JP2022500886A - Beam failure recovery - Google Patents

Abstract

The embodiments of the present disclosure provide methods, devices, and computer-readable media for beam failure recovery. In an exemplary embodiment, a method implemented on a terminal device is provided. This method provides at least a primary cell (PCell) and a secondary cell (SCell) for the network device to service the terminal device, and in response to a beam failure detected in the SCell, the PCell and SCell. From, the beam fault recovery (BFR) request comprises determining the first cell to be transmitted to the network device and the response to the BFR request to determine the second cell to be received from the network device. The method further comprises transmitting a BFR request to the network device in the first cell. Further, this method further comprises monitoring the control channel search space in the second cell in order to receive a response to the BFR request from the network device. [Selection diagram] FIG. 4

Description

The embodiments of the present disclosure generally relate to the field of telecommunications, in particular to methods, devices, and computer readable media for beam fault recovery.

Channel / signal transmission relies on directional links because of the increased free-space propagation loss in the higher frequency bands supported by the new radio access (NR). In other words, conventional communication systems require communication based on a directional beam rather than omnidirectional communication. However, directional links require fine tuning of the transmit and receive beams achieved by a series of operations known as beam management. For example, beam management generally includes operations such as beam sweeping, beam measurement, beam determination, and beam reporting. By repeating these operations periodically, the optimum transmission / reception beam pair can be updated over time.

Beam failure can occur when the quality of the beam pair of the associated control channel is sufficiently degraded (eg, compared to the threshold or timeout of the associated timer). When a beam failure occurs, a mechanism to recover from the beam failure may be activated. Beam fault recovery mechanisms on the terminal device (eg, user equipment (UE)) side typically detect beam faults, identify new candidate beams, transmit beam fault recovery requests, and respond to beam fault recovery requests from network devices. Including operations such as monitoring. For example, the terminal device monitors the beam fault detection reference signal (RS) to assess whether a beam fault has occurred. In the event of a beam fault, the terminal device monitors the beam-specific RS to find new candidate beams. Once the candidate beam has been identified, the terminal device sends a beam fault recovery request containing information about the identified candidate beam to the network device. The terminal device monitors the control channel search space to detect the response to the beam failure recovery request from the network device. When the terminal device receives the beam recovery acknowledgment from the network device, a new beam pair is established and it can be determined that the beam fault has recovered.

In NR, a network device (eg, next generation NodeB (gNB)) can provide one primary cell (PCell) and at least one secondary cell (SCell) to service the terminal device. However, in the current 3GPP specification, the beam fault recovery procedure can only be applied to beam faults that occur in the PCell.

In general, exemplary embodiments of the present disclosure provide methods, devices, and computer-readable media for beam fault recovery.

In the first aspect, a method implemented in a terminal device is provided. In this method, the network device provides at least a primary cell (PCell) and a secondary cell (SCell) to serve the terminal device, and in response to a beam failure detected in the SCell, the PCell and From the SCell, determine the first cell in which the beam fault recovery (BFR) request is transmitted to the network device and the second cell in which the response to the BFR request is received from the network device, and in the first cell the BFR to the network device. It comprises transmitting a request and monitoring the control channel search space in a second cell to receive a response to a BFR request from a network device.

In the second aspect, a terminal device is provided. The terminal device comprises a processor and a memory attached to the processor. Memory, when executed by a processor, stores instructions that cause a terminal device to perform an operation. In the above operation, the network device provides at least a primary cell (PCell) and a secondary cell (SCell) to serve the terminal device, and in response to the detection of a beam failure in the SCell, the PCell and From the SCell, determine the first cell in which the beam fault recovery (BFR) request is transmitted to the network device and the second cell in which the response to the BFR request is received from the network device, and in the first cell the BFR to the network device. It involves transmitting the request and monitoring the control channel search space in the second cell to receive a response to the BFR request from the network device.

In the third aspect, a computer-readable medium in which the instructions are stored is provided. When the instructions are executed on at least one processor, the at least one processor causes the method according to the first aspect of the present disclosure to be executed.

In a fourth aspect, a computer program product tangibly stored in a computer-readable medium is provided. This computer program product, when executed on at least one processor, includes instructions that cause the at least one processor to perform the method according to the first aspect of the present disclosure.

Other features of the present disclosure can be easily understood by the following description.

Through a more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other purposes, features, and advantages of the present disclosure will become more apparent.

Shown is an exemplary communication network 100 in which embodiments of the present disclosure can be implemented.

An exemplary scenario 201 for the network 100 shown in FIG. 1 is shown.

Another exemplary scenario 202 for the network 100 shown in FIG. 1 is shown.

A problem that may occur in the BFR procedure in the exemplary scenario 202 shown in FIG. 2B is shown. A problem that may occur in the BFR procedure in the exemplary scenario 202 shown in FIG. 2B is shown.

A flowchart of an exemplary method 400 for beam failure recovery according to some embodiments of the present disclosure is shown.

It is a simplified block diagram of the device 500 suitable for the embodiment of the present disclosure.

In the entire drawing, the same or similar reference numbers represent the same or similar elements.

The principles of the present disclosure will be described with reference to some exemplary embodiments. It is understood that these embodiments are described for purposes of illustration only and will assist one of ordinary skill in the art in understanding and implementing the present disclosure without suggesting any limitation on the scope of the present disclosure. The disclosures described herein can be carried out in various embodiments other than those described below.

Unless otherwise defined in the following description and claims, all technical and scientific terms used herein are the same as commonly understood by those skilled in the art to which this disclosure belongs. It has meaning.

