Per layer scaling for channel state information codebooks

Abstract

A user equipment (UE), baseband processor, and network device are described. The baseband processor can receive control signaling that configures channel state information reference signal (CSI-RS) resources corresponding to CSI-RS ports. The CSI-RS ports may be associated with a first and second layer. The baseband process may obtain first measurements and second measurements of the CSI-RS resources with a plurality of CSI-RS ports corresponding to the first layer and the second layer, respectively. The baseband processor applies a first scaling factor to the first measurements, and a second scaling factor to the second measurements to obtain second scaled measurements for the second layer. The baseband processor then selects, using a first type of codebook, a precoding matrix indicator based at least in part on the first scaled measurements and the second scaled measurements, and transmits a CSI report including the selected precoding matrix indicator.

Description

PER LAYER SCALING FOR CHANNEL STATE INFORMATION CODEBOOKSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This Patent Cooperation Treaty patent application claims priority to U. S. Provisional Patent Application No. 63 / 718,548, filed November 8, 2024, and titled “Per Layer Scaling for Channel State Information Codebooks,” the content of which is incorporated herein by reference as if fully disclosed herein in its entirety.TECHNICAL FIELD

[0002] This application relates generally to wireless communication systems, including systems, apparatuses, and methods for per-layer scaling for channel state information codebooks.BACKGROUND

[0003] Wireless mobile communication technology uses various standards and protocols to transmit data between a network device (e.g., a base station, a radio head, etc.) and a wireless communication device. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G), 3GPP new radio (NR) (e.g., 5G), and IEEE 802.11 standard for wireless local area networks (WLAN) (commonly known to industry groups as Wi-Fi®).

[0004] As contemplated by the 3GPP, different wireless communication systems standards and protocols can use various radio access networks (RANs) for communicating between a network device of the RAN (which may also sometimes be referred to generally as a RAN node, a network node, or simply a node) and a wireless communication device known as a user equipment (UE).3GPP RANs can include, for example, global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next-Generation Radio Access Network (NG-RAN).

[0005] Each RAN may use one or more radio access technologies (RATs) to perform communication between the network device and the UE. For example, the GERAN implements GSM and / or EDGE RAT, the UTRAN implements universal mobile telecommunication system (UMTS) RAT or other 3 GPP RAT, the E-UTRAN implements LTE RAT (sometimes simply referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT,5G NR RAT, or simply NR). In certain deployments, the E-UTRAN may also implement NR RAT. In certain deployments, NG-RAN may also implement LTE RAT.

[0006] A network device used by a RAN may correspond to that RAN. One example of an E- UTRAN network device is an E-UTRAN Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB). One example of an NG-RAN network device is a next generation Node B (also sometimes referred to as a g Node B or gNB).

[0007] A RAN provides its communication services with external entities through its connection to a core network (CN). For example, E-UTRAN may utilize an Evolved Packet Core (EPC), while NG-RAN may utilize a 5G Core Network (5GC).BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0009] FIG. 1 shows an example wireless communication system, according to one or more aspects described herein.

[0010] FIG. 2 shows an example signaling diagram, according to one or more aspects described herein.

[0011] FIG. 3A shows a first example antenna configuration, according to one or more aspects described herein.

[0012] FIG. 3B shows a second example antenna configuration, according to one or more aspects described herein.

[0013] FIG. 4 shows an example method of wireless communication at a user equipment (UE), according to one or more aspects described herein.

[0014] FIG. 5 shows another example method of wireless communication at a network device, according to one or more aspects described herein.

[0015] FIG. 6 illustrates an example architecture of a wireless communication system, according to one or more aspects described herein.

[0016] FIG. 7 illustrates an example system for performing signaling between a wireless device and a network device, according to one or more aspects described herein.DETAILED DESCRIPTION

[0017] Various embodiments are described with regard to a processor (e.g., baseband processor), wireless device (e.g., a user equipment (UE)), or a network device. However, reference to a processor, wireless device, or network device is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component or device that may establish a wireless connection and is configured with the hardware, software, and / or firmware to exchange information and data over the wireless connection. Therefore, the processors, wireless devices, and network devices described herein are used to represent any appropriate electronic components or devices.

[0018] Multiple input multiple output (MIMO) is a radio access technology that uses multiple antennas to create multiple spatial paths between transmitters and receivers. One feature of MIMO is spatial multiplexing, which enables multiple data streams to be transmitted simultaneously across different spatial paths. This may increase data rates without use an increased amount of bandwidth since each stream may be independently transmitted and decoded. MIMO may also be used for beamforming, where signals are directed toward specific spatial direction, for example UEs served by a network device transmitted using beamforming, by adjusting the phase and amplitude of signals transmitted from each antenna. In some examples, an increased quantity of antennas used for beamforming using MIMO may support a larger number of simultaneous connections with finer control of spatial multiplexing and beamforming.

[0019] A network device that is using beamforming in a MIMO system to provide a quantity of beams may transmit channel state information reference signals (CSI-RS) for each of the beams. The UE may measure the CSI-RS of the various beams to measure the quality of the channel from each beam direction. The measurements may include a received signal strength indicator (RSSI), a reference signal received power (RSRP), and / or reference signal received quality (RSRQ).

[0020] A CSI-RS port is a logical entity used by a network device (e.g., a base station using MIMO) to transmit CSI-RS for UEs, including UEs served by the network device. A CSI-RS port is a virtual or logical construct that represents a unique spatial path, angle, or direction for CSI-RS transmission. The CSI-RS port is logical, and not a physical antenna. For example, a single physical antenna may support multiple logical CSI-RS ports. This flexibility allows the same hardware to send reference signals along different spatial paths, which the UE then measures and reports back to the base station. In one example, by using the measurements of CSI-RS, the network device determines the most effective beam direction for each user, which may support adaptive and precise beamforming. The CSI measurement report may include parameters for achannel quality indicator (CQI), precoding matrix indicator (PMI), and rank indicator (RI). The CQI value is a numerical indicator that reflects the overall channel quality, where a higher CQI allows the network to use higher modulation schemes and coding rates, which increase the data rate. The RI represents the number of independent data streams, or spatial layers, that can be transmitted simultaneously over a channel. The PMI is a recommendation for the optimal precoding configuration, allowing the network to focus its transmission and provide reliable, high-quality connectivity in complex and varying channel conditions. The PMI indicates the best possible precoding matrix for the current channel conditions, helping the base station direct its beamformed signals more accurately toward the UE.

[0021] The number of CSI-RS ports may vary depending on the deployment. In a simple configurations, there may be a single CSI-RS port, while in massive MIMO scenarios with many antennas, the quantity of CSI-RS ports may be relatively larger (e.g., 32, 64, or more CSI-RS ports). In such cases, the CSI-RS ports often form an array corresponding to a larger grid of virtual antennas, allowing fine-grained beamforming with spatially targeted beams.

