% vim: set ts=2 sw=2 noet:
\begin{tikzpicture}[
		blk/.style = {
			draw, rectangle, thick, black,
			minimum width = 15mm,
			minimum height = 3mm,
			outer sep = 1mm,
			pattern = vertical lines,
			pattern color = lightgray,
		},
	]

	\foreach \i in {0,1,...,4}{
		\coordinate (blkC\i) at (15mm*\i,0);
		\node[blk] (blk\i) at (blkC\i) {};
		\node[below] (phi\i) at (blk\i.south west) {\(\varphi_{\i}\)};
	}
	% last phase 
	\node[below] (phi5) at (blk4.south east) {\(\varphi_{5}\)};

	% first block
	\node[blk, minimum width = 10mm, xshift = 2.5mm, fill = red!30] (S) at (-15mm,0) {};
	\node[anchor = east] at (S.west) {Input};

	% last block
	\node[blk, minimum width = 9mm, xshift = -3mm, fill = blue!30] (E) at ($(blk4)+(15mm,0)$) {};

	% labels
	\draw[thick, latex-] (blk3.north) to[out = 90, in = 180] ++(5mm,6mm)
		node[right] {Chunk of \(N\) samples};

	\draw[thick, latex-] (blk0.north east) ++(-1mm,0) to[out = 90, in = 0] ++(-5mm,6mm)
		node[left] (tags) {Phase tags};
\end{tikzpicture}