RU2779078C2 - System and method for restoration of communication beam - Google Patents

Abstract

FIELD: communication technology.

SUBSTANCE: invention relates to a communication technology; it can be used in an access node and user equipment for the restoration of communication beams. The method includes generation of a configuration message including information indicating a set of reference signals of the first type of reference signals and a set of reference signals of the second type of reference signals, used for identification of a new beam, and information indicating resources of a random access channel, allocated for transmission of preamble sequences, while each resource of the random access channel is connected to the reference signal of the first type of reference signals, sending to one or several user equipment (hereinafter – UE) of the configuration message, reception from UE of the preamble sequence in one of resources of the random access channel, and determination of UE identifier according to the preamble sequence and one of resources of the random access channel.

EFFECT: increase in the quality of communication due to the provision of restoration of communication beams.

15 cl, 31 dwg

Description

[1] This application claims priority over U.S. Provisional Application No. 15/890,925 filed Feb. 7, 2018 entitled "System and Method for Communications Beam Recovery", which in turn claims priority U.S. Provisional Application No. 62/479,965, filed March 31, 2017, entitled "Systems and Methods for Beam Recovery and Resource Allocation", U.S. Provisional Application No. 62/521,110, filed June 16 2017 titled “System and Method for Communications Beam Recovery”, U.S. Provisional Application No. 62/544,420 filed Aug. 11, 2017 titled “System and Method for Communications Beam Recovery”. for Communications Beam Recovery"), and U.S. Provisional Application No. 62/581,314 filed November 3, 2017 entitled "System and Method for Communicati ons Beam Recovery"), and all of these patent applications are incorporated herein by reference as if they were reproduced in their entirety.

Technical field

[2] The present disclosure relates generally to a digital communication system and method, and in particular embodiments, to a communication path restoration system and method.

State of the art

[3] One possible deployment scenario for fifth generation (5G) new radio communications ("New Radio", NR) system architecture uses high frequencies (HF) (6 gigahertz (GHz) and higher, such as operating frequencies at millimeter wavelengths (millimeter wave wave (mmWave)) to use more available bandwidth and less interference than what is available at crowded lower frequencies (below 6 GHz. However, path loss is a major problem for HF. Beamforming can be used to overcome problems of high losses in the transmission path for HF.

[4] Under specific conditions, the user equipment (UE) device may detect that all existing communication paths between the evolved NodeB (Node B) (eNB) and the UE are not functioning properly (i.e., there is a failure and/or loss of a beam), and there is a need to restore this state.

[5] Therefore, there is a need for mechanisms that support link recovery.

The essence of the invention

[6] Exemplary embodiments provide a system and method for restoring a communication beam.

[7] According to an exemplary embodiment, a method for operating an access node is provided. The method includes generating, by the access node, a configuration message including information indicating a set of reference signals of a first type of reference signals and a set of reference signals of a second type of reference signals used to identify a new beam, and information indicating random access channel resources allocated for transmission. preamble sequences, with each random access channel resource associated with a reference signal of the first type of reference signals, sending, by the access node, to one or more user equipments (UE), configuration messages, receiving, by the access node from the UE, a preamble sequence in one of the resources the random access channel and determining by the access node the identifier of the UE in accordance with the preamble sequence and one of the resources of the random access channel.

[8] Optionally, in any of the previous embodiments, an embodiment is provided wherein each reference signal in the first reference signal set has a quasi-aligned (QCLed) or spatial similarity relationship with another subset of the reference signals of the second reference signal set of the second reference signal type. signals.

[9] Optionally, in any of the previous embodiments, an embodiment is provided wherein the configuration message is sent in at least one of a Radio Resource Control (RRC) message, a Medium Access Control (MAC) (MAC) message (MAC –CE), or a Downlink Control Indicator (DCI) message.

[10] Optionally, in any of the previous embodiments, an embodiment is presented in which the set of first type reference signals comprises a set of synchronization signals (SS).

[11] Optionally, in any of the previous embodiments, an embodiment is presented in which the second type reference signal set comprises a channel state information (CSI-RS) reference signal set.

[12] Optionally, in any of the previous embodiments, an embodiment is provided in which random access channel resources comprise Physical Random Access Channel (PRACH) resources.

[13] Optionally, in any of the preceding embodiments, an embodiment is presented in which each random access channel resource is also associated with a reference signal of the second type of reference signals.

[14] Optionally, in any of the previous embodiments, an embodiment is provided wherein the configuration message further comprises at least one of: temporal location information relating to the first random access channel resource, frequency location information, relating to the first random access channel resource, preamble sequence information relating to the first random access channel of the resource, or a first association between the index of the first reference signal and the first random access channel resource.

[15] Optionally, in any of the previous embodiments, an embodiment is provided wherein the configuration message further comprises at least one of: temporal location information relating to the second random access channel resource, frequency location information, related to the second random access channel resource, preamble sequence information related to the second random access channel resource, or a second association between the index of the second reference signal and the second random access channel resource.

[16] Optionally, in any of the preceding embodiments, the embodiment further includes determining, by the access node, the index of the identified reference signal as the index of the first reference signal when the preamble sequence is received in the first random access channel resource, and determining by the access node the index the identified reference signal as the second reference signal index when the preamble sequence is received on the second random access channel resource.

[17] Optionally, in any of the previous embodiments, the embodiment further includes sending the access node to the UE a response to recover from beam failure on the control channel.

[18] Optionally, in any of the previous embodiments, an embodiment is presented in which the control channel comprises a physical downlink control channel (PDCCH).

[19] Optionally, in any of the previous embodiments, an embodiment is provided in which a control channel is spatially quasi-aligned (QCLed) with an identified reference signal.

[20] According to an exemplary embodiment, an access node is provided. The access node includes a storage store containing instructions and one or more processors that interact with the storage store. One or more processors execute instructions for generating a configuration message including information indicating a set of reference signals of a first type of reference signals and a set of reference signals of a second type of reference signals used to identify a potentially suitable beam, and information indicating random access channel resources allocated to transmit preamble sequences, wherein each random access channel resource is associated with a reference signal of the first type of reference signals, send a configuration message to one or more UEs, receive, from the UE, a preamble sequence in one of the random access channel resources, and determine the UE ID in accordance with a preamble sequence and one of the random access channel resources.

[21] Optionally, in any of the previous embodiments, an embodiment is provided in which the configuration message is sent in at least one of an RRC message, a MAC-CE message, or a DCI message.

[22] Optionally, in any of the preceding embodiments, an embodiment is provided wherein one or more processors further execute instructions for determining an identified reference signal index as a first reference signal index when a preamble sequence is received on a first random access channel resource. , and determining an index of the identified reference signal as the index of the second reference signal when the preamble sequence is received on the second random access channel resource.

[23] Optionally, in any of the preceding embodiments, an embodiment is provided in which one or more processors further execute instructions to send a response to the UE for beam failure recovery over a control channel.

[24] Optionally, in any of the previous embodiments, an embodiment is provided wherein each reference signal in the first reference signal set has a quasi-aligned (QCLed) or spatial similarity relationship with another subset of the reference signals of the second reference signal set of the second reference signal type. signals.

[25] In accordance with an exemplary embodiment, a durable computer-readable medium is provided. The non-volatile computer-readable medium stores programming for execution by one or more processors to generate a configuration message including information indicating a set of reference signals of a first type of reference signals and a set of reference signals of a second type of reference signals used to identify a potentially suitable beam, and information indicating resources random access channel allocated to transmit preamble sequences, wherein each random access channel resource is associated with a reference signal of the first type of reference signals, sending a configuration message to one or more UEs, receiving, from the UE, a preamble sequence in one of the random access channel resources, and determining a UE ID according to the preamble sequence and one of the random access channel resources.

[26] Optionally, in any of the preceding embodiments, an embodiment is provided wherein one or more processors further execute instructions for determining an identified reference signal index as a first reference signal index when a preamble sequence is received on a first random access channel resource. , and determining an index of the identified reference signal as the index of the second reference signal when the preamble sequence is received in the second random access channel resource.

[27] Optionally, in any of the foregoing embodiments, an embodiment is provided in which one or more processors further execute instructions to send a response to the UE for beam failure recovery over a control channel.

[28] According to an exemplary embodiment, a user equipment (UE) operation method is provided. The method includes tracking, by the UE, a first set of reference signals of a first type of reference signals transmitted by an access node, wherein each reference signal in the first set of reference signals has a quasi-aligned (QCLed) or spatial similarity relationship with another subset of reference signals of the second set of second type reference signals. reference signals, identifying by the UE the second reference signal from the second set of reference signals as a potentially suitable beam, identifying by the UE the first reference signal from the first set of reference signals that is quasi-aligned (QCLed) or spatially similar to the second reference signal, and transmitting, by the UE to the access node, a preamble sequence in the random access channel resource that is associated with the first reference signal of the first set of reference signals, thereby identifying a potentially suitable beam for communication at the access node.

[29] Optionally, in any of the previous embodiments, an embodiment is provided wherein the first reference signal set comprises a synchronization signal (SS) set, and wherein the second reference signal set comprises a channel state information (CSI–) reference signal set. RS).

[30] Optionally, in any of the previous embodiments, an embodiment is provided in which the first set of reference signals comprises cell-specific reference signals.

[31] Optionally, in any of the previous embodiments, an embodiment is provided in which the second set of reference signals comprises UE-specific reference signals.

[32] Optionally, in any of the previous embodiments, an embodiment is provided further comprising receiving, by the UE, information about a quasi-aligned (QCLed) or spatially similar relationship between the first reference signal set and the second reference signal set in at least at least one of a Radio Resource Control (RRC) message, a Medium Access Control (MAC) (MAC-CE) message, or a Downlink Control Indicator (DCI) message.

[33] Optionally, in any of the previous embodiments, an embodiment is provided in which a random access channel resource is selected from a plurality of random access channel resources in accordance with a first reference signal.

[34] Optionally, in any of the previous embodiments, an embodiment is provided wherein at least one of the temporal location of the random access channel resource, the frequency location of the random access channel resource, or the preamble sequence information relating to the random access channel resource access is selected in accordance with the first reference signal.

[35] Optionally, in any of the previous embodiments, an embodiment wherein at least one of the temporal location of the random access channel resource, the frequency location of the random access channel resource, or the preamble sequence information related to the random access channel resource , is received in at least one of an RRC message, a MAC-CE message, or a DCI message.

[36] According to an exemplary embodiment, a method for operating an access node is provided. The method includes sending, by the access node to the UE, first information about a quasi-aligned (QCLed) or spatially similar relationship between each reference signal in the first reference signal set of the first reference signal type and another subset of the reference signals of the second reference signal set of the second reference signal type, sending by the access node to the UE second information indicating a random access channel resource from the plurality of random access channel resources to use when a reference signal from the second reference signal set is identified as a potential candidate beam, and receiving by the access node from the UE a preamble sequence in the random access channel resource , thereby identifying a potentially suitable beam.

[37] Optionally, in any of the previous embodiments, an embodiment is provided further comprising assigning a random access channel resource or a preamble sequence to the UE by the access node.

[38] Optionally, in any of the previous embodiments, an embodiment is provided wherein the first reference signal set of the first reference signal type comprises a synchronization signal (SS) signal set, and wherein the second reference signal set of the second reference signal type comprises a signal set CSI-RS.

[39] Optionally, in any of the previous embodiments, an embodiment is provided in which the first information is sent in at least one of the first RRC message, the first MAC-CE message, or the first DCI message, and in which the second information is sent in at least one of the second RRC message, the second MAC-CE message, or the second DCI message.

[40] According to an exemplary embodiment, a UE is provided. The UE includes a storage store containing instructions and one or more processors that interact with the storage store. One or more processors execute instructions to track the first set of reference signals of the first type of reference signals transmitted by the access node, each reference signal in the first set of reference signals having a quasi-aligned (QCLed) or spatial similarity relationship with another subset of the reference signals of the second set of reference signals of the second type of reference signals, identifying a second reference signal from the second set of reference signals as a potentially suitable beam, identifying a first reference signal of the first set of reference signals that is quasi-aligned (QCLed) or spatially similar to the second reference signal, and transmitting to the access node, the preamble sequence in a random access channel resource that is associated with the first reference signal of the first set of reference signals, thereby identifying a potentially suitable beam for communication at the access node.

[41] Optionally, in any of the previous embodiments, an embodiment is provided wherein the first reference signal set comprises an SS signal set and wherein the second reference signal set comprises a CSI-RS signal set.

[42] Optionally, in any of the preceding embodiments, an embodiment is provided in which one or more processors further execute instructions for receiving information about a quasi-aligned (QCLed) or spatially similar relationship between the first set of reference signals and the second set of reference signals. in at least one of an RRC message, a MAC-CE message, or a DCI message.

[43] Optionally, in any of the preceding embodiments, an embodiment is provided wherein one or more processors further execute instructions for selecting a random access channel resource from a plurality of random access channel resources in accordance with a first reference signal.

[44] Optionally, in any of the preceding embodiments, an embodiment is provided wherein one or more processors further execute instructions for selecting at least one of a random access channel resource location in time, a random access channel resource frequency location access or preamble sequence information related to the random access channel resource.

[45] According to an exemplary embodiment, an access node is provided. The access node includes a storage store containing instructions and one or more processors that interact with the storage store. One or more processors execute instructions to send, to the UE, first information about a quasi-aligned (QCLed) or spatially similar relationship between each reference signal in the first reference signal set of the first reference signal type and another subset of reference signals from the second reference signal set of the second reference signal type. signals, sending to the UE second information indicating a random access channel resource from a plurality of random access channel resources to use when a reference signal from the second reference signal set is identified as a potential candidate beam, and receiving from the UE a preamble sequence in the random access channel resource, such thus identifying a potentially suitable beam.

[46] Optionally, in any of the preceding embodiments, an embodiment is provided in which one or more processors further execute instructions to assign a random access channel resource or a preamble sequence to a user equipment (UE).

[47] Optionally, in any of the previous embodiments, an embodiment is provided in which the first information is sent in at least one of the first RRC message, the first MAC-CE message, or the first DCI message, and in which the second information is sent in at least one of the second RRC message, the second MAC-CE message, or the second DCI message.

[48] According to an exemplary embodiment, a method for operating a UE is provided. The method includes determining, by the UE, a first resource identifier of a first reference signal associated with a first reference signal type transmitted by an access node, determining, by a UE, a second resource identifier of a second reference signal associated with a second reference signal type transmitted by an access node, sending by the UE a beam failure recovery request message including a sequence in a beam failure random access channel (BRACH) resource identified according to at least one of the first identifier or the second identifier, and receiving by the UE the message with a response to recover from beam failure.

[49] Optionally, in any of the previous embodiments, an embodiment is presented in which the method further comprises sending by the UE information for recovery and monitoring by the UE of a downlink control channel.

[50] Optionally, in any of the previous embodiments, an embodiment is provided in which the recovery information comprises a first identifier.

[51] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the recovery information comprises at least one of a second identifier or an in-group identifier identifying a third reference signal resource from a first reference signal resource group that spatially quasi-aligned (QCLed) with the resource of the second reference signal identified by the second identifier.

[52] Optionally, in any of the previous embodiments, an embodiment is provided in which the beam failure response message contains a transmission grant, and in which the recovery information is transmitted in accordance with the transmission grant.

[53] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, a sequence configuration from an access node.

[54] Optionally, in any of the previous embodiments, an implementation is presented in which the configured sequence from the access node is different for different UEs.

[55] Optionally, in any of the foregoing embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, an association report with information about at least one of the associations between one or more reference signal resources and one or more BRACH resources, associations between one or more reference signaling resources and one or more BRACH response resources, or associations between one or more BRACH resources and one or more BRACH response resources.

[56] Optionally, in any of the previous embodiments, an embodiment is provided wherein the association message conveys known relationship information, in terms of positions in time and/or frequency, of a first resource type relative to a second resource type.

[57] Optionally, in any of the previous embodiments, an embodiment is provided in which the BRACH resource is further identified according to the association message.

[58] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, first quasi-alignment (QCL) information associated with the first reference signal of the first reference signal type and more than one of reference signals of the second reference signal type; and/or second QCL information associated with one reference signal of the second reference signal type and more than one of the reference signals of the first reference signal type.

[59] Optionally, in any of the preceding embodiments, an embodiment is provided in which the second resource identifier of the second reference signal associated with the second reference signal type is determined in accordance with the first QCL information and/or the second QCL information.

[60] Optionally, in any of the preceding embodiments, an embodiment is provided wherein a second resource identifier of a second reference signal associated with a second reference signal type is determined by tracking the second signal resources associated with the second reference signal type.

[61] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the first resource identifier of the first reference signal associated with the first reference signal type is determined by tracking the first reference signal resources associated with the first reference signal type.

[62] Optionally, in any of the previous embodiments, an embodiment is provided wherein a first position in time and/or frequency associated with a beam failure response message is determined in accordance with a second position in time and /or frequency of a resource carrying a beam fail recovery request message and an association message carrying at least one of associations between one or more reference signal resources and one or more BRACH resources or associations between one or more reference signal resources and one or more resources to respond to BRACH.

[63] Optionally, in any of the previous embodiments, an embodiment is provided in which the third position in time and/or frequency of the resource carrying the beam fail recovery request message is determined according to the fourth position in time and/ or by the frequency of at least one of the first reference signal resource associated with the first reference signal type or the second reference signal resource associated with the second reference signal type.

