Mechanism for Beam Reciprocity Determination and Uplink Beam Management
A method of beam reciprocity state reporting and uplink beam management in wireless communication systems with beamforming is proposed. In one novel aspect, a UE determines its UE beam reciprocity state and sends a “UE beam reciprocity state” message to a BS, which triggers proper uplink beam management accordingly. The UE beam reciprocity state message can take place when UE tries to register to the network. For example, according to factory setting, UE reports at least “Positive” or “Negative” in this message. Beam reciprocity state can be updated by a “UE beam reciprocity state update” message. An auxiliary information can be transmitted to the BS for UL beam management if UE reports “Negative” for beam reciprocity state. The auxiliary information indicates the uncertainty level of UE beams.
1 . A method comprising:
obtaining a beam reciprocity state by a user equipment (UE) in a beamforming communication network;
providing the beam reciprocity state to a base station, wherein the beam reciprocity state indicates a positive or a negative UE beam reciprocity state; and
performing an uplink beam management procedure when the beam reciprocity state indicates the negative UE beam reciprocity state, wherein the UE receives resource configuration and transmits reference signals over the configured resource using corresponding UE beams.
2 . The method of claim 1 , wherein the beam reciprocity state is obtained according to a factory setting.
3 . The method of claim 1 , wherein the beam reciprocity state is provided via a beam reciprocity state message or a beam reciprocity state update message.
4 . The method of claim 1 , wherein the UE transmits auxiliary information that comprises an uncertainty level of UE beams to the base station when the UE reports the negative beam reciprocity state.
5 . The method of claim 4 , wherein the auxiliary information is represented by a bit string, and wherein a value of the bit string indicates the uncertainly level of the UE beams.
6 . The method of claim 1 , further comprising:
performing a beam reciprocity determination procedure when the beam reciprocity state indicates an unsure UE beam reciprocity state.
7 . The method of claim 6 , wherein the beam reciprocity determining procedure further involves:
receiving resource configuration from the base station;
performing uplink transmission based on the resource configuration using a selected number of UE beams;
receiving resource indices with stronger metric from the base station; and
determining the beam reciprocity state based on the received resource indices and downlink beam management results.
8 . A User Equipment (UE) comprising:
a radio frequency (RF) transmitter that transmits a beam reciprocity state to a base station in a beamforming communication network, wherein the UE obtains the beam reciprocity state that indicates a positive or a negative UE beam reciprocity state; and
a beam management circuit that performs an uplink beam management procedure when the beam reciprocity state indicates the negative UE beam reciprocity state, wherein the UE receives resource configuration and transmits reference signals over the configured resource using corresponding UE beams.
9 . The UE of claim 8 , wherein the beam reciprocity state is obtained according to a factory setting.
10 . The UE of claim 8 , wherein the beam reciprocity state is provided via a beam reciprocity state message or a beam reciprocity state update message.
11 . The UE of claim 8 , wherein the UE transmits auxiliary information that comprises an uncertainty level of UE beams to the base station when the UE reports the negative beam reciprocity state.
12 . The UE of claim 11 , wherein the auxiliary information is represented by a bit string, and wherein a value of the bit string indicates the uncertainly level of the UE beams.
13 . The UE of claim 8 , further comprising:
a beam monitoring circuit that performs a beam reciprocity determination procedure when the beam reciprocity state indicates an unsure UE beam reciprocity state.
14 . The UE of claim 13 , wherein the beam reciprocity determining procedure further involves receiving resource configuration, performing uplink transmission based on the resource configuration using a selected number of UE beams, receiving resource indices with stronger metric, and determining the beam reciprocity state based on the received resource indices and downlink beam management results.
15 . A method, comprising:
receiving a beam reciprocity state from a user equipment (UE) by a base station in a beamforming communication network, wherein the beam reciprocity state indicates a positive or a negative UE beam reciprocity state; and
triggering an uplink beam management procedure when the beam reciprocity state indicates the negative UE beam reciprocity state, wherein the beam management procedure involves configuring resource and receiving reference signals over the configured resource with corresponding UE beams.
16 . The method of claim 15 , wherein the base station receives the beam reciprocity state via a beam reciprocity state message or a beam reciprocity state update message.
17 . The method of claim 15 , wherein the base station receives auxiliary information that comprises an uncertainty level of UE beams when the beam reciprocity state is negative.
18 . The method of claim 17 , wherein the auxiliary information is represented by a bit string, and wherein a value of the bit string indicates the uncertainly level of UE beams.
19 . The method of claim 15 , wherein the base station triggers a beam reciprocity determination procedure when the beam reciprocity state indicates an unsure UE beam reciprocity state.
20 . The method of claim 19 , wherein the beam reciprocity determining procedure further involves configuring resource to the UE and transmitting resource indices with stronger metric from the base station.