Allocate power so as to maximise the throughput of each user of a multi-user MIMO group, with the constraint that over time all users in the group have equal throughput. This differs from equal capacity per slot in that each user may be assigned multiple slots as well as unequal power. This is illustrated in FIG. 4. Total throughput is maximised on any given slot for any two users. Power is shared between the spatial modes such that the total number of slots used by the two users is minimised. The membership of the MIMO group may change between slots and thus throughput is not necessarily equalised on a slot by slot basis.