Method, apparatus, and storage medium for channel state information reporting

Abstract

A user equipment (UE) configured to report channel state information (CSI) to a wireless network. The UE transmits a first sounding reference signal (SRS) on an uplink (UL) channel; receives a first channel state information reference signal (CSI-RS) on a downlink (DL) channel, wherein based on the first SRS, the first CSI-RS includes a first CSI-RS parameter configuration; performs a first CSI-RS measurement based on the first CSI-RS parameter configuration; transmits a first CSI report including the first CSI-RS measurement; transmits a second SRS on the UL channel; receives a second CSI-RS on the DL channel, wherein based on the second SRS, the second CSI-RS includes a second CSI-RS parameter configuration; performs a second CSI-RS measurement based on the second CSI-RS parameter configuration; and transmits a second CSI report including the second CSI-RS measurement.

Description

Technical Field

[0001] This application generally relates to wireless communication systems and, more particularly, to channel state information reporting. Background Art

[0002] In 5G New Radio (NR) wireless communication, a 5G NR network may allocate one or more frequency subbands to a User Equipment (UE) to exchange information with the network. These subbands are allocated to the UE based on measured channel conditions, and the UE reports the measured channel conditions to the network's Next Generation Node B (gNB) based on Channel State Information (CSI) measurements made by the UE on CSI Reference Signals (CSI-RS). In Time Division Duplex (TDD) communication, the gNB may use channel reciprocity to determine the Downlink (DL) channel conditions based on the CSI measurements provided by the UE for the Uplink (UL) channel. 3GPP Release 15 and Release 16 provide Type II port selection codebooks that utilize this channel reciprocity. Summary of the Invention

[0003] Some exemplary embodiments relate to a User Equipment (UE) having: a transceiver configured to connect to a base station; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: transmitting a first Sounding Reference Signal (SRS) on an Uplink (UL) channel to the base station; receiving a first Channel State Information Reference Signal (CSI-RS) on a Downlink (DL) channel from the base station, wherein the first CSI-RS includes a first CSI-RS parameter configuration based on the first SRS; performing a first CSI-RS measurement based on the first CSI-RS parameter configuration; transmitting a first CSI report including the first CSI-RS measurements to the base station; transmitting a second SRS on the UL channel to the base station; receiving a second CSI-RS on the DL channel from the base station, wherein the second CSI-RS includes a second CSI-RS parameter configuration based on the second SRS; performing a second CSI-RS measurement based on the second CSI-RS parameter configuration; and transmitting a second CSI report including the second CSI-RS measurements to the base station.

[0004] Other exemplary embodiments relate to one or more processors configured to perform operations. These operations include: transmitting a first sounding reference signal (SRS) to a base station of a wireless network on an uplink (UL) channel; receiving a first channel state information reference signal (CSI-RS) from the base station on a downlink (DL) channel, where the first CSI-RS includes a first CSI-RS parameter configuration based on the first SRS; performing a first CSI-RS measurement based on the first CSI-RS parameter configuration; transmitting a first CSI report including these first CSI-RS measurements to the base station; transmitting a second SRS to the base station on the UL channel; receiving a second CSI-RS from the base station on the DL channel, where the second CSI-RS includes a second CSI-RS parameter configuration based on the second SRS; performing a second CSI-RS measurement based on the second CSI-RS parameter configuration; and transmitting a second CSI report including these second CSI-RS measurements to the base station.

[0005] Another exemplary embodiment relates to a method that includes: transmitting a first sounding reference signal (SRS) to a base station on an uplink (UL) channel of a wireless network; receiving a first channel state information reference signal (CSI-RS) from the base station on a downlink (DL) channel, where the first CSI-RS includes a first CSI-RS parameter configuration based on the first SRS; performing a first CSI-RS measurement based on the first CSI-RS parameter configuration; transmitting a first CSI report including these first CSI-RS measurements to the base station; transmitting a second SRS to the base station on the UL channel; receiving a second CSI-RS from the base station on the DL channel, where the second CSI-RS includes a second CSI-RS parameter configuration based on the second SRS; performing a second CSI-RS measurement based on the second CSI-RS parameter configuration; and transmitting a second CSI report including these second CSI-RS measurements to the base station. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 An exemplary network arrangement according to various exemplary embodiments is shown.

[0007] Figure 2 An exemplary UE according to various exemplary embodiments is shown.

[0008] Figure 3 An exemplary base station configured to establish a connection with a user equipment according to various exemplary embodiments is shown.

[0009] Figure 4 A method of reconfiguring channel state information (CSI) resources according to various exemplary embodiments is shown.

