Method and apparatus for dmrs-free space CCA transmission and reception

Abstract

A method performed by a wireless transmit / receive unit (WTRU) may include receiving a PDSCH associated with a spatial CCA transmission, where the spatial CCA transmission includes RE groups, including: a first RE group; a second RE group; a third RE group; and a fourth RE group; constructing a first spatial CCA view and a second spatial CCA view in a receiving antenna domain in the spatial CCA area; and decoding the first RE group, the second RE group, and the fourth RE group in the spatial CCA transmission.

Description

[0001] Cross-reference to related applications This application claims the benefit of U.S. Provisional Application No. 63 / 525,209, filed July 6, 2023, the contents of which are incorporated herein by reference. Background Technology

[0002] Machine learning can refer to a type of algorithm that solves problems based on learning from experience (“data”) without explicit programming (“configuration rule set”). Machine learning can be considered a subset of AI. Different machine learning paradigms can be envisioned based on the nature of the data or feedback available for learning the algorithm. For example, supervised learning methods may involve learning a function that maps inputs to outputs based on labeled training examples, where each training example can be a pair consisting of an input and a corresponding output. For example, unsupervised learning methods may involve detecting patterns in data that does not have pre-existing labels. For example, reinforcement learning methods may involve performing a sequence of actions in an environment to maximize cumulative rewards. In some embodiments, it is possible to apply machine learning algorithms using a combination or interpolation of the methods mentioned above. For example, semi-supervised learning methods may use a combination of a small amount of labeled data and a large amount of unlabeled data during training. In this respect, semi-supervised learning can be considered to fall between unsupervised learning (without labeled training data) and supervised learning (with only labeled training data). Summary of the Invention

[0003] A method performed by a wireless transmit / receive unit (WTRU) may include: receiving a physical downlink shared channel (PDSCH) associated with a spatial canonical correlation analysis (CCA) transmission, wherein the spatial CCA transmission includes a group of resource elements (REs), including: a first RE group for carrying data associated with a first layer; a second RE group for carrying data from a first layer and a second layer, wherein the transmission power difference between the first layer and the second layer is greater than a threshold; a third RE group for carrying CCA phase correction reference symbols; and a fourth RE group for carrying data from the first layer and data from the second layer, wherein the transmission power of the first layer is equal to the transmission power of the second layer; constructing a first spatial CCA view and a second spatial CCA view in a receive antenna domain within a spatial CCA region; and decoding the first RE group, the second RE group, and the fourth RE group in the spatial CCA transmission. The method may further include receiving configuration information associated with the spatial CCA transmission. The method may further include using the third RE group for phase correction.

[0004] Configuration information may include layer-specific spatial CCA region configuration. Configuration information may include configuration information including the overlap percentage between the first and second layers. Spatial CCA regions may include a first RE group, a second RE group, and a third RE group. A first spatial CCA view can be constructed from a first set of receiving antenna elements, and a second spatial CCA view can be constructed from a second set of receiving antenna elements. The first set of receiving antenna elements may not overlap with the second set of receiving antenna elements. Attached Figure Description

[0005] A more detailed understanding can be obtained by referring to the following description, which is given by way of example in conjunction with the accompanying drawings, wherein the same reference numerals in the figures indicate the same elements, and wherein: Figure 1A This is a system diagram illustrating an example communication system in which one or more of the disclosed embodiments may be implemented; Figure 1B The illustration shows an embodiment that can be used Figure 1A The diagram shows a system illustration of an example wireless transmit / receive unit (WTRU) used in a communication system. Figure 1C The illustration shows an embodiment that can be used Figure 1A The diagram illustrates a system diagram of an example radio access network (RAN) and an example core network (CN) used within a communication system. Figure 1D The illustration shows an embodiment that can be used Figure 1A The diagram shows another example RAN and another example CN used in the communication system illustrated in the figure. Figures 2A to 2D This is a diagram illustrating NR DMRS symbol configuration type 1 for 4×4 MIMI; Figure 3 This is a diagram illustrating channel estimation and equalization based on DMRS; Figure 4 is a diagram illustrating various PDSCH transmission methods; Figure 5 This is a diagram illustrating a PDSCH with spatial CCA transmission; Figure 6 This is a diagram illustrating a PDSCH with spatial CCA transmission; Figure 7 This is a flowchart illustrating the program executed by the WTRU; Figure 8 This is a graph illustrating the BER performance of Layer 1; Figure 9 This is a diagram illustrating a PDSCH with spatial CCA transmission; and Figure 10 This is a graph showing throughput compared to SNR. Detailed Implementation