[64] Optionally, in any of the previous embodiments, an embodiment is provided in which the first reference signal comprises a channel state information reference signal (CSI-RS) and the second reference signal comprises a wideband reference signal (WBRS).

[65] Optionally, in any of the previous embodiments, an embodiment is provided wherein the WBRS comprises at least one of synchronization signals (SS), wide beam channel state information reference signals (WB CSI-RS) , wide beam channel state information reference signals (CSI-RS), SS-simulating CSI-RS, cell-specific CSI-RS, group CSI-RS, or common CSI-RS.

[66] Optionally, in any of the previous embodiments, an embodiment is provided in which the CSI-RS comprises at least one of the narrow beam CSI-RS or a UE-specific CSI-RS.

[67] Optionally, in any of the previous embodiments, an embodiment is provided in which the fifth position in time and/or frequency of the BRACH resource carrying the sequence is different from the sixth position in time and/or frequency of the random access channel ( RACH) used for initial access purposes.

[68] Optionally, in any of the previous embodiments, an embodiment is presented in which the second identifier is not explicitly transmitted by the UE.

[69] Optionally, in any of the previous embodiments, an embodiment is provided in which the second identifier is implicitly determined by the access node according to the positions in time and/or frequency of the BRACH resource carrying the sequence.

[70] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the downlink control channel signal is spatially quasi-collated (QCL) with the first reference signal resource identified by the first identifier.

[71] According to an exemplary embodiment, a method for operating an access node is provided. The method includes configuring by an access node preamble sequences in a BRACH resource for user equipments (UEs), receiving by the access node a beam failure recovery request message including the sequence in a beam failure random access channel (BRACH) resource, identifying by the access node UE associated with the sequence, and sending by the access node a message with a beam failure recovery response, including granting a transmission to the UE.

[72] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises receiving, by the access node, the recovery information from the UE, setting up, by the access node, a control channel according to the recovery information, and transmitting, by the access node, a signal control channel in accordance with the subset of information for recovery.

[73] Optionally, in any of the foregoing embodiments, an embodiment is provided wherein the recovery information includes a first resource identifier of a first reference signal associated with a first reference signal type transmitted by an access node, and wherein setting up a control channel contains the setting of the control channel in accordance with the first identifier.

[74] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the recovery information comprises a second identifier of a second resource associated with a second reference signal transmitted by the access node and an intra-group identifier identifying a resource group of the first reference signal, associated with the first type of reference signals, which is spatially quasi-aligned (QCLed) with the resource of the second reference signal associated with the second type of reference signals, and wherein the setting of the control channel includes determining the first resource identifier of the first reference signal associated with the first type of reference signals, transmitted by the access node, in accordance with the second identifier and intra-group identifier and setting the control channel in accordance with the first identifier.

[75] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the recovery information comprises an intra-group identifier identifying a group of first reference signal resources associated with a first reference signal type that is spatially quasi-aligned (QCLed) with a second reference signal resource. the reference signal associated with the second reference signal type, wherein setting the control channel includes determining a second second resource identifier associated with the second reference signal transmitted by the access node, determining a first resource identifier of the first reference signal associated with the first reference signal type, transmitted by the access node, in accordance with the second identifier and the intragroup identifier, and setting the control channel in accordance with the first identifier.

[76] Optionally, in any of the previous embodiments, an embodiment is provided in which the beam failure recovery response message comprises a transmission grant, and in which the recovery information is received in accordance with the transmission grant.

[77] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises transmitting, by the access node, one or more precoded first reference signals in one or more first reference signal resources associated with the first reference type. signals, and transmitting, by the access node, one or more pre-coded second reference signals in one or more second reference signal resources associated with the second type of reference signals.

[78] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises configuring, by the access node, a sequence for the UE.

[79] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises sending, by the access node, a connectivity message carrying at least one of the connectivity between one or more reference signaling resources and one or more BRACH resources, associations between one or more BRACH resources and one or more BRACH response resources, or associations between one or more reference signaling resources and one or more BRACH response resources.

[80] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises sending, by the access node, quasi-alignment (QCL) information between the resources of the first reference signals associated with the first type of reference signals and the resources of the second reference signals associated with the second type of reference signals.

[81] According to an exemplary embodiment, a user equipment (UE) operating method is provided. The method includes determining, by the UE, a first resource identifier of a first reference signal associated with a first reference signal type transmitted by the access node, determining, by the UE, a second resource identifier of a second reference signal associated with a second reference signal type transmitted by the access node, sending, by the UE, a beam failure recovery request message including a sequence selected from one or more sequences associated with the UE, wherein the beam failure recovery request message is transmitted on a beam failure random access channel (BRACH) resource , identified according to the second identifier, and monitoring, by the UE, the downlink control channel.

[82] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, a configuration of a plurality of sequences associated with the UE from an access node.

[83] Optionally, in any of the foregoing embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, an association message conveying at least one of the associations between one or more reference signaling resources and one or more BRACH resources, associations between one or more reference signaling resources and one or more BRACH response resources, or associations between one or more BRACH resources and one or more BRACH response resources.

[84] Optionally, in any of the foregoing embodiments, an embodiment is provided wherein the BRACH resource is further identified according to an association message conveying associations between one or more reference signaling resources and one or more BRACH resources.

[85] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, QCL information between first reference signal resources associated with the first reference signal type and second reference signal resources associated with with the second type of reference signals.

[86] Optionally, in any of the previous embodiments, an implementation is presented in which the second identifier of the second resource associated with the second reference signal is determined in accordance with the QCL information.

[87] Optionally, in any of the previous embodiments, an embodiment is provided in which the second identifier of the second resource associated with the second reference signal is determined by tracking the second resources associated with the second reference signal.

[88] Optionally, in any of the previous embodiments, an embodiment is provided in which a plurality of sequences associated with a UE comprise extension sequences, each extension sequence including a base sequence common to all extension sequences and a unique tail subsequence.

[89] Optionally, in any of the previous embodiments, an implementation is presented in which a plurality of sequences associated with a UE contains sequences that are different from each other.

[90] According to an exemplary embodiment, a method for operating an access node is provided. The method includes receiving, by an access node, a beam fail recovery request message including a sequence in a beam fail random access channel (BRACH) resource, identifying by the access node a user equipment (UE) associated with the sequence, determining, by the access node, the second resource identifier of the second reference signal associated with the second type of reference signals, in accordance with the position of the BRACH resource, determining, by the access node, an intra-group identifier identifying the group of resources of the first reference signal associated with the first type of reference signals, which is spatially quasi-aligned (QCL) with resource of the second reference signal associated with the second type of reference signals, determining, by means of the access node, the first resource identifier of the first reference signal associated with the first type of reference signals, in accordance with the second identifier and the intragroup identifier, and setting, by means of access node, control channel in accordance with the first identifier.

[91] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises configuring by the access node one or more sequences for the UE, and sending the access node a plurality of sequences to the UE.

[92] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises transmitting, by the access node, precoded first reference signals in the first reference signal resources associated with the first reference signal type, and transmitting, by the access node access, pre-coded second reference signals in the resources of the second reference signals associated with the second type of reference signals.

[93] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises sending, by the access node, a connectivity message, carrying at least one of the connectivity between one or more reference signaling resources and one or more BRACH resources, associations between one or more reference signaling resources and one or more BRACH response resources, or associations between one or more BRACH resources and one or more BRACH response resources.

[94] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises sending, by the access node, QCL information between the first reference signal resources associated with the first reference signal type and the second reference signal resources associated with with the second type of reference signals.

[95] According to an exemplary embodiment, a user equipment (UE) operation method is provided. The method includes determining, by the UE, a beam index of a replacement beam according to a first reference signal received from the access node, identifying, by the UE, a beam failure random access channel (BRACH) resource according to the beam index, and an association between the beam indices and the beam indices. blocks, and sending by the UE a preamble sequence in the BRACH resource.

[96] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises receiving, by the UE, the association between beam indices and block indices.

[97] Optionally, in any of the previous embodiments, an embodiment is provided in which the association between beam indices and block indices is received from an access node.

[98] Optionally, in any of the previous embodiments, an embodiment is provided in which the relationship between beam indices and block indices is a direct relationship between beam indices and block indices.

[99] Optionally, in any of the previous embodiments, an embodiment is provided in which the relationship between beam indices and block indices is an indirect relationship between beam indices and block indices.

[100] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises selecting, by the UE, a preamble sequence from one or more preamble sequences.

[101] In accordance with an exemplary embodiment, a method for operating an access node is provided. The method includes receiving by an access node from a user equipment (UE) a preamble sequence in a beam failure random access channel (BRACH) resource, determining by the access node a replacement beam beam index selected by the UE in accordance with a reference signal transmitted by the access node, wherein the index of the beam is determined according to the block index associated with the BRACH resource and the relationship between the beam indices and the block indices, and the access node completes the beam failure recovery procedure according to the beam index.

[102] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises signaling by the access node the association between beam indices and block indices.

[103] Optionally, in any of the previous embodiments, an embodiment is provided in which the association between beam indices and block indices is signaled in a Radio Resource Control (RRC) message.

[104] Optionally, in any of the previous embodiments, an embodiment is provided wherein the method further comprises identifying by the access node a UE identifier.

[105] Optionally, in any of the previous embodiments, an embodiment is presented in which the beam failure recovery procedure is terminated in accordance with the UE ID.

[106] According to an exemplary embodiment, a user equipment (UE) operation method is provided. The method includes selecting, by a UE, a resource for carrying a preamble to an access node from one or more resources, wherein a plurality of resources are shared by other UEs in at least one of a code sequence domain, a time domain, or a frequency domain, and sending, by the UE , to the access node of the preamble associated with the UE in the selected resource.

[107] In accordance with an exemplary embodiment, a method for operating an access node is provided. The method includes configuring, by the access node, one or more resources to carry preambles from user equipments (UEs), wherein a plurality of resources are shared by the user equipments in at least one of code sequence domain, time domain, or frequency domain, and sending, access node, configuration to user equipment (UE).

[108] Optionally, in any of the preceding embodiments, an embodiment is provided wherein the method further comprises receiving, by an access node, from a subset of user equipments (UEs), preambles in a plurality of resources.

[109] The use of the above embodiments allows user equipments (UEs) to participate and assist in beam restoration in the event of beam loss or failure.

Brief description of the drawings

[110] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

[111] Figure 1 illustrates an example of a wireless communication system in accordance with the exemplary embodiments described herein;

[112] Figure 2 illustrates an exemplary ray tracking system in accordance with the exemplary embodiments described herein;

[113] Figure 3A illustrates a flowchart of exemplary operations occurring at an access node participating in a beam recovery procedure in accordance with the exemplary embodiments described herein;

[114] Figure 3B illustrates a flowchart of exemplary operations occurring at a UE participating in a beam recovery procedure in accordance with the exemplary embodiments described herein;

[115] Figure 4 illustrates a diagram highlighting an example of one-to-one connectivity between a transmitting WBRS resource precoder and receiving BRACH resource combiners in accordance with the exemplary embodiments described herein;

[116] Figure 5 is a diagram providing a detailed view of an exemplary BRACH resource in accordance with the exemplary embodiments described herein;

[117] Figure 6 illustrates a flowchart of exemplary operations occurring at an access node involved in beam recovery using BFRS in accordance with the exemplary embodiments described herein;

[118] Figure 7 illustrates a diagram highlighting exemplary connectivity between resources and beams used in beam reconstruction in accordance with the exemplary embodiments described herein;

[119] Figure 8 illustrates a flowchart of exemplary operations occurring at a UE participating in beam recovery using BFRS in accordance with the exemplary embodiments described herein;

[120] Figure 9 illustrates a diagram emphasizing UE communication during beam recovery in accordance with the exemplary embodiments described herein;

[121] Figure 10A illustrates a flowchart of exemplary operations occurring at an access node involved in beam recovery using RS on beam failure, which includes one or more reference signals in accordance with the exemplary embodiments described herein;

[122] Figure 10B illustrates a flowchart of exemplary operations occurring at a UE participating in beam recovery, where the UE monitors one or more reference signals in accordance with the exemplary embodiments described herein;

[123] Figure 11 illustrates a diagram highlighting exemplary BRACH preamble transmission and response reception in multiple resources in accordance with the exemplary embodiments described herein;

[124] Figure 12 illustrates a diagram highlighting the sending of a BRACH preamble and detection of a response in accordance with the exemplary embodiments described herein;

[125] Figure 13 illustrates an exemplary beam pattern for synchronization signals (SS) and CSI-RS in accordance with the exemplary embodiments described herein;

[126] Figure 14 illustrates a graphical representation of two precoders that are spatially quasi-aligned (QCLed) in accordance with the exemplary embodiments described herein;

[127] Figure 15 illustrates a beam pattern of precoders for a first beam and one or more second beams, where the precoders have a one-to-many SQCL (OMSQ) relationship in accordance with the exemplary embodiments described herein;

[128] Figure 16 illustrates a beam pattern of precoded signals, highlighting potential relationships in accordance with the exemplary embodiments described herein;

[129] Figure 17 illustrates a flowchart of operations occurring at an access node using OMSQ relationships to change beams in accordance with the exemplary embodiments described herein;

[130] Figure 18 illustrates a flowchart of operations occurring in a UE using OMSQ relationships to change beams according to the exemplary embodiments described herein;

[131] Figure 19 illustrates first exemplary BRACH resources in accordance with exemplary embodiments described herein;

[132] Figures 20A and 20B illustrate relative index tables for block indices of an exemplary BRACH block configuration and relative indexes for CSI-RS beam indices in accordance with the exemplary embodiments described herein;

[133] Figure 20C illustrates an exemplary feedforward relationship table between beam indices and block indices according to the exemplary embodiments described herein;

[134] Figure 21 illustrates a second example of BRACH resources in accordance with the exemplary embodiments described herein;

[135] Figure 22A illustrates a flowchart of exemplary operations occurring at a UE initiating recovery from beam failure, according to the exemplary embodiments described herein;

[136] Figure 22B illustrates a flowchart of exemplary operations occurring at an access node involved in beam failure recovery according to the exemplary embodiments described herein;

[137] Figure 23 illustrates an exemplary communication system in accordance with the exemplary embodiments described herein;

[138] Figures 24A and 24B illustrate exemplary devices that may implement the methods and ideas of the present disclosure; and

[139] Figure 25 illustrates a block diagram of a computing system that may be used to implement the devices and methods disclosed herein.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[140] The creation and use of exemplary embodiments are discussed in detail below. However, it should be understood that the present disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific embodiments for making and using the embodiments and do not limit the scope of the present disclosure.

[141] Figure 1 illustrates an example of a wireless communication system 100. Communication system 100 includes an access node 105 serving user equipment (UE) 115. In a first mode of operation, communication to and from UE 115 occurs via access node 105. In the second mode of operation, communication to and from UE 115 does not occur via access node 105, however, access node 105 typically allocates resources used by UE 115 for communication. Access nodes can also be commonly referred to as evolved NodeBs (Node Bs) (eNBs), base stations, NodeBs, master eNBs (MeNBs), secondary eNBs (SeNBs), next generation (NG) NodeBs (gNBs), master gNBs (MgNBs), secondary gNBs (SgNBs), remote radio units, access points, and the like, while UEs may also be commonly referred to as mobile devices, mobile stations, terminals, subscribers, users, stations, and the like.

[142] While it is understood that communication systems may use multiple access nodes capable of communicating with multiple UEs, only one access node and one UE are shown for simplicity.

[143] As discussed earlier, path loss in communication systems operating at high frequencies (HF) (6 gigahertz (GHz) and higher, such as millimeter-wave (mmWave) operating frequencies) is high, and beamforming can be used to overcome large path losses. As shown in Figure 1, both the access node 105 and the UE 115 communicate using beam-formed transmissions and receptions. As an example, access node 105 communicates using one or more communication beams, including beams 110 and 112, while UE 115 communicates using one or more communication beams, including beams 120 and 122.

[144] A beam may be a predefined set of beamforming weights in the context of codebook-based precoding, or a dynamically defined set of beamforming weights in the context of codebook-based precoding (e.g., eigenvalue beamforming (EBB)) . The beam can also be predefined with a set of phase shift preprocessors that combine the signals from the antenna array in the radio frequency (RF) domain. It should be appreciated that the UE may rely on codebook-based precoding for uplink signal transmission and downlink signal reception, while TRP may rely on non-codebook-based precoding for specific beamforming for signaling. downlink and/or receive uplink signals.

[145] There are many limitations that can limit the performance of a UE, which include the following:

– Electromagnetic coupling: Electrical currents on the surface of the UE antenna cause various forms of electromagnetic coupling that affect the characteristic impedance and aperture efficiency of the antenna;

– Physical size: In general, the display panel and battery of the UE take up the largest percentage of the UE volume, while various other devices (including sensors, cameras, speakers, etc.) also take up a significant portion of the remaining volume and are usually placed along the edges of the UE. Antennas (third generation (3G), fourth generation (4G), new radio communications (NR) fifth generation (5G), etc.) are also present. Energy consumption, heat dissipation, etc. also affect the physical dimensions;

– Usage: The intended use of the UE also affects the performance of the UE; As an example, the user's hand can reduce the gain of an antenna array by an average of 10 dB when it completely covers the array; and

– Antenna array configuration: Multiple antenna arrays can be used; potentially requiring multiple radio frequencies (RF) integrated circuits (ICs) and single baseband ICs (BBs) (BBICs).

