Methods, apparatuses, and media for selecting reference signals for determining beam failure detection and radio link monitoring

Abstract

Implementations include computer-readable storage media, user equipment, methods of performing operations, and integrated circuits. The operations include receiving a plurality of control resource sets (CORESETs); selecting at least one reference signal (RS) corresponding to at least one activated transmission configuration indicator (TCI) state in the CORESETs; analyzing the at least one RS and determining beam failure detection (BFD) or radio link monitoring (RLM) based on the selected at least one reference signal.

Description

BACKGROUND

[0001] A user equipment (UE) can establish a connection with at least one of a plurality of different networks or network types. When establishing a network connection, such as for example, a connection with a 5G New Radio (NR) network, a g-NodeB (gNB) transmits downlink control information (DCI) to the UE via a physical downlink control channel (PDCCH) in a search space (SS).

[0002] The PDCCH and DCI are transmitted to the UE via one or more control resource sets (CORESETs), each CORESET including a transmission configuration indicator (TCI) state configured by the gNB. The PDCCH can include a synchronization signal block (SSB) and a channel state information (CSI) reference signal (RS) that the UE can use to determine a hypothetical block error rate (BLER). The UE uses the BLER to determine beam failure detection (BFD) and / or radio link monitoring (RLM). When the hypothetical BLER for all RSs is above a predetermined threshold, the UE can count a beam failure instance (for BFD) or determine that the RSs are out of sync (for RLM). SUMMARY

[0003] Some example embodiments include a computer-readable storage medium including a set of instructions which, when executed by a processor, cause the processor to perform operations. The operations include receiving a plurality of control resource sets (CORESETs); selecting at least one reference signal (RS) corresponding to at least one activated transmission configuration indicator (TCI) state in the CORESETs; analyzing the at least one RS and determining beam failure detection (BFD) or radio link monitoring (RLM) based on the selected at least one reference signal.

[0004] Other example embodiments relate to a user equipment (UE) including a transceiver and a processor. The transceiver is configured to connect to one or more g-NodeBs (gNBs). The processor is configured to receive, from the gNBs, a plurality of control resource sets (CORESETs); select at least one reference signal (RS) corresponding to at least one activated transmission configuration indicator (TCI) state in the CORESETs; analyze the at least one RS and determine beam failure detection (BFD) and radio link monitoring (RLM) based on the selected at least one reference signal. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 An example network arrangement is shown in accordance with various example embodiments.

[0006] Figure 2 An example UE is shown in accordance with various example embodiments.

[0007] Figure 3A A method of determining reference signals (RSs) for beam failure detection and radio link monitoring is shown in accordance with various example embodiments.

[0008] Figure 3B A method of determining RSs for beam failure detection and radio link monitoring is shown in accordance with various example embodiments.

[0009] Figure 3C A method of determining RSs for beam failure detection and radio link monitoring is shown in accordance with various example embodiments.

[0010] Figures 4A-4C A block diagram showing an example of RS selection in accordance with various example embodiments. DETAILED DESCRIPTION

[0011] Example embodiments can be further understood with reference to the following description and the related drawings in which like elements are referred to with the same reference numerals. The example embodiments relate to a user equipment (UE) transmitting UCI information to a g-nodeB (gNB) of a 5G New Radio (NR) network. The example embodiments relate to the UE receiving a PDCCH and the robustness of that reception.

[0012] The example embodiments are described with respect to a UE. However, the use of a UE is for illustrative purposes only. The example embodiments can be utilized with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, the UE described herein is used to represent any electronic component.

[0013] The example embodiments are also described with respect to a network that includes a 5G New Radio (NR) radio access technology (RAT). However, the example embodiments are not limited to a 5G RAT as the example embodiments can be applied to any network that includes functionality described herein with respect to a 5G RAT, e.g., beamforming, reference signals, TCI states, etc., whether described using the same terminology or different terminology.