[0022] Network entities increasingly use a larger total quantity of antenna elements, which may enable an increased quantity of beams. The quantity of antenna elements continues to increase, especially for mid-frequency and high-frequency bands. According to current techniques, a limited quantity of CSI-RS ports may be supported in designs, which may be less than a quantity of antenna elements. For example, a maximum of 32 CSI-RS ports may supported for downlink CSI acquisition and MIMO operation.

[0023] As an example, a Type I (or Type U) codebook may be a standardized set of precoding matrices established to optimize data transmission in MIMO systems (e.g., when using Uniform Planar Arrays (UPA) or Uniform Linear Arrays (ULA). This type of codebook contains predefined matrices that shape and direct data streams across multiple antennas, allowing for efficient beamforming and spatial multiplexing. With Type I codebooks, different beamwidths can be utilized to create either broad (wide) beams for wide coverage or more focused (narrow) beams for improved signal quality in specific locations, which is particularly useful in dense or distant areas.

[0024] Feedback from the UE is needed in this process, where the UE provides the PMI to the network device (e.g.,. serving base station) in a CSI report. The UE identifies to the network device the preferred precoding matrix in the Type I codebook based on current channel conditions. This real-time feedback enables the network to apply the most suitable precoding configuration for optimizing data rate, beamforming precision, and reliability. However, existing codebook designsmay be limited in a quantity of CSI-RS ports that they support. As further techniques expand the total quantity of CSI-RS ports (e.g., greater than 32 ports, such as 64, 96, or 128 ports) existing codebook designs may be inadequate, for example for PMI-based codebook techniques. For example, where a network device utilizes beamforming with a quantity of layers greater than 1 (e.g., 2, 3, or 4 layers), it may be beneficial to treat different layers differently for purposes of precoding. Existing techniques are inadequate to address multiple layer precoding, including PMI-based codebooks.

[0025] In light of these and other challenges, techniques that support per-layer scaling factors for PMI-based codebook selection are described. A UE, including the baseband processor of the UE, can receive control signaling that configures CSI-RS resources corresponding to CSI-RS ports. The CSI-RS ports may be associated with a first and second layer (e.g., of the antenna array used by the network entity for transmission). The baseband process may obtain first measurements and second measurements of the CSI-RS resources with a plurality of CSI-RS ports corresponding to the first layer and the second layer, respectively. The baseband processor applies a first scaling factor to the first measurements, and a second scaling factor to the second measurements to obtain second scaled measurements for the second layer. The baseband processor then selects, using a first type of codebook, a PMI based at least in part on the first scaled measurements and the second scaled measurements, and transmits a CSI report including the selected PMI.

[0026] FIG. 1 shows an example wireless communications system 100, according to one or more aspects described herein. In one or more embodiments, wireless communications system 100 supports one or more aspects of per-layer scaling for channel state information codebooks, as further described herein.

[0027] Wireless communications system 100 includes a UE 102 having a wireless connection with a network device 104. The UE 102 may be served by the network device 104 within a coverage area of the network device 104. The network device 104 may include components that enable the network device 104 to perform beamforming (e.g., hybrid beamforming), and the network device 104 may communicate using a plurality of beams 130.

[0028] The network device 104 may have a wireless connection with a UE 102, which may be used for data and control communications, as well as the UE 102 to provide CSI reports, as further described herein.

[0029] The network device may use an antenna array 140 to perform beamforming using MIMO techniques as further described herein. The antenna array 140 may include an array of paired antenna elements, for example in a N1X N2arrangement. Each antenna element pair mayinclude a first antenna element 146 and a second antenna element 148 that is cross polarized and orthogonal to the first antenna element 146. In some examples, the network device may transmit on multiple layers (e.g., 2 layers) using such cross-polarized antenna elements. The network device 104 may adjust the shape of beams of the plurality of beams 130 by adjusting a signal power to each of the antenna elements of its antenna array 140.

[0030] In some cases, the network device 104 may desire to avoid transmitting toward certain other objects, such as a satellite terminal 108 or another network device 106. In such case, the network device 104 may adjust its beamforming so that a respective beam toward such object may cause less interference at the object. For example, the network device 104 may adjust the beamforming parameters for the beam 134 to reduce interference experienced at the satellite terminal 108, or adjust the parameters for the beam 136 to reduce the interference experienced at the network device 106. Similarly, the network device 104 may adjust the beamforming parameters for the beam 132 to increase the signal strength and / or or quality at the UE 102.

[0031] However, different layers used by the network device 104 may experience different channels and thus respond different during beamforming. According to current techniques, a UE 102 may select a PMI for a PMI-based codebook without regard to a layer used for transmission. As such, the wireless communications system 100 may benefit from the ability to differently scale layers as part of PMI selection. Using a per-layer approach may result in better, more accurate PMI selection, and thus communication quality and performance for the UE 102 that is being served by the network device 104.

[0032] In some examples, the per-layer scaling techniques described herein may apply for a quantity of CSI-RS ports greater than some threshold value (e.g., greater than 32 ports). That is a UE 102 may use per-layer scaling for a quantity of CSI-RS ports that satisfy a threshold value (e.g.. by being greater than the threshold value or ports), and not perform per-layer scaling for a quantity of CSI-RS ports that do not satisfy the threshold value (e.g.. by being less than or equal to the threshold value or ports).

[0033] In other examples, the per-layer scaling techniques described herein may apply for a particular set or range of CSI-RS ports less than some threshold value (e.g., less than or equal to 32 ports). That is a UE 102 may use per-layer scaling for a quantity of CSI-RS ports that satisfy a threshold value (e.g.. by being greater than the threshold value or ports), and may or may not perform per-layer scaling for a quantity of CSI-RS ports that do not satisfy the threshold value depending on whether the quantity of CSI-RS ports is one of a specified set of port quantities. In one example, per-layer scaling may be applicable to 16, 24, or 32 ports. In another example, per-layer scaling may be applicable to 24, or 32 ports. In another example, per-layer scaling may be applicable to 8, 12, 16, 24, or 32 ports.

[0034] In some examples, the per-layer scaling techniques described herein may apply for a quantity of CSI-RS ports less than some threshold value (e.g., less than or equal to 32 ports), but the UE 102 may not use a second codebook mode (e.g., CodebookMode=2) as a result. That is, the first spatial basis may be selected coarsely, with per-subband spatial basis refinement used.

[0035] In other examples, the per-layer scaling techniques described herein may apply for a quantity of CSI-RS ports less than some threshold value (e.g., less than or equal to 32 ports), but the UE 102 may not use a first codebook mode (e.g., CodebookMode=l) as a result. That is, the first spatial basis may be selected freely (e.g., without restriction).