[0010] Figure 5 An exemplary diagram is shown that illustrates CSI resource configuration according to various exemplary embodiments. Detailed Description

[0011] The exemplary embodiments may be further understood with reference to the following description and the related drawings, in which like elements are denoted by like reference numerals. The exemplary embodiments describe devices, systems, and methods for a 5G New Radio (NR) network to improve Channel State Information (CSI) configuration of a User Equipment (UE).

[0012] The exemplary embodiments are described with reference to a network including a 5G New Radio NR Radio Access Technology (RAT). However, the exemplary embodiments may be implemented in other types of networks using the principles described herein.

[0013] The exemplary embodiments are also described with reference to a UE. However, the use of the UE is for illustrative purposes only. The exemplary embodiments can be utilized with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, the UE described herein is used to represent any electronic component.

[0014] As noted above, the gNB may use Time Division Duplex (TDD) communication channel reciprocity to determine the downlink (DL) channel conditions based on the CSI measurements provided by the UE for the uplink (UL) channel. Although there is no exact reciprocity in Frequency Division Duplex (FDD) communication as in TDD, there may be partial reciprocity. For example, in FDD communication, the angle of arrival / departure and the channel delay profile between the UL carrier and the DL carrier are similar. Currently, 5G NR communication does not utilize the partial reciprocity exhibited by FDD communication.

[0015] According to some exemplary embodiments, the partial channel reciprocity in FDD is utilized to allow CSI report reconfiguration to address changes in channel conditions and reduce the overhead associated with performing CSI measurements at the UE.

[0016] Figure 1FIG. 0 shows an exemplary network arrangement 100 in accordance with various exemplary embodiments. The exemplary network arrangement 100 includes a UE 110. It should be noted that any number of UEs may be used in the network arrangement 100. Those skilled in the art will understand that the UE 110 may alternatively be any type of electronic component configured to communicate via a network, such as a mobile phone, a tablet computer, a desktop computer, a smart phone, a phablet, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It should also be understood that an actual network arrangement may include any number of UEs used by any number of users. Therefore, for illustrative purposes, only an example with a single UE 110 is provided.

[0017] The UE 110 may be configured to communicate with one or more networks. In the example of the network arrangement 100, the networks with which the UE 110 may communicate wirelessly are a 5G New Radio (NR) radio access network (5GNR-RAN) 120, an LTE radio access network (LTE-RAN) 122, and a wireless local area network (WLAN) 124. However, it should be understood that the UE 110 may also communicate with other types of networks, and the UE 110 may also communicate with a network via a wired connection. Thus, the UE 110 may include a 5G NR chipset for communicating with the 5GNR-RAN 120, an LTE chipset for communicating with the LTE-RAN 122, and an ISM chipset for communicating with the WLAN 124.

[0018] The 5G NR-RAN 120 and the LTE-RAN 122 may be part of a cellular network that may be deployed by a cellular provider (e.g., Verizon, AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 may include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macro cell base stations, micro cell base stations, small cell base stations, femto cell base stations, etc.) configured to send and receive traffic from UEs equipped with appropriate cellular chipsets. The WLAN 124 may include any type of wireless local area network (WiFi, hotspots, IEEE 802.11x networks, etc.).

[0019] The UE 110 may be connected to the 5G NR-RAN 120 via gNB 120A and / or gNB 120B. During operation, the UE 110 may be within the range of multiple gNBs. Thus, simultaneously or alternatively, the UE 110 may be connected to the 5GNR-RAN 120 via gNBs 120A and 120B. Additionally, the UE 110 may communicate with eNB 122A of the LTE-RAN 122 to transmit and receive control information for downlink and / or uplink synchronization with respect to the connection to the 5GNR-RAN 120.

[0020] Those skilled in the art will understand that any relevant process can be executed for the UE 110 to connect to the 5G NR-RAN 120. For example, as described above, the 5G NR-RAN 120 can be associated with a specific cellular provider where the UE 110 and / or its user have protocol and credential information (e.g., stored on the SIM card). When the presence of the 5G NR-RAN 120 is detected, the UE 110 can transmit the corresponding credential information to be associated with the 5G NR-RAN 120. More specifically, the UE 110 can be associated with a specific base station (e.g., gNB 120A of the 5G NR-RAN 120).

[0021] In addition to the networks 120, 122, and 124, the network arrangement 100 further includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 (e.g., 5GC of NR) can be regarded as an interconnected set of components that manage the operations and traffic of the cellular network. The cellular core network 130 also manages the traffic flowing between the cellular network and the Internet 140.

