| 摘要 |
PURPOSE:To omit the necessity of synchronism by allowing a receiving side to square a transmitting signal obtained by synthesizing a false noise signal including data to be transmitted and to demodulate the squared signal through a filter means. CONSTITUTION:When it is defined that the code of data to be transmitted is D(t), a false noise code of a false noise code generator 1 is P(t) and a reference frequency signal of an oscillator 3 is cosomegat, the output of a mixer 4 becomes P(t).D(t)cosomegat. On the other hand, the output of a mixer 6 is -P(t)sinomegat, so that the output of an adder 7 becomes P(t).D(t)cosomegat -P(t)sinomegat and is transmitted through a band pass filter 8. The receiving side squares said transmitting signal by a mixer and receives the squared signal as 1 -D(t)sin2omegat. When the receiving signal is passed through the band pass filter, -D(t)sinomegat can be obtained. Since the filtered signal does not include the code P(t), the signal can be demodulated. |
