  We examine the shot noise spectrum properties of coherent resonant tunneling
in coupled quantum dots in both series and parallel arrangements by means of
quantum rate equations and MacDonald's formula. Our results show that, for a
series-CQD with a relatively high dot-dot hopping $\Omega$,
$\Omega/\Gamma\gtrsim 1$ ($\Gamma$ denotes the dot-lead tunnel-coupling
strength), the noise spectrum exhibits a dip at the Rabi frequency, $2\Omega$,
in the case of noninteracting electrons, but the dip is supplanted by a peak in
the case of strong Coulomb repulsion; furthermore, it becomes a dip again for a
completely symmetric parallel-CQD by tuning enclosed magnetic-flux.
