ApplicationNo. 05/646729 filed on 01/05/1976
US Classes:455/202, Suppressed carrier455/240.1, Variable automatic gain control loop gain455/265With local oscillator synchronization or locking
ExaminersPrimary: Griffin, Robert L.
Assistant: Ng, Jin F.
Attorney, Agent or Firm
AbstractAn automatic gain control (hereinafter referred to as AGC) circuitry is used in conjunction with a Costas loop detector to provide positive gain control during the acquisition and tracking modes of the operation of a receiver. The circuitry includes circuitry for deriving a noise estimate signal from one channel of the Costas loop and circuitry for subtracting the noise estimate signal from the data and noise signal combination in the other channel of the Costas loop for providing the automatic gain control signal to prevent false locking.