function W_syms = calcWiener(drm_mode, drm_bw)
% calcWiener('B', '10k');
fs = 12000;
fd_max = 0.1;
tau_max = 0.0001;

[params, spec_occ] = drm_params(drm_mode, drm_bw);
N = params.nu
Ts = params.nu/fs
dF = 1/Ts

frames_per_window = 2*params.y
window_delay = params.y
num_symbols_per_frame = params.nspf
num_carrier_per_symbol = spec_occ.kmax - spec_occ.kmin - 1
num_symbols_per_frame = num_symbols_per_frame * num_carrier_per_symbol

% PHI = auto-covariance-matrix
f_cut_t = 0.0675*1/window_delay; % two-sided maximum doppler frequency (normalized w.r.t symbol duration Ts) 
f_cut_k = 1.75*params.ng/params.nu; % two-sided maximum echo delay (normalized w.r.t useful symbol duration Tu)

W_syms = cell( params.y, 1 );

for d=0:window_delay-1
    k2_pos = [];
    t2_pos = [];
    for s=0:frames_per_window-1
        [c, p, a] = getRefGain(params, spec_occ, s+d);
        k2_pos = [k2_pos c];                            % length = window_delay*frames_per_window
        t2_pos = [t2_pos ones(1, length(c))*(s)];       % length = window_delay*frames_per_window
    end
    
    PHI = zeros(length(k2_pos));
    % PHI
    for k1=1:length(k2_pos)
        k2 = [1:length(k2_pos)];
        k1_pos = k2_pos(k1);
        t1_pos = t2_pos(k1);
        PHI(k1,k2) = sinc(f_cut_k*(k1_pos-k2_pos)) .* sinc(f_cut_t*(t1_pos-t2_pos));
    end
    PHI_inv = inv(PHI + eye(length(PHI))*0.0001);

    THETA = zeros(1, length(k2_pos));
    % THETA
    carriers = spec_occ.kmin:spec_occ.kmax;
    for k1=1:length(carriers)
        k2 = [1:length(k2_pos)];
        k1_pos = carriers(k1);
        t1_pos = window_delay;
        THETA(k2) = sinc( (k1_pos-k2_pos)*f_cut_k ).*sinc( (t1_pos-t2_pos)*f_cut_t );
        W_syms{d+1}(:, k1) = transpose( THETA*PHI_inv );
    end
end