Low-overhead channel state information (CSI) feedback for multiple transmission point (TRP) transmissions

Abstract

A method and apparatus for low-overhead CSI feedback for multi-TRP transmissions are disclosed. In one embodiment, a method implemented in a wireless device includes: receiving a configuration of a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, K being an integer; receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting; measuring a channel based at least in part on the NZP CSI-RS resources; and sending a channel state information (CSI) feedback report based at least in part on: channel measurement; and report quantity configuration; and the CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

Description

Technical Field

[0001] The present disclosure relates to wireless communications, and more particularly, to low overhead channel state information (CSI) feedback for multiple transmission point (TRP) transmissions. Background Art

[0002] The next generation of mobile wireless communication systems (3rd Generation Partnership Project (3GPP) 5th Generation (5G)) or New Radio (NR) can support a variety of use cases and a variety of deployment scenarios. The latter include deployment at low frequencies (e.g., below 6 GHz) and very high frequencies (e.g., up to 10 GHz).

[0003] Similar to Long Term Evolution (LTE), NR uses cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) in the downlink (i.e., from a network node, gNB, eNB, or base station to a wireless device (WD) such as a user equipment (UE)) and CP-OFDM and DFT-S-OFDM (DFT-spread OFDM) in the uplink (i.e., from a WD to a network node (e.g., gNB)). In the time domain, the NR downlink and uplink can be organized into subframes of the same size, each of which is 1 millisecond (ms). A subframe can also be divided into multiple time slots of equal length.

[0004] The slot length may depend on the subcarrier spacing. For a subcarrier spacing of Δf=15 kHz, there may be only one slot per subframe, and each slot may include 14 OFDM symbols.

[0005] Data scheduling in NR can be based on time slots as in LTE, an example of which is shown in Figure 1 , where a 14-symbol slot is used, where the first two symbols contain the Physical Downlink Control Channel (PDCCH) and the remaining symbols contain the Physical Data Channel (PDCH) (e.g., the Physical Downlink Data Channel (PDSCH) or the Physical Uplink Data Channel (PUSCH)).

[0006] Different subcarrier spacing values ​​are supported in NR. The supported subcarrier spacing values ​​(also called different parameter sets) can be given by Δf=(15×2 α )kHz, where α is a non-negative integer (Δf=15kHz is the basic subcarrier spacing also used in LTE). As an example, the time slot durations under different subcarrier spacings are shown in Table 1.

[0007] Table 1: Slot lengths under different parameter sets.

[0008] <![CDATA[ Parameter Set ]]> <![CDATA[ Slot length ]]> <![CDATA[ RB BW ]]> 15kHz 1ms 180kHz 30kHz 0.5ms 360kHz 60kHz 0.25ms 720kHz 120kHz 125μs 1.44MHz 240kHz 62.5μs 2.88MHz

[0009] In the frequency domain, the system bandwidth can be divided into resource blocks (RBs), each of which corresponds to 12 consecutive subcarriers. RBs can be numbered starting from 0 at one end of the system bandwidth. An example of a basic NR physical time-frequency resource grid is shown in Figure 2 , where only one resource block (RB) within one 14-symbol slot is shown. One OFDM subcarrier during one OFDM symbol interval forms one resource element (RE).

[0010] Downlink (from base station to wireless device) transmission can be dynamically scheduled, i.e., in each time slot, the network node (e.g., gNB) can send downlink control information (DCI) about which WD data is to be sent to it and on which RBs in the current downlink time slot through the physical downlink control channel (PDCCH). PDCCH is usually sent in the first one or two OFDM symbols of each time slot in NR. WD data is carried on PDSCH. WD can first detect and decode PDCCH, and if the decoding is successful, WD decodes the corresponding PDSCH based on the decoded control information in PDCCH.

[0011] PDCCH can also be used to dynamically schedule uplink data transmission. Similar to the downlink, the WD first decodes the uplink grant in the PDCCH, and then sends data through the PUSCH based on the decoded control information in the uplink grant (such as modulation order, coding rate, uplink resource allocation, etc.).

[0012] Spatial multiplexing

[0013] Multiple antenna technology can significantly increase the data rate and reliability of wireless communication systems. Performance can be improved if both the transmitter and the receiver are equipped with multiple antennas, thereby forming a multiple-input multiple-output (MIMO) communication channel. Such systems and / or related technologies are generally referred to as MIMO.

[0014] An integral part of NR is support for MIMO antenna deployment and MIMO related technologies. Spatial multiplexing is one of the MIMO technologies used to achieve high data rates under favorable channel conditions. Figure 3 An illustration of an example of spatial multiplexing operation is provided in .

[0015] like Figure 3 As shown in , the symbol vector s = [s1, s2, ..., s r ] T The information is multiplied by N T xr precoder matrix w, the precoder matrix w is used to T (corresponding to N TThe transmit energy is distributed in a subspace of the 2-dimensional vector space (number of antenna ports). The precoder matrix is ​​usually selected from a codebook of possible precoder matrices and is usually indicated by a precoder matrix indicator (PMI), which specifies a unique precoder matrix in the codebook for a given number of symbol streams. The r symbols in s each correspond to a MIMO layer, and r is called the transmission rank. In this way, spatial multiplexing is achieved because multiple symbols can be sent simultaneously on the same time-frequency resource element (RE). The number of symbols r is usually adapted to suit the current channel characteristics.

[0016] At N with a specific RE n R The signal received at the WD of a receiving antenna can be given by the following formula:

[0017] y n =H n Ws+e n ,

[0018] Among them, y n YesN R ×1 received signal vector, H n is N at RE R ×N T Channel matrix, e n is the N received by WD at RE R × 1 noise and interference vectors. The precoder w can be a wideband precoder, which is constant in frequency, or frequency selective (ie, varies in frequency).

[0019] The precoder matrix is ​​usually chosen to match N R x N T MIMO channel matrix H n This is also often referred to as closed-loop precoding and essentially aims to focus the transmit energy into a subspace that is strong in the sense of delivering most of the transmit energy to the WDs. Additionally, the precoder matrix can also be chosen to aim to orthogonalize the channel, meaning that inter-layer interference is reduced after appropriate linear equalization of the WDs.

[0020] The transmission rank, and therefore the number of spatial multiplexing layers, is reflected in the number of columns of the precoder. The transmission rank also depends on the signal and noise plus interference ratio (SINR) observed at the WD. Generally, higher rank transmissions require higher SINR. For efficient performance, a transmission rank can be selected that matches the channel characteristics and interference. The precoding matrix, transmission rank, and channel quality can be part of the channel state information (CSI), which is usually measured by the WD and fed back to the network node or gNB.

[0021] NR MIMO data transmission

[0022] An example of NR data transmission over multiple MIMO layers is shown in Figure 4 q. Depending on the total number or rank of MIMO layers, one codeword (CW) or two codewords may be used. In NR Release 15, one codeword is used when the total number of layers is equal to or less than 4, and two codewords are used when the number of layers is greater than 4. Each codeword may include coded data bits for a transport block (TB). After bit-level scrambling, the scrambled bits may be mapped to complex-valued modulation symbols of codeword q. According to Table 7.3.1.3-1 of the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 38.211 (reproduced below), these complex-valued modulation symbols can then be mapped to layer x(i)=[x (0) (i) ... x (v-1) (i)] T superior, Where v is the number of layers, is the number of modulation symbols per layer.

[0023] Table 7.3.1.3-1: Codeword-layer mapping for spatial multiplexing.

[0024]

[0025] For demodulation purposes, a demodulation reference signal (DMRS) (also called a DMRS port) may be sent along each data layer. Vector Block It can be mapped to the DMRS antenna port according to the following formula:

[0026]

[0027] in, The DMRS antenna port set {p0, ..., p v-1} and port-layer mapping.

[0028] CSI Feedback

[0029] For CSI feedback, NR can use an implicit CSI mechanism, where the WD feedback of downlink channel state information typically includes a transmission rank indicator (RI), a precoder matrix indicator (PMI), and a channel quality indicator (CQI) for each codeword. Based on the configuration, the CQI / RI / PMI report can be wideband or subband.

[0030] RI may correspond to the recommended number of layers to be spatially multiplexed and thus transmitted in parallel on an effective channel; PMI may identify a recommended precoding matrix to be used; CQI may indicate a recommended modulation level (e.g., quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (16QAM), etc.) and a coding rate for each codeword or TB. NR supports sending one or two codewords to a WD in one slot, where two codewords are used for 5 to 8 layer transmission and one codeword is used for 1 to 4 layer transmission. Therefore, there is a relationship between the CQI and SINR of the spatial layer on which the codeword is transmitted, and for two codewords, two CQI values ​​are fed back.

[0031] Channel State Information Reference Signal (CSI-RS)

[0032] For CSI measurement and feedback, a dedicated reference signal for CSI-RS can be defined. CSI-RS resources may include 1 to 32 CSI-RS ports, and each port is typically sent on each transmit antenna (or virtual transmit antenna, if the port is precoded and mapped to multiple transmit antennas) and is used by WD to measure the downlink channel between each transmit antenna port and each receive antenna port of WD. Antenna ports are also called CSI-RS ports. The number of antenna ports supported in NR can be {1, 2, 4, 8, 12, 16, 24, 32}. By measuring the received CSI-RS, WD can estimate the channel that the CSI-RS is traversing, including the radio propagation channel, potential precoding or beamforming, and antenna gain. CSI-RS for the above purpose may also be referred to as non-zero power (NZP) CSI-RS. However, there is also zero power (ZP) CSI-RS that can be used for purposes other than coherent channel measurement.

[0033] The CSI-RS may be configured to be transmitted in specific REs in one slot and / or a plurality of specific slots. Figure 5 An example of CSI-RS resources mapped to REs for 12 antenna ports is shown, where 1 RE per RB per port is shown.

[0034] In addition, interference measurement resources (CSI-IM) for CSI feedback are also defined in NR for WD to measure interference. CSI-IM resources may include 4 REs, such as 4 REs adjacent in frequency in the same OFDM symbol, or 2×2 REs adjacent in both time and frequency in a time slot. By measuring both the NZP CSI-RS-based channel and the CSI-IM-based interference, the WD can estimate the effective channel and noise plus interference to determine the CSI, i.e., rank, precoding matrix, and channel quality.

[0035] In addition, the WD in NR can be configured to measure interference based on one or more NZP CSI-RS resources.

[0036] CSI framework in NR

[0037] In NR, a WD may be configured with multiple CSI report settings (e.g., with a higher-level parameter CSI-ReportConfig) and multiple CSI resource settings (e.g., with a higher-level parameter CSI-ResourceConfig). Each CSI resource setting may have an associated identifier (e.g., a higher-level parameter CSI-ResourceConfigId) and a list that may include S≥1 CSI resource sets (e.g., given by a higher-level parameter csi-RS-ResourceSetList), where the list includes a reference to an NZP CSI-RS resource set, or the list includes a reference to a CSI-IM resource set. For periodic and semi-persistent CSI resource settings, the number of configured CSI resource sets may be limited to S=1.

[0038] For aperiodic CSI reporting, a CSI trigger state list can be configured using the high-level parameter CSI-AperiodicTriggerStateList. Each trigger state includes at least one CSI report setting. For an aperiodic CSI resource setting with S>1 CSI resource sets, only one aperiodic CSI resource set in the aperiodic CSI resource set is associated with the CSI trigger state, and the WD is configured by the high-level according to the resource setting and according to the trigger state to select a CSI-IM resource set or NZP CSI-RS resource set from the resource setting. DCI can be used to dynamically select a CSI trigger state.

[0039] According to 3GPP TS 38.331 v15.3.0, an example of a CSI-ReportConfig parameter or information element (IE) is as follows:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] Each CSI report setting may include one or more of the following information:

[0046] - CSI resource settings on NZP CSI-RS resources for channel measurement;

[0047] - CSI resource settings on CSI-IM resources for interference measurement;

[0048] - Optionally, CSI resource settings for NZP CSI-RS resources for interference measurement;

[0049] - The temporal behavior used for reporting, e.g., periodic, semi-persistent, or aperiodic reporting;

[0050] - Frequency granularity, e.g. wideband or sub-band CQI and PMI respectively;

[0051] - Reporting quantities, e.g., CSI parameters to be reported, such as RI, PMI, CQI, Layer Indicator (LI), and CSI-RS Resource Indicator (CRI), in case there are multiple NZP CSI-RS resources in one resource set;

[0052] - Codebook type, e.g. Type I or II (if reported), and codebook subset restrictions; and

[0053] - Measurement limitations.

[0054] When K is configured in the corresponding NZP CSI-RS resource set s When >1 NZP CSI-RS resource is used for channel measurement, WD can select K s >1 NZP CSI-RS resource, and an NZP CSI-RS resource indicator (CRI) may be reported by the WD to indicate the selected NZP CSI-RS resource in the resource set to the network node (e.g., gNB). The WD may derive other CSI parameters (i.e., RI, PMI, and CQI) based on the reported CRI, where CRI k (k ≥ 0) corresponds to the configured (k+1)th entry of the associated NZP CSI-RS Resource in the corresponding NZP CSI-RS ResourceSet for channel measurement, and the (k+1)th entry of the associated CSI-IM Resource in the corresponding CSI-IM-ResourceSet for interference measurement. The CSI-IM-ResourceSet (if configured) also has K s >1 resource.