[0022] The IMS 150 can generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functions for the UE 110 to communicate with various networks.

[0023] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. The UE 110 will be described with reference to Figure 1 the network arrangement 100. The UE 110 can represent any electronic device and can include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 can include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, one or more antenna panels, etc. For example, the UE 110 can be coupled to an industrial device via one or more ports.

[0024] The processor 205 may be configured to execute multiple engines of the UE 110. For example, the engines may include a CSI management engine 235. The CSI management engine 235 may perform various operations related to performing CSI measurements on channels and providing CSI reports (e.g., via the gNB) back to the network.

[0025] The above engines are merely exemplary as applications (e.g., programs) executed by the processor 205. The functions associated with the engines may also be represented as separate integrated components of the UE 110, or may be modular components coupled to the UE 110, e.g., integrated circuits with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engines may also be embodied as one application or separate multiple applications. Additionally, in some UEs, the functionality described for the processor 205 is shared between two or more processors such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of the UE.

[0026] The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, while the I / O device 220 may be a hardware component that enables a user to make inputs. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touchscreen). The transceiver 225 may be a hardware component configured to establish connections with the 5G NR-RAN 120, LTE-RAN 122, WLAN 124, etc. Thus, the transceiver 225 may operate on multiple different frequencies or channels (e.g., a set of contiguous frequencies).

[0027] Figure 3 An exemplary network cell, in this case a gNB 120A, is shown according to various exemplary embodiments. The gNB 120A may represent any access node of a 5G NR network that the UE 110 may use to establish a connection. Figure 3 The gNB 120A shown may also represent the gNB 120B.

[0028] The gNB 120A may include a processor 305, a memory arrangement 310, input / output (I / O) devices 320, a transceiver 325, and other components 330. The other components 330 may include, for example, a power supply, data acquisition devices, ports for electrically connecting the gNB 120A to other electronic devices, etc.

[0029] The processor 305 may be configured to execute multiple engines of the gNB 120A. For example, these engines may include a CSI management engine 335 for performing operations including reconfiguring CSI resources for use by the UE 110 when performing CSI measurements. An example of this process will be described in more detail below.

[0030] The above engines are merely exemplary as applications (e.g., programs) executed by the processor 305. The functions associated with the engines may also be represented as stand-alone integrated components of the gNB 120A, or may be modular components coupled to the gNB 120A, e.g., integrated circuits with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. Additionally, in some gNBs, the functions described for the processor 305 are split among multiple processors (e.g., a baseband processor, an application processor, etc.). The exemplary aspects may be implemented in any of these or other configurations of the gNB.

[0031] The memory 310 may be a hardware component configured to store data related to operations performed by the UEs 110, 112. The I / O device 320 may be a hardware component or port that enables a user to interact with the gNB 120A. The transceiver 325 may be a hardware component configured to exchange data with the UE 110 and any other UE in the network arrangement 100. The transceiver 325 may operate at various different frequencies or channels (e.g., a set of contiguous frequencies). Thus, the transceiver 325 may include one or more components (e.g., radio components) to enable data exchange with various networks and UEs.

[0032] Figure 4 A method 400 for reporting interference fluctuations is shown according to various exemplary embodiments. At 405, the UE 110 transmits a sounding reference signal (SRS) on an uplink (UL) channel to the gNB 120a (or 120b). Based on the SRS, due to the partial reciprocity of the UL channel and the downlink (DL) channel, the gNB 120a learns about the DL channel. At 410, the UE 110 receives CSI reference signal (CSI-RS) configuration parameters from the gNB 120a.

[0033] In some exemplary embodiments, the CSI-RS configuration parameters may include CSI-RS resources in a non-zero power CSI-RS resource set (NZP-CSI-RS-ResourceSet). In such a scenario, the maximum number of M CSI-RS resources, such as, for example, channel measurement resources (CMR) and / or interference measurement resources (IMR), may be configured by gNB 120a via radio resource control (RRC) signaling. Based on the SRS received at 405, gNB 120a indicates to UE 110 which of the M CSI-RS resources UE 110 should use to perform CSI measurements. This indication of which of the M CSI-RS resources should be utilized may be performed via a medium access control control element (MAC-CE) or downlink control information (DCI) depending on whether the CSI-RS resource is a periodic (P-CSI) resource, a semi-persistent (SP-CSI) resource, or an aperiodic (AP-CSI) resource. For example, in the case of P-CSI, SP-CSI, or AP-CSI, a MAC-CE may be used to indicate to UE 110 which of the M CSI-RS resources UE 110 should use. In some embodiments, in the case of AP-CSI, DCI may alternatively be used.

