Satellite direct radio broadcast system

• US 6,249,514 B1
• Filed: 07/30/1998
• Issued: 06/19/2001
• Est. Priority Date: 12/08/1995
• Status: Expired due to Fees

• Current Assignee: Worldspace International Network Incorporated
• Original Assignee: Worldspace International Network Incorporated
• Inventors: Campanella, S. Joseph
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/124,997
• Time in Patent Office: 1,055 Days
• Field of Search: 370/315, 370/316, 370/319, 370/321, 370/307, 370/330, 370/485, 370/486, 370/487, 455/4.1, 455/4.2, 455/5.1, 455/6.1, 455/6.2, 455/6.3, 455/13.3, 455/3.2, 455/12.1, 348/10, 348/11, 348/12, 348/13, 348/7, 348/6
• US Class Current: 370/316
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04H 20/74 of satellite networks
• CPC Class Codes: H04H 40/90 specially adapted for satellite broadcast receiving
• CPC Class Codes: H04H 60/14 Arrangements for conditional access to broadcast information or to broadcast-related services

Abstract

A satellite direct audio broadcast system includes a plurality of fixed-rate, uniform, frequency division multiple access (“FDMA”) uplinks and a time division multiplexed (“TDM”) downlink. Source audio channels may be divided among and transmitted through a selectable number of fixed-rate uplinks so as to have selectable audio quality at the receiver. Fixed-rate FDMA uplinks include information designating related channels as containing related source information. On-board the satellite baseband processing selects uplink information channels for inclusion into none, one or multiple TDM downlinks. Transmitted audio information may be scrambled, and authorization downloaded to receivers to permit descrambling for paid subscription service.

Claims

1. A method of generating a signal for transmission to a receiver, said method comprising the steps of:

dividing a program for broadcast to said receiver into a number of uniform rate channels that are each characterized by a selected minimal signal rate;

providing each of said channels with a control word, said control word comprising data selected from the group consisting of bits representing a number of related digital signal groups, each of said digital signal groups comprising a number of the plurality of channels, bits uniquely identifying the digital signal group to which one of the plurality of channels associated with the control word belongs, bits representing the number of the plurality of channels in the corresponding digital signal group, bits uniquely identifying the channel among the plurality of channels that corresponds to the control word, bits representing a number of sub-ensembles constituting at least one digital signal group, bits representing the number of the plurality of channels in a sub-ensemble, bits uniquely identifying a sub-ensemble, bits for indicating which of audio, video and data constitute a corresponding one of the plurality of channels, and blocking bits to prevent reception of at least sub-ensembles of selected ones of the plurality of channels by a receiver;

selectively routing said channels to at least one time division multiplexed downlink, the order and placement of said channels in said downlinks being predetermined; and

transporting said channels via said at least one time division multiplexed downlink to said receiver.

2. A communication system for broadcasting programs comprising at least one broadcast station configured to generate a plurality of channels, at least one of said programs to be broadcast being divided among a number of said channels, said broadcast station being operable to generate a time division multiplexed uplink comprising selected ones of said channels and a control word, said control word identifying a digital signal group to which a plurality of said selected ones of said channels belong and providing instructions to facilitate recombining of said selected ones of said channels during reception thereof, said broadcast station being programmable to selectively route said selected ones of said channels to said uplink such that the placement of said channels in said uplink is predetermined.

3. A communication system as claimed in claim 2, wherein said broadcast station is operable to generate a time division multiplexed second uplink and to control the routing of said channels to one of said uplink, said second uplink, both of said uplink and said second uplink, and neither of said uplink and said second uplink.

4. A communication system as claimed in claim 2, further comprising a space segment configured to frequency translate and repeat said uplink in a downlink.

5. A method of broadcasting programs from a plurality of sources comprising the steps of:

obtaining information signals corresponding to a program from at least one program source;

dividing said information signals of said program into a number of prime rate channels, each of said prime rate channels comprising a control word to identify which of said prime rate channels are related to the same said program to facilitate reception of said program; and

selectively routing said prime rate channels into a time division multiplexed uplink such that the placement and order of said prime rate channels in said uplink is predetermined.

6. A method as claimed in claim 5, further comprising the steps of:

repeating said uplink in a downlink via a space segment for reception at a radio receiver;

demultiplexing said downlink to recover said prime rate channels;

extracting said control words from said prime rate channels; and

recombining selected ones of said prime rate channels in accordance with said control words to recover said program.

7. A method as claimed in claim 6, further comprising the step of reducing error in said uplink prior to retransmission via said downlink.

8. A receiver in a broadcast communication system comprising:

an antenna and radio frequency front end for receiving a time division multiplexed downlink, said downlink comprising a plurality of prime rate channels, a program being broadcast by said communications system comprising at least one of said prime rate channels, the order and placement of said prime rate channels corresponding to said broadcast in said downlink being predetermined to facilitate reception thereof, said prime rate channels each comprising a control word providing instructions to said receiver to recombine said prime rate channels to recover said program;

a demultiplexer to recover said prime rate channels from said downlink in accordance with the predetermined order and placement of said prime rate channels therein;

an input device to allow a user to select said program;

a processor programmed to extract said prime rate channels having said control words which correspond to an output signal generated by said input device; and

an output device to playback said prime rate channels selected by said user.

9. A signal comprising broadcast information embodied in a carrier wave comprising:

a plurality of information channels comprising said broadcast information, said plurality of information channels being combined to create digital signal groups;

at least one control word, said control word comprising data selected from the group consisting of bits representing a number of related said digital signal groups, bits uniquely identifying the digital signal group to which a selected one of said information channels belongs, bits representing the number of said information channels in a corresponding one of said digital signal groups, and bits uniquely identifying a selected one of said information channels;

wherein said signal is multiplexed and the order and placement of said information channels in the multiplexed said signal is predetermined to facilitate identification of said information channels therein.

10. A signal as claimed in claim 9, wherein selected ones of said plurality of information channels are combined to create a sub-ensemble within one of said digital signal groups, said control word comprising data selected from the group consisting of bits representing a number of sub-ensembles within said one of said digital signal groups, bits representing the number of said information channels in one of said sub-ensembles, and bits uniquely identifying at least one of said sub-ensembles.