[0055] For non-periodic CSI reporting in NR, more than one CSI report setting with different NZP CSI-RS resource settings for channel measurement and / or CSI-IM resource settings for interference measurement can be configured within a single CSI trigger state and triggered simultaneously with DCI. In this case, multiple CSI reports associated with one CSI report setting can be aggregated in a single physical uplink shared channel (PUSCH) and sent from the WD to a network node (e.g., gNB). Each CSI trigger state can include up to 16 CSI report settings in NR. The 3-bit CSI request field in the uplink DCI (i.e., DCI format 0-1) can be used to select one of the trigger states for CSI reporting. When the number of CSI trigger states configured by the radio resource control (RRC) is greater than 7, a media access control (MAC) control element (CE) can be used to select 7 active trigger states from the trigger states configured by the RRC.

[0056] Data transmission through multiple transmission points or panels

[0057] Dynamic Point Selection (DPS)

[0058] In 3GPP NR Release 15 (Rel-15), dynamic transmission point selection (DPS) may be supported, wherein a single transmission point (TRP) may be dynamically selected for sending data to a WD. Different TRPs may be selected at different times. In this case, a network node (e.g., a gNB) may request the WD to measure and feedback downlink (DL) CSI separately for each TRP, and the network node (e.g., a gNB) may compare the measurement feedback reports and then decide which TRP to use for data transmission to the WD. Since the TRPs may be located at different physical locations, the propagation channels to the WD may also be different. Different antenna transmit beams may be used in the TRP, and therefore different receive beams may be used at the WD. In order to facilitate the reception of physical downlink shared channel (PDSCH) data from different TRPs or different beams within the same or different TRPs, a transmission configuration indicator (TCI) state is introduced in 3GPP NR Rel-15.

[0059] The TCI state may include quasi co-location (QCL) information between the DMRS for PDSCH and one or two DL reference signals, such as CSI-RS or synchronization signal blocks (SSBs). The types of QCL information supported in NR may include:

[0060] - 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0061] - 'QCL-TypeB': {Doppler shift, Doppler spread}

[0062] - 'QCL-TypeC': {Doppler shift, average delay}

[0063] - 'QCL-TypeD': {spatial reception parameters}

[0064] To support synchronization and channel tracking for DPS, the WD can be configured with multiple TCI states (e.g., one state for each TRP), and one of these states can be selected and indicated in the DCI. The QCL information is used by the WD to apply one or more channel characteristics estimated from the DL reference signal (CSI-RS or SSB) and associated with the DL reference signal (CSI-RS or SSB) to DMRS-based channel estimation for PDSCH reception. For example, the channel is first estimated based on the CSI-RS, and the channel delay spread and Doppler shift parameters are estimated from the source reference signal (RS) (e.g., CSI-RS in this case), that is, channel analysis is performed. Typically, the source RS indicated by the TCI state is a periodic RS on which the WD can continuously track the channel and perform channel analysis. This information is then used to determine channel filtering parameters based on the DMRS during PDSCH reception.

[0065] To support CSI feedback for DPS, the WD may be configured with multiple CSI reporting settings, one for each TRP. In each CSI reporting setting, a single NZP CSI-RS resource is included in the CSI resource setting for channel measurement, and a single CSI-IM resource is included in the CSI resource setting for interference measurement. These multiple CSI reporting settings may be included in a single aperiodic CSI trigger state. For example, for two TRPs, the following may be configured for the WD:

[0066] -CSI Report Setup #1:

[0067] - NZP CSI-RS resource for channel measurement: {NZP CSI-RS resource #1}

[0068] -CSI-IM resource used for interference measurement: {CSI-IM resource #1}

[0069] -CSI Report Setup #2:

[0070] - NZP CSI-RS resource for channel measurement: {NZP CSI-RS resource #2}

[0071] -CSI-IM resource for interference measurement: {CSI-IM resource #2}

[0072] -Aperiodic CSI triggering state #k (k=3)

[0073] -{CSI report setting #1, CSI report setting #2}

[0074] In this case, a DCI with the CSI bit field set to "100" can be sent to the WD to select the CSI trigger state k=3 (note that the CSI bit field "000" can mean "no trigger", "001" selects the trigger state k=0, "010" selects the state k=1, "011" selects the state k=2, and so on). After receiving the DCI, the WD can immediately measure and report the CSI for the two TRPs in the physical uplink shared channel (PUSCH), for example, {CSI for TRP#1, CSI for TRP#2}.

[0075] Non-coherent joint transmission (NC-JT)

[0076] NC-JT refers to MIMO data transmission over multiple TRPs, where different MIMO layers are sent over different TRPs. Figure 6 An example is shown in , where the PDSCH is sent to the WD via two TRPs, with each TRP carrying one codeword (CW). For example, when the WD has 4 receive antennas and each TRP has only 2 transmit antennas, the WD can support up to 4 MIMO layers, but each TRP can send up to 2 MIMO layers. In this case, by sending data to the WD on two TRPs, the peak data rate to the WD can be increased because up to 4 aggregation layers from the two TRPs can be used. This can be beneficial when the traffic load, and therefore the resource utilization, is low in each TRP. This scheme can also be beneficial when the WD is within the line of sight (LOS) of two TRPs and the rank per TRP is limited (even if there are more transmit antennas available at each TRP).

[0077] This type of NC-JT is supported in LTE with two TRPs. For the purpose of CSI feedback, the WD can be configured with two NZP CSI-RS resources (one resource for each TR) and an interference measurement resource using the CSI process. Due to the complexity of the WD, a limitation of up to 8 CSI-RS ports per CSI-RS resource is introduced for this feedback mode (however, each TRP may have more than 8 transmission chains, in which case the transmission chain can be virtualized to be reduced to 8 ports). By considering the mutual interference between the two codewords (CW) from the two TRPs, the WD calculates the CSI for each NZP CSI-RS resource and reports RI pairs (RI1, RI2), PMI pairs (PMI1, PMI2), and CQI pairs (CQI1, CQI2). With the use of two CWs scheduled using a single or two PDSCHs (although only a single PDSCH is supported in LTE), different modulation and coding schemes (MCS) can be used for the two TRPs. An advanced receiver with CW-level interference cancellation (CWIC) can be used at the WD. In addition, when the reception of one CW has an error, only the CW can be retransmitted. Here, the maximum number of TRPs that can be supported in NC-JT using a single PDSCH can be two, because only two CWs are supported within a single PDSCH in LTE and NR.

[0078] Currently only DPS-based multi-TRP transmission is supported in NR. Currently no NC-JT CSI feedback is specified in NR. Summary of the invention

[0079] Some embodiments advantageously provide methods and apparatus for CSI feedback that allow dynamic switching between a single TRP transmission and NC-JT or URLLC with low CSI feedback overhead (compared to existing CSI feedback techniques).

[0080] In one embodiment, a method implemented in a network node is provided. The method includes one or more of the following:

[0081] Send downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs)

[0082] A channel state information (CSI) reporting setting with K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources is configured for the WD, each resource being associated with one TRP;

[0083] Based on the CSI reporting setting, assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs, requesting a CSI feedback report from the WD; and / or

[0084] Based on the CSI feedback report, scheduling downlink channel transmission to the WD. In another embodiment, a method implemented in a wireless device (WD) is provided. The method includes one or more of the following:

[0085] receiving a CSI feedback request based on a channel state information (CSI) reporting configuration for K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources, each resource being associated with a transmission point (TRP); and / or

[0086] Based on the received CSI reporting settings, assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs,

[0087] Measure and send channel state information (CSI) feedback reports.

[0088] According to one aspect of the present disclosure, a method implemented in a wireless device is provided. The method includes: receiving a configuration of a channel state information (CSI) report setting for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement and a report quantity configuration, where K is an integer. The method includes: receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting. The method includes: measuring a channel based at least in part on the NZP CSI-RS resource. The method includes: sending a channel state information (CSI) feedback report based at least in part on: the channel measurement; and the report quantity configuration. The CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

[0089] In some embodiments of this aspect, the first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources. In some embodiments of this aspect, the second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low-delay URLL transmission. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first layer indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator. In some embodiments of this aspect, the second CSI feedback further includes identifications of the first NZP CSI-RS resource and the second NZP CSI-RS resource.

[0090] In some embodiments of this aspect, the method further includes: determining whether to include the second CSI feedback in the CSI feedback report. In some embodiments of this aspect, determining whether to include the second CSI feedback further includes: if each rank of the first CSI feedback is below a threshold, determining to include the second CSI feedback. In some embodiments of this aspect, the CSI feedback report further includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments of this aspect, the CSI feedback report includes only the second CSI feedback.

[0091] According to another aspect of the present disclosure, a method implemented in a network node is provided. The method includes: configuring a wireless device with a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer. The method includes: sending a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting. The method includes: receiving a channel state information (CSI) feedback report, the CSI feedback report being based at least in part on the CSI report setting. The method includes: the CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

[0092] In some embodiments of this aspect, the first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources. In some embodiments of this aspect, the second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low-delay URLL transmission. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first layer indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

[0093] In some embodiments of this aspect, the second CSI feedback further includes identifications of the first NZP CSI-RS resource and the second NZP CSI-RS resource. In some embodiments of this aspect, the CSI feedback report includes both the first CSI feedback and the second CSI feedback. In some embodiments of this aspect, if each rank of the first CSI feedback is below a threshold, the CSI feedback report includes the second CSI feedback. In some embodiments of this aspect, the CSI feedback report further includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments of this aspect, the CSI feedback report includes only the second CSI feedback.

[0094] According to another aspect of the present disclosure, a wireless device configured to communicate with a network node is provided. The wireless device includes a processing circuit, and the processing circuit is configured to enable the wireless device to: receive a configuration of a channel state information (CSI) report setting for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement and a report quantity configuration, where K is an integer. The processing circuit is configured to enable the wireless device to: receive a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting. The processing circuit is configured to enable the wireless device to: measure a channel based at least in part on the NZP CSI-RS resources. The processing circuit is configured to enable the wireless device to: send a channel state information (CSI) feedback report based at least in part on: the channel measurement; and the report quantity configuration. The CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

[0095] In some embodiments of this aspect, the first CSI feedback includes one CSI for each of the K NZP CSI-RS resources. In some embodiments of this aspect, the second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low-delay URLL transmission. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator. In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first layer indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

[0096] In some embodiments of the aspect, the second CSI feedback further includes identifications of the first NZP CSI-RS resource and the second NZP CSI-RS resource. In some embodiments of the aspect, the processing circuit is configured to cause the wireless device to perform the following operations: determine whether to include the second CSI feedback in the CSI feedback report. In some embodiments of the aspect, the processing circuit is further configured to cause the wireless device to determine whether to include the second CSI feedback by being configured to cause the wireless device to perform the following operations: if each rank of the first CSI feedback is below a threshold, determine to include the second CSI feedback. In some embodiments of the aspect, the CSI feedback report further includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments of the aspect, the CSI feedback report includes only the second CSI feedback.

[0097] According to another aspect of the present disclosure, a network node configured to communicate with a wireless device is provided. The network node includes a processing circuit. The processing circuit is configured to enable the network node to: configure the wireless device with a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer. The processing circuit is configured to enable the network node to: send a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting. The processing circuit is configured to enable the network node to: receive a channel state information (CSI) feedback report, the CSI feedback report being based at least in part on the CSI report setting, and the CSI feedback report including at least one of a first CSI feedback and a second CSI feedback.

[0098] In some embodiments of the aspect, the first CSI feedback includes one CSI for each of the K NZP CSI-RS resources. In some embodiments of the aspect, the second CSI feedback includes CSI for one of a non-coherent joint NC-JT transmission and an ultra-reliable low-delay URLL transmission. In some embodiments of the aspect, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator.

[0099] In some embodiments of this aspect, the second CSI feedback includes a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator. In some embodiments of this aspect, the second CSI feedback also includes an identifier of the first NZP CSI-RS resource and the second NZP CSI-RS resource. In some embodiments of this aspect, the CSI feedback report includes both the first CSI feedback and the second CSI feedback. In some embodiments of this aspect, if each rank of the first CSI feedback is below a threshold, the CSI feedback report includes the second CSI feedback. In some embodiments of this aspect, the CSI feedback report also includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments of this aspect, the CSI feedback report includes only the second CSI feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Embodiments of the present invention and their attendant advantages and features will be more readily understood and more fully appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0101] Figure 1 An example of an NR time domain structure with 15kHz subcarrier spacing is shown;

[0102] Figure 2 An example of a NR physical resource grid is shown;

[0103] Figure 3 An example of a transmission structure for a precoded spatial multiplexing mode in LTE is shown;

[0104] Figure 4 An example of NR MIMO data transmission via multiple antennas is shown;

[0105] Figure 5 An example of RE allocation for 12-port CSI-RS resources in NR is shown;

[0106] Figure 6 An example of NC-JT is shown;

[0107] Figure 7 An example of sending a single CW through multiple TRPs is shown;

[0108] Figure 8 An example of data transmission through multiple TRPs to improve reliability is shown;

[0109] Fig. 9 is a schematic diagram illustrating an exemplary network architecture of a communication system connected to a host computer via an intermediate network according to the principles of the present disclosure;

[0110] Fig.10 is a block diagram of a host computer communicating with a wireless device via a network node over at least a partially wireless connection according to some embodiments of the present disclosure;

[0111] Fig.11 is a flow chart illustrating an exemplary method for executing a client application at a wireless device implemented in a communication system including a host computer, a network node, and a wireless device according to some embodiments of the present disclosure;

[0112] Fig.12 is a flow chart illustrating an exemplary method for receiving user data at a wireless device implemented in a communication system including a host computer, a network node, and a wireless device according to some embodiments of the present disclosure;

[0113] Fig.13 is a flow chart illustrating an exemplary method for receiving user data from a wireless device at a host computer implemented in a communication system including a host computer, a network node, and a wireless device according to some embodiments of the present disclosure;

[0114] Fig.14 is a flow chart illustrating an exemplary method for receiving user data at a host computer implemented in a communication system including a host computer, a network node, and a wireless device according to some embodiments of the present disclosure;

[0115] Fig.15 is a flow chart of an exemplary process for a report setting unit in a network node according to some embodiments of the present disclosure;

[0116] Fig.16 is a flow chart of an exemplary process for a reporting unit in a wireless device according to some embodiments of the present disclosure;

[0117] Fig.17 shows an example of layer indication for NC-JT CSI feedback according to some embodiments of the present disclosure; and

[0118] Fig.18 An example of CSI feedback for URLLC according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0119] An alternative to NC-JT is to use a single PDSCH and a single CW over multiple TRPs, Figure 7An example is shown in , where different layers are sent from three TRPs. This allows data transmission over more than 2 TRPs.

