資源簡介
MTALB對BPSK信號的仿真程序!編碼是m序列來的,頻譜仿真!

代碼片段和文件信息
clc;
clear?all;
close?all;
connections1=[1?0?1?0];
registers1=[1?1?1?1];
sequence1=ssmlsrs1_Fab(connections1registers1);?%(1/0)
Tb1=0.3e-3;?%編碼脈沖寬度,0.3ms
Tf=6e-3;?????%發(fā)射脈沖寬度,6ms
Tz=0.02e-3;??%子碼寬度,0.02ms
Fz=1/Tz;?
f1=300000;???%載頻300KHz
fs=12e6;?????%采樣率12M%%%%%%%%%%%%%%07
timestep=1/fs;?%采樣間隔
t=0:timestep:Tb1-timestep;
fd=0;
fc=f1+fd;?
y=sin(2*pi*fc*t);?%基本碼型?sin函數(shù)作為載波
N2=fs/fc;???????%fd=0時一個sin周期上的采樣點(diǎn)數(shù)
N1=N2*6;?????%一個碼元填充6個周期的sin,故采樣點(diǎn)數(shù)為6倍
for?ii=1:length(sequence1)?
????for?jj=1:N1
????????seq1((ii-1)*N1+jj)=sequence1(ii);??????%seq1:采樣后的子碼(M序列)
????end
end
N3=N1*15;??%0.3ms采樣出3600個點(diǎn),40*6*15
for?ii=1:N3
?????if?seq1(ii)==1
?????????????y1(ii)=y(ii);
?????else??y1(ii)=-y(ii);????%y1:基本碼型經(jīng)m序列調(diào)制之后所需的寬帶信號!
?????end
end
figure(1);
subplot(311);
plot(seq1);????????????%M序列
subplot(312);
plot(y);???????????????????%y為sin數(shù)據(jù)
subplot(313);
plot(y1);????????????????%y1為0.3ms數(shù)據(jù)
y11=fft(y1);
%?y11=fftshift(y11);
figure(2);
plot(abs(y11));???????%寬帶信號的頻譜圖
%?[YI]=max(abs(y11));
%?ff=fs*I/N3???????????????%載波頻率估計
Z1=0;
Y=y1‘;
PP=1024;%FFT點(diǎn)數(shù)
TT=20;%譜的平均次數(shù)
a3=-1024000:4000:1024000;%循環(huán)頻率
ff=-(1024000-2000):2000:1024000-2000;%頻率
Z=zeros(length(ff)length(a3));%幅度
%?DD=10*log10(var(Y));%信號功率
%?noise=wgn(100000015);%產(chǎn)生噪聲
%?noise=randn(64001);%產(chǎn)生噪聲
for?T1=1:TT
????u=fft(Y((351+(T1-1)*350):(PP+T1*350)));%信號頻譜
%?????u=zeros(PP1);
%?????v=fft(noise((151+(T1-1)*150):(PP+T1*150)));%噪聲頻譜
????v=zeros(PP1);
????UV=u+v;uv=zeros(PP1);
????uv(1:(PP/2)1)=UV((PP/2+1):PP);uv((PP/2+1):PP1)=UV(1:(PP/2));%平移到正負(fù)頻率點(diǎn)上
????uv=repmat(uv21);
????z=zeros(length(ff)length(a3));
????for?k=1:length(a3)
????????for?i=1:length(ff)
?????????????if?(((0.0005*(ff(i)-a3(k)/2)+513)<=0)|((0.0005*(ff(i)+a3(k)/2)+513)<=0))%考慮超過范圍時,利用FFT頻譜的周期性平移
????????????????if?((0.0005*(ff(i)-a3(k)/2)+513)<=0)
????????????????????z(ik)=uv(0.0005*(ff(i)-a3(k)/2)+513+1024)*conj(uv(0.0005*(ff(i)+a3(k)/2)+513));
????????????????else?
????????????????????z(ik)=uv(0.0005*(ff(i)-a3(k)/2)+513)*conj(uv(0.0005*(ff(i)+a3(k)/2)+513+1024));
????????????????end
????????????????Z(ik)=Z(ik)+(1/TT)*z(ik);
????????????else
????????????????z(ik)=uv(0.0005*(ff(i)-a3(k)/2)+513)*conj(uv(0.0005*(ff(i)+a3(k)/2)+513));
????????????????Z(ik)=Z(ik)+(1/TT)*z(ik);
????????????end
????????end??
????end
?Z=abs(Z);
Z1=Z1+Z/TT;
end
[xy]=meshgrid(a3ff);
mesh(xyabs(Z1));??%畫三維圖
xlabel(‘循環(huán)頻率(Hz)‘);
ylabel(‘頻率(Hz)‘);
zlabel(‘幅度‘);
?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????469??2012-08-16?10:12??ssmlsrs1_Fab.m
?????文件???????2745??2013-03-08?20:54??kuandaixinhao_sin_xunhuanpuxiangguan.m
-----------?---------??----------?-----??----
?????????????????3214????????????????????2
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