  Recent experiments have revealed incommensurate charge density wave (CDW) in
the pseudogap regime in underdoped cuprates, e.g. YBa$_2$Cu$_3$O$_{6+\delta}$
and HgBa$_2$CuO$_{4+\delta}$. However, its relationship with the pseudogap is
still controversial. In this work, we take a phenomenological synthesis of the
doped resonating valence bond (RVB) state and the CDW order. Starting from the
Yang-Rice-Zhang Green's function ansatz for the doped RVB state [Phys. Rev. B
{\bf 73}, 174501 (2006)], in which the Fermi surface is partially truncated
into four nodal hole-like Fermi pockets by the antinodal RVB gap, we show that
the CDW order at the wavevectors connecting the tips of the Fermi arcs (the
hotspots) induces Fermi surface reconstruction, giving rise to an electron-like
Fermi pocket ($\alpha$ orbit) and a new hole-like Fermi pocket ($\beta$ orbit).
The $\alpha$ orbit is formed by joining the Fermi arcs at the hotspots and it
dominates the quantum oscillation Fourier spectrum, while the $\beta$ orbit is
formed by joining the outer patches of the original hole pockets, which has
vanishingly small spectral weight. The areas enclosed by these orbits are
extracted from the density of states oscillation in magnetic field and
quantitatively agree with the experiments.
