Sum of squares root calculation means of IQ data

摘要

P To overcome the problem that methods using, for example, a ROM to obtain a value of a square root have a disadvantage of requiring a memory resource and methods using a simple approximate expression only for sums of squares and to obtain a value of a square root have low precision and are used in a demodulation circuit of a communication device or the like to possibly lead to the occurrence of errors. PSOLUTION: When a square root of the sum of the square of I and the square of Q, wherein I am a real part and Q is an imaginary part of a base band obtained by an I/Q demodulator, is obtained in demodulation processing or the like of a communication device, a means for calculating the square root of the square sum of IQ data includes a first divider for dividing the sum of the square of I and the square of Q by X wherein X is the sum of I and Q, an adder for adding X to the calculation results of the divider and a second divider for dividing the calculation results of the adder by 2 and takes the calculation results of the second divider as new X to repeat the calculations in the first divider, the adder and the second divider. PCOPYRIGHT: (C)2011 and JPO& INPIT