A method and apparatus for configuring resource mapping of dynamic channel state information reference signals

Abstract

Systems, methods, apparatuses, and computer program products are provided for dynamic and partial sharing of downlink (DL) reference signal (RS) resources for channel measurement.

Description

Technical Field

[0001] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE) or Fifth Generation (5G) radio access technology or New Radio (NR) access technology, or may relate to other communication systems. For example, certain embodiments may relate to systems and / or methods for dynamic and partial sharing of downlink (DL) reference signal (RS) resources for channel measurement. Background Art

[0002] Examples of mobile or wireless telecommunication systems may include Universal Mobile Telecommunication System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), Advanced LTE (LTE-A), MulteFire, LTE-A Pro, and / or Fifth Generation (5G) radio access technology or New Radio (NR) access technology. 5G wireless systems refer to the Next Generation (NG) radio systems and network architectures. 5G systems are mainly built on 5G New Radio (NR), but 5G (or NG) networks can also be built on E-UTRA radio. It is estimated that NR provides a bit rate of 10 - 20 Gbit / s or higher, and can support at least service categories such as enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) as well as massive machine type communication (mMTC). NR is expected to provide ultra-wideband and ultra-robust low-latency connections and large-scale networks to support the Internet of Things (IoT). As IoT and machine-to-machine (M2M) communications become more and more common, the need for networks that can meet the requirements of low power consumption, low data rate, and long battery life will continue to grow. Next Generation Radio Access Network (NG-RAN) represents the RAN of 5G, which can provide both NR and LTE (and Advanced LTE) radio access. Note that in 5G, a node that can provide radio access function to a user equipment (UE) (i.e., similar to Node B, NB in UTRAN or evolved NB, eNB in LTE) can be named as Next Generation NB (gNB) when built on NR radio, and can be named as Next Generation eNB (NG-eNB) when built on E-UTRA radio. Brief Description of the Drawings

[0003] To correctly understand the example embodiments, reference should be made to the drawings, in which:

[0004] Figure 1 Examples of NZP-CSI-RS resources and CSI-RS resource mapping information elements (IE) are shown;

[0005] Figure 2 An example resource mapping configuration is shown;

[0006] Figure 3 Some examples of three possible configurations of CSI-RS resource mapping for eight antenna ports are shown;

[0007] Figure 4a An example of a ZP-CSI-RS resource information element is shown;

[0008] Figure 4b An example of a CSI-IM resource information element is shown;

[0009] Figure 5 An example of using static beams to statically share CSI-RS resources according to an example is shown;

[0010] Figure 6a A table showing an example depicting four UEs partially sharing virtual antenna ports according to an example embodiment is shown;

[0011] Figure 6b An example showing four UEs sharing ten unique beams with UE-specific mapping according to an example embodiment is shown;

[0012] Figure 7a An example flowchart of a method according to an embodiment is shown;

[0013] Figure 7b An example flowchart of a method according to an embodiment is shown;

[0014] Figure 8 Examples of different configurations of frequencyDomainAllocation in RRC according to an example embodiment are shown;

[0015] Figure 9a An example flowchart of a method according to an embodiment is shown;

[0016] Figure 9b An example flowchart of a method according to an embodiment is shown;

[0017] Figure 10a An example block diagram of a device according to an embodiment is shown; and

[0018] Figure 10b An example block diagram of a device according to an embodiment is shown. Detailed Description

[0019] It will be readily appreciated that components of certain example embodiments, as generally described and illustrated in the figures herein, can be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of some example embodiments of a system, method, apparatus, and computer program product for dynamic and partial sharing of channel measurement downlink (DL) reference signal (RS) resources is not intended to limit the scope of certain embodiments, but rather represents selected example embodiments.

[0020] Features, structures, or characteristics of the example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the use of the phrases "certain embodiments", "some embodiments", or other similar language throughout this specification means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Thus, the appearances of the phrases "in certain embodiments", "in some embodiments", "in other embodiments", or other similar language throughout this specification are not necessarily all referring to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments.

[0021] Additionally, if desired, the different functions or processes discussed below can be performed in a different order and / or simultaneously with each other. Further, if desired, one or more of the described functions or processes may be optional or may be combined. Accordingly, the following description should be regarded as illustrative of the principles and teachings of certain example embodiments and not as limiting thereof.

[0022] The expected significant gains of massive multiple-input multiple-output (MIMO) depend at least in part on reliable channel state information (CSI) knowledge of the downlink (DL) channel at the network node (e.g., gNB) side. This is needed to be able to design appropriate DL precoders, perform scheduling, etc.

[0023] In a frequency-division duplex (FDD) 5G system, the gNB obtains DL channel information from UE CSI reports. The UE measures the downlink reference signals (e.g., CSI-RS) transmitted by the gNB and uses these measurements to calculate the downlink CSI and perform feedback according to the CSI report configuration. For precoding matrix indicator (PMI) reports, 5G NR specifies type I, type II, and port selection type II codebooks. 5G NR also specifies enhanced type II.

[0024] In 5G, CSI-RS is configured per device, i.e., it is UE-specific. However, CSI-RS resources can be shared among many UEs. Optimizing the CSI-RS configuration depends on the network. For example, for non-zero power (NZP)-CSI-RS, the resource mapping can be configured in the radio resource configuration (RRC) using the NZP-CSI-RS resource and the CSI-RS-ResourceMapping information element (IE), as shown in the example of Figure 1 as shown.

[0025] Using at least the CSI-RS-ResourceMapping information element (IE) in the received RRC configuration, the UE can determine the CSI-RS resource mapping to its antenna port within the physical resource block (PRB). As an example, the UE can configure the following parameters in the RRC, for example:

[0026] density = 1, nrofPorts = p8, cdm type = fd-CDM2,

[0027] frequencyDomainAllocation.other = 011110,

[0028] firstOFDMSymbolinTimeDomain = 3.

[0029] Given this RRC configuration, the following resource mapping configuration can be inferred: [(2, 3), (4, 3), (6, 3), (8, 3), (3, 3), (5, 3), (7, 3), (9, 3)], which in turn notifies the UE of the mapping between its antenna port and the CSI-RS resource elements, as shown in Figure 2 as shown, i.e., the UE should look at these resources to measure DL CSI or interference. Figure 2 Shows a possible configuration of 8 antenna ports (APs).

[0030] Through different configurations of CSI-RS-ResourceMapping, there are several options available for configuring the CSI resource element pattern per UE. Figure 3 Shows some examples of possible configurations of the CSI-RS resource mapping for 8 antenna ports.