As used herein, the singular forms "one (a)", "one (an)", and "the" are unless the context clearly indicates otherwise. , Intended to include the plural. The term "contains" and its variants are read as an open term meaning "contains, but is not limited to". The term "based on" is read as "at least partially based". The terms "one embodiment" and "embodiment" are read as "at least one embodiment". The term "another embodiment" is read as "at least one other embodiment". Terms such as "first" and "second" can refer to different objects or the same object. The following may include other explicit and implicit definitions.

In some examples, the value, procedure, or device is referred to as "best," "lowest," "highest," "minimum," "maximum," and so on. Such statements are selectable from many used functional choices and are intended to indicate that such choices do not need to be better, smaller, higher, or more preferred than other choices. Please understand what you are doing.

As mentioned above, beam failure can occur when the quality of the beam pair of the associated control channel is sufficiently degraded (eg, compared to a given threshold or timeout of the associated timer). When a beam failure occurs, a mechanism to recover from the beam failure may be activated. Beam fault recovery mechanisms on the terminal device side typically include actions such as beam fault detection, new candidate beams, transmission of beam fault recovery requests, and monitoring of responses to beam fault recovery requests from network devices.

In NR, a network device (eg, next-generation NodeB (gNB)) can provide one primary cell (PCell) and at least one secondary cell (SCel) to service the terminal device. However, in the current 3GPP specification, the beam fault recovery procedure can only be applied to beam faults that occur in the PCell.

The embodiments of the present disclosure provide a solution for beam failure recovery to solve one or more of the above and other potential issues. The solution for beam fault recovery according to the embodiment of the present disclosure can be applied to beam faults generated in SCell. Moreover, embodiments of the present disclosure allow faster beam fault recovery than conventional beam fault recovery schemes.

Hereinafter, the principles and embodiments of the present disclosure will be described in detail with reference to FIGS. 1 to 5.

FIG. 1 shows an exemplary communication network 100 in which the embodiments of the present disclosure can be implemented. The network 100 includes a network device 110 and a terminal device 120 serviced by the network device 110. The network 100 may provide one or more serving cells 102 to provide services to the terminal device 120. It should be understood that the number of network devices, terminal devices and / or serving cells does not imply any limitation on the present disclosure and is for illustrative purposes only. The network 100 may include any suitable number of network devices, terminal devices and / or serving cells suitable for carrying out the embodiments of the present disclosure.

As used herein, the term "terminal device" refers to any device that has wireless or wired communication capabilities. Examples of terminal devices include image capture devices such as user equipment (UE: User Equipment), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, and digital cameras. , Game devices, music storage / playback devices, or Internet devices that enable wireless or wired Internet access and browsing, and the like, but are not limited thereto. For the purposes of the study, some embodiments will be described below with reference to the UE as an example of the terminal device 220.

As used herein, the term "network device" or "base station" (BS) refers to a device that can provide or host a cell or coverage that a terminal device can communicate with. Examples of network devices include Node B (NodeB or NB), Evolved NodeB (eNodeB or eNB), next-generation NodeB (gNB), remote radio unit (RRU: Remote Radio Unit), radio head (RH: Radio Head), remote. Examples include, but are not limited to, a remote radio head (RRH) and a low power node such as a femto node or a pico node.

For example, in some scenarios, network 100 may support carrier aggregation (CA), where two or more component carriers (CC) are aggregated to support wider bandwidth. In the CA, the network device 110 provides a plurality of serving cells (eg, one serving cell per CC) including one primary cell (PCell) and at least one secondary cell (SCell) to provide services to the terminal device 120. May be provided. The terminal device 120 can establish a radio resource control (RRC) connection with the network device 110 in the PCell. Once the RRC connection between the network device 110 and the terminal device 120 has been established and the SCell has been activated via upper layer signaling, the SCell can provide additional radio resources.

In some other scenarios, for example, the terminal device 120 may establish a connection with two different network devices (not shown in FIG. 1), thereby providing radio resources for the two network devices. Can be used. The two network devices may be defined as a master network device and a secondary network device, respectively. The master network device may provide a group of serving cells, also referred to as a "master cell group (MCG)". The secondary network device may also provide a group of serving cells, also referred to as a "secondary cell group (SCG)". For dual connectivity operation, the term "special cell (SpCell)" refers to the Pcell of the MCG or the primary Cell of the SCG, depending on whether the terminal device 120 is associated with the MCG or SCG, respectively. May be good. Other than dual connectivity operations, the term "SpCell" may also refer to PCell.

In the communication network 100 shown in FIG. 1, the network device 110 can communicate data and control information to the terminal device 120, and the terminal device 120 can also communicate data and control information to the network device 110. The link from the network device 110 to the terminal device 120 is called a downlink (DL), and the link from the terminal device 120 to the network device 110 is called an uplink (UL).

Communication in the network 100 may comply with any appropriate standard, and the standards here are Global System for Mobile Communications (GSM), Long Term Evolution (LTE), and Long Term Evolution. LTE Evolution, LTE Advanced (LTE-A: LTE-Advanced), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Wireless Access Network (GERAN) : GSM EDGE Radio Access Network), etc., but not limited to these. In addition, communication may be performed according to any generation of communication protocols currently known or developed in the future. Examples of communication protocols are 1st generation (1G), 2nd generation (2G), 2.5G, 2.75G, 3rd generation (3G), 4th generation (4G), 4.5G, 5th generation ( 5G) communication protocols include, but are not limited to.

The network device 110 (eg, next generation NodeB (gNB)) may include one or more transmission reception points (TRPs) or antenna panels. As used herein, the term "TRP" refers to an antenna array (with one or more antenna elements) available for network devices located at a particular geographic location. For example, the network device 110 may be connected to multiple TRPs at different geographic locations to achieve better coverage. One or more TRPs may be contained in the same serving cell or may be contained in different serving cells.

