基于matlab的汉明码4FSK通信系统仿真代码

%Function:(7,4)Hamming Code and 4FSK Modulation %Author:HarryChing %Date:2012/11/03 %Testbench:Matlab R2008a function main N=1200;%Set data bits of random binary number K=7*N/4;%The data bits after（7,4）Hamming Code M = 4;%4FSK SNRpBit=0:2:20;%Signal to Noise Ratio per bit SNR=SNRpBit./log2(M);%Signal to Noise Ratio per symbol x=randint(1,N,2);%Generate N bits binary number x1=hammingcode(x);%Hamming Code x2=reshape(x1,K/2,2);%1*K array to 2*K/2 array x3=bi2de(x2);%Change 2 to 4 scale x4=reshape(x3,1,K/2);%Reshape to 1*K/2 array figure(1) bar(x4); axis([0 4.5 0 3]) title('随机产生的数字信息','FontName','楷体','FontSize',20) y = fsk4mod(x4);%4FSK modulation y1 = raychannel(y);%4FSK pass Rayleigh Channel y11 = raymultipathchannel(y);%4FSK pass Rayleigh Multi-path Channel %%%%%%The BER of two channel models is as follows%%%%%% for i = 1:length(SNR) if i==1 y2=awgnchannel(y1,SNR(i));%Pass Gaussian noise Channel Fs=1280;%Sampling Frequency numPlot=4;%Set plot number numModPlot=numPlot*Fs; t=[0:numModPlot-1]./Fs; figure(5) plot(t,y2(1:length(t))); title('瑞利信道下加入高斯白噪声后的4FSK信号','FontSize',20) xlabel('Time','FontSize',15); ylabel('Amplitude','FontSize',15); y3=fsk4demod(y2); y4=reshape(y3,K/2,1); y5=de2bi(y4); y6=reshape(y5,1,K); y7=decode(y6,7,4,'hamming'); [errorSym ratioSym]=symerr(x,y7); Pe1(i)=ratioSym; else y2=awgnchannel(y1,SNR(i));%Pass Gaussian noise Channel y3=fsk4demod(y2); y4=reshape(y3,K/2,1); y5=de2bi(y4); y6=reshape(y5,1,K); y7=decode(y6,7,4,'hamming'); [errorSym ratioSym]=symerr(x,y7); Pe1(i)=ratioSym; end end for i = 1:length(SNR) if i==1 y22=awgnchannel(y11,SNR(i));%Pass Gaussian noise Channel Fs=1280;%Sampling Frequency numPlot=4;%Set plot number numModPlot=numPlot*Fs; t=[0:numModPlot-1]./Fs; figure(6) plot(t,y2(1:length(t))); title('多径信道下加入高斯白噪声后的4FSK信号','FontSize',20) xlabel('Time','FontSize',15); ylabel('Amplitude','FontSize',15); y33=fsk4demod(y22); y44=reshape(y33,K/2,1); y55=de2bi(y44); y66=reshape(y55,1,K); y77=decode(y66,7,4,'hamming'); [errorSym ratioSym]=symerr(x,y77); Pe11(i)=ratioSym; else y22=awgnchannel(y11,SNR(i));%Pass Gaussian noise Channel y33=fsk4demod(y22); y44=reshape(y33,K/2,1); y55=de2bi(y44); y66=reshape(y55,1,K); y77=decode(y66,7,4,'hamming'); [errorSym ratioSym]=symerr(x,y77); Pe11(i)=ratioSym; end end figure(7) semilogy(SNR,Pe1,'o-b',SNR,Pe11,'*-r','LineWidth',3); xlabel('SNR','FontSize',15); ylabel('Pe','FontSize',15); legend('瑞利信道','多径信道') title('不同信道下误码率-信噪比曲线','FontName','楷体','FontSize',20) grid on