Methods and nodes for non-codebook-based UL transmission for TRP with hybrid beamforming

Abstract

There is provided a method in a wireless device. The method comprises: receiving a dynamic message, the dynamic message comprising an indication of an association between one or more Channel State Information (CSI) reference signals (RSs) and one or more uplink (UL) reference signals for determining precoding information; receiving a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL reference signals; and sending one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

Description

Methods and nodes for non-codebook-based UL transmission for TRP with hybrid beamformingRELATED APPLICATIONS

[0001] This application claims the benefits of priority of US 63 / 726,278, entitled “Non- codebook-based UL transmission for TRP with hybrid beamforming" and filed at the USPTO on November 28, 2024, which is hereby incorporated by reference in its entiretyTECHNICAL FIELD

[0002] This application relates to communication networks and particularly to methods and nodes for non-codebook-based UL transmissions for Transmit Receive Point (TRP) with hybrid beamforming.BACKGROUND

[0003] Physical Uplink Shared Channel (PUSCH) precoding

[0004] For PUSCH scheduled by a dynamic grant, the network (NW) configures in Radio Resource Control (RRC) the transmission scheme by the higher-layer parameter txConfig in PUSCH-Config Information Element (IE). Two transmission schemes are supported: Codebook (CB)-based precoding and Non CB (NCB)-based precoding. CB-based precoding can be used for non-calibrated User Equipments (UEs) and / or for Frequency Division Duplexing (FDD) (i.e., Uplink (UL) / Downlink (DL) reciprocity does not need to hold). NCB-based precoding, on the other hand, relies on UL / DL reciprocity and is, hence, intended for Time Division Duplexing (TDD).

[0005] One benefit with NCB precoding compared to CB precoding is that the UE can beamform the Sounding Reference Signal (SRS) towards the gNB, which means that the SRS can be received with higher power at the gNB compared to the CB operation, which means that NCB- precoding will be especially useful compared to CB-precoding in UL coverage limited scenarios. In such scenarios, it is also common to use DL codebook-based operation instead of DL reciprocity based on operation based on SRS, since the SRS used for determining the DL precoding can typically not then be received with sufficient link budget to make a reliable DL channel estimation. Hence the combination of DL codebook-based operation and NCB will be very useful, especially in UL coverage limited scenarios, but also in normal scenarios (by e.g. using Type II codebook in DL and NCB in UL).

[0006] NCB-based precoding

[0007] NCB-based PUSCH is enabled if the higher-layer parameter txConfig in PUSCH- Config IE is set to nonCodebook and is intended for reciprocity-based UL transmission. ForPUSCH scheduled by a Dynamic Grant (DG), NCB-based PUSCH transmission can be summarized in the following steps, which are illustrated in Fig. 1.

[0008] In step 1), which is optional, the NW transmits Channel State Information (CSI)- Reference Signal (RS), which enables the UE to estimate the DL channel and to compute an UL precoder.

[0009] In step 2), the UE transmits SRS, which is configured in an SRS resource set with higher-layer parameter usage in SRS-Config IE set to nonCodebook. Up to eight SRS resources (depending on UE capability), each with a single SRS port, can be configured in the SRS resource set, where the UE selects a suitable precoder for each SRS resource based on the CSI-RS.

[0010] In step 3), the NW measures the UL channel based on the received SRS, selects the preferred SRS resource(s), and indicates the selection via the SRI field in DL Control Information (DCI).

[0011] In step 4), the UE receives the DCI and performs PUSCH transmission with a transmission rank that equals the number of indicated SRS resources (one PUSCH layer per SRS resource, or, equivalently, one PUSCH layer per SRS port).

[0012] CRI based CSI reporting

[0013] In New Radio (NR) up to Rel-18, when multiple CSI-RS resources are configured for channel measurement in a CSI report configuration for type I CB based CSI feedback, one of the CSI-RS resources is first selected by the UE and CSI associated with the selected CSI-RS resource is computed and reported. In this case, a CSI-RS resource indicator (CRI) is also reported to indicate the selected CSI-RS resource.

[0014] One use case of such CSI reporting is to support hybrid analog and digital beamforming due to hardware restrictions. For example, analog beam is implemented for elevation beamforming where multiple analog beams, one at a time, are formed in the elevation domain while within each of the analog beams, digital beamforming is performed in the azimuth direction. Another use case is to support hybrid time-domain and frequency-domain digital beamforming. For example, different elevation beams can be formed in digital time-domain, one in each time instant. For each such an elevation beam, frequency-domain digital beamforming can be performed in the azimuth direction.

[0015] An example is shown in Fig. 2, where four analog beams are formed in the elevation dimension. The four beams are transmitted at different time instances. Each of the analog beams is associated with a Non-Zero Power (NZP) CSI-RS resource comprising eight beamformed CSI- RS antenna ports. In this case, a UE measures downlink channels based on the four NZP CSI-RS resources and determines the best beam among the four beams. The CSI feedback comprises aCRI indicating the selected beam or the associated NZP CSI-RS resource, Rank indicator (RI), Precoding matrix indicator (PMI) and one or two Channel Quality Indicators (CQIs) associated with the NZP CSI-RS resource. The PMI indicates a precoding matrix for the beamformed antenna ports. Fig. 2 also shows, in the left-hand side, the gNB antennas and each of the analog beams in the elevation dimension being associated with a CSI-RS resource that comprises eight beamformed CSI-RS antenna ports.

[0016] In NR up to Rel 19, two, four or eight NZP CSI-RS resources can be configured for the purpose and up to eight CSI-RS ports per NZP CSI-RS resource can be configured. In addition, the total number of NZP CSI-RS antenna ports across all the configured NZP CSI-RS resources cannot exceed 32.

[0017] In NR Rel- 19, it has been agreed to enhance CRI based CSI reporting to support up to32 CSI-RS ports per CSI-RS resource. As part of this enhancement, it was agreed that the UE can be configured with K CSI-RS resources (where K is up to 8), and that the UE can be configured to report the CSI for M out of the K CSI-RS resources (where M can be up to 4). The purpose of introducing a scheme where the UE reports CSI for more than one CSI-RS resource (analog beam) is that it is useful for the network to have CSI for multiple different analog beams in order to facilitate simultaneous co-scheduling of UEs (since the network only can generate one analog beam at each time instance, the analog beam then needs to be shared across multiple UEs, and the more analog beams the network has CSI for from respective UEs, the easier it is for the network to find common analog beam to use for multiple UEs).

