2 Relay.zip_Decode and forward_amplify and decode _because3rk_re

clc clear all; nr_of_bits = 2^10; %Generating a QPSK signal % Number of symbols to transfer nr_of_symbols = nr_of_bits/2; bit_sequence = floor(rand(1,nr_of_bits)*2)*2-1; s = bit_sequence(1:nr_of_symbols) + j*bit_sequence(nr_of_symbols + 1:nr_of_bits); %s=symbol sequence b1=sign(real(s)); b2=sign(imag(s)); SNR_dB=[0:2:20]; maxerrors=2*logspace(5,3,length(SNR_dB)); SNR=10.^(SNR_dB./10); N0=1./SNR; frame=512; relay_mode='AAF'; combining_type='MRC'; errors=zeros(length(SNR_dB),1); index=zeros(length(SNR_dB),1); for snr_ind=1:length(SNR_dB) sprintf('current SNR is %d', SNR_dB(snr_ind)) while errors(snr_ind) < maxerrors(snr_ind) index(snr_ind)=index(snr_ind)+1; %defining the Channel gains ch_h1=1/sqrt(2)*(randn(1)+j*randn(1)); ch_h2=1/sqrt(2)*(randn(1)+j*randn(1)); ch_h3=1/sqrt(2)*(randn(1)+j*randn(1)); ch_h4=1/sqrt(2)*(randn(1)+j*randn(1)); ch_h5=1/sqrt(2)*(randn(1)+j*randn(1)); %direct link r=ch_h1.*s+sqrt(N0(snr_ind)/2)*(randn(1,frame)+j*randn(1,frame) ); direct_rx=r; %sender to relay1 s2rl1_rx = channel(s,SNR_dB(snr_ind),ch_h2); relay_out1 = relaysend(s,s2rl1_rx,SNR(snr_ind),ch_h2,relay_mode); %relay1 to destn r2d1_rx = channel(s,SNR_dB(snr_ind),ch_h3); %sender to relay2 s2rl2_rx = channel(s,SNR_dB(snr_ind),ch_h4); relay_out2 = relaysend(s,s2rl2_rx,SNR(snr_ind),ch_h4,relay_mode); %relay2 to destn r2d2_rx = channel(s,SNR_dB(snr_ind),ch_h5); %receiver combining final_rx=receiver_combining(direct_rx,r2d1_rx,r2d2_rx,ch_h1,ch_h2,ch_h3,ch_h4,ch_h5,combining_type,relay_mode); b1_hat=sign(real(final_rx)); b2_hat=sign(imag(final_rx)); errors(snr_ind)=errors(snr_ind)+sum(b1 ~= b1_hat) + sum(b2 ~= b2_hat); end end BER=errors./frame./index./2; % two bits per symbol th=(1-BER).^frame; BER_an = 1/2*(1- sqrt( SNR./(1+SNR) ) ); %analytical BER hold on xlabel('SNR(dB)'); ylabel('BER'); %legend('AAF MRC','ANALYTICAL'); %semilogy(SNR_dB,BER,SNR_dB,BER_an); %semilogy(SNR_dB,BER_an);