Merge branch 'main' of cau-git.rz.uni-kiel.de:nt/mitarbeiter/silas/imdd_simulation

2026-03-25 09:33:44 +01:00
parent e16806b520 5b90bc11a0
commit 69578b3c43
14 changed files with 1033 additions and 24 deletions
--- a/Functions/Minimal_examples/matched_filter_minimal.m
+++ b/Functions/Minimal_examples/matched_filter_minimal.m
@@ -52,11 +52,17 @@ symbols = PAMmapper(M,0).map(bits);
 symbols.fs = fsym;

 symbols.spectrum("displayname",'Symbols','fignum',1);
+
+
 %% RRC Shaping
-rcalpha     = 1;
-Pform       = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rrc","pulselength",16,"alpha",rcalpha);
-Digi_sig = Pform.process(symbols);
-Digi_sig.spectrum("displayname",'Signal after pluse shaping','fignum',1);
+
+for rcalpha = 0.1:0.2:1
+    % rcalpha     = 0.5;
+    Pform       = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",16,"alpha",rcalpha);
+    Digi_sig = Pform.process(symbols);
+    % Digi_sig.spectrum("displayname",'Signal after pluse shaping','fignum',1);
+    Digi_sig.eye(fsym,M,"fignum",0.1*10,"mode",1);
+end

