A communication apparatus includes a reference signal generating section,
a transmitting section, a propagation estimating section, a first data
acquiring section, and a decoding section. The reference signal
generating section generates a first reference signal to enable a
communicating party to estimate a propagation environment. The
transmitting section transmits the first reference signal. The
propagation estimating section estimates a first propagation estimation
value of the propagation environment using a second reference signal
transmitted from the communicating party. The first data acquiring
section generates first data using the first propagation estimation
value. The decoding section decodes a transmission signal encoded using a
second propagation estimation value that is estimated by the
communicating party using the first reference signal, to obtain second
data using the first data.