Precoding Information

Abstract

11. A method and apparatus for providing channel state information reporting, comprising: receiving configuration information for configuring a measurement window to form a compression matrix of a port selection codebook from a codebook set of vector components, the configuration information specifying a size of the measurement window that is common to all of at least one layer to be reported; selecting a number of indices of the measurement window based on the configuration information to form a compression matrix from the codebook set of vector components; remapping selected indices associated with the vector components of the compression matrix to indices of a reference vector component, the indices of the reference vector component being remapped to a first index of the measurement window; and reporting channel state information to a network including a precoding matrix indicator, the precoding matrix indicator including information of the compression matrix after remapping.

Description

[Technical field]

[0001] The present disclosure relates to methods, apparatus, and computer program products for communicating precoding information between communication devices. [Background technology]

[0002] A communication session can be established between two or more communication devices, such as users or terminal devices, base stations / access points, and / or other nodes. A communication session can be provided, for example, by a communication network and one or more compatible communication devices. A communication device on the network side provides an access point to the system and is equipped with appropriate signal transmission / reception equipment to enable communication, e.g., to allow other devices to access the communication system. A communication session can include, for example, data communication to convey information such as voice, video, electronic mail (email), text messages, multimedia, and / or content data. Non-limiting examples of services provided include two-way or multi-way calls, data communication, multimedia services, and access to a data network system such as the Internet.

[0003] In a mobile or wireless communication system, at least a part of a communication session between at least two devices is carried out over a wireless or radio link. Examples of wireless systems include public land mobile networks (PLMNs), satellite-based communication systems, and various wireless local networks, e.g., wireless local area networks (WLANs). A user can access a broader communication system by means of an appropriate communication device or terminal. A communication device is often referred to as user equipment (UE) or user device. A communication device is provided with appropriate signal transmission and reception equipment to enable communication, e.g., to enable access to a communication network or direct communication with other users. A communication device may access a carrier provided by a station (e.g., a base station) in a radio access network, and transmit and / or receive information on the carrier.

[0004] A feature of most modern systems is the capability for multipath operation, where a communication device may communicate via multiple paths. Multipath communication may be provided by a mechanism known as multiple-input / multiple-output (MIMO).

[0005] Communication systems and related devices typically operate according to a given standard or specification that sets out the operations that the various entities associated with the system are permitted to perform and how they are accomplished. The communication protocols and / or parameters used for the connection are also typically specified. An example of a communication system is UTRAN (3G Radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology, and the so-called Fifth Generation (5G) or New Radio (NR) networks. 5G is standardized by the 3rd Generation Partnership Project (3GPP). Successive versions of the standard are known as Releases (Rel). In 3GPP 5GNR, standardization work is underway to further enhance aspects of MIMO Channel State Information (CSI). Summary of the Invention

[0006] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are defined in the dependent claims.

[0007] Certain aspects will now be described in more detail, by way of example only, with reference to the following examples and the accompanying drawings, in which: [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an example of a system in which the present invention can be implemented. [Diagram 2] FIG. 2 illustrates an example of a control device. [Diagram 3] 1 is a diagram of an example of frequency domain (FD) components outside a reporting window. [Figure 4] 1 is a flow chart according to a particular example. [Diagram 5] 1 is a flow chart according to a particular example. [Figure 6] 1 is a signaling flowchart between two communication devices according to an example. [Figure 7] FIG. 1 illustrates two example configured measurement and reporting windows. [Figure 8] FIG. 1 illustrates two example configured measurement and reporting windows. [Figure 9] 4 is a flow chart according to a further example. [Figure 10] 4 is a flow chart according to a further example. [Figure 11] FIG. 13 is another example of a measurement and reporting window. [Figure 12] FIG. 13 is a diagram illustrating an example of index mapping. [Figure 13] FIG. 13 is a diagram illustrating an example of index mapping. [Figure 14] FIG. 13 is a diagram illustrating an example of index mapping. [Figure 15] FIG. 13 is a diagram illustrating an example of index mapping. [Figure 16]FIG. 13 is a diagram illustrating an example of index mapping. [Figure 17] FIG. 13 is a diagram illustrating an example of index mapping. [Figure 18] FIG. 1 illustrates another solution for solving the out-of-window problem according to an embodiment. [Figure 19] FIG. 1 illustrates a method according to some embodiments. [Figure 20] FIG. 1 illustrates a method according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following description provides an exemplary illustration of some possibilities for implementing the present invention. Although the specification may refer to "an", "one" or "some" example or embodiment(s) in several places in the text, this does not necessarily mean that each reference is to the same example of the embodiment(s) or that a particular feature applies only to a single example or embodiment. Single features of different examples and embodiments may be combined to provide other embodiments.

[0010] A wireless communication system provides wireless communication for devices connected to the system. Typically, access points such as base stations are provided to enable communication. In the following, various scenarios are described using a 3GPP 5G radio access architecture with MIMO capabilities as an example of an access architecture. However, the embodiments are not necessarily limited to such architectures. Some examples of possible other systems are Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long Term Evolution (LTE), LTE-A (LTE Advanced), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth, Personal Communication Services (PCS), ZigBee, Wideband Code Division Multiple Access (WCDMA), Ultra Wideband (UWB) technology-based systems, sensor networks, Mobile Ad-Hoc Networks (MANET), Cellular Internet of Things (IoT) RAN, and Internet Protocol Multimedia Subsystem (IMS), or any combination and further development thereof.

[0011] 1 shows a wireless system 1 including a radio access system 2. The radio access system may include one or more access points, or base stations 12. A base station may provide one or more cells. An access point may include any node (e.g., TRP, 3GPP 5G base station, e.g., gNB, eNB, user device, e.g., UE, etc.) that can transmit / receive radio signals.