[0018] There currently exist certain challenge(s). One problem with using CRI based CSI reporting in DL (where one CSI-RS resource is transmitted per time domain / analog beam) in combination with NCB for UL, is that the CSI-RS resource used by the UE to determine a suitable UL channel for precoding the SRS resource is hardcoded in RRC (using the parameter associatedCSI-RS in SRS config IE as specified in TS 38.331 version 18.2.0), while which time domain / analog beam that the Transmission Reception Point (TRP) would like to use for UL reception of a specific UE can vary dynamically. For example, the time domain / analog beam used in UL for a specific UE can change when the UE moves around in the cell, when a path to the UE gets blocked, or depending on which other UEs the TRP would like to multiplex UL reception from the specific UE with (which is the reason why CRI based CSI reporting in NR introduced the possibility to configure the UE to report CSI for multiple time domain / analog beams for DL transmissions, where which time domain / analog TRP beams that the UE shall report CSI for is either explicitly indicated by the network and / or based on the highest estimated performance by the UE).

[0019] RRC-reconfiguration of the CSI-RS resource associated with the SRS when the UE changes the analog beam introduces high latency and overhead.

[0020] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.

[0021] For example, methods for signaling and configurations are proposed to dynamically indicate one or more CSI-RS resource(s) associated with hybrid beamforming at a TRP to be used for determining a UL channel, whose parameters are used for precoding SRS for NCB. Moreover, there are also provided methods to determine the gap period between the reception of a CSI-RS resource and the transmission of the corresponding SRS by the UE, when the UE is dynamically indicated about the CSI-RS resource(s) the UE should use to determine precoders to use for transmitting SRSs for the NCB operation.

[0022] As mentioned above, the problem to be solved is how to dynamically indicate to the UE which CSI-RS resource(s) the UE shall use to precode the SRSs for the NCB operation with low latency and overhead. This may be based on DCI or MAC CE indication. Moreover, methods are also provided for indicating the gap period and / or the reference time of the gap period between the reception of the CSI-RS resource(s) and the transmission of the corresponding SRS by the UE. Such a setup is of interest in cases with, e.g., large antenna arrays, hybrid beamforming and / or high mobility scenarios where the UE moves quickly in the cell area.

[0023] For example, there is provided a method in a wireless device. The method comprises: receiving a dynamic message, the dynamic message comprising an indication of an association between one or more CSI-RSs and one or more UL RSs for determining precoding information; receiving a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL RSs; and sending one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs. A wireless device for implementing this method is also provided.

[0024] Also, a method in a network node is provided. The method comprises: sending a dynamic message, to the wireless device, the dynamic message comprising an indication of an association between one or more CSI-RSs and one or more UL RSs for determining precoding information; sending a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL RSs; and receiving one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs. A network node for implementing this method is also provided.

[0025] Certain embodiments may provide one or more of the following technical advantage(s).

[0026] One advantage is that the UE can attain relevant CSI-RS resources for SRS transmission by reusing CSI-RS resources used for CRI based CSI reporting (hence without transmitting additional CSI-RS resource dedicated for NCB UL transmission, which would have required additional CSI-RS overhead). Moreover, the proposed schemes / embodiments guarantee the minimum gap period between the reception of CSI-RS resource(s) and the transmission of the corresponding SRS, which reduce the problem with channel aging with outdated CSI, which can significantly deteriorate performance for moving UEs. In this way, the proposed schemes address one of the issues in hybrid beamforming, which is of interest in both Rel-20 and 6G. This is particularly important because NCB-based operation is of interest in different cases, such as cases with hybrid beamforming, large antenna arrays and / or high mobility scenarios.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Exemplary embodiments will be described in more detail with reference to the following figures, in which:

[0028] Fig. 1 illustrates an example of a NCB-based precoding procedure.

[0029] Fig. 2 illustrates an example of a CSI report for hybrid beamforming with multiple NZP CSI-RS resources, one NZP CSI-RS resource per beam.

[0030] Fig. 3 illustrates a signal diagram of a communication procedure between a UE and a gNB, according to an embodiment.

[0031] Fig. 4 illustrates a flow chart of a method in a UE / wireless device, according to an embodiment.

[0032] Fig. 5 illustrates a flow chart of a method in a network node, according to an embodiment.

[0033] Fig. 6 shows an example of a communication system, according to an embodiment.

[0034] Fig. 7 shows another example of a communication system, according to an embodiment.

[0035] Fig. 8 shows a schematic diagram of a wireless device, according to an embodiment.

[0036] Fig. 9 shows a schematic diagram of a network node, according to an embodiment.

[0037] Fig. 10 illustrates a block diagram illustrating a virtualization environment.DETAILED DESCRIPTION

[0038] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0039] In the following, CSI-RS and SRS are used as the main DL-RS and UL-RS, respectively, defined in 5G. However, the proposed scheme / solution is applicable to other types of DL-RSs and UL-RSs that are considered in 5G / 6G.

[0040] As mentioned above, the gNB configures a set of CSI-RS resources for the UE, to measure on, for determining precoders or precoding matrices for the UL transmissions. One of the CSI-RS resources is associated with a SRS resource, which means that this CSI-RS resource is used to determine the precoding matrix for precoding the SRS that the UE sends to the gNB. As an example, referring to Fig. 2, the gNB can determine that beam #3 or CSI-RS #3 is associated with a SRS resource. This association is indicated in a RRC configuration, for example. When receiving beam #3, the UE can determine the precoders (e.g. UL precoders) based on beam 3# (or CSI-RS #3) to be used for sending the SRS to the gNB. However, when the UE moves (within the cell), it is possible that beam #3 becomes not suitable anymore for the UE to use for determining the UL precoders. In this case, if the gNB sends a RRC -reconfiguration to indicate another association between a CSI-RS resource and the SRS, it will introduce high latency and overhead. Therefore, a solution is needed, that does not introduce latency and overhead. For example, a solution may be to introduce a dynamic indication of the CSI-RS resource used for SRS precoding. Example embodiments are provided below.

