Working Kerr effect; PDM; speedups; removed unused files

[4yp.git] / pdm_adaptiveCMA.m

function [x, y] = pdm_adaptiveCMA(rx, ry)
  taps = 19; % ODD taps
  hxx = zeros(taps, 1);
  hxy = zeros(taps, 1);
  hyx = zeros(taps, 1);
  hyy = zeros(taps, 1);
  %% hxx: real indices  -K, ..., 0, ..., K.   K = floor(taps/2)
  %%    MATLAB indices   1      1+K     taps
  %% initialize hxx, hxx[0] = 1, hxx[k] = hxx[-k] = 0
  hxx(ceil(taps/2)) = 1;
  hxy(ceil(taps/2)) = 1;
  hyx(ceil(taps/2)) = 1;
  hyy(ceil(taps/2)) = 1;

  mu = 1e-3;
  numSymbs = length(rx);

  %% Check average energy of symbols
  rx = rx / sqrt(mean(abs(rx) .^ 2));
  ry = ry / sqrt(mean(abs(ry) .^ 2));

  x = zeros(numSymbs, 1);
  y = zeros(numSymbs, 1);
  converged = 0;
  convergeCount = 0;
  convergeIdx = Inf;

  for it = 1:numSymbs
    if it <= (taps - 1) / 2;
      xp = [zeros((taps - 1) / 2 - it + 1, 1); rx(1:it + (taps - 1) / 2)];
      yp = [zeros((taps - 1) / 2 - it + 1, 1); ry(1:it + (taps - 1) / 2)];
    elseif it + (taps - 1) / 2 > numSymbs
      xp = [rx(it - (taps - 1) / 2 : end); zeros(it + (taps - 1) / 2 - numSymbs, 1)];
      yp = [ry(it - (taps - 1) / 2 : end); zeros(it + (taps - 1) / 2 - numSymbs, 1)];
    else
      xp = rx(it - (taps - 1) / 2 : it + (taps - 1) / 2);
      yp = ry(it - (taps - 1) / 2 : it + (taps - 1) / 2);
    end

    xout = sum(hxx .* xp) + sum(hxy .* yp);
    yout = sum(hyx .* xp) + sum(hyy .* yp);
    ex = 1 - abs(xout) ^ 2;
    ey = 1 - abs(yout) ^ 2;

    if abs(ex) < 0.01
      convergeCount = convergeCount + 1;
    else
      convergeCount = 0;
    end
    if ~converged && convergeCount >= 10
      converged = 1;
      convergeIdx = it;
    end

    x(it) = xout;
    y(it) = yout;

    hxx = hxx + mu * ex * xout * conj(xp);
    hxy = hxy + mu * ex * xout * conj(yp);
    hyx = hyx + mu * ey * yout * conj(xp);
    hyy = hyy + mu * ey * yout * conj(yp);


    if sum(abs(hxx - hyx)) < 0.01 && sum(abs(hxy - hyy)) < 0.01
      hxx = 0.5 * (hxx + flipud(conj(hyy)));
      hyy = conj(flipud(hxx));
      hxy = 0.5 * (hxy - conj(flipud(hyx)));
      hyx = -conj(flipud(hxy));
    end

  end
end