FIG. 2A shows an exemplary scenario 201 for the network 100 shown in FIG. As shown in FIG. 2A, for example, the network device 110 of FIG. 1 may provide the PCell 210 and SCell 220 to provide services to the terminal device 120. PCell210 and SCell220 may overlap each other. The network device 110 may be connected to a TRP 230 located on both the PCell 210 and SCell 220.

The network device 110 is routed through a control channel (eg, Physical Downlink Control Channel (PDCCH)) due to inaccurate adjustment of the beam, blockage effect, movement of the terminal device 120, or for some other reason. When the terminal device 120 cannot be reached, a beam failure may occur. For example, the terminal device 120 may detect such a situation by estimating the quality of virtual PDCCH reception transmitted over the beam used by the network device 110 to reach the terminal device 120. To perform beam fault detection, the terminal device 120 may estimate the quality of virtual PDCCH reception based on the reception of a predetermined reference signal (RS). In the following description, this reference signal may be referred to as "beam fault detection RS" or "beam fault detection RS". Examples of the beam fault detection RS include a periodic channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), or a combination thereof. Not limited to these.

In the example shown in FIG. 2A, PDCCH can be transmitted on both PCell210 and SCell220. For example, as shown in FIG. 2A, the PDCCH is transmitted from the TRP 230 to the terminal device 120 via the DL beam 240-1 in the PCell 210 and from the TRP 230 to the terminal device 120 via another DL beam 240-2 in the SCell 220. May be done. In this case, the beam fault can be detected in the PCell 210 or SCell 220.

In some embodiments, in response to the detection of a beam fault in the SCell 220, the terminal device 120 was first configured for the SCell to identify a candidate beam for recovery from the beam fault. A set of beam-specific RSs may be monitored. The terminal device 120 may include information about the candidate beam in the Beam Failure Recovery (BFR) request and may transmit a BFR request including information about the candidate beam to the network device 110 in the first cell.

In some embodiments, the network device 110 provides at least the PCell 210 and SCell 220 to service the terminal device 120, and the terminal device 120 responds to the detection of a beam failure in the SCell 220. From the PCell 210 and SCell 220, the first cell in which the BFR request is transmitted to the network device 110 and the second cell in which the response to the BFR request is received from the network device 110 may be determined. The terminal device 120 may send a BFR request to the network device 110 in the determined first cell. The terminal device 120 may then monitor the control channel search space in the second cell in order to receive a response to the BFR request from the network device 110.

In some embodiments, a pseudo-collocation (QCL) type may be configured for RS. Pseudo-colocation types are QCL-TypeA {Doppler shift, Doppler spread, average delay, delay spread}, QCL-TypeB {Doppler shift, Doppler spread}, QCL-TypeC {Doppler shift, average delay}, and QCL-TypeD {space. It may be one of the values of the Rx parameter}.

In some embodiments, the beam fault recovery procedure may be different for different scenarios. The PCell 210 and S Cell 220 may be associated with the first frequency range FR1 and the second frequency range FR2, respectively. For example, the first frequency range FR1 may be less than 6 GHz and the second frequency range FR2 may be 6 GHz or more. In some embodiments, for example, in the exemplary scenario 201 shown in FIG. 2A, the first frequency range FR1 may be the same as or different from the second frequency range FR2. In some embodiments, the BFR is required only in the SCell in this case, but may not be required in the PCell. In some embodiments, for example, in the exemplary scenario 201 shown in FIG. 2A, PCell210 and SCell220 may be configured in the same frequency range, eg FR2. In some embodiments, in this case the DL beam in the PCell and the DL beam in the SCell have similar properties. For example, if the DL beam in the PCell is blocked, the DL beam in the SCell may also be blocked at the same time. In some embodiments, for example, in the exemplary scenario 201 shown in FIG. 2A, both PCell210 and SCell220 may be configured in the same frequency range, eg FR1. In some embodiments, BFR may not be required for both PCell210 and SCell220 in this case. For example, if not all RSs configured for PCell210 and SCell220 are configured with QCL-TypeD, BFR may not be required for both PCell210 and SCell220.

In some embodiments, for example, in the exemplary scenario 201 shown in FIG. 2A, the PCell 210 and S Cell 220 may be configured in the same frequency range. For example, in this case, an in-band CA to which an in-band continuous CC is aggregated may be supported. In some embodiments, in this case, if a beam fault is detected in the SCell, another beam fault may be detected simultaneously in the PCell. In some embodiments, the BFR may be required only in the PCell in this case. Further, if the beam fault detection RS is configured for the SCell 220, the beam fault detection RS may be QCLed with at least one beam fault detection RS configured for the PCell 210 and a QCL-TypeD. Alternatively or additionally, if the beam specific RS is configured for the SCell 220, this beam specific RS may be QCLed with at least one beam specific RS configured for the PCell 210 and a QCL-TypeD. .. That is, in this case, cross-carrier pseudo-collocation (QCL) can be supported.

In some embodiments, for example, in the exemplary scenario 201 shown in FIG. 2A, the PCell 210 and S Cell 220 may be configured in the same frequency range. For example, in this case, an in-band CA in which the in-band continuous CC is aggregated may be supported. In some embodiments, in this case, the set of beam fault detection RSs may be configured solely for the PCell instead of the SCell. Correspondingly, the set of beam specific RSs may also be configured exclusively for PCells instead of SCells.