[0041] For example, Fig. 3 illustrates a signal diagram of a communication procedure 100 between a UE 101 and a gNB 102, in the context of hybrid beamforming, for indicating a CSI-RS associated with a SRS, according to an embodiment. The communication procedure 100 comprises:

[0042] In step 105, the gNB sends a configuration of CSI-RS resources to the UE, e.g. the configuration may comprise a plurality of CSI-RS resources, with one CSI-RS resource associated with a SRS resource. The configuration is sent via higher layers (e.g. via RRC signalling). The gNB can send other configurations, of course, such as a configuration of the SRS resources.

[0043] In step 110, the gNB transmits the CSI-RSs to the UE, e.g. the gNB transmits a plurality of beams, each beam corresponding to a CSI-RS, for example. The CSI-RSs may be transmitted periodically or based on a trigger (e.g., initial access or mobility event). Also, each beam has an associated CSI-RS resource identifier, allowing the UE to differentiate between the beams.

[0044] In step 115, the UE measures the received beams / CSI-RSs and may select the strongest CSI-RS beam(s) based on different metrics, e.g., Reference Signal Received Power (RSRP), Signal-to-Interference-plus-Noise Ratio (SINR), Reference Signal Received Quality (RSRQ), CQI, etc.

[0045] After the UE selects the appropriate CSI-RS beam(s), it uses the associated beamforming / precoding information to precode its uplink SRS, in step 120.

[0046] In step 125, the UE sends the precoded SRS to the gNB. The precoded SRS is typically sent across the same bandwidth or subband as the CSI-RS to maintain consistency in channel estimation. The UE may also indicate the beam that was used to determine the precoding information to the gNB. This is the CRI -based CSI reporting.

[0047] Alternatively, among the received beams, in step 115, the UE measures the beam or corresponding CSI-RS beam that is indicated to be used for precoding a SRS, i.e. that is associated with the SRS.

[0048] In step 120, the UE can precode a SRS with precoding information determined based on the measured CSI-RS beam of step 115.

[0049] In step 125, the UE sends the precoded SRS to the gNB.

[0050] Then, in step 130, the TRP uses the received SRS to measure the UL channel characteristics, e.g., channel gain, phase, etc. and properly configure the analog beamformers and the digital precoding weights in the hybrid beamforming architecture.

[0051] The whole process / procedure may be performed once or iteratively.

[0052] In step 135, the UE moves around in the cell, for example.

[0053] In step 140, the gNB sends a DCI, comprising a bitfield to indicate one or more CSI-RS resources to be used for determining the UL precoders for the SRS (i.e. one or more CSI-RS resources associated with a SRS resource set). Instead of a DCI, the gNB can use a Medium Access Control (MAC) Control Element (CE) for transmitting the same information to the UE. Furthermore, the DCI / MAC CE can trigger the UE to send a SRS to the gNB. Also, the DCI / MAC CE may comprise other information, such as an indication of a gap reference for the gap period, as will be explained below.

[0054] Upon receipt of the DCI or MAC-CE, the UE can perform the same actions as in steps 110-125.

[0055] And if the UE moves again, then, the gNB can send another DCI / MAC-CE for indicating other CSI-RS resources for determining the UL precoders.

[0056] In the following, some examples of indications of CSI-RS resource(s) associated with the SRS resources are provided.

[0057] In some examples, it is assumed that the indicated CSI-RS resource associated with anSRS resource set used for the NCB operation (or similar reciprocity-based UL transmission scheme in 6G) is associated with an CSI-RS resource set used for CRI-based CSI reporting.

[0058] In one example, the UE should use a specific CSI-RS resource included in a CRI-basedCSI report (for example, the last transmitted CRI-based CSI report by that UE before the SRS transmission) to precode the SRSs for the NCB operation. Such a predefined rule needs to be captured in the specification. As such, the DCI can indicate to the UE to use the CSI-RS resource provided / determined in its last CRI-based CSI report. For example, the CSI-RS resource in the CRI-based CSI report that the UE should use to precode the SRSs can be determined by using one of the following methods:

[0059] - The CSI-RS resource with the highest reported CQI in the CRI-based CSI report; or

[0060] - The CSI-RS resource located in a specific location in the CRI-based CSI report (e.g. the first CRI in the CRI-based CSI report).

[0061] It should be noted that it is important that the TRP knows which CSI-RS resource (i.e. which time domain / analog TRP beam) the UE uses to precode the SRSs with, since the TRP typically needs to use one time domain / analog beam when receiving the SRS and associated PUSCH, and if there is a mis-match between the time domain / analog beam that the UE uses to precode the SRS and the time domain / analog beam the network uses to receive the corresponding SRS / PUSCH, there will be a significant degradation in performance.

[0062] In one example, the network (e.g. gNB) dynamically indicates using, e.g. DCI, which CSI-RS resource in a set of CSI-RS resources (e.g. where the set of CSI-RS resources are the CSI- RS resources used for CRI-based CSI reporting) that the UE should use when determining the precoders for the SRSs for the NCB operation. For example, a new bitfield is introduced in a DCI (e.g. the DCI that can trigger an aperiodic SRS transmission), and where the size of the bitfield is equal to 21og(N), where, e.g., N is equal to the number of CSI-RS resources in a set of CSI-RS resources (e.g. where the set of CSI-RS resources are the CSI-RS resources used for CRI-based CSI reporting).

[0063] In one example, the network can indicate multiple CSI-RS resources to be used to determine SRSs precoding for the NCB operation, and where the UE should transmit one separate set of SRSs for each indicated CSI-RS resource (which could be used to facilitate multiplexing of multiple UEs in UL as described before). In this case, for example, a new bitfield is introduced in a DCI triggering an aperiodic SRS transmission, and where the size of the bitfield is equal to N, where, e.g., N is equal to the number of CSI-RS resources in a set of CSI-RS resources (e.g. where the set of CSI-RS resources are the CSI-RS resources used for CRI-based CSI reporting), and where each of the N bits indicates if the UE should use the corresponding CSI-RS resource to precode a set of SRSs for the NCB operation or not.

