hilbert

 

	int i,k;
	float	anarg,imp_del,tmp,argval,window;
	int no_samples;
	char impResponseFile[200];
	int	impFlag;
	FILE* fp;

 

pcount = impl;
/*
 * allocate necessary storage
 */
if( (temp = (cap_fft_scalar*)calloc(fftl,sizeof(cap_fft_scalar))) == NULL
	 || (temp2 = (cap_fft_scalar*)calloc(fftl,sizeof(cap_fft_scalar))) == NULL
	 || (iresp = (cap_fft_cpx*)calloc(fftl,sizeof(cap_fft_cpx))) == NULL
	 || (freqBuffCx = (cap_fft_cpx*)calloc(fftl,sizeof(cap_fft_cpx))) == NULL
	 || (save = (cap_fft_scalar*)calloc(impl,sizeof(cap_fft_scalar))) == NULL  ) {
	fprintf(stderr,"hilbert: can't allocate work space\n"); 
	return(2);
}
imp_del=(float)impl/2.0-0.5;
for( i=0; i< impl; i++) {
	anarg=(float)i-imp_del;
	if(anarg != 0.0)
	{
		tmp = sin( fbw * PI * anarg);
		argval = 2*PI*(float)i/(float)(impl-1);
		/*
		 * Blackman window
		 */
		window= 0.42 -0.5*cos(argval) + 0.08*cos(2*argval);
		temp[i] = TWO_OVER_PI*tmp*tmp/anarg*window; 
	}
	else
		temp[i] = 0.0;
}

	preverse = cap_fftr_alloc(fftl, INVERSE_FFT, NULL,NULL);
	pforward = cap_fftr_alloc(fftl, FORWARD_FFT, NULL,NULL);
	
	
	
	cap_fftr(pforward, temp,iresp);
        norm=1.0/(float)fftl;
	
	
	
	

    // rfft(iresp, fftl);

 

	for(no_samples=MIN_AVAIL();no_samples >0; --no_samples) {
		IT_IN(0);
		temp[pcount++] = x(0);
		if(pcount == fftl) {
			for(i=0; i
    

 

	free(temp); free(iresp); free(save); free(temp2); free(freqBuffCx);
	free(preverse);
        free(pforward);

/*  Capsim (r) Text Mode Kernel (TMK) Star Library (Blocks)
    Copyright (C) 1989-2002  XCAD Corporation 

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    http://capsimtmk.sourceforge.net
    XCAD Corporation
    Raleigh, North Carolina */

 

/* hilbert.s */
/***********************************************************************
                             hilbert()
************************************************************************
"Discrete Hilbert Transform":
Reference:
A.V. Oppenheim amd R. W. Schafer,"Digital Signal
Processing",pp 360-363,Prentice-Hall,1974 
A Blackman window is used in the design.
It then uses the overlap save method for fast convolution to model the
hilbert transform impulse response.
The parameters are as follows:
Param.	1 - (int) implexp: log2 [ length of impulse response in samples].
Note: The larger the length, the better the approximation. However, the
simulation efficiency suffers considerably.
Convolution is performed by the fft overlap-save method (described in
Oppenheim & Schafer, Digital Signal Processing, pp. 113).
The FFT length must be greater than the impulse response length.
For efficiency, it should probably be more than twice as long.

hilbert


"Discrete Hilbert Transform":
Reference:
A.V. Oppenheim amd R. W. Schafer,"Digital Signal
Processing",pp 360-363,Prentice-Hall,1974 
A Blackman window is used in the design.
It then uses the overlap save method for fast convolution to model the
hilbert transform impulse response.
The parameters are as follows:
Param.	1 - (int) implexp: log2 [ length of impulse response in samples].
Note: The larger the length, the better the approximation. However, the
simulation efficiency suffers considerably.
Convolution is performed by the fft overlap-save method (described in
Oppenheim & Schafer, Digital Signal Processing, pp. 113).
The FFT length must be greater than the impulse response length.
For efficiency, it should probably be more than twice as long.


Programmer: Sasan H. Ardalan, Overlap-save method by M. R. Civanlar
Date: July 26, 1990

*/