[0036] In other examples, the per-layer scaling techniques described herein may apply for a quantity of CSI-RS ports less than some threshold value (e.g., less than or equal to 32 ports), and apply for a rank greater than 1 or 2 (e.g., apply to rank 3 or 4. For example, for rank 3 or 4 (RI=3 / 4) and a quantity of CSI-RS ports greater than a threshold value (e.g., greater than or equal to 16 ports). The spatial basis creation may be the same as the other RI and number of CSI-RS ports. In a typical Type I codebook, the spatial basis for RI=3 / 4 (rank 3 or 4) and number of CSI-RS ports greater than or equal to 16 is created differently by using a fragmented spatial basis. That is, each vertical and horizontal direction uses two spatial basis each with half the size.

[0037] FIG. 2 shows an example signaling diagram 200, according to one or more aspects described herein. In one or more embodiments, signaling diagram 200 supports one or more aspects of per-layer scaling for channel state information codebooks, as further described herein.

[0038] Signaling diagram 200 includes messages and signals exchanged between a UE 102 and network device 104. As further described herein, network device 104 may deploy an array of antenna elements (e.g., 32, or more than 32) and operate using a PMI-based codebook (e.g., a Type I, which may also be referred to as a first type of codebook).

[0039] The UE 102 may provide the network device 104 with UE capability signaling 202. In some examples, the UE capability signaling 202 indicates a capability of the UE 102 to support per-layer scaling.

[0040] In one or more examples, the UE 102 transmits, for receipt by the network device 104, UE capability signaling indicating a capability to support per-layer scaling. In some examples, the UE capability signaling 202 may indicate a capability of the UE 102 to support a codebook enhancement (e.g., for a Type I codebook) to support up an increased quantity of CSI-RS ports(e.g., up to 128 ports, more than 32 ports, and so on) that supports a per-layer scaling factor applied on top of a power control offset configured for the associated CSI-RS resources. In some examples, the UE capability signaling 202 may have candidate values that indicate that the UE 102 does not support scaling, supports scaling only a first layer (e.g., RI= 1 ), or supports scaling for both a first layer and a second layer (e.g., RI=1 and RI=2). In other examples, the UE capability signaling 202 may have candidate values that indicate that the UE 102 does not support scaling, supports scaling only a first layer (e.g., RI=1), supports scaling only a second layer (e.g., RI=2), or supports scaling for both a first layer and a second layer (e.g., RI=1 and RI=2). In some examples, the UE 102 may not report the UE capability signaling to indicates that the UE 102 does not support per-layer scaling at all.

[0041] The capability of the UE 102 to support per-layer scaling indicated by the UE capability signaling 202 may be per band and per band combination. In other examples, the capability may be per feature set (per band per band combination). In other examples, the capability may be per band combination. In other examples, the capability may be per band.

[0042] In some examples, the UE capability signaling 202 may indicate a capability to support a first Type I codebook scheme (e.g., Type I codebook scheme- A) for a first range of CSI-RS port quantities (e.g., greater than 32 ports). In other examples, the UE capability signaling 202 may indicate a capability to support a second Type I codebook scheme (e.g., Type I codebook scheme -B) for the first range of CSI-RS port quantities. In some examples, the UE capability signaling 202 may indicate a capability to support the first Type I codebook scheme for a second range of CSI-RS port quantities (e.g., less than or equal to 32 ports). In some examples, the UE capability signaling 202 may indicate a capability to support the second Type I codebook scheme for the second range of CSI-RS port quantities. Such UE capability signaling may be per band and per band combination. In other examples, the capability may be per feature set (per band per band combination). In other examples, the capability may be per band combination. In other examples, the capability may be per band.

[0043] In some examples, there may be a basic feature or other default for the codebook scheme. In one example, the second Type I codebook scheme (e.g., Type I codebook scheme-B) for the first range of CSI-RS port quantities (e.g., greater than 32 ports) may be set as a default. In another example, the first Type I codebook scheme (e.g., Type I codebook scheme-A) for the first range of CSI-RS port quantities (e.g., greater than 32 ports) may be set as a default.

[0044] The network device 104 provides to the UE 102 a CSI-RS configuration 204. The CSI-RS configuration 204 may be at least partially responsive to the UE capability signaling 202. Insome examples, the CSI-RS configuration 204 indicates resources for the UE 102 to use to receive reference signals (e.g., CSI-RS) that the UE 102 is to measure to determine CSI. The indicated CSI-RS resources include resources on which the network device 104 will transmit CSI-RS using a set of CSI-RS ports. In some examples, each resource corresponds to a CSI-RS ports, though other configurations may be used consistent with the techniques described herein. Different resources of the CSI-RS resources correspond to different layers used by the network device 104 for transmission.

[0045] In one or more examples, the network device 104 provides (configures) to the UE 102 with a CSI reporting configuration 218. The CSI reporting configuration 218 (e.g., CS1-ReportConflg) may indicate to the UE 102 resources for providing the CSI report 216, as well as one or more settings for the contents of the CSI report 216. In some examples, the CSI reporting configuration 218 may have candidate values that indicates that the UE 102 is not to use per-layer scaling, use per-layer scaling only a first layer (e.g., RI=1), or use per-layer scaling for both a first layer and a second layer (e.g., RI=1 and RI=2). In some examples, the CSI reporting configuration 218 may have candidate values that indicates that the UE 102 is not to use per-layer scaling, use per-layer scaling only a first layer (e.g., RI=1), use per-layer scaling only a second layer (e.g., RU2), or use per-layer scaling for both a first layer and a second layer (e.g., RU I and RU2). In some examples, the network device 104 may not provide an information element configuring per-layer scaling, and thereby configure the UE 102 to use per-layer scaling at all.

[0046] In some examples, the CSI reporting configuration 218 may configure the UE 102 such that, for each spatial basis Si, the same scaling factor Si is configured for both RI=1 and RI=2. In other examples, the CSI reporting configuration 218 may configure the UE 102 such that, for each spatial basis Si, different scaling factors Si are configured for RU I and RU2.

[0047] In addition to the CSI-RS configuration 204 that the UE 102 uses to receive and measure CSI-RS transmitted by the network device 104, the network device 104 provides the UE 102 with a set of scaling factors 206 for each layer used for transmission of the CSI-RS by the network device 104. Generally, the set of scaling factors 206 may include any quantity of scaling factors that correspond to the quantity of layers used by the network device 104. For purposes of clarity of description, two layers are discussed. In the case of two layer, a first scaling factor of the set of scaling factors 206 may be applied to a first set of measurements of CSI-RS on the configured CSI-RS resources to obtain first scaled measurement values. Similarly, a second scaling factor of the set of scaling factors 206 may be applied to a second set of measurements of CSI-RS on the configured CSI-RS resources to obtain second scaled measurement values.