[0064] In some examples, the dynamic indication of which CSI-RS resource(s) that a UE shall use to precode SRSs for the NCB operation is done by MAC-CE signaling instead of DCI. It should be understood that other dynamic signalings as known in the art could be used as well.

[0065] In NR, there is a gap period defined, indicating the minimum time required by the UE between a received CSI-RS resource (which is the reference time of the gap period) and the corresponding SRS transmission for the NCB operation (where the purpose of the gap period is to give the UE time to process the CSI-RS resource and calculate suitable precoders for the SRSs). That is, the gap period defines the minimum time interval between the reception of a CSI-RS resource and the transmission of the corresponding SRS by the UE. In NR, the gap period is indicated through RRC signaling. In some of the examples described above where the UE is configured with a set of candidate CSI-RS resources that can be used to determine the precoder for SRSs for NCB, it is unclear how to define the reference time of the gap period (e.g., which CSI-RS resource the reference time is associated with). In one example, the reference time of the gap period is based on the last CSI-RS resource (in the set of CSI-RS resources) received by the UE. In one example, the reference time of the gap period is based on the last received CSI-RS resource of the CSI-RS resource(s) that was indicated to be used for the corresponding SRS transmission (which will reduce the delay of when the SRS can be transmitted compared to the previous example, which will improve the performance). Such pre-defined rules need to be captured in the specification. In another example, the UE is informed jointly about which CSI-RS resources are relevant for precoding the SRS resources and the required gap period / reference time of the gap period. The DCI or MAC CE can indicate the gap period and / or reference time of the gap period to the UE. The same dynamic message (DCI or MAC CE) can have both indications (e.g. the reference time of the gap period and the CSI-RS resource associated with the SRS). Or alternatively, 2 separate dynamic messages can be sent to the UE, a first one containing the indication of the CSI-RS resource associated with the SRS and a second one containing the indication of the gap period / reference time of the gap period.

[0066] The proposed schemes herein enable to dynamically indicate the UE which CSI-RS resource(s) the UE shall use to precode SRSs for the NCB operation with low latency and overhead. Such an approach, which is of interest in cases with, e.g., large arrays, hybrid beamforming and / or high mobility, addresses one of the topics of interest in Rel-20 and 6G.

[0067] Now turning to Fig. 4, an example of a flow chart of a method 200 in a wireless device for communicating with a network node will be described. The wireless device can be the UE 101 of Fig. 3, the UE 612 of Fig. 6 and the UE 800 of Fig. 8. The network node can be a gNB or a TRPcomprises:

[0068] Step 210: receiving a dynamic message, the dynamic message comprising an association between one or more CSI-RSs and one or more UL reference signals for determining precoding information;

[0069] Step 220: receiving a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL reference signals;

[0070] Step 230: sending one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

[0071] In some examples, the one or more UL RSs comprise one or more SRSs. In some examples, the wireless device can receive a RRC configuration of a plurality of CSI-RS resources for carrying the plurality of CSI-RSs. In some examples, the one or more CSI-RSs associated with the one or more UL RSs are indicated in a CSI report previously transmitted by the wireless device. In some examples, one of the one or more CSI-RSs associated with the one or more UL reference signals is a CSI-RS with a highest reported CQI. In some examples, one of the one or more CSI- RSs associated with the one or more UL reference signals is located in a specific location in a CSI report. In some examples, the dynamic message is DCI or MAC CE. In some examples, the DCI or MAC CE comprises a bitfield to indicate one of the one or more CSI-RSs associated with the one or more UL RSs. In some examples, a size of the bitfield is equal to 21og(N), where N is equal to the number of CSI-RSs in the plurality of CSI-RSs. In some examples, the dynamic message comprises a bitfield to indicate more than one CSI-RSs. In some examples, a size of the bitfield is equal to N, where N is equal to the number of CSI-RSs in the plurality of CSI-RSs and where each of the N bits indicates if the wireless device should use a corresponding CSI-RS to determine information to precode one or more UL RSs. In some examples, the dynamic message further comprises an indication of a reference time for a gap period. Alternatively, the wireless device can receive another dynamic message, which comprises an indication of a reference time for a gap period. In some examples, the indicated reference time is based on a last received CSI-RS of the plurality of CSI-RSs. In some examples, the indicated reference time is based on a last received CSI-RS of the plurality of CSI-RSs, that was indicated to be associated with one or more UL RSs. In some examples, the one or more UL reference signals are used for reciprocity based UL transmission of PUSCH.

[0072] Fig. 5 illustrates an example flow chart of a method 300 in a network node for communicating with a wireless device. The wireless device can be the UE 101 of Fig. 3, the UE612 of Fig. 6 and the UE 800 of Fig. 8. The network node can be a gNB or a TRP 102 of Fig. 3, the network node 610 of Fig. 6 and the network node 900 of Fig. 9. Method 300 comprises:

[0073] Step 310: sending a dynamic message to the wireless device, the dynamic message comprising an indication of an association between one or more Channel State Information (CSI) reference signals (RSs) and one or more uplink (UL) reference signals for determining precoding information;

[0074] Step 320: sending a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL RSs;

[0075] Step 330: receiving one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

