halfway merged and pulled?!

2025-12-15 15:41:02 +01:00
parent 7d0a634b87
commit b8cecae895
145 changed files with 19835 additions and 0 deletions
--- a/projects/ECOC_2025/auswertung_algorithms/mpi_dsp_debug.m
+++ b/projects/ECOC_2025/auswertung_algorithms/mpi_dsp_debug.m
@@ -0,0 +1,60 @@
+
+load("ffe_debug_snapshot.mat");
+
+
+dc_buffer_len = logspace(0,3,12);
+dc_buffer_len = 1024;
+
+mu_dc = logspace(-3,0,24);
+
+parfor d = 1:length(mu_dc)
+
+    eq_lin = FFE_DCremoval_adaptive_mu("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",...
+        0.0002,"mu_tr",0,"order",25,"sps",2,"decide",0,...
+        "mu_dc",mu_dc(d),...
+        "dc_buffer_len",1024, ...
+        "ffe_buffer_len",1,...
+        "smoothing_buffer_length",0,...
+        "smoothing_buffer_update",1,...
+        "adaptive_mu_mode",0);
+    % 
+    % eq_lin = FFE("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",...
+    %     0.0002,"mu_tr",0,"order",25,"sps",2,"decide",0);
+
+    ffe_results = ffe(eq_lin,M,Scpe_sig,Symbols,Tx_bits,...
+        "precode_mode",duob_mode,...
+        'showAnalysis',0,...
+        "postFFE",[],...
+        "eth_style_symbol_mapping",0);
+
+    ffe_results.metrics.print
+
+    % % eq_lin = FFE_DFE("epochs_tr",5,"epochs_dd",5,"len_tr",4096*2,"ffe_mu_dd",1e-4,"dfe_mu_dd",5e-4,"ffe_mu_tr",0,"dfe_mu_tr",0,"ffe_order",21,"dfe_order",2,"sps",2,"decide",0);
+    % 
+    % eq_lin = FFE("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",...
+    %     0.0002,"mu_tr",0,"order",25,"sps",2,"decide",0);
+    % pf_    = Postfilter("ncoeff",2,"useBurg",1);
+    % mlse_  = MLSE_viterbi("duobinary_output",0,'M',4,'trellis_states',PAMmapper(4,0).levels);
+    % 
+    % [ffe_results2, mlse_results] = vnle_postfilter_mlse(eq_lin, pf_, mlse_, M, Scpe_sig, Symbols, Tx_bits, ...
+    %     "precode_mode", duob_mode,...
+    %     'showAnalysis', 1, ...
+    %     "postFFE", [],...
+    %     "eth_style_symbol_mapping", 0);
+
+    ber(d) = ffe_results.metrics.BER;
+
+    
+end
+
+figure(10)
+hold on
+plot(mu_dc,ber,'LineWidth',1,'DisplayName',sprintf('DC buffer len = 1024'),'Marker','.','MarkerSize',10);
+xlabel('BER');
+xlabel('MU DC');
+title('BER Optimization over dc\_buffer\_len');
+yline([4.85e-3,2e-2],'HandleVisibility', 'off','LineWidth',1,'LineStyle','--');
+ylim([9e-4, 0.5]);
+set(gca, 'YScale', 'log'); % BER is usually plotted log-scale
+legend('show', 'Location', 'best');
+grid on;
--- a/projects/ECOC_2025/auswertung_algorithms/run_offline_dsp.m
+++ b/projects/ECOC_2025/auswertung_algorithms/run_offline_dsp.m
@@ -0,0 +1,118 @@
+% === SETTINGS ===
+
+dsp_options.append_to_db = 0;
+dsp_options.max_occurences = 15;
+dsp_options.database_path = 'C:\Users\Silas\Documents\MATLAB\Datensätze\sioe_labor\';
+dsp_options.database_name = 'silas_labor_newdsp_newstructure.db';
+dsp_options.storage_path = 'Z:\2024\sioe_labor\';
+
+dsp_options.parameters = struct();
+dsp_options.parameters.mu_dc = [0.005];
+
+% === Get Run ID's ===
+db = DBHandler("pathToDB", [dsp_options.database_path, dsp_options.database_name], "type", "sqlite");
+fp = QueryFilter();
+% fp.where('Runs', 'run_id','EQUALS', 5108);            
+fp.where('Runs', 'is_mpi','EQUALS', 0);                
+fp.where('Runs', 'fiber_length','EQUALS', 1);       
+fp.where('Runs', 'wavelength','EQUALS', 1310);         
