Methods, apparatuses and systems for phase-continuous frequency-selective precoding processing

Abstract

Methods, apparatus, systems, devices, and computer program products are provided for phase-continuous frequency-selective precoding processing. Included in these categories are methods used in conjunction with dynamic precoding resource block group (PRG) configuration and codebook-based transmission configuration. A typical such method can include any of the following: receiving signaling indicating transmission precoding information; determining a candidate PRG size using any of the transmission precoding information, a rule for determining a PRG size, and a configured PRG size; and configuring or reconfiguring a wireless transmit / receive device in accordance with the candidate PRG size. Another typical method can include: reporting a transmission coherence capability of a wireless transmit / receive unit; receiving a codebook subset restriction (CBSR) corresponding to the transmission coherence capability; determining a transmission precoding matrix index (TPMI) size based on the CBSR; receiving a TPMI; and detecting or decoding the TPMI based on the determined TPMI size.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201880015364.3, filed January 13, 2018, entitled “Method, Apparatus, and System for Phase-Continuous Frequency-Selective Precoding Processing,” the contents of which are incorporated herein by reference. BACKGROUND TECHNICAL FIELD

[0003] The present application relates to wireless communications.

[0004] RELATED ART

[0005] In Long Term Evolution (LTE), a precoding resource block group (PRG) can be used to configure the granularity of precoding in the frequency domain, and can be used to facilitate channel estimation at a wireless transmit / receive unit (WTRU), whereby the WTRU performs channel estimation over a group of contiguous physical resource blocks (PRBs). In LTE, the PRG depends on the system bandwidth, and for system bandwidths of 1.4 MHz, 3-5 MHz, 10 MHz, 10 MHz and above, the possible values are 1, 2, 3, 2, respectively. The WTRU can assume that the channel used to convey a symbol on a demodulation reference signal antenna port in a first PRB within a PRG can be inferred from the channel used to convey another symbol on the same demodulation reference signal antenna port in a second PRB within the same PRG. In another example, the WTRU can assume that the same precoder is used for a demodulation reference signal antenna port in a first PRB within a PRG and the same demodulation reference signal antenna port in a second PRB within the same PRG. Hereinafter, PRB, RB, and virtual RB (VRB) are used interchangeably.

[0006] In LTE, the available resource blocks can be divided into groups for allocation by using resource block groups (RBGs). The number of resource blocks in a RBG also depends on the system bandwidth, and for system bandwidths of 1.4 MHz, 3-5 MHz, 10 MHz, 10 MHz and above, the possible values are 1, 2, 3, 4, respectively.

[0007] In NR, selective precoding processing can be improved compared to LTE (e.g., by more flexibly choosing the precoding resolution). In LTE, the values used to select PRBs and PRGs from (“PRB and PRG sizes”) are very limited, and precoding operations are applied for specific PRB and PRG sizes. While such an approach has some benefits in terms of feedback overhead, it can have deficiencies in exploiting the frequency selectivity of the channel.

[0008] An alternative approach can be to perform frequency-selective precoding processing with a finer resolution than the precoding resolution of LTE, thereby enhancing MIMO performance. With similar assumptions of WTRU-specific and / or demodulation reference signals (collectively referred to as "DMRS") and precoding procedures and codebooks as LTE, if higher resolution is taken for frequency-selective precoding processing, it can pose significant challenges for channel estimation. There can be discontinuity on the effective channel due to abrupt changes between selected adjacent precoders. As such, wideband channel estimation can not be achievable, resulting in some distortion or poor channel estimation.

[0009] In phase-continuous precoding processing, adjacent precoders can be designed to be phase-continuous, thereby taking into account smoothing of channel estimation regardless of whether precoding processing is performed on reference symbols. Some proposed approaches for performing phase-continuous precoding processing include (i) performing time-domain pruning and filtering processing based on DFT / IDFT processing, thereby ensuring phase continuity (see, e.g., "Discussion on phase continuity and PRB bundling," published by Qualcomm Incorporated in 3GPP Tdoc Rl- 1612045, 3GPP TSG-RAN WG1 Meeting #87, Reno, USA, Nov. 14-18, 2016, hereinafter referred to as "[1]"); and (ii) frequency-smoothed beamforming processing using a smooth singular value decomposition (SVD) (including finite impulse response (FIR) filtering processing on the nearest adjacent subcarriers, or an orthogonal iteration-based approach) to generate eigenvectors.

[0010] However, for precoded DMRS, the reference signals in adjacent resources can be modified by different precoders. This can hinder channel estimation averaging across resources and can degrade channel estimation accuracy. Accordingly, precoding processing and precoder mechanisms can be necessary to allow smooth transition between adjacent precoders.

[0011] In addition to designing phase-continuous precoding processing, information exchange can be necessary to allow the WTRU and the base station (e.g., gNB) to be aware of each other's transmitter and receiver capabilities, and / or to inform the other of using phase-continuous precoding processing to enable each receiver to implement channel estimation smoothing processing.

[0012] High-resolution frequency-selective precoding processing can be applicable to DL and UL MIMO operations. As such, procedures and support mechanisms can be necessary to enable such high-resolution frequency-selective precoding. BRIEF DESCRIPTION OF DRAWINGS

[0013] A more detailed understanding can be had from the following description, which is given by way of example in conjunction with the accompanying drawings. These figures, like the detailed description, are examples. As such, the figures and detailed description are not to be considered limiting, and other examples, as well as equivalents to the examples, are possible and contemplated. Furthermore, the same reference numerals in different figures represent the same element, and some elements are not drawn to scale.

[0014] Figure 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments can be implemented;

[0015] Figure 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that can be used within the communications system 100 of FIG. 1A; Figure 1A

[0016] is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that can be used within the communications system 100 of FIG. 1A in accordance with an embodiment; Figure 1C Figure 1A is a system diagram illustrating another example RAN and an example CN that can be used within the communications system 100 of FIG. 1A in accordance with an embodiment;

[0017] Figure 1D Figure 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments can be implemented;

[0018] Figure 2 is a system diagram illustrating an example communications system in which one or more disclosed embodiments can be implemented;

[0019] Figure 3 is a flowchart illustrating a typical procedure for performing phase-continuous precoding processing using cyclic delay diversity (CDD);

[0020] Figure 4 is a graph illustrating a capacity comparison of adaptive CDD precoding processing with other precoding mechanisms.

[0021] Figure 5 includes two graphs illustrating edge element distortion of time-domain smoothing precoders;

[0022] Figure 6 is a flowchart illustrating a typical procedure for performing phase-continuous precoding processing with non-zero edge smoothing processing;

[0023] Figure 7 illustrates an example of phase-continuous precoding processing with non-zero edge smoothing processing;

[0024] Figure 8 ​​includes two charts showing performance comparison of a phase-continuous precoding process with non-zero edge smoothing with other precoding methods;

[0025] Figure 9 is a flowchart showing a typical procedure for performing a phase-continuous precoding process with a phase transition region;

[0026] Figure 10 shows an example of a phase-continuous precoding process with a phase transition region;

[0027] Figure 11 is a flowchart showing a typical procedure for performing a phase-continuous precoding process with one or more phase transition regions;

[0028] Figures 12-14 is a flowchart showing a typical procedure related to a phase-continuous precoding process;

[0029] Figure 15 is a block diagram showing an example of a frequency-selective precoding process for multi-subband transmission;

[0030] Figure 16 is a block diagram showing an example of frequency-selective precoding for localized scheduling with different bandwidth components;

[0031] Figure 17 is a block diagram showing an example of a frequency-selective precoding process for localized scheduling with various bandwidth components;

[0032] Figure 18 is a flowchart showing a typical procedure related to a phase-continuous precoding process;

[0033] Figure 19 shows an example transmission precoding matrix index (TPMI) indication mechanism with supplemental midband TPMI information;

[0034] Figures 20-21 is a flowchart showing a typical procedure related to a phase-continuous precoding process;

[0035] Figure 22 is a block diagram showing an example of a frequency-selective precoding process using a subband precoder;

[0036] Figure 23 is a block diagram showing an example of a frequency-selective precoding process based on a transmission precoding matrix index using a primary subband; and

[0037] Figure 24is a block diagram illustrating a frequency selective precoding process based on an example using a transmission precoding matrix index of a primary subband. DETAILED DESCRIPTION

[0038] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples can be practiced without some or all of these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the following description. Further, embodiments and examples not specifically described herein can be implemented and / or used, and thus, are not excluded from the scope of the embodiments and examples described herein.

[0039] Example Communication System

[0040] The methods, apparatus and systems provided herein are well suited to communications involving wired and wireless networks. Wired networks are well known. An overview of various types of wireless devices and infrastructure is provided in Figures 1A-1D The various components of the network can use, perform, be arranged to perform, be adapted to perform, and / or be configured to perform the methods, apparatus and systems provided herein.

[0041] Figure 1A is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments can be implemented. The example communication system 100 is provided for illustration purposes only and is not limiting on the disclosed embodiments. The communication system 100 can be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communication system 100 can enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 can employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DFT-s-OFDM), unique-word OFDM (UW-OFDM), resource block-filter OFDM, filter bank multicarrier (FBMC), and the like.

[0042] As Figure 1AAs shown, the communication system 100 can include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d can be any type of device configured to

[0043] The communication system 100 can also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b can be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b can be a base transceiver station (BTS), a Node-B, an eNode B (eNB), a Home Node B (HNB), a Home eNode B (HeNB), a gNode B (gNB), NR Node B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b can include any number of interconnected base stations and / or network elements.

[0044] The base stations 114a can be a part of the RAN 104 / 113, which can also include other base stations and / or network equipment (not shown) such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base stations 114a and / or the base stations 114b can be configured to transmit and / or receive wireless signals on one or more carrier frequencies

[0045] The base stations 114a, 114b can communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over the air interface 116, which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 can be established using any suitable radio access technology (RAT).

[0046] More specifically, as noted above, the communications system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA can include communication protocols

[0047] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-A Pro.

[0048] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0049] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as New Radio (NR) Radio Access, which can establish the air interface 116 using NR.

[0050] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, the base station 114a and WTRUs 102a, 102b, 102c can implement LTE wireless access and NR wireless access (e.g., using dual connectivity (DC) principles). Thus, the air interface utilized by WTRUs 102a, 102b, 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0051] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0052] Figure 1A The base station 114b in FIG. 13 can be a wireless router, Home Node B, Home eNode B, or access point, for example, and can utilize any suitable RAT for facilitating wireless connectivity access points employing the IEEE 802.11 functionality, such as wireless fidelity (Wi-Fi), wireless fidelity, IEEE 802.11a, b, g, n, ac, ad, and / or ay, or Bluetooth®, Bluetooth Low Energy, to name a few. Cellular telecommunications industry standards, LTE, LTE-A, LTE-A Pro, NR, 5G, GSM, UMTS, CDMA2000, WiMAX, and / or other standards, to name a few, can also be utilized. The base station 114b and the WTRUs 102c, 102d in Figure 1A FIG. 13 can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (EUTRA), Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (i.e., Wi-Fi), IEEE 802.15, 5G (e.g., NR), and / or the like. The base station 114b and the WTRUs 102c, 102d

[0053] The RAN 104 / 113 can be in communication with the CN 106 / 115, which can be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data can have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 can provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 10, the RAN 104 / 113 and / or the CN 106 / 115 can be in direct or indirect communication with other those networks. For example, the CN 106 / 115 can also Figure 1A communicate with other networks (not shown) that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which can employ a NR radio technology, the CN 106 / 115 can also be connected to another RAN (not shown) that employs a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0054] The CN 106 / 115 can also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 can include circuit-switched telephone networks that provide infrastructure for the provision of voice telephony. The Internet 110 can include a global system of interconnected computer networks and devices that use the Transmission Control Protocol / Internet Protocol (TCP / IP) suite of protocols. The networks 112 can include wired or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 can include another CN that can be similar to the CN 106 / 115, although of a different size, and / or owned / operated by a different service provider. In particular, the networks 112 can include another RAN and / or another CN, which can be similar to the RAN 104 and the CN 106 / 115, although of a different size, and / or owned / operated by a different service provider.

[0055] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 can include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d can include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in Figure 1 A can be configured to communicate with the base station 114a, which can employ a cellular-based radio technology, and with the base station 114b, which can employ an IEEE 802 radio technology. Figure 1A The WTRU 102c shown in Figure 1 A can be configured to communicate with the base station 114a using a cellular-based radio technology and with the base station 114b using an IEEE 802 radio technology.

[0056] Figure 1B Figure 1 B is a system diagram illustrating an example WTRU 102. The example WTRU 102 is shown comprised of a mobile device such as a mobile station, a subscriber station, a portable Figure 1B As shown, the WTRU 102 can include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138, among others. It should be appreciated that the WTRU 102 can include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0057] The processor 118 can be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 can perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, however, it will be appreciated that the processor 118 and the transceiver 120 can be integrated together, e.g., in an electronic package or chip.

[0058] The transmit / receive element 122 can be configured to transmit signals to, and receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 can be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit / receive element 122 can be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0059] In addition, although the transmit / receive element 122 is depicted in the Figure 1B WTRU 102 can include any number of transmit / receive elements 122. For example, the WTRU 102 can include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0060] The transceiver 120 can be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 can have multi-mode capabilities. Thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0061] The processor 118 of the WTRU 102 can be coupled to, and can receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 can also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 can access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 can include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 can include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 can access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0062] The processor 118 can receive power from the power source 134, and can be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 can be any suitable device for powering the WTRU 102. For example, the power source 134 can include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0063] The processor 118 can also be coupled to the GPS chipset 136, which can be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 can receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on

[0064] The processor 118 can further couple to other peripherals 138, which can include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 can include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands- free headset, an A / V port, a subwoofer, a power meter, a memory stick, and the like. The peripheral 138 can include one or more sensors that can be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, a compass sensor, a proximity sensor, a temperature sensor, a time sensor, a geo-location sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0065] The WTRU 102 can include a full duplex radio for which transmission and reception of some or all signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and the downlink (e.g., for reception) can be concurrent and / or simultaneous. The full duplex radio can include an interference management unit to reduce and / or substantially eliminate self-interference and / or cross- interference due to concurrent transmission and reception. In an embodiment, the WTRU 102 can include a half duplex radio for which transmission and reception of some or all signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)) are not concurrent and / or simultaneous.

[0066] Figure 1C is a system diagram illustrating the RAN 104 and the CN 106 according to another embodiment. As noted above, the RAN 104 can employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 can also be in communication with the CN 106.

[0067] The RAN 104 can include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 can include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c can implement MIMO technology. Thus, the eNode-B 160a, for example, can use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0068] Each of the eNode-Bs 160a, 160b, 160c can be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), and the like. As shown, the eNode-Bs 160a, 160b, 160c can communicate with one another over an X2 interface. Figure 1C

[0069] Figure 1C The core network 106 shown in Figure 1 can include a mobility management gateway (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0070] MME 162 can be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an SI interface and can serve as a control node. For example, the MME 162 can be responsible for authenticating users of the WTRUs 102a, 102b, 102c, for activating and deactivating

[0071] SGW 164 can be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0072] The SGW 164 can be connected to the PDN gateway 166, which can provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0073] ​The CN 106 can facilitate communications with other networks. For example, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional landline communications devices. For example, the CN 106 can include, or can communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0074] Although WTRU is described in Figures 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal can use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0075] In representative embodiments, the other network 112 can be a WLAN.

[0076] A WLAN using an infrastructure Basic Service Set (BSS) mode can have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can have access to or be attached to a Distribution System (DS) or a wireline / wireless network that carries traffic in and / or out of the BSS. Traffic to STAs that originates from outside the BSS can arrive through the AP and can be delivered to the STAs. Traffic originating from a STA that is destined for outside the BSS can be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS can be sent through the AP, for example, in situations in which the STAs are unable to communicate directly with each other. The traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent directly between the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, DLS can use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode can not have an AP, and all STAs in the IBSS, can communicate directly with each other. The IBSS mode of communication can sometimes be referred to as an“ad-hoc” mode of communication.

[0077] In using an 802.1 lac infrastructure mode of operation or similar mode of operation, an AP can transmit beacons on a fixed channel (e.g., a primary channel). The primary channel can have a fixed width (e.g., 20 MHz bandwidth) or a dynamically set width by signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access with collision avoidance (CSMA / CA) (e.g., in 802.11 systems) can be implemented. For CSMA / CA, STAs, including the AP (e.g., each of the STAs) can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, the particular STA can back off. In a designated BSS, only one STA (e.g., only one station) can transmit at any given time.

[0078] High Throughput (HT) STAs can use a 40 MHz wide channel for communication, e.g., by combining a 20 MHz primary channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0079] Very High Throughput (VHT) STAs can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz wide channels can be formed by combining contiguous 20 MHz channels. A 160 MHz wide channel can be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data can be passed through a segment parser that can divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, can be done on each stream separately. The streams can be mapped on to the two 80 MHz channels, and data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above described operations can be reversed for the 80+80 configuration, and the combined data can be sent to the Medium Access Control (MAC).

