WIRELESS COMMUNICATION SYSTEM, BASE STATION, WIRELESS COMMUNICATION DEVICE, AND WIRELESS COMMUNICATION METHOD

摘要

The number of radio communication apparatuses allowed to transmit data on a certain channel is increased. A base station (10) classifies at least some of radio communication apparatuses (21 through 25) belonging to the same cell into a plurality of groups. The base station (10) assigns to a first group a signal sequence (31) that is orthogonal to a signal sequence obtained by a cyclic shift thereof, and assigns to a second group a signal sequence (33) that is orthogonal to a signal sequence obtained by a cyclic shift thereof and that is different from the signal sequence (31) and from the signal sequence obtained by a cyclic shift of the signal sequence (31). The radio communication apparatus (21, 22) belonging to the first group performs spread modulation on data using the signal sequence (31) or a signal sequence (32) obtained by a cyclic shift of the signal sequence (31). The radio communication apparatus (23, 24) belonging to the second group performs spread modulation on data using the signal sequence (33) or a signal sequence (34) obtained by a cyclic shift of the signal sequence (33).