CSF29008 2015-2
Plano de Ensino e Cronograma
Desenvolvimento Pedagógico - Andamento do Cronograma 2015/2
- Suspensão do calendário acadêmico pela direção do Campus de 30 de Julho a 1 de Outubro;
Semestre 2015-2 - Prof. Bruno Fontana da Silva / ??? | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Notas de Aula
Modelos do Canal de Comunicação sem Fio |
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Simulações
- Dois raios
- Hata e Cost231
Campo eletromagnético |
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% 5.4.1 A Computer Experiment (Andreas Molisch, Wireless Communications)
clear all; close all; clc;
% Consider the following simple computer experiment. The signals from several IOs are incident
% onto an RX that moves over a small area. The IOs are distributed approximately uniformly around
% the receiving area. They are also assumed to be sufficiently far away so that all received waves
% are homogeneous plane waves, and that movements of the RX within the considered area do not
% change the amplitudes of these waves. The different distances and strength of the interactions are
% taken into account by assigning a random phase and a random amplitude to each wave. We are
% then creating eight constituting waves Ei with absolute amplitudes |a_i|, angle of incidence (with
% respect to the x-axis) φ_i and phase ϕ_i.
fc = 900e6; Tc = 1/fc; % frequência da portadora;
c = 3e8; % speed of light
wl = c*Tc; % comprimento de onda
k = 2*pi/wl; % número de onda
% Fasores
% a = [169 213 87 256 17 126 343 297 0]; % φ, azimuti
% e = [311 32 161 356 191 56 268 131 0]; % ϕ_i, elevação
% Ep = [1 .8 1.1 1.3 .9 .5 .7 .9 1000]; % |a_i|, amplitudes
a=0;
e=180;
Ep = 1;
L = 100;
x = linspace(0,5*wl,L); % Eixo 0 < x < 5*wl (L pontos)
y = linspace(0,5*wl,L); % Eixo 0 < y < 5*wl (L pontos)
En = zeros(L,L); % buffer
for xx=1:length(x) % índices de x
for yy = 1:length(y) % índices de y
for n = 1:length(a) % índices de componentes
% E(x,y) = sum Ep*exp{-jk[x*cos(a) + y*sin(a)]}*exp{je}
% fasores do campo elétrico(x,y) em t=0;
% Ep*exp(-j [k d + d0/k])
En(xx,yy) = En(xx,yy) + Ep(n)*exp(-1i*k*(x(xx)*cosd(a(n))+y(yy)*sind(a(n))))*exp(1i*e(n)*pi/180);
end
end
end
figure;
subplot(2,2,1);
surf(x,y,real(En)); zlabel('Real');
subplot(2,2,2);
surf(x,y,imag(En)); zlabel('Imaginário');
subplot(2,1,2);
surf(x,y,abs(En)); zlabel('|E|');
figure;
hist(abs(En(:)),100)
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Modelo de Clarke-Jakes (Canal Plano com Desvanecimento Rayleigh) |
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<syntaxhighlight lang=matlab> % Clarke-Jakes Narrowband Model clear all; close all; clc; N = 4096; % frequency points Nz = 1*2^16; % frequency zero-padding fd = 300; % Doppler shift fc = 900e6; % carrier frequency delta = 0; % ignore infinity PSD values Vz = zeros(1,Nz/2); % zero-padding vector f = linspace(fc-fd+delta,fc+fd-delta,N); % frequency vector; df = 2*fd/N; B = 2*fd+Nz*df; % bandwidth Ts = 1/B; % sample-time T = (N+Nz)*Ts; % total time %% Doppler PSD Pr = 1/4; A = Pr; D = 1-(abs((f-fc))/fd).^2; Sf = A./pi/fd./sqrt(D); % PSD % Sf(1) = Sf(2); Sf(end) = Sf(end-1); % ignore infinity PSD values % Sf(1) = 0; Sf(end) = 0; % ignore infinity PSD values % Sf(1) = 0.5*(max(Sf)); Sf(end) = Sf(1); % ignore infinity PSD values m1 = (Sf(2)-Sf(3))/(f(2)-f(3)); m2 = (Sf(end-1)-Sf(end-2))/(f(end-1)-f(end-2)); Sf(1) = m1*(f(1)-f(2))+Sf(2); Sf(end) = m2*(f(end)-f(end-1))+Sf(end-1);