[146] It is noted that the movement of the UE can lead to a significant deterioration in signal quality. However, movement can be detected using a variety of sensors, including:

– Three-dimensional (3D) gyroscopes with root mean square noise (RMS) of the order of 0.04 degrees per second;

– 3D accelerometers with RMS noise on the order of 1 milligal; and

– Magnetometers.

If the movement of the UE is known, then it may be possible to quickly follow the beams used by the UE.

[147] Figure 2 illustrates an exemplary ray tracking system 200. The beam tracking system 200 may be located at the UE. The ray tracking system 200 uses data from one or more sensors (including position information from positioning systems to provide information (such as Global Positioning System (GPS)), 3G gyro information, 3D accelerometer information, magnetometer information, etc.) for tracking beams. The data module 205 receives the sensor data and processes the data, providing the processed data to the motion classification module 210, which classifies the type of motion the UE is undergoing. The movement classification module 210 also receives information from the training data module 215, which provides information to the movement classification module 210 based on historical data to help classify the movement of the UE. The classified movement is provided to the detector 220. The detector 220 may consider whether the movement of the UE requires beam tracking adjustment. If beam tracking adjustment is required, solutions for beam tracking adjustment are generated. Example solutions include beam adjustment for a situation where the UE is stationary 225, beam adjustment for a situation where the UE is rotating 226, beam adjustment for a situation where the UE is experiencing offset 227, and beam adjustment for a situation where the UE is locked 228.

[148] Resources may be allocated for beam recovery purposes. As used herein, resources refer to time resources, frequency resources, preamble sequence resources, or a combination thereof. Beam recovery resources may be allocated when the UE establishes an active link with the access node. Each UE may be assigned one or more unique beam recovery resources. In the first exemplary embodiment, beam recovery resources are beam recovery random access channel (BRACH) preambles that can be transmitted in the BRACH domain. It should be noted that the BRACH region may be the same or different from the Physical Random Access Channel (PRACH) region used for initial access purposes in terms of positions in time and/or frequency in the entire operating band. In the second exemplary embodiment, beam recovery resources are sets of unique resources (ie, multiple resources can be assigned to each UE), where for each UE, each resource can be used for beam restoration purposes. As used herein, resources, regions, and preambles for beam failure recovery refer to BRACH resources, regions, and preamble. It should be noted that they may also be referred to as PRACH resources, areas and preambles for beam failure recovery purposes. The discussion presented here will use BRACH for simplicity.

[149] With regard to BRACH and PRACH, in the first exemplary embodiment, if two channels use different or orthogonal resources in time or frequency, then the same sequence can be used in both BRACH and PRACH. As an illustrative example, if the UE is assigned the first sequence to transmit in the PRACH region, then the UE may also use the first sequence to transmit in the BRACH region. In the second exemplary embodiment, if the same sequence is used as a PRACH preamble and a BRACH preamble, different scrambling codes may be used. As an illustrative example, if a first UE is assigned to use a first sequence for transmission in the PRACH region, then that first sequence, when scrambling with the first scrambling sequence, may be used by the first UE for transmission in the BRACH region. It should be noted that the scrambling sequence for different UEs may be the same or different. It is also noted that there may be multiple BRACH resources, each occupying a different time-frequency location. In such a situation, the same sequence may be used in different BRACHs.

[150] In the third exemplary embodiment, the sequences used as the PRACH preamble sequence and the BRACH preamble sequence directly may be orthogonal. In a fourth exemplary embodiment, if the BRACH and PRACH use the same and/or overlapping time and/or frequency resources, then the PRACH preamble sequence and the BRACH preamble sequence may be orthogonal to each other. It should be noted that there may be multiple BRACH resources, each occupying the same position in time and/or frequency. In such a situation, multiple orthogonal preamble sequences may be used for multiple BRACH resources, each uniquely identifying a unique BRACH resource. In general, multiple BRACHs may exist for each UE, and each BRACH may be uniquely identified by location in time and/or frequency, as well as by the preamble sequence used by the UE to transmit a beam failure event.

[151] Figure 3A illustrates a flow diagram of exemplary operations 300 occurring at an access node participating in a beam recovery procedure. Operations 300 may indicate operations occurring at the access node when the access node participates in a beam recovery procedure.

[152] Operations 300 begin with the access node configuring BRACH preamble sequences (block 305). In general, the configuration may be conveyed to the UE in a radio resource configuration message, a medium access control element message, a downlink control indicator message, or a combination thereof. The configuration message should provide the UE with information on which preamble sequence to use, at which time and frequency position to transmit the preamble, such as the time and frequency location of the BRACH, and so on. The BRACH preamble sequences may be transmitted from the UE on the BRACHs when needed, for example, to request beam restoration. The access node may configure a unique BRACH preamble sequence for each UE. Alternatively, one BRACH preamble sequence may be assigned to multiple UEs. Alternatively, a plurality of BRACH preamble sequences may be assigned to each UE. The access node also transmits BRACH preamble sequences to the UE. The access node sends, for example, in a broadcast manner, reference signals to assist user equipments (UEs) in detecting a beam failure as well as identifying a new beam (block 307). The reference signals may include beam recovery reference signals (BRRS), wide beam reference signals (WBRS) (such as synchronization signals (SS), wide beam channel state information reference signals (WB CSI–RS), wide beam CSI–RS SS CSI-RS, Cell-Specific CSI-RS, Group CSI-RS, Common CSI-RS, Layer 3 Mobility CSI-RS, etc.), Channel State Information Reference Signals (CSI-RS), etc. .d. may be transmitted by the access node so that the UE may make measurements to determine if a beam failure has occurred. The reference signals may also help the UE determine recovery information useful when setting up a replacement DL control channel, or in other words, if a new beam has been identified. In the following discussion, the term beam failure reference signal (BFRS) is used to represent the above reference signals, which may include BRRS, WBRS, CSI-RS, or combinations thereof. It should be noted that the reference signal for determining or detecting a beam failure and the reference signal for identifying a new beam may be the same set of reference signals or different sets of reference signals. The access node receives the BRACH preamble from the UE on the BRACH (block 309). The access node transmits a beam recovery request response (block 310), which may or may not include granting a UL to the UE to send additional recovery information. If the UL grant for the UE to send the additional recovery information is enabled, then the access node receives the additional recovery information from the UE (block 311). The additional information for recovery may include information useful in setting up a DL control channel with the UE. The access node establishes a DL control channel (step 313). The access node sends DL control messages on the DL control channel (block 315). DL control messages may include control signaling. In an alternative embodiment, steps 309 and 311 may be performed together, meaning that the preamble as well as the recovery information are received by the access node in one transmission. In such a situation, steps 310, 313, and 315 may be performed together.

[153] Figure 3B illustrates a flowchart of exemplary operations 350 occurring at a UE participating in a beam recovery procedure. Operations 350 may indicate operations occurring at the UE when the UE participates in a beam recovery procedure.

[154] Operations 350 begin with the UE receiving a BRACH preamble sequence configuration as well as a BRACH channel configuration from the access node (block 355). As discussed earlier, the BRACH preamble sequence configuration provides information to the UE as to which preamble to transmit in the event of a beam failure, while the BRACH channel configuration provides information to the UE as to which position in time and frequency to transmit the BRACH preamble sequence. Such configuration messages may be received by the UE in a Radio Resource Control (RRC) message, a Medium Access Control (MAC) (MAC-CE) message, a Downlink Control Indicator (DCI) message, or a combination thereof. The UE monitors downlink (DL) channels or signals, such as DL control channels, DL reference signals, synchronization signals, and so on (block 357). The UE may monitor channels or DL signals to determine if a failure or beam loss has occurred. For example, if the UE cannot detect the existence of a particular resource such as BRRS, WBRS (e.g., SS, WB CSI-RS, wideband CSI-RS, simulating SS CSI-RS, cell-specific CSI-RS, group CSI-RS, common CSI-RS, etc.), CSI-RS (e.g., narrow beam CSI-RS, per-UE CSI-RS, layer 3 mobility CSI-RS, etc.), etc., UE can determine that a beam failure has occurred. The UE performs a check to determine if a beam failure has occurred (block 359). If no beam failure has occurred, the UE returns to step 357 to continue tracking channels or DL signals. For example, if the measurement performed at the UE does not satisfy the beam failure condition, then the UE determines that no beam failure has occurred. If the measurement meets the beam failure condition, then the UE determines that a beam failure has occurred.

[155] If a beam failure occurs, then the UE performs BFRS measurements and obtains recovery information (step 361). As an illustrative example, the UE measures specific reference signals, ie BFRS, such as BRSS, WBRS, CSI-RS, etc., for reacquisition or resynchronization with the beams transmitted by the access node. The UE may determine the information to recover, including the DL transmission path(s) (or associated indexes/indices) of the reference signals from the access node, or which DL transmission path provides sufficient quality. In other words, the UE determines that the DL transmission beam has a signal quality that meets a threshold, which may be specified in a communication system operator's technical standard or determined through cooperation between the UE and the access node. Alternatively, the UE selects the DL transmission beam with the highest signal quality. The measurements can also improve timing or frequency synchronization. The location in time or frequency of the reference signals may be transmitted from the access node a priori and may be periodically allocated in the time and frequency domains. Such signaling may be included in an RRC message, a MAC-CE message, a DCI message, or a combination thereof.

[156] The UE transmits a BRACH preamble (step 363) if a beam failure is detected and a new beam has been identified. The transmission of the BRACH preamble initiates beam recovery. In the first exemplary embodiment, the UE transmits its own preamble sequence in the BRACH region. The BRACH region may be non-orthogonal or orthogonal to the PRACH region in the time or frequency domain. In the second exemplary embodiment, the UE transmits control or commands in a script without being granted in Resource Elements (REs). Handover of control or commands is a non-provisioning approach and may use REs pre-allocated to the UE. Uplink (UL) transmission may be based on time or frequency synchronization previously performed. The UE monitors the DL channels to respond to the beam recovery request, which may or may not include granting the UL to transmit additional recovery information (block 364). If a UL grant is received, then the UE sends additional recovery information (block 365). Additional information for recovery may include an index or indices of DL transmission beams or DL reference signals to identify a new beam from the access node, channel quality indicator(s) (such as received reference signal power (RSRP), received reference signal quality (RSRQ ), received signal strength, signal-to-noise ratio (SNR), signal-to-noise-plus-interference ratio (SINR), received signal strength indicator (RSSI), etc.), and other information useful to the access point when establishing a channel DL controls. The UE receives DL control messages on a DL control channel established by the access node (block 367). Alternatively, steps 363 and 365 may be performed in the same transmission. In this situation, step 364 and step 367 may be performed together.

[157] In general, the UE may monitor a reference signal, such as BFRS, to determine if a beam failure condition has been satisfied and if a new beam has been identified. As an example, BFRS includes a set of CSI-RS signals for beam steering purposes. As another example, BFRS includes a set of SS signals. In general, BFRS includes CSI-RS signals, WBRS signals, or both CSI-RS signals and WBRS signals. It should be noted that the reference signals for determining or detecting a beam failure and the reference signals for identifying a new beam may be the same set of reference signals or different sets of reference signals. In other words, the reference signal for beam failure detection includes CSI-RS signals, WBRS signals, or both CSI-RS signals and WBRS signals, and the new beam identification reference signal includes CSI-RS signals, WBRS signals, or both. CSI–RS signals and WBRS signals.

[158] According to an exemplary embodiment, techniques are provided using BFRS (for beam failure detection and new beam identification), which includes both a CSI-RS signal set and a WBRS set. It should be noted that BFRS, including a reference signal for beam failure detection with both CSI-RS and WBRS, and a new reference signal for beam identification, also with both CSI-RS and WBRS, is one exemplary option. implementation. Other exemplary embodiments include the following: a reference signal for beam failure detection includes CSI-RS only, WBRS only, or both; and the new reference signal for beam failure identification includes CSI-RS only, WBRS only, or both. According to another exemplary embodiment, techniques are provided using a beam failure RS that includes only CSI-RS. Both exemplary embodiments use a common structure. There is a difference in the exemplary embodiment in which the UE uses a single BRACH resource (identified using detected CSI-RS, WBRS, or a combination thereof) or multiple BRACH resources to transmit the BRACH preamble.

[159] The example communication system below is used to facilitate discussion. However, the exemplary embodiments presented herein may function with other communication system configurations. An example communication system includes the following:

– Access nodes that configure user equipments (UEs) with one or more unique BRACH preamble sequences within a BRACH region. The UE, for beam recovery purposes, may use one of the configured BRACH preamble sequence to send a beam recovery request in the BRACH region. Typically, the BRACH region is parameterized with at least its time and frequency location information, and the time-frequency parameters may be included in the radio resource configuration message.

– Access nodes send multiple BFRSs (including WBRS signals or CSI-RS signals or both) toN resources (whereN is an integer). Miscellaneous BFRS precoding can be used in different resources. It should be noted that here BFRS is mainly used for the new beam identification function, but BFRS can be used for the beam failure detection function.

– Access nodes can configureBareas or BRACH resources (whereB – integer), for example, via an RRC message, a MAC-CE message, a DCI message, or a combination thereof. For example,B=N, but it is not necessary thatB=N.Nregions or BRACH resources may appear afterNBFRS resources (that is, resources containingN BFRs signals). Access nodes can signal relationship or connectivity betweenN (as well asB in general) BRACH resources andNBFS resources. In general, an access node may signal an association or association betweenNBRACH resources andNBFS resources. An illustrative example of a relationship or connectivity is that the transmitting precoderNBFRS resources and receive combiner (also commonly referred to as a precoder on the receiver side)NBRACH resources have a one-to-one relationship, for example, the transmitting precoder of the first BFRS resource have a one-to-one relationship of matching beams with the receive combiner of the first BRACH resource. Another illustrative example of a relationship or connection is that the locationNBRACH resources in time and frequency can be determined from the locationsN BFRS resources in time and frequency relative to the reference resource, or vice versa.In other words, if a first BFRS resource containing a first BFRS reference is identified, then the UE should use the first BRACH resource at the first time-frequency location to transmit preamble sequences for beam failure recovery; and so on and so forth. Conversely, if the UE uses the first BRACH resource in the first frequency-temporary location for transmission of preamble sequences for beam failure recovery, it must explicitly or implicitly inform the access node that the first BFRS resource containing the first BFRS reference signal has been identified in the UE; and so on and so forth. Alternatively, the relationship is specified in the technical standard or by the communications system operator. If a relationship or association is specified in a technical standard or by a communications system operator, then explicit signaling of such relationship or association may not be required.

[160] Figure 4 illustrates a diagram 400 highlighting exemplary one-to-one connectivity between a transmitting WBRS resource precoder and receiving BRACH resource combiners. As shown in Figure 4, BFRS region 405 represents BFRS resources 407, 408, and 409, as well as access node DL transmission beams 410, 411, and 412, while BRACH region 415 represents BRACH resources 417, 418, and 419, as well as beams 420, 421 and 422 receive the UL of the access node. It should be noted that while the access node's beam is shown in Figure 4, similar UE beams may be shown in place.

[161] As shown in diagram 400, there is a one-to-one relationship or relationship between the access node's DL transmit path transmit precoders and the access node's UL receive path combiner. In the specific example shown in Figure 4, the one-to-one relationship or relationship is referred to as beam matching (BC). In communication systems that operate at higher frequencies, such as millimeter wave (mmWave) communication systems, communication devices typically have a large number of transmit or receive antennas, which have fewer radio frequency (RF) circuits. From the point of view of a communication device, beamforming transmit and receive beams must have the same (or substantially the same) radiation pattern (in terms of peak or non-peak beam direction, peak or non-peak beam gain, peak or non-peak beamwidth, etc., e.g. ) in the spatial domain. This means that for each beam formed by a beam, the response of the beam in all directions must be the same (or nearly the same) from the point of view of the transmitter and receiver. This is known as the ray matching condition, and when the ray matching condition is met, the ray matching is achieved. For example, the transmit DL transmit beam precoder 410 and the receive UL receive beam combiner 420 have beam mapping. Figure 4 also illustrates the association or relation of time-frequency location of the BRACH resource and BFRS resources. For example, if the BFRS at position 407 is identified as a recovered new beam, then the UE should use the BRACH resource 417 (at a specific time-frequency location) to transmit preamble sequences to recover from beam failure; conversely, if BRACH resource 417 (at a particular time-frequency location) is used by the UE to send preamble sequences for beam failure recovery, then it shall carry that the BFRS at position 407 has been identified as a new beam recovered.

