  Gravitational waves emitted by high redshift sources propagate through
various epochs of the Universe including the current era of measurable,
accelerated expansion. Historically, the calculation of gravitational wave
power on cosmological backgrounds is based on various simplifications,
including a $1/r$-expansion and the use of an algebraic projection to retrieve
the radiative degrees of freedom. On a de Sitter spacetime, recent work has
demonstrated that many of these calculational techniques and approximations do
not apply. Here we calculate the power emitted by a binary system on a de
Sitter background using techniques tailored to de Sitter spacetime. The common
expression for the power radiated by this source in an FLRW spacetime,
calculated using far wave-zone techniques, gives the same expression as the
late time expansion specialized to the de Sitter background in the
high-frequency approximation.
