I have calculated BER please check whether it is right or not

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imran khan 2019-11-15

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https://ww2.mathworks.cn/matlabcentral/answers/491335-i-have-calculated-ber-please-check-whether-it-is-right-or-not

编辑： Adam Danz 2019-11-16

I have calculated BER(bit error rate) please check whether it is right or not.I want to confirm that my output is right or not becuase i have no idea about BER(bit error rate).

clc,close all,clear all
codn=100;
EbN0=1:12;
q=1.6e-19; %
% signal-to-noise ratio in dB.
SNR=10.^(EbN0./10); % signal-to-noise ratio
Ib=202e-6; % Background Noise Current+interfernce
N0=2*q*Ib; % Noise Spectral Density, 2*q*Ib
%sgma=1;
%  fc=6e+3;
fs=360;
bode=10;
code=round(rand(1,codn));
code_len=round(1/bode/(1/fs)) % no of samples/symbol
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
    size(x)
    sgma(iii)=sqrt(N0/2/0.1);
    x=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^nextpow2(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)*0.1; % sampling time = 0.1
    MF_out_downsamp=MF_out(code_len:code_len:end);
    MF_out_downsamp=MF_out_downsamp(1:100);
    Rx_th=zeros(1,100);
    Rx_th(find(MF_out_downsamp>1/2))=1;
    [nerr ber(iii)]=biterr(code,Rx_th);
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');
grid on
title('Bit error probability curve for OOK ');
legend('simulation','theory');

% PARAMETERS FOR DATA RATE ARE;
% T=10ms
% 
% F(signal frequency)=1/T=0.1KHZ
% 
% Fs(sampling frequency)=360HZ
% 
% bode=10
% 
% N=4096
% 
% No.of bits in 1ms=10 bits
% 
% No.of bits in 1s=10k bits/sec
% 
% data rate will be=10kb/sec

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imran khan 2019-11-15

Sorry dear fellows.Code which i have pasted was mistakenly wrong.Now,i have pasted my new code for which i have to know myBER(bit error rate).In my output it shows it nothing.When i put some error it shows straight line for which i have doubt it is right or not.

Adam Danz 2019-11-16

编辑：Adam Danz 2019-11-16

Thanks @Daniel.

Imran, I'd like to help out but I don't know where to start. If you have a matlab related question, please let us know where we can help. If there's a section of your code that you're doubting, please point to that section so we don't have to guess.

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