Uplink Multi-Input Multi-Output Codebook for Advanced Wireless Communication Systems

Abstract

The present disclosure relates to a communication method and system for fusing a fifth-generation (5G) communication system by using Internet of Things (IoT) technology to support higher data rates beyond a fourth-generation (4G) system. The present disclosure provides a UE, which includes: a transceiver; and a processor, coupled to the transceiver and configured to: send a message including the UE's coherence capability, an indication for TPMI, and the number of layers to a BS; receive an RRC message including a UL codebook subset and a UL maximum rank from the BS, where the UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for the maximum number of layers; receive a DCI including an indication for TPMI and the number of layers from the BS; and send UL data to the BS via a PUSCH based on the indication for TPMI and the number of layers, where when the number of layers = 1, a precoder for UL transmission using four antenna ports for the UE is determined based on the TPMI index in the indication for TPMI, the number of layers, and the UL codebook subset.

Description

[0001] This application is a divisional application of the invention patent application with an international filing date of December 22, 2017, a Chinese application number of 201780079543.9, and an invention title of "Uplink Multiple-Input Multiple-Output Codebook for Advanced Wireless Communication". Technical Field

[0002] This application generally relates to wireless communication systems. More specifically, the present disclosure relates to a codebook for uplink (UL) multiple-input multiple-output (MIMO) communication in advanced wireless communication systems. Background Art

[0003] In order to meet the demands for increased wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Thus, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems". The 5G communication system is considered to be implemented in a higher frequency (mmWave) band (e.g., 60 GHz band) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies have been discussed in 5G communication systems. In addition, in 5G communication systems, system network improvements are being developed based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), receiver interference cancellation, etc. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM) and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0004] The Internet is a human - centered network for generating and consuming information, and is now evolving towards the Internet of Things (IoT), in which distributed entities such as IoT exchange and process information without human intervention. Through connection with cloud servers, the Internet of Everything (IoE) combining IoT technology and big - data processing technology has emerged. Recently, technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology", which are required for IoT implementation, for example, sensor networks, machine - to - machine (M2M) communication, and machine - type communication (MTC), have been studied. Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. Through the integration and combination of existing information technology (IT) and various industrial applications, IoT can be applied to multiple fields such as smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart appliances, and advanced medical services.

[0005] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine - type communication (MTC), and machine - to - machine (M2M) communication can be implemented through beamforming, MIMO, and array antennas. Cloud radio access network (RAN), as an application of the above - mentioned big - data processing technology, can also be considered an example of the convergence between 5G technology and IoT technology.

[0006] The fifth generation (5G) mobile communication, initially expected to be commercialized around 2020, has recently gathered momentum, increasing global technical activities with various candidate technologies from industry and academia. Candidate enablers for 5G mobile communication include massive antenna technologies from traditional cellular bands to high frequencies to provide beamforming gain and support increased capacity, new waveforms (e.g., new radio access technologies (RATs)) to flexibly accommodate various services / applications with different requirements, new multiple access schemes to support massive connectivity, etc. The International Telecommunication Union (ITU) has classified the usage scenarios for International Mobile Telecommunications (IMT) in 2020 and beyond into 3 main groups, such as enhanced mobile broadband, massive machine type communication (MTC), and ultra-reliable and low-latency communication. In addition, the ITC has also specified target requirements, such as a peak data rate of 20 gigabits per second (Gb / s), a user experience data rate of 100 megabits per second (Mb / s), a 3-fold increase in spectral efficiency, support for mobility up to 500 kilometers per hour (km / h), a latency of 1 millisecond (ms), a connection density of 106 devices / km2, a 100X improvement in network energy efficiency, and an area communication capacity of 10 Mb / s / m2. Although it is not required to meet the requirements simultaneously, the design of 5G networks can provide flexibility to support various applications that meet some of the above requirements based on usage scenarios. Summary of the Invention

[0007] There is a need for a method to support higher data rates beyond fourth generation (4G) communication systems such as Long Term Evolution (LTE).

[0008] This disclosure relates to a fifth generation (5G) or 5G communication system that provides for supporting higher data rates beyond fourth generation (4G) communication systems such as Long Term Evolution (LTE). Embodiments of this disclosure provide a UL MIMO codebook for an advanced wireless communication system.

[0009] In one embodiment, a user equipment (UE) is provided. The UE includes a processor and a transceiver operatively connected to the processor. The transceiver is configured to send a message reporting the coherence capability of the UE for an indication of a transmit precoding matrix indicator (TPMI) and the number of layers to a base station (BS); the transceiver is configured to receive an indication of the TPMI and the number of layers from the BS via downlink control information (DCI) signaling; and the transceiver is configured to send uplink (UL) data to the BS via a physical uplink shared channel (PUSCH) based on the received TPMI indication and the number of layers. Wherein, the number of bits in the DCI signaling for the indication of the TPMI and the number of layers is determined by a coherence state that depends on the coherence capability reported by the UE.

[0010] In another embodiment, a BS is provided. The BS includes a processor and a transceiver operatively connected to the processor. The transceiver is configured to:

[0011] receive, from a user equipment (UE), a message reporting the UE's coherence capability, for indicating a precoding matrix indicator (TPMI) and the number of layers; the transceiver is configured to send, to the UE, an indication of the TPMI and the number of layers via downlink control information (DCI) signaling; and the transceiver is configured to receive uplink (UL) data from the UE via a physical uplink shared channel (PUSCH) based on the sent indication of the TPMI and the number of layers. Wherein, the number of bits in the DCI signaling for the indication of the TPMI and the number of layers is determined by a coherence state, which depends on the coherence capability reported by the UE.

[0012] In another embodiment, a method for operating a UE is provided. The method includes sending, to a base station (BS), a message reporting the UE's coherence capability, for indicating a precoding matrix indicator (TPMI) and the number of layers; the method includes receiving, from the BS, an indication of the TPMI and the number of layers via downlink control information (DCI) signaling; and the method includes sending uplink (UL) data to the BS via a physical uplink shared channel (PUSCH) based on the received indication of the TPMI and the number of layers. Wherein, the number of bits in the DCI signaling for the indication of the TPMI and the number of layers is determined by a coherence state, which depends on the coherence capability reported by the UE.

[0013] In another embodiment, a UE is provided, which includes: a transceiver; and a processor, coupled to the transceiver and configured to: send, to the BS, a message including the UE's coherence capability, for the indication of the TPMI and the number of layers; receive, from the BS, an RRC message including a UL codebook subset and a UL maximum rank, wherein the UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for the maximum number of layers, receive, from the BS, DCI including an indication of the TPMI and the number of layers; and send UL data to the BS via the PUSCH based on the indication of the TPMI and the number of layers, wherein, when the number of layers = 1, a precoder for UL transmission using four antenna ports for the UE is determined based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, according to the following:

[0014]

[0015] In another embodiment, a base station (BS) is provided. The BS includes a transceiver; and a processor coupled to the transceiver and configured to: receive a message including the UE's coherence capability from a user equipment (UE) for indicating a precoding matrix indicator (TPMI) and the number of layers; send a radio resource control (RRC) message including an uplink (UL) codebook subset and UL maximum rank to the UE based on the UE's coherence capability, where the UL codebook subset indicates one of three coherence states and the UL maximum rank indicates a value for the maximum number of layers, send downlink control information (DCI) including an indication of the TPMI and the number of layers to the UE; and receive UL data from the UE via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, where when the number of layers = 1, a precoder for UL transmission of the UE using four antenna ports is determined based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset according to the following:

[0016]

[0017] In another embodiment, a method performed by a user equipment (UE) is provided. The method includes: sending a message including the UE's coherence capability to a base station (BS) for indicating a precoding matrix indicator (TPMI) and the number of layers; receiving a radio resource control (RRC) message including an uplink (UL) codebook subset and UL maximum rank from the BS, where the UL codebook subset indicates one of three coherence states and the UL maximum rank indicates a value for the maximum number of layers, receiving downlink control information (DCI) including an indication of the TPMI and the number of layers from the BS; and sending UL data to the BS via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, where when the number of layers = 1, a precoder for UL transmission of the UE using four antenna ports is determined based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset according to the following:

[0018]

[0019] In another embodiment, a method performed by a base station (BS) is provided. The method includes: receiving, from a user equipment (UE), a message including the UE's coherence capability, for an indication of a transmit precoding matrix indicator (TPMI) and number of layers; sending, based on the UE's coherence capability, a radio resource control (RRC) message to the UE, the RRC message including an uplink (UL) codebook subset and UL maximum rank, where the UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for a maximum number of layers, sending, to the UE, a downlink control information (DCI) including an indication of the TPMI and number of layers; and receiving, based on the indication of the TPMI and number of layers, UL data from the UE via a physical uplink shared channel (PUSCH), where, when the number of layers = 1, based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, a precoder for UL transmission using four antenna ports for the UE is determined according to the following:

[0020]

[0021] Other technical features can be readily understood by those skilled in the art from the following drawings, description, and claims.

[0022] Before the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used in this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with each other. The terms "transmit," "receive," and "communicate," and their derivatives, include both direct and indirect communication. The terms "include" and "comprise," and their derivatives, mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with," and its derivatives, means including, included within, interconnected with, containing, having, connected or coupled with, coupled or communicating with, cooperating, interlacing, juxtaposed, proximate, bound or having an affinity for, having, owning, having a relationship to, and so forth. The term "controller" represents any device, system, or part thereof that controls at least one operation. Such a controller can be implemented in hardware, or a combination of hardware and software, and / or firmware. The functions associated with any particular controller may be centralized or distributed, whether locally or remotely. When used with a list of items, the phrase "at least one" means that different combinations of one or more of the listed items may be used, and only one item in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0023] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed of computer-readable program code and contained in a computer-readable medium. The terms "application program" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, related data, or portions thereof that are adapted to be implemented in a suitable computer-readable program. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium excludes wired, wireless, optical, or other communication links that transmit transitory electrical signals or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and then be rewritten, such as rewritable optical discs or erasable memory devices.

[0024] Certain other words and phrases are defined in this patent document. One of ordinary skill in the art should understand that, in many if not most instances, such definitions apply to the prior and future use of such defined words and phrases.

[0025] This disclosure relates to providing a fifth generation (5G) or 5G communication system for supporting higher data rates beyond fourth generation (4G) communication systems such as Long Term Evolution (LTE). Embodiments of this disclosure provide UL MIMO codebooks for advanced wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more fully understand this disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

[0027] Figure 1 An exemplary wireless network in accordance with an embodiment of this disclosure is shown;

[0028] Figure 2 An example eNB in accordance with an embodiment of this disclosure is shown;

[0029] Figure 3 An example UE in accordance with an embodiment of this disclosure is shown;

[0030] Figure 4A An example high-level diagram of an orthogonal frequency division multiple access transmission path in accordance with an embodiment of this disclosure is shown;

[0031] Figure 4BShows an example high-level diagram of an orthogonal frequency division multiple access (OFDMA) receive path according to an embodiment of the present disclosure.

[0032] Figure 5 Shows an example network slice according to an embodiment of the present disclosure;

[0033] Figure 6 Shows an example number of digital chains according to an embodiment of the present disclosure;

[0034] Figure 7 Shows an example of multiplexing two slices according to an embodiment of the present disclosure;

[0035] Figure 8 Shows an example antenna port layout at a user equipment (UE) according to an embodiment of the present disclosure;

[0036] Figure 9 Shows an exemplary uplink codebook structure according to an embodiment of the present disclosure; and

[0037] Figure 10 Shows a flowchart of a method for uplink multiple-input multiple-output (MIMO) codebook operation according to an embodiment of the present disclosure. Detailed Description

[0038] The following discussion Figures 1 to 10 and the various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0039] The following documents are incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS

[0040] 36.211 v14.4.0, "E-UTRA, Physical Channels and Modulation (REF 1)"; 3GPP TS 36.212 v14.4.0, "E-UTRA, Multiplexing and Channel Coding; (REF 2)"; 3GPP TS 36.213 v14.4.0, "E-UTRA, Physical Layer Procedures (REF 3)"; 3GPP TS 36.321 v14.4.0, "E-UTRA, Medium Access Control (MAC) Protocol Specification (REF 4)"; 3GPP TS 36.331 v14.4.0, "Radio Resource Control (RRC) Protocol Specification (REF 5)"; and 3GPP TR 22.891 v1.2.0, "Technical Specification Group Services and System Aspects; Feasibility Study on New Services and Technologies for Markets, Enablers, Phase 1, (Release 14)"; 3GPP RAN 1 Meeting #89, "Chair's Notes;"; and 3GPP TS 38.214 v1.1.0, "NR, Physical Layer Procedures for Data". To meet the demands of increased wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0041] The 5G communication system is considered to be implemented in a higher frequency (mmWave) band (e.g., 60 GHz band) in order to achieve higher data rates. To reduce the propagation loss of radio waves and increase the transmission coverage, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antenna technology, etc. are discussed in the 5G communication system.

[0042] In addition, in the 5G communication system, system network improvement development is being carried out based on advanced small cells, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul communication, mobile network, cooperative communication, coordinated multi-point (CoMP) transmission and reception, interference mitigation and cancellation, etc.

[0043] In the 5G system, hybrid frequency shift keying and quadrature amplitude modulation (FQAM) and sliding window superimposed coding (SWSC) have been developed as adaptive modulation and coding (AMC) technologies, as well as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies.

[0044] The following Figures 1 - 4B describes various embodiments implemented in a wireless communication system and uses orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication technologies. Figures 1 - 3The description does not imply any physical or structural limitations on the ways in which different embodiments can be implemented. The different embodiments of the present disclosure can be implemented in any suitably arranged communication system.

[0045] Figure 1 An exemplary wireless network according to an embodiment of the present disclosure is shown. Figure 1 The embodiment of the wireless network shown is for illustrative purposes only. Other embodiments of the wireless network 100 can be used without departing from the scope of the present disclosure.

[0046] As Figure 1 shown, the wireless network includes eNBs 101, 102, and 103. eNB 101 communicates with eNBs 102 and 103. eNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data networks.

[0047] eNB 102 provides wireless broadband access to network 130 for a first plurality of user equipments (UEs) within the coverage area 120 of eNB 102. The first plurality of UEs includes: UE 111, which can be located in a sub-band (SB); UE 112, which can be located in an enterprise (E); UE 113, which can be located in a WiFi hotspot (HS); UE 114, which can be located in a first residence (R); UE 115, which can be located in a second residence (R); and UE 116, which can be a mobile device (M), such as a mobile phone, a wireless laptop, a wireless PDA, etc. eNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within the coverage area 125 of eNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of eNBs 101 - 103 can communicate with each other and with UEs 111 - 116 using 5G, LTE, LTE-A, WiMAX, WiFi, or other wireless communication technologies.

[0048] Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as a transmission point (TP), a transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a Wi-Fi access point (AP), or other wireless-enabled devices. The base station can provide wireless access according to one or more wireless communication protocols, e.g., 5G 3GPP New Radio Interface / Access (NR), Long Term Evolution (LTE), LTE Advanced (LTE-A), High-Speed Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For convenience, in this patent document, the terms "BS" and "TRP" may be used interchangeably to refer to the network infrastructure components that provide wireless access to remote terminals. Additionally, depending on the network type, the term "user equipment" or "UE" can refer to any component such as a "mobile station", "subscriber station", "remote terminal", "wireless terminal", "reception point", or "user equipment". For convenience, in this patent document, the terms "user equipment" and "UE" are used to refer to the remote wireless devices that wirelessly access the BS, whether the UE is a mobile device (e.g., a mobile phone or a smart phone) or is generally considered a fixed device (e.g., a desktop computer or a vending machine).

[0049] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with an eNB, such as coverage areas 120 and 125, can have other shapes, including irregular shapes, depending on the configuration of the eNB and the variations in the radio environment associated with natural and man-made obstacles.

[0050] As described in more detail below, one or more of UEs 111 - 116 include circuitry, programming, or a combination thereof for an uplink MIMO codebook in an advanced wireless communication system. In certain embodiments, one or more of eNBs 101 - 103 include circuitry, programming, or a combination thereof for an uplink MIMO codebook in an advanced wireless communication system.

[0051] Although Figure 1 an example of a wireless network is shown, it is possible to Figure 1Make various changes. For example, a wireless network can include any number of eNBs and any number of UEs in any suitable arrangement. Moreover, eNB 101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each of eNBs 102 - 103 can communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. In addition, eNBs 101, 102, and / or 103 can provide access to other or additional external networks, such as an external telephone network or other types of data networks.

[0052] Figure 2 An example eNB 102 according to an embodiment of the present disclosure is shown. Figure 2 The embodiment of eNB 102 shown in is for illustration only, and Figure 1 eNBs 101 and 103 can have the same or similar configurations. However, eNBs have a wide variety of configurations, and Figure 2 do not limit the scope of the present disclosure to any particular implementation of eNBs.

[0053] As Figure 2 shown, eNB 102 includes a plurality of antennas 205a - 205n, a plurality of RF transceivers 210a - 210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. eNB 102 also includes a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0054] RF transceivers 210a - 210n receive input RF signals, such as signals transmitted by UEs in network 100, from antennas 205a - 205n. RF transceivers 210a - 210n down-convert the input RF signal to generate an IF or baseband signal. The IF or baseband signal is sent to RX processing circuitry 220, which produces a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 220 sends the processed baseband signal to controller / processor 225 for further processing.

[0055] TX processing circuitry 215 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from controller / processor 225. TX processing circuitry 215 encodes, multiplexes, and / or digitizes the output baseband data to produce a processed baseband or IF signal. RF transceivers 210a - 210n receive the output processed baseband or IF signal from TX processing circuitry 215 and up-convert the baseband or IF signal to an RF signal transmitted via antennas 205a - 205n.

[0056] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the eNB 102. For example, the controller / processor 225 may control the reception of forward channel signals and the transmission of reverse channel signals via the RF transceivers 210a - 210n, the RX processing circuitry 220, and the TX processing circuitry 215 according to well-known principles. The controller / processor 225 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 225 may support beamforming or directional routing operations, where the output signals from the multiple antennas 205a - 205n are weighted differently to effectively steer the output signals in a desired direction. The controller / processor 225 may support any of a large variety of other functions within the eNB 102.

[0057] The controller / processor 225 is also capable of executing programs and other processes residing in the memory 230, such as the OS. The controller / processor 225 may move data into or out of the memory 230 as needed for the execution process.

[0058] The controller / processor 225 is also coupled to the backhaul or network interface 235. The backhaul or network interface 235 allows the eNB 102 to communicate with other devices or systems via a backhaul connection or via a network. The backhaul or network interface 235 may support communication via any suitable wired or wireless connection. For example, when the eNB 102 is implemented as part of a cellular communication system (such as one supporting 5G, LTE, or LTE-A), the interface 235 may allow the eNB 102 to communicate with other eNBs via a wired or wireless backhaul connection. When the eNB 102 is implemented as an access point, the interface 235 may allow the eNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. The interface 235 includes any suitable structure that supports communication via a wired or wireless connection, such as Ethernet or an RF transceiver.

[0059] The memory 230 is coupled to the controller / processor 225. A portion of the memory 230 may include RAM, and another portion of the memory 230 may include flash memory or other ROM.

[0060] Although Figure 2 an example of the eNB 102 is shown, various changes may be made to Figure 2 it. For example, the eNB 102 may include Figure 2 any number of each component shown in Figure 2The various components in can be combined, further subdivided, or omitted, and additional components can be added according to specific needs.

[0061] Figure 3 FIG. 4 shows an example UE 116 according to an embodiment of the present disclosure. Figure 3 The embodiment of the UE 116 shown in is for illustrative purposes only, and Figure 1 the UEs 111-115 may have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3 do not limit the scope of the present disclosure to any particular implementation of the UE.

[0062] As Figure 3 shown, the UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a TX processing circuit 315, a microphone 320, and a receive (RX) processing circuit 325. The UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, a touch screen 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0063] The RF transceiver 310 receives an input RF signal transmitted by the eNB of the network 100 from the antenna 305. The RF transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuit 325, which produces a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuit 325 sends the processed baseband signal to the speaker 330 (e.g., for voice data) or to the processor 340 for further processing (e.g., for web browsing data).

[0064] The TX processing circuit 315 receives analog or digital voice data from the microphone 320 or other output baseband data from the processor 340 (e.g., network data, email, or interactive video game data). The TX processing circuit 315 encodes, multiplexes, and / or digitizes the output baseband data to produce a processed baseband or IF signal. The RF transceiver 310 receives the output processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal to an RF signal transmitted via the antenna 305.

[0065] The processor 340 may include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, according to well-known principles, the processor 340 can control the reception of forward channel signals and the transmission of reverse channel signals via the RF transceiver 310, the RX processing circuit 325, and the TX processing circuit 315. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0066] The processor 340 is also capable of executing other processes and programs residing in the memory 360, such as processes for CSI reporting on the uplink channel. The processor 340 may move data into or out of the memory 360 as needed for the execution of processes. In some embodiments, the processor 340 is configured to execute the application program 362 based on the OS 361 or in response to signals received from the eNB or the operator. The processor 340 is also coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices (such as laptop computers and handheld computers). The I / O interface 345 is the communication path between these accessories and the processor 340.

[0067] The processor 340 is also coupled to the touch screen 350 and the display 355. The operator of the UE 116 can use the touch screen 350 to input data into the UE 116. The display 355 may be a liquid crystal display, a light-emitting diode display, or other display capable of presenting text and / or at least limited graphics, such as from a website.