[0048] During operation of the UE 102 to perform CST measurements, the UE 102 may receive CSI-RS on the set of CSI-RS resources, including CSI-RS 208 transmitted by the network device 104 on a first layer (e.g., layer 1) and CSI-RS 210 transmitted by the network device 104 on a second layer (e.g., layer 2). The UE 102, having measured received and measured CSI-RS, at 212 may perform CSI-RS scaling, where the UE 102 applies the scaling factors associated with respective ones of the CSI-RS resources to the CSI-RS resources. Based on the scaled measurement values, and using a first type of codebook (e.g., a Type I codebook), the UE 102 may select a precoding matrix indicator (PMI) based on the first scaled measurements and the second scaled measurements. The selected PMI may be included in a CSI report 216 transmitted to the network device 104 by the UE 102.

[0049] Further described herein are multiple different techniques to select and apply the set of scaling factors 206. It should be understood that aspects of some examples may be combined with aspects of other examples.

[0050] In one or more examples, a power control offset may be configured for an associated CSI-RS resource. For example, the network device 104 may have previously provided configuration signaling to the UE 102 that identifies or otherwise indicates a power control offset that is applicable for each resources of the set of CSI-RS resources. The scaling factor for that CSI-RS resource may be applied on top of that power control offset. The candidate scaling factors may be selected from a set of indexed candidate values.

[0051] In one or more examples, the codebook may be a Type I codebook to support up to 128 ports. The described examples support per-layer scaling factors applied on top of power control offset configured for the associated CSI-RS resources, for example for rank 2 (e.g., R1 = v = 2) or higher. The scaling factor (s,) may be applied to a spatial basis (z) on top of the power control offset configured for the associated CSI-RS resource. The candidate values for si can be:Without the scaling factor, the total energy spent on spatial basis i is EPREPDSCH■ rJ- v (where EPRE is the energy per resource element, and PDSCH is physical downlink shared channel), where EPREPDSCHis configured as powerControlOffset, and may denote a ratio between PDSCH EPRE to CSI-RS EPRE scaling factor. In some examples, each spatial basis i can be associated with Ti 6 {1, 2} layers, reported by the UE. The powerControlOffset may be assumed to be the ratio of PDSCH EPRE to the non-zero power (NZP) CSI-RS EPRE when the UE derives CSI feedbackand takes values in the range of [-8,15] dB with a 1 dB step size. With a scaling factor, the energy spent on a spatial basis i is EPREPDSCH■ r v ■ s~2. Here, s~2= (s2) which is a function of the configured scaling factor s,.

[0052] In another example, a power control offset may be configured for an associated CSI-RS resource. For example, the network device 104 may have previously provided configuration signaling to the UE 102 that identifies or otherwise indicates a power control offset that is applicable for each resources of the set of CSI-RS resources. The first scaling factor and the second scaling factor are functions of a first quantity of layers (e.g., corresponding to the plurality of CSI- RS ports) and a second quantity of layers associated with a spatial basis.

[0053] In one or more examples, the codebook may be a Type I codebook to support up to 128 ports. The described examples support per-layer scaling factors applied on top of power control offset configured for the associated CSI-RS resources, for example for rank 2 (e.g., R1 = v = 2) or higher. With scaling, the energy spent of spatial basis i is EPREPDSCH-r v ■ s~2, in whichis a function of the configured Si, and dependents on one of the rank or the number of layers associated with the spatial basis i. Thae rank (the number of layers) may be 2 (v = 2)). The number of layer associated with the spatial basis i may be reported by the UE 102, and may have a value of one or two (r(G {1, 2}).

[0054] In another example, the first scaling factor and the second scaling factor are a minimum of a first value and a second value, the first value being one, and the second value a function of a first quantity of layers (e.g., corresponding to the plurality of CSI-RS ports) and a second quantity of layers associated with the spatial basis. The codebook may be a Type I codebook to support up to 128 ports. The described examples support per-layer scaling factors applied on top of power control offset configured for the associated CSI-RS resources. For rank 2 (e.g., R1 = v = 2) the scaling of the energy spent on spatial basis i, i.e., sf2, may be calculated as s2■ v / r^ In another examples, also for rank 2 (e.g., RI = v = 2) the scaling of the energy spent on spatial basis i, i.e., S2, may be calculated as min (1, s2- v / r^.

[0055] In another example, the first scaling factor and the second scaling factor are based at least in part on whether the first layer uses a same spatial basis as the second layer, or the first layer uses a different spatial basis from the second layer. The codebook may be a Type I codebook to support up to 128 ports. The described examples support per-layer scaling factors applied on top of power control offset configured for the associated CSI-RS resources. For rank 2 (e.g., Rl = v = 2) the scaling of the energy spent on spatial basis I, i.e., s(~2, may be calculated differently for when the two layer use the same spatial basis or when the two layers use a different spatial basis.When the two layers use the same spatial basis (rf= 2), then the scaling factor s(~2= s2. When the two layers use a different spatial basis i and j (rt= rj = 1), if / when s2= s2= 1, then s(~2= Sj~2= 1. However, if / when s2= 1 and s2< 1, then sy~2= s2■ v / rj = 2 ■ s2and s(~2= 2 ■The equation for s(~2may help ensure that a total EPRE can be used, such that scaling up is allowed.

[0056] FIG. 3 A shows a first example antenna configuration 301, according to one or more aspects described herein. FIG. 3B shows a second example antenna configuration 302, according to one or more aspects described herein.

[0057] The per-layer scaling techniques described herein may apply for a quantity of CSI-RS ports less than some threshold value (e.g., less than or equal to 32 ports). In an example of rank 3 or 4, and greater than or equal to 16 CSI-RS ports, the code book structure may be as follows:r V V VV1 1[c ■ V C ‘ V1—c - v — C ■ v

[0058] For the first and third layer, a UE 102 may report of selected spatial basis v is that same as R=I. For the second and fourth layer, the spatial basis v is selected from v with {fc1,fc2} in vertical and horizontal distance. In some examples, (k1,fc2} 'sreported in i1 3. In some examples, a co-phasing c is also reported, where c G {1, j}, and c is reported in i2.

[0059] With reference to the first example antenna configuration 301, for the second and fourth layer, a UE 102 may report of selected spatial basis v from v with { q, k2in vertical and horizontal distance. For N1> N2= 1, including ( / ! / ,, / V2) = (8,1), (12,1), (16,1). In such case, Krcan be selected from {01, 2O1;3Oq, 40^ and K2is 0. For example, antenna configuration 301 illustrates the selection of spatial basis in a (8,1), (12,1), or (16,1) from within an antenna array 140 having an arbitrary size of Nrx N2, where the first six elements are shown. The spatial basis for Kois basis 311. The spatial basis for K are basis 312, basis 313, basis 314, and basis 315.

