clc关闭所有清除所有%基本载波聚合简单的OFDM传输链% OFDM 2048点%可用带宽是8 MHz %输入Parameters-1图= 224 e-6;%有用的OFDM符号周期T =图/ 2048;%基带小学时期G = 0;%的1/4、1/8、1/16和1/32δ= G *你;%保护带时间t =δ+你;%总OFDM符号周期Kmax = 1705;%的副载波Kmin = 0;FS = 4096;%传输线/ FFT长度q = 10;%载波周期小学时期比fc = q * 1 / T; %carrier frequency Rs=4*fc; %simulation period t=0:1/Rs:Tu; %Data generator-1 (A) M=Kmax+1; rand('state',0); a=-1+2*round(rand(M,1)).'+i*(-1+2*round(rand(M,1))).'; A=length(a); info=zeros(FS,1); info(1:(A/2)) = [ a(1:(A/2)).']; %Zero padding info((FS-((A/2)-1)):FS) = [ a(((A/2)+1):A).']; %Subcarriers generation (B) carriers=FS.*ifft(info,FS); tt=0:T/2:Tu; figure(1); subplot(211); stem(tt(1:20),real(carriers(1:20))); subplot(212); stem(tt(1:20),imag(carriers(1:20))); figure(2); f=(2/T)*(1:(FS))/(FS); subplot(211); plot(f,abs(fft(carriers,FS))/FS); subplot(212); pwelch(carriers,[],[],[],2/T); % D/A simulation-1(A) L = length(carriers); chips = [ carriers.';zeros((2*q)-1,L)]; p=1/Rs:1/Rs:T/2; g=ones(length(p),1); %pulse shape figure(3); stem(p,g); dummy=conv(g,chips(:)); u=[dummy(1:length(t))]; % (C) figure(4); subplot(211); plot(t(1:400),real(u(1:400))); subplot(212); plot(t(1:400),imag(u(1:400))); figure(5); ff=(Rs)*(1:(q*FS))/(q*FS); subplot(211); plot(ff,abs(fft(u,q*FS))/FS); subplot(212); pwelch(u,[],[],[],Rs); [b,a] = butter(13,1/20); %reconstruction filter [H,F] = freqz(b,a,FS,Rs); %[H,F] = FREQZ(b,a,FS,Rs); figure(6); plot(F,20*log10(abs(H))); uoft = filter(b,a,u); %baseband signal (D) figure(7); subplot(211); plot(t(80:480),real(uoft(80:480))); subplot(212); plot(t(80:480),imag(uoft(80:480))); figure(8); subplot(211); plot(ff,abs(fft(uoft,q*FS))/FS); subplot(212); pwelch(uoft,[],[],[],Rs); %Upconverter-1(A) to 91MHz s_tilde=(uoft.').*exp(1i*2*pi*fc*t); s=real(s_tilde); %passband signal (E) figure(9); plot(t(80:480),s(80:480)); figure(10); subplot(211); %plot(ff,abs(fft(((real(uoft).').*cos(2*pi*fc*t)),q*FS))/FS); %plot(ff,abs(fft(((imag(uoft).').*sin(2*pi*fc*t)),q*FS))/FS); plot(ff,abs(fft(s,q*FS))/FS); subplot(212); %hold on; %pwelch(((real(uoft).').*cos(2*pi*fc*t)),[],[],[],Rs); %pwelch(((imag(uoft).').*sin(2*pi*fc*t)),[],[],[],Rs); pwelch(s,[],[],[],Rs); % Input parameters-2(B) Tu1=200e-6; %useful OFDM symbol period T1=Tu1/2048; %baseband elementary period G1=0; %choice of 1/4, 1/8, 1/16, and 1/32 delta1=G1*Tu1; %guard band duration Ts1=delta1+Tu1; %total OFDM symbol period Kmax1=1705; %number of subcarriers Kmin1=0; FS1=4096; %IFFT/FFT length q1=10; %carrier period to elementary period ratio fc1=q1*1/T1; %carrier frequency Rs1=4*fc1; %simulation period t1=0:1/Rs1:Tu1; %Data generator-2 (B) M1=Kmax1+1; rand('state',0); a1=-1+2*round(rand(M1,1)).'+i*(-1+2*round(rand(M1,1))).'; A1=length(a1); info=zeros(FS1,1); info(1:(A1/2)) = [ a1(1:(A1/2)).']; %Zero padding info((FS1-((A1/2)-1)):FS1) = [ a1(((A1/2)+1):A1).']; %Subcarriers generation (B) carriers1=FS1.*ifft(info,FS1); tt1=0:T1/2:Tu1; figure(11); subplot(211); stem(tt1(1:20),real(carriers1(1:20))); subplot(212); stem(tt1(1:20),imag(carriers1(1:20))); figure(12); f1=(2/T1)*(1:(FS1))/(FS1); subplot(211); plot(f1,abs(fft(carriers1,FS1))/FS1); subplot(212); pwelch(carriers1,[],[],[],2/T1); % D/A simulation-2 (B) L1 = length(carriers1); chips1 = [ carriers1.';zeros((2*q1)-1,L1)]; p1=1/Rs1:1/Rs1:T1/2; g1=ones(length(p1),1); %pulse shape figure(13); stem(p1,g1); dummy1=conv(g1,chips(:)); u1=[dummy1(1:length(t1))]; % (C) figure(14); subplot(211); plot(t1(1:400),real(u1(1:400))); subplot(212); plot(t1(1:400),imag(u1(1:400))); figure(15); ff1=(Rs1)*(1:(q1*FS1))/(q*FS1); subplot(211); plot(ff1,abs(fft(u1,q1*FS1))/FS1); subplot(212); pwelch(u1,[],[],[],Rs1); [b1,a1] = butter(13,1/20); %reconstruction filter [H1,F1] = freqz(b1,a1,FS1,Rs1); %[H,F] = FREQZ(b,a,FS,Rs); figure(16); plot(F1,20*log10(abs(H1))); uoft1 = filter(b1,a1,u1); %baseband signal (D) figure(17); subplot(211); plot(t1(80:480),real(uoft1(80:480))); subplot(212); plot(t1(80:480),imag(uoft1(80:480))); figure(18); subplot(211); plot(ff1,abs(fft(uoft1,q1*FS1))/FS1); subplot(212); pwelch(uoft1,[],[],[],Rs1); %Upconverter-2 (B) to about 110 MHz s_tilde1=(uoft1.').*exp(1i*2*pi*fc1*t1); s1=real(s_tilde1); %passband signal (E) figure(19); plot(t1(80:480),s1(80:480)); figure(20); subplot(211); %plot(ff,abs(fft(((real(uoft).').*cos(2*pi*fc*t)),q*FS))/FS); %plot(ff,abs(fft(((imag(uoft).').*sin(2*pi*fc*t)),q*FS))/FS); %hold on plot(ff1,abs(fft(s1,q1*FS1))/FS1); subplot(212); %pwelch(((real(uoft).').*cos(2*pi*fc*t)),[],[],[],Rs); %pwelch(((imag(uoft).').*sin(2*pi*fc*t)),[],[],[],Rs); pwelch(s1,[],[],[],Rs1); figure(21); pwelch(s,[],[],[],Rs)+pwelch(s1,[],[],[],Rs1);