[0068] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0069] Although Figure 3 an example of the UE 116 is shown, various changes can be made. For example, Figure 3 the various components in Figure 3 can be combined, further subdivided, or omitted, and additional components can be added according to specific needs. As a specific example, the processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Moreover, although Figure 3 the UE 116 is shown configured as a mobile phone or a smartphone, the UE can be configured to operate as other types of mobile or fixed devices.

[0070] Figure 4A is a high-level diagram of the transmission path circuit. For example, the transmission path circuit can be used for orthogonal frequency division multiple access (OFDMA) communication.Figure 4B is a high-level diagram of a receive path circuit. For example, the receive path circuit can be used for orthogonal frequency division multiple access (OFDMA) communication. In Figure 4A and 4B for downlink communication, the transmit path circuit can be implemented in a base station (eNB) 102 or a relay station, and the receive path circuit can be implemented in a user equipment (e.g., Figure 1 user equipment 116). In other examples, for uplink communication, the receive path circuit 450 can be implemented in a base station (e.g., Figure 1 eNB 102) or a relay station, and the transmit path circuit can be implemented in a user equipment (e.g., Figure 1 user equipment 116).

[0071] The transmit path circuit includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an inverse fast Fourier transform (IFFT) block 415 of size N, a parallel-to-serial (P-to-S) block 420, a cyclic prefix addition block 425, and an upconverter (UC) 430. The receive path circuit 450 includes a downconverter (DC) 455, a cyclic prefix removal block 460, a serial-to-parallel (S-to-P) block 465, a fast Fourier transform (FFT) block 470 of size N, a parallel-to-serial (P-to-S) block 475, and a channel decoding and demodulation block 480.

[0072] Figure 4A At least some components in 400 and 4B 450 can be implemented in software, while other components can be implemented by configurable hardware or a combination of software and configurable hardware. In particular, note that the FFT blocks and IFFT blocks described in this disclosure document can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation.

[0073] Furthermore, although this disclosure relates to embodiments implementing fast Fourier transform and inverse fast Fourier transform, this is merely exemplary and should not be construed as limiting the scope of this disclosure. It should be understood that in alternative embodiments of this disclosure, the fast Fourier transform function and the inverse fast Fourier transform function can be easily replaced by a discrete Fourier transform (DFT) function and a discrete Fourier inverse transform (IDFT) function, respectively. It should be understood that for the DFT and IDFT functions, the value of the N variable can be any integer (i.e., 1, 4, 3, 4, etc.), while for the FFT and IFFT functions, the value of the N variable can be any integer that can be a power of 2 (i.e., 1, 2, 4, 8, 16, etc.).

[0074] In the transmit path circuit 400, the channel coding and modulation block 405 receives a set of information bits, applies coding (e.g., LDPC coding) and modulation (e.g., quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to the input bits to generate a series of frequency-domain modulated symbols. The serial-to-parallel block 410 converts (i.e., demultiplexes) the serial modulated symbols into parallel data to produce N parallel symbol streams, where N is the IFFT / FFT size used in BS102 and UE 116. The IFFT block 415 of size N then performs an IFFT operation on the N parallel symbol streams to produce a time-domain output signal. The parallel-to-serial block 420 converts (i.e., multiplexes) the parallel time-domain output symbols from the IFFT block 415 of size N to produce a serial time-domain signal. The cyclic prefix addition block 425 then inserts a cyclic prefix into the time-domain signal. Finally, the upconverter 430 modulates (i.e., upconverts) the output of the cyclic prefix addition block 425 to an RF frequency for transmission via the wireless channel. The signal may also be filtered at baseband before being converted to the RF frequency.

[0075] The transmitted RF signal arrives at UE 116 after passing through the wireless channel and performs operations opposite to those at eNB 102. The downconverter 455 downconverts the received signal to a baseband frequency, and the cyclic prefix removal block 460 removes the cyclic prefix to produce a serial time-domain baseband signal. The serial-to-parallel block 465 converts the time-domain baseband signal to a parallel time-domain signal. Then, the FFT block 470 of size N performs the FFT algorithm to produce N parallel frequency-domain signals. The parallel-to-serial block 475 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates and then decodes the modulated symbols to recover the original input data stream.

[0076] Each of eNBs 101-103 may implement a transmit path similar to that transmitted to user devices 111-116 in the downlink, and may implement a receive path similar to that received from user devices 111-116 in the uplink. Similarly, each of user devices 111-116 may implement a transmit path corresponding to the architecture used to transmit to eNBs 101-103 in the uplink, and may implement a receive path corresponding to the architecture used to receive in the downlink of eNBs 101-103.

[0077] 5G communication system use cases have been identified and described. These use cases can be broadly classified into three different groups. In one example, enhanced mobile broadband (eMBB) is identified as having high bit / second requirements, with less stringent latency and reliability requirements. In another example, ultra-reliable and low latency (URLL) is identified with lower bit / second requirements. In yet another example, massive machine type communication (mMTC) is identified, where multiple devices can be up to 100,000 to 1 million / km², but the reliability / throughput / latency requirements can be less stringent. This scenario may also involve power efficiency requirements as battery consumption should be minimized as much as possible.

[0078] In LTE technology, a time interval X that can include one or more of a DL transmission portion, protection, a UL transmission portion, and combinations thereof can be indicated dynamically and / or semi-statically, regardless of how they are. Additionally, in one example, the DL transmission portion of the time interval X includes downlink control information and / or downlink data transmission and / or reference signals. In another example, the UL transmission portion of the time interval X includes uplink control information and / or uplink data transmission and / or reference signals. Further, the use of DL and UL does not exclude other deployment scenarios (e.g., sidelink, backhaul, relay). In some embodiments of the present disclosure, "subframe" is another name for "time interval X", or vice versa. To enable 5G networks to support these diverse services, it is called network slicing.

[0079] In some embodiments, "subframe" and "time slot" can be used interchangeably. In some embodiments, "subframe" refers to a transmission time interval (TTI), which can include an aggregation of "time slots" for data transmission / reception by a UE.

[0080] Figure 5 A network slice 500 according to an embodiment of the present disclosure is shown. Figure 5 The embodiment of the network slice 500 shown is for illustration only. Figure 5 One or more of the components shown can be implemented in a dedicated circuit configured to perform the functions, or one or more of the components can be implemented by one or more processors executing instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0081] As Figure 5As shown, the network slice 500 includes the operator's network 510; multiple RANs 520; multiple eNBs 530a, 530b; multiple small cell base stations 535a, 535b; a URLL slice 540a; a smartwatch 545a; a car 545b; a truck 545c; smart glasses 545d; a power meter 555a; a temperature sensor 555b; an mMTC slice 550a; an eMBB slice 560a; a smartphone (e.g., a mobile phone)

[0082] 565a; a laptop 565b and a tablet 565c (e.g., a tablet PC).

[0083] The operator's network 510 includes multiple radio access networks 520 - RAN associated with network devices (e.g., eNBs 530a and 530b), small cell base stations (femto / pico eNBs or Wi-Fi access points) 535a and 535b, etc. The operator's network 510 can support various services that rely on the slice concept. In one example, the network supports four slices 540a, 550a, 550b, and 560a. The URLL slice 540a is used to serve UEs that require URLL services, such as cars 545b, trucks 545c, smartwatches 545a, smart glasses 545d, etc. Two mMTC slices 550a and 550b serve UEs that require mMTC services, such as power meters and temperature control (e.g., 555b), and one eMBB slice 560a that requires eMBB serves devices such as cellular phones 565a, laptops 565b, and tablets 565c.

[0084] In short, network slicing is a method of handling various different quality of service (QoS) at the network level. To effectively support these various QoSs, slice - specific PHY optimizations may also be required. Devices 545a / b / c / d, 555a / b, 565a / b / c are examples of different types of user equipment (UE). Figure 5 The different types of user equipment (UE) shown need not necessarily be associated with a specific type of slice. For example, cellular phones 565a, laptops 565b, and tablets 565c are associated with the eMBB slice 560a, but this is for illustration only, and these devices can be associated with any type of slice.

[0085] In some embodiments, a device is configured with more than one slice. In one embodiment, a UE (e.g., 565a / b / c) is associated with two slices, namely, the URLL slice 540a and the eMBB slice 560a. This is useful for supporting online gaming applications, where graphical information is sent through the eMBB slice 560a and user interaction - related information is exchanged through the URLL slice 540a.

[0086] In the current LTE standard, there is no shard-level PHY available, and most PHY functions are utilized shard-agnostically. A UE is typically configured with a single set of PHY parameters (including transmit time interval (TTI) length, OFDM symbol length, subcarrier spacing, etc.), which may prevent the network from: (1) quickly adapting to dynamically changing QoS; (2) supporting various QoS simultaneously.

[0087] In some embodiments, corresponding PHY designs are disclosed to address different QoS through the network slicing concept. Note that "slice" is a term introduced to conveniently refer to a logical entity associated with common characteristics (e.g., numerology, upper layers (including media access control / radio resource control (MAC / RRC)), and shared UL / DL time-frequency resources). Alternative names for "slice" include virtual cell, super cell, cell, etc.

[0088] Figure 6 An example number of digital chains 600 according to an embodiment of the present disclosure is shown. Figure 6 The embodiments of the number of digital chains 600 shown are for illustration only. Figure 6 One or more of the components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more of the components may be implemented by one or more processors executing instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0089] The LTE specification supports up to 32 CSI-RS antenna ports, which enables the eNB to be equipped with a large number of antenna elements (e.g., 64 or 128). In this case, multiple antenna elements are mapped to one CSI-RS port. For next-generation cellular systems such as 5G, the maximum number of CSI-RS ports may remain the same or increase.

[0090] For the mmWave (millimeter wave) band, although the number of antenna elements can be larger for a given form factor, the number of CSI-RS ports - which can correspond to the number of digital precoding ports - tends to be limited due to hardware limitations as Figure 6 shown (e.g., the feasibility of installing a large number of ADC / DACs at mmWave frequencies). In this case, one CSI-RS port is mapped to a large number of antenna elements that can be controlled by a set of analog phase shifters 601. Then, one CSI-RS port can correspond to a subarray that generates a narrow analog beam through analog beamforming 605. The analog beam can be configured to scan a wider range of angles 620 by changing the phase shifter group over symbols or subframes. The number of subarrays (equal to the number of RF chains) is the same as the number of CSI-RS ports N CSI-PORT is the same. The digital beamforming unit 610 spans NCSI-PORT The analog beams perform linear combination to further increase the precoding gain. Although the analog beams are broadband (and thus not frequency selective), the digital precoding can vary between frequency subbands or resource blocks.

[0091] To implement digital precoding, an effective design of CSI-RS is a key factor. For this purpose, three types of CSI reporting mechanisms corresponding to three types of CSI-RS measurement behaviors are supported in the LTE specification: 1) "CLASS A" CSI reporting, which corresponds to non-precoded CSI-RS; 2) "CLASS B" reporting, with K = 1 CSI-RS resource corresponding to CSI-RS for UE-specific beamforming;

[0092] 3) "CLASS B" reporting, with K > 1 CSI-RS resources corresponding to CSI-RS for cell-specific beamforming.

[0093] For non-precoded (NP) CSI-RS, a cell-specific one-to-one mapping between the CSI-RS ports and the TXRUs is utilized. Here, different CSI-RS ports have the same wide beamwidth and direction, and thus are typically the cell coverage area. For beamformed CSI-RS, the beamforming operation (cell-specific or UE-specific) is applied to the non-zero power (NZP) CSI-RS resources (which consist of multiple ports). Here, (at least at a given time / frequency) the CSI-RS ports have a narrow beamwidth and thus do not have cell-wide coverage, and (at least from the eNB perspective) at least some combinations of CSI-RS port resources have different beam directions.

[0094] In cases where the DL long-term channel statistics can be measured from the UL signal at the serving eNodeB, UE-specific BF CSI-RS can be easily used. This is typically feasible when the UL-DL duplex distance is small enough. However, when this condition does not hold, the eNodeB needs some UE feedback to obtain an estimate of the DL long-term channel statistics (or any representation of the DL-long-term channel statistics). To facilitate such a process, the first BF CSI-RS is sent periodically at T1 (ms) and the second NP CSI-RS is sent periodically at T2 (ms), where T1 ≤ T2. This method is called hybrid CSI-RS. The implementation of hybrid CSI-RS depends largely on the CSI process and the definition of NZP CSI-RS resources.

[0095] In the LTE specification, a codebook-based transmission scheme is used to support UL SU-MIMO transmission. That is, the UL grant (including DCI format 4) includes a single PMI field (and RI), which indicates a single precoding vector or matrix (from a predefined codebook) that the UE can use for scheduled UL transmission. Therefore, when multiple PRBs are allocated to the UE, the single precoding matrix indicated by the PMI implies the use of wideband UL precoding.

[0096] Although it is simple, this is clearly suboptimal because the typical UL channel is frequency-selective and the UE is frequency-scheduled to transmit using multiple PRBs. Another disadvantage of LTE UL SU-MIMO is the lack of support for the case where accurate UL-CSI cannot be obtained at the eNB (which is essential for the correct operation of codebook-based transmission). This can occur in the case of high-mobility UEs or in the case of bursty inter-cell interference in a cell with poor isolation.

[0097] Therefore, for the following reasons, new components need to be designed to achieve more efficient support for UL MIMO. First, it is desirable to support frequency-selective (or sub-band) precoding for UL MIMO as much as possible. Second, UL MIMO can provide competitive performance even when accurate UL-CSI cannot be obtained at the eNB. Third, the proposed UL MIMO solution may be able to utilize UL-DL reciprocity, where the UE uses CSI-RS to provide UL-CSI estimation for the TDD scenario.

[0098] In the LTE UL codebook, precoders with antenna selection have been supported to keep the peak-to-average power ratio (PAPR) low and to keep the cubic metric (CM) small for rank > 1. Antenna selection provides performance improvement in some cases, especially for SC-FDMA-based UL in LTE. However, for the 5G NR system, it has been agreed in 3GPP RAN1 that UL will mainly be based on CP-OFDM, although SC-FDMA can also be supported. It is not clear whether antenna selection can show any performance gain in the case of CP-OFDM-based UL. Whether or not antenna selection is considered, there are several alternatives for the UL codebook in 5G NR. This disclosure presents some of these alternatives.

[0099] Figure 7 An example of multiplexing two shards 700 according to an embodiment of the present disclosure is shown. Figure 7 The embodiment of multiplexing two shards 700 shown is for illustration only. Figure 7One or more of the components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0100] To efficiently utilize PHY resources and multiplex various shards (with different resource allocation schemes, numerologies, and scheduling strategies) in the DL-SCH, a flexible and self-contained frame or subframe design is used. In Figure 7 Two exemplary instances of multiplexing two shards within a common subframe or frame are depicted. In Figure 7 a shard may consist of one or two transmission instances, where one transmission instance includes control (CTRL) components (720a, 760a, 760b, 720b, and 760c) and data components (730a, 770a, 770b, 730b, and 770c). In Figure 7 two shards (e.g., 710) are multiplexed in the frequency domain, while a shard (e.g., 750) is multiplexed in the time domain.

[0101] In the present disclosure, briefly, both FDD and TDD are considered duplexing methods for DL and UL signaling. Although the exemplary descriptions and embodiments employ orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA), the present disclosure can be extended to other OFDM-based transmission waveforms or multiple access schemes such as filtered OFDM (F-OFDM). The present disclosure encompasses several components that can be used in combination with each other or combined with each other, or can operate as independent schemes.

[0102] LTE UL codebooks for 2 and 4 antenna ports are provided in Tables 1-5, where the scaling factor for 2 antenna ports and a = 2 for 4 antenna ports. Note that for 2 ports, rank 1, codebook indices 4 and 5 correspond to antenna selection (with half power), and rank 2 corresponds to antenna selection for each layer, i.e., layer 0 transmitted from antenna port 20 and layer 1 transmitted from antenna port 21. Antenna selection for 4 antenna ports is similar as follows.

[0103] Table 1. Codebook transmitted on antenna ports {20, 21}

[0104]

[0105] Table 2. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 1

[0106]

[0107] Table 3. Codebooks Transmitted on Antenna Ports {40, 41, 42, 43}, where v = 2

[0108]

[0109] Table 4. Codebooks Transmitted on Antenna Ports {40, 41, 42, 43}, where v = 3

[0110]

[0111] Table 5. Codebooks Transmitted on Antenna Ports {40, 41, 42, 43}, where v = 4

[0112]

[0113] In the following, we assume that N1 and N2 are the numbers of antenna ports with the same polarization in the first and second dimensions, respectively. For a 2D antenna port layout, we have N1 > 1, N2 > 1, and for a 1D antenna port layout, we either have N1 > 1 and N2 = 1 or N2 > 1 and N1 = 1. In the remainder of this disclosure, a 1D antenna port layout with N1 > 1 and N2 = 1 is considered. However, this disclosure is applicable to other 1D port layouts with N2 > 1 and N1 = 1. For a (single-polarization) co-polarized antenna port layout, the total number of antenna ports is N1N2 and for a dual-polarized antenna port layout, the total number of antenna ports is 2N1N2. Figure 8 Illustrations of antenna port layouts for {2, 4, 8} antenna ports at the UE are shown.

[0114] Figure 8 An example antenna port layout 800 at the UE according to an embodiment of the present disclosure is shown. Figure 8 The embodiment of the antenna port layout 800 shown is for illustrative purposes only. Figure 7 One or more of the components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more of the components may be implemented by one or more processors executing instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure. In the present disclosure, UL antenna ports refer to SRS ports.

[0115] In some embodiments 0, the UL codebook W for the {2, 4, 8} ports is based on a precoding vector that is one of four alternatives according to Table 6, where d m1 and d m2 are precoding vectors of lengths N1 and N2, respectively, and, is in-phase for a dual-polarized antenna port layout.

[0116] Table 6. Precoding Vectors

[0117]

[0118] In one example, the precoding vector is an oversampled DFT vector, i.e.,

[0119]

[0120] where O1 and O2 are two-dimensional oversampling factors and can take values from the set {2, 4, 8}. O1 and O2 can take the same values as in the DL codebook. Alternatively, they take different values from those in the DL codebook.

[0121] In another example, the precoding vector includes antenna "shut-off" similar to the LTE UL codebook (Table 1-5), where a subset of antenna ports is shut off and the corresponding components of the precoding vector are set to zero.

[0122] In one alternative, the maximum number of layers for UL transmission is equal to the number of antenna ports at the UE. In another alternative, the maximum number of layers for UL transmission is at most 4 layers, i.e., at most 2 layers for 2 antenna ports and at most 4 layers for 4 and 8 antenna ports.

[0123] In the remainder of this disclosure, dual-polarized antenna ports are assumed. However, the embodiments of this disclosure are general and applicable to single-polarized or co-polarized antenna ports.

[0124] In sub-embodiment 0-0, the UL codebook (CB0) is a two-stage codebook W = W1W2, where the W1 codebook is for the WB component of the codebook including beam / precoder groups, and the W2 codebook is for the SB component of the codebook including beam / precoder and in-phase selection. Note that, for example, if both DL and UL transmissions are based on CP-OFDM, the same two-stage codebook can also be used as the DL codebook. Also note that for 2 dual-polarized antenna ports, W1 is an identity. An example of the two-stage codebook is the DL LTE codebook (as shown in the LTE specification codebook).

[0125] In sub - embodiment 0 - 1, the UL codebook (CB1) is the same as the LTE UL codebook for 2 and 4 antenna ports (Table 1 - 5). For 8 antenna ports, some alternatives for the UL codebook are as follows. In one example of Alt 0 (no antenna shut - off), the UL codebook is the same as the DL codebook for 8 ports. In another example of Alt 1 (with antenna shut - off), the UL codebook is based on the following two steps. In this example of antenna shut - off, assuming dual - polarized antenna ports, 2 out of 4 pairs of dual - polarized antenna ports are shut off. There are six such combinations. In this example of the codebook, for the remaining 4 ports (which are not shut off), the DL codebook for 4 ports or the LTE UL codebook for 4 ports is used. In another example of Alt 2, a new codebook for 8 ports is used.

[0126] In one alternative, the codebook for this sub - embodiment is a two - stage codebook W = W1W2 similar to that of sub - embodiment 0 - 0, where the W1 codebook is for antenna shut - off and the W2 codebook is for the precoding vectors of the remaining antenna ports (not shut off). Note that in this alternative, the antenna shut - off can be WB or SB. In another alternative, the codebook for this sub - embodiment is a two - stage codebook W = W1W2, where W1 is an identity and W2 is for both antenna shut - off and the precoding vectors of the remaining antenna ports (not shut off).

[0127] In sub - embodiment 0 - 2, the UL codebook (CB2) is a union of the UL codebooks in sub - embodiments 0 - 0 and 0 - 1 (CB0 and CB1). In this sub - embodiment, the codebook can be a two - stage codebook W =

[0128] W1W2, where the W1 and W2 codebooks are unions of the W1 and W2 codebooks of CB0 and CB1 (in sub - embodiments 0 - 0 and 0 - 1) respectively.

[0129] In sub - embodiment 0 - 3, the UL codebook is rank - dependent, where one of CB0, CB1, and CB2 is used for a given rank r. Some examples of such codebooks are as follows: the rank - 1 codebook is according to CB0 (sub - embodiment 0 - 0), and the rank>1 codebook is according to CB1 (sub - embodiment 0 - 1); the rank - 1 codebook is according to CB1 (sub - embodiment 0 - 1), and the rank>1 codebook is according to CB0 (sub - embodiment 0 - 0); the rank - 1 codebook is according to CB0 (sub - embodiment 0 - 0), and the rank>1 codebook is according to CB2 (sub - embodiment 0 - 2); the rank - 1 codebook is according to CB2 (sub - embodiment 0 - 2), and the rank>1 codebook is according to CB0 (sub - embodiment 0); the rank - 1 codebook is according to CB1 (sub - embodiment 0 - 1), the rank>1 codebook is according to CB2 (sub - embodiment 0 - 2); and the rank - 1 codebook is according to CB2 (sub - embodiment 0 - 2), and the rank>1 codebook is according to CB1 (sub - embodiment 0 - 1).

