Patent Description:
Relatedly, document 3GPP R1-<NUM> describes codebook design for channel-state-information, CSI, feedback, document 3GPP R1-<NUM> describes type II CSI reporting, and document <CIT> describes CSI feedback processing and reporting for EB/FD-MIMO.

Embodiments and aspects that do not fall within the scope of the claims are merely examples used for explanation of the invention. In one aspect of the disclosure, a method of wireless communication according to appended claim <NUM> is defined.

In an additional aspect of the disclosure, an apparatus configured for wireless communication, according to appended claim <NUM> is defined.

In an additional aspect of the disclosure, a computer program code according to appended claim <NUM> is defined.

The Appendix provides further details regarding various embodiments of this disclosure and the subject matter therein forms a part of the specification of this application.

The detailed description set forth below, in connection with the appended drawings and appendix, is intended as a description of various configurations and is not intended to limit the scope of the disclosure.

This disclosure relates generally to providing or participating in authorized shared access between two or more wireless communications systems, also referred to as wireless communications networks. In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, <NUM>th Generation (<NUM>) or new radio (NR) networks, as well as other communications networks. As described herein, the terms "networks" and "systems" may be used interchangeably.

The present disclosure is concerned with the evolution of wireless technologies from LTE, <NUM>. <NUM>, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

In particular, <NUM> networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order to achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for <NUM> NR networks. The <NUM> NR will be capable of scaling to provide coverage (<NUM>) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ~<NUM> nodes/km<NUM>), ultra-low complexity (e.g., ~<NUM> of bits/sec), ultra-low energy (e.g., ~<NUM>+ years of battery life), and deep coverage with the capability to reach challenging locations; (<NUM>) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., -<NUM>% reliability), ultra-low latency (e.g., ~ <NUM>), and users with wide ranges of mobility or lack thereof; and (<NUM>) with enhanced mobile broadband including extreme high capacity (e.g., ~ <NUM> Tbps/km<NUM>), extreme data rates (e.g., multi-Gbps rate, <NUM>+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

The <NUM> NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI); having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD)/frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in <NUM> NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than <NUM> FDD/TDD implementations, subcarrier spacing may occur with <NUM>, for example over <NUM>, <NUM>, <NUM>, <NUM>, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than <NUM>, subcarrier spacing may occur with <NUM> over <NUM>/<NUM> bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the <NUM> band, the subcarrier spacing may occur with <NUM> over a <NUM> bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of <NUM>, subcarrier spacing may occur with <NUM> over a <NUM> bandwidth.

<FIG> is a block diagram illustrating <NUM> network <NUM> including various base stations and UEs configured according to aspects of the present disclosure. The <NUM> network <NUM> includes a number of base stations <NUM> and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each base station <NUM> may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used.

A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in <FIG>, the base stations 105d and 105e are regular macro base stations, while base stations 105a-105c are macro base stations enabled with one of <NUM> dimension (3D), full dimension (FD), or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

The <NUM> network <NUM> may support synchronous or asynchronous operation.

The UEs <NUM> are dispersed throughout the wireless network <NUM>, and each UE may be stationary or mobile. A UE may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as internet of everything (IoE) devices. UEs 115a-115d are examples of mobile smart phone-type devices accessing <NUM> network <NUM> A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. UEs 115e-<NUM> are examples of various machines configured for communication that access <NUM> network <NUM>. A UE may be able to communicate with any type of the base stations, whether macro base station, small cell, or the like. In <FIG>, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations.

In operation at <NUM> network <NUM>, base stations 105a-105c serve UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a-105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by UEs 115c and 115d.

<NUM> network <NUM> also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE 115e, which is a drone. Redundant communication links with UE 115e include from macro base stations 105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer), UE <NUM> (smart meter), and UE <NUM> (wearable device) may communicate through <NUM> network <NUM> either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE 115f communicating temperature measurement information to the smart meter, UE <NUM>, which is then reported to the network through small cell base station 105f. <NUM> network <NUM> may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-<NUM> communicating with macro base station 105e.

<FIG> shows a block diagram of a design of a base station <NUM> and a UE <NUM>, which may be one of the base station and one of the UEs in <FIG>. At the base station <NUM>, a transmit processor <NUM> may receive data from a data source <NUM> and control information from a controller/processor <NUM>. The control information may be for the PBCH, PCFICH, PHICH, PDCCH, EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmit processor <NUM> may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor <NUM> may also generate reference symbols, e.g., for the PSS, SSS, and cell-specific reference signal. A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a through 232t. Downlink signals from modulators 232a through 232t may be transmitted via the antennas 234a through 234t, respectively.

