Patent ID: 6980539

Claim:
A method for transmitting signals from a radio base station in a mobile communication system, the method comprising the steps of: (a) copying each data symbol of a data symbol sequence to be transmitted and arranging copied data symbols on a frequency axis; (b) doubly spreading the data symbol sequence, to obtain a spread data symbol sequence, by multiplying the copied data symbols arranged on the frequency axis by spreading codes including a short code and a long code, the short code being a code having a repetition period equal to a number of copies made from one data symbol and to be multiplied in the frequency axis direction, and the long code being a code having a repetition period longer than the number of copies made from one data symbol and longer than a number of sub-carriers and to be multiplied in the frequency axis direction and a time axis direction; and (c) transmitting the spread data symbol sequence by using a plurality of sub-carriers.