[0130] In sub - embodiments 0 - 4, the UL codebook is extended to the multi - panel case, where there are more than one antenna panel at the UE, and each antenna panel corresponds to a 1D or 2D antenna port, as Figure 8 shown. The extension of the UL codebooks CB0, CB1, and CB2 can be similar to the DL codebook for multi - panels. For antenna shutdown, there may be the following alternatives. In one example of antenna - panel shutdown, each antenna panel is either on or off. In another example of antenna - port shutdown, the antenna ports in each antenna panel are either on or off. For different panels, the antenna - port shutdown can be the same or different.

[0131] In sub - embodiments 0 - 5, the UL codebook is extended to hybrid beamforming, where precoding is in the RF (analog) and digital (baseband) domains. Such hybrid beamforming is required for millimeter - wave communication systems. In such a hybrid setup, antenna shutdown can be in at least one of the RF and digital domains. In one alternative, antenna shutdown is only in the RF domain, i.e., each RF link is on or off. In another alternative, antenna shutdown is only in the digital domain, i.e., the (digital) antenna ports associated with each RF link can be turned off.

[0132] The following embodiments (Embodiments 1 - 5) are examples of UL codebook configurations. Similar examples based on combinations of some of these embodiments can be constructed in a straightforward manner.

[0133] In some Embodiment 1, the UL codebook configuration is the same as the DL codebook configuration, e.g., based on RRC, MAC CE, or DCI signaling.

[0134] In some Embodiment 2, the UL codebook is parameterized by at least one codebook parameter (e.g., N1 and N2) for the number of two - dimensional antenna ports, and O1 and O2 for the oversampling factor in two dimensions, and the UE is configured with at least one of these codebook parameters by RRC, MAC CE, or DCI signaling. Some alternatives for UL codebook parameter configuration are as follows. In one Example 0, N1, N2, O1, and O2 are fixed, so no signaling is required for configuration. In one Example 1, all of N1, N2, O1, and O2 are configured. In one Example 2, some of N1, N2, O1, and O2 are configured. In such an example, N1 and N2 are fixed, for example, for a 1D port layout; and O1 and O2 are configured. In such an example, O1 and O2 are fixed, for example, (4,4) or (8,8) for a 2D port layout, and (4,1) or (8,1) for a 1D port layout; and N1, N2 are configured.

[0135] In some embodiments 3, the UE is configured with the UL antenna turn-off parameter AntennaTurnOffEnabled to enable / disable antenna turn-off. Such configuration can be based on RRC, based on MAC CE or DCI signaling. If AntennaTurnOffEnabled is set to "ON", then two precoders with and without antenna turn-off are considered in PMI selection. Or, if AntennaTurnOffEnabled is set to "OFF", then only the precoder without antenna turn-off is considered in PMI selection. Additionally, the UE can also be configured with the antenna ports to be turned off, and can also be configured to report the PMI indicating the precoding vector according to the configured antenna port turn-off.

[0136] In some embodiments 4, the UE is configured with a UL codebook via high-layer RRC signaling or based on more dynamic MAC CE or DCI signaling according to at least one of the following alternatives. In one example, one of CB0, CB1, and CB2 can be configured. In another example, one of CB0 and CB2 can be configured. In yet another example, one of CB1 and CB2 can be configured. In yet another example, one of CB0 and CB1 can be configured.

[0137] In some embodiments 5, the UE is configured with CB2 as the UL codebook, and can be configured with one of the following three types of UL codebooks via RRC, based on MAC CE or DCI signaling. In one example, CB0 is fixed and CB1 is configured. In another example, CB1 is fixed and CB0 is configured. In yet another example, CB0 and CB1 are configured.

[0138] In some embodiments 6, the UE is configured with UL antenna turn-off (see the foregoing embodiment 3), and then the PMI / TPMI selection / indication is based on at least one of the following alternatives. In one example of Alt 6-0, antenna turn-off is configured for all ranks. In one example of Alt 6-1, antenna turn-off is configured for certain ranks, for example, antenna turn-off is only configured for rank 1. In one example of Alt 6-2, if the UL transmission is based on DFT-S-OFSM, then antenna turn-off is configured. In one example of Alt 6-3, if the UL transmission is based on CP-OFDM, then antenna turn-off is configured. In one example of Alt6-4, antenna turn-off is configured regardless of whether the UL transmission is based on DFT-S-OFSM or based on CP-OFDM. In one example of Alt 6-5, it is a combination of at least two of Alt 6-0 to Alt 6-4.

[0139] In some embodiments 7, the UE is configured with a UL codebook, and the UL codebook structure is as Figure 9As shown, there are M (or K1) groups of precoders and one group of precoders includes N (or K2) precoders, where the value of N is the same for all groups of precoders or different for different groups of precoders. Since for UL transmission based on precoder cycling (where a group of precoders cycles in the frequency domain, e.g., at the RE level or RB level), the TPMI indicates a group of precoders, it is necessary to group the precoders in the UL codebook for cycling.

[0140] According to the proposed UL codebook structure, which can be similar to the DL codebook structure, a two - level codebook W = W1W2 is proposed for UL, where the first - level codebook W1 is used to form groups of precoders. The two - level codebook can also be used for UL transmission schemes with frequency - selective (selecting a single precoder for each SB) precoder selection or frequency - non - selective (selecting a single precoder WB) precoder selection, e.g., to reduce the number of candidate precoders for selection, where the second - level codebook W2 is used to perform precoder selection.

[0141] Two examples of the UL codebook W are the LTE UL codebook for 2 and 4 ports, and the DL CSI codebook for 2, 4 (and 8 if supported) ports in NR or 5G. In a variant of this embodiment, the W1 codebook performs beam grouping (assuming dual - polarized antenna ports at the UE with the same two polarizations), e.g., DFT beams, and the W2 codebook performs beam selection (and in - phase selection for the two polarizations).

[0142] Figure 9 An example uplink codebook structure 900 according to an embodiment of the present disclosure is shown. Figure 9 The embodiment of the uplink codebook structure 900 shown is for illustration only. Figure 9 One or more of the components shown can be implemented in a dedicated circuit configured to perform the functions, or one or more of the components can be implemented by one or more processors executing instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0143] Table 7 shows an example of precoder grouping for the LTE rank - 1 UL codebook for 4 ports, where there are six groups of precoders (M = 6), as follows: Group 0: includes codebook indices 0 - 3; Group 1: consists of codebook indices 4 - 7; Group 2: consists of codebook indices 8 - 11; Group 3: consists of codebook indices 12 - 15; Group 4: consists of codebook indices 16 - 19; and Group 5: consists of codebook indices 20 - 23.

[0144] Table 7. Example of precoder grouping for rank - 1

[0145]

[0146] Examples of precoder groupings for the LTE rank 1-2 UL codebook for 2 ports are shown in Tables 8 and 9. Let i be the codebook index in the LTE UL codebook table (Table 1), then the first and second TPMI can be obtained according to and i2 = i mod 4. Similarly, from the first and second TPMI, the codebook index (i) in the LTE UL codebook table can be obtained according to i = 4i1 + i2.

[0147] Table 8. Examples of precoder groupings for 2 antenna ports (W1)

[0148]

[0149] Table 9. Examples of precoder groupings for 2 antenna ports (W2)

[0150]

[0151] Two examples of precoder groupings for the LTE rank 1-4 UL codebook for 4 ports are shown in Tables 10 and 11, where there are K1 precoder groups (which include the W1 component of the codebook) and each precoder group includes: K2 precoders (including the W2 component of the codebook). The first TPMI i1 (which is configured as WB) is used to indicate / configure the precoder group, and the second TPMI i2 (where SB is configured) is used to indicate / configure the precoder within the precoder group (configured / indicated). The indication of the first TPMI is via higher layer signaling (e.g., RRC) or via dynamic DCI-based signaling. Similarly, the indication of the second TPMI is via higher layer signaling (e.g., RRC) or via dynamic DCI-based signaling. Moreover, the indication of the first and second TPMI is joint (by a single signaling) or separate (by two separate signals).

[0152] Let i be the codebook index in the LTE UL codebook table (Tables 2 - 5), then the first and second TPMI can be obtained according to and i2 = i mod K2. Similarly, from the first and second TPMI, the codebook index (i) in the LTE UL codebook table can be obtained according to i = K1i1 + i2.

[0153] Table 10. Examples of precoder groupings for 4 antenna ports

[0154]

[0155] Table 11. Examples of precoder groupings for 4 antenna ports

[0156]

[0157] In some embodiments 7A, the UE is configured with a UL codebook, which is an extension of the UL codebook in Embodiment 7, where for at least one of rank 1 to rank 4, in addition to the precoders in the LTE UL codebook (Tables 2 - 5), N additional precoders are included.

[0158] In an example 7A-0, for layer 1 or rank 1, the following N = 8 additional precoders are included in the UL codebook. Note that the number of precoder groups is now K1 = 8, which requires 3 bits for the first TPMI indication.

[0159]

[0160] In an example 7A-1, for layer 1 or rank 1, the following N = 8 additional precoders are included in the UL codebook. Note that the number of precoder groups is now K1 = 8, which requires 3 bits for the first TPMI indication.

[0161]

[0162] In some embodiments 8, the UE is configured with a two-stage UL codebook W = W1W2, where the first-stage codebook W1 is used to select a precoder group, and the second-stage W2 codebook is used to select a precoder from the selected precoder group. In such an embodiment, for UL transmission based on precoder cycling, the W1 codebook is used. In such an embodiment, for UL transmission based on frequency-selective precoder selection or frequency-nonselective precoder selection, at least one of the following alternatives is considered.

[0163] In an example of Alt 8-0, the W1 and W2 codebooks are used. In this case, two PMIs for W1 and W2 are indicated respectively, namely PMI1 and PMI2, where PMI1 indicates the precoder group and PMI2 represents the precoder in the selected precoder group. Alternatively, PMI1 and PMI2 are jointly represented as a single PMI.

[0164] In another example of Alt 8-1, the overall codebook W is used. In this case, a single PMI is indicated.

[0165] In some embodiments 9, the UE is configured with a two-stage UL codebook W = W1W2, which is the same as the two-stage DL codebook known as the type-I SP codebook for 2, 4, and 8 ports, and is parameterized by parameters such as two-dimensional port numbers (N1, N2), two-dimensional oversampling factors (O1, O2), and the number of beams (L = 1, 4) selected by W1 beam groups. For the UL codebook, (N1, N2) and (O1, O2) are fixed as follows:

[0166]

[0167] where the number of beams is fixed (e.g., L = 1) or configured as L = 1 and 4.

[0168] In sub - embodiment 9 - 0, if the UE is configured with frequency - selective precoding in the UL, the number of beams is fixed to 1, i.e., L = 1. This is to reduce the SB TPMI signaling overhead in the UL - related DCI signaling.

[0169] In sub - embodiment 9 - 1, if the UE is configured with frequency - non - selective precoding in the UL, the number of beams is fixed (e.g., L = 1) or configured from L = 1 and 4 using 1 - bit signaling in the UL - related DCI or via higher - layer RRC or MAC - CE - based signaling.

[0170] In sub - embodiment 9 - 2, if the UE is configured with precoder group signaling using the W1 codebook, the number of beams is fixed to L = 4.

[0171] In some embodiments 10, the UE is configured with a port - selection codebook in the UL (similar to the LTE specification Class B, K = 1 codebook). The usage of this codebook is when the SRS is precoded / beamformed. The UL port - selection codebook is based on at least one of the following alternatives. In one example of Alt 10 - 0, one port is selected per layer and ports are not shared across layers. For example, for 2 ports, the rank - 1 and rank - 2 codebooks are respectively and In another example of Alt 10 - 1, a subset of antenna ports is selected or combined per layer and ports are shared across layers. An example of such a codebook is the LTE UL codebook. Another example is the LTE specification Class B, K = 1 codebook. In one example of Alt 10 - 2, all antenna ports are selected or combined per layer and ports are shared across layers. An example of such a codebook is the LTE DL codebook. In one example of Alt 10 - 3, a combination of Alt 10 - 0 and Alt 10 - 2.

[0172] In some embodiments 11, the UE is configured with frequency - selective precoding in the UL according to at least one of the following schemes. In one example of Scheme 0, the number of SB TPMIs is fixed (N), where the size of each SB (number of PRBs) is fixed and independent of UL scheduling. For example, if B is the size of the UL BW (number of SBs) and if N is divisible by B, the SB size is B / N, otherwise the SB size is for the remaining n SBs where n is the remainder of B / N. In an example of Scenario 1, the number of SB TPMIs is fixed (N), where the size of each SB (number of PRBs) varies according to UL scheduling. For example, if B is the number of scheduled SBs in UL and if N is divisible by B, the SB size is B / N, otherwise the SB size is for the remaining n SBs where n is the remainder of B / N. In an example of Scenario 2, the number of SB TPMIs is 2; the first TPMI is associated with the best M selected SBs, and the second TPMI is associated with the remaining B - M SBs, where B is the number of scheduled SBs in UL. The value M is fixed or configured for the UE or the value M depends on B, e.g., M = min(1, B / 2). In an example of Scenario 3, an extension of Scenario 2 to more than 2 SB TPMIs. In an example of Scenario 4, the number of SB TPMIs is M + 1; the first M TPMIs are associated with the best M selected SBs (1 TPMI per SB), and 1 TPMI is associated with the remaining B - M SBs, where B is the number of scheduled SBs in UL. The value M is fixed or configured for the UE, or the value M depends on B. In an example of Scenario 5, the number of TPMIs is equal to the number of scheduled SBs in UL.

[0173] In Scenarios 2, 3, and 4 above, information about the location of the best M selected SBs needs to be signaled. In an alternative, this information is signaled in the same UL related DCI that contains the TPMI. In another alternative, this information is signaled separately in another UL related DCI signaling or in another UL transmission, the information of which is included in the first UL related DCI.

[0174] In some embodiments 12, 1-bit signaling is used to configure the UL codebook with or without antenna shutoff. In an example, this 1-bit signaling only applies to rank 1. Use at least one of the following alternatives. In an example of Alt 12-0, the 1-bit signaling corresponds to signaling for UL waveform, CP-OFDM, or DFT-S-OFDM. For example: If CP-OFDM UL waveform is signaled, the codebook without shutoff is used; otherwise (DFT-S-OFDM), the codebook with antenna shutoff is used. The 1-bit signaling can be signaled via higher layer RRC signaling. Or, the 1-bit signaling is signaled via MAC CE based signaling. Or, the 1-bit signaling is signaled via UL related DCI signaling.

[0175] In an example 1 of Alt 12-0, the LTE UL codebook is divided into two parts (Part 1 and Part 2), and Part 1 of the LTE UL codebook without antenna shutdown is for CP-OFDM and Part 2 of the LTE UL codebook with antenna shutdown is for DFT-S-OFDM. For 2 ports, the former requires 2 bits for rank-1 TPMI signaling and the latter requires 1 bit. Similarly, for 4 ports, the former requires 4 bits for rank-1 TPMI signaling and the latter requires 3 bits.

[0176] In an example 2 of Alt 12-9, the LTE UL codebook is divided into two parts (Part 1 and Part 2), and Part 1 of the LTE UL codebook without antenna shutdown is for CP-OFDM and the whole of the LTE UL codebook (Part 1 and Part 2) is for DFT-S-OFDM. For 2 ports, the former requires 2 bits for rank-1 TPMI signaling and the latter requires 3 bits. Similarly, for 4 ports, the former requires 4 bits for rank-1 TPMI signaling and the latter requires 5 bits.

[0177] In an example of Alt 12-1, in addition to the signaling for the UL waveform, 1-bit signaling is separate for the UL codebook. In an example of Alt 12-2, the UE reports the 1-bit signaling as a WB CSI component, for example, as part of the WB first TPMI (i1).

[0178] In some embodiments 13, the UE is configured with a UL codebook that is based on a codebook for Ng≥1 antenna panels or multiple antenna groups, where each antenna panel or antenna group includes P = 1 (e.g., co-pol) or 2 antenna ports (e.g., dual-pol). In such embodiments, the same codebook is used for single and multiple antenna panels at the UE. For example: For 2 ports, (N g , N1, N2, P) = (1,1,1,2), (2,1,1,1); for 4 ports, (N g , N1, N2, P) = (2,1,1,2), (4,1,1,1); for 8 ports, (N g , N1, N2, P) = (4,1,1,2),

[0179] (8,1,1,1).

[0180] In an alternative, the UL codebook includes a precoder with a Kronecker product structure. Some examples are as follows: [1, a, b, ab], [1, a, b, -(ab)*], [1, a, b,

[0181] (ab)*, [1, a, b, -(ab)], [1, a, b, ab*], [1, a, b, -ab*], [1, a, b, a*b], and [1, a, b, -a*b], where a and b belong to the QPSK alphabet {1, j, -1, -j}, and where "*" represents complex conjugation.

[0182] In another alternative, the UL codebook has a precoder structure [1, a, b, c], where a, b, and c belong to the QPSK alphabet {1, j, -1, -j}. In another alternative, the UL codebook has a precoder structure [1, a, b2c2, b3c3], where a belongs to the QPSK alphabet {1, j, -1, -j}, and b2 and b3 belong to the QPSK alphabet {1, j, -1, -j} or the alphabet c2 and c3 belong to In another alternative, the UL codebook has a precoder structure [1, b1c1, b2c2, b3c3], where b1, b2, and b3 belong to the QPSK alphabet {1, j, -1, -j} or the alphabet and c1, c2, and c3 belong to

[0183]

[0184] In some embodiments 14, the UL codebook has a precoder structure including an amplitude scaling component a, where the amplitude scaling is fixed or configured (e.g., via higher layer RRC signaling). For a 2-Tx or 2-port UL codebook, the amplitude scaling a is based on at least one of the following alternatives: where 1 bit is used to indicate a; where 1 bit is used to represent a; and, where 2 bits are used to represent a.

[0185] For a 4-Tx or 4-port UL codebook, the amplitude scaling a is based on at least one of the following alternatives: where 1 bit is used to indicate where 1 bit is used to represent a; and where 2 bits are used to represent a. The indication of a is WB as a separate WB TPMI component or in conjunction with the WB TPMI. Additionally, in the case of a rank > 1 TPMI indication, the indication is common to all layers or the indication is independent for all layers.

[0186] In some embodiments 15A, the UE is configured with a 4-Tx UL codebook for 1 SRS resource including 4 ports, where the precoder includes at least one of the following structures. In one example of Alt 15A-0 (with antenna selection), for each layer, a subset of ports is selected, and the selected ports are combined to obtain the precoder for that layer. For example, for each layer, half of the ports (i.e., 2 ports) are selected. One example is the precoder in the LTE UL codebook.

[0187] In another example of Alt 15A-1 (without antenna selection), for each layer, all ports are selected and combined to obtain the precoder. Two examples are the NR type I CSI codebook for a single panel and the NR type I CSI codebook for a multi-panel (MP). In another example of Alt 15A-2 (both with and without antenna selection): a combination of Alt 15A-0 and Alt 15A-1.

[0188] In some embodiments 15B, the UE is configured with a 4-Tx UL codebook for 2 SRS resources, having 2 ports per resource or having 2 panels, each panel having 2 ports, where the precoder includes at least one of the following structures. In one example of Alt 15B-0 (coherent precoder), a single TPMI indicates the precoder across 2 resources or 2 panels. Two examples of such a precoder are the NR type I CSI codebook for MP and the LTE UL codebook. The coherent precoder is applicable to all ranks or certain ranks (e.g., only rank 1). In another example of Alt 15B-1 (non-coherent precoder), for each layer, one of the 2 resources or 2 panels is selected, and a 2-Tx codebook (DL or UL 2-Tx codebook) is used for the precoder of the selected ports, where the selection of the resource or panel is based on the SRI (SRS resource indicator) or on the codebook as part of the PMI. The non-coherent precoder is applicable to all ranks or certain ranks (e.g., rank > 1). In another example of Alt 15B-2 (both coherent and non-coherent precoders), a combination of the coherent (Alt 15B-0) and non-coherent precoders (Alt 15B-1), where such a combination is either applicable to all ranks or only to certain ranks (e.g., only rank 1).

[0189] Moreover, in addition to the coherent and / or non-coherent precoders, antenna port selection is also considered, where the port selection is restricted within a resource or not restricted by two resources.

[0190] In some embodiments 15C, the UE is configured with a 4-Tx UL codebook for 4 SRS resources, having 1 port per resource or having 4 panels, each panel having 1 port, where the precoder includes at least one of the following structures. In one example of Alt 15C-0 (coherent precoder), a single TPMI indicates the precoder across 4 resources or 4 panels. Two examples of such precoders are the NR type I CSI codebook for MP and the LTE UL codebook. The coherent precoder is applicable to all ranks or certain ranks (e.g., only rank 1). In another example of Alt 15C-1 (non-coherent precoder), a subset of 4 resources or 4 panels is selected per layer. In one example, a single resource or panel is selected per layer. Alternatively, 2 resources or panels are selected, and a 2-Tx codebook (DL or UL 2-Tx codebook) is used for the precoder of the selected ports. The selection of resources or panels is either based on the SRI (SRS resource indicator) or on the codebook as part of the PMI. The non-coherent precoder is applicable to all ranks or certain ranks (e.g., rank > 1). In another example of Alt 15C-2 (both coherent and non-coherent precoders), a combination of the coherent (Alt 15C-0) and non-coherent precoders (Alt 15C-1), where such a combination is either applicable to all ranks or only to certain ranks (e.g., only rank 1).