[0080] 802.11af and 802.11ah support sub-1 GHz operating modes. In 802.11af and 802.11ah, the channel operating bandwidth and carrier are scaled down compared to 802.11η and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidth in TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidth using non-TVWS spectrum. In accordance with typical embodiments, 802.11ah can support meter type control / machine type communication (MTC), e.g., MTC devices in a macro coverage area. MTC devices can have certain capabilities, e.g., include limited capabilities that support (e.g., only support) certain and / or limited bandwidth. MTC devices can include a battery, and the battery life of the battery is above a threshold (e.g., to maintain a long battery life).

[0081] For WLAN systems that can support multiple channels and channel bandwidths (e.g., 802.11η, 802.11ac, 802.11af, and 802.11ah), the systems include a channel that can be designated as a primary channel. The bandwidth of the primary channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by a STA that is derived from all STAs operating in the BSS that support the minimum bandwidth operating mode. In the example of 802.11ah, even though the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes, the width of the primary channel can be 1 MHz for STAs (e.g., MTC type devices) that support (e.g., only support) 1 MHz mode. Carrier sensing and / or network allocation vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy (e.g., because a STA (that only supports 1 MHz operating mode) is transmitting to the AP), then the entire available frequency band can be considered busy even though most of the frequency band remains idle and available for use.

[0082] In the United States, the available frequency band for 802.11ah is 902 MHz to 928 MHz. In Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is 916.5 MHz to 927.5 MHz. Depending on the country code, the total bandwidth available for 802.11ah is 6 MHz to 26 MHz.

[0083] Figure 1Dis a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As described above, the RAN 113 can employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 can also be in communication with the CN 115.

[0084] The RAN 113 can include gNBs 180a, 180b, 180c, although it will be appreciated that the RAN 113 can include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c can implement MIMO technology. For example, gNBs 180a, 180b, 180c can use beamforming to transmit and / or receive signals to and / or from the gNBs 180a, 180b, 180c. Thus, the gNBs 180a, 180b, 180c can use MIMO techniques that can include spatial multiplexing, beamforming, and / or transmit diversity. The gNBs 180a, 180b, 180c can be configured to communicate to and / or receive from any number of WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c can communicate with the WTRUs 102a, 102b, 102c using the OFDM

[0085] The WTRUs 102a, 102b, 102c can use transmission associated with scalable numerology to communicate with gNBs 180a, 180b, 180c. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can be different for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different amounts of OFDM symbols and / or lasting different lengths of absolute time).

[0086] The gNBs 180a, 180b, 180c can be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c without also accessing other RANs (e.g., eNode-Bs 160a, 160b, 160c). In the standalone configuration, the WTRUs 102a, 102b, 102c can utilize WTRUs 102a, 102b, 102c one or more of the gNBs 180a, 180b, 180c as a mobile anchor point. In the standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In the non-standalone configuration, the WTRUs 102a, 102b, 102c communicate with the gNBs 180a, 180b, 180c while also communicating with another RAN, such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c can implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously using a single RAN protocol context. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c can serve as a mobile anchor point for WTRUs 102a, 102b, 102c and the gNBs 180a, 180b, 180c can provide additional coverage and / or throughput to WTRUs 102a, 102b, 102c served by base stations 160a, 160b, 160c.

[0087] Each of the gNBs 180a, 180b, 180c can be associated with a certain cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, implement dual connectivity, implement interworking with one or more other RATs, route user plane and control plane data for one or more RAN nodes (e.g., as in a CU / DU split architecture), and the like. As shown, the gNBs 180a, 180b, 180c can communicate with one another over an Xn interface. Figure 1D

[0088] Figure 1D ​The CN 115 can include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0089] The AMF 182a, 182b can be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and can serve as the control-plane anchor for the WTRUs 102a, 102b, 102c. For example, the AMF 182a, 182b can handle authentication of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selection of a particular SMF 183a, 183b, management of the WTRU 102a, 102b, 102c registration area, termination of NAS signaling, mobility management, and the like. The AMF 162 can utilize network slicing to customize CN support for the WTRUs 102a, 102b, 102c based on the types of services being utilized, e.g., depending on whether the WTRU 102a, 102b, 102c is accessing services that rely on ultra-reliable low-latency (URLLC) access, enhanced massive mobile broadband (eMBB) access, and / or MTC access, etc. The AMF 162 can provide a control plane function for switching between the RAN 113 and other RANs (not illustrated) using other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0090] The SMF 183a, 183b can be connected to AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b can also be connected to the UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b can select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b can perform other functions, such as managing and allocating IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type can be IP-based, non-IP based, Ethernet-based, and the like.

[0091] The UPF 184a, 184b can be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which can provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b can perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering of downlink packets, and providing mobility anchoring, among other examples.

[0092] The CN 115 can facilitate communications with other networks. For example, the CN 115 can include, or can communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. Further, the CN 115 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c can be connected to a local DN 185a, 185b through the UPF 184a, 184b via the N3 interface and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0093] In view of the Figures 1A-1D and the corresponding description of Figures 1A-1D one or more or all of the functions described with respect to one or more of the above-described elements can be executed by one or more emulation components / devices (not shown). These emulation devices can be one or more devices configured to emulate one or more or all of the functions described herein. For example, these emulation devices can be used to test other devices and / or to simulate a network and / or WTRU functionality.

[0094] The one or more emulation devices can perform one or more or all of the functions while being implemented at least partially as a part of the wired and / or wireless communication network. The one or more emulation devices can perform one or more or all of the functions while being temporarily implemented / deployed as a part of the wired and / or wireless communication network. The emulation devices can directly couple to the other devices to perform the testing, and / or can perform the testing using over-the-air, wireless communications.

[0095] The one or more emulation devices can perform one or more or all of the functions while not being implemented / deployed as a part of the wired and / or wireless communication network. For example, the emulation devices can be used in a testing laboratory and / or a testing scenario that is not deployed, such as a test bed, to implement tests on one or more components. The one or more emulation devices can be test equipment. The emulation devices can transmit and / or receive data using direct RF coupling and / or wireless communications via RF circuitry (which can include one or more antennas, for example).

[0096] Figure 2 An example communication system 200 in which embodiments herein can be implemented or deployed is illustrated. The communication system 200 is provided for exemplification purposes only and should not be construed as limiting the disclosed embodiments. As shown, the communication system 200 includes a base station 202 and WTRUs 204a, 204b. As those skilled in the art will immediately appreciate, the communication system 200 can include any number of base stations and WTRUs. Figure 2 The base station 202, as shown, can be any of the base station 114 Figure 2 , the eNode B 160 , and the gNB 180

[0097] . The base station 202 can also include similar and / or different functions as the base station 114, the eNode B 160, and the gNB 180. For example, the base station 202 can include functionality for supporting 5G and implementing the procedures, techniques, etc. contained herein. Figure 1A Figure 1C Figure 1D

[0098] ​​The base stations 202 can be configured for small cell operation and / or deployment. The base stations 202 can be configured to support any of centimeter wave (cmW) and millimeter wave (mmW) operations. To simplify the description, the term "xmW" can be used herein to refer to any of cmW and mmW. Additionally and / or alternatively, the base stations 202 can also be configured to support various (e.g., all or some) functionalities and / or features related to small cell operation and / or deployment as specified in 3GPP Release 12. In this regard, the base stations 202 are capable of operating the xmW air interface in parallel, concurrently, and / or employing other manners associated with an LTE, LTE-A, or similar type of (collectively referred to as "LTE") air interface. The base stations 202 can be equipped with at least one of various advanced antenna configurations and beamforming techniques, such as techniques that can allow the base stations 202 to concurrently transmit LTE downlink channels in a wide beam pattern and xmW channels in one or more narrow beam patterns. The base stations 202 can also be configured to use LTE uplink configurations adapted with features and procedures (e.g., the features and procedures detailed herein) for supporting WTRUs that do not have or are not using xmW uplink transmission capabilities.

[0099] As an example, each of the WTRUs 204a, 204b can be any of the WTRUs 102 Figures 1A-1D ) detailed herein. Each of the WTRUs 204a, 204b can likewise include similar and / or different functionality as the WTRUs 102. The WTRUs 204a, 204b can include functionality to support 5G and implement the processes, techniques, etc. detailed herein. To simplify the description, when "WTRU 204" is used herein, it can refer to any of the WTRUs 204a, 204b.

[0100] Each of the WTRUs 204a, 204b can be configured to support xmW operation. The WTRUs 204a, 204b can be further configured to support various (e.g., all or some) functions and / or features related to user equipment operation and / or deployment as specified by 3GPP Release 12. Each of the WTRUs 204a, 204b can operate the LTE and xmW air interfaces in parallel, simultaneously, and / or in other interrelated manners. Each of the WTRUs 204a, 204b can have two sets of antennas and accompanying RF links; one set configured to operate in the LTE band and the other set configured to operate in the xmW band. However, the disclosure is not limited in this regard, and the WTRUs can have any number of sets of antennas and accompanying RF links. Each of the WTRUs 204a, 204b can include one or more baseband processors, and the baseband processors can include functions related to baseband processing of the LTE band and the xmW band separately or at least partially combined. As an example, the baseband processing functions can share hardware structures for the xmW and LTE air interfaces.

[0101] The term "effective channel" as used herein can refer to a product of a precoding process and an actual wireless channel. Also, the term "tone-wise precoding process" as used below can mean a phase-continuous precoding operation, and vice versa.

[0102] SUMMARY

[0103] The present disclosure relates, inter alia, to methods, apparatus, systems, devices, and computer program products for phase-continuous frequency-selective multiple-input multiple-output (MIMO) precoding processes. The method can include any one of the following: (i) performing a phase-continuous precoding process using cyclic delay diversity (CDD), (ii) performing a phase-continuous precoding process with a non-zero edge smoothing process, (iii) performing a phase-continuous precoding process with a phase transition region, (iv) performing a phase-continuous precoding process for non-continuous transmission.

[0104] In an embodiment, performing a phase-continuous precoding process using CDD can include determining a respective plurality of CDD-based precoding matrices for a plurality of precoding resource sets (PRSs), precoding a first PRS of the plurality of PRSs using a respective first CDD-based precoding matrix of the at least plurality of CDD-based precoding matrices and a first matrix adapted to provide an initial precoding phase, and precoding a second PRS of the plurality of PRSs using a respective second CDD-based precoding matrix of the at least plurality of CDD-based precoding matrices and a second matrix adapted to provide phase continuity from the precoded first PRS.

[0105] A first of these methods can be implemented in a first device configured to communicate with a second device, and the method can include informing the first device of a capability of the second device, and determining whether the second device supports phase-continuous precoding processing based on the capability of the second device. The first and second devices can be a base station and a wireless transmit / receive unit (WTRU), respectively (or vice versa).

[0106] A second of these methods can be implemented in a first device configured to communicate with a second device, and the method can include informing, by the first device, that a particular transmission is using a phase-continuous precoder in a control channel. The first and second devices can be a base station and a WTRU, respectively (or vice versa).

[0107] A third of these methods can include each of a plurality of WTRUs signaling to a base station whether it is using phase-continuous precoding processing for a multi-user transmission.

[0108] A fourth of these methods can include transmitting a single bit on a control channel to indicate tone-wise precoding processing versus wideband precoding processing. A fifth of these methods can include transmitting information to implicitly indicate tone-wise precoding processing versus wideband precoding processing by embedding the information in a demodulation reference signal (DMRS).

[0109] A sixth of these methods can include receiving a precoding resource block group (PRG) size, and determining whether to activate tone-wise precoding processing (or wideband precoding processing) based on the PRG size. In an embodiment, the PRG size is the size of a scheduling grant or corresponds to the size of a scheduling grant.

[0110] A seventh of these methods can include decoding a control channel at a device, and implementing channel estimation smoothing at the device when it is discovered that a data channel has been precoded with phase-continuous precoding processing.

[0111] An eighth of these methods can include blindly estimating at a device whether a data channel has been precoded with phase-continuous precoding processing, and decoding the data channel assuming that no phase-continuous precoding processing has been performed if the data channel cannot be decoded.

[0112] A ninth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device, signaling indicating transmission precoding information for: (i) a plurality of sub-bands of a first bandwidth assigned to the second device; and (ii) one or more second bandwidths. The signaling can include a resource allocation defining the first bandwidth. As an example, the signaling can be a grant. Alternatively, the signaling can include a combination of a grant and higher layer signaling.

[0113] A tenth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device, signaling indicating transmission precoding information for: (i) a plurality of sub-bands of a first bandwidth assigned to the second device; and (ii) one or more second bandwidths; and transmitting a grant containing a resource allocation defining a third bandwidth, the third bandwidth including at least one segment of the one or more second bandwidths.

[0114] In any of the methods provided herein, the transmission precoding information can include one or more transmission precoding information indications, the one or more transmission precoding information indications including one or more transmission precoding matrix index (TPMI) indications. Alternatively, the transmission precoding information can include one or more sounding reference signal (SRS) resource indicators (SRIs). The SRIs can include one or more (e.g., respective) transmission precoding information indications. Each SRI can associate one or more SRS ports with one of the transmission precoding information indications. Each SRI can include an indication of the one or more SRS ports and one of the transmission precoding information indications. The transmission precoding information indications can correspond to any of a single-stage codebook and a two-stage codebook.

[0115] The transmission precoding information can include one or more first transmission precoding information indications for the plurality of subbands and one or more second transmission precoding information indications for the one or more second bandwidths. The first transmission precoding information indications can be one or more TPMI indications, and the second transmission precoding information indications can include one or more TPMI indications. Alternatively, the transmission precoding information can include one or more first SRIs and one or more second SRIs. The first SRIs can include one or more first transmission precoding information indications for the plurality of subbands. The second SRIs can include one or more second transmission precoding information indications for the one or more second bandwidths. Each first SRI can associate one or more SRS ports with one of the first transmission precoding information indications. Each second SRI can associate one or more SRS ports with one of the second transmission precoding information indications. Each first SRI can include an indication of one or more SRS ports and one of the first transmission precoding information indications. Each second SRI can include an indication of one or more SRS ports and one of the second transmission precoding information indications.

[0116] The first transmission precoding information indications can be updated at a different rate than the second transmission precoding information indications. For example, the first transmission precoding information indications can be updated more frequently than the second transmission precoding information indications.

[0117] The first SRIs can be updated at a different rate than the second SRIs. For example, the first SRIs can be updated more frequently than the one or more second SRIs.

[0118] The first transmission precoding information indications can correspond to a two-stage codebook. The second transmission precoding information indications can correspond to a one-stage codebook.

[0119] In an embodiment, the first transmission precoding information indications can correspond to one or more (e.g., respective) narrowband precoder components, and the second transmission precoding information indications can correspond to one or more (e.g., respective) midband precoder components. In an embodiment, the first transmission precoding information indications can correspond to one or more (e.g., respective) narrowband precoder components, and the second transmission precoding information indications can correspond to one or more (e.g., respective) wideband precoder components.

[0120] In an embodiment, the plurality of subbands can have a respective plurality of bandwidths, and the first bandwidth can span the plurality of bandwidths. The plurality of subbands can be contiguous or non-contiguous. The plurality of subbands can correspond to a selective set of subbands (e.g., best M subbands) of the first bandwidth.

[0121] A tenth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device in connection with a first license of a plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of a first bandwidth assigned to the second device, and (ii) one or more second bandwidths; transmitting, to the second device in connection with a second license of the plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of a third bandwidth assigned to the second device, and (ii) the one or more second bandwidths; and transmitting, to the second device in connection with a third license of the plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of a fourth bandwidth assigned to the second device, and (ii) one or more fifth bandwidths.

[0122] An eleventh of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device in connection with a first license of a plurality of licenses, one or more first SRIs and one or more second SRIs, where each first SRI includes a first indication of one or more first SRS ports and first transmission precoding information associated with one of a plurality of sub-bands of a first bandwidth assigned to the second device, and where each second SRI includes a second indication of one or more second SRS ports and second transmission precoding information associated with one of one or more second bandwidths; transmitting, to the second device in connection with a second license of the plurality of licenses, one or more third SRIs and the second SRIs, where each third SRI includes a third indication of one or more third SRS ports and third transmission precoding information associated with one of a plurality of sub-bands of a third bandwidth assigned to the second device; and transmitting, to the second device in connection with a third license of the plurality of licenses, one or more fourth SRIs and one or more fifth SRIs, where each fourth SRI includes a fourth indication of one or more fourth SRS ports and fourth transmission precoding information associated with one of a plurality of sub-bands of a fourth bandwidth assigned to the second device, and where each fifth SRI includes a fifth indication of one or more fifth SRS ports and fifth transmission precoding information associated with one of one or more fifth bandwidths.

[0123] A twelfth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device in connection with a first license of a plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of a first bandwidth assigned to the second device, and (ii) one or more second bandwidths; transmitting, to the second device in connection with a second license of the plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of a third bandwidth assigned to the second device, and (ii) the one or more second bandwidths; and transmitting, to the second device in connection with a third license of the plurality of licenses, transmission precoding information for (i) a plurality of sub-bands of the third bandwidth assigned to the second device, and (ii) one or more fourth bandwidths.

