test16qam.c

该文件包内包含了一个16QAM调制解调程序

/*
******************************************************************
ANSI C source code
filename:
	Test16QAM.c
abstract:
	to test the algorithms
author:
	Shen Ke
version:
	V 1.0
******************************************************************
*/

#include <stdio.h>
#include "QAMSoftDem.h"
#include "time.h"
#include "math.h"
#include "stdlib.h"


void main ()
{
	struct AWGN channel;
	struct AWGN *ch;		
	int signum;
	int bitlen ;
	int siglen ;
	int outlen;
	double sig_real[2500],out_real[2500];
	double sig_img[2500],out_img[2500];
	double pb;
	int outbit[10000];
	int i,j;	
	int inbit[10000];
	int err[5000];
	FILE *fp,*fpout;
	
	
	channel.ix=30323;
	channel.iy=173;
	channel.iz=13;
	channel.snr=10;      //singal SNR   
	channel.rate = 4;
	channel.I_sigma=2*(channel.rate)*(pow(10.0,(channel.snr/10)));
	channel.sigma=sqrt(1/channel.I_sigma);
	ch=&channel;
	j=0;

	srand((unsigned)time(NULL));
	s1=rand();
	s2=rand();

	fp = fopen("input.txt","w");
	fpout = fopen("output.txt","w");
	bitlen = 10000;
	siglen = bitlen/4;
	printf("The sigma is:%f\n",channel.sigma);

	for(i=0;i<bitlen;i++)
	{
		inbit[i]=generate_binary_source();
		 if(i%4==0) {
			fprintf(fp,"\n");
		}
		fprintf(fp,"%d",inbit[i]);
	}
	
	signum=GrayMap16QAM(inbit,bitlen,sig_real,sig_img);
	awgn_channel(sig_real,sig_img,out_real,out_img,ch,siglen);
	outlen=QAMDem(out_real,out_img,siglen,outbit);
	printf("The result(%d bits) is :",outlen);
	for(i=0;i<outlen;i++)
	{
		if (i%4==0) {
			fprintf(fpout,"\n");
		}
		fprintf(fpout,"%d",outbit[i]);
	}
	if (bitlen!=outlen) {
		printf("Wrong demodule!!");
	}
	else
	{
		for(i=0;i<bitlen;i++)
		{
			if (inbit[i]!=outbit[i]) {
				err[j++]=outbit[i];
				
			}
		}
	}
	
	
	pb = (double) j/10000.0;	
	printf("When the snr is %f,the Pb is %f.\n",ch->snr,pb);


}