+fp.where('Runs', 'db_mode','EQUALS', 1);              
+fp.where('Runs', 'rop_attenuation','EQUALS', 0);      
+fp.where('Runs', 'pam_level','EQUALS', 4);     
+fp.where('Runs', 'bitrate','EQUALS', 360e9);    
+% fp.where('Runs', 'power_pd_in','GREATER_THAN', 7);    
+[dataTable,~] = db.queryDB(fp, db.getTableFieldNames('Runs'));
+
+% === Initialize DataStorage ===
+wh = DataStorage(dsp_options.parameters);
+wh.addStorage("ffe_package");
+wh.addStorage("mlse_package");
+wh.addStorage("vnle_package");
+wh.addStorage("dbtgt_package");
+wh.addStorage("dbenc_package");
+
+% === RUN IT ===
+
+% [results,wh] = submitJobs(dataTable.run_id(:), dsp_options, "serial", 'wh', wh, 'waitbar', true);
+% wh.getStoValue('ffe_package',0.005);
+% wh.getStoValue('mlse_package',0.005);
+
+[dataTable,~] = db.queryDB(fp, [db.getTableFieldNames('Runs');db.getTableFieldNames('Results');db.getTableFieldNames('Equalizer')]);
+
+dataTable = cleanUpTable(dataTable);
+
+% === Look at it ===
+y_var = 'BER_precoded';
+x_var = 'bitrate';
+fixedVars = {'equalizer_structure', x_var};
+
+[dataTableClean, outliersTable] = removeGroupOutliers(dataTable, fixedVars, y_var);
+
+% --- Group and aggregate ---
+dataTableGrpd_mean = groupIt(fixedVars, dataTableClean, @mean);
+dataTableGrpd_min  = groupIt(fixedVars, dataTableClean, @min);
+dataTableGrpd_max  = groupIt(fixedVars, dataTableClean, @max);
+
+% Choose a color map
+cols = linspecer(numel(unique(dataTableGrpd_mean.equalizer_structure)));
+
+figure;
+hold on;
+
+% Get unique equalizer structures for grouping
+unique_eq = unique(dataTableGrpd_mean.equalizer_structure);
+
+for i = 1:numel(unique_eq)
+    eq_val = unique_eq(i);
+
+    % Filter grouped data for this equalizer structure
+    filt = dataTableGrpd_mean.equalizer_structure == eq_val;
+
+    x = dataTableGrpd_mean.(x_var)(filt);
+    y_mean = dataTableGrpd_mean.(y_var)(filt);
+    y_min  = dataTableGrpd_min.(y_var)(filt);
+    y_max  = dataTableGrpd_max.(y_var)(filt);
+
+    % Bounds for boundedline (distance from mean)
+    y_lower = y_mean - y_min;
+    y_upper = y_max - y_mean;
+    y_bounds = [y_lower, y_upper];
+
+    % --- Bounded line (mean ± min/max) ---
+    if exist('boundedline', 'file')
+        [hl, hp] = boundedline(x, y_mean, y_bounds, ...
+            'alpha', 'transparency', 0.1, ...
+            'cmap', cols(i,:), ...
+            'nan', 'fill', ...
+            'orientation', 'vert');
+        set(hl, 'LineWidth', 1.2, 'DisplayName', sprintf('Eq %s', eq_val));
+        set(hp, 'HandleVisibility', 'off');
+    else
+        % If boundedline is not available, use errorbar
+        errorbar(x, y_mean, y_lower, y_upper, ...
+            'o-', 'Color', cols(i,:), 'LineWidth', 1.2, ...
+            'DisplayName', sprintf('Eq %d', eq_val),'HandleVisibility', 'off');
+    end
+
+    % --- Normal line (mean only) ---
+    plot(x, y_mean, '-', 'Color', cols(i,:), 'LineWidth', 1.5, ...
+        'DisplayName', sprintf('Mean Eq %s', eq_val),'HandleVisibility', 'off');
+
+    % --- Scatter plot for individual points (from original data) ---
+    % Filter original data for this group
+    orig_filt = dataTableClean.equalizer_structure == eq_val;
+    x_scatter = dataTableClean.(x_var)(orig_filt);
+    y_scatter = dataTableClean.(y_var)(orig_filt);
+
+    scatter(x_scatter, y_scatter, 10,cols(i,:), 'filled', ...
