fm

Capsim Block Documentation

Short Description

This star produces samples of the output every 1/fs seconds. The phase of an FM signal is the integral of the input. This is accomplished digitally as : phase=phase+in

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Input Connections
Port Type Name
0 float in
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Output Connections
Port Type Name
0 float out
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Parameters
Num Description Type Name Default Value
0 Sampling rate float fs
1 Center frequency float fo
2 Amplitude float A
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States
Num Type Name Initial Value Description
0 float phase 0.
1 float t 0.
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Declarations
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Initialization Code
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Main Code



 

	while(IT_IN(0))
	{
		if(IT_OUT(0) ) {
			KrnOverflow("fm",0);
			return(99);
		}
		phase=phase+in(0);
		t=t+1/fs;
		out(0)=A*(float)sin((double)(2.*PI*fo*t+phase));
	}
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Wrapup Code
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License



/*  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 */
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Description



 

/************************************************************************
 *									*
 *	fm.s:		frequency modulator				*
 *									*
 *	parameters:	fs, sampling frequency				*
 *			fo, center frequency				*
 * 			A, amplitude					*
 *									*
 *	inputs:		in, the signal to be modulated			*
 *									*
 *	outputs:	A*sin(2.*PI*fo*t+phase)				*
 *									*
 *	description:	This star produces samples of the output	*
 *			every 1/fs seconds.  The phase of an FM 	*
 *			signal is the integral of the input.  This	*
 *			is accomplished digitally as :			*
 *			phase=phase+in.					*
 *									*
 *									*
 *						*
 *									*

fm


 *									*
 *	description:	This star produces samples of the output	*
 *			every 1/fs seconds.  The phase of an FM 	*
 *			signal is the integral of the input.  This	*
 *			is accomplished digitally as :			*
 *			phase=phase+in.					*
 *									*
 *
 *	parameters:	fs, sampling frequency				*
 *			fo, center frequency				*
 * 			A, amplitude					*
 *									*
 *	inputs:		in, the signal to be modulated			*
 *									*
 *	outputs:	A*sin(2.*PI*fo*t+phase)				*


 John T. Stonick
 
 ************************************************************************/