To achieve accurate channel estimation by a user device.

A communication method installed in a spread spectrum communication system includes a plurality of user devices subordinate to one cell. The communication method includes a process of transmitting data codes from a base station to the user device at regular time positions in a transmission time interval with a plurality of subcarrier frequencies during the transmission of a data group. The data code includes a first pilot code adapted to each user device and a second pilot code fixed to the plurality of user devices. The first pilot code for each user is inserted into a data group for each user device.