Video signal distribution system

• US 5,555,016 A
• Filed: 06/17/1994
• Issued: 09/10/1996
• Est. Priority Date: 07/06/1993
• Status: Expired due to Fees

• Current Assignee: MCEL PLC, EEV Ltd. (Teledyne Technologies Incorporated)
• Original Assignee: MCEL PLC, Plessey Semiconductors Limited (Plessey Group Holdings Ltd.)
• Inventors: Wilson, Alan T., Turner, executor, Ronald, Hilder, Graham M., Hobden, Mervyn K., Rhodes, deceased, John G. L.
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US08/261,455
• Time in Patent Office: 816 Days
• Field of Search: 348/6, 455/3.2, 455/102, 455/103, 455/45, 455/108, 358/86
• US Class Current: 725/73
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

In a video signal distribution system in which a plurality of video signals are modulated onto individual carrier signals spaced over a band of frequencies to form a composite signal for transmission over cables of the system, a point-to-point radio link forming part of the distribution system is provided in which the composite signal is transmitted as double side band amplitude modulation of a single microwave carrier signal.

Claims

1. A video signal distribution system for transmitting a wide-band composite signal having a plurality of video signals modulated on respective sub-carriers of respective different frequencies spaced over a band of frequencies, said distribution system comprising:

a microwave point-to-point radio link including a transmitter arrangement having balanced modulator means for amplitude modulating said composite signal onto a microwave carrier frequency signal to provide a double side-band suppressed carrier amplitude modulated signal, means for combining said amplitude modulated signal with a carrier frequency reference signal, means for adjusting the relative phase and amplitude of said microwave carrier frequency signal and said carrier frequency reference signal to provide a substantially pure double side-band amplitude modulated combined signal, and means for amplifying said combined signal for transmission over said microwave point-to-point radio link.

2. The system in accordance with claim 1, wherein the radio link includes a receiver arrangement for frequency modulating signals on a return path as a carrier signal at the frequency of said microwave carrier frequency signal.

3. The system in accordance with claim 1, and further comprising means for transmitting the carrier amplitude modulated signal over the radio link with circular polarization.

4. A video signal distribution system for transmitting a wide-band composite signal having a plurality of video signals modulated on respective sub-carriers of respective different frequencies spaced over a band of frequencies, said distribution system comprising:

a microwave point-to-point radio link having a transmitter station and a receiver station, means at the transmitter station for modulating said composite signal onto a single microwave carrier signal to provide a double side-band amplitude modulated carrier signal for transmission over said microwave point-to-point radio link, and means at the receiver station for modulating signals on a return path as frequency modulation of a carrier signal at the frequency of said single microwave carrier signal for transmission over said microwave point-to-point radio link to the transmitter station.

5. A video signal distribution system for transmitting a wide-band composite signal having a plurality of video signals modulated on respective sub-carriers of respective different frequencies spaced over a band of frequencies, said distribution system comprising:

a microwave point-to-point radio link having a transmitter station, means at the transmitter station for modulating said composite signal onto a single microwave carrier signal to provide a double side-band amplitude modulated carrier signal, and means for transmitting said amplitude modulated carrier signal over said microwave point-to-point radio link with circular polarization.