Impacts of the simulated standard siren on estimating cosmological
  parameters
  We propose a method based on the process of extracting gravitational wave
(GW) parameters from GW signals to simulate the binary neutron-star (BNS)
merging events. We simulate 1000 GW standard sirens based on the observation of
the Einstein Telescope (ET). Almost all the simulated GW data are in the
redshift range of $[0,3]$. The role of the GW standard siren in the inference
of the cosmological parameters is investigated. We find that the GW data can
help improve the accuracy of cosmological parameters. Moreover, the degeneracy
of cosmological parameters is broken by the GW data. The GW standard siren is
helpful for the constraint of the cosmological parameters.