[0076] In some examples, the one or more UL reference signals comprise one or more SRSs. In some examples, the network node can send a RRC configuration of a plurality of CSI-RS resources for carrying the plurality of CSI-RSs. In some examples, the one or more CSI-RSs associated with the one or more UL reference signals are indicated in a CSI report previously transmitted by the wireless device. In some examples, one of the one or more CSI-RSs associated with the one or more UL reference signals is a CSI-RS with a highest reported CQI. In some examples one of the one or more CSI-RSs associated with the one or more UL reference signals is located in a specific location in a CSI report. In some examples the dynamic message is DCI or MAC CE. In some examples, the DCI or MAC CE comprises a bitfield to indicate one of the one or more CSI-RSs associated with the one or more UL RSs. In some examples, a size of the bitfield is equal to 21og(N), where N is equal to the number of CSI-RSs in the plurality of CSI-RSs. In some examples, the dynamic message comprises a bitfield to indicate more than one CSI-RSs. In some examples, a size of the bitfield is equal to N, where N is equal to the number of CSI-RSs in the plurality of CSI-RSs and where each of the N bits indicates if the wireless device should use a corresponding CSI-RS to determine information to precode one or more UL RSs. In some examples, the dynamic message further comprises an indication of a reference time for a gap period. Alternatively, the network node can send another dynamic message, which comprises an indication of a reference time for a gap period. In some examples, the indicated reference time is based on a last transmitted CSI-RS of the plurality of CSI-RSs. In some examples, the indicated reference time is based on a last transmitted CSI-RS of the plurality of CSI-RSs, that was indicated to be associated with one or more UL RSs. In some examples, the one or more UL reference signals are used for reciprocity based UL transmission of PUSCH.

[0077] In another embodiment, the association between one or more CSI-RSs and one or moreUL RSs can be done implicitly. For example, the UE can obtain a CSI-RS associated with a SRSfrom a previous CSI report or a rule from its memory, the rule related to the association of the CSI- RS and SRS. As such, there can be provided a method, in a wireless device, the method comprising: obtaining an indication of an association between one or more Channel CSI-RSs and one or more UL RSs for determining precoding information, wherein the indication of the association is from a CSI report; receiving a plurality of CSI-RSs, the plurality of CSI-RSs comprising the one or more CSI-RSs associated with the one or more UL RSs; and sending one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

[0078] Fig. 6 shows an example of a communication system 600 in accordance with some embodiments.

[0079] In the example, the communication system 600 includes a telecommunications network 602 that includes an access network 604, such as a radio access network (RAN), and a core network 606, which includes one or more core network nodes 608. The access network 604 includes one or more access network nodes or base stations of various types, access network nodes 610A and 610B are depicted (which may be collectively referred to as network nodes 610), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points (APs). Some embodiments of the access network 604 may include more than one access network technology. The network nodes 610 of access network 604 facilitate direct or indirect connection of wireless devices, also referred to as UEs, such as by connecting UEs 612A, 612B, 612C, and 612D (one or more of which may be generally referred to as UEs 612 to the core network 606 over one or more wireless connections.

[0080] Moreover, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunications network 602 includes one or more Open- RAN (ORAN) network nodes. An ORAN network node is a network node in the telecommunications network 602 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other network nodes to implement one or more functionalities of any network node in the telecommunications network 602, including one or more access network nodes 610 and / or core network nodes 608.

[0081] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-realtime) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). An ORAN network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN network node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies.

[0082] The network nodes 610 facilitate direct or indirect connection of one or more UEs 612 to the core network 606 over one or more wireless connections. Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 600 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 600 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0083] The UEs 612 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 610 and other communication devices. Similarly, the network nodes 608, 610 are arranged, capable, configured, and / or operable to communicate directly or indirectly (e.g., via other devices of telecommunications network 602) with the UEs 612 and / or with other network nodes or equipment in the telecommunications network 602 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunications network 602. More specifically, UEs 612 may send messages, data, and / or other signals to network nodes 608, 610 or other elements of the telecommunications network 602 by transmitting such signals to the relevant device directly without the signals passing through any intervening devices or by transmitting such signals to the relevant device indirectly through an intervening device (or multiple intervening devices) that then transmit the signal to therelevant device. Similarly, network nodes 608, 610 may send messages, data, and other signals to UEs 6122, other network nodes 608, 610, and other devices in telecommunications network 602 directly or indirectly. As one specific example, a core network node 108 may transmit a particular message to a UE 612 by transmitting the message to an access network node 610 that will then transmit the message to the intended UE 612. Similarly, a core network node 108 may receive a particular message from a UE 612 by receiving the message from an access network node 610 that itself received the message from the UE 612.

[0084] In the depicted example, the core network 606 connects elements of the access network604 (e.g., one or more of the network nodes 610) to one or more host computing systems, such as host 616. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 606 includes one or more core network nodes (e.g., core network node 608) of various types, one or more of which may be generally referred to as network nodes 608. Network nodes 608 are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, access network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 608. Example core network nodes provide functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0085] The host 616 may be under the ownership or control of a service provider other than an operator or provider of the access network 604 and / or the telecommunications network 602. The host 616 may be operated by the service provider or on behalf of the service provider. The host 616 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0086] As a whole, the communication system 600 of Fig. 6 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 600 may be configured to operate according to predefined rules or procedures, such as specific standards that include, butare not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Uong Term Evolution (UTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802. 11 standards (Wi-Fi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (Wi-Max), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, Li-Fi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. Moreover, the communication system 600 may be configured to support multiple different standards, protocols, or other rule sets, with individual components supporting all of the relevant rule sets or with different components or sub-systems within the communication system 600 supporting different standards, protocols, or rule sets.

[0087] As one example, in certain embodiments, access network 604 may contain some access network nodes 610 that support 3GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 610 support (or the same access network nodes 610 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, telecommunications network 602 may support multiple generations of related communication standards (e.g., 4G and 5G 3GPP communication standards) and, as a result, may include an access network 104 and / or a core network 106 that supports multiple different standard generations or may include multiple access networks 104 and / or multiple core networks 106 with individual networks 104, 106 supporting different standard generations.

[0088] Telecommunications network 602 may support network slicing to provide different logical networks to different devices that are connected to the telecommunications network 602. For example, the telecommunications network 602 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0089] In some examples, one or more of the UEs 612 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 604 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 604. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) NR - Dual Connectivity (EN-DC).

[0090] In the example, the hub 614 communicates with the access network 604 to facilitate indirect communication between one or more UEs (e.g., UE 612C and / or 612D) and network nodes (e.g., network node 61 OB). In some examples, the hub 614 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 614 may be a broadband router enabling access to the core network 606 for the UEs. As another example, the hub 614 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 610, or by executable code, script, process, or other instructions in the hub 614.

