A Method for Speed Up the Allpass Transformation Algorithm

Two algorithms for calculating the phase transformation, which consists in calculating the outputs of a chain of phase links, are considered. The algorithms are based on the idea of synthesis of a dual phase link, which allows calculating the outputs of a cascade of two-phase links in one pass. To synthesize dual phase links, the representation of digital filters by the space state method is used. The proposed algorithms are implemented in the C language, and they are compared with the direct form of implementation of the phase transformation. During the experiments, the speed of calculating the chain of phase links on a personal computer with an Intel Core i7-37700 processor was estimated using the profiler built into the Visual Studio environment. The results showed that both algorithms allow accelerating the calculation of the chain of phase links by 1.3 and 1.8 times, respectively.