A method for providing bit loading computation in a multi-carrier communication system, the method comprising measuring the signal to noise ratios (SNRs) for carriers and determining in dependence of the SNR a related number of bits to be loaded (=allocated) to the respective carrier, is characterised in that it comprises the steps of:

a) providing a sliding window,
b) moving the sliding window over the frequency spectrum of the carriers,
c) for each position of the window determining bit allocation for the newly introduced carrier(s),
d) in the event that a predetermined average power spectrum density threshold (TPSD) of the carriers over the window is exceeded, selecting at least one carrier within the window for power spectrum density reduction at the expense of at least one bit.