| 摘要 |
PROBLEM TO BE SOLVED: To make the circuit scale and the product small without use of a PLL circuit in the carrier recovery by conducting inverse spread processing based on a reception signal and inverse spread code so as to extract a carrier signal and limiting a voltage while keeping the phase. SOLUTION: A spread reception signal is given to a double balanced mixer 11 and to a multiplier 15. The reception signal is inversely spread by an inverse spread code PNo in the double balanced mixer 11 and only a carrier component is extracted. Then the inversely spread and extracted carrier component is filtered by a narrow band filter 12. The carrier signal is given to a limiter amplifier circuit 14, this signal is given to the limiter amplifier circuit 14, from which a desired prescribed voltage in phase with a carrier signal before input is outputted. Furthermore, the phase is in phase with the spread signal via the phase shifter 13. A multiplier 15 ANDs the reception signal and an output of the amplifier 14 and a base band signal is generated via a low pass filter 16. |
