| 摘要 |
PURPOSE: To conduct synchronization of a broad band signal string of an independent receiver and simultaneous retrieval with respect to a carrier frequency quickly by scanning a carrier frequency only with selection of an individual frequency. CONSTITUTION: A correlation device 2 receives an RF signal. An oscillator 5 generates a frequency FL close to a carrier frequency FP and a controller 4 controls the frequency via a potentiometer 51. An oscillator 30 provides a clock to allow the controller 4 to control a half bit shifter 31 and provides an FS whose speed is equal to a speed of a pseudo signal string SQ to a generator 3 and generates periodically a local pseudo signal SL. The correlation device 2 allows a modulator 21 to modulates the frequency FL with a signal LSL and a modulator 22 receives it to modulate the frequency FP. Furthermore, after a BPF and a rectifier, the controller 4 controls an integration device 25 to inhibit read of the signal FS for a local signal string generator 3 and an integration output SI is given to a comparator 26, which compares it with a reference signal, from which a logic output SC is obtained and fed to the controller 4. Thus, the carrier frequency is quickly obtained. |
