Implementation of fast angle calculation and rotation using on-line CORDIC

The authors present several modifications to the CORDIC method to improve the speed and efficiency of its implementation when it is used for calculating angle and rotation for Given´s method. The main contributions are: (i) the introduction of redundant (carry-free) addition to replace time-consuming conventional additions; (ii) the use of online arithmetic to reduce the communication bandwidth, maximize the overlap between successive operations, and replace area-expensive shifters by delays; (iii) the use of angles in decomposed forms to eliminate angle accumulation recurrences. These modifications contributed to a speedup of about 4.5 with respect to standard CORDIC. Some considerations are given with respect to the complexity of implementation; however, a more detailed analysis would require actual VLSI implementation.<>