| 摘要 |
PURPOSE:To transmit information by twice as much as a linear vestigial side- band wave modulator by providing two vestigial side-band wave modulators and adding their vestigial side band wave modulated signals together. CONSTITUTION:A signal f(t) is inputted to an input terminal 1 and a phase difference branching filter 21 sends out an in-phase output and an orthogonal output which is 90 deg. advanced in phase. Those outputs are supplied to an orthogonal modulator 31, which multiplies the in-phase output by a carrier cosomegact and the orthogonal output by a carrier sinomegact and inputs the results to a subtracting circuit, obtaining the 1st vestigial side-band wave modulated signal. Similarly, a signal g(t) from an input terminal 12 is supplied to an orthogonal modulator 32 through a phase branching filter 22 to obtain the 2nd vestigial side-band wave modulated signal. Then, the 1st and the 2nd vestigial side-band wave modulated signals are summed up by an adding circuit 50. Consequently, information is transmitted by twice as much as one linear vestigial side-band wave modulator. |