[0060] With reference to the second example antenna configuration 302, for the second and fourth layer, a UE 102 may report of selected spatial basis v from v with {kr, k2) in vertical and horizontal distance. For> N2> 1, including ( / V1; / V2) = (4,2), (4,3), (6,2), (4,4), (8,2). In such case, (KltK2) can be selected from(2O 0)}. For example, antenna configuration 302 illustrates the selection of spatial basis in a (4,2), (4,3), (6,2), (4,4), (8,2) from within an antenna array 140 having an arbitrary size of X N2, where six elements are shown. The spatial basis for K^, K2~) can be selected from basis 322, basis 323, basis 324, and basis 325.

[0061] FIG. 4 shows an example method 400 of wireless communication by a UE, according to one or more aspects described herein. In some cases, the UE may be the wireless device 702 or UE 102. In some cases, the method 400 may be performed by a baseband processor of the UE. In some embodiments, the baseband processor may include one or more processor cores, and memory that is coupled to the processor core(s). The memory may store instructions that, when executed by the processor core(s), causes the baseband processor to perform the operations of the method 400. As the baseband processor performs the operations of the method 400, the baseband processor may also cause other components of the UE to perform, or discontinue, various operations.

[0062] At 402, the method 400 includes receiving configuration signaling for CSI-RS resources. In some embodiments, the method 400 includes receiving control signaling that configures a plurality of CSI-RS resources corresponding to a plurality of CSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer.

[0063] At 404, the method 400 includes obtaining measurements of reference signals transmitted on multiple layers. In some embodiments, the method 400 includes obtaining first measurements and second measurements of the CSI-RS resources with a plurality of CSI-RS ports corresponding to the first layer and the second layer, respectively.

[0064] At 406, the method 400 includes applying a scaling factor for the first layer measurements. In some embodiments, the method 400 includes applying a first scaling factor to the first measurements to obtain first scaled measurements for the first layer.

[0065] At 408, the method 400 includes applying a scaling factor for the second layer measurements. In some embodiments, the method 400 includes applying a second scaling factor to the second measurements to obtain second scaled measurements for the second layer.

[0066] At 410, the method 400 includes selecting a preceding matrix indicator. In some embodiments, the method 400 includes selecting, using a first type of codebook, a precoding matrix indicator based at least in part on the first scaled measurements and the second scaled measurements.

[0067] At 412, the method 400 includes transmitting a CSI report. In some embodiments, the method 400 includes transmitting a CSI report that includes the selected precoding matrix indicator.

[0068] In one or more embodiments, the method further includes receiving configuration signaling including an indication of the first scaling factor for the first layer and the second scaling factor for the second layer.

[0069] In one or more embodiments, the method further includes receiving configuration signaling including an indication of a power control offset, where the first scaling factor and the power control offset is applied to the first measurements to obtain the first scaled measurements, and the second scaling factor and the power control offset is applied to the second measurements to obtain the second scaled measurements. In some embodiments, candidate values for the first scaling factor and the second scaling factor are selected from a set of indexed candidate values; the first scaling factor and the second scaling factor are functions of a first quantity of layers (e.g., corresponding to the plurality of CSI-RS ports) and a second quantity of layers associated with a spatial basis; or the first scaling factor and the second scaling factor are a minimum of a first value and a second value, the first value being one, and the second value a function of a first quantity of layers (e.g., corresponding to the plurality of CSI-RS ports) and the second quantity of layers associated with the spatial basis.

[0070] In some embodiments, the first scaling factor and the second scaling factor are based at least in part on whether the first layer uses a same spatial basis as the second layer, or the first layer uses a different spatial basis from the second layer.

[0071] In one or more embodiments, the method further includes transmitting, for receipt by a network device, UE capability signaling indicating a capability to support per-layer scaling.

[0072] In one or more embodiments, the method further includes transmitting, for receipt by a network device, UE capability signaling indicating a capability to support per-layer and per-CSI reporting configuration scaling.

[0073] In one or more embodiments, the method further includes transmitting, for receipt by a network device, UE capability signaling indicating a capability to support one or more of a first Type I codebook scheme for a first range of CSI-RS port quantities, a second Type I codebook scheme for the first range of CSI-RS port quantities, the first Type I codebook scheme for a second range of CSI-RS port quantities, or the second Type I codebook scheme for the second range of CSI-RS port quantities.

[0074] In one or more embodiments, the method further includes transmitting, for receipt by a network device, UE capability signaling indicating a capability to support per-layer scaling for a set of CSI-RS port quantities, where the first scaling factor is applied to the first measurements and the second scaling factor is applied to the second measurements based at least in part on the plurality of CSI-RS ports being one of the set of CSI-RS port quantities.

[0075] In one or more embodiments, the method further includes selecting, for the first layer and the second layer, a first spatial basis for the codebook; and selecting, for a third layer and a fourth layer of the plurality of CSI-RS ports, a second spatial basis for the codebook.

[0076] The method 400 may be variously embodied, extended, or adapted, as described in the following paragraphs and elsewhere in this description.

[0077] FIG. 5 shows an example method 500 of wireless communication by a network device, according to one or more aspects described herein. In one or more embodiments, method 500 supports one or more aspects of per-layer scaling for channel state information codebooks, as further described herein. In some cases, the network device may be the network device 104, network device 720, or one of the other network devices described herein. The method 500 may be performed using a processor, a transceiver, or other components of the network device.

[0078] At 502, the method 500 includes transmitting configuration signaling for CSI-RS resources. In some embodiments, the method 500 includes transmitting, to a UE, control signaling that configures a plurality of CSI-RS resources corresponding to a plurality of CSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer.

[0079] At 504, the method 500 includes transmitting an indication of the first scaling factor and the second scaling factor. In some embodiments, the method 500 includes transmitting, to the UE, configuration signaling comprising an indication of a first scaling factor for the first layer and a second scaling factor for the second layer.

[0080] At 506, the method 500 includes receiving a CSI report. In some embodiments, the method 500 includes receiving a CSI report that includes a precoding matrix indicator selected by the UE responsive to first reference signals and second reference signals.

