A method is provided for operating a cellular radio communication system
with a base station, which may be switched between an operating state
without closed-loop antenna diversity and an operating state with
closed-loop antenna diversity, emitting a downlink signal with a
weighting vector and a user station, for receiving the downlink signal
and transmitting an uplink signal to the base station, delivering
back-coupling information to the base station in the operating state with
closed-loop antenna diversity, representing a determined weighting
vector. On transition of the radio communication system into the
operating state with closed-loop antenna diversity, the user station
delivers back-coupling information, representing a weighting vector
determined and known before the transition into the operating state with
closed-loop antenna diversity, to the base station until a current
weighting vector is determined by measurement, and then delivers the
back-coupling information representing the current weighting vector.