In some embodiments, the PCell 210 and S Cell 220 may be associated with a first frequency range FR1 and a second frequency range FR2, respectively. For example, in the exemplary scenario 201 shown in FIG. 2A, FR1 may be different from FR2. Further, the frequency range associated with the SCell 220 may exceed the frequency range associated with the PCell 210. In some embodiments, the determined first cell in which the BFR request is transmitted to the network device 110 may be the SCell 220 (eg, in this case also referred to as "BFR on SCell UL" in the text below. ). Alternatively, in some embodiments, the determined first cell in which the BFR request is transmitted to the network device 110 may be the PCell 210 (eg, in this case, "BFR on PCell" in the text below. Also called "UL"). In some other embodiments, the determined second cell in which the response to the BFR request is received from the network device 110 may be the PCell 210 (eg, in this case, "BFR on PCell" in the text below. Also called "DL"). Alternatively, in some other embodiments, the determined second cell in which the response to the BFR request is received from the network device 110 may be SCell220 (eg, in this case, in the text below). Also called "BFR on SCell DL"). In some embodiments, the determined first cell in which the BFR request is transmitted to the network device 110 is the SCell 220 and the determined second cell in which the response to the BFR request is received from the network device 110. May be PCell210 (eg, in this case also referred to as "BFR on SCell UL and PCell DL" in the text below).

In some embodiments, for the case of "BFR on SCell UL", the transmission of the BFR request may be triggered by a PDCCH order. In some embodiments, in this case, the terminal device 120 may transmit the request for the PDCCH order on the PCell 210 before transmitting the BFR. In some embodiments, the request for a PDCCH order may be transmitted via a physical uplink control channel (PUCCH) or a physical random access channel (PRACH) within the PCell 210. For example, a request for a PDCCH order may be transmitted on the PCell 210 using at least one of a particular sequence, a particular time resource, a particular frequency resource, and a particular cyclic shift of the PUCCH or PRACH sequence. For example, the index of the identified candidate beam does not have to be carried in the request. In response to receiving a PDCCH order from the network device 110, the terminal device may transmit a BFR request to the network device 110 on the SCell 220. That is, in this case, the PDCCH order can trigger the transmission of BFR across carriers. In some embodiments, for example, a field occupying some reserved bits in the PDCCH order can be used to indicate the index of the cell to which the BFR request is transmitted. For example, 3 bits may be used in the PDCCH order to indicate the cell index.

In some embodiments, the bitfield of the random access preamble index in the PDCCH order may be fixed to 0 if the PDCCH order triggers the PRACH transmission of the BFR request in the SCell 220. For example, the 6 bits for a random access preamble index may be fixed at 0. In some embodiments, the fields of the SS / PBCH index and / or the fields of the PRACH mask index may be reserved.

In some embodiments, if the PDCCH order triggers a PRACH transmission of a BFR request on the SCell 220, the terminal device 120 may ignore the bit field of the random access preamble index in the PDCCH order. In some embodiments, the random access preamble index for PRACH transmission of the BFR request on the SCell 220 may be based on the index of the identified candidate beam on the SCell 220.

In some embodiments, for the case of "BFR on SCell UL", the transmission of the BFR request may be triggered by the PDCCH order. In some embodiments, in this case, the terminal device 120 may transmit the request for the PDCCH order in the SCell 220 before transmitting the BFR. In response to receiving a PDCCH order from the network device 110, the terminal device may transmit a BFR request to the network device 110 on the SCell 220. In some embodiments, the DL beam for PDCCH order transmission in this case may be the identified candidate beam. For example, the index of the identified candidate beam may be carried in a BFR request.

In some embodiments, in the case of "BFR on SCell UL", in response to the beam failure detected in SCell 220, the terminal device 120 does not request a PDCCH order from the network device 110, but in SCell 220. The BFR request may be transmitted directly to the network device 110. In some embodiments, the BFR request provides a Physical Random Access Channel (PRACH) to initiate a non-competitive Random Access (CFRA) procedure for the BFR. It may be transmitted via. Contention Based Random Access (CBRA) may not be supported by SCell. Thus, in some embodiments, when the BFR timer expires, the SCell failure may be reported to the network device 100 on the PCell 210 instead of initiating the CBRA procedure on the SCell 220. For example, additional states in the Channel State Information (CSI) report can be used to indicate a SCell failure. Alternatively or additionally, a particular PRACH resource may be configured for reporting SCell failures in PCells. In addition, it may not be necessary to use one of the set of candidate beams (corresponding to the set of beam-specific RSs) configured for the PCell to report SCell failures.

In some embodiments, for the case of "BFR on SCell UL", the transmission of the BFR request may be triggered by the PDCCH order. In some embodiments, in this case, the terminal device 120 may transmit the request for the PDCCH order on the PCell 210 before transmitting the BFR. In response to receiving a PDCCH order from the network device 110, the terminal device may transmit a BFR request to the network device 110 on the SCell 220. That is, in this case, the PDCCH order can trigger the transmission of BFR across carriers. In some embodiments, for example, a field occupying some reserved bits in the PDCCH order can be used to indicate the index of the cell in which the BFR request is triggered.

In some embodiments, in the case of "BFR on SCell UL and PCell DL", the terminal device 120 does not request a PDCCH order from the network device 110 in response to the beam failure detected in the SCell 220. , SCell 220 may transmit the BFR request directly to the network device 110. In some embodiments, the BFR request may be transmitted via a physical random access channel (PRACH) to initiate a non-competitive-based random access (CFRA) procedure for the BFR. Conflict-based random access (CBRA) may not be supported by SCell. Thus, in some embodiments, when the BFR timer expires, the SCell failure may be reported to the network device 100 on the PCell 210 instead of initiating the CBRA procedure on the SCell 220. For example, additional states in the Channel State Information (CSI) report can be used to indicate a SCell failure. Alternatively or additionally, a particular PRACH resource may be configured for reporting SCell failures in PCells. In addition, it may not be necessary to use one of the set of candidate beams (corresponding to the set of beam-specific RSs) configured for the PCell to report SCell failures.