[0012] A communication device 10 is located within the coverage area of ​​the radio access system 2 such that the device 10 is able to communicate with an access point 12. Communication 11 from the device 10 to the access point 12 is generally referred to as the uplink (UL). Communication 13 from the access point 12 to the device 10 is generally referred to as the downlink (DL). In this example, the downlink is shown diagrammatically to include up to four beams per polarization in the spatial domain (SD).

[0013] It should be noted that the broader communication system is shown only as cloud 1 and may include many elements, which are not shown for clarity. For example, a 5G-based system may be composed of a terminal or user equipment (UE), a 5G radio access network (5GRAN) or next generation radio access network (NG-RAN), a 5G core network (5GC), one or more application functions (AF) and one or more data networks (DN). The 5G-RAN may include one or more gNodeBs (gNBs) or one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) centralized unit functions. The 5GC may also include entities such as a network slice selection function (NSSF), a network exposure function, a network repository function (NRF), a policy control function (PCF), a unified data management (UDM), an application function (AF), an authentication server function (AUSF), an access and mobility management function (AMF), and a session management function (SMF).

[0014] The device 10 may be any suitable communication device adapted for wireless communication. A wireless communication device may be provided by any device capable of transmitting and receiving radio signals. Non-limiting examples include a mobile station (MS) (e.g. a mobile device such as a mobile phone or a "smartphone"), a computer equipped with a wireless interface card or other wireless interface equipment (e.g. a USB dongle), a personal digital assistant (PDA) or tablet equipped with wireless communication capabilities, a machine type communication (MTC) device, an Internet of Things (IoT) type communication device or any combination thereof. The device may be provided as part of another device. The device may receive signals over the air or radio interface via a suitable device for reception and may transmit signals via a suitable device for transmission of radio signals. The communication may take place via multiple paths. To enable the communication devices 10 and 12 of MIMO type, multiple antenna elements are provided. These are indicated diagrammatically by antenna arrays 14 and 15.

[0015] A communication device such as the access point 12 or the user device 10 is provided with a data processing device comprising at least one processor and at least one memory. Figure 2 shows an example of a data processing device 50 comprising processor(s) 52, 53 and memory(s) 51. Figure 2 further shows connections between elements of the device and interfaces for connecting the data processing device to other components of the device.

[0016] The at least one memory may include at least one ROM and / or at least one RAM. The communication device may include other possible components used in the execution of the software and hardware-assisted tasks it is designed to perform, such as controlling access to and communication with the access system and other communication devices, and implementing the device positioning features described herein. At least one processor may be coupled to the at least one memory. The at least one processor may be configured to execute appropriate software code to perform one or more of the following aspects. The software code may be stored in the at least one memory, such as at least one ROM.

[0017] In the following, certain aspects of measurements, configurations and signaling for multipath, or multibeam, wireless transmission related operations using 5G terminology are described. In a frequency division duplexing (FDD) based system, full uplink-downlink (UL-DL) channel reciprocity cannot be assumed due to the duplexing distance between the uplink (UL) and downlink (DL) channels. However, partial channel reciprocity can be assumed based on characteristics such as the angle of emission (AoD), angle of reception (AoA), and delay of the propagation multipath. The UL-DL partial reciprocity property can be considered in the signaling between the communication devices. For example, the gNB can estimate the UL sounding reference signal (SRS) to obtain delay related information such as frequency domain (FD) components. This can be the same as the UE selection made through the DL channel state information reference signal (CSI-RS). The gNB can then further precode the beamformed CSI-RS resource that already includes the spatial domain (SD) beam with the selected FD components. The CSI-RS port must be configured to convey multiple sets of FD components via CSI-RS. TIFF0007644267000001.tif32It has been recognized that MIMO CSI feedback operation can be enhanced by utilizing partial uplink / downlink (UL / DL) reciprocity. Enhancements to CSI measurements and reporting can be made based on evaluation and, if necessary, based on the specification of port selection codebook extensions (e.g., based on existing 3GPP Rel.15 / 16 Type II port selection). Information related to angle(s) and delay(s) is estimated at the gNB based on SRS by utilizing DL / UL reciprocity of angle and delay, and the remaining DLC ​​SI is reported by the UE. This is primarily targeted at Frequency Range 1 (FR1) Frequency Division Duplexing (FDD) to achieve a better tradeoff between UE complexity, performance, and reporting overhead. For example, the Type II port selection (PS) codebook was extended in 3GPP Rel-16 by introducing a frequency domain (FD) compression operation to the 3GPP Rel-15 Type II port selection codebook. Such an extended Type II (eTypeII) port selection (PS) codebook is described, for example, in section 5.2.2.26 of 3GPP TS38.214 v16.30 of September 2020.

[0018] The 3GPP Rel-16 extended Type II (eTypeII) port selection (PS) codebook (CB) contains three codebook components: the port selection matrix (W 1 ), a discrete Fourier transform (DFT)-based compression matrix (W f ), and the coupling coefficient matrix (W 2 ) is included in the example. 1 is size 2N 1 N 2 × 2L, providing the spatial domain components, and the linear combination coefficient (LCC) matrix W 2 The size is 2L x M ν However, the DFT-based compressed matrix W f provides delay information (each column represents a delay tap) to create a filter of size N 3 ×M νThe parameter N 1 is the number of port antennas in the horizontal domain, and N 2 is the number of port antennas in the vertical domain, L is the orthogonal vector / beam per polarization, and N 3 is the number of PMI frequency subbands. ν is the number of components in the frequency domain (FD).

[0019] The same codebook structure is adopted in the further extended type II (FeTypeII) PS codebook of 3GPP Rel-17 for partial UL-DL channel reciprocity in frequency division duplex (FDD) operation. Below, we compare the compression matrix (W f ) and their potential consequences.