Sfz = [Vz Sf Vz]; % zero-padded PSD %% Frequency Domain Hp = sqrt(1/2)*(randn(1,N/2) +1i*randn(1,N/2)); % positive components Hn = conj(Hp(end:-1:1)); % negative components H = [Vz Hp Hn Vz]; % zero-padded comp. Hf = sqrt(Sfz).*H; % zero-padded equivalent spectrum %% Time domain ri = ((N+Nz)/2)*ifft(real(Hf),N+Nz); % real components rq = ((N+Nz)/2)*ifft(imag(Hf),N+Nz); % imaginary components hr = sqrt(abs(ri).^2+abs(rq).^2); % rayleigh envelope hrms = sqrt(var(hr)+mean(hr)^2); % rms value hnorm = hr/hrms; % normalizing fading t = linspace(0,T-Ts,N+Nz); % time vector %% MATLAB Rayleigh Channel h2 = rayleighchan(Ts,fd); h2.ResetBeforeFiltering = 0; % do not reset h2.StoreHistory = 1; % save path gains after filter h2.StorePathGains=1; h2.NormalizePathGains = 0; % do not normalize E[norm(h)] y = filter(h2,[1 ones(1,N+Nz-1)]);
%_________________________________________________________________________% %% Histogram 1 figure; Mh = 50; % bin numbers [fn,bin] = hist(hnorm,Mh); % get bins and cumulative frequencies yhist = fn/trapz(bin,fn); % calculate relative frequencies xx = linspace(min(bin),max(bin),100); % x vector in bins yy = spline(bin,yhist,xx); % interpolation of histogram envelope set(gca,'linewidth',3,'fontsize',30); grid; % sigr = 1/sqrt(2); sigr = mean(hnorm)*sqrt(2/pi); PDF_theor = bin.*exp(-bin.^2/(2*sigr^2))/(sigr^2); bcor = [0.5 0.5 1]; bar(bin,yhist,'FaceColor',bcor,'edgecolor',bcor); hold on; % histogram bar plot plot(xx,yy,':','color',[0 0 1],'linewidth',3); % envelope plot plot(bin,PDF_theor,'-ok','linewidth',3); grid on; % theoretical PDF title('RMS-Normalized Rayleigh Amplitude Fading Histogram','fontsize',30); ylabel('Estimated PDF','fontsize',30); xlabel('Amplitude Levels','fontsize',30); legend('Normalized Histogram','Histogram Envelop','Theoretical Rayleigh PDF'); set(gca,'fontsize',30,'linestyleorder','-','linewidth',3); %% Histogram 2 (MATLAB channel) figure; Mh = 50; % bin numbers [fn,bin] = hist(abs(h2.PathGains),Mh); % get bins and cumulative frequencies yhist = fn/trapz(bin,fn); % calculate relative frequencies xx = linspace(min(bin),max(bin),100); % x vector in bins yy = spline(bin,yhist,xx); % interpolation of histogram envelope set(gca,'linewidth',3,'fontsize',30); grid; % sigr = 1/sqrt(2); sigr = mean(abs(h2.PathGains))*sqrt(2/pi); PDF_theor = bin.*exp(-bin.^2/(2*sigr^2))/(sigr^2); bcor = [0.5 0.5 1]; bar(bin,yhist,'FaceColor',bcor,'edgecolor',bcor); hold on; % histogram bar plot plot(xx,yy,':','color',[0 0 1],'linewidth',3); % envelope plot plot(bin,PDF_theor,'-ok','linewidth',3); grid on; % theoretical PDF title('MATLAB RMS-Normalized Rayleigh Amplitude Fading Histogram','fontsize',30); ylabel('Estimated PDF','fontsize',30); xlabel('Amplitude Levels','fontsize',30); legend('Normalized Histogram','Histogram Envelop','Theoretical Rayleigh PDF'); set(gca,'fontsize',30,'linestyleorder','-','linewidth',3); </syntaxhighlight} |
- Rayleigh Plano (BPSK e AWGN)
Exercícios
Material Complementar On-line
Palestra da ANATEL "Sistema Móvel Pessoal no Brasil", 02/06/2015
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TELECO - Portal sobre Telecomunicações criado por grupo de profissionais brasileiros
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Princípios de reuso de frequência em sistemas celulares de telefonia
Práticas de planejamento de sistemas celulares de telefonia
Simulador de Configuração do AP TP-Link TL-WDR4300