Patent ID: 7315529

Claim:
A method of pre-distorting a signal (S i (t)) to be transmitted over an uplink transmission channel to a base station by a mobile terminal (i), each symbol (d i ) transmitted by said mobile terminal being spread with a coding sequence (c i (l)) over a plurality of carriers (l) to produce a plurality of corresponding frequency components (d i c i (l)) of said signal (S i (t)), comprising: weighting each frequency component (d i c i (l)) by a weighting coefficient (ω i (l)) corresponding to a channel response coefficient (h i (l)) of a corresponding downlink transmission channel at a corresponding frequency (f l ) and to a value of a noise variance (σ 2 ) affecting said plurality of carriers, the weighting coefficient ω i (l) being ω i ⁡ ( l ) = α ′ ⁢ h i * ⁡ ( l ) β ⁢ K - 1 N ⁢  h i ⁡ ( l )  2 + σ 2 where, K is a number of active mobile terminals served by said base station, N is a length of said coding sequence, α′ is a normalisation coefficient, β is a real weighting coefficient, and * denotes a conjugate operation.