| 摘要 |
PURPOSE:To make the most of circuits which are usually essential to be unnecessary and to enable the circuit to be simplified and to reduce cost by multiplying a spreading code signal and a spreading signal, executing inverse diffusion, synchronously detecting an obtained signal and demodulating an information signal. CONSTITUTION:An N-multiple circuit 34 N-multiplies a control signal C(t) from a control signal detection circuit 33, generates a clock signal Sc(t) and supplies it to a spreading code generation circuit 27. On the other hand, a mono-multi- vibrator 35 inputs the signal C(t), generates a reset signal and outputs it to the circuit 27. Therefore, the circuit 27 works in the quite same way as a spreading code generation circuit 26 and the signal outputted by the circuit 27 is made to be a generated spreading code P(t). Next, a multiplier 8 multiplies the code P(t) and an addition signal S1(t), executes the inverse diffusion and obtains a demodulated two-phase PSK signal through a BPF 23. A multiplier 9 multiplies the PSK signal and a regenerating carrier obtained from a carrier recovery unit 36 and executes the synchronous detection. Then, information data [d(t)] is demodulated through an LPF 16 and outputted to an output terminal Out2. |
