Patent ID: 8086181

Claim:
A method comprising: at a base station, receiving uplink signals transmitted from at least one mobile terminal, the uplink signals being sent using a training sequence assigned to the at least one mobile terminal; estimating a vector channel impulse response for the mobile terminal based on the training sequence contained in the uplink signals; estimating a spatial signature based on the training sequence for the mobile terminal; generating one or more uplink nulling weights for the mobile terminal using the estimated spatial signature and interference information representing interfering signals; generating a scalar channel impulse response from the vector channel impulse response, wherein generating the scalar channel response comprises performing a nulling operation based on the vector channel impulse response with the uplink nulling weights to derive the scalar channel impulse response; detecting one or more uplink symbols contained in uplink signals received from the mobile terminal using the scalar channel impulse response; generating one or more downlink nulling weights from the uplink nulling weights; beamforming downlink signals via a plurality of antennas of the base station to the mobile terminal using the downlink nulling weights; computing an interference intensity after the nulling operation using the uplink nulling weights; and determining whether to switch a carrier for the mobile terminal based on the interference intensity.