| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital modulation apparatus capable of efficiently performing modulation for a plurality of signatures, using a simple configuration. <P>SOLUTION: The apparatus comprises a first phase rotation means 11 for make the phases of a plurality of I and Q data phase-rotate by +π/4 or -π/4, respectively, a summation means 12 for adding the I and Q data after phase rotation, and a second phase rotation means 14 for making the I and Q data after summation phase-rotate only by a multiple of π/2, when the phase of spreading code composed of QPSK is decomposed into sum of phases constituted of multiples of +π/4, or -π/4 and π/2. <P>COPYRIGHT: (C)2009,JPO&INPIT |