[0006] Figure 1A This is a diagram illustrating an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multiple access system providing content such as voice, data, video, messaging, and broadcasting to multiple wireless users. The communication system 100 enables multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may 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 Unique Word Discrete Fourier Transform Spread Spectrum OFDM (ZT-UW-DFT-S-OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), and the like.

[0007] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, it will be appreciated that the disclosed embodiments are contemplated to any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, and 102d—any of which can be referred to as a Station (STA)—can be configured to transmit and / or receive wireless signals and can include User Equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and the like. Any of WTRUs 102a, 102b, 102c, and 102d can be interchangeably referred to as a UE.

[0008] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106, the Internet 110, and / or other networks 112. For example, base stations 114a and 114b may be base transceiver stations (BTS), Node-Bs, eNode Bs (eNBs), home Node Bs, home eNode Bs, next-generation NodeBs such as gNodeBs (gNBs), new radio (NR) NodeBs, site controllers, access points (APs), wireless routers, and the like. Although base stations 114a and 114b are each depicted as a single element, it will be appreciated that base stations 114a and 114b may include any number of interconnected base station and / or network elements.

[0009] Base station 114a may be part of RAN 104, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, and the like. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for radio services to a specific geographic area, which may be relatively fixed or may change over time. The cell may also be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0010] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116. Air interface 116 can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) can be used to establish air interface 116.

[0011] More specifically, as described above, the communication 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, etc. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish an air interface 116 using Wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink (UL) Packet Access (HSUPA).

[0012] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0013] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies, such as NR radio access, which can use NR to establish air interface 116.

[0014] In one embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access, for example, using the dual connectivity (DC) principle. Therefore, the air interface utilized by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0015] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Global Microwave Access Interoperability (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), GSMEDGE (GERAN), and the like.

[0016] Figure 1A Base station 114b can be, for example, a wireless router, a home Node B, a home eNode B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for drone use), roads, and the like. In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (LAN) (WLAN). In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c, 102d can utilize cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish picocells or femtocells. Figure 1A As shown, base station 114b can be directly connected to Internet 110. Therefore, base station 114b does not need to access Internet 110 via CN 106.

[0017] RAN 104 can communicate with CN 106, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data can have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. CN 106 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, and / or perform advanced security functions such as user authentication. Although in Figure 1AAs not shown, but will be appreciated, RAN 104 and / or CN 106 can communicate directly or indirectly with other RANs that use the same RAT as or a different RAT than RAN 104. For example, in addition to connecting to RAN 104, which may utilize NR radio technology, CN 106 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0018] CN 106 can also serve as a gateway for WTRUs 102a, 102b, 102c, and 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 or a different RAT.

[0019] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multi-mode capability (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example... Figure 1A The WTRU 102c shown can be configured to communicate with base station 114a, which can employ cellular-based radio technology, and with base station 114b, which can employ IEEE 802 radio technology.