[0124] A thirteenth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device in connection with a first license of a plurality of licenses, one or more first SRIs and one or more second SRIs, where each first SRI can include a first indication of one or more first SRS ports and first transmission precoding information associated with one of a plurality of sub-bands of a first bandwidth assigned to the second device, and where each second SRI can include a second indication of one or more second SRS ports and second transmission precoding information associated with one of one or more second bandwidths; transmitting, to the second device in connection with a second license of the plurality of licenses, one or more third SRIs and the second SRIs, where each third SRI can include a third indication of one or more third SRS ports and third transmission precoding information associated with one of a plurality of sub-bands of a third bandwidth assigned to the second device; and transmitting, to the second device in connection with a third license of the plurality of licenses, the third SRIs and one or more fourth SRIs, where each fourth SRI can include a fourth indication of one or more fourth SRS ports and fourth transmission precoding information associated with one of one or more fourth bandwidths.

[0125] A fourteenth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of a first bandwidth assigned to the second device, and (ii) one or more second bandwidths; transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of a third bandwidth assigned to the second device, and (ii) the second bandwidths; and transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of a fourth bandwidth assigned to the second device, and (ii) one or more fifth bandwidths.

[0126] A fifteenth of these methods can be implemented in a first device configured to communicate with a second device and can include transmitting, to the second device, one or more first SRIs and one or more second SRIs, where each first SRI can include a first indication of one or more first SRS ports and first transmission precoding information associated with one of a plurality of sub-bands of a first bandwidth assigned to the second device, and where each second SRI can include a second indication of one or more second SRS ports and second transmission precoding information associated with one or more second bandwidths; transmitting, to the second device, one or more third SRIs and one or more second SRIs, where each third SRI can include a third indication of one or more third SRS ports and third transmission precoding information associated with one of a plurality of sub-bands of a third bandwidth assigned to the second device; and transmitting, to the second device, one or more fourth SRIs and one or more fifth SRIs, where each fourth SRI can include a fourth indication of one or more fourth SRS ports and fourth transmission precoding information associated with one of a plurality of sub-bands of a fourth bandwidth assigned to the second device, and where each fifth SRI includes a fifth indication of one or more fifth SRS ports and fifth transmission precoding information associated with one or more fifth bandwidths.

[0127] A sixteenth of these methods can be implemented in a first device configured to communicate with a second device and can include transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of a first bandwidth assigned to the second device and (ii) one or more second bandwidths; transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of a third bandwidth assigned to the second device and (ii) the second bandwidth; and transmitting, to the second device, signaling to indicate transmission precoding information for (i) a plurality of sub-bands of the third bandwidth assigned to the second device and (ii) one or more fourth bandwidths.

[0128] A seventeenth of these methods can be implemented in a first device configured to communicate with a second device, and can include transmitting one or more first SRIs and one or more second SRIs to the second device, where each first SRI can include a first indication of one or more first SRS ports and first transmission precoding information associated with one of a plurality of sub-bands of a first bandwidth assigned to the second device, and where each second SRI can include a second indication of one or more SRS ports and second transmission precoding information associated with one of one or more second bandwidths; transmitting one or more third SRIs and the second SRIs to the second device, where each third SRI can include a third indication of one or more third SRS ports and third transmission precoding information associated with one of a plurality of sub-bands of a third bandwidth assigned to the second device; and transmitting the third SRIs and one or more fourth SRIs to the second device, where each fourth SRI can include a fourth indication of one or more fourth SRS ports and fourth transmission precoding information associated with one of one or more fourth bandwidths.

[0129] An eighteenth of these methods can be implemented in the second device, and can include receiving signaling from the first device. In different embodiments, the eighteenth method can include any one of: determining from the transmission precoding information a plurality of precoders corresponding to a plurality of sub-bands; using the plurality of precoders to perform precoding processing on assigned resources at the plurality of sub-bands; determining from the transmission precoding information a second precoder corresponding to at least one segment of the one or more second bandwidths; and using the second precoder to perform precoding processing on assigned resources at one or more sub-bands of the first bandwidth outside of the plurality of sub-bands; receiving a grant containing a resource allocation defining a third bandwidth, the third bandwidth including at least one segment of the second bandwidth; determining from the transmission precoding information a third precoder corresponding to the at least one segment; and using the third precoder to perform precoding processing on assigned resources at the at least one segment. The second and third precoders can be the same.

[0130] Those skilled in the art will recognize that the second device can use the functionality disclosed in the eighteenth method or similar functionality to perform methods complementary to the ninth through seventeenth methods.

[0131] Typical example of phase-continuous precoding processing

[0132] By using different types of phase-continuous precoding processing, a smooth transition between adjacent precoders can be allowed. Typical examples of such phase-continuous precoding processing can include any of the following: (i) phase-continuous precoding processing using CDD, (ii) phase-continuous precoding processing with non-zero edge smoothing processing, (iii) phase-continuous precoding processing with phase transition regions, and (iv) phase-continuous precoding processing for non-continuous transmissions.

[0133] Examples of one or more typical phase-continuous precoding processing using cyclic delay diversity

[0134] Figure 3 is a flowchart illustrating a typical procedure 300 for performing phase-continuous precoding processing using CDD. The typical procedure 300 can be implemented in a device such as a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). The typical procedure 300 can also be implemented in devices other than base stations and WTRUs.

[0135] As shown in Figure 3 the device can determine a respective plurality of CDD-based precoding matrices for a plurality of precoding resource sets (PRSs) (302). The device can precode a first PRS of the plurality of PRSs using a respective first CDD-based precoding matrix of the at least plurality of CDD-based precoding matrices and a first matrix adapted to provide an initial precoding phase (304). The device can precode a second PRS of the plurality of PRSs using a respective second CDD-based precoding matrix of the at least plurality of CDD-based precoding matrices and a second matrix adapted to provide phase continuity from the precoded first PRS (306).

[0136] In embodiments, the device can determine the respective plurality of CDD-based precoding matrices at least in part by determining, for each (or any) PRS of the plurality of PRSs, a cyclic delay parameter for the PRS. The cyclic delay parameter can be specific to the PRS. In embodiments, the device can determine the respective plurality of CDD-based precoding matrices at least in part by adapting a CDD-based precoding matrix for each (or any) PRS using the determined PRS-specific cyclic delay parameter, thereby determining the respective plurality of CDD-based precoding matrices.

[0137] In an embodiment, the second matrix can be adapted to force a starting phase of a cyclic phase shift of the second PRS to begin at an ending phase of a cyclic phase shift of the first PRS, thereby providing phase continuity from the precoded first PRS. In one embodiment, each PRS can comprise a fraction of a resource block or a resource block bundle.

[0138] It is contemplated that a MIMO system can use N RB scheduled resource blocks for transmission, where N RB scheduled resource blocks can be contiguous or non-contiguous. Each N RB scheduled resource blocks can define M RE resource elements.

[0139] In an embodiment, a frequency selective phase continuity precoding process can be constructed and / or defined as y = W1W2x, where W1, W2 can be first and second beamforming matrices, and x can be a transmission symbol vector. The first beamforming matrix W1may be determined to be a wideband precoder for the entire scheduled channel. If W1= I is chosen (where I is an identity matrix), the system is converted to a single precoder operation.

[0140] In an embodiment, the second beamforming matrix W2may be defined to be a CDD beamforming operation that results in an artificial frequency selective channel. As an example, the second beamforming matrix W2may be defined as:

[0141] W2= W CDD S (1)

[0142] where W CDD represents a CDD beamforming operation that results in an artificial frequency selective channel, and where the matrix S can be a configurable precoding matrix. The matrix S can be any one of an identity matrix, an Hadamard matrix, an LTE-based precoder, etc. Alternatively, the matrix S can be dynamically configured on or cycled through a predefined set of potential precoders.

[0143] The second beamforming matrix W2and / or the CDD beamforming matrix W CDD may be defined in terms of a set of N RE resource elements. The PRS can be defined to be a fraction of a resource block or a resource block bundle, whereby the number of resource elements per PRS is N RE ≤ M RE . The number of PRS in a scheduled transmission can be denoted by N PRS .

[0144] In an embodiment, the IFFT size is N IFFT, each PRS has N RE resources elements and has υ antenna ports, for the l-th PRS, the CDD based beamforming matrix W2and the CDD beamforming matrix W CDD may be defined as a diagonal matrix as follows:

[0145]

[0146] where is a cyclic delay parameter; i is a subcarrier index within the l-th PRS, where 0≤i≤N RE -1; and l represents the PRS index, where 1≤l≤N PRS . The matrix Θ l is a diagonal matrix that implements an initial phase offset. For the first PRS (l = 1), if no phase offset is desired, the matrix Θ1may be set to the identity matrix (e.g., Θ1= I). Each of the l PRSs can be characterized by a different parameter κ l , and each RE can be precoded differently.

[0147] To ensure phase continuity of the effective channel over the l PRSs, the matrix Θ l (l > 1) can be modified as follows:

[0148]

[0149] where such a matrix Θ l (l > 1) can represent the phase state of the precoder of the last subcarrier of the previous PRS among the l PRSs. By including the matrix Θ l , the starting phase of the cyclic phase shift of the l-th PRS can be made to start from the last CDD phase of the (l-1)-th PRS. The use of the matrix Θ l has the benefit that abrupt phase transitions at the boundaries of the l PRSs can be mitigated. If the non-contiguous resource blocks are assumed to be very close (e.g., one of the non-contiguous resource blocks is very close to another one of the non-contiguous resource blocks), the typical phase-continuous precoding process provided herein using CDD can also be used for non-contiguous resource blocks.

[0150] In an embodiment, the transmitter unit can select the cyclic delay parameter κ lThe pre-defined set can be fixed or configurable. The fixed set can be defined or derived based on cell-based characteristics, such as system bandwidth or deployment requirements (e.g., urban vs. suburban). The configurable set can be defined or derived based on any of the WTRU's mobility state, multi-user MIMO (MU-MIMO) requirements, and MIMO channel characteristics (e.g., rank).

[0151] Cyclic delay parameter K l may be adaptively selected based on the estimated PRS-by-PRS CSI. The estimated CSI can be based on any of the following: direct measurements on the reference signals, reported values, and channel reciprocity. As an example, by adaptively adjusting the cyclic delay parameter K l , the frequency selectivity of the effective channel for each PRS can be adjusted across antennas. As an example, the result of the cross-antenna adjustment can be to optimize a MIMO performance metric. The metric optimization can include any of the following: maximizing capacity, maximizing SNR / SINR / SNLR, etc.

[0152] Figure 4 is a graph showing capacity comparisons for adaptive CDD precoding processing with other precoding mechanisms. The comparisons are based on capacity estimates for a 4x4 MIMO system. As a baseline, shown are the calculated capacities for full SVD and LTE-based beamforming processing. For the evaluations given, MMSE beamforming processing is used. For adaptive CDD, different values or resolutions / steps for the cyclic delay parameter K l are used. As shown, the LTE-based precoding processing is similar in performance to adaptive CDD. And as can be readily seen, there is no significant improvement when using high resolution feedback for the cyclic delay parameter K l .

[0153] Cyclic delay parameter K l may be selected (e.g., for open-loop MIMO) based on any of the WTRU mobility and channel characteristics. Alternatively, the cyclic delay parameter K l may be randomly selected or cycled over a set of pre-defined values.

[0154] For UL MIMO, the WTRU can determine the cyclic delay parameter K l set from control signaling (e.g., any of RRC signaling and dynamic Ll control signaling). Alternatively, the WTRU can autonomously determine the optimal cyclic delay parameter K l .

[0155] A WTRU can indicate to the network that it is using a tone-by-tone precoding process (and / or that it is using a tone-by-tone precoding process instead of a wideband precoding process) by transmitting a one-bit feedback. A WTRU can indicate to the network that the WTRU determines the cyclic delay parameter K from a set of pre-designated cyclic delay parameters K that the network can use for UL multi-user MIMO operation l The set of cyclic delay parameters K l determined in [1]. This information can be transmitted on any of the UL feedback channel, UL data related control channel, and UL data.

[0156] For open-loop MU-MIMO, each co-scheduled WTRU can use a different set of CDD precoding parameters. Alternatively, each co-scheduled WTRU can use the same set of CDD precoding parameters (or a different set of non-orthogonal CDD precoding parameters) since there is no need to have orthogonal precoders across multiple WTRUs performing transmission based on the same allocation. The network can choose to indicate to the co-scheduled WTRUs the set of CDD parameters. The WTRU should then (but not necessarily) follow the information provided by the network to determine its CDD parameters.

[0157] A procedure to ensure that the influence of the precoder on the data symbols remains continuous by smoothing the time representation of the precoding vector has been proposed in [1]. The proposal in [1] seems to rely on the assumption that if the precoding vector p i,j has high frequency components, then it can be made smooth in frequency by performing a pruning process in its dual domain (i.e., time). However, when pruning is performed on the high frequency components as proposed and inverse transformed to time with a DFT operation, the first and last elements of p i,j can potentially be distorted (e.g., significantly distorted). This distortion is believed to be due to the fact that the pruning process in frequency corresponds to a circular filtering operation; as a result, the first and last elements of p i,j become similar to each other. However, in practice, the first and last elements of p i,j can potentially be different, where the significance of this difference depends on the size of p i,j . For example, if there are 48 subcarriers (i.e., M = 48), then the precoding vector can be in As shown in Figure 5 , if 40 components are pruned in the time domain and transformed to the frequency domain, then the vector results in significantly distorted edge elements.

[0158] Examples of one or more typical phase-continuous precoding processes with non-zero edge smoothing

[0159] Figure 6 This is a flowchart illustrating a typical process 600 for performing phase-continuous precoding processing with non-zero edge smoothing. This typical process 600 can be performed in a device such as a base station (e.g., any one of base station 114, eNodeB 160, gNB 180, and base station 202) or a WTRU (e.g., any one of WTRU 102 and WTRU 204). This typical process 600 can also be implemented in devices other than base stations and WTRUs.

[0160] like Figure 6 As shown, the device can extend the first precoded vector by padding it with zeros (e.g., at its head and tail) (602). The device can perform an IDFT on the extended precoded vector to convert it into a time-domain signal (604). The device can trim the time-domain signal (606). The device can perform a Discrete Fourier Transform (DFT) on the trimmed time-domain signal to form a second precoded vector (608). The second precoded vector may have the same dimension as the first precoded vector.

[0161] In an embodiment, the device may extend the first precoded vector (602) at least in part by: (i) inputting zeros on the head and / or tail inputs of the IDFT, and (ii) inputting the precoded vector to the inputs of the IDFT between the head and tail inputs. In an embodiment, the device may trim the time-domain signal (606) at least in part by setting one or more elements of the time-domain signal to zero. Such elements of the time-domain signal may include groups or sets of elements corresponding to the high-frequency components of the time-domain signal.

[0162] In an embodiment, frequency-selective phase-sequential precoding can be constructed and / or defined as y = W1W2x, where W1 and W2 are first and second beamforming matrices, and x is a transmission symbol vector. The first beamforming matrix W1 can be determined as a wideband precoder for the entire scheduling channel. If W1 = I is chosen for the first beamforming matrix (where I is the identity matrix), then the system is converted into a single precoder operation.

[0163] In an embodiment, the second beamforming matrix W2 may include several precoded vectors. For example, the second beamforming matrix W2 may be selected as... Where `diag{·}` is the block diagonalization operator, and This is the precoding matrix derived for the m-th subcarrier or subblock. The derived precoding matrix... It can be based on a set of orthogonal precoders {P1,P2,…,P}k ,…,P K}. The precoding matrix p i,j may be a column matrix, e.g. [{P1} i,j ,{P2} i,j ,…,{P m} i,j} M ,…,{P i,j} T where its m-th element is filled with the element located at the i-th row and j-th column of the precoding matrix P m for the m-th subcarrier or subblock. The precoding vector p i,j may be extended into a vector where and are functions of p i,j and T1+T2=T. After extending the vector p i,j , a time domain filtering operation can be applied on by using the following operations:

[0164] 1) performing a M+T IDFT,

[0165] 2) pruning the obtained time domain signal (e.g. setting some elements to zero (e.g. a set of elements corresponding to higher frequency components), and

[0166] 3) performing a M+T DFT.

[0167] After the time domain filtering operation, the size of the resulting vector can be in . The first T1 and last T2 elements of this resulting vector can be punctured. The result of the aforementioned operations is that the elements that are distorted are removed. Figure 7 An exemplified flow about the aforementioned operations is shown.

[0168] Without loss of generality, and may be derived based on p i,j . For example,

[0169] {h i,j} k = {p i,j}1, {t i,j} m = {p i,j} < , i.e. the elements of h i,j are identical to the first elements of p i,j and the elements of t i,j are identical to the last elements of p i,j .

[0170] {h i,j} l =2{p i,j}1-{p i,j}2,[t i,k ] m =2{p i,j} M -{p i,j} M-1 , that is, the elements of h i,j are identical and are derived based on distinguishing the first two consecutive samples, and the elements of t i,j are identical and are derived based on distinguishing the last two consecutive samples.

[0171] Figure 8 includes two graphs showing performance comparison of the phase-continuous precoding with non-zero edge smoothing to other precoding methods. In Figure 8 , the performance of the phase-continuous precoding with non-zero edge smoothing is compared to the method given in [1], and the real and imaginary parts of are plotted, where n is the subcarrier index. The method in [1] results in significant distortion on the edge elements of , while the distortion on the edge resulting from applying the phase-continuous precoding with non-zero edge smoothing is significantly reduced.

