clear?all;
clc;
num=100;??????????????????????????????????%原始信息序列長度
samp=100;?????????????????????????????????%采樣點數(shù)
delta_T=1/samp;???????????????????????????%采樣間隔
N=samp*num;???????????????????????????????%總的采樣點數(shù)
msg_orig=randint（1num）;??????????????????%序列生成
data1=2*msg_orig-1;???????????????????????%單/雙極性變換

ry_I=raylrnd（0.81num/2）;????????????????%以0.8為參數(shù)的瑞利衰落
ry_Q=raylrnd（0.81num/2）;????????????????%以0.8為參數(shù)的瑞利衰落

for?i=1:num
????data1_orig（samp*（i-1）+1:samp*i）=data1（i）;%對data1進行采樣
end
for?i=1:2000
????data（i）=data1_orig（i）;
end
%--------------------------------------------畫信源及頻譜圖-----------------------

figure（1）;
subplot（212）;??????????????????????????????
pwelch（data1_orig[][][]10）;??????????????
subplot（211）;
x1=0+0.01:0.01:100;
plot（x1data1_orig）;??????????????????????????
axis（[0?10?-1.2?1.2]）;???????????????????????

%----------------------------------將信息源分成兩路?，并對第I路信號抽樣-------------
data11=zeros（1samp*num/2）;??????????????
for?i1=1:num/2??
????data11（samp*（i1-1）+1:samp*i1）=data1（2*i1-1）;???????%I路信號是信源的第奇數(shù)個碼元，并對它抽樣
end

data12=zeros（1samp*num/2）;????????????????????????????%Q路信號時信源的第偶數(shù)個碼元，并對其抽樣
for?i2=1:num/2??
????data12（samp*（i2-1）+1:samp*i2）=data1（2*i2）;
end

%------------------------------------------對余弦載波抽樣------------------------------
for?j1=1:samp*num/2??????????????????????
????a1（j1）=cos（（j1-1）*2*pi/100）;???????????%每個余弦波每個周期采50個點
end

%------------------------------------------對正弦載波抽樣------------------------------
for?j2=1:samp*num/2??????????????????????
????a2（j2）=sin（（j2-1）*2*pi/100）;
end

%---------------------------------------------調(diào)制------------------------------------
data21=data11.*a1;??????????????????????????????%I路用余弦調(diào)制?????????????????????????
data22=data12.*a2;??????????????????????????????%Q路用正弦調(diào)制

%--------------------------------------為兩路信號加上瑞利衰落--------------------------
for?i=1:num/2
????data21_ray（i）=data21（i）*ry_I（i）;
????data22_ray（i）=data22（i）*ry_Q（i）;
end

data2_modul=data21+data22;????????????????????%調(diào)制后總的信號
data2_ray=data21_ray+data22_ray;??????????????%加瑞利衰落后總的信號

for?i=1:1000
????data2_modul_t（i）=data2_modul（i）;
end
%-----------------------------------------畫調(diào)制后的信號波形和頻譜圖---------------
figure（2）;?????
subplot（212）;
pwelch（data2_modul[][][]10）;

subplot（211）;
x2=0+0.01:0.01:10;
plot（x2data2_modul_t）;


data3=awgn（data2_modul1‘measured‘）;???????????%經(jīng)過AWGN信道
for?i=1:1000
????data3_t（i）=data3（i）;
end
%-----------------------------------畫經(jīng)過高斯信道后的信號波形和頻譜圖----------------------
figure（3）;????
subplot（212）;
pwelch（data3[][][]10）;

subplot（211）;
plot（x2data3_t）;


%------------------------------------------------星座圖-----------------------------------
clear;?????????????????????????????????????????
N=1000;
s00=[1?0];?s01=[0?-1];?s11=[-1?0];?s10=[0?1];???%??信號映射
SNRindB1=8;
E=1;????????????????????????????????????????????%?碼元能量
snr=10^（SNRindB1/10）;?
sgma=sqrt（E/snr）/2;?
for?

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????5259??2010-11-06?11:06??QPSK_MOD.m