Method and apparatus for power control offset scaling for coherent joint transmission

Abstract

In accordance with an example embodiment of the present invention, there is provided a method, an apparatus, and a computer program product configured to at least: select an integer N0 number of channel state information reference signal (CSI-RS) resources from an integer NTRP number of network configured CSI-RS resources to a set of resources associated with a CSI reporting configuration, where Nlt; nTRP is carried out; determining a scaling factor for the resource set; determining at least one CSI component based, at least in part, on a hypothesis that a ratio of energy per resource unit (EPR) of a transmission of a PDSCH signal to EPRE of a transmission of an nth CSI-RS resource equals a scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n belongs to [1, N], and determining at least one CSI component based on a hypothesis that the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the nth CSI-RS resource equals a scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set; and transmitting a CSI report to a network, the CSI report comprising the determined at least one CSI component.

Description

[0001] Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 595,211, filed on November 1, 2023, the contents of which are hereby incorporated by reference in their entirety. Technical Field

[0003] The present application relates generally to channel state information (CSI) determination and reporting for coherent joint transmission in wireless networks. Background Art

[0004] In 3GPP New Radio (NR) Release 18, a new feature called Type II CJT is specified, which extends the support of Type II codebook to multi-transmission point (multi-TRP) channel state information (CSI) reporting for coherent joint transmission (CJT) with up to 4 distributed remote radio heads (RRHs) or transmission points (TRPs). The difference between this CJT and the previously defined non-coherent joint transmission (NCJT) is that it assumes that each multiple-input multiple-output (MIMO) layer can transmit from the antenna ports of multiple TRPs, while in NCJT, each MIMO layer can only transmit from a single TRP.

[0005] Both NCJT and CJT assume that the MIMO layers completely overlap in time and frequency resources, and they both require accurate time synchronization between TRPs within the cyclic prefix of the symbol. Additionally, CJT also assumes phase synchronization between TRPs so that the precoding of the MIMO layer can be applied across the antenna ports of multiple TRPs.

[0006] From the user equipment (UE) perspective, layer reception is transparent with respect to the transmit TRP, with the difference that during the CSI feedback phase, for NCJT the precoding weights associated with a layer apply to a single TRP among the configured TRPs used for CSI feedback, whereas for CJT the precoding weights are associated with all selected TRPs.

[0007] In Type II CJT, the UE is configured to measure K s =N TRP CSI-RS resources, where N TRP is the maximum number of configurable TRPs / TRP groups, and it selects N ≤ N TRPCSI / RS resources are used for CSI reporting. Therefore, the CJT CSI calculation at the UE (typically including CQI (channel quality indicator), PMI (precoder matrix indicator) and RI (rank indicator)) is based on the assumption that υ MIMO layers are transmitted from the antenna ports of N selected CSI-RS resources, where υ is the rank indicated by RI. Several other assumptions for CQI / PMI / RI calculation applicable to the time slots associated with the CQI calculation (i.e., CSI reference resources) are specified in clause 5.2.2.5 of 3GPP TS 38.214, including an assumption about the ratio of the energy per resource element (EPRE) of the physical downlink shared channel (PDSCH) to the CSI-RS EPRE (hereinafter also referred to as the power control ratio or Pc ratio). The UE uses this Pc ratio assumption to determine the transmission power of the PDSCH signal based on the measured CSI-RS power, so that the CQI of the transmission assumption associated with the CSI calculation can be estimated.

[0008] Figure 1 shows an example of a multi-TRP system consisting of up to N TRPs connected via backhaul links. TRP = 4 TRPs (or TRP groups) are formed and transmit coherently to one or more co-scheduled UEs. In this example, it is assumed that each remote radio head (RRH) / TRP has the same array geometry N 1 xN 2 , with N in azimuth for each of the two polarizations 1 antenna ports and has N elevation angles 2 antenna ports, so each TRP has a total of 2N 1 ×N 2 In the example, each TRP is equipped with a 2×2 dual-polarized array, so that the total number of transmit antenna ports across the TRP is N TRP ×2N 1 ×N 2 =32.

