A radiocommunication system comprising: a network infrastructure incorporating a radiocommunication station, and a radiocommunication terminal comprising: means for communicating with the network infrastructure incorporating the radiocommunication station, and means for receiving and processing several versions of a signal transmitted with polarisation diversity according to n_pol polarisations by said radiocommunication station, means for measuring, at least for some of the versions of a signal transmitted by said radiocommunication station according to a predetermined polarisation among n_pol, a mean power contribution of the noise interfering with a useful signal relating to said transmitted signal, and means for transmitting said mean power contribution of the noise, measured for each predetermined polarisation among n_pol, to the radiocommunication network infrastructure; said mean power contribution of the noise, measured for each predetermined polarisation among n_pol, being used by the radiocommunication station for adaptively controlling respective transmission powers of said version of the signal in order to obtain an optimal transmission power distribution of the signal between the polarisations based on the minimisation of a cost function relative to a quality of the signal received by the radiocommunication terminal. a network infrastructure incorporating a radiocommunication station, and a radiocommunication terminal comprising: means for communicating with the network infrastructure incorporating the radiocommunication station, and means for receiving and processing several versions of a signal transmitted with polarisation diversity according to n_pol polarisations by said radiocommunication station, means for measuring, at least for some of the versions of a signal transmitted by said radiocommunication station according to a predetermined polarisation among n_pol, a mean power contribution of the noise interfering with a useful signal relating to said transmitted signal, and means for transmitting said mean power contribution of the noise, measured for each predetermined polarisation among n_pol, to the radiocommunication network infrastructure; means for communicating with the network infrastructure incorporating the radiocommunication station, and means for receiving and processing several versions of a signal transmitted with polarisation diversity according to n_pol polarisations by said radiocommunication station, means for measuring, at least for some of the versions of a signal transmitted by said radiocommunication station according to a predetermined polarisation among n_pol, a mean power contribution of the noise interfering with a useful signal relating to said transmitted signal, and means for transmitting said mean power contribution of the noise, measured for each predetermined polarisation among n_pol, to the radiocommunication network infrastructure; said mean power contribution of the noise, measured for each predetermined polarisation among n_pol, being used by the radiocommunication station for adaptively controlling respective transmission powers of said version of the signal in order to obtain an optimal transmission power distribution of the signal between the polarisations based on the minimisation of a cost function relative to a quality of the signal received by the radiocommunication terminal.