Add new functions

Functions/EQ_visuals/analyzeEQperformance.m

@@ -0,0 +1,150 @@
+function analyzeEQperformance(ref_bits,ref_symbols,rx_signal,eq_signal,eq_decisions,fsym,M,options)
+arguments
+    ref_bits 
+    ref_symbols 
+    rx_signal 
+    eq_signal 
+    eq_decisions 
+    fsym 
+    M 
+    options.postfilterclass
+    options.eqclass
+    options.mlseclass
+    options.db_precoded
+    options.displayname
+end
+
+% toolkit to visualize stuff related to DSP of IM/DD
+%%% Preps
+if isempty(eq_decisions)
+    eq_decisions = PAMmapper(M,0).quantize(eq_signal);
+end
+
+%%% Demap eqlzd signal to determine BER
+if options.db_precoded
+    eq_hd = PAMmapper(M,0).quantize(eq_signal);
+    eq_hd = Duobinary().encode(eq_hd);
+    eq_hd = Duobinary().decode(eq_hd,"M",M);
+    rx_bits = PAMmapper(M,0).demap(eq_hd);
+else
+    rx_bits = PAMmapper(M,0).demap(eq_signal);
+end
+
+[~,numerr,ber_sd,errpos] = calc_ber(rx_bits.signal,ref_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
+% fprintf('SD BER: %.2e \n',ber_sd);
+
+%%% Demap provided decisions to determine BER
+rx_bits = PAMmapper(M,0).demap(eq_decisions);
+[~,numerr,ber_mlse,errpos] = calc_ber(rx_bits.signal,ref_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
+% fprintf('MLSE BER: %.2e \n',ber_mlse);
+
+
+
+%%% Noise prior to DSP (is thius accurate with resampling?)
+rx_resampled = rx_signal.normalize("mode","rms").resample("fs_out",fsym);
+rx_noise = rx_resampled-ref_symbols;
+
+%%% Noise after to soft-decision DSP 
+eq_noise = eq_signal-ref_symbols;
+
+
+col = cbrewer2('paired',12);
+lines = numel(findall(figure(200), 'Type', 'Line'))+1;
+darkcoloridx = max(mod(2*lines,12),2);
+lightcoloridx = max(mod(2*lines-1,12),1);
+
+%%% Separate Classes
+constellation = unique(ref_symbols.signal);
+received_sd = NaN(numel(constellation),length(ref_symbols));
+received_hd = NaN(numel(constellation),length(ref_symbols));
+lvlcol = cbrewer2('Set1',numel(constellation));
+for lvl = 1:numel(constellation)
+    %Separate the equalized signal into the
+    %respective levels based on the actually
+    %transmitted level!
+    received_sd(lvl,ref_symbols.signal==constellation(lvl)) = eq_signal.signal(ref_symbols.signal==constellation(lvl));
+    received_hd(lvl,ref_symbols.signal==constellation(lvl)) = eq_decisions.signal(ref_symbols.signal==constellation(lvl));
+end
+
+%%% bursts
+% Find differences between consecutive elements
+diff_indices = diff(errpos);
+
+% Identify the start of new sequences (when the difference is not 1)
+sequence_starts = [1, find(diff_indices ~= 1) + 1]; % Include the first index
+sequence_ends = [sequence_starts(2:end) - 1, length(errpos)]; % Calculate end indices
+
+% Initialize burst count and print bursts longer than 10
+burst_len = 1:10;
+burst_count = zeros(length(burst_len),1);
+for t = 1:numel(burst_len)
+    for i = 1:length(sequence_starts)
+        % Extract current sequence
+        current_burst = errpos(sequence_starts(i):sequence_ends(i));
+        % Check if the sequence length matches criterion
+        if length(current_burst) == burst_len(t)
+            burst_count(t) = burst_count(t) + 1;
+        end
+    end
+end
+
+burst_symbols = burst_count .* burst_len';
+burst_rate =  burst_symbols ;%./ length(rx_signal);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%% Rx Spectrum %200
+rx_signal.spectrum("displayname",sprintf('Rx %d GBd PAM%d',fsym.*1e-9,M),'fignum',200,'normalizeTo0dB',1,'color',col(darkcoloridx,:));
+xline([-fsym/2,fsym/2].*1e-9,'Color',col(mod(lines,12)+2,:),'HandleVisibility','off');
+ylim([-20,3]);
+%%% EQ Spectrum
+% 
+
+%%% EQ Time Series %210
+showEQTimeSignal(eq_signal,ref_symbols)
+
+
+%%% EQ Noise Spectrum + inverted Postfilter %220 
+showEQNoisePSD(eq_noise,options.postfilterclass.burg_coeff,"fignum",220,"color",col(darkcoloridx,:));
+
+%%% EQ SNR Spectrum %230
+fft_length = 2^13;
+[s_lin,w] = pwelch(eq_signal.signal,hanning(fft_length),fft_length/2,fft_length,eq_signal.fs,"centered","psd","mean");
+[n_lin,w] = pwelch(eq_noise.signal,hanning(fft_length),fft_length/2,fft_length,eq_noise.fs,"centered","psd","mean");
+w = w.*1e-9;
+snr_dbm = 10*log10(s_lin./n_lin);
+
+figure(230)
+hold on
+plot(w,snr_dbm,'DisplayName','SNR after EQ','LineWidth',1,'Color',col(darkcoloridx,:));
+xlabel("Frequency in GHz");
+edgetick = 2^(nextpow2(eq_signal.fs*1e-9));
+xticks(-edgetick:16:edgetick);
+xlim([-128 128]);
+ylim([-20,35]);
+grid minor
+yticks(-200:10:100);
+grid on; grid minor;
+legend('Interpreter','none');
+title('Noise of soft decision signal (not MLSE)');
+
+%%% FFE histogram %240
+showLevelHistogram(eq_signal,ref_symbols)
+
+%%% Confusion Matrix
+showLevelConfusionMatrix(eq_decisions,ref_symbols,"fignum",250)
+
+
+%%% Burst Count
+figure(260)
+hold on
+plot(burst_len,burst_rate,'Marker','x','Color',col(darkcoloridx,:),"displayname",sprintf('Rx %d GBd PAM%d; %s',fsym.*1e-9,M,options.displayname));
+xlabel('length of error burst');
+ylabel('occurences')
+grid on
+set(gca, 'YScale', 'log');
+
+
+autoArrangeFigures
+
+end