[0081] In one or more embodiments, the method further includes receiving UE capability signaling indicating a capability to support per-layer scaling, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

[0082] In one or more embodiments, the method further includes receiving UE capability signaling indicating a capability to support per-layer scaling and per-CSI reporting configuration scaling, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

[0083] In one or more embodiments, the method further includes receiving UE capability signaling indicating a capability of the UE to support one or more of a first Type I codebook scheme for a first range of CSI-RS port quantities, a second Type I codebook scheme for the firstrange of CSI-RS port quantities, the first Type I codebook scheme for a second range of CSI-RS port quantities, or the second Type I codebook scheme for the second range of CSI-RS port quantities, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

[0084] In one or more embodiments, the method further includes receiving UE capability signaling indicating a capability of the UE to support per-layer scaling for a set of CSI-RS port quantities, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

[0085] The method 500 may be variously embodied, extended, or adapted, as described in the following paragraphs and elsewhere in this description.

[0086] Embodiments contemplated herein include one or more non-transitory computer-readable media storing instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of the method 400 or 500. In the context of method 400, this non-transitory computer-readable media may be, for example, a memory of a UE (such as a memory 706 of a wireless device 702 that is a UE, as described herein). In the context of method 500, this non-transitory computer-readable media may be, for example, a memory of a network device (such as a memory 724 of a network device 720, as described herein).

[0087] Embodiments contemplated herein include an apparatus having logic, modules, or circuitry to perform one or more elements of the method 400 or 500. In the context of method 400, this apparatus may be, for example, an apparatus of a UE (such as a wireless device 702 that is a UE). In the context of method 500, this apparatus may be, for example, an apparatus of a network device (such as a network device 720, as described herein).

[0088] Embodiments contemplated herein include an apparatus having one or more processors and one or more computer-readable media, using or storing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 400 or 500. In the context of method 400, this apparatus may be, for example, an apparatus of a UE (such as a wireless device 702 that is a UE, as described herein). In the context of the method 500, this apparatus may be, for example, an apparatus of a network device (such as a network device 720, as described herein).

[0089] Embodiments contemplated herein include a signal as described in or related to one or more elements of the method 400, or 500.

[0090] Embodiments contemplated herein include a computer program or computer program product having instructions, wherein execution of the program by a processor causes the processor to carry out one or more elements of the method 400 or 500. In the context of method 400, the processor may be a processor of a UE (such as a processor(s) 704 of a wireless device 702 that is a UE, as described herein), and the instructions may be, for example, located in the processor and / or on a memory of the UE (such as a memory 706 of a wireless device 702 that is a UE, as described herein). In the context of method 500, the processor may be a processor of a network device (such as a processor(s) 722 of a network device 720, as described herein), and the instructions may be, for example, located in the processor and / or on a memory of the network device (such as a memory 724 of a network device 720, as described herein).

[0091] FIG. 6 illustrates an example architecture of a wireless communication system, according to embodiments described herein. The following description is provided for an example wireless communication system 600 that operates in conjunction with the LTE system standards or specifications and / or 5G or NR system standards or specifications, as provided by 3GPP technical specifications.

[0092] As shown, the wireless communication system 600 includes UE 602 and UE 604 (although any number of UEs may be used). In this example, the UE 602 and the UE 604 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also comprise any mobile or non-mobile computing device configured for wireless communication.

[0093] The UE 602 and UE 604 may be configured to communicatively couple with a RAN 606. In embodiments, the RAN 606 may be NG-RAN, E-UTRAN, etc. The UE 602 and UE 604 utilize connections (or channels) (shown as connection 608 and connection 610, respectively) with the RAN 606, each of which comprises a physical communications interface. The RAN 606 can include one or more network devices, such as base station 612 and base station 614, that enable the connection 608 and connection 610.

[0094] In this example, the connection 608 and connection 610 are air interfaces to enable such communicative coupling and may be consistent with RAT(s) used by the RAN 606, such as, for example, an LTE and / or NR.

[0095] In some embodiments, the UE 602 and UE 604 may also directly exchange communication data via a sidelink interface 616. The UE 604 is shown to be configured to access an access point (shown as AP 618) via connection 620. By way of example, the connection 620 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11protocol, wherein the AP 618 may comprise a Wi-Fi® router. In this example, the AP 618 may be connected to another network (for example, the Internet) without going through a CN 624.

[0096] In embodiments, the UE 602 and UE 604 can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other or with the base station 612 and / or the base station 614 over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an orthogonal frequency division multiple access (OFDMA) communication technique (e.g., for downlink communications) or a single carrier frequency division multiple access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

[0097] In some embodiments, all or parts of the base station 612 or base station 614 may be implemented as one or more software entities running on server computers as part of a virtual network. In addition, or in other embodiments, the base station 612 or base station 614 may be configured to communicate with one another via interface 622. In embodiments where the wireless communication system 600 is an LTE system (e.g., when the CN 624 is an EPC), the interface 622 may be an X2 interface. The X2 interface may be defined between two or more network devices of a RAN (e.g., two or more eNBs and the like) that connect to an EPC, and / or between two eNBs connecting to the EPC. In embodiments where the wireless communication system 600 is an NR system (e.g., when CN 624 is a 5GC), the interface 622 may be an Xn interface. The Xn interface is defined between two or more network devices of a RAN (e.g., two or more gNBs and the like) that connect to the 5GC, between a base station 612 (e.g., a gNB) connecting to the 5GC and an eNB, and / or between two eNBs connecting to the 5GC (e.g., CN 624).

[0098] The RAN 606 is shown to be communicatively coupled to the CN 624. The CN 624 may comprise one or more network elements 626, which are configured to offer various data and telecommunications services to customers / subscribers (e.g., users of UE 602 and UE 604) who are connected to the CN 624 via the RAN 606. The components of the CN 624 may be implemented in one physical device or separate physical devices including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0099] In embodiments, the CN 624 may be an EPC, and the RAN 606 may be connected with the CN 624 via an SI interface 628. In embodiments, the SI interface 628 may be split into two parts, an S 1 user plane (S 1-U) interface, which carries traffic data between the base station 612 orbase station 614 and a serving gateway (S-GW), and the SI -MME interface, which is a signaling interface between the base station 612 or base station 614 and mobility management entities (MMEs).

[0100] In embodiments, the CN 624 may be a 5GC, and the RAN 606 may be connected with the CN 624 via an NG interface 628. In embodiments, the NG interface 628 may be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the base station 612 or base station 614 and a user plane function (UPF), and the SI control plane (NG-C) interface, which is a signaling interface between the base station 612 or base station 614 and access and mobility management functions (AMFs).

[0101] Generally, an application server 630 may be an element offering applications that use internet protocol (IP) bearer resources with the CN 624 (e.g., packet switched data services). The application server 630 can also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 602 and UE 604 via the CN 624. The application server 630 may communicate with the CN 624 through an IP communications interface 632.