At the UE <NUM>, the antennas 252a through 252r may receive the downlink signals from the base station <NUM> and may provide received signals to the demodulators (DEMODs) 254a through 254r, respectively. A MIMO detector <NUM> may obtain received symbols from all the demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols.

On the uplink, at the UE <NUM>, a transmit processor <NUM> may receive and process data (e.g., for the PUSCH) from a data source <NUM> and control information (e.g., for the PUCCH) from the controller/processor <NUM>. The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the modulators 254a through 254r (e.g., for SC-FDM, etc.), and transmitted to the base station <NUM>. At the base station <NUM>, the uplink signals from the UE <NUM> may be received by the antennas <NUM>, processed by the demodulators <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by the UE <NUM>. The processor <NUM> may provide the decoded data to a data sink <NUM> and the decoded control information to the controller/processor <NUM>.

The controller/processor <NUM> and/or other processors and modules at the base station <NUM> may perform or direct the execution of various processes for the techniques described herein. The controllers/processor <NUM> and/or other processors and modules at the UE <NUM> may also perform or direct the execution of the functional blocks illustrated in <FIG>, and/or other processes for the techniques described herein. The memories <NUM> and <NUM> may store data and program codes for the base station <NUM> and the UE <NUM>, respectively.

In some cases, UE <NUM> and base station <NUM> may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs <NUM> or base stations <NUM> may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE <NUM> or base station <NUM> may perform a listen before talk (LBT) procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedback for its own transmitted packets as a proxy for collisions.

Use of a medium-sensing procedure to contend for access to an unlicensed shared spectrum may result in communication inefficiencies. This may be particularly evident when multiple network operating entities (e.g., network operators) are attempting to access a shared resource. In <NUM> network <NUM>, base stations <NUM> and UEs <NUM> may be operated by the same or different network operating entities. In some examples, an individual base station <NUM> or UE <NUM> may be operated by more than one network operating entity. In other examples, each base station <NUM> and UE <NUM> may be operated by a single network operating entity. Requiring each base station <NUM> and UE <NUM> of different network operating entities to contend for shared resources may result in increased signaling overhead and communication latency.

<FIG> illustrates an example of a timing diagram <NUM> for coordinated resource partitioning. The timing diagram <NUM> includes a superframe <NUM>, which may represent a fixed duration of time (e.g., <NUM>). Superframe <NUM> may be repeated for a given communication session and may be used by a wireless system such as <NUM> network <NUM> described with reference to <FIG>. The superframe <NUM> may be divided into intervals such as an acquisition interval (A-INT) <NUM> and an arbitration interval <NUM>. As described in more detail below, the A-INT <NUM> and arbitration interval <NUM> may be subdivided into sub-intervals, designated for certain resource types, and allocated to different network operating entities to facilitate coordinated communications between the different network operating entities. For example, the arbitration interval <NUM> may be divided into a plurality of sub-intervals <NUM>. Also, the superframe <NUM> may be further divided into a plurality of subframes <NUM> with a fixed duration (e.g., <NUM>). While timing diagram <NUM> illustrates three different network operating entities (e.g., Operator A, Operator B, Operator C), the number of network operating entities using the superframe <NUM> for coordinated communications may be greater than or fewer than the number illustrated in timing diagram <NUM>.

The A-INT <NUM> may be a dedicated interval of the superframe <NUM> that is reserved for exclusive communications by the network operating entities. In some examples, each network operating entity may be allocated certain resources within the A-INT <NUM> for exclusive communications. For example, resources <NUM>-a may be reserved for exclusive communications by Operator A, such as through base station 105a, resources <NUM>-b may be reserved for exclusive communications by Operator B, such as through base station 105b, and resources <NUM>-c may be reserved for exclusive communications by Operator C, such as through base station 105c. Since the resources <NUM>-a are reserved for exclusive communications by Operator A, neither Operator B nor Operator C can communicate during resources <NUM>-a, even if Operator A chooses not to communicate during those resources. That is, access to exclusive resources is limited to the designated network operator. Similar restrictions apply to resources <NUM>-b for Operator B and resources <NUM>-c for Operator C. The wireless nodes of Operator A (e. g, UEs <NUM> or base stations <NUM>) may communicate any information desired during their exclusive resources <NUM>-a, such as control information or data.

