Modified vector rotational CORDIC (MVR-CORDIC) algorithm and its application to FFT

The CORDIC algorithm is a well-known iterative method for the computation of vector rotation. However, the major disadvantage is its relatively slow computational speed. For applications that require forward rotation (or vector rotation) only, we propose a new scheme, the Modified Vector Rotational CORDIC (MVR-CORDIC) algorithm, to improve the speed performance of CORDIC algorithm. The basic idea of the proposed scheme is to reduce the iteration number directly while maintaining the SQNR performance. This can be achieved by modifying the basic microrotation procedure of the CORDIC algorithm. In addition, three searching algorithms are suggested to find the corresponding directional and rotational sequences. In the example of a 128-point FFT, we have shown that by using the proposed MVR-CORDIC algorithm, the hardware complexity is only 33% compared with conventional CORDIC-based FFT. Meanwhile, the SQNR performance is 7 dB better than the conventional CORDIC approach.