[0031] Note that the same field "CSI-RS-ResourceMapping" also exists in the RRC configuration of ZP CSI-RS, which is used for interference measurement from other cells or for indicating a set of resources on which the physical downlink shared channel (PDSCH) of a specific user is not transmitted. An example of the ZP-CSI-RS-Resource IE is shown in Figure 4a as shown.

[0032] A similar method can also be applied to CSI interference measurement (IM) reference signals that can be used for interference measurement. Figure 4b An example of the CSI-IM-Resource IE is shown, where the fields subcarrierLocation-p0, symbolLocation-p0, subcarrierLocation-p1, and symbolLocation-p1 can be updated in the MAC-CE or DCI.

[0033] Certain example embodiments described herein can be applicable at least to NZP-CSI RS, CSI-IM, and / or ZP-CSI-RS, which will be discussed in more detail below.

[0034] Spatial beamforming CSI-RS has been introduced, referred to as type B CSI feedback. In NR, spatial beamforming CSI-RS resources are used for port selection type II codebooks and enhanced port selection type II codebooks.

[0035] In fact, spatial beamforming CSI-RS can also be applied to the UE in a transparent manner. For example, in the case where the gNB has obtained spatial information about the downlink (DL) channel of a particular UE from the uplink (UL) sounding reference signal (SRS) transmitted from that UE, the gNB can decide how to use this information to construct a long-term beam for creating a UE-specific virtual antenna port to that UE. In this case, the gNB can beamform the CSI-RS using these weights.

[0036] Further CSI enhancements are expected to be provided for NR. For example, further enhancements for MIMO in NR can be provided, which can include CSI reporting for specifying DL multi-transmission reception points (TRPs) and / or multi-panel transmissions to enable more dynamic channel / interference assumptions for non-coherent joint transmission (NCJT), targeting both frequency range 1 (FR1) and frequency range 2 (FR2). Additionally, if needed, type II port selection codebook enhancements (e.g., based on previous type II port selections) can be provided, where information related to (multiple) angles and (multiple) delays can be estimated at the gNB based on UL reference signal transmissions by exploiting DL / UL reciprocity of angles and delays, and the remaining DL CSI can be reported by the UE, mainly for FDD FR1, to achieve a better trade-off between UE complexity, performance, and reporting overhead.

[0037] It is expected that, in addition to the spatial domain, partial reciprocity will be utilized to enhance the port selection codebook in the delay domain. The port selection codebook is already based on spatial beamforming CSI-RS.

[0038] As described above, CSI-RS can be shared in practice to save DL resources among UEs in the same cell. However, in the case where CSI-RS is beamformed (either in the spatial and / or delay domain), considering the current semi-static configuration of channel measurement resources (provided via RRC), sharing CSI-RS resources (i.e., using the same resource elements) among UEs in the same cell may no longer be reasonable. In fact, the precoding of CSI-RS can be changed, for example, according to UE feedback or estimated wideband channel information from UE UL reference signal transmissions. If the shared CSI-RS resources are not changed accordingly, the UE will subsequently measure resources that do not carry meaningful information on its channel, i.e., resources precoded with spatial beams and frequency domain (FD) components outside the UE-specific channel support. In addition, considering the latency required for this process, a solution based on RRC reconfiguration may be impractical.

[0039] This may lead to a large amount of DL resources being required, especially in the case where CSI-RS is configured to be periodic, as it should scale with the number of UEs and the number of estimated ports. With the eventual introduction of FD precoding into CSI-RS, more UE-specific DL resources will be needed.

[0040] The problem may become severe when using multi-TRP communication. In the case where a UE is connected to more than one TRP, it is desirable for the UE to use UE-specific SD / FD CSI-RS resources from all serving TRPs to measure CSI and / or interference.

[0041] As described above, one solution to the problem of increasing DL overhead is to divide a sector (cell) into a number of sub-sectors, for example, using wide beams as shown in Figure 5 As an example, Figure 5 shows static sharing of CSI-RS resources using static beams. This effectively divides the cell into a number of groups (4 in the example of Figure 5 ), and all UEs within a wide beam will change their UE-specific beams to match the beams of the sub-sectors. In other words, the CSI-RS resources are no longer UE-specific but sub-sector-specific. This can control the increase in DL overhead such that it does not scale with the number of UEs but increases with the number of sub-sectors or groups. Another solution is to increase the period of DL CSI-RS transmissions. The CSI-RS resources can be configured to have a period of, for example, 4 - 640 time slots.

[0042] One embodiment provides a method in which CSI-RS resources can be effectively and dynamically shared among UEs even when using UE-specific CSI-RS. Since long-term spatial and delay beamforming weights are typically derived from a fixed codebook, this means that two UEs can have one or several common spatial beams and / or FD components, although their other components can be different. Note that, as discussed herein, a reference to CSI-RS resource sharing among UEs can mean that they will use the same resource elements in the PRB, and thus DL overhead reduction can be achieved.

[0043] In the assumed example where there is 100% overlap in the selection of spatial beams and / or FD components by two UEs, i.e., the channel measurement CSI-RS resources will be precoded with the same weights, the gNB can configure the two UEs with the same CSI-RS mapping and thus save CSI-RS overhead. However, this may be a rare case, especially in FR1 with non-line-of-sight (NLOS) conditions.

[0044] Another issue is that the selection of spatial beams and / or FD components should be time-varying, where it will change with channel variations due to UE mobility and propagation environment evolution or with traffic variations (e.g., a new user enters the system or an existing user enters the idle mode); while the CSI-RS mapping in the current specification is rather static as it is provided to the UE in the RRC configuration. Adopting a solution based on RRC reconfiguration may not be practical.

[0045] In fact, RRC reconfiguration can include a rather large delay exceeding the channel stability time, i.e., the time interval during which the channel support in the spatial and delay domains is constant.

[0046] In some scenarios, UEs that are close in location can partially share similar spatial beams and / or FD components. In this case, implementing partial sharing of the channel measurement CSI-RS resource elements will reduce DL overhead and thus improve performance.

[0047] According to one embodiment, a solution is provided to implement dynamic and partial sharing of channel measurement CSI-RS resources (and thus resource elements).

[0048] One embodiment may relate to a method in which, in RRC, the gNB may use a CSI-RS resource pool to configure one or more UEs, where the CSI-RS resource pool contains more ports than the number of ports that the (multiple) UEs will use for actual channel measurements. Optionally, the gNB may notify the UE of the actual number of ports. In one embodiment, the gNB may, for example, configure and transmit to the UE an updated or first UE-specific mapping for CSI-RS resources within a resource pool that has already been RRC-configured via a Media Access Control Control Element (MAC-CE) / Downlink Control Information (DCI) using a bitmap, a combined index, and / or an explicit index. Some embodiments may provide a new dynamic signaling function in the MAC CE or DCI for the gNB to notify the UE of the updated or first UE-specific mapping for CSI-RS resources. In this case, the MAC CE or DCI is used to select one mapping from the possible mappings provided in the RRC.