[0020] In 3GPP Rel-16, the network can optimize the compression matrix W by configuring a parameter combination paramCombination-r16 that depends on the reported rank ν. f The number of vector DFTs that form M ν Configure. M ν The components can be understood to represent frequency domain (FD) bases or components. More generally, the parameters include appropriate vectors or components. In the accompanying figures, the components are defined by the x-axis to represent the DFT transform in the frequency domain. Since the components correspond to the channel delays, this domain can also be referred to as the "delay domain". The UE then obtains, for each layer, a delay-domain matrix of length N from the DFT-codebook. 3 M ν vectors can be selected, where N 3 is the number of precoding matrix indicator (PMI) subbands, which is equal to the size of the DFT codebook. The selection is done separately for each layer, so that each W f is considered to be layer specific. The UE 3 If ≦19, then N 3We select these DFT vectors from the entire codebook set of vectors, but 3 If >19, then size N=2M ν In the window mechanism, if component 0 is included in the window and the window position is common for all layers, the UE selects the optimal position for the window. In practice, the UE selects the first component M initial ∈{-N+1,-N+2,...,0} and report it. Note that M initial Negative values ​​of mean that the window is N 3 Enclosing a set of components, i.e., all candidate components are modulo N 3 This means that it is expressed as:

[0021] W in 3GPP Rel-16 f The design principle in the report is that the strongest coefficient for each layer is the W 2 , is found in the first column of the bitmap associated with the non-zero coefficients of W. 2 is size K 1 ×M ν The bitmap indicates the location of the reported non-zero coefficients, and the magnitude and phase of the coefficients are reported sequentially following the bitmap indication. 1 ≦P is the number of CSI-RS ports that the UE is configured to select. This is ensured by configuring the UE to apply two cyclic shifts for each layer 1. The first cyclic shift

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[0022] According to 3GPP Rel-16, the matrix W 2The location of the strongest coefficient in is reported for each layer because it is 2 Because it serves as an amplitude reference for other non-zero coefficients in gNB, the reported position can only include the row index. 2 is layer-specific. Therefore, the gNB receiving the report will determine that the strongest coefficient is component 0, i.e., W 2 Therefore, the strongest coefficient indicator (SCI) is the beam index, i.e., the W 2 In fact, it only shows the row index of N 3 The window mechanism used in 3GPP Rel-16 for >19 is that the UE shifts the strongest coefficient component for each layer to position 0 and then applies a common M initial Determine the best value of and then M initial A different M for each layer in a window of length N starting from ν In this way, all M ν The components are circularly shifted

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[0023] W f can be assumed to be common to all layers. In such a case, M initial Or the proposed indicators, such as the location of the strongest coefficients, can be layer common.

[0024] For the FeTypeII PS codebook, the current consensus is that ν This means that all components, a.k.a. the frequency domain (FD) basis, are constrained within a single window / set of size N. At least for rank 1, W fThe FD bases used for quantization are restricted within a single window / set of size N configured in the UE. It is proposed that the FD bases within the window must be contiguous from the orthogonal DFT matrix. An alternative is that the FD bases within the set can be contiguous / non-contiguous and are freely selected by the gNB from the orthogonal DFT matrix. Other conditions, e.g., W f Whether or not you can turn on / off the M ν associated values, and W f It remains to be determined whether this applies when the gNB is turned off. The measurement window configured by the gNB is W f M ν In some cases, the choice of vectors may be restricted and layer common. Moreover, it is unclear and subject to different interpretations. For example, using a window, M ν For each layer, M ν We may limit the maximum separation between the N components. Note that this is 3 >19, which is different from the window in Rel-16PS, where the size is 2M ν The window IntS in is common to all layers, so that it limits the maximum separation between the selected components across all layers after aligning the components of the strongest coefficients. Another possible interpretation is that the window IntS in 2 The idea is that the UE measures (at least) the DFT vectors in the window (but may measure more) and constructs a set of M ν components that, if necessary, after a suitable shift, fall within the configured window. Note that the selected components are all M ν If the FD components fit into the window after a common cyclic shift to N, the UE calculates components beyond N to find the optimal M outside the configured measurement window containing FD components from 0 to N to 1. ν In practice, we may choose W f Two different choices of W2 is generated, but the same W f can be reported as

[0025] Parameters N and M ν Regarding the relationship between ν The candidate values ​​for N are smaller than Rel-16, with only 1, 2 (and possibly 4) being considered. The Rel-17 window / set size is also smaller compared to Rel-16, with the most likely candidate values ​​being 1, 2, 3, and 4. At least for rank 1, N and M ν Regarding the relationship between N and M, ν > or N ≥ M ν is proposed. Candidate values ​​for N are under consideration, but could be, for example, 2 or 4.

[0026] The difference between the window / set mechanism in Rel-17 and that in Rel-16 is that the window / set selection is done by the gNB instead of the UE, by taking advantage of the partial reciprocity of delay between the UL and DL channels in FDD operation. However, the location of the strongest coefficient in each layer is determined in the UE, since the fast fading component of the channel is not reciprocal. Therefore, if the same design principle as in Rel-16 is reused, i.e., the gNB selects the window / set by the UE, the UE will select the window / set by the UE. f If we expect the strongest coefficient in the first column of ν It is possible to shift this component.

[0027] Such out-of-window problems are addressed in the Rel-17 port selection (PS) codebook design, e.g., M ν >W at 1 fFor illustration, consider an example with parameter combination N=M=2, where the window is formed by two successive Digital Fourier Transform (DFT) components, 0 and 1. Figure 3 shows the frequency domain (FD) components for two layers and a network configuration window of size N=2. For each layer, the vertical bars represent M ν The height of the bars corresponds to the W = 2 FD component for the port with the strongest coefficient in each layer. 2 1 illustrates the magnitude of the coupling coefficients of each layer. Each layer is composed of K CSI-RS ports selected by the UE from a total of P CSI-RS ports. 1 ≦P ports, and therefore for each layer, 2 The size of is K 1 ×M ν Note that M ν Note also that the components are common to all ports in a layer, and in this case, they are common to all layers, i.e., they are layer-common. However, in Figure 3, the strongest K 1 M ν M for the ports where coefficients are found ν Only the amplitudes of the coefficients are illustrated.