[0014] Currently, a PDCCH includes one TCI state configured for each CORESET. According to example embodiments, each CORESET can be configured with multiple TCI states by the gNB such that one PDCCH can be transmitted via multiple beams. In such cases, the UE is configured to select one or more reference signals (RSs) from the TCI states of the CORESET and / or to calculate a hypothetical block error rate (BLER) for selecting the RSs to be used in beam failure detection (BFD) and radio link monitoring (RLM). However, in such arrangements, the UE can have to determine how to select the RSs to perform RLM / BFD and detect the hypothetical BLER based on these RSs. Example embodiments will also address these issues.

[0015] Figure 1 An example network arrangement 100 is shown in accordance with various example embodiments. The example network arrangement 100 includes a UE 110. Those skilled in the art will appreciate that the UE 110 can be any type of electronic component configured to communicate via a network, such as a mobile phone, a tablet computer, a desktop computer, a smart phone, a phablet, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It will also be appreciated that a practical network arrangement can include any number of UEs used by any number of users. Thus, only an example with a single UE 110 is provided for illustrative purposes.

[0016] The UE 110 can be configured to communicate with one or more networks. In the example network arrangement 100, the networks with which the UE 110 can wirelessly communicate are a 5G New Radio (NR) Radio Access Network (5G NR-RAN) 120, a LTE Radio Access Network (LTE-RAN) 122, and a Wireless Local Area Network (WLAN) 124. However, it will be appreciated that the UE 110 can also communicate with other types of networks, and that the UE 110 can also communicate with networks through wired connections. Thus, the UE 110 can include a 5G NR chipset to communicate with the 5G NR-RAN 120, an LTE chipset to communicate with the LTE-RAN 122, and an ISM chipset to communicate with the WLAN 124.

[0017] 5G NR-RAN 120 and LTE-RAN 122 can be part of a cellular network that can be deployed by a cellular provider (e.g., Verizon, AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 can include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell base station, microcell base station, small cell base station, femtocell base station, etc.) configured to send and receive traffic from UEs equipped with the appropriate cellular chipset. WLAN 124 can include any type of wireless local area network (WiFi, hotspot, IEEE 802. l lx network, etc.).

[0018] UE 110 can be connected to 5G NR-RAN 120 via gNB 120A. gNB 120A can be configured with the necessary hardware (e.g., antenna arrays), software, and / or firmware to perform massive multiple-input multiple-output (MIMO) functionality. Massive MIMO can refer to a base station configured to generate multiple beams for multiple UEs. During operation, UE 110 can be within range of multiple gNBs. Thus, simultaneously or alternatively, UE 110 can also be connected to 5G NR-RAN 120 via gNB 120B. The reference to two gNBs 120A, 120B is for illustrative purposes only. Exemplary embodiments can apply to any appropriate number of gNBs. Additionally, UE 110 can communicate with eNB 122A of LTE-RAN 122 to transmit and receive control information for downlink and / or uplink synchronization relative to the connection to 5G NR-RAN 120.

[0019] Those skilled in the art will appreciate that any relevant procedures can be performed for UE 110 to connect to 5G NR-RAN 120. For example, as described above, 5G NR-RAN 120 can be associated with a particular cellular provider at which UE 110 and / or its user has agreement and credential information (e.g., stored on a SIM card). Upon detecting the presence of 5G NR-RAN 120, UE 110 can transmit the corresponding credential information in order to associate with 5G NR-RAN 120. More specifically, UE 110 can associate with a particular base station (e.g., gNB 120A of 5G NR-RAN 120).

[0020] In addition to the networks 120, 122, and 124, the network arrangement 100 includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 can be viewed as an interconnected set of components that manage the operation and traffic of the cellular network. The cellular core network 130 also manages traffic that flows between the cellular network and the Internet 140. The IMS 150 can generally be described as an architecture for delivering multimedia services to UEs 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UEs 110. The network services backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network services backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that can be used to extend the functionality of the UEs 110 in communicating with various networks.

