EP 0135192 A2 19850327 - Encoding of transmitted program material.
Title (en)
Encoding of transmitted program material.
Title (de)
Kodierung von gesendetem Programmaterial.
Title (fr)
Codage de programme transmis.
Publication
Application
Priority
US 53319383 A 19830916
Abstract (en)
An audio program is encoded with a subaudible binary code. A first value bit (mark) is a first frequency signal and a second value bit (space) is a second frequency signal. The coded message includes an initialization period constituted by a signal having the mark frequency. In decoding, the mark and space signals are detected through first and second band pass filters specific to the mark and space signal frequencies. The mark and space frequencies are sufficiently different to permit separate filtering. The time duration for each bit of the code is substantial. The decoder through a phase locked loop and integrator reads the bit on the basis of the average value of the bit over the duration of the bit. A synchronization signal provides for synchronous reading of the code. This signal that initiates the decoding operation is generated only in response to the coincident detection of the initialization signal, the notch and a mark response at the phase locked loop.
IPC 1-7
IPC 8 full level
H04H 20/00 (2008.01); H04H 20/14 (2008.01); H04H 20/31 (2008.01); H04H 60/31 (2008.01); H04N 7/00 (2011.01)
CPC (source: EP)
H04H 20/31 (2013.01)
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
EP 0135192 A2 19850327; EP 0135192 A3 19870429; AU 3290084 A 19850321; BR 8404640 A 19850813; JP S6086932 A 19850516
DOCDB simple family (application)
EP 84110927 A 19840913; AU 3290084 A 19840911; BR 8404640 A 19840914; JP 19185584 A 19840914