Uplink transmit diversity
The present disclosure discloses a method in a wireless access network node for controlling a UE. The UE comprises at least two transmit antennas, and is capable of uplink transmit diversity. There is an antenna weight associated with each transmit antenna. First, the wireless access network node determines that the antenna weights of the user equipment may be controlled. Then, it creates a control signal that comprises control information and transmits it to the user equipment. The control information controls a UE autonomous selection of the antenna weights in the UE.
1. A method in a wireless access network node for controlling a user equipment, wherein the user equipment is capable of uplink transmit diversity and comprises at least two transmit antennas and wherein the method comprises:
creating a control signal comprising control information that defines one or more control parameters for autonomous switching of the transmit antennas by the user equipment; and
transmitting the control signal to the user equipment.
2. The method of claim 1 , wherein the control information comprises an order to the user equipment to make an autonomous selection of the antennas.
3. The method of claim 2 , wherein the control information comprises an order to the user equipment to make an autonomous selection of the antennas at a specified time.
4. The method of claim 1 , wherein the control information comprises an order to enable, disable or toggle use by the user equipment of uplink transmit diversity.
5. The method of claim 1 , wherein the control information comprises permission to the user equipment to autonomously select the antennas.
6. The method of claim 5 , wherein the control information comprises information indicating a number of allowed autonomous user equipment selections of the antennas.
7. The method of claim 5 , wherein the control information comprises information on a time period during which the user equipment may autonomously select the antennas.
8. The method of claim 5 , wherein the control information comprises permission to the user equipment to autonomously select the antennas until it receives an order to stop.
9. The method of claim 5 , wherein the control information comprises permission to the user equipment to autonomously select the antennas until a serving cell change occurs.
10. The method of claim 5 , wherein the control information comprises permission to the user equipment to autonomously select the antennas at a specified time.
11. The method of claim 1 , wherein the control signal is transmitted to the user equipment using a reserved value.
12. The method of claim 1 , wherein the control signal is transmitted to the user equipment on the Medium Access Control layer 2.
13. The method of claim 1 , wherein the control signal is transmitted to the user equipment using a reserved Transport Format and Resource Indicator value, and wherein the control signal is transmitted on a High Speed-Shared Control Channel.
14. The method of claim 1 , wherein the control signal is transmitted to the user equipment as an absolute grant value “inactive” on a secondary Enhanced Dedicated Transport Channel-Radio Network Temporary Identifier over an Enhanced Dedicated Transport Channel-Absolute Grant Channel.
15. The method of claim 1 , wherein the control signal is transmitted on a physical channel that is allocated primarily for controlling uplink transmit diversity.
16. The method of claim 1 , allocated the network node and the user equipment are configured for multi-carrier operation, and wherein the control information comprises an indication of a carrier on which the user equipment is to base its selection of antennas.
17. The method of claim 1 , wherein the network node and the user equipment are configured for multi-carrier operation, wherein the control signal is transmitted on a downlink carrier, and wherein the control signal is an instruction to the user equipment to base the autonomous selection of antennas on an uplink carrier corresponding to the downlink carrier.
18. A method in a user equipment configured to be used in a wireless access network and to be controlled by a wireless network node, wherein the user equipment is capable of uplink transmit diversity and comprises at least two transmit antennas and wherein the method comprises:
receiving a control signal from the wireless network node, the control signal comprising control information that defines one or more control parameters for autonomous switching of the transmit antennas by the user equipment; and
performing autonomous selection of the antennas according to the control information.
19. A method in a user equipment configured to be used in a wireless access network and to be controlled by a wireless network node, wherein the user equipment is capable of uplink transmit diversity and comprises at least two transmit antennas, wherein an antenna weight is associated with each transmit antenna, and wherein the method comprises:
performing an autonomous selection of the transmit antennas by the user equipment; and
transmitting a control signal to the wireless network node, the control signal comprising information of the autonomous selection of the antennas.
20. The method of claim 19 , wherein the control signal is transmitted to the wireless network node using a reserved Enhanced-Dedicated Channel Transport Format Combination Indicator.
21. The method of claim 19 , wherein the control signal comprises information on a performed autonomous selection of the antennas.
22. The method of claim 19 , wherein the control signal comprises information on a planned autonomous selection of the antennas.
23. A wireless access network node configured to control a user equipment that is capable of uplink diversity and comprises at least two transmit antennas, wherein the wireless access network node comprises:
a signal unit configured to create a control signal comprising control information that defines one or more control parameters for autonomous switching of the transmit antennas by the user equipment; and
a transmitter configured to transmit the control signal to the user equipment.
24. A user equipment configured to be used in a wireless access network and to be controlled by a wireless network node, wherein the user equipment is capable of uplink transmit diversity and comprises at least two transmit antennas, and wherein the user equipment comprises:
a receiver configured to receive a control signal from the wireless network node, the control signal comprising control information that defines one or more control parameters for autonomous switching of the transmit antennas by the user equipment; and
an antenna selector configured to autonomously select the antennas.