[0120] In one case, a network node (e.g., a gNB) may configure a WD with multiple CSI report settings, some for DPS and others for NC-JT. The WD then feeds back two CSI reports, one for dynamic point selection (DPS) and the other for NC-JT. The network node (e.g., a gNB) may decide whether to use DPS or NC-JT based on the CSI report and other information available at the network node (e.g., a gNB). In another scenario, a network node (e.g., a gNB) may configure a WD with N>1 NZP CSI-RS resources, each associated with a TRP, in a CSI resource setting as part of a CSI report setting for channel measurement. The WD may be allowed to select m=(1,2,…,N) preferred NZP CSI-RS resources. In this case, the WD will feed back a single CSI report that includes at least an indicator of the “number of selected resources”, i.e., NSRI, which indicates how many resources are selected and a set of selected CSI-RS resource indicators (CRIs), i.e., {CRI1,…,CRI NRI}. NSRI=1 may mean that only a single TRP is selected, ie, DPS transmission is preferred, while NRI>1 may indicate that NC-JT transmission is preferred.

[0121] Multi-TRP transmission for Ultra-Reliable Low-Latency Communication (URLLC)

[0122] In addition to using multiple TRP transmissions to increase data throughput and increase spectrum efficiency, another application of multiple TRP transmissions is to provide increased reliability for data transmission in a kind of "TRP diversity", which is particularly useful in certain mission-critical applications such as autonomous driving, industrial control, and factory automation. In these applications, the key requirements are about reliability (e.g., low block error rate (BLER)) and / or latency. In this case, as an example, one can Figure 8 As shown, the same data packet is sent through multiple TRPs, where two PDSCHs carry the same coded data payload but have the same or different redundancy versions (RVs) so that the WD can perform soft combining on the data received from the two PDSCHs.

[0123] The same or different time / frequency resources can be used for PDSCHs sent in different TRPs. When the same time-frequency resources are used in different TRPs, different MIMO layers are used for PDSCHs sent from different TRPs, and the MIMO receiver at the WD should be able to separate the MIMO layers for PDSCH decoding. In this case, each layer / PDSCH can use a reference signal that is orthogonal to the reference signal used by other transmitted layers / PDSCHs in the same resource. In another scenario, different time-frequency resources can be used in different TRPs. The codewords carried by PDSCHs from different TRPs can have the same or different RVs, and soft combining is performed at the WD. When the same RV is used, chase combining (CC) can be performed, and when different RVs are used, soft combining based on incremental redundancy (IR) can be performed.

[0124] In another case, the same PDSCH can simply be repeated on multiple TRPs in the same resource with the same DMRS ports and the same RV, and the composite signal is received by the WD in a single frequency network (SFN) manner. Therefore, in this case, the multiple TRPs are "hidden" from the WD's perspective because the WD only observes a single layer. This is typically applicable to small deployments, such as indoors and at medium and low carrier frequencies. Only DPS-based multi-TRP transmissions are currently supported in NR, so NC-JT CSI feedback is not specified. Although LTE-like CSI feedback for NC-JT can theoretically be used in NR, there are some limitations. In order to support dynamic switching between single TRP transmission and NC-JT transmission on multiple TRPs, multiple CSI reporting settings can be configured for the WD. Unfortunately, the feedback overhead can be large, especially when a large number of antenna ports are deployed per TRP. For example, if a WD is configured with three TRPs, and data can be sent to the WD from any one TRP in case of DPS, or from any two TRPs in case of NC-JT, then in order to support dynamic TRP selection and dynamic switching between DPS and NC-JT, the WD may need to be configured to measure and report the following CSI:

[0125] - For DPS, CSI#1 for TRP#1, CSI#2 for TRP#2, CSI#3 for TRP#3,

[0126] - Each CSI includes {RI, PMI and CQI}

[0127] - NC-JT CSI#4 for {TRP#1, TRP#2}, NC-JT CSI#5 for {TRP#1, TRP#3}, NC-JT CSI#6 for {TRP#2, TRP#3}

[0128] - Each NC-JT CSI consists of a pair of {RI, PMI, CQI}, one associated with each TRP in the corresponding TRP pair

[0129] Compared to DPS, the CSI overhead for supporting dynamic switching between DPS and NC-JT will increase nearly three times compared to DPS when only the current NR or LTE CSI reporting method is used.

[0130] CSI feedback for multiple TRP transmissions for URLLC is not currently supported in NR by considering soft combining of multiple PDSCHs at the WD. Therefore, there is a problem in enabling dynamic switching between single TRP and URLLC transmission without significantly increasing the CSI feedback overhead.

[0131] Accordingly, some embodiments of the present disclosure provide a joint CSI feedback technique for supporting the possibility of performing dynamic switching between a single TRP transmission with DPS and NC-JT, which may include one or more of the following:

[0132] 1. Configure a single CSI report setting for single TRP transmission and NC-JT transmission assumptions. For the case where three TRPs are configured for a WD, the single TRP transmission assumption includes three single TRP transmissions, each from one of the three TRPs, and the NC-JT transmission assumption includes three NC-JT transmissions, each from a pair of TRPs of the three TRPs.

[0133] 2. Whether to report CSI for NC-JT in CSI reporting is determined by the WD and depends on some conditions. One such condition is related to the estimated rank of each single TRP transmission hypothesis. When the rank of any TRP is greater than the configured threshold (e.g., 2), CSI for NC-JT transmission hypothesis is not reported.

[0134] a. Report the CSI for the NC-JT transmission hypothesis only if the rank of the single TRP transmission hypothesis CSI for all TRPs is equal to or below the threshold

[0135] b. In another example, the condition may be related to the estimated WD throughput of single transmission and NC-JT transmission. On any TRP of a pair of TRPs assuming NC-JT transmission, whether the throughput using NC-JT is lower than the throughput using a single TRP transmission.

[0136] 3. When reporting NC-JT CSI, no additional PMI per TRP is reported in a specific NC-JT CSI. When the rank of the NC-JT transmission hypothesis CSI for a TRP is the same as the corresponding rank of the single TRP transmission hypothesis CSI, the PMI of the NC-JT transmission hypothesis is the same as the PMI in the single TRP transmission hypothesis CSI. When the rank of the TRP used for the NC-JT transmission hypothesis is less than the rank of the single TRP transmission hypothesis CSI, a subset of the layers of the single TRP transmission hypothesis CSI is used for the NC-JT transmission hypothesis, and the layer indicator is reported as part of the NC-JT transmission hypothesis CSI referring to the single TRP transmission hypothesis CSI.

[0137] 4. Use two-part CSI encoding: the first part has a fixed payload size and contains the rank of the assumed CSI for a single TRP transmission. The second part has a variable payload size and contains the remaining CSI.

[0138] For URLLC transmission requirements, some embodiments of the present disclosure also provide joint CSI feedback that supports the possibility of performing dynamic switching between single TRP transmission and URLLC, which may include one or more of the following:

[0139] 1. A single CSI reporting setting is configured for both single TRP transmission hypothesis feedback and URLLC CSI feedback.

[0140] 2. In one embodiment, the rank per TRP for URLLC CSI feedback may be limited to 1, and thus no rank is reported in the CSI for URLLC in this case.

[0141] 3. There is no dedicated PMI per TRP reported for URLLC CSI. Instead, one of the MIMO layers of a single TRP CSI for each TRP is selected and reported by utilizing a layer indicator (LI) per TRP. The bit width of the layer indicator varies depending on the rank of the assumed CSI for a single TRP transmission. If a single layer is selected, no LI is fed back for that TRP.

[0142] 4. Two parts of CSI encoding may be used: the first part has a fixed payload size and contains the rank for a single TRP CSI. The second part has a variable payload size and includes the remaining CSI, including the URLLC CSI.

[0143] Some embodiments provided in the present disclosure advantageously introduce CSI feedback, which allows a network node (e.g., a gNB) to perform dynamic switching between a single TRP transmission and NC-JT or URLLC with low CSI feedback overhead (compared to existing CSI feedback techniques).

[0144] Before describing the exemplary embodiments in detail, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to low overhead CSI feedback for multi-TRP transmissions. Accordingly, components are represented by conventional symbols in the drawings where appropriate, and only those specific details relevant to understanding the embodiments are shown so as not to obscure the present disclosure with details that would be readily apparent to one of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the specification.

[0145] As used herein, relational terms such as "first" and "second", "top" and "bottom" may be used only to distinguish one entity or element from another entity or element, without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the concepts described herein. As used herein, the singular forms "one", "an", and "the" are intended to also include the plural forms, unless the context clearly indicates otherwise. It will also be understood that when used herein, the terms "include" and / or "comprise" specify the presence of stated characteristics, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other characteristics, integers, steps, operations, elements, components, and / or combinations thereof.

[0146] In the embodiments described herein, connection terms such as "in communication with..." may be used to indicate electrical communication or data communication, which may be achieved, for example, by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling, or optical signaling. Those skilled in the art will recognize that multiple components may interoperate, and modifications and variations are possible to achieve electrical communication and data communication.

[0147] In some embodiments described herein, the terms "coupled," "connected," and the like may be used herein to indicate a connection (although not necessarily a direct one) and may include wired and / or wireless connections.

[0148] The term "network node" used herein may be any type of network node included in a radio network, and may also include any of the following: base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node (e.g., MSR BS), multi-cell / multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission point, transmission node, remote radio unit (RRU) remote radio head (RRH), core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, coordination node, positioning node, MDT node, etc.), external node (e.g., third-party node, node outside the current network), node in distributed antenna system (DAS), spectrum access system (SAS) node, unit management system (EMS), etc. The network node may also include test equipment. In some embodiments, the network node may include one or more TRPs. In some embodiments, multiple TRPs may be included in a single network node or distributed on more than one network node. As used herein, the term "radio node" may also be used to denote a wireless device (WD), such as a wireless device (WD) or a radio network node.

[0149] In some embodiments, the non-limiting terms wireless device (WD) or user equipment (UE) may be used interchangeably. The WD herein may be any type of wireless device capable of communicating with a network node or another WD via a radio signal, such as a wireless device (WD). The WD may also be a radio communication device, a target device, a device-to-device (D2D) WD, a machine-type WD, or a WD capable of machine-to-machine communication (M2M), a low-cost and / or low-complexity WD, a sensor equipped with a WD, a tablet computer, a mobile terminal, a smart phone, a laptop embedded device (LEE), a laptop mounted device (LME), a USB adapter, a customer premises equipment (CPE), an Internet of Things (IoT) device, or a narrowband IoT (NB-IOT) device, etc.

[0150] In addition, in some embodiments, the general term "radio network node" is used. It can be any type of radio network node, which can include any of the following: base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, multi-cell / multicast coordination entity (MCE), relay node, access point, radio access point, remote radio unit (RRU) remote radio head (RRH).

[0151] In some embodiments, a TRP may be associated with a network node. In some embodiments, a multi-TRP may include more than one TRP associated with one or more network nodes.

[0152] Although the description herein may be explained in the context of a downlink (DL) channel (eg, PDSCH), it should be understood that these principles may also be applicable to other channels, such as other DL channels, or even some uplink channels (eg, PUSCH).

[0153] Any two or more embodiments described in this disclosure may be combined with each other in any manner.

[0154] Note that although terminology from one particular wireless system (e.g., 3GPP LTE and / or New Radio (NR)) may be used in the present disclosure, this should not be considered to limit the scope of the present disclosure to only the above-mentioned systems. Other wireless systems (including but not limited to Wideband Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB), and Global System for Mobile Communications (GSM)) may also benefit from utilizing the concepts covered within the present disclosure.

[0155] It is also noted that the functions described herein as being performed by a wireless device or network node may be distributed across multiple wireless devices and / or network nodes. In other words, it is contemplated that the functions of the network nodes and wireless devices described herein are not limited to being performed by a single physical device and may in fact be distributed across several physical devices.

[0156] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and will not be interpreted as an idealized or overly formal meaning unless explicitly defined as such herein.

[0157] Referring again to the drawings, wherein like elements are designated by like reference numerals, Fig. 9, a schematic diagram of a communication system 10 according to an embodiment is shown, the communication system 10 is, for example, a 3GPP type cellular network that can support standards such as LTE and / or NR (5G), which includes an access network 12 such as a radio access network and a core network 14. The access network 12 includes a plurality of network nodes 16a, 16b, 16c (collectively referred to as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (collectively referred to as coverage areas 18). Each network node 16a, 16b, 16c can be connected to the core network 14 via a wired or wireless connection 20. A first wireless device (WD) 22a located in the coverage area 18a is configured to be wirelessly connected to or paged by the corresponding network node 16a. A second WD 22b in the coverage area 18b can be wirelessly connected to the corresponding network node 16b. Although multiple WDs 22a, 22b (collectively referred to as wireless devices 22) are shown in this example, the disclosed embodiments are equally applicable to situations where only a single WD is in the coverage area or a single WD is connected to a corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include more WDs 22 and network nodes 16.