[0091] As another example, the hub 614 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 614 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 614 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 614 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 614 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0092] The hub 614 may have a constant / persistent or intermittent connection to the network node 610B. The hub 614 may also allow for a different communication scheme and / or schedule between the hub 614 and UEs (e.g., UE 612C and / or 612D), and between the hub 614 and the core network 606. In other examples, the hub 614 is connected to the core network 606 and / or one or more UEs via a wired connection. Moreover, the hub 614 may be configured to connect to an M2M service provider over the access network 604 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 610 while still connected via the hub 614 via a wired or wireless connection. In some embodiments, the hub 614 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 610B. In other embodiments, the hub 614 may be a nondedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 610B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0093] Fig. 7 is another example of a communication system 700 according to some embodiments. As used herein, the communication system 700 includes multiple access points (APs) 710 (with four exemplary APs 710A, 710B, 710C, and 710D being depicted) and multiple wireless devices, referred to in the context of communication system 700 as stations (STAs) 712(referred to individually as STA 712A, STA 712B, STA 712C, STA 712D, and STA 712E). STA 712A is served by AP 710A in a first basic service set (BSS) 720A. STA 710B and STA 710C are served by AP 710B in a second BSS, BSS 720B. STA 712D is served by AP 710C in athird BSS, BSS 720C. STA 712E is served by AP 710D in a fourth BSS, BSS 720D. Stations 712 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like. Further, stations 712 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0094] Each of STAs 712 may connect through a radio link to one of APs 710. For example, depending on location or channel conditions experienced by a given STA 712, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0095] Each AP 710 may provide data connectivity to STAs 712 connected to a particular AP710. As illustrated, APs 710 may be connected to a data network 730. In this way, APs 710 may also provide data connectivity between STAs 712 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like. Accordingly, the radio link established between a given STA 712 and its serving AP 710 may be used for providing various kinds of services to STA 712, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 712 and / or on a device linked to STA 712. By way of example, Figure 7 illustrates an application service platform 732 provided in data network 730. The application(s) executed on STA 712 and / or on one or more other devices linked to STA 712 may use the radio link for data communication with one or more other STA 712 and / or the application service platform 732, thereby enabling utilization of the corresponding service(s) at STA 712.

[0096] Fig. 8 shows a wireless device 800, which may be configured to operate in communication system 600 of Figure 6 or in communication system 700 of Fig. 7. The wireless device 800 may be alternatively referred to as a UE 800, like a UE 612 within the context of communication system 600, or as a station (STA) 800 or as a non-access-point station (non-AP STA) 800, like a STA 712 within the context of the communication system 700, in accordancewith respective embodiments. As used herein, a wireless device refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Examples of a wireless device include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, and wireless terminal. Other examples include any type of UE identified by the 3GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0097] A wireless device 800 may support device -to-de vice (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to- everything (V2X). In other examples, wireless device 800 may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, wireless device 800 may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, wireless device 800 may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0098] In particular embodiments, wireless device 800 includes processing circuitry 802 that is operatively coupled via a bus 804 to an input / output interface 806, a power source 808, a memory 810, a communication interface 812, and / or any other component, or any combination thereof. Certain embodiments of wireless device 800 may include all or a subset of the components shown in Fig. 8. The level of integration between the components may vary from one embodiment of wireless device 800 to another. In general, in a particular embodiment of wireless device 800, processing circuitry 802, input / output interface 806, power source 808, memory 810, and communication interface 812 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of wireless device 800. Further, certain embodiments of wireless devices 800 may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0099] The processing circuitry 802 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored asmachine-readable computer programs in the memory 810. The processing circuitry 802 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 802 may include multiple central processing units (CPUs). Furthermore, the processing circuitry 802 may be configured to perform any steps of method 200 of Fig. 4.

[0100] In the example, the input / output interface 806 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into wireless device 800. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0101] In some embodiments, the power source 808 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used to supply power to circuitry or to charge an associated battery. The power source 808 may further include power circuitry for delivering power from the power source 808 itself, and / or an external power source, to the various parts of wireless device 800 via input circuitry or an interface such as an electrical power cable. Power source 808 may perform any formatting, converting, or other modification to make accessible power suitable for the respective components of the wireless device 800 to which power is supplied.

[0102] The memory 810 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 810 includes one or more programs 814, such as an operating system, web browser application, a widget, gadget engine, orother application, and corresponding data 816. The memory 810 may store, for use by wireless device 800, any of a variety of various operating systems or combinations of operating systems.

[0103] The memory 810 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 810 may allow wireless device 800 to access instructions, programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 810, which may be or comprise a device-readable storage medium.

[0104] The processing circuitry 802 may be configured to communicate with an access network or other network via or using the communication interface 812. The communication interface 812 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 822. The communication interface 812 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another wireless device or a network node in an access network). Each transceiver may include a transmitter 818 and / or a receiver 820 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 818 and receiver 820 may be coupled to one or more antennas (e.g., antenna 822) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0105] In the illustrated embodiment, communication functions of the communication interface 812 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocolsand / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0106] In particular embodiments, wireless device 800 may provide an output of data captured via a sensor, through its communication interface 812, via a wireless connection to a network node, and / or in any appropriate manner. Data captured by sensors of a wireless device 800 can be communicated through a wireless connection to a network node via another wireless device 800. In particular embodiments, such output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0107] As another example, wireless device 800 comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, wireless device 800 may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0108] Wireless device 800, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. In particular embodiments, wireless device 800 represents an loT device that comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the example embodiment of wireless device 800 shown in Fig. 8.

