Facing problem in ploting figures

i want to plot last two figures in one plot can anybody help me

clc,close all,clear all
codn=100;
EbN0=20:30;
q=1.6e-19; %
% signal-to-noise ratio in dB.
 
Ib=202e-6; % Background Noise Current+interfernce
N0=2*q*Ib; % Noise Spectral Density, 2*q*Ib
fs=360;
bode=10;
code=round(rand(1,codn))
code_len=round(1/bode/(1/fs)) % no of samples/symbol
SNR=10.^(EbN0./code_len);
sgma=zeros(1,length(SNR));
ber=zeros(1,length(SNR));
for iii=1:length(SNR)
 for ii=1:codn  
     x((ii-1)*code_len+1:code_len*ii)=code(ii);
 end
 cl=SNR(iii)
 size(x)
 sgma(iii)=sqrt(N0/2/0.1);
%  y=x+sgma(iii)*randn(1,length(x)); % if want to add noise
 x2 = x-(1/2);    % get rid of most of the dc peak
pt=ones(1,code_len);
rt=pt;
% set up time and frequency arrays
length(x)
 u = length(x2);
 N = 2^ceil(log2(abs(u)));
 
delt = 1/fs;
delf1=fs/u;
figure(1)
tvec2=(1:length(x2))*delt;
plot(tvec2,((x2(1,:)+0.5)))
title('orignal baseband')
 xlabel('time');
 ylabel('amplitude')
ylim([-1 1.5]);
 y = fftshift(fft(x2)/N);  
z=abs(y);
figure(2)
fvec2=(-length(x2)/2:length(x2)/2-1)*delf1;
plot(fvec2,z)
title('FFT')
xlabel('frequency')
 ylabel('amplitude')
 figure(3)
 z=y;
 z(abs(fvec2)>50 & abs(fvec2)<=150)=0;
 plot(fvec2,abs(z))
 xlabel('frequency removed from 50 to 150 HZ');
ylabel('amplitude')
figure(4)
zf=fftshift(z)*N;
zifft=ifft(zf)+0.5;
MF_out=conv(zifft,rt)*0.5; % sampling time = 0.1
MF_out_downsamp=MF_out(code_len:code_len:end);
MF_out_downsamp=MF_out_downsamp(1:10);
Rx_th=zeros(1,codn);
%Rx_th(find(MF_out_downsamp>1/2))=1;
%Rx_th(find(MF_out_downsamp>mean(abs(MF_out_downsamp))))
for k=1:length(MF_out_downsamp)
                    if MF_out_downsamp(k)>mean(abs(MF_out_downsamp))
    Rx_th(k)=1;
                end
                    if code(k)>mean(abs(code))
                        code(k)=1;
 
end
end
nra=code==Rx_th
nerr=length(nra)-sum(nra)
ber(iii)=1/10^(nerr/length(nra)*cl)
end
plot(tvec2,(abs(zifft)))
ylim([-1 1.5])
title('recovered signal')
xlabel('time');
 ylabel('amplitude')
 figure;
 semilogy(EbN0,ber,'b');
 xlabel('Eb/N0,(dB)');
ylabel('Bit Error Rate (BER)');
 grid on
 title('Bit error probability curve for OOK ');

legend('simulation','theory'); 


 
codn=1000;
EbN01=20:30;
q=1.6e-19; %
% signal-to-noise ratio in dB.
 
Ib=202e-6; % Background Noise Current+interfernce
N0=2*q*Ib; % Noise Spectral Density, 2*q*Ib
fs=3600;
bode=100;
code=round(rand(1,codn))
code_len=round(1/bode/(1/fs)) % no of samples/symbol
SNR=10.^(EbN0./code_len);
sgma=zeros(1,length(SNR));
ber=zeros(1,length(SNR));
for iii=1:length(SNR)
 for ii=1:codn  
     x((ii-1)*code_len+1:code_len*ii)=code(ii);
 end
 cl=SNR(iii)
 size(x)
 sgma(iii)=sqrt(N0/2/0.1);
%  y=x+sgma(iii)*randn(1,length(x)); % if want to add noise
 x2 = x-(1/2);    % get rid of most of the dc peak
pt=ones(1,code_len);
rt=pt;
% set up time and frequency arrays
length(x)
 u = length(x2);
 N = 2^ceil(log2(abs(u)));
 
delt = 1/fs;
delf1=fs/u;
figure(1)
tvec2=(1:length(x2))*delt;
plot(tvec2,((x2(1,:)+0.5)))
title('orignal baseband')
 xlabel('time');
 ylabel('amplitude')
ylim([-1 1.5]);
 y = fftshift(fft(x2)/N);  
z=abs(y);
figure(2)
fvec2=(-length(x2)/2:length(x2)/2-1)*delf1;
plot(fvec2,z)
title('FFT')
xlabel('frequency')
 ylabel('amplitude')
 figure(3)
 z=y;
 z(abs(fvec2)>50 & abs(fvec2)<=150)=0;
 plot(fvec2,abs(z))
 xlabel('frequency removed from 50 to 150 HZ');
ylabel('amplitude')
figure(4)
zf=fftshift(z)*N;
zifft=ifft(zf)+0.5;
MF_out=conv(zifft,rt)*0.5; % sampling time = 0.1
MF_out_downsamp=MF_out(code_len:code_len:end);
MF_out_downsamp=MF_out_downsamp(1:10);
Rx_th=zeros(1,codn);
%Rx_th(find(MF_out_downsamp>1/2))=1;
%Rx_th(find(MF_out_downsamp>mean(abs(MF_out_downsamp))))
for k=1:length(MF_out_downsamp)
                    if MF_out_downsamp(k)>mean(abs(MF_out_downsamp))
    Rx_th(k)=1;
                end
                    if code(k)>mean(abs(code))
                        code(k)=1;
 
end
end
nra=code==Rx_th
nerr=length(nra)-sum(nra)
ber1(iii)=1/10^(nerr/length(nra)*cl)
end
plot(tvec2,(abs(zifft)))
ylim([-1 1.5])
title('recovered signal')
xlabel('time');
 ylabel('amplitude')
 figure;
 semilogy(EbN0,ber,'b');
 hold on
  semilogy(EbN0,ber1,'r');
 xlabel('Eb/N0,(dB)');
ylabel('Bit Error Rate (BER)');
 grid on
 title('Bit error probability curve for OOK ');
legend('simulation','theory');  

Answer 1

[Himanshu]

Hey Imran,

By default, new plots clear existing plots and reset axes properties, such as the title. However, you can use the hold on command to combine multiple plots in the same axes. You can find an example of the same in the following docuentaion link:

https://in.mathworks.com/help/matlab/creating_plots/combine-multiple-plots.html#:~:text=the%20tiledlayout%20function.-,Combine%20Plots%20in%20Same%20Axes,-By%20default%2C%20new

Hope this is helpful!

Answer 2

[埃博拉酱]

As @Himanshu said, use hold to preserve old plots is a possible solution. But I prefer to use line instead of plot - it won't reset the previous plot, and will be able to do the same thing as plot, with a slight difference in syntax.