In some embodiments, CFRA-based BFR may be supported in SCell 220 with respect to the case of "BFR on SCell UL and PCell DL". In some embodiments, in this case, the terminal device 120 may monitor the control channel search space on the PCell 210 in order to receive a response to the BFR request from the network device 110. For example, the BFR request may be transmitted on the SCell 220 via the PRACH resource. In some embodiments, the PRACH resource may be QCLed with the identified candidate beam in the SCell 220. In some embodiments, the "BFR on SCell UL and PCell DL" is not available if the QCL-TypeD is not configured for any RS in the PCell 210.

In some embodiments, in the case of "BFR on SCell UL and PCell DL", the terminal device 120 monitors the response to the BFR request on the PCell 210 while the BFR request is being transmitted over the PRACH on the SCell 220. May be good. In some embodiments, the subcarrier spacing (SCS) associated with the PCell may differ from the SCS associated with the SCell. In some embodiments, in this case, the time interval for monitoring the response in the PCell may be determined based on the SCS associated with the PCell210 or SCell220. For example, assuming that the slot for transmitting the BFR request in the SCell 220 is slot # n, the slot for receiving the response to the BFR request in the PCell 210 may be the slot # (n'+ k). Here, slot # n'is the nearest slot in PCell 210 that overlaps slot # n in SCell 220, and the time interval k can be determined based on the SCS associated with PCell 210 or SCell 220.

In some embodiments, when a BFR request is transmitted on the SCell 220 (eg, to initiate a CFRA-based BFR) and the BFR timer for the CFRA-based BFR expires, the CBRA-based BFR can be triggered. .. For example, a CBRA-based BFR can only be triggered by the PDCCH order. In some embodiments, in this case, in response to receiving a PDCCH order to trigger a CBRA-based BFR, the terminal device 120 initiates a CBRA-based BFR via the PRACH. The request may be transmitted. In some embodiments, the terminal device 120 may monitor the response to the BFR request on the PCell 210.

FIG. 2B shows another exemplary scenario 202 for the network 100 shown in FIG. As shown in FIG. 2B, for example, the network device 110 of FIG. 1 may provide the PCell 210 and SCell 220 to provide services to the terminal device 120. For example, PCell210 and SCell220 do not have to overlap each other. The network device 110 may be connected to two TRP230-1 and 230-2 located at PCell210 and SCell220, respectively.

If the network device 110 becomes unable to reach the terminal device 120 via the control channel (eg, PDCCH) due to inaccurate adjustment of the beam, blockage effect, movement of the terminal device 120, or for some other reason. Beam obstruction may occur. For example, the terminal device 120 may detect such a situation by estimating the quality of virtual PDCCH reception transmitted over the beam used by the network device 110 to reach the terminal device 120. To perform beam fault detection, the terminal device 120 may estimate the quality of virtual PDCCH reception based on the reception of a predetermined beam fault detection RS.

In the example shown in FIG. 2B, PDCCH can be transmitted on both PCell210 and SCell220. For example, as shown in FIG. 2B, PDCCH is transmitted from TRP230-1 to terminal device 120 via DL beam 240-1 in PCell210 and from TRP230-2 via another DL beam 240-2 in SCell220. It may be transmitted to the terminal device 120. In this case, the beam fault can be detected in PCell210 or SCell220. For example, in response to the detection of a beam fault in the SCell 220, the terminal device 120 first sets a set of beam-specific RSs configured for the SCell to identify candidate beams for recovery from the beam fault. May be monitored. The terminal device 120 may transmit a BFR request containing information about the candidate beam to the network device 110 in order to initiate a random access procedure for the BFR. The terminal device 120 may then monitor the control channel search space to receive a response to the BFR request.

In the exemplary scenario 202 shown in FIG. 2B, the BFR request is transmitted from the terminal device 120 to the network device 110 on the PCell 210, and the response to the BFR request is transmitted from the network device 110 to the terminal device 120 on the PCell 210 (ie,). Assuming "BFR on PCell UL and PCell DL"), some problems may occur.

3A and 3B show problems that may occur in the BFR procedure in the exemplary scenario 202 shown in FIG. 2B. As shown in FIG. 3A, TRP230-1 and 230-2 located in PCell210 and SCell220, respectively, are separated from each other. It may be detected that the DL beam 240-2 from the TRP 230-2 has failed and the candidate beam 310 may be identified for recovery from the beam failure. In the current 3GPP specification, the BFR request may be transmitted from the terminal device 120 to the network device 110 in the direction of the candidate beam 320. In this case, as shown in FIG. 3A, the TRP230-1 in the PCell210 cannot receive the BFR request. Further, in the current 3GPP specification, the response to the BFR request may be transmitted from the network device 110 to the terminal device 120 in the direction of the candidate beam 320. In this case, as shown in FIG. 3B, the terminal device 120 cannot receive the response to the BFR request. That is, the current 3GPP specification cannot support BFR on PCell UL and PCell DL.

The embodiments of the present disclosure can solve the problems as shown in FIGS. 3A and 3B.

In some embodiments, the network device 110 provides at least the PCell 210 and SCell 220 to service the terminal device 120, and the terminal device 120 responds to the detection of a beam failure in the SCell 220. From the PCell 210 and SCell 220, the first cell in which the beam fault recovery (BFR) request is transmitted to the network device 110 and the second cell in which the response to the BFR request is received from the network device 110 may be determined. The terminal device 120 may transmit the BFR request to the network device 110 in the determined first cell. The terminal device 120 may then monitor the control channel search space in the second cell in order to receive a response to the BFR request from the network device 110.

