120 lines
3.2 KiB
Matlab
120 lines
3.2 KiB
Matlab
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function [rStr, crcResult] = bpsk_rx_func(rxdata)
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global cyc;
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seq_sync = tx_gen_m_seq([1 0 0 0 0 0 1]);
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local_sync = tx_modulate(seq_sync, 'BPSK');
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rx_signal=rxdata;
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%% matched filtering
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fir = rcosdesign(1,128,4);
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rx_sig_filter = upfirdn(rx_signal,fir,1);
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%% normalization
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c1=max([abs(real(rx_sig_filter.')),abs(imag(rx_sig_filter.'))]);
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rx_sig_norm=rx_sig_filter ./c1;
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%% sampling synchronization
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[time_error,rx_sig_down]=rx_timing_recovery(rx_sig_norm.');
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% rx_sig_down=rx_sig_norm(1:4:end).';
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%% package search
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[rx_frame,cor_abs,th_max,index_s]=rx_package_search(rx_sig_down,local_sync,703);
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%% coarse freq synchronization
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coarse_sync_seq=rx_frame(1:8);
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[deltaf1,out_signal1] = rx_freq_sync(coarse_sync_seq,4,rx_frame);
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%% first fine freq synchronization
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fine_sync_seq_1=out_signal1(1:120);
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[deltaf2,out_signal2] = rx_freq_sync(fine_sync_seq_1,2,out_signal1);
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%% second fine freq synchronization
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fine_sync_seq_2=out_signal2(1:120);
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[deltaf3,out_signal3]=rx_freq_sync(fine_sync_seq_2,2,out_signal2);
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deltaf=deltaf1+deltaf2+deltaf3;
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%% initial phase estimate
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[out_signal4,ang]=rx_phase_sync(out_signal3,local_sync);
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%% phase track
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rx_no_syn_seq=out_signal4(127+1:end);
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[out_signal6,phase_curve]=rx_phase_track(rx_no_syn_seq);
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%% delete pilot
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out_signal7=rx_delete_pilot(out_signal6);
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%% time domain equalize
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out_signal8=rx_time_equalize(out_signal7);
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%% signal demod
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[soft_bits_out,evm] = rx_bpsk_demod(out_signal8);
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Si=[1 1 0 1 1 0 0];
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m=0;
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for i=1:length(soft_bits_out)
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[c,Si]=descramble(soft_bits_out(i),Si);
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m=m+1;
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y(m)=c;
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end
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soft_bits_out=y;
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%% crc32 check
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ret=crc32(soft_bits_out(1:length(soft_bits_out)-32)).';
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crc_bits_32=soft_bits_out(length(soft_bits_out)-31:length(soft_bits_out));
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crc_outputs=sum(xor(ret,crc_bits_32),2);
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if crc_outputs==0
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crc_32='YES';
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crcResult = 1;
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% disp(char(b.'));
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% disp(char(y));
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% disp(char(soft_bits_out(1:end-32)));
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else
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crc_32='NO';
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crcResult = 0;
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end
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cyc=cyc+1;
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msg=soft_bits_out(1:end-32).';
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w = [128 64 32 16 8 4 2 1];
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Nbits = numel(msg);
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Ny = Nbits/8;
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y = zeros(1,Ny);
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for i = 0:Ny-1
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y(i+1) = w*msg(8*i+(1:8));
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end
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a=[y zeros(1,4)];
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b=reshape(a,64,1);
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%b=reshape(a,16,4);
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%% display
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%{
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%figure(2);clf;
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%subplot(231);
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plot(real(rx_signal),'r');
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hold on;
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%plot(imag(rx_signal),'b');
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grid on;
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title('rx original signal');
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%subplot(232);
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pwelch(rx_signal,[],[],[],40e6,'centered','psd');
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%}
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% text(0.15,1.0,['֡ͬ<D6A1><CDAC><EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD>',b.']);
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receivedStr = deblank(char(b.'));
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rStr = receivedStr;
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%{
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%disp(receivedStr);
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%disp(char(b.'));
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% plot(phase_curve);
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axis square;
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subplot(233);
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plot(real(out_signal8),imag(out_signal8),'b*');
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title('constellation');
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axis([-1.5 1.5 -1.5 1.5]);
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axis square;
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subplot(234);
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plot(phase_curve+pi*2);
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title('phae track');
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%subplot(235);
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text(0.15,1.0,['֡ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD>',num2str(index_s,5)]);%,'FontSize',12
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text(0.15,0.8,['Ƶƫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD>',num2str(deltaf/1e3,3),'KHz']);
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text(0.15,0.6,['<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģʽ<EFBFBD><EFBFBD>', 'BPSK']);
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text(0.15,0.4,['<EFBFBD><EFBFBD><EFBFBD>ݳ<EFBFBD><EFBFBD>ȣ<EFBFBD>', '500','bytes']);
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text(0.15,0.2,['evm<EFBFBD><EFBFBD>', num2str(evm.*100,3),'%']);
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text(0.15,0.0,['crc\_32<33><32>', crc_32]);
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axis off;
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% figure(2)
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% plot(cor_abs);
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%}
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end
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