[0028] For layer 1, the strongest coefficients are found in component 1 of port. Therefore, by reusing the same design principle as for Rel-16PS, the cyclic shift -1 is modulo N 3=13 to move the FD component with the strongest coefficient to component 0. The shift is cyclic since component 0 is shifted to -1 (which corresponds to component -1 mod 13 = 12) while component 1 is shifted to component 0. For layer 2, no shift is needed since the strongest coefficient is already found in component 0. After the shift on layer 1, one component has moved outside the window configured by the gNB. This is shown in the possible scenario for layer 1 (A). In the possible scenario for layer (B), both components are inside the window. Due to this difference, the UE needs to signal one of the two combinations for each layer to the gNB.

[0029] It is not possible in Rel-17 to reuse the indicators defined in the Rel-16 CB without modification. In fact, the indicators defined in the window mechanism of the Rel-16 normal and port selection CBs 1,5 (Layer common M initial ) is common to both layers, and it is not possible to find a window position common to both layers in Figure 7. 1,6,l (Layer specific W f ) is also not appropriate because the window size N=2 is i 1,6,l When substituted in the provisions of f A single component for is obtained as follows:

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[0030] Therefore, W f If is constrained within a window of size N, then W defined in Rel-16 f By reusing the indicator for, in the case of Figure 3, W f Although there are no reports of this, gNB has two W-bands for Layer 1 (A) and Layer 2 (B).f It is not possible to distinguish between the two.

[0031] The problem outside the window shown in (A) of 3 is that the strongest coefficient is W 2 This can be avoided by not following the Rel-16 design principle found in the first column of ν It can be any of the components. However, this approach requires a cumbersome change of the omission rules for PMI to Uplink Control Information (UCI) mapping in Part 2 of CSI reporting. UCI omission is a mechanism by which the UE drops part of the PMI payload when the Physical Uplink Shared Channel (PUSCH) resources are not sufficient to accommodate the full report. The omission rules for Rel-16 Type IICB are to assign the higher priority value Pri(l,i,f) to W 2 It is designed to be assigned to the first column of W 2 Since we can split M into two parts and assign them to different priority groups, the strongest coefficient for each layer is unlikely to be omitted. ν If there is a possibility that the strongest coefficient may be present in any of the components, the probability that the strongest coefficient will be omitted increases, which may affect performance if omission occurs.

[0032] In the following, W f Reporting window for W f Examples for measurement windows for are described in more detail below. The reporting window can be configured by a network entity, e.g., gNB, and the UE can be configured accordingly. The size of the reporting window can be defined in various ways. Examples for this are described in more detail below.

[0033] FIG. 4 illustrates an example flow chart for the operation of a device (e.g., device 10 of FIG. 1) that receives and uses configuration information. In the method, a precoding matrix indicator for channel state information reporting configured by a port selection codebook is provided. Configuration information for configuring a measurement window of a compression matrix of a port selection codebook (the configuration information specifies a size of the measurement window) is received (100). The device can then select the number of components of the measurement window based on the configuration information (102). The reporting window of the compression matrix is ​​indicated based on a circular shift of the measurement window such that the strongest component in each layer is shifted to a predetermined component position. (show) (104). According to the example, the strongest component is shifted to the component with index 0.

[0034] A more detailed example of a transmission layer specific indication of the initial position is shown in FIG.

[0035] According to a possibility, the reporting window is configured as an extension of the measurement window. An example of this is shown in FIG. 8, where the extension is modified without the need to report an indication of the reporting window. In this case, the operation in block 104 of FIG. 4 includes using the received configuration of the reporting window to define an extension of the measurement window such that the frequency domain component of the strongest coefficient in each layer is shifted to a predefined component position. For example, the strongest component is shifted to the component position with index 0.

[0036] FIG. 5 illustrates an example flow chart for operations in a device provided in an access network (e.g., access point 12 of FIG. 1) for configuring the device for signaling information related to multi-channel communication. In the method, the device transmits configuration information for configuring a measurement window of a compression matrix of a port selection codebook (200). The configuration information specifies the number of frequency domain coefficient components of the measurement window. Then, a channel state information report including a precoding matrix indicator is received (202). The report window of the port selection codebook is received based on a circular shift of the measurement window such that the frequency domain component of the strongest coefficient in each layer is shifted to a predetermined component (e.g., the component with index 0). Then, the device reconfigures a precoder based on the precoding matrix indicator (204).

[0037] According to an alternative, instead of a cyclic shift, the reporting window is configured as an extension of the measurement window, an example of which is shown in FIG.

[0038] A more detailed example of a possible use of clustered precoding is given below.

[0039] FIG. 6 shows an example signaling flow chart for port selection codebook configuration, measurement and reporting between two communication devices, more specifically between a UE 10 and a gNB 12, where a specific window size is conveyed to the UE. More specifically, the gNB 12 sends a message 60 to the UE. The message includes: ν The example includes an upper layer configuration that includes a window-side parameter N that limits the selection of vectors. The example shows that the configuration includes the element "CodebookConfig-r17".

[0040] The UE may respond with a sounding reference signal (SRS) 61, and the gNB may then determine a set of CSI-RS vector pairs in the spatial and frequency domains (62). The gNB may exploit partial UL-DL reciprocity, e.g., as described above. Each CSI-RS port is then precoded across transmit (tx) antennas and frequency units with a precoder vector pair (63). The precoded CSI-RS is conveyed to the UE via message 64.