[0172] Examples of one or more typical phase-continuous precoding processes with phase transition regions

[0173] Figure 9 is a flowchart illustrating a typical procedure 900 for performing a phase-continuous precoding with phase transition regions. The typical procedure 900 can be implemented in a device, such as a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). The typical procedure 900 can also be implemented in devices other than base stations and WTRUs.

[0174] As shown in Figure 9 , the device can obtain first and second precoding matrices (e.g., from one or more codebooks) (902). The device can generate a transition region by interpolating the first and second precoding matrices to provide phase continuity between the first and second precoding matrices (904). The transition region can have a length, and the length of the transition region can be fixed or configurable.

[0175] In an embodiment, phase-continuous precoding processing can be supported by creating a codebook in which each precoder is pairwise continuous with every other member of the codebook. Alternatively, matrix interpolation can be used to facilitate soft phase transitions across PRS boundaries. In this alternative, a fixed or dynamic phase-continuous transition region can be created based on or with the existing codebook. The transition region can use a defined matrix interpolation scheme in the codebook transition. One simple example of this processing is shown in FIG. 10. As shown, instead of a sudden transition between PMI1 and PMI2, a transition region is defined between the two resources that transitions from PMI1 to PMI2 in a phase-continuous manner. The length of this interpolation region can be either fixed or configured through higher layer signaling or L1 control. Figure 10 One simple example of this processing is shown in FIG. 10. As shown, instead of a sudden transition between PMI1 and PMI2, a transition region is defined between the two resources that transitions from PMI1 to PMI2 in a phase-continuous manner. The length of this interpolation region can be either fixed or configured through higher layer signaling or L1 control.

[0176] Figure 11 A flow diagram illustrating a representative process 1100 for performing phase-continuous precoding processing with one or more phase transition regions is shown. The representative process 1100 can be implemented in a first device, such as a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). The representative process 1100 can also be implemented in devices other than base stations and WTRUs.

[0177] To perform the representative process 1100, the first device can be communicably coupled with a second device. The second device can be a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). In an embodiment, if the first device is a WTRU, then the second device can be a base station. Alternatively, if the first device is a base station, then the second device can be a WTRU.

[0178] As Figure 11As shown, the first device can estimate the channel based on a non-precoded reference signal (RS) or a beamformed RS (1102). A beamformer can also be used in addition to a precoder. The first device can estimate a precoder (e.g., a "best" precoder) for each of the scheduled PRSs of the plurality of PRSs based on a MIMO performance criterion (1104). The first device can estimate or otherwise determine a matrix interpolation mechanism (e.g., a "best" matrix interpolation mechanism) for a transition region between each (or at least two) of the plurality of PRSs (1106). In embodiments, the first device can determine the matrix interpolation mechanism estimate at least in part by any of defining one or more transition regions and determining matrix interpolation parameters based on one or more system parameters. The one or more transition regions can be one or more regions for which matrix interpolation can be performed. In embodiments, the matrix interpolation parameters can include any of envelope characteristics and subspace or inter-column interference parameters. The envelope characteristics can include constant modulus and / or cubic metric requirements. The subspace or inter-column interference parameters can include column orthogonality and / or semi-orthogonality parameters. In embodiments, the one or more transition regions can be fixed and / or standardized. In embodiments, the one or more transition regions can be dynamically estimated based on the channel or the scheduled transmission bandwidth. As an example, the one or more transition regions can be defined based on a frequency selectivity and / or mobility of the channel.

[0179] Alternatively (e.g., in a non-reciprocal system), the first device can feedback / forward a channel representation to the second device (1108). The channel representation can include a PMI for transmission in a control channel. Alternatively, the channel representation can include any of one or more PMIs and one or more SNRs.

[0180] Alternatively, the first device can feedback / forward one or more parameters for performing matrix interpolation to the second device (1110).

[0181] The second device can construct a precoder (not shown). The second device can communicate precoded information to the first device (not shown). The second device can signal to the first device to indicate use of a phase-continuous precoder and / or other indication regarding activation of channel estimation smoothing (not shown).

[0182] The first device can communicate an indication to the second device to indicate use of a phase-continuous precoder and / or other indication to activate channel estimation smoothing (1112). The first device can feedback / forward a second (in time) representation of the channel to the second device (1114). The second representation of the channel can include any of one or more PMIs and one or more SNRs.

[0183] The second device can construct the phase-continuous precoder based at least in part on the reconstructed quantized channel.

[0184] The second device can receive a second representation (not shown) of the channel. The second device can reconstruct the quantized channel based at least in part on the second representation (not shown). The second device can construct the phase-continuous precoder based at least in part on the reconstructed quantized channel. Alternatively, the second device can construct the phase-continuous precoder using any of the methods discussed herein.

[0185] Examples of one or more typical phase-continuous precoding processes for non-continuous transmissions

[0186] In embodiments, the first and second devices can process all non-continuous groups independently, and can only allow channel estimation smoothing processing to be performed within the interior of a continuous PRS. Alternatively, a parameter (e.g., maximum) PRS inter-distance for smoothing processing can be specified. The parameter can be static, semi-static, or dynamic. Resources that are greater than or do not fall within the specified PRG distance can be processed independently.

[0187] In embodiments, the second device can send information to the first device in a scheduling grant to specify PRS that can be processed together. Additional information (e.g., weighting vectors) can also be sent between the first and second devices to assist in the smoothing process. Alternatively, the first device can test different methods in a semi-blind manner and can compare them to information sent by the second device. The information can be sent in a control channel. The control channel can be one or more channels for the second device to send channel estimates on the boundary between PRS to the first device for comparison.

[0188] Typical transmission aspects and procedures

[0189] Examples of one or more typical phase-continuous precoding capability exchange and signaling

[0190] The gNB’s capability can be signaled in the NR-PBCH during the initialization procedure, and the capability can be carried in the master information block (MIB) or some system information block (SIB). Since this information is not necessary for the WTRU’s startup, it can be signaled in a lower tier (or secondary PBCH) for a hierarchical or multi-level NR-PBCH that first only transmits basic information.

[0191] The capability information of the WTRU can be provided to the network in a capability information element (IE), which can be signaled as a Chest Phase Continuity IE. The WTRU capability IE can be an RRC message sent by the WTRU to the network, which in most cases is sent during the initial registration procedure. The WTRU capability IE can inform all the details about its capabilities. An example of the WTRU capability IE can be shown as follows:

[0192] ENUMERATED{phase_cont_channel, phase_cont_PMI, both, none, spare}, where "phase_cont_channel" can indicate that the WTRU supports phase-continuous precoder design based on channel estimation, "phase_cont_PMI" can indicate that the WTRU supports phase-continuous precoder based on PMI, "both" can indicate that the WTRU supports both methods, "none" can indicate that the WTRU does not support phase-continuous precoder design, and "spare" is reserved for future use.

[0193] As an alternative, the transmitter (gNB and / or WTRU) can indicate whether a particular transmission uses phase-continuous precoder in the control channel (NR-PDCCH for downlink transmission and NR-PUCCH for UL transmission).

[0194] It should be noted that in the process of downlink multi-user transmission with mixed receivers with and without phase-continuous precoder capability, the transmitter can have the following options:

[0195] 1. Perform transmission using only phase-continuous precoder.

[0196] 2. Perform transmission using only non-phase-continuous precoder.

[0197] 3. Perform transmission using a mix of phase-continuous and non-phase-continuous precoder.

[0198] In the uplink multi-user transmission scenario, each WTRU can independently perform transmission based on its used processing and can signal the gNB. In one method, the gNB can restrict WTRUs that cannot perform phase-continuous precoding processing from joining the network.

[0199] A one-bit information related to wideband precoding processing versus tone-by-tone precoding processing can be conveyed on the UL control channel (e.g., PUCCH) carrying ACK / NACK. Alternatively, the WTRU can implicitly indicate the one-bit information by embedding it in the DMRS. For example, the DMRS can be scrambled with a unique sequence for tone-by-tone precoding mode of operation and can be scrambled with a different scrambling sequence for wideband precoding mode of operation.

[0200] Alternatively, information related to tone-by-tone DL precoding processing can be implicitly indicated by the size of the PRG. The WTRU can determine the activation of tone-by-tone precoding processing from the size of the DL scheduling grant. For example, a DL scheduling grant with a certain size can indicate tone-by-tone precoding processing at the gNB.

[0201] In LTE, the size of RBG and PRG is defined or determined in accordance with the system bandwidth as listed in Table 1 below.

[0202] Table 1

[0203] System BW (MHz) RBG size PRG size 1.4 1 1 3 2 2 5 2 2 10 3 3 15 4 2 20 4 2

[0204] In an embodiment, any contiguous scheduling selected from a pre-defined set of RBG sizes can indicate a PRG size as wide as the size of the scheduled RBs and other (e.g., pre-defined) values. If the WTRU determines that the size of the contiguously scheduled RBs belongs to the pre-defined set, it can detect tone-by-tone precoding processing. As an example, any contiguous scheduling of RBG > 4 can indicate a PRG size as wide as the size of the scheduled RBs as opposed to the entries in Table 1. And, if the WTRU determines contiguous scheduling of RBG > 4, it can detect tone-by-tone precoding processing.

[0205] In localized or distributed transmission, the PRG size can be determined from the configured RBG size. The RBG size can be signaled or otherwise provided on any of L1, L2, and higher layer control signaling and / or channels in either dynamic or semi-static manner.

[0206] For a given RBG size configuration, the PRG size can be determined from the size of one or more contiguous portions of the scheduled transmission. In an embodiment, if a localized or distributed transmission is scheduled for contiguous portions equal to or wider than x RBGs, the PRG size can be determined (e.g., set) to be as wide as the span of the contiguous portions of the transmission, or can be determined according to another predefined rule. Table 2 shows an example case where the PRG size is increased from 2 RBs to 4 RBs in the case of a scheduled transmission having contiguous portions wider than x RBGs.

[0207] Table 2

[0208]

[0209] In an embodiment, an information element or other portion (collectively referred to as an "IE") of downlink control information (DCI) can be used to indicate whether to use a predefined PRG size for UL / DL transmissions (e.g., 1 or 2 PRB transmissions). The DCI IE can be as small as a single bit. The DCI IE can be (e.g., set to) a value that indicates to the WTRU to use a predefined PRG size for UL / DL transmissions. Alternatively, the DCI IE can be (e.g., set to) a value that signals to the WTRU to use an alternative rule to determine the PRG size. If the DCI IE is larger than a single bit, the DCI IE can be (e.g., set to) one of a plurality of different values that signals to the WTRU to use a respective one of a plurality of alternative rules to determine the PRG size. Hereinafter, the DCI IE is used interchangeably with DCI bit, DCI bit field, DCI field, DCI codepoint, DCI state of the DCI field, and DCI state.

[0210] In an embodiment, the absence of a DCI IE or the absence of a DCI (e.g., a particular DCI format) having such a DCI IE can be an (e.g., implicit) signal to the WTRU to use an alternative rule or one or more of a plurality of alternative rules to determine the PRG size.

[0211] In embodiments, an alternative / replacement rule for determining PRG size can be based on (or defined based on) the size of the RBG, e.g., PRG size = k * RBG size, where k can be a non-zero real number (e.g., a positive integer). Alternatively, a replacement / alternative rule for determining PRG size can be based on and / or associated with the bandwidth part and / or the scheduled bandwidth. In embodiments, a replacement / alternative rule for determining PRG size can be based on (and / or implemented with) Table 3, and where x can be either a pre-defined value configured or determined through assistance information (e.g., UE assistance information) or feedback. Table 3 lists typical examples of RBG and PRG sizes for various typical system bandwidth examples. In embodiments, the RBG and PRG sizes (e.g., typical examples thereof listed in Table 3) can be configured per cell, per one or more sectors or other portions of a cell, and / or per WTRU. The typical examples listed in Table 3 regarding RBG and PRG sizes and system bandwidth are provided for illustrative purposes and do not limit the disclosed embodiments.

[0212] Table 3

[0213]

[0214] In embodiments, multiple different PRG sizes can be considered for a given system and / or scheduled bandwidth. For example, the multiple different PRG sizes can include a small PRG size, a large PRG size, and one or more medium PRG sizes. By considering and / or using a small PRG size, a (e.g., very) narrowband frequency-selective precoding operation and / or precoder cycling can be enabled and / or facilitated. A small PRG size can be small in size and / or very small compared to the scheduled bandwidth (e.g., a small fraction of the scheduled bandwidth). A large PRG size can be as wide as the RBG size, or can be a multiple (e.g., an integer multiple) of the RBG size. Alternatively and / or additionally, a large PRG size can be a large fraction of the scheduled bandwidth part. By considering and / or using a large PRG size, improved channel estimation at the receiver (WTRU) can be enabled and / or facilitated. Each or any of the medium PRG sizes can be based on (e.g., dependent on) the channel frequency selectivity. Each or any of the medium PRG sizes can be directly linked to or based on the configured RBG size. For example, a medium PRG size can be based on a function of the configured RBG size, e.g., PRG = RBG / 2^L, where L can be a fixed value per RBG. The multiple different PRG sizes can include a maximum PRG size. The maximum PRG size can be the wideband bandwidth, the scheduled bandwidth, or the maximum allowed bandwidth.

[0215] In an embodiment, the process of selecting from different configurations (e.g., the above configurations) can be implemented by using an "IE" ("selection IE"). The selection IE can be as small as a single bit. The selection IE can be signaled or otherwise provided on any of L1, L2, and higher layer control signaling and / or channels (including, by way of example, DCI and / or RRC signaling) based on any of dynamic and semi-static manners.

[0216] In an embodiment, the selection IE can be a single bit in DCI and can be used to indicate that one option (e.g., one PRG size out of small, large, and medium PRG sizes) is selected over the other options. In addition, the selection distinction among the remaining options can be based on any of explicit and implicit UE assistance.

[0217] In an embodiment, the selection IE can be a single bit and can be used to indicate that a first option (small PRG size) is selected over the other options (large and medium PRG sizes). The selection of a second option (large PRG size) over a third option (medium PRG size) can be based on any of explicit and implicit UE assistance. Alternatively, the selection of a second option (large PRG size) over a third option (medium PRG size) can be based on one or more parameters of another system configuration, e.g., CSI-RS, etc. Table 4 below lists a set of example values for different values of the selection IE. The selection IE can be a single bit and can be used to indicate PRG size determination methods, where a first method can be based on explicit determination and a second method can be based on implicit determination. The explicit determination can use PRG sizes that can be configured by higher layer signaling. The implicit determination can use two PRG sizes and one of the PRG sizes can be determined implicitly.

[0218] Table 4

[0219]

[0220] There can not be much gain (e.g., in terms of channel estimation accuracy) in using very wide PRG sizes (e.g., PRG size > 8) and performance degradation can result in producing a channel with high frequency selectivity. Table 5 below lists examples of two implicitly determined PRG size options for each RBG size in a system with RBG size set {2, 4, 8, 16} in addition to the explicitly determined small PRG size option. The two implicitly determined PRG size options can be the medium and large PRG size options. Alternatively, one of the two implicitly determined PRG size options can be the maximum PRG size option. The maximum PRG size option can be the wideband bandwidth, the scheduled bandwidth, or the maximum allowed bandwidth.

[0221] Table 5

[0222]

[0223] Table 6 below lists examples of two implicitly determined PRG size options for each RBG size in a system with RBG size set {2, 4, 8, 16} in addition to the explicitly determined wideband (or scheduled bandwidth) PRG size option. The two implicitly determined PRG size options can be the medium and large PRG size options. Alternatively, one of the two implicitly determined PRG size options can be the maximum PRG size option.

[0224] Table 6

[0225]

[0226] Table 7 below lists examples of two implicitly determined PRG size options for each RBG size in a system with RBG size set {2, 4, 8, 16} in addition to the explicitly determined wideband (or scheduled bandwidth) PRG size option. The two implicitly determined PRG size options can be the small and large PRG size options. Alternatively, one of the two implicitly determined PRG size options can be any two of the small, medium, large, and maximum PRG size options.

[0227] Table 7

[0228]

[0229] In embodiments, the role of the IE can be overridden with an implicit indication, whereby the use of a small PRG size (or any other option) is indicated. Examples of conditions that trigger the implicit indication can be based on any of the configured transmission mode, specific use cases, parameter configurations, and other system configurations (e.g., CSI-RS), among others. In addition and / or alternatively, if the conditions that trigger the implicit indication are absent, then an IE (which can be as small as a single bit) can be used to indicate that the second option is dynamically selected over the other options. As an example, the IE can be used to indicate that frequency selective (medium PRG size) precoding processing and wideband (large PRG size) precoding processing are dynamically selected. Table 8 below lists a set of example values for different values of the IE determined implicitly and explicitly.

