| 摘要 |
PURPOSE:To surely attain communication of information by providing a 1st equipment comprising a spread means spreading a spectrum of a carrier signal and a transmission means sending a signal spread by the spread means, and providing a 2nd equipment comprising an inverse spread means inversely spreading a spectrum of a received signal and a demodulation means demodulating a signal from the inverse spread means to the system. CONSTITUTION:A carrier signal outputted from a carrier signal generating circuit 20 is subject to frequency conversion and a signal subject to spread spectrum processing by a spread circuit 26 is sent via an antenna 27. On the other hand, a reception code from a reception code generating circuit 35 in a 2nd equipment B being a receiver side and a signal subject to frequency conversion are multiplied to apply inverse spread to the spectrum, a band pass filter 37 extracts a desired signal component and it is demodulated by a demodulation circuit 38. Then a 1st equipment A selects an output from a 2nd frequency generating circuit 22 and the 2nd equipment B selects an output from a 4th frequency generating circuit 32. Thus, even when other communication system is in existence, the information is communicated surely. |