[0191] In some embodiments 16, the UE is configured with an N-Tx codebook for N ports in at least one resource, where the precoder in the rank-1 (or 1 layer) codebook is used in whole or in part to design higher rank (rank > 1) codebooks. In one example, for DL, N ∈ {2, 4, 8, 12, 16, 24, 32} and at least one resource corresponds to a CSI-RS resource. In another example, for UL, N ∈ {2, 4, 8} and at least one resource corresponds to an SRS resource. For UL, the N ports correspond to one or more SRS resources according to at least one of the following alternatives: a single SRS resource including N ports; N / 2 SRS resources, each containing 2 ports; and N SRS resources, each containing 1 port.

[0192] Moreover, regardless of the waveform used for transmission (e.g., DFT-S-OFDM or CP-OFDM), the rank-1 codebook can be the same. For example, for UL, the rank 1 codebook can be the same for DFT-S-OFDM and CP-OFDM waveforms. Alternatively, the rank-1 codebooks for two UL waveforms (e.g., DFT-S-OFDM or CP-OFDM) are the same, except that the scaling factor a of the columns of the normalized precoding matrix is different for the two waveforms. In one example, for DFT-S-OFDM, the scaling factor is the same as in the LTE UL codebook, i.e., For 2 antenna ports, and a = 2, for 4 antenna ports, and for CP - OFDM, the scaling factor where r corresponds to the rank and n corresponds to the number of non - zero terms in the precoding matrix. In another example, for DFT - S - OFDM, the scaling factor is a = 1 or For 2 antenna ports, and a = 1 or or 2, for 4 antenna ports, and for CP - OFDM, the scaling factor is the same as in the previous example.

[0193] The codebook for N = 4 is based on at least one of the following alternatives. In one example of Alt 16 - 0, for N = 4, the rank - 1 codebook is the LTE UL 4 - Tx rank - 1 codebook, where the scaling (or power normalization) factor (a) in the precoder is a = 1 or a = 2 or Note that a = 2 is used in the LTE UL 4 - Tx codebook. An example of the rank - 1 codebook table is part of the rank - 1 codebook shown in Table 12 (with codebook indices 0 - 23). The total number of precoders in the rank - 1 codebook is 24. The rank - 1 codebook can be divided into two types of codebooks (CB). In one example of CB0, the first codebook includes 16 precoders that combine all 4 ports (all 4 entries in the precoder are non - zero). In other words, the precoder assumes full coherence where all ports can transmit coherently. In another example of CB1, the second codebook includes 8 precoders that combine 2 ports (2 entries in the precoder are non - zero and the remaining 2 entries are zero). In other words, the precoder assumes partial coherence, i.e., pairs of ports can transmit coherently.

[0194] The rank 2 - 4 codebooks are constructed using all the precoders in the rank - 1 codebook. Similar to the rank - 1, the rank 2 - 4 codebooks can also be divided into two types of codebooks (CB). For example, for rank - 2, the total number of rank - 2 precoding matrices is 12, which can be divided as follows. In one instance of CB0, the first codebook includes 8 rank - 2 precoding matrices that combine all 4 ports per layer (i.e., all 4 entries in the precoder for each layer are non - zero). In another instance of CB1, the second codebook includes 4 rank - 2 precoding matrices that combine 2 ports per layer (i.e., 2 entries in the precoder for each layer are non - zero and the remaining 2 entries are 0).

[0195] An example of the rank-2 codebook table is a part of the rank-2 codebook shown in Table 13 (with codebook indices 0 - 11). For rank-3, the total number of rank-3 precoding matrices is 12, which can be divided as follows. In one instance of CB0, the first codebook includes 8 rank-3 precoding matrices that combine all 4 ports per layer (i.e., all 4 entries in the pre-encoder for each layer are non-zero). In another instance of CB1, the second codebook includes 4 rank-3 precoding matrices that combine 2 ports per layer (i.e., 2 entries in the pre-encoder for each layer are non-zero and the remaining 2 entries are 0).

[0196] An example of the rank-3 codebook table is a part of the rank-3 codebook shown in Table 14 (with codebook indices 0 - 11). For rank-4, the total number of rank-4 precoding matrices is 6, which can be divided as follows. In one instance of CB0, the first codebook includes 4 rank-4 precoding matrices that combine all 4 ports per layer (i.e., all 4 entries in the pre-encoder for each layer are non-zero). In another instance of CB1, the second codebook includes 2 rank-4 precoding matrices that combine 2 ports per layer (i.e., 2 entries in the pre-encoder for each layer are non-zero and the remaining 2 entries are 0).

[0197] An example of the rank-4 codebook table is a part of the rank-4 codebook shown in Table 15 (with codebook indices 0 - 5). The total number of rank 1 - 4 pre-encoders / precoding matrices is 24 + 12 + 12 + 6 = 54. Thus, if the codebook is used for UL transmission, the codebook requires 6 bits for joint TRI and TPMI indication.

[0198] In the variant of Alt 16 - 0, the rank-4 codebook includes additional precoding matrices and the corresponding rank-4 codebook table is as shown in Table 15. Thus, the total number of rank 1 - 4 pre-encoders / precoding matrices is 55.

[0199] The scaling factor (a) in the rank 1-4 codebook for this alternative is based on at least one of the following alternatives. In one example of Alt 16-0A, the scaling factor is the same (e.g., a = 2) regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) and rank 1-4 used for UL transmission. In another example of Alt 16-0B, regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) used for UL transmission for rank 1 only, the scaling factor is the same (e.g., a = 2), and the scaling factor for at least one of ranks 2-4 can be different from that of rank 1 (e.g., for CP-OFDM). For example, a = √n, where n is the number of non-zero entries in a column of the precoding matrix, implies the following for codebooks Table 13, Table 14, and Table 15. In one example of rank 2, in Table 13, a = 2 is used for codebook indices 0-7, for codebook indices 8-11. In another example of rank 3, in Table 14, a = 2 is used for codebook indices 0-7, for codebook indices 8-11. In yet another example of rank 4, in Table 15, a = 2 is used for codebook indices 0-3, for codebook indices 4-5. If the rank-4 codebook includes additional precoding matrices then a = 2 is used.

[0200] In one example of Alt 16-0C, for the two UL waveforms (DFT-S-OFDM or CP-OFDM) of rank 1, the scaling factor can be different. At least one of the following examples is independently used for DFT-S-OFDM and CP-OFDM. In one instance of Ex 16-0A, a = 2 is used for codebook indices 0-23 in Table 12. In one instance of Ex 16-0B, a = 2 is used for codebook indices 0-15 and for codebook indices 16-23 in Table 12. For example, Ex 16-0A is used for DFT-S-OFDM and Ex 16-0B is used for CP-OFDM. The scaling factor for at least one of ranks 2-4 can be the same as or different from the scaling factor of rank 1 (e.g., for CP-OFDM). If the scaling factor is different, the scaling factor follows the example in Alt 16-0B.

[0201] In one example of Alt 16-1, the rank-1 codebook is the same as in Alt 16-0, and at least one of the rank 2-4 codebooks is constructed using a subset of the precoders in the rank-1 codebook. At least the following sub-alternatives are used. In one instance of Alt16-1A, the rank-2 codebook is a subset of CB0, CB1, or CB0 ∪ CB1, where CB0 and CB1 are the rank-2 codebook partitions explained in Alt 16-0, and the notation A ∪ B represents the union of sets A and B. In one instance of Alt 16-1B, the rank-3 codebook is a subset of CB0, CB1, or CB0 ∪ CB1, where CB0 and CB1 are the rank-3 codebook partitions explained in Alt 16-0. In one instance of Alt 16-1C, the rank-4 codebook is a subset of CB0, CB1, or CB0 ∪ CB1, where CB0 and CB1 are the rank-4 codebook partitions explained in Alt 16-0. In one instance of Alt 16-1D, a combination of Alt 16-1A and Alt 16-1B. In one instance of Alt16-1E, a combination of Alt 16-1A and Alt 16-1C. In one instance of Alt 16-1F, a combination of Alt 16-1B and Alt 16-1C. In one instance of Alt 16-1G: a combination of Alt 16-1A, Alt 16-1B, and Alt16-1C.

[0202] The rank 2, rank-3, and rank-4 codebooks according to any of these sub-alternatives are obtained by selecting a subset of the precoding matrices (or a subset of the codebook indices) in Tables 13, 14, and 15, respectively.

[0203] In a variant of Alt 16-1, the rank-4 codebook includes additional precoding matrices The scaling factor (a) in the rank 1-4 codebooks for this alternative is according to at least one of Alt 16-0A, 16-0B, and 16-0C.

[0204] In one example of Alt 16-2, for N = 4, the rank-1 codebook includes all the precoders in the LTE UL 4-Tx rank-1 codebook, where the scaling (or power normalization) factor (a) of the precoders is a = 1 or a = 2 or Note that a = 2 is used in the LTE UL 4-Tx codebook. In addition, the rank-1 codebook also includes four single-port selection precoders Table 12 shows an example of the rank-1 codebook. The total number of precoders in the rank-1 codebook is 24 + 4 = 28. The rank-1 codebook can be divided into three types of codebooks (CB). In one instance of CB0, it is the same as the rank-1 CB0 in Alt16-0. In one instance of CB1, it is the same as the rank-1 CB1 in Alt 16-0. In one instance of CB2, the third codebook includes 4 port selection precoders that select 1 out of 4 ports (1 entry in the precoder is non-zero while the remaining 3 entries are 0). In other words, assume the precoders are non-coherent, i.e., no port pair can transmit coherently.

[0205] Construct a rank 2-4 codebook using all the precoders in the rank-1 codebook. Similar to rank-1, the rank 2-4 codebook can also be divided into three types of codebooks (CB). For example, for rank-2, the total number of rank-2 precoding matrices is 16, which can be divided as follows. In one instance of CB0, it is the same as the rank-2 CB0 in Alt 16-0. In one instance of CB1, it is the same as the rank-2 CB1 in Alt 16-0. In one instance of CB2, the third codebook includes 4 rank-2 precoding matrices that select 1 out of 4 ports per layer. At least one of the following examples is used for the four rank-2 precoding matrices: In one example of Ex16-2A, In one example of Ex 16-2B, In one example of Ex 16-2C, any 4 from this set

[0206]

[0207] For Ex 16-2A, the code table for rank-2 is shown in Table 13. For Ex 16-2B, the rank-2 precoding matrix corresponding to codebook index 14 in Table 13 is replaced by p 26,27 。For Ex 16-2C, the rank-2 precoding matrices corresponding to codebook indices 12 - 15 in Table 13 are replaced by any four of the following: p 24，24 ,p 24，26 ,p 25，26 ,p 25，27 ,p 24，27 ,and p 26，27 。

[0208] For rank-3, the total number of rank-3 precoding matrices is 16, which can be divided as follows. In one example of CB0, it is the same as the rank-3 CB0 in Alt 16-0. In one example of CB1, it is the same as the rank-3 CB1 in Alt 16-0. In one example of CB2, the third codebook includes 4 rank-3 precoding matrices that select 1 out of 4 ports per layer. The four rank-3 precoding matrices are

[0209] Table 14 shows an example of the rank-3 codebook table. For rank-4, the total number of rank-4 precoding matrices is 7, which can be partitioned as follows. In one example of CB0, it is the same as the rank-4 CB0 in Alt 16-0. In one example of CB1, it is the same as the rank-4 CB1 in Alt16-0. In one example of CB2, the third codebook includes 1 rank-4 precoding matrix It selects 1 out of 4 ports for each layer.

[0210] Table 15 shows an example of the rank-4 codebook table. The total number of rank 1-4 pre-encoders / precoding matrices is 28 + 16 + 16 + 7 = 67. Therefore, if the codebook is used for UL transmission, then the codebook requires 7 bits for joint TRI and TPMI indication.

[0211] In a variant of Alt 16-2, CB2 of the rank-2 codebook includes less than 4 precoding matrices, and CB2 of the rank-3 codebook includes less than 4 precoding matrices. For example, CB2 of the rank-2 codebook includes 3 precoding matrices For example, CB2 of the rank-3 codebook includes 2 precoding matrices, for example

[0212] Therefore, the total number of rank 1-4 pre-encoders / precoding matrices is 28 + 15 + 14 + 7 = 64. Therefore, if the codebook is used for UL transmission, the codebook requires 6 bits for joint TRI and TPMI indication. By respectively replacing the precoding matrices corresponding to codebook indices 12-14 with p 24,25 , p 25,26 and p 26,27 , and removing the precoding matrix corresponding to codebook index = 15, the corresponding rank-2 codebook table is obtained from Table 13. By respectively replacing the precoding matrices corresponding to codebook indices 12-13 with p 24,25,26 and p 25,26,27 , and removing the precoding matrices corresponding to codebook indices 14-15, the corresponding rank-3 codebook table is obtained from Table 14.

[0213] The scaling factor (a) in the rank 1-4 codebook for this alternative is based on at least one of the following alternatives. In one example of Alt 16-2A, regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) used for UL transmission and rank 1-4, the scaling factor is the same (e.g., a = 2). In the example of Alt 16-2B, regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) used for UL transmission only for rank 1, the scaling factor is the same (e.g., a = 2), and the scaling factor for at least one of ranks 2-4 can be different from that of rank 1 (e.g., for CP-OFDM). For example, where n is the number of non-zero entries in the columns of the precoding matrix, Tables 13, 14, and 15 of the codebook imply the following. In one instance of rank 2, in Table 13, a = 2 is used for codebook indices 0-7, for codebook indices 8-11, and a = 1 is used for codebook indices 12-15. In one instance of rank 3, in Table 14, a = 2 is used for codebook indices 0-7, for codebook indices 8-11, a = 1 is used for codebook indices 12-15. In one instance of rank 4, in Table 15, a = 2 is used for codebook indices 0-3, for codebook indices 4-5, a = 1 is used for codebook index 6.

[0214] In one example of Alt 16-2C, for the two UL waveforms (DFT-S-OFDM or CP-OFDM) of rank 1, the scaling factors can be different. At least one of the following examples is independently used for DFT-S-OFDM and CP-OFDM. In one instance of Ex 16-2A, a = 2 is used for codebook indices 0-27 in Table 12. In one instance of Ex 16-2B, in Table 12, a = 2 is used for codebook indices 0-23, for codebook indices 24-27. In one instance of Ex 16-2C, in Table 12, a = 2 is used for codebook indices 0-23, a = 1 is used for codebook indices 24-27. In one instance of Ex16-2D, in Table 12, a = 2 is used for codebook indices 0-15, for codebook indices 16-23, and a = 1 is used for codebook indices 24-27.

[0215] For example, Ex 16-2A is used for DFT-S-OFDM, and Ex 16-2D is used for CP-OFDM. The scaling factor for at least one of ranks 2-4 can be the same as or different from the scaling factor of rank 1 (e.g., for CP-OFDM). If the scaling factors are different, the scaling factors are based on the example in Alt 16-2B.

[0216] In some embodiments Alt 16-3, the rank-1 codebook is the same as in Alt 16-2, and at least one of the rank 2-4 codebooks is constructed using a subset of the precoders in the rank-1 codebook. At least the following sub-alternatives are used.

[0217] In one example of Alt 16-3A, the rank-2 codebook is a subset of CB0, CB1, CB2, CB0 ∪

[0218] CB1, CB1 ∪ CB2, or CB0 ∪ CB2, where CB0, CB1, and CB2 are the rank-2 codebook partitions explained in Alt 16-2. In another example of Alt 16-3B, the rank-3 codebook is a subset of CB0, CB1, CB2, CB0 ∪ CB1, CB1 ∪ CB2, or CB0 ∪ CB2, where CB0, CB1, and CB2 are the rank-3 codebook partitions explained in Alt 16-2. In yet another example of Alt 16-3C, the rank-4 codebook is a subset of CB0, CB1, CB2, CB0 ∪ CB1, CB1 ∪ CB2, or CB0 ∪ CB2, where CB0, CB1, and CB2 are the rank-4 codebook partitions explained in Alt 16-2. In another example of Alt 16-3D, a combination of Alt 16-3A and Alt 16-3B. In yet another example of Alt 16-3E, a combination of Alt 16-3A and Alt 16-3C. In yet another example of Alt 16-3F, a combination of Alt 16-3B and Alt 16-3C. In yet another example of Alt 16-3G, a combination of Alt 16-3A, Alt 16-3B, and Alt 16-3C.

[0219] The rank 2, rank-3, and rank-4 codebooks according to any of these sub-alternatives are obtained by selecting subsets of precoding matrices (or subsets of codebook indices) in Tables 13, 14, and 15, respectively. The scaling factor (a) in the rank 1-4 codebooks used for this replacement is based on at least one of Alt 16-2A, 16-2B, and 16-2C.

[0220] Table 12.

[0221] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 1

[0222]

[0223] Table 13. Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0224]

[0225] Table 14. Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 3

[0226]

[0227] Table 15.

[0228] Codebook for transmission on antenna ports {3000, 3001, 3002, 3003}, where v = 4

[0229]

[0230] In some embodiments 16A, the rank-3 and rank-4 codebooks in embodiment 16 are replaced by codebooks constructed using only the BPSK alphabet {1, -1} for the precoding matrix that selects more than 1 port per layer. Exemplary rank-3 and rank-4 codebook tables are shown in Tables 16 and 17 respectively. The scaling factor (a) in these rank 3-4 codebooks is according to at least one of Alt 16-0A, 16-0B, 16-0C, Alt 16-2A, 16-2B, and 16-2C.

[0231] Table 16.

[0232] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 3

[0233]

[0234] Table 17.

[0235] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 4

[0236]

[0237] In some embodiments 16B, the codebook partition type (from CB0, CB1, and CB2) in the rank 1-4 codebook as explained in embodiment 16 is determined / configured according to at least one of the following alternatives. In one example of Alt 16B-0, the codebook partition type is fixed for ranks 1-4, where the codebook type is the same for ranks 1-4, e.g., CB0; or different for ranks 1-4, e.g., CB0 for rank 1, CB1 for ranks 2-3, and CB2 for rank 4. In another example of Alt 16B-1, the codebook partition type is fixed for a subset of rank values. For example, for ranks > r, the codebook type is fixed, where r = 2. The subset of rank values is fixed or configured via higher layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling. In yet another example of Alt 16B-2, the codebook partition type is configured for all ranks via higher layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling. This configuration is common for all ranks (1 or 2-bit signaling) or independent for each rank (1 or 2-bit signaling per rank, thus 4 or 8 bits for ranks 1-4). In yet another example of Alt 16B-3, the codebook partition type is configured via higher layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling for a subset of rank values. This configuration is common for some rank values (1 or 2-bit signaling) or independent for each rank (1 or 2-bit signaling per rank). The subset of rank values is fixed or configured via higher layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling.

[0238] In a variant of this embodiment (e.g., embodiment 16X), the codebook partition type (from CB0, CB1, and CB2) in the rank 1-4 codebook as explained in embodiment 16 is determined / configured using bitmap B or field F via higher layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling. If configured via higher layer (e.g., RRC) signaling, this configuration is an example of the codebook subset restriction where the gNB sends, via RRC signaling, to the UE the codebook partition type for the uplink codebook, and the size (number of bits) of the TPMI-related signaling field in the UL-related DCI is determined according to the number of precoding matrices after applying the codebook subset restriction to the UL codebook.

[0239] If bitmap B is common for all ranks 1-4, then use at least one of the following alternatives. In one example of Alt 16B-0, 2-bit bitmap B = b0b1 is used for codebook partition type pairs (CBx, CBy), where (x, y) is (0,1), (1,2), or (1,2), where b0 is the most significant bit (MSB) and b1 is the least significant bit (LSB) or b0 is the LSB and b1 is the MSB. In one example of Alt16B-1, 3-bit bitmap B = b0b1b2 is used for codebook partition type triples (CB0, CB1, CB2), where b0 is the MSB and b2 is the LSB or b0 is the LSB and b2 is the MSB.

[0240] If bit b i = 0, then the corresponding codebook partition type CB i is not used for TPMI indication, and if bit b i = 1, then the corresponding codebook partition type CB i is used for TPMI indication. Or, if bit b i = 1, then the corresponding codebook partition type CB i is not used for TPMI indication, and if bit b i = 0, then the corresponding codebook partition type CB i is used for TPMI indication.

[0241] If bitmap B is independent for all or a subset of ranks 1-4, then bitmap B is a concatenation of R bitmaps B0...B R-1 , where R is the number of rank values for which we have independent bitmaps. For example, if R = 4, then bitmap B is a concatenation of 4 bitmaps B0...B3, where B0 is the bitmap for rank value 1, B3 is the bitmap for rank value 4, or B_0 is the bitmap for rank value 4 and B3 is the bitmap for rank value 1. For each bitmap B i , use at least one of Alt 16B-0 or Alt 16B-1. Thus, the maximum length of the bitmap is 8 bits (Alt 16B-0) or 12 bits (Alt 16B-1).