[0230] Table 8

[0231]

[0232] In embodiments, for each RBG size, a wireless transmit / receive device (e.g., gNB and / or WTRU) can be configured with a default PRG size. An IE can be configured and / or used to indicate a switch between a small PRG size and the default PRG size (e.g., using a default value defined by the PRG). The default PRG size can be based on a (e.g., fixed) relationship or function with any of the following: RBG size, scheduled bandwidth, other system configuration parameters, and any configured value. As an example, the small PRG size value can be a fixed size. Alternatively, the small PRG size value can be configured (e.g., semi-statically) to take any of {1, 2} PRBs. Table 9 below lists example values for the default and small PRG sizes based on example RBG and IE values.

[0233] Table 9

[0234]

[0235] In embodiments, for each RBG size, a wireless transmit / receive device (e.g., gNB and / or WTRU) can be configured with a set of values for small, medium, and large PRG sizes. Table 10 below lists example PRG sizes corresponding to each PRG in a system with an example set of RBG sizes {2, 4, 8, 16}.

[0236] Table 10

[0237]

[0238] In embodiments, a medium size PRG value can be considered as a default PRG size (e.g., in response to a particular RBG size configuration). Alternatively and / or additionally, the default value can be defined based on an implicit rule (e.g., scheduled transmission, system bandwidth, DMRS configuration, etc.). Alternatively and / or additionally, the default value can be defined based on a (e.g., direct) relationship and / or function of the selected RBG size. Alternatively and / or additionally, the default value can be arbitrarily configured.

[0239] In embodiments, an IE (e.g., a DCI field) can be turned on and off (or otherwise set) to assist in performing the PRG size selection process. For example, if a DCI bit field remains off after an RBG size configuration, the PRG size can remain as a default value (e.g., a medium PRG). Alternatively, if the DCI bit field is turned on, a state bO can indicate a change in the PRG size from the default value to a small PRG size (e.g., 2 PRBs and / or a small PRG size necessary for certain scenarios (MU-MIMO pairing process)). Alternatively, if the DCI bit field is turned on and the state is set to bl, the PRG size can be switched to a large PRG size (e.g., to enable better channel estimation). In an embodiment, an off DCI bit field can indicate (e.g., can always indicate) to keep the current PRG size.

[0240] In embodiments, if the current PRG size has been set to a minimum PRG size, a turned on DCI bit with state bO can indicate a switch (e.g., a switch back) to a default value. Alternatively, if the current PRG size has been set to a maximum PRG size, a turned on DCI bit with state bl can indicate a switch (e.g., a switch back) to a default value. In embodiments, both of the above methods can be used to switch back to a default value. Alternatively, only one of the above methods is used to switch back to a default value, and the other state is reserved.

[0241] In embodiments, a wireless transmit / receive device (e.g., a gNB and / or a WTRU) can determine an implicitly determined PRG size based on any configured value and appropriate rules (e.g., examples of which are described above). For example, the configured value can be, can be based on, can be associated with, and / or can depend on one or more parameters of different system configurations.

[0242] In embodiments, the configured value can be based on, can be associated with, and / or can depend on a size of an active bandwidth part. For example, the configured value can represent N consecutive PRBs of an active bandwidth part. For example, the active bandwidth part can be a configured RBG and / or subband.

[0243] In an embodiment, the implicitly determined PRG size can be based on a fixed relationship with the configuration value. For example, if the configuration value represents N contiguous PRBs of the active bandwidth part, the implicitly determined PRG size can be determined using the equation PRG = N x M PRBs, where M can be a fixed value, a configurable value, and / or can be determined based on the size of the active bandwidth part. In an embodiment, M can be any number (e.g., any integer) that results in the use of the same precoder to perform precoding processing on M subbands and is greater than or equal to 1 (i.e., M > 1). In an embodiment, M can be any number (e.g., any integer) that satisfies the equation (1 / N) < M < 1 and results in (i) subband partitioning, and (ii) possibly using different precoders to perform precoding processing on each portion. In an embodiment, for a given N, the PRG size can be scaled based on the duration of the transmission. The duration can depend on whether any of multi-slot (slot aggregation), slot, and non-slot are used. For example, for multi-slot transmission, the PRG size can be scaled down, thereby providing higher transmission diversity.

[0244] In an embodiment, the configuration value and / or the appropriate rule can be, can be based on, can be associated with, and / or can depend on the location or range of the set of PRBs within the scheduled or other bandwidth (“PRB location”). In an embodiment, if (i) the scheduled or other bandwidth can be divided into a number of portions (e.g., segments), and (ii) each portion can be associated with a respective configuration value corresponding to a (pre-)configured PRG size, the appropriate rule can be to select the configuration value (pre-configured PRG size) corresponding to the particular PRB location within such bandwidth. The wireless transmit / receive device (e.g., gNB and / or WTRU) can use such rule to determine the implicitly determined PRG size, which can be implemented using a lookup table (e.g., Table 11 below). Table 11 lists example bandwidth portions of the scheduled or other bandwidth and their respective configuration values. The (pre-)configured PRG sizes of the different portions can be the same or different.

[0245] Table 11

[0246] RB location Configuration value X0- X1 RB PRG size 1 X1+1 - X2 RB PRG size 2 … … X (最后-1) +1-X 最后 RB]]> PRG size K

[0247] In an embodiment, the multiple configuration values (e.g., PRG size 1, PRG size 2, and so on) for each part can be configured using any of L1, L2, and higher layer control signaling and / or channels, including, by way of example, DCI and / or RRC signaling. In an embodiment, one of the multiple configuration values can be considered as the default PRG size. The wireless transmit / receive devices (e.g., gNBs and / or WTRUs) can be semi-statically or dynamically configured to one of the remaining PRG sizes using any of L1, L2, and higher layer control signaling and / or channels, including, by way of example, DCI and / or RRC signaling. Table 12 below lists two configuration values, configuration value 1 and configuration value 2, for each bandwidth part. Each of configuration values 1 and 2 can correspond to a configured (preconfigured) PRG size. As listed in Table 12, configuration value 1 corresponds to the default PRG size (e.g., preconfigured). Configuration value 2 can be configured by RRC signaling, or dynamically configured by the content of the received IE.

[0248] Table 12

[0249]

[0250] The wireless transmit / receive devices (e.g., gNBs and / or WTRUs) can be configured to have different levels of DMRS density in frequency and time, and / or have a larger span in frequency than the actual resource allocation. In an embodiment, the configuration value and / or the appropriate rule can be, can be based on, can be associated with, and / or can depend on the DMRS configuration. By way of example, the appropriate rule can be to select one of the multiple configuration values ((pre)configured PRG sizes) based on the configured density of DMRS in frequency domain. The wireless transmit / receive devices (e.g., gNBs and / or WTRUs) can use such a rule to determine the implicitly determined PRG size, which can be implemented with a lookup table (e.g., Table 13 below). The configured density of DMRS in frequency domain can be based on the number of DMRS subcarriers per symbol. Table 13 lists the exemplified DMRS density configurations and their corresponding configuration values ((pre)configured PRG sizes).

[0251] Table 13

[0252] DMRS density configuration PRG Configuration 1a: 1 symbol, comb-2+2 cyclic shifts PRG size 1 Configuration 2a: 1 symbol, 2-FD-OCC PRG size 2 … …

[0253] In an embodiment, an appropriate rule can be to select one of the multiple configured values ((pre)configured PRG size) based on the configured density of DMRS in time domain. Such a rule can be used by a wireless transmit / receive device (e.g., gNB and / or WTRU) to determine the implicitly determined PRG size, which can be implemented with a lookup table (e.g., Table 14 below). The configured density of DMRS in time domain can be based on the number of DMRS symbols per slot. Table 14 lists example DMRS density configurations and their corresponding configured values ((pre)configured PRG size).

[0254] Table 14

[0255] DMRS density configuration PRG Configuration 1a: 1 symbol, comb-2+2 cyclic shifts PRG size 1 Configuration 1b: 2 symbols, 2 cyclic shifts + 2-TD-OCC PRG size 2 … …

[0256] In an embodiment, a wireless transmit / receive device (e.g., gNB and / or WTRU) can be configured with a DCI field that can be used to indicate the PRG size of a scheduled PDSCH. The DCI field can be as small as a single bit. The DCI field can be any of the IEs provided herein above and / or below. The wireless transmit / receive device can also be configured with one or multiple PRG candidate values. The one or more PRG candidate values can be configured with any of L1, L2, and higher layer control signaling and / or channels (including, by way of example, DCI and / or RRC signaling). The wireless transmit / receive device can select one value from the one or multiple configured PRG candidate values based on (e.g., in response to) the DCI field indicating (e.g., being set to) a first value (e.g., “1”). If two configured PRG candidate values are used, one value can be implicitly determined. The wireless transmit / receive device can determine which of the two (or multiple) PRG candidate values to use based on one or more of the following:

[0257] One or more candidate values can be used, and the candidate values can include 2, 4, and the scheduled bandwidth, where the candidate values can be referred to as PRG size. By way of example, three candidate values can be used, e.g., PRG size 1 (PRG1), PRG size 2 (PRG2), and PRG size 2 (PRG3), where PRG size 1 = 2, PRG size 2 = 4, and PRG size 3 = the scheduled bandwidth.

[0258] The PRG size between two (or more) candidate values can be determined using one or more types of parameters (e.g., PRG parameters). The PRG parameter type can include any of the following: scheduled bandwidth, RBG size, subband size for CSI reporting, PDCCH REG bundling size, bandwidth size, bandwidth part size, BWP size, and DMRS configuration. The DMRS configuration can include any of the following: DMRS pattern, DMRS density within PRB and slot, orthogonal multiplexing method (e.g., TD-OCC, FD-OCC), number of orthogonal DMRS ports, and number of symbols for DMRS.

[0259] The PRG parameter type can be determined based on the configured two (or more) PRG candidate values. For example, if a first set of PRG candidate values {PRG1, PRG2} is configured for a DCI field indicating (e.g., set to) a first value (e.g., “1”), a first PRG parameter type (e.g., DMRS configuration) can be used to determine the PRG size of the scheduled PDSCH. If a second set of PRG candidate values {PRG1, PRG3} is configured for a DCI bit field indicating (e.g., set to) a first value (e.g., “1”), a second PRG parameter type (e.g., RBG size) can be used to determine the PRG size of the scheduled PDSCH between two (or more) candidate values.

[0260] In an embodiment, if candidate values {PRG1, PRG2} are configured, then

[0261] If the DM-RS density satisfies (e.g., is higher than) a threshold, then PRG size = PRG1; and / or

[0262] If the DM-RS density does not satisfy (e.g., is lower than) a threshold, then PRG size = PRG2.

[0263] In an embodiment, if candidate values {PRG1, PRG2} are configured, then

[0264] If the DM-RS density satisfies (or alternatively does not satisfy) a first threshold, then PRG size = PRG1; and / or

[0265] If the DM-RS density satisfies (or alternatively does not satisfy) a second threshold, then PRG size = PRG2.

[0266] In an embodiment, if candidate values {PRG1, PRG3} are configured, then

[0267] If the scheduled bandwidth satisfies (e.g., is smaller than) a threshold (e.g., N RB ), then PRG size = PRG1, and / or

[0268] If the scheduled bandwidth does not satisfy (e.g., is greater than) a threshold (e.g., N RB ), then PRG size = PRG3.

[0269] In an embodiment, if the configured candidate values are {PRG1, PRG3}, then

[0270] If the scheduled bandwidth satisfies (or alternatively does not satisfy) a first threshold (e.g., N RB ), then PRG size = PRG1, and / or

[0271] If the scheduled bandwidth satisfies (or alternatively does not satisfy) a second threshold (e.g., N RB ), then PRG size = PRG3.

[0272] In an embodiment, if the configured candidate values are {PRG2, PRG3}, then

[0273] If the RBG satisfies (e.g., is less than) a threshold (e.g., N RBG ), then PRG size = PRG2; and / or

[0274] If the RBG does not satisfy (e.g., is greater than) a threshold (e.g., N RBG ), then PRG size = PRG3.

[0275] In an embodiment, if the configured candidate values are {PRG2, PRG3}, then

[0276] If the RBG satisfies (or alternatively does not satisfy) a first threshold (e.g., N RBG ), then PRG size = PRG2, and / or

[0277] If the RBG satisfies (or alternatively does not satisfy) a second threshold (e.g., N RBG ), then PRG size = PRG3.

[0278] Alternatively, the wireless transmit / receive device can select one of the configured PRG candidate values based on (e.g., in response to) the DCI field indicating (e.g., being set to) a second value (e.g., "0"). The DCI field can transition between indicating the first value and the second value, whereby the wireless transmit / receive device can switch from one of the configured PRG candidate values to the other (with or without performing an implicit selection differentiation).

[0279] The implicitly determinable PRG size can be determined in multiple stages. For example, a first candidate value can be used if the DMRS density is above (below or otherwise satisfies) a predefined or configured threshold. Otherwise, the PRG can be determined based on another PRG parameter type (e.g., RBG size, scheduled bandwidth, bandwidth part size, BWP size, etc.). If candidate values {PRG1, PRG2} are configured, and the DMRS density for the scheduled PDSCH satisfies (e.g., is above) a threshold, the candidate value PRG1 can be used as the PRG size. Otherwise (or as an alternative), the PRG size can be determined based on the RBG size. As an example, a first candidate value (e.g., PRG1) can be used if the RBG size satisfies (e.g., is greater than) a predefined threshold. If the RBG size does not satisfy (e.g., is less than) the predefined threshold, a second candidate value (e.g., PRG2) can be used.

[0280] In an embodiment, a larger (or maximum) candidate value among the configured candidate values can be used as the PRG size if the scheduled bandwidth satisfies (e.g., is greater than) a first threshold. A smaller (or minimum) candidate value among the configured candidate values can be used as the PRG size if the DMRS density satisfies (e.g., is above) a second threshold. If the scheduled bandwidth does not satisfy (e.g., is less than) the first threshold and the DMRS density does not satisfy (e.g., is below) the second threshold, the PRG size can be determined based on the RBG size.

[0281] The PRG size can be determined based on a priority of the PRG parameter type. One or more PRG parameter types can be used to determine the PRG size, and the PRG parameter types have a priority in determining the PRG size. For example, the DMRS density can be considered as the highest priority. If the condition on the DMRS density is satisfied, the PRG size can be determined based on the DMRS density. If the condition is not satisfied, a PRG parameter type of a second priority (e.g., scheduled bandwidth) can be used to determine the PRG size, and so on. One or more of the following can be applied as the priority of the PRG parameter type:

[0282] Example 1: DMRS density (or configuration) > scheduled bandwidth > RBG size > BWP

[0283] Sub-band size > PDCCH REG bundle size; and

[0284] Example 2: scheduled bandwidth > DM-RS density (or configuration) > RBG size > sub-band size.

[0285] Figure 12is a flowchart illustrating a representative procedure 1200 used in conjunction with phase-continuous precoding processing. The representative procedure 1200 can be implemented in a first device, such as a base station (e.g., any of the base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of the WTRUs 102 and 204). The representative procedure 1200 can also be implemented in devices other than base stations and WTRUs.

[0286] To perform the representative procedure 1200, the first device can be communicably coupled with a second device. The second device can be a base station (e.g., any of the base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of the WTRUs 102 and 204). In embodiments, if the first device is a WTRU, then the second device can be a base station. Alternatively, if the first device is a base station, then the second device can be a WTRU.

[0287] As shown, the first device can receive signaling indicating transmission precoding information (1202). The first device can determine a PRG size using any of the indicated transmission precoding information, rules for determining PRG size, and a configured PRG size (1204). The first device can perform configuration or reconfiguration in accordance with the determined PRG size (1206). The first device can apply precoding processing in accordance with the determined PRG size (1208). Figure 12

[0288] In embodiments, the signaling indicating transmission precoding information can be signaled or otherwise provided on any of Ll, L2, and higher layer control signaling and / or channels in either dynamic and semi-static manner. In embodiments, the signaling indicating transmission precoding information can be as small as a single bit. In embodiments, the signaling indicating transmission precoding information can include information for other purposes different from or in addition to transmission precoding, and wherein the transmission precoding information can be inferred from the information different from or in addition to transmission precoding information. In embodiments, the signaling indicating transmission precoding information can be or can include an IE. The IE can be any of or a combination of the IEs disclosed herein above and / or below. The IE can be as small as one bit.

[0289] ​The rule can be signaled or otherwise provided to the first device on any of LI, L2, and higher layer control signaling and / or channels in any of a dynamic and semi-static manner. The rule can include any of the rules disclosed herein above and / or below, and / or can contain any of the information contained in those rules. As an example, as described above, the rule can include information for determining a PRG size from a configured RBG size. The RBG size can be signaled or otherwise provided on any of LI, L2, and higher layer control signaling and / or channels in any of a dynamic and semi-static manner. As another example, as disclosed above, the rule can include information for determining a PRG size from a size of one or more contiguous portions of a scheduled transmission.

[0290] In embodiments, the IE can be (e.g., set to) a value that indicates to use a predefined PRG size, and can be (e.g., set to) another value that signals to use an alternative rule to determine the PRG size. If the IE exceeds one bit, the IE can be (e.g., set to) a value that signals to use a respective one of a plurality of alternative rules to determine the PRG size. In embodiments, absence of the IE or signaling information that there is no IE at all can be an (e.g., implicit) signal to use an alternative rule or one or more of a plurality of alternative rules to determine the PRG size.

