Patent ID: 8861466

Claim:
A wireless transmit/receive unit (WTRU), comprising: first circuitry configured to receive information from a base station indicating an assignment of periodic time slots to transmit sounding signals; second circuitry configured to transmit sounding signals to the base station in the assigned periodic time slots in response to the received information, wherein the WTRU does not transmit any data at a same time that the WTRU transmits the sounding signals, wherein: a timing of transmission of the sounding signals in response to the received information in a time division duplex (TDD) mode differs from a timing of transmission of the sounding signals in response to the received information in a frequency division duplex (FDD) mode, and the transmitted sounding signals of the WTRU are distinguishable from sounding signals from other WTRUs; and third circuitry configured to receive beamformed downlink transmissions from the base station based on the transmitted sounding signals.