Functions/EQ_visuals/showEQNoisePSD.m

@@ -0,0 +1,44 @@
+function showEQNoisePSD(eq_noise, options)
+arguments
+    eq_noise 
+    options.postfilter_taps = NaN
+    options.fignum (1,1) double = NaN % Default to NaN if not provided
+    options.displayname (1,:) char = '' % Default to an empty string if not provided
+    options.color = [0.2157    0.4941    0.7216];
+end
+
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+    hold on
+    ax = gca;
+    % N = numel(ax.Children);
+    N = sum(arrayfun(@(x) strcmp(x.LineStyle, '-'), ax.Children));
+    cmap = linspecer(8);
+    options.color = cmap(mod(N, size(cmap, 1)) + 1, :);
+
+    % Ensure the figure is ready before calling spectrum
+    eq_noise.spectrum("displayname", options.displayname, "fignum", fig.Number, "normalizeTo0dB", 1,"color",options.color);
+    title('Noise of soft decision signal (not MLSE)')
+
+    if ~isnan(options.postfilter_taps)
+        % Hold on to the figure for further plotting
+        hold on;
+    
+        % Compute the frequency response of the postfilter
+        [h, w] = freqz(1, options.postfilter_taps, length(eq_noise), "whole", eq_noise.fs);
+        h = h / max(abs(h)); % Normalize the filter response
+    
+        % Adjust frequency axis to center at 0
+        w_ = (w - eq_noise.fs / 2);
+    
+        % Plot the inverted postfilter response
+        plot(w_ * 1e-9, 20 * log10(fftshift(abs(h))), 'DisplayName', ['Burg Coeffs: ', num2str(round(options.postfilter_taps, 2)), ' '], 'LineWidth', 1,'Color',options.color,'LineStyle','--');
+    
+        % Ensure a legend is displayed
+        legend('show');
+    end
+end