+        'MarkerFaceAlpha', 0.5, 'DisplayName', sprintf('Scatter Eq %s', eq_val),'HandleVisibility', 'off');
+end
+
+yline([2.2e-4,4.85e-3,2e-2],'HandleVisibility', 'off','LineWidth',1,'LineStyle','--');
+set(gca, 'YScale', 'log'); % BER is usually plotted log-scale
+xlabel(x_var, 'Interpreter', 'none');
+ylabel(y_var, 'Interpreter', 'none');
+legend('show', 'Location', 'best');
+grid on;
+title(sprintf('%s vs. %s', y_var, x_var), 'Interpreter', 'none');
+hold off;
--- a/projects/ECOC_2025/dsp_standalone_2.m
+++ b/projects/ECOC_2025/dsp_standalone_2.m
@@ -0,0 +1,63 @@
+
+
+
+savePath = 'Z:\2025\ECOC Silas\ecoc_2025\';
+databasePath = 'C:\Users\Silas\Documents\MATLAB\imdd_simulation\projects\ECOC_2025\';
+database_name = 'ecoc2025_loops.db';
+db = DBHandler("type","mysql");
+% db = DBHandler("pathToDB", [databasePath, database_name],"type","sqlite");
+
+filterParams = db.tables;
+% filterParams.Configurations = struct('run_id', run_id);
+filterParams.Configurations = struct( ...
+    'symbolrate',      112e9, ... %[224,336,360,390,420,448]
+    'fiber_length',     0, ...
+    'db_mode',        '"no_db"', ...
+    'interference_attenuation', [], ...
+    'interference_path_length', 0, ...
+    'is_mpi',           1, ...
+    'pam_level',        4, ...
+    'wavelength',       1310, ...
+    'precomp_amp',      [], ...
+    'signal_attenuation', [], ...
+    'v_awg',            [], ...     
+    'v_bias',           2.65 ...
+    );
+
+selectedFields = {'Runs.run_id','Runs.loop_id','Runs.tx_bits_path','Runs.tx_signal_path','Runs.tx_symbols_path','Runs.rx_sync_path','Runs.rx_raw_path',...
+    'Configurations.db_mode','Configurations.pam_level','Configurations.bitrate','Configurations.symbolrate','Configurations.fiber_length','Configurations.wavelength','Configurations.precomp_amp','Measurements.power_rop','Configurations.v_bias',...
+    'Configurations.interference_attenuation', 'Configurations.interference_path_length'};
+
+[dataTable,sql_query] = db.queryDB(filterParams, selectedFields);
+
+dataTable(dataTable.loop_id~=217,:) = [];
+
+num_occ = 10;
+run_par = true;
+run_id = dataTable.run_id;
+
+params.dc_buffer_len = 224;
+params.ffe_buffer_len = 1;
+params.smoothing_buffer_length = 0;
+params.smoothing_buffer_update = 0;
+params.mu_dc = 0.005;
+
+futures_list = parallel.FevalFuture.empty();
+for id = 1:length(dataTable.run_id)
+    run_id = dataTable.run_id(id);
+    [out, futures_list(id)] = submit_dsp(run_id, databasePath, database_name, savePath,"parallel",run_par,'max_occurences',num_occ,'paramstruct',params);
+end
+
+% Extract all ber_mlse values from the vnle_pf_package using cellfun
+ber_mlse = cellfun(@(pkg) pkg.ber_mlse, future.OutputArguments{1,1}.vnle_pf_package);
+ber_vnle = cellfun(@(pkg) pkg.ber_vnle, future.OutputArguments{1,1}.vnle_pf_package);
+
+figure(101)
+hold on;
+scatter(1:num_occ,ber_mlse,15,'Marker','*');
+scatter(1:num_occ,ber_vnle,15,'Marker','*');
+legend('Interpreter', 'latex');
+xlabel('Occurences');
+ylabel('BER');
+grid on;
+beautifyBERplot;
--- a/projects/ECOC_2025/dsp_test/hyperparam_tuning.m
+++ b/projects/ECOC_2025/dsp_test/hyperparam_tuning.m
@@ -0,0 +1,58 @@
+
+
+Scpe_sig = load("imdd_simulation\projects\ECOC_2025\dsp_test\pam4_scopesignal.mat");Scpe_sig = Scpe_sig.Scpe_sig;
+Tx_bits = load("imdd_simulation\projects\ECOC_2025\dsp_test\pam4_bits.mat");Tx_bits = Tx_bits.Tx_bits;
+Symbols = load("imdd_simulation\projects\ECOC_2025\dsp_test\pam4_symbols.mat");Symbols = Symbols.Symbols;
+
+eq_ = FFE_DCremoval("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",1e-5,"mu_tr",0,"order",50,"sps",2,"decide",0,"mu_dc",0.005,"dc_buffer_len",1);
+
+% savePath = 'Z:\2025\ECOC Silas\ecoc_2025\';
+% databasePath = 'C:\Users\Silas\Documents\MATLAB\imdd_simulation\projects\ECOC_2025\';
+% database_name = 'ecoc2025_loops.db';
+% db = DBHandler("type","mysql");
+
+params = (logspace(-6,-2,20));
+params = floor((logspace(2,3,20)));
+params = 224;
+
+for i = 1:length(params)
+
+    eq_ = FFE_DCremoval_adaptive_mu("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",...
