Method of allocating communication codes to channels set up in respect of mobile terminals in communication in a cell of a radiocommunication system, in which the cell is served by a fixed station having means of adjustment of send/receive parameters defining a respective antenna pattern in respect of each mobile terminal in the cell, in which the allocated communication codes form part of a set of codes some at least of which are mutually orthogonal. In response to channel setup or reconfiguration request in respect of a first mobile terminal in the cell, the allocation to the said channel of a code nonorthogonal to at least one code of the set already allocated to another channel set up in respect of a second mobile terminal in the cell is conditionally admitted, as a function of a comparison between the send/receive parameters determined in respect of the first and second terminals.