[0049] According to some embodiments, the UE-specific mapping of CSI-RS resources may be indicated via at least one of the following: RRC containing a list of N possible CSI-RS mappings; in the MAC-CE, a subset of the N possible CSI-RS resource mappings that are activated, e.g., N a ; and in the DCI, the gNB may indicate which of the N a active resource mappings should be selected. Using the MAC-CE to activate a subset of the possible mappings and using the DCI to select one mapping may result in reducing the bit width required to convey the selection in the DCI.

[0050] In some embodiments, the UE-specific mapping may be performed over a group of resources rather than individual resources to reduce the mapping overhead in the DL. The size of the resource group may be fixed in the specification or configured in the RRC.

[0051] According to one embodiment, the UE-specific mapping provided in the RRC, activated in the MAC-CE, and selected in the DCI may be performed over a group of resources rather than individual resources to reduce the mapping overhead in the DL. The size of the group of resources may be fixed in the specification or specified in the RRC.

[0052] In one embodiment, the mapping may relate to UE-specific ports on a first polarization, since the mapping of UE-specific ports on a second polarization may be inferred from the mapping of UE-specific ports on the first polarization. According to one embodiment, a default mapping may be provided in the RRC configuration.

[0053] In some embodiments, a subset of resources provided in the RRC default mapping is updated. In other words, a part of the mapping provided in the RRC configuration can remain constant while another part can be updated in the MAC-CE and / or DCI. According to one embodiment, different groups can be updated at different periods.

[0054] Another embodiment may relate to a method in which the gNB can configure the UE with a resource pool that can include the number of ports allocated to the UE in the RRC configuration. In one embodiment, the gNB can transmit one or two shift values, k shift and l shift , to the UE in the MAC-CE / DCI, by which the UE can know that it should shift the existing resource mapping (configured in the RRC) in frequency and / or time within the PRB.

[0055] Certain embodiments can provide new dynamic signaling functions in the MAC CE or DCI to allow the gNB to use the shift values k shift and l shift to notify the UE of a new shifted resource mapping. In one embodiment, a new field can be added for nrofPortsUE in the RRC. In some embodiments, it may be desirable for the UE to update the channel measurement resources for a given CSI report setting based on an indication from the gNB.

[0056] The utility of certain embodiments can be to be able to utilize partial UL / DL reciprocity. In fact, if dynamic CSI-RS sharing is not enabled, any method that uses delay information in CSI-RS precoding, in addition to spatial beamforming, can benefit from an increase in CSI-RS overhead. This is because the gNB will need to transmit additional information about spatial / delay domain support via the selected CSI-RS precoding.

[0057] Certain embodiments can also be used for, e.g., beam management purposes. In fact, instead of reporting the CRI on the entire number of configured resources, the embodiments can be used as a means to limit the beam measurements to the dynamically indicated resources, such that the fields required for beam indication in the UCI can be reduced. For example, this can be used in the high-frequency range where beam search is performed over a large number of narrow beams.

[0058] Figure 6a and Figure 6b show an example embodiment with 4 UEs, where each UE selects 8 virtual antenna ports (spatial beams), with L = 4 beams for each polarization. Note that it is common practice to assume the same beam weights for two antenna polarizations at a given antenna element location. The 4 beams selected by each UE are as shown in the Figure 6a table. It should also be noted thatFigure 6a and Figure 6b shows an example, since according to some embodiments, any number of UEs or beams may be included.

[0059] According to one embodiment, if the gNB transmits DL CSI-RS signals as UE-specific, the amount of DL overhead required is N users × 2L = 32 resource elements (32 is the maximum number of CSI-RS ports considered). In Figure 6a and Figure 6b an example of partial overlapping beam selection among UEs is provided. As can be seen in this example, there is no complete intersection between the sets of beams selected by different UEs. However, four UEs selected 10 unique beams. This means that the gNB does not need 32 CSI-RS resource elements to transmit the selected beams, and 20 CSI resource elements are sufficient (2 CSI-RS ports per cross-polarized beam).

[0060] In one embodiment, if the CSI-RS resources are configured as, for example, Figure 6b shown, when only 10 different beams are needed, the proposed UE-specific mapping indication can reduce the number of resource elements of the required CSI-RS to only 20. Compared with the configured UE-specific CSI-RS (where the gNB needs 32 resource elements to transmit 4 beams for each of the 4 UEs), this represents a gain of 12 resource elements. Again, note that Figure 6b the configuration in

[0061] is only an example, and according to some embodiments to be discussed below, other configurations are possible. N In this example, the case of spatial beamforming CSI-RS can be seen. However, the DL overhead can increase with the introduction of FD precoding, especially in the case of multi-TRP operation. In multi-TRP operation, for a collaborative set of N TRPs, the UE can report CSI based on interference assumptions, i.e., 2

[0062] -1 interference assumptions should be considered. This results in a significant increase in the CSI reporting configuration in RRC. Some embodiments can be used to reduce any redundancy in the required channel measurement and interference measurement resource configurations, since a resource pool can be provided in RRC and the CMR / IMR are dynamically specified via the methods provided by some embodiments.

[0063] Figure 7aShows an example flowchart of a dynamic UE-specific mapping method according to an example embodiment. In certain example embodiments, Figure 7a The flowchart may be executed by a network entity or network node in a communication system such as LTE or 5G NR. For example, in some example embodiments, the network node that executes Figure 7a The method may include a base station, an access node, an eNB, a gNB, and / or an NG-RAN node, etc.

[0064] As Figure 7a As shown in the example of, the method may include: at 700, indicating in the RRC to the UE a CSI-RS resource mapping for calculating CSI feedback in the RRC, where the number of ports is greater than the actual number of ports that the UE is configured to measure. Optionally, the indication at 700 may include transmitting an initial UE-specific mapping. The method may further include: at 705, indicating to the UE an updated UE-specific mapping in the MAC-CE or DCI. As Figure 7a As further shown in the example of, the method may include: at 710, receiving CSI feedback from the UE and using it to reconstruct the precoder W.

[0065] Figure 7b Shows an example flowchart of a dynamic UE-specific mapping method according to another example embodiment. In certain example embodiments, Figure 7b The flowchart may be executed by a network entity or network node in a communication system such as LTE or 5G NR. For example, in some example embodiments, the network entity that executes Figure 7b The method may include a UE, a mobile station, a user equipment, an IoT device, etc.

