A signal pair interference power ratio of the received signal at a user
terminal is obtained and this ratio is then compared with the signal pair
interference power ratio required for correct demodulation. Accordingly,
the user terminals can be classified into those in the non-interference
domain and those in the interference domain. A plurality of access points
make the simultaneous communications to the user terminals in the
non-interference domain and also make the communications on the
time-division basis to the user terminals in the interference domain.
Thereby, it is now possible to solve the problem, in the communication
system in which the total throughput of the system can be improved
through simultaneous transmissions from a plurality of access points with
the wireless access system to connect the user terminals to the wired
network via the access points, that the throughput of the user terminal
which cannot demodulate correctly the desired signal if the data packets
collide with each other is more deteriorated than the user terminal which
can correctly demodulate the desired signal because the desired signal
pair interference power ratio is large even when the data packets collide
with each other.