MULTICARRIER TRANSMISSION SYSTEM

PROBLEM TO BE SOLVED: To prevent remarkable decrease in a communication capacity and to detect the same channel interference in real time on the receiver side. SOLUTION: A multiplexer 1 inserts a pilot signal for synchronization to a head of a frame of transmission information and a demultiplexer 2 distributes n sets of outputs, one of which is used for a pilot signal and the other (n-1) sets of which are used for information data and they are distributed and outputted. After each output is modulated, a shifter 4 is used to shift each frequency to be a multicarrier frequency. A level converter 6 changes a level of the pilot signal and the resultant output in given by a combining device 7. The receiver side detects channel interference by using a non-signal part of the specific pilot carrier.