ASK调制MATLAB代码。

Rb=1*10^6; %码元速率 Fs=8*Rb; %采样频率 LenData=Len*Fs/Rb; %数据长度 Fc=70*10^6; %载波频率 Qn=8; %量化位数 a=0.8; %成形滤波器滚降因子 Len=1024; %产生载波信号 t=0:1/Fs:Len/Rb; carrier=cos(2*pi*Fc*t); carrier=carrier(1:LenData); %产生随机分布的二进制数据 %code_2ask=randint(1,Len,2); code_2ask=(randi(2,Len,1)-1)'; %对基带数据以Fs速率采样 code_2ask_upsamp=rectpulse(code_2ask,Fs/Rb); %对基带数据进行成形滤波,同时进行Fs/Rb倍采样 code_2ask_filter=rcosflt(code_2ask,1,Fs/Rb); %产生未进行成形滤波的2ASK信号 ASK2=carrier.*code_2ask_upsamp; %产生成形滤波后的2ASK信号 ASK2_filter=carrier.*code_2ask_filter(1:LenData)'; %获取2ASK信号的频谱 ASK2_Spec=20*log10(abs(fft(ASK2,1024))); ASK2_Spec=ASK2_Spec-max(ASK2_Spec); ASK2_filter_Spec=20*log10(abs(fft(ASK2_filter,1024))); ASK2_filter_Spec=ASK2_filter_Spec-max(ASK2_filter_Spec); %产生随机分布的四进制数据 %code_4ask=randint(1,Len,4); code_4ask=(randi(4,Len,1)-1)'; %对基带数据以Fs速率采样 code_4ask_upsamp=rectpulse(code_4ask,Fs/Rb); %对基带数据进行成形滤波,同时进行Fs/Rb倍采样 code_4ask_filter=rcosflt(code_4ask,1,Fs/Rb); %产生未进行成形滤波的4ASK信号 ASK4=carrier.*code_4ask_upsamp; %产生成形滤波后的4ASK信号 ASK4_filter=carrier.*code_4ask_filter(1:LenData)'; %获取4ASK信号的频谱 ASK4_Spec=20*log10(abs(fft(ASK4,1024))); ASK4_Spec=ASK4_Spec-max(ASK4_Spec); ASK4_filter_Spec=20*log10(abs(fft(ASK4_filter,1024))); ASK4_filter_Spec=ASK4_filter_Spec-max(ASK4_filter_Spec); %绘图 if IsPlot==1 figure(1);x=0:200;x=x/Fs*(10^6); subplot(221);plot(x,ASK2(100:300));xlabel('时间(us)');ylabel('幅度(v)'); title('未经成形滤波的2ASK时域波形');grid on; subplot(222);plot((0:200),ASK2_filter(100:300));xlabel('时间(us)');ylabel('幅度(v)'); title('成形滤波后的2ASK时域波形');grid on; subplot(223);plot((0:200),ASK4(100:300));xlabel('时间(us)');ylabel('幅度(v)'); title('未经成形滤波的4ASK时域波形');grid on; subplot(224);plot((0:200),ASK4_filter(100:300));xlabel('时间(us)');ylabel('幅度(v)'); title('成形滤波后的4ASK时域波形');grid on; figure(2);x=0:length(ASK2_Spec)-1;x=x/length(x)*Fs/10^6; subplot(221);plot(x,ASK2_Spec);xlabel('频率(MHz)');ylabel('幅度(dB)'); title('未经成形滤波的2ASK频谱');grid on; subplot(222);plot(x,ASK2_filter_Spec);xlabel('频率(MHz)');ylabel('幅度(dB)'); title('成形滤波后的2ASK频谱');grid on; subplot(223);plot(x,ASK4_Spec);xlabel('频率(MHz)');ylabel('幅度(dB)'); title('未经成形滤波的4ASK频谱');grid on; subplot(224);plot(x,ASK4_filter_Spec);xlabel('频率(MHz)');ylabel('幅度(dB)'); title('成形滤波后的4ASK频谱');grid on; end; %量化数据并写入文本文件中 if IsOutput==1 norm_Data=ASK2/max(abs(ASK2));%归一化处理 Q_s=round(norm_Data*(2^(Qn-1)-1)); fid=fopen('D:\ModemPrograms\Chapter_5\E5_1_ASKMod\ASK2.txt','w'); for i=1:length(Q_s) B_s=dec2bin(Q_s(i)+(Q_s(i)<0)*2^Qn,Qn); for j=1:Qn if B_s(j)=='1' tb=1; else tb=0; end fprintf(fid,'%d',tb); end fprintf(fid,'\r\n'); end fprintf(fid,';'); fclose(fid); norm_Data=ASK2_filter/max(abs(ASK2_filter));%归一化处理 Q_s=round(norm_Data*(2^(Qn-1)-1)); fid=fopen('D:\ModemPrograms\Chapter_5\E5_1_ASKMod\ASK2_filter.txt','w'); for i=1:length(Q_s) B_s=dec2bin(Q_s(i)+(Q_s(i)<0)*2^Qn,Qn); for j=1:Qn if B_s(j)=='1' tb=1; else tb=0; end fprintf(fid,'%d',tb); end fprintf(fid,'\r\n'); end fprintf(fid,';'); fclose(fid); norm_Data=ASK4/max(abs(ASK4));%归一化处理 Q_s=round(norm_Data*(2^(Qn-1)-1)); fid=fopen('D:\ModemPrograms\Chapter_5\E5_1_ASKMod\ASK4.txt','w'); for i=1:length(Q_s) B_s=dec2bin(Q_s(i)+(Q_s(i)<0)*2^Qn,Qn); for j=1:Qn if B_s(j)=='1' tb=1; else tb=0; end fprintf(fid,'%d',tb); end fprintf(fid,'\r\n'); end fprintf(fid,';'); fclose(fid); norm_Data=ASK4_filter/max(abs(ASK4_filter));%归一化处理 Q_s=round(norm_Data*(2^(Qn-1)-1)); fid=fopen('D:\ModemPrograms\Chapter_5\E5_1_ASKMod\ASK4_filter.txt','w'); for i=1:length(Q_s) B_s=dec2bin(Q_s(i)+(Q_s(i)<0)*2^Qn,Qn); for j=1:Qn if B_s(j)=='1' tb=1; else tb=0; end fprintf(fid,'%d',tb); end fprintf(fid,'\r\n'); end fprintf(fid,';'); fclose(fid); end