PHASE ANGLE DATA AND TRIGONOMETRIC FUNCTION CONVERSION CIRCUIT, AND SYNTHESIS DIVERSITY RECEIVER

摘要

PROBLEM TO BE SOLVED: To realize an arithmetic circuit that derives a trigonometric function from input angle data predicted in advance at a low cost by using only number of storage components being 1/4 of conventional numbers. ;SOLUTION: An angle of 360° is divided into 1/n equally and the value (n) is expressed as binary angle data. Absolute value data of sine value data and cosine value data from 0 to 90 degrees of the angle data are stored respectively in memories 1, 2. The absolute value data of sine value data and cosine value data of corresponding angle data are outputted based on other bits of the angle data expressed in a binary number than high-order 2-bit data, and the two bits of the most significant bit and the succeeding digit bit are used to select the sine value data or the cosine value data and to provide a sign (t) to the selected data.;COPYRIGHT: (C)1998,JPO