Portable radio terminal and AFC control method
AssigneeNEC Corporation
InventorsMariko Matsumoto, Shigeru Ono
Life of this patent
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Abstract
A portable radio terminal for realizing automatic frequency control (AFC) for automatically controlling the oscillation frequency of an oscillator includes a unit for intermittently performing AFC operation, and a unit for shortening an AFC operation stop period when the frequency shift of the oscillation frequency is large. An AFC control method is also disclosed.
Claims6
A portable radio terminal for realizing automatic frequency control (AFC) for automatically controlling an oscillation frequency of an oscillator, comprising:
- means for updating a frequency shift to the oscillator to a first value corresponding to an average of a most recently detected frequency shift value and at least one previously detected frequency shift value when the most recently detected frequency shift of the oscillation frequency is smaller than a predetermined value and frequency shifts in the same direction are detected a predetermined number of time;
- and
- means for updating a frequency shift to the oscillator to a second value corresponding to the frequency shift added to the most recently detected frequency shift value when the most recently detected frequency shift of the oscillation frequency is greater than or equal to the predetermined value.
An AFC control method of realizing automatic frequency control (AFC) for automatically controlling an oscillation frequency of an oscillator, comprising:
- updating a frequency shift to the oscillator to a first value corresponding to an average of a most recently detected frequency shift value and at least one previously detected frequency shift value when the most recently detected frequency shift of the oscillation frequency is smaller than a predetermined value and frequency shifts in the same direction are detected a predetermined number of times;
- and
- updating a frequency shift to the oscillator to a second value corresponding to the frequency shift added to the most recently detected frequency shift value when the most recently detected frequency shift of the oscillation frequency is greater than or equal to the predetermined value.
Dependencies are inferred from the claim text.