Improvements in, or relating to, multi-carrier transmission systems

The present invention provides a multi-carrier transmission system, for example a DKT system, in which channel information is transmitted between two transceivers using a plurality of sub-carriers modulated with symbols, each of which represents a plurality of bits, each of said transceivers including a receiver and a transmitter wherein a fixed maximum value is determined for the number of bits for each symbol, and wherein the system is adapted to determine the bit capacity per symbol of each of said plurality of sub carriers and to increase the number of bits represented by a symbol transmitted over those of the sub carriers having a capacity less than the fixed maximum value, to the maximum value when adding channel coding bits. The fixed maximum value for the number of bits for each symbol can be determined on the basis of the bit capacity of one of the sub-carriers.e having the highest theoretical bit capacity and may be at least as large as said theoretical bit capacity.