[162] Figure 5 shows a diagram 500 representing a detailed view of an exemplary BRACH resource. As shown in Figure 5, a BRACH region 505 represents BRACH resources, such as a BRACH resource 507 . A BRACH resource, such as BRACH resource 507, may include time and frequency locations. As shown in diagram 500, BRACH resource 507 includes one or more time locations and one or more frequency locations. BRACH resource 507 includes a first resource 510 allocated for PRACH transmissions and a second resource 512 allocated for BRACH transmissions. In the above illustration, each BRACH resource, such as BRACH resource 507, includes BRACH resources (eg, second resource 512), and the UE may select one BRACH resource fromN BRACH resources with indexnblock to send the preallocated preamble. Indexnblock may carry a piece of information from log2(N)-bits from the UE to the access node. This piece of information may be used to convey from the UE to the access node which BFRS (of the N BFRS signals) has been identified in the UE. Typically, an access node may send a message (e.g., an RRC message, a MAC-CE message, a DCI message, or a combination thereof) in advance to the UE to configure the association between BRACH blocks and the information carried in them, so that both the access node and The UE knew that sending the preamble in the first ofN resources BRACH is "00...01", which means that the first of N BFRS signals has been identified, sending a preamble in the second ofN resources BRACH is "00…10", which means that the second ofN BFRS signals have been identified, and sending the preamble toN-ohm fromNBRACH resource is "11...11", meaning that the Nth of N BFRS signals has been identified, and so on, while each bit of the sequence here has a length of log2(N) bits and may be, for example, an index of a newly identified beam of N BFRS signals from the UE. Alternatively, for each ofNBRACH resources BRACH resource inside can be duplicatedK once,what gives in the endK*N resources BRACH, and the UE may select one of the K*N resources BRACH to send a preallocated preamble while indexnblock can transfer log2(K*N) bits of information from the UE to the access node. Typically, the access node may send a message in advance to the UE so that both the access node and the UE are aware of the association between BRACH blocks and the information carried in them. As an example, the information carried by the BRACH block index is the index of the newly identified beam from the UE. BRACH blocks may also include resources for other purposes. In some exemplary embodiments, the BRACH resource may be allocated exclusively for BRACH transmissions. It should be noted that the BRACH and PRACH channels may be different in terms of time and/or frequency location.

[163] In accordance with an exemplary embodiment, beam failure recovery techniques are provided using a BFRS that includes two different BFRS sets, such as a first BFRS set and a second BFRS set. It should be noted that the two sets of BFRSs may be two subsets of the available BFRSs. It is also possible that in a particular case only one set of reference signals is needed, eg only a set of first BFRSs or only a set of second BFRSs, which can be seen as a special case of the approach that uses two sets of BFRSs. The inclusion of two different sets of BFRS allows the UE to identify more beam options from the access node that are potentially suitable to replace the missing beam, possibly using a layered approach that potentially simplifies detection and decoding and also reduces signaling overhead. As an illustrative example, instead of scanning a large number of narrow beamwidth beams (eg, CSI-RS), which may take a significant amount of time, the UE may scan fewer wide beamwidth beams (eg, WBRS). Scanning fewer broad beamwidth beams reduces the required scan time, thereby causing the search space for the reconstructed beam to be significantly smaller than the search space for narrow beamwidth beams. Once the wide beamwidth beam(s) have been identified, the UE can scan for a much smaller number of narrow beamwidth beams that may be potential beams to replace the missing beam.

[164] Figure 6 illustrates a flow diagram of exemplary operations 600 occurring at an access node involved in beam recovery using BFRS. Operations 600 may indicate operations occurring at the access node as the access node participates in beam recovery using BFRS. BFRS may include two different reference signals such as CSI-RS and WBRS. Alternatively, the BFRS may include one reference signal, eg only CSI-RS or WBRS.

[165] Operations 600 begin with the access node configuring BRACH preamble sequences (block 605). The access node may configure a unique BRACH preamble sequence for each UE. Alternatively, one BRACH preamble sequence may be assigned to multiple UEs. Alternatively, a plurality of BRACH preamble sequences may be assigned to each UE. The access node also sends information regarding the BRACH preamble sequences to the UE, for example, via an RRC message, a MAC-CE message, a DCI message, or a combination thereof. The access node optionally sends relationships or associations between BFRS signals and BRACH resources and response resources on BRACH to the UE (block 607). The relationships or associations between BFRS resources and BRACH resources (as well as BRACH response resources) may be fixed and may assist the UE in determining which BRACH resource, at least in terms of time-frequency location, to use for transmitting the BRACH preamble. In other words, the UE needs to know the time-frequency location of the first BRACH resource to transmit the preamble sequence if the UE identifies the first BFRS as a new beam, the time-frequency location of the second BRACH resource to transmit the preamble sequence if the second BFRS is identified as a new beam; and so on and so forth. Conversely, the access node needs to know that the UE has identified the first BFRS as a new beam if it receives the preamble sequence at the time-frequency location of the first BRACH resource; that the UE has identified the second BFRS as a new beam if it receives the preamble sequence at the time-frequency location of the second BRACH resource; and so on and so forth. The association or relationship may also assist the UE in determining on which BRACH response resource to receive the BRACH preamble response. A detailed discussion of the relationships between BFRS and BRACH resources is provided below.

[166] Relationships or associations between BFRS signals and BRACH resources, as well as resources for a BRACH response, can be represented in data form to provide simple and efficient signaling. As an illustrative example, consider the situation where BFRS resources are designated:1a,1b,1c etc.; BRACH resources are designated:2a,2b,2c etc.; and resources for BRACH response are designated:a,b,c and so on. In the first illustrative example relationships or relatednesses can be signaled in pairs, for example:

1a , 2a to convey that resources 1a and 2a are related or have a relationship;

1b , 2b to convey that resources 1b and 2b are related or have a relationship;

1c , 2c to convey that resources 1c and 2c are related or have a relationship;

1c , 2b to convey that resources 1c and 2b are related or have a relationship

1a , a to convey that resources 1a and a are related or have a relationship;

1b , b to convey that resources 1b and b are related or have a relationship; and

1b , c to convey that resources 1b and c are related or have a relationship .

Exemplary Relationships or relatedness can also be signaled in tabular form with a list of related resources, for example:

1a , 2a to convey that resources 1a and 2a are related or have a relationship;

1b , 2b to convey that resources 1b and 2b are related or have a relationship;

1c , 2b , 2c to convey that resources 1c and 2b and 2c are related or have a relationship;

1a , a to convey that resources 1a and a are related or have a relationship; and

1b , b , c to convey that resources 1b and b and c are related or have a relationship.

[167] The access node sends a BFRS including only WBRS, only CSI-RS, or both WBRS and CSI-RS, eg, using DL transmission beams (block 609). In a situation where the BFRS includes only CSI-RS or WBRS, the access node will send, for example, only CSI-RS or WBRS on DL beams. However, if the BFRS includes both CSI-RS and WBRS, then the access node will send both CSI-RS and WBRS on the DL beams. The access node receives the BRACH preamble from the UE where the beam failed (block 611). As an illustrative example, when the BFRS includes both CSI-RS and WBRS signals, then a BRACH preamble is received in the BRACH resource associated with m-th BFRS. In other words, the BRACH preamble is received in the BRACH resource that was associated withm-th BFRS. As another illustrative example, when the BFRS includes only CSI-RS signals or WBRS signals, then a BRACH preamble is received in the BRACH resource associated withn–th BFRS. In addition, the BRACH preamble is received in the UL receive beam of the access node, i. e. beam corresponding to the access node's DL transmission beam used for transmissionm-wow orn–wow BFRS. The access node identifies the UE (block 613). The access node may be able to identify the UE, eg, in accordance with the BRACH preamble. The access node may also be able to identify a new beam from the UE according to the time and frequency location of the BRACH. As an example, the access node may use the techniques presented in Figure 4 and the associated discussion, in which, for example, if the UE uses the BRACH resource 417 (at a specific time-frequency location) to transmit preamble sequences for beam failure recovery, then use BRACH resource 417 carries information that the BFRS at position 407 has been identified as a recovered new beam. The access node may or may not generate a UL resource grant for the UE (block 615). The UL resource grant is for allocating resources to allow the UE to send additional recovery information to the access node. The access node sends a response, eg, a BFR response, optionally providing the UL resource (or related information) to the UE (block 617). In a situation where the RACH response on beam failure includes a UL resource grant (or related information), the access node receives a UL transmission (block 619) that includes additional information to recover from the UE. Additional information for recovery may include additional information, for example, related ton. The access node performs DL control channel rebuilding or assists in beam steering (block 621). The access node uses the additional recovery information provided from the UE to rebuild the DL control channel or assist in beam steering. It should be noted that steps 611 and 619 may be performed simultaneously, and steps 613, 615, 617 and 621 may be performed simultaneously, subsequently. In addition, it should be noted that steps 611 and 619 can be combined into one step in the case where the BFRS contains only CSI-RS signals or WBRS signals.

[168] Figure 7 illustrates a diagram 700 highlighting an exemplary relationship between resources and beams used in beam recovery. As shown in Figure 7, BFRS region 705 represents BFRS resources (e.g., BFRS resource 710) and access node DL transmission beams (e.g., beam 715) used for BFRS transmission, BRACH region 707 represents BRACH resources (e.g., BRACH resource 712) and UL receive beams (eg, beam 717) used to receive BRACH preambles and UL transmit beams (eg, beam 722) used to transmit BRACH preambles, and response area 709 represents resources for a response (eg, resource 714 for a response) and UL receive beams (eg, beam 719) used to receive responses. It should be noted that beam precoder 715 and beam combiner 717 may have beam mapping, and beam precoder 722 and beam combiner 719 may have beam mapping. In addition, there is a one-to-one relationship between the BFRS resource 710 and the BRACH resource 712, as well as a one-to-one relationship between the BRACH resource 712 and the response resource 714.

[169] Beam mapping between different beams and one-to-one associations between resources help the access node and the UE determine which resources and beams to use for receiving and transmitting. By way of example, if the UE has determined that the BFRS transmitted over DL transmission path 715 is its selected best candidate among the set of potential candidate BFRSs, then the UE is able to determine (eg, from beam matching and one-to-one associations) that it shall transmit the BRACH preamble in BRACH resource 712 using beam 722. In addition, the UE may determine (again, from beam matching and one-to-one associations) that it should monitor or receive a response in resource 714 for the response, possibly using beam 719. Obviously, the use of beam mapping and one-to-one relationships makes it easier to determine which resources and beams to use.

[170] Figure 8 illustrates a flowchart of exemplary operations 800 occurring in a UE participating in beam recovery using BFRS. Operations 800 may indicate operations occurring at the UE when the UE participates in beam recovery using BFRS. BFRS may include two different reference signals such as CSI-RS and WBRS. Alternatively, the BFRS may include one reference signal, eg only CSI-RS or WBRS.

[171] Operations 800 begin with the UE receiving a BRACH preamble sequence configuration from the access node (block 805). The UE further receives relationships or associations between BFRS resources and BRACH resources, as well as resources for a BRACH response from the access node (block 807). The relationships or associations between BFRS resources and BRACH resources (and resources for a BRACH response) may be fixed and may assist the UE in determining which BRACH resource to use to transmit the BRACH preamble, and possibly which resource for the BRACH response to receive the response. to the BRACH preamble.

[172] Relationships or associations between BFRS signals and BRACH resources, as well as resources for a BRACH response, can be represented in data form to provide simple and efficient signaling. As an illustrative example, consider the situation where BFRS resources are designated:1a,1b,1c etc.; BRACH resources are designated:2a,2b,2c etc.; and resources for BRACH response are designated:a,b,c and so on. In the first illustrative example relationships or relatednesses can be signaled in pairs, for example:

1a , 2a to convey that resources 1a and 2a are related or have a relationship;

1b , 2b to convey that resources 1b and 2b are related or have a relationship;

1c , 2c to convey that resources 1c and 2c are related or have a relationship;

1c , 2b to convey that resources 1c and 2b are related or have a relationship

1a , a to convey that resources 1a and a are related or have a relationship;

1b , b to convey that resources 1b and b are related or have a relationship; and

1b , c to convey that resources 1b and c are related or have a relationship .

Exemplary Relationships or relatedness can also be signaled in tabular form with a list of related resources, for example:

1a , 2a to convey that resources 1a and 2a are related or have a relationship;

1b , 2b to convey that resources 1b and 2b are related or have a relationship;

1c , 2b , 2c to convey that resources 1c and 2b and 2c are related or have a relationship;

1a , a to convey that resources 1a and a are related or have a relationship; and

1b , b , c to convey that resources 1b and b and c are related or have a relationship.

[173] The UE monitors the BFRS (e.g., CSI-RS signals, WBRS signals, or both CSI-RS signals and WBRS signals) and determines the best BFRS index(es) (e.g., CSI-RS beam(s), beam(s) ) WBRS, or CSI-RS and WBRS beams) (step 809) As a result of tracking, the UE obtains a beam index per CSI-RS only, per WBRS only, or per CSI-RS and WBRS beams. beam can be represented by indexn resources (integer value). In a situation where the BFRS includes only CSI-RS or WBRS, the beam index is either the CSI-RS beam index or the WBRS (reference signal present in the BFRS). Whereas in a situation where the BFRS includes both CSI-RS and WBRS, the beam index can be either a CSI-RS beam index or a WBRS beam index, depending on which beam (CSI-RS or WBRS) better. Since the beam index can be a CSI-RS or WBRS beam index, the beam index report should make it clear which reference signal the beam index is associated with. As an illustrative example, consider the situation where there are four CSI-RS beams and four WBRS beams. Then, beam indices 1 to 4 may be used for four CSI-RS beams, and beam indices 5 to 8 may be used for four WBRS beams, for example. There would then be no confusion as to which reference the beam index is associated with. Note that a UE may receive more than one beam index. In such a situation, the indices are denotedn1,n2and so on. For example, in a situation where a BFRS contains a CSI-RS, then the nth CSI-RS resource out of N possible resources The CSI-RS may be the best (in terms of quality, for example) from the UE's point of view and may be used by the access node to rebuild the DL control channel or to assist in beam steering.

[174] The UE may determine the remaining BFRS best beam(s) index(es) (block 811), which may include only CSI-RS signals, or only WBRS signals. In a situation where the BFRS includes both CSI-RS and WBRS, the UE may have previously determined either the CSI-RS or WBRS index(es). The UE may now determine the remaining WBRS index (or indices) (if the CSI-RS index (or indices) was previously determined) or CSI-RS (if the WBRS index (or indices) was previously determined). As a result, the UE obtains a beam index based on the BFRS. The beam index can be represented by the indexm BFRS resource (integer value); or, in other words, the indexm of the CSI-RS resource in the case where the BFRS includes only CSI-RS signals, the indexm resourceWBRSin the case where the BFRS includes only the WBRS. Note that a UE may receive more than one beam index. In such a situation, the indices are denotedmone,m2so Further.m–th BFRS resource out of M possible resources WBRS is the best (in terms of signal quality, for example) from a UE's point of view and can be used by an access node to rebuild a DL control channel or to assist in beam steering.

[175] The UE optionally selects a BRACH preamble (block 813). In a situation where the UE is configured with one or more BRACH preambles, the UE selects one of the one or more BRACH preambles. In a situation where the UE is configured with a unique BRACH preamble that can be transmitted on one or more BRACHs, the UE selects one of the one or more BRACHs and transmits the configured preamble. Selecting one of the one or more BRACH preambles allows the UE to implicitly signal information without the need for explicit signaling of that information. For example, if there are four BRACH preambles in one or more BRACH preambles, the UE may implicitly signal two bits of information by transmitting one of the four BRACH preambles. As another example, if there are four BRACHs available for the UE to send one BRACH preamble, then the UE may implicitly signal two bits of information by transmitting the preamble on one of the four BRACHs. In any case, the 2-bit information may be used by the UE to carry the identified new beam index m .

[176] UE, using the relationship or connectivity betweenm–th resource BRACH andm-th BFRS resource to determinem–th BRACH resource, sends the BRACH preamble tom-th BRACH resource (block 815).m-th BRACH resource matchesm–mu a BFRS resource index, which is determined by the UE as the best WBRS beam, and a relationship or association between the BRACH and BFRS resources. Sending BRACH preamble in mth resource BRACH (selected for its relationship withm–m BFRS resource) provides the UE with an excellent opportunity that the BRACH preamble will successfully arrive at the access node, thereby reducing the delay of the beam recovery process.

[177] The UE receives a response, such as a BFR response, in a BRACH response (block 817). The response may optionally include a UL grant to allow the UE to send a subsequent (or additional) message including a report with additional information such as a subset of the beam index, beam quality information, and so on. The response may be received on a Physical Downlink Shared Channel (PDSCH) or a Physical Downlink Control Channel (PDCCH) or a broadcast channel. The response may be addressed with an identifier identifying the BRACH preamble (or the access node may send the BRACH preamble directly). The response may also include a timing alignment instruction to synchronize subsequent UL transmissions from the UE. The response may be received in a time synchronization window, possibly by a receive combiner associated with the transmit precoder used to transmit the BRACH preamble. The timing window that the UE uses to receive the response corresponds to the BRACH resource used to send the BRACH preamble. The UE may send additional information (eg, beam index subset, beam quality information, etc.) according to the UL grant (block 819). Alternatively, the UE may transmit the BRACH preamble along with additional information (eg, beam index subset, beam quality information, etc.). In this situation, providing a UL in the response is not required.

[178] Figure 9 illustrates a diagram 900 emphasizing UE communication during beam recovery. Diagram 900 displays a BRACH region 905 where the UE sends a BRACH preamble on one or more BRACH resources. As an example, the UE sends a BRACH preamble using the UL transmission beam 907 . Diagram 900 also displays a response region 910 where the UE receives a response (such as a BFR response) from the access node. As an example, the UE receives a response using a DL receive beam 912 within a time window that is configured by the access node. Such a time window configuration may be specified, for example, in terms of a time window start position, a time window end position, a time window duration, and so on. As another example, such a time window configuration may be specified in a technical standard or signaled in an RRC message, a MAC-CE message, a DCI message, or a combination thereof.

