/*
?*?Soft?decision?Fano?sequential?decoder?for?K=32?r=1/2?convolutional?code
?*?Copyright?1994?Phil?Karn?KA9Q
?*/
#define	LL?1	/*?Select?Layland-Lushbaugh?code?*/

#include?
#include?
#include?
#include?“fano.h“

struct?node?{
	unsigned?long?encstate;	/*?Encoder?state?of?next?node?*/
	long?gamma;		/*?Cumulative?metric?to?this?node?*/
	int?metrics[4];		/*?Metrics?indexed?by?all?possible?tx?syms?*/
	int?tm[2];		/*?Sorted?metrics?for?current?hypotheses?*/
	int?i;			/*?Current?branch?being?tested?*/
};

/*?Convolutional?coding?polynomials.?All?are?rate?1/2?K=32?*/
#ifdef	NASA_STANDARD
/*?“NASA?standard“?code?by?Massey?&?Costello
?*?Nonsystematic?quick?look-in?dmin=11?dfree=23
?*?used?on?Pioneer?10-12?Helios?AB
?*/
#define	POLY1	0xbbef6bb7
#define	POLY2	0xbbef6bb5
#endif

#ifdef	MJ
/*?Massey-Johannesson?code
?*?Nonsystematic?quick?look-in?dmin=13?dfree>=23
?*?Purported?to?be?more?computationally?efficient?than?Massey-Costello
?*/
#define	POLY1	0xb840a20f
#define?POLY2	0xb840a20d
#endif

#ifdef	LL
/*?Layland-Lushbaugh?code
?*?Nonsystematic?non-quick?look-in?dmin=??dfree=?
?*/
#define	POLY1	0xf2d05351
#define	POLY2	0xe4613c47
#endif

/*?Convolutional?encoder?macro.?Takes?the?encoder?state?generates
?*?a?rate?1/2?symbol?pair?and?stores?it?in?‘sym‘.?The?symbol?generated?from
?*?POLY1?goes?into?the?2-bit?of?sym?and?the?symbol?generated?from?POLY2
?*?goes?into?the?1-bit.
?*/
#define	ENCODE（symencstate）{\
	unsigned?long?_tmp;\
\
	_tmp?=?（encstate）?&?POLY1;\
	_tmp?^=?_tmp?>>?16;\
	（sym）?=?Partab[（_tmp?^?（_tmp?>>?8））?&?0xff]?<	_tmp?=?（encstate）?&?POLY2;\
	_tmp?^=?_tmp?>>?16;\
	（sym）?|=?Partab[（_tmp?^?（_tmp?>>?8））?&?0xff];\
}


/*?Convolutionally?encode?a?packet.?The?input?data?bytes?are?read
?*?high?bit?first?and?the?encoded?packet?is?written?into?‘symbols‘
?*?one?symbol?per?byte.?The?first?symbol?is?generated?from?POLY1
?*?the?second?from?POLY2.
?*
?*?Storing?only?one?symbol?per?byte?uses?more?space?but?it?is?faster
?*?and?easier?than?trying?to?pack?them?more?compactly.
?*/
int
encode（
unsigned?char?*symbols		/*?Output?buffer?2*nbytes?*/?
unsigned?char?*data		/*?Input?buffer?nbytes?*/
unsigned?int?nbytes）		/*?Number?of?bytes?in?data?*/
{
	unsigned?long?encstate;
	int?sym;
	int?i;

	encstate?=?0;
	while（nbytes--?!=?0）{
		for（i=7;i>=0;i--）{
			encstate?=?（encstate?<>?i）?&?1）;
			ENCODE（symencstate）;
			*symbols++?=?sym?>>?1;
			*symbols++?=?sym?&?1;
		}
		data++;
	}
	return?0;
}

/*?Decode?packet?with?the?Fano?algorithm.
?*?Return?0?on?success?-1?on?timeout
?*/
int
fano（
unsigned?long?*metric	/*?Final?path?metric?（returned?value）?*/
unsigned?long?*cycles	/*?Cycle?count?（returned?value）?*/
unsigned?char?*data	/*?Decoded?output?data?*/
unsigned?char?*symbols	/*?Raw?deinterleaved?input?symbols?*/
unsigned?int?nbits	/*?Number?of?output?bits?*/
int?mettab[2][256]	/*?Metric?table?[se

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????823??1999-05-10?12:52??viterbi-3.0.1\encode27.c

?????文件????????914??1999-05-10?12:52??viterbi-3.0.1\encode37.c

?????文件???????5742??1997-10-28?06:13??viterbi-3.0.1\genviterbi.pl

?????文件???????1252??1999-05-11?16:34??viterbi-3.0.1\Makefile

?????文件???????2945??1999-05-10?12:52??viterbi-3.0.1\metrics.c

?????文件???????4858??1999-08-07?08:56??viterbi-3.0.1\README

?????文件???????1504??1999-05-11?16:43??viterbi-3.0.1\sim.c

?????文件????????922??1997-10-28?06:13??viterbi-3.0.1\tab.c

?????文件???????5016??1999-08-07?08:53??viterbi-3.0.1\viterbi.c

?????文件???????4821??1999-08-07?08:53??viterbi-3.0.1\viterbi27.c

?????文件???????2735??1999-05-11?16:44??viterbi-3.0.1\viterbi27.h

?????文件???????5828??1999-08-07?08:53??viterbi-3.0.1\viterbi37.c

?????文件???????2674??1997-10-28?06:13??viterbi-3.0.1\viterbi37.h

?????文件???????8990??1997-10-28?06:13??viterbi-3.0.1\vitfilt27.c

?????文件??????10011??1997-10-28?06:13??viterbi-3.0.1\vitfilt37.c

?????文件???????5560??1999-08-07?08:54??viterbi-3.0.1\vittest.c

?????目錄??????????0??2006-04-17?11:49??viterbi-3.0.1

?????文件???????7048??1995-07-27?14:24??fano1.1\fano.c

?????文件????????378??1995-07-24?16:30??fano1.1\fano.h

?????文件????????317??1995-07-27?13:20??fano1.1\Makefile

?????文件???????2871??1995-07-24?16:32??fano1.1\metrics.c

?????文件???????4934??1995-08-06?13:51??fano1.1\README

?????文件???????6372??1995-07-27?14:25??fano1.1\seqtest.c

?????文件???????1397??1995-03-17?03:53??fano1.1\sim.c

?????文件????????922??1995-03-16?16:04??fano1.1\tab.c

?????目錄??????????0??2006-04-17?11:49??fano1.1

?????文件????????217??1997-08-09?15:01??rs32\Makefile

?????文件????????562??1997-08-09?15:20??rs32\README

?????文件??????12152??1997-08-09?14:55??rs32\rs32.c

?????文件???????1890??1997-08-09?14:56??rs32\rs32.h

............此處省略33個文件信息