Features of Spectral Analysis Using Complex Discrete Cosine Transform

The primary method for spectral analysis of the sound broadcasting signal remains the Fast Fourier Transform. One of its drawbacks is insufficient resolution, which does not allow for the assessment of closely spaced spectral components of the sound signal. The resolution of the Discrete Cosine Transform is twice as high, but its use has been limited by the wide spectrum of side lobes. The authors have developed a method for a complex Discrete Cosine Transform with compensation for side lobes and improved accuracy in determining the parameters of spectral components through multiple transpositions of the sound signal spectrum.