| 摘要 |
PURPOSE:To simplify a circuit constitution by converting a received spectrum diffusion signal into a binary signal, generating a pseudo noise(PN) code whose phase is at a prescribed value, and executing a digital synchronizing processing. CONSTITUTION:When the output of a code/phase detecting circuit 16 is at an L, a code generating circuit 3 shifts the phase of the PN code for one bit, etc., at a prescribed cycle, a multiplication result by means of a first multiplying circuit 4 between the PN code and the binarized received spectrum diffusion signal by means of a binarizing circuit 2 is counted by a third counting circuit 15 reset by the signal at a cycle shorter than shift timing, and when a counted value becomes not less than a reference value, the output of the circuit 16 invertes to an H, phase shift stops, an NR code on a transmitting side and the NR code from the circuit 3 are made into a synchronization established condition, and the information signal is demodulated from the output of the circuit 4. Further, half-cycle advance/delay PN code from the circuit 3 is counted by first and second counting circuits 7 and 8 in the same way, and the synchronous dislocation of the code PN from the circuit 3 is controlled through a VCO 14, etc. The constitution of the demodulating circuit is simplified by the digital processing. |
