/*******************************************************************************************
MAP?decoder?Simulation?in?C

Note?:
-------
This?program?is?used?to?simulate?the?Maximum?A-Posteriori?Probability?algorithm?in?C.
Since?this?program?is?used?only?for?simulation?I?have?not?done?much?of?code?optimization?（as
well?as?memory?optimization）.?So?this?program?might?run?a?bit?slower.?I‘ll?try?to?optimize?the
code?and?memory?requirements?and?update?this?program?as?soon?as?possible.

Parameters?:
---------------
Thus?MAP?algorithm?will?decode?a?single?convolutional?code.?The?parameters?of?the?convolutional
code?can?be?easily?set?by?modifying?the?N_STATES?POSSIBLE_INPUTS?NextStates[]?and?ActualOutputs[][]
in?accordance?with?the?code?that?you?have?used.

Documentation?:
----------------
Detailed?comments?are?provided?throughout?this?Code.?There?will?not?be?much?problems?in?reading?it.
For?some?good?explanation?about?this?algorithm?please?visit?this?page.

http://www.redrival.com/rvc/faq/map.htm

This?page?is?a?FAQ?on?this?algorithm?that?I?have?prepared.?It?is?better?to?read?that?FAQ?first?before
going?thro‘?this?code.
For?comments?and?suggestion?drop?me?line?at?vc@lucent.com.

Important?Notes?:
------------------
1.?I?have?used?Likehood?ratios?instead?of?Log-Likehood?ratios?currently?because?of?some?numerical
???instability?problems.?I?will?correct?the?code?later.
2.?The?trellis?is?assumed?to?be?terminated.?If?this?is?not?the?case?the?funtion?InitializeBetas（）
???has?to?be?modified.?（A?general?purpose?function?can?also?be?provided..?but?unnecessary?‘cause
???the?trellis?is?normally?terminated?in?most?cases）.


********************************************************************************************/

#include?
#include?
#include?“intleave.h“

/*?Some?global?Constants?*/
/*?Defines?the?possible?no?of?inputs?for?a?given?state.?It?will?be?2^（input?block?length）.*/

#define?POSSIBLE_INPUTS?2
#define?N_STATES?4?/*?Total?no?of?states?in?the?state?machine?*/
#define?BLOCK_LENGTH?18?/*?Length?of?the?block?to?be?decoded?*/
#define?NUM_OUTPUTS?2?/*?No?of?outputs?in?the?Convolutional?Encoder.?*/

/*?List?of?Global?Variables?and?Arrays?used?*/
/*?========================================?*/
/*?This?table?holds?the?values?of?the?next?states?*/
/*?This?table?can?also?be?calculated?dynamically?using?the?static?variables?and?bit?shifts.*/
int?NextStates[N_STATES*POSSIBLE_INPUTS]?=?{02203113};
/*?This?array?holds?the?actual?outputs?of?the?channel?encoder?*/
int?ActualOutputs[N_STATES*POSSIBLE_INPUTS][NUM_OUTPUTS]?=?{{00}{11}{00}{11}{01}{10}{01}{10}};
/*?This?array?holds?tha?outputs?that?were?received?from?the?demodulator?（Corrupted?Outputs）?*/
//int??NoisyOutputs[NUM_OUTPUTS][BLOCK_LENGTH]?=?{{00}{11}{01}{10}{01}{11}{00}{11}{01}{10}{01}{11}{00}{11}{01}{10}{01}{11}};
int?NormalOutputs[BLOCK_LENGTH][NUM_OUTPUTS]?=?{{00}{11}{01}{10}{01}{11}{00}{11}{01}{10}{01}{11}{0

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1526??2000-01-05?14:24??intleave.cc
?????文件?????????321??2000-01-03?18:48??intleave.h
?????文件???????19325??2000-04-03?02:52??MapDecoder.cpp