In some embodiments, for example, in the exemplary scenario 202 shown in FIG. 2B, the determined first cell in which the BFR request is transmitted to the network device 110 is the PCell 210 and the response to the BFR request is from the network device 110. The determined second cell to be received may also be a PCell 210 (ie, "BFR on PCell UL and PCell DL").

In some embodiments, for beam faults in SCell 220, there may be only one PRACH resource configured in PCell 210 to carry a BFR request or beam fault report. In this case, it is not necessary to associate the identified new candidate beam with the PRACH resource. For example, the PCell 210 may configure a new SCell measurement in response to receiving a BFR request or beam fault report.

In some embodiments, if the BFR request is transmitted on the PCell 210, the UL beam for the transmission of the BFR request may reuse the beam on the PCell 210. For example, the QCL parameter for the transmission of a BFR request (ie, PRACH transmission) is not determined based on the identified new candidate beam, but rather the lowest identifier configured in the most recent slot for the PCell210. One of the TCI (Transmission Configuration Indicator) states of the core set (CORESET), or the beam fault detection RS or beam fault detection RS having the lowest identifier in the PCell 210, or some other in the PCell 210. It may be determined based on the RS or TCI status. For example, the terminal device 120 may determine the UL beam for transmission of the BFR request based on a set of beam fault detection resources configured for the PCell.

In some embodiments, one PRACH resource for the transmission of the BFR request may correspond to one beam in the PCell 210 and another beam in the S Cell 220. Beam failures that occur in PCell 210 or S Cell 220 may be indicated by different cyclic shift (CS) values or different cover codes used for PRACH transmission.

In some embodiments, a first set of PRACH resources, sequences or preambles is configured for transmission of the BFR request in the PCell210 and a second set of PRACHs to indicate the identified different candidate beams in the PCell210. Resources, sequences or preambles may be used. In some embodiments, the transmission of the BFR request on the SCell 220 may also be based on at least one of a set of PRACH resources, sequences, or preambles. In some embodiments, if the BFR request for beam failure in the SCell 220 is transmitted in the PCell 210, the timing advance value in the PCell 210 may be applied to the PRACH transmission of the BFR request. For example, if there is no time lag between the BFR requests received by the network device 110 (because the timing advance value was applied to the PRACH transmission of the BFR request), the PRACH transmission may be considered as the BFR for the beam failure in the SCell 220. In some embodiments, if the BFR request for beam failure in the PCell 210 is transmitted in the PCell 210, there may not be a timing advance value available in the PCell 210. For example, if there is a time lag between the BFR requests received by the network device 110 (because the timing advance value is not applied to the PRACH transmission of the BFR request), the PRACH transmission may be considered as a BFR for a beam failure in the PCell 210.

In some embodiments, if the response to the BFR request is received on the PCell210, the DL beam for transmission of the response may reuse the beam on the PCell210. For example, the QCL parameters for a control resource set (“CORESET-BFR”) configured for the BFR are not determined based on the identified new candidate beam, for example, the most recent slot for the PCell210. The TCI state of the CORESET with the lowest identifier configured in, or any one of the beam fault detection RSs or beam fault detection RSs with the lowest identifier in the PCell210, or some other RS in the PCell210. Alternatively, it may be determined based on the TCI state. For example, the terminal device 120 may determine the DL beam for response detection based on a set of beam fault detection resources configured for PCell. For example, the response to the BFR request may be a random access response (RAR) received by the PCell 210. The RAR received by the PCell 210 may indicate recovery from a beam failure in the S Cell 220.

In some embodiments, if the response to the BFR request for the SCell is received by the PCell 210, the response may not have a timing adjustment command. In some embodiments, the response to the BFR request may be transmitted via the PDCCH. In some embodiments, the PDCCH may be a compact PDCCH. For example, there may be no scheduling information in PDCCH. As another example, the response may not have a timing adjustment command. In some embodiments, the response to the BFR request may be DCI format 0_0 and / or DCI format 1_0. In some embodiments, the response to the BFR request may be transmitted via the PDCCH having a CSI request and / or a PDCCH order.

In some embodiments, when the BFR request is transmitted on the PCell210 and the response to the BFR request is received on the SCell220, the QCL parameters for the CORESET-BFR are determined based on the identified new candidate beam. May be good. However, in some embodiments, if the SCell 220 is not configured with CORESET-BFR, the BFR may not be required in the SCell 220.

In some embodiments, the first set of BFR parameters in the PCell 210 (eg, BFR counter, BFR time, etc.) may be used for beam failure in the PCell 210. In some embodiments, when the BFR request for beam failure in SCell 220 is transmitted in PCell 210, the second set of BFR parameters in PCell 210 (eg, BFR counter, BFR time, etc.) is due to beam failure in SCell 220. May be used for. For example, the first set of BFR parameters may be different from the second set of BFR parameters. In some embodiments, the BFR in the SCell 220 may reuse the preamble resource used for the BFR in the PCell 210, but a BFR counter or timer for the BFR in the SCell 220 and a counter for the BFR in the PCell 210. Alternatively, the timers may be separated from each other.

In some embodiments, as described above, in order to perform beam fault detection, the terminal device 120 may estimate the quality of virtual PDCCH reception based on the reception of a predetermined reference signal (RS). .. For example, RS may be CSI-RS. The receive power of the CSI-RS in the SCell 220 may be determined based on the SSB defined in the SCell 220. However, in some embodiments, SSB may not be defined in SCell 220. In some embodiments, in this case the power of the CSI-RS in the SCell 220 may be determined based on the power of the SSB in the PCell 210.

FIG. 4 shows a flowchart of an exemplary method 400 for beam fault recovery according to some embodiments of the present disclosure. Method 400 can be implemented with the terminal device 120 shown in FIGS. 1, 2A and / or 2B. It should be appreciated that method 400 includes additional actions not shown and / or may omit some of the actions shown, and the scope of the present disclosure is not limited in this regard.

