clear?all;
close?all;
clc
Ts?=?1;%碼元速率
N_sample?=?100;?%采樣速率
dt?=?Ts?/?N_sample;
N?=?10000;?%碼元個數
t?=?0?:?dt?:?（N?*?N_sample?-?1）?*?dt;
RAN?=?randi（[01]1N）;?%?隨機0?1序列
gt1?=?ones（1N_sample）;

code?=?[];
RAN0?=?RAN;
Progressbar=waitbar（0‘Please?wait（1/2）...‘）;%創建進度條
for?i?=?1?:?N
????waitbar（i/N）;?
????if（RAN0（i）?==?0）
????????RAN0（i）?=?-1;
????end
????code?=?[code?RAN0（i）*gt1];?%采樣后碼元
end
close（Progressbar）;


fc?=?5;
CarrierWave?=?sin（2*pi*fc*t）;???%載波信號
BPSK_Wave?=?code.*?CarrierWave;?%調制
fft_code1?=?fftshift（fft（BPSK_Wave））;?%?求序列的頻譜
PE1?=?10?*?log10（abs（fft_code1）?.^?2?/?（N?*?Ts））;?%?公式法求功率譜密度
PEL1?=?（-length（fft_code1）?/?2?:?length（fft_code1）?/?2?-?1）?/?N;?%?轉換成對應頻率（-L/2:L/2-1）*fs/L
%%%%%%%%%%%%%%?繪制信號?%%%%%%%%%%%%%%%%%%
figure?（1）
subplot（311）;plot（tcode）;axis（[010-1.51.5]）;title（‘碼元序列‘）;xlabel（‘t/s‘）;ylabel（‘幅度‘）;%碼元序列
subplot（312）;plot（tBPSK_Wave）;axis（[010-1.51.5]）;title（‘BPSK波形‘）;xlabel（‘t/s‘）;ylabel（‘幅度‘）;%BPSK波形
subplot（313）;plot（PEL1PE1）;axis（[fc-5fc+5-100100]）;xlabel（‘頻率/HZ‘）;ylabel（‘P/dB‘）;title（‘功率譜密度‘）;%功率譜密度
%%%%%%%%%%%%%%%%%計算誤碼率?%%%%%%%%%%%%%%%%%%%
Pe?=?[];
h=waitbar（0‘Please?wait（2/2）...‘）;%創建進度條
%%%%%%%%%%%%%???加入高斯噪聲????????%%%%%%%%%%%%%%%
SNR?=?-30?:?30;
SNR0?=?SNR+10*log10（25）;%等效窄帶噪聲信噪比
for?i?=1?:?length（SNR）;
????BPSK_Noise?=?awgn（BPSK_WaveSNR（i））;
????waitbar（i/length（SNR））;?

%%%%%%%%%%%%%%%%%帶通濾波器%%%%%%%%%%%%%%%%%%%%%%
??????BPF?=?fir1（101[（fc-1）/（N_sample/2）（fc+1）/（N_sample/2）]）;
??????BPSK_BPF?=?filter（BPF1BPSK_Noise）;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%??????
??%%%%%%%%%%%%????BPSK信號的解調（相干）%%%%%%%%%%%%%
%?????BPSK_Demo?=?BPSK_Noise.*?CarrierWave?;%相干解調
%?????fp?=?1;?%截至頻率2.5hz
%?????fcm?=?2*fp/N_sample;?%歸一化頻率
%?????LPF??=?fir1（30fcm）;?%反復實驗得出階數
%?????BPSK_LPF?=?filter2（LPFBPSK_Demo）;?%此處不用conv卷積，因為長度增加??
??????fp?=?1;
??????BPSK_LPF?=?demodulation（BPSK_NoiseCarrierWavefpN_sample）;??%將帶通后解調過程壓縮為子函數輸出為過低通后波形
????%%%%%%%%%%%%%%%%?抽樣判決?%%%%%%%%%%%%%%%%%%%
????code_back?=?[];
????????count?=?0;
????????for?q?=?1:N*N_sample
????????????if（BPSK_LPF（q）?>?0）
????????????????code_back?=?1;?????
????????????else
????????????????code_back?=?-1;
????????????end
????????????if?（code_back?~=?code（q））
????????????????count?=?count?+?1;
????????????end
????????end
????????error?=?count?/?（N*N_sample）;
????????Pe?=?[Pe?error];
end
close（h）;

figure?（2）
snr?=?10.^（0.1.*SNR）;
Pe_theor?=?（erfc（sqrt（snr）））.*（1-0.5*erfc（sqrt（snr）））;
semilogy（SNR0Pe‘b‘）;xlabel（‘SNR/db‘）;ylabel（‘誤碼率‘）;hold?on;title（‘BPSK誤碼率曲線‘）;
semilogy（SNRPe_theor‘r‘）;grid?on;legend（‘實際值‘‘理論值‘）;axis（[-4810^-41]）%xlabel（‘SNR/db‘）;ylabel（‘誤碼率/10^x‘）;title（‘BPSK誤碼率曲線‘）;

?屬性????????????大小?????日期????時間???名稱
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?????文件???????2957??2018-05-31?15:16??BPSK.m

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?????????????????2957????????????????????1