[0158] In addition, it is contemplated that the WD 22 may communicate with multiple network nodes 16 and multiple types of network nodes 16 simultaneously and / or be configured to communicate with multiple network nodes 16 and multiple types of network nodes 16, respectively. For example, the WD 22 may have dual connectivity with a network node 16 supporting LTE and the same or different network node 16 supporting NR. As an example, the WD 22 may communicate with an eNB for LTE / E-UTRAN and a gNB for NR / NG-RAN.

[0159] The communication system 10 itself can be connected to a host computer 24, which can be embodied in the hardware and / or software of a stand-alone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer 24 can be under the ownership or control of a service provider, or can be operated by or on behalf of a service provider. The connections 26, 28 between the communication system 10 and the host computer 24 can extend directly from the core network 14 to the host computer 24, or can extend via an optional intermediate network 30. The intermediate network 30 can be one of a public, private, or managed network, or a combination of more than one of them. The intermediate network 30 (if any) can be a backbone network or the Internet. In some embodiments, the intermediate network 30 can include two or more sub-networks (not shown).

[0160] Overall, Fig. 9 The communication system realizes the connectivity between one of the connected WD 22a, 22b and the host computer 24. The connectivity can be described as an over-the-top (OTT) connection. The host computer 24 and the connected WD 22a, 22b are configured to use the access network 12, the core network 14, any intermediate network 30 and possible other infrastructure (not shown) as intermediaries to transmit data and / or signaling via the OTT connection. The OTT connection can be transparent because at least some of the participating communication devices through which the OTT connection passes do not know the routes of the uplink and downlink communications. For example, the network node 16 may not be notified or does not need to be notified of the past routes of the incoming downlink communications with data from the host computer 24 to be forwarded (e.g., handed over) to the connected WD 22a. Similarly, the network node 16 does not need to know the future routes of the outgoing uplink communications from the WD 22a to the host computer 24.

[0161] In some embodiments, the network node 16 is configured to include a report setting unit 32 configured to:

[0162] Configure the wireless device with a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer;

[0163] sending a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI reporting configuration; and

[0164] A channel state information (CSI) feedback report is received, the CSI feedback report being based at least in part on the CSI report setting; and the CSI feedback report comprising at least one of a first CSI feedback and a second CSI feedback.

[0165] In some embodiments, the network node 16 is configured to include a report setting unit 32 configured to perform one or more of the following operations:

[0166] Send downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs);

[0167] A channel state information CSI reporting setting having K>1 non-zero power channel state information reference signal NZP CSI-RS resources is configured for the WD, each resource being associated with a TRP; and / or

[0168] Requesting a CSI feedback report from the WD based on the CSI reporting setting by assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs; and / or

[0169] Based on the CSI feedback report, downlink channel transmission to the WD is scheduled.

[0170] In some embodiments, the wireless device 22 is configured to include a reporting unit 34 configured to:

[0171] Receiving a configuration of a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer;

[0172] receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI reporting configuration;

[0173] Based at least in part on the NZP CSI-RS resources, measuring the channel; and

[0174] Sending a channel state information (CSI) feedback report based at least in part on:

[0175] Channel measurements; and

[0176] Report quantity configuration; and

[0177] The CSI feedback report includes at least one of the first CSI feedback and the second CSI feedback.

[0178] In some embodiments, the wireless device 22 is configured to include a reporting unit 34 that is configured to perform one or more of the following operations:

[0179] Receiving a CSI feedback request based on a channel state information (CSI) reporting configuration having K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources, each resource being associated with a transmission point (TRP); and / or

[0180] Based on the received CSI report setting, assuming data transmission from each of the K TRPs and data transmission from each of M>1 TRPs among the K TRPs, the channel state information CSI feedback report is measured and fed back.

[0181] According to one embodiment, reference will now be made to Fig.10An example implementation of the WD 22, network node 16, and host computer 24 discussed in the previous paragraphs is described. In the communication system 10, the host computer 24 includes hardware (HW) 38, which includes a communication interface 40 configured to establish and maintain a wired or wireless connection with different communication devices of the communication system 10. The host computer 24 also includes a processing circuit 42, which may have storage and / or processing capabilities. The processing circuit 42 may include a processor 44 and a memory 46. In particular, in addition to or in place of a processor (e.g., a central processing unit) and a memory, the processing circuit 42 may include an integrated circuit for processing and / or control, such as one or more processors and / or processor cores and / or an FPGA (field programmable gate array) and / or an ASIC (application-specific integrated circuit) suitable for executing instructions. The processor 44 may be configured to access (e.g., write to and / or read from) a memory 46, which may include any type of volatile and / or non-volatile memory, such as cache and / or buffer memory and / or RAM (random access memory) and / or ROM (read only memory) and / or optical memory and / or EPROM (erasable programmable read-only memory).

[0182] Processing circuitry 42 may be configured to control any of the methods and / or processes described herein and / or cause these methods and / or processes to be performed, for example, by host computer 24. Processor 44 corresponds to one or more processors 44 for performing the functions of host computer 24 described herein. Host computer 24 includes memory 46, which is configured to store data, programming software code, and / or other information described herein. In some embodiments, software 48 and / or host application 50 may include instructions that, when executed by processor 44 and / or processing circuitry 42, cause processor 44 and / or processing circuitry 42 to perform the processes described herein for host computer 24. The instructions may be software associated with host computer 24.

[0183] The software 48 can be executed by the processing circuit 42. The software 48 includes a host application 50. The host application 50 is operable to provide services to remote users such as WD 22 connected via an OTT connection 52 that terminates at the WD 22 and the host computer 24. When providing services to remote users, the host application 50 can provide user data sent using the OTT connection 52. "User data" can be data and information described herein as implementing the described functions. In one embodiment, the host computer 24 can be configured to provide control and functionality to a service provider, and can be operated by or on behalf of the service provider. The processing circuit 42 of the host computer 24 can enable the host computer 24 to observe, monitor, control the network node 16 and / or the wireless device 22, send to the network node 16 and / or the wireless device 22, and / or receive from the network node 16 and / or the wireless device 22. The processing circuitry 42 of the host computer 24 may include a monitoring unit 54 configured to enable a service provider to observe, monitor, control, send to, and / or receive from the network nodes 16 and / or wireless devices 22.

[0184] The communication system 10 also includes a network node 16 disposed in the communication system 10, and the network node 16 includes hardware 58 that enables it to communicate with the host computer 24 and the WD 22. The hardware 58 may include a communication interface 60 for establishing and maintaining a wired or wireless connection to the interface of different communication devices of the communication system 10, and a radio interface 62 for establishing and maintaining at least a wireless connection 64 with the WD 22 located in the coverage area 18 served by the network node 16. The radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The communication interface 60 may be configured to facilitate a connection 66 with the host computer 24. The connection 66 may be direct, or the connection 66 may pass through the core network 14 of the communication system 10 and / or through one or more intermediate networks 30 external to the communication system 10.

[0185] In the illustrated embodiment, the hardware 58 of the network node 16 also includes a processing circuit 68. The processing circuit 68 may include a processor 70 and a memory 72. In particular, in addition to or in place of a processor (e.g., a central processing unit) and a memory, the processing circuit 68 may include an integrated circuit for processing and / or control, such as one or more processors and / or processor cores and / or an FPGA (field programmable gate array) and / or an ASIC (application-specific integrated circuit) adapted to execute instructions. The processor 70 may be configured to access (e.g., write to and / or read from) the memory 72, which may include any type of volatile and / or non-volatile memory, such as a cache and / or buffer memory and / or a RAM (random access memory) and / or a ROM (read-only memory) and / or an optical memory and / or an EPROM (erasable programmable read-only memory).

[0186] Thus, the network node 16 also has software 74, which is stored internally, for example, in the memory 72, or stored in an external memory (e.g., a database, a storage array, a network storage device, etc.) that is accessible by the network node 16 via an external connection. The software 74 can be executed by the processing circuit 68. The processing circuit 68 can be configured to control any method and / or process described herein and / or cause these methods and / or processes to be performed, for example, by the network node 16. The processor 70 corresponds to one or more processors 70 for performing the network node 16 functions described herein. The memory 72 is configured to store data, programming software code, and / or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and / or the processing circuit 68, cause the processor 70 and / or the processing circuit 68 to perform the processes described herein for the network node 16, for example, with reference to Fig.15 For example, the processing circuit 68 of the network node 16 may include a report setting unit 32 configured to perform one or more of the following operations:

[0187] Send downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs);

[0188] A channel state information CSI reporting setting having K>1 non-zero power channel state information reference signal NZP CSI-RS resources is configured for the WD, each resource being associated with a TRP; and / or

[0189] Requesting a CSI feedback report from the WD based on the CSI reporting setting by assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs; and / or

[0190] Based on the CSI feedback report, downlink channel transmission to the WD is scheduled.

[0191] In some embodiments, the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT transmission if certain conditions are met. In some embodiments, the CSI feedback report also includes an indicator indicating whether NC-JT CSI is present in the report.

[0192] In some embodiments, the CSI feedback report includes one of: a single transmission point (TRP) assumption and a non-coherent joint transmission (NC-JT) transmission assumption; and one of a single TRP assumption and a non-coherent joint transmission (NC-JT) transmission assumption. In some embodiments, the CSI feedback report depends on a specific condition. In some embodiments, the CSI feedback report depends on a rank threshold. In some embodiments, the CSI feedback report includes a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0193] The communication system 10 also includes the already mentioned WD 22. The WD 22 may have hardware 80, which may include a radio interface 82 configured to establish and maintain a wireless connection 64 with a network node 16 serving the coverage area 18 in which the WD 22 is currently located. The radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers.

[0194] The hardware 80 of the WD 22 also includes a processing circuit 84. The processing circuit 84 may include a processor 86 and a memory 88. In particular, in addition to or in place of a processor (e.g., a central processing unit) and a memory, the processing circuit 84 may include an integrated circuit for processing and / or control, such as one or more processors and / or processor cores and / or an FPGA (field programmable gate array) and / or an ASIC (application-specific integrated circuit) adapted to execute instructions. The processor 86 may be configured to access (e.g., write and / or read) the memory 88, which may include any kind of volatile and / or non-volatile memory, such as a cache and / or buffer memory and / or a RAM (random access memory) and / or a ROM (read-only memory) and / or an optical memory and / or an EPROM (erasable programmable read-only memory).

[0195] Therefore, WD 22 may also include software 90, which is stored in a memory 88 at, for example, WD 22, or in an external memory (e.g., a database, a storage array, a network storage device, etc.) accessible by WD 22. The software 90 may be executed by the processing circuit 84. The software 90 may include a client application 92. The client application 92 may be operable to provide services to human or non-human users via WD 22 with the support of the host computer 24. In the host computer 24, the executing host application 50 may communicate with the executing client application 92 via an OTT connection 52 terminated at WD 22 and the host computer 24. When providing services to the user, the client application 92 may receive request data from the host application 50 and provide user data in response to the request data. The OTT connection 52 may transmit both request data and user data. The client application 92 may interact with the user to generate user data provided by the user.

[0196] Processing circuit 84 may be configured to control any of the methods and / or processes described herein and / or cause these methods and / or processes to be performed, for example, by WD 22. Processor 86 corresponds to one or more processors 86 for performing the functions of WD 22 described herein. WD 22 includes memory 88, which is configured to store data, programming software code, and / or other information described herein. In some embodiments, software 90 and / or client application 92 may include instructions that, when executed by processor 86 and / or processing circuit 84, cause processor 86 and / or processing circuit 84 to perform the processes described herein for WD 22, such as reference 20. Fig.16 For example, the processing circuit 84 of the wireless device 22 may include a reporting unit 34 configured to perform one or more of the following operations:

[0197] Receiving a CSI feedback request based on a channel state information (CSI) reporting configuration having K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources, each resource being associated with a transmission point (TRP); and / or

[0198] Based on the received CSI report setting, assuming data transmission from each of the K TRPs and data transmission from each of M>1 TRPs among the K TRPs, the channel state information CSI feedback report is measured and fed back.

[0199] In some embodiments, the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT if certain conditions are met. In some embodiments, the CSI feedback report also includes an indicator indicating whether NC-JT CSI is present in the CSI feedback report.

[0200] In some embodiments, the CSI feedback report depends on a specific condition. In some embodiments, the CSI feedback report depends on a rank threshold. In some embodiments, the CSI feedback report includes a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0201] In some embodiments, the internal workings of network node 16, WD 22, and host computer 24 may be as follows: Fig.10 shown, and independently, the surrounding network topology can be Fig. 9 The surrounding network topology.

[0202] exist Fig.10 In the figure, the OTT connection 52 has been abstractly drawn to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicitly referencing any intermediate devices and the exact routing of the messages via these devices. The network infrastructure can determine the routing, and the network infrastructure can be configured to hide the routing from the WD 22 or from the service provider operating the host computer 24, or both. When the OTT connection 52 is active, the network infrastructure can further make a decision according to which the network infrastructure dynamically changes the routing (e.g., based on load balancing considerations or reconfiguration of the network).

[0203] The wireless connection 64 between WD 22 and network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improves the performance of OTT services provided to WD 22 using OTT connection 52 (wherein the wireless connection 64 can form the final segment). More specifically, the teachings of some of these embodiments can improve data rates, latency, and / or power consumption, thereby providing benefits such as reduced user waiting time, relaxed file size restrictions, better responsiveness, and extended battery life.