At block 410, the network device provides at least a primary cell (PCell) and a secondary cell (SCell) to service the terminal device, and in response to a beam failure detected in the SCell, the terminal device. Determines from the PCell and SCell a first cell in which the beam fault recovery (BFR) request is transmitted to the network device and a second cell in which the response to the BFR request is received from the network device.

At block 420, the terminal device transmits the BFR request to the network device in cell 1.

At block 430, the terminal device monitors the control channel search space in the second cell to receive a response to the BFR request from the network device.

In some embodiments, the first cell is a SCell and the second cell is either a PCell or a SCell. The terminal device may transmit the BFR request by transmitting the request for the PDCCH order in the PCell and transmitting the BFR request in the SCell to the network device in response to receiving the PDCCH order from the network device.

In some embodiments, the second cell is the SCell and the PDCCH order is received from the network device in either the PCell or the SCell.

In some embodiments, the first cell is a PCell and the terminal device determines a first resource for transmission of a BFR request based on a set of beam fault detection resources configured for the PCell. The BFR request may be transmitted by transmitting the BFR request to the network device via one resource.

In some embodiments, the second cell is a PCell and the terminal device determines the pseudo-collocation (QCL) parameters associated with the control channel search space based on the candidate beam and the control channel based on the QCL parameters. The control channel search space is monitored by monitoring the search space.

In some embodiments, the first cell is a SCell and the second cell is a PCell. The terminal device determines the QCL parameters associated with the physical random access channel (PRACH) for transmission of the BFR request based on the candidate beam and transmits the BFR request via the PRACH based on the QCL parameters. A BFR request may be transmitted.

It can be seen that the embodiments of the present disclosure provide a solution for beam failure recovery. The solution for beam fault recovery according to the embodiments of the present disclosure can be applied to beam faults generated in SCell. In addition, the embodiments of the present disclosure have enabled faster beam fault recovery than conventional beam fault recovery schemes.

FIG. 5 is a simplified block diagram of the device 500 suitable for the embodiment of the present disclosure. The device 500 can be regarded as a further exemplary embodiment of the network device 110 or terminal device 120 shown in FIG. Thus, the device 500 can be implemented in or at least a portion of the network device 110 or the terminal device 120.

As shown, the device 500 includes a processor 510, a memory 520 connected to the processor 510, appropriate transmitters (TX) and receivers (RX) 540 connected to the processor 510, and a TX / RX 540. Includes a connected communication interface. The memory 510 stores at least a part of the program 530. The TX / RX540 is for bidirectional communication. The TX / RX 540 has at least one antenna to facilitate communication, but in practice there may be more than one access node referred to herein. The communication interface is an X2 interface for bidirectional communication between eNBs, an S1 interface for communication between MME (Mobility Management Entity) / S-GW (Serving Gateway) and eNB, and an eNB and a relay node (RN). It may represent any interface required for communication with other network elements, such as the Un interface for communication between or the Uu interface for communication between the eNB and the terminal device.

Program 530, when executed by the associated processor 510, allows device 500 to operate in accordance with embodiments of the present disclosure, as described herein with reference to FIGS. 1-4. Expected to include instructions. The embodiments of the present specification may be implemented by computer software that can be executed by the processor 510 of the device 500, by hardware, or by a combination of software and hardware. Processor 510 may be configured to implement various embodiments of the present disclosure. Further, the combination of the processor 510 and the memory 520 may form a processing means 550 suitable for implementing the various embodiments of the present disclosure.

The memory 520 may be of any type suitable for the local technology network, and non-limiting examples include non-temporary computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems. It may be implemented using any suitable data storage technique such as optical memory devices and systems, fixed memory devices and removable memory. Although device 500 shows only one memory 520, device 500 may have multiple memory modules that are physically separate. The processor 510 may be of any type suitable for local technology networks and is based on non-limiting examples of general purpose computers, dedicated computers, microprocessors, DSPs (Digital Signal Processors), and multi-core processor architectures. It may include one or more of the processors. The device 500 may have a plurality of processors, such as application-specific integrated circuit chips, that are time dependent on the clock that synchronizes the main processor.

In general, the various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some embodiments may be implemented in hardware and others may be implemented in firmware or software that may be run by a controller, microprocessor, or other computing device. Various aspects of the embodiments of the present disclosure have been exemplified and described using block diagrams, flowcharts, or any other image representation, but these blocks, devices, systems, techniques or techniques described herein. Understand that the method may be implemented, as a non-limiting example, with hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof. I want to be.

The present disclosure further provides at least one computer program product tangibly stored in a non-temporary computer-readable storage medium. A computer program product is a computer-executable instruction executed on a device on the target real or virtual processor, such as those contained in a program module, to perform the process or method described above with reference to FIG. including. In general, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or perform specific abstract data types. The functions of the program modules can be combined or divided among the program modules described in various embodiments. Machine-executable instructions for a program module may be executed within a local device or a distributed device. In distributed devices, program modules may be located on both local and remote storage media.

The program code for performing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes are provided to the processor or controller of a general purpose computer, dedicated computer, or other programmable data processing device, and when the program code is executed by the processor or controller, a flow chart and / or a block diagram. The functions / operations specified in are realized. The program code may be run entirely on the machine, part of it may be run on the machine, it may be run as a stand-alone software package, part of it may be run on the machine, and part of it. May be run on a remote machine, or may be run entirely on a remote machine or server.

The program code is embodied on a machine-readable medium that can be any tangible medium that can contain or store programs for use by or in connection with an instruction execution system, device, or device. May be done. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, devices, or any suitable combination described above. More specific examples of machine-readable storage media include electrical connections with one or more wires, portable computer diskettes, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), and erasable programmable. Read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination described above.

