Dear Rayan,

To work properly you have construct the Nonreturnzero block to biplolar nonreturn zero block. To trouble shoot the model please display the signal waveform after the nonreturn zero block and after the BPSK block.After the integration on one bit time T you have to compare the result with zero level.

Best wishes

Dear,

A lot of errors in your program, you need to correct it frist.

dear,

try this program:

%"Author: Krishna"

clear N = 10^6 % number of bits or symbols rand('state',100); % initializing the rand() function randn('state',200); % initializing the randn() function % Transmitter ip = rand(1,N)>0.5; % generating 0,1 with equal probability s = 2*ip-1; % BPSK modulation 0 -> -1; 1 -> 1 n = 1/sqrt(2)*[randn(1,N) + j*randn(1,N)]; % white gaussian noise, 0dB variance Eb_N0_dB = [-3:10]; % multiple Eb/N0 values for ii = 1:length(Eb_N0_dB) % Noise addition y = s + 10^(-Eb_N0_dB(ii)/20)*n; % additive white gaussian noise % receiver - hard decision decoding ipHat = real(y)>0; % counting the errors nErr(ii) = size(find([ip- ipHat]),2); end simBer = nErr/N; % simulated ber theoryBer = 0.5*erfc(sqrt(10.^(Eb_N0_dB/10))); % theoretical ber % plot close all figure semilogy(Eb_N0_dB,theoryBer,'b.-'); hold on semilogy(Eb_N0_dB,simBer,'mx-'); axis([-3 10 10^-5 0.5]) grid on legend('theory', 'simulation'); xlabel('Eb/No, dB'); ylabel('Bit Error Rate'); title('Bit error probability curve for BPSK modulation');

Dear Khalid Al-Hussaini,

Thanks for the time and patience you answered my question. I tried writing the program to show BER curve. The programming flow was same to yours, so is result. Sorry, my title is not suitable enough. Displaying the signal waveform is my main purpose at this time rather than BER.

After this code finishing, I should check it. It seems to be right from the waveform (the phase of two carriers shifted by 180º ) so I further check BER. I think even if the program was designed from different viewpoints, the BER should be logical. I cannot check my program with this way?

Dear Abdelhalim Zekry,

Pretty thanks for your reply. Like your word, I displayed the signal waveform after the integration. I also showed received signal waveform. Are these images all correct? Because of verifying my program I further calculated the BER in this code, which makes me get a confused result.