| 摘要 |
PURPOSE:To attain the narrow band of the spectrum of a modulated wave and also to keep envelepes constant by making use of relative phase information that corresponds to a combination of not less than three continuous bits of input data. CONSTITUTION:Every time one bit of input data 1 is inputted, relative phase shift information that corresponds to a combination of three continuous bits of input data is read out of memory 3 and applies to adder 6, where it is added of the final phase of absolute phase shift information, preceding by one time slot, from latch circuit 7, obtaining absolute phase shift information theta(t) that corresponds to input data. From this absolute phase shift information, a sine value and cosine value are operated and their results are converted into analog signals, which are applied to carrier suppression amplitude modulators 18 and 19, where carriers sinomegact and cosomegact are modulated. Then, their outputs are added together so as to obtain digital phase modulated wave sintheta(t) sinomegact+costheta(t)cosomegact. |