[0066] In one embodiment, Figure 7b The method may include: at 730, receiving a CSI-RS mapping in the RRC and receiving an optional UE-specific mapping from a network node (e.g., gNB). At 735, the method may include receiving an updated UE-specific mapping from the network node in the MAC-CE or DCI. Also as Figure 7b As shown in the example of, the method may include: at 740, receiving CSI-RS at a new location using the new mapping and obtaining an estimate of the channel frequency response (CFR). The method may further include: at 745, deriving a CSI feedback report from the CFR. In an embodiment, Figure 7b The method may include: at 750, providing feedback CSI information to the network node.

[0067] Note that the periods of processes 705, 710 at the gNB and processes 735, 750 at the UE are much smaller than the frequencies at which RRC is transmitted at the gNB and UE in processes 700, 730 respectively. Thus, some embodiments allow the resource mapping to change dynamically with the channel and traffic.

[0068] As described above, Figure 6b An example application of dynamic UE-specific mapping is shown (e.g., as shown in the flowcharts of Figure 7a and Figure 7b ), where the UE may be configured with more antenna ports than the actual number of its virtual CSI ports. For example, Figure 6b UE4 in the example of

[0069] is RRC-configured with nrofPorts = p24 in IE CSI-RS-ResourceMapping instead of nrofPorts = p8. In an embodiment, a new field may also be added to distinguish between two values (e.g., nrofPorts = p24 and nrofPortsUE = p8).

[0070] In addition, in an embodiment, new signaling from the gNB may be transmitted, where UE4 is configured with UE-specific mapping via RRC (as a default configuration) and / or MAC-CE and / or (downlink control information) DCI, which guides the UE to identify its own 8 resources in 24 resource pools shared with other UEs. For example, the mapping in the DL may be in the form of at least one of the following: (a) a bitmap (e.g., 1100 0000 1100 1100 0000 1100), (b) an explicit index configuration (e.g., [1 8 09 11 18 10 19]), or (c) a combined index. Figure 6a in which both UE1 and UE4 in 11 have b3 replaced by b 11 then the gNB may replace b3 with b

[0071] According to some embodiments, another way to convey UE-specific mapping in the DL may include: (1) RRC contains a list of N possible CSI-RS resource mappings for a particular UE; (2) in the MAC-CE, a subset of the N possible CSI-RS resource mappings is activated, e.g., N a<N possible CSI-RS mappings are activated; and / or (3) in the DCI, the gNB may indicate which of the N a active resource mappings should be selected.

[0072] As described above, the manner of constructing beamforming CSI-RS can change with changes in the channel and MU-MIMO grouping. Therefore, the example embodiments are configured to dynamically update the UE-specific mapping in the MAC-CE or DCI to allow the gNB to dynamically configure CSI resources in the case of a new UE arrival or a scheduling change occurring, etc. The MAC-CE latency can be as small as 3 ms, so it is sufficient to track such changes, which are expected to occur on average every ~50 ms. It should be noted that this mechanism does not need to be associated with a specific CSI reporting period. This can significantly reduce the actual number of dynamic configurations in practice. For example, in the case of non-periodic CSI-RS transmission and CSI reporting, the dynamic mapping information will not be transmitted regularly. In this case, it may still be feasible to transmit the UE-specific mapping in a capacity-constrained framework such as the DCI.

[0073] In some embodiments, the symmetry in the CSI resource mapping between two polarizations can also be utilized to reduce the DL mapping overhead. For example, this mapping can be used to direct the UE to the resources used on the first polarization. From this information and with the knowledge of the total number of pool ports, the UE can infer the mapping of the second polarization. For example, as Figure 6b shown in the example of, UE4 can send only the first part of the bitmap [1100 0000 1100], or in the case of explicit configuration, only send [1 8 0 9].

[0074] In certain embodiments, a part of the UE-specific mapping is updated in the MAC-CE or DCI, while another part remains unchanged. For example, the default UE-specific mapping is provided in the RRC, and only a subset of the resources is updated in the MAC-CE or DCI.

[0075] According to some embodiments, in order to reduce the overhead of the UE-specific mapping, the UE-specific mapping can be performed on a group of resources rather than individual resources. Although this provides less flexibility for the gNB in controlling the CSI-RS resource sharing among UEs, it will significantly reduce the mapping overhead in the DL.

[0076] In some embodiments, different CSI-RS resource groups can be updated at different periods. For example, this can be achieved when the update message within the MAC-CE or DCI contains the CSI-RS resource group index that needs to be updated. Alternatively, if it is within the RRC configuration, different update periods can be assigned to different groups of resources.

[0077] Another embodiment may relate to low DL overhead dynamic CSI resource mapping shift. As described above, using the field IE CSI-RS-ResourceMapping in the RRC configuration, the UE is able to determine the exact CSI-RS resource mapping to its antenna ports within a physical resource block (PRB). In some embodiments, by changing the frequencyDomainAllocation and firstOFDMSymbolInTimeDomain fields, a certain degree of flexibility in CSI-RS resource mapping can be achieved among a group of two or more UEs, as shown in the example of Figure 8 . More specifically, Figure 8 's example shows some different configurations of frequencyDomainAllocation in the RRC.

[0078] However, relying on the RRC to allow dynamic sharing among UEs may not be possible because its semi-static nature does not seem suitable for dealing with the time-varying channels as described above. Therefore, some embodiments may be configured to send new fields in the MAC-CE or DCI to indicate to the UE to shift its existing configuration in the frequency (sub-carrier) and / or time domain (OFDM symbol) to allow for a certain degree of CSI resource sharing with other UEs. The new fields (e.g., called k shift and l shift ) will indicate to the UE to shift its entire resource configuration by k shift resources in frequency and by l shift resources in time.

[0079] In fact, according to some embodiments, k shift and l shift can take values from -6 to 6 or -7 to 7 respectively. These values can also be extracted from a smaller set of selections to reduce the DL signaling overhead. This approach has the advantage of at least having a smaller DL overhead, for example, it can make this type of signaling easily fit into the DCI with limited capacity.

[0080] Figure 9a shows an example flow chart of a dynamic CSI resource mapping shift method according to an example embodiment. In some example embodiments, Figure 9a 's flow chart can be executed by a network entity or network node in a communication system such as LTE or 5G NR. For example, in some exemplary implementations, the network node executing Figure 9a 's method may include a base station, an access node, an eNB, a gNB, and / or an NG-RAN node, etc.

[0081] As Figure 9aAs shown in the example of , the method may include: at 900, indicating in RRC to the UE the CSI-RS resource mapping for calculating CSI feedback in RRC. The method may further include: at 905, indicating in MAC-CE or DCI the updated time and / or frequency offset applied to the mapping provided in RRC. In some embodiments, the method may further include: at 910, receiving CSI feedback from the UE and using the CSI feedback to reconstruct the precoder W.

