| 摘要 |
PURPOSE: An AFC(Automatic Frequency Controller) of a multi-carrier CDMA system is provided to detect locked fingers of many fingers to calculate an average frequency error, to reflect substantially-generated errors, so as to compensate an exact frequency error. CONSTITUTION: A BBA(Base Band Analog) chip(10) receives each finger signal, and outputs in-phase components and orthogonal components as baseband signals. A PN despreading block(11) despreads the in-phase components and the orthogonal components. A CPFDD(Cross Product Frequency Difference Detector)(13) detects frequency errors of each of the finger signals from in-phase and orthogonal components filtered in pilot filters(12). A lock state detector(21) extracts finger signals having energy levels more than a regular energy level from each finger signal. A divider(20) divides the detected frequency errors by the number of locked fingers detected from the lock state detector(21). An adder(14) adds each frequency error to output an average frequency error. A loop filter(15) inputs the average frequency error, and outputs a voltage level suppressing influence of the error. A VCO(Voltage Controlled Oscillator)(16) supplies a frequency in accordance with the voltage level to an exterior as a receiving reference signal by making a voltage of the loop filter(15) as a control voltage. |
