CHÖÔNG 15: TRÌNH TÍNH TOAÙN TUYEÁN VI BA
#include <stdio.h>
#include <conio.h>
#include <string.h>
#include <math.h>
#include "c:\hien\viba.h"
double f,ha,h1,h2,d,Ao,feeder,Lv,Aa,lamda,G,A,
FMa, FMb,Gt;
double
A1,pr,pt,RXa,RXb,loseA,loseB,G1,po,pa,pb,Ta,Tb;
double khongkhadung,Za,Zb,p10,p60;
double mem =3.95,e=2.71828,giandoan,tong_giandoan;
double erfc_fun(double x)
{
double k;
int i;
for (i=0;i<260;i++)
if(erfd[i]==x)
k=erfdr[i];
return k;
}
double arround(double x)
{
double nguyen,thapphan,tamp,tmp,temp;
thapphan = modf(x,&nguyen);
thapphan = thapphan*100;
tamp = modf(thapphan,&temp);
if(tamp<=0.3) tamp = 0;
if(0.3<tamp && tamp <=0.7) tamp =0.5;
if(tamp>0.7) tamp =1;
thapphan = temp + tamp;

case '2' : feeder_type = 2.5; break;
case '3' : feeder_type = 2; break;
case '4' : feeder_type = 7.8; break;
default : feeder_type =3.4;
}
printf("\nCho biet do cao anten tai tram A (m):
"); scanf("%lf",&h1);
printf("Cho biet do cao anten tai tram B (m):
"); scanf("%lf",&h2);
lf1 = 1.5*h1;
lf2 = 1.5*h2;
loseA = lf1*3.28*feeder_type/100;
loseB = lf2*3.28*feeder_type/100;
feeder = loseA + loseB;
printf("Ton that feeder tai tram A: %.3lf dB\n",
loseA);
printf("Ton that feeder tai tram B: %.3lf dB\n",
loseB);
printf("Ton that feeder: %.3lf dB\n", feeder);
}
void vatchan() //ton hao cua bo suy hao hoac cac
vat chanx
{
double d1[100],d2[100], hc[100],V[100],c,tmp;
int i, vc;
printf("Co bao nhieu vat chan: ");
scanf("%d",&vc);
for(i=0; i<vc; i++)
{
printf("Cho biet khoang cach tu tram A den

printf("Ton hao khi quyen: %.3lf dB ",Aa);
}
void total()//tong ton hao
{
double renhanh,bodaunoi;
printf("Cho biet ton hao re nhanh ( 2dB-8dB ):
"); scanf("%lf",&renhanh);
printf("Cho biet ton hao cac bo dau noi( 0.5dB-
1dB) : "); scanf("%lf",&bodaunoi);
A = Ao + Aa + feeder + renhanh + bodaunoi + Lv;
printf("Tong ton hao la: %.3lf dB", A);
}
void line_lose() //ton hao tuyen truyen
{
while(1)
{
clrscr();
printf("Ton that tuyen:\n");
printf("1. Ton that duong truyen cua khong gian
tu do\n");
printf("2. Ton that feeder\n");
printf("3. Ton hao cua bo suy hao hoac cac vat
chan\n");
printf("4. Ton hao khi quyen \n");
printf("5. Tong ton hao \n");
printf("s. Exit\n");
printf("Select: \n");
switch( getch())
{
case '1' : free_space_lose(); break;

printf("\n");
printf("Do loi cua anten: %.3lf dB\n",G);
printf("Do loi may phat: %.3lf dB\n",G1);
printf("Tong do loi: %.3lf dB\n", Gt);
printf("Tong ton hao: %.3lf dB\n", A1);
printf("Muc dau vao cua may thu: %.3lf dBm\n",
pr);
printf("Do du tru fading phang FMa: %.3lf dB,voi
BER = 10^-3\n", FMa);
printf("Do du tru fading phang FMb: %.3lf dB,voi
BER = 10^-6\n", FMb);
getch();
}
void fading() //gom xac suat fading nhiue tia, xs
tai cac nguong, thoi gian fading
{
double a,c, alpha,beta,c2;
double gamma,M,nuy,K,t;
clrscr();
printf("Cho biet he so cai tien dac trung cho dia
hinh a (0.25 - 4): ");
scanf("%lf",&a);
printf("Cho biet he so dia hinh C: \n");
printf(" 1. 1 cho dia hinh trung binh co khi hau
on doi\n");
printf(" 2. 4 cho dia hinh tren mat nuoc bo bien
hay khi hau am uot\n");
printf(" 3. 0.25 cho dia hinh mien nui va khi hau
kho\n");
switch (getch())