[0021] Figure 2 An exemplary UE 110 is shown in accordance with various exemplary embodiments. The UE 110 will be described with reference to the network arrangement 100 of Figure 1 The UE 110 can represent any electronic device and can include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 can include, for example, an audio input device, an audio output device, a battery providing a limited power supply, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, one or more antenna panels, etc.

[0022] The processor 205 can be configured to execute a number of engines of the UE 110. For example, the engines can include a BFD / RLM management engine 235. The BFD / RLM management engine 235 can perform various operations related to selecting one or more RSs configured in a TCI state of a CORESET, determining a BLER of the selected RSs, and / or determining BFD and RLM based on the RSs.

[0023] The engines described above are exemplary only as applications (e.g., programs) executed by the processor 205. The functionality associated with the engines can also be represented as standalone combined components of the UE 110 or can be modular components coupled to the UE 110, e.g., integrated circuits with or without firmware. For example, an integrated circuit can include input circuitry for receiving signals and processing circuitry for processing the signals and other information. The engines can also be embodied as one application or as multiple applications separated. Furthermore, in some UEs, the functionality described with respect to the processor 205 is shared between two or more processors, such as a baseband processor and an application processor. The exemplary embodiments can be implemented in any of these or other configurations of the UE.

[0024] Memory arrangement 210 can be a hardware component configured to store data related to operations performed by UE 110. Display device 215 can be a hardware component configured to display data to a user, while I / O device 220 can be a hardware component that enables user input. Display device 215 and I / O device 220 can be separate components or can be integrated together, such as a touch screen. Transceiver 225 can be a hardware component configured to establish a connection with 5G NR-RAN 120, LTE-RAN 122, WLAN 124, and the like. Thus, transceiver 225 can operate on multiple different frequencies or channels (e.g., a contiguous set of frequencies).

[0025] Figure 3A Method 300 of determining RS for beam failure detection and radio link monitoring is shown, in accordance with various example embodiments. Method 300 is performed by UE 110 and allows for selection of RS to determine BFD and RLM. At 305, the UE receives CORESETs configured by gNB 120A or 120b. In some embodiments, the gNB can explicitly configure the UE 110 with RS to use for BFD and RLM. In such cases, method 300 jumps to 320 and determines BFD and RLM using the explicitly configured RS. However, if the gNB does not explicitly configure the BFD / RLM RS, then the method proceeds to 310.

[0026] At 310, the UE selects all RS in all TCI states of the CORESET. Subsequently, at 315, the UE 110 computes hypothetical BLERs for these RS. In some embodiments, the UE 110 computes a hypothetical BLER for each of the selected RS. In some embodiments, the UE 110 computes a combined hypothetical BLER for all selected RS.

[0027] In some embodiments, a signal to interference plus noise ratio (SINR) from all RS is used to determine the combined hypothetical BLER. In some embodiments, the minimum SINR can be used to determine the combined hypothetical BLER. In some embodiments, alternatively, the maximum SINR can be used to determine the combined hypothetical BLER. In some embodiments, alternatively, the average SINR can be used to determine the combined hypothetical BLER.

[0028] In some embodiments, the combined hypothetical BLER is determined using the measured BLER from all RSs. In some embodiments, the minimum measured BLER can be used to determine the combined hypothetical BLER. In some embodiments, alternatively, the maximum measured BLER can be used to determine the combined hypothetical BLER. In some embodiments, alternatively, the average measured BLER can be used to determine the combined hypothetical BLER.

[0029] As can be seen from the above examples, there are multiple mathematical and / or statistical ways to combine the measurements of RSs to compute the hypothetical BLER. However, it should be appreciated that the example embodiments can include any way of combining the measurements of RSs.

[0030] In general, the gNB transmits different RSs using the same transmission power. However, in some cases, there can be a transmission power difference (power offset) between the selected RSs. In such cases, the UE 110 can take the power offset into account when determining the combined hypothetical BLER. In some embodiments, the minimum power offset can be used to determine the combined hypothetical BLER. In some embodiments, the maximum power offset can be used to determine the combined hypothetical BLER. In some embodiments, the average power offset can be used to determine the combined hypothetical BLER. It should be noted that in such cases, the gNB 120A or 120B can communicate the power offset for each RS to the UE 110 via radio resource control (RRC) signaling.