[0291] In embodiments, if the first device is configured for a dynamic PRG size configuration, it can perform functions (1202)-(1216). Alternatively, if the first device is not configured for a dynamic PRG size configuration, the first device can not perform one or more of functions (1202)-(1216). An IE signaled to turn on or turn off the dynamic PRG size configuration can be used to configure the first device.

[0292] Figure 13 FIG. 13 shows a flowchart of a representative procedure 1300 used in conjunction with phase-continuous precoding processing. The representative procedure 1300 can be implemented in a first device, such as a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). The representative procedure 1300 can also be implemented in devices other than base stations and WTRUs.

[0293] To perform representative process 1300, the first device may be communicatively coupled to the second device. The second device may be a base station (e.g., any of base station 114, eNodeB 160, gNB 180, and base station 202) or a WTRU (e.g., any of WTRU 102 and WTRU 204). In an embodiment, if the first device is a WTRU, then the second device may be a base station. Alternatively, if the first device is a base station, then the second device may be a WTRU.

[0294] Typical process 1300 can be considered as typical process 1200. Figure 12 Examples of implementations. For example... Figure 13 As shown, the first device can receive signaling from the second device (1302). The first device can determine whether the signaling indicates that dynamic PRG size configuration is enabled or disabled (1304). If the signaling indicates that dynamic PRG size configuration is enabled, then the first device can determine, based on the IE value contained in the signaling, which set of multiple configured PRG sizes to select a candidate PRG size from (1306). The first device can determine whether the determined set of PRG sizes defines a single configured PRG size (1308). If the determined set of PRG sizes defines a single configured PRG size, then the first device can select the single configured PRG size as a candidate PRG size (1310). The first device can determine whether the determined set of PRG sizes defines multiple configured PRG sizes (1312). If the determined set of PRG sizes defines multiple configured PRG sizes, then the first device can select one of the multiple configured PRG sizes as a candidate PRG size based on configured rules (1314). The first device can perform configuration or reconfiguration according to the selected candidate PRG size (1316). If the first device determines that the signaling indicates that dynamic PRG size configuration is enabled (1302), then the first device can select either the fixed or the default PRG size (1318).

[0295] The first device can receive signaling (not shown) containing an IE for configuring dynamic PRG size configuration. The first device can perform configuration for dynamic PRG size configuration according to such an IE (not shown).

[0296] In an embodiment, the IE can be as small as a single bit. The IE can be a PRG size indicator or a similar type of IE, and can be standardized.

[0297] In an embodiment, the configured rule can be any of the rules disclosed hereinabove or hereinafter. In an embodiment, the configured rule can explicitly specify which of a plurality of configured PRG sizes to select. In an embodiment, the configured rule can specify one or more criteria for implicitly determining which of a plurality of configured PRG sizes to select.

[0298] In an embodiment, the plurality of configured PRG sizes can include first and second PRG size options, and the configured rule can specify selecting which of the first and second PRG size options based at least in part on the RBG size. Alternatively, the configured rule can specify selecting which of the first and second PRG size options based at least in part on the RBG size and any explicit and implicit assistance information. In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based at least in part on the RBG size and a previously configured PRG size. In an embodiment, the RGB size can be signaled or otherwise provided on any of L1, L2, and higher layer control signaling and / or channels based on any of dynamic and semi-static manners.

[0299] In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based at least in part on a particular number of contiguously scheduled resource blocks. As an example, the particular number of contiguously scheduled resource blocks can be a minimum number of contiguously scheduled resource blocks.

[0300] In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based on any configured value. In an embodiment, the configured value can be based on, associated with, and / or dependent on a size of an active bandwidth part. The active bandwidth part can be any of the configured RBG and subband.

[0301] In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based on a fixed relationship to a configured value. The configured value can represent N contiguous physical PRBs of an active bandwidth part, and the fixed relationship can be defined as the equation PRG = NxM PRBs, where M is a fixed value, a configurable value, or determined based on a size of the active bandwidth part. M can be any number greater than or equal to 1 (i.e., M > 1) that results in using the same precoder to perform precoding processing on M subbands. Alternatively, M can be any number that satisfies the equation (1 / N) < M < 1 and results in (i) subband partitioning and (ii) using possibly different precoders to perform precoding processing on each portion. In an embodiment, for a given N, the PRG size can be scaled based on a duration of a transmission.

[0302] In an embodiment, the configured value can be based on a PRB location within a bandwidth. In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based on a PRB location within a bandwidth. In an embodiment, the PRB location can be associated with one of the configured PRG sizes.

[0303] In an embodiment, the configured value can be based on a DMRS configuration. In an embodiment, the configured rule can specify selecting which of a plurality of configured PRG sizes based on a DMRS configuration. For example, the configured rule can specify selecting which of a plurality of configured PRG sizes based on a configured DMRS density in either of a frequency domain and a time domain.

[0304] In an embodiment, the plurality of configured PRG sizes can include first and second PRG size options, and the configured rule can specify selecting the first PRG size option based at least in part on a preference of the first PRG size option over the second PRG size option.

[0305] In an embodiment, the configured value can include a parameter related to a system configuration. In an embodiment, the configured value can include an arbitrary value.

[0306] In an embodiment, the plurality of configured PRG sizes can include a first PRG size option, and the rule can specify selecting the first PRG size option in the event of a configured state change indication to change from a current PRG size to the first PRG size option.

[0307] In an embodiment, a first wireless transmit / receive device (e.g., gNB and / or WTRU) can determine a PRG size for frequency selective precoding processing based on received feedback. The first wireless transmit / receive device can perform channel measurements based on periodic or aperiodic reference signal transmissions (e.g., CSI-RS, SRS, and / or other types of reference signals). The first wireless transmit / receive device can estimate the frequency selectivity of the channel based on the measurements. The estimation can be based on a full channel response or based on sparse measurements. The first wireless transmit / receive device can determine a degree of selectivity based on the estimate of the frequency selectivity of the channel. The first wireless transmit / receive device can transmit an IE to a second wireless transmit / receive device (e.g., WTRU and / or gNB) to indicate the frequency selectivity (estimate) of the channel. The definition of the IE associated with the estimate of the frequency selectivity of the channel can be listed in a table and can be configured by the gNB and / or other network components (e.g., in a semi-static manner). As an example, the IE can be a 2 nn bits of different RBG sizes. The indices in the table can correspond to different PRG size values depending on the bandwidth part, service, numerology, etc.

[0308] The second wireless transmit / receive device can detect the IE. The second wireless transmit / receive device can select the indicated PRG size in order to perform precoding processing. The second wireless transmit / receive device can transmit a transmission that is precoded in accordance with the indicated PRG size for precoding processing. The first wireless transmit / receive device can receive a transmission from the second wireless transmit / receive device that is precoded in accordance with the indicated PRG size for precoding processing.

[0309] For UL transmission, if the gNB has determined the WTRU capability for tone-wise precoding processing, it can trigger the WTRU tone-wise precoding processing by assigning a specific range of RBG sizes. In this way, if the WTRU determines that the size of the scheduled RB is selected from a predefined set of RBG sizes, it can detect the activation of tone-wise UL precoding processing.

[0310] Whether to use phase-continuous precoding processing can be signaled through a control channel. The control channel can use its own separate reference signal and precoder, and this information can be decoded and used for estimating the channel for the data channel.

[0311] For a common RS for the control channel and the data channel, the receiver can decode the control channel, and if it finds that the data channel is precoded in a phase-continuous manner, the receiver can implement channel estimation smoothing processing, thereby improving the performance of the data channel decoding process.

[0312] In an embodiment, the receiver can blindly estimate whether the precoder for the data channel is phase-continuous. The receiver can first decode the data assuming that there is phase-continuous precoding processing, and if it fails, the receiver can decode the data assuming that there is no phase-continuous precoding processing. It should be noted that since after determining that the precoder is phase-continuous, it can be assumed that the precoder can always remain in that state, the blind estimation can be used for the first few transmissions.

[0313] Typical TPMI mechanism for frequency-selective precoding processing

[0314] In uplink transmission with codebook-based precoding with frequency selectivity, one or more TPMIs and / or their indication for WTRU to use for uplink transmission can be provided by gNB. The TPMI can be signaled or otherwise provided (collectively referred to as "signaled") based on any of dynamic and semi-static manner, and any of L1, L2, and higher layer control signaling and / or channels can be used.

[0315] In codebook-based precoding, codebook entries can be addressed (e.g., can be retrieved) by TPMI. The size and / or number of bits for each TPMI can correspond to the size of the codebook. For example, for each entry in the codebook to be uniquely addressed by TPMI, the size and / or number of bits for each TPMI depends on the number of entries in the codebook (size of the codebook).

[0316] In an embodiment, the codebook can be defined for all or multiple WTRUs. Depending on the transmission capability of each WTRU, it can be directed to use (e.g., only use) a subset of the codebook. The TPMI size can be adjusted depending on the WTRU transmission capability. Codebook subset restriction (CBSR) can be based on different operational requirements. As an example, CBSR can be implemented for different purposes, such as: reducing inter-cell and / or intra-cell interference, assisting MU pairing processing, WTRU mobility, WTRU transmission capability, etc. As an example, three forms of uplink transmission in terms of WTRU capability are currently considered in NR, i.e., full-coherent, non-coherent, or partial-coherent.

[0317] For full-coherent, all ports corresponding to ports in SRS resource can be transmitted coherently. For non-coherent, all ports corresponding to ports in SRS resource can not be transmitted coherently. For partial-coherent, port pairs corresponding to ports in SRS resource can be transmitted coherently. For each mode of WTRU capability, only a subset of the codebook is needed. In this way, the TPMI size can be adjusted to match the multiplicity of the subset, and extra overhead for TPMI indication can be avoided.

[0318] Table 15 below describes an example of codebook for supporting 4Tx rank 1 transmission.

[0319] Table 15

[0320]

[0321] All entries in this table can be addressed with a TPMI of size (at least) 5 bits. However, not all entries in the codebook are necessary for a given WTRU capability. For example, for a WTRU with non-coherent transmission capability only, a TPMI of size 2 bits can be used to address any of the 24-27 entries. Table 16 below contains an example of covering the codebook by using TPMI for each coherent capability case.

[0322] Table 16

[0323] Coherence capability Codeword Bits Full coherence 0-27 5 Partial coherence 16-27 4 Non-coherent 24-27 2

[0324] In an embodiment, if a WTRU is configured, the TPMI size can be determined entirely by the WTRU coherent transmission capability. Once a WTRU declares a certain coherent capability, the gNB and WTRU can determine the TPMI size based on the declaration only. In this way, each coherent capability case can be (e.g., directly) indicated with a CBSR as shown in Table 17 below.

[0325] Table 17

[0326] Coherence capability Codeword Bits TPMI content Full coherence 0-27 5 0-27 Partial coherence 16-27 4 0-15 Non-coherent 24-27 2 0-3

[0327] In an embodiment, the index of TPMI can be reordered to match the TPMI content as set forth in Table 18 below. Unlike Table 16, Table 18 does not contain entries 12-15.

[0328] Table 18

[0329]

[0330] Table 19

[0331] Coherence capability Codeword Bits TPMI content Full coherence 0-31 5 0-31 Partial coherence 0-11 4 0-11 Non-coherent 0-3 2 0-3

[0332] In an embodiment, after a WTRU declares a coherent transmission capability, the relevant CBSR can be indicated to the WTRU dynamically or semi-statically. For dynamic indication, the indicated CBSR can expire (or become invalid) after a certain number of transmissions, time slot number, or after a timer expires. Alternatively, the dynamically indicated CBSR can be indicated as part of the uplink SPS configuration (sps-ConfigUL) and can be applied at SPS activation.

[0333] The codebook entries corresponding to each coherent transmission capability listed in Table 20 can be associated with the indicated WTRU coherent transmission capability. In an embodiment, the TPMI size can be determined jointly by the WTRU coherent transmission capability and gNB instruction (e.g., based on the entries in Table 20).

[0334] Table 20

[0335]

[0336] In an embodiment, once the WTRU coherence capability is declared, the gNB can configure the desired CBSR for the WTRU by using a bitmap that matches the multiplicity of the subset required for each WTRU coherence capability. For full coherence, a 3-bit bitmap can be used. For partial coherence, a 2-bit bitmap can be used. For non-coherent, no bitmap is used. Other bitmaps can also be used.

[0337] In addition to (or in place of) the WTRU coherence capability, the bitmap can reflect other considerations for defining the CBSR. For example, as shown in Table 21 below, if the gNB prefers to use only a subset of 0-15 precoders, the indices 0-15 can be divided in two different configurations. Again, the bitmap length can be determined as needed to provide support for WTRU transmission coherence.

[0338] Table 21

[0339]

[0340] The bitmap configuration for the WTRU can be done through RRC signaling or in a dynamic manner. For dynamic indication, the indicated CBSR expires (or invalidates) after a certain number of transmissions, slot number, or upon expiration of a timer. Alternatively, the dynamically indicated CBSR can be indicated as part of the uplink SPS configuration (sps-ConfigUL) and applied upon SPS activation.

[0341] Figure 14 FIG. 14 is a flowchart illustrating a representative process 1400 for use in connection with a codebook-based (e.g., UL or DL) transmission configuration. The representative process 1400 can be implemented in a first device, such as a base station (e.g., any of the base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of the WTRUs 102 and 204). The representative process 1400 can also be implemented in devices other than base stations and WTRUs.

[0342] To perform typical process 1400, the first device may be communicatively coupled to the second device. The second device may be a base station (e.g., any of base station 114, eNodeB 160, gNB 180, and base station 202) or a WTRU (e.g., any of WTRU 102 and WTRU 204). In an embodiment, if the first device is a WTRU, then the second device may be a base station. Alternatively, if the first device is a base station, then the second device may be a WTRU.

[0343] like Figure 14 As shown, the first device can transmit a report to the second device for reporting the transmission coherence capability of the first device (1402). The first device can receive a CBSR corresponding to the reported transmission coherence capability from the second device (1404). The first device can determine the TPMI size based on the CBSR (1406). The first device can receive the TPMI (e.g., from the second device) (1408). The first device can detect and / or decode the TPMI based on the determined TPMI size (1410). The first device can determine a codebook subset (not shown) based on the received TPMI and CBSR.

[0344] In this embodiment, CBSR can be a higher-layer parameter. In this embodiment, the reported transmission coherence capability can be any of full coherence, partial coherence, or incoherence.

[0345] In one embodiment, the first device may reorder the TPMI index based on the CBSR. In another embodiment, the first device may receive higher-layer signaling containing a bitmap for configuring the CBSR for the WTRU, and may use the bitmap to configure its own CBSR.

[0346] Figure 15 This is a block diagram illustrating an exemplary frequency-selective precoding process for transmission over multiple subbands. As shown, this frequency-selective uplink precoding process can be for M (e.g., centralized or distributed) subbands. Each of the M subbands can define a bandwidth corresponding to the frequency resources (collective subcarriers) of one or more RBs. The M subbands can collectively define the scheduled bandwidth for the WTRU.

[0347] The M narrowband precoders {W(1), W(2), ..., W(M)} corresponding to the M subbands can be implicitly or explicitly advertised to the WTRU for use in conjunction with resource allocation (e.g., also advertised by signaling) considered for uplink transmission. The precoder W can represent a single-level or two-level precoder mechanism. If a two-level codebook is supported, then the subband precoder W can correspond to the second beamforming matrix W2.

[0348] For configurations with multiple SRS ports for WTRU to use for uplink transmission, SRI can be provided by gNB. The SRI can be used to associate TPMI with SRS port(s). A single SRI can be used to associate TPMI with one SRS port or more than one (e.g., a group) of SRS ports. In this case, the number of SRI indicated by gNB can be equal to or less than the number of TPMI indicated by the gNB. In an embodiment, only some of the SRI indicated by gNB can be used to associate TPMI with SRS port(s).

[0349] Typical examples of supplemental TPMI and SRI mechanism for frequency selective precoding processing

[0350] To simplify the explanation above and below, in most cases, the present disclosure and the disclosed different embodiments are described in connection with TPMI and / or its indication. It will be appreciated by those skilled in the art that some or all of the present disclosure and the disclosed different embodiments described in connection with TPMI and / or its indication are applicable to SRI (e.g., in an equivalent manner).

[0351] Similar to TPMI, SRI can define a set of indices. The set of indices defined by SRI can include a first index corresponding to (e.g., identifying or indicating) one or more SRS ports and a second index corresponding to (e.g., identifying or indicating) a precoding matrix associated with such SRS port(s). Given that SRI and TPMI can have a one-to-one or many-to-one relationship, SRI can have a length defined in accordance with a corresponding number of configured SRS ports, and the number can be equal to or less than the number of TPMI indicated by gNB. It will be appreciated by those skilled in the art that some or all of the present disclosure and the disclosed different embodiments described in connection with TPMI and / or its indication can be modified accordingly for SRI.

