10 Notational Conventions

The following notational conventions are used throughout the rest of this document . Unless otherwise explicitly indicated, lower-case letters are used to represent time domain signals, while upper-case letters represent signals that have been processed by a transformation, such as the fast Fourier transform. Boldface characters (e.g. $\mX$) represent matrices and underlined boldface characters (e.g. $\vw$) represent vectors. In adaptive filters contexts, the filter input signal is called $x(n)$, its output signal $y(n)$, the error signal $e(n)$, the desired signal $d(n)$, the vector of filter coefficients $\vw (n)$, and the adaptation constant (step size) is called $\mu$. Code fragments, examples, and ASPT routine names are printed in fixed font (e.g. asptlms()).