When communicating over an exclusive resource, a network operating entity does not need to perform any medium sensing procedures (e.g., listen-before-talk (LBT) or clear channel assessment (CCA)) because the network operating entity knows that the resources are reserved. Because only the designated network operating entity may communicate over exclusive resources, there may be a reduced likelihood of interfering communications as compared to relying on medium sensing techniques alone (e.g., no hidden node problem). In some examples, the A-INT <NUM> is used to transmit control information, such as synchronization signals (e.g., SYNC signals), system information (e.g., system information blocks (SIBs)), paging information (e.g., physical broadcast channel (PBCH) messages), or random access information (e.g., random access channel (RACH) signals). In some examples, all of the wireless nodes associated with a network operating entity may transmit at the same time during their exclusive resources.

In some examples, resources may be classified as prioritized for certain network operating entities. Resources that are assigned with priority for a certain network operating entity may be referred to as a guaranteed interval (G-INT) for that network operating entity. The interval of resources used by the network operating entity during the G-INT may be referred to as a prioritized sub-interval. For example, resources <NUM>-a may be prioritized for use by Operator A and may therefore be referred to as a G-INT for Operator A (e.g., G-INT-OpA). Similarly, resources <NUM>-b may be prioritized for Operator B, resources <NUM>-c may be prioritized for Operator C, resources <NUM>-d may be prioritized for Operator A, resources <NUM>-e may be prioritized for Operator B, and resources <NUM>-f may be prioritized for operator C.

The various G-INT resources illustrated in <FIG> appear to be staggered to illustrate their association with their respective network operating entities, but these resources may all be on the same frequency bandwidth. Thus, if viewed along a time-frequency grid, the G-INT resources may appear as a contiguous line within the superframe <NUM>. This partitioning of data may be an example of time division multiplexing (TDM). Also, when resources appear in the same sub-interval (e.g., resources <NUM>-a and resources <NUM>-b), these resources represent the same time resources with respect to the superframe <NUM> (e.g., the resources occupy the same sub-interval <NUM>), but the resources are separately designated to illustrate that the same time resources can be classified differently for different operators.

When resources are assigned with priority for a certain network operating entity (e.g., a G-INT), that network operating entity may communicate using those resources without having to wait or perform any medium sensing procedures (e.g., LBT or CCA). For example, the wireless nodes of Operator A are free to communicate any data or control information during resources <NUM>-a without interference from the wireless nodes of Operator B or Operator C.

A network operating entity may additionally signal to another operator that it intends to use a particular G-INT. For example, referring to resources <NUM>-a, Operator A may signal to Operator B and Operator C that it intends to use resources <NUM>-a. Such signaling may be referred to as an activity indication. Moreover, since Operator A has priority over resources <NUM>-a, Operator A may be considered as a higher priority operator than both Operator B and Operator C. However, as discussed above, Operator A does not have to send signaling to the other network operating entities to ensure interference-free transmission during resources <NUM>-a because the resources <NUM>-a are assigned with priority to Operator A.

Similarly, a network operating entity may signal to another network operating entity that it intends not to use a particular G-INT. This signaling may also be referred to as an activity indication. For example, referring to resources <NUM>-b, Operator B may signal to Operator A and Operator C that it intends not to use the resources <NUM>-b for communication, even though the resources are assigned with priority to Operator B. With reference to resources <NUM>-b, Operator B may be considered a higher priority network operating entity than Operator A and Operator C. In such cases, Operators A and C may attempt to use resources of sub-interval <NUM> on an opportunistic basis. Thus, from the perspective of Operator A, the sub-interval <NUM> that contains resources <NUM>-b may be considered an opportunistic interval (O-INT) for Operator A (e.g., O-INT-OpA). For illustrative purposes, resources <NUM>-a may represent the O-INT for Operator A. Also, from the perspective of Operator C, the same sub-interval <NUM> may represent an O-INT for Operator C with corresponding resources <NUM>-b. Resources <NUM>-a, <NUM>-b, and <NUM>-b all represent the same time resources (e.g., a particular sub-interval <NUM>), but are identified separately to signify that the same resources may be considered as a G-INT for some network operating entities and yet as an O-INT for others.

To utilize resources on an opportunistic basis, Operator A and Operator C may perform medium-sensing procedures to check for communications on a particular channel before transmitting data. For example, if Operator B decides not to use resources <NUM>-b (e.g., G-INT-OpB), then Operator A may use those same resources (e.g., represented by resources <NUM>-a) by first checking the channel for interference (e.g., LBT) and then transmitting data if the channel was determined to be clear. Similarly, if Operator C wanted to access resources on an opportunistic basis during sub-interval <NUM> (e.g., use an O-INT represented by resources <NUM>-b) in response to an indication that Operator B was not going to use its G-INT, Operator C may perform a medium sensing procedure and access the resources if available. In some cases, two operators (e.g., Operator A and Operator C) may attempt to access the same resources, in which case the operators may employ contention-based procedures to avoid interfering communications. The operators may also have sub-priorities assigned to them designed to determine which operator may gain access to resources if more than operator is attempting access simultaneously.