+        0.0002,"mu_tr",0,"order",25,"sps",2,"decide",0,...
+        "mu_dc",0.005,"dc_buffer_len",1, ...
+        "ffe_buffer_len",1,...
+        "smoothing_buffer_length",0,...
+        "smoothing_buffer_update",1);
+
+    result = ffe(eq_,4,Scpe_sig,Symbols,Tx_bits,"precode_mode",db_mode.no_db,'showAnalysis',1,"postFFE",[],"eth_style_symbol_mapping",0);
+    ber_ffe(i) = result.metrics;
+    fprintf("    FFE Results:                    %.2e\n", ber_ffe(i));
+
+    % db.addProcessingResult(run_id, result.resultsVNLE, result.equalizerConfigVNLE);
+
+    % eq_ = FFE_adaptive_decision("epochs_tr",5,"epochs_dd",3,"len_tr",4096*2,"mu_dd",...
+    %     0.0003,"mu_tr",0,"order",50,"sps",2,"decide",1,"buffer_length",params(i));
+    % 
+    % result = vnle(eq_,4,Scpe_sig,Symbols,Tx_bits,"precode_mode",db_mode.no_db,'showAnalysis',1,"postFFE",[],"eth_style_symbol_mapping",0);
+    % ber_dc(i) = result.ber_vnle;
+    % 
+    % fprintf("   FFE+dc tr. Results:             %.2e\n", ber_dc(i));
+
+end
+
+figure(103435)
+hold on;
+% scatter(params,ber_dc,15,'Marker','o','LineWidth',1,'DisplayName','DC tracking');
+% [a,b]=min(ber_dc);
+% scatter(params(b),a,45,'Marker','x','MarkerEdgeColor','r','LineWidth',1);
+
+scatter(params,ber_ffe,15,'Marker','square','LineWidth',1);
+[a,b]=min(ber_ffe);
+scatter(params(b),a,45,'Marker','x','MarkerEdgeColor','r','LineWidth',1,'DisplayName','FFE');
+
+legend('Interpreter', 'latex');
+xlabel('Occurences');
+ylabel('BER');
+grid on;
+beautifyBERplot;
+ylim([1e-4,0.1 ])
--- a/projects/ECOC_2025/ecoc2025.db
+++ b/projects/ECOC_2025/ecoc2025.db
--- a/projects/ECOC_2025/ecoc2025.sqbpro
+++ b/projects/ECOC_2025/ecoc2025.sqbpro
--- a/projects/ECOC_2025/ecoc2025_einmessung.db
+++ b/projects/ECOC_2025/ecoc2025_einmessung.db
--- a/projects/ECOC_2025/ecoc2025_fail.db
+++ b/projects/ECOC_2025/ecoc2025_fail.db
--- a/projects/ECOC_2025/ecoc2025_loops
+++ b/projects/ECOC_2025/ecoc2025_loops
--- a/projects/ECOC_2025/ecoc2025_loops.db
+++ b/projects/ECOC_2025/ecoc2025_loops.db
--- a/projects/ECOC_2025/sqlite_sequence.sql
+++ b/projects/ECOC_2025/sqlite_sequence.sql
@@ -0,0 +1,163 @@
+BEGIN TRANSACTION;
+CREATE TABLE IF NOT EXISTS "Configurations" (
+	"configuration_id"	INTEGER,
+	"run_id"	INTEGER,
+	"unique_elab_id"	TEXT,
+	"bitrate"	REAL,
+	"symbolrate"	REAL,
+	"pam_level"	INTEGER,
+	"db_mode"	TEXT,
+	"pulsef_alpha"	INTEGER,
+	"v_bias"	REAL,
+	"v_awg"	REAL,
+	"precomp_amp"	REAL,
+	"rop_attenuation"	REAL,
+	"wavelength"	REAL,
+	"laser_power"	REAL,
+	"fiber_length"	REAL,
+	"pd_in_desired"	REAL,
+	"is_mpi"	BIT,
+	"signal_attenuation"	REAL,
+	"interference_path_length"	REAL,
+	"interference_attenuation"	REAL,
+	"pam_source"	TEXT,
+	PRIMARY KEY("configuration_id" AUTOINCREMENT),
+	FOREIGN KEY("run_id") REFERENCES "Runs"("run_id")
+);
+CREATE TABLE IF NOT EXISTS "EqualizerParameters" (
+	"eq_id"	INTEGER,
