%ofdm
clcclear?all
para=128;?%并行信道數
nd=20;?%每個信道傳輸的符號數
ber=zeros（115）;
snr=zeros（115）;
h2=waitbar（0‘please?wait...‘‘name‘‘當前進度‘）;
for?SNR=1:15;
????waitbar（SNR/15）;
????nloop=200;%仿真次數
????noe=0;%錯誤數據數
????nod=0;%總數據數
????for?ns=1:nloop%仿真循環
????????oridata=randi（[0?1]1para*nd）;
????????oridata_a=reshape（oridata2para*nd/2）;
????????oridata_b=bi2de（oridata_a‘‘left-msb‘）‘;
????????h=modem.pskmod（4）;%設置qpsk調制
????????qpsk_data=modulate（horidata_b）;
????????para_data=reshape（qpsk_dataparand/2）;
????????ifft_data=ifft（para_data）;
????????
????????r_data=real（ifft_data）;
????????i_data=imag（ifft_data）;
????????r_data1=[r_data（para-para/4+1:para:）;r_data];%保護間隔一般不大于傳送數據的四分之一
????????i_data1=[r_data（para-para/4+1:para:）;i_data];
????????r_out=reshape（r_data11（para+para/4）*nd/2）;
????????i_out=reshape（i_data11（para+para/4）*nd/2）;
????????data=r_out+i_out.*1i;
????????
????????rdata=awgn（dataSNR‘measured‘）?;%加入噪聲
????????%rdata=awgn（dataSNR）?;%加入噪聲
????????
????????r_data2=real（rdata）;%加噪后信號實部
????????i_data2=imag（rdata）;
????????r_data3=reshape（r_data2para+para/4nd/2）;?%實部矩陣
????????i_data3=reshape（i_data2para+para/4nd/2）;?%同上
????????r_data4=r_data3（para/4+1:para+para/4:）;?%去實部保護間隔
????????i_data4=i_data3（para/4+1:para+para/4:）;?%同上
????????
????????get_data=r_data4+i_data4*1i;
????????fft_data=fft（get_data）;
????????iqpsk_data=reshape（fft_data1para*nd/2）;
????????h1?=?modem.pskdemod（4）;
????????f_data=demodulate（h1iqpsk_data）;
????????demodata=de2bi（f_data‘left-msb‘）‘;
????????demodata1=reshape（demodata1para*nd）;
????????
????????noe2=sum（abs（demodata1-oridata））;
????????nod2=length（oridata）;
????????
????????noe=noe+noe2;?%循環仿真
????????nod=nod+nod2;?%同上
????end
????ber（1SNR）=?noe/nod;?%誤碼率
????snr（1SNR）=SNR;?%信噪比
????scatterplot（iqpsk_data）;
end
close（h2）;
semilogy（snrber‘-*‘）;?%畫圖
grid?on;
xlabel（‘SNR‘）;?
ylabel（‘BER‘）;?
title（‘Performance?of?OFDM?under?the?channel?AWGN‘）?

?屬性????????????大小?????日期????時間???名稱
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?????文件???????2103??2015-04-19?19:39??OFDM.m

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?????????????????2103????????????????????1