Functions/EQ_visuals/showEQNoiseSNR.m

@@ -0,0 +1,70 @@
+function showEQNoiseSNR(tx_signal, rx_signal, options)
+arguments
+    tx_signal
+    rx_signal 
+    options.fs_tx
+    options.fs_rx
+    options.fignum (1,1) double = NaN % Default to NaN if not provided
+    options.displayname (1,:) char = '' % Default to an empty string if not provided
+    options.color = [0.2157    0.4941    0.7216];
+end
+
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+
+    if isa(tx_signal,'Signal')
+        options.fs_tx = tx_signal.fs;
+        tx_signal = tx_signal.signal;
+    end
+    if isa(rx_signal,'Signal')
+        options.fs_rx = rx_signal.fs;
+        rx_signal = rx_signal.signal;
+    end
+
+
+    hold on
+    ax = gca;
+
+    % N = numel(ax.Children);
+    N = sum(arrayfun(@(x) strcmp(x.LineStyle, '-'), ax.Children));
+    cmap = linspecer(8);
+    options.color = cmap(mod(N, size(cmap, 1)) + 1, :);
+
+    % Ensure the figure is ready before calling spectrum
+    title('SNR of received Signal')
+
+    fft_length = 2^(nextpow2(length(tx_signal))-7);
+    
+    [s_lin,w] = pwelch(tx_signal,hanning(fft_length),fft_length/2,fft_length,options.fs_tx,"centered","psd","mean");
+    [n_lin,w] = pwelch(rx_signal,hanning(fft_length),fft_length/2,fft_length,options.fs_rx,"centered","psd","mean");
+
+    w = w.*1e-9;
+    snr_dbm = 10*log10(s_lin./n_lin);
+
+    % figure(231)
+    hold on
+    plot(w,snr_dbm,'DisplayName','SNR','LineWidth',0.5,'Color',options.color);
+    xlabel("Frequency in GHz");
+
+    edgetick = 2^(nextpow2(options.fs_tx*1e-9));
+    ticks = -edgetick:16:edgetick;
+    xticks(ticks);
+
+    [~,b]=min(abs((-edgetick:16:edgetick)-max(w)));
+    xlim([-ticks(b+1) ticks(b+1)]);
+    
+    max_snr = ceil(max(snr_dbm)/10)*10;
+    min_snr = floor(min(snr_dbm)/10)*10;
+    ylim([min_snr,max_snr]);
+    yticks(-200:10:100);
+
+    grid on; grid minor;
+    legend('Interpreter','none');
+    title('Noise of soft decision signal (not MLSE)');
+
+
+end

