| 摘要 |
PURPOSE:To reduce transmission power by decreasing peak amplitude without decreasing the distance between the shortest signal points. CONSTITUTION:When a digital signal of channels P,Q is inputted, the signal is converted into a digital signal corresponding to a new signal point changed by a signal point change logical circuit 1 and all input signals are converted into binary 5-column digital signals S3,S4. The signal are inputted to binary 5-column digital-analog converting circuits 2,3 to obtain 18-value analog signal S5,S6, which are inputted to ring modulators 6,7 after high frequency cut-off. A pi/2 phase shift circuit 8 is provided to a circuit of the channel P and the shape of all signal point groups is changed from a square into a circle so that the peak amplitude is minimized without decreasing the distance between the shortest signal points. |
