function plotcumcoherence(obj)
mu = cumcoherence(obj);
v = conv(mu,[1 1]);
ind = find(v<1, 1, 'last');
plot(1:obj.len,mu);
hold on
line([ind ind], [min(mu) max(mu)],'Color','red');
title(['Minimum allowed sparsity (Tanner):' num2str(ind/obj.len)]);
grid on
end