[0009] Currently, it has been agreed that the UE can assume that the Pc ratio follows the power control offset (powerControlOffset) value configured commonly for all N selected CSI-RS resources. It has also been agreed that in CJT transmission, the precoders combined across the N selected CSI-RS resources are normalized for each layer, and the PDSCH across all N selected resources is used in the CSI calculation. However, for N TRP For each CSI-RS resource in the CSI-RS resources, it is assumed that there is no restriction on the configuration of the Pc ratio.

[0010]

[0011]

[0012] The protocol has been adopted in 3GPP TS38.214 v.18.0.0, making:

[0013]

[0014] An alternative interpretation of the protocol (proposed but not adopted) is that the UE may assume that for all j=1, ..., N, the PDSCH signal for the v layer transmitted on the NP antenna ports will have the same EPRE as the CSI-RS resource σ transmitted on the corresponding P antenna ports j The ratio of the CSI-RS EPRE is equal to the powerControlOffset of the corresponding CSI-RS resource.

[0015] Another alternative interpretation of the protocol (proposed but not adopted) is that the UE may assume that the PDSCH signal for the v layer will have the same EPRE as for all CSI-RS resources σ j The ratio of the CSI-RS EPRE of j=1, ..., N is equal to the powerControlOffset of the corresponding CSI-RS resource.

[0016] In all three proposed interpretations, the definition of the PDSCH to CSI-RS EPRE ratio is understood to be the same, as it is the ratio between the energy of all PDSCH ports (i.e., layers) υ multiplexed in an RE and the energy of all CSI-RS ports from a given CSI-RS resource multiplexed in an RE. In other words, the energy of all CSI-RS ports from a given CSI-RS resource multiplexed in a resource σ should be considered. j How many PDSCH ports are mapped in one RE and transmitted on P CSI-RS ports: all υ. Therefore, the energy of all these υ ports multiplexed in one RE is included in the PDSCH EPRE calculation. Then, the CSI-RS resource σ multiplexed in one RE should be considered j How many ports out of the P ports are included in the CSI-RS EPRE calculation.

[0017] In summary, the Pc ratio of the CSI-RS resources agreed to be configured for CJT CSI reporting is calculated as follows:

[0018] 1. PDSCH energy is summed over all layers transmitted on a port of a CSI-RS resource. The energy of one layer is not split into the portion of energy transmitted by each TRP.

[0019] 2. Sum the CSI-RS energy over all ports of the CSI-RS resource mapped to the same RE. Summary of the invention

[0020] Various aspects of examples of the invention are set out in the claims.

[0021] According to a first aspect of the present invention, an apparatus comprises: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least: TRP An integer number N of channel state information reference signal (CSI-RS) resources are selected from the network configured CSI-RS resources to a resource set associated with the CSI reporting configuration, where N <N TRP ; Determine the scaling factor for the resource set, where N0 <N TRP when the scaling factor is not equal to 1; determining at least one CSI component based at least in part on the following assumption, the at least one CSI component including one or more of PMI, RI or CQI, the assumption being that a ratio of energy per resource element (EPRE) of a transmission of a PDSCH signal to an EPRE of a transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset, the power control offset being configured for the nth CSI-RS resource in a resource set, where n∈[1,N]; and transmitting a CSI report to a network, the CSI report including the determined at least one CSI component.

[0022] According to a second aspect of the present invention, a method comprises: TRP An integer number N of channel state information reference signal (CSI-RS) resources are selected from the network configured CSI-RS resources to a resource set associated with the CSI reporting configuration, where N <N TRP ; Determine the scaling factor for the resource set, where N0 <N TRP when the scaling factor is not equal to 1; determining at least one CSI component based at least in part on the following assumption, the at least one CSI component including one or more of PMI, RI or CQI, the assumption being that a ratio of energy per resource element (EPRE) of a transmission of a PDSCH signal to an EPRE of a transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset, the power control offset being configured for the nth CSI-RS resource in a resource set, where n∈[1,N]; and transmitting a CSI report to a network, the CSI report including the determined at least one CSI component.

