%?MATLAB?script?for?System?Simulation?Homework
close?all;
clear?all;

%?Carrier?frequency?for?modulation?and
%?demodulation
????Fc?=5e6;
%??
%?QPSK?transmitter?
%?
data=5000;%??Input?binary?data?of?5MHz
rand_data?=randn（1data）;
for?i=1:data
??if?rand_data（i）>=0.5
????input（i）=1;
??else
????input（i）=0;
??end
end
%Series?to?Parallel
for?i=1:data
??if?rem（i2）==1
?????if?input（i）==1
????????I（i）=1;
????????I（i+1）=1;
?????else
????????I（i）=-1;
????????I（i+1）=-1;
?????end
??else
?????if?input（i）==1
????????Q（i-1）=1;
????????Q（i）=1;
?????else
????????Q（i-1）=-1;
????????Q（i）=-1;
?????end
???end
end
Q=[0Q];
%?Zero?insertion
zero=5;????%?Sampling?rate?is?25MHz
for?i=1:zero*data
???if?rem（izero）==1
??????Izero（i）=I（fix（（i-1）/zero）+1）;
??????Qzero（i）=Q（fix（（i-1）/zero）+1）;
???else
??????Izero（i）=0;
??????Qzero（i）=0;
???end
end

%Pulse?shaping?filter
NT?=50;
N=2*zero*NT;
Fs=25e6;
rf=0.5;
psf=rcosfir（rfNTzeroFs‘sqrt‘）;

Ipulse=?conv（Izeropsf）;
Qpulse=?conv（Qzeropsf）;

%Modulation
for?i=1:zero*data+N
???t（i）=（i-1）/（Fc*zero）;
???Imod（i）=Ipulse（i）.*cos（2*pi*Fc*t（i））;
???Qmod（i）=Qpulse（i）.*（-1）*sin（2*pi*Fc*t（i））;
end
sum=Imod+Qmod;

plot（tsum）;
axis（[0.000040?0.000045?-1.5?1.5]）
K=1024;
SUM=fft（sumK）;
Pxx=abs（SUM）.^2/K;
index=0:K-1;
index=index/K*2*pi;
figure（2）
plot（indexPxx）
set（gca‘XTickLabel‘{‘0‘‘pi/4‘‘pi/2‘‘3pi/4‘‘pi‘‘5pi/4‘‘3pi/2‘‘7pi/4‘‘2pi‘}）
%?Create?AWGN?complex?noise
EbNodBVals=0:2:10;????????????%unit=dB?:the?power?of?noise?
for?SNR=1:length（EbNodBVals）
??EbNo=10.^（EbNodBVals（SNR）./10）;?
??EsNo=EbNo;
??Es=2;???????