Television distribution system and method

• US 6,005,605 A
• Filed: 05/09/1997
• Issued: 12/21/1999
• Est. Priority Date: 03/17/1995
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Bell Atlantic Network Services, Inc. (Verizon Communications Inc.)
• Inventors: Schneider, Allan, Kostreski, Bruce
• Primary Examiner(s): Harvey, David E.
• Application Number:
  US08/854,210
• Time in Patent Office: 956 Days
• Field of Search: 348/21, 348/385, 348/386, 348/387, 348/471, 348/472, 375/200, 375/201, 375/202, 375/205, 375/18, 375/203, 375/204, 375/207, 375/206, 375/208, 375/240, 375/241, 455/51.2, 455/51.1, 455/52.1-52.3, 455/3.1, 455/3.2, 455/4.1, 455/4.2, 455/6.3, 455/503, 379/58-60
• US Class Current: 348/21
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
• CPC Class Codes: H04N 1/0035 User-machine interface; Control console input or output arrangements for computers G06F3/00
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4302 Content synchronisation processes, e.g. decoder synchronisation
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/025 Systems for the transmission of digital non-picture data, e.g. of text during the active part of a television frame transmission of digital non-picture data during the vertical blanking interval only H04N7/088
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

Within a desired service area, multiple transmitters at separately located sites simultaneously broadcast the same multi-channel, multi-program signal. Broadcast waves from the transmitters propagate substantially throughout the service area and overlap in a substantial portion of the area. The signals are broadcast as spread spectrum signals and the receivers include despreaders with rake capabilities to obtain enhanced output signals with multi-path reception. In the preferred implementation, the channels are 6 MHz wide channels broadcast in the super high frequency microwave portion of the spectrum. Each such channel carries a multiplexed digital data stream containing packets of information for a plurality of programs, e.g., television programs.

Claims

1. A frequency simulcasting system for transmitting a signal carrying broadband data from multiple spaced transmitting sites for reception in a reception area wherein at least certain of said transmitting sites are disposed to enclose at least a portion of said reception area, the method comprising the steps of:

a) substantially simultaneously transmitting from said transmitting sites the same signal so that the areas of propagation from said respective transmitting sites overlap over at least a substantial portion of the enclosed reception area and also extend therebeyond;

b) said same signal transmitted from said transmitting sites including multiplexed channels each including multiplexed streams of digital data transmitted as spread spectrum signals;

c) selecting at a receiving site one of said multiplexed channels and from the multiplexed stream of digital data in that channel selecting one set of broadband data from said digital data; and

d) reproducing at least a portion of said one set of said broadband data as sensorily perceptible information.

18. A method according to claim 1 wherein at least one of said transmitting sites transmits in a directional pattern directed into said area.

19. A method according to claim 1 wherein a plurality of said transmitting sites transmit in directional patterns directed into said reception area.

20. A method according to claim 19 including a transmitting site transmitting in a substantially omni-directional pattern.

25. The method of claim 1, wherein said broadband data is compressed digital video data.

2. An RF frequency simulcasting system for transmitting a signal carrying digital broadband data from multiple spaced transmitting sites to multiple receivers in a first reception area and to multiple receivers in a second reception area wherein at least certain of said transmitting sites are disposed to enclose at least a portion of said first area, the method comprising the steps of:

a) substantially simultaneously transmitting from said transmitting sites the same signal so that the areas of propagation from said respective transmitting sites overlap over at least a substantial portion of said first reception area and also cover a substantial portion of said second reception area;

b) said same signal transmitted from said transmitting sites including frequency multiplexed channels each including multiplexed streams of digital data in digitally compressed form transmitted as spread spectrum signals;

c) selecting with at least one of said receivers one of said frequency multiplexed channels and from the compressed multiplexed stream of digital data in that channel selecting one set of digital broadband data from said digital data; and

d) displaying at least a portion of the selected digital broadband data.

3. A method according to claim 2 wherein said selecting includes despreading the spread spectrum signals received at said at least one receiver and processing the despread signals to provide a processed output signal having a signal to noise ratio exceeding the signal to noise ratio obtainable from any single one of the processed signals.