[0242] For the TPMI indication in UL-related DCI, regardless of whether all or a subset of the three codebook partition types (CB0, CB1, CB2) are used to determine the precoding matrix indicated by TPMI, the TPMI payload (number of bits) can remain the same (unaffected). For example, for the TPMI payload, it can be assumed that the precoding matrix for all three types of codebook partition types is used. Alternatively, the TPMI payload can be adjusted according to the codebook partition type used. An exemplary table of TPMI and transmit rank indicator (TRI) payload sizes (assuming CB0, CB1, CB2 are available for TPMI indication) is shown in Table 18, where the rank 1-4 codebooks are assumed to be Tables 12, 13, 14, and 15. If any two of CB0, CB1, CB2 are available for TPMI indication, the table is reduced from Table 18 to 3 rows (2 for one of the two codebook partition types and 1 for the two codebook partition types).

[0243] Table 18. TPMI and TRI Payload

[0244]

[0245] Note that in this variant (16X), regardless of the UL transmission capabilities of the UE, the bitmap configuring the codebook partition type remains the same. As an example, the UE is capable of at least one of the following UL transmissions. In one example of full coherence, all ports can transmit coherently. In one example of partial coherence, port pairs can transmit coherently. In one example of incoherence, port pairs cannot transmit coherently.

[0246] Next, a variant where the bitmap B depends on the UE capabilities is provided. Assume the rank 1 codebook of TPMI, Table 12, as an example in the following variants (16X-1 and 16X-2). For rank > 1 TPMI, the codebook tables for rank > 1 proposed in this disclosure can be used.

[0247] In a variant of this embodiment (e.g., Embodiment 16X-1), the codebook configuration or partition type (from CB0, CB1, and CB2) in the rank 1-4 codebooks as explained in Embodiment 16 is determined / configured based on the UE capabilities (indicated by the UE) for UL transmission using the bitmap B via high-layer (RRC) signaling or MAC CE-based signaling or dynamic DCI-based signaling. If configured via high-layer (e.g., RRC) signaling, this configuration is an example of the gNB sending to the UE via RRC signaling a codebook subset restriction of the codebook partition type for the uplink codebook, where the size (number of bits) of the TPMI-related signaling field in the UL-related DCI is determined according to the number of precoding matrices after applying the codebook subset restriction to the UL codebook. At least one of the following alternatives can be used for CBSR via RRC signaling.

[0248] In an alternative (Alt 16X-1-0), if the UE can be fully coherent, it can also be partially coherent and non-coherent. Thus, a 3-bit bitmap B can be used to configure one of seven possible groups of precoders (or combinations of codebook partition types). Two example tables of such a configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 19 and 20. Alternatively, a 2-bit field F is used to configure one of three codebook partition types (CB0, CB1, and CB2), where, for example, CB0, CB1, and CB2 are indicated by F = 00, 01, 10 or 10, 01, 00 respectively.

[0249] In an alternative (Alt 16X-1-0), if the UE can be partially coherent, it can also be non-coherent. Thus, a 2-bit bitmap B can be used to configure one of three possible groups of precoders (or combinations of codebook partition types). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 21 and 22. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB1 and CB2), where, for example, CB1 and CB2 are indicated by F = 0 and 1 or 1 and 0 respectively.

[0250] In an alternative (Alt 16X-1-0), if the UE can be non-coherent, it can only be non-coherent. Thus, the group of precoders (or codebook partition type) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0251] Table 19. Codebook Configuration and TPMI Payload

[0252]

[0253] Table 20. Codebook Configuration and TPMI Payload

[0254]

[0255] Table 21. Codebook Configuration and TPMI Payload

[0256]

[0257] Table 22. Codebook Configuration and TPMI Payload

[0258]

[0259] In another alternative (Alt 16X-1-1), if the UE can be fully coherent, it can also be partially coherent. Thus, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 23 and 24. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB0 and CB1), where, for example, CB0 and CB1 are indicated by F = 0 and 1 or 1 and 0, respectively.

[0260] In another alternative (Alt 16X-1-1), if the UE can be partially coherent, then it can also be non-coherent. Thus, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 21 and 22. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB1 and CB2), where, for example, CB1 and CB2 are represented by F = 0 and 1 or 1 and 0, respectively.

[0261] In another alternative (Alt 16X-1-1), if the UE can have non-coherence, it can only have non-coherence. Thus, the set of precoders (or codebook partition type) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0262] Table 23. Codebook Configuration and TPMI Payload

[0263]

[0264] Table 24. Codebook Configuration and TPMI Payload

[0265]

[0266] In another alternative (Alt 16X-1-2), if the UE can be fully coherent, it can also be partially coherent. Thus, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 23 and 24. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB0 and CB1), where, for example, CB0 and CB1 are indicated by F = 0 and 1 or 1 and 0, respectively.

[0267] In another alternative (Alt 16X-1-2), if the UE can be non-coherent, then it can only be non-coherent, and if the UE can be partially coherent, then it can only be partially coherent. Thus, the set of precoders (or codebook partition types) is fixed (CB1), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 3 bits.

[0268] In another alternative (Alt 16X-1-2), if the UE can have non-coherence, then it can only have non-coherence, and if the UE can be non-coherent, then it can only have non-coherence. Thus, the set of precoders (or codebook partition types) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0269] In another alternative (Alt 16X-1-3), if the UE can be partially coherent, then it can also have non-coherence. Thus, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 21 and 22. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB1 and CB2), where, for example, CB1 and CB2 are indicated by F = 0 and 1 or 1 and 0, respectively.

[0270] In another alternative (Alt 16X-1-3), if the UE can be fully coherent, then it can only be fully coherent. Thus, the set of precoders (or codebook partition types) is fixed (CB0), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 4 bits.

[0271] In another alternative (Alt 16X-1-3), if the UE can be non-coherent, then it can only be non-coherent. Thus, the set of precoders (or codebook partition types) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0272] In a variant of the embodiment (Embodiment 16X-2), the codebook configuration or partition type (from CB0, CB1, and CB2) in the rank 1-4 codebook as described in Embodiment 16 is determined based on the UE capability (indicated by the UE) for UL transmission without any signaling / configuration. The PMI payload is adjusted based on the UE capability. Use at least one of the following alternatives.

[0273] In an example of Alt 16X-2-0, the codebook partition type is one-to-one mapped to the UE capabilities for UL transmission. For example, if the UE is fully coherent, CB0 is used as the UL codebook and the TPMI payload is 4 bits; if the UE is partially coherent, CB1 is used as the UL codebook and the TPMI payload is 3 bits; if the UE is non-coherent, CB2 is used as the UL codebook, and the TPMI payload is 2 bits.

[0274] In another example of Alt 16X-2-1, the codebook partition type is (CB0, CB1) for full and partial coherence or CB2 for non-coherence, where the TPMI payload is fixed at 5 bits for the former and 2 bits for the latter.

[0275] In yet another example of Alt 16X-2-2, the codebook partition type is (CB1, CB2) for partial and non-coherence or CB0 for full coherence, where the TPMI payload is fixed at 4 bits for both the former and the latter. In yet another example of Alt 16X-2-3, the codebook partition type is (CB0, CB2) for full and non-coherence or CB1 for partial coherence, where the TPMI payload is fixed at 5 bits for the former and 3 bits for the latter.

[0276] In a variant of this embodiment (Embodiment 16Y), the codebook subset restriction (CBSR) is configured by the gNB to the UE via RRC signaling using a bitmap B on the UL codebook (e.g., the rank 1-4 codebook in Embodiment 16), where the bitmap restricts the use of each precoding matrix in the codebook for TPMI indication. In one example, the bitmap B is a concatenation of R bitmaps B0...B R-1 where R is the number of rank values for which we have CBSR. For example, if R = 4, then the bitmap B is a concatenation of 4 bitmaps B0...B3, where B0 is the bitmap for rank value 1, B3 is the bitmap for rank value 4, or B0 is the bitmap for rank value 4. Thus, the total length of the bitmap is where Ni is the number of precoding matrices in the rank i codebook. In another example, after applying the codebook subset restriction to the UL codebook, the size (number of bits) of the TPMI-related signaling field in the UL-related DCI is determined based on the number of precoding matrices.

[0277] In a variant of this embodiment (Embodiment 16Z), the codebook subset restriction (CBSR) is configured by the gNB for the UE on the UL codebook (e.g., the rank 1-4 codebook in Embodiment 16) via RRC signaling using bitmap B or status configuration S. Where the bitmap or status configuration restricts the use of a set of precoding matrices in the codebook for TPMI indication. An example of precoder grouping is explained in Embodiment 7, where the first TPMI (i1) is used for the precoder group, and the second TPMI (i2) is used for the precoders in each precoder group. Then, the CBSR restricts the first TPMI (i1).

[0278] In Embodiment 16C, the rank 2-4 codebooks are the same as in Embodiment 16, and the rank-1 codebook table includes 4 additional rank-2 precoders (codebook indices 28-31). Some examples of the four additional precoders are as follows: where the normalization factor b = 2 or where the normalization factor b = 2 or and the normalization factor b = 2 or

[0279] In some Embodiments 17, the rank 2 codebook includes at least one of the following four types of codebooks (CB). In one example, CB0 is a subset or all of the rank-2 precoding matrices in CB0 in Embodiment 16 / 16A / 16B / 16C, and examples of the normalization factor are c = 2 or In another example, CB1 is a subset or all of the rank-2 precoding matrices in CB1 in Embodiment 16 / 16A / 16B / 16C, and examples of the normalization factor are c = 2 or In yet another example, CB2 is a subset or all of the rank-2 precoding matrices in CB2 in Embodiment 16 / 16A / 16B / 16C, and examples of the normalization factor are c = 2 or In yet another example, CB3 is a subset or all of the rank-2 precoding matrices in the LTE UL 4-Tx rank-2 codebook, and where the precoders (columns of the precoding matrix) for each layer are normalized to or 1 / 2. In such an example, v and v are the rank-1 precoders corresponding to codebook indices m and n, respectively. or 1 / 2. In such an example, v m and v n are the rank-1 precoders corresponding to codebook indices m and n, respectively.

[0280] Rank-2 Codebook This table is based on at least one of the following alternatives. In one example of Alt 17-0, a subset or all of the rank-2 precoding matrices in CB0 and CB3. An exemplary rank-2 codebook table is shown in Table 25. In another example of Alt 17-1, a subset or all of the rank-2 precoding matrices in CB0, CB2, and CB3. Four exemplary rank-2 codebook tables are shown in Tables 26-31.

[0281] Table 25.

[0282] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0283]

[0284] Table 26.

[0285] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0286]

[0287] Table 27.

[0288] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0289]

[0290] Table 28.

[0291] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0292]

[0293] Table 29A. Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0294]

[0295] Table 29B. Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0296]

[0297] Table 30. Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0298]

[0299] Table 31.

[0300] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 2

[0301]

[0302] In some embodiments 18, the rank-3 codebook includes at least one of the following four types of codebooks (CB). In one example, CB0 is a subset or all of the rank-3 precoding matrix in CB0 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2 or In another example, CB1 is a subset or all of the rank-3 precoding matrix in CB1 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2 or In yet another example, CB2 is a subset or all of the rank-3 precoding matrix in CB2 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2 or In yet another example, CB3 is a subset or all of the rank-3 precoding matrix in the LTE UL 4-Tx rank-3 codebook, and the precoder (column of the precoding matrix) for each layer is normalized to or 1 / 2. In such an example, v , v and v are the rank-1 precoders corresponding to the codebook indices m, n, and p, respectively. m , v n and v p are the rank-1 precoders corresponding to the codebook indices m, n, and p, respectively.

[0303] The rank-3 codebook table is based on at least one of the following alternatives. In one example of Alt 18-0, a subset or all of the rank-3 precoding matrices in CB0 and CB3. An exemplary rank-3 codebook table is shown in Table 32. In another example of Alt 18-1, a subset or all of the rank-3 precoding matrices in CB0, CB2, and CB3. An exemplary rank-3 codebook table is shown in Table 33.

[0304] Table 32.

[0305] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 3

[0306]

[0307] Table 33.

[0308] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 3

[0309]

[0310] In some embodiments 19, the rank-4 codebook includes at least one of the following four types of codebooks (CB). In one example, CB0 is a subset or all of the rank-4 precoding matrices in CB0 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2. In another example, CB1 is a subset or all of the rank-4 precoding matrices in CB1 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2. In yet another example, CB2 is a subset or all of the rank-4 precoding matrices in CB2 in embodiments 16 / 16A / 16B / 16C, and an example of the normalization factor is c = 2. In yet another example, CB3 is a subset or all of the rank-4 precoding matrices in the LTE UL 4-Tx rank-4 codebook, and the precoder (columns of the precoding matrix) for each layer is normalized to 1 / 2. In such an example, v , v , v and v m , v n , v p and v q are rank-1 precoders corresponding to codebook indices m, n, p, and p respectively.

[0311] The rank-4 codebook table is based on at least one of the following alternatives. In one example of Alt 19-0, a subset or all of the rank-4 precoding matrices in CB0 and CB3. An exemplary rank-4 codebook table is shown in Table 34. In another example of Alt 19-1, a subset or all of the rank-4 precoding matrices in CB0, CB1, and CB3. An exemplary rank-4 codebook table is shown in Table 35.

[0312] Table 34.

[0313] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 4

[0314] Codebook (or TPMI) index Number of layers υ = 4 0 Rank - 4 pre - coding matrix in LTE UL 4 - Tx Codebook 1 <![CDATA[p 0,2,8,10 >

[0315] Table 35.

[0316] Codebook for transmission on 4 antenna ports {3000, 3001, 3002, 3003}, where v = 4

[0317] Codebook (or TPMI) index Number of layers υ = 4 0 Rank - 4 pre - coding matrix in LTE UL 4 - Tx Codebook 1 <![CDATA[p 0,2,8,10 > 2 <![CDATA[p 16,17,20,21 >

[0318] In the foregoing embodiments 16 / 17 / 18 / 19, the mapping of the codebook index to the precoder or precoding matrix in the codebook table is for illustration only. Any other mapping is also included in these embodiments.

[0319] In some embodiments 20, for N = 2, the rank-1 codebook is the LTE UL 2-Tx rank-1 codebook, except for the scaling (or power normalization) factor (a) in the precoder, which is a = 1 or a = 2 or The total number of precoders in the rank-1 codebook is 6. The rank-1 codebook can be divided into two types of codebooks (CB). In an example of CB0, the first codebook includes 4 precoders that combine 2 ports (both entries in the precoder are non-zero). In other words, the precoder assumes full coherence, i.e., 2 ports can be transmitted coherently. In another example of CB1, the second codebook includes 2-port selection precoders that select 1 out of 2 ports (1 entry in the precoder is non-zero and the remaining 1 entry is 0). In other words, the precoder assumes incoherence, i.e., 2 ports cannot be transmitted coherently.

[0320] All precoders in the rank-1 codebook are used to construct the rank 2 codebook. Similar to rank-1, the rank 2 codebook can also be divided into two types of codebooks (CB). For example, the total number of rank-2 precoding matrices is 3, which can be divided as follows. In an example of CB0, the first codebook includes 2 rank-2 precoding matrices that combine all 2 ports per layer (i.e., both entries in the precoder per layer are non-zero). In another example of CB1, the second codebook includes 1 rank-2 precoding matrix that selects 1 out of 2 ports per layer (i.e., 1 entry in the precoder per layer is non-zero and the remaining 1 entry is zero).

[0321] Examples of the rank-1 and rank-2 codebooks are shown in Table 36. The scaling factor (a) in the rank 1-2 codebook is based on at least one of the following alternatives. In an example of Alt 20A, the scaling factor is the same (e.g., ), regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) used for UL transmission and rank 1-2. In another example of Alt 20B, the scaling factor is the same (e.g., ), regardless of the UL waveform (DFT-S-OFDM or CP-OFDM) used for UL transmission only for rank 1, and the scaling factor for rank 2 can be different from that for rank 1 (e.g., for CP-OFDM).

[0322] For example, where n is the number of non-zero entries in a column of the precoding matrix, and for the codebooks in Table 36, this means the following. In one instance of rank 2, in Table 36, is used for codebook indices 0 - 1, and a = 1 is used for codebook index 2.

[0323] In yet another example of Alt 20C, for two UL waveforms (DFT-S-OFDM or CP-OFDM) of rank 1, the scaling factors can be different. At least one of the following examples is independently used for DFT-S-OFDM and CP-OFDM. In one instance of Ex 20A, is used for codebook indices 0 - 5 in Table 36. In one instance of Ex 20B, in Table 36, is used for codebook indices 0 - 3, and a = 1 is used for codebook indices 4 - 5. In one instance of Ex 20C, in Table 36, a = √2 is used for codebook indices 0 - 3, and a = 2 is used for codebook indices 4 - 5. For example, Ex 20A or Ex 20C is used for DFT-S-OFDM and Ex 20B is used for CP-OFDM. The scaling factors for rank 2 can be the same as or different from those for rank 1 (e.g., for CP-OFDM). If the scaling factors are different, the scaling factors follow the examples in Alt 20B.

[0324] is directly extended to embodiments regarding codebook partition type determination / configuration and codebook subset restriction for the N = 2-port case (e.g., the foregoing embodiments 16B / 16X / 16Y / 16Z and their variants).

[0325] Table 36.

[0326] Codebook for transmission on 2 antenna ports {3000, 3001}, rank v,

[0327]

[0328] For 4 antenna ports [port numbers to be added #],..., and for a UE configured with the higher layer parameter CodebookType set to 'TypeI-SinglePanel', except when the number of layers v ∈ {2, 3, 4}, each PMI value corresponds to three codebook indices i 1,1 , i 1,2 , i2. When the number of layers v ∈ {2, 3, 4}, each PMI value corresponds to four codebook indices i 11 , i 12 , i 13 , i2. The codebooks...... are given in Tables 37A - G respectively. The mapping from i 1,3 to k1 and k2 for 2-layer reporting is given in Table 37B. When P is given in Table 37CCSI-RS <At 16:00, from i 1,3 The mapping to k1 and k2 is used for layer 3 and layer 4 reports. The quantity and...... is

[0329]

[0330] The values of N1 and N2 are respectively configured with the higher layer parameters CodebookConfig - N1 and CodebookConfig - N2. The supported configurations of (N1, N2) for the corresponding values of the given number of CSI - RS ports and (O1, O2) are given in Table 37A. The number P of CSI - RS ports CSI-RS is 2N1N2. If the value of CodebookConfig - N2 is set to 1, the UE can only use i 1,2 = 0 and may not report i 1,2 .

[0331] Table 37A. Supported configurations (N1, N2) and (O1, O2)

[0332]

[0333] Table 37B. Mapping of i 13 to k1 and k2 for layer 2 CSI reporting

[0334]

[0335] Table 37C. When P CSI-RS <At 16:00, mapping of i 13 to k1 and k2 for layer 3 and layer 4 CSI reporting

[0336]

[0337] Table 37D.

[0338] Codebook for layer 1 CSI reporting using antenna ports [3000 to 2999 + P CSI-RS

[0339] Table 37E. Codebook for layer 2 CSI reporting using antenna ports [3000 to 2999 + P CSI-RS

[0340] Table 37F. Codebook for layer 3 CSI reporting using antenna ports [3000 to 2999 + P CSI-RS ​​​

[0341] Table 37G. Codebook for 4-layer CSI reporting using antenna ports [3000 to 2999+P CSI-RS .

[0342]

[0343] In some embodiments 21, the UE is indicated by TPMI via UL-related DCI using a 4-Tx (or 4-port) UL codebook, where the precoder or precoding matrix indicated by the TPMI corresponds to at least one of the following: fully coherent, partially coherent, and non-coherent precoders as previously defined in the present disclosure. The codebook can be divided into three precoder subsets or three types of coherent precoding matrices. Details of the rank 1-4 codebooks are as follows.

[0344] In sub-embodiment 21A, the rank 1 codebook includes at least one of the following types of precoders. In one example of CB0 (fully coherent), the precoder corresponds to transmissions from all 4 ports. The scaling factor α for normalizing the precoder is according to at least one embodiment / alternative mentioned previously in the present disclosure. For example, a = 2. At least one of three alternatives is used. In one alternative of Alt 21A-0, the precoder corresponding to the codebook or TPMI index 0-15 in the LTE UL rank-1 4-Tx codebook is used. At least one of the following examples is used. In one example Ex 21A-0-0 of this alternative, there are 16 precoders in the LTE UL rank-1 4-Tx codebook and all of them are used. In another example Ex 21A-0-1 of this alternative, a subset of 16 precoders is used. For example, 8 out of 16 precoders are used, where the 8 precoders correspond to the codebook or TPMI index set {i = 0-7} or {2i: i = 0-7} = {0,2,4,6,8,10,12,14} or {2i + 1: i = 0-7} = {1,3,5,7,9,11,13,15}.

[0345] In another alternative of Alt 21A-1, the precoder for the single antenna panel for L = 1 or CodebookMode = 1 in the NR DL rank-1 4-Tx type I CSI codebook is used. At least one of the following examples is used. In one example Ex 21A-1-0 of this alternative, there are 32 precoders in the NR DL rank-1 4-Tx type I CSI codebook for the single antenna panel for L = 1 or CodebookMode = 1, and all of them are used. The PMI(i 1,1 , i 1,2 , i2) indicates 32 precoders, where {i 1,1= {0 - 7}, i 1,2 = 0, and {i2 = 0 - 3}. The mapping from PMI(i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 4i 1,1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 4 and i 1,1 = (k - i2) / 4.

[0346] In another example Ex 21A-1-1 of this alternative, a subset of 32 precoders is used. For example, 16 out of 32 precoders are used, which correspond to {i 1,1 = 0, 2, 4, 6}, i 1,2 = 0 and {i2 = 0 - 3} in the NR DL 4-Tx codebook. Note that these precoders correspond to an effective oversampling factor O1 = 2 in the DFT beam v 1，m . The mapping from PMI(i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 4*(i 1,1 / 2) + i2 = 2i 1，1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 4 and i 1,1 = (k - i2) / 2.

