叉车防撞UWB
clear all
close all
% 调制
bit_in = randint(1e3, 1, [0 1]);
三相混合步进电机bit_I = bit_in(1:2:1e3);
镀铬工艺bit_Q = bit_in(2:2:1e3);
data_I = -2*bit_I+1;
data_Q = -2*bit_Q+1;
data_I1=repmat(data_I',20,1);
data_Q1=repmat(data_Q',20,1);
for i=1:1e4
data_I2(i)=data_I1(i);
data_Q2(i)=data_Q1(i);
end;
f=0:0.1:1;
xrc=0.5+0.5*cos(pi*f);
data_I2_rc=conv(data_I2,xrc)/5.5;
data_Q2_rc=conv(data_Q2,xrc)/5.5;
f1=1;
t1=0:0.1:1e3+0.9;
n0=rand(size(t1));
I_rc=data_I2_rc.*cos(2*pi*f1*t1);
Q_rc=data_Q2_rc.*sin(2*pi*f1*t1);
QPSK_rc=(sqrt(1/2).*I_rc+sqrt(1/2).*Q_rc);
QPSK_rc_n0=QPSK_rc+n0;
% 解调蒸汽消毒锅
I_demo=QPSK_rc_n0.*cos(2*pi*f1*t1);
Q_demo=QPSK_rc_n0.*sin(2*pi*f1*t1);
% 低通滤波
I_recover=conv(I_demo,xrc);
Q_recover=conv(Q_demo,xrc);
I=I_recover(11:10010);
alysa_queenQ=Q_recover(11:10010);
t2=0:0.05:1e3-0.05;
t3=0:0.1:1e3-0.1;
% 抽样判决
data_recover=[];
for i=1:20:10000
data_recover=[data_recover I(i:1:i+19) Q(i:1:i+19)];
end;
bit_recover=[];
for i=1:20:20000
if sum(data_recover(i:i+19))>0
data_recover_a(i:i+19)=1;
bit_recover=[bit_recover 1];
else
data_recover_a(i:i+19)=-1;
bit_recover=[bit_recover -1];
end
end
error=0;
dd = -2*bit_in+1;
ddd=[dd'];
ddd1=repmat(ddd,20,1);
for i=1:2e4
ddd2(i)=ddd1(i);
end
for i=1:1e3
if bit_recover(i)~=ddd(i)
error=error+1;
end
end
p=error/1000;
figure(1)
subplot(2,1,1);plot(t2,ddd2);axis([0 100 -2 2]);title('原序列');
subplot(2,1,2);plot(t2,data_recover_a);axis([0 100 -2 2]);title('解调后序列');
clear all
t=0:0.001:10;
x=sin(2*pi*t);
snr=20;
y=awgn(x, snr,10);
subplot(2,1,1);plot(t,x);title('正弦信号x') subplot(2,1,2);plot(t,y);title('叠加了高斯白噪声后的正弦信号')
z=y-x;
var(z)
Jakes(Rayleigh.m)
function [h]=rayleigh(fd,t)
N=40;
wm=2*pi*fd;
N0=N/4;
Tc=zeros(1,length(t));
Ts=zeros(1,length(t));
P_nor=sqrt(1/N0);
theta=2*pi*rand(1,1)-pi;
for ii=1:N0
alfa(ii)=(2*pi*ii-pi+theta)/N;
fi_tc=2*pi*rand(1,1)-pi;
fi_ts=2*pi*rand(1,1)-pi;
Tc=Tc+cos(cos(alfa(ii))*wm*t+fi_tc);
Ts=Ts+cos(sin(alfa(ii))*wm*t+fi_ts);
end;
h=P_nor*(Tc+j*Ts );
clear all
snr=-3:3;
SimulationTime=0;
ex7main;
ser1=ser;ber1=ber;
for ii=1:length(snr)
SNR=snr(ii);
sim('ex11');
ber(ii)=BER(1);
ser(ii)=SER(1);
end
semilogy(snr,ber,'-rs',snr,ser,'-r^',snr,ber1,'-ro',snr,ser1,'-r*')
legend('Rayleigh衰落+AWGN信道BER','Rayleigh衰落+AWGN信道SER','AWGN信道BER','AWGN信道SER')
减温减压装置技术要求title('QPSK在AWGN和多径Rayleigh衰落信道下的性能')
xlabel('信噪比（dB）')
ylabel('误符号率和误比特率')