4. A method according to claim 3 wherein said processing includes the use of Rake techniques.

5. An RF frequency simulcasting system for transmitting a signal carrying digital broadband data from multiple spaced transmitting sites to multiple receivers in a reception area wherein at least certain of said transmitting sites are disposed to enclose at least a portion of said reception area, the method comprising the steps of:

a) simultaneously transmitting from said transmitting sites the same spread spectrum signal so that the areas of propagation from said respective transmitting sites overlap over at least a major portion of said enclosed reception area and also cover a substantial area therebeyond;

b) said same spread spectrum signal transmitted from said transmitting sites including frequency multiplexed channels each including multiplexed streams of digital data in digitally compressed form;

c) selecting with at least one of said receivers one of said frequency multiplexed channels and from the compressed multiplexed stream of digital data in that channel selecting one set of digital broadband data from said digital data; and

d) displaying at least a portion of the selected digital broadband data.

6. A method according to claim 5 wherein said signals transmitted from said transmitting sites are transmitted as spread spectrum signals and wherein said selecting includes despreading and processing the signals received at said at least one receiver site to provide a processed output signal having a signal to noise ratio exceeding the signal to noise ratio obtainable from any single one of the processed signals.

7. A method according to claim 5 wherein said signals transmitted from said transmitting sites are transmitted as spread spectrum signals and wherein said despreading and processing includes plural despreading with a time differential between at least two despreading steps to produce at least two despread signals having said time differential therebetween.

8. A method according to claim 7 including the step of combining said signals after eliminating said time differential.

9. A method according to claim 8 wherein the signal to noise ratio of said combined signal is higher than the signal to noise ratio of either of the signals which were combined.

10. An RF frequency simulcasting system for transmitting a signal carrying digital broadband data from multiple spaced transmitting sites to multiple receivers in a first reception area and to multiple receivers in a second reception area wherein at least certain of said transmitting sites are disposed to enclose at least a portion of said first area, the method comprising the steps of:

a) simultaneously transmitting from said transmitting sites the same frequency hopping spread spectrum signal so that the areas of propagation from said respective transmitting sites overlap over at least a portion of said first reception area and also cover a substantial portion of said second reception area;

b) said same frequency hopping spread spectrum signal transmitted from said transmitting sites including frequency multiplexed channels each including multiplexed streams of digital data in digitally compressed form;

c) selecting, with at least one of said receivers, one of said frequency multiplexed channels and from the multiplexed stream of digital data in that channel selecting one set of digital broadband data from said digital data; and

d) displaying at least a portion of the one set of said digital broadband data.

11. A method according to claim 10 wherein said transmitting sites include a first transmitting site within said first reception area and a plurality of secondary transmitting sites substantially within said first reception area, and a head end signal source connected to said primary and secondary transmitting sites, including the step of delivering from said head end signal source to each of said transmitting sites a program signal which is simultaneously transmitted from each of said transmitting sites.

12. A method according to claim 11 wherein the transmitted program signal is received by at least one receiver at multiple times, and including the steps of individually despreading at least two of said of said signals at different times, delaying the first despread signal by the differential of despreading times, and combining said delayed signal and the later despread signal to produce a synchronized combined output signal.

13. A method according to claim 12 wherein said signals are received at said receiver by an antenna which is omni-directional in azimuth.

14. An RF frequency simulcasting system for broadcasting a broadband signal from multiple spaced transmitting sites to multiple receivers in a first reception area and to multiple receivers in a second reception area wherein at least certain of said transmitting sites are disposed to enclose at least a portion of said first area, the method comprising the steps of:

a) simultaneously transmitting from said transmitting sites the same frequency hopping spread spectrum signal so that the areas of propagation from said respective transmitting sites overlap over at least a major portion of said first reception area and also cover a substantial portion of said secondary reception area;

b) said same frequency hopping spread spectrum signal transmitted from said transmitting sites including frequency multiplexed channels each including multiplexed streams of digital data in digitally compressed form;

c) selecting with at least one of said receivers one of said frequency multiplexed channels and from the multiplexed stream of digital data in that channel selecting one set of digital broadband data from said digital data desired by the user of the particular receiver; and

d) displaying at least a portion of said one set of digital broadband data for viewing by the user.