[0023] According to a third aspect of the present invention, a non-transitory computer readable medium or a computer program is encoded with instructions which, when executed by a processor, cause an apparatus to at least: TRPAn integer number N of channel state information reference signal (CSI-RS) resources are selected from the network configured CSI-RS resources to a resource set associated with the CSI reporting configuration, where N <N TRP ; Determine the scaling factor for the resource set, where N0 <N TRP when , the scaling factor is not equal to 1; determining at least one CSI component based at least in part on the following assumption, the at least one CSI component including one or more of PMI, RI or CQI, the assumption being that a ratio of a transmission per resource element energy (EPRE) of a PDSCH signal to a transmission EPRE of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset, the power control offset being configured for the nth CSI-RS resource in a resource set, where n∈[1,N]; and transmitting a CSI report to a network, the CSI report including the determined at least one CSI component.

[0024] According to a fourth aspect of the present invention, an apparatus comprises means for performing the following operations: TRP An integer number N of channel state information reference signal (CSI-RS) resources are selected from the network configured CSI-RS resources to a resource set associated with the CSI reporting configuration, where N <N TRP ; Determine the scaling factor for the resource set, where N0 <N TRP when , the scaling factor is not equal to 1; determining at least one CSI component based at least in part on the following assumption, the at least one CSI component including one or more of PMI, RI or CQI, the assumption being that a ratio of a transmission per resource element energy (EPRE) of a PDSCH signal to a transmission EPRE of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset, the power control offset being configured for the nth CSI-RS resource in a resource set, where n∈[1,N]; and transmitting a CSI report to a network, the CSI report including the determined at least one CSI component. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] For a more complete understanding of example embodiments of the present invention, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0026] Figure 1 An example of a multi-TRP system is illustrated;

[0027] Figure 2 illustrates various embodiments of the present invention; and

[0028] Figure 3 A block diagram of an example wireless device according to an embodiment of the present invention is illustrated. DETAILED DESCRIPTION

[0029] The previously described protocol does not restrict the network configuration. For example, if different TRPs experience different path losses, the Pc ratios of the corresponding CSI-RS resources may be configured with different values, because the EPRE for the transmission of one CSI-RS resource may be different from the EPRE for the transmission of another CSI-RS resource. Therefore, a UE that does not support PMI calculation with different ratios will have to select N CSI-RS resources that are configured with the same ratio.

[0030] Another problem is that gNB configures N for channel measurement. TRP The Pc ratio of CSI-RS resources is unknown when the number of TRPs selected by the UE is N≤N TRP . Description E PDSCH is the maximum EPRE allowed to be transmitted by TRP, and is the CSI-RS resource σ j EPRE, assuming that the gNB operates at the maximum power level for each TRP, then for resource σ j The Pc ratio depends on the number N of configured TRPs TRP ,Right now:

[0031] CSI-RS resource σ j of

[0032] However, if the UE selects N≤N TRP If the TRP is used for CSI reporting, the assumed Pc ratio should be assumed to come from N rather than N TRP CJT transfer of TRPs, i.e., it should be assumed that:

[0033] CSI-RS resource σ j of

[0034] Otherwise, the reported CQI will be overestimated. TRP =2 configuration, for N TRP =4 configuration, the CQI reported for N=2 TRPs will be 3dB higher.

[0035] Therefore, the above adopted protocol should be modified so that the UE can assume that the PDSCH signal for layer v will have the same EPRE and σ for all CSI-RS resources j The ratio of CSI-RS EPRE (where j = 1, ..., N), which is equal to N / N TRP Multiply by the powerControlOffset of the corresponding CSI-RS resource.

[0036] The advantages of pre-scaling the CQI calculation for CJT CSI reporting are described below. Although the detailed calculation of CQI depends on the UE implementation and no specific detailed calculation is required to implement the embodiments of the present invention, certain UE assumptions about the mapping of PDSCH layers to CSI-RS ports and PDSCH transmit power are specified to avoid incorrect CQI determination.

[0037] In the current CJT CSI reporting, the UE can support PDSCH transmissions up to rank 4, so a single PDSCH codeword and a single CQI are calculated per codeword. The CQI can be reported per subband or wideband over the configured reporting band. For CJT transmission, as mentioned above, the UE assumes that the signal of each PDSCH port (i.e., layer) is transmitted on all CSI-RS ports of the N selected CSI-RS resources, each CSI-RS resource has P ports, and the power of the PMI of each layer is normalized on these N×P ports independently of other layers.