[0347] In yet another alternative of Alt 21A-2, precoders from the LTE specification DL rank-1 Householder codebook are used. At least one of the following examples is used. In one example Ex 21A-2-0 of this alternative, there are 16 precoders in the LTE specification DL rank-1 Householder codebook and all of them are used. In another example Ex 21A-2-1 of this alternative, a subset of 16 precoders is used. For example, 8 out of 16 precoders are used, where 8 precoders correspond to the PMI indices {i = 0 - 7} or {2i: i = 0 - 7} = {0, 2, 4, 6, 8, 10, 12, 14} or {2i + 1: i = 0 - 7} = {1, 3, 5, 7, 9, 11, 13, 15}.

[0348] In another example of CB1 (partially coherent), the precoder corresponds to transmissions from 2 out of 4 ports. The scaling factor a for normalizing the precoder is according to at least one embodiment / alternative mentioned previously in the present disclosure. For example, a =. At least one alternative is used. In one alternative of Alt21A-3, a precoder corresponding to the codebook or the TPMI index 16-23 in the LTE UL rank-1 4-Tx codebook is used. In another alternative of Alt 21A-4, the precoder corresponds to where e_x is a 4×1 port selection vector that has a value of 1 at entry x and values of 0 at the remaining 3 entries, and Note that there are 6 possible values for the pair (i, j) ∈ {(0,1), (0,2), (0,3), (1,2), (1,3),

[0349] (2,3)}, where the 4 entries of the vector e_x are numbered 0, 1, 2, and 3. Thus, the maximum number of precoders is 6×4 = 24. In another alternative of Alt 21A-5, it is the same as Alt 21A-4, except that (i, j) takes values from a subset S of {(0,1), (0,2), (0,3), (1,2), (1,3), (2,3)}. For example, S = {(0,1), (1,2), (2,3), (0,3)} or S = {(0,2), (1,3),

[0350] (0,1), (2,3)} or S = {(0,2), (1,3)}.

[0351] In another example of CB2 (non-coherent), the precoder corresponds to transmissions from 1 out of 4 ports. As described in Embodiment 16 (Alt 16-2), there are 4 such precoders. The scaling factor a for normalizing the precoder is according to at least one embodiment / alternative mentioned previously in the present disclosure. For example, a = 1.

[0352] In sub-embodiment 21B, the rank 2 codebook includes at least one of the following types of precoding matrices. In one example of CB0 (fully coherent), the precoding matrix corresponds to transmissions from all 4 ports of each layer (where the layer corresponds to the column of the precoding matrix). The scaling factor a for normalizing each column of the precoding matrix is according to at least one embodiment / alternative mentioned previously in the present disclosure. For example, a = 2. Note that in addition to the scaling factor a, a pass is also applied to the two layers through Normalization. Use at least one of three alternatives. In one alternative of Alt 21B-0, as proposed in CB0 in Embodiment 16, use a rank-1 precoder in the LTE UL rank-1 4-Tx codebook (codebook indices 0-15) to form a rank-2 precoding matrix. Use at least one of the following examples. In one instance of Ex 21B-0-0, form 8 rank-2 precoding matrices. For example, the precoding matrices corresponding to TPMI indices 0-7 in Table 13. In another instance of Ex 21B-0-1, form 16 rank-2 precoding matrices. For example, the precoding matrices corresponding to TPMI indices 0-15 in Table 13.

[0353] In another alternative of Alt 21B-1, use a rank-2 precoding matrix in the NR DL rank-2 4-Tx type I CSI codebook for a single antenna panel with L = 1 or CodebookMode = 1. Use at least one of the following examples. In one instance of Ex21B-1-0, there are 32 rank-2 precoding matrices in the NR DL rank-2 4-Tx type I CSI codebook for a single antenna panel with L = 1 or CodebookMode = 1 and use all of them. Use PMI(i 1,1 , i 1,2 , i 1,3 , i2) to indicate 32 rank-2 precoding matrices, where {i 1,1 = 0-7}, i 1,2 = 0, {i 1，3 = 0,1} and {i2 = 0-1}.

[0354] The mapping from PMI(i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 4i 1,1 + 2i 1,3 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2, i 1,3 = (k - i2) / 2 mod 2, and i 1,1 = (k - i2 - 2i 1,3 ) / 4.

[0355] In another instance of Ex 21B-1-1, use a subset of 32 precoding matrices. For example, use 8 rank-2 precoding matrices, which in the NR DL 4-Tx rank-2 codebook correspond to {i 1,1 =

[0356] {0, 2, 4, 6}, i 1,2 = i 1,3 = 0 and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v 1，m and v 1+k1，m+k2 in with an effective oversampling factor O1 = 2 and (k1, k2) = (0, 0). The mapping from the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2 * (i 1,1 / 2) + i2 = i 1，1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = k - i2.

[0357] In one example of Ex 21B-1-2, a subset of 32 precoding matrices is used. For example, 8 rank-2 precoding matrices are used, which in the NR DL 4-Tx rank-2 codebook correspond to {i 1,1 = 0, 4}, i 1,2 = 0, {i 1,3 = 0, 1} and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v 1，m and v l+k1，m+k_2 in with an effective oversampling factor O1 = 1 and (k1, k2) = (0, 0), (4, 0). The mapping from the PMI (i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 4 * (i 1,1 / 4) + 2 * i 1,3 + i2 = i 1,1 + 2i 1,3 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2, i 1,3 = (k - i2) / 2 mod 2, and i 1,1 = k - i2 - 2i 1,3 .

[0358] In another example of Ex 21B-1-3, a subset of 32 precoding matrices is used. For example, 16 rank-2 precoding matrices are used, which correspond to {i 1,1 = 0-7} in the NR DL 4-Tx rank-2 codebook, i 1,2 = i 1,3 = 0 and {i2 = 0-1}. Note that these precoders correspond to the effective oversampling factor O1 = 2 and (k1, k2) = (0,0) in the DFT beams v 1，m and v 1+k1，m+k2 of two layers. The mapping from the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2i 1,1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = (k - i2) / 2.

[0359] In yet another example of Ex 21B-1-4, a subset of 32 precoding matrices is used. For example, 16 rank-2 precoding matrices are used, which in the NR DL 4-Tx rank-2 codebook correspond to {i 1,1 =

[0360] 0, 2, 4, 6}, i 1,2 = 0, {i 1,3 = 0, 1} and {i2 = 0-1}. Note that these precoders correspond to the effective oversampling factor O1 = 2 and (k1, k2) = (0,0), (4,0) in the DFT beams v 1，m and v l+k1，m+k2 of two layers. The mapping from the PMI (i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 4*(i 1,1 / 2) + 2*i 1,3 + i2 = 2i 1,1 + 2i 1,3 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i 1,3 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2, i 1,3 = (k - i2) / 2 mod 2, and i 1,1 = (k - i2 - 2i 1,3 ) / 2.

[0361] In another alternative of Alt 21B-2, a rank-2 precoding matrix from the LTE specification DL rank-2 Householder codebook is used. At least one of the following examples is used. In one instance of Ex21B-2-0, there are 16 rank-2 precoding matrices in the LTE specification DL rank-2 Householder codebook and all of them are used. In another instance of Ex 21B-2-1, a subset of the 16 precoding matrices is used. For example, 8 of the 16 rank-2 precoding matrices are used, where the 8 precoding matrices correspond to PMI indices {i = 0-7} or {2i: i = 0-7} = {0, 2, 4, 6, 8, 10, 12, 14} or {2i + 1: i = 0-7} = {1, 3, 5, 7, 9, 11, 13, 15}.

[0362] In another example of CB1 (partially coherent), the precoding matrix corresponds to the transmission of 2 out of 4 ports per layer. The scaling factor a for normalizing each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in this disclosure. For example, Note that in addition to the scaling factor a, normalization is also applied to the two layers by At least one alternative is used. In one alternative of Alt 21B-3, a precoding matrix corresponding to codebook indices 0-15 in the LTE UL rank-2 4-Tx codebook is used. In another alternative of Alt 21B-4, a rank-1 precoder from the LTE UL rank-1 4-Tx codebook (codebook indices 16-23) as proposed in CB1 in Example 16 is used to form a rank-2 precoding matrix. At least one of the following examples is used.

[0363] In one instance of Ex 21B-4-0, 8 rank-2 precoding matrices are formed. For example, where defined earlier in this disclosure, and (m, n) = (16, 17), (18, 19), (20, 21),

[0364] (22, 23), (16, 20), (17, 21), (18, 22), (19, 23). In another instance of Ex 21B-4-1, 16 rank-2 precoding matrices are formed. For example, {P m，n} where P m，n is defined earlier in this disclosure, and (m, n) = (16, 17), (18, 19), (20, 21), (22, 23), (17, 20),

[0365] (17, 21), (18, 22), (19, 23), (16, 21), (17, 20), (18, 23), (19, 22),

[0366] (16, 22), (17, 23), (18, 20), (19, 21).

[0367] In another example (non - coherent) of CB2, the precoding matrix corresponds to the transmission of 1 out of 4 ports per layer. The scaling factor a for normalizing each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in the present disclosure. For example, a = 1. Note that in addition to the scaling factor a, normalization is also applied to two layers through As explained in Example 16 (Alt 16 - 2), there are at most 6 such precoding matrices. At least one alternative is used. In one alternative of Alt21B - 5, all 6 precoding matrices, as explained in Example 16 (Alt 16 - 2), are given by

[0368] In another alternative of Alt 21B - 6, a subset of 6 precoding matrices is used. For example, 4 out of 6 precoding matrices are used. For example, the precoding matrices corresponding to TPMI indices 12 - 15 in Table 13.

[0369] In sub - embodiment 21C, the rank - 3 codebook includes at least one of the following types of precoding matrices. In one example of CB0 (fully coherent), the precoding matrix corresponds to the transmission from all 4 ports of each layer (where the layer corresponds to the column of the precoding matrix). The scaling factor a for normalizing each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in the present disclosure. For example, a = 2. Note that in addition to the scaling factor a, normalization is also applied to three layers through At least one of three alternatives is used.

[0370] In one alternative of Alt 21C - 0, the rank - 1 precoders in the LTE UL rank - 14 - Tx codebook (codebook indices 0 - 15) proposed in CB0 as in Example 16 are used to form the rank - 3 precoding matrix. At least one of the following examples is used. In one instance of Ex 21C - 0 - 0, 2 rank - 3 precoding matrices are formed. For example, the precoding matrices corresponding to TPMI indices 0 - 1 in Table 14. In another instance of Ex 21C - 0 - 1, 4 rank - 3 precoding matrices are formed. For example, the precoding matrices corresponding to TPMI indices 0 - 3 are shown in Table 14. In yet another instance of Ex 21C - 0 - 2, 8 rank - 3 precoding matrices are formed. For example, the precoding matrices corresponding to TPMI indices 0 - 7 are shown in Table 14.

[0371] In another alternative of Alt 21C-1, a rank-3 precoding matrix in the NR DL rank-3 4-Tx type-I CSI codebook for a single-antenna panel with L = 1 or CodebookMode = 1 is used. At least one of the following examples is used. In one instance of Ex21C-1-0, there are 16 rank-3 precoding matrices in the NR DL rank-3 4-Tx type-I CSI codebook for a single-antenna panel with L = 1 or CodebookMode = 1 and all of these matrices are used. The 16 rank-3 precoding matrices are represented by PMI(i 1,1 , i 1,2 , i 1,3 , i2), where {i 1,1 = 0 - 7}, i 1,2 = i 1,3 = 0, and {i2 = 0 - 1}. The mapping from PMI(i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2i 1,1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod2 and i 1,1 = (k - i2) / 2.

[0372] In another instance of Ex 21C-1-1, a subset of 16 precoding matrices is used. For example, 2 rank-3 precoding matrices are used, which correspond to {i 1,1 = 0}, i 1,2 = i 1,3 = 0 and {i2 = 0 - 1} in the NR DL 4-Tx rank-3 codebook. Note that these precoders correspond to the effective oversampling factor O1 = 1 and (k1, k2) = (4,0) in the three-layer DFT beams v 1， m and v 1+k1，m+k2 . The mapping from PMI i2 in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i2) in the NR DL 4-Tx codebook is given by i2 = k.

[0373] In yet another instance of Ex 21C-1-2, a subset of 16 precoding matrices is used. For example, 4 rank-3 precoding matrices are used, which correspond to {i 1,1 =

[0374] 0,2}, i 1,2 = i1,3 = 0 and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v of three layers 1，m and v 1+k1，m+k2 with oversampling factor O1 = 2 and (k1, k2) = (4, 0) in. From the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook, the mapping is given by k = 2 * (i 1,1 / 2) + i2 = i 1，1+i2 . The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = k - i2,

[0375] In yet another example of Ex 21C-1-3, a subset of 16 precoding matrices is used. For example, 4 rank-3 precoding matrices are used, which in the NR DL 4-Tx rank-3 codebook correspond to {i 1,1 = 0 - 3}, i 1,2 = i 1,3 = 0 and {i2 = 0}. Note that these precoders correspond to the DFT beams v of three layers 1，m and v 1+k1，m+k2 with oversampling factor O1 = 4 and (k1, k2) = (0, 0) in. From the PMI (i 1,1 ) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook, the mapping is given by k = i 1,1 . The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 ) in the NR DL 4-Tx codebook is given by i 1,1 = k.

[0376] In yet another example of Ex 21C-1-4, a subset of 16 precoding matrices is used. For example, 8 rank-3 precoding matrices are used, which in the NR DL 4-Tx rank-3 codebook correspond to {i 1,1 = 0 - 3}, i 1,2 = i 1,3 = 0 and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v of three layers 1， m and v 1+k1，m+k2 with oversampling factor O1 = 4 and (k1, k2) = (0, 0) in. From the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook, the mapping is given by k = 2i 1,1+i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = (k - i2) / 2.

[0377] In yet another alternative of Alt 21C-2, the rank-3 precoding matrices in the LTE specification DL rank-3 Householder codebook are used. At least one of the following examples is used. In one instance of Ex 21C-2-0, there are 16 rank-3 precoding matrices in the LTE specification DL rank-3 Householder codebook and all of them are used. In another instance of Ex 21C-2-1, a subset of the 16 precoding matrices is used. For example, 8 of the 16 rank-3 precoding matrices are used, where the 8 precoding matrices correspond to the PMI indices {i = 0 - 7} or {2i: i = 0 - 7} = {0, 2, 4, 6, 8, 10, 12, 14} or {2i + 1: i = 0 - 7} = {1, 3, 5, 7, 9, 11, 13, 15}.

[0378] In yet another example of CB1 (partially coherent), the precoding matrix corresponds to the transmission of 2 out of 4 ports per layer. The scaling factor a for each column of the normalized precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in this disclosure. For example, Note that in addition to the scaling factor a, normalization is also applied to the three layers through . At least one alternative is used. In one alternative of Alt 21C-3, the precoding matrices corresponding to the codebook indices 0 - 11 in the LTE UL rank-3 4-Tx codebook are used.

[0379] In another alternative of Alt 21C-4, the rank-3 precoding matrix is formed using the rank-1 precoders in the LTE UL rank-1 4-Tx codebook (codebook indices 16 - 23), as proposed in CB1 in Embodiment 16 above. At least one of the following embodiments is used. In one instance of Ex 21C-4-0, 2 rank-3 precoding matrices are formed. For example, the precoding matrices corresponding to the TPMI indices 8 - 9 are shown in Table 14. In one instance of Ex 21C-4-1, 4 rank-3 precoding matrices are formed. For example, the precoding matrices corresponding to the TPMI indices 8 - 11 are shown in Table 14. In another instance of Ex21C-4-2, 8 rank-3 precoding matrices are formed. For example, the precoding matrices corresponding to the TPMI indices 8 - 11 in Table 14, and 4 additional precoding matrices P m，n，p, where (m, n, p) = (16, 20, 21), (17, 20, 21), (18, 22, 23), (19, 22, 23).

[0380] In another example of CB2 (non - coherent), the precoding matrix corresponds to the transmission of 1 out of 4 ports per layer. The scaling factor a for normalizing each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in the present disclosure. For example, a = 1. Note that in addition to the scaling factor a, normalization is applied to three layers by . There are 4 such precoding matrices as described in the aforementioned embodiment 16 (Alt 16 - 2).

[0381] In sub - embodiment 21D, the rank - 4 codebook includes at least one of the following types of precoding matrices. In one example of CB0 (fully coherent), the precoding matrix corresponds to the transmission from all 4 ports of each layer (where the layer corresponds to the column of the precoding matrix). The scaling factor a for normalizing each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in the present disclosure. For example, a = 2. Note that in addition to the scaling factor a, normalization is applied to four layers by . At least one of three alternatives is used.

[0382] In one alternative of Alt 21D - 0, a rank - 4 precoding matrix is formed using the rank - 1 precoder in the LTE UL rank - 1 4 - Tx codebook (codebook indices 0 - 15) as proposed in CB0 of the aforementioned embodiment 16. At least one of the following embodiments is used. In one instance of Ex 21D - 0 - 0, 1 rank - 4 precoding matrix is formed. For example, the precoding matrix corresponding to TPMI index 0 is shown in Table 15. In another instance of Ex 21D - 0 - 1, 2 rank - 4 precoding matrices are formed. For example, the precoding matrices corresponding to TPMI indices 0 - 1 are shown in Table 15. In yet another instance of Ex21D - 0 - 2, 4 rank - 4 precoding matrices are formed. For example, the precoding matrices corresponding to TPMI indices 0 - 3 are shown in Table 15.

[0383] In another alternative of Alt 21D-1, a rank-4 precoding matrix in the NR DL rank-4 4-Tx type I CSI codebook for a single-antenna panel with L = 1 or CodebookMode = 1 is used. At least one of the following examples is used. In one instance of Ex21D-1-0, there are 16 rank-4 precoding matrices in the NR DL rank-4 4-Tx type I CSI codebook for a single-antenna panel with L = 1 or CodebookMode = 1 and all of these matrices are used. Using PMI(i 1,1 , i 1,2 , i 1,3 , i2) represents 16 rank-4 precoding matrices, where {i 1,1 = 0-7}, i 1,2 = i 1,3 = 0, {i2 = 0-1}. The mapping from PMI(i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2i 1,1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = (k - i2) / 2.

[0384] In another instance of Ex 21D-1-1, a subset of 16 precoding matrices is used. For example, 2 rank-4 precoding matrices are used, which in the NR DL 4-Tx rank-4 codebook correspond to {i 1,1 = 0}, i 1,2 = i 1,3 = 0 and {i2 = 0-1}. Note that these precoders correspond to the effective oversampling factor O1 = 1 and (k1, k2) = (4,0) in the four-layer DFT beams v 1，m and v 1+k1，m+k2 . The mapping from PMI i2 in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to PMI(i2) in the NR DL 4-Tx codebook is given by i2 = k.

[0385] In yet another instance of Ex 21D-1-2, a subset of 16 precoding matrices is used. For example, 4 rank-4 precoding matrices are used, which in the NR DL 4-Tx rank-4 codebook correspond to {i 1,1 = 0,2}, i 1,2 = i 1,3= 0 and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v of four layers 1， m and v 1+k1，m+k2 with oversampling factor O1 = 2 and (k1, k2) = (4, 0) in. From the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2 * (i 1,1 / 2) + i2 = i 1，1 + i2. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = k - i2.

[0386] In yet another example of Ex 21D-1-3, a subset of 16 precoding matrices is used. For example, 4 rank-4 precoding matrices are used, which in the NR DL 4-Tx rank-4 codebook correspond to {i 1,1 = 0 - 3}, i 1,2 = i 1,3 = 0 and {i2 = 0}. Note that these precoders correspond to the DFT beams v 1，m and v 1+k1，m+k2 with oversampling factor O1 = 4 and (k1, k2) = (0, 0) in. From the PMI (i 1,1 ) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = i 1,1 . The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 ) in the NR DL 4-Tx codebook is given by i 1,1 = k.

[0387] In yet another example of Ex 21D-1-4, a subset of 16 precoding matrices is used. For example, 8 rank-4 precoding matrices are used, which in the NR DL 4-Tx rank-4 codebook correspond to {i 1,1 = 0 - 3}, i 1,2 = i 1,3 = 0 and {i2 = 0 - 1}. Note that these precoders correspond to the DFT beams v 1， m and v 1+k1，m+k2 with oversampling factor O1 = 4 and (k1, k2) = (0, 0) in. From the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook to the TPMI index (k) in the proposed UL codebook is given by k = 2i 1,1+i2 is given. The reverse mapping from the TPMI index (k) in the proposed UL codebook to the PMI (i 1,1 , i2) in the NR DL 4-Tx codebook is given by i2 = k mod 2 and i 1,1 = (k - i2) / 2.

[0388] In another alternative of Alt 21D-2, the rank-4 precoding matrix in the LTE specification DL rank-4 Householder codebook is used. At least one of the following examples is used. In one instance of Ex 21D-2-0, there are 16 rank-4 precoding matrices in the LTE specification DL rank-4 Householder codebook and all of them are used. In another instance of Ex 21D-2-1, a subset of 16 precoding matrices is used. For example, 8 out of 16 rank-4 precoding matrices are used, where the 8 precoding matrices correspond to the PMI indices {i = 0 - 7} or {2i: i = 0 - 7} = {0, 2, 4, 6, 8, 10, 12, 14} or {2i + 1: i = 0 - 7} = {1, 3, 5, 7, 9, 11, 13, 15}.

