| 摘要 |
The receiver for receiving data carried by the carrier frequency signal and, in a heterodyning system, for downconverting the received signal to a suitable intermediate frequency signal. The modulator and the downconverter are formed on a single semiconductor body, or chip of silicon. The receiver section is adapted to receive, over a predetermined overall bandwidth, signals having carrier frequencies within a plurality of frequency channels, each one of the channels having a predetermined channel bandwidth. The downconverted signals are converted into corresponding digital signals. A demodulator includes a pair of filters having Hilbert-Transform relationship with respect to each other. The receiver includes: a first automatic gain control circuit (AGC) which is responsive to an output of the digital signal processor, for adjusting the gain of the AGC circuit in accordance with the output of the digital signal processor; and, a second AGC circuit fed by the digital signals and the output of the digital signal processor, for adjusting the gain of the magnitude of the digital signals in accordance with the output of the digital signal processor.
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