Patent ID: 6148187
Filing Date: 2000-11-14
Classification: H03J,H03L

Abstract:
An automatic frequency control method comprising the steps of:quasi-synchronously detecting the received signal using the oscillation output of a voltage controlled oscillator as a reference signal;regenerating the received carrier from the quasi-synchronous detection output, to synchronously detect the quasi-synchronous detection output to regenerate the received data;feeding back remaining frequency error information of the quasi-synchronously detected signal to a frequency control circuit for controlling said voltage controlled oscillator;storing frequency control values successively outputted from said frequency control circuit in a corresponding relationship to ambient temperatures of said voltage controlled oscillator at the time; andreading out, upon turning on of the power supply or upon changing over a channel, one of the frequency control values corresponding to the current ambient temperature of said voltage controlled oscillator and supplying the read out frequency control value as the initial set value to said voltage controlled oscillator;wherein the stored frequency control values are updated in response to a frame synchronization condition based on said regenerated received data.