[0031] At 320, the UE 110 compares the computed hypothetical BLER or the combined hypothetical BLER for each RS to a predetermined threshold. If the hypothetical BLER for all of the selected RSs is above the predetermined threshold, the UE 110 determines that there is a beam failure instance (for BFD purposes) and / or an out-of-sync beam (for RLM purposes) at 325.

[0032] Figure 3B A method 340 of determining RSs for beam failure detection and radio link monitoring is shown in accordance with various example embodiments. The method 350 is also performed by the UE 110 and allows for the selection of RSs to determine BFD and RLM. In some cases, the gNB 120a or 120b can send several CORESETs. At times, the number of CORESETs (active TCI states) can exceed the number of RSs that the UE 110 can utilize to determine BFD / RLM. In such cases, the UE 110 can prioritize and select a subset of the CORESETs.

[0033] At 345, the UE 110 receives the CORESETs configured by the gNB 120A or 120B. At 350, the UE 110 determines whether the number of RSs available for BFD / RLM is less than the number of active TCI states in the active bandwidth part including the CORESET. If the number of RSs is less than the number of active TCI states, the UE proceeds to 355, which is discussed below. If the number of RSs is not less than the number of active TCI states, the UE 110 proceeds to 360, where the UE 110 selects all RSs in all TCI states. If all RSs are selected, the method can proceed as described above with respect to 315-320 of FIG. 3. Figure 3A

[0034] At 355, because the number of RSs to be used for BFD / RLM is less than the number of active TCI states, the UE 110 selects RSs for BFD / RLM based on, for example, the number of TCI states in a given CORESET, the periodicity of the associated search space (SS), or the CORESET ID. In some example embodiments, the UE 110 first gives higher priority to CORESETs with a higher number of active TCI states. If two or more CORESETs have the same number of active TCI states, the CORESET with the smaller minimum periodicity in the associated SS can be selected. However, if the minimum periodicity is the same for the CORESETs, the CORESET with the smaller CORESET ID can be selected.

[0035] Figures 4A-4C FIGS. 4A-4D are block diagrams illustrating examples of RS selection procedures according to various example embodiments. These figures provide a visual example of the selection procedures discussed above in Figure 3A and Figure 3B However, it should be noted that these visualizations are provided as examples and in no way limit the number of different scenarios and criteria regarding RS selection by the UE.

[0036] In Figures 4A-4C , it is assumed that the UE 110 is only able to utilize up to four (4) RSs for BFD / RLM purposes. As shown in Figures 4A-4C , five TCI states can be configured for three CORESETs configured by the gNB 120a or 120b. CORESET 1, which corresponds to SS1, can include TCI 1 and TC2. CORESET 2, which corresponds to SS2, can include TCI 3. CORESET 3, which corresponds to SS 3, can include TCI 4 and TCI 5. Each TCI state has a corresponding CSI-RS with a number corresponding to its respective TCI state.

[0037] In​Figure 4A In the example shown, the UE 110 selects the CORESETs based on the selection criteria described above, e.g., giving first priority to the CORESET with the most TCI states. In this case, CORESET 1 and CORESET 3 are given priority and selected because they have two TCI states compared to one for CORESET 2. This results in the selection of CSI-RS 1, CSI-RS 2, CSI-RS 4, and CSI-RS 5 for BFD / RLM purposes, as shown. Figure 4A Because the maximum number of RS is determined based on the first priority criterion, e.g., the number of TCI states per CORESET, additional priority criteria, e.g., periodicity and CORESET ID, are not used in this example. However, if fewer than the maximum number of RS are selected based on the first priority criterion, additional criteria can be applied to arrive at the maximum number of RS.

