Gif stuff

nonlinear MLSE investigation
trying hard to implment ML-based pre Equalization to find the branch metrics

Functions/Theory/CCDM/ccdm_gpt_example.m

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+%% Target source entropy for PS-PAM8
+clear; clc;
+
+M = 8;
+a = -(M-1):2:(M-1);      % PAM-8 amplitude levels: [-7 -5 -3 -1 1 3 5 7]
+H_target = 2.79;          % desired entropy [bits/symbol]
+
+% Objective: find nu such that H(PA) = H_target
+f = @(nu) entropy_MB(a,nu) - H_target;
+nu_opt = fzero(f, [0, 2]);   % search ν in reasonable range
+
+% Compute final distribution
+P = exp(-nu_opt*a.^2);
+P = P/sum(P);
+H = -sum(P .* log2(P));
+
+fprintf('Shaping parameter ν = %.4f\n', nu_opt);
+fprintf('Entropy H(A) = %.3f bits/symbol\n', H);
+disp('Probability vector (P_A):');
+disp(P.');
+
+%% Helper: entropy function
+function H = entropy_MB(a,nu)
+    P = exp(-nu*a.^2);
+    P = P/sum(P);
+    H = -sum(P .* log2(P));
+end