2DPSK调制和解调系统的matlab仿真

Roof0102

function y=dpsk2()
fs = 30000;
Time_Hold_On = 0.01;
Num_Unit = fs * Time_Hold_On;
) R1 \# Q7 `+ v3 [High_Level = ones ( 1, Num_Unit );
Low_Level = zeros ( 1, Num_Unit );
( s1 A7 Z2 }. Uw = 300;
A = 1;
7 C4 q% R/ f4 ]Sign_Set =randi(2,1,8)-1;
! h2 n4 @  Z: c" `* W  |7 wLenth_Of_Sign = length ( Sign_Set );
st = zeros ( 1, Num_Unit * Lenth_Of_Sign );
- F4 \* P5 }* h" L  p8 gsign_orign = zeros ( 1, Num_Unit * Lenth_Of_Sign );
3 ~5 W6 V: g' K# J7 W% wsign_result = zeros ( 1, Num_Unit * Lenth_Of_Sign );
t = 0 : 1/fs : Time_Hold_On * Lenth_Of_Sign - 1/fs;
for I = 1 : Lenth_Of_Sign
if Sign_Set(I) == 1
sign_orign( (I-1)*Num_Unit + 1 : I*Num_Unit) = High_Level;
$ }% ^5 r9 g0 t, M8 p6 P& ielse
sign_orign( (I-1)*Num_Unit + 1 : I*Num_Unit) = Low_Level;
1 j6 A, s# I) _. B2 s' wend
$ i- D# g* b6 @. x5 u4 r4 i2 xend
5 F8 B) Q8 y& T5 ]8 yfor I = 1 : Lenth_Of_Sign
; r, {, @/ [- U( Q; iif Sign_Set(I) == 1
. @. }$ I' F1 _6 Q2 A. ust( (I-1)*Num_Unit + 1 : I*Num_Unit) = A * cos ( 2 * pi * w * t( (I-1)*Num_Unit + 1 : I*Num_Unit ) + ( pi / 2 ) );
/ S7 K, P. a8 k/ Q9 ~' Gelse
st( (I-1)*Num_Unit + 1 : I*Num_Unit) = A * cos ( 2 * pi * w * t( (I-1)*Num_Unit + 1 : I*Num_Unit ) );
$ A+ \! R7 ~  Cend
end
- x& s- Y" }/ [1 f  Z5 Z
figure
) `* ]( p$ J8 A7 F+ Csubplot ( 2, 1, 1 )
plot(t, sign_orign);
axis( [ 0 , Time_Hold_On *( Lenth_Of_Sign + 1), - (A / 2), A + (A / 2) ] );
) O4 N4 k: ]4 C* Atitle ( '原始信号' );
grid

subplot ( 2, 1, 2 );
$ J7 Q3 z& w, |& s; aplot ( t, st );
axis( [ 0 , Time_Hold_On *( Lenth_Of_Sign + 1), - 3*(A / 2), 3*(A / 2) ] );
title ( '调制后的信号' );
grid
  V6 ^/ @. \$ T, X7 Edt = st .* cos ( 2 * pi * w * t );

9 j* H! H6 T) X: L7 ^figure
subplot(2,1,1)
! P; ]5 i$ D+ {7 N' C! v" s  ^4 jplot ( t, dt );
2 p8 ~" U& D0 Zaxis( [ 0 , Time_Hold_On *( Lenth_Of_Sign + 1), - 3*(A / 2), 3*(A / 2) ] );
title ( '相乘后的波形' );
grid
[N,Wn] = buttord( 2*pi*50, 2*pi*150,3,25,'s'); %临界频率采用角频率表示
[b,a]=butter(N,Wn,'s');
[bz,az]=impinvar(b,a,fs); %映射为数字的

dt = filter(bz,az,dt);
- K+ x$ I; i7 Q* K8 v& x+ p
subplot(2,1,2)
" Y$ H. w  U8 G: W( aplot ( t, dt );
axis( [ 0 , Time_Hold_On *( Lenth_Of_Sign + 1), - 3*(A / 2), 3*(A / 2) ] );
% g8 m5 q! c2 a3 Ttitle ( '低通滤波后的波形' );
7 F# ~+ r8 Z0 A* x$ }- G' Zgrid
for I = 1 : Lenth_Of_Sign
; D  B# r2 Q+ i6 D7 aif dt((2*I-1)*Num_Unit/2) < 0.25
sign_result( (I-1)*Num_Unit + 1 : I*Num_Unit) = High_Level;
& L! X2 ^; X, }else
sign_result( (I-1)*Num_Unit + 1 : I*Num_Unit) = Low_Level;
end
end

figure
plot ( t, sign_result );
axis( [ 0 , Time_Hold_On *( Lenth_Of_Sign + 1), - 3*(A / 2), 3*(A / 2) ] );
title ( '逆码变换后的波形' );
grid
, m! L4 J8 {  Y+ G7 `

Blah

也就是可以直接对调制信号进行解调，理想信道下接收端信号与发送端信号完全相同
2 v. x" C" X1 \/ O& Q9 ?, m

Jame33

再看看其他人是怎么说的

land

同问，求结果