Transmitter for multi-carrier transmission and multi-carrier transmitting method

A transmitter for multi-carrier transmission configured to transmit a plurality of sub-carriers having a plurality of symbol durations comprising:

• spreaders configured to spread and transmit symbols over the symbol durations in a plurality of sub-carriers, using sub-carrier spreading factor assigned in the direction of the sub-carriers and time-base spreading factor assigned in the direction of the time base;
• and
• a controller configured to change the sub-carrier spreading factor or the time-base spreading factor, based on the condition of a propagation path between the transmitter and a receiver for multi-carrier transmission.

A multi-carrier transmitting method for multi-carrier transmission for transmitting a plurality of sub-carriers having at least one pilot symbol duration comprising:

• allocating a plurality of pilot symbol patterns which are orthogonal to each other, to the at least one pilot symbol durations in at least two sub-carriers.

A multi-carrier transmitting method for transmitting a plurality of sub-carriers having a plurality of symbol durations comprising:

• spreading and transmitting symbols over the symbol durations in a plurality of sub-carriers, using sub-carrier spreading factor assigned in the direction of the sub-carriers and time-base spreading factor assigned in the direction of the time base;
• and
• changing the sub-carrier spreading factor or the time-base spreading factor, based on the condition of a propagation path between the transmitter and a receiver for multi-carrier transmission.