15. A method according to claim 14 wherein said transmitting sites include a primary transmitting site within said first reception area and a plurality of secondary transmitting sites substantially within said first reception area, and a head end signal source connected to said primary and secondary transmitting sites, including the step of delivering from said head end signal source to each of said transmitting sites a program signal which is simultaneously transmitted from each of said transmitting sites.

16. A method according to claim 15 wherein the transmitted program signal is received at each of certain of said receivers at multiple times, and including the steps of individually despreading at least two of said of said signals at different times at said certain receivers receiving multiple signals, delaying the first despread signal at each such receiver by the differential of despreading times at said receiver, and combining said delayed signal and the later despread signal at each said receiver to produce at each such receiver a combined output signal.

17. A method according to claim 16 wherein said signals are received at said receivers by antennas which are omni-directional in azimuth.

21. An RF frequency simulcasting system for transmitting a signal carrying broadband information from multiple spaced transmitting sites for reception in a reception area, the method comprising the steps of:

a) simultaneously transmitting from said transmitting sites the same signal so that the areas of propagation from said respective transmitting sites substantially overlap each other over at least a major portion of the reception area, said signal transmitted from said transmitting sites including multiplexed channels transmitted as spread spectrum signals;

b) receiving a signal containing at least one time delayed copy of said transmitted spread spectrum signals at one of the receiving sites;

c) processing at least a portion of the received signal to acquire a single copy of a signal corresponding to a selected one of the multiplexed channels; and

d) presenting broadband information contained in the acquired signal to a user in sensorially perceptible form.

22. A method as in claim 21, wherein the step of processing comprises delay equalizing the spread spectrum signals.

23. A method as in claim 21 wherein:

each multiplexed channel includes a multiplexed stream of digital data representing a plurality of programs; and

the presenting step comprises (a) selecting data for one program and for one of said multiplexed streams of digital data, and (b) reproducing the selected data as sensorially perceptible information.

26. The method of claim 21, wherein said program information comprises digital broadband data.

24. A system for simulcasting an RF signal to a reception area comprising:

multiple spaced transmitting antennas located substantially within said reception area transmitting said signal into said reception area;

said signal including multiplexed channels transmitted as spread spectrum signals;

at least one receiver at a receiving site in said reception area receiving a signal containing at least one time delayed copy of said spread spectrum signals;

said receiver including a spread spectrum despreader and processing means for processing a broadband signal outputted by said despreader;

said despreader selecting one of said multiplexed channels and providing input to said processing means;

a graphic display device connected to receive output from said processing means and presenting at least a portion of said output as a graphic display.

27. The system of claim 24, wherein the spread spectrum despreader outputs a compressed digital broadband signal, the processing means comprising a digital video decoder that decodes the compressed digital broadband signal to output at least one of a decompressed digital video signal and a decompressed digital audio signal.

28. An RF simulcasting system for transmitting a broadband signal from multiple spaced transmitting antennas to multiple receivers in a first reception area and to multiple receivers in a second reception area wherein said antennas are disposed outward from a centroid of said first reception area comprising:

multiple spaced transmitting antennas located substantially within said first reception area simulcast transmitting said broadband signal into said first reception area and into said second reception area to receivers in said reception areas;

said signal including multiplexed channels each including multiplexed streams of digital compressed broadband data transmitted as spread spectrum signals;

at least one of said receivers in one of said reception areas receiving said signal;

said receiver including at least including at least one despreader, at least one demultiplexer, at least one decoder, and at least one demodulator;

said receiver selecting one of said multiplexed channels and from the multiplexed stream of digital broadband data in that channel one set of said digital data; and

a television set connected to receive at least said set of digital broadband data from said receiver and presenting at least a portion of said digital data as a graphic display.