NSGT_REAL - Nonstationary Gabor transform for real signals
Usage
[c,Ls] = nsgt_real(f,g,shift,M) [c,Ls] = nsgt_real(f,g,shift) c = nsgt_real(...)
Input parameters
| f | A real-valued signal to be analyzed (For multichannel signals, input should be a matrix which each column storing a channel of the signal). |
| g | Cell array of frequency side analysis windows |
| shift | Vector of time shifts |
| M | Number of frequency channels (optional). If M is constant, the output is converted to a matrix |
Output parameters
| c | Transform coefficients (matrix or cell array) |
| Ls | Original signal length (in samples) |
Description
Given the cell array g of windows, the time shift vector shift, and channel numbers M, nsgt_real computes the corresponding nonstationary Gabor transform of f, computing only the positive frequency samples. Let \(P(n)=\sum_{l=1}^{n} shift(l)\) , then the output c = nsgt_real(f,g,shift,M) is a cell array with
\begin{equation*}
c\{n\}(m) = \sum_{l=0}^{Ls-1} f[l]\overline{g\{n\}[l-P(n)]}e^{-2\pi i(l-P(n))m/M(n)},
\end{equation*}
where m runs from 0 to floor( M(n)/2 ).
For more details, see nsgt.