[0109] As yet another specific example, in an loT scenario, wireless device 800 may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another wireless device and / or a network node. Wireless device 800 may in this case be an M2M device, which may in a 3GPP context be referredto as an MTC device. As one particular example, wireless device 800 may implement the 3GPP NB-IoT standard. In other scenarios, wireless device 800 may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0110] In practice, any number of wireless devices 800 may be used together with respect to a single use case. For example, a first wireless device 800 might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second wireless device 800 that is a remote controller operating the drone. When a user makes changes from the remote controller, the first wireless device 800 may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second wireless device 800 can also include more than one of the functionalities described above. For example, wireless device 800 might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0111] Fig. 9 shows a network node 900 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunications network. In accordance with respective embodiments, network node 900 may be configured to operate in communication system 600 of Fig. 6, like network nodes 608 or 610, or in communication system 700 of Figure 7, like an AP 710 or a station 712. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs (NBs), evolved NBs (eNBs) and NRNBs (gNBs)), TRPs, O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0112] Network nodes 900 may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. Network node 900 may be a relay node or a relay donor node controlling a relay. Network nodes 900 may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0113] Other examples of network nodes 900 include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllerssuch as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi -cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0114] In particular embodiments, network node 900 includes a processing circuitry 902, a memory 904, a communication interface 906, and a power source 908. In general, in a particular embodiment of network node 900, processing circuitry 902, memory 904, communication interface 906, and power source 908 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of network node 900.

[0115] The network node 900 may be composed of multiple distinct network entities (e.g., a NB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 900 comprises multiple such entities (e.g., BTS and BSC), one ormore of the separate entities may be shared among several network nodes. For example, a single RNC may control multiple NBs. In such a scenario, each unique NB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 900 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 904 or portions of memory 904 for different RATs) and some components may be reused (e.g., a same antenna 910 may be shared by different RATs). The network node 900 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 900, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 900.

[0116] The processing circuitry 902 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other components, such as the memory 904, to provide network node 900 functionality.

[0117] In some embodiments, the processing circuitry 902 includes a system on a chip (SOC). In some embodiments, the processing circuitry 902 includes one or more of radio frequency (RF)transceiver circuitry 912 and baseband processing circuitry 914. In some embodiments, the RF transceiver circuitry 912 and the baseband processing circuitry 914 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 912 and baseband processing circuitry 914 may be on the same chip or set of chips, boards, or units. Furthermore, the processing circuitry 902 may be configured to perform any steps of method 300 of Fig. 5.

[0118] The memory 904 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 902. The memory 904 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 902 and utilized by the network node 900. The memory 904 may be used to store any calculations made by the processing circuitry 902 and / or any data received via the communication interface 906. In some embodiments, the processing circuitry 902 and memory 904 is integrated.

[0119] The communication interface 906 is used in wired or wireless communication of signaling and / or data with UEs, other network nodes, and / or any other network equipment. In the illustrated embodiment, communication interface 906 comprises port(s) / terminal(s) 916 to send and receive data, for example to and from a network over a wired connection. In particular embodiments, network node 800 may be capable of wireless communication and communication interface 906 may also include radio front-end circuitry 918 that may be coupled to, or in certain embodiments a part of, an antenna 910. Particular embodiments of radio front-end circuitry 918 include filter(s) 920 and amplifier(s) 922. The radio front-end circuitry 918 may be connected to an antenna 910 and processing circuitry 902. The radio front-end circuitry may be configured to condition signals communicated between antenna 910 and processing circuitry 902. The radio front-end circuitry 918 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 918 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 920 and / or amplifiers 922. The radio signal(s) may then be transmitted via the antenna 910. Similarly, when receiving data, the antenna 910 may collect radio signals which are then convertedinto digital data by the radio front-end circuitry 918. The digital data may be passed to the processing circuitry 902. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0120] In certain alternative embodiments, network node 900 may be capable of wireless communication but does not include separate radio front-end circuitry 918, instead, the processing circuitry 902 includes radio front-end circuitry and is connected to the antenna 910. Similarly, in some embodiments, all or some of the RF transceiver circuitry 912 is part of the communication interface 906. In still other embodiments, the communication interface 906 includes one or more ports or terminals 916, the radio front-end circuitry 918, and the RF transceiver circuitry 912, as part of a radio unit (not shown), and the communication interface 906 communicates with the baseband processing circuitry 914, which is part of a digital unit (not shown).

[0121] The antenna 910 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 910 may be coupled to the radio front-end circuitry 918 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 910 is separate from the network node 900 and connectable to the network node 900 through one or more interfaces or ports.

[0122] The antenna 910, communication interface 906, and / or the processing circuitry 902 may be configured to perform some or all of the receiving operations and / or obtaining operations described herein as being performed by the network node 900. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 910, the communication interface 906, and / or the processing circuitry 902 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the network node 900. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0123] The power source 908 provides power to the various components of network node 900 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 908 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 900 with power for performing the functionality described herein. For example, the network node 900 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 908. As a further example, the power source 908 may comprise a source of power in the form of a battery or battery pack which is connected to, orintegrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0124] Embodiments of the network node 900 may include additional components beyond those shown in Figure 9 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 900 may include user interface equipment to allow input of information into the network node 900 and to allow output of information from the network node 900. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 900.

[0125] Fig. 10 is a block diagram illustrating a virtualization environment 1000 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1000 hosted by one or more of hardware nodes, such as a hardware computing device that operates as an access network node, UE, core network node, or host. Further, in embodiments in which a virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1000 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[0126] Applications 1002 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0127] Hardware 1004 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1006 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VM 1008A and VM 1008B (which may be collectively referred to as VMs 1008), and / or perform any of the functions,features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1006 may present a virtual operating platform that appears like networking hardware to one or more of the VMs 1008.

[0128] The VMs 1008 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by virtualization layer 1006. Different embodiments of the instance of a virtual appliance 1002 may be implemented on one or more of VMs 1008, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0129] In the context of NFV, each of the VMs 1008 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1008, and that part of hardware 1004 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more of the VMs 1008 on top of the hardware 1004 and corresponds to an application 1002.

[0130] Hardware 1004 may be implemented in a standalone network node with generic or specific components. Hardware 1004 may implement some functions via virtualization. Alternatively, hardware 1004 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1010, which, among others, oversees lifecycle management of applications 1002. In some embodiments, hardware 1004 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1012 which may alternatively be used for communication between hardware nodes and radio units.

[0131] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or softwareneeded to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0132] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0133] The above-described embodiments are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the description.

