Electronic device and method for beam failure recovery

1. A method, comprising:

wirelessly receiving at least one signal from a network including a first cell configured for an electronic device;

determining whether beam failure occurs on the first cell based on at least one signal quality of the at least one signal; and

in response to the beam failure being determined to occur on the first cell,

performing a first step of a 2-step beam failure recovery request (BFRQ) procedure by transmitting a BFRQ to the network when no resource is available for reporting information of the first cell to the network, the BFRQ being a PUCCH transmission with PUCCH format 0 or PUCCH format 1 indicating the beam failure at the electronic device;

receiving an uplink (UL) grant signal from the network after transmitting the BFRQ, the UL grant signal granting a resource to the electronic device; and

performing a second step of the 2-step BFRQ procedure by reporting the information of the first cell to the network using the granted resource, the information of the first cell indicating a cell index of the first cell.

2. The method according to claim 1 , further comprising:

receiving at least one second signal from the network;

identifying a new beam for the first cell when at least one signal quality of the at least one second signal is equal to or larger than a threshold, the new beam corresponding to one of the at least one second signal; and

reporting information of the new beam to the network after transmitting the BFRQ to the network.

3. The method according to claim 2 , further comprising:

reporting the information of the first cell and the information of the new beam to the network using a medium access control (MAC) control element (CE) transmitted on a Physical Uplink Shared Channel (PUSCH) granted by the UL grant signal.

4. The method according to claim 2 , wherein the performing the first step of the 2-step BFRQ procedure comprises:

transmitting the BFRQ using a Physical Uplink Control Channel (PUCCH).

5. The method according to claim 4 , wherein the transmitting the BFRQ comprises:

transmitting the BFRQ using a PUCCH resource that is sequence-based in a scheduling request (SR)-like configuration that includes a resource identifier (ID), a period and an offset of a PUCCH transmission occasion using the PUCCH resource.

6. The method according to claim 4 , wherein:

the electronic device is served by a second cell configured with the PUCCH; and

the method further includes transmitting the BFRQ using the PUCCH configured for the second cell.

7. The method according to claim 4 , wherein

the resource includes a Physical Uplink Shared Channel (PUSCH) to the electronic device, and

the method further includes receiving configuration information for the PUCCH.

8. The method according to claim 7 , further comprising:

reporting the information of the first cell and the information of the new beam using a medium access control (MAC) control element (CE) transmitted on the PUSCH granted by the UL grant signal.

9. An electronic device, comprising:

a transceiver configured to wirelessly receive at least one signal from a network including a first cell configured for an electronic device; and

processing circuitry configured to:

determine whether beam failure occurs on the first cell based on at least one signal quality of the at least one signal; and

in response to the beam failure being determined to occur on the first cell,

perform a first step of a 2-step beam failure recovery request (BFRQ) procedure by transmitting a BFRQ to the network when no resource is available for reporting information of the first cell to the network, the BFRQ being a PUCCH transmission with PUCCH format 0 or PUCCH format 1 indicating the beam failure at the electronic device; and

perform a second step of the 2-step BFRQ procedure by reporting the information of the first cell to the network using a resource granted by the network, wherein the information of the first cell indicates a cell index of the first cell, an uplink (UL) grant signal is received from the network after the BFRQ is transmitted, and the resource is granted to the electronic device by the UL grant signal.

10. The electronic device according to claim 9 , wherein

the transceiver is configured to receive at least one second signal from the network; and

the processing circuitry is further configured to:

identify a new beam for the first cell when at least one signal quality of the at least one second signal is equal to or larger than a threshold, the new beam corresponding to one of the at least one second signal; and

report information of the new beam to the network after transmitting the BFRQ to the network.

11. The electronic device according to claim 10 , wherein the processing circuitry is further configured to:

report the information of the first cell and the information of the new beam to the network using a medium access control (MAC) control element (CE) transmitted on a Physical Uplink Shared Channel (PUSCH) granted by the UL grant signal.

12. The electronic device according to claim 10 , wherein the processing circuitry is further configured to:

transmit the BFRQ using a Physical Uplink Control Channel (PUCCH).

13. The electronic device according to claim 12 , wherein the processing circuitry is further configured to:

transmit the BFRQ using a PUCCH resource that is sequence-based in a scheduling request (SR)-like configuration that includes a resource identifier (ID), a period and an offset of a PUCCH transmission occasion using the PUCCH resource.

14. The electronic device according to claim 12 , wherein:

the electronic device is served by a second cell configured with the PUCCH; and

the processing circuitry is further configured to transmit the BFRQ using the PUCCH configured for the second cell.

15. The electronic device according to claim 12 , wherein

the transceiver is configured to:

receive configuration information for the PUCCH; and

the resource includes a Physical Uplink Shared Channel (PUSCH) to the electronic device.

16. The electronic device according to claim 15 , wherein the processing circuitry is further configured to:

report the information of the first cell and the information of the new beam using a medium access control (MAC) control element (CE) transmitted on the PUSCH granted by the UL grant signal.

17. A non-transitory computer readable medium having computer readable instructions stored thereon which, when executed by a processing circuit, cause the processing circuit to perform a method, the method comprising:

wirelessly receiving at least one signal from a network including a first cell configured for an electronic device;

determining whether beam failure occurs on the first cell based on at least one signal quality of the at least one signal; and

in response to the beam failure being determined to occur on the first cell,

performing a first step of a 2-step beam failure recovery request (BFRQ) procedure by transmitting a BFRQ to the network when no resource is available for reporting information of the first cell to the network, the BFRQ being a PUCCH transmission with PUCCH format 0 or PUCCH format 1 indicating the beam failure at the electronic device;

receiving an uplink (UL) grant signal from the network after transmitting the BFRQ, the UL grant signal granting a resource to the electronic device; and

performing a second step of the 2-step BFRQ procedure by reporting the information of the first cell to the network using the granted resource, the information of the first cell indicating a cell index of the first cell.

18. The non-transitory computer readable medium according to claim 17 , wherein the method further comprises:

receiving at least one second signal from the network;

identifying a new beam for the first cell when at least one signal quality of the at least one second signal is equal to or larger than a threshold, the new beam corresponding to one of the at least one second signal; and reporting information of the new beam to the network after transmitting the BFRQ to the network.