maltab二进制数字基带传输系统

clear; close all; clc; type = 1; %信源类型,为1，基带信号为0和1；为2，基带信号为-1和1 a = 0.8; %滚降系数 L = 10000; %信源长度 period = 10; %周期扩大倍数 x1 = Binary_sources(type,L); %信源 x2 = AMI_code(type,x1); %转换为AMI码 x3 = add_zeros(x2,period); %周期扩大20倍 hn = rcosdesign(a,6,4,'sqrt'); %平方根升余弦滚降滤波器 y1 = my_filter(x3,hn); %通过发送滤波器 SNR1 = [25,10,0,-5]; %SNR1为计算误码率随信噪比变化 p = (length(SNR1)); %信噪比 figure(5); for n = 1:1:length(SNR1) ype = my_filter(add_noise(SNR1(n),y1),hn); %添加噪声,经过接收滤波器 subplot(length(SNR1),1,n); eye_pic(ype,period);title(sprintf("接收滤波器输出信号波形的眼图(当前信噪比：%d dB，)",SNR1(n))); p(n) = Pe_calculate(AMI_Binary(type,judgement(type,sample(ype,period))),x1); %采样+判决+码型反转+计算误码率 end %% 画图 SNR2 = 20; y2 = add_noise(SNR2,y1); %在y1上添加噪声 y3 = my_filter(y2,hn); %通过接收滤波器 y4 = sample(y3,period); %对y3抽样 y5 = judgement(type,y4); %判决 y6 = AMI_Binary(type,y5); %码型反转 pe = Pe_calculate(y6,x1); figure(1); subplot(411);stem(x1);axis([0 40 -1.2 1.2]);title("信源信号"); subplot(412);stem(x2);axis([0 40 -1.1 1.1]);title("AMI码"); subplot(413);stem(x3);axis([0 600 -1.1 1.1]);title("周期扩大后"); subplot(414);stem(hn);axis([0 30 -0.5 1]);title("根升余弦单位脉冲响应"); figure(2); subplot(311);plot(y1);axis([0 600 -1.1 1.1]);title("经过发送滤波器的信号"); subplot(312);plot(y2);axis([0 600 -1.1 1.1]);title(sprintf("添加噪声后的信号(当前信噪比：%d dB，误码率：%d)",SNR2, pe)); subplot(313);plot(y3);axis([0 600 -1.1 1.1]);title("经过接收滤波器的信号"); figure(3); subplot(311);stem(y4);axis([0 40 -2.1 2.1]);title("抽样的信号"); subplot(312);stem(y5);axis([0 40 -1.1 1.1]);title("判决后的信号"); subplot(313);stem(y6);axis([0 40 -1.1 1.1]);title("码型反转后的信号"); figure(4); %SNR1的误码率图 plot(SNR1,p); grid on; legend ('信噪比-误码率'); xlabel('dB');