| 摘要 |
<P>PROBLEM TO BE SOLVED: To make a circuit small in scale, and to achieve simplified configuration. <P>SOLUTION: A serial-parallel converter 12 divides signals of transmission code rows into an in-phase-side signal and a quadrature-side signal, and mapping circuits 13-1 and 13-2 perform mapping and oversampling circuits 14-1 and 14-2 insert zeros into the signal after mapping for oversampling. A delay circuit 2 delays the quadrature-side signal after oversampling by one clock. An adder 3 adds the in-phase-side signal after oversampling with the quadrature-side signal with one clock delayed, and a band pass filter 4 subjects the added signal to filter processing having raised cosine roll-off characteristics in which a frequency band with a predetermined width from the center of modulated frequency on a frequency axis is cut-off frequency. The delay circuit 2, the adder 3 and the band pass filter 4 are used to generate an optional modulated signal instead of the conventional low-pass filter, oscillator, phase shifter, and multiplier. <P>COPYRIGHT: (C)2011,JPO&INPIT |