[179] Figure 10A illustrates a flowchart of exemplary operations 1000 occurring at an access node participating in beam recovery using BFRS that includes one or more reference signals, e.g., CSI-RS only, SS only, or CSI-RS and SS. Operations 1000 may indicate operations occurring at the access node as the access node participates in beam recovery using RS on beam failure that includes one or more reference signals, e.g., CSI-RS only or SS only, or both CSI-RS and SS.

[180] Operations 1000 begin with the access node configuring BRACH preamble sequences (block 1005). The access node may configure a unique BRACH preamble sequence for each UE. Alternatively, multiple BRACH preamble sequences may be assigned to one UE. In addition, one BRACH preamble may be assigned to multiple UEs. The access node also sends information about the BRACH preamble sequence to user equipments (UEs). The access node optionally sends relationships or associations (e.g., in an RRC message, a MAC-CE message, a DCI message, or a combination thereof) between BFRS resources (e.g., only CSI-RS resources, only SS resources, or CSI-RS and SS resources). ) and BRACH resources as well as resources to respond on BRACH to user equipments (UEs) (block 1007). The relationship or association between BFRS resources and BRACH resources (as well as resources for a BRACH response) can assist the UE in determining which BRACH resource to use to transmit the BRACH preamble, and potentially in which BRACH response resource to receive the BRACH preamble response. Relationships or associations between BFRS resources and BRACH resources may allow the UE to determine the location in time or the frequency of the former of the location in time or the frequency of the latter, or vice versa. In other words, if the UE determines the first BFRS resource index, then the relationships or associations allow the UE to determine the first BRACH resource at the first time-frequency location to be used by the UE to transmit the first BRACH preamble sequence; and if the UE determines the second BFRS resource index, then the relationships or associations allow the UE to determine the second BRACH resource at the second time-frequency location to be used by the UE to transmit the second BRACH preamble sequence; and so on.

[181] The access node sends spatially quasi-collated (SQCL) information (or representations thereof) to the UE (block 1009). SQCL defines the relationship between two reference or data signals such that the two signals can be considered to have similar characteristics. The SQCL information may include associations between CSI-RS resources and SS signals. For example, in SCL one-to-one connectivity, each CSI-RS signal is associated with one SS signal such that the transmit precoder for the CSI-RS signal is the same as the transmit precoder for the SS signal. It is possible that multiple CSI-RS signals are associated with one SS, and vice versa. The SQCL information may be signaled to the UE from the access node in an RRC message, a MAC-CE message, a DCI message, or a combination thereof, and stored in tabular form or in the memory of the UE. The access node sends a BFRS including CSI-RS, WBRS, or CSI-RS and WBRS, eg using DL beams (block 1011). One potential purpose of SQCL information signaling may be to allow the UE to find a proper WBRS signal based on the detected BFRS when the BFRS does not include WBRS, for example. For example, if a CSI-RS signal is detected (as a component in BFRS), then a WBRS that is quasi-co-located (SQCLed) with that particular CSI-RS can be identified; and if the WBRS (as a component in the BFRS) is found, then the WBRS as such (which is, of course, SQCLed with itself) can be determined. In other words, whether the detected BFRS signal is a CSI-RS signal, a WBRS signal, or both, an appropriate WBRS can be identified based on the SQCL information.

[182] The access node receives the BRACH preamble from the UE that experienced beam failure (block 1013). The BRACH preamble is received in the BRACH resource associated with the m -th WBRS. In addition, the BRACH preamble may be received on the UL receive beam, which is the beam corresponding to the access node's DL transmit beam used to transmit the mth WBRS. Typically, the access node keeps track of all BRACH resources for BRACH preambles. The access node identifies the UE (block 1015). The access node may compare the received signals across multiple BRACH resources and determine which UE requested beam restoration (eg, by analyzing the received BRACH preamble and the BRACH preamble for UE assignments). In the situation where a UE is assigned more than one preamble sequence that can be transmitted on the BRACH, the access node analyzes which sequence is being transmitted by the identified UE and detects the assumed CSI-RS or WBRS beam index. In the situation where a UE is assigned a single preamble sequence that may be transmitted on more than one BRACH, the access node analyzes which channel the identified UE is using to transmit the preamble sequences and detects an assumed CSI-RS or WBRS beam index. In a situation where an access node receives multiple BRACH preambles from a single UE, the access node can determine which BRACH resource provided the best quality, potentially conveying to the access node which resource to reply should send a response, such as a BFR response. The access node may be able to identify the UE, eg, in accordance with the BRACH preamble. The access node may generate a UL resource grant for the UE (block 1017). The UL resource grant is for resources that allow the UE to send additional recovery information to the access node. The additional recovery information may include the additional recovery information discussed previously (eg, in the discussion in Figure 6) as well as channel quality information such as SNR, SINR, RSRP, RSRQ, RSSI, and so on. The access node sends a response, such as a BFR response, possibly with a UL resource grant (or related information) to the UE (block 1019). The response may be sent on the PDSCH or PDCCH, or on a broadcast channel. The response may be addressed using an identifier identifying the detected BRACH preamble, or the access node may send the detected BRACH preamble directly. The access node receives a UL transmission from the UE (block 1021). The UL transmission may, for example, include additional information for recovery, such as one or more n CSIs - RS, from the UE, or beam quality information from the UE. The access node performs DL control channel rebuilding or assists in beam steering (block 1023). The access node uses the recovery information provided from the UE to rebuild the DL control channel or assist in beam steering (UL or DL) in the next period. Alternatively, steps 1017 and 1019 may be omitted, which means that steps 1013 and 1021 may be performed in a single transmission.

[183] Figure 10B illustrates a flowchart of exemplary operations 1050 occurring at a UE participating in beam recovery, where the UE is tracking one or more reference signals. Operations 1050 may indicate operations occurring at the UE as the UE participates in beam recovery when the UE is tracking only one reference signal, eg, CSI-RS only, WBRS only, or both CSI-RS and WBRS.

[184] Operations 1050 begin with the UE receiving a BRACH preamble sequence configuration from the access node (block 1055). The UE further receives relationships or associations between BFRS resources (only CSI-RS resources, only SS resources, and CSI-RS and SS resources) and BRACH resources, as well as resources for a BRACH response from the access node (block 1057). The relationship or association between BFRS resources and BRACH resources (as well as resources for a BRACH response) may assist the UE in determining which BRACH resource to use to transmit the BRACH preamble based on the detected BFRS or identified WBRS, and possibly which resource to respond on. BRACH accept response to BRACH preamble. The UE receives the SQCL information (block 1059). The SQCL information includes the associations between the CSI-RS and SS signals. The SQCL information may be used by the UE to determine the CSI-RS beam indices from the WBRS beam indices and to determine the WBRS beam indices from, for example, the WBRS beam indices. For example, with one-to-one connectivity, each CSI-RS signal is associated with one WBRS signal. It is possible that several CSI-RS signals are associated with one WBRS, and vice versa. The SQCL information may be signaled to the UE in an RRC message, a MAC-CE message, a DCI message, or a combination thereof, and stored in tabular form or in the memory of the UE.

[185] The UE monitors BFRS signals (CSI-RS signals or WBRS signals in general) and determines the index(es) of the best, in terms of quality, for example, CSI-RS beam(s) or WBRS beams (block 1061). As a result, the UE obtains a beam index per CSI-RS or a beam index per WBRS. The beam index can be represented by CSI-RS resource index n (integer value) or WBRS resource index m . It should be noted that a UE may obtain more than one beam index.

[186] The UE determines the WBRS best beam(s) index(es) (block 1063). Note that if the detected beam is a WBRS signal with indexm best WBRS resource,then the identified ray is just an indexm best WBRS resource. It should be noted that if the detected beam is a CSI–RS signal with an indexn best CSI resource-RS, UE uses SQCL information to determine indexmof the best WBRS beam(s) from the indexn beam CSI-RS.It should be noted that the UE may obtain a plurality of BFRS best beam indices when the UE acquires a plurality of beam indices.m-th WBRS resource fromMof possible resources, the WBRS may be the best from the UE's point of view (eg, in terms of quality) and may be used by the access node to rebuild the DL control channel and to assist in beam steering.

[187] The UE optionally selects a BRACH preamble (block 1065). In a situation where the UE is configured with more than one BRACH preamble, the UE selects one of the more than one BRACH preamble. UE using the relationship betweenm-th resource BRACH andm-th WBRS resource to determinem–th BRACH resource, sends the BRACH preamble tom–th resource or BRACH region (block 1067).m-th BRACH resource matchesm–mu the WBRS resource index determined by the UE as the best WBRS beam and according to the relationship between the BRACH and WBRS resources. Sending the BRACH preamble tom-ohm The BRACH resource gives the UE an increased likelihood that the BRACH preamble will successfully arrive at the access node (eg, by using a resource associated with a beam or a best quality resource), thereby reducing delays in the beam recovery process.

[188] The UE receives a response, such as a BFR response (block 1069). The response may include granting a UL to allow the UE to transmit a subsequent message (eg, on a physical uplink shared channel (PUSCH)) including, for example, a CSI-RS beam index report. The response may be received on the PDSCH or PDCCH, or on a broadcast channel. The response may be addressed with an identifier identifying the BRACH preamble (or the access node may send the BRACH preamble directly). The response may also include a time alignment instruction to synchronize subsequent UL transmissions from the UE. The response may be received in a time synchronization window, possibly by a receive combiner associated with the transmit precoder used to transmit the BRACH preamble. The timing window that the UE uses to receive the response corresponds to the BRACH resource used to send the BRACH preamble. The UE keeps track of all timing windows, with each timing window corresponding to one of the BRACH resources used to send the BRACH preamble for the response. UE sends one or more indexesn CSI–RS resources according to the UL grant (block 1071) if the UL grant is included in the BFR response.

[189] Figure 11 shows a diagram 1100 illustrating an example of transmitting a BRACH preamble and receiving a response over multiple resources. As shown in Figure 11, BFRS region 1105 represents BFRS resources and DL transmit beams of the access node used for BFRS transmission, BRACH region 1107 represents BRACH resources (eg, BRACH resources 1116, 1118, and 1120) and UL receive beams (eg, beams 1110 . ) and UL receive beams (eg, beams 1121, 112 and 1125) used to receive responses such as BFR responses. Multiple beams and resources may be used to increase the likelihood that BRACH preambles or responses will be successfully received. It should be noted that associations or relationships between BRACH resources and BFRS resources are maintained in a situation where multiple beams and resources are used.

[190] Figure 12 illustrates a diagram 1200 highlighting sending a BRACH preamble and detecting a response. As shown in Figure 12, the UE sends a BRACH preamble in one or more BRACH resources 1205 . However, the UE keeps track of the timing windows associated with all BRACH resources to ensure that the 1210 response is received.

[191] Thus, a UE initiating beam recovery:

– Locates a BFRS resource index, may be a CSI-RS resource, an SS resource, or both;

– Identifies an indexm WBRS resource based on SQCL information between CSI–RS and SS;

– Sends the BRACH preamble in the m th BRACH resource in the BRACH region ;

– Tracks the responses in the response area to receive the response;

– May send a message with additional recovery information such as one or more n CSI-RS indexes;

– Can track DL control channel, DL control channel and one or more indicesn CSI-RS can be spatially quasi-aligned (QCLed).

[192] Thus, the access node participating in beam recovery receives or determines the following information:

– Information A: identifier of the UE requesting beam restoration;

– Information B (n): identified or reported resource index or a CSI-RS beam (CRI) used by the access node to recover the DL control channel. CRI can contain two parts:

B 1 - WBRS index (or indices),

B2 - CSI-RS index (or indices) with a group of multiple CSI-RSs that are spatially quasi-aligned (QCLed) with a WBRS with a WBRS index (or indices). B2 is referred to as an intragroup index.

WhenB1 andB2 access node can restoreB. It should be noted that CSI–RS and WBRS can be two BFRS subsets. Thus, two-part information can be signaled as a whole, not individually like the BFRS index. Here, the set of BFRS signals can simply be considered as a combination (such as combining, concatenating, etc.) of CSI-RS signals and WBRS signals.

[193] Figure 13 illustrates an exemplary beam pattern 1300 for SS and CSI-RS. As shown in Figure 13, the precoder for an exemplary SS has a beam contour 1305, while precoders such as CSI-RS1, CSI-RS2, CSI-RS3, and CSI-RS4 have beam contours 1310, 1312, 1314, and 1316, respectively. . For discussion purposes, let the CSI–RS1 index ben, the SS index is equal tom, and the intragroup CSI–RS1 index in the CSI–RS group associated with SS, is equal toi.Then if indicesmandi known (e.g., reported from the UE), then one can determinen. Similarly, if indexes are knownnandm, then it is possible to determinei. Besides,if known indicesn andi, then you can definem. It is noted that in Figure 13 SS is an example of WBRS.

[194] In the first exemplary embodiment, the access node configures a UE-specific preamble sequence for each UE. The UE initiating beam recovery may send its UE-specific preamble sequence, which is detected by the access node. The access node will be able to determine the identity of the UE that sent the UE-specific preamble, thereby obtaining informationA. U.E. sends the CRI using the UL grant, thereby directly providing the CRI to the access node, thereby providing informationB to the access point.

[195] In the second exemplary embodiment, the access node configures a UE-specific UE preamble sequence for each UE. The UE initiating beam recovery may send its UE-specific preamble sequence, which is detected by the access node. The access node will be able to determine the identity of the UE that sent the UE-specific preamble, thereby obtaining informationA. Besides,the access node can determine which BRACH resource carried the UE-specific preamble, thereby obtaining informationB1, which is the identified indexm resource SS based on discovered indexn resource CSI-RS if a CSI-RS resource index is found, or self-identified indexm resource if an SS resource index is found. The UE may send the intragroup index using the UL grant, thereby providing informationB2 to the access node. The access node may use the informationBone andB2 to determine informationb.If the intragroup indexi not is sent, then the access node can use the informationB1 (which is the identified index m of the resource SS) directly.

[196] In the third exemplary embodiment, the access node configures a group of UE-specific preamble sequences for each UE. All preambles in a group are associated with one UE. The UE initiating beam recovery may send a UE-specific preamble sequence from its group of UE-specific preamble sequences. The access node detects the UE-specific preamble sequence, determines the group of UE-specific preamble sequences from the UE-specific preamble, and determines the identifier of the UE that sent the UE-specific preamble, thereby obtaining informationA.In one example, the access node is configured to determine which BRACH resource carried the individual preamble, thereby obtaining information B1. In addition, the access node can determine which preamble sequence in the group of UE-specific preamble sequences is the UE-specific preamble, and derive an intra-group index of the UE-specific preamble, thereby obtaining informationB2.Access node uses informationB1 andB2 to determine informationB. In another embodiment, the access node may determine informationB directly by analyzing which preamble sequence is used by the identified UE and which BRACH resource carried the preamble sequence. It should be noted that in this case, the access node and the UE a priori negotiating which combination of UE preamble sequence and BRACH resource corresponds to which beam index. This may be done in advance by the access node sending, for example, a binding table between each beam index and the corresponding combinations or associations of UE preamble sequences and the BRACH resource.

[197] In the fourth exemplary embodiment, the access node configures a UE-specific preamble sequence for each UE. The UE initiating beam recovery may send a UE-specific preamble sequence that is detected by the access node. The access node will be able to determine the identity of the UE that sent the UE-specific preamble, thereby obtaining the informationA. Besides,the access node can determine which BRACH resource carried the UE-specific preamble, thereby obtaining information B1. The UE sends another sequence before or after the UE-specific preamble sequence at the predetermined location. This other sequence carries the intragroup index and has been matcheda prioribetween the UE and the access node, or defined by the technical standard or the operator. The access node determines which other sequence is sent, thereby obtaining informationB2.Access node uses informationB1 andB2 to determine information b.

[198] In another embodiment, the access node may determine information B directly by analyzing which sequence is used by the identified UE and which BRACH resource carried the preamble sequence. It should be noted that in this case, the access node and the UEa priorinegotiating which combination of UE preamble sequence and BRACH resource corresponds to which beam index. This may be done in advance by the access node sending a binding table between each beam index and the corresponding combinations or associations of the UE preamble sequence and the BRACH resource.

[199] In the fifth exemplary embodiment, the access node configures UE-specific preamble sequences for each UE and for each direction, assigns a plurality of BRACHs (potentially in the frequency domain) to each UE. It should be noted that there are multiple BRACH opportunities in the time domain, with each BRACH opportunity corresponding to a potentially different WBRS direction. The UE initiating beam recovery may send the UE-specific preamble sequence on one subchannel (in the frequency domain, for example) and one opportunity (eg, in the time domain). The access node detects the UE-specific preamble sequence and the BRACH subchannel, and determines the identity of the UE that sent the UE-specific preamble, thereby obtaining the informationA.It should be noted that the access node can assign allLsubchannels. It is possible that each UE may use any ofLsubchannels. It is also possible that each UE may only use a portion such asL1 ofLsubchannels. Such a restriction may be signaled by the access point to the UE in advance, for example, in an RRC message. If each of the UEs is able to use allLsubchannels, then the access node may analyze the BRACH subchannels to detect a piece of informationB, but may not be able to detect the idA UE.If each of the UEs can use only a part ofLsubchannels, then the access node can parse the BRACH subchannel to detect a piece of informationB, as well as to detect part of the identifierA U.E. AT in one example, the access node can determine which BRACH capability carried the UE-specific preamble, thereby receiving informationB1. In addition, the access node can determine which BRACH subchannel is used by the identified UE, and derives an intra-group index of the UE-specific preamble, thereby obtaining informationB2.Access node uses informationBone andB2 to determine informationB. Alternatively, the access node can identify informationB directly by analyzing which BRACH capability is used in the time domain and which BRACH subchannel is used in the frequency domain by the identified UE. It should be noted that in this case, the access node and the UE negotiate which combination or association of time domain BRACH capability and time domain BRACH subchannel corresponds to which beam index. This can be done in advance by sending the access node a binding table between each beam index and the corresponding combinations or associations of a time domain BRACH opportunity and a frequency domain BRACH subchannel.

