The course is an introduction to the Fourier spectral analysis of
both periodic and nonperiodic functions. The exposition starts with
the more transparent case of univariate functions being generalized to
the multivariate case at the final stage.
Numerous application examples are given throughout.
The periodic case: Fourier series and the sequence of Fourier coefficients
as a spectral representation of periodic functions. Fourier series
are considered to be a special case of an orthogonal expansion and
its equivalent forms are given. Various convergence concepts are
introduced and relation to integral operators of periodic convolution
and correlation is established.
The view of Parseval identity as a power spectral density.
Nonperiodic case: integral (continuous) Fourier transform (IFT) and its
inverse being explained as a nonperiodic analogy to the spectrum of
Fourier coefficients and the backward Fourier series expansion.
Fundamental properties of IFT, relation to nonperiodic integral
convolution and correlation operators.
Syllabus
Fourier series (FS):
3 equivalent forms of FS (complex, trigonometric and
amplitude-phase form),
Dirichlet kernel and pointwise convergence,
Fejér kernel and convergence in mean, convergence in spaces
$L^1$ and $L^2$, statements on cyclic convolution and correlation,
Parseval identities.
Fourier transform (FT):
existence and inversion (theorems by Fourier and Plancherel),
properties, statements on convolution and correlation,
Parseval identities, examples.
Multivariate Fourier series and transforms.
Literature
HOWELL, Kenneth B. Principles of Fourier Analysis (Principles of Fourier Analysis). Boca Raton-London-New York-Washington: Chapman & Hall, 2001. 776 pp. Studies in Advanced Mathematics. ISBN 0-8493-8275-0. info
BRACEWELL, Ronald Newbold. Fourier transform and its applications. 2nd ed. New York: McGraw-Hill, 1986. xx, 474 s. ISBN 0-07-007015-6. info
BRIGHAM, E. Oran. Fast Fourier transform. Englewood Cliffs: Prentice Hall, 1974. 252 s. ISBN 0-13-307496-. info
KUFNER, Alois and Jan KADLEC. Fourierovy řady (Fourier series). Praha: Academia, 1969. info
LASSER, Rupert. Introduction to fourier series. New York: Marcel Dekker, 1996. vii, 285 s. ISBN 0-8247-9610-1. info
HARDY, G. H. and W. W. ROGOSINSKI. Fourierovy řady : Fourier series (Orig.). Vyd. 1. Praha: SNTL - Nakladatelství technické literatury, 1971. 155 s. info