Method for reducing the crest factor

A method for reducing a crest factor of a data symbol to be transmitted in a multi-carrier data transmission system, the data symbol being a function of a plurality of signals provided within a predetermined data frame, each of the plurality of signals allocated to a carrier, each carrier occupying at least one frequency from a transmit data spectrum, at least one carrier being reserved which is not provided for the data transmission, the method comprising:

• receiving the predetermined data frame, the predetermined data frame exhibiting the data symbol and a cyclic prefix which is derived from a part of the data symbol;
• and
• performing crest factor reduction corresponding to the predetermined data frame based at least in part on peak values within the cyclic prefix of the predetermined data frame, by:
• (a) filtering the data symbol and the cyclic prefix;
• (b) determining whether a time-domain function of the data symbol and of the cyclic prefix within the predetermined data frame exhibits at least one peak value that exceeds a first threshold;
• (c) determining an amplitude of an exhibited peak value and an associated position within the predetermined data frame;
• (d) generating a correction function by scaling and transposing a sample correction function in dependence on the amplitude and associated position of the exhibited peak value;
• (e) using the at least one carrier which is not available for data transmission for generating the sample correction function in the time-domain;
• and
• (f) modifying the data symbol to be transmitted by superimposing the correction function.