In some examples, a network operating entity may intend not to use a particular G-INT assigned to it, but may not send out an activity indication that conveys the intent not to use the resources. In such cases, for a particular sub-interval <NUM>, lower priority operating entities may be configured to monitor the channel to determine whether a higher priority operating entity is using the resources. If a lower priority operating entity determines through LBT or similar method that a higher priority operating entity is not going to use its G-INT resources, then the lower priority operating entities may attempt to access the resources on an opportunistic basis as described above.

In some examples, access to a G-INT or O-INT may be preceded by a reservation signal (e.g., request-to-send (RTS)/clear-to-send (CTS)), and the contention window (CW) may be randomly chosen between one and the total number of operating entities.

In some examples, an operating entity may employ or be compatible with coordinated multipoint (CoMP) communications. For example an operating entity may employ CoMP and dynamic time division duplex (TDD) in a G-INT and opportunistic CoMP in an O-INT as needed.

In the example illustrated in <FIG>, each sub-interval <NUM> includes a G-INT for one of Operator A, B, or C. However, in some cases, one or more sub-intervals <NUM> may include resources that are neither reserved for exclusive use nor reserved for prioritized use (e.g., unassigned resources). Such unassigned resources may be considered an O-INT for any network operating entity, and may be accessed on an opportunistic basis as described above.

In some examples, each subframe <NUM> may contain <NUM> symbols (e.g., <NUM>-µs for <NUM> tone spacing). These subframes <NUM> may be standalone, self-contained Interval-Cs (ITCs) or the subframes <NUM> may be a part of a long ITC. An ITC may be a self-contained transmission starting with a downlink transmission and ending with a uplink transmission. In some embodiments, an ITC may contain one or more subframes <NUM> operating contiguously upon medium occupation. In some cases, there may be a maximum of eight network operators in an A-INT <NUM> (e.g., with duration of <NUM>) assuming a <NUM>-µs transmission opportunity.

Although three operators are illustrated in <FIG>, it should be understood that fewer or more network operating entities may be configured to operate in a coordinated manner as described above. In some cases, the location of the G-INT, O-INT, or A-INT within superframe <NUM> for each operator is determined autonomously based on the number of network operating entities active in a system. For example, if there is only one network operating entity, each sub-interval <NUM> may be occupied by a G-INT for that single network operating entity, or the sub-intervals <NUM> may alternate between G-INTs for that network operating entity and O-INTs to allow other network operating entities to enter. If there are two network operating entities, the sub-intervals <NUM> may alternate between G-INTs for the first network operating entity and G-INTs for the second network operating entity. If there are three network operating entities, the G-INT and O-INTs for each network operating entity may be designed as illustrated in <FIG>. If there are four network operating entities, the first four sub-intervals <NUM> may include consecutive G-INTs for the four network operating entities and the remaining two sub-intervals <NUM> may contain O-INTs. Similarly, if there are five network operating entities, the first five sub-intervals <NUM> may contain consecutive G-INTs for the five network operating entities and the remaining sub-interval <NUM> may contain an O-INT. If there are six network operating entities, all six sub-intervals <NUM> may include consecutive G-INTs for each network operating entity. It should be understood that these examples are for illustrative purposes only and that other autonomously determined interval allocations may be used.

It should be understood that the coordination framework described with reference to <FIG> is for illustration purposes only. For example, the duration of superframe <NUM> may be more or less than <NUM>. Also, the number, duration, and location of sub-intervals <NUM> and subframes <NUM> may differ from the configuration illustrated. Also, the types of resource designations (e.g., exclusive, prioritized, unassigned) may differ or include more or less subdesignations.