[0352] If single-stage precoding processing is assumed, the signaled TPMI can include narrowband and wideband components. The wideband component can be based on a bandwidth equal to or larger than the scheduled transmission. As an example, in Figure 15 {W(1), W(2), …, W(M)} can be narrowband precoders, and W WBThe wideband precoder can be a wideband precoder (e.g., for any of the system bandwidth that can be supported by the UE as a capability, the available system bandwidth, and the entire bandwidth). The information about the wideband precoder can be signaled at the same rate or at a different rate (e.g., higher / lower frequency) than the narrowband precoder. As an example of different indication rates, the information about the narrowband precoder can be signaled in every UL grant, and the information about the wideband precoder can be signaled less frequently, e.g., in every few UL grants or in a subset of the set of UL grants. Alternatively, the information about the wideband precoder can be signaled in every UL grant, and the information about the narrowband precoder can be signaled less frequently, e.g., once in every few UL grants or in a subset of the set of UL grants. Here, the term "narrowband precoder" and the term "subband precoder" can be used interchangeably.

[0353] The WTRU can decode the received narrowband and wideband indications at the corresponding rates. If a resource re-scheduling occurs, the WTRU can use the available wideband precoder for the newly allocated resources until it is informed of a change / update to W1. As an example and with reference to Figure 16 , the uplink resource allocation for subframe (i+1) can be different from the uplink resource allocation in subframe i. For transmissions in subframe (i+1) where the uplink resource allocation contains resources on one or more allocated subbands ("newly allocated subbands") that were not used in subframe i, the WTRU can use W WB to perform precoding on the resources on such newly allocated subbands. For distributed resource allocation, the WTRU can use W WB to perform precoding on the resources on newly allocated subbands within the earlier scheduled bandwidth.

[0354] The WTRU can receive the wideband TPMI with higher layer signaling (e.g., MA-CE or RRC) and the narrowband TPMI in the uplink grant. The wideband TPMI can remain valid until it is updated, or can be terminated after a certain period of time (e.g., in response to a timer expiring). Alternatively, the wideband TPMI can be refreshed after a period of time (e.g., to prevent it from expiring, as an example).

[0355] The WTRU can receive the wideband TPMI in the (e.g., each) uplink grant encoded with an RNTI. As an example, one or more C-RNTIs can be assigned to the WTRU, and one of the C-RNTIs can be determined or selected to scramble the CRC of the uplink grant DCI to indicate the wideband TPMI, and the subband TPMI can be indicated in the DCI.

[0356] In an embodiment, the precoding information can be split into narrowband and midband W MB precoding components. The midband components can correspond to a bandwidth that is wider than the bandwidth corresponding to the narrowband components and narrower than the system bandwidth. The span of the bandwidth of the respective midband components can be as wide as the entire system bandwidth or less than the entire system bandwidth. The entire (e.g., system / available) bandwidth can be split into N (continuous or non-continuous) parts / segments and N midband precoders {W MB (1), W MB (2),..., W MB (N)} can be signaled for performing precoding processing on their corresponding N parts / segments. Information about the midband precoders as well as the narrowband precoders can be signaled at the same or different rates.

[0357] The WTRU can decode the received narrowband and wideband indications at the corresponding rates. If a resource re-scheduling changes, the WTRU can use the available midband precoders for the newly allocated resources until it is informed of a change / update regarding W1. As an example and with reference to Figure 17 , the entire (e.g., system and / or available) bandwidth can be split into 4 parts and the uplink resource allocation for subframe (i+1) can be different than the uplink resource allocation in subframe i. For transmission in subframe (i+1) where the uplink resource allocation contains resources on newly allocated subbands, the WTRU can use the most relevant midband precoders {W MB (1), W MB (2)} to perform precoding processing on the resources on the newly allocated subbands. For distributed resource allocation, the WTRU can use W WB (not shown) to perform precoding processing on the resources on the newly allocated subbands that are within the earlier scheduled bandwidth.

[0358] In an embodiment, a wideband TPMI with one or more best M subband TPMIs can be signaled in the associated uplink grant. As an example, the best M subband TPMIs can be used for subband precoding processing for the selected subbands and the wideband TPMI can be used for the remaining subbands within the scheduled bandwidth.

[0359] The information (e.g., bit field) for indicating the wideband TPMI and the best M TPMIs with the associated best M subband indices can be provided in the uplink grant. For example, if there are K subbands (e.g., K > M) in the scheduled bandwidth, the wideband TPMI can be used for the K subbands except for the subbands indicated as the best M subbands, and one or more subband TPMIs can be used for the respective subbands indicated as the best M subbands.

[0360] In an embodiment, the value of M can be predetermined based on the system bandwidth. In an embodiment, the value of M can be determined depending on the scheduled bandwidth or the number of subbands within the scheduled bandwidth. In an embodiment, the value of M can be fixed. In an embodiment, the value of M can be configured by higher layer signaling. In an embodiment, the value of M can be "0" (e.g., when DFT-s-OFDM is used for the uplink waveform and / or there is no subband TPMI in the uplink grant).

[0361] In different cases, the indication of the supplemental TPMI information can not be necessary. In an embodiment, for example, the transmission of the supplemental TPMI indication can be activated and / or deactivated as needed. In an embodiment, the transmission of the supplemental TPMI indication can be initially deactivated and later activated. Alternatively, the transmission of the supplemental TPMI indication can be initially activated and later deactivated. Such activation and / or deactivation occurs in response to explicit signaling and / or messaging. The activation and / or deactivation occurs in response to timer expiration or timeout, etc., implicit signaling and / or messaging, and / or other implicit methods.

[0362] In an embodiment, the WTRU can be configured by higher layer signaling to activate / deactivate the transmission of the supplemental TPMI information. In an embodiment, the WTRU can dynamically determine the presence of the supplemental TPMI information by or based on the format of the received PDCCH. For example, if the indicated TPMI vector does not match the size of the scheduled transmission, the presence of the TPMI information can be indicated as part of the DCI payload. In an embodiment, the WTRU can detect the presence of the supplemental TPMI information by checking an IE (which can be as small as a single bit) in the DCI. The IE can indicate the presence of the supplemental TPMI information in a separate payload conveyed by LI (PDSCH) or L2 (MAC CE).

[0363] Figure 18is a flowchart illustrating a representative procedure 1800 used in conjunction with phase-continuous precoding processing. The representative procedure 1800 can be implemented in a first device, such as a base station (e.g., any of the base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of the WTRUs 102 and WTRUs 204). The representative procedure 1800 can also be implemented in devices other than base stations and WTRUs.

[0364] To perform the representative procedure 1800, the first device can be communicably coupled with a second device. The second device can be a base station (e.g., any of the base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of the WTRUs 102 and WTRUs 204). In embodiments, if the first device is a WTRU, then the second device can be a base station. Alternatively, if the first device is a base station, then the second device can be a WTRU.

[0365] As shown in Figure 18 the first device can receive signaling indicating transmission precoding information for one or more sub-bands of a first bandwidth and one or more other bandwidths (1802). The first device can determine, from the transmission precoding information, first and second sets of precoders corresponding to the plurality of sub-bands of the first bandwidth and the other bandwidths, respectively (1804). The first device can perform precoding processing for the first bandwidth sub-bands using the first precoders for transmission at a first transmission event (1806). The first device can perform precoding processing for transmission at a second transmission event using at least some of the first and / or second precoders for newly allocated resources (1808). Benefits of performing the representative procedure 1800 are that the number of bits used to signal transmission precoding information is reduced because no additional bits (or a reduced number of additional bits) are needed to signal transmission precoding information for the second transmission event.

[0366] In embodiments, the transmission precoding information can include first and second TPMI indications. In embodiments, the first TPMI indication can correspond to (e.g., a respective) narrowband precoder component. In embodiments, the second TPMI indication can correspond to (e.g., a respective) midband precoder component. In embodiments, the second TPMI indication can correspond to (e.g., a respective) wideband precoder component. In embodiments, the second TPMI can correspond to any of the midband and wideband precoder components. In embodiments, the transmission precoding information can be as small as a single bit. In embodiments, the transmission precoding information can be an IE.

[0367] Reference is now made to Figure 19The figure shows an example TPMI indication mechanism with supplemental mid-band TPMI information. Figure 18 The TPMI indication mechanism illustrated can be considered a typical process 1800 ( Figure 18 Examples of ).

[0368] like Figure 19 As shown, the first device can receive signaling (1902) indicating a first license for transmission on the i-th time slot and a narrowband precoding TPMI and a supplementary intermediate frequency band precoding TPMI for the i-th time slot. The first device can perform the transmission on the i-th time slot using a precoder corresponding to the narrowband precoding TPMI (1904). The first device can receive signaling (e.g., DCI) indicating a second license for transmission on the i+n-th time slot (1906). The first device can perform the transmission on the i+n-th time slot using a precoder corresponding to at least some narrowband precoding TPMIs and / or intermediate frequency band precoding TPMIs (1908). Since no additional bits are needed (or the number of additional bits is reduced) to signal the transmission precoding information for the transmission on the i+n-th time slot, similar to typical process 1700, Figure 19 The TPMI indication mechanism with supplemental mid-band TPMI information also has the benefit of reducing the number of bits used to signal the transmission of precoded information. Some additional bits can be used to signal the transmission of precoded information in order to provide TPMI for any portion of the scheduled transmission bandwidth that was not previously indicated, and / or update the previously specified TPMI.

[0369] Typical adaptive resolution TPMI mechanism for frequency selective precoding processing

[0370] For uplink transmission, TPMI indication can be signaled using either dynamic or semi-static methods, and any of L1, L2, and higher-layer control signaling and / or channels can be used. The capacity of the control channel for TPMI indication of M narrowband precoders {W(1), W(2), ..., W(M)} can generally be assumed to be fixed. The precoding W can represent a single-level or two-level precoding mechanism. If a two-level codebook is supported, then the subband precoding W can correspond to the second beamforming matrix W2.

[0371] Typical example of adaptive codebook resolution

[0372] In an uplink grant (DCI), the number of bits used for one or more TPMI indication can be fixed (as an example, although the number of scheduled RBs and / or the number of subbands corresponding to the scheduled RBs can change from grant to grant). In this case, codebook subsampling can be used for one or more (e.g., each) subband. By way of example, a reference number of subbands can be defined, configured, or determined to be a value Nsub; if the number of subbands within the scheduled bandwidth is equal to or less than Nsub, then all code words in the codebook can be used for one or more subband TPMI. If the number of subbands within the scheduled bandwidth is greater than Nsub, then codebook subsampling can be used for one or more subband TPMI, and the number of code words in the codebook used for one or more subband TPMI can be limited.

[0373] In an embodiment, codebook subsampling can be referred to as codebook subset restriction with reduced TPMI indication. In an embodiment, codebook subsampling can be predefined or predetermined based on the number of subbands in the scheduled bandwidth and / or Nsub. In an embodiment, Nsub can be predefined or fixed. In an embodiment, Nsub can be configured by higher layer signaling. If the number of subbands is less than Nsub, then codebook oversampling can be used. The oversampling can be based on an oversampling factor of the codebook generation process. By way of example, the codebook can use an oversampled DFT matrix, a reference oversampling factor (e.g., O = 4) can be used when the number of subbands is the same as Nsub, and a larger oversampling factor (e.g., O = 8) can be used when the number of subbands is less than Nsub.

[0374] Assuming the capacity of the TPMI indication channel is fixed, in a solution, the size of the codebook used can be re-adjusted in accordance with the change in resource allocation size. As such, the indicated TPMI index can refer to a corresponding member of the downsampled mother codebook.

[0375] In an embodiment, a WTRU can decode a received control payload (e.g., DCI) and can determine from it the size of the resource allocation corresponding to the received UL grant. From the decoded resource allocation size, the WTRU can further decode the received TPMI information in order to determine the TPMI for each subband, determine the sampling rate of the mother codebook, and / or select a per-subband precoder based on the decoded per-subband TPMI and the downsampled codebook. If a resource re-scheduling changes, the WTRU can employ codebook downsampling procedures until it is informed of a higher resolution for W1 update.

[0376] Table 22 lists the exemplary parameters and corresponding values ​​used to perform codebook downsampling processing. According to Table 22, the number of bits per TPMI can be adjusted to support 32 RB transmissions using the same DCI size as that used for 16 RB transmissions in subframe i.

[0377] Table 22

[0378]

[0379]

[0380] Figure 20 This is a flowchart illustrating a typical process 2000 used in conjunction with phase-continuous precoding processing. This typical process 2000 can be implemented in a first device, such as a base station (e.g., any one of base station 114, eNodeB 160, gNB 180, and base station 202) or a WTRU (e.g., any one of WTRU 102 and WTRU 204). This typical process 2000 can also be implemented in devices other than base stations and WTRUs.

[0381] To perform typical process 2000, the first device may be communicatively coupled to the second device. The second device may be a base station (e.g., any of base station 114, eNodeB 160, gNB 180, and base station 202) or a WTRU (e.g., any of WTRU 102 and WTRU 204). In an embodiment, if the first device is a WTRU, then the second device may be a base station. Alternatively, if the first device is a base station, then the second device may be a WTRU.

[0382] like Figure 20 As shown, a first device can receive (e.g., from a second device) signaling comprising a fixed number of bits indicating transmission precoding information regarding: (i) a number of subbands assigned to a first bandwidth of the first device, and (ii) one or more second bandwidths (2002). The first device can perform adaptive codebook resolution based on the indicated transmission precoding information (2004). Although not shown, the first device can: (i) perform channel measurements based on reference signal transmissions; (ii) determine a frequency selectivity estimate of the channel based on the measurements; (iii) determine the degree of selectivity based on the frequency selectivity estimate; and / or (iv) send an IE to the second device indicating the frequency selectivity (estimate) of the channel.

[0383] In an embodiment, the first device can perform codebook subsampling based on the number of subbands, whereby to at least in part perform the adaptive codebook resolution processing. In an embodiment, the first device can perform codebook subsampling processing based on the number of subbands satisfying a threshold, whereby to at least in part perform the adaptive codebook resolution processing. The threshold can be or can be based on a reference number of subbands. In an embodiment, the first device can perform codebook oversampling processing based on the number of subbands, whereby to at least in part perform the adaptive codebook resolution processing. In an embodiment, the first device can perform codebook oversampling processing based on the number of subbands satisfying a threshold, whereby to at least in part perform the adaptive codebook resolution processing, where the threshold is or is based on a reference number of subbands.

[0384] Typical adaptive PRG size adjustment example

[0385] As noted above, the number of bits for one or more TPMI indication usage in the uplink grant DCI can be fixed. Although the number of RBs in the scheduled RBs can change from grant to grant, this number can be fixed. In this case, an adaptive subband size adjustment process can be used. In accordance with the adaptive subband size adjustment process, the number of subbands can be limited to a certain number (e.g., Nsub), and the number of RBs for a subband (e.g., precoding resource granularity; PRG) can be determined based on the number of scheduled RBs. As an example, if (i) the number of PRBs allocated for the uplink transmission is 32, (ii) the subband size can be determined to be 8 PRBs, and 4 TPMIs can be provided in the uplink grant, then the maximum number of subbands can be limited to 4 (e.g., Nsub = 4).

[0386] In an embodiment, the maximum number of subbands can be predefined or fixed. In an embodiment, the maximum number of subbands can be configured via higher layer signaling. In an embodiment, the number of subbands can be determined based on a downlink DCI that matches in size to the uplink grant DCI. In an embodiment, the maximum number of subbands can be determined based on the system bandwidth or maximum supportable bandwidth of the WTRU.

[0387] Assuming that the capacity for the TPMI indication channel is fixed, in a solution, the PRG size can be re-adjusted in accordance with the change in resource allocation size. Thereby, the indicated TPMI index can refer to the corresponding new PRG size definition.

[0388] In an embodiment, the WTRU can decode the received control payload (e.g., DCI) to determine the resource allocation size corresponding to the received UL grant. The WTRU can further decode the received TPMI information to determine the TPMI for each subband and / or to determine the PRG size according to the decoded resource allocation size. If the resource re- scheduling changes, the WTRU can employ the new PRG size definition until it is informed of a higher resolution for Wl update.

[0389] Table 23 lists example parameters and corresponding values for performing an adaptive PRG size adjustment process. According to Table 23, it is assumed that the DCI size is fixed and the size of the PRG is adjusted to support 32 RB transmissions using the same DCI size as for 16 RB transmissions in subframe i.

[0390] Table 23

[0391] Subframe i Subframe (i+1) Number of scheduled RBs 16 32 PRG size 4 8 Number of bits per TPMI 4 4 DCI size 16 16 Codebook size 16 16

[0392] Figure 21 FIG. 21 is a flow diagram illustrating a representative procedure 2100 for use with phase-continuous precoding processing. The representative procedure 2100 can be implemented in a first device, such as a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). The representative procedure 2100 can also be implemented in devices other than base stations and WTRUs.

[0393] To perform the representative procedure 2100, the first device can be communicably coupled with a second device. The second device can be a base station (e.g., any of base stations 114, eNode-Bs 160, gNBs 180, and base stations 202) or a WTRU (e.g., any of WTRUs 102 and WTRUs 204). In an embodiment, if the first device is a WTRU, then the second device can be a base station. Alternatively, if the first device is a base station, then the second device can be a WTRU.

