function [nr_of_errors_in_rate, nr_of_errors_in_rate1, nr_of_errors_in_rate2, theta1, theta2, alpha1, alpha2, sample_nr, indata_est,training1_est,training2_est,i_symbols, q_symbols]=receive_for_channel3(received_vector1,received_vector2,training_sequence1,training_sequence2,data_block,fs,T,fc,pulsetype)%   [output1, output2]=functionname(input1, input2)%%	Variable:	Explanation:%	nr_of_errors_in_rate    -   Percent of bits with error%   theta1                  -   the angle estimated by used channel-estimator%   %	received_vector     -   received vector from channel (1x1 experiment)%   training_sequence1  -   used training sequence%   data_block          -   true data-block sent over channel%   fs                  -   used sample-frequency%   T                   -   symbol-time   %   fc                  -   carrier-frequency%   pulsetype           -   used pulsetype, 2 for root-raised-cosine%%   Short Theoretical Background for the Function:%%   Receiving in two antennas!%   Assuming received_vector is normalized and correct size. Two transmitters used!%   Used when doing experiment over real acoustic channel the 27th.%   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     %%% Function part of simulation for Space-Time%%% coding project, group Grey-2001.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   Author: Stefan Uppg錼d%   Date: 27/3-2001%   Version: 1.0%   Revision (Name & Date & Comment):%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%        model = 1;    training_length1 = length(training_sequence1);    training_length2 = length(training_sequence2);    %%% Alamouti coding performed on training-sequence???    [training_sequence1, s_antenna2]=alamouti(training_sequence1,1);    [s_antenna1, training_sequence2]=alamouti(training_sequence2,1);        
    receive1 = received_vector1;    receive2 = received_vector2;        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    %%% Receiving in receive-antenna 1.    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%            %%%    %%% Make the signal unbiased, removing the signals mean.    %%%        [receive1]=remove_mean(receive1);        %%%    %%% Down-conversion and lowpassfiltering.    %%%        [quad, inphase]=down_converter(receive1,fc,fs,T,(fc/(fs/2)),20);  % Function call for low_pass() /T Grey        figure(2), subplot(2,2,1), plot(1:length(quad),quad);    title('Quad after down-conv.');    subplot(2,2,2), plot(1:length(inphase),inphase);    title('Inphase after down-conv.');             %%%%%%%%    %%%%%%%% Do the frequency-offset compensation if initial-state.    %%%%%%%%        run_offset = 1;    if (run_offset == 0)        [freq_diff, delta_theta, alfa]=freq_offset(inphase, quad, fs, fc)    end        %freq_diff = 0.0237;    %delta_theta = 2*pi*(((1/(1-freq_diff/fc))-1)*fc*(1/(fs*(1-(freq_diff/fc)))));    %delta_theta = 9.3490*10^-6;       % estimated angle-shift/sampel for sinus sampled at 16 kHz.    delta_theta = -2.00000*10^-5;       % estimated angle-shift/sampel for sinus sampled at 8 kHz 2500 carrier freq.        a = 0:(length(inphase)-1);    rotation_vector = exp(-j*a*delta_theta);                               % Rotation compensating vector.         compensated_received = complex(inphase,quad) .* rotation_vector;    inphase = real(compensated_received);    quad    = imag(compensated_received);                %%%    %%% Matchedfiltering and lowpassfiltering.    %%%        [mf_quad_block]=matched_filter(fs, T, pulsetype, quad);    % Quadrature-part    [mf_inphase_block]=matched_filter(fs, T, pulsetype, inphase);    % Inphase-part        subplot(2,2,3), plot(1:length(mf_quad_block),mf_quad_block);    title('Quad after MF');    subplot(2,2,4), plot(1:length(mf_inphase_block),mf_inphase_block);    title('Inphase after MF');            %%%    %%% Performing synchronization    %%%        %[corr_maxi,sample_nri]=synchronization_long(mf_inphase_block, fs, T, training_sequence1, model)  %%% CALLING THE SYNC_LONG FUNCTION!    %[corr_maxq,sample_nrq]=synchronization_longb(mf_quad_block, fs, T, training_sequence1, model)        [corr_maxi,sample_nri,sum_of_r_times_c1i,sum_of_r_times_d2i]=synchronization2(mf_inphase_block, fs, T, training_sequence1, training_sequence2, model);    [corr_maxq,sample_nrq,sum_of_r_times_c1q,sum_of_r_times_d2q]=synchronization2(mf_quad_block, fs, T, training_sequence1, training_sequence2, model);    max_i1 = max(sum_of_r_times_c1i)    max_i2 = max(sum_of_r_times_d2i)    max_q1 = max(sum_of_r_times_c1q)    max_q2 = max(sum_of_r_times_d2q)    corr_maxi    sample_nri    corr_maxq    sample_nrq            if corr_maxq > corr_maxi       % choose the correlation with the biggest max value        sample_nr = sample_nrq;    else        sample_nr = sample_nri;    end            %%%    %%% Down-Sampling    %%%        block_length=length(data_block) + length(training_sequence1) + length(training_sequence2);    [inphase_symbols]=down_sampler(mf_inphase_block,sample_nr,fs,T,block_length);    [quad_symbols]=down_sampler(mf_quad_block,sample_nr,fs,T,block_length);        figure(3), subplot(1,2,2), plot(mf_inphase_block), hold on    for(i=0:block_length-1)        plot(i*(fs*T)+sample_nr,inphase_symbols(i+1),'o');    end    hold off    title('received data and samplepoints. (not yet combined!)');    subplot(1,2,1), stem([training_sequence1 data_block]), title('Sent data.');        figure(4), subplot(1,2,1), plot(inphase_symbols,quad_symbols,'x'), axis([-2 2 -2 2]), title('Signals after MF and sampled')        %%    %% Calculating influence of freq_offset. IS INSTEAD DONE AFTER DOWNCONVERTER.    %%        %[quad_symbols, inphase_symbols, theta]=freq_offset_compensate(quad_symbols,inphase_symbols);    %theta    %figure(7), plot(inphase_symbols,quad_symbols,'x'), axis([-6 6 -6 6]), title('Signals after freq-offset compensation.'), grid on
	    %%%    %%% Estimating Channel 1 and 2.    %%%
           %[alpha1,theta1]=chan_estim7(quad_symbols(1:training_length1),inphase_symbols(1:training_length1),bpsk(training_sequence1,1),1,0.95);        [alpha1,theta1] = channel_estimatorb(quad_symbols(1:training_length1), ...       inphase_symbols(1:training_length1), training_sequence1, model, 1)        if model == 1
       %[alpha2,theta2]=chan_estim5(quad_symbols(training_length1+1:training_length1+ ...       %training_length2),inphase_symbols(training_length1+1:training_length1+ ...       %training_length2), bpsk(training_sequence2,model))       %[alpha2,theta2]=chan_estim7(quad_symbols(training_length1+1:training_length1+training_length2),...       %    inphase_symbols(training_length1+1:training_length1+training_length2),bpsk(training_sequence1,1),1,0.95);               [alpha2,theta2] = channel_estimatorb(quad_symbols(training_length1+1:training_length1+ ...
       training_length2), inphase_symbols(training_length1+1:training_length1+ ...
       training_length2), training_sequence2, model, 2)    elseif model == 0        alpha2 = 1;        theta2 = 0;    end        q_symbols = quad_symbols;    i_symbols = inphase_symbols;        % set true values instead:    %alpha1 = 1;    %theta1 = 0;    %alpha2 = 1;    %theta2 = 0;    
     %%%
     %%% No combiner used since only 1 antenna is used to send from so far.