NR supports Type II category <NUM> CSI feedback reporting for ranks <NUM> and <NUM>. Precoding matrix indicators (PMIs) are used for spatial channel information feedback. The PMI codebook assumes the following precoder structure:
For rank <NUM>: <MAT>, W is normalized to <NUM>
For rank <NUM>: <MAT>, columns of W are normalized to <MAT><MAT> (weighted combination of L beams). The value of L is configurable: L ∈ {<NUM>,<NUM>,<NUM>}, bk1,k2 corresponds to an oversampled 2D DFT beam, r = <NUM>,<NUM> corresponds to the polarization of the beam, l = <NUM>,<NUM> corresponds to the layer, <MAT> corresponds to the wideband (WB) beam amplitude or power scaling factor for beam i and on polarization r and layer l, <MAT> corresponds to the subband (SB) beam amplitude or power scaling factor for beam i and on polarization r and layer l, cr,l,i corresponds to the beam combining coefficient or phase for beam i and on polarization r and layer l. The precoder may be configurable between QPSK (<NUM> bits) and 8PSK (<NUM> bits), and the amplitude scaling mode may be configurable between WB and SB (with unequal bit allocation) and WB-only.

Beam selection generally is performed for wideband only, in which the unconstrained beam selection is made from orthogonal basis: <MAT> <MAT> where q<NUM> = <NUM>,. ,O<NUM> - <NUM>, q<NUM> = <NUM>,. ,O<NUM> - <NUM> correspond to rotation factors; and <MAT> correspond to orthogonal beam indices. The following values of (N<NUM>,N<NUM>) and (O<NUM>,O<NUM>) in Table <NUM> may be supported:.

Amplitude scaling may be independently selected for each beam, polarization, and layer. A UE may be configured to report wideband amplitude with or without subband amplitude. For example, with wideband <MAT> and subband <MAT>, <MAT>and <MAT> are possible. With a wideband <MAT> only configuration, <MAT> is possible. The wideband amplitude value set (<NUM> bits) may include <MAT> <MAT>. The PMI payload can vary depending on whether an amplitude is zero or not, while the subband amplitude value set (<NUM> bit) may include <MAT>.

Phase for combining coefficients may also be independently selected for each beam, polarization, and layer. In a subband only configuration, the phase value set may either include <MAT> (<NUM> bits) or <MAT> (<NUM> bits).

The wideband amplitude, subband amplitude, and subband phase components for each of the beam, polarization, and layer values may then be quantized and reported in (X,Y,Z) bits. For each layer, for the leading (strongest) coefficient out of <NUM>L coefficients, (X, Y, Z) = (<NUM>,<NUM>,<NUM>). The leading (strongest) coefficient = <NUM>.

For wideband and subband amplitude configurations, (X, Y)=(<NUM>,<NUM>) and Z∈(<NUM>,<NUM>} for the first (K-<NUM>) leading (strongest) coefficients out of (<NUM>-<NUM>) coefficients, and (X,Y,Z) = (<NUM>,<NUM>,<NUM>) for the remaining (<NUM>-K) coefficients. For L=<NUM>, <NUM>, and <NUM>, the corresponding value of K may be <NUM> (=<NUM>), <NUM>, and <NUM>, respectively. The following coefficient index information may reported in a wideband-only configuration. The index of strongest coefficient out of <NUM> coefficients (per layer). The (K-<NUM>) leading coefficients are determined implicitly from reported (<NUM>-<NUM>) wideband amplitude coefficients per layer without additional signaling. For wideband-only amplitude, i.e. Y=<NUM>. (X, Y)= (<NUM>, <NUM>) and Z∈{<NUM>,<NUM>}. The index of the strongest coefficient out of <NUM> coefficients is reported per layer in a wideband manner.

For NR networks, seven feedback components may be included for CSI reporting. Fewer or greater numbers of feedback components are also possible based on the particular codebook configurations. One example collection of such CSI feedback components are: (<NUM>) the rank indicator; (<NUM>) an indication of beam selection (PMIb), wideband only, and inclusive of PMIb,<NUM> to PMIb,L-<NUM> for L beams, where L may be preconfigured, and an indication of a rotation factor selection (PMIq); (<NUM>) a dominant beam index (PMId), for each layer, inclusive of PMId,l; (<NUM>) an indication of wideband amplitude (PMIp,wb), for each layer and polarization, inclusive of PMIp,wb,r,l,b (where r is polarization and l is layer); (<NUM>) an indication of subband amplitude (PMIp,sb), for each layer and polarization, inclusive of PMIp,sb,r,l,b; (<NUM>) an indication of subband phase (PMIc), for each layer and polarization, inclusive of PMIc,r,l,b; and (<NUM>) the channel quality indicator (CQI), wideband or subband, where a single codeword is assumed for use in the CSI feedback. As noted, in some codebook configurations, PMIp,sb may not be a part of the CSI feedback components. Aspects of the present disclosure are directed to providing overhead reduction schemes.