[0041] The UE can then calculate the CSI reporting amount configured in, for example, “CSI-ReportConfig” including the PMI (65). The PMI reported by message 66 is based on the selected M ν The precoder vector pair may include one index for each layer associated with the vector. The gNB may then combine the received PMI with the CSI-RS precoder vector pair determined at 62 to obtain precoders for the physical downlink shared channel (PDSCH) and demodulation reference signal (DMRS) at 67. The precoded data and DMRS may then be signaled to the UE (68).

[0042] In the following, as an example, an extended codebook arrangement for signaling port selection channel state information (PS CSI) is described in more detail, in which a UE reports a precoding matrix indicator (PMI) in channel state information (CSI) that is composed of a port selection codebook as follows: f M ν The DFT-based vectors are constrained within a constructed measurement window of size N, and the strongest coefficients in each layer are denoted by W 2 The PMI is expected to be placed in the first column of the bitmap of reported non-zero coefficients of W. The gNB can then reconstruct the precoder from the PMI. One or more indices of the PMI are fThis is associated with a reporting window for the measurement window, which may differ from the configured measurement window.

[0043] This may be particularly relevant in the context of frequency domain (FD) compression operations. In certain applications, the compression operation may be moved, at least partially or mostly, from the UE to the gNB. The extension is based on the assumption of partial reciprocity of cluster delays in the UL and DL channels and flexibility in the use of frequency domain components.

[0044] A first example is illustrated in FIG. ν If −1 nonzero components are reported, it is indicated for the reporting window. The reporting is done for layers l=1,...,ν, of size N and initial point

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[0045] One index can be reported per layer. The index can correspond to the circular shift required to move the strongest coefficient component to a given component (preferably 0). The measurement window configured by the gNB is W f M ν The reporting window can be a layer-specific shifted version of the layer-common measurement window. The reporting window can be obtained based on the configured measurement window by applying a circular shift such that the component of the strongest coefficient is moved to component 0, and an index indicating the shift for each layer is reported to the gNB.

[0046] M νThe components may be configured to be contiguous. The index associated with the reporting window may correspond to the component of the strongest coefficient within the configured measurement window. A circular shift of the W-index ("circular shift of index to the left") may be added by the UE prior to reporting to the W-index containing the bitmap of reported non-zero coefficients and the corresponding indices of the amplitudes and phases of these non-zero coefficients. 2 Column of modulo M ν , so that the strongest coefficients are moved to the first column. ν It can be configured to not report -1 nonzero components. A negative integer-valued circular shift (denoted -index above) is applied to component x modulo y and is a circular shift to the left, i.e., subtracting the index from x, and is denoted by the operation (x-index) mod y. Conversely, a circular shift of a positive integer-valued index is denoted by the operation (x+index) mod y.

[0047] The second example is shown in Figure 8, with a size of 2N-1 and a fixed initial point.

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[0048] It is possible that the strongest component is already at the first component position (component 0 in Figs. 7 and 8). In such a case, the UE may selectively use a reporting window that corresponds to the measurement window. According to an example, the UE may be configured to determine whether the strongest tap on any layer is on a component different from the first component and selectively apply changes from the measurement window to the reporting window accordingly. If necessary, the UE may selectively indicate changes to the gNB. Figs. 9, 10, and 11 relate to an example where the measurement window size and position are kept as is. Instead, the UE takes other actions taking into account the strongest component, which will be explained in more detail later in this specification.

[0049] In a more specific configuration, for example, 3GPP Rel-17 type port selection (PS) can be applied, where N=M ν In the example of Figures 7 and 8, where N=2, it becomes possible to report binary indices per layer. ν >2 or N>M ν >2, and M ν In other possible configurations with the additional constraint that the components must be consecutive, the example of Fig. 7 may be more efficient in terms of signaling overhead compared to the second example. Also, in these cases, the first example uses an index for each layer l=1,...,ν, corresponding to the component of the strongest coefficient before the circular shift. l ∈{0,1,...,M ν Note that this index can also be described as reporting {-1}. l teeth

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[0050] The UE performs a cyclic shift so that the strongest coefficients are moved to the first column.

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[0051] In the following, we use the index i 1,5 and i 1,6,l Further possible details for the modification are described below.

[0052] In the first example, W for layers l=1,...,ν f M ν The vectors are

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[0053] This is illustrated in FIG.

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[0054] Non-zero index

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[0055] To operate according to FIG. 7, the UE

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[0056] Within the reporting window for Layer 1

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[0057] To operate according to FIG. 8, the UE

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[0058] N=M ν In the special case of =2, both previous examples require only one bit of signaling per layer. In detail, in the first example, i 1,5,1 Only ∈{0,1} is reported, i 1,6,1 = 0 is not reported. On the other hand, in the second example, i 1,6,1 Only ∈{0,1} is reported.

[0059] However, N=M ν >2, the first example requires fewer bits than the second example. 1,5,1 ∈{0,1,...,M ν -1} is reported, and i 1,6,1 =0 is not reported. Therefore, for each layer, [log 2 M ν ] bits are required. On the other hand, the second example requires N=M ν = 3, 3 bits for N=Mν This quickly becomes inefficient, requiring 5 bits for =4, etc. On the other hand, the first example requires 2 bits in both of these two cases.

[0060] Also, the selected M ν components of size N>M ν If the gNB is configured to measure N consecutively within a measurement window, the first example is ν By specifying the same signaling as in the case of i 1,5,1 ∈{0,1,...,M ν -1}. Such a configuration can still be used by reporting only the W f This has a positive effect on UL overhead reduction since no further information on W needs to be fed back by the UE. f M ν This refers to the fact that the components are arranged to be contiguous within a window of size N.

[0061] 9, 10 and 11 relate to an embodiment in which no change is applied to the size and position of the reporting window relative to the measurement window configuration as such: instead, the strongest reported component can be shown, which can be in a different position than the first column.

