Patent attributes
When communications of the same data are performed using a multi-carrier modulation method between a plurality of base stations and a mobile station at the same time and with the same frequency, a standing wave interference is generated to lower the carrier electric field level and the bit error rate is increased if the mobile station is located in an area where the reception powers of the electric waves from the base stations are almost identical. In order to prevent this, phase differences are set between the sub-carriers at the base station so as to enable the mobile station to avoid a situation in which all the sub-carriers are mutually cancelled. Thus, it is possible to easily correct an error, thereby improving the quality of communication.