Transmodulated broadcast delivery system for use in multiple dwelling units

• US 5,970,386 A
• Filed: 01/27/1997
• Issued: 10/19/1999
• Est. Priority Date: 01/27/1997
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Williams, Jim C.
• Primary Examiner(s): Miller, John W.
• Application Number:
  US08/787,336
• Time in Patent Office: 995 Days
• Field of Search: 455/3.1, 455/3.2, 455/4.1, 455/4.2, 455/6.1, 455/189.1, 455/190.1, 455/17, 455/22, 455/23, 348/6, 348/8, 348/723, 348/724, 370/485, 370/486
• US Class Current: 725/69
• CPC Class Codes: H04H 20/63 to plural spots in a confined site, e.g. MATV [Master Antenna Television]
• CPC Class Codes: H04H 40/90 specially adapted for satellite broadcast receiving
• CPC Class Codes: H04N 21/2143 located in a single building, e.g. hotel, hospital or museum arrangements specially adapted for plural spots in a confined site in broadcast systems H04H20/63; adaptations for transmission by electric cable for domestic distribution in television systems H04N7/106
• 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 21/2665 Gathering content from different sources, e.g. Internet and satellite
• 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

Abstract

A system for redistributing a broadband audio-visual-data signal to a multiplicity of receiver units within a multiple dwelling unit (MDU) includes a main receiving antenna that receives a broadband video/audio/data signal having a number of individual program multiplex signals therein and a transmodulator device that transmodulates the individual program multiplex signals associated with the broadband signal from a first modulation scheme to a second modulation scheme to reduce the bandwidth of the broadband signal. The transmodulated signals are broadcast over a cable network, along with terrestrial signals, to individual receiver units at the MDU. The receiver units demodulate the transmodulated and/or terrestrial signals and provide user-specified channels to television sets for display.

Claims

1. A signal distribution system for distributing a first signal and a second signal over a communication channel to a plurality of individual receivers at a local site, wherein the first signal is modulated according to a first modulation scheme and the second signal is modulated according to a second modulation scheme, the distribution system comprising:

a main receiver disposed at the local site for receiving the first signal;

a second receiver that receives the second signal;

a transmodulator coupled to the main receiver that remodulates the first signal from the first modulation scheme to a third modulation scheme to produce a transmodulated signal, wherein the third modulation scheme differs from the first modulation scheme by other than a mere frequency shift;

a signal combiner coupled to the second receiver and to the transmodulator that combines the transmodulated signal at a first set of carrier frequency bands and the second signal modulated according to the second modulation scheme at a second set of carrier frequency bands to produce a combined signal; and

a transmitter that transmits the combined signal over the communication channel in a manner capable of being received at the plurality of individual receivers.

2. The signal distribution system of claim 1, wherein the signal combiner includes a first frequency-translator that translates the transmodulated signal to the first set of carrier frequency bands.

3. The signal distribution system of claim 1, wherein the signal combiner includes means for automatically determining the carrier frequency bands associated with the received second signal, means for locating a continuous frequency band of a predetermined width which is not used by the received second signal, and a signal translator that translates a portion of the transmodulated signal to the located continuous unused frequency band.

4. The signal distribution system of claim 3, wherein the locating means includes a further signal translator that translates a portion of the received second signal from one carrier frequency band to another carrier frequency band to produce the continuous unused frequency band of the predetermined width.

5. The signal distribution system of claim 1, further including a reception device coupled to the communication channel at one of the plurality of individual receivers, wherein the reception device includes means for receiving the transmodulated signal and means for demodulating the received transmodulated signal.

6. The signal distribution system of claim 1, wherein the first signal includes a plurality of program multiplex signals and wherein the transmodulator includes means for separately remodulating each of the plurality of the program multiplex signals from the first modulation scheme to the third modulation scheme to produce the transmodulated signal having a plurality of individual transmodulated signals.

7. The signal distribution system of claim 6, wherein the signal combiner includes a frequency-translator that frequency translates each of the plurality of individual transmodulated signals to a different carrier frequency band.

8. The signal distribution system of claim 7, wherein the frequency-translator includes means for frequency shifting a first subset of the plurality of individual transmodulated signals to a first region of adjacent carrier frequency bands and for frequency shifting a second subset of the plurality of individual transmodulated signals to a second region of adjacent carrier frequency bands, wherein the first and second regions are non-adjacent to each other.

9. The signal distribution system of claim 8, wherein the signal combiner further includes means for positioning a portion of the second signal at a carrier frequency band located between the first region and the second region.

10. The signal distribution system of claim 6, wherein the second signal includes a multiplicity of individual terrestrial signals, wherein the signal combiner includes a selection device which selects a subset of the plurality of individual transmodulated signals and the multiplicity of individual terrestrial signals, and wherein the signal combiner combines only the selected subset of signals at the first and second sets of carrier frequency bands to produce the combined signal.

11. The signal distribution system of claim 1, wherein the first modulation scheme is a quadrature phase shift keying (QPSK) modulation scheme and the third modulation scheme is a quadrature amplitude modulation (QAM) scheme and wherein the transmodulator includes a QPSK demodulator coupled to a QAM modulator.

12. The signal distribution system of claim 11, wherein the QAM modulator comprises a 128-QAM modulator.

13. The signal distribution system of claim 1, wherein the first modulation scheme is an 8-PSK (phase shift keying) modulation scheme and the third modulation scheme is a quadrature amplitude modulation (QAM) scheme of the order of 16 or higher, and wherein the transmodulator includes a PSK demodulator coupled to a QAM modulator.