+	"equalizer_structure"	REAL,
+	"M"	INTEGER,
+	"target_constellation"	TEXT,
+	"db_target"	INTEGER,
+	"diff_precode"	INTEGER,
+	"postFFE"	INTEGER,
+	"NpostFFE"	INTEGER,
+	"Ne1"	INTEGER,
+	"Ne2"	INTEGER,
+	"Ne3"	INTEGER,
+	"Nb1"	INTEGER,
+	"Nb2"	INTEGER,
+	"Nb3"	INTEGER,
+	"K"	INTEGER,
+	"DCmu"	REAL,
+	"ideal_dfe"	INTEGER,
+	"training_length"	INTEGER,
+	"training_loops"	INTEGER,
+	"TRmu1"	REAL,
+	"TRmu2"	REAL,
+	"TRmu3"	REAL,
+	"TRmuDFE"	REAL,
+	"dd_loops"	INTEGER,
+	"DDmu1"	REAL,
+	"DDmu2"	REAL,
+	"DDmu3"	REAL,
+	"DDmuDFE"	REAL,
+	"MLSE_mode"	TEXT,
+	"MLSE_trellis_states"	TEXT,
+	"comment"	TEXT,
+	"config_hash"	TEXT,
+	UNIQUE("config_hash"),
+	PRIMARY KEY("eq_id" AUTOINCREMENT)
+);
+CREATE TABLE IF NOT EXISTS "Measurements" (
+	"measurement_id"	INTEGER,
+	"run_id"	INTEGER,
+	"power_laser"	REAL,
+	"power_rop"	REAL,
+	"power_pd_in"	REAL,
+	"power_mpi_interference"	REAL,
+	"power_mpi_signal"	REAL,
+	"voa_class"	TEXT,
+	"pdfa_class"	TEXT,
+	"laser_class"	TEXT,
+	PRIMARY KEY("measurement_id" AUTOINCREMENT),
+	FOREIGN KEY("run_id") REFERENCES "Runs"("run_id")
+);
+CREATE TABLE IF NOT EXISTS "Results" (
+	"result_id"	INTEGER,
+	"run_id"	INTEGER,
+	"eqParam_id"	INTEGER,
+	"date_of_processing"	DATETIME DEFAULT (datetime('now', 'localtime')),
+	"numBits"	INTEGER,
+	"numBitErr"	INTEGER,
+	"BER"	REAL,
+	"numBitErr_precoded"	REAL,
+	"BER_precoded"	REAL,
+	"SNR"	REAL,
+	"SNR_level"	TEXT,
+	"GMI"	REAL,
+	"AIR"	REAL,
+	"EVM"	REAL,
+	"EVM_level"	TEXT,
+	"Alpha"	REAL,
+	"result_hash"	TEXT UNIQUE,
+	"MLSE_dir"	INTEGER,
+	PRIMARY KEY("result_id" AUTOINCREMENT),
+	FOREIGN KEY("eqParam_id") REFERENCES "EqualizerParameters"("eq_id"),
+	FOREIGN KEY("run_id") REFERENCES "Runs"("run_id")
+);
+CREATE TABLE IF NOT EXISTS "Runs" (
+	"run_id"	INTEGER,
+	"date_of_run"	DATETIME DEFAULT (datetime('now', 'localtime')),
+	"tx_bits_path"	TEXT,
+	"tx_symbols_path"	TEXT,
+	"rx_sync_path"	TEXT,
+	"rx_raw_path"	TEXT,
+	"filename"	TEXT,
+	"tx_signal_path"	TEXT,
+	PRIMARY KEY("run_id" AUTOINCREMENT)
+);
+CREATE VIEW "View_ResultOverview" AS
+SELECT
+    -- Run info
+    Runs.run_id,
+    Runs.date_of_run,
+	
+    Results.BER,
+    Results.SNR,
+    Results.GMI,
+    Results.AIR,
+    Results.EVM,
+    Results.Alpha,
+	
+    -- Configurations
+    Configurations.symbolrate,
+    Configurations.pam_level,
+    Configurations.db_mode,
+    Configurations.pulsef_alpha,
+    Configurations.v_bias,
+    Configurations.v_awg,
+    Configurations.precomp_amp,
+    Configurations.is_mpi,
+	Configurations.signal_attenuation,
+    Configurations.interference_path_length,
+    Configurations.interference_attenuation,
+
+    -- Measurement data
+    Measurements.power_laser,
+    Measurements.power_rop,
+    Measurements.power_pd_in,
+    Measurements.power_mpi_interference,
+    Measurements.power_mpi_signal,
+
+    -- Equalizer parameters
