OFDM automatic frequency control device and method thereof
AssigneeFujitsu Limited
InventorsMakoto Yoshida, Tetsuya Yano
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Abstract
An OFDM frequency control device converts an incoming signal from analog to digital and calculates a correlation value between the guard interval and data part from which the guard interval is copied, of the A/D converted incoming signal. Then, the device averages such correlation values for the first frame through a plurality of frames and detects the peak of the averaged correlation value. Then, by detecting the phase of the peak position, the device generates the control signal for an oscillator. The control signal is set in such a way that a control amount for each time should be a control step α and is applied to the oscillator. Furthermore, α is appropriately controlled based on detected information.
Claims22
An automatic frequency control device in an OFDM (Orthogonal Frequency Divisional Multiplexing) system, comprising:
- a correlation unit calculating a correlation value between a guard interval and data of an incoming signal;
- an averaging unit averaging correlation values across a plurality of symbols and a plurality of frames;
- a peak position detecting unit detecting a peak position of the averaged correlation value;
- and
- a control unit controlling an oscillator using a prescribed step, based on the detected peak position.
An automatic frequency control method in an OFDM (Orthogonal Frequency Divisional Multiplexing) system, comprising:
- calculating a correlation value between a guard interval and data of an incoming signal;
- averaging correlation values across a plurality of symbols and a plurality of frames;
- detecting a peak position of the averaged correlation value;
- and
- controlling an oscillator using a prescribed step, based on the detected peak position.
Dependencies are inferred from the claim text.