[0020] Figure 1B This is a system diagram illustrating the example WTRU 102. For example... Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keyboard 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripheral devices 138, etc. It will be appreciated that WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0021] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, and the like. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, and transceiver 120 may be coupled to transmitting / receiving element 122. Although Figure 1B While the processor 118 and transceiver 120 are depicted as separate components, it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0022] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, transmitting / receiving element 122 can be, for example, a transmitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It will be appreciated that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0023] Despite Figure 1B While the transmit / receive element 122 is described as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0024] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As described above, WTRU 102 can have multimode capability. Therefore, transceiver 120 can include multiple transceivers for example enabling WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0025] The processor 118 of WTRU 102 can be coupled to and receive user input data from: a speaker / microphone 124, a keyboard 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit). The processor 118 can also output user data to the speaker / microphone 124, keyboard 126, and / or display / touchpad 128. Furthermore, the processor 118 can access information from and store data in any suitable type of memory (such as non-removable memory 130 and / or removable memory 132). Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, memory stick, secure digital storage (SD) 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 WTRU 102 (such as a server or home computer (not shown)).

[0026] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may 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.

[0027] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via air interface 116, and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information using any suitable location determination method while remaining consistent with the embodiments.

[0028] The processor 118 may be further coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or videos), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, and the like. Peripheral devices 138 may include one or more sensors. These sensors may be one or more of the following: gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors, geolocation sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, attitude sensors, biosensors, humidity sensors, and the like.

[0029] WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with a specific subframe for both UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing by a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with a specific subframe for UL (e.g., for transmission) or DL ​​(e.g., for reception) may be concurrent and / or simultaneous.

[0030] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to one embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using E-UTRA radio technology. RAN 104 can also communicate with CN 106.

[0031] RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, for example, eNode-B 160a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a.

[0032] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in the UL and / or DL, and the like. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0033] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although the foregoing elements are depicted as part of CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0034] The MME 162 can connect to each of the eNode-Bs 162a, 162b, and 162c in RAN 104 via the S1 interface and can be used as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c, and so on. The MME 162 can provide control plane functions for switching between RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0035] The SGW 164 can connect to each of the eNode-Bs 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions such as anchoring the user plane during inter-eNode B handover, triggering paging when DL data is available for WTRUs 102a, 102b, and 102c, managing and storing the context of WTRUs 102a, 102b, and 102c, and so on.

[0036] The SGW 164 can be connected to the PGW 166, which can provide WTRU 102a, 102b, 102c with access to packet-switched networks (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0037] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRU 102a, 102b, 102c with access to a circuit-switched network such as PSTN 108 to facilitate communication between WTRU 102a, 102b, 102c and conventional landline communication equipment. For example, CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRU 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0038] Despite WTRU in Figures 1A-1D While described as a wireless terminal, it is envisioned that in certain representative embodiments, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with a communication network.

[0039] In a representative embodiment, another network 112 may be a WLAN.

[0040] In Infrastructure Basic Services Set (BSS) mode, a WLAN may have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP may have access to or interfacing with a Distributed System (DS) or carry services within and / or out of the BSS to another type of wired / wireless network. Traffic originating outside the BSS destined for a STA can reach and be delivered to the STA via the AP. Traffic originating from a STA destined outside the BSS can be sent to the AP for delivery to the appropriate destination. For example, traffic between STAs within the BSS can be sent via the AP, where the source STA can send traffic to the AP, and the AP can deliver traffic to the destination STA. 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 between a source STA and a destination STA (e.g., directly between the source and destination STAs) using Direct Link Establishment (DLS). In a particular representative embodiment, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to as the "self-organizing" communication mode in this document.

[0041] When using 802.11ac infrastructure operating mode or a similar operating mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of a fixed width (e.g., a wide bandwidth of 20 MHz) or a dynamically configured width. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In a particular representative embodiment, such as in an 802.11 system, Carrier Sense Multiple Access (CSMA / CA) with collision avoidance can be implemented. For CSMA / CA, each STA, including the AP, can listen on the primary channel. If the primary channel is listened to / detected by a particular STA and / or determined to be busy, that particular STA can back off. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0042] High-throughput (HT) STAs can communicate using a 40 MHz wide channel, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels.