[0082] Figure 9b FIG. shows an example flowchart of a dynamic CSI resource mapping shifting method according to another example embodiment. In certain example embodiments, Figure 9b the flowchart may be executed by a network entity or network node in a communication system (such as LTE or 5G NR). For example, in some example embodiments, the network entity that executes Figure 9b the method may include a UE, a mobile station, a user equipment, an Internet of Things device, etc.

[0083] In an embodiment, Figure 9b the method may include: at 930, receiving in RRC from a network node (e.g., gNB) a fixed CSI-RS mapping. The method may further include: at 935, receiving from the network node an updated UE-specific offset from MAC-CE or DCI and calculating a new CSI-RS mapping. Also as Figure 9b shown in the example of , the method may include: at 940, using the new mapping to receive CSI-RS at a new location and obtaining an estimate of the CFR. The method may further include: at 945, deriving a CSI feedback report from the CFR. In an embodiment, Figure 9b the method may then include: at 950, providing feedback CSI information to the network node.

[0084] Figure 10a FIG. shows an example of apparatus 10 according to an embodiment. In an embodiment, apparatus 10 may be a node, host, or server in a communication network or serving such a network. For example, apparatus 10 may be a satellite, a base station, a Node B, an evolved Node B (eNB), a 5G Node B or access point, a next-generation Node B (NG-NB or gNB), a high-altitude platform station (HAPS), an integrated access and backhaul (IAB) node, and / or a WLAN access point associated with a radio access network (such as an LTE network, 5G, or NR).

[0085] It should be understood that in some example embodiments, the apparatus 10 may include an edge cloud server as a distributed computing system, where the server and the radio nodes may be independent devices communicating with each other via a wireless circuit path or via a wired connection, or where they may be located in the same entity and communicate via a wired connection. For example, in some example embodiments where the apparatus 10 represents a gNB, it may be configured in a central unit (CU) and distributed unit (DU) architecture that divides the gNB functions. In such an architecture, the CU may be a logical node that includes gNB functions such as the transmission of user data, mobility control, radio access network sharing, positioning, and / or session management, etc. The CU may control the operation of the (one or more) DUs through a fronthaul interface. The DU may be a logical node that includes a subset of the gNB functions, depending on the function split option. It should be noted that those of ordinary skill in the art will understand that the apparatus 10 may include Figure 10a components or features not shown in

[0086] As Figure 10a shown in the example of, the apparatus 10 may include a processor 12 for processing information and executing instructions or operations. The processor 12 may be any type of general-purpose or special-purpose processor. In fact, for example, the processor 12 may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture, or any other processing component.

[0087] Although Figure 10a a single processor 12 is shown, multiple processors may be used according to other example embodiments. For example, it should be understood that in some embodiments, the apparatus 10 may include two or more processors, which may form a multi-processor system that can support multi-processing (for example, in this case, the processor 12 may represent a multi-processor). In some embodiments, the multi-processor system may be tightly coupled or loosely coupled (for example, to form a computer cluster).

[0088] The processor 12 may execute functions associated with the operation of the apparatus 10, which may include, for example, precoding of antenna gain / phase parameters, encoding and decoding of individual bits forming communication messages, formatting of information, and overall control of the apparatus 10, including processes related to the management of communication resources.

[0089] Device 10 may also include or be coupled to a memory 14 (internal or external), which may be coupled to the processor 12 and is used to store information and instructions that can be executed by the processor 12. The memory 14 may be one or more memories and have any type suitable for the local application environment, and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 14 may include random access memory (RAM), read-only memory (ROM), static storage devices such as magnetic disks or optical discs, hard disk drives (HDDs), or any other type of non-transitory memory or computer-readable medium, or other appropriate storage components. The instructions stored in the memory 14 may include program instructions or computer program code, which, when executed by the processor 12, enable the device 10 to perform the tasks described herein.

[0090] In one embodiment, device 10 may also include or be coupled to (internal or external) a drive or port configured to accept and read external computer-readable storage media, such as optical discs, USB drives, flash drives, or any other storage media. For example, the external computer-readable storage media may store computer programs or software for execution by the processor 12 and / or the device 10.

[0091] In some embodiments, device 10 may also include or be coupled to one or more antennas 15 for transmitting signals and / or data to and receiving signals and / or data from the device 10. Device 10 may also include or be coupled to a transceiver 18 configured to transmit and / or receive information. The transceiver 18 may include, for example, multiple radio interfaces that may be coupled to the (multiple) antennas 15, or may include any other appropriate transceiver components. In certain embodiments, the radio interfaces may correspond to multiple radio access technologies, including one or more of the following: GSM, NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identification (RFID), ultra-wideband (UWB), MulteFire, etc. According to an example embodiment, the radio interfaces may include components such as filters, converters (e.g., digital-to-analog converters, etc.), mappers, fast Fourier transform (FFT) modules, etc., for example, to generate symbols or signals for transmission via one or more downlinks and receive symbols (e.g., via the uplink).

[0092] Accordingly, transceiver 18 may be configured to modulate information onto a carrier waveform for transmission by antennas 15 and demodulate information received via antennas 15 for further processing by other elements of device 10. In other example embodiments, transceiver 18 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, device 10 may include an input device and / or an output device (I / O device), or input / output components.

[0093] In one embodiment, memory 14 may store software modules that provide functionality when executed by processor 12. The module may include, for example, an operating system that provides operating system functionality for device 10. The memory may also store one or more functional modules, such as applications or programs, to provide additional functionality for device 10. The components of device 10 may be implemented in hardware or as any suitable combination of hardware and software.

[0094] According to some embodiments, processor 12 and memory 14 may be included in or may form part of a processing circuitry or control circuitry. Additionally, in some embodiments, transceiver 18 may be included in or may form part of a transceiver circuitry.

[0095] As used herein, the term "circuitry" may refer to only hardware circuit implementations (e.g., analog and / or digital circuitry), combinations of hardware circuits and software, combinations of analog and / or digital hardware circuits and software / firmware, any portion of (multiple) hardware processors (including digital signal processors) working together with software to cause a device (e.g., device 10) to perform various functions, and / or (multiple) hardware circuits and / or (multiple) processors or portions thereof that operate using software but for which the software may not be present when not needed for operation. As a further example, as used herein, the term "circuitry" may also cover implementations that include only hardware circuits or processors (or multiple processors), or portions of hardware circuits or processors, along with their accompanying software and / or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, a cellular network node or device, or other computing or network device.

[0096] As described above, in certain embodiments, device 10 may be a network node or a RAN node, such as a base station, an access point, Node B, eNB, gNB, HAPS, IAB node, a WLAN access point, etc. For example, in some embodiments, device 10 may be configured to perform one or more of the processes depicted in any of the flowcharts or signaling diagrams described herein, such as Figure 7a 、 Figure 7b 、 Figure 9a or Figure 9bThose shown. In some embodiments, as discussed herein, apparatus 10 may be configured to perform processes related to coordinating UL power control.