In addition, the actions are drawn in a particular order, which means that such actions are performed in the particular order or sequence shown, or all drawn, in order to achieve the desired result. It should not be understood as requiring the action to be performed. In certain situations, multitasking and parallel processing may be advantageous. Similarly, although the above description contains details of some particular embodiments, they should not be construed as limiting the scope of the present disclosure and are specific features of the particular embodiment. Should be interpreted as an explanation for. Certain features described in the context of separate embodiments may be implemented in combination with a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable subcombination.

Although the present disclosure has been described in terms specific to structural features and / or methodological behaviors, the present disclosure, limited to the scope of the appended claims, is not necessarily limited to the particular features or behaviors described above. I want you to understand. Rather, the particular features and behaviors described above are described as exemplary embodiments that implement the claims.

Claims (19)

It ’s a method that is implemented on terminal devices.
The network device provides at least a primary cell (PCell) and a secondary cell (SCell) to service the terminal device, and the PCell and said in response to a beam failure detected in the SCell. Determining from the SCell a first cell in which a beam fault recovery (BFR) request is transmitted to the network device and a second cell in which a response to the BFR request is received from the network device.
To transmit the BFR request to the network device in the first cell,
Monitoring the control channel search space in the second cell to receive a response to the BFR request from the network device.
How to prepare. The frequency corresponding to the SCell exceeds the frequency corresponding to the PCell.
The method according to claim 1. The first cell is the SCell, and the second cell is either the PCell or the SCell.
Transmission of the BFR request is
The PCell is used to transmit a request for a physical downlink control channel (PDCCH) order.
In response to receiving the PDCCH order from the network device, the SCell transmits the BFR request to the network device.
including,
The method according to claim 1. The second cell is the SCell, and the PDCCH order is received from the network device in either the PCell or the SCell.
The method according to claim 3. The first cell is the PCell.
Transmission of the BFR request is
Determining the first resource for transmission of the BFR request based on the set of beam fault detection resources configured for the PCell.
To transmit the BFR request to the network device via the first resource,
including,
The method according to claim 1. The second cell is the PCell.
Monitoring the control channel search space is
Determining a second resource for monitoring the control channel search space in the PCell based on the set of beam fault detection resources configured for the PCell.
Monitoring the control channel search space via the second resource,
including,
The method according to claim 5. Transmission of the BFR request is
Identifying a candidate beam for recovery from the beam failure in the SCell, and
Including information about the candidate beam in the BFR request and
To transmit the BFR request to the network device in the first cell,
including,
The method according to claim 1. The second cell is the SCell,
Monitoring the control channel search space is
Determining the pseudo-collocation (QCL) parameters associated with the control channel search space based on the candidate beam.
Monitoring the control channel search space based on the QCL parameters
including,
The method according to claim 7. The first cell is the SCell, the second cell is the PCell, and
Transmission of the BFR request is
Determining the QCL parameters associated with the physical random access channel (PRACH) for transmission of the BFR request based on the candidate beam.
Transmission of the BFR request via the PRACH based on the QCL parameter and
including,
The method according to claim 7. It ’s a terminal device,
With the processor
A memory connected to the processor and storing instructions,
Equipped with
When the instruction is executed by the processor, the terminal device receives the instruction.
The network device provides at least a primary cell (PCell) and a secondary cell (SCell) to service the terminal device, and the PCell and said in response to a beam failure detected in the SCell. Determining from the SCell a first cell in which a beam fault recovery (BFR) request is transmitted to the network device and a second cell in which a response to the BFR request is received from the network device.
To transmit the BFR request to the network device in the first cell,
Monitoring the control channel search space in the second cell to receive a response to the BFR request from the network device.
To perform actions including
Terminal device. The frequency corresponding to the SCell exceeds the frequency corresponding to the PCell.
The terminal device according to claim 10. The first cell is the SCell, and the second cell is either the PCell or the SCell.
Transmission of the BFR request is
The PCell is used to transmit a request for a physical downlink control channel (PDCCH) order.
In response to receiving the PDCCH order from the network device, the SCell transmits the BFR request to the network device.
including,
The terminal device according to claim 10. The second cell is the SCell, and the PDCCH order is received from the network device in either the PCell or the SCell.
The terminal device according to claim 12. The first cell is the PCell.
Transmission of the BFR request is
Determining the first resource for transmission of the BFR request based on the set of beam fault detection resources configured for the PCell.
To transmit the BFR request to the network device via the first resource,
including,
The terminal device according to claim 10. The second cell is the PCell.
Monitoring the control channel search space is
Determining a second resource for monitoring the control channel search space in the PCell based on the set of beam fault detection resources configured for the PCell.
Monitoring the control channel search space via the second resource,
including,
The terminal device according to claim 14. Transmission of the BFR request is
Identifying a candidate beam for recovery from the beam failure in the SCell, and
Including information about the candidate beam in the BFR request and
To transmit the BFR request to the network device in the first cell,
including,
The terminal device according to claim 10. The second cell is the SCell,
Monitoring the control channel search space is
Determining the pseudo-collocation (QCL) parameters associated with the control channel search space based on the candidate beam.
Monitoring the control channel search space based on the QCL parameters
including,
The terminal device according to claim 16. The first cell is the SCell, the second cell is the PCell, and
Transmission of the BFR request is
Determining the QCL parameters associated with the physical random access channel (PRACH) for transmission of the BFR request based on the candidate beam.
Transmission of the BFR request via the PRACH based on the QCL parameter and
including,
The terminal device according to claim 16. A computer-readable medium containing instructions that, when executed on at least one processor, cause the at least one processor to perform the method of any one of claims 1-9.

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