[0043] Very High Throughput (VHT) STAs can support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels can be formed by combining adjacent 20 MHz channels. A 160 MHz channel can be formed by combining eight adjacent 20 MHz channels, or by combining two non-adjacent 80 MHz channels—this can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel coding, the data passes through a segment resolver, which splits the data into two streams. Each stream can be processed separately using Inverse Fast Fourier Transform (IFFT) and time-domain processing. These streams can be mapped onto two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0044] 802.11af and 802.11ah support sub-1 GHz operating modes. Compared to the operating modes used in 802.11n and 802.11ac, the channel operating bandwidth and carrier in 802.11af and 802.11ah are reduced. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV Blank (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support metering-type control / machine-type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have specific capabilities (e.g., limited capabilities) including support (e.g., support only) specific and / or limited bandwidths. MTC devices may include batteries with a battery life exceeding a threshold (e.g., to maintain a very long battery life).

[0045] WLAN systems that support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. 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 the STAs that support the minimum bandwidth operating mode among all STAs operating in the BSS. In the example of 802.11ah, for STAs that support (e.g., only support) the 1 MHz mode (e.g., MTC type devices), the primary channel can be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier Sense and / or Network Assignment Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example because an STA (which only supports the 1 MHz operating mode) is transmitting to the AP, all available bands can be considered busy, even if most bands remain idle.

[0046] In the United States, the available frequency bands for 802.11ah are from 902 MHz to 928 MHz. In South Korea, the available bands are from 917.5 MHz to 923.5 MHz. In Japan, the available bands are from 916.5 MHz to 927.5 MHz. The total available bandwidth for 802.11ah is 6 MHz to 26 MHz, depending on the country code.

[0047] Figure 1D This diagram illustrates a system diagram of RAN 104 and CN 106 according to one embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using NR radio technology. RAN 104 can also communicate with CN 106.

[0048] RAN 104 may include gNBs 180a, 180b, and 180c, although it should be understood that RAN 104 may include any number of GNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, GNBs 180a and 108b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Thus, for example, gNB 180a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers (not shown) to WTRU 102a. A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c can implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0049] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can differ for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute durations).

[0050] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without access to other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more of gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate / connect with gNBs 180a, 180b, and 180c, while also communicating / connecting with another RAN such as eNode-Bs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c, as well as one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-Bs 160a, 160b, and 160c can act as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0051] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slicing support, DC, interoperability between NR and E-UTRA, routing of user plane data to User Plane Functions (UPF) 184a and 184b, routing of control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, and the like. Figure 1D As shown, gNB180a, 180b, and 180c can communicate with each other via the Xn interface.

[0052] Figure 1DThe CN 106 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although the foregoing elements are depicted as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0053] AMF 182a and 182b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 104 via the N2 interface and can be used as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different Protocol Data Unit (PDU) sessions with different requirements), selecting specific SMF 183a and 183b, managing registration areas, terminating Non-Access Layer (NAS) signaling, mobility management, and so on. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service types being used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services that rely on Ultra Reliable Low Latency (URLLC) access, services that rely on Enhanced Massive Mobile Broadband (eMBB) access, services for MTC access, and so on. AMF 182a and 182b can provide control plane functions for switching between RAN 104 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0054] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 106 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 106 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure service routes through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, and so on. PDU session types can be IP-based, non-IP-based, Ethernet-based, and so on.

[0055] UPF 184a and 184b can be connected via an N3 interface to one or more of gNB 180a, 180b, and 180c in RAN 104. This N3 interface provides WTRU 102a, 102b, and 102c with access to a packet-switched network (such as the Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-destination PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, and so on.

[0056] CN 106 can facilitate communication with other networks. For example, CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) acting as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRUs 102a, 102b, and 102c may connect to local DNs 185a and 185b via UPF 184a and 184b through the N3 interface to UPF 184a and 184b and the N6 interface between UPF 184a and 184b and DNs 185a and 185b.

