Patent Number: 6,169,723

Title: Computationally efficient analysis and synthesis of real signals using discrete fourier transforms and inverse discrete fourier transforms

Abstract: The present invention significantly reduces the number of complex computations that must be performed to compute a DFT or IDFT when a pattern is identified in an original input data sequence and is used to modify the data sequence in order to reduce the size of the sequence to be transformed. A DFT (IDFT) is performed on the modified input data sequence to generate a transformed sequence. The transformed data sequence is then manipulated to generate an output sequence that corresponds to the DFT (IDFT) of the original input data sequence without having actually calculated the DFT (IDFT) of the entire, original input data sequence. Three symmetrical patterns are used in the invention to simplify and render more efficient DFT and IDFT computations: Hermite symmetry, index-reversed, complex-conjugate symmetry, and mirror symmetry. As a result, the number of complex multiplications required to perform the DFT (or IDFT) is considerably less than the number of complex multiplications required to calculate the DFT (or IDFT) of the original input data sequence. The computational reduction increases signal processing speed and decreases power consumption, both attributes are highly desirable in virtually every DFT/IDFT application.

Inventors: Fertner; Antoni (Solna, SE), Hyll; Mattias (Stockholm, SE), Orling; Anders (Stockholm, SE)

Assignee: Telefonaktiebolaget LM Ericsson

International Classification: G06F 17/14 (20060101); G01R 023/16 ()

Expiration Date: 01/02/2018