[0034] In some exemplary embodiments, the CSI-RS configuration parameters may include the number of ports for each CSI-RS resource in the NZP-CSI-RS-ResourceSet. In such a scenario, the maximum number of N ports for each CSI-RS resource (e.g., CMR, IMR) may be configured by gNB 120a via RRC. In some embodiments, for each CSI-RS resource, the number of N ports is the same. Based on the SRS received at 405, gNB 120a indicates to UE 110 which of the N ports for each CSI-RS resource in the CSI-RS resources UE 110 should use to perform CSI measurements. This indication of which of the N ports for each CSI-RS resource in the CSI-RS resources should be utilized may be performed via a MAC-CE or DCI depending on whether the CSI-RS resource is a P-CSI resource, an SP-CSI resource, or an AP-CSI resource. For example, in the case of P-CSI, SP-CSI, or AP-CSI, a MAC-CE may be used to indicate to UE 110 which of the N ports for each CSI-RS resource in the CSI-RS resources UE 110 should use. In some embodiments, in the case of AP-CSI, DCI may alternatively be used.

[0035] In some exemplary embodiments, the CSI-RS configuration parameters may include CSI-RS resources in an NZP-CSI-RS-ResourceSet, each CSI-RS resource having a different number of ports, such as Figure 5 shown. In such a scenario, the gNB 120a may configure, via RRC, a maximum of M CSI-RS resource quantities (four are shown in Figure 5 , 502a to 502d). For each of the NZP-CSI-RS resources 502a to 502d, the gNB 120a may configure a different number of ports (nrofPorts). For example, as Figure 5 shown, the NZP-CSI-RS resource 502a is configured with 8 ports, the NZP-CSI-RS resource 502b is configured with 12 ports, the NZP-CSI-RS resource 502c is configured with 16 ports, and the NZP-CSI-RS resource 502d is configured with 32 ports. Based on the SRS received at 405, the gNB 120a indicates to the UE 110 which of the M CSI-RS resources the UE 110 should use to perform CSI measurements. Depending on whether the CSI-RS resource is a P-CSI resource, an SP-CSI resource, or an AP-CSI resource, this indication of which of the M CSI-RS resources should be utilized may be performed via a MAC-CE or DCI. For example, in the case of P-CSI, SP-CSI, or AP-CSI, a MAC-CE may be used to indicate which of the N ports for each CSI-RS resource in the CSI-RS resources the UE 110 should use. In some embodiments, in the case of AP-CSI, DCI may alternatively be used. Since each resource has a different number of ports associated with that resource, the activation of the resource also implicitly indicates the number of ports that should be utilized. It should be noted that Figure 5 is illustrative, and the number of resources and ports may be different from that shown in Figure 5 .

[0036] At 415, the UE 110 performs CSI measurements based on the allocated CSI-RS resources. At 420, the UE 110 transmits a CSI report to the gNB120a. As Figure 4 shown, the method 400 may be repetitive (continuous). For example, the UE 110 continuously sends SRS to the gNB 120a on the UL channel. Based on the received SRS, the gNB 120a may change the configuration of the CSI-RS configuration parameters. When the UE110 receives the updated parameters at 410, the UE 110 performs CSI measurements based on the updated parameters at 415 and transmits a CSI report to the gNB at 420.

[0037] As part of the CSI report, the UE 110 reports a precoding matrix indicator (PMI) for each subband of a bandwidth part (BWP). The gNB can utilize channel reciprocity to estimate the channel frequency selectivity on the UL side and then perform CSI subband precoding. The gNB 120a precodes each subband of the CSI in a different way such that when the UE receives the precoded channel, the precoded channel exhibits lower frequency selectivity. That is, the gNB 120a compensates for the frequency selectivity of the channel on the gNB side to reduce the frequency selectivity on the UE side. Accordingly, the CSI reporting overhead at the UE 110 is reduced. In other words, the gNB 120a detects the selectivity in the frequency domain on the UL channel and then reverses the selectivity such that after port selection for CSI transmission on the UE side, the channel exhibits significantly lower frequency selectivity.