[0038] The UE can use the CSI-RS resource σ j Pc offset definition To derive the total transmit power of PDSCH across v layers on one subcarrier:

[0039]

[0040] where x (p) is the PDSCH signal of layer p, N CDM is the number of CDM groups. Factor is used to convert CSI-RS resources σ j Scaling factors mapped to REs as defined in clause 7.4.1.5.3 of 3GPP TS 38.211. PDSCH transmission is specified in clause 5.2.2.5.1b of TS 38.214 as:

[0041]

[0042]

[0043] Since it is currently proposed to change the notation in the above-cited standard specification to represent N as N 0 , so the two symbols are used interchangeably here.

[0044] Assuming the maximum allowed transmit power per antenna, the total PDSCH transmit power depends on the number of transmit TRPs. TRPThe effect of selecting N out of the CSI-RS resources for CJT transmission is to silence a subset of the configured TRPs and their corresponding antennas, thereby reducing the assumed transmit power for the PDSCH transmission. When calculating this power reduction factor, the effect of power backoff is not taken into account, and if the precoding weights applied to the antenna ports have different magnitudes, power backoff is required to ensure that the maximum per-antenna power constraint is met. This power backoff adjustment is typically applied at the gNB depending on the actual PDSCH precoding weights, which can be different from the reported PMI weights. Therefore, under the assumption of equal magnitude PDSCH precoding weights, or averaging over all possible precoders, the total transmitted PDSCH power for CJT transmissions scales linearly with the number of active TRPs, i.e., the total transmitted PDSCH power assuming N transmitting TRPs is N times the total transmitted PDSCH power assuming 1 transmitting TRP, and for 1≤N≤N TRP , is the assumption that N TRP N / N of the total transmit PDSCH power of the transmit TRP TRP times.

[0045] Since the gNB usually does not know in advance the number N of CSI-RS resources / TRPs selected by the UE, the gNB j The configured Pc ratio can be expressed as:

[0046]

[0047] The UE can select the jth CSI-RS resource σ according to the configuration j The total transmission PDSCH power is obtained by using the Pc ratio of (j=1, ..., N), as follows:

[0048]

[0049] This is equivalent to assuming that the Pc ratio is a fraction N / N of the Pc ratio configured for the resource. TRP .

[0050] Apply scaling factor N / N TRP Ensure that the UE has N <N TRP This can lead to a bias towards selecting fewer TRPs for transmission: if the assumed total transmit power is independent of the number of active TRPs, and cross-layer interference increases with the number of active TRPs, the estimated CQI tends to increase as the number of active TRPs decreases because there are more interfering transmit antennas.

[0051] Figure 2In 210, the UE receives a CSI configuration, wherein the CSI configuration is consistent with an integer (N TRP ) CSI-RS resources. The CSI configuration is typically received from a network node such as a base station. The UE may receive additional such CSI configurations indicating the same or different number of CSI-RS resources, and may receive additional CSI configurations that do not provide CSI-RS resources, each of which may be received from the same network node or a different network node. For simplicity, the embodiments are described with respect to a single received CSI configuration, but such limitation is not implied.

[0052] Based at least in part on the CSI configuration, the UE receives TRP CSI-RS resources select N CSI-RS resources for CSI reporting, that is, the UE selects N CSI-RS resources for CSI reporting. TRP N CSI-RS resources among the CSI-RS resources are selected into a resource set associated with the CSI reporting configuration.

[0053] When N <N TRP When , the UE may determine the scaling factor in 230. The scaling factor may be N / N TRP Alternatively, the scaling factor can be N / N TRP When N=N TRP The UE may also determine the scaling factor, but in this case the scaling factor may be 1.

[0054] At 240, the UE may determine at least one CSI component for one or more of the N selected CSI-RS resources, where an individual CSI-RS resource is denoted as σ j , j=1…N.

[0055] The determination of the CSI component may be based at least in part on the assumption that the EPRE of the transmission of the PDSCH signal is consistent with the corresponding CSI-RS resource σ j The ratio of the EPRE of the transmission (called the ratio of the EPRE of the CSI-RS resource σ j The assumed Pc) is equal to the scaling factor multiplied by the power control offset, which is the power control offset for the corresponding CSI-RS resource σ j And configured.