[0038] In some embodiments, the UE 110 can alternatively first select the CORESETs with the smaller minimum periodicity in the associated SS. However, if the minimum periodicity is the same for the CORESETs, the CORESET with the smaller CORESET ID is selected. In some embodiments, the number of remaining RS that the UE 110 can use for BFD / RLM can still be less than the number of active TCI states for a given CORESET. In some embodiments, the UE 110 can ignore (not select) such CORESETs.

[0039] Figure 4B The example shown in FIG. 3B illustrates an example selection procedure in which the UE 110 prioritizes periodicity and ignores the remaining CORESETs, as described above. Thus, in this example, the UE 110 selects CORESET 1 with a 5 ms periodicity and CORESET 2 with a 10 ms periodicity. This selection results in three RS: CSI-RS 3, CSI-RS 1, and CSI-RS 2. Although these three RS are fewer than the four that the UE 110 is capable of utilizing, CORESET 3 has two TCI states configured. Selecting CORESET 3 would result in five RS, which is greater than the example maximum of four RS, and thus the UE 110 cannot perform BFD / RLM for this CORESET. Accordingly, CORESET 3 is ignored and the three RS initially selected are used.

[0040] In some embodiments, UE 110 may fill the maximum number of RSs by selecting a subset of TCI states for a particular CORESET. This selection of the subset of TCI states may be based on the periodicity of the RSs of the TCI states (e.g., the smallest periodicity), or if the periodicity is the same, may be based on the TCI state ID (e.g., the lowest TCI state ID).

[0041] Figure 4C The example shown in is essentially similar to Figure 4B However, in Figure 4C In this example, instead of ignoring CORESET 3, UE 110 uses the above selection criteria to select an RS (the RS with smaller periodicity) from CORESET 3. Therefore, the resulting RSs are CSI-RS 3, CSI-RS 1, CSI-RS 2, and CSI-RS 5, which fills the maximum number of RSs to 4 in this example.

[0042] In some implementations, the UE 110 may count RSs corresponding to different TCI states activated for a CORESET as one (1) RS for BFD / RLM purposes. As described above, the number of CORESETs may still be determined using the periodicity of the associated SS and the CORESET-ID.

[0043] return Figure 3B , at 365, after selecting the RS, UE 110 may now use the measured RS to determine BFD and / or RLM.

[0044] Figure 3C A method 370 for determining an RS for beam failure detection and radio link monitoring according to various exemplary embodiments is shown. Method 370 is also performed by UE 110 and allows for selection of an RS for determining BFD and RLM. At 375, UE 110 receives a CORESET configured by gNB 120A or 120B. At 380, UE 110 selects an RS from all TCI states. In some embodiments, the selection of a single RS may be configured by the gNB via higher layer signaling (e.g., RRC signaling, medium access control (MAC) control element (CE)), etc.

[0045] In some embodiments, the UE 110 can select the RS based on one or more predetermined criteria. In some embodiments, the predetermined criteria can include, for example, a TCI state ID, periodicity of the RS associated with the TCI, resource type (e.g., periodic, aperiodic, semi-persistent), RS resource ID, measured or latest reported reference signal received power (RSRP) or SINR, and / or transmission power. For example, the UE 110 can select the RS with the smallest periodicity. If two or more RSs have the same periodicity, the UE 110 can select the RS associated with the TCI with the lowest TCI state ID. Alternatively, the UE 110 can select, for example, the RS with the highest measured / reported RSRP or SINR. Alternatively, the UE 110 can select, for example, the RS with the highest transmission power.

[0046] At 385, the UE 110 calculates the hypothetical BLER based on the selected RS. At 390, the UE 110 determines the BFD and RLM.

[0047] Although this patent application describes various combinations of various embodiments each having different features, one of skill in the art will understand that any feature of one embodiment can be combined with features of other embodiments or features that are not inconsistent with the operation of the apparatus of the disclosed embodiments or the described functions in a manner not disclosed herein without departing from the scope of the present disclosure.

