Mobile communication system and method for providing common channel coverage using beamforming antennas
A wireless transmit/receive unit (WTRU) includes circuitry configured to receive information from a base station indicating an assignment of periodic time slots to transmit sounding signals and circuitry configured to transmit sounding signals to the base station in the assigned periodic time slots in response to the received information, wherein a timing of transmission of the sounding signals in response to the received information differs between a time division duplex mode and a frequency division duplex mode, and wherein the transmitted sounding signals are distinguishable from sounding signals from other WTRUs.
1. A base station comprising:
first circuitry configured to transmit information to a wireless transmit/receive unit (WTRU) indicating an assignment of periodic time slots to transmit sounding signals;
second circuitry configured to receive sounding signals from the WTRU in the assigned periodic time slots in response to the transmitted information, wherein the base station does not receive any data from the WTRU at a same time that the base station receives the sounding signals from the WTRU, wherein a timing of reception of the sounding signals in response to the transmitted information in a time division duplex (TDD) mode differs from a timing of reception of the sounding signals in response to the transmitted information in a frequency division duplex (FDD) mode, and the received sounding signals of the WTRU are distinguishable from sounding signals from other WTRUs; and
third circuitry configured to transmit beamformed downlink transmissions to the WTRU based on the received sounding signals.
2. The base station according to claim 1 , further comprising:
fourth circuitry configured to transmit beamformed downlink transmissions simultaneously with a plurality of beamformed downlink transmissions from a plurality of cells.
3. The base station according to claim 1 , wherein the second circuitry receives the sounding signals in the FDD mode.
4. The base station according to claim 1 , wherein the second circuitry receives the sounding signals in the TDD mode.
5. A method performed by a base station, comprising:
transmitting information from the base station to a wireless transmit/receive unit (WTRU), the information indicating an assignment of periodic time slots to transmit sounding signals;
receiving sounding signals at the base station from the WTRU in the assigned periodic time slots in response to the transmitted information, wherein the base station does not receive any data from the WTRU at a same time that the base station receives the sounding signals from the WTRU, wherein a timing of reception of the sounding signals in response to the transmitted information in a time division duplex (TDD) mode differs from a timing of reception of the sounding signals in response to the transmitted information in a frequency division duplex (FDD) mode, and the received sounding signals of the WTRU are distinguishable from sounding signals from other WTRUs; and
transmitting a beamformed downlink transmission from the base station to the WTRU based on the transmitted sounding signals.
6. The method according to claim 5 , further comprising:
transmitting by the base station beamformed downlink transmissions simultaneously with a plurality of beamformed downlink transmissions from a plurality of cells.
7. The method according to claim 5 , wherein the sounding signals are received in an FDD mode.
8. The method according to claim 5 , wherein the sounding signals are received in a TDD mode.