[0097] According to this embodiment, apparatus 10 may be controlled by memory 14 and processor 12 to indicate in RRC to the UE a CSI-RS resource mapping for calculating CSI feedback in RRC, where the number of ports is greater than the actual number of ports the UE is configured to measure. Optionally, apparatus 10 may be controlled by memory 14 and processor 12 to transmit an initial UE-specific mapping. In an embodiment, apparatus 10 may be controlled by memory 14 and processor 12 to indicate in MAC-CE or DCI to the UE an updated UE-specific mapping. According to certain embodiments, apparatus 10 may be controlled by memory 14 and processor 12 to receive CSI feedback from the UE and use the CSI feedback to reconstruct precoder W.

[0098] According to another embodiment, apparatus 10 may be controlled by memory 14 and processor 12 to indicate in RRC to the UE a CSI-RS resource mapping for calculating CSI feedback in RRC. In an embodiment, apparatus 10 may be controlled by memory 14 and processor 12 to indicate in MAC-CE or DCI an updated time and / or frequency offset applied to the mapping provided in RRC. In some embodiments, apparatus 10 may be controlled by memory 14 and processor 12 to receive CSI feedback from the UE and use the CSI feedback to reconstruct precoder W.

[0099] Figure 10b An example of apparatus 20 according to another embodiment is shown. In an embodiment, apparatus 20 may be a node or element in a communication network or associated with such a network, such as a UE, mobile equipment (ME), mobile station, mobile device, fixed device, IoT device, or other device. As described herein, a UE may alternatively be referred to as, for example, a mobile station, mobile equipment, mobile unit, mobile device, user equipment, subscriber station, wireless terminal, tablet, smartphone, IoT device, sensor, or NB-IoT device, etc. As an example, apparatus 20 may be implemented in, for example, a wireless handheld device, wireless plug-in accessory, etc.

[0100] In some example embodiments, device 20 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage devices, etc.), one or more radio access components (e.g., modems, transceivers, etc.), and / or a user interface. In some embodiments, device 20 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and / or any other radio access technology. It should be noted that those of ordinary skill in the art will understand that device 20 may include Figure 10b components or features not shown in

[0101] As Figure 10b shown in the example of, device 20 may include or be coupled to a processor 22 (or processing component) for processing information and executing instructions or operations. Processor 22 may be any type of general-purpose or special-purpose processor. In fact, processor 22 may include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), application specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although Figure 10b a single processor 22 is shown, multiple processors may be used according to other embodiments. For example, it should be understood that in certain embodiments, device 20 may include two or more processors, which may form a multiprocessor system that can support multiprocessing (e.g., in this case, processor 22 may represent a multiprocessor). In certain embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0102] Processor 22 may perform functions associated with the operation of device 20, and as some examples, include precoding of antenna gain / phase parameters, encoding and decoding of individual bits forming communication messages, formatting of information, and overall control of device 20, including processes related to the management of communication resources.

[0103] The apparatus 20 may also include or be coupled to a memory 24 (internal or external), which may be coupled to the processor 22 and is used to store information and instructions that can be executed by the processor 22. The memory 24 may be one or more memories and of any type suitable for the local application environment, and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 24 may include random access memory (RAM), read-only memory (ROM), static storage devices such as magnetic disks or optical discs, hard disk drives (HDDs), or any other type of non-transitory memory or computer-readable medium, or other storage components. The instructions stored in the memory 24 may include program instructions or computer program code that, when executed by the processor 22, enable the apparatus 20 to perform the tasks described herein.

[0104] In one embodiment, the apparatus 20 may also include or be coupled to (internal or external) a drive or port configured to accept and read external computer-readable storage media, such as optical discs, USB drives, flash drives, or any other storage media. For example, the external computer-readable storage media may store computer programs or software for execution by the processor 22 and / or the apparatus 20.

[0105] In some embodiments, the apparatus 20 may also include or be coupled to one or more antennas 25 for receiving downlink signals and for transmitting via the uplink from the apparatus 20. The apparatus 20 may also include a transceiver 28 (or transceiver component) configured to transmit and receive information. The transceiver 28 may also include a radio interface (e.g., a modem) coupled to the antenna 25. The radio interface may correspond to a variety of radio access technologies, including GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components such as filters, converters (e.g., digital-to-analog converters, etc.), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc. to process symbols carried by the downlink or uplink, such as OFDMA symbols.

[0106] For example, the transceiver 28 can be configured to modulate information onto a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of the device 20. In other embodiments, the transceiver 28 can be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, the device 20 can include an input and / or output device (I / O device), or input / output component. In certain embodiments, the device 20 can further include a user interface, such as a graphical user interface or a touch screen.

[0107] In an embodiment, the memory 24 stores software modules that provide functionality when executed by the processor 22. The module can include, for example, an operating system that provides operating system functionality for the device 20. The memory can also store one or more functional modules, such as applications or programs, to provide additional functionality for the device 20. The components of the device 20 can be implemented in hardware or as any suitable combination of hardware and software. According to an example embodiment, the device 20 can optionally be configured to communicate with the device 10 via a wireless or wired communication link 70 according to any radio access technology, such as NR.

[0108] According to some embodiments, the processor 22 and / or the memory 24 can be included in or form part of a processing circuitry or a control circuitry. Additionally, in some embodiments, the transceiver 28 can be included in or form part of a transceiver circuitry.

[0109] As described above, according to some embodiments, the device 20 can be, for example, a UE, a mobile device, a mobile station, an ME, an IoT device, and / or an NB-IoT device. According to certain embodiments, the device 20 can be controlled by the memory 24 and the processor 22 to perform functions associated with the example embodiments described herein. For example, in some embodiments, the device 20 can be configured to execute one or more of the processes depicted in any of the flowcharts or signaling diagrams described herein, such as Figure 7a , Figure 7b , Figure 9a or Figure 9b as shown. In certain embodiments, for example, the device 20 can be configured to execute a process related to real-time coordinated UL power control.

[0110] For example, in some embodiments, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive CSI-RS mapping in RRC and receive optional UE-specific mapping from a network node (e.g., gNB). In one embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive updated UE-specific mapping from a network node from MAC-CE or DCI. According to an embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive CSI-RS at a new location using the new mapping and obtain an estimate of the CFR. In one embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to derive a CSI feedback report from the CFR and provide CSI feedback information to the network node.