     %%%
     
     [combined_signal]=combiner(alpha1(end), theta1(end), alpha2(end), theta2(end), ...
        inphase_symbols, quad_symbols, model);
    figure(4), subplot(1,2,2), plot(combined_signal,'x'), axis([-6 6 -6 6]), title('Signals after combiner, just before detector.')    grid on    
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    %%% Receiving in receive-antenna 2.    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%            %%%    %%% Make the signal unbiased, removing the signals mean.    %%%        [receive2]=remove_mean(receive2);        %%%    %%% Down-conversion and lowpassfiltering.    %%%        [quad2, inphase2]=down_converter(receive2,fc,fs,T,(fc/(fs/2)),20);        figure(2), subplot(2,2,1), plot(1:length(quad2),quad2);    title('Quad2 after down-conv.');    subplot(2,2,2), plot(1:length(inphase2),inphase2);    title('Inphase2 after down-conv.');             %%%%%%%%    %%%%%%%% Do the frequency-offset compensation if initial-state.    %%%%%%%%        run_offset = 1;    if (run_offset == 0)        [freq_diff2, delta_theta2, alfa2]=freq_offset(inphase2, quad2, fs, fc)    end        %freq_diff2 = 0.0237;    %delta_theta2 = 2*pi*(((1/(1-freq_diff/fc))-1)*fc*(1/(fs*(1-(freq_diff/fc)))));    %delta_theta2 = 9.3490*10^-6;       % estimated angle-shift/sampel for sinus sampled at 16 kHz.    delta_theta2 = -2.00000*10^-5;       % estimated angle-shift/sampel for sinus sampled at 8 kHz 2500 carrier freq.        a = 0:(length(inphase2)-1);    rotation_vector2 = exp(-j*a*delta_theta2);                               % Rotation compensating vector.         compensated_received2 = complex(inphase2,quad2) .* rotation_vector2;    inphase = real(compensated_received2);    quad    = imag(compensated_received2);        %%%    %%% Matchedfiltering and lowpassfiltering.    %%%        [mf_quad_block2]=matched_filter(fs, T, pulsetype, quad2);    % Quadrature-part    [mf_inphase_block2]=matched_filter(fs, T, pulsetype, inphase2);    % Inphase-part        subplot(2,2,3), plot(1:length(mf_quad_block2),mf_quad_block2);    title('Quad after MF');    subplot(2,2,4), plot(1:length(mf_inphase_block2),mf_inphase_block2);    title('Inphase after MF');            %%%    %%% Performing synchronization    %%%                [corr_maxi2,sample_nri2,sum_of_r_times_c1i2,sum_of_r_times_d2i2]=synchronization2(mf_inphase_block2, fs, T, training_sequence1, training_sequence2, model);    [corr_maxq2,sample_nrq2,sum_of_r_times_c1q2,sum_of_r_times_d2q2]=synchronization2(mf_quad_block2, fs, T, training_sequence1, training_sequence2, model);    max_i12 = max(sum_of_r_times_c1i2)    max_i22 = max(sum_of_r_times_d2i2)    max_q12 = max(sum_of_r_times_c1q2)    max_q22 = max(sum_of_r_times_d2q2)    corr_maxi2    sample_nri2    corr_maxq2    sample_nrq2            if corr_maxq2 > corr_maxi2       % choose the correlation with the biggest max value        sample_nr2 = sample_nrq2;    else        sample_nr2 = sample_nri2;    end            %%%    %%% Down-Sampling    %%%        block_length=length(data_block) + length(training_sequence1) + length(training_sequence2);    [inphase_symbols2]=down_sampler(mf_inphase_block2,sample_nr2,fs,T,block_length);    [quad_symbols2]=down_sampler(mf_quad_block2,sample_nr2,fs,T,block_length);        figure(3), subplot(1,2,2), plot(mf_inphase_block2), hold on    for(i=0:block_length-1)        plot(i*(fs*T)+sample_nr,inphase_symbols2(i+1),'o');    end    hold off    title('received data and samplepoints. (not yet combined!)');    subplot(1,2,1), stem([training_sequence1 data_block]), title('Sent data.');        figure(4), subplot(1,2,1), plot(inphase_symbols2,quad_symbols2,'x'), axis([-2 2 -2 2]), title('Signals after MF and sampled')        %%    %% Calculating influence of freq_offset. IS INSTEAD DONE AFTER DOWNCONVERTER.    %%        %[quad_symbols2, inphase_symbols2, theta2]=freq_offset_compensate(quad_symbols2,inphase_symbols2);    %theta2    %figure(7), plot(inphase_symbols2,quad_symbols2,'x'), axis([-6 6 -6 6]), title('Signals after freq-offset compensation.'), grid on
	    %%%    %%% Estimating Channel 3 and 4.    %%%
               %[alpha3,theta3]=chan_estim7(quad_symbols2(1:training_length1),inphase_symbols2(1:training_length1),bpsk(training_sequence1,1),1,0.95);        [alpha3,theta3] = channel_estimatorb(quad_symbols2(1:training_length1), ...       inphase_symbols2(1:training_length1), training_sequence1, model, 1)        if model == 1
       %[alpha4,theta4]=chan_estim5(quad_symbols2(training_length1+1:training_length1+ ...       %training_length2),inphase_symbols2(training_length1+1:training_length1+ ...       %training_length2), bpsk(training_sequence2,model))       %[alpha4,theta4]=chan_estim7(quad_symbols2(training_length1+1:training_length1+training_length2),...       %    inphase_symbols2(training_length1+1:training_length1+training_length2),bpsk(training_sequence1,1),1,0.95);               [alpha4,theta4] = channel_estimatorb(quad_symbols2(training_length1+1:training_length1+ ...
       training_length2), inphase_symbols2(training_length1+1:training_length1+ ...
       training_length2), training_sequence2, model, 2)    elseif model == 0        alpha4 = 1;        theta4 = 0;    end        q_symbols2 = quad_symbols2;    i_symbols2 = inphase_symbols2;        % set true values instead:    %alpha3 = 1;    %theta3 = 0;    %alpha4 = 1;    %theta4 = 0;    
     %%%
     %%% No combiner used since only 1 antenna is used to send from so far.
     %%%
     
     [combined_signal2]=combiner(alpha3(end), theta3(end), alpha4(end), theta4(end), ...
        inphase_symbols2, quad_symbols2, model);
    figure(4), subplot(1,2,2), plot(combined_signal,'x'), axis([-6 6 -6 6]), title('Signals after combiner, just before detector.')    grid on        inphase_symbols1 = real(combined_signal);    inphase_symbols2 = real(combined_signal2);    inphase_symbols = inphase_symbols1 + inphase_symbols2;        figure(5), subplot(1,3,1), plot(inphase_symbols1(training_length1+training_length2:end),'x'), subplot(1,3,2), plot(inphase_symbols2(training_length1+training_length2:end),'x'), subplot(1,3,3), plot(inphase_symbols(training_length1+training_length2:end),'x')        %%%
    %%% Detector
    %%%
    [indata_est1,training1_est,training2_est]=detector(inphase_symbols1,training_length1,training_length2,model);    [indata_est2,training1_est,training2_est]=detector(inphase_symbols2,training_length1,training_length2,model);
            [indata_est,training1_est,training2_est]=detector(inphase_symbols,training_length1,training_length2,model);    disp('Received data is:')
    indata_est;
    disp('Sent data is:')    data_block;    nr_of_errors1 = sum(abs(data_block-indata_est1))    nr_of_errors_in_rate1 = nr_of_errors1/length(data_block)    nr_of_errors2 = sum(abs(data_block-indata_est2))    nr_of_errors_in_rate2 = nr_of_errors2/length(data_block)            nr_of_errors = sum(abs(data_block-indata_est))    nr_of_errors_in_rate = nr_of_errors/length(data_block)