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US 4,554,542 AGranted
Guard tone capture method
AssigneeMotorola, Inc.
InventorArman V. Dolikian
Life of this patent
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AssigneeMotorola, Inc.
InventorArman V. Dolikian
Estimating the term…
A decoder for receiving and decoding a coded signal includes a particular frequency f.sub.o with a first and second amplitude. The first amplitude of the frequency f.sub.o is associated with the end of a first coded message while the second amplitude of the frequency f.sub.o is associated with the beginning of a second coded message. The decoder includes a receiver for receiving the coded signal, a tone detector circuit for detecting the frequency f.sub.o, a level sensor responsive to the receiver output, a function block for performing a command and a control unit responsive to the tone detector circuit and the sensor means. The tone detector and control unit operate in one of at least two possible states. In the first state the control unit causes the tone detector to respond to the first amplitude of the frequency f.sub.o. When the level sensor senses the second amplitude of the frequency f.sub.o the control unit responds by placing the tone detector circuit into its second state. In its second state, the tone detector circuit detects whether the level sensor was tripped by the frequency f.sub.o or by some other frequency. If the tone detector circuit detects the frequency f.sub.o, the control unit causes the decoder to end its decoding of the first message and begin the decoding of a second message. If the tone detector circuit in its second state fails to detect the frequency f.sub.o, the control unit returns the tone detector circuit to its first state so it may continue to decode the first amplitude of the frequency f.sub.o associated with the first coded message.
A decoder for receiving and decoding a series of coded messages wherein a first amplitude of a particular frequency ends a first coded message and a second amplitude of said particular frequency begins a second coded message, said decoder comprising,
A method for detecting and decoding a coded signal including first and second messages, wherein a first amplitude of a first frequency is associated with a first coded message, and a second amplitude of said first frequency is associated with a second coded message, said method comprising the steps of,
A decoder for receiving and decoding a series of coded messages from a remote terminal wherein a first amplitude of a first frequency is associated with a first coded message and a second amplitude of a first frequency followed by a second frequency is associated with second coded message, said decoder comprising;
Dependencies are inferred from the claim text.