[0062] In the flowchart of Figure 9, the device receives configuration information for configuring a measurement window of a compressed matrix of a port selection codebook (300). The configuration information specifies the size of the measurement window. The device then selects (302) the number of coefficient components of the measurement window based on the configuration information. When reporting, the device indicates (304) the row and column index of the location of the strongest coefficient component in the matrix of non-zero coupling coefficients for each layer and applies a circular shift to the columns of the matrix of non-zero coupling coefficients for each layer such that the strongest coefficient is shifted to the first column.

[0063] The flow chart of Figure 10 relates to operations in a network device receiving a report. The device sends configuration information for configuring a measurement window of a compressed matrix of a port selection codebook (400). The configuration information specifies the number of components of the measurement window. A CSI report including PMI is then received (402). In the report, row and column indices are indicated for the position of the strongest coefficient in the matrix of non-zero coupling coefficients for each layer, and a circular shift is applied to the columns of the matrix of non-zero coupling coefficients for each layer such that the first column is shifted to the specified column index.

[0064] The UE uses W for the first component, not the component with the strongest coefficient. f Since there are no components outside the window, the layer-specific M initial is not necessary. The UE still uses the shift for the strongest coefficient.

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[0065] UE is

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[0066] Figures 12-17 show the index mapping for N values ​​2, 3, and 4. Alignment of the W2 and Wf indices can be done by shifting the W2 index (examples in Figures 15-17) or the Wf index (examples in Figures 12-14). The flow chart in Figure 10 shows the W 2Regarding the gNB shift above.

[0067] As previously observed, in both of the above examples, N=M ν = 2 corresponds to the strongest coefficient component, and the index for each layer l = 1, ..., ν l ∈{0,1,...,M ν Another possible explanation is that the index value (i 1,5,1 or i 1,6,1 FD component index

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[0068] In Figure 16, f The index to report is N=M ν Component index for =3

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[0069] Figure 17 shows the W f The index to report is N=M ν Component index for =4

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[0070] N=M ν =3 and N=M ν For f-index = 4, Figs. 16 and 17 show the same results, respectively. l )modN 3 (f∈{0,1,...,M ν}) in gNB. ν The values ​​of the components are shown and sorted in ascending order.

[0071] A communication device (e.g., user equipment) may f M ν The method may further include a method for reporting PMI in a CSI report configured by a port selection codebook, the port selection codebook being constrained within a configured measurement window of size N, the strongest coefficient in each layer being W 2 The network device (e.g., gNB) may include means for reconstructing the PMI from the precoder. The PMI may be associated with one or more indices of a W that may be different from the configured measurement window. f A reporting window can be associated with a reporting window for each layer, and the reporting window can be common to all layers. νThe components may be configured to be contiguous, and the index associated with the reporting window corresponds to the component of the strongest coefficient in the configured measurement window. The circular shift of the index includes the bitmap of reported non-zero coefficients and the matrix of amplitudes and phases of these non-zero coefficients, such that the strongest coefficients are moved to the first column. 2 In this case, M ν -1 nonzero component may not be reported.

[0072] Let us look at other possible solutions to the outside window problem with reference to Figures 18-20. In fact, in Rel-16, the layer-specific W f The components of are modulo N 3 The ongoing work in Rel-17 to specify the FeTypeII PS codebook is ν components (aka frequency domain or FD based) of size N and initial point M init It was agreed that the metric would be limited to a single window of 0.

[0073] However, in Rel-17, due to the window / set restriction of size N constructed by gNB, SCI is limited to the FD component of the strongest coefficient, i.e.,

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[0074] In addition, the compression matrix W f M associated with the vector components of ν The codebook indices are

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[0075] An example for this window configuration is illustrated in Figure 3, where the strongest coefficients of layers 1 and 2 are in two different components. f The first component is common to all layers and is not reported.

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[0076] N and M ν The current consensus on the relationship between N and M ν In this case, W f must be reported and can be layer-common or layer-specific. To minimize overhead and follow the Rel-16 design, in this case, W f teeth,

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[0077] For Rel-17 port selection codebook,

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[0078] In one embodiment, the FD base is the strongest coefficient

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[0079] In gNB,

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[0080] The proposed solution is to use the first basis

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[0081] In Rel-16, f is layer specific, but the reference component is that of the strongest coefficient for layer l, so W f The component index of

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[0082] However, in Rel-17, f It was reported that (N>M ν ), the strongest coefficient is

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[0083] W f There are two possible components that can be taken as a reference for W: the component with the strongest coefficient as in Rel-16, or the "first" selected component, i.e. the component with the lowest index value {0,1,...,N-1} in the window. Layer-common or layer-specific W f Depending on the selection of W f The following mapping choices are available for

[0084] 1. Layer common

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[0085] 2. Layer Specific

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[0086] W f If no shift is specified for, the UE may use, for example,

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[0087] W 2 Regarding the shifts applied to the columns of , there are in fact two possible options: no shift, or

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[0088] W f and W 2 For all the above alternatives of index mapping, we have the corresponding SCI for layer l.

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[0089] In the above cases 1.a and 1.b, N=4>M ν =2 and layer common

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[0090] In the case of 1.a, W f The ingredients are:

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[0091] In gNB, W is used for precoder reconstruction. fUsing =[0,3] is incorrect because

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[0092] In the case of 1.b, W f The ingredients are

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[0093] In this example, W f and W 2 Whatever solution is adopted for the representation of the SCI, the index

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[0094] Tables 1 and 2 show the layer-common and layer-specific W f In the case of W f Ingredients and W 2 We summarize the above mapping options for the column index of W. f Mapping and demapping of N>M ν Only applicable when N=M ν In the case of W f is layer-wide and fixed by configuration.