<FIG> is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to UE <NUM> as illustrated in <FIG> is a block diagram illustrating UE <NUM> configured according to one aspect of the present disclosure. UE <NUM> includes the structure, hardware, and components as illustrated for UE <NUM> of <FIG>. For example, UE <NUM> includes controller/processor <NUM>, which operates to execute logic or computer instructions stored in memory <NUM>, as well as controlling the components of UE <NUM> that provide the features and functionality of UE <NUM>. UE <NUM>, under control of controller/processor <NUM>, transmits and receives signals via wireless radios 800a-r and antennas 252a-r. Wireless radios 800a-r includes various components and hardware, as illustrated in <FIG> for eNB <NUM>, including modulator/demodulators 254a-r, MIMO detector <NUM>, receive processor <NUM>, transmit processor <NUM>, and TX MIMO processor <NUM>.

At block <NUM>, a UE determines a plurality of CSI feedback components. For example, the UE, such as UE <NUM>, may determine the number of CSI feedback components that would be defined based on the codebook configuration. Accordingly, UE <NUM>, under control of controller/processor <NUM> would execute measurement logic <NUM>, stored in memory <NUM>. The execution environment of measurement logic <NUM> allows UE <NUM> to measure the channel environment around UE <NUM>. The various CSI feedback components may then be determined by accessing PMI codebook <NUM>, in memory <NUM>, using the knowledge of the channel environment. In one example implementation, the seven CSI feedback components addressed above may include RI, PMIb, PMId, PMIp,wb, PMIp,sb, PMIc, and CQI, each of which, where applicable, is determined independently for each beam, polarization, and layer. At block <NUM>, the UE identifies a set of discarded CSI feedback components based on a component value of a particular PMI feedback component. For example, UE <NUM>, under control of controller/processor <NUM>, executes discarded payload logic <NUM>, stored in memory <NUM>. The execution environment of discarded payload logic <NUM> allows UE <NUM> to identify ones of the determined CSI feedback components that will be considered discarded components based on the value of certain PMI feedback components. For instance, a value of one of the PMI feedback components, such as either PMIb or PMIp,wb may be used by UE <NUM> to determine which of the other CSI feedback components may be considered a discarded component. Thus, depending on which beam has been indicated by PMIb, UE <NUM> may determine which of the other PMI feedback components would be unnecessary for reporting. Similarly, by determine what the wideband amplitude value is of PMIp,wb, UE <NUM> may also determine the other corresponding PMI feedback components that would be unnecessary to report. The particular PMI feedback component that will be used to identify the discarded component may be predetermined at UE <NUM>, either through signaling, such as higher or lower layer signaling, or preconfigured UE settings. The various aspects for determining such discarded components will be discussed further below.

At block <NUM>, the UE generates an adjusted CSI report, wherein the adjusted CSI report includes the plurality of CSI feedback components adjusted according to the set of discarded CSI feedback components. After determining which of the CSI feedback components may be discarded as not necessary for reporting, UE <NUM> executes CSI report generator <NUM>, in memory <NUM>, and generates the adjusted CSI report to accommodate for the discarded components. For example, as discussed further below, UE <NUM> may completely drop the discarded components from the CSI feedback report, or it may assign a fixed value associated with the discarded components. At block <NUM>, the UE transmits the adjusted CSI report to the serving base station. For example, UE <NUM> would transmit the resulting adjusted CSI report via wireless radios 800a-r and antennas 252a-r.

<FIG> is a block diagram illustrating a UE 115a configured according to one aspect of the present disclosure. UE 115a would determine each of the CSI feedback components including precoder related components <NUM>, which are used for determining the precoder (e.g., RI <NUM>, PMIb <NUM>, PMId <NUM>, PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM>, and CQI <NUM>). Various aspects of the present disclosure are directed to providing schemes for overhead reduction in such CSI reporting. For example, in a first optional aspect, the discarded components may be implicitly indicated through the beam indication of PMIb <NUM>. For example, if PMIb,n = PMIb,<NUM>,(<NUM><=n<L) then the associated feedback component of PMIp,wb,r,l,b>=n ,PMIp,sb, r,l,b>=n ,PMIc,r,l,b>=n may be regarded as "discarded payload" or discarded components. The effect is equivalent to falling back to L=n beams for the linear combination codebook. In a variation of this first option, if n= <NUM>, then the UE would fall back to a Type I CSI feedback, in which all of the other PMI components of PMId <NUM>, PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM>, would be regarded as discarded components, and the PMI of the corresponding Type I codebook would, instead, be fed back to base station 105a.