[200] Table 1 provides a summary of four exemplary embodiments.

First option Second option Third option Fourth option Consistency, Provision, or Provision-Based Reporting Versus Only Consistency-Based Reporting Early Early Late Late Determine UE ID based on preamble sequence preamble sequence preamble sequence preamble sequence n report Explicitly, the report is based on the provision Not explicitly Not explicitly Not explicitly m report Not required Implicit, position-based BRACH Implicit, position-based BRACH Implicit, position-based BRACH i report Not required Explicit reporting based on provision Implicit in the preamble Implicit in the preamble

Table 1: Summary of exemplary embodiments.

[201] As discussed earlier, QCL defines a relationship between two reference or data signals such that the two signals can be considered to have similar characteristics. Exemplary characteristics include carrier frequency, time offset, frequency offset, spatial precoding vectors, and so on. SQCL is a category of QCL with two precoded or beamformed signals that are precoded using the same or similar precoder. As an illustrative example, the first signal SIG1 (eg, the reference or data signal) and the second signal SIG2 (eg, the reference or data signal) are spatially quasi-collated (QCLed) if they are transmitted using the same precoder. In other words,

X1=Precoder*SIG1; X2=Precoder*SIG2,

where X1 is precoded SIG1 and X2 is precoded SIG2, and SIG1 and SIG2 are the first signal and the second signal without precoding, respectively.

[202] Figure 14 illustrates a graphical representation 1400 of two precoders that are spatially quasi-aligned (QCLed). The first beam diagram 1405 represents the precoder for the first signal, and the second beam diagram 1410 represents the precoder for the second signal. The beam patterns overlap because the two precoders are identical.

[203] According to an exemplary embodiment, technologies are provided for identifying beams using one-to-one beam mapping. The methods identify the first beam using a one-to-many mapping of the first beams to the second beams when one of the second beams is known, and vice versa. As an illustrative example, in a communication system with one or more first beams and one or more second beams and multiple anchors, one with many first beams with second beams, as long as any two or more first beams are not associated with the same second beam, as only the second beam (eg, CSI-RS beam) is identified, then it is possible to determine the first beam (eg, WBRS beam) that is associated with the second beam using one-to-many referencing.

[204] Let the first beam be a precoded signal SIG0 that is precoded using a P_0 precoder, and one or more second beams be a set ofN previously encoded signals SIG1, .., SIGN, which precoded using precoders P_1.1, ..., P_1.N. The first beam and one or more second beams are said to have a one-to-many anchor if the precoder patterns P_1.1, .., P_1.N are in the beam pattern of the precoder P_0. One-to-many anchor beams are said to have an SQCL one-to-many relationship (OMSQ). Figure 15 illustrates a precoder pattern 1500 for a first beam and one or more second beams, where the precoders have an OMSQ relationship. As shown in Figure 15, N equals four. The first beam pattern 1505 represents the precoder P_0 for the first beam, while the beam patterns 1510, 1512, 1514, and 1516 represent the precoders P_1.1, ..., P_1.4 for every second beam in the plurality of second beams.

[205] Regarding the relationship between precoders P_0 and {P_1.1, .., P_1.N}, consider a virtual signal X1 that contains a signal S that is precoded with P_1.1, .., P_1.N together at the same time (as opposed to being N signals that are separately precoded with P_1.1 , ..., P_1.N, respectively, one signal at a time), and the pre-coded signal X0, which contains the signal S pre-coded with P_0. The virtual signal X1 contains X_1.1, .., X_1.N,where X_1.1 is the S signal precoded using the P_1.1 precoder and X_1.N is the S signal precoded using the precoderaP_1.N. If the virtual signal X1 and the precoded signal X0 are the same (within the allowable difference between precoders P_0 and {P_1.1, .., P_1.N} as defined by the technical standard), then the precoders P_0 and {P_1.1, ..,P_1.N} have an OMSQ relationship. Similarly, the virtual signal X1 and the signal X0 have an OMSQ relationship. It should be noted that in the example presented here, the signal X0 (or precoder P_0) is one, and the virtual signal X1 (or precoders {P_1.1, .., P_1.N}) are a set from a one-to-many binding.

[206] It should be noted that the precoders {P_1.1, .., P_1.N} usually differ from each other. Therefore, there is no QCL relationship between precoders {P_1.1, .., P_1.N}.However, a typical relationship between precoders {P_1.1, .., P_1.N} may that their respective beam patterns are adjacent to each other in terms of their beam contours.

[207] It should be noted that the relationship between the precoder P_0 and any one of the precoders {P_1.1, .., P_1. N} (or the signal X0 and any one of the signals X_1. 1, .., X_1.N) is that the beam pattern of the signal X0 covers a wider range of angles than the beam pattern of any of the signals X_1.1, . ., X_1.N. In addition, the signal X0 and any of the signals X_1.1, .., X_1.N are correlated. Signals that have an OMSQ relationship are also called correlated. Figure 16 illustrates a precoded signal pattern 1600 highlighting potential relationships. Circuit 1600 includes beam patterns for X_0 signal 1605, X_1.1 signal 1610, and X_2 signal 1615. As shown in Figure 16, X_0 signal and X_1.1 signal are correlated, but X_2 signal (which was precoded using a different precoder ) is not correlated with either X_0 or X_1.1. In some cases, signaling the OMSQ relationship between signal X_0 1605 and X_1.1 1610 provides guidance to the receiver in selecting a receiver (eg, a receive combiner). For example, the OMSQ relationship assumes that the receiver used for X_0 1605 can be used to receive X_1.1 1610, and vice versa. On the other hand, the OMSQ relationship suggests that the receiver used for X_2 1615 may not be used to efficiently receive X_1.1 1610.

[208] According to an exemplary embodiment, the OMSQ relationship is used to identify alternative signals used in communication. As an illustrative example, if the first signal has become unavailable or unreliable, an alternative signal can be identified using the OMSQ relationship between the first signal and one or more second signals. An alternative signal (one of one or more second signals) may be used instead of the first signal.

[209] As an illustrative first example, consider the situation where the transmitter sends reference signals X_0 1605, X_1.1 1610, and X_2 1615. The transmitter may report that signals X_0 1605 and X_1.1 1610 have an OMSQ relationship, or that signals X_0 1605 and {X_1.1, .., X_1. N} have an OMSQ relationship. The receiver may initially use the information in the X_1.1 signal 1610. However, the X_1.1 signal 1610 becomes unreliable or unavailable, and the receiver can no longer reliably receive the X_1.1 signal 1610. The receiver may use the OMSQ relationship between the X_0 signals 1605 and X_1 .1 1610 and use signal X_0 1605 as a fallback for signal X_1.1 1610. It should be noted that since signals X_0 1605 and X_2 1615 do not have an OMSQ relationship (or at least the transmitter has not provided information that the two signals have an OMSQ relationship), the receiver will not use the X_2 signal 1615 as a fallback to the X_0 signal 1605.

[210] As an illustrative second example, consider the situation where a transmitter sends reference signals X_0 1605, X_1.1 1610, and X_2 1615. The transmitter may provide information conveying that signals X_0 1605 and X_1.1 1610 have an OMSQ relationship, or that signals X_0 1605 and {X_1.1, .., X_1 . N} have an OMSQ relationship. The transmitter may signal to the receiver, which is currently receiving signal X_1.11610, that the transmitter will start using a higher layer signal (signal X_0 1605). The transmitter, knowing the OMSQ relationship between X_0 1605 and X_1.1 1610, starts receiving X_0 1605 instead of X_2 1615 because X_2 1615 and X_1.1 1610 do not have OMSQ relationship.

[211] It should be noted that the above discussion is focused mainly in the field of corners. There may be a power difference (eg, due to a difference in transmit power or precoding gain) between one signal (eg, X_0 signal 1605) and many signals (eg, signals {X_1.1, ..., X_1). N}) that are aggregated. The transmitter may send additional signaling including the power difference between one signal and multiple signals (assuming the transmit power is equal for each of the multiple signals).

[212] Figure 17 illustrates a flowchart of operations 1700 occurring at an access node using an OMSQ relationship to change beams. Operations 1700 may indicate operations occurring at the access node since the access node uses the OMSQ relationship to change beams.

[213] Operations 1700 begin with the access node sending OMSQ relationship information to the UE (block 1705). During normal operations, the access node performs a check to determine if a beam change is warranted (block 1707). A beam change may be justified if one or more UEs provide feedback on beam quality, eg, below a threshold. As another example, a beam change may be justified if the access node receives a BRACH preamble carrying information about the occurrence of a beam failure. If a beam change is not justified, then the access node continues to send signals on beams (block 1715).

[214] However, if the beam change is justified, then the access node selects an alternate beam according to the OMSQ relationship information (block 1709). The access node optionally triggers an alternate beam (block 1711). The access node may send alternate beam index information, for example. The access node sends signals on the alternate beam (block 1713). The access node may also send information regarding only the default beam switching operation, i.e., switching the transmission beam from the current transmission beam to the default standby beam (current transmission beam). In this case, for example, signal X_0 1605 is reserved for signal X_1.1 1610 by default. This may cause the UE to switch to the default backup beam receiver X_0 1605.

[215] Figure 18 illustrates a flowchart of operations 1800 occurring in a UE using an OMSQ relationship to change beams. Operations 1800 may indicate operations occurring at the UE as the UE uses OMSQ relationships to change beams.

[216] Operations 1800 begin with the UE receiving OMSQ relationship information from the access node (block 1805). During normal operations, the UE checks to determine if the beam it received has become unreliable (or unavailable) (block 1807). For example, a beam may be considered unreliable if the quality of the signal associated with the beam falls below a threshold. As another example, if one or more attempts to decode a transmission using a beam fail, then the beam may be considered unreliable. For example, a beam may be considered unavailable if the UE can no longer detect signals on the beam. If the beam remains reliable, the UE continues to receive signals on the beam (block 1813).

[217] If the beam has become unreliable (or unavailable), the UE selects an alternate beam according to the OMSQ relationship information (block 1809) and receives signals in the alternative beam (block 1811). The UE may change its receive precoder, eg, to one associated with an alternate beam, to begin receiving signals on the alternate beam. Alternatively, if the UE receives information instructing the UE to use the alternate beam, the UE starts receiving signals on the alternate beam regardless of beam reliability or unreliability.

[218] In this disclosure, the focus has been on sending a beam failure recovery request using a random access BRACH that potentially differs from the PRACH in time or frequency locations within a frequency band (category B). In co-assigned use cases, document numbers HW85458110US01 titled "Method for Response to PUCCH-based Beam Failure Recovery Request" and HW85457640US01 titled "System and Method for Reporting a Beam Failure System and Method for Beam Failure Recovery Request Reporting, which are hereby incorporated by reference herein, two other ways of transmitting a request are presented, one based on sending a request via a scheduling request, which is a special message carried on the PUCCH (category P1), the other based on the sending of a failed status report (SR) request on the PUCCH (category P2).

[219] It remains unclear when different methods are supported (for example, both category B and category P1, both category B and category P2, or all categories B, P1 and P2 are supported), how the UE chooses which method to use. For discussion purposes, assume that both category B and category P are supported, and that category P can be either category P1 or category P2, or both categories P1 and P2.

[220] It should be noted that the time and frequency locations of Category B channel (i.e., BRACH channel resources) and Category P channel (i.e., either PUCCH resources carrying SRs for P1 or PUCCH resources carrying non-SRs for P2) must be defined or configured in advance. From the UE's point of view, it may transmit a BRACH preamble sequence on a Category B channel resource, or it may transmit a PUCCH content (SR or non-SR) on a Category P channel resource. A UE cannot and should not transmit a BRACH preamble sequence on a Category P channel resource. , and the UE shall not transmit PUCCH content (SR or non-SR) on a Category B channel resource.

[221] For a category B channel resource, there is a resource for a category B response, where the UE can monitor to listen for responses for any preamble transmission in the category B channel resource. For a category P channel resource, there is a resource for a category P response, where the UE can monitor to listen for responses for any PUCCH transmission (SR or non-SR) on a Category P channel resource.

[222] It should be noted that before the UE actually sends a response, such as a BFR response, on a category B channel, the UE must already know when to expect to receive a response by resource tracking for a category B response within a particular time window of sizes W1 , starting from time T1 later. Similarly, before the UE actually sends a response on the Category P channel, the UE must already know when to expect to receive a response by tracking the Category P response resource within a specific time window of size W2 starting from time T2 later.

[223] There may be two possibilities in terms of whether the UE has full control over which channel to use to send a response.

[224] A UE with full authority in determining which channel to use to send a response may be configured by the access node. In one embodiment, the access node may preconfigure (using a message) telling the UE that it should either always use a category B channel, a category P1 channel, or a category P2 channel, or to prioritize category B, P1, or P2 channels (UE must use the category B channel first if the category B channel has a higher priority than the P1 or P2 channels).

[225] In another embodiment, the access node may configure in the message (or as specified by the technical standard) that the UE may use a category P channel (and the associated method for sending requests) only if the UE is out of beam.

[226] In another embodiment, the access node may configure in the message (or as specified by the technical standard) that the UE can use a category P channel (and the associated method for sending requests) only if the UE knows that its uplink control channels and the downlink control channels are not reciprocal. For example, the UE can infer that the uplink or downlink channels are not reciprocal by comparing its transmit beams of the uplink control channels and the receive beams of the downlink control channels and find that they are significantly different from each other. . The access node may also send a message to the UE whether the receive beams of the uplink control channels (at the access node side) and the receive beams of the downlink control channels (at the access node side) are the same or different, based on which the UE can make inferring whether the downlink control and uplink control channels are reciprocal or not.

[227] In another embodiment, the access node may configure in the message (or as specified in the technical standard) that the UE may use a category P channel (and an associated method for sending a request) if the carrier of the category P channel is different from the carrier associated with the failure. beam.

[228] In another embodiment, the access node may configure in the message (or as specified in the technical standard) that the UE may use a Category P channel (and associated method for sending a request) if the UE has identified a new beam or not.

[229] Alternatively, the UE may have its own say in choosing which channel to use to send the BFR response.

[230] In one embodiment, the UE may select whichever channel (category B channel or category P channel) it likes, depending on which channel resource arrives first, in the hope of recovering from beam failure as soon as possible.

[231] In another embodiment, the UE may choose whichever channel it wants will depend on which response should come first (eg, based on knowledge of W1, T1, W2, T2), in the hope of recovering from a beam failure as soon as possible.

[232] In another embodiment, the UE may select any channel depending on whether the UE has identified a new potential candidate beam. For example, the UE may choose to transmit on a Category B channel (and the associated method for sending a request) if it identifies a new potential candidate beam or if it does not identify a new potential candidate beam.

[233] In another embodiment, the UE may select any channel depending on its own knowledge of whether the uplink or downlink control channels are reciprocal. For example, the UE may choose to transmit on a Category B channel (and an appropriate method for sending a request) if it concludes that the downlink control and uplink control channels are not mutual, or if the UE is not beam-matched.

[234] If the UE has used category P channel resources to send responses and continues to monitor category P response resources and does not find a positive response in them, then the UE should use category B channel resources to send responses.

[235] If the UE has used category B channel resources to send responses and continues to monitor category B response resources and does not find a positive response in them, then the UE should use category P channel resources to send requests on beam failure.

[236] If the UE has used category P channel resources to send responses and sees that category B channel resources become available before resources for category P response arrive, then the UE should use category B channel resources to send responses.

[237] If the UE has used category B channel resources to send responses and sees that category P channel resources become available before category B response resources arrive, then the UE should use category P channel resources to send responses.

[238] If the opportunity for the UE to use Category B and Category P channel resources arrives substantially at the same time, then the UE may select a resource (e.g., Category B or Category P channel resources) to send a response based on a preconfigured priority between category B and category P channel resources. If the UE capability allows, then the UE may also send a response using both category B and category P resources simultaneously.

[239] Figure 19 illustrates a first example of BRACH resources 1900. As shown in Figure 19, BRACH resources 1900 consist of 64 BRACH blocks, such as BRACH blocks 1905, 1907, 1909, and 1911, located in the time domain, frequency domain, and sequence domain. Each BRACH block is the smallest unit used by the UE to send a BRACH preamble to initiate beam failure recovery. Each BRACH block is unique in terms of time, frequency, and sequence. As an illustrative example, the access node allocates four temporal BRACH opportunities, such as temporal BRACH opportunity 1915. In a particular BRACH time opportunity, the access node allocates four BRACH frequency opportunities (sub-channels), such as sub-channels 1920, 1922, and 1924. For each time-frequency opportunity, the access node allocates four preamble sequences that correspond to individual BRACH blocks (such as blocks 1905, 1907 , 1909 BRACH). The exemplary configuration with four BRACH time opportunities, four BRACH frequency opportunities, and four preamble sequences is presented for discussion purposes only and is not intended to limit the scope or nature of the exemplary embodiments.

