  We present a power spectral density analysis of the short cadence Kepler data
for the cataclysmic variable V1504 Cygni. We identify three distinct periods:
the orbital period (1.669\pm0.005 hours), the superhump period (1.733\pm0.005
hours), and the infrahump period (1.628\pm0.005 hours). The results are
consistent with those predicted by the period excess-deficit relation.