[0204] In some embodiments, a measurement process may be provided for the purpose of monitoring data rates, delays, and other factors on which one or more embodiments are improved. In response to changes in the measurement results, there may also be an optional network function for reconfiguring the OTT connection 52 between the host computer 24 and the WD 22. The measurement process and / or network function for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22 or in both. In an embodiment, a sensor (not shown) may be deployed in a communication device through which the OTT connection 52 passes or is associated with such a communication device; the sensor may participate in the measurement process by providing the value of the monitored quantity of the above example or providing the value of other physical quantities from which the software 48, 90 can calculate or estimate the monitored quantity. The reconfiguration of the OTT connection 52 may include message formats, retransmission settings, preferred routes, etc. The reconfiguration does not need to affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such processes and functions may be known and practiced in the art. In some embodiments, the measurements may involve proprietary WD signaling that facilitates the host computer 24's measurement of throughput, propagation time, latency, etc. In some embodiments, the measurements may be achieved because the software 48, 90 causes messages (particularly empty or "dummy" messages) to be sent using the OTT connection 52 during which it monitors propagation time, errors, etc.

[0205] Thus, in some embodiments, the host computer 24 includes processing circuitry 42 configured to provide user data, and a communication interface 40 configured to forward the user data to a cellular network for transmission to the WD 22. In some embodiments, the cellular network also includes a network node 16 having a radio interface 62. In some embodiments, the network node 16 is configured to and / or the processing circuitry 68 of the network node 16 is configured to perform the functions and / or methods described herein to prepare / initiate / maintain / support / end a transmission to the WD 22, and / or to prepare / terminate / maintain / support / end receipt of a transmission from the WD 22.

[0206] In some embodiments, host computer 24 includes processing circuitry 42 and communication interface 40 configured to receive user data originating from a transmission from WD 22 to network node 16. In some embodiments, WD 22 is configured to and / or includes a radio interface 82 and / or processing circuitry 84 configured to perform the functions and / or methods described herein to prepare / initiate / maintain / support / end a transmission to network node 16, and / or to prepare / terminate / maintain / support / end receipt of a transmission from network node 16.

[0207] although Fig. 9 and 10Various "units" (e.g., report setting unit 32 and report unit 34) are shown as being within respective processors, but it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, these units may be implemented within the processing circuitry in hardware or in a combination of hardware and software.

[0208] Fig.11 FIG. 1 is a diagram showing a communication system (eg Fig. 9 and 10 24, a network node 16, and a WD 22, which may be reference Fig.10 1 and 2. The method of claim 1 further includes a method for transmitting a user data to a network node 16 and a WD 22. In a first step of the method, the host computer 24 provides user data (block S100). In an optional substep of the first step, the host computer 24 provides user data by executing a host application (e.g., host application 50) (block S102). In a second step, the host computer 24 initiates a transmission carrying user data to the WD 22 (block S104). In an optional third step, in accordance with the teachings of the embodiments described throughout the present disclosure, the network node 16 sends the user data carried in the transmission initiated by the host computer 24 to the WD 22 (block S106). In an optional fourth step, the WD 22 executes a client application (e.g., client application 92) associated with the host application 50 executed by the host computer 24 (block S108).

[0209] Fig.12 FIG. 1 is a diagram showing a communication system (eg Fig. 9 The communication system may include a host computer 24, a network node 16, and a WD 22, which may be reference Fig. 9 and 10 1 and 2. The method further includes a host computer 24, a network node 16, and a WD 22 as described above. In a first step of the method, the host computer 24 provides user data (block S110). In an optional substep (not shown), the host computer 24 provides user data by executing a host application (e.g., host application 50). In a second step, the host computer 24 initiates a transmission carrying user data to the WD 22 (block S112). According to the teachings of the embodiments described throughout the present disclosure, the transmission may pass through the network node 16. In an optional third step, the WD 22 receives the user data carried in the transmission (block S114).

[0210] Fig.13 FIG. 1 is a diagram showing a communication system (eg Fig. 9The communication system may include a host computer 24, a network node 16, and a WD 22, which may be reference Fig. 9 and 10 Those host computers 24, network nodes 16 and WD 22 described above. In the optional first step of the method, WD 22 receives input data provided by the host computer 24 (box S116). In the optional sub-step of the first step, WD 22 executes the client application 92, and the client application 92 provides user data in response to the received input data provided by the host computer 24 (box S118). Additionally or alternatively, in the optional second step, WD 22 provides user data (box S120). In the optional sub-step of the second step, WD provides user data (box S122) by executing a client application (e.g., client application 92). When providing user data, the executed client application 92 can further consider the user input received from the user. Regardless of the specific manner of providing user data, WD 22 can initiate the transmission of user data to the host computer 24 in an optional third sub-step (box S124). In a fourth step of the method, host computer 24 receives user data sent from WD 22 (block S126 ) in accordance with the teachings of the embodiments described throughout this disclosure.

[0211] Fig.14 FIG. 1 is a diagram showing a communication system (eg Fig. 9 The communication system may include a host computer 24, a network node 16, and a WD 22, which may be reference Fig. 9 and 10 1 and 2. In an optional first step of the method, the network node 16 receives user data from the WD 22 in accordance with the teachings of the embodiments described throughout the present disclosure (block S128). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (block S132).

[0212] Fig.151 is a flowchart of an exemplary process in a network node 16 according to some embodiments of the present disclosure. One or more blocks and / or functions and / or methods performed by the network node 16 may be performed by one or more units of the network node 16 according to an exemplary method, for example, by a report setting unit 32 in a processing circuit 68, a processor 70, a radio interface 62, etc. The exemplary method includes configuring (block S134) a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources for channel measurement to a wireless device 22, for example, via the report setting unit 32, the processing circuit 68, the processor 70, and / or the radio interface 62, where K is an integer. The method includes, for example, sending (block S136) a CSI feedback report request for CSI measurement and feedback via the report setting unit 32, the processing circuit 68, the processor 70, and / or the radio interface 62 based at least in part on the CSI report setting. The method includes receiving (block S138) a channel state information (CSI) feedback report, e.g., via a report setting unit 32, a processing circuit 68, a processor 70, and / or a radio interface 62, the CSI feedback report being based at least in part on the CSI report setting. The CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

[0213] In some embodiments, the first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources. In some embodiments, the second CSI feedback includes CSI for one of non-coherent joint (NC-JT) transmission and ultra-reliable low delay (URLL) transmission. In some embodiments, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator. In some embodiments, the second CSI feedback includes a first rank indicator and a first layer indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

[0214] In some embodiments, the second CSI feedback further includes an identification of the first NZP CSI-RS resource and the second NZP CSI-RS resource. In some embodiments, the CSI feedback report includes both the first CSI feedback and the second CSI feedback. In some embodiments, if each rank of the first CSI feedback is below a threshold, the CSI feedback report includes the second CSI feedback. In some embodiments, the CSI feedback report further includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments, the CSI feedback report includes only the second CSI feedback.

[0215] In some embodiments, a method implemented in a network node 16 includes, for example, sending downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs) via a report setting unit 32 and / or processing circuit 68 and / or a radio interface 62. The example process includes one or more of the following steps. The process may include, for example, configuring a channel state information (CSI) report setting with K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources for WD 22 via the report setting unit 32 and / or processing circuit 68, each resource being associated with a TRP. The example process may include, based on the CSI report setting, assuming data transmission from each of the K TRPs and data transmission from each of the M>1 TRPs of the K TRPs, for example, requesting a CSI feedback report from WD 22 via the report setting unit 32 and / or processing circuit 68. The example process may include scheduling downlink channel transmissions to WD 22 based on the CSI feedback report.

[0216] In some embodiments, the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT if certain conditions are met. In some embodiments, the CSI feedback report also includes an indicator indicating whether NC-JT CSI is present in the report.

[0217] In some embodiments, the CSI feedback report includes one of: CSI for both a single transmission point (TRP) assumption and a non-coherent joint transmission (NC-JT) transmission assumption; and CSI for one of a single TRP assumption and a non-coherent joint transmission (NC-JT) transmission assumption. In some embodiments, the CSI feedback report depends on a specific condition. In some embodiments, the CSI feedback report depends on a rank threshold. In some embodiments, the CSI feedback report includes a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0218] Fig.16 is a flowchart of an exemplary process in a wireless device 22 according to some embodiments of the present disclosure. One or more blocks and / or functions and / or methods performed by WD22 may be performed by one or more units of WD 22 according to an exemplary method, such as by a reporting unit 34 in a processing circuit 84, a processor 86, a radio interface 82, etc. The exemplary method includes one or more of the following steps. The method may include, for example, receiving (block S140) a configuration of a channel state information (CSI) report setting for at least K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources for channel measurement and a report quantity configuration, K being an integer, via a reporting unit 34, a processing circuit 84, a processor 86, and / or a radio interface 82, for example. The method includes receiving (block S142) a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting, such as via a reporting unit 34, a processing circuit 84, a processor 86, and / or a radio interface 82. The method includes measuring (block S144) a channel based at least in part on the NZP CSI-RS resource, e.g., via the reporting unit 34, the processing circuit 84, the processor 86, and / or the radio interface 82. The method includes sending (block S146) a channel state information (CSI) feedback report based at least in part on: the channel measurement; and a report quantity configuration, e.g., via the reporting unit 34, the processing circuit 84, the processor 86, and / or the radio interface 82. The CSI feedback report includes at least one of a first CSI feedback and a second CSI feedback.

[0219] In some embodiments, the first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources. In some embodiments, the second CSI feedback includes CSI for one of non-coherent joint (NC-JT) transmission and ultra-reliable low delay (URLL) transmission. In some embodiments, the second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator. In some embodiments, the second CSI feedback includes a first rank indicator and a first layer indicator associated with the first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with the second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

[0220] In some embodiments, the second CSI feedback further includes an identification of the first NZP CSI-RS resource and the second NZP CSI-RS resource. In some embodiments, the method further includes determining, for example via the reporting unit 34, the processing circuit 84, the processor 86 and / or the radio interface 82, whether to include the second CSI feedback in the CSI feedback report. In some embodiments, determining whether to include the second CSI feedback further includes determining, for example via the reporting unit 34, the processing circuit 84, the processor 86 and / or the radio interface 82, that the second CSI feedback is included if each rank of the first CSI feedback is below a threshold. In some embodiments, the CSI feedback report further includes an indicator indicating whether the second CSI feedback is present in the CSI feedback report. In some embodiments, the CSI feedback report includes only the second CSI feedback.

[0221] In some embodiments, the process may include, for example, via the reporting unit 34 and / or the processing circuit 84 and / or the radio interface 82, receiving a CSI feedback request based on a channel state information (CSI) reporting setting for K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources, each resource being associated with a transmission point (TRP). The example process may include measuring and sending a channel state information (CSI) feedback report via the reporting unit 34 and / or the processing circuit 84 and / or the radio interface 82 based on the received CSI reporting setting, assuming data transmission from each of the K TRPs and data transmission from each of the M>1 TRPs of the K TRPs.

[0222] In some embodiments, the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT if certain conditions are met. In some embodiments, the CSI feedback report also includes an indicator indicating whether NC-JT CSI is present in the CSI feedback report.

[0223] In some embodiments, the CSI feedback report depends on a specific condition. In some embodiments, the CSI feedback report depends on a rank threshold. In some embodiments, the CSI feedback report includes a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0224] Having generally described some embodiments of CSI feedback for multi-TRP transmissions that can reduce CSI feedback signaling overhead (compared to the prior art), a more detailed description of some embodiments is described below, which can be implemented by WD 22, network node 16 and / or host computer 24.

[0225] CSI feedback for multiple TRPs with single TRP transmission assumption

[0226] In one embodiment, the DL PDSCH transmission to WD 22 may be from any of multiple TRPs. In this case, the network node 16 (e.g., gNB) may benefit from having CSI corresponding to all TRPs in order to make an informed scheduling decision.

[0227] In this embodiment, a single CSI reporting setup may be configured to WD 22 to determine CSI assuming a single TRP transmission assumption, i.e., a hypothetical PDSCH transmission from one TRP for which CSI is determined. Hereinafter, such CSI is referred to herein as "single TRP CSI". However, in contrast to the prior art, WD 22 is indicated in the CSI reporting setup as part of the configuration, i.e., multiple such single TRP CSIs are to be determined and reported as part of the CSI report. In some embodiments, the number of single TRP CSIs to be determined and reported as part of the CSI report is configured to WD 22 by RRC.

[0228] Assuming that CSI feedback for K TRPs is required, WD 22 may be configured by higher layers with K NZP CSI-RS resources {NZP CSI-RS#1, NZP CSI-RS#2,…, NZP CSI-RS#K} for channel measurement and K CSI-IM resources {CSI-IM#1, CSI-IM#2,…, CSI-IM#K} for interference measurement, which are associated with a single CSI report setting, wherein the resource pair {NZP CSI-RS#k, CSI-IM#k} is associated with the kth TRP. WD 22 may therefore perform measurements used to determine a single TRP CSI, namely CSI#k, for the kth TRP based on the resource pair {NZP CSI-RS#k, CSI-IM#k}. In some embodiments, WD 22 reports all K CSIs {CSI#1, CSI#2,…, CSI#K} as part of a single CSI report in PUSCH or PUCCH. Each CSI may contain RI, PMI and one or two CQIs (depending on the reported RI).

[0229] WD 22 may not always report all K CSIs, because those CSIs corresponding to TRPs received at low power at WD 22, for example, may not be used for scheduling by network node 16 (e.g., gNB) in practice. In order to strike a balance between scheduling flexibility and CSI feedback overhead, in one embodiment, WD 22 selects and reports M (>1) best CSIs from the K CSIs. In this case, a combined signaling scheme (using The M associated resource pairs are reported using M CSIs (with an overhead of 10 bits). Using the M CSIs, the network node 16 (e.g., gNB) can schedule PDSCH from any of the M associated TRPs.