[240] It should be noted that the access node may allocate more than one BRACH opportunity in the frequency domain or more than one preamble sequence in the sequence domain to each UE for beam failure recovery purposes. In addition, although multiple UEs may share the same BRACH frequency opportunity to transmit preamble sequences, different UEs typically have different preamble sequences for UE identification purposes.

[241] In accordance with an exemplary embodiment, the relationship between the CSI-RS beam index and the block index for a BRACH block is used to allow easy identification of the block index from the beam index or vice versa. This is a special case where the BFRS consists of only CSI–RS. The association or relationship between CSI-RS beam indices and block indices for BRACH blocks allows one index to be identified when the other index is known. The association or relationship may be defined by a technical standard, a communications system operator, or through interaction between an access node and a UE. The association or relationship may be provided to the UE during initial connection to the communication system. Alternatively, the connectivity or relationship may be programmed into the UE or after being determined by joint measures.

[242] In accordance with an exemplary embodiment, an indirect relationship or relation between the CSI-RS beam index and the block index for a BRACH block is used to allow easy identification of the block index from the beam index, or vice versa. Indirect connectivity relates the relative CSI-RS beam index indices to the relative block indices of the BRACH block indices, with respect to a common reference signal, eg WBRS. The common reference signal is called the relative reference signal (RRS). Such CSI-RS and BRACH block indirection between beam indices and block indices may be signaled by the access node via RRC signaling, MAC-CE signaling, DCI signaling, or a combination thereof, for example, or indicated by a technical standard and stored in devices.

[243] Figure 20A shows a relative index table 2000 for block indexes in an exemplary BRACH block configuration. Table 2000 shows relative block indices of the BRACH block configuration shown in Figure 19. Table 2000 includes columns for BRACH index 2005, BRACH time index 2007, BRACH secondary index 2009, BRACH frequency index 2011, and BRACH sequence index 2013. The secondary BRACH index can be considered as a combination of the BRACH frequency index and the BRACH sequence index. Note that if only one subchannel is available, then the BRACH frequency index is always 1. If only one sequence is available for the UE, then the BRACH sequence index is always 1. The values in the 2005 BRACH index correspond to the absolute BRACH index, while the values in The 2007 time index corresponds to the BRACH temporal capabilities, the values in the 2009 BRACH secondary index correspond to the beam indices for the CSI-RS beams of the BRACH time opportunity, the values in the 2011 BRACH frequency index correspond to the BRACH frequency capabilities, and the values in the 2012 BRACH sequence index correspond to the preamble sequence indices. As an example, the absolute BRACH index 25 corresponds to the second BRACH temporal opportunity, the ninth CSI-RS beam of the second BRACH temporal opportunity, which happens to occupy the third BRACH frequency opportunity, and the preamble sequence A. In general, each of the 64 absolute BRACH indices can be referred tom-th primary beam index WBRS andi–th secondary beam index CSI–RS,wherem is the WBRS index to which the BRACH block corresponds, and i-is the index of a BRACH block in a group of BRACH blocks that have the same samemth WBRS index.

[244] Figure 20B shows a relative index table 2050 for CSI-RS beam indices. Table 2050 shows relative CSI-RS beam index indices corresponding to the BRACH block configuration shown in Figure 19. Table 2050 includes columns for CSI-RS index 2055, WBRS anchor index 2057, and secondary index 2059. Values in CSI-RS index 2055 correspond to the absolute CSI-RS beam indices, while the values in the associated WBRS index 2057 correspond to the WBRS indices corresponding to the CSI-RS beam index, and the values of the secondary index 2059 correspond to the CSI-RS beam indices of the CSI-RS beams relative to the WBRS index. As an example, an absolute CSI-RS index of 17 corresponds to the second beam of the WBRS and the first beam of the CSI-RS relative to the second beam of the WRBS. In general, each of the 64 absolute BFRS indices (for example, CSI-RS) can be assignedm–th index of the BRACH primary block, andi–th secondary index of the BRACH block, wherem is the BFRS index (CSI–RS) with which the BFRS beam (CSI–RS) is quasi-aligned (QCLed) corresponding to the absolute BFRS index (CSI–RS), andi is BFRS index (CSI-RS) in a BFRS group (CSI-RS) sharing the same mth primary index of the BRACH block. If BFRS is WBRS thenm-th BFRS index is just the index itselfmWBRs, andi–The th secondary index is not required, which is a special case of the above general case.

[245] Tables 2000 and 2050 provide a single example of an indirect relationship between beam indices and block indices. Other indirect connections are also possible. The access node and the UE may negotiate CSI-RS or SS indirect association with BRACH so that the UE can determine the BRACH block index based on the CSI-RS index or SS index. Similarly, the indirect association of CSI-RS or SS with BRACH allows the access node to determine the CSI-RS index or SS index based on the BRACH block index. The access node and user equipments (UE) may also negotiate indirect secondary associations so that the UE can determine the secondary BRACH block index based on the secondary CSI-RS index, and the access node can determine the secondary CSI-RS index based on the secondary BRACH block index. Note that each secondary BRACH block index corresponds to a combination of a BRACH subchannel index and a BRACH sequence index.

[246] In accordance with an exemplary embodiment, a direct relationship between the BFRS beam index (CSI-RS, SS or CSI-RS and SS) and the block index for the BRACH block is used to allow easy identification of the block index from the beam index or vice versa. The BFRS beam index (CSI-RS, SS or CSI-RS and SS) may be considered as an absolute BFRS beam index, while the block index for a BRACH block may be considered as an absolute BRACH block index. Such CSI-RS and BRACH block direct association (usually one-to-one) between beam indices and block indices may be signaled, for example, by an access node via RRC signaling, or indicated by an engineering standard and stored in devices.

[247] Figure 20C shows a table 2070 of an example of a direct relationship between beam indices and block indices. Table 2070 shows beam indices and block indices of the BRACH block configuration shown in Figure 19. Table 2070 includes columns for BFRS index 2075 and BRACH index 2077. Values in BFRS index 2075 correspond to beam indices for BFRS beams, and values in BRACH index 2077 correspond to block indices for BRACH blocks. Table 2070 shows the only example of a direct relationship between beam indices and block indices. Other direct connections are also possible. Other exemplary relationships may include shifts, rotations, mathematical manipulations, and so on. regarding indexes.

[248] In general, for both direct and indirect connectivity, the UE may determine a BRACH block to transmit preamble sequences to initiate beam failure recovery based on the detected BFRS index. Similarly, at the access node, the access node may determine the UE ID by parsing the preamble sequence and determine the BFRS index based on the index of the BRACH block where the preamble sequence is received.

[249] Figure 21 shows a second example of BRACH resources 2100. As shown in Figure 21, one or more BRACH resources are grouped into three time opportunities, time opportunities 2105, 2107, and 2109. Each time opportunity includes BRACH resources in the frequency domain (eg, four different subchannels) and code domain (eg, four different code sequences). Although the BRACH resources 2100 are organized into three temporal opportunities with four sub-channels and four code sequences each, the exemplary embodiments presented here are applicable with other BRACH resource configurations. Therefore, the configuration shown in Figure 21 should not be construed as limiting the nature or scope of the exemplary embodiments.

[250] As shown in Figure 21, there are three possibilities for each UE to send a BRACH preamble. Each temporal opportunity may correspond to a different spatial direction in terms of the WBRS beam direction. For each time opportunity, the UE may select one of the four sub-channels and one of the four code sequences (A, B, C, and D) to transmit the BRACH preamble. Therefore, the actual subchannel index and the actual preamble index that the UE uses for transmission convey 4 bits of information (corresponding to 16 different choices). The 4 bits of information may be used at the UE to, for example, carry the intended beam index to the access node. Therefore, there is a need for F*S*U=4*4*1=16, where F is the number of subchannels per UE, S is the number of code sequences per UE, and U is the number of UEs to allow one UE to perform transfer with carry Log2(F*S*U)=4 bits of information.

[251] To allow K user equipments (UEs) to transmit simultaneously while each UE transmission carries 4-bit data, more subchannels in the frequency domain or more code sequences in the sequence domain, or both, may be required. However, the number of subchannels and the number of code sequences are usually limited. When the number of UEs (K) is large, it is necessary for multiple UEs to share either sub-channels or code sequences.

[252] In a situation where multiple UEs share code sequences, instead of allocating BRACH resources (such as P1A, P1B, P1C, and P1D) to one UE, the access node may allocate a subset of BRACH resources (such as P1A and P1B) to the first UE and another a subset of BRACH resources (eg, P1C and P1D) to the second UE. Suppose then that each UE can still choose one of the four sub-channels to transmit, then each UE can choose one of the eight (e.g. S=2 (halved due to Sequence Based Restriction (SBR)) and F=4) resources to transfer. Therefore, the transmission carries Log2(8)=3 bits of information. Note that the total amount of resources (S*F*U) remains unchanged (16).

[253] In a situation where multiple UEs share subchannels, instead of assigning subchannels (such as subchannels 1, 2, 3, and 4) to one UE, the access node may assign a subset of subchannels (such as subchannels 1 and 2) to the first UE and another subset subchannels (eg, subchannels 3 and 4) to the second UE. Suppose then that each UE can still choose one of the four code sequences to transmit, then each UE can choose one of the eight (e.g. F=2 (halved due to FBR) and S=4 ) resources to transfer. Therefore, the transmission carries Log2(8)=3 bits of information. Note that the total amount of resources (S*F*U) remains unchanged (16). It should also be noted that in this situation, the P1A sequence, if found on subchannels 1 and 2, should be discovered by the access node as the P1A sequence sent by the first UE, whereas if the P1A sequence is found on subchannels 3 and 4, then the access node must determine that the P1A sequence was sent by the second UE. In other words, in order to determine the UE ID, the access node needs to discover not only which BRACH preamble is being received, but also where it is being received.

[254] Also note that a combination of the sharing presented above is possible. In other words, the access node configures multiple UEs to share BRACH resources, where:

– Multiple UEs share the same subchannel but differ in different code sequences;

– Multiple UEs share the same code sequences but differ on different subchannels; or

– Several UEs differ on different subchannels and different code sequences (ie, do not share anything).

[255] It should be noted that in Figure 21, the same code sequence is used in all four sub-channels with different timing capabilities (eg, P1A code sequence is used in all four sub-channels). It is possible that different code sequences will be used on the sub-channels of each time opportunity. As an example, the first subchannel uses the P1A code sequence, the second subchannel uses the Q1A code sequence, the third subchannel uses the R1A code sequence, and the fourth subchannel uses the S1A code sequence.

[256] Figure 22A shows a flowchart of exemplary operations 2200 occurring at a UE initiating beam failure recovery. Operations 2200 may indicate operations occurring at the UE when the UE initiates recovery from a beam failure.

[257] Operations 2200 begin with the UE receiving beam index associations with the BRACH index (block 2205). Beam index associations with the BRACH index may be direct associations or indirect associations. Beam index associations with the BRACH index may be received from the access node serving the UE. Alternatively, the associations of the beam index with the BRACH index may be programmed into the UE. The UE detects a new beam and determines a beam index for the new beam (block 2207). The new beam may be a replacement beam for the missing beam. The UE determines the BRACH index (block 2209). The BRACH index may be determined from the beam index according to the associations of the beam index with the BRACH index. The UE may optionally select a BRACH preamble (block 2211). In a situation where the UE is configured with one or more BRACH preambles, the UE may select a BRACH preamble from a plurality of BRACH preambles. Alternatively, the UE may be configured with one BRACH preamble, but with one or more code sequences with which to encode the BRACH preamble. In such a situation, the UE may optionally select a code sequence from a plurality of code sequences. The UE sends the BRACH preamble in the BRACH resource corresponding to the BRACH index (block 2213).

[258] Figure 22B shows a flowchart of exemplary operations 2250 occurring at an access node involved in beam failure recovery. Operations 2250 may indicate operations occurring at the access node as the access node participates in beam failure recovery.

[259] Operations 2250 begin with the access node sending beam index associations with the BRACH index (block 2255). Beam index associations with the BRACH index may be direct associations or indirect associations. Beam index associations with the BRACH index may be received from the access node serving the UE. Alternatively, the associations of the beam index with the BRACH index may be programmed into the UE. The access node receives the BRACH preamble in the BRACH resource (block 2257). The access node determines a beam index for the beam carrying the signal transmitted by the access node (block 2259). The beam index may be determined from the BRACH resource index according to the associations of the beam index with the BRACH index. The access node identifies the UE identifier (block 2261). The UE ID is determined from the received BRACH preamble.

[260] With regard to resource allocation, the allocation can be made at the beginning, when the UE establishes an active link with the access node. For example, each UE may be assigned a unique resource to recover. In the first situation, a potentially unique random access channel resource preamble is assigned to reconstruct a beam in the random access channel region, with the random access channel region potentially the same or different from the random access channel region used for initial access purposes. In the second situation, a potentially unique set of REs in an area is assigned. REs can be identified using a unique combination of code, time or frequency resources.

[261] If the random access channel region for beam failure recovery and the random access channel region for initial access use different or orthogonal time or frequency resources, then the same random access channel resource preamble can be used. For example, if one UE is assigned a first sequence to transmit in the random access channel region for initial access, the UE may also use the same first sequence to transmit in the random access channel region for beam failure recovery.

[262] If the random access channel region for beam failure recovery and the random access channel region for initial access use the same random access channel resource preamble, a different scrambling code may be used. For example, if the UE is assigned a first sequence to transmit in the random access channel region for initial access, the UE may use the same first sequence (but scrambled with a different scrambling sequence) to transmit in the random access channel region to recover from beam failure. Note that the scrambling sequences for different UEs may be the same or different. Also note that the random access channel resource preamble sequences used in the random access channel region for beam failure recovery and the random access channel region for initial access may be orthogonal to each other.

[263] If the random access channel region for beam failure recovery and the random access channel region for initial access use the same or overlapping time-frequency resources, then the preamble sequences of the random access channel resources may be orthogonal to each other.

[264] An example of a beam failure recovery procedure includes:

0a. The access node configures the UE with a unique preamble sequence to use in the random access channel domain for beam failure recovery;

0b. The access node broadcasts on the broadcast channel some resources (eg, beam recovery signals, synchronization signals, etc.) that the UE can use to make measurements in case of a beam failure;

1. The UE monitors one or more downlink control channels; Upon determining that a beam failure or loss has occurred, the UE may initiate a beam recovery procedure;

2. UE makes downlink measurements:

– In specific resources (e.g., beam recovery signals, synchronization signals, etc.) for reacquisition or resynchronization with the downlink transmission beam(s) from the access node (e.g., a downlink transmission beam with sufficient quality), downlink reception beam(s) at the UE (eg, downlink reception beam with sufficient quality), or to improve time or frequency synchronization.

– The resource location may be pre-broadcast by the access node and may be allocated periodically in the time or frequency domains;

3a. The UE transmits a preamble sequence in the random access channel region to recover from a beam failure. In the first situation, the UE transmits its own unique preamble sequence in the random access channel region for beam failure recovery (the random access channel region for beam failure recovery may not be orthogonal or orthogonal to the random access channel region for initial access in time or frequency domain) . In the second situation, the UE may transmit control or command in a non-grant scripted manner in resource elements (REs) (this UE-initiated non-grant transfer may use REs previously allocated to the UE, for example). The uplink transmission may be based on time or frequency synchronization previously performed;

3b. The UE may transmit the results of the downlink measurement. As an example, the UE may transmit the best downlink transmission beam(s), such as beam indices. As an example, the UE may transmit the best downlink receive beam(s), such as beam indices. As an example, the UE may transmit associated channel quality information such as SINR, SNR, RSSI, RSRQ, RSRP, and so on. The UE may also send other information to the access node to help establish a new downlink control channel;

4. The access node receives the preamble sequence and the corresponding downlink measurements. The access node may use the received information to establish a new downlink control channel from the access node to the UE; and

5. The access node may send control signaling to the UE using the newly established downlink control channel.

[265] Figure 23 illustrates an example of a communication system 2300. In general, system 2300 allows multiple wireless or wired users to send and receive data and other content. System 2300 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single channel FDMA. carrier (SC-FDMA) or non-orthogonal multiple access (NOMA).

[266] In this example, communication system 2300 includes electronic devices (EDs) 2310a-2310c, radio access networks (RANs) 2320a-2320b, core network 2330, public switched telephone network (PSTN) 2340, Internet 2350, and other networks 2360 While Figure 23 shows specific amounts of these components or elements, any number of these components or elements may be included in system 2300.

[267] EDs 2310a-2310c are configured to operate and/or communicate in system 2300. For example, EDs 2310a-2310c are configured to transmit and/or receive over wireless or wired communication channels. Each ED 2310a-2310c is any suitable end user device and may include (or may be referred to as) a user equipment/device (UE), wireless transmit/receive unit (WTRU), mobile station, fixed or mobile subscriber module, cellular phone, personal digital assistant (PDA), smartphone, laptop, computer, touch pad, wireless sensor, or consumer electronics device.

[268] RANs 2320a-2320b herein include base stations 2370a-2370b, respectively. Each base station 2370a-2370b is configured to wirelessly communicate with one or more EDs 2310a-2310c to provide access to the core network 2330, PSTN 2340, Internet 2350, and/or other networks 2360. For example, base stations 2370a-2370b may include itself (or represent) one or more of several well-known devices such as base transceiver station (BTS), Node-B (NodeB), evolved NodeB (eNodeB), Home Node B, home node eNodeB, site controller, access point ( AP) or wireless router. EDs 2310a-2310c are configured to interact and communicate with the Internet 2350 and can access the core network 2330, PSTN 2340, and/or other networks 2360.