Functions/EQ_visuals/showEQTimeSignal.m

@@ -0,0 +1,54 @@
+function showEQTimeSignal(eq_signal,ref_symbols,options)
+
+    arguments
+        eq_signal
+        ref_symbols
+        options.fignum (1,1) double = NaN % Default to NaN if not provided
+        options.displayname (1,:) char = '' % Default to an empty string if not provided
+        options.color = [0.2157    0.4941    0.7216];
+    end
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+
+
+    M = numel(unique(ref_symbols.signal));
+    lvlcol = cbrewer2('Set1',M);
+    col = cbrewer2('paired',2);
+
+    eq_decisions = PAMmapper(M,0).quantize(eq_signal);
+    rx_bits = PAMmapper(M,0).demap(eq_signal);
+    ref_bits = PAMmapper(M,0).demap(ref_symbols);
+
+    %%% Separate Classes
+    constellation = unique(ref_symbols.signal);
+    received_sd = NaN(numel(constellation),length(ref_symbols));
+    received_hd = NaN(numel(constellation),length(ref_symbols));
+    lvlcol = cbrewer2('Set1',numel(constellation));
+    for lvl = 1:numel(constellation)
+        %Separate the equalized signal into the
+        %respective levels based on the actually
+        %transmitted level!
+        received_sd(lvl,ref_symbols.signal==constellation(lvl)) = eq_signal.signal(ref_symbols.signal==constellation(lvl));
+        received_hd(lvl,ref_symbols.signal==constellation(lvl)) = eq_decisions.signal(ref_symbols.signal==constellation(lvl));
+    end
+
+    [~,numerr,ber_sd,errpos] = calc_ber(rx_bits.signal,ref_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
+
+    %%% EQ Time Series %210
+    eq_signal.plot("fignum",fig.Number,"displayname",'Equalized Signal','color',col(1,:),'clear',1);
+    hold on
+
+    try
+        yline(PAMmapper(M,0).get_demodulation_thresholds,'HandleVisibility','off','LineStyle','--');
+    
+        for c = 1:M
+            scatter(errpos./eq_signal.fs,received_sd(c,errpos),1,'x','MarkerEdgeColor',lvlcol(c,:),'LineWidth',2,'DisplayName',sprintf('Tx Lvl: %d',c));
+        end                 
+    end
+
+end
+

Functions/EQ_visuals/showEQcoefficients.m

@@ -0,0 +1,58 @@
+function showEQcoefficients(n1, n2, n3, options)
+    % Show filter coefficients as stem plot
+    % n1, n2, and n3 in different subplots
+    % Scale all y-axis to -1 and 1
+
+    arguments
+        n1
+        n2
+        n3
+        options.fignum (1,1) double = NaN % Default to NaN if not provided
+        options.displayname (1,:) char = '' % Default to an empty string if not provided
+        options.color = [0.2157, 0.4941, 0.7216];
+        options.clf = 0; % Clear figure before plotting new
+    end
+
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+
+    if options.clf
+        clf(fig); % Clear the figure if requested
+    end
+
+    hold on
+    ax = gca;
+    N = numel(ax.Children);
+
+    % Set up a colormap for consistent coloring
+    cmap = linspecer(8);
+    options.color = cmap(mod(N, size(cmap, 1)) + 1, :);
+
+    % Create subplots for n1, n2, n3
+    for i = 1:3
+        subplot(3, 1, i);
+        switch i
+            case 1
+                stem(n1, 'Color', options.color, 'LineWidth', 1,'Marker','.','MarkerSize',10);
+                title(sprintf('1st order Filter Coefficients: %d',numel(n1)));
+            case 2
+                stem(n2, 'Color', options.color, 'LineWidth', 1,'Marker','.','MarkerSize',10);
+                title(sprintf('2nd order Filter Coefficients: %d',numel(n2)));
+            case 3
+                stem(n3, 'Color', options.color, 'LineWidth', 1,'Marker','.','MarkerSize',10);
+                title(sprintf('3rd order Filter Coefficients: %d',numel(n3)));
+        end
+        ylim([-1, 1]); % Scale y-axis to -1 and 1
+        grid on;
+        grid minor
+        xlabel('Coefficient Index');
+        ylabel('Amplitude');
+    end
+
+    % Ensure the layout is tight for better visibility
+    sgtitle('Filter Coefficients'); % Overall title
+end