[0394] As Figure 21As shown, the first device can receive (e.g., from the second device) signaling containing a fixed number of bits (2102) used to indicate transmission precoding information regarding: (i) a number of subbands of a first bandwidth assigned to the first device, and (ii) one or more second bandwidths. The first device can perform an adaptive precoding resource granularity size adjustment process based on the indicated transmission precoding information (2104). Although not shown, the first device can (i) perform channel measurements based on reference signal transmissions; (ii) determine a channel frequency selectivity estimate based on the measurements; (iii) determine a selectivity degree based on the frequency selectivity estimate; and / or (iv) transmit an IE to the second device indicating the frequency selectivity estimate of the channel.

[0395] In embodiments, the first device can determine and / or set the precoding resource granularity based on the allocated resources and the fixed number of bits, whereby the adaptive precoding resource granularity size adjustment process is performed at least in part based thereon. In embodiments, the first device can determine whether to adjust or maintain the number of subbands based on the allocated resources and the fixed number of bits, whereby the precoding resource granularity is determined and / or set at least in part based thereon.

[0396] Typical PMI reuse example

[0397] For a given bandwidth part, the WTRU can be configured with a fixed number of TPMIs (N TPMI ) without considering the number of RBs scheduled for transmission. N TPMI may be configured in a dynamic, semi-static manner, or can be determined based on a table related to the bandwidth part size. In the uplink grant DCI, the total number of bits for one or more TPMIs can be a fixed value. Thus, once the BWP is configured, the WTRU can determine N TPMI to facilitate TPMI DCI detection. For a given bandwidth part, the WTRU can also be configured with a number of subbands (N 子带 ) for frequency selective precoding processing.

[0398] In embodiments, if the number of configured TPMIs is greater than or equal to the number of subbands configured for frequency selective precoding processing, i.e., N TPMI ≥ N 子带 , then a unique TPMI can be assigned for each subband. Figure 22 An example of such frequency selective precoding processing is shown. In accordance with the example shown in Figure 22 , the number of configured subbands can match the number of TPMIs.

[0399] In an embodiment, if the number of configured TPMIs is less than the number of subbands configured for frequency-selective precoding processing, i.e., N TPMI <N 子带 then some TPMIs can be assigned to more than one subband. In an embodiment, TPMIs can be indicated only for a specific set of subbands. The specific set of subbands can be referred to as the primary subbands. The WTRU can use the received TPMIs for the primary subbands to perform precoding processing on one or more subbands adjacent to the primary subbands, which can be on one or both sides of the primary subbands. In an embodiment, the TPMI of the closest primary subband can be applied. Figure 23 An example case is shown where the TPMIs of the indicated primary subbands {1, 3, 5, 7} are also applied on the subbands {2, 4, 6, 8} immediately adjacent to them.

[0400] The primary subbands can be specified based on a uniform and structured pattern (as shown in Figure 23 ) and / or based on a non-uniform pattern (as shown in Figure 24 ).

[0401] A process to assign primary subbands in a fair and balanced manner on scheduled transmissions can be supported. To this end, in an embodiment, the pattern of primary subbands can be cycled for each transmission event. Figure 24 An example case is shown for a non-uniform pattern with cycling. Alternatively and / or in addition, the pattern used to specify the primary subbands can be changed randomly from transmission event to transmission event. Alternatively and / or in addition, the pattern of primary subbands can be defined based on a time index (e.g., slot number, etc.).

[0402] Although the typical examples provided herein regarding transmission precoding information are provided in the context of uplink, similar or complementary methods, procedures and techniques can be applied in the context of downlink in accordance with the above description.

[0403] Cited documents

[0404] The documents cited herein by reference are:

[0405] “Discussion on phase continuity and PRB bundling”, Qualcomm Incorporated, 3GPP Tdoc Rl- 1612045, 3GPP TSG-RAN WG1 Meeting #87, Reno, USA, November 14-18, 2016;

[0406] “On Enhanced Frequency Selective Precoding for MIMO Transmission,” InterDigital Communications, 3GPP TSG RAN WG1 AH_NR Meeting, Spokane, USA, January 16-20, 2017; and

[0407] PCT Patent Application Serial No. PCT / US16 / 64551 filed December 2, 2016.

[0408] CONCLUSION

[0409] While the features and elements are provided in particular combinations, one of ordinary skill in the art will appreciate that each feature and element can be used alone or in any combination with the other features and elements. In addition, the disclosure is not limited to the specific embodiments described herein. The described embodiments are merely exemplary and are not exhaustive of the scope of the disclosure. Many modifications and variations are possible in light of this disclosure. Any feature or element of the description can be used with any other feature or element. The specification and drawings should be regarded as illustrative only and should not be considered restrictive in any way. The disclosure is not limited to the precise details described herein. Any use of the terms “invention” or variants thereof is not intended to limit the scope of the disclosure to a specific application, but rather the claims should be construed consistent with the full scope of the disclosure. The disclosure is not limited to the specific methods and devices described herein, but extends to equivalent methods and devices that perform substantially the same functions in substantially the same way to achieve substantially the same results.

[0410] It should also be understood that the terms used herein are for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the term “video” can refer to any one of a snapshot, a single image, and / or a plurality of images displayed on a time basis. By way of further example, the term “user equipment” and its acronym “UE” as used herein can refer to (i) a wireless transmit and / or receive unit (WTRU) as described above; (ii) any one of a plurality of embodiments of a WTRU as described above; (iii) a device having wireless capability and / or wired capability (e.g., connectivity), particularly, the device is configured with some or all of the structure and functionality of a WTRU as described above; (iii) a device having wireless capability and / or wired capability configured with relatively less structure and functionality as compared to all of the structure and functionality of a WTRU as described above; or (iv) a similar device. The terms “comprise(s),” “include(s),” “having,” “has,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended terms.Figures 1A-1D Details of an example WTRU that can be used in connection with any of the WTRUs described herein are provided.

[0411] Furthermore, the described methods can be implemented in a computer program, software, or firmware incorporated in a computer- readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0412] Various modifications to these aspects can be possible without departing from the scope of the disclosure. Although the examples provided herein are primarily described in terms of a handheld device, those of ordinary skill in the art will recognize that the examples described herein can apply to any appropriate type of device, and can be implemented by any appropriate type of voltage source, such as a battery or the like, which provides any appropriate voltage.

[0413] Additionally, in the above embodiments, processing platforms, computing systems, controllers and other devices that include processors are mentioned. These devices can include at least one central processing unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or

[0414] Those of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents a physical, quantitative, comprehension, or transformative process that manipulates electrical signals by machines or computers. The acts and symbolically represented operations or instructions manipulate electrical signals to transform the electrical signals into other electrical signals representing data bits that are stored in memory systems by a storage medium that changes the physical storage means of the memory systems with electrical, magnetic, light, or organic properties. These activities further transform the memory locations to hold different data bits, thereby further transforming the internal structure of the computer.

[0415] Data bits can also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory ("RAM")) or non-volatile (e.g., Read-Only Memory ("ROM")) mass storage system readable by the CPU. The computer readable medium can include cooperating or interconnected computer readable media, which exist exclusively in the processing system, or distributed among multiple interconnected processing systems located locally or remotely from the processing system. It is understood that the illustrative embodiments are not limited to the above-mentioned memory or storage, and that other platforms and memories can support the described methods.

[0416] In the illustrative embodiments, any of the operations, processes, etc. described herein can be implemented as computer readable instructions residing on a computer readable medium. Such computer readable instructions can be executed by a processor of a mobile unit, network element, and / or any other computing device.

[0417] There is little distinction between the use of hardware and software in the described aspects of the system. The use of hardware and software is generally (but not always, in that in certain contexts the choice between hardware and software can become significant) a design choice representing cost vs. efficiency based on the particular application and performance constraints present. The processes and / or systems and / or other technologies described herein can be implemented by various carriers (e.g., hardware, software and / or firmware) and the preferred carrier can vary based on the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementation determines that speed and accuracy are paramount, the implementation can opt for using hardware and / or firmware carriers. If flexibility is paramount, then an implementation can opt for using software implementations. As another alternative, an implementation can opt for some combination of hardware, software and / or firmware.

[0418] The above detailed description has discussed various embodiments of apparatus and / or processes by way of using block diagrams, flowcharts, and / or examples. As such block diagrams, flowcharts, and / or examples contain one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or any combination thereof. In an embodiment, several portions of the subject matter described herein can be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing media utilized to actually carry out the distribution, whether the

[0419] Those skilled in the art will recognize that the description of apparatus and / or process set forth herein is not specifically limited to any single set of experimental parameters, as such apparatus and / or process can be practiced with any number of experimental parameters. Those skilled in the art will further appreciate that the description of apparatus and / or process set forth herein is also not specifically limited to any single implementation or set of implementations, as such apparatus and / or process can be practiced with other apparatus and / or process. Those skilled in the art will also recognize that the description of apparatus and / or process set forth herein is also not specifically limited to any single data processing system, as such apparatus and / or process can be practiced with any number of data processing systems or other device that includes an appropriate device for interfacing to the system, such as an appropriate device for interfacing to a system bus. It is also within the scope of the present description that, within the scope of the present description, various tasks and / or operations can be re-ordered, combined, and / or divided into other tasks and / or operations.

[0420] The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0421] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate the plural terms to the singular form and / or single terms to plural form, and are within the scope of the present description. Accordingly, the singular form "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0422] Those skilled in the art will appreciate that, in general, the terms used herein, including in the appended claims (for example the subject matter of the appended claims) are intended to be interpreted broadly such that the terms "comprises", "comprising", "includes", "including" and "has", "having" are not intended to be limiting; for example, the terms "comprises", "comprising", "includes", "including" and "has", "having" should be interpreted as "including but not limited to" or "having at least" etc. Those skilled in the art will further appreciate that if a specific number of an introduced claim recitation is intended, the language "at least one" or "one or more" will be explicitly recited in the claim. For example, if a claim recitation of "at least one of A and B" or "one or more of A and B" is intended, the language "at least one of A and B" or "one or more of A and B" will be explicitly recited in the claim. Conversely, if a specific number of an introduced claim recitation is intended, the language "at least one of A and B" or "one or more of A and B" will not be explicitly recited in the claim. For example, the recitation "at least one of A, B, and C" or "one or more of A, B, and C" will not be interpreted to require at least one of A, at least one of B, and at least one of C.Those skilled in the art will further appreciate that virtually any disjunctive word and / or phrase presenting two or more alternative items, whether in the description, claims, or drawings, can be understood to disclose the items individually or the item choices themselves individually or the items in any combination in any order and / or in any group. For example, the phrases "A or B" or "at least one of A and B" can be understood to mean "A or B or any combination of A and B."

[0423] Further still, as used herein, the term "any of" followed by a listing of a plurality of items and / or categories of items, is intended to include "any of the items" individually, "any of the items" in combination, "any of the items" in any number of combinations and / or subcombinations, and "any of the items" in any order. Further, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero.

[0424] Further still, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0425] As will be understood by those familiar with the art, for any and all purposes, such as providing a written description, all ranges disclosed herein are meant to include any and all subranges subsumed therein. Any maximum numerical limitation getting recited is intended to include each lower numerical limitation. Any minimum numerical limitation getting recited is intended to include each higher numerical limitation. Bronzino, Principles of Quantitative Analysis, 2nd Ed., pp. 123-127, McGraw-Hill Book Co., NY, 1974. As will be understood by those familiar with the art, any reference to an element herein also is intended to mean the element by itself, unless otherwise indicated. For example, if a process is described that includes a step of providing an element, it is understood that the process can be performed without providing the element. As will be understood by those familiar with the art, if a process or method is described that includes an element acting as a source of, or to provide, an element, then it is understood that the process or method can be performed without providing the element from the source or by the element. Finally, as will be appreciated by those familiar with the art, a reference to a process or method comprising a step of providing an element or a group of elements does not, unless otherwise indicated, imply that the element or group of elements are necessarily provided by that process or method. As will be understood by those familiar with the art, if a process or method is described that includes a step of providing an element, it is understood that, unless otherwise specified, the process or method can be performed without providing the element.

[0426] Moreover, unless specifically stated otherwise, the claims should not be construed as limited to the order that the steps are presented herein.

Claims

1. A method implemented in a wireless transmit / receive unit (WTRU), the method comprising: receiving a first transmission indicating (i) a first plurality of uplink frequency resources allocated to the WTRU in a first time slot and (ii) a plurality of subbands of a first frequency band for a bandwidth and a plurality of transmission precoding matrix indices (TPMIs) for a second frequency band for the bandwidth, wherein the first plurality of uplink frequency resources correspond to a respective plurality of frequencies of the first frequency band; determining, based on the plurality of TPMIs and one or more codebooks, a plurality of first precoders corresponding to the plurality of subbands of the first frequency band and a second precoder corresponding to the second frequency band; performing precoding of first information using the plurality of first precoders; transmitting the precoded first information using the first plurality of uplink resources during the first time slot; receiving a second transmission indicating a second plurality of uplink frequency resources allocated to the WTRU in a second time slot, wherein the second plurality of uplink frequency resources correspond to a respective plurality of frequencies including at least one frequency of the second frequency band and zero or more frequencies of the plurality of subbands; performing precoding of second information using the second precoder and zero or more of the plurality of first precoders according to the second plurality of uplink frequency resources corresponding to the at least one frequency of the second frequency band and the zero or more frequencies of the plurality of subbands, respectively; and transmitting the precoded second information on the second plurality of uplink frequency resources during the second time slot. Any of the first and second transmissions include respective downlink control information, wherein the first downlink control information indicates the first plurality of uplink frequency resources and the plurality of TPMIs, and wherein the second downlink control information indicates the second plurality of uplink frequency resources.

2. The method of claim 1, wherein, The first frequency band is a scheduled bandwidth.

3. The method of claim 1 or 2, wherein, The first frequency band and the second frequency band are any of adjacent, contiguous, and non-contiguous.

4. The method of claim 1 or 2, wherein, The plurality of TPMIs includes a first plurality of TPMIs and a second TPMI, wherein the first plurality of TPMIs refer to a respective plurality of narrowband precoder components, and wherein the second TPMI refers to a mid-band precoder component.

5. The method of claim 1 or 2, wherein, 6. The method of claim 5, wherein the first plurality of TPMIs are updated at a different rate than the second TPMI. The first transmission includes an indicator to indicate the plurality of TPMIs, and wherein the indicator is as small as a single bit.

7. The method of claim 1 or 2, wherein, The one or more codebooks include any of a single-level codebook and a two-level codebook.

8. The method of claim 1 or 2, wherein, The plurality of subbands correspond to a best M subbands of the first frequency band.

9. The method of claim 1 or 2, wherein, 10. A wireless transmit / receive unit (WTRU) comprising circuitry including a transmitter, a receiver, a processor, and a memory, the WTRU configured to: ​ receiving a first transmission indicating (i) a first plurality of uplink frequency resources allocated to the WTRU in a first time slot and (ii) a plurality of sub-bands for a first frequency band of a bandwidth and a plurality of transmission precoding matrix indices (TPMIs) for a second frequency band of the bandwidth, wherein the first plurality of uplink frequency resources correspond to a respective plurality of frequencies of the first frequency band; determining, based on the plurality of TPMIs and one or more codebooks, a plurality of first precoders corresponding to the plurality of sub-bands of the first frequency band and a second precoder corresponding to the second frequency band; performing precoding of first information using the plurality of first precoders; transmitting the precoded first information using the first plurality of uplink resources during the first time slot; receiving a second transmission indicating a second plurality of uplink frequency resources allocated to the WTRU in a second time slot, wherein the second plurality of uplink frequency resources correspond to a respective plurality of frequencies including at least one frequency of the second frequency band and zero or more frequencies of the plurality of sub-bands; performing precoding of second information using the second precoder and zero or more of the plurality of first precoders according to the second plurality of uplink frequency resources corresponding to the at least one frequency of the second frequency band and the zero or more frequencies of the plurality of sub-bands, respectively; and transmitting the precoded second information on the second plurality of uplink frequency resources during the second time slot.

11. The WTRU of claim 10, wherein any of the first transmission and the second transmission comprises respective downlink control information, wherein the first downlink control information indicates the first plurality of uplink frequency resources and the plurality of TPMIs, and wherein the second downlink control information indicates the second plurality of uplink frequency resources.

12. The WTRU of claim 10 or 11, wherein the first frequency band is a scheduled bandwidth.

13. The WTRU of claim 10 or 11, wherein the first frequency band and the second frequency band are any of: adjacent, contiguous, and non-contiguous.

14. The WTRU of claim 10 or 11, wherein the plurality of TPMIs includes a first plurality of TPMIs and a second TPMI, wherein the first plurality of TPMIs refer to a respective plurality of narrowband precoder components, and wherein the second TPMI refers to a mid-band precoder component.

15. The WTRU of claim 14, wherein the first plurality of TPMIs are updated at a different rate than the second TPMI.

16. The WTRU of claim 10 or 11, wherein the first transmission includes an indicator to indicate the plurality of TPMIs, and wherein the indicator is as small as a single bit.

17. The WTRU of claim 10 or 11, wherein the one or more codebooks include any of a single-stage codebook and a two-stage codebook. ​ 18. The WTRU of claim 10 or 11, wherein the plurality of sub-bands corresponds to a best M sub-bands of the first frequency band.

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