Another contender in the arctangent race
Richard G. Lyons · IEEE Signal Processing Magazine · 2004
Fast and accurate methods for computing the arctangent of a complex number x = I + jQ have been the subject of extensive study because estimating the angle /spl theta/ of a complex value has so many applications in the field of signal processing. Practitioners interested in high-speed arctangent computations typically use look-up tables where the values of I and Q specify an address in read-only memory (ROM) containing an approximation of angle /spl theta/. In this paper, another method to compute the arctangent approximation is proposed that uses neither the look-up table nor high order polynomials.