Multiplexing of digitally encoded NTSC and HDTV signals over single microwave communication link from television studio to tower transmitter facility for simultaneous broadcast (simulcast) to customer sites by transmitter facility

• US 5,412,426 A
• Filed: 04/16/1993
• Issued: 05/02/1995
• Est. Priority Date: 04/16/1993
• Status: Expired due to Fees

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Totty, Ronald E.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US08/048,620
• Time in Patent Office: 746 Days
• Field of Search: 358/142, 358/141, 358/12, 358/11, 358/133
• US Class Current: 375/240.01
• 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 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• 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 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 7/015 High-definition television systems

Abstract

Simulcasting from a television transmitter facility of both NTSC video signals, via a UHF/VHF portion of the broadcast spectrum, and digital HDTV signals, over a prescribed UHF portion of the broadcast spectrum, is accomplished by converting the NTSC video signals into digital format at the television studio and multiplexing the digitally formatted NTSC signals and digital HDTV signals into a combined NTSC/HDTV digital television signal. The combined NTSC/HDTV digital television signal is transmitted over a common microwave radio frequency communication channel linking the television studio with the television transmitter facility. At the television transmitter facility, the combined NTSC/HDTV digital television signal is demultiplexed into separate HDTV and NTSC video digital signals. The digital NTSC video signals are converted into analog NTSC format, and the NTSC video signals and the HDTV signals are simulcast from the television transmitter facility.

Claims

1. A method of transmitting NTSC video signals and digital HDTV signals, from a television studio sourcing each of said NTSC video and digital HDTV signals, over a common microwave communication channel to a television transmitter facility for broadcast therefrom to customer sites comprising the steps of:

(a) at said television studio, converting said NTSC video signals into digital format;

(b) multiplexing digitally formatted NTSC signals obtained in step (a) and said digital HDTV signals into a combined NTSC/HDTV digital television signal; and

(c) transmitting the combined NTSC/HDTV digital television signal obtained in step (b) over a first sub-portion of the bandwidth of said common microwave communications channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio.

2. An arrangement for transmitting NTSC video signals and digital HDTV signals, from a television studio sourcing each of said NTSC video and digital HDTV signals, over a common microwave communication channel to a television transmitter facility for broadcast therefrom to customer sites, comprising, at said television studio, a digital codec which is operative to convert said NTSC video signals in to digital format, a multiplexer which is operative to multiplex digitally formatted NTSC produced by said codec with said digital HDTV signals into a combined NTSC/HDTV digital television signal, and a transmitter, coupled to the output of said multiplexer and being operative to transmit the combined NTSC/HDTV digital television signal over said common microwave communication channel linking said television studio with said television transmitter facility;

and wherein the transmitter at said television studio is operative to transmit the combined NTSC/HDTV digital television signal over a first sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio.

3. A method of simulcasting from a television transmitter facility each of NTSC video signals, via a UHF/VHF portion of the broadcast spectrum, and digital HDTV signals, over a prescribed UHF portion of the broadcast spectrum, comprising the steps of:

(a) at a television studio, which sources NTSC video signals to be broadcast by said television transmitter facility, converting said NTSC video signals into digital format;

(b) multiplexing digitally formatted NTSC signals obtained in step (a) and said digital HDTV signals into a combined NTSC/HDTV digital television signal;

(c) transmitting the combined NTSC/HDTV digital television signal obtained in step (b) over a first sub-portion of the available bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio;

(d) at said television transmitter facility, demultiplexing said combined NTSC/HDTV digital television signal into separate HDTV and NTSC digital paths;

(e) converting digital NTSC video signals, demultiplexed in step (c) into said NTSC digital path, into analog NTSC format; and

(f) simulcasting, from said television transmitter facility, each of the NTSC video signals obtained in step (c) and said HDTV signals.

4. A method of transmitting first and second respectively different types of television signals from a television studio over a common microwave communication channel to a television transmitter facility for broadcast therefrom to customer sites comprising the steps of:

(a) at said television studio, multiplexing said first and second respectively different types of television signals into a combined television signal; and

(b) transmitting the combined television signal obtained in step (a) over a first sub-portion of the bandwidth of said common microwave communications channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio.

5. An arrangement for transmitting first and second respectively different types of television signals from a television studio over a common microwave communication channel to a television transmitter facility for broadcast therefrom to customer sites, comprising, at said television studio, a multiplexer which is operative to multiplex said first and second respectively different types of television signals into a combined television signal, and a transmitter, coupled to the output of said multiplexer and being operative to transmit said combined television signal over first sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio.

6. A method of simulcasting from a television transmitter facility each of first and second respectively different types of television signals over a prescribed portion of the broadcast spectrum, comprising the steps of:

(a) at a television studio, which sources said first and second respectively different types of television signals to be broadcast by said television transmitter facility, multiplexing said first and second respectively different types of television signals into a combined television signal;

(b) transmitting the combined television signal obtained in step (a) over a first sub-portion of the available bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility, so as to make a remaining sub-portion of the bandwidth of said common microwave communication channel linking said television studio with said television transmitter facility available for use as a return transmission link from said television transmitter facility to said television studio;

(c) at said television transmitter facility, demultiplexing said combined television signal into said separate first and second respectively different types of television signals; and

(d) simulcasting, from said television transmitter facility, each of said first and second respectively different types of television signals.