[0095] [Table 1]

[0096] Table 1 W f Ingredients and W 2 Summary of UE mapping options for column indexes of SCI. In all cases, SCI is

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[0098] Table 2 W f Ingredients and W 2 Summary of gNB’s demapping options for column indexes of . In all cases, SCI is

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[0099] Figure 19 illustrates a method for a reporting device, such as a user equipment, according to the principles described above, for example in Figure 18. The method may be for providing channel state information reports configured with a port selection codebook. The method includes receiving, at step 1900, configuration information for configuring a measurement window of a compression matrix of the port selection codebook. The configuration information defines a size of the measurement window. In one embodiment, the size of the measurement window N is determined by a compression matrix W f The number of codebook indices that the device can select to define v Greater than.

[0100] In step 1902, the UE calculates a compressed matrix W f A number of codebook indices of the measurement window are selected based on the configuration information to form a vector component of the compression matrix.

[0101] In step 1904, the UE calculates a matrix W of non-zero coupling coefficients for the layer. 2 This step remaps the matrix W of non-zero coupling coefficients for the layer such that the strongest coefficient is remapped to the first column. 2This may include remapping columns of

[0102] In step 1906, the UE remaps the codebook indexes such that the codebook index corresponding to the column index of the predetermined coefficient of the first layer is remapped to the first index of the measurement window. The remapping may be referred to as a circular shift. In one embodiment, the predetermined coefficient is the strongest coefficient. In one embodiment, the predetermined coefficient is the first coefficient. In one embodiment, this step may include subtracting the codebook index corresponding to the column index of the strongest coefficient of the first layer from all codebook indices of the compression matrix and reporting all codebook indices (except the first one) of the compression matrix of the port selection codebook after applying a modulo arithmetic of the size of the measurement window N. In one embodiment, the codebook indices of the measurement window and the compression matrix are DFT vectors.

[0103] FIG. 20 illustrates a method for a device receiving a report, such as a gNB, according to the principles described above in FIG. 18. In step 2000, the gNB receives a compressed matrix W f The configuration information defines the number of components N of the measurement window. In one embodiment, the size of the measurement window N is determined by the compressed matrix W f The number of codebook indices that the UE can select to define v Greater than.

[0104] In step 2002, the gNB receives a channel state information report including a precoding matrix indicator (PM). The row and column indices are the matrix W of non-zero combining coefficients. 2 The PMI is calculated for the position of the strongest coefficient in the layer of fIn one embodiment, these indices are remapped at the transmitter side as described above, for example with the strongest coefficients being shifted to the first index.

[0105] In step 2004, the gNB calculates the compressed matrix W for one of the codebook indices, whose position is a function of the column index of a given coefficient of the first layer and the number of elements of the compressed matrix. f In one embodiment, the predetermined coefficient is the strongest coefficient. This is done when the column index of the strongest coefficient in the first layer is found to be non-zero.

[0106] This step 2004 is a step in which the demapping of the codebook index of the compression matrix W f and applying a modulo arithmetic of the measurement window size N. In one embodiment, the function for locating one codebook index may include subtracting one of the codebook indexes from all codebook indexes of the compressed matrix W f The number of components in M v is obtained by subtracting the non-zero column index of the strongest coefficient of the first layer from

[0107] In one embodiment, the matrix W of non-zero coupling coefficients 2 and the codebook compression matrix W f are aligned based on the indicated column index of the strongest coefficient.

[0108] In step 2006, the gNB constructs a precoder based on the received channel state information report.

[0109] In some circumstances of the description, f is assumed to be layer-common, but the solution is layer-specific W f In one embodiment, the compressed matrix Wf are remapped with respect to the codebook index corresponding to the column index of the strongest coefficient in each layer.

[0110] Although the above describes exemplary embodiments, it should be noted that there are several variations and modifications that may be made to the disclosed solutions without departing from the scope of the present invention. Different features from different embodiments may be combined.

[0111] Thus, the embodiments may vary within the scope of the appended claims. In general, some embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. For example, certain aspects may be implemented in hardware, and other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, but the embodiments are not limited thereto. Although various embodiments may be illustrated and described as block diagrams, flow charts, or using some other graphical representations, it is well understood that these blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controller or other computing device, or some combination thereof.

[0112] The embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the relevant entity, or by hardware, or by a combination of software and hardware. It is further noted in this regard that any of the foregoing procedures may represent program steps, or interconnected logic circuits, blocks, and functions, or a combination of program steps and logic circuits, blocks, and functions. The software may be stored on physical media, such as memory chips or memory blocks implemented within a processor, magnetic media, such as hard disks or floppy disks, and optical media, such as CDs, e.g. DVDs and data variants thereof.

[0113] The memory may be of any type suitable for the local technology environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The data processor may be of any type suitable for the local technology environment and may include, by way of non-limiting examples, one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), gate level circuits, and processors based on multi-core processor architectures.

[0114] Alternatively or additionally, some embodiments may be implemented using circuitry that may be configured to perform one or more of the functions and / or method steps described above, and that may be provided within a network entity and / or within a communication device and / or a server and / or a device.

[0115] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0116] (a) hardware-only circuit implementations (e.g., implementations in analog and / or digital circuitry only); (b) A combination of hardware circuitry and software that: (i) A combination of analog and / or digital hardware circuitry(s) and software / firmware; and (ii) any portion of the software (including digital signal processor(s)), hardware processor(s) with software and memory(s) that operate as a whole to cause the communications device and / or the device and / or the server and / or the network entity to perform the various functions described above; and (c) Hardware circuit(s) and / or processor(s), e.g., microprocessor(s) or part of a microprocessor(s), that requires software (e.g., firmware) for operation, but may be absent if software is not required for operation.

[0117] This definition of a circuit applies to all uses of the term in this application, including any claims. As a further example, the term "circuit" as used in this application also covers an embodiment simply of a hardware circuit or processor (or processors), or of a portion of a hardware circuit or processor and its (or their) associated software and / or firmware. The term "circuit" also covers integrated devices, for example.