[0048] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unintentional or unauthorized access or use of data, and every effort should be made to secure user's consent to the manner in which their personal information is collected, used, and shared.

[0049] Those skilled in the art will understand that the exemplary embodiments described above can be implemented in any of a variety of suitable software configurations or hardware configurations, or combinations thereof. Exemplary hardware platforms for implementing the exemplary embodiments can include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, and the like. In other examples, the exemplary embodiments of the above-described methods can be embodied as a program including lines of code stored on a non-transitory computer readable storage medium, which when compiled can be executed on a processor or microprocessor.

[0050] It will be apparent to those skilled in the art that various modifications can be made to the disclosed embodiments without departing from the spirit or scope of the disclosure. Thus, it is intended that the disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims

1. A computer-readable storage medium comprising a set of instructions, wherein the set of instructions, when executed by a processor, causes a processor of a user equipment (UE) to perform operations comprising: Receive multiple control resource sets CORESET; selecting at least one reference signal RS corresponding to a plurality of activated transmission configuration indicator TCI states in the CORESET; analyzing the at least one RS; as well as determining beam failure detection (BFD) based on the selected at least one RS, wherein the UE utilizes a predetermined maximum number of RSs for BFD, and wherein, when the predetermined maximum number of RSs is less than the plurality of activated TCI states, the at least one RS is selected based on an associated search space (SS) having a minimum periodicity, When multiple associated SSs have the minimum periodicity, the at least one RS is selected based on the minimum periodicity and a CORESET ID.

2. The computer-readable storage medium of claim 1, wherein the plurality of RSs are all RSs in all TCI states configured in the plurality of CORESETs.

3. The computer-readable storage medium of claim 2, wherein analyzing the at least one RS comprises: Calculating hypothesized block error rates (BLERs) of the multiple RSs; as well as comparing the hypothesized BLER with a predetermined threshold, If the hypothetical BLER is greater than the predetermined threshold, beam failure instances or out-of-sync instances are counted.

4. The computer-readable storage medium of claim 3, wherein one of: (i) determining the hypothesized BLER for each of the plurality of RSs, or (ii) determining a combined hypothesized BLER for all of the plurality of RSs is performed.

5. The computer-readable storage medium of claim 4, wherein the combined hypothesized BLER is determined using a signal to interference plus noise ratio (SINR) from all of the RSs.

6. The computer-readable storage medium of claim 4, wherein the combined hypothesized BLER is determined using a power offset of a transmit power of each of the plurality of RSs.

7. The computer-readable storage medium of claim 1, wherein the operations are performed when a network does not explicitly configure a BFD reference signal.

8. A user equipment (UE), comprising: a transceiver configured to connect to one or more g-NodeBs (gNBs); A processor configured to: receiving a plurality of control resource sets (CORESETs) from the gNB; selecting at least one reference signal RS corresponding to a plurality of activated transmission configuration indicator TCI states in the CORESET; analyzing the at least one RS; as well as determining beam failure detection (BFD) based on the selected at least one RS, wherein the UE utilizes a predetermined maximum number of RSs for BFD, and wherein, when the predetermined maximum number of RSs is less than the plurality of activated TCI states, the at least one RS is selected based on an associated search space (SS) having a minimum periodicity, When multiple associated SSs have the minimum periodicity, the at least one RS is selected based on the minimum periodicity and a CORESET ID.

9. The UE according to claim 8, wherein the plurality of RSs are all RSs of all TCI states configured in the plurality of CORESETs.

10. The UE according to claim 8, wherein the processor analyzes the at least one RS by: Calculating hypothesized block error rates (BLERs) of the multiple RSs; and comparing the hypothesized BLER with a predetermined threshold, If the hypothetical BLER is greater than the predetermined threshold, beam failure instances or out-of-sync instances are counted. The UE of claim 10 , wherein the hypothesized BLER is determined for each of the plurality of RSs.

12. The UE of claim 10, wherein a combined hypothesized BLER is determined for all of the plurality of RSs.

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