[0038] Generally, the UE 110 performs CSI reporting for each subband. In the 3GPP Release 15 and Release 16 Type II port selection codebooks, wideband PMI reporting is not allowed. However, according to the embodiments of the present disclosure, when performing CSI measurement (i.e., performing PMI reporting), wideband PMI reporting can be utilized to reduce the overhead at the UE 110. In such a scenario, when "numberOfPMI-SubbandsPerCQI-Subband-r16 = 1", the UE 110 reports one PMI for the entire BWP. When "numberOfPMI-SubbandsPerCQI-Subband-r16 = 2", the UE 110 reports two PMIs for the entire BWP, one PMI for one half of the BWP and the other PMI for the other half of the BWP. In some embodiments, since the 3GPP Release 15 and Release 16 Type II port selection codebooks do not allow PMI subband reporting for a BWP with less than 24 physical resource blocks (PRBs), the wideband PMI reporting discussed above can be utilized to perform PMI reporting for a BWP with less than 24 PRBs. In such a scenario, only wideband PMI reporting (and no subband PMI reporting) is allowed.

[0039] In some exemplary embodiments, the CSI reporting overhead at the UE 110 can be further or alternatively reduced by allowing the BWP to have a larger subband size. In some embodiments, Table 5.2.1.4-2 of 3GPP 38.214 can be modified to include the additional subband sizes shown in bold in the following table.

[0040] Bandwidth Part (PRB) Subband Size (PRB) 24-72 4、8、16、32 73-144 8、16、32、64、144 145-275 16、32、64、128、275

[0041] To enable the UE 110 to learn the updated table, the additional subband size for CSI reporting may be transmitted to the UE via RRC, MAC-CE, or DCI. As noted above, the UE 110 performs CSI reporting for each subband. By allowing a larger subband size, the number of subbands is reduced, thus advantageously reducing the number of CSI reports and the associated overhead on the UE side.

[0042] In some embodiments, Table 5.2.1.4-2 of 3GPP 38.214 may remain as it is, and the gNB 120a may configure the CSI configuration such that the UE 110 uses a bundling factor K to bundle subbands. K may have any desired value, such as, for example, 1, 2, 4, 8, etc., and may be configured via RRC, MAC-CE, or DCI. After configuration, the UE 110 increases the subband size to the value configured by multiplying the subbandSize in CSI-ReportConfig by K. For example, if subbandSize is configured to 8 and K = 2, the result will be a subband size of 16. Then, the UE 110 performs CSI reporting based on the increased subband size. By increasing the subband size, the number of subbands is reduced, thus advantageously reducing the number of CSI reports and the associated overhead on the UE side.

[0043] According to the 3GPP Release 15 and Release 16 Type II port selection codebooks, multiple ports (L) (L = 1, 2, or 4) are continuously selected every d ports (d = 1, 2, 3, 4). For example, 4 consecutive ports may be selected starting from every 3 ports. Thus, 4 consecutive ports may be selected starting from ports 0, 3, 6, etc. In some exemplary embodiments, the CSI reporting overhead at the UE 110 may be further or alternatively reduced by increasing the number of d ports such that L consecutive ports may be selected every d ports, where d may have a value greater than 4 (e.g., 5, 6, etc.). Therefore, due to the increased restriction on the starting port, the number of possible selections of L consecutive ports is reduced, which advantageously reduces the processing overhead on the UE side when determining which ports should be used in the CSI report.

[0044] According to the 3GPP Release 15 and Release 16 Type II port selection codebooks, the port selection is determined based on the following equation

[0045]

[0046] where W1 is the port selection matrix, is the compression factor matrix, and is the frequency basis matrix. Currently, the CSI Type II port selection includes W1, W2, W fReporting of the channel quality indicator (CQI). In some embodiments, when there is partial channel reciprocity, the CSI reporting overhead at the UE 110 can be further or alternatively reduced by allowing the UE 110 to report one value or a subset of these four values. When the gNB 120a determines a precoder for the PMI of a channel that does not exhibit much change, the UE 110 does not need to report all of W1, W2, W f and CQI. Instead, the UE 110 can report one value or a subset of these values. For example, if the gNB 120a determines a precoder for the PMI of a channel that does not exhibit much change but experiences channel fading, then W1 and W f remain relatively unchanged, and the UE 110 can report only W2 and CQI or only W2.

[0047] In some exemplary embodiments, the gNB 120a can select a subset of the N3 (19 or 38 subbands) base frequencies for frequency-domain CSI feedback overhead compression. By selecting a subset of the N3 base frequencies, the CSI reporting overhead and computational complexity at the UE 110 are advantageously reduced. For example, the gNB 120a can instruct the UE 110 not to perform CSI measurements on a part of the N3 base frequencies corresponding to the high-frequency selective components of the channel.

[0048] In some exemplary embodiments, the UE 110 can additionally use the SRS to provide noise feedback to the gNB 120a (e.g., at 405). When the number of transmit antennas is equal to the number of receive antennas, in some embodiments, the UE 110 can implicitly provide noise feedback to the gNB 120a by performing noise whitening. This noise whitening is achieved by measuring the noise covariance matrix R nn and using the inverse square root of the noise covariance matrix as the precoder when precoding the SRS. After the gNB 120a decodes the SRS, the gNB 120a knows the channel conditions (noise).