[0102] FIG. 7 illustrates an example system 700 for performing signaling 738 between a wireless device 702 and a network device 720, according to embodiments described herein. The system 700 may be a portion of a wireless communication system as herein described. The wireless device 702 may be, for example, a UE of a wireless communication system. The network device 720 may be, for example, a base station (e.g., an eNB or a gNB) or a radio head of a wireless communication system.

[0103] The wireless device 702 may include one or more processor(s) 704. The processor(s) 704 may execute instructions such that various operations of the wireless device 702 are performed, as described herein. The processor(s) 704 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0104] The wireless device 702 may include a memory 706. The memory 706 may be a non-transitory computer-readable storage medium that stores instructions 708 (which may include, for example, the instructions being executed by the processor(s) 704). The instructions 708 may also be referred to as program code or a computer program. The memory 706 may also store data used by, and results computed by, the processor(s) 704.

[0105] The wireless device 702 may include one or more transceiver(s) 710 (also collectively referred to as a transceiver 710) that may include radio frequency (RF) transmitter and / or receiver circuitry that use the antenna(s) 712 of the wireless device 702 to facilitate signaling (e.g., the signaling 738) to and / or from the wireless device 702 with other devices (e.g., the network device 720) according to corresponding RATs.

[0106] The wireless device 702 may include one or more antenna(s) 712 (e.g., one, two, four, eight, or more). For embodiments with multiple antenna(s) 712, the wireless device 702 may leverage the spatial diversity of such multiple antenna(s) 712 to send and / or receive multiple different data streams on the same time and frequency resources. This behavior may be referred to as, for example, multiple input multiple output (MIMO) behavior (referring to the multiple antennas used at each of a transmitting device and a receiving device that enable this aspect). MIMO transmissions by the wireless device 702 may be accomplished according to precoding (or digital beamforming) that is applied at the wireless device 702 that multiplexes the data streams across the antenna(s) 712 according to known or assumed channel characteristics such that each data stream is received with an appropriate signal strength relative to other streams and at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream). Some embodiments may use single user MIMO (SU-MIMO) methods (where the data streams are all directed to a single receiver) and / or multi-user MIMO (MU-MIMO) methods (where individual data streams may be directed to individual (different) receivers in different locations in the spatial domain).

[0107] In some embodiments having multiple antennas, the wireless device 702 may implement analog beamforming techniques, whereby phases of the signals sent by the antenna(s) 712 are relatively adjusted such that the (joint) transmission of the antenna(s) 712 can be directed (this is sometimes referred to as beam steering).

[0108] The wireless device 702 may include one or more interface(s) 714. The interface(s) 714 may be used to provide input to or output from the wireless device 702. For example, a wireless device 702 that is a UE may include interface(s) 714 such as microphones, speakers, a touchscreen, buttons, and the like in order to allow for input and / or output to the UE by a user of the UE. Other interfaces of such a UE may be made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 710 / antenna(s) 712 already described) that allow for communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi®, Bluetooth®, and the like).

[0109] The wireless device 702 may include CSI reporting manager 716. The CSI reporting manager 716 may be implemented via hardware, software, or combinations thereof. For example, the CSI reporting manager 716 may be implemented as a processor, circuit, and / or instructions 708 stored in the memory 706 and executed by the processor(s) 704. In some examples, the CSI reporting manager 716 may be integrated within the processor(s) 704 and / or the transceiver(s) 710. For example, the CSI reporting manager 716 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor(s) 704 or the transceiver(s) 710.

[0110] The CSI reporting manager 716 may be used for various aspects of the present disclosure, for example, aspects of FIGs. 1-7, from a wireless device or UE perspective. The CSI reporting manager 716 may be configured, for example, to perform receiving control signaling that configures a plurality of CSI-RS resources corresponding to a plurality of CSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer; obtaining first measurements and second measurements of the CSI-RS resources with a plurality of CSI-RS ports corresponding to the first layer and the second layer, respectively; applying a first scaling factor to the first measurements to obtain first scaled measurements for the first layer; applying a second scaling factor to the second measurements to obtain second scaled measurements for the second layer; and selecting, using a first type of codebook, a precoding matrix indicator based at least in part on the first scaled measurements and the second scaled measurements; transmitting a CSI report that includes the selected precoding matrix indicator.

[0111] The network device 720 may include one or more processor(s) 722. The processor(s) 722 may execute instructions such that various operations of the network device 720 are performed, as described herein. The processor(s) 722 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0112] The network device 720 may include a memory 724. The memory 724 may be a non-transitory computer-readable storage medium that stores instructions 726 (which may include, for example, the instructions being executed by the processor(s) 722). The instructions 726 may also be referred to as program code or a computer program. The memory 724 may also store data used by, and results computed by, the processor(s) 722.

[0113] The network device 720 may include one or more transceiver(s) 728 (also collectively referred to as a transceiver 728) that may include RF transmitter and / or receiver circuitry that usethe antenna(s) 730 of the network device 720 to facilitate signaling (e.g., the signaling 738) to and / or from the network device 720 with other devices (e.g., the wireless device 702) according to corresponding RATs.

[0114] The network device 720 may include one or more antenna(s) 730 (e.g., one, two, four, or more). In embodiments having multiple antenna(s) 730, the network device 720 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as has been described.

[0115] The network device 720 may include one or more interface(s) 732. The interface(s) 732 may be used to provide input to or output from the network device 720. For example, a network device 720 of a RAN (e.g., a base station, a radio head, etc.) may include interface(s) 732 made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 728 / antenna(s) 730 already described) that enables the network device 720 to communicate with other equipment in a network, and / or that enables the network device 720 to communicate with external networks, computers, databases, and the like for purposes of operations, administration, and maintenance of the network device 720 or other equipment operably connected thereto.

[0116] The network device 720 may include at least one CSI reporting manager 734. The CSI reporting manager 734 may be implemented via hardware, software, or combinations thereof. For example, the CSI reporting manager 734 may be implemented as a processor, circuit, and / or instructions 726 stored in the memory 724 and executed by the processor(s) 722. In some examples, the CSI reporting manager 734 may be integrated within the processor(s) 722 and / or the transceiver(s) 728. For example, the CSI reporting manager 734 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor(s) 722 or the transceiver(s) 728.

[0117] The CSI reporting manager 734 may be used for various aspects of the present disclosure, for example, aspects of FIGs. 1-7, from a network device perspective. The CSI reporting manager 734 may be configured, for example, to perform transmitting, to a UE, control signaling that configures a plurality of CSI-RS resources corresponding to a plurality of CSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer; transmitting, to the UE, configuration signaling comprising an indication of a first scaling factor for the first layer and a second scaling factor for the second layer; transmitting, using the plurality of CSI-RS ports, first reference signals on the first layer and second reference signals on the second layer; and receiving a CSI report that includes a precoding matrix indicator selected by the UE responsive to the first reference signals and the second reference signals.

