| 摘要 |
PURPOSE: An automatic frequency controller for a DS/CDMA(Direct Sequence/Code Division Multiple Access) receiver and a control method thereof are provided to perform a synchronous capture and trace of a pseudo-noise code by compulsorily adjusting a frequency difference when the frequency difference is high caused by a problem of an initial receiving state or other channels. CONSTITUTION: A frequency difference detector(FDD)(100) despreads a received DS/CDMA signal to an I channel and a Q channel, extracts pilot channels included in the despreaded signals. A control unit(202) outputs a control signal when an output value of the FDD(100) is larger than a certain value. A frequency difference tracing unit(200) selects one between an output value of the FDD(100) and a value set by a user and outputs the selected one. A frequency difference compensating unit including a loop filter(100), a PDM(Pulse Density Modulator)(111), an LPF(112), and an amplifier(114) performs a loop filtering of an output of the frequency difference tracing unit(200) and outputs a compensated oscillation signal as the filtered result. |