[0057] Given Figures 1A to 1D and Figures 1A to 1D The corresponding descriptions herein regarding one or more of the functions of WTRU 102a-d, base station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device described herein may be performed by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0058] Simulation devices can be designed to perform one or more tests on other devices in a laboratory environment and / or a carrier network environment. For example, one or more simulation devices can perform one or more functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device and / or use over-the-air wireless communication to perform tests for testing purposes.

[0059] One or more emulation devices may perform one or more functions (including all functions) but are not implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in test scenarios in a test laboratory and / or in non-deployed (e.g., testing) wired and / or wireless communication networks to perform testing of one or more components. One or more emulation devices may be test equipment. Emulation devices may transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0060] The following abbreviations and acronyms may be involved: ACK confirmation BLER block error rate BWP bandwidth portion CAP channel access priority CAPC Channel Access Priority Level CCA Canonical Correlation Analysis CCE control channel element CE control elements CG configured licenses or unit groups CP cyclic prefix CP-OFDM vs. Conventional OFDM (depending on the cyclic prefix) CQI Channel Quality Indicator CRC Cyclic Redundancy Check CSI Channel State Information CW Competition Window CWS Competition Window Size CO channel occupancy DAI Downlink Allocation Index DCI Downlink Control Information DFI downlink feedback information DG Dynamic Scheduling DL downlink DMRS demodulation reference signal DRB Data Radio Bearer eLAA Enhanced Licensing Assisted Access FeLAA Further Enhanced Licensed Assisted Access HARQ Hybrid Automatic Repeat Request LAA Authorized Assisted Access LBT Listen before you speak LTE Long Term Evolution (e.g., from 3GPP LTE R8 and above) NACK (Negative) MCS modulation and coding scheme MIMO (Multiple Input Multiple Output) NR New Radio OFDM (Orthogonal Frequency Division Multiplexing) PHY physical layer PID (Process ID) PO paging timing PRACH (Physical Random Access Channel) PSS Master Synchronization Signal RA (Random Access) RACH Random Access Channel RAR Random Access Response RCU Radio Access Network Central Unit RE Resource Components RF radio front end RLF radio link failure RLM radio link monitoring RNTI Radio Network Identifier RO RACH timing RRC Radio Resource Control RRM Radio Resource Management RS reference signal RSRP reference signal received power RSSI Received Signal Strength Indicator SDU Service Data Unit SRS Detection Reference Signal SS synchronization signal SSS secondary synchronization signal SWG switching interval (within a self-contained subframe) SPS (Semi-persistent scheduling) SUL supplements uplink TB Conveyor Block TBS conveyor block size TRP Transmit / Receive Point TSC Time-Sensitive Communication TSN Time-Sensitive Networking UE User Equipment UL uplink URLLC Ultra-Reliable and Low-Latency Communication WBWP Wideband Components WTRU Wireless Transmit / Receive Unit WLAN (Wireless Local Area Network) Machine learning can refer to algorithms that solve problems based on learning from experience (e.g., “data”) without explicit programming (e.g., “configuring a set of rules”). Machine learning can be considered a subset of AI. Different machine learning paradigms can be envisioned based on the nature of the data or feedback available for learning the algorithm. For example, supervised learning methods may involve learning a function that maps inputs to outputs based on labeled training examples, where each training example can be a pair consisting of an input and a corresponding output. For example, unsupervised learning methods may involve detecting patterns in data that does not have pre-existing labels. For example, reinforcement learning methods may involve performing a sequence of actions in an environment to maximize cumulative rewards. In some embodiments, it is possible to apply machine learning algorithms using a combination or interpolation of the methods mentioned above. For example, semi-supervised learning methods may use a combination of a small amount of labeled data and a large amount of unlabeled data during training. Semi-supervised learning falls between unsupervised learning (without labeled training data) and supervised learning (with only labeled training data).

