| 摘要 |
PURPOSE:To provide a multicarrier digital modulator for which the average power/peak power ratio of a transmitted modulated waveform is small. CONSTITUTION:A serial/parallel converter 1 separates a transmissive digital signal sequence into four systems. While using the signal sequences supplied by the serial/parallel converting means, IQ coders 2-5 generate transmissive signals on phase amplitude planes corresponding to respective sub carrier waves. Transmission roll-off filters 6-9 perform band limitations. Modulators 10-13 generate (n) pieces of sub modulated waves from the outputs of transmission roll-off filters and sub carrier waves from sub carrier wave oscillators 14-17. Adders 18-1 and 18-2 add the (n) pieces of sub modulated waves so that the transmissive modulated wave can be generated. An amplitude limiter 19 limits the amplitude of the transmissive modulated wave at a previously set desired amplitude level so that an envelope suppressed modulated wave can be generated. An interpolator 20 generates an interpolated waveform corresponding to the envelope suppressed modulated wave and limits its band. |