In a second optional aspect, the discarded components may be implicitly indicated through the wideband amplitude PMIp,wb <NUM> For example, when PMIp,wb,r,l,n = <NUM>, then the associated feedback component of PMIp,sb,r,l,n ,PMIc,r,l,n may be regarded as discarded components. A third optional aspect may include jointly utilizing the first and second alternative options.

The different alternative schemes for overhead reduction may be triggered in various ways. For example, UE 115a may be triggered for overhead reduction through a predefined (e.g., always enabled) mechanism, or through signaling from base station 105a for enabling/disabling the various optional schemes via higher-layer configuration signaling, semi-static configuration signaling, or dynamic configuration signaling. Thus, both of the first and second alternative options can be enabled/disabled by signaling from base station 105a. For example, selection based on PMIb <NUM> may be enabled/disabled by semi-static configuration signaling from base station 105a, while the selection based on PMIp,wb <NUM> may always enabled.

The feedback components that are identified as discarded payload may be handled in different ways. In a first optional aspect, UE 115a may elect not to transmit any of the discarded components, thus, reducing the overall payload size. For example, if, based on PMIb <NUM>, UE 115a identifies the polarization, beam, and layer components for PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM> as being discarded components, the generation of adjusted CSI report <NUM> would not include these components, in which the overall payload size of adjusted CSI report <NUM> would resultantly be reduced.

In a second optional aspect, UE 115a may transmit adjusted CSI report <NUM> with a fixed payload. The fixed payload may, for example, consist of all '<NUM>'s or another predefined pattern when the components are identified as discarded components. For example, if, based on PMIp,wb <NUM>, UE 115a identifies the polarization, beam, and layer components for PMIp,sb <NUM>, and PMIc <NUM> as being discarded components, the generation of adjusted CSI report <NUM> would include the fixed payload associated with the discarded components, in which the overall payload size of adjusted CSI report <NUM> would remain the same. The consistent payload size would also make further joint encoding possible.

<FIG> is a block diagram illustrating a UE 115a configured according to one aspect of the present disclosure. In additional aspects of the present disclosure, certain CSI feedback components of CSI feedback may be dependent on correct decoding of other CSI feedback components. Dependency in the context of CSI feedback means that the component is effective only when the other component depended upon is decoded correctly. Dependency arrows <NUM> identify which of the precoder related components <NUM> have such dependency on other CSI feedback components. For example, effective PMId <NUM> may depend on the correct decoding of the rank indicator, RI <NUM>. Effective PMIp,wb <NUM> may depend on the correct decoding of RI <NUM> and PMIb <NUM> (where the overhead reduction scheme selection is based on PMIb <NUM>). Effective PMIp,sb <NUM> and PMIc <NUM> may depend on the correct decoding of PMId <NUM> and PMIp,wb <NUM> (where the overhead reduction scheme selection is based on PMIp,wb <NUM>). Additionally, effective CQI <NUM> may depend on constructed precoder related components <NUM> (which includes RI <NUM> and all of the PMI components, PMIb <NUM>, PMId <NUM>, PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM>.

<FIG> are block diagrams illustrating a UE 115a configured according to aspects of the present disclosure. Additional aspects of the present disclosure provide for joint coding of the CSI feedback components. The relationship between the joint coding and treatment of discarded bits may be defined such that when the payload bits can be determined based on previous decoded components, then the reduced payload option may be applied. However, when the payload bits cannot be determined based on the previous decoded components (such as when the widebank amplitude-based selection option is enabled and PMIp,wb <NUM> and PMIp,sb <NUM> are encoded in one packet, where the size of PMIp,sb <NUM> has dependency with PMIp,wb <NUM>), then the fixed payload option may be used. The various joint coding schemes available in the aspects of the present disclosure may be selected dependent on whether the reduced payload option or fixed payload option is used for the overhead savings.

Joint coding schemes for CSI feedback may provide single packet (<FIG>), two packet (<FIG>), or three packet transmissions (<FIG>). In the first joint coding option of <FIG>, a single packet <NUM> may be encoded in adjusted CSI report <NUM> for CSI feedback. In such aspects, all of CSI feedback components (e.g., RI <NUM>, PMIb <NUM>, PMId <NUM>, PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM>, and CQI <NUM>) would be encoded in single packet <NUM>. The fixed payload option may be used when either the beam selection-based or wideband amplitude-based selection options for discarded components is enabled.