[0230] Different from the existing CSI reporting in NR version-15 with the same multi-NZP CSI-RS and CSI-IM configuration (where WD 22 first selects one of the resource pairs and then measures and reports the corresponding CSI associated with the resource pair), in some embodiments of the present disclosure, a new reporting quantity indicator may be introduced in the CSI reporting setting to indicate the desired report.

[0231] Efficient CSI feedback with low overhead for NC-JT

[0232] Traditionally, the network node 16 controls scheduling of single or multiple TRP transmissions to the WD 22. Each of these transmissions may require different CSI feedback and to be able to dynamically switch between a single TRP transmission and an NC-JT transmission with multiple TRPs, the network node 16 may have CSI with two transmission hypotheses to make scheduling decisions with the correct link adaptation. Unfortunately, the feedback of all CSI associated with different hypotheses may result in a large CSI feedback overhead. Therefore, in some embodiments of the present disclosure, the WD 22 is configured to participate in the selection of assumptions for CSI feedback, for example, the WD 22 may choose to feedback CSI for a single TRP or multiple TRPs.

[0233] For NC-JT (e.g., where multiple TRPs are sent to the same WD 22 simultaneously), it has been observed that this feature provides system performance benefits over DPS (e.g., where only one TRP is being sent to WD 22) only (or primarily) under the following conditions:

[0234] - When the WD 22 is able to receive transmissions from multiple TRPs with comparable signal strengths; this is typically observed by the WD 22 at the cell edge or in indoor deployments;

[0235] - the rank (number of MIMO layers) supported by each TRP is low (e.g., 1 or 2 layers), even if WD 22 is equipped with more receive antennas and is therefore able to receive more than these few layers from a single TRP (this typically happens when the rank of the propagation channel between the TRP and WD 22 is of low rank, such as in line-of-sight channel conditions); and

[0236] - Network load (and therefore resource utilization) is low (typically <30% resource utilization to gain significant benefit from NC-JT).

[0237] Therefore, some embodiments of the present disclosure provide that CSI for NC-JT is reported only when the above conditions are met. In some embodiments, to achieve this, a rank threshold R is introduced for WD 22. th , so that WD 22 dynamically determines whether to report NC-JT CSI for each CSI report to be fed back. In some embodiments, WD 22 can determine whether to report NC-JT CSI based on data throughput estimation, and if the data throughput using NC-JT is lower than the data throughput using a single TRP transmission, NC-JT CSI is not reported.

[0238] For K TRPs, WD 22 may be configured with a CSI reporting setting with K NZP CSI-RS resources for channel measurement and K CSI-IM resources for interference measurement, i.e.,

[0239] -{NZP CSI-RS#1,NZP CSI-RS#2,...,NZP CSI-RS#K}

[0240] -{CSI-IM#1, CSI-IM#2, ..., CSI-IM#K}, where the resource pair {NZP CSI-RS#k, CSI-IM#k} is associated with the kth TRP, k=1, ...,K.

[0241] In some embodiments, WD 22 first measures and estimates a single TRP transmission hypothesis CSI separately based on each CSI resource pair. For the kth TRP, CSI#k is determined based on the resource pair {NZP CSI-RS#k, CSI-IM#k}. This produces K CSIs, each corresponding to a single TRP transmission hypothesis {CSI#1, CSI#2,..., CSI#K}. Each CSI may include RI, PMI, and one or two CQIs, i.e., CSI#k=(RI#k, PMI#k, CQI#k).

[0242] WD 22 can then compare the rank of each single TRP CSI with the rank threshold R th The rank threshold can be configured to WD 22 through RRC signaling or predefined in the standard specification, for example. If the rank of any one of the K single TRP CSIs exceeds the rank threshold R th, a decision is made, for example, by WD 22 not to report NC-JT CSI but to report CSI for one or more single TRP transmission assumptions. In another example, WD 22 may compare the data throughput using NC-JT with the data throughput using a single TRP transmission. If the data throughput using NC-JT is lower than the data throughput using a single TRP transmission, then NC-JT CSI is not reported.

[0243] In this case, it is likely that WD 22 is close to one of the TRPs, which is favorable for high-rank (greater than R_th) PDSCH transmissions from that TRP, but unfavorable for scheduling NC-JT transmissions. That is, in some embodiments, the network node 16 scheduler is likely not to schedule NC-JT transmissions in this case anyway, and therefore, omitting CSI corresponding to the NC-JT transmission assumption may not have a negative impact.

[0244] An example with two TRPs is shown in Table 2 (below), where R th =2. In this example, WD 22 determines two single TRP transmission hypothesis CSIs, each CSI including a corresponding RI. Assuming that the maximum RI of each hypothesis is 4, 16 possible combinations can be reported, and each combination can be mapped to an index of a table. In some embodiments, NC-JT CSI is fed back only for some of these combinations, corresponding to if the index is 1, 2, 5, or 6, then in addition to the two single TRP transmission hypothesis CSIs, the NC-JT transmission hypothesis CSI is also fed back. Therefore, NC-JT CSI is reported (e.g., by WD 22 to the network node 16) only in four of the 16 possible rank combinations, resulting in a reduction in feedback overhead because the NC-JT CSI can be omitted for 12 of the 16 possible cases.

[0245] Table 2: Rank threshold R used when considering two TRPs th = 2 to determine whether to report NC-JT CSI.

[0246]

[0247] If the reported RI of all K single TRP CSIs is lower than or equal to a threshold, or if the data throughput using NC-JT is lower than the data throughput using a single TRP transmission, then CSI for NC-JT is reported in addition, or alternatively, CSI for NC-JT is reported instead of single TRP CSI.

[0248] That is, in one embodiment, when NC-JT CSI is reported, single TRP CSI is not reported. Thus, WD 22 performs hypothesis selection and decides between single TRP or multi-TRP CSI feedback. Taking 2 TRPs as an example, let (R k ,W k ,Q k ) represents the rank indicator (RI), precoding matrix indicator (PMI), and CQI corresponding to the kth TRP. In one embodiment, a selection indicator is included (e.g., by WD 22) as part of the CSI report to indicate the selection between a single TRP CSI or multiple TRP CSIs (e.g., NC-JT CSI). If WD 22 decides to feed back a single TRP CSI, WD 22 sets the selection indicator to indicate a single TRP CSI selection. If WD 22 decides to feed back multiple TRP CSIs, WD 22 sets the selection indicator to indicate multiple TRP CSI selections. Although the above example is limited to 2 TRPs, the embodiment can be extended to more than 2 TRPs.

[0249] In another embodiment, also in the case of NC-JT (depending on the threshold R th ) reports (eg, by WD 22 to network node 16) a single TRP CSI feedback. Then, the following method may be employed to reduce CSI feedback overhead by reusing or sharing the single TRP PMI feedback information in the NC-JT feedback assumption.

[0250] In some embodiments, the CSI for NC-JT may include

[0251]

[0252] in, are the NC-JT rank indicator (RI), precoding matrix indicator (PMI), and CQI associated with the kth TRP, respectively. This assumes that one codeword is sent per TRP. If different layers of the codeword are sent through different TRPs, then a joint CQI can be determined and reported instead.

[0253] When a single TRP CSI is reported along with the CSI for NC-JT (e.g., by WD 22 to network node 16), the portion of the CSI corresponding to the NC-JT transmission assumption (e.g., It may not need to be reported and therefore may be omitted in some embodiments.

[0254] In one embodiment, if is equal to the rank in CSI#k for the single TRP transmission assumption, then Same as PMI in CSI#k. If Less than the rank in CSI#k for a single TRP transmission, then the layer indicator (LI) is reported, for example, the NC-JT CSI report for the kth TRP in, is the layer indicator of the kth TRP. The layer indicator indicates which subset of layers in the reported single TRP PMI are used for NC-JT. Such an embodiment can further reduce the feedback overhead for NC-JT CSI. Fig.17 An example is shown in FIG. 1 , where the NC-JT rank for TRP2 is 1 (ie, ), while the corresponding single TRP CSI has a rank of 2. Since the rank threshold is 2 in this example, the NC-JT CSI is additionally reported. For TRP1, the same layers reported in the single TRP CSI are also used for NC-JT. For TRP2, since the rank used for NC-JT is 1 and the rank of the single TRP CSI is 2, the layer indicator is used to indicate the layer in TRP2 for NC-JT. In this case, the layer indicator has selected layer 1, i.e., Assuming the single TRP precoding matrix reported for TRP2 is W = [w1, w2], then for NC-JT transmission, w2 can be used by the network node 16 to precode the PDSCH transmission through TRP2. For TRP, because the NC-JT rank is the same as the single TRP CSI rank, the same precoding matrix corresponding to the PMI reported in the single TRP CSI can be used for NC-JT transmission from TRP1. In this example, WD 22 reports the following CSI:

[0255] Single TRP CSI:

[0256] оCSI#1=(RI#1,PMI#1,CQI#1), for TRP#1

[0257] oCSI#2=(RI#2,PMI#2,CQI#2), for TRP#2

[0258] NC-JT CSI, if one codeword per TRP is used for NC-JT:

[0259] o It is associated with TRP#1

[0260] o It is associated with TRP#2

[0261] NC-JT CSI, if a single codeword for both TRPs is used for NC-JT:

[0262] o It is associated with TRP#1

[0263] o It is associated with TRP#1

[0264] o combined with CQI

[0265] One advantage of this method can be that there is no separate PMI for NC-JT reporting, which can save a large amount of feedback overhead.

[0266] In some scenarios, the number M (1 < M < K) of TRPs participating in NC-JT transmission can be less than the K TRPs configured for CSI reporting. In this case, WD 22 can first select the best M TRPs and then report NC-JT CSI based on the selected TRPs. For example, when K = 3 and M = 2, WD 22 can report a single TRP CSI for all 3 TRPs, i.e., {CSI#1, CSI#2, CSI#3}. If the rank of all three individual TRP CSIs is equal to or less than the rank threshold R th , then WD 22 selects 2 out of the 3 TRPs for reporting NC-JT CSI. Otherwise, NC-JT CSI is not reported.

[0267] This selection can be based on specific criteria, such as maximizing the throughput of WD 22. A new definition of CRI or another newly introduced indicator can also be used to report the selected TRPs. For example, CRI = 0 is used to indicate TRP1 and TRP2; CRI = 1 indicates TRP1 and TRP3; CRI = 2 indicates TRP2 and TRP3. The remaining NC-JT CSI measurements and reports based on the two selected TRPs can be the same as the NC-JT CSI measurements and reports discussed above. M can be configured semi-statically by RRC.

[0268] In another embodiment, only the set of possible TRPs (or equivalent CSI-RS resources) that can participate in NC-JT transmission is the same as those configured in the active transmission configuration indicator (TCI) state for PDSCH transmission. In NR Rel.15, each TCI state includes CSI-RS resources (or SSB indexes) that will be used for time and frequency synchronization, so DPS can be supported by dynamically selecting different TCI states (i.e., the TCI state is equal to the TRP) in the DCI when scheduling the PDSCH. In NR Rel.16, the extended TCI state can be supported and defined by the fact that each such TCI state includes two or more CSI-RS resources for time / frequency synchronization. Therefore, such TCI states can be used for NC-JT scheduling. The combination of TRPs available for selection in the CSI report of NC-JT can be the same as those configured in these extended and active TCI states (note that there are also non-active TCI states that cannot be used for PDSCH scheduling unless they are first activated by, for example, MAC CE signaling). This also means that K < M TRPs can participate in NC-JT transmission. A typical example is M = 3 TRPs and NC-JT with K = 2 TRPs, which can be represented by three different active and extended TCI states. The single-TRP CSI report can also be connected to the configured and active TCI states, where WD 22 only selects a single-TRP CSI if the CSI-RS resource is among the active TCI states.

[0269] In the further extension described above, the CSI-RS resource indicator (CRI) is related to the active TCI state. For example, when reporting CRI = 0, the selected CSI-RS resource (or resources in the case of an extended TCI state) refers to the active TCI state with the lowest identity, and so on.

[0270] Note that for the purpose of CSI feedback, the TRP selection may not be explicitly indicated. Instead, the TRP can be implicitly indicated by the indication of the NZP CSI-RS resource (through which the TRP can be associated) configured for channel measurement.

[0271] Two-part CSI encoding

[0272] For the low overhead NC-JT CSI feedback method discussed in the previous section, the CSI payload size may vary depending on the rank value of both the single TRP CSI and the NC-JT CSI associated with each TRP. Before receiving the CSI report, the network node 16 may not know the exact CSI payload size of each CSI. In some embodiments, for example, to ensure correct decoding of the CSI report, the CSI may be divided into two CSI parts, where each CSI part is encoded separately. In some embodiments, the payload size of the first CSI part is deterministic and known to the network node 16 before receiving the CSI report, while the payload size of the second CSI part depends on the information encoded in the first CSI part. In order to receive the CSI report, the network node 16 can decode the first CSI part, and after successful decoding, the payload size of the second CSI part can be determined, which can enable the network node 16 to continue and decode the second CSI part.

