/* CHANNEL.H - Declarations regarding channels. */

/* Copyright (c) 2001 by Radford M. Neal 
 *
 * Permission is granted for anyone to copy, use, or modify this program 
 * for purposes of research or education, provided this copyright notice 
 * is retained, and note is made of any changes that have been made. 
 *
 * This program is distributed without any warranty, express or implied.
 * As this program was written for research purposes only, it has not been
 * tested to the degree that would be advisable in any important application.
 * All use of this program is entirely at the user's own risk.
 */


/* TYPES OF CHANNEL, AND CHANNEL PARAMETERS.  The global variables declared
   here are located in channel.c. */

typedef enum { BSC, AWGN, AWLN } channel_type;

extern channel_type channel;	/* Type of channel */

extern double error_prob;	/* Error probability for BSC */
extern double std_dev;		/* Noise standard deviation for AWGN */
extern double lwidth;		/* Width of noise distributoin for AWLN */


/* PROCEDURES TO DO WITH CHANNELS. */

int  channel_parse (char **, int);
void channel_usage (void);