| 摘要 |
PURPOSE:To reduce jitters of a reproduced carrier wave, by setting a multiplier at the input side of a nonlinear element in order to multiply an input m-phase PSK wave by a rectified cosine waveform using the symbol time of said PSK wave as its half period, and then to have m-multiplication by the nonlinear element. CONSTITUTION:The phase transition of m-phase shift keying PSK of a multiplier 6 is shown by the vector of a product of 4-phase PSK wave and a shaped waveform (dospit/T)<m> in the case of m=4. When an input PSK wave 1' changes to 1 from 0, the output of the multiplier 6 does not shift directly to 1 from 0 but shifts to 1 after once shifting to the original point from 0. Therefore the phase jitters are not virtually included to a reproduced carrier wave 2' of m- multiplication for the output of a nonlinear element 3'. Thus the self-noise produced here are substantially equal to AM noises and can be eliminated by setting an amplitude limiter at the output side of the wave 2'. |