+    EqualizerParameters.equalizer_structure,
+    EqualizerParameters.db_target,
+    EqualizerParameters.diff_precode
+
+
+FROM Results
+
+-- Join related tables
+LEFT JOIN Runs ON Results.run_id = Runs.run_id
+LEFT JOIN Configurations ON Configurations.run_id = Runs.run_id
+LEFT JOIN Measurements ON Measurements.run_id = Runs.run_id
+LEFT JOIN EqualizerParameters ON Results.eqParam_id = EqualizerParameters.eq_id;
+CREATE INDEX IF NOT EXISTS "idx_run_id_on_Configurations" ON "Configurations" (
+	"run_id"
+);
+CREATE INDEX IF NOT EXISTS "idx_run_id_on_Measurements" ON "Measurements" (
+	"run_id"
+);
+COMMIT;
--- a/projects/ECOC_2025/theory/analytic_mpi_evaluation.m
+++ b/projects/ECOC_2025/theory/analytic_mpi_evaluation.m
@@ -0,0 +1,85 @@
+% This script is used to evaluate Fig. 1b) in the paper "Adaptive Removal of Multipath Interference in Short Reach 112 GBd PAM-4 IM/DD Systems"
+
+%% Parameters
+df       = 1e6;        % Laser linewidth [Hz]
+SIR_dB   = 20;                % Interference attenuation [dB]
+alpha    = 10^(-SIR_dB/20);   % Interference attenuation [linear]
+n_fiber  = 1.467;             % Refractive index
+c        = physconst('lightspeed'); % [m/s]
+
+L        = linspace(0,250,50); % Interference delay [m]  
+tau      = n_fiber./c.*L;       % Interference time (= tau) [s]
+
+tau_c = 1/(pi*df);              % laser coherence time [s]
+L_c   = (c/n_fiber)*tau_c;      % laser coherence length [m]
+
+var_sat = 2*alpha^2;            % Analytical saturation of variance
+
+%% Monte–Carlo Simulation
+fs               = 100e9;            % sampling rate [Hz]
+Tsim             = 50e-6;            % sim duration [s]
+N                = round(Tsim*fs);   % number of samples for each realization
+max_delay_samples  = round(max(tau)*fs); % largest delay that is evaluated (based on max. Interference delay)
+phase_noise_std   = sqrt(2*pi*df/fs); % standard dev. phase noise
+
+num_realizations = 50;             % number of parallel runs
+monte_carlo_variance = zeros(num_realizations, length(L));
+parfor r = 1:num_realizations
+
+    % generate a realization of phase noise random walk
+    dphi = phase_noise_std * randn(1, N + max_delay_samples); % matlab randn process has std = 1
+    phi  = cumsum(dphi);
+    phi_direct  = phi(max_delay_samples+1 : max_delay_samples+N);
+    var_k = zeros(1, length(L));
+    for t = 1:length(tau)
+
+        nd = round( tau(t)*fs ); % delay in samples for current interference time
+        phi_delayed = phi(max_delay_samples+1-nd : max_delay_samples+N-nd); %cut out interfering signal part (was earlier)
+
+        E = exp(1j*phi_direct) + alpha*exp(1j*phi_delayed); % E-fields combined
+        I = abs(E).^2; % photo current as magnitude square of E-field
+        var_k(t) = var(I);
+
+    end
+    monte_carlo_variance(r, :) = var_k;
+end
+
+avg_of_mc_variances = mean(monte_carlo_variance, 1);
