SVD by constant-factor-redundant-CORDIC

Abstract

A constant-factor-redundant-CORDIC (CFR-CORDIC) scheme is developed where the scale factor is forced to be constant while computing angles for SVD (singular value decomposition). Based on the scheme, a fixed-point implementation of SVD is presented with the following additional features: (1) the final scaling operation is done by shifting; (2) the number of iterations in the CORDIC rotation unit is reduced by about 25% by expressing the direction of the rotation in radix-2 and radix-4; and (3) the conventional number representation of rotated output is obtained on-the-fly, not from a carry-propagate adder. The authors compare this scheme with previously proposed ones and show that it provides an execution time similar to that of redundant CORDIC with variable scaling factor, with significant saving in area.<>