| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of calculating phase rotation, which calculates phase rotation used for digital phase modulation in half or less of the time required before. Ž<P>SOLUTION: A digital signal processor includes: a substitution part for substituting a complex number used for digital modulation with a predetermined expression for square operation; and a calculation control part controlling the number of square calculation. The method of calculating phase rotation includes steps of: expanding a multiplier to be multiplied by a complex number being input data to an exponent with a base of 2 by software operating on the digital signal processor; executing the square calculation of the complex number being input data; substituting the result of the square calculation with a predetermined complex number; executing square calculation by using the substituted expression as input data; and controlling the square calculation step and the substitution step to be repeated the number of times obtained by subtracting 1 from the exponent. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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