A communication system employs a transmitting device and a receiving device. The transmitting device allocates certain data, based on transmission data, to both a non-superposed band, corresponding to a frequency band with no interference signal present, and a superposed band, corresponding to a frequency band where an interference signal is present. Alternatively, the transmitting device allocates the data to the non-superposed band while giving a higher priority to the non-superposed band. The transmitting device then generates and transmits a multicarrier signal based on the allocation, so that the receiving device can receive it.