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最新推荐文章于 2025-05-20 22:27:03 发布

氵一如既往灬

最新推荐文章于 2025-05-20 22:27:03 发布

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文章标签： python 算法人工智能

本文链接：https://blog.youkuaiyun.com/index00101/article/details/129717834

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%% Friis模型
% d = linspace(1000,100000,10000);%基站到移动设备,10000个点
d = 1000:7.5:100000;%每7.5m取一个点衰落阴影空间变化尺度30入
f = 1.2e9;c = 3e8
x = c/f;%波长，单位米
n = 2;
PL_Friis = 10*n*log10((4*pi*d)/x);%数组d不能做除数不然会报错
figure(1);

% loglog(d,PL_Friis);%画出对数坐标的图(双对数
semilogx(d/1000,PL_Friis,'color',[106/255 90/255 205/255],'LineWidth',1.5);%单对数
title('3 Model PL');
xlabel('T-R distance d /km');
ylabel('PL/dB');
set(gca,'XGrid','on');%开启X主坐标虚线
set(gca,'YGrid','on')
set(gca,'xminortick','on');%开启x坐标下面的分区
set(gca,'yminortick','on');%开启Y坐标下面的分区
hold on;
grid on;
%% 两径模型（默认d>>ht*hr
ht = 40; hr = 1.5;%天线高度
Gt = 1; Gr = 1;%天线增益假设是1
PL_2 = 40*log10(d) - (10*log10(Gt) + 10*log10(Gr) + 20*log10(ht) + 20*log10(hr))
semilogx(d/1000,PL_2,'color',[4/255 107/255 255/255],'LineWidth',1.5);
hold on;
grid on;%开启网格
%% Hata_shadowing_city
f1 = f/1000000%模型中的f是MHz单位
a = (1.1*log10(f1)-0.7)*hr-(1.56*log10(f1)-0.8);%little city
a1 = 3.2*(log10(11.75*hr))^2-4.97;%big city
shadowing = 7.5*randn(size(d));%产生随机数，射方差也是7.5=30入
PL_hata_city = 69.55+26.16*log10(f1)-13.82*log10(ht)-a1+(44.9-6.55*log10(ht))*log10(d/1000)+shadowing;%d的单位是km，f的单位是MHz
semilogx(d/1000,PL_hata_city,'r','LineWidth',0.5);%颜色绿，宽度0.5
legend('Friis Law','Ground-reflection Model','Okumura-Hata with shadowing')




% grid on；%结束的意思