| 摘要 |
PURPOSE:To obtain a spread spectrum communication system in which the data transmission of a high reliability can be attained even at the time of using the transmission line of a bad transmission quality. CONSTITUTION:In a transmitter 70, a carrier 21 from a carrier oscillator 11 is multiplied by a signal 24 obtained by the EXOR of an PN code 22 outputted from a PN code generator 12 and a transmission data 23, mixed with the output of a multiplier 72 multiplied by the PN code 22 by a mixer 73, and transmitted through a high pass filter 15 to a battery line 51. In a receiver 90, a received signal 94 inputted through a high pass filter 31 is separated into two frequency bands by band pass filters 91 and 92, multiplied by a multiplier 39, and a correlation signal 45 of an intermediate frequency (f)IF is taken out from a band pass filter 37. This signal is modulated by a demodulated by a demodulator 38, and the received data 47 are obtained. |
