UE-assisted SRS resource allocation
A dynamic UE capability message specifying a number of beams to be evaluated within different groups of UE TX beam directions associated with different antenna arrays of a UE may be communicated to a transmit receive point (TRP). Each group of UE TX beam directions may include beam directions that are candidates for uplink data transmission. Based on information in the dynamic UE capability message, the TRP can assign SRS resources (for uplink beam management or uplink channel sounding) and/or schedule a multi-layer MIMO uplink transmission in accordance with a UE capability constraint. This may ensure that the SRS resources assignment and/or scheduled multi-layer MIMO uplink transmission is consistent with the UE's beamforming capabilities.
1. A method for uplink beam management, the method comprising:
transmitting, by a user equipment (UE), a first uplink control message to a serving transmit receive point (TRP) indicating whether the UE has beam correspondence;
transmitting, by the UE, a second uplink control message to the serving TRP recommending a number of uplink resources to be allocated for each UE reported TRP transmit (TX) beam for uplink beam management based on whether the UE has beam correspondence, the second uplink control message recommending that a single uplink resource be allocated for each UE reported TRP TX beam when the UE has beam correspondence and recommending that multiple uplink resources be allocated for each UE reported TRP TX beam when the UE lacks beam correspondence; and
receiving, by the UE, a downlink control message from the serving TRP allocating one or more uplink resources for beamformed reference signal transmissions by the UE.
2. The method of claim 1 , wherein the downlink control message includes an indication of a TRP TX beam that is associated with the one or more uplink resources allocated by the downlink control message.
3. The method of claim 1 , further comprising:
transmitting, by the UE, one or more beamformed reference signals over the one or more uplink resources allocated by the downlink control message.
4. A user equipment (UE) comprising:
a processor; and
a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
transmit a first uplink control message to a serving transmit receive point (TRP) indicating whether the UE has beam correspondence;
transmit a second uplink control message to the serving TRP recommending a number of uplink resources to be allocated for each UE reported TRP transmit (TX) beam for uplink beam management based on whether the UE has beam correspondence, the second uplink control message recommending that a single uplink resource be allocated for each UE reported TRP TX beam when the UE has beam correspondence and recommending that multiple uplink resources be allocated for each UE reported TRP TX beam when the UE lacks beam correspondence; and
receive a downlink control message from the serving TRP allocating one or more uplink resources for beamformed reference signal transmissions by the UE.
5. The UE of claim 4 , wherein the downlink control message includes an indication of a TRP TX beam that is associated with the one or more uplink resources allocated by the downlink control message.
6. The UE of claim 4 , wherein the programming further includes instructions to transmit one or more beamformed reference signals over the one or more uplink resources allocated by the downlink control message.
7. A method for uplink beam management, the method comprising:
receiving, by a serving transmit receive point (TRP), a first uplink control message from a user equipment (UE), the first uplink control message indicating whether the UE has beam correspondence;
receiving, by the serving TRP, a second uplink control message from the UE, the second uplink control message recommending a number of uplink resources to be allocated for each UE reported TRP transmit (TX) beam for uplink beam management based on whether the UE has beam correspondence, the second uplink control message recommending that a single uplink resource be allocated for each UE reported TRP TX beam when the UE has beam correspondence and recommending that multiple uplink resources be allocated for each UE reported TRP TX beam when the UE lacks beam correspondence; and
transmitting, by the serving TRP, a downlink control message to the UE, the downlink control message allocating one or more uplink resources for beamformed reference signal transmissions by the UE.
8. The method of claim 7 , wherein the downlink control message includes an indication of a TRP TX beam that is associated with the one or more uplink resources allocated by the downlink control message.
9. The method of claim 7 , further comprising:
receiving, by the serving TRP, one or more beamformed reference signals over the one or more uplink resources allocated by the downlink control message.
10. A serving transmit receive point (TRP) comprising:
a processor; and
a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive a first uplink control message from a user equipment (UE), the first uplink control message indicating whether the UE has beam correspondence;
receive a second uplink control message from the UE, the second uplink control message recommending a number of uplink resources to be allocated for each UE reported TRP transmit (TX) beam for uplink beam management based on whether the UE has beam correspondence, the second uplink control message recommending that a single uplink resource be allocated for each UE reported TRP TX beam when the UE has beam correspondence and recommending that multiple uplink resources be allocated for each UE reported TRP TX beam when the UE lacks beam correspondence; and
transmit a downlink control message to the UE, the downlink control message allocating one or more uplink resources for beamformed reference signal transmissions by the UE.
11. The serving TRP of claim 10 , wherein the downlink control message includes an indication of a TRP TX beam that is associated with the one or more uplink resources allocated by the downlink control message.
12. The serving TRP of claim 10 , wherein the programming further includes instructions to:
receive one or more beamformed reference signals over the one or more uplink resources allocated by the downlink control message.