Simulcast broadcasting system and method

• US 5,003,617 A
• Filed: 08/06/1990
• Issued: 03/26/1991
• Est. Priority Date: 10/21/1988
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Epsom, Robert L., Wilson, Christopher H., Erickson, Paul M., Cizek, Paul J.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Smith, Ralph
• Application Number:
  US07/563,894
• Time in Patent Office: 232 Days
• Field of Search: 455/18, 455/16, 455/51, 455/33, 455/67, 455/226, 455/57, 455/53, 455/49, 455/56, 455/13
• US Class Current: 455/503
• CPC Class Codes: H04B 7/2625 using common wave
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency

Abstract

A simulcast broadcast system wherein two signals (103 and 106) intended for simultaneous broadcast are transmitted from a source site (100) to remote sites (200) discrete from one another. At the remote sites, the two signals are separately processed, including the introduction of appropriate delay (305 and 312), prior to combining them for broadcast in conjunction with other remote sites. One or more monitoring sites (400) can also be provided to monitor reception coherence within the system and to provide operating measurement information to allow automatic control of various simulcast system parameters, including delay.

Claims

1. A method of simulcasting a broadcast signal from at least two remote sites, said broadcast signal comprising at least a combined first signal and a second separate signal, the method comprising the steps of:

(a) transmitting from a source site said first signal to said at least two remote sites;

(b) separately transmitting from any source site said second separate signal to said at least two remote sites;

(c) at said least two remote sites, delaying said first and second signals by a predetermined amount to provide delayed first and second signals, which predetermined amount may be different for each of said at least two remote sites;

(d) combining said delayed first and second signals to provide a composite signal; and

(e) broadcasting said composite signal substantially simultaneously from said at least two remote sites to provide said broadcast signal.

2. The method of claim 1 and further including are steps of:

(f) monitoring, at least from time to time, said broadcast signal as broadcast by at least some of said at least two remote sites;

(g) determining whether said broadcast signal as monitored has acceptable reception coherence;

(h) automatically varying at least one of said first signal, said second signal, said composite signal, and said broadcast signal as required to improve said reception coherence.