%E:\大學課件&科學瀏覽器\大三下\光纖通信\光纖實驗\ACO?OFDM
clc;
clear?all?;
global?N_IFFT;
global?N_sc;
N_IFFT=64;%IFFT點數
N_sc=128;%有效數據的子載波數
BitperSymbol=4;%每符號的比特數
DataSymlength=256;%傳輸的符號數
%?Data_Bitlength=DataSymlength*N_sc*BitperSymbol;
N_cp=16;%循環前綴的個數

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%?
%產生數據信號（X_DataY_Data），round四舍五入取整
X_BitSource=round（rand（1DataSymlength*BitperSymbol*N_sc））;??%131072

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%?
%串并變換，每一行是一個子載波
X_input=reshape（X_BitSourceN_sc[]）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%M-QAM調制??
%SymbolOrder?=?Binary時
%0??4??8??12
%1??5??9??13
%2??6??10?14
%3??7??11?15
hI?=?modem.qammod（‘M‘2^BitperSymbol?‘PhaseOffset‘?0?‘SymbolOrder‘‘Binary‘?‘InputType‘?‘bit‘）;
X_Data?=?modulate（hIX_input）;

figure（1）;
plot（X_Data‘*r‘）;title（‘16QAM調制后的X-Data‘）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%矩陣調整
X1_zero=X_Data;
X1_zero_half=X1_zero（1:N_sc/8:）;???%X路數據的一半

%奇數子載波上數據置0
for?k=1:N_sc/2^BitperSymbol
???X1_zero_half（2*k-11:DataSymlength*BitperSymbol）=zeros（1DataSymlength*BitperSymbol）;
end????

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Hermitian對稱關于第17行共軛對稱
X1_zero_j=conj（X1_zero_half）;???%求共軛

%初始化后半段信號
X1_zero_j_z=zeros（N_sc/8DataSymlength*BitperSymbol）;

for?i?=?1:N_sc/16
????k=（N_sc/16+1）-i;
????????X1_zero_j_z（2*i1:DataSymlength*BitperSymbol）?=?X1_zero_j（2*k1:DataSymlength*BitperSymbol）;
end??

X1_zero?=?vertcat（X1_zero_halfX1_zero_j_z）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%ifft變換，結果為實數
X1_ifft_output=ifft（X1_zero）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%零值處限幅，小于0的置0
X1_ifft_output_x=X1_ifft_output;
X1_ifft_output_x（find（X1_ifft_output<0））=0;

figure（2）;
subplot（211）;
stem（X1_ifft_output‘r.‘）;title（‘限幅前X1‘）;
subplot（212）;
stem（X1_ifft_output_x‘r.‘）;title（‘限幅后X1‘）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%加cp
%頭部加cp
X1_cp=vertcat（X1_ifft_output_x（（（end-N_cp+1）:end）:）X1_ifft_output_x）;
figure（3）;
subplot（211）;
stem（X1_cp‘r‘）;title（‘X1?with?CP‘）;
subplot（212）;
stem（X1_ifft_output_x‘r‘）;title（‘X1?without?CP‘）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%并串變換
X1_OFDMSymbol=reshape（X1_cp.‘[]1）.‘;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%高斯白噪聲信道
RX1=awgn（X1_OFDMSymbol30）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%串并變換，加了16行的CP
RX1_para=reshape（RX1[]N_sc/4+N_cp）.‘;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%去掉CP，去掉前16行，剩下的是數據
RX1_cutCP=RX1_para（N_cp+1:N_cp+N_sc/4?:?）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%FFT運算
RX1_QAMSymbol=fft（RX1_cutCP）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%逆限幅
RX1_QAMSymbol_2=2*RX1_QAMSymbol;
RX1_QAMSymbol_2_z=RX1_QAMSymbol_2;
for?i=1:16;
????RX1_QAMSymbol_2_z（（2*i）-1:）=X_Data（（2*i）-1:）;?%奇數位恢復
end
figure（4）;
plot（RX1_QAMSymbol_2_z‘r.‘）;title（‘FFT后RX1‘）;
axis（[-4?4?-4?4]）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?%解碼
%?DX1_Bit=zeros（N_scDataSymlength*BitperSymbol）;
%?
%?for?i=1:32
%?????for?j=1:1024
%?????????if?real（RX1_QAMSymbol_2_z（ij））?>?2?&&?imag（RX1_QAMSymbol_2_z（ij））?>?2?%11

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????4472??2018-06-05?15:07??ACO_OFDM.m

-----------?---------??----------?-----??----

?????????????????4472????????????????????1