In soft hand over in a code division multi access mobile radio communication
system,
interference in a down link caused by transmission from a plurality of base stations
for one mobile station, can be restricted. Control of transmission power is performed
according to command from the mobile station only in the base station serving as
a primary base station which has minimum propagation loss with the mobile station
during soft hand over, and the base stations other than the primary base station
perform transmission with restricting output. In comparison with the transmission
power control performed by the conventional plural base station transmission, interference
for the peripheral mobile station can be reduced to achieve higher down link capacity.
Also, upon restricting transmission power of the base station other than the base
stations having small propagation loss with the mobile station among base station
group in soft hand over, by moderately attenuating the transmission power instead
of restricting abruptly, degradation of the reception quality can be prevented
when error is caused in selection of the base station.