TECHNICAL FIELD

The present application relates generally to wireless communication technology including beam-formed transmission and reception.

BACKGROUND

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

High frequency bands (e.g., above 6 GHz) are used in 5th Generation (5G) wireless communication systems to increase system capacity. Beamforming schemes can be employed to focus transmitted and/or received signal in a desired direction to compensate for path loss of high frequency signals. For example, a base station may employ multiple beams to cover a serving area in a 5G system.

SUMMARY

Aspects of the disclosure provide an electronic device including processing circuitry and a method for beam failure recovery (BFR). When beam failure is determined to occur on at least one of a plurality of cells configured for the electronic device, the processing circuitry can send a BFR scheduling request (SR) to a network. The BFR SR can indicate the beam failure and requesting resources to report the beam failure. The processing circuitry can receive priority scheduling for the resources from the network. The processing circuitry can send a BFR request (BFRQ) using the resources. The BFRQ can indicate cell information of the at least one of the plurality of cells and new beam information of one or more new candidate beams for the at least one of the plurality of cells.

In an embodiment, the plurality of cells includes a primary cell (PCell) and a secondary cell (SCell). The at least one of the plurality of cells includes the SCell. The processing circuitry can send the BFR SR to the network using a Physical Uplink Control Channel (PUCCH) configured for the PCell. The processing circuitry can receive the priority scheduling for a BFRQ MAC control element (CE) that indicates a cell index of the SCell and a new beam index for a new candidate beam for the SCell. The resources can include the BFRQ MAC CE. The cell information can include the cell index. The one or more new candidate beams can include the new candidate beam. The new beam information can include the new beam index. The processing circuitry can send the BFRQ MAC CE using a Physical Uplink Shared Channel (PUSCH) configured for the PCell and receive a BFR response (BFRR) from the network.

In an embodiment, the plurality of cells includes a PCell and an SCell. The at least one of the plurality of cells includes the SCell. The processing circuitry can send the BFR SR to the network using a PUCCH configured for the PCell. The processing circuitry can receive scheduling for an aperiodic. CSI (A-CSI) that indicates a cell index of the SCell and a new beam index for a new candidate beam for the SCell. The resources can include the A-CSI, the cell information can include the cell index, the one or more new candidate beams can include the new candidate beam, and the new beam information can include the new beam index. The processing circuitry can send the A-CSI on a PUCCH configured for the PCell and receive a BFRR from the network.

In an embodiment, the at least one of the plurality of cells is a PCell configured with one or more serving control channels to communicate with the network. The processing circuitry can determine that the beam failure occurs on the PCell when at least one of the one or more serving control channels fails.

In an example, the processing circuitry can send the BFR SR to the network using a PUCCH configured for the PCell. The processing circuitry can receive the priority scheduling for a BFRQ MAC CE that indicates a cell index of the PCell and a new beam index for a new candidate beam for the PCell. The resources can include the BFRQ MAC CE, the cell information can include the cell index, the one or more new candidate beams can include the new candidate beam, and the new beam information can include the new beam index. The processing circuitry can send the BFRQ MAC CE using a PUSCH configured for the PCell and receive a new beam update from the network.

In an example, the processing circuitry can send the BFR SR includes sending the BFR SR to the network using a PUCCH configured for the PCell. The processing circuitry can receive scheduling for an A-CSI that indicates a cell index of the PCell and a new beam index for a new candidate beam. The resources can include the A-CSI, the cell information can include the cell index, the one or more new candidate beams can include the new candidate beam, and the new beam information can include the new beam index. The processing circuitry can send the A-CSI on a PUCCH configured for the PCell and receive a new beam update from the network.

In an embodiment, the BFR SR has a BFR SR configuration including a period and an offset. In an example, the BFR SR configuration is associated with a PUCCH format 0 that includes multiple cyclic shifts. One or more of the multiple cyclic shifts can be configured for at least one of: 1) the BFR SR and 2) the BFR SR and at least one of hybrid automatic repeat requests (HARQs). In an example, when the BFR SR is scheduled at a same time with a SR, the processing circuitry can send the BFR SR prior to sending the SR or send the BFR SR and the SR simultaneously.

In an example, the plurality of cells includes a first subset of cells and a second subset of cells, the BFR SR configuration is configured for the first subset of cells to report a beam failure for the first subset of cells where the first subset of cells includes the at least one of the plurality of cells. Another BFR SR configuration is configured for the second subset of cells to report a beam failure for the second subset of cells.

In an embodiment, the resources include a BFRQ MAC CE sent on a PUSCH. The BFRQ MAC CE indicates the cell information and the new beam information. The cell information includes at least one cell index corresponding to the at least one of the plurality of cells. The new beam information includes at least one new beam index for the at least one of the plurality of cells. In an example, the at least one of the plurality of cells includes an SCell and/or a PCell.

In an embodiment, the resources include an A-CSI sent on a PUCCH. The A-CSI indicates the cell information and the new beam information. The cell information includes at least one cell index corresponding to the at least one of the plurality of cells. The new beam information includes at least one new beam index for the at least one of the plurality of cells. In an example, the at least one of the plurality of cells includes an SCell and/or a PCell.