[0273] To this end, the first CSI part may include the rank of a single TRP CSI for all K TRPs, i.e., {RI#1,...,RI#K}. In addition, the first CPSI part may also include an NC-JT CSI presence indicator, which explicitly indicates whether NC-JT CSI is present in the second part. For each TRP, the payload size of a single TRP PMI and whether one or two CQIs are present may also depend on the rank of the corresponding single TRP CSI, and thus the PMI and at least the CQI (if present) for the second codeword may be included in the second CSI part. The NC-JT CSI may also depend on the rank of a single TRP CSI and may therefore be included in the second CSI part. In some embodiments, the NC-JT layer indicator for each TRP may also depend on the NC-JT rank of the TRP, but a fixed bit length may be used to avoid introducing a third CSI part. For example, if Rth=2, 1 bit is allocated per TRP, the bit value for layer 0 is "0" if the NC-JT rank of the TRP is 1, the bit value for layer 1 is "1", and the bit is ignored if the NC-JT rank is 2. If CRI is used to select M from K TRPs for NC-JT, the CRI may also be included in the second part.

[0274] Low-overhead CSI feedback for URLLC

[0275] URLLC transmission may be considered different from the previous use cases in the sense that the primary goal may not be to maximize spectral efficiency but to maximize transmission robustness by sending the same data payload from multiple TRPs. Because WD 22 may support both normal enhanced mobile broadband (eMBB) services with normal reliability requirements and URLLC traffic, some embodiments of the present disclosure may provide unified CSI feedback for both use cases.

[0276] Therefore, in order to support dynamic switching between single TRP transmission and URLLC transmission on K (K>1) TRPs, WD22 can be configured with a CSI reporting setting with K NZP CSI-RS resources for channel measurement and CSI-IM resources for interference measurement, i.e.

[0277] ·{NZP CSI-RS#1,NZP CSI-RS#2,...,NZP CSI-RS#K}

[0278] ·{CSI-IM#1,CSI-IM#2,...,CSI-IM#K},

[0279] Among them, the resource pair {NZP CSI-RS#k, CSI-IM#k} is associated with the kth TRP. WD 22 can first measure the single TRP transmission hypothesis CSI for each resource pair. For the kth TRP, CSI#k is measured based on the resource pair {NZP CSI-RS#k, CSI-IM#k}. This produces K single TRP transmission hypothesis CSIs, namely {CSI#1, CSI#2,..., CSI#K}. Each such CSI may include RI, PMI, and one or two CQIs, namely CSI#k=(RI#k, PMI#k, CQI#k).

[0280] For URLLC, in one scenario, the reported rank for all TRPs is the same, in particular, only rank 1 transmissions from each TRP may be allowed. In this case, the rank may not be reported in the URLLC CSI. A single layer for URLLC may be selected from the layers reported in the single TRP transmission assumption CSI. The selection may be intended to maximize the signal-to-noise-and-interference ratio (SINR). Therefore, PMI may not be reported in the URLLC CSI feedback. Alternatively, a layer indicator (LI) may be used to indicate one of the layers in the single TRP assumption CSI for each TRP. If a separate codeword is sent from each TRP, CQI may also be reported for each TRP. Therefore, the reported URLLC CSI may include in, They are the layer indicator and CQI of the kth TRP respectively. Fig.18An example is shown in FIG. 1 , where two TRPs are used. In this example, layer 1 is selected in TRP1 and layer 0 is selected for URLLC in TRP2. In this example, WD 22 may report the following CSI:

[0281] Single TRP CSI:

[0282] оCSI#1=(RI#1,PMI#1,CQI#1), for TRP#1

[0283] oCSI#2=(RI#2,PMI#2,CQI#2), for TRP#2

[0284] URLLC CSI:

[0285] o It is associated with TRP#1

[0286] o It is associated with TRP#2

[0287] One benefit of this approach may be that there is no PMI reported for URLLC, which can save a lot of feedback overhead.

[0288] In some embodiments, if a single CW is transmitted on all TRPs, a single CQI may be reported. Thus, the reported URLLC CSI includes Among them, Q URLLC It is the joint CQI.

[0289] In another case, if up to rank 2 is also supported for URLLC, the per-TRP rank for URLLC can also be reported together with the layer indicator and CQI indicator. Thus, the URLLC CSI may include

[0290] In URLLC, the same or different resources may be used in each TRP. In the case where the same resources are used in all TRPs, WD 22 may consider inter-TRP interference when calculating CSI. In addition, WD 22 may be required to know the type of soft combining, i.e., IR or CC, so that CSI can be measured correctly. Therefore, information related to whether the same or different resources are used, the type of soft combining, and whether SFN type transmission is used may be signaled from the network to WD 22 or predefined / predetermined.

[0291] In one embodiment, when non-overlapping resources are used for multiple TRPs (i.e., resources associated with different TRPs are non-overlapping in the frequency domain, time domain, or both), there may be no inter-TRP interference. In such a case where non-overlapping resources are used for scheduling, URLLC CSI may not be required, and the scheduler can use a single TRP CSI. In some embodiments, when WD 22 is configured for URLLC transmission in non-overlapping resources, WD 22 only feeds back a single TRP CSI and can skip URLLC CSI.

[0292] NC-JT or URLLC only CSI Feedback

[0293] In this embodiment, CSI reporting for NC-JT or URLLC is configured separately from single TRP CSI reporting. For example, WD 22 can be configured (e.g., by network node 16) with a CSI reporting setting having K>1 NZP CSI-RS resources for channel measurement and one or K CSI-IM resources for interference measurement, where each of the K NZP CSI-RS resources is associated with one TRP. In the CSI reporting setting, an indicator can also be configured to indicate whether the CSI report is for NC-JT or for URLLC. The rank limit per TRP or NZP CSI-RS resource can also be included in the CSI reporting setting to apply the maximum rank per TRP.

[0294] For NC-JT, WD 22 can select and report back preferably 1<M<K TRPs (or NZP CSI-RS resources) and the associated NC-JT CSI, where M can be predefined in the standard or signaled to WD 22, e.g., by network node 16 via RRC signaling to WD 22. The NC-JT CSI can include a rank indicator and a precoding matrix indicator for each selected TRP and a channel quality indicator for each codeword. In some embodiments, the NC-JT CSI report can be triggered only when specific conditions are met in the single TRP CSI feedback. For example, network node 16 determines that WD 22 is at the cell edge and within the line-of-sight (LOS) condition to two TRPs through the single TRP CSI feedback and / or reference signal received power (RSRP) report.

[0295] For URLLC, an indicator related to whether the same or non-overlapping frequency resources will be used in each TRP can be included in the reporting setting (e.g., by network node 16). Additionally, in some embodiments, an indicator related to whether the transmission will be repeated in time can also be included.

[0296] Some embodiments can include one or more of the following embodiments:

[0297] Combined single TRP and multi-TRPCSI feedback

[0298] 1. A method for CSI feedback, such as for dynamically switching between a single transmission point (TRP) and multiple transmission points for PDSCH transmission of a WD 22 in a wireless network, wherein the method comprises one or more of the following operations:

[0299] - For example, by the network node 16 configuring the WD 22 with one or more CSI reporting settings including K>1 NZP CSI-RS resources, each resource being associated with one TRP;

[0300] - requesting CSI feedback from the WD 22, for example by the network node 16, based on one or more CSI reporting settings; and

[0301] - measuring and / or reporting CSI with one or both of a single TRP transmission assumption and a multiple TRP transmission assumption by WD 22; and / or

[0302] - Scheduling PDSCH transmission to the WD 22, for example by the network node 16, based on the CSI feedback.

[0303] 2. The method according to embodiment 1, wherein the one or more CSI report settings further include K>1 CSI-IM resources for interference measurement.

[0304] 3. A method according to embodiments 1 and 2, wherein the CSI for a single TRP transmission assumption includes one CSI for each of K>1 NZP CSI-RS resources.

[0305] 4. A method according to embodiments 1 to 3, wherein the CSI for a single TRP transmission assumption associated with each NZP CSI-RS resource also includes one or more of a rank indicator (RI), a precoding matrix indicator (PMI), and a channel quality indicator (CQI).

[0306] 5. A method according to embodiments 1 to 4, wherein the CSI for the multi-TRP transmission assumption includes CSI for one or both of non-coherent joint transmission (NC-JT) or ultra-reliable low latency (URLLC) transmission.

[0307] 6. A method according to embodiments 1 to 5, wherein CSI for NC-JT is measured and / or reported only when specific conditions are met, wherein these conditions may be that the ranks of CSI for a single TRP transmission are all below a threshold, or that the data throughput using NC-JT is lower than the data throughput using a single TRP transmission.

[0308] 7. The method of embodiment 6, wherein the threshold is signaled to WD 22 or is pre-specified.

[0309] 8. A method according to embodiments 1 to 6, wherein the CSI for NC-JT includes a rank indicator, and / or a layer indicator, and / or a channel quality indicator for each of K>1 NZP CSI-RS resources.

[0310] 9. The method of embodiment 8, wherein the layer indicator associated with the NZP CSI-RS resource indicates the MIMO layer in a single TRP CSI associated with the same NZP CSI-RS resource for NC-JT transmission.

[0311] 10. The method of embodiments 8 to 9, wherein the layer indicator implicitly indicates a precoding matrix for NC-JT, wherein the precoding matrix includes a subset of columns of the precoding matrix associated with a single TRP CSI.

[0312] 11. A method according to embodiments 1 to 10, wherein, when the K NZP CSI-RS resources configured in one or more CSI reporting settings are greater than the number of M>1 TRPs used for NC-JT transmission, WD 22 may first select M NZP CSI-RS resources, and then measure and / or report NC-JT CSI based on the selected M NZP CSI-RS resources.

[0313] 12. The method of embodiment 11, wherein the selected M NZP CSI-RS resources are also reported as part of the NC-JT CSI.

[0314] 13. A method according to embodiments 1 to 5, wherein the CSI for URLLC can be measured based on all K NZP CSI-RS resources or a subset of K NZP CSI-RS resources, and / or if a subset of K NZP CSI-RS resources is used, the selected subset can also be reported.

[0315] 14. The method according to embodiments 1 to 13, wherein, for URLLC, WD 22 is also signaled (i.e., received via, for example, a network node) information regarding whether fully overlapping resources or non-overlapping resources are to be used in the K TRPs.

[0316] 15. The method of embodiments 1 to 14, wherein the CSI for URLLC includes one or more of a rank indicator, a layer indicator for each of K>1 NZP CSI-RS resources, and a channel quality indicator.

[0317] 16. The method of embodiment 15, wherein the layer indicator indicates, for example implicitly, a precoding matrix for URLLC transmission, wherein, optionally, the precoding matrix comprises a subset of columns of the precoding matrix associated with a single TRP CSI.

[0318] 17. The method of embodiment 5, wherein the indication of whether the CSI is used for NZ-JT or URLLC is configured in the CSI report settings or signaled separately to WD 22.

[0319] 18. The method of embodiments 1 to 15, wherein the CSI report comprises a first part and a second part, wherein the size of the first part is fixed and the size of the second part depends on the first part.

[0320] 19. The method of embodiment 18, wherein the first part includes one or more of a rank indicator for a single TRP CSI and an indicator as to whether NC-JT CSI is present, and the second part contains the rest of the CSI feedback

[0321] 20. The method of embodiment 9, wherein the first portion is encoded first before encoding the second portion at WD 22.

[0322] 21. The method of embodiments 9 to 11, wherein the first portion is first decoded at the network node.

[0323] Separate single TRP and multi-TRP CSI feedback:

[0324] 1. A method for CSI feedback, such as for dynamically switching between a single transmission point (TRP) and multiple transmission points for PDSCH transmission of a WD 22 in a wireless network, wherein the method comprises one or more of the following operations:

[0325] - For example, by the network node 16 configuring the WD 22 with one or more CSI reporting settings including K>1 NZP CSI-RS resources, each resource being associated with one TRP;

[0326] - requesting CSI feedback from the WD 22, for example by the network node 16, based on one or more CSI reporting settings; and

[0327] - measuring and / or reporting CSI with single TRP transmission assumption or multiple TRP transmission assumption by WD 22; and / or

[0328] - Scheduling PDSCH transmission to the WD 22, for example by the network node 16, based on the CSI feedback.

[0329] 2. The method according to (1), wherein one or more CSI report settings further comprise K>1 CSI-IM resources for interference measurement.

[0330] 3. The method according to (1), wherein an indication of whether the CSI feedback is for a single TRP transmission assumption or a multi-TRP transmission assumption is signaled in the CSI report setting.

[0331] 4. The method according to (1), wherein the CSI for a single TRP transmission assumption comprises K CSIs, each CSI being measured on a pair of resources from K NZP CSI-RS resources and CSI-IM resources, where K is an integer greater than or equal to 1.

[0332] 5. The method according to (4), wherein each of the K CSIs comprises one or more of a rank indicator (RI), a precoding matrix indicator (PMI), and a channel quality indicator (CQI).

[0333] 6. The method according to (1), wherein the multi-TRP transmission assumption can be used for NC-JT transmission or URLLC transmission.

[0334] 7. The method according to (1) to (6), wherein an indication of whether the CSI is for NC-JT or for URLLC is signaled in the CSI report setting or signaled separately.

[0335] 8. The method according to (1) to (6), wherein the CSI for a multi-TRP transmission assumption comprises one or more of an RI, a PMI, and a CQI associated with each of the K NZP CSI-RS resources.

[0336] 9. The method according to (1) to (6), wherein the CSI for a multi-TRP transmission assumption comprises one or more of an RI and a PMI and a CQI associated with each of the K NZP CSI-RS resources.

[0337] 10. The method according to (1) to (8), wherein WD 22 can first select M<K NZP CSI-RS resources from the K NZP CSI-RS resources, and measure and / or report the multi-TRP CSI based on the selected M NZP CSI-RS resources.

[0338] 11. The method according to (9), wherein the selected M NZP CSI-RS resources are also reported as a CSI-RS resource indicator (CRI).

[0339] 12. The method according to (1) to (11), wherein, for URLLC, WD 22 is also signaled (i.e., receives) information regarding whether fully overlapping resources or non-overlapping resources are to be used in the K TRPs.