[0049] In some exemplary embodiments, the UE 110 can explicitly provide noise feedback to the gNB 120a by feeding back R nn to the gNB 120a. In some embodiments, due to the large size of the matrix, the UE 110 can compress R nn . Since R nn is a positive semi-definite Hermitian matrix therefore in some embodiments, the UE 110 can only quantize and feed back the lower (or upper) triangular part of R nn to the gNB 120a. Alternatively, the UE 110 can use singular value decomposition (SVD) to decompose R nn into (R​nn ) i，j = U * A * U', where L is a diagonal matrix with non - negative diagonal elements, and U is a unitary orthogonal matrix. In such a scenario, UE 110 only quantifies and feeds back the diagonal elements of L. U can be quantified or approximated by selecting a predefined orthogonal basis.

[0050] Example

[0051] In a first embodiment, a user equipment (UE) comprises: a transceiver configured to connect to a base station; and a processor communicatively coupled to the transceiver and configured to perform operations including: receiving, on a downlink (DL) channel, a channel state information reference signal (CSI - RS) from the base station, where the CSI - RS includes a configuration of CSI - RS parameters, and where the CSI - RS has a configured bandwidth part (BWP) with less than 24 physical resource blocks (PRBs); determining a precoding matrix indicator (PMI) based on the CSI - RS; and transmitting a CSI report including the PMI to the base station, where the PMI is a wideband PMI.

[0052] In a second embodiment, the UE according to the first embodiment, wherein the operations further include: determining a wideband channel quality indicator (CQI) based on the CSI - RS, where the CSI report further includes the wideband CQI.

[0053] In a third embodiment, the UE according to the first embodiment, wherein the channel state information (CSI) is determined based on a 3GPP Release 15 Type II port selection codebook.

[0054] In a fourth embodiment, the UE according to the first embodiment, wherein the channel state information (CSI) is determined based on a 3GPP Release 16 enhanced Type II port selection codebook.

[0055] In a fifth embodiment, a base station of a wireless network comprises: a transceiver configured to connect to a user equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform operations including: configuring a bandwidth part (BWP) of a channel state information reference signal (CSI - RS), where the CSI - RS includes a CSI report configuration; configuring a sub - band size, where the configured sub - band size is part of the CSI report configuration, and where the configured sub - band size is between 4 and 275 physical resource blocks (PRBs); transmitting the CSI - RS to the UE; and receiving a CSI report based on the CSI - RS from the UE.

[0056] In the sixth embodiment, the base station according to the fifth embodiment, wherein the configured sub-band size is selected from at least three sub-band sizes.

[0057] In the seventh embodiment, the base station according to the fifth embodiment, wherein the configured sub-band size is based on a bundling factor multiplied by a predefined sub-band size value.

[0058] In the eighth embodiment, a base station for a 5G New Radio (NR) wireless network includes: a transceiver configured to connect to a User Equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform operations including: configuring a Channel State Information Reference Signal (CSI-RS); transmitting the CSI-RS to the UE; and receiving, from the UE, a CSI report based on the CSI-RS, wherein the CSI report indicates a selection of one or more consecutive CSI-RS ports, and wherein a first port of the one or more consecutive CSI-RS ports is a first, second, third, fourth, fifth, or sixth CSI-RS port.

[0059] In the ninth embodiment, the base station according to the eighth embodiment, wherein the one or more consecutive CSI-RS ports are selected by wrapping around.

[0060] In the tenth embodiment, a User Equipment (UE) includes: a transceiver configured to connect to a base station; and a processor communicatively coupled to the transceiver and configured to perform operations including: transmitting a Sounding Reference Signal (SRS) to the base station on an Uplink (UL) channel; receiving, on a Downlink (DL) channel, a Channel State Information Reference Signal (CSI-RS) from the base station, wherein the CSI-RS includes a configuration of CSI-RS ports; performing CSI-RS measurements on the CSI-RS; and transmitting a CSI report including the CSI-RS measurements to the base station, wherein the CSI report includes a subset of 3GPP Release 16 Type II port selection parameters, and wherein the 3GPP Release 16 Type II port selection parameters include a spatial basis selection matrix, a frequency basis selection matrix, a compression coefficient combination matrix, and a Channel Quality Indicator.

[0061] In the eleventh embodiment, the UE according to the tenth embodiment, wherein the subset includes one parameter of the 3GPP Release 16 Type II port selection parameters.