Functions/EQ_visuals/showErrorBurstCount.m

@@ -0,0 +1,47 @@
+function showErrorBurstCount(eq_signal,ref_symbols,options)
+arguments
+    eq_signal
+    ref_symbols
+    options.fignum (1,1) double = NaN % Default to NaN if not provided
+    options.displayname (1,:) char = '' % Default to an empty string if not provided
+end
+
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+
+    if numel(unique(eq_signal.signal)) > 20
+        M = numel(unique(ref_symbols.signal));
+        eq_signal = PAMmapper(M,0).quantize(eq_signal);
+    end
+    
+    diff_indices = eq_signal.signal == ref_symbols.signal;
+
+
+    % Identify the start of new sequences (when the difference is not 1)
+    sequence_starts = [1, find(diff_indices ~= 1) + 1]; % Include the first index
+    sequence_ends = [sequence_starts(2:end) - 1, length(errpos)]; % Calculate end indices
+
+    % Initialize burst count and print bursts longer than 10
+    burst_len = 1:10;
+    burst_count = zeros(length(burst_len),1);
+    for t = 1:numel(burst_len)
+        for i = 1:length(sequence_starts)
+            % Extract current sequence
+            current_burst = errpos(sequence_starts(i):sequence_ends(i));
+            % Check if the sequence length matches criterion
+            if length(current_burst) == burst_len(t)
+                burst_count(t) = burst_count(t) + 1;
+            end
+        end
+    end
+
+    burst_symbols = burst_count .* burst_len';
+    burst_rate =  burst_symbols ;%./ length(rx_signal);
+
+
+
+end

Functions/EQ_visuals/showLevelConfusionMatrix.m

@@ -0,0 +1,27 @@
+function showLevelConfusionMatrix(decided_symbols,ref_symbols,options)
+arguments
+    decided_symbols
+    ref_symbols
+    options.M = NaN
+    options.fignum (1,1) double = NaN % Default to NaN if not provided
+    options.displayname (1,:) char = '' % Default to an empty string if not provided
+end
+
+% Determine the figure number to use or create a new figure
+if isnan(options.fignum)
+    fig = figure; % Create a new figure and get its handle
+else
+    fig = figure(options.fignum); % Use the specified figure number
+end
+
+if length(unique(decided_symbols.signal))>20
+    assert(~isnan(options.M),'Provide either decided symbol sequence or modulation order M (PAM-4 -> M=4)');
+    decided_symbols = PAMmapper(options.M,0).quantize(decided_symbols);
+end
+
+%%% Confusion Matrix
+cm = confusionchart(ref_symbols.signal,decided_symbols.signal,'RowSummary','row-normalized','ColumnSummary','column-normalized','Title','Confusion Matrix','XLabel','Decisions','YLabel','Transmitted');
+
+
+end
+

Functions/EQ_visuals/showLevelHistogram.m

@@ -0,0 +1,50 @@
+function showLevelHistogram(eq_signal,ref_symbols,options)
+arguments
+    eq_signal
+    ref_symbols
+    options.fignum (1,1) double = NaN % Default to NaN if not provided
+    options.displayname (1,:) char = '' % Default to an empty string if not provided
+end
+
+    if isa(eq_signal,'Signal')
+        eq_signal = eq_signal.signal;
+    end
+    if isa(ref_symbols,'Signal')
+        ref_symbols = ref_symbols.signal;
+    end
+
+    % Determine the figure number to use or create a new figure
+    if isnan(options.fignum)
+        fig = figure; % Create a new figure and get its handle
+    else
+        fig = figure(options.fignum); % Use the specified figure number
+    end
+
+    %%% Separate Classes
+    constellation = unique(ref_symbols);
+    received_sd = NaN(numel(constellation),length(ref_symbols));
+    lvlcol = cbrewer2('Set1',numel(constellation));
+    for lvl = 1:numel(constellation)
+        %Separate the equalized signal into the
+        %respective levels based on the actually
+        %transmitted level!
+        received_sd(lvl,ref_symbols==constellation(lvl)) = eq_signal(ref_symbols==constellation(lvl));
+    end
+    
+    
+    
+    %%% FFE histogram 
+    clf
+    for lvl = 1:numel(constellation)
+        intermediate = received_sd(lvl,:);
+        cnt(lvl) = round(numel(intermediate(~isnan(intermediate)))./length(eq_signal),3).*100;
+        hold on
+        histogram(received_sd(lvl,:),1000,"EdgeAlpha",0,'DisplayName',['Lvl ',num2str(lvl),' | ',num2str(cnt(lvl)),' %'],'FaceColor',lvlcol(lvl,:),'Normalization','pdf');
+    end
+    legend
+    grid on
+
+
+
+end
+