[0118] For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as set forth herein. For example, a baseband processor (or processor) as described herein in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein. For another example, circuitry associated with a UE, network device, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein.

[0119] Any of the above described embodiments may be combined with any other embodiment (or combination of embodiments), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description but is not intended to be exhaustive or to limit the scope of embodiments to the precise form described. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0120] Embodiments and implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that include specific logic for performing the operations or may include a combination of hardware, software, and / or firmware.

[0121] The systems described herein pertain to specific embodiments but are provided as examples. These embodiments can be combined into single systems, partially combined into other systems, split into multiple systems or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. The parameters, attributes, aspects, etc. are merely described in one or more embodiments for clarity, and it is recognized that the parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically disclaimed herein.

[0122] Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be consideredillustrative and not restrictive, and the description is not to be limited to the details given herein but may be modified within the scope and equivalents of the appended claims.

Claims

CLAIMS1. A baseband processor comprising a memory and configured to:receive control signaling that configures a plurality of channel state information reference signal (CSLRS) resources corresponding to a plurality of CSLRS ports, the plurality of CSLRS ports associated with at least a first layer and a second layer;obtain first measurements and second measurements of the CSLRS resources with a plurality of CSLRS ports corresponding to the first layer and the second layer, respectively; apply a first scaling factor to the first measurements to obtain first scaled measurements for the first layer;apply a second scaling factor to the second measurements to obtain second scaled measurements for the second layer;select, using a first type of codebook, a precoding matrix indicator based at least in part on the first scaled measurements and the second scaled measurements; andtransmit a CSI report that includes the selected precoding matrix indicator.

2. The baseband processor of claim 1, further configured to:receive configuration signaling comprising an indication of the first scaling factor for the first layer and the second scaling factor for the second layer.

3. The baseband processor of claim 1, further configured to:receive configuration signaling comprising an indication of a power control offset, wherein the first scaling factor and the power control offset is applied to the first measurements to obtain the first scaled measurements, and the second scaling factor and the power control offset is applied to the second measurements to obtain the second scaled measurements.

4. The baseband processor of claim 3, wherein:candidate values for the first scaling factor and the second scaling factor are selected from a set of indexed candidate values;the first scaling factor and the second scaling factor are functions of a first quantity of layers and a second quantity of layers associated with a spatial basis; orthe first scaling factor and the second scaling factor are a minimum of a first value and a second value, the first value being one, and the second value are a function of the first quantity of layers and the quantity of layers associated with the spatial basis.

5. The baseband processor of claim 1, wherein:the first scaling factor and the second scaling factor are based at least in part on whether the first layer uses a same spatial basis as the second layer, or the first layer uses a different spatial basis from the second layer.

6. The baseband processor of claim 1, further configured to:transmit, for receipt by a network device, UE capability signaling indicating a capability to support per-layer scaling.

7. The baseband processor of claim 1, further configured to:transmit, for receipt by a network device, UE capability signaling indicating a capability to support per-layer and per-CSI reporting configuration scaling.

8. The baseband processor of claim 1, further configured to:transmit, for receipt by a network device, UE capability signaling indicating a capability to support one or more of a first Type I codebook scheme for a first range of CSI-RS port quantities, a second Type I codebook scheme for the first range of CSI-RS port quantities, the first Type I codebook scheme for a second range of CSI-RS port quantities, or the second Type I codebook scheme for the second range of CSI-RS port quantities.

9. The baseband processor of claim 1, further configured to:transmit, for receipt by a network device, UE capability signaling indicating a capability to support per-layer scaling for a set of CSI-RS port quantities, wherein the first scaling factor is applied to the first measurements and the second scaling factor is applied to the second measurements based at least in part on the plurality of CSI-RS ports being one of the set of CSI-RS port quantities.

10. The baseband processor of claim 1, further configured to:select, for the first layer and the second layer, a first spatial basis for the codebook; and select, for a third layer and a fourth layer of the plurality of CSI-RS ports, a second spatial basis for the codebook.

11. A method of wireless communication at a user equipment (UE), comprising: receiving control signaling that configures a plurality of channel state information reference signal (CSI-RS) resources corresponding to a plurality of CSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer;obtaining first measurements and second measurements of the CSI-RS resources with a plurality of CSI-RS ports corresponding to the first layer and the second layer, respectively; applying a first scaling factor to the first measurements to obtain first scaled measurements for the first layer;applying a second scaling factor to the second measurements to obtain second scaled measurements for the second layer;selecting, using a first type of codebook, a precoding matrix indicator based at least in part on the first scaled measurements and the second scaled measurements; andtransmitting a CSI report that includes the selected precoding matrix indicator.

12. The method of claim 11, further comprising:receiving configuration signaling comprising an indication of the first scaling factor for the first layer and the second scaling factor for the second layer.

13. The method of claim 11, further comprising:receiving configuration signaling comprising an indication of a power control offset, wherein the first scaling factor and the power control offset is applied to the first measurements to obtain the first scaled measurements, and the second scaling factor and the power control offset is applied to the second measurements to obtain the second scaled measurements.

14. The method of claim 11, further comprising:transmitting, to a network device, UE capability signaling indicating a capability to support per-layer scaling.

15. The method of claim 11, further comprising:transmitting, for receipt by a network device, UE capability signaling indicating a capability to support per-layer and per-CSI reporting configuration scaling.

16. A method of wireless communication at a network device, comprising:transmitting, to a user equipment (UE), control signaling that configures a plurality of channel state information reference signal (CSI-RS) resources corresponding to a plurality ofCSI-RS ports, the plurality of CSI-RS ports associated with at least a first layer and a second layer;transmitting, to the UE, configuration signaling comprising an indication of a first scaling factor for the first layer and a second scaling factor for the second layer; andreceiving a CSI report that includes a precoding matrix indicator selected by the UE responsive to first reference signals and second reference signals.

17. The method of claim 16, further comprising:receiving UE capability signaling indicating a capability to support per-layer scaling, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

18. The method of claim 16, further comprising:receiving UE capability signaling indicating a capability to support per-layer scaling and per-CSI reporting configuration scaling, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

19. The method of claim 16, further comprising:receiving UE capability signaling indicating a capability of the UE to support one or more of a first Type I codebook scheme for a first range of CSI-RS port quantities, a second Type I codebook scheme for the first range of CSI-RS port quantities, the first Type I codebook scheme for a second range of CSI-RS port quantities, or the second Type I codebook scheme for the second range of CSI-RS port quantities, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

20. The method of claim 16, further comprising:receiving UE capability signaling indicating a capability of the UE to support per-layer scaling for a set of CSI-RS port quantities, the indication of the first scaling factor and the second scaling factor transmitted at least in part in response to the capability.

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