POWER LINE CARRIER SPREAD SPECTRUM COMMUNICATION EQUIPMENT

摘要

PURPOSE:To improve S/N and the reliability of communication by applying pre-emphasis to a direct spread signal and sending the result in a flat spectrum at a specific frequency band. CONSTITUTION:A transmitter 7 sends an output being the result of outputs of a carrier generating means 10 and a pseudo noise generating means 11 to a data 9 by a mixer 12 through a filter 13. The filter 13 blocks frequencies of 10kHz or below and 450kHz or over and attenuates the frequencies in a form of a reciprocal of (sinx/x)<2> around 230kHz. The signal passes through a filter 17 emphasizing the frequency in a form of (sinx/x)<2> around the frequency of 230kHz attenuated by the filter 13 at first in a receiver 8 to restore the spectrum of the sent signal. Then a pseudo noise generating means 11 in a transmitter 7 uses a pseudo noise generator means 18 to generate pseudo noise synchronously with the pseudo noise and the data 21 is demodulated by the same way as a conventional equipment.