 %% RRC Matched Filtering
 Pform       = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rrc","pulselength",16,"alpha",rcalpha);
--- a/Functions/Theory/Dissertation/dispersion_around_zdw.m
+++ b/Functions/Theory/Dissertation/dispersion_around_zdw.m
@@ -21,23 +21,23 @@ for k = 1:size(scenarios, 1)
    Zr = scenarios{k,1};
    Sr = scenarios{k,2};
    col = scenarios{k,3};
-
+    
    [S_mesh, Z_mesh] = meshgrid(Sr, Zr);
    D_all = zeros(length(lambda_nm), 4);
    for i = 1:4
        D_all(:,i) = (S_mesh(i)/4) .* (lambda_nm - (Z_mesh(i)^4)./(lambda_nm.^3));
    end
-
+    
    D_min_env = min(D_all, [], 2);
    D_max_env = max(D_all, [], 2);
-
+    
    [hl, hp] = boundedline(lambda_nm, (D_min_env+D_max_env)/2, (D_max_env-D_min_env)/2, ...
        'cmap','alpha', col);
-
+    
    hp_handles(k) = hp;
    set(hl, 'Visible', 'off');
-
-
+    
+    
    if k == 1
        D_wide_min = D_min_env;
        D_wide_max = D_max_env;
@@ -49,6 +49,14 @@ for k = 1:size(scenarios, 1)
        %     'HandleVisibility', 'off'); % Hide from legend
        % Capture Wide Spec (k=1) bounds for the TikZ measurement lines
        hp.FaceAlpha = 0.5;
+        % ho = outlinebounds(hl, hp);
+        % % Change properties
+        % set(ho, 'Color', 'k', ...         % Make it black
+        %     'LineStyle', '--', ...    % Make it dashed
+        %     'LineWidth', 1, ...     % Make it thin
+        %     'HandleVisibility', 'off'); % Hide from legend
+        % Capture Wide Spec (k=1) bounds for the TikZ measurement lines
+        hp.FaceAlpha = 0.5;
    else
        hp.FaceAlpha = 0.8;
    end
--- a/Functions/Theory/Dissertation/pmd_vs_length.m
+++ b/Functions/Theory/Dissertation/pmd_vs_length.m
@@ -0,0 +1,116 @@
+
+% pmd_vs_length.m
+% ------------------------------------------------------------
+% Plots the Foschini-Poole (1991) analytical variance formula for PMD:
+%
+%   sigma_T^2(z) = 2*(Delta_beta1)^2 * lc^2
+%                  * [ exp(-z/lc) + z/lc - 1 ]
+%
+% and overlays the two asymptotic regimes:
+%   - Short-reach  (z << lc) : sigma_T(z) ~ (Delta_beta1) * z
+%   - Long-haul    (z >> lc) : sigma_T(z) ~ Dp * sqrt(z)
+%
+% Parameters follow typical SMF values from the literature.
+% ------------------------------------------------------------
+
+clear; clc;
+
+%% ── Parameters ──────────────────────────────────────────────────────────────
+% Intrinsic local birefringence  [ps/km]
+Delta_beta1 = 1e-1;           % typical value, adjust as needed
+
+% Correlation length [km]
+lc          = 0.01;           % ~50 m, typical for G.652 SMF
+
+% PMD parameter  [ps / sqrt(km)]  —  derived from the two above
+Dp          = Delta_beta1 * sqrt(2 * lc);
+
+% Distance axis [km]
+z_max       = 10;            % maximum distance
+z           = linspace(0.001, z_max, 10000);   % avoid z = 0 in log plot
+
+%% ── Exact Foschini-Poole formula (sigma_T in ps) ────────────────────────────
+sigma_T_sq  = 2 .* Delta_beta1.^2 .* lc.^2 ...
+    .* (exp(-z ./ lc) + z ./ lc - 1);
+sigma_T     = sqrt(sigma_T_sq);          % RMS DGD  [ps]
+
+%% ── Asymptotic regimes ───────────────────────────────────────────────────────
+% Short-reach: linear growth  (z << lc)
+sigma_T_short = Delta_beta1 .* z;        % [ps]
+
+% Long-haul: square-root growth  (z >> lc)
+sigma_T_long  = Dp .* sqrt(z);          % [ps]
+
+%% ── Plot ─────────────────────────────────────────────────────────────────────
+figure('Color','w','Position',[100 100 760 480]);
+hold on;
+
+% Color palette (matching dissertation style)
+c_exact = [0.1216, 0.4706, 0.7059];      % blue  – exact
+c_short = [0.8392, 0.1529, 0.1569];      % red   – short-reach asymptote
+c_long  = [0.1961, 0.6314, 0.1725];      % green – long-haul asymptote
+
+% Exact solution
+h_exact = plot(z, sigma_T, ...
+    'Color', c_exact, 'LineWidth', 2.0, ...
+    'DisplayName', 'Exact (Foschini \& Poole)');
+
+% Short-reach asymptote  σ_T ≈ Δβ₁ · z
+h_short = plot(z, sigma_T_short, ...
+    'Color', c_short, 'LineWidth', 1.4, 'LineStyle', '--', ...
+    'DisplayName', '$\sigma_T \approx \Delta\beta_1 \cdot z$  \quad ($z \ll l_c$)');
+
+% Long-haul asymptote  σ_T ≈ D_p √z
+h_long  = plot(z, sigma_T_long, ...
+    'Color', c_long,  'LineWidth', 1.4, 'LineStyle', ':', ...
+    'DisplayName', '$\sigma_T \approx D_p \sqrt{z}$  \quad ($z \gg l_c$)');
+
+%% ── Axes & decoration ────────────────────────────────────────────────────────
+ax = gca;
+set(ax, 'XScale', 'log', 'YScale', 'log');
+
+% ── X-axis: linear-style tick labels on log scale ────────────────────────
+x_ticks = [1e-3, 1e-2, 1e-1, 1, 10];
+ax.XTick = x_ticks;
+ax.XTickLabel = arrayfun(@(v) sprintf('%g km', v), x_ticks, 'UniformOutput', false);
+
+% ── Y-axis: linear-style tick labels on log scale ────────────────────────
+y_ticks = [1e-3, 1e-2, 1e-1, 1, 10];
+ax.YTick = y_ticks;
+ax.YTickLabel = arrayfun(@(v) sprintf('%g ps', v), y_ticks, 'UniformOutput', false);
+
+xlabel('Fiber length $z$ [km]',              'Interpreter', 'latex');
+ylabel('RMS DGD $\sigma_T$ [ps]',            'Interpreter', 'latex');
+
+grid on; box on;
+xlim([min(z) z_max]);
+
+legend([h_exact, h_short, h_long], ...
+    'Location', 'northwest', 'Interpreter', 'latex', 'FontSize', 9);
+
+% Parameter annotation
+anno_str = sprintf( ...
+    ['$\\Delta\\beta_1 = %.3g$ ps/km\n' ...
+    '$l_c = %.0f$ m\n' ...
+    '$D_p = \\Delta\\beta_1\\sqrt{2l_c} = %.4g$ ps/$\\sqrt{\\mathrm{km}}$'], ...
+    Delta_beta1, lc*1e3, Dp);
+
+annotation('textbox', [0.57 0.14 0.38 0.22], ...
+    'String',        anno_str, ...
+    'Interpreter',   'latex', ...
+    'FontSize',      8.5, ...
+    'BackgroundColor','w', ...
+    'EdgeColor',     [0.5 0.5 0.5], ...
+    'LineWidth',     0.8, ...
+    'FitBoxToText',  'on');
+
+%% ── Regime transition marker ─────────────────────────────────────────────────
+% Mark the crossover region around z = lc
+xline(lc, '--', ...
+    'Color', [0.5 0.5 0.5], 'LineWidth', 0.8, ...
+    'HandleVisibility', 'off');
+text(lc * 1.15, min(sigma_T)*3, '$l_c$', ...
+    'Interpreter', 'latex', 'Color', [0.4 0.4 0.4], 'FontSize', 9);
+
+%% ── Export (uncomment to use) ────────────────────────────────────────────────
+% mat2tikz_improved('C:\...\tikz\pmd\pmd_vs_length.tikz')