[0389] In yet another example of CB1 (partially coherent), the precoding matrix corresponds to the transmission of 2 out of 4 ports per layer. According to at least one of the embodiments / alternatives mentioned previously in the present disclosure, the scaling factor a for normalizing each column of the precoding matrix is used. For example, Note that in addition to the scaling factor a, normalization is applied for the four layers by . At least one alternative is used. In one alternative of Alt 21D-3, as proposed in CB1 in Embodiment 16, the rank-1 precoder in the LTE UL rank-1 4-Tx codebook (codebook indices 16 - 23) is used to form the rank-4 precoding matrix. At least one of the following examples is used.

[0390] In one instance of Ex 21D-3-0, 1 rank-4 precoding matrix is formed. For example, the precoding matrix corresponding to the TPMI index 4 in Table 15. In another instance of Ex 21D-3-1, 2 rank-4 precoding matrices are formed. For example, the precoding matrices corresponding to the TPMI indices 4 - 5 in Table 15. In another instance of Ex 21D-3-2, 4 rank-4 precoding matrices are formed. For example, the precoding matrices corresponding to the TPMI indices 4 - 5 in Table 15, and 2 additional precoding matrices P m，n，p，q , where (m, n, p, q) = (16, 17, 22, 23),

[0391] (18, 19, 20, 21).

[0392] In another example of CB2 (non - coherent), the precoding matrix corresponds to the transmission of 1 out of 4 ports per layer. The scaling factor a that normalizes each column of the precoding matrix is according to at least one of the embodiments / alternatives mentioned previously in this disclosure. For example, a = 1. Note that, in addition to the scaling factor a, normalization is applied for the four layers by as described in Embodiment 16 (Alt 16 - 2). There are 4 such precoding matrices.

[0393] Examples of rank - 1 to 4 codebooks are as follows. The corresponding TPMI / TRI payloads (number of bits) are summarized in Table 38. In one example, the rank - 1 codebook includes 16 + 8 + 4 = 28 pre - encoders of the following three types. In one instance, CB0 (fully coherent) includes 16 pre - encoders (indicated by TPMI indices 0 - 15) according to one of the following: LTE UL codebook (Ex 21A - 0 - 0); NR DL Type - I CSI codebook (Ex 21A - 1 - 1); and LTE specification DL Householder codebook (Ex 21A - 2 - 0). In another example, according to Alt 21A - 3, CB1 (partially coherent) includes 8 pre - encoders (indicated by TPMI indices 16 - 23). In yet another instance, according to CB2 in Sub - embodiment 21A, CB2 (non - coherent) includes 4 pre - encoders (indicated by TPMI indices 24 - 27).

[0394] In another example, rank - 2 includes 8 + 16 + 6 = 30 precoding matrices of the following three types. In one instance, CB0 (fully coherent) includes 8 precoding matrices (indicated by TPMI indices 0 - 7) according to one of the following: LTE UL codebook (Ex 21B - 0 - 0); NR DL Type - I CSI codebook (Ex 21B - 1 - 1); and LTE specification DL Householder codebook (Ex 21B - 2 - 1). In another instance, according to Alt 21B - 3, CB1 (partially coherent) includes 16 precoding matrices (represented by TPMI indices 8 - 23). In yet another instance, CB2 (non - coherent): includes 6 precoding matrices (represented by TPMI indices 24 - 29) according to Alt 21B - 5.

[0395] In yet another example, rank 3 includes 8 + 12 + 4 = 24 precoding matrices of the following three types. In one instance, CB0 (fully coherent) includes 8 precoding matrices (indicated by TPMI indices 0 - 7) according to one of the following: LTE UL codebook (Ex 21C-0-2); NR DL type I CSI codebook (Ex 21C-1-4); and LTE specification DL Householder codebook (Ex 21C-2-1). In another instance, according to Alt 21C-3, CB1 (partially coherent) includes 12 precoding matrices (represented by TPMI indices 8 - 19). In yet another instance, CB2 (incoherent) includes 4 precoding matrices according to CB2 in sub - embodiment 21C (represented by TPMI indices 20 - 23).

[0396] In yet another example, rank 4 includes 4 + 2 + 1 = 7 precoding matrices of the following three types. In one instance, CB0 (fully coherent): includes 4 precoding matrices (indicated by TPMI indices 0 - 3) according to one of the following: LTE UL codebook (Ex 21D-0-2); NR DL type I CSI codebook (Ex 21D-1-3); and LTE specification DL Householder codebook (Ex 21D-2-1). In another example, according to Ex 21D-3-1, CB1 (partially coherent) includes 2 precoding matrices (represented by TPMI indices 4 - 5). In yet another instance, CB2 (incoherent) includes 1 precoding matrix according to CB2 in sub - embodiment 21D (represented by TPMI index 6).

[0397] Table 38. Number of bits

[0398]

[0399] In all embodiments of the present disclosure, antenna shutdown and antenna selection or antenna port shutdown and antenna port selection have been used interchangeably, and they mean selecting a subset of antennas or antenna ports for transmission, where the unselected or shut - down antennas or antenna ports correspond to zero values in the precoder.

[0400] In a variant of the foregoing embodiment (Embodiment 16Z), via RRC signaling using bitmap B or coherence state configuration S on the UL codebook (e.g., rank 1 - 4 codebooks in Embodiment 16), the gNB configures a codebook subset restriction (CBSR) to the UE. Where the bitmap or state configuration restricts the use of a set of precoding matrices in the codebook for TPMI indication. For the sake of brevity, in the remainder of the present disclosure, the coherence state is referred to as the state.

[0401] In one example, precoder grouping is explained in Embodiment 7, where the first TPMI (i1) is used for the precoder group and the second TPMI (i2) is used for the precoders in each precoder group. Then, the CBSR restricts the first TPMI (i1). In another example, the precoding grouping is as follows. The state configuration includes three states S = {s1, s2, s3}, where each of the three states corresponds to a precoder group based on the coherence type (fully coherent transmission, partially coherent transmission, and non - coherent transmission). The definitions of these three states are as follows. In one instance, the first state (e.g., s1) corresponds to "fully + partially + non - coherent", i.e., the precoder group includes all precoders (TPMIs) for fully coherent, partially coherent, and non - coherent transmission in the UL codebook. In another instance, the second state (e.g., s2) corresponds to "partially + non - coherent", i.e., the precoder group includes all precoders (TPMIs) for partially coherent and non - coherent transmission in the UL codebook. In yet another instance, the third state (e.g., s3) corresponds to "non - coherent", i.e., the precoder group includes all precoders (TPMIs) for non - coherent transmission in the UL codebook.

[0402] Note that only one of the three states can be configured among the three states through the RRC signaling of the parameter ULCodebookSubset. For a UE capable of fully coherent transmission, the gNB can configure any of the three states. For a UE capable of partially coherent transmission, the gNB can only configure the second and third states (because the first state includes fully coherent transmission precoders that the UE cannot support). Similarly, for a UE capable of non - coherent transmission, the gNB can only configure the third state (because the first and second states include fully coherent and partially coherent transmission precoders that the UE cannot support).

[0403] The size of the DCI field for TPMI indication (e.g., the number of bits of the TPMI) is determined by the configured state. For the example of the number of precoders and coherence type of rank 1 - 4 as shown in Table 39, the size of the DCI field for TPMI indication (# bits for TPMI / TRI indication), for the three states, is 6, 5, and 4 respectively as shown in Table 40. Note that for state s1, the number of precoders is the sum of the fully, partially, and non - coherent precoders. Similarly, for state s2, it is the sum of the partially and non - coherent precoders.

[0404] Table 39. Example of the number of precoders of 4 - Tx UL codebook

[0405]

[0406] Table 40. # TPMI / TRI bits for the three states

[0407]

[0408] In addition to the RRC signaling for configuring one of the three states, the RRC signaling also includes (separate from or combined with the configuration of one of the three states) a configuration for limiting the maximum TRI value for TPMI indication by the parameter ULmaxRank. For example, for N (2, 4, or 8) SRS ports, log2N bits or N states are used to configure the maximum TRI value. This means that for 2 and 4 ports, 1 and 2 bits or 2 and 4 states are used to limit the maximum TRI. For 4 SRS ports, examples of separate and combined RRC configurations are shown in Tables 41 and 42 respectively. The same applies to 2 SRS ports, which are shown in Tables 43 and 44 respectively, where for the fully coherent case, the number of rank-1 and rank-2 precoders is 4 and 2, and for the non-coherent case is 2 and 1. Note that there is no partially coherent case for 2 SRS ports. Details of the joint indication of precoder information (TPMI) in DCI, the number of layers in the three coherent states, and the bit fields for different ULmaxRank values are summarized in Tables 42A, 42B, 42C, and 42D for 4 antenna ports and Tables 44A and 44B for antenna ports. Note that if ULmaxRank is not configured by RRC, the default value of ULmaxRank = the number of antenna ports at the UE. Similarly, if ULCodebookSubset is not configured by RRC, the default value of ULCodebookSubset = the coherent capability reported by the UE.

[0409] Table 41. States and #TPMI / TRI bits for separate configuration for 4 SRS ports

[0410]

[0411] Table 42. States and #TPMI / TRI bits for combined configuration for 4 SRS ports

[0412]

[0413] Table 42A.

[0414] Precoding information and number of layers for 4 antenna ports if ULmaxRank = 1

[0415] Table 42B. Precoding information and number of layers for 4 antenna ports if ULmaxRank = 2

[0416] Table 42C. Precoding Information and Number of Layers for 4 Antenna Ports if ULmaxRank = 3

[0417] Table 42D. Precoding Information and Number of Layers for 4 Antenna Ports if ULmaxRank = 4

[0418] Table 43. Status and #TPMI / TRI Bits for Separated Configuration of 2 SRS Ports

[0419]

[0420] Table 44. Status and #TPMI / TRI Bits for Joint Configuration of 2 SRS Ports

[0421]

[0422] Table 44A. Precoding Information and Number of Layers for 2 Antenna Ports if ULmaxRank = 1

[0423] Table 44B. Precoding Information and Number of Layers for 2 Antenna Ports if ULmaxRank = 2

[0424]

[0425] In some embodiments 22, a 4-Tx UL codebook (codebook for 4 SRS ports) is used and the UE is configured / indicated with a WB TPMI in the DCI for CP-OFDM based UL MIMO transmission, where the codebook includes pre-coders / pre-coding matrices of rank 1-4 according to at least one (or a combination) of the following alternatives. In one alternative of Alt 22-0, the number of TPMIs and the corresponding pre-coders / pre-coding matrices are according to Table 45. In another alternative of Alt 22-1, the number of TPMIs and the corresponding pre-coders / pre-coding matrices are according to Table 45, except that the 4 pre-coding matrices for rank 3 and the partially coherent case are replaced with the 4 pre-coding matrices for rank 3 and the partially coherent case in Table 46.

[0426] In another alternative of Alt 22-2, the number I of TPMs and the corresponding precoder / precoding matrix are according to Table 45, except that the 4 precoding matrices for rank 3 and partially coherent cases are replaced by the 4 precoding matrices for rank 3 and partially coherent cases in Table 46. In yet another alternative of Alt 22-3, the number of TPM I and the corresponding precoder / precoding matrix are according to Table 45, except that the 4 precoding matrices for rank 3 and partially coherent cases are replaced by the 4 precoding matrices for rank 3 and partially coherent cases in Table 48. In another alternative of Alt 22-4, the number of TPM I and the corresponding pre-coder / precoding matrix are according to Table 46. In another alternative of Alt 22-5, the number of TPM I and the corresponding precoder / precoding matrix are according to Table 47. In yet another alternative of Alt 22-6, the number of TPM I and the corresponding precoder / precoding matrix are according to Table 48. In another alternative of Alt 22-7, it is the same as Table 46 or Table 47 or Table 48, except for rank 4. In this case, for full coherence: 2 TPMIs are used, which correspond to (i11 = 0,1; i2 = 0). In this case, for partial coherence, 2 TPMIs are used, which correspond to where a = 2 or In yet another alternative of Alt 22-8, the number of TPM I and the corresponding precoder / precoding matrix are according to Table 58.

[0427] The number of TPMIs depends on the UE capabilities (reported by the UE) as described below. In one example, if the UE is capable of full-coherent transmission (reported in the UE capability report), then TPMIs corresponding to any full-coherent, partial-coherent, or non-coherent precoder / precoding matrix can be used to configure / indicate the UE. Thus, the number of bits required for TPMI indication for a given rank is

[0428] number.

[0429] In another example, if the UE is capable of partial-coherent transmission (reported in the UE capability report), then TPMIs corresponding to any partial-coherent or non-coherent precoder / precoding matrix can be used to configure / indicate the UE. Thus, the number of bits required for TPMI indication for a given rank is

[0430] where B is the total number of partial-coherent and non-coherent precoding matrices.

[0431] In yet another example, if the UE is capable of non-coherent transmission (reported in the UE capability report), the UE can be configured / indicated with a TPMI that corresponds only to the non-coherent precoder / precoding matrix. Thus, the number of bits required to indicate a given rank TPMI is where B is the total number of non-coherent precoding matrices.

[0432] Table 45. TPMI and number of precoders / precoding matrices per rank, and UE coherence capability

[0433] Table 46. TPMI and number of precoders / precoding matrices per rank, and UE coherence capability

[0434] Table 47. TPMI and number of precoders / precoding matrices per rank, and UE coherence capability

[0435] Table 48. TPMI and number of precoders / precoding matrices per rank, and UE coherence capability

[0436] Table 49. Codebooks transmitted on antenna ports {40, 41, 42, 43}, where v = 1

[0437]

[0438] In some embodiments, the rank indicator or transmit rank indicator (RI or TRI) is equivalently referred to as the number of layers. For example, RI or TRI = 1 is equivalent to the number of layers = 1, RI or TRI = 2 is equivalent to the number of layers = 2, RI or TRI = 3 is equivalent to the number of layers = 3, and RI or TRI = 4 is equivalent to the number of layers = 4.

[0439] In sub - embodiment 22A, the rank 1 - 4 codebooks according to Alt 22 - 4 (or Table 46) are shown in Tables 49 - 52. The corresponding TRI / TPMI indication payload (bits) are shown in Table 53. For a given TRI value or number of layers, the precoders in the UL codebook are indexed by the TPMI index according to at least one of the following schemes. In numbering scheme 1, the TPMI indices of non - interfering precoders are first numbered from index 0 to index N1 - 1, where N1 is the number of non - interfering precoders, the TPMI indices of partially interfering precoders are next numbered from index N1 to index N1+N2 - 1, where N2 is the number of partially interfering precoders, and finally the TPMI indices of fully interfering precoders are numbered from index N1+N2 to index N1+N2+N3 - 1, where N3 is the number of fully interfering precoders. In numbering scheme 2, the TPMI indices of fully interfering precoders are first numbered from index 0 to index N3 - 1, the TPMI indices of partially interfering precoders are next numbered from index N3 to index N2+N3 - 1, and finally the TPMI indices of non - interfering precoders are numbered from index N2+N3 to index N1+N2+N3 - 1. The TPMI indices according to the two numbering schemes are shown in Tables 49 - 52.

[0440] In sub - embodiment 22B, the rank 1 - 4 codebooks according to Alt 22 - 4 (or Table 46) are shown in Tables 49 - 52, except that the scaling factor (1 / a) at the start of all rank and coherence type precoder expressions is replaced by 1 / 2.

[0441] Table 50. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 2

[0442]

[0443] Table 51. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 3

[0444]

[0445] Table 52. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 4

[0446]

[0447] Table 53. TPMI / TRI indication payload (bits)

[0448]

[0449] In Sub - embodiment 22C, the rank 1 - 4 codebooks are shown in Tables 54 - 57. Note that the precoders / precoding matrices for rank 1, rank 2, and rank 4, and the fully coherent case are the same as those of (TPMI 0 - 15),

[0450] (TPMI 0 - 7 and (TPMI 0 - 3) are the same.

[0451] They are in Tables 49, 50, and 52 respectively. For rank 3 and full coherence, the 4 precoding matrices of (TPMI 0 - 3) are and

[0452]

[0453] Table 54. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 1

[0454]

[0455] Table 55. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 2

[0456]

[0457] Table 56. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 3

[0458]

[0459] Table 57. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 4

[0460]

[0461] Table 58. Number of TPMI and precoder / precoding matrices for each rank, and UE coherence capability

[0462]

[0463] In Sub - embodiment 22D, the 4 - Tx UL codebook is according to Alt 22 - 8. Specifically, the rank 1 codebook is according to Table 49. The rank 2 codebook is according to Table 50. The rank 3 codebook is according to one of Table 59 or Table 60. The rank 4 codebook is according to one of Table 61 or Table 62. The corresponding TRI / TPMI indication payload (bits) is shown in Table 63.

[0464] Table 59. Codebook transmitted on antenna ports {40, 41, 42, 43}, where v = 3

[0465]

[0466] Table 60. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 3

[0467]

[0468] Table 61. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 4

[0469]

[0470] Table 62. Codebook for transmission on antenna ports {40, 41, 42, 43}, where v = 4

[0471]

[0472] Table 63. TPMI / TRI indication payload (bits)

[0473]

[0474] Figure 10 A flowchart of method 1000 for uplink MIMO codebook operation according to an embodiment of the present disclosure is shown, which can be executed by a UE such as Figure 3 the UE 116 in Figure 10 The embodiment of method 1000 shown in Figure 10 is for illustration only. One or more components shown in

[0475] The process begins with the UE sending a message reporting coherent capabilities (step 1005). For example, in step 1005, the UE may report the UE's coherent capabilities to the BS for TPMI and layer indication. For example, the UE may have 2, 4, or 8 antenna ports and may be able to transmit and / or receive on all, some, or only one antenna port. In these scenarios, the UE may report full, partial, and non-coherent, respectively.

[0476] Then, the UE receives an indication of the TPMI and the number of layers (step 1010). For example, in step 1010, the UE receives the indication via DCI signaling. Here, the number of bits in the DCI signaling for the indication is determined by the coherence state, which depends on the coherence capabilities reported by the UE. For example, the BS can configure one of three coherence states from full, partial, or non-coherent states, where each coherence state corresponds to a subset of the UL codebook for indicating the TPMI and the number of layers. The BS configures the coherence state for the UE based on and not exceeding the coherence capabilities reported by the UE. For example, if the UE reports full coherence, the BS can configure any one of the full, partial, or non-coherent states such that the UE uses / is configured for: any full, partial, or non-phase precoder for the full coherence state; a partial or non-phase precoder for the partial coherence state; and only a non-phase precoder for the non-coherent state. In this way, the BS can save bits in the DCI signaling by configuring a state that is not much more than the state instead of always configuring and signaling the full coherence state. In one embodiment, the UE can also receive the ULCodebookSubset and ULmaxRank via higher layer radio resource control (RRC) signaling, where the ULCodebookSubset indicates the configured coherence state and the ULmaxRank indicates the value for the maximum number of layers. Here, the UE can determine the coherence state and the value of the maximum number of layers, and the number of bits in the DCI signaling for the indication is determined by the coherence state and the value of the maximum number of layers.

[0477] Thereafter, the UE transmits UL data based on the received indication of the TPMI and the number of layers (step 1015). For example, in step 1015, the UE selects a precoder according to the configured state, and then precodes and transmits the precoded data via the PUSCH.

[0478] Although Figure 10 illustrates an example of a method for the uplink MIMO codebook operation of the UE, various changes can be made to Figure 10 it. For example, although shown as a series of steps, the individual steps in each figure can overlap, occur in parallel, occur in a different order, occur multiple times, or not be performed in one or more embodiments. In another embodiment, the method can be implemented by a BS such as Figure 2 the eNB 102 in Figure 10 but implemented from the opposite perspective, that is, as described in connection with

[0479] In the remainder of this disclosure, the UL antenna port refers to the SRS port. In some embodiments, the UE reports its coherence capabilities for UL MIMO transmission. As an example, the UE is capable of at least one of the following UL transmissions. In one example of full coherence, all ports can transmit coherently. In another example of partial coherence, port pairs can transmit coherently. In yet another example of incoherence, no port pairs can transmit coherently.

[0480] An N-Tx codebook for N ports in at least one resource is proposed, where a higher-rank (rank > 1) codebook is designed using all or a subset of the precoders in a rank-1 (or 1-layer) codebook. In one example, for DL, N ∈ {2, 4, 8, 12, 16, 24, 32} and at least one resource corresponds to a CSI-RS resource. In another example, for UL, N ∈ {2, 4, 8} and at least one resource corresponds to an SRS resource. For UL, the N ports correspond to one or more SRS resources according to at least one of the following alternatives: a single SRS resource including N ports; N / 2 SRS resources, each containing 2 ports; and N SRS resources, each containing 1 port.

[0481] Rank 1-4 codebooks can be partitioned into two (CB0, CB1) or three (CB0, CB1, CB2) types of codebooks (CB). In one example of CB0, the first codebook includes a precoder that combines all N ports (all N entries in the precoder are non-zero). In other words, the precoder assumes full coherence where all ports can transmit coherently. In another example of CB1, the second codebook includes a precoder that combines N / 2 ports (N / 2 entries in the precoder are non-zero while the remaining N / 2 entries are zero). In other words, the precoder assumes partial coherence, i.e., port pairs can transmit coherently. In yet another example of CB2, the third codebook includes an N-port selection precoder that selects 1 out of N ports (1 entry in the precoder is non-zero while the remaining N - 1 entries are zero). In other words, the precoder assumes incoherence, i.e., no port pairs can transmit coherently.

