| 摘要 |
PURPOSE:To facilitate the simplification of circuit constitution by removing unnecessary frequency components in an inverse diffusion signal and demodulating a primary modulation wave signal. CONSTITUTION:A modulation part 10 is constituted by connecting an adder 2, a multiplier 3, a frequency conversion circuit (multiplier) 4, LPF(low pass filter) 7, a diffused code generation circuit (PNG) 9 BPF(band pass filter) 14 and a primary modulation circuit 42, etc. A demodulation part 20 is constituted by connecting plural band filters 15-19, an adder 22, two multipliers 5 and 6 and a primary demodulation circuit 23, etc. In the demodulation part 20, the outputs of plural narrow band filters 17-19 are added and the unnecessary frequency components in the inversely diffused signal obtained by inversely diffusing the outputs by a square action are removed and the primary modulation wave signal is demodulated. Thus, a clock recovering circuit, a diffused code generation circuit, a pull-in circuit consisting of a loop and a synchronization holding circuit, all of which are necessary constitution conditions so far in inverse diffusion, are eliminated. |