[0340] Additionally, some embodiments of the present disclosure may include one or more of the following:

[0341] Embodiment A1. A network node configured to communicate with a wireless device (WD), the network node being configured to and / or comprising a radio interface and / or comprising a processing circuit configured to perform one or more of the following operations:

[0342] Send downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs);

[0343] A channel state information (CSI) reporting setting with K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources is configured for the WD, each resource being associated with one TRP;

[0344] Requesting a CSI feedback report from the WD based on the CSI reporting settings, assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs; and / or

[0345] Based on the CSI feedback report, downlink channel transmission to the WD is scheduled.

[0346] Embodiment A2. The network node of embodiment A1, wherein the CSI feedback report includes K individual TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and one or more CSIs for NC-JT transmission are reported if a specific condition is met.

[0347] Embodiment A3. The network node of embodiment A1, wherein the CSI feedback report further includes an indicator indicating whether NC-JT CSI is present in the report.

[0348] Embodiment A4. The network node of embodiment A1, wherein the CSI feedback report comprises a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0349] Embodiment B1. A method implemented in a network node, the method comprising one or more of the following operations:

[0350] Send downlink channel transmissions from a single transmission point (TRP) and / or multiple transmission points (multi-TRPs);

[0351] A channel state information (CSI) reporting setting with K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources is configured for the WD, each resource being associated with one TRP;

[0352] Requesting a CSI feedback report from the WD based on the CSI reporting settings, assuming data transmission from each of the K TRPs and data transmission from each of M>1 of the K TRPs; and / or

[0353] Based on the CSI feedback report, downlink channel transmission to the WD is scheduled.

[0354] Embodiment B2. The method of embodiment B1, wherein the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and one or more CSIs for NC-JT transmission are reported if certain conditions are met.

[0355] Embodiment B3. The method according to embodiment B1, wherein the CSI feedback report further includes an indicator indicating whether NC-JT CSI is present in the report.

[0356] Embodiment B4. The method according to embodiment B1, wherein the CSI feedback report comprises a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0357] Embodiment C1. A wireless device (WD) configured to communicate with a network node, the WD configured to and / or including a radio interface and / or a processing circuit configured to perform one or more of the following operations:

[0358] receiving a CSI feedback request based on a channel state information (CSI) reporting configuration having K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources, each resource being associated with a transmission point (TRP); and / or

[0359] Assuming data transmission from each of K TRPs and data transmission from each of M>1 TRPs among K TRPs, channel state information (CSI) feedback reports are measured and fed back based on the received CSI report settings.

[0360] Embodiment C2. The WD of embodiment C1, wherein the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT transmission if certain conditions are met.

[0361] Embodiment C3. The WD of embodiment C1, wherein the CSI feedback report further includes an indicator indicating whether NC-JT CSI exists in the CSI feedback report.

[0362] Embodiment C4. The WD of embodiment C1, wherein the CSI feedback report comprises a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0363] Embodiment D1. A method implemented in a wireless device (WD), the method comprising one or more of the following operations:

[0364] receiving a CSI feedback request based on a channel state information (CSI) reporting configuration for K>1 non-zero power channel state information reference signal (NZP CSI-RS) resources, each resource being associated with a transmission point (TRP); and / or

[0365] Assuming data transmission from each of the K TRPs and data transmission from each of M>1 TRPs among the K TRPs, channel state information (CSI) feedback reports are measured and sent based on the received CSI report settings.

[0366] Embodiment D2. The method of embodiment D1, wherein the CSI feedback report includes K single TRP CSIs, each TRP CSI is associated with one of the K NZP CSI-RS resources, and includes one or more CSIs for NC-JT if certain conditions are met.

[0367] Embodiment D3. The method according to embodiment D1, wherein the CSI feedback report further includes an indicator indicating whether NC-JT CSI exists in the CSI feedback report.

[0368] Embodiment D4. The method according to embodiment D1, wherein the CSI feedback report comprises a first part and a second part, the size of the first part is fixed, and the size of the second part depends on the first part.

[0369] As will be appreciated by those skilled in the art, the concepts described herein may be embodied as methods, data processing systems, computer program products, and / or computer storage media storing executable computer programs. Therefore, the concepts described herein may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects, all of which are generally referred to herein as "circuits" or "modules." Any process, step, action, and / or function described herein may be performed and / or associated with a corresponding module, which may be implemented in software and / or firmware and / or hardware. In addition, the present disclosure may take the form of a computer program product on a tangible computer-usable storage medium, which contains a computer program code that may be executed by a computer. Any suitable tangible computer-readable medium may be utilized, including a hard disk, a CD-ROM, an electronic storage device, an optical storage device, or a magnetic storage device.

[0370] Some embodiments are described herein with reference to the flowcharts and / or block diagrams of methods, systems, and computer program products. It will be understood that each square block of the flowchart and / or block diagram, and the combination of square blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer (to thereby produce a special-purpose computer), a processor of a special-purpose computer or other programmable data processing device to produce a machine, so that these instructions, when executed via a processor of a computer or other programmable data processing device, produce a device that implements the function / operation specified in one or more square blocks in the flowchart and / or block diagram.

[0371] These computer program instructions may also be stored in a computer-readable memory or storage medium, which may cause a computer or other programmable data processing device to work in a specific manner so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions / operations specified in one or more blocks in the flowchart and / or block diagram.

[0372] Computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps to implement the functions / operations specified in one or more boxes in the flowchart and / or block diagram.

[0373] It will be understood that the functions / actions noted in the blocks may occur in a different order than that noted in the operational diagram. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the opposite order, depending on the functions / actions involved. Although some figures include arrows on the communication paths to illustrate the primary direction of communication, it will be understood that communication may occur in the opposite direction to the arrows shown.

[0374] Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language (e.g. The computer program code for performing the operations of the present disclosure may be written in a conventional procedural programming language (e.g., C++). However, the computer program code for performing the operations of the present disclosure may also be written in a conventional procedural programming language (e.g., the "C" programming language). The program code may be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer, partially on a remote computer, or entirely on the remote computer. In the case of a remote computer, the remote computer may be connected to the user's computer via a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet).

[0375] Many different embodiments have been disclosed herein in conjunction with the above description and accompanying drawings. It will be understood that literally describing and illustrating every combination and subcombination of these embodiments would be overly repetitive and confusing. Therefore, all embodiments may be combined in any manner and / or combination, and this specification including the accompanying drawings will be interpreted as constituting a complete written description of all combinations and subcombinations of the embodiments described herein, as well as the manner and process of making and using them, and will support claims to any such combination or subcombination.

[0376] Those skilled in the art will appreciate that the embodiments described herein are not limited to what has been specifically shown and described above. In addition, unless otherwise noted above, it should be noted that not all drawings are to scale. Based on the above teachings, various modifications and variations are possible without departing from the scope of the following claims.

Claims

1. A method implemented in a wireless device (22), the method comprising: Receiving (S140) a configuration of a channel state information CSI report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal NZP CSI-RS resources for channel measurement, K being an integer; Based at least in part on the CSI reporting configuration, receiving (S142) a CSI feedback report request for CSI measurement and feedback; Based at least in part on the NZP CSI-RS resources, measuring (S144) a channel; and Sending (S146) a channel state information (CSI) feedback report based at least in part on: the channel measurements; and the report quantity configuration; and The CSI feedback report includes a first CSI feedback and a second CSI feedback.

2. The method according to claim 1, wherein: The first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources.

3. The method according to claim 1, wherein: The second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low delay URLL transmission.

4. The method according to any one of claims 1 to 3, wherein: The second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator.

5. The method according to any one of claims 1 to 3, wherein: The second CSI feedback includes a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

6. The method according to any one of claims 1 to 3, wherein: The second CSI feedback also includes identifiers of the first NZP CSI-RS resource and the second NZP CSI-RS resource.

7. The method according to any one of claims 1 to 3, further comprising: and determining whether to include the second CSI feedback in the CSI feedback report.

8. The method according to claim 7, wherein: Determining whether to include the second CSI feedback further includes: If each rank of the first CSI feedback is lower than a threshold, it is determined to include the second CSI feedback.

9. The method according to any one of claims 1 to 3 and 8, wherein The CSI feedback report further includes an indicator indicating whether the second CSI feedback exists in the CSI feedback report.

10. The method according to any one of claims 1 to 3 and 8, wherein The CSI feedback report only includes the second CSI feedback.

11. A method implemented in a network node (16), the method comprising: Configuring (S134) a wireless device (22) with a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer; Based at least in part on the CSI reporting configuration, sending (S136) a CSI feedback report request for CSI measurement and feedback; as well as receiving (S138) a channel state information (CSI) feedback report, the CSI feedback report being based at least in part on the CSI reporting configuration; and The CSI feedback report includes a first CSI feedback and a second CSI feedback.

12. The method according to claim 11, wherein: The first CSI feedback includes one CSI associated with each of the K NZP CSI-RS resources.

13. The method according to claim 11, wherein: The second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low delay URLL transmission.

14. The method according to any one of claims 11 to 13, wherein: The second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator.

15. The method according to any one of claims 11 to 13, wherein: The second CSI feedback includes a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

16. The method according to any one of claims 11 to 13, wherein: The second CSI feedback also includes identifiers of the first NZP CSI-RS resource and the second NZP CSI-RS resource.

17. The method according to any one of claims 11 to 13, wherein: The CSI feedback report includes both the first CSI feedback and the second CSI feedback.

18. The method according to any one of claims 11 to 13, wherein: If each rank of the first CSI feedback is lower than a threshold, the CSI feedback report includes the second CSI feedback.

19. The method according to any one of claims 11 to 13, wherein: The CSI feedback report further includes an indicator indicating whether the second CSI feedback exists in the CSI feedback report.

20. The method according to any one of claims 11 to 13, wherein: The CSI feedback report only includes the second CSI feedback.

21. A wireless device (22) configured to communicate with a network node (16), the wireless device (22) comprising a processing circuit (84), the processing circuit (84) configured to cause the wireless device (22) to: Receiving a configuration of a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer; receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI reporting configuration; Based at least in part on the NZP CSI-RS resources, measuring a channel; and Sending a channel state information (CSI) feedback report based at least in part on: the channel measurements; and the report quantity configuration; and The CSI feedback report includes a first CSI feedback and a second CSI feedback.

22. The wireless device (22) of claim 21, wherein: The first CSI feedback includes one CSI for each of the K NZP CSI-RS resources.

23. The wireless device (22) of claim 21, wherein: The second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low delay URLL transmission.

24. The wireless device (22) according to any one of claims 21 to 23, wherein: The second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator.

25. The wireless device (22) according to any one of claims 21 to 23, wherein: The second CSI feedback includes a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

26. The wireless device (22) according to any one of claims 21 to 23, wherein: The second CSI feedback further includes identifiers of the first NZP CSI-RS resource and the second NZP CSI-RS resource.

27. The wireless device (22) according to any one of claims 21 to 23, wherein: The processing circuit (84) is further configured to cause the wireless device (22) to perform the following operations: and determining whether to include the second CSI feedback in the CSI feedback report.

28. The wireless device (22) of claim 27, wherein: The processing circuit (84) is further configured to cause the wireless device (22) to determine whether to include the second CSI feedback by being configured to cause the wireless device (22) to: If each rank of the first CSI feedback is lower than a threshold, it is determined to include the second CSI feedback.

29. The wireless device (22) according to any one of claims 21 to 23 and 28, wherein: The CSI feedback report further includes an indicator indicating whether the second CSI feedback exists in the CSI feedback report.

30. The wireless device (22) according to any one of claims 21 to 23 and 28, wherein: The CSI feedback report only includes the second CSI feedback.

31. A network node (16) configured to communicate with a wireless device (22), the network node (16) comprising a processing circuit (68), the processing circuit (68) configured to cause the network node (16) to: Configuring a wireless device (22) with a channel state information (CSI) report setting and a report quantity configuration for at least K>1 non-zero power channel state information reference signal (NZP) CSI-RS resources for channel measurement, where K is an integer; sending a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI reporting configuration; as well as A channel state information (CSI) feedback report is received, the CSI feedback report being based at least in part on the CSI reporting configuration, and the CSI feedback report comprising a first CSI feedback and a second CSI feedback.

32. The network node (16) according to claim 31, wherein: The first CSI feedback includes one CSI for each of the K NZP CSI-RS resources.

33. The network node (16) of claim 31, wherein: The second CSI feedback includes CSI for one of non-coherent joint NC-JT transmission and ultra-reliable low delay URLL transmission.

34. The network node (16) according to any one of claims 31 to 33, wherein: The second CSI feedback includes a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first precoding matrix indicator and the second precoding matrix indicator.

35. The network node (16) according to any one of claims 31 to 33, wherein: The second CSI feedback includes a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first rank indicator and the second rank indicator and the first layer indicator and the second layer indicator.

36. The network node (16) according to any one of claims 31 to 33, wherein: The second CSI feedback further includes identifiers of the first NZP CSI-RS resource and the second NZP CSI-RS resource.

37. The network node (16) according to any one of claims 31 to 33, wherein: The CSI feedback report includes both the first CSI feedback and the second CSI feedback.

38. The network node (16) according to any one of claims 31 to 33, wherein: If each rank of the first CSI feedback is lower than a threshold, the CSI feedback report includes the second CSI feedback.

39. The network node (16) according to any one of claims 31 to 33, wherein: The CSI feedback report further includes an indicator indicating whether the second CSI feedback exists in the CSI feedback report.

40. The network node (16) according to any one of claims 31 to 33, wherein: The CSI feedback report only includes the second CSI feedback.

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