/* Test a rate 1/2 soft decision sequential decoder * Copyright 1994 Phil Karn, KA9Q */#include <stdio.h>#include <stdlib.h>#include <math.h>#include <curses.h>#include "fano.h"#define	RATE	0.5#define	OFFSET	128struct stat {	unsigned long cycles;	unsigned long count;};main(argc,argv)int argc;char *argv[];{	double ebn0,mebn0,esn0,mesn0,noise,mnoise,s;	int mettab[2][256];	int amp,nbits,i,bit;	unsigned char *psymbols,*symbols;	unsigned char *data,*decdata;	unsigned long metric,cycles,totcycles;	long t,ntrials;	long seed;	extern char *optarg;	extern int optind;	unsigned long limit;	int delta;	struct stat stats[25];	unsigned long errors;	int range;	FILE *output;	int quiet;	int timetest;	timetest = 0;	totcycles = 0;	amp = 100;	mebn0 = ebn0 = 5.0;	nbits = 1152;	ntrials = 10;	delta = 17;	limit = 10000;	quiet = 0;	time(&seed);	while((i = getopt(argc,argv,"a:e:n:N:d:l:qs:tm:")) != EOF){		switch(i){		case 'a':	/* Signal amplitude in units */			amp = atoi(optarg);			break;		case 'e':	/* Eb/N0 in dB */			mebn0 = ebn0 = atof(optarg);			break;		case 'm':	/* Metric table Eb/N0 in dB */			mebn0 = atof(optarg);			break;		case 'n':	/* Number of data bits */			nbits = atoi(optarg);			break;		case 'N':	/* Number of trials (frames) */			ntrials = atoi(optarg);			break;		case 'd':	/* Decoder threshold adjustment (delta) */			delta = atoi(optarg);			break;		case 'l':	/* Limit on decoder operations/bit */			limit = atoi(optarg);			break;		case 'q':	/* Suppress curses update */			quiet++;			break;		case 's':	/* Seed for random number generator */			seed = atoi(optarg);			break;		case 't':	/* Timetest mode */			timetest = 1;			break;		}	}	if(optind >= argc){		usage();		exit(1);	}	srandom(seed);	output = fopen(argv[optind],"w+");	esn0 = ebn0 + 10*log10(RATE);	/* actual Es/N0 in dB */	mesn0 = mebn0 + 10*log10(RATE);	/* metric table Es/N0 in dB */	/* Compute noise voltage. The 0.5 factor accounts for BPSK seeing	 * only half the noise power, and the sqrt() converts power to	 * voltage.	 */	noise = sqrt(0.5/pow(10.,esn0/10.));	mnoise = sqrt(0.5/pow(10.,mesn0/10.));		data = malloc(nbits/8);	decdata = malloc(nbits/8);	psymbols = malloc(nbits*2);	symbols = malloc(nbits*2);	/* Generate metrics analytically, with gaussian pdf */		gen_met(mettab,amp,mnoise,RATE,4);	/* Generate data (all 0's) and encode */	memset(data,0,nbits/8);#ifndef	notdef	for(i=0;i<nbits/8 - 5;i++)		data[i] = 0x55;#endif#ifdef	notdef	data[0] = 0x40;#endif	encode(psymbols,data,nbits/8);	if(timetest){		memcpy(symbols,psymbols,2*nbits);		modnoise(symbols,2*nbits,100.,noise);		for(t=1;t<=ntrials;t++)			fano(&metric,&cycles,decdata,symbols,nbits,mettab,delta,limit);		printf("Ntrials = %ld, cycles = %ld\n",ntrials,cycles);		exit(0);	}	errors = 0;	memset(stats,0,sizeof(stats));	i = 0;	for(range = 1; range < 100000; range *= 10){		stats[i++].cycles = range;		stats[i++].cycles = range * 2;		stats[i++].cycles = range * 4;		stats[i++].cycles = range * 6;		stats[i++].cycles = range * 8;	}	if(!quiet)		initscr();	for(t = 1;t <= ntrials;t++){		memcpy(symbols,psymbols,2*nbits);		modnoise(symbols,2*nbits,100.,noise);		i = fano(&metric,&cycles,decdata,symbols,nbits,mettab,delta,limit);		totcycles += cycles;		if(i == 0){			cycles /= nbits;			if(memcmp(data,decdata,nbits/8) != 0)				errors++;		} else			cycles = limit + 1;	/* For binning */				for(i=0;i<25;i++){			if(cycles < stats[i].cycles)				break;			stats[i].count++;		}		/* Don't write to the file each and every time */		if((t & 31) == 0 || t == ntrials){			rewind(output);			fprintf(output,"Seed %ld Amplitude %d units, Eb/N0 = %lg dB metric table Eb/N0 = %lg dB\n",seed,amp,ebn0,mebn0);			fprintf(output,"Frame length = %d bits, delta = %d, cycle limit = %ld, #frames = %ld\n",			  nbits,delta,limit,ntrials);			fprintf(output,"decoding errors: %ld\n",errors);			fprintf(output,"Average N: %lf\n",			 (double)totcycles/stats[0].count/nbits);			fprintf(output,"  N >=  count fraction\n");			for(i=0;i<25;i++){				fprintf(output,"%6d %6ld %.2lg\n",stats[i].cycles,				 stats[i].count,(double)stats[i].count/t);				if(stats[i].cycles >= limit || stats[i].count == 0)					break;			}		}		if(!quiet){			erase();			move(0,0);			printw("Seed %ld Amplitude %d units, Eb/N0 = %lg dB metric table Eb/N0 = %lg dB\n",seed,amp,ebn0,mebn0);			printw("Frame length = %d bits, delta = %d, cycle limit = %ld, #frames = %ld\n",			 nbits,delta,limit,ntrials);			printw("decoding errors: %ld\n",errors);			printw("Average N: %lf\n",(double)totcycles/stats[0].count/nbits);			printw("  N >=  count fraction\n");			for(i=0;i<25;i++){				printw("%6d %6ld %.2lg\n",stats[i].cycles,				   stats[i].count,(double)stats[i].count/t);				if(stats[i].cycles >= limit || stats[i].count == 0)					break;			}			refresh();		}	}	if(!quiet)		endwin();	printf("Seed %ld Amplitude %d units, Eb/N0 = %lg dB metric table Eb/N0 = %lg dB\n",seed,amp,ebn0,mebn0);	printf("Frame length = %d bits, delta = %d, cycle limit = %ld, #frames = %ld\n",	 nbits,delta,limit,ntrials);	printf("decoding errors: %ld\n",errors);	printf("Average N: %lf\n",(double)totcycles/stats[0].count/nbits);	printf("  N >=  count fraction\n");	for(i=0;i<25;i++){		printf("%6d %6ld %.2lg\n",stats[i].cycles,		   stats[i].count,(double)stats[i].count/ntrials);		if(stats[i].cycles >= limit || stats[i].count == 0)			break;	}}usage(){	printf("Usage: seqtest [options] output_file\n");	printf("Option&default 	meaning\n");	printf("-a 100		signal amplitude in units\n");	printf("-e 5.0		Signal Eb/N0 in dB (also sets -m)\n");	printf("-m 5.0		Eb/N0 in dB for metric table calc\n");	printf("-n 1152		Number of bits per frame\n");	printf("-N 10		Number of frames to simulate\n");	printf("-d 17		Decoder threshold (delta)\n");	printf("-l 10000	Decoder timeout, fwd motions per bit\n");	printf("-s [cur time]	seed for random number generator\n\n");	printf("-q		select quiet mode (default off)\n");	printf("-t		select timetest mode (default off)\n");}