function [snr_all, snr_per_level] = calc_snr(tx_signal, eq_noise)
    % CALC_SNR Calculates overall SNR and level-wise SNR for a PAM-M constellation.
    %
    %   [snr_all, snr_per_level] = calc_snr(tx_signal, eq_noise)
    %
    %   Inputs:
    %       tx_signal - Vector of transmitted signal values.
    %       eq_noise  - Vector of corresponding noise samples.
    %
    %   Outputs:
    %       snr_all       - Overall SNR computed using all signal values.
    %       snr_per_level - A vector where each element is the SNR computed
    %                       for a unique amplitude level in tx_signal.
    %
    %   The function first computes the overall SNR using the full signal vectors.
    %   Then it uses the unique levels in tx_signal to calculate the SNR for
    %   the symbols corresponding to each level separately.
    
    if isa(tx_signal,'Signal')
        tx_signal = tx_signal.signal;
    end
    
    if isa(eq_noise,'Signal')
        eq_noise = eq_noise.signal;
    end
    
    % Calculate overall SNR using the complete signals
    snr_all = snr(tx_signal, eq_noise);
    
    % Get the unique amplitude levels in the transmitted signal
    levels = unique(tx_signal);
    
    % Preallocate an array to store the SNR for each unique level
    % Loop over each unique level to compute the SNR for that level
    for i = 1:length(levels)
        % Find indices where tx_signal equals the current level
        idx = (tx_signal == levels(i));
    
        % Compute the SNR for these indices
        snr_per_level(i) = snr(tx_signal(idx), eq_noise(idx));
    
    end
end