[0056] The determination of the at least one CSI component may be based at least in part on the assumption that, for each CSI-RS resource in the N selected resources (resource sets), the EPRE of the transmission of the PDSCH signal is consistent with the corresponding CSI-RS resource σ j The ratio of the EPRE of the transmission (called the ratio of the EPRE of the CSI-RS resource σ jThe assumed Pc) is equal to the scaling factor multiplied by the power control offset, which is the power control offset for the corresponding CSI-RS resource σ j And configured.

[0057] Since the power control offsets configured for individual CSI-RS resources may be different or the same, the Pc assumed for the individual CSI-RS resources will be different or the same accordingly.

[0058] As part of determining at least one CSI component, the UE may j The corresponding total transmitted PDSCH power is determined as:

[0059] or

[0060]

[0061] Where N CDM is the number of CDM groups, and is the parameter β of the j-th CSI-RS resource specified in 3GPP New Radio CSIRS .

[0062] In 250, the UE may determine at least one of a PMI, an RI, or a CQI based at least in part on the CSI component or based at least in part on the assumption that for each CSI-RS resource in the N selected resources, for the CSI-RS resource σ j Pc is equal to the scaling factor multiplied by the power control offset, which is the power control offset for the corresponding CSI-RS resource σ j At least one of PMI, RI or CQI may be indicated in a CSI report to a network node.

[0063] In 260, the UE may indicate the scaling factor to the network node, which may be performed at any time after determining the scaling factor. The indication may be sent in a CSI report including at least one of PMI, RI or CQI, or may be included in a different message, possibly sent earlier or later.

[0064] The indication of the scaling factor may indicate the scaling factor itself, an integer N of selected CSI-RS, or an indication of selected CSI-RS resources. The indication of the selected CSI-RS resources may, for example, include a bitmap indicating the N indicated in the CSI reporting configuration. TRP Which CSI-RS resources among the CSI-RS resources are selected.

[0065] Figure 3A block diagram of an example wireless device (300) according to an embodiment of the present invention is depicted. The wireless device may include at least one processor (320), at least one memory (310) coupled to the at least one processor (320), and at least one suitable transceiver (330, 331) coupled to at least one antenna unit (350, 351) via at least one amplifier (340, 341), the transceiver having a transmitter and a receiver coupled to the at least one processor (320). The at least one memory (310) may store a computer program that, when executed by the at least one processor (320) (e.g., in combination with any one of the at least one transceiver (330, 331), the at least one amplifier (340, 341), and the at least one antenna unit (350, 351), may perform an embodiment of the present invention. For example, a user device (such as a mobile phone, a car, a watch, or a drone) may be implemented in the device 300.

[0066] Embodiments of the present invention may be implemented in software (executed by one or more processors), hardware (e.g., a dedicated integrated circuit or a field programmable gate array), or a combination of software and hardware. In an exemplary embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional non-transitory computer-readable media.

[0067] Software, hardware, or a combination thereof, or apparatus 300 or a portion thereof may provide means for performing embodiments of the present invention.

[0068] While various aspects are set out above, other aspects include other combinations of features from the described embodiments, not just the combinations described above.

Claims

1. A method for a user device, comprising: From the integer N TRP An integer number N0 of the channel state information reference signal CSI-RS resources (210) configured by the network is selected (220) to a resource set associated with the CSI reporting configuration, where N0 <N TRP ; Determine (230) a scaling factor for the resource set, wherein when N0 <N TRP When , the scaling factor is not equal to 1; determining (240) at least one CSI component, the at least one CSI component comprising one or more of a precoder matrix indicator, a rank indicator, or a channel quality indicator, based at least in part on an assumption that a ratio of an energy per resource unit (EPRE) for transmission of a physical downlink shared channel (PDSCH) signal to an EPRE for transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n∈[1,N0]; as well as A CSI report is transmitted (250) to a network, the CSI report comprising the determined at least one CSI component.