In the second joint coding option of <FIG>, two packet encoding (packet <NUM> and packet <NUM>) in adjusted CSI report <NUM> may include two different sub-options. Various aspects of this two-packet encoding implementation may provide for any variety of pairings of CSI feedback components between packet <NUM> and packet <NUM>. In one example of a first sub-option, RI <NUM> and PMIb <NUM> may be encoded in packet <NUM>, while PMId <NUM>, PMIp,wb <NUM>, PMIp,sb <NUM>, and PMIc <NUM> may be encoded in packet <NUM>. If the wideband amplitude-based selection option is enabled, then the fixed payload option may be used for packet <NUM>. However, if the beam indication-based selection option is enabled and the wideband amplitude-based selection option is disabled, the reduced payload option may be used for packet <NUM>.

In one example of a second sub-option of the second joint coding option of <FIG>, RI <NUM>, PMIb <NUM>, PMId <NUM>, and PMIp,wb <NUM> may be encoded in packet <NUM>, while PMIp,sb <NUM> and PMIc <NUM> may be encoded in packet <NUM>. If the beam indication-based selection option is enabled, the reduced payload option may be used for packet <NUM> (PMIp,wb <NUM> depends on PMIb <NUM>). Whenever either the beam indication-based selection option or the wideband amplitude-based selection option are enabled, the reduced payload option may be used for packet <NUM>.

In a third joint coding option of <FIG>, three packet encoding provides for encoding of the CSI feedback components into three packets (packet <NUM>, packet <NUM>, and packet <NUM>) in adjusted CSI report <NUM>. In one example implementation RI <NUM> and PMIb <NUM> are encoded into packet <NUM>, PMId <NUM>, PMIp,wb <NUM> are encoded into packet <NUM>, and PMIp,sb <NUM> and PMIc <NUM> are encoded into packet <NUM> UE 115a may use the reduced payload option for encoding packets <NUM> and <NUM>, when either of the beam indication-based selection option or wideband amplitude-based selection option are enabled.

In another example implementation illustrated through <FIG>, the pairings of CSI feedback components may include RI <NUM> encoded by itself into packet <NUM>, PMIb <NUM>, PMId <NUM>, and PMIp,wb <NUM> encoded into packet <NUM>, and PMIp,sb <NUM> and PMIc <NUM> encoded into packet <NUM>. In such implementation, the fixed payload option for encoding packets <NUM> and <NUM>, when either of the beam indication-based selection option or wideband amplitude-based selection option are enabled, with the reduced payload option being available for encoding packet <NUM> may be used.

It should be noted that with regard to the different example pairings described for the joint coding options of <FIG>, each packet of the different options may include different CSI feedback components for the joint encoding. The aspects of the present disclosure are not limited only to the described example pairings.

In additional aspects, when a CSI-RS resource indicator (CRI) is to be jointly encoded into CSI feedback of adjusted CSI report <NUM>, it may be placed in first packet (e.g., single packet <NUM>, packet <NUM>, or packet <NUM>, respectively). When CQI <NUM> is to be jointly encoded in CSI feedback of adjusted CSI report <NUM>, it may either be carried in the first packet (e.g., single packet <NUM>, packet <NUM>, or packet <NUM>, respectively), or in the last packet (e.g., packet <NUM> or packet <NUM>, respectively.

The functional blocks and modules in <FIG> may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.

Claim 1:
A method of wireless communication for precoding matrix indicator, PMI, feedback for 3GPP New Radio, NR, type II channel state information, CSI, feedback, the method comprising:
determining (<NUM>), by a user equipment, UE (<NUM>), a plurality of channel state information, CSI, feedback components;
identifying (<NUM>), by the UE (<NUM>), a set of discarded CSI feedback components of the plurality of CSI feedback components based on a component value of a precoding matrix indicator, PMI, component of the plurality of CSI feedback components, wherein the PMI component includes one of:
a beam indication precoding matrix indicator, PMIb, (<NUM>);
a wideband amplitude precoding matrix indicator, PMIp,wb, (<NUM>);
a combination thereof; and
generating (<NUM>), by the UE (<NUM>), an adjusted CSI report, wherein the adjusted CSI report includes the plurality of CSI feedback components adjusted according to the set of discarded CSI feedback components, and
wherein the generating (<NUM>) the adjusted CSI report includes:
generating a set of adjusted CSI components, wherein the set of adjusted CSI components includes the plurality of CSI feedback components in which the set of discarded CSI feedback components are replaced with a fixed component value associated with the set of discarded CSI feedback components; and
transmitting (<NUM>), by the UE (<NUM>), the adjusted CSI report to a serving base station (<NUM>).