+std_of_mc_variances = std(monte_carlo_variance, 0, 1);
+
+%% Analytic variance
+L_        = linspace(0,250,500); % Interference delay [m]  
+tau_      = n_fiber./c.*L_;
+analytic_variance = 2*alpha^2 * (1 - exp(-2*pi*df.*tau_)).^2;
+
+%% Plot 
+cols =     [0.3467    0.5360    0.6907
+            0.9153    0.2816    0.2878
+            0.4416    0.7490    0.4322];
+
+coherence_length_multiples = 0.5:0.5:ceil(L(end)/L_c);
+
+figure();
+hold on;
+plot(L, avg_of_mc_variances, 'LineWidth',2, 'DisplayName','Simulation','Color',cols(1,:),'LineStyle','-');
+errorbar(L, avg_of_mc_variances,std_of_mc_variances, 'LineWidth',0.7,'LineStyle','none', 'DisplayName','Simulation','Color',cols(1,:),'HandleVisibility','off');
+
+plot(L_, analytic_variance, 'LineWidth',2, 'DisplayName','Analytic','Color',cols(2,:),'LineStyle','-');
+xticks(coherence_length_multiples.*L_c);
+xticklabels(round(coherence_length_multiples.*L_c,1));
+
+norm_to_coherence_len = 1;
+if norm_to_coherence_len
+    xticklabels(coherence_length_multiples);
+    xlabel('$n \cdot L_c$', 'FontSize',12);
+else
+    xlabel('Interference Delay [m]', 'FontSize',12);
+end
+
+xline(L_c.*coherence_length_multiples, 'LineWidth',1.5, 'DisplayName','Coh. Length','HandleVisibility','off','Color',[0.7,0.7,0.7],'LineStyle','-');
+xlim([0,L(end)]);
+yline(var_sat, '-.k','LineWidth',1.5, 'DisplayName','Saturation: 2$\alpha ^2$');
+grid on;
+ylabel('Intensity Variance', 'FontSize',12);
+title(sprintf('MPI Variance; %d MHz; SIR: %d dB',df.*1e-6,SIR_dB), 'FontSize',14);
+legend('Location','southeast');
--- a/projects/ECOC_2025/theory/coherence_length_plot.m
+++ b/projects/ECOC_2025/theory/coherence_length_plot.m
@@ -0,0 +1,32 @@
+%% Parameters
+df       = linspace(1,50e6,10000);   % Laser FWHM linewidth [Hz]
+n_fiber  = 1.467;                      % Fiber group index
+c        = 3e8;                        % Speed of light [m/s]
+
+% Compute coherence length (1/e of mean-fringe decay)
+tau_c = 1./(pi*df);
+L_c   = (c.* tau_c/n_fiber) ;          % Coherence length [m]
+
+%% Plot
+figure('Color','w'); 
+loglog(df/1e6, L_c, 'LineWidth',2,'LineStyle','-'); % linewidth in MHz
+% xticks([0.1, 1, 10, 50]);
+% yticks([1, 10, 100, 1000]);
+% yticklabels({'1','10','100','1000'})
+grid on; box on;
+xlabel('Laser linewidth [MHz]','FontSize',12,'Interpreter','latex');
+ylabel('Coherence length [m]','FontSize',12,'Interpreter','latex');
+title('Coherence Length vs. Laser Linewidth','FontSize',14,'Interpreter','latex');
+
+%% Annotate some key points
+% hold on;
+% freqs = [150e3, 1e6, 10e6, 50e6]; % [Hz]
+% for f = freqs
+%     x = f/1e6;
+%     y = (c/n_fiber) * (1/(pi*f));
+%     scatter(x,y,'Marker','x','LineWidth',1,'MarkerEdgeColor','black');
+% 
+%     text(x*1.1,y, sprintf('%.2f MHz', f/1e6), ...
+%         'FontSize',10,'HorizontalAlignment','left');
+% 
+% end