2. The method of claim 1, wherein the scaling factor is determined to be equal to N0 divided by N TRP .

3. The method according to claim 1 or 2, wherein the at least one CSI component is determined at least in part based on the following assumption, which is that: for each CSI-RS resource in the resource set, the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the corresponding CSI-RS resource is equal to the scaling factor multiplied by the power control offset, which power control offset is configured for the corresponding CSI-RS resource.

4. The method according to any one of claims 1 to 3, further comprising: The total transmission power of the PDSCH signal is determined according to the following: in is the power control offset configured for the nth CSI-RS resource in the resource set; N CDM is the number of CDM groups, and is the parameter β specified in 3GPP New Radio for the nth CSI-RS resource CSIRS .

5. The method according to any one of claims 1 to 3, further comprising: An indication of the scaling factor is transmitted (260) to a network.

6. The method of claim 5, wherein the indication comprises: The scaling factor, the selected integer N0, or an indication of the selected CSI-RS resource.

7. An apparatus for communication, comprising: at least one processor; as well as 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: From the integer N TRP An integer number N0 of the channel state information reference signal CSI-RS resources configured by the network is selected into a resource set associated with the CSI report configuration, where N0 <N TRP ; Determine a scaling factor for the resource set, where N0 <N TRP When , the scaling factor is not equal to 1; determining at least one CSI component, the at least one CSI component comprising one or more of a precoder matrix indicator, a rank indicator, or a channel quality indicator, based at least in part on an assumption that a ratio of an energy per resource unit EPRE for transmission of a physical downlink shared channel (PDSCH) signal to an EPRE for transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n∈[1,N0]; as well as A CSI report is transmitted to a network, the CSI report including the determined at least one CSI component.

8. The apparatus of claim 7, wherein the scaling factor is determined to be equal to N0 divided by N TRP .

9. An apparatus according to claim 7 or 8, wherein the at least one CSI component is determined at least in part based on the following assumption, which is that: for each CSI-RS resource in the resource set, the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the corresponding CSI-RS resource is equal to the scaling factor multiplied by a power control offset, which power control offset is configured for the corresponding CSI-RS resource.

10. The device according to any one of claims 7 to 9, wherein the device is further configured to: The total transmission power of the PDSCH signal is determined according to the following: in is the power control offset configured for the nth CSI-RS resource in the resource set; N CDM is the number of CDM groups, and is the parameter β specified in 3GPP New Radio for the nth CSI-RS resource CSIRS .

11. The device according to any one of claims 7 to 10, further comprising: An indication of the scaling factor is transmitted to a network.

12. The apparatus of claim 11, wherein the indication comprises: The scaling factor, the selected integer N0, or an indication of the selected CSI-RS resource.

13. An apparatus for communication, comprising: For an integer N TRP A component for selecting (220) an integer N0 number of channel state information reference signal CSI-RS resources (210) configured by the network to a resource set associated with the CSI reporting configuration, where N0 <N TRP ; means for determining (230) a scaling factor for the resource set, wherein when N0 <N TRP When , the scaling factor is not equal to 1; means for determining (240) at least one CSI component, the at least one CSI component comprising one or more of a precoder matrix indicator, a rank indicator, or a channel quality indicator based at least in part on an assumption that a ratio of an energy per resource unit EPRE for transmission of a physical downlink shared channel (PDSCH) signal to an EPRE for transmission of the nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n∈[1,N0]; as well as Means for transmitting (250) a CSI report to a network, the CSI report comprising the determined at least one CSI component.

14. The apparatus of claim 13, wherein the scaling factor is determined to be equal to N0 divided by N TRP .

15. An apparatus according to claim 13 or 14, wherein the at least one CSI component is determined at least in part based on the following assumption, which is that: for each CSI-RS resource in the resource set, the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the corresponding CSI-RS resource is equal to the scaling factor multiplied by a power control offset, which power control offset is configured for the corresponding CSI-RS resource.

16. The device according to any one of claims 13 to 15, wherein the device further comprises: means for determining the total transmission power of the PDSCH signal according to: in is the power control offset configured for the nth CSI-RS resource in the resource set; N CDM is the number of CDM groups, and is the parameter β specified in 3GPP New Radio for the nth CSI-RS resource CSIRS .