[0111] In another embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive a fixed CSI-RS mapping in RRC from a network node (e.g., gNB). According to an embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive updated UE-specific offsets from a network node from MAC-CE or DCI and calculate a new CSI-RS mapping. In certain embodiments, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive CSI-RS at a new location using the new mapping and obtain an estimate of the CFR. According to an embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to derive a CSI feedback report from the CFR and provide feedback CSI information to the network node.

[0112] Accordingly, certain example embodiments provide several technical improvements, enhancements, and / or advantages over prior art processes and constitute at least an improvement in the technical field of wireless network control and management. As discussed in detail above, certain embodiments provide systems and methods for implementing dynamic and partial sharing of channel measurement CSI-RS resources (and thus resource elements). As a result of the example embodiments, CSI-RS resources can be effectively and dynamically shared among UEs. In addition, certain embodiments are capable of reducing DL overhead, thereby obtaining performance gains. Accordingly, the use of certain example embodiments improves the functionality of communication networks and their nodes, such as base stations, eNBs, gNBs, and / or UEs or mobile stations.

[0113] In some example embodiments, the functionality of any method, process, signaling diagram, algorithm, or flowchart described herein may be implemented by software and / or computer program code or portions of code stored in a memory or other computer-readable or tangible medium and executed by a processor.

[0114] In some example embodiments, a device may be included in or associated with at least one software application, module, unit, or entity configured to perform (multiple) arithmetic operations, or a program or a part thereof (including added or updated software routines) configured to be executed by at least one operating processor. The program (also referred to as a program product or a computer program, including software routines, applets, and macros) may be stored in any device-readable data storage medium and may include program instructions for performing a specific task.

[0115] A computer program product may include one or more computer-executable components configured to perform some example embodiments when the program runs. The one or more computer-executable components may be at least one software code or a portion of the code. Modifications and configurations for implementing the functions of the example embodiments may be performed as (multiple) routines, which may be implemented as (multiple) added or updated software routines. In one example, the (multiple) software routines may be downloaded to the device.

[0116] As an example, the software or computer program code or a portion of the code may be in source code form, object code form, or some intermediate form, and it may be stored in some carrier, distribution medium, or computer-readable medium, which may be any entity or device capable of carrying the program. For example, such a carrier may include a recording medium, computer memory, read-only memory, electro-optical and / or electrical carrier signals, telecommunication signals, and / or software distribution packages. Depending on the required processing capabilities, the computer program may be executed in a single electronic digital computer or distributed among multiple computers. The computer-readable medium or computer-readable storage medium may be a non-transitory medium.

[0117] In other example embodiments, the functions may be performed by hardware or circuitry included in the device, such as by using an application-specific integrated circuit (ASIC), programmable gate array (PGA), field-programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functions may be implemented as a signal, such as an intangible component carried by an electromagnetic signal downloaded from the Internet or other networks.

[0118] According to example embodiments, a device such as a node, device, or corresponding component may be configured as a circuitry, computer, or microprocessor, such as a single-chip computer element, or configured as a chipset, which may include at least a memory for providing storage capacity for (multiple) arithmetic operations and / or an arithmetic processor for performing (multiple) arithmetic operations.

[0119] Those of ordinary skill in the art will readily understand that the example embodiments discussed above can be practiced with processes in a different order and / or with hardware elements in a different configuration compared to those disclosed. Thus, although some embodiments have been described based on these example embodiments, it will be apparent to those skilled in the art that certain modifications, variations, and alternative constructions will be apparent while remaining within the spirit and scope of the example embodiments.

[0120] One embodiment may relate to a method that includes determining or receiving, at a network node, information related to an actual number of ports configured for a user equipment for channel measurement. The method may further include determining a CSI-RS resource pool for the user equipment. The CSI-RS resource pool may be provided in an RRC configuration and may include a number of ports that is excessive compared to the actual number of ports. The method may then include transmitting, to the user equipment, a user equipment-specific mapping for the configuration of the CSI-RS resource pool via at least one of a MAC-CE or DCI.

[0121] Another embodiment may relate to a device that includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to at least determine or receive information related to an actual number of ports configured for a user equipment for channel measurement, and determine a CSI-RS resource pool for the user equipment. The CSI-RS resource pool may be provided in an RRC configuration and may include a number of ports that is excessive compared to the actual number of ports. The at least one memory and the computer program code may further be configured to, with the at least one processor, cause the device to at least transmit, to the user equipment, a user equipment-specific mapping for the configuration of the CSI-RS resource pool via at least one of a MAC-CE or DCI.

[0122] Another embodiment relates to a device that may include means for determining or receiving information related to an actual number of ports configured for a user equipment for channel measurement. The device may further include means for determining a CSI-RS resource pool for the user equipment. The CSI-RS resource pool may be provided in an RRC configuration and may include a number of ports that is excessive compared to the actual number of ports. The device may further include means for transmitting, to the user equipment, a user equipment-specific mapping for the configuration of the CSI-RS resource pool via at least one of a MAC-CE or DCI.

[0123] Another embodiment relates to a method that may include: determining or receiving, at a network node, information related to an actual number of ports configured for a user equipment for channel measurement. The method may further include determining a CSI-RS resource pool of the user equipment. The CSI-RS resource pool is provided in an RRC configuration and includes the actual number of ports. The method may include transmitting, to the user equipment, one or two shift values via at least one of a MAC-CE or DCI, by which the user equipment learns that the user equipment should shift an existing resource mapping in frequency and / or time within a PRB.

[0124] Another embodiment relates to a device that may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to at least determine or receive information related to an actual number of ports configured for a user equipment for channel measurement, and determine a CSI-RS resource pool of the user equipment. The CSI-RS resource pool is provided in an RRC configuration and includes the actual number of ports. The at least one memory and the computer program code are configured to, with the at least one processor, cause the device to at least transmit, to the user equipment, one or two shift values via at least one of a MAC-CE or DCI, by which the user equipment learns that the user equipment should shift an existing resource mapping in frequency and / or time within a PRB.

[0125] Another embodiment relates to a device that may include means for determining or receiving information related to an actual number of ports configured for a user equipment for channel measurement. The device may further include means for determining a CSI-RS resource pool of the user equipment. The CSI-RS resource pool is provided in an RRC configuration and includes the actual number of ports. The device may include means for transmitting, to the user equipment, one or two shift values via at least one of a MAC-CE or DCI, by which the user equipment learns that the user equipment should shift an existing resource mapping in frequency and / or time within a PRB.

[0126] Another embodiment relates to a method that may include: receiving, at the user equipment, a CSI-RS mapping in RRC and optionally receiving a user equipment specific mapping from a network node. The method may further include receiving, from the network node, an updated user equipment specific mapping from a MAC-CE or DCI. The method may then include using the updated user equipment specific mapping to receive CSI-RS at a new location, and obtaining an estimate of CFR, deriving a CSI feedback report from the CFR, and providing CSI feedback information to the network node.