[0482] For N = 2, as an example, rank 1 and rank-2 codebooks are obtained by selecting a subset of precoding matrices (or a subset of codebook indices) in Table 64. For N = 4, as an example, rank 1, rank 2, rank-3, and rank-4 codebooks are obtained by selecting subsets of precoding matrices (or subsets of codebook indices) in Tables 65, 66, 67, and 68, respectively.

[0483] In some embodiments, the scaling factor a in the UL codebook is fixed or configured via a higher layer (e.g., RRC) or based on MAC CE or DCI-based signaling.

[0484] Table 64. Codebook and Rank v for Transmission on Two Antenna Ports {3000, 3001}

[0485]

[0486] Table 65. Codebook for Transmission on Four Antenna Ports {3000, 3001, 3002, 3003}, where v = 1

[0487]

[0488] Table 66. Codebook for Transmission on Four Antenna Ports {3000, 3001, 3002, 3003}, where v = 2

[0489]

[0490] Table 67. Codebook for Transmission on Four Antenna Ports {3000, 3001, 3002, 3003}, where v = 3

[0491]

[0492] Table 68. Codebook for Transmission on Antenna Ports {3000, 3001, 3002, 3003}, where v = 4

[0493]

[0494] In this disclosure, the codebook index and the rank are respectively referred to as the Transmitted PMI (TPMI) and the Transmitted RI (TRI). In the case where multiple SRS resources are configured for the UE, the UE is configured / indicated with at least one SRS Resource Indicator (SRI), which selects at least one SRS resource through UL-related DCI. This disclosure includes embodiments related to the codebook subset restriction of the N-port UL codebook.

[0495] In some embodiments 23, the UE is configured with a CBSR on the UL codebook through higher layer signaling (e.g., RRC) to restrict the precoding matrix for TPMI / TRI / SRI indication (via UL-related DCI signaling) to a subset of all precoding matrices in the UL codebook. In the case where multiple SRS resources are configured for the UE, the SRI indication may include a single SRI or multiple SRIs. Similarly, the TPMI indication may include a single TPMI or multiple TP-MIs, and the TRI indication may include a single TRI or multiple TRIs. The CBSR restricts at least one of coherence or codebook partition type or TRI value.

[0496] Determine and / or configure a subset of the precoding matrix for TPMI / TRI / SRI indication according to at least one of the following alternatives. In one alternative of Alt 23-0, there is no restriction on coherence or codebook partitioning type nor on the TRI value. That is, there is no CBSR via RRC signaling. In one alternative of Alt23-1, CBSR restricts the coherence or codebook partitioning type but not the TRI value, where bit bitmap B = b0...b L-1 is used to restrict the coherence or codebook partitioning type of the N-port UL codebook, where M N is the number of coherence or codebook partitioning types. Note that for N = 2, M2 = 2, which corresponds to (CB0, CB2), and for N = 4, M4 = 3, which corresponds to (CB0, CB1, CB2). Thus, for example, for N = 2, L = 2 bits are used, and for N = 4, L = 3 bits are used. Here, the restriction is common for all ranks or TRI values. In a variant, CBSR independently restricts the coherence or codebook partitioning type for each rank or TRI value, where bits are used to restrict the coherence or codebook partitioning type of the N-port UL codebook. For example, for N = 2, L = 4 bits are used, and for N = 4, L = 12 bits are used.

[0497] In one alternative of Alt 23-2, CBSR restricts the TRI value but not the coherence or codebook partitioning type, where L = N bit bitmap B = b_0...b_(L-1) is used to restrict the TRI value of the N-port UL codebook. For example, for N = 2, L = 2 bits are used, and for N = 4, L = 4 bits are used.

[0498] In one alternative of Alt 23-2-0, when TRI and TPMI are encoded and / or indicated separately, then the number of bits for TRI indication is adjusted based on CBSR on the TRI value. For example, for N = 4, if CBSR restricts the TRI value to {1, 2}, then in addition to the TPMI / SRI indication, 1 bit indication is used to indicate the TRI value in the UL-related DCI signaling. Note that due to CBSR on the TRI value, 1 bit is saved in the TRI indication in the UL-related DCI. Regardless of CBSR, the DCI payload (number of bits) remains the same, or the number of bits saved by CBSR on the TRI value is reduced. If the DCI payload remains the same, zero padding is used to keep the payload the same, where zeros are padded as LSB or MSB bits.

[0499] In an alternative of Alt 23-2-1, when TRI and TPMI are jointly encoded and / or indicated, regardless of the CBSR, the TRI / TPMI payload (number of bits) remains the same or is reduced to the number of bits required to indicate TRI / TPMI using an unrestricted precoder over the CBSR on the RI value. Similarly, regardless of the CBSR, the DCI payload (number of bits) remains the same or is reduced by the number of bits saved by the CBSR. If the TRI / TPMI or DCI payload remains the same, zero-padding is used to keep the payload the same, where the zero-padding is the LSB or MSB bits.

[0500] In an alternative of Alt 23-3, the CBSR restricts the coherence or codebook partitioning type and the TRI value, where L = L1 + L2 bitmaps B = B1B2 or B1B2 = is used to restrict the coherence or codebook partitioning type and the TRI value of an N-port UL codebook., where L1 = bits for the CBSR of the coherence or codebook partitioning type, and L2 = N bits for the CBSR on the TRI value. For example, for N = 2, L = 2 + 2 = 4 bits are used, and for N = 4, L = 3 + 4 = 7 bits are used.

[0501] In an alternative of 23-3-0, when TRI and TPMI are encoded / indicated separately, then the number of bits indicated for TRI and TPMI is adjusted based on the CBSR on the TRI value. For example, for N = 4, the CBSR restricts the TRI value to {1, 2} and the coherence or codebook partitioning type to CB0, then 1 bit indication is used to indicate the TRI value, and 4 bit indication is used to indicate the TPMI value from Table 65 in the UL-related DCI signaling in addition to the TPMI / SRI indication (if TRI = 1). Note that due to the CBSR on the TRI value and the coherence or codebook partitioning type, 1 bit is saved in the TRI indication and 1 bit is saved in the TPMI indication in the UL-related DCI. Regardless of the CBSR, the DCI payload (number of bits) remains the same or is reduced by the number of bits saved by the CBSR on the TRI value and the coherence or codebook partitioning type. If the DCI payload remains the same, zero-padding is used to keep the payload the same, where zero is padded as the LSB or MSB bits.

[0502] In an alternative of 23-3-1, when jointly encoding / indicating TRI and TPMI, regardless of CBSR, the TRI / TPMI payload (number of bits) remains the same, or is reduced to the number of bits required to indicate TRI / TPMI via CBSR and coherence or codebook partition type on the RI value using a precoder not limited by CBSR. Similarly, regardless of CBSR, the DCI payload (number of bits) remains the same, or the number of bits saved by CBSR is reduced. If the TRI / TPMI or DCI payload remains the same, zero-padding is used to keep the payload the same, where the zero-padding is the LSB or MSB bits. In bitmap B = b0...b L-1 , bit b0 is the least significant bit (LSB), and bit b_(L-1) is the most significant bit (MSB). Alternatively, bit b0 is the MSB and bit b L-1 is the LSB.

[0503] A bitmap or a part of bitmap B used by CBSR to limit coherence or codebook partition type is based on at least one of the following. In an alternative of Alt 23-4, a 2-bit bitmap B = b_0b_1 is used for a codebook partition type pair (CBx, CBy), where (x, y) is (0,1), (1,2), or (1,2), where b_0 is the most significant bit (MSB), b1 is the least significant bit (LSB) or b0 is the LSB and b1 is the MSB. In an alternative of Alt 23-5, a 3-bit bitmap B = b0b1b2 is used for a codebook partition type triple (CB0, CB1, CB2), where b0 is the MSB and b2 is the LSB or b0 is the LSB and b2 is the MSB.

[0504] If bit b i = 0, the corresponding codebook partition type CBi is not used for TPMI indication, and if bit b i = 1, the corresponding codebook partition type CBi is used for TPMI indication. Alternatively, if bit b i = 1, the corresponding codebook partition type CBi is not used for TPMI indication, and if bit b i = 0, the corresponding codebook partition type CBi is used for TPMI indication.

[0505] If bitmap B is independent for all or a subset of ranks 1-4, bitmap B is a concatenation of R bitmaps B0...B R-1 where R is the number of rank values for which we have an independent bitmap. For example, if R = 4, then bitmap B is a concatenation of 4 bitmaps B0...B3, where B0 is the bitmap for rank value 1, B3 is the bitmap for rank value 4, or B0 is the bitmap for rank value 4 and B3 is the bitmap for rank value 1. The bitmap B = b0...b used to limit the TRI value L-1The description is similar.

[0506] An exemplary TPMI and transmit rank indicator (TRI) payload size table (assuming CB0, CB1, CB2 are available for TPMI indication) is shown in Table 69, where the rank 1-4 codebooks are assumed to be Tables 65, 66, 67, and 68. If any two of CB0, CB1, or CB2 can be used for TPMI indication, the table reduces from Table 69 to 3 rows (2 for one of the two codebook partition types and 1 for the two codebook partition types).

[0507] Table 69. TPMI and TRI Payload

[0508]

[0509] In some embodiments 24, the bitmap B = B1B2 is used for CBSR on coherence or codebook partition type and TRI value, where part B1 of the bitmap is used for coherence or codebook partition type, and part B2 of the bitmap is used for TRI value. Alternatively, part B2 of the bitmap is used for coherence or codebook partition type, and part B1 of the bitmap is used for TRI value. Further, B1 corresponds to the MSB bits, B2 corresponds to the LSB bits, or B1 corresponds to the LSB bits, B2 corresponds to the MSB bits. A bitmap of length N is used for CBSR on TRI value, and at least one of the following alternatives is used for CBSR on coherence or codebook partition type.

[0510] In one alternative of Alt 24-0, if the UE is capable of full coherence, it is also capable of partial coherence and incoherence. Thus, a 3-bit bitmap B can be used to configure one of 7 possible precoder groups (or codebook partition type combinations). Two example tables of this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 70 and 71. Alternatively, a 2-bit field F is used to configure one of three codebook partition types (CB0, CB1, and CB2), e.g., where CB0, CB1, and CB2 are indicated by F = 00, 01, 10 or 10, 01, 00 respectively.

[0511] If the UE is capable of partial coherence, then it is also capable of incoherence. Thus, a 2-bit bitmap B can be used to configure one of 3 possible precoder (or codebook partition type combinations) groups. Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 72 and 73. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB1 and CB2), where, e.g., CB1 and CB2 are indicated by F = 0 and 1 or 1 and 0 respectively.

[0512] If the UE can be non-coherent, then it can only be non-coherent. Therefore, the set of precoders (or codebook partition types) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0513] Table 70. Codebook Configuration and TPMI Payload

[0514]

[0515] Table 71. Codebook Configuration and TPMI Payload

[0516]

[0517] Table 72. Codebook Configuration and TPMI Payload

[0518]

[0519] Table 73. Codebook Configuration and TPMI Payload

[0520]

[0521] In an alternative of Alt 24-1, if the UE can be fully coherent, then it can also be partially coherent. Therefore, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 74 and 75. Alternatively, a 1-bit field F can be used to configure one of two codebook partition types (CB0 and CB1), where, for example, CB0 and CB1 are indicated by F = 0 and 1 or 1 and 0 respectively.

[0522] If the UE can be partially coherent, then it can also be non-coherent. Therefore, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Tables 72 and 73. Alternatively, a 1-bit field F can be used to configure one of two codebook partition types (CB1 and CB2), where, for example, CB1 and CB2 are represented by F = 0 and 1 or 1 and 0 respectively.

[0523] If the UE can be non-coherent, then it can only be non-coherent. Therefore, the set of precoders (or codebook partition types) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0524] Table 74. Codebook Configuration and TPMI Payload

[0525]

[0526] Table 75. Codebook Configuration and TPMI Payload

[0527]

[0528] In an alternative of Alt 24-2, if the UE can be fully coherent, it can also be partially coherent. Therefore, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Table 74 and Table 75. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB0 and CB1), where, for example, CB0 and CB1 are indicated by F = 0 and 1 or 1 and 0, respectively.

[0529] If the UE can be partially coherent, it can only be partially coherent. Therefore, this set of precoders (or codebook partition type) is fixed (CB1), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 3 bits.

[0530] If the UE can be non-coherent, it can only be non-coherent. Therefore, this set of precoders (or codebook partition type) is fixed (CB2), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 2 bits.

[0531] In an alternative of Alt 24-3, if the UE can be partially coherent, it can also be non-coherent. Therefore, a 2-bit bitmap B can be used to configure one of three sets of possible precoders (or codebook partition type combinations). Two example tables for this configuration and the corresponding TPMI overhead (number of bits) are shown in Table 72 and Table 73. Alternatively, a 1-bit field F is used to configure one of two codebook partition types (CB1 and CB2), where, for example, CB1 and CB2 are represented by F = 0 and 1 or 1 and 0, respectively.

[0532] If the UE can be fully coherent, then it can only be fully coherent. Therefore, this set of precoders (or codebook partition type) is fixed (CB0), and no additional signaling via RRC for codebook or partition type configuration is required. Note that in this case, the TPMI payload is 4 bits.

[0533] If the UE can be non-coherent, then it can only be non-coherent. Thus, the set of precoders (or codebook partitioning type) is fixed (CB2), and no additional signaling for codebook or partitioning type configuration via RRC is required. Note that in this case, the TPMI payload is 2 bits.

[0534] In some embodiments 25, in addition to the CBSR on the coherence or codebook partitioning type and TRI value according to at least one of Alt 23-0 to Alt 23-3 (e.g., embodiment 23), the CBSR also restricts the use of each precoding matrix in the UL codebook. For example, using a bitmap B3, where the bitmap B3 is a concatenation of R bitmaps B0...B R-1 where R is the number of rank values for which we have CBSR. For example, if R = 4, then the bitmap B is a concatenation of 4 bitmaps B 3,0 ...B 3,3 where B 3,0 is the bitmap for rank value 1, B 33 is the bitmap for rank value 4, or B 30 is the bitmap for rank value 4, B 33 is the bitmap for rank value 1. Thus, the total length of the bitmap where N i is the number of precoding matrices in the rank i codebook.

[0535] After applying the codebook subset restriction to the UL codebook, the size (number of bits) of the TPMI-related signaling field in the UL-related DCI is determined according to the number of precoding matrices.

[0536] Although the present disclosure has been described using exemplary embodiments, various changes and modifications can be suggested to those skilled in the art. The present disclosure is intended to embrace these changes and modifications that fall within the scope of the appended claims.

[0537] None of the descriptions in this application should be construed as implying that any particular element, step, or function is an essential element that must be included in the scope of the claims. The scope of the patent subject matter is defined only by the claims.

Claims

1. A user equipment (UE), the UE comprising: A transceiver; And A processor, coupled to the transceiver and configured to: Send a message including the UE's coherence capability to a base station (BS) for indicating a transmission precoding matrix indicator (TPMI) and the number of layers; Receive a radio resource control (RRC) message including an uplink (UL) codebook subset and a UL maximum rank from the BS, where the UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for the maximum number of layers, Receive downlink control information (DCI) including an indication of the TPMI and the number of layers from the BS; and Send UL data to the BS via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, Wherein when the number of layers = 1, based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, determine a precoder for UL transmission of the UE using four antenna ports according to the following:

2. The UE according to claim 1, Among them, When the number of layers = 2, based on the TPMI index in the indication of the TPMI and the number of layers, determine a precoder for UL transmission of the UE using four antenna ports according to the following:

3. The UE according to claim 1, Among them, When the number of layers = 3, based on the TPMI index in the indication of the TPMI and the number of layers, determine a precoder for UL transmission of the UE using four antenna ports according to the following: Wherein when the number of layers = 4, based on the TPMI index in the indication of the TPMI and the number of layers, determine a precoder for UL transmission of the UE using four antenna ports according to the following:

4. The UE according to claim 1, wherein, The coherence capability of the UE is one of full, partial, or non - coherent; For the first coherence state among the three coherence states, the subset of the UL codebook includes full, partial, and non - coherent precoders, For the second coherence state among the three coherence states, the subset of the UL codebook includes only partial and non - coherent precoders, and For the third coherence state among the three coherence states, the subset of the UL codebook includes only non - coherent precoders.

5. The UE according to claim 1, Among them, The number of bits of the indication included in the DCI is determined based on the UL codebook subset and the UL maximum rank configured by the RRC message.

6. The UE according to claim 1, Among them, The UL codebook subset is configured for the UE by the BS based on and not exceeding the UE's coherence capability.

7. A base station (BS), the BS comprising A transceiver; and A processor, coupled to the transceiver and configured to: Receive a message including the UE's coherence capability from a user equipment (UE) for indicating a transmission precoding matrix indicator (TPMI) and the number of layers; Send a Radio Resource Control (RRC) message including an uplink (UL) codebook subset and a UL maximum rank to a UE based on the UE's coherent capabilities, where, The UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for the maximum number of layers, Send downlink control information (DCI) including an indication of the TPMI and the number of layers to the UE; and Receive UL data from the UE via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, Wherein, when the number of layers = 1, based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, determine the precoder for UL transmission using four antenna ports for the UE according to the following items:

8. The BS according to claim 7, Among them, when the number of layers = 2, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission using four antenna ports for the UE according to the following items:

9. The BS according to claim 7, Among them, when the number of layers = 3, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission using four antenna ports for the UE according to the following items: Wherein, when the number of layers = 4, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission using four antenna ports for the UE according to the following items:

10. The BS according to claim 7, Among them, The coherence capability of the UE is one of full, partial, or non - coherent; For the first coherence state among the three coherence states, the subset of the UL codebook includes full, partial, and non - coherent precoders, For the second coherence state among the three coherence states, the subset of the UL codebook includes only partial and non - coherent precoders, and For the third coherence state among the three coherence states, the subset of the UL codebook includes only non - coherent precoders.

11. The BS according to claim 7, Among them, The number of bits of the indication included in the DCI is determined based on the UL codebook subset configured by the RRC message and the UL maximum rank.

12. The BS according to claim 7, Among them, The UL codebook subset is configured for the UE by the BS based on and not exceeding the coherence capability of the UE.

13. A method performed by a user equipment (UE), the method comprising: Sending a message including the coherence capability of the UE to a base station (BS) for sending an indication of a precoding matrix indicator (TPMI) and the number of layers; Receiving a radio resource control (RRC) message including an uplink (UL) codebook subset and a UL maximum rank from the BS, wherein the UL codebook subset indicates one of three coherence states, and the UL maximum rank indicates a value for the maximum number of layers, Receiving downlink control information (DCI) including an indication of the TPMI and the number of layers from the BS; and Sending UL data to the BS via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, Wherein, when the number of layers = 1, based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, determine the precoder for UL transmission using four antenna ports for the UE according to the following items:

14. The method according to claim 13, Among them, when the number of layers = 2, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission using four antenna ports for the UE according to the following items:

15. The method according to claim 13, Among them, When the number of layers = 3, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission of the UE using four antenna ports according to the following: Wherein, when the number of layers = 4, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission of the UE using four antenna ports according to the following:

16. The method according to claim 13, wherein, The coherence capability of the UE is one of full, partial, or non - coherent; For the first coherence state among the three coherence states, the subset of the UL codebook includes full, partial, and non - coherent precoders, For the second coherence state among the three coherence states, the subset of the UL codebook includes only partial and non - coherent precoders, and For the third coherence state among the three coherence states, the subset of the UL codebook includes only non - coherent precoders.

17. The method according to claim 13, Among them, including the number of bits in the indication in the DCI is determined based on the UL codebook subset configured by the RRC message and the UL maximum rank.

18. The method according to claim 13, Among them, The UL codebook subset is configured for the UE by the BS based on and not exceeding the coherence capability of the UE.

19. A method performed by a base station (BS), the method including: Receiving, from a user equipment (UE), a message including the coherence capability of the UE, an indication for transmitting a precoding matrix indicator (TPMI), and the number of layers; Sending, based on the coherence capability of the UE, a radio resource control (RRC) message including an uplink (UL) codebook subset and a UL maximum rank to the UE, wherein the UL codebook subset indicates one of the three coherence states, and the UL maximum rank indicates a value for the maximum number of layers, Sending downlink control information (DCI) including an indication of the TPMI and the number of layers to the UE; and Receiving UL data from the UE via a physical uplink shared channel (PUSCH) based on the indication of the TPMI and the number of layers, Wherein, when the number of layers = 1, based on the TPMI index in the indication of the TPMI, the number of layers, and the UL codebook subset, determine the precoder for UL transmission of the UE using four antenna ports according to the following:

20. The method according to claim 19, Among them, When the number of layers = 2, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission of the UE using four antenna ports according to the following:

21. The method according to claim 19, Among them, When the number of layers = 3, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission of the UE using four antenna ports according to the following: Wherein, when the number of layers = 4, based on the TPMI index in the indication of the TPMI and the number of layers, determine the precoder for UL transmission of the UE using four antenna ports according to the following:

22. The method according to claim 19, Among them, The coherence capability of the UE is one of full, partial, or non - coherent; For the first coherent state among the three coherent states, the subset of the UL codebook includes full, partial, and non-coherent precoders. For the second coherent state among the three coherent states, the subset of the UL codebook includes only partial and non-coherent precoders, and For the third coherent state among the three coherent states, the subset of the UL codebook includes only non-coherent precoders.

23. The method according to claim 19, Among them, wherein the number of bits of the indication in the DCI is determined based on the subset of the UL codebook configured by the RRC message and the UL maximum rank.

24. The method according to claim 19, Among them, wherein the subset of the UL codebook is configured by the BS for the UE based on and not exceeding the coherent capability of the UE.

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