[0062] In a twelfth embodiment, a user equipment (UE) includes: a transceiver configured to connect to a base station; and a processor communicatively coupled to the transceiver and configured to perform operations including: determining a noise covariance feedback associated with a downlink (DL) channel; and transmitting a sounding reference signal (SRS) on the UL channel to the base station, where the SRS includes the noise covariance feedback.

[0063] In a thirteenth embodiment, the UE according to the twelfth embodiment, where the noise covariance feedback is based on a noise covariance matrix (Rnn).

[0064] In a fourteenth embodiment, the UE according to the thirteenth embodiment, where the operations further include: applying an inverse square root of the noise covariance matrix (R_nn^(-1 / 2)) to the SRS to whiten the noise on the UL channel.

[0065] In a fifteenth embodiment, the UE according to the thirteenth embodiment, where the operations further include: compressing the noise covariance matrix (Rnn) to obtain a compressed noise covariance matrix; and transmitting the compressed noise covariance matrix to the base station.

[0066] In a sixteenth embodiment, the UE according to the fifteenth embodiment, where compressing the noise covariance matrix includes: quantizing the noise covariance matrix; and transmitting one triangular part of either the lower triangular part or the upper triangular part of the quantized noise covariance matrix to the base station.

[0067] In a seventeenth embodiment, the UE according to the fifteenth embodiment, where compressing the noise covariance matrix includes: using singular value decomposition (SVD) to decompose the noise covariance matrix to obtain a diagonal matrix with non-negative diagonal elements and a unitary orthogonal matrix; quantizing the non-negative diagonal elements of the diagonal matrix; and transmitting the quantized non-negative diagonal elements of the diagonal matrix to the base station.

[0068] Those skilled in the art will understand that the above-described exemplary embodiments can be implemented with any suitable software configuration or hardware configuration or a combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, an Intel x86-based platform with a compatible operating system, Windows OS, Mac platform and MAC OS, mobile devices with operating systems such as iOS, Android, etc. In other examples, the exemplary embodiments of the above methods can be embodied as a program including lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, can be executed on a processor or a microprocessor.

[0069] Although this patent application describes various combinations of various aspects each having different features, those skilled in the art will understand that any feature of one aspect can be combined with the features of other aspects in any manner not negated by the disclosure or with features that are not operationally or logically inconsistent with the operation of the devices of the aspects disclosed herein or the functions thereof.

[0070] As is well known, the use of personally identifiable information should follow privacy policies and practices that are recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of the authorized use should be clearly explained to users.

[0071] It will be apparent to those skilled in the art that various modifications can be made to the present disclosure without departing from the essence or scope thereof. Accordingly, the present disclosure is intended to cover modifications and variations of the present disclosure provided they are within the scope of the appended claims and their equivalents.

Claims

1. A user equipment (UE) comprising: a transceiver configured to connect to a base station; and a processor communicatively coupled to the transceiver and configured to perform operations including: receiving a radio resource control (RRC) transmission configuring a maximum number of non-zero power channel state information reference signal (NZP-CSI-RS) resources; transmitting a first sounding reference signal (SRS) on an uplink (UL) channel to the base station; receiving a first CSI-RS from the base station on a downlink (DL) channel, wherein based on the first SRS, the first CSI-RS includes a first configuration of CSI-RS parameters, and wherein the first configuration of CSI-RS parameters includes a first number of NZP-CSI-RS resources; performing a first CSI-RS measurement based on the first configuration of CSI-RS parameters; transmitting a first CSI report including the first CSI-RS measurement to the base station; transmitting a second SRS on the UL channel to the base station; receiving a second CSI-RS from the base station on the DL channel, wherein based on the second SRS, the second CSI-RS includes a second configuration of CSI-RS parameters, and wherein the second configuration of CSI-RS parameters includes a second number of NZP-CSI-RS resources, the second number of NZP-CSI-RS resources being different from the first number of NZP-CSI-RS resources, and wherein the second configuration is received via one of a media access control control element (MAC-CE) transmission or a downlink control information (DCI) transmission, and wherein the second number of NZP-CSI-RS resources is a subset of the maximum number of NZP-CSI-RS resources; performing a second CSI-RS measurement based on the second configuration of CSI-RS parameters; and transmitting a second CSI report including the second CSI-RS measurement to the base station.

2. The UE according to claim 1, wherein each NZP-CSI-RS resource of the first number of NZP-CSI-RS resources includes a different number of ports, and wherein each NZP-CSI-RS resource of the second number of NZP-CSI-RS resources includes a different number of ports.