14. The signal distribution system of claim 1, wherein the first modulation scheme is a 16-QAM (quadrature amplitude modulation) scheme and the third modulation scheme is a QAM scheme of the order of 32 or 64 or 256 or higher, and wherein the transmodulator includes a 16-QAM demodulator coupled to a 32-QAM or a 64-QAM or a 256-QAM or higher order QAM modulator.

15. The signal distribution system of claim 1, wherein the first signal is a digital signal and the second signal is an analog signal.

16. A signal distribution system for distributing a composite signal having a plurality of individual program multiplex signals modulated according to a first modulation scheme therein over a communication channel in a manner capable of being received by a plurality of individual receivers at a local site, the distribution system comprising:

a main receiver disposed at the local site for receiving the composite signal;

a plurality of transmodulator channels coupled to the main receiver, each of which remodulates one of the plurality of individual program multiplex signals from the first modulation scheme to a second modulation scheme to produce one of a plurality of transmodulated signals, wherein the second modulation scheme differs from the first modulation scheme by other than a mere frequency shift;

a combiner coupled to the plurality of transmodulator channels that combines the plurality of transmodulated signals at different carrier frequency bands to produce a combined signal; and

a transmitter that transmits the combined signal over the communication channel in a manner capable of being received by the plurality of individual receivers at the local site.

17. The signal distribution system of claim 16, further including a reception device coupled to the communication channel at one of the plurality of individual receivers, wherein the reception device includes means for receiving the combined signal and means for demodulating a selected one of the transmodulated signals within the recombined signal.

18. The signal distribution system of claim 16, wherein the combiner includes a first frequency-translator that translates a first subset of the plurality of transmodulated signals to a first region of adjacent carrier frequency bands and a second frequency-translator that translates a second subset of the plurality of transmodulated signals to a second region of adjacent carrier frequency bands, wherein the first and second regions are non-adjacent to each other.

19. The signal distribution system of claim 16, wherein the combiner includes a selection device which selects a subset of the plurality of transmodulated signals based on a priority criterion, and wherein the signal combiner combines only the selected subset of transmodulated signals to produce the combined signal.

20. The signal distribution system of claim 16, wherein the first modulation scheme is a quadrature phase shift keying (QPSK) modulation scheme and the second modulation scheme is a quadrature amplitude modulation (QAM) scheme and wherein each of the plurality of transmodulator channels includes a QPSK demodulator coupled to a QAM modulator.

21. The signal distribution system of claim 20, wherein the QAM modulator comprises a 128-QAM modulator.

22. A method of distributing first and second signals over a communication channel to a plurality of individual receivers at a local site, wherein the first signal is modulated according to a first modulation scheme and the second signal is modulated according to a second modulation scheme, the method comprising the steps of:

receiving the first signal;

receiving the second signal;

remodulating the first signal from the first modulation scheme to a third modulation scheme to produce a transmodulated signal, wherein the third modulation scheme differs from the first modulation scheme by other than a mere frequency shift;

combining the transmodulated signal at a first set of carrier frequency bands and the second signal modulated according to the second modulation scheme at a second set of carrier frequency bands to produce a combined signal; and

transmitting the combined signal over the communication channel in a manner capable of being received at the plurality of individual receivers.

23. The signal distribution method of claim 22, further including the steps of determining the carrier frequency bands used by the received second signal, locating a continuous frequency band of a predetermined width which is not used by the received second signal and translating a portion of the transmodulated signal to the located continuous unused frequency band.

24. The signal redistribution method of claim 23, wherein the locating step includes the step of translating a portion of the received second signal from one carrier frequency band to another carrier frequency band to produce the continuous unused frequency band of the predetermined width.

25. The signal redistribution method of claim 22, wherein the first signal includes a plurality of individual program multiplex signals and wherein the remodulating step includes the step of separately remodulating each of the plurality of the individual program multiplex signals from the first modulation scheme to the third modulation scheme to produce the transmodulated signal.

26. The signal redistribution method of claim 22, wherein the step of remodulating includes the steps of remodulating a subset of the plurality of individual program multiplex signals to the third modulation scheme and remodulating a different subset of the plurality of individual program multiplex signals to a fourth modulation scheme.

27. A signal distribution system for distributing a composite signal having a first total bandwidth over a communication channel having a second usable bandwidth that is less than the first total bandwidth, wherein the composite signal includes a plurality of individual program multiplex signals modulated according to a first modulation scheme, the distribution system comprising:

a main receiver disposed at the local site for receiving the composite signal;

a plurality of transmodulator channels coupled to the main receiver, each of which remodulates one of the plurality of individual program multiplex signals from the first modulation scheme to a second modulation scheme to produce one of a plurality of transmodulated signals having a bandwidth that is less than the bandwidth of an associated one of the plurality of individual program multiplex signals;

a combiner coupled to the plurality of transmodulator channels that combines the plurality of transmodulated signals to produce a combined signal having a third total bandwidth that is less than or equal to the second usable bandwidth; and

a transmitter that transmits the combined signal over the communication channel in a manner capable of being received by the plurality of individual receivers at the local site.

28. The signal distribution system of claim 27, wherein the first modulation scheme is a quadrature phase shift keying (QPSK) modulation scheme and the second modulation scheme is a quadrature amplitude modulation (QAM) scheme and wherein each of the plurality of transmodulator channels includes a QPSK demodulator coupled to a QAM modulator.