[0118] It should be noted that although the embodiments have been described in relation to a particular architecture, similar principles can be applied to other systems. Thus, although certain embodiments have been described above by way of example with reference to a particular exemplary architecture for wireless networks, technical standards, and protocols, the features described herein may be applied to any other suitable forms of systems, architectures, and devices other than those illustrated and detailed in the above examples. It should also be noted that different combinations of different embodiments are possible. Although exemplary embodiments have been described above, it should also be noted herein that there are several variations and modifications that may be made to the disclosed solutions without departing from the spirit and scope of the present invention.

Claims

1. An apparatus (10), comprising: The port selection codebook compression matrix (W f ) measurement window (N 3 receiving configuration information (CodebookConfig-r17) for configuring the measurement window (N xN), the configuration information (CodebookConfig-r17) 3 2. The method of claim 1, further comprising: The compressed matrix (W f ) based on the configuration information (CodebookConfig-r17) to form the measurement window (N 3 A certain number of codebook indices (n 3 ), wherein the codebook index (n 3 ) is the compressed matrix (W f ) vector components of said selecting; The selected codebook index (n 3 ) in the measurement window (N 3 The reference vector component (n xN) having the lowest index among the selected codebook indexes. 3 (0) ), wherein the reference vector components (n 3 (0) ) such that a codebook index of is zero after said mapping; reporting channel state information (CSI) including a precoding matrix indicator (PMI) to a network, the precoding matrix indicator (PMI) including information of the compression matrix after mapping; An apparatus (10) comprising:

2. The configuration information (CodebookConfig-r17) further includes the compressed matrix (W f ) Size (M v 2. The apparatus (10) of claim 1, further comprising:

3. The selected codebook index (n 3 ) is smaller than a certain number of indices in the codebook set of vector components. 3 3. The apparatus (10) of claim 2, wherein the size (N) is smaller than the size (N) of the first and second arrays (xN).

4. The precoding matrix indicator (PMI) is, after the mapping, the compression matrix (W f ), excluding the first index, of the selected codebook index (n 3 2. The device (10) of claim 1, further comprising:

5. The number of codebook indexes (n 3 ) is selected by selecting the number of codebook indices (n 3 2. The apparatus (10) of claim 1, characterized in that

6. The apparatus (10) of claim 1, wherein the mapping comprises subtracting the indices of the reference vector components from all indices of the compressed matrix.

7. determining, for each of the at least one reported layer, a position of a strongest coefficient in a matrix of non-zero coupling coefficients; for each of the at least one reported layer, indicating a row and column index of the location of the strongest coefficient in the matrix of non-zero coupling coefficients; 2. The apparatus (10) of claim 1.

8. The selected codebook index (n 3 2. The apparatus (10) of claim 1, wherein the at least one layer is reported and the at least one layer is common to all of the at least one layer.

9. The measurement window (N 3 xN) and the codebook index (n 3 2. The apparatus of claim 1, wherein the vector components associated with each of the vectors include DFT vectors.

10. The measurement window (N 3 4. The apparatus of claim 3, wherein a first index of said set of vector components (xN) corresponds to a first index of said codebook set of vector components.

11. The reference vector component (n 3 (0) ) is the index of the measurement window (N 3 2. The apparatus of claim 1, further comprising: an offset relative to a first index of the first vector (xN).

12. The reference vector component (n 3 (0) ) is the index of the measurement window (N 3 2. The apparatus of claim 1, further comprising: an offset to an index of the strongest coefficient of the iterative ...

13. The user equipment (10) is provided with a measurement window (N 3 transmitting configuration information (CodebookConfig-r17) for configuring the measurement window (N xN), 3 .times.N, wherein said transmitting defines a number (N) of components of said signal; The compressed matrix (W f ) information, and receiving a channel state information (CSI) report including a precoding matrix indicator (PMI) with the selected codebook index (n 3 ) is mapped to the measurement window (N 3 The reference vector component (n xN) having the lowest index among the selected codebook indexes. 3 (0) ) and the reference vector components (n 3 (0) ) is zero after said mapping; reconfiguring a precoder based on the precoding matrix indicator (PMI); An apparatus (12) comprising:

14. A method for an apparatus (10), comprising: The port selection codebook compression matrix (W f ) measurement window (N 3 receiving configuration information (CodebookConfig-r17) for configuring the measurement window (N xN), the configuration information (CodebookConfig-r17) 3 2. The method of claim 1, further comprising: The compressed matrix (W f ) based on the configuration information (CodebookConfig-r17) to form the measurement window (N 3 A certain number of codebook indices (n 3 ), wherein the codebook index (n 3 ) is the compressed matrix (W f ) vector components of said selecting; The selected codebook index (n 3 ) in the measurement window (N 3 The reference vector component (n xN) having the lowest index among the selected codebook indexes. 3 (0) ), wherein the reference vector components (n 3 (0) ) such that a codebook index of is zero after said mapping; reporting channel state information (CSI) including a precoding matrix indicator (PMI) to a network; A method comprising:

15. A method for an apparatus (12), comprising: The user equipment (10) is provided with a measurement window (N 3 transmitting configuration information (CodebookConfig-r17) for configuring the measurement window (N xN), 3 .times.N, wherein said transmitting defines a number (N) of components of said signal; The compressed matrix (W f ) information, and receiving a channel state information (CSI) report including a precoding matrix indicator (PMI) with the selected codebook index (n 3 ) is mapped to the measurement window (N 3 The reference vector component (n xN) having the lowest index among the selected codebook indexes. 3 (0) ) and the reference vector components (n 3 (0) ) is zero after said mapping; reconfiguring a precoder based on the precoding matrix indicator (PMI); A method comprising:

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