3. The UE according to claim 1, wherein the first configuration of CSI-RS parameters includes a first number of ports for each CSI-RS resource, and the second configuration of CSI-RS parameters includes a second number of ports for each CSI-RS resource, and wherein the first number of ports is different from the second number of ports.

4. The UE according to claim 3, wherein the second number of ports is the same for each CSI-RS resource.

5. The UE according to claim 3, wherein the operations further include: receiving a radio resource control (RRC) transmission configuring a maximum number of ports.

6. The UE according to claim 5, wherein the second configuration is received via one of a MAC-CE transmission or a DCI transmission, and wherein the second number of ports is a subset of the maximum number of ports.

7. A computer-readable storage medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations including the following: Receiving a radio resource control (RRC) transmission of a maximum number of non-zero power channel state information reference signal (NZP-CSI-RS) resources; Transmitting a first sounding reference signal (SRS) on an uplink (UL) channel to a base station of a wireless network; Receiving a first CSI-RS on a downlink (DL) channel from the base station, wherein based on the first SRS, the first CSI-RS includes a first configuration of CSI-RS parameters, and wherein the first configuration of CSI-RS parameters includes a first number of NZP-CSI-RS resources; Performing a first CSI-RS measurement based on the first configuration of CSI-RS parameters; Transmitting a first CSI report including the first CSI-RS measurement to the base station; Transmitting a second SRS on the UL channel to the base station; Receiving a second CSI-RS on the DL channel from the base station, wherein based on the second SRS, the second CSI-RS includes a second configuration of CSI-RS parameters, and wherein the second configuration of CSI-RS parameters includes a second number of NZP-CSI-RS resources, the second number of NZP-CSI-RS resources being different from the first number of NZP-CSI-RS resources, and wherein the second configuration is received via one of a medium access control control element (MAC-CE) transmission or a downlink control information (DCI) transmission, and wherein the second number of NZP-CSI-RS resources is a subset of the maximum number of NZP-CSI-RS resources; Performing a second CSI-RS measurement based on the second configuration of CSI-RS parameters; and Transmitting a second CSI report including the second CSI-RS measurement to the base station.

8. The computer-readable storage medium according to claim 7, wherein each of the first number of NZP-CSI-RS resources includes a different number of ports, and wherein each of the second number of NZP-CSI-RS resources includes a different number of ports.

9. The computer-readable storage medium according to claim 7, wherein the first configuration of CSI-RS parameters includes a first number of ports for each CSI-RS resource, and the second configuration of CSI-RS parameters includes a second number of ports for each CSI-RS resource, and wherein the first number of ports is different from the second number of ports.

10. The computer-readable storage medium according to claim 9, wherein the second number of ports is the same for each CSI-RS resource.

11. The computer-readable storage medium according to claim 9, wherein the operation further comprises: Receiving radio resource control (RRC) transmissions of a maximum number of configured ports.

12. The computer-readable storage medium according to claim 11, wherein the second configuration is received via one of medium access control control element (MAC-CE) transmission or downlink control information (DCI) transmission, and wherein the second number of ports is a subset of the maximum number of ports.

13. A method for wireless communication, comprising: Receiving radio resource control (RRC) transmissions of a maximum number of configured non-zero power channel state information reference signal (NZP-CSI-RS) resources; Transmitting a first sounding reference signal (SRS) on an uplink (UL) channel of a wireless network to a base station; Receiving a first CSI-RS on a downlink (DL) channel from the base station, wherein based on the first SRS, the first CSI-RS comprises a first configuration of CSI-RS parameters, and wherein the first configuration of CSI-RS parameters comprises a first number of NZP-CSI-RS resources; Performing a first CSI-RS measurement based on the first configuration of CSI-RS parameters; Transmitting a first CSI report comprising the first CSI-RS measurement to the base station; Transmitting a second SRS on the UL channel to the base station; Receiving a second CSI-RS on the DL channel from the base station, wherein based on the second SRS, the second CSI-RS comprises a second configuration of CSI-RS parameters, and wherein the second configuration of CSI-RS parameters comprises a second number of NZP-CSI-RS resources, the second number of NZP-CSI-RS resources being different from the first number of NZP-CSI-RS resources, and wherein the second configuration is received via one of medium access control control element (MAC-CE) transmission or downlink control information (DCI) transmission, and wherein the second number of NZP-CSI-RS resources is a subset of the maximum number of NZP-CSI-RS resources; Performing a second CSI-RS measurement based on the second configuration of CSI-RS parameters; and Transmitting a second CSI report comprising the second CSI-RS measurement to the base station.

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