17. The device according to any one of claims 13 to 16, further comprising: Means for transmitting (260) an indication of the scaling factor to a network.

18. The apparatus of claim 17, wherein the indication comprises: The scaling factor, the selected integer N0, or an indication of the selected CSI-RS resource.

19. A computer-readable medium encoded with instructions that, when executed by a processor, cause an apparatus to at least: From the integer N TRP An integer number N0 of the channel state information reference signal CSI-RS resources configured by the network is selected into a resource set associated with the CSI report configuration, where N0 <N TRP ; Determine a scaling factor for the resource set, where N0 <N TRP When , the scaling factor is not equal to 1; determining at least one CSI component, the at least one CSI component comprising one or more of a precoder matrix indicator, a rank indicator, or a channel quality indicator, based at least in part on an assumption that a ratio of an energy per resource unit EPRE for transmission of a physical downlink shared channel (PDSCH) signal to an EPRE for transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n∈[1,N0]; as well as A CSI report is transmitted to a network, the CSI report including the determined at least one CSI component.

20. The computer-readable medium of claim 19, wherein the scaling factor is determined to be equal to N0 divided by N TRP .

21. A computer-readable medium according to claim 19 or 20, wherein the at least one CSI component is determined at least in part based on the following assumption, which is that: for each CSI-RS resource in the resource set, the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the corresponding CSI-RS resource is equal to the scaling factor multiplied by a power control offset, which power control offset is configured for the corresponding CSI-RS resource.

22. The computer readable medium of any one of claims 19 to 21, wherein the apparatus is further caused to: The total transmission power of the PDSCH signal is determined according to the following: in is the power control offset configured for the nth CSI-RS resource in the resource set; N CDM is the number of CDM groups, and is the parameter β specified in 3GPP New Radio for the nth CSI-RS resource CSIRS .

23. The computer-readable medium of any one of claims 19 to 22, further comprising: An indication of the scaling factor is transmitted to a network.

24. The computer-readable medium of claim 23, wherein the indication comprises: The scaling factor, the selected integer N0, or an indication of the selected CSI-RS resource.

25. A computer program product comprising instructions which, when the program is executed by a computer, cause the computer to: From the integer N TRP An integer number N0 of the channel state information reference signal CSI-RS resources (210) configured by the network is selected (220) to a resource set associated with the CSI reporting configuration, where N0 <N TRP ; Determine (230) a scaling factor for the resource set, wherein when N0 <N TRP When , the scaling factor is not equal to 1; determining (240) at least one CSI component, the at least one CSI component comprising one or more of a precoder matrix indicator, a rank indicator, or a channel quality indicator, based at least in part on an assumption that a ratio of an energy per resource unit (EPRE) for transmission of a physical downlink shared channel (PDSCH) signal to an EPRE for transmission of an nth CSI-RS resource is equal to the scaling factor multiplied by a power control offset configured for the nth CSI-RS resource in the resource set, where n∈[1,N0]; as well as A CSI report is transmitted (250) to a network, the CSI report comprising the determined at least one CSI component.

26. The computer program product of claim 25, wherein the scaling factor is determined to be equal to N0 divided by N TRP .

27. A computer program product according to claim 25 or 26, wherein the at least one CSI component is determined at least in part based on the following assumption, which is that: for each CSI-RS resource in the resource set, the ratio of the EPRE of the transmission of the PDSCH signal to the EPRE of the transmission of the corresponding CSI-RS resource is equal to the scaling factor multiplied by a power control offset, which power control offset is configured for the corresponding CSI-RS resource.

28. A computer program product according to any one of claims 25 to 27, wherein the apparatus is further caused to: The total transmission power of the PDSCH signal is determined according to the following: in is the power control offset configured for the nth CSI-RS resource in the resource set; N CDM is the number of CDM groups, and is the parameter β specified in 3GPP New Radio for the nth CSI-RS resource CSIRS .

29. The computer program product according to any one of claims 25 to 28, further comprising: An indication of the scaling factor is transmitted to a network.

30. The computer program product of claim 29, wherein the indication comprises: The scaling factor, the selected integer N0, or an indication of the selected CSI-RS resource.

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