基于Matlab和Simulink实现数字信号载波传输仿真（源码+数据）.rar

%4-QAM和4-FSK通过rayleigh衰落信道仿真 clear all nsymbol = 100000; %每种SNR下发送的符号数 SymbolRate = 1000; %fuhaosulv nsamp = 50; %每个符号的取样点数 fs = nsamp*SymbolRate; %采样频率 fd = 100; % Rayleigh衰落信道的最大多普勒频移 chan = rayleighchan(1/fs,fd); %生成Rayleigh衰落信道 M=4; graycode = [0 1 3 2]; EsN0 = 0:2:20; snr1 = 10.^(EsN0/10); %信噪比转换为线性值 msg = randi([0,1],1,nsymbol); msg1 = graycode(msg+1); % Gray映射 x1 = qammod(msg1,M); %基带4-QAM调制 x1 = rectpulse(x1,nsamp); x2 = fskmod(msg1,M, SymbolRate, nsamp,fs); %4-FSK调制 spow1 = norm(x1).^2/nsymbol; %求每个符号的平均功率 spow2 = norm(x2).^2/nsymbol; %求每个符号的平均功率 for indx=1:length(EsN0) sigma1 = sqrt(spow1/(2*snr1(indx))); %根据符号功率求噪声功率 sigma2 = sqrt(spow2/(2*snr1(indx))); %根据符号功率求噪声功率 fadeSig1 = filter(chan,x1); fadeSig2 = filter(chan,x2); rx1 = fadeSig1+sigma1*(randn(1,length(x1))+j*randn(1,length(x1))); %加高斯白噪声 rx2 = fadeSig2+sigma1*(randn(1,length(x2))+j*randn(1,length(x2))); %加高斯白噪声 y1 = intdump(rx1,nsamp); %相关 y1 = qamdemod(y1,M); demsg1 = graycode(y1+1); [err,ber1(indx)] = biterr(msg,demsg1,log2(M)); [err,ser1(indx)] = symerr(msg,demsg1); y2 = fskdemod(rx2,M,SymbolRate,nsamp,fs); demsg2 = graycode(y2+1); [err,ber2(indx)] = biterr(msg,demsg2,log2(M)); [err,ser2(indx)] = symerr(msg,demsg2); end semilogy(EsN0,ber1,"-ko", EsN0, ser1, "-k*", EsN0, ser2, "-ro", EsN0, ber2, "-r*"); title("4-QAM和4-FSK调制信号在rayleigh衰落信道下性能") xlabel("EbN0"); ylabel("误比特率P和误符号率"); legend("4-QAM误比特率", "4-QAM误符号率", "4-FSK误符号率", "4-FSK误比特率")