CCANA

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CCANA - general Cohen class analysis

A general Cohen class analysis SPAtom.

Usage:

SPU CCANA WAVE HOPSIZE ITYP FTYP ANALYTICSIGNAL MAXSIZE DTYP LSIG WSIG LSMO WSMO EPS DB AMAX AREF

Inputs:
WAVE
The input signal wave item (mono).
HOPSIZE
The distance between frames in samples.
ITYP
The input frame alignment (values: BEGIN, CENTER).
FTYP
The input filter (NONE, DOUBLESRATE, HALFBANDWIDTH, ANALYTICSIGNAL).
MAXSIZE
The maximum signal queue length.
DTYP
The Cohen class distribution type (WIGNERVILLE, CHOIWILLIAMS).
LSIG
The signal window length in samples.
WSIG
The signal window type. The following values are supported(RECTANGLE, HANNING, HAMMING).
LSMO
The smoothing window length in samples.
WSMO
DTYP=WIGNERVILLE -> smoothing window type (RECTANGLE, HANNING, HAMMING)
DTYP=CHOIWILLIAMS -> smoothing window coef. sigma (0 < sigma)
EPS
DTYP=WIGNERVILLE -> not used
DTYP=CHOIWILLIAMS -> minimum smoothing window value
DB
1 if the amplitude scale is in dB, 0 otherwise. The default is 0.
AMAX
An amplitude value > 0. The default is 1.
AREF
A reference amplitude > 0. The default is 1.
Outputs:
Y
The amplitudes.
DT
The time resolution in seconds
DF
The frequency resolution in Hz.
LMAX
The maximum frame length in samples.
I
The number of processed frames.
N
The maximum number of frames.
SR
The sampling rate in Hz.
Function:

The SPAtom CCANA implements a Psuedo Wigner-Ville Distribution (PWD), a Smoothed Pseudo Wigner-Ville Distribution (SPWD) and a Choi-Williams Distribution (CWD).

Pseudo Wigner-Ville Distribution (PWD)

5501.png

where

k - Frequency index, k = 0..N/4

hn - Symmetrical, real signal window function of length 2N-1

xn - The complex signal of length 2(N-1)+1

n - The time index (sample index), n = -(N-1)..(N-1)

N - The transformation length

Smoothed Pseudo Wigner-Ville Distribution (SPWD)

5503.png

where

k - The frequency index, k = 0..N/4

hn - The symmetrical real signal window of length 2N-1

gm - The symmetrical real smoothing window of length 2M-1

xm±n - The real/complex signal of length 2(M-1)+2(N-1)+1

m - The shift index, m = -(M-1)..(M-1)

n - The time index (sample index), n = -(N-1)..(N-1)

M - The smoothing length

N - The transformation length

Choi-Williams Distribution (CWD)

5504.png

where

k - The frequency index, k = 0..N/2

hn - The symmetrical real signal window of length 2N-1

s - The distribution parameter (>0)

xm±n - The real/complex signal of length 2(M-1)+2(N-1)+1

m - The shift index, m = -(M-1)..(M-1)

n - The time index (sample index), n = -(N-1)..(N-1)

M - The smoothing length

N - The transformation length.