60 lines
1.5 KiB
Matlab
60 lines
1.5 KiB
Matlab
L = 4; % Oversampling factor
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fsym = 1e9/4;
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rollOff = 0.5; % Pulse shaping roll-off factor
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htx = rcosdesign(rollOff,16, L, 'sqrt');
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hrx = conj(fliplr(htx));
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signal = zeros(1000,1);
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signal(500) = 1;
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Digi_sig = Informationsignal(signal,"fs",fsym);
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% Digi_sig = Digi_sig.resample("fs_out",L*fsym);
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%
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% Digi_sig_tx = Digi_sig.filter(htx,1);
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% Digi_sig_rx = Digi_sig_tx.filter(hrx,1);
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%
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% figure;plot(Digi_sig_tx.signal);hold on;plot(Digi_sig_rx.signal),plot(Digi_sig.signal);
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%
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%
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%
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%
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pulsef = Pulseformer("alpha",1,"matched",0,"fdac",Digi_sig.fs*L,"fsym",fsym,"pulse","rrc","pulselength",16);
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Digi_sig = pulsef.process(Digi_sig);
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pulsef = Pulseformer("alpha",1,"matched",1,"fdac",Digi_sig.fs,"fsym",fsym,"pulse","rrc","pulselength",16);
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Digi_sig_matched = pulsef.process(Digi_sig);
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% Filter:
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htx = rcosdesign(rollOff,16, L, 'sqrt');
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% Note half of the target delay is used, because when combined
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% to the matched filter, the total delay will be achieved.
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hrx = conj(fliplr(htx));
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figure
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plot(htx)
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title('Transmit Filter')
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xlabel('Index')
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ylabel('Amplitude')
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figure
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plot(hrx)
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title('Rx Filter (Matched Filter)')
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xlabel('Index')
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ylabel('Amplitude')
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p = conv(htx,hrx);
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figure
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plot(p)
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title('Combined Tx-Rx = Raised Cosine')
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xlabel('Index')
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ylabel('Amplitude')
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% And let's highlight the zero-crossings
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zeroCrossings = NaN*ones(size(p));
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zeroCrossings(1:L:end) = 0;
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zeroCrossings((rcDelay)*L + 1) = NaN; % Except for the central index
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hold on
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plot(zeroCrossings, 'o')
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legend('RC Pulse', 'Zero Crossings')
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hold off |