非常基础的双极性NRZ码元序列通过升余弦滚降系统冲激响应

Posted 2021-07-07 fpga&matlab

close all;

alpha=0.2;

Ts=1e-2;

Fs=1e3;

Rs=50;

M=2;

Num=100;

Samp_rate=Fs/Rs;

Eye_num=2;

NRZ=2*randint(1,Num,M)-M+1;

figure(1);

stem(NRZ);

title('双极性NRZ码元序列');

k=1;

for ii=1:Num

    for jj=1:Samp_rate

        Samp_data(k)=NRZ(ii);

        k=k+1;

    end

end

[ht,a]=rcosine(1/Ts,Fs,'fir',alpha);

figure(2);

subplot(2,1,1);

plot(ht);

ylabel('冲激响应');

title('升余弦滚降系统冲激响应');

st=conv(Samp_data,ht)/(Fs*Ts);

subplot(2,1,2);

plot(st);

ylabel('信号幅度');

title('经过升弦滚降系统后的码元');

eyediagram(st,40)

ylabel('信号幅度');

title('基带信号眼图');

D91