuits, with a first of the interface connector circuits for connecting the distribution circuit to a display device under control of the controller, and a second of the interface connector circuits for connecting the data distribution circuit to a storage device under control of the controller circuit.

Abstract: Interactive internet activities are a very popular means for gathering information for business, personal, medical, entertainment and other purposes. Most internet interaction is asymmetrical in nature in that a client's requests for information are much smaller (in data size) than the resulting information delivered by the server. Although the client/internet link is inherently asymmetrical, there remains a great deal of interaction and overhead required between the client and the server that increases the bandwidth needs for the client's upstream request channel. There are many advantages to reducing this upstream traffic volume and thereby making the internet interaction even more asymmetrical. Such compression of request data could allow more clients to utilize a single upstream data path instead of separate paths.