[269] In the embodiment shown in Figure 23, base station 2370a forms part of RAN 2320a, which may include other base stations, elements, and/or devices. Also, base station 2370b forms part of RAN 2320b, which may include other base stations, elements, and/or devices. Each base station 2370a-2370b operates to transmit and/or receive wireless signals in a specific geographic area or region, sometimes referred to as a "cell". In some embodiments, multiple input multiple output (MIMO) technology may be used, having multiple transceivers for each cell.

[270] Base stations 2370a-2370b communicate with one or more EDs 2310a-2310c over one or more radio interfaces 2390 using wireless links. The radio interfaces 2390 may use any suitable radio access technology.

[271] It is contemplated that system 2300 may use multi-channel access functionality, including such schemes as described above. In specific embodiments, base stations and EDs implement LTE, LTE-A, and/or LTE-B. Of course, other multiple access schemes and wireless protocols may be used.

[272] RANs 2320a-2320b communicate with core network 2330 to provide EDs 2310a-2310c with voice, data, applications, Voice over Internet Protocol (VoIP), or other services. It is understood that RANs 2320a-2320b and/or core network 2330 may communicate directly or indirectly with one or more other RANs (not shown). Core network 2330 may also serve as a gateway to access other networks (such as PSTN 2340, Internet 2350, and other networks 2360). In addition, some or all of the EDs 2310a-2310c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and/or protocols. Instead of (or in addition to) wireless communications, EDs may communicate via wired links with a service provider or switch (not shown) and the Internet 2350.

[273] Although Figure 23 illustrates one example of a communication system, various changes can be made to Figure 23. For example, communication system 2300 may include any number of EDs, base stations, networks, or other components in any suitable configuration.

[274] Figures 24A and 24B illustrate exemplary devices that may implement the methods and ideas of the present disclosure. In particular, Figure 24A illustrates an exemplary ED 2410 and Figure 24B an exemplary base station 2470. These components may be used in a system 2300 or any other suitable system.

[275] As shown in Figure 24A, ED 2410 includes at least one processing module 2400. The processing module 2400 implements various processing operations of the ED 2410. For example, the processing module 2400 may perform signal coding, data processing, power control, I/O processing, or any other functionality that allows the ED 2410 to function in the system 2300. The processing module 2400 also supports methods and ideas described in more detail above. Each processing module 2400 includes any suitable processing or computing device configured to perform one or more operations. Each processing module 2400 may, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or ASIC.

[276] ED 2410 also includes at least one transceiver 2402. Transceiver 2402 is configured to modulate data or other content for transmission via at least one antenna or NIC (network interface controller) 2404. Transceiver 2402 is also configured to the ability to demodulate data or other content received by at least one antenna 2404. Each transceiver 2402 includes any suitable structure for generating signals for wireless or wired transmission and/or processing signals received wirelessly or wired. Each antenna 2404 includes any suitable structure for transmitting and/or receiving wireless or wired signals. One or more transceivers 2402 may be used in ED 2410, and one or more antennas 2404 may be used in ED 2410. Although shown as a single functional unit, transceiver 2402 may also be implemented using at least one transmitter and at least at least one individual receiver.

[277] ED 2410 further includes one or more input/output devices 2406 or interfaces (such as a wired Internet interface 2350). I/O devices 2406 facilitate interaction with the user or other devices (network communications) on the network. Each input/output device 2406 includes any suitable structure for providing information or receiving/providing information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communication.

[278] In addition, ED 2410 includes at least one memory 2408. Memory 2408 stores instructions and data used, generated, or collected in ED 2410. For example, memory 2408 may store software or firmware instructions. performed by the processing module(s) 2400 and the data used to reduce or eliminate interference in incoming signals. Each memory 2408 includes any suitable volatile and/or nonvolatile storage and retrieval device(s). Any suitable type of memory may be used, such as Random Access Memory (RAM), Read Only Memory (ROM), hard disk, optical disk, Subscriber Identity Module (SIM) card, memory card, secure digital (SD) memory card, etc. similar.

[279] As shown in Figure 24B, base station 2470 includes at least one processing module 2450, at least one transceiver 2452, which includes functionality for the transmitter and receiver, one or more antennas 2456, at least one memory 2458 and one or more input/output devices or interfaces 2466. A scheduler, which should be understood by a person skilled in the art, is connected to the processing module 2450. The scheduler may be included with or separate from base station 2470. Processing module 2450 implements various processing operations of base station 2470 such as signal coding, data processing, power control, I/O processing, or any other functionality. Processing module 2450 may also support the methods and ideas described in more detail above. Each processing module 2450 includes any suitable processing device or computing device configured to perform one or more operations. Each processor 2450 may, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or ASIC.

[280] Each transceiver 2452 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 2452 further includes any suitable structure for processing signals received wirelessly or wired from one or more EDs or other devices. Although shown as an integrated transceiver 2452, the transmitter and receiver may be separate components. Each antenna 2456 includes any suitable structure for transmitting and/or receiving wireless or wired signals. Although a common antenna 2456 is shown connected to a transceiver 2452, one or more antennas 2456 can be connected to the transceiver(s) 2452, allowing separate antennas 2456 to be connected to the transmitter and receiver if installed as separate components. Each memory 2458 includes any suitable volatile and/or nonvolatile storage and retrieval device(s). Each I/O device 2466 facilitates interaction with the user or other devices (network communications) on the network. Each input/output device 2466 includes any suitable structure for providing information or receiving/providing information from a user, including communication over a network interface.

[281] Figure 25 depicts a block diagram of a computing system 2500 that can be used to implement the devices and methods disclosed herein. For example, the computing system may be any of a UE, an access network (AN), a mobility management (MM), a session management (SM), a user plane gateway (UPGW), and/or an access layer (AS). Specific devices may use all of the components shown, or only a subset of the components, and levels of integration may vary from device to device. In addition, a device may contain multiple instances of a component, such as multiple processing modules, processors, memories, transmitters, receivers, and so on. The computing system 2500 includes a processing module 2502. The processing module includes a central processing unit (CPU) 2514, a memory 2508, and may further include a mass storage device 2504, a video adapter 2510, and an I/O interface 2512 connected to the bus 2520.

[282] Bus 2520 may be one or more of any type of a variety of bus architectures, including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 2514 may comprise any type of electronic data processor. The memory 2508 may comprise any type of permanent system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read only memory (ROM), or a combination thereof. In an embodiment, memory 2508 may include ROM for use in booting and DRAM for storing programs and data for use in executing programs.

[283] Mass storage device 2504 may include any type of temporary storage device configured to store data, programs, and other information and provide access to data, programs, and other information via bus 2520. Mass storage device 2504 may include, for example, one or more solid state drives, hard disk drives, magnetic disk drives, or optical disk drives.

[284] The video adapter 2510 and the I/O interface 2512 provide interfaces for connecting external input and output devices to the processing module 2502. As shown, examples of input and output devices include a display 2518 connected to a video adapter 2510 and a mouse/keyboard/printer 2516 connected to an I/O interface 2512. Other devices may be connected to the processing module 2502 and additional or fewer interface cards may be used. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface to an external device.

[285] The processing module 2502 also includes one or more network interfaces 2506, which may include wired links, such as an Ethernet cable, and/or wireless links for accessing nodes or various networks. Network interfaces 2506 allow the processing module 2502 to communicate with remote units via networks. For example, network interfaces 2506 may provide wireless communication through one or more transmitter/transmit antennas and one or more receiver/receiver antennas. In one embodiment, the processing module 2502 is connected to a local area network 2522 or a wide area network for data processing and communication with remote devices such as other processing modules, the Internet, or remote repositories.

[286] It should be understood that one or more steps of the methods of the embodiments provided herein may be performed by respective blocks or modules. For example, the signal may be transmitted by a transmission unit or a transmission module. The signal may be received by a receiving unit or a receiving module. The signal may be processed by a processing unit or a processing module. Other steps may be performed by a determination block/module, a tracking block/module, an identification block/module, a setup block/module, and/or a configuration block/module. The respective blocks/modules may be hardware, software, or a combination thereof. For example, one or more modules/modules may be integrated circuits such as field programmable gate arrays (FPGAs) or application specific integrated circuits (ASICs).

[287] While the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions, and alternatives may be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Statement 1. The method of functioning of the access node, and the method contains the steps in which:

generating, by the access node, a configuration message including information indicating a set of reference signals of the first type of reference signals and a set of reference signals of the second type of reference signals used to determine a new beam, and information indicating random access channel resources allocated for transmitting preamble sequences, each resource of the random access channel is associated with a reference signal of the first type of reference signals;

sending, by the access node, to one or more user equipments (UEs) a configuration message;

receiving, by the access node, from the UE a preamble sequence in one of the random access channel resources; and

determining, by the access node, a UE identifier according to the preamble sequence and one of the random access channel resources.

Statement 2. The method according to Statement 1, wherein each reference signal in the first reference signal set has a quasi-co-registration (QCLed) or spatial similarity relationship with another subset of the reference signals of the second reference signal set of the second reference signal type.

Claim 3: The method according to Claim 1, wherein the configuration message is sent in at least one of a radio resource control (RRC) message, a medium access control (MAC) (MAC-CE) message, or a downlink control indicator message. (DCI).

Statement 4. The method according to Statement 1, wherein the set of first type reference signals comprises a set of synchronization signals (SS).

Claim 5: The method according to Claim 1, wherein the second type reference signal set comprises a channel state information (CSI-RS) reference signal set.

Claim 6: The method according to Claim 1, wherein the random access channel resources comprise physical random access channel (PRACH) resources.

Claim 7: The method according to Claim 1, wherein each random access channel resource is also associated with a reference signal of the second reference signal type.

Claim 8. The method according to Claim 1, wherein the configuration message further comprises at least one of: time location information related to the first random access channel resource, frequency location information related to the first random access channel resource, information about a preamble sequence relating to the first random access channel resource, or a first association between the first reference signal index and the first random access channel resource.

Claim 9. The method according to Claim 8, wherein the configuration message further comprises at least one of: time location information related to the second random access channel resource, frequency location information related to the second random access channel resource, information about a preamble sequence related to the second random access channel resource, or a second association between the second reference signal index and the second random access channel resource.

Statement 10. The method according to Statement 1, further comprising the steps of:

determining, by the access node, an index of the identified reference signal as the index of the first reference signal when the preamble sequence is received in the first random access channel resource; and

determining, by the access node, an index of the identified reference signal as the index of the second reference signal when the preamble sequence is received in the second random access channel resource.

Claim 11: The method according to Claim 10, further comprising sending, by the access node to the UE, a beam fail recovery response over a control channel.

Clause 12: The method according to Clause 11, wherein the control channel comprises a physical downlink control channel (PDCCH).

Statement 13: The method according to Statement 11 wherein the control channel is spatially quiescently aligned (QCLed) with the identified reference signal.

Statement 14. Access node containing:

memory containing instructions; and

one or more processors interacting with the storage store, wherein the one or more processors execute instructions for:

generating a configuration message including information indicating a set of reference signals of a first type of reference signals and a set of reference signals of a second type of reference signals used to identify a potentially suitable beam, and information indicating random access channel resources allocated for transmitting preamble sequences, wherein each random access channel resource is associated with a reference signal of the first type of reference signals,

sending a configuration message to one or more user equipments (UEs),

receiving from the UE a preamble sequence in one of the random access channel resources, and

determining a UE ID according to the preamble sequence and one of the random access channel resources.

Clause 15: An access node according to Clause 14, wherein the configuration message is sent in at least one of a radio resource control (RRC) message, a medium access control (MAC) (MAC-CE) message, or a downlink control indicator message. communications (DCI).

Statement 16: The access node according to Statement 14, wherein the one or more processors further execute instructions for determining the index of the identified reference signal as the index of the first reference signal when the preamble sequence is received in the first random access channel resource, and determining the index of the identified reference signal as an index of the second reference signal when the preamble sequence is received on the second random access channel resource.

Clause 17: An access node according to Clause 14 wherein one or more processors further execute instructions to send a response to the UE for beam failure recovery over the control channel.

Clause 18: An access node according to Clause 14, wherein each reference signal in the first reference signal set has a quasi-co-alignment (QCLed) or spatial similarity relationship with another subset of the reference signals of the second reference signal set of the second reference signal type.

Statement 19 A non-volatile computer-readable medium storing programming for execution by one or more processors for:

generating a configuration message including information indicating a reference signal set of a first reference signal type and a reference signal set of a second reference signal type used to determine a potential candidate beam, and information indicating random access channel resources allocated for transmitting preamble sequences, wherein each random access channel resource is associated with a reference signal of the first type of reference signals,

sending a configuration message to one or more user equipments (UEs),

receiving from the UE a preamble sequence in one of the random access channel resources, and

determining a UE ID according to the preamble sequence and one of the random access channel resources.

Clause 20: A durable computer-readable medium according to Clause 19, wherein one or more processors further execute instructions for determining the index of the identified reference signal as the index of the first reference signal when a preamble sequence is received in the first random access channel resource, and determining the index of the identified reference signal in as the second reference signal index when the preamble sequence is received on the second random access channel resource.

Clause 21: A durable computer-readable medium in accordance with Clause 19, wherein one or more processors further execute instructions to send a beam failback response to the UE over a control channel.

Claims (33)

1. A user equipment (UE) operating method, comprising the steps of: tracking the first set of reference signals of the first type of reference signals and the second set of reference signals of the second type of reference signals; identifying a second reference signal from the second set of reference signals as a potential candidate beam, wherein the second reference signal is not associated with a random access resource; identifying a first reference signal from the first set of reference signals that is quasi-aligned with the second reference signal; and transmitting a preamble sequence in a random access channel resource that is associated with the first reference signal. 2. The method of claim 1, wherein the first set of reference signals comprises synchronization signals (SS), while the second set of reference signals comprises channel state information (CSI-RS) reference signals. 3. The method of claim 1 or 2, wherein identifying the second reference signal from the second set of reference signals as a potential candidate beam comprises determining that the signal quality of the second reference signal meets a threshold value. 4. The method according to any one of claims 1 to 3, further comprising receiving, by the UE, information about the first set of reference signals and the second set of reference signals in at least one of a radio resource control (RRC) message, an element message control (CE), medium access control (MAC) (MAC-CE), and downlink control indicator (DCI) messages. 5. The method of functioning of the access node, containing the steps at which: generating a configuration message containing information indicating a set of reference signals of the first type of reference signals and a set of reference signals of the second type of reference signals as a plurality of potentially suitable beams for beam failure recovery, and containing information indicating random access channel resources allocated for random access; send a configuration message; and receiving a preamble sequence in a random access channel resource that is associated with a first reference signal from a first reference signal set, wherein the first reference signal is quasi-aligned with a second reference signal from a second reference signal set, the second reference signal being identified as a potentially suitable beam, wherein the second reference signal is not associated with the random access resource. 6. The method of claim 5, wherein the configuration message is included in at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE) message (MAC-CE), and a downlink control indicator message. communications (DCI). 7. The method according to claim 5 or 6, wherein the set of first type reference signals comprises a set of synchronization signals (SS). 8. The method according to any one of claims 5 to 7, wherein the second type reference signal set comprises a channel state information (CSI-RS) reference signal set. 9. User equipment (UE) containing: at least one processor; and a memory coupled to the at least one processor and storing program instructions which, when executed by the at least one processor, instruct the user equipment: track the first set of reference signals of the first type of reference signals and the second set of reference signals of the second type of reference signals; identify a second reference signal from the second set of reference signals as a potential candidate beam, wherein the second reference signal is not associated with a random access resource; identify a first reference signal from the first set of reference signals that is quasi-aligned with the second reference signal; and transmit the preamble sequence in the random access channel resource that is associated with the first reference signal. 10. The user equipment of claim 9, wherein the first set of reference signals comprises synchronization signals (SS) and the second set of reference signals comprises channel state information (CSI-RS) reference signals. 11. The user equipment of claim 9 or 10, wherein identifying the second reference signal from the second set of reference signals as a potential candidate path comprises determining that the signal quality of the second reference signal meets a threshold. 12. Access node containing: at least one processor; and a memory connected to at least one processor and storing program instructions, which, when executed by at least one processor, instruct the access node: generate a configuration message containing information indicating the reference signal set of the first reference signal type and the reference signal set of the second reference signal type as a plurality of potentially suitable beams for beam failure recovery, and containing information indicating random access channel resources allocated for random access; send a configuration message; and receive a preamble sequence in a random access channel resource that is associated with a first reference signal from a first reference signal set, wherein the first reference signal is quasi-aligned with a second reference signal from a second reference signal set, wherein the second reference signal is identified as a potential candidate beam, wherein the second reference signal is not associated with the random access resource. 13. The access node of claim 12, wherein the configuration message is sent in at least one of a radio resource control (RRC) message, a medium access control (MAC) control element (CE) message (MAC-CE), and a downstream control pointer message. communication lines (DCI). 14. A communications device comprising at least one processor configured to access a computer program from memory and execute the computer program to cause the device to implement the method of any one of claims 1-4. 15. A communications device comprising at least one processor configured to access a computer program from memory and execute the computer program to cause the device to implement the method of any one of claims 5-8.

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