[0127] Another embodiment relates to an apparatus that may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least receive a CSI-RS mapping in RRC and optionally receive a user equipment specific mapping from a network node, receive an updated user equipment specific mapping from a MAC-CE or DCI, use the updated user equipment specific mapping to receive CSI-RS at a new location, and obtain an estimate of CFR, derive a CSI feedback report from the CFR, and provide CSI feedback information to the network node.

[0128] Another embodiment relates to an apparatus that may include means for receiving a CSI-RS mapping in RRC and optionally receiving a user equipment specific mapping from a network node. The apparatus may further include means for receiving an updated user equipment specific mapping from a network node from a MAC-CE or DCI. The apparatus may further include means for using the updated user equipment specific mapping to receive CSI-RS at a new location and obtaining an estimate of CFR, means for deriving a CSI feedback report from the CFR, and means for providing CSI feedback information to the network node.

[0129] Another embodiment relates to a method that may include receiving a fixed CSI-RS mapping from a network node in radio resource control (RRC), and receiving an updated user equipment specific offset from a network node from a MAC-CE or DCI, and calculating a new CSI-RS mapping. The method may further include using the new CSI-RS mapping to receive CSI-RS at a new location, and obtaining an estimate of CFR, deriving a CSI feedback report from the CFR, and providing CSI feedback information to the network node.

[0130] Another embodiment relates to an apparatus that may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus to at least receive a fixed CSI-RS mapping from a network node in radio resource control (RRC), and receive an updated user equipment specific offset from a network node from a MAC-CE or DCI, and calculate a new CSI-RS mapping. The at least one memory and the computer program code may further be configured to, with the at least one processor, cause the apparatus to at least use the new CSI-RS mapping to receive CSI-RS at a new location, and obtain an estimate of CFR, derive a CSI feedback report from the CFR, and provide CSI feedback information to the network node.

[0131] Another embodiment relates to an apparatus that may include components for receiving a fixed CSI-RS mapping from a network node in Radio Resource Control (RRC), and components for receiving an updated user equipment specific offset from the network node from a MAC-CE or DCI and calculating a new CSI-RS mapping. The apparatus may further include components for receiving CSI-RS at a new location using the new CSI-RS mapping and obtaining an estimate of the CFR, components for deriving a CSI feedback report from the CFR, and components for providing CSI feedback information to the network node.

Claims

1. A method for communication, comprising: At a terminal device, receiving, from a network node, a channel state information reference signal CSI-RS resource mapping configured in a radio resource control RRC configuration, wherein the RRC configuration includes a list of N possible CSI-RS resource mappings; Receiving a Media Access Control (MAC) Control Element (CE) and Downlink Control Information (DCI) from the network node, the MAC CE including an activated subset of the N possible CSI-RS resource mappings, the activated subset having N a activated CSI-RS resource mappings, the DCI including an indication of which of the N a activated CSI-RS resource mappings is to be selected as a configured user equipment-specific mapping, wherein the user equipment-specific mapping is performed over different CSI-RS resource subgroups, and the different CSI-RS resource subgroups are updated at different times; Receiving, using the user equipment specific mapping, CSI-RS from the network node; And Providing, to the network node, channel state information CSI feedback information for the CSI-RS.

2. The method according to claim 1, further comprising: Receiving, in a MAC CE or DCI, an updated user equipment specific offset from the network node; And Calculating, based on the updated user equipment specific offset, a shifted CSI-RS resource mapping.

3. The method according to claim 1, further comprising: Obtaining an estimation of the channel frequency response CFR of the CSI-RS.

4. The method according to claim 3, further comprising: Deriving the CSI feedback information from the CFR.

5. A device for communication, comprising: At least one processor; And At least one memory, including computer program code, The at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least Receive, from a network node, a channel state information reference signal CSI-RS resource mapping configured in a radio resource control RRC configuration, wherein the RRC configuration includes a list of N possible CSI-RS resource mappings; Receiving a media access control (MAC) control element (CE) and downlink control information (DCI) from the network node, the MAC CE including an activated subset of the N possible CSI-RS resource mappings, the activated subset having N a activated CSI-RS resource mappings, the DCI including an indication of which of the N a activated CSI-RS resource mappings is to be selected as a configured user equipment-specific mapping, wherein the user equipment-specific mapping is performed over different CSI-RS resource subgroups, and the different CSI-RS resource subgroups are updated at different times; Receive, using the user equipment specific mapping, CSI-RS from the network node; And Provide, to the network node, channel state information CSI feedback information for the CSI-RS.

6. The device according to claim 5, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the device to Receive, in a MAC CE or DCI, an updated user equipment specific offset from the network node; and Calculate, based on the updated user equipment specific offset, a shifted CSI-RS resource mapping.

7. The device according to claim 5, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the device to Obtain an estimation of the channel frequency response CFR of the CSI-RS.

8. The device according to claim 7, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the device to Derive the CSI feedback information from the CFR.

9. A device for communication, comprising: At least one processor; And At least one memory, including computer program code, The at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least Determine information related to the actual number of ports configured for channel measurement for a terminal device; Determine a channel state information reference signal (CSI-RS) resource pool of the terminal device, wherein the CSI-RS resource pool is provided in a radio resource control (RRC) configuration and includes a number of ports that is excessive compared to the actual number of ports; And Transmit radio resource control (RRC) configuration, media access control (MAC) control element (CE), and downlink control information (DCI) to the terminal device, where the RRC configuration includes a list of N possible CSI-RS resource mappings, the MAC CE includes an activated subset of the N possible CSI-RS resource mappings, the activated subset has N a activated CSI-RS resource mappings, and the DCI includes an indication of which of the N a activated CSI-RS resource mappings will be selected as the configured user equipment-specific mapping, where the user equipment-specific mapping is performed over different CSI-RS resource subgroups, and the different CSI-RS resource subgroups are updated at different times.

10. The apparatus according to claim 9, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the apparatus to transmit updated user equipment specific offsets to the terminal device in a MAC CE or DCI.

11. The apparatus according to claim 9, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to transmit the user equipment specific mapping or the updated user equipment specific offsets using at least one of the following: A bitmap; A combined index; or An explicit index configuration.

12. The apparatus according to claim 9, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the apparatus to notify the terminal device of the actual number of ports.

13. The apparatus according to claim 9, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, further cause the apparatus Receive, from the terminal device, channel state information (CSI) feedback information for a channel state information reference signal transmitted to the terminal device, the CSI feedback information being derived from an estimation of a channel frequency response (CFR) of the CSI-RS.

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