Claims

CLAIMS1. A method (200) performed by a wireless device (101, 612, 800) for communicating with a network node (102, 610, 900), the method comprising:- receiving (210) a dynamic message, the dynamic message comprising an indication of an association between one or more Channel State Information (CSI) reference signals (RSs) and one or more uplink (UL) reference signals, for determining precoding information;- receiving (220) a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL reference signals; and- sending (230) one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

2. The method of claim 1, wherein the one or more UL reference signals comprise one or more Sounding Reference Signals (SRSs).

3. The method of any one of claims 1 to 2, further comprising receiving a Radio Resource Control (RRC) configuration of a plurality of CSI-RS resources for carrying the plurality of CSI- RSs.

4. The method of any one of claims 1 to 3, wherein the one or more CSI-RSs associated with the one or more UL reference signals are indicated in a CSI report previously transmitted by the wireless device.

5. The method of any one of claims 1 to 4, wherein one of the one or more CSI-RSs associated with the one or more UL reference signals is a CSI-RS with a highest reported Channel Quality Indicator (CQI).

6. The method of any one of claims 1 to 5, wherein one of the one or more CSI-RSs associated with the one or more UL reference signals is located in a specific location in a CSI report.

7. The method of any one of claims 1 to 6, wherein the dynamic message is Downlink Control Information (DCI) or Medium Access Control (MAC) Control Element (CE).

8. The method of claim 7, wherein the DCI or MAC CE comprises a bitfield to indicate one of the one or more CSI-RSs associated with the one or more UL RSs.

9. The method of claim 8, wherein a size of the bitfield is equal to 21og(N), where N is equal to the number of CSI-RSs in the plurality of CSI-RSs.

10. The method of any one of claims 1 to 7, wherein the dynamic message comprises a bitfield to indicate more than one CSI-RSs.

11. The method of claim 10, wherein a size of the bitfield is equal to N, where N is equal to the number of CSI-RSs in the plurality of CSI-RSs and where each of the N bits indicates if the wireless device should use a corresponding CSI-RS to determine information to precode one ormore UL RSs.

12. The method of any one of claims 1 to 11, wherein the dynamic message further comprises an indication of a reference time for a gap period.

13. The method of any one of claims 1 to 11, further comprising receiving another dynamic message, which comprises an indication of a reference time for a gap period.

14. The method of claim 12 or 13, wherein the indicated reference time is based on a last received CSI-RS of the plurality of CSI-RSs.

15. The method of claim 12 or 13, wherein the indicated reference time is based on a last received CSI-RS of the plurality of CSI-RSs, that was indicated to be associated with one or more UL RSs.

16. The method of any one of claims 1 to 15, wherein the one or more UL reference signals are used for reciprocity based UL transmission of Physical Uplink Shared Channel (PUSCH).

17. A method (300) performed by a network node (102, 610, 900) for communicating with a wireless device (101, 612, 800), the method comprising:- sending (310) a dynamic message, to the wireless device (101, 612, 800), the dynamic message comprising an indication of an association between one or more Channel State Information (CSI) reference signals (RSs) and one or more uplink (UL) reference signals for determining precoding information;- sending (320) a plurality of CSI-RSs, the plurality of CSI- RSs comprising the one or more CSI-RSs associated with the one or more UL RSs; and- receiving (330) one or more UL reference signals using the precoding information determined based on the associated one or more CSI-RSs.

18. The method of claim 17, wherein the one or more UL reference signals comprise one or more Sounding Reference Signals (SRSs).

19. The method of any one of claims 17 to 18, further comprising sending a Radio Resource Control (RRC) configuration of a plurality of CSI-RS resources for carrying the plurality of CSI- RSs.

20. The method of any one of claims 17 to 19, wherein the one or more CSI-RSs associated with the one or more UL reference signals are indicated in a CSI report previously transmitted by the wireless device.

21. The method of any one of claims 17 to 20, wherein one of the one or more CSI-RSs associated with the one or more UL reference signals is a CSI-RS with a highest reported Channel Quality Indicator (CQI).

22. The method of any one of claims 17 to 21, wherein one of the one or more CSI-RSs associated with the one or more UL reference signals is located in a specific location in a CSI report.

23. The method of any one of claims 17 to 22, wherein the dynamic message is Downlink Control Information (DCI) or Medium Access Control (MAC) Control Element (CE).

24. The method of claim 23, wherein the DCI or MAC CE comprises a bitfield to indicate one of the one or more CSI-RSs associated with the one or more UL RSs.

25. The method of claim 24, wherein a size of the bitfield is equal to 21og(N), where N is equal to the number of CSI-RSs in the plurality of CSI-RSs.

26. The method of any one of claims 17 to 23, wherein the dynamic message comprises a bitfield to indicate more than one CSI-RSs.

27. The method of claim 26, wherein a size of the bitfield is equal to N, where N is equal to the number of CSI-RSs in the plurality of CSI-RSs and where each of the N bits indicates if the wireless device should use a corresponding CSI-RS to determine information to precode one or more UL RSs.

28. The method of any one of claims 17 to 27, wherein the dynamic message further comprises an indication of a reference time for a gap period.

29. The method of any one of claims 17 to 27, further comprising sending another dynamic message, which comprises an indication of a reference time for a gap period.

30. The method of claim 28 or 29, wherein the indicated reference time is based on a last transmitted CSI-RS of the plurality of CSI-RSs.

31. The method of claim 28 or 29, wherein the indicated reference time is based on a last transmitted CSI-RS of the plurality of CSI-RSs, that was indicated to be associated with one or more UL RSs.

32. The method of any one of claims 17 to 31, wherein the one or more UL reference signals are used for reciprocity based UL transmission of Physical Uplink Shared Channel (PUSCH).

33. A wireless device (101, 612, 800) for communicating with a network node, comprising: processing circuitry (802) configured to perform the method of any one of claims 1 to 16; and a power source (808) configured to supply power to the processing circuitry.

34. A network node (102, 610, 900) for communicating with a wireless device, the network node comprising: processing circuitry (902) configured to perform the method of any one of claims 17 to 32; a power source circuitry (908) configured to supply power to the processing circuitry.

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