A novel implementation of a chirp Z-transform using a CORDIC processor

An efficient implementation of the chirp Z transform (CZT) using a CORDIC (coordinate rotation digital computer) processor is presented. In particular, it is shown that a scaling operation in the CZT algorithm can be conveniently implemented with a norm correction (normalization) computation, which is often considered as an overhead in the CORDIC algorithm. Furthermore, since the desired frequencies of CZT are specified before computation, it is possible to reduce the total number of CORDIC iterations by finding a most economical representation of the angle in terms of the elementary CORDIC rotation angles. A simple suboptimal solution is proposed to solve this difficult optimization problem. This implementation is most effective when very few complex frequencies on the Z plane are to be evaluated via CZT