[0061] Deep learning can refer to a class of machine learning algorithms that employ artificial neural networks, such as deep neural networks (DNNs). DNNs are a special class of human brain-inspired machine learning models where the input is linearly transformed and passed multiple times through a non-linear activation function. A DNN typically consists of multiple layers, each composed of a linear transformation and a given non-linear activation function. DNNs can be trained using training data via the backpropagation algorithm. DNNs have demonstrated state-of-the-art performance in various fields, including speech, vision, natural language processing, and various supervised, unsupervised, and semi-supervised machine learning settings. The term "AI / ML-based approach" can refer to learning behaviors and / or conformities through data-driven learning without explicit configuration of action step sequences. Such approaches enable the learning of complex behaviors that might be difficult to specify and / or implement using legacy methods.

[0062] Factor analysis techniques are prominent in the machine learning, data analytics, and signal processing communities. For example, Principal Component Analysis (PCA), Coupled Matrix Factorization (CMF), Independent Component Analysis (ICA), and Canonical Correlation Analysis (CCA) are widely used for compression, dimensionality reduction, visualization, and subspace estimation. These techniques all operate in an unsupervised manner, but their applications vary depending on the objective. Some of these tools extract latent components from a single data view / matrix (e.g., PCA, ICA), while others aim to recover latent common information from multiple data views / matrices (e.g., CMF, CCA).

[0063] Canonical correlation analysis (CCA) is a machine learning technique widely used in various fields, including machine learning and signal processing. CCA is a multi-view analysis technique that seeks to discover potential common information between two views of data. While single-view analysis techniques (such as PCA) aim to extract strong components from a given data matrix, multi-view analysis tools (such as CCA) seek to jointly analyze different views of the data. From an optimization perspective, CCA is based on the "difference" criterion that forces it to amplify only the common content between different views. If one view includes a very strong component that is missing in the other view, then CCA can ignore the principal components, no matter how strong they are, as long as they are not common. CCA can operate in a linear style (called linear CCA) or a non-linear style (called kernel CCA (KCCA), deep CCA (DCCA), or non-linear CCA). The main difference is that in linear CCA, the goal is to extract potential common features by finding two linear projections of two given data views, while in the non-linear case, the projections can often be non-linear (e.g., based on DNNs).

[0064] In its simplest form, CCA seeks to find two vectors. and (referred to as CCA canonical vectors, and in this disclosure as CCA combiners), such that the vectors derived from two linear projections... and The obtained N-dimensional components are maximally correlated, where and There are two given data views. Within the optimization framework, the CCA formula is given as follows: The scaling constraint is used to exclude all zero and meaningless instances. Furthermore, the CCA correlation coefficient is defined as: in Indicates the real part of a given complex vector x. Problem (1) allows for a simple algebraic implementation via eigenvalue decomposition. In particular, the overall complexity requires solving for the principal eigenvectors of the matrix, which involves multiplication of the autocovariance matrix and the crosscovariance matrix.

[0065] Coherent demodulation of signals transmitted via the radio interface typically requires knowledge of the (precoded / effective) wireless channel. The channel estimation process at the receiver in NR relies on the transmission of the physical channel accompanied by the demodulation reference signal (DMRS). The DMRS is generated using pseudo-random sequences based on known system parameters at the receiver. Parameters controlling sequence generation include scrambling identity, symbol position, and the number of OFDM symbols in a time slot. DMRS operation in NR includes several predefined options for the (uniform / equally spaced) mode and density of the RS based on the physical channel, configurable using (DCI-based) scheduling and higher-level configuration to cater to different use cases and WTRU capabilities.

[0066] The configuration of DMRS can include density and mode in the resource grid, duration, start symbol (e.g., preloaded DMRS), and coverage code to distinguish antenna ports sharing the same time / frequency resources (for single-user and multi-user MIMO cases). Depending on the physical channel and the WTRU capability, the parameter set of DMRS can be different (e.g., for PDSCH DMRS, there are configuration type 1 or type 2, mapping type A or type B, start symbol for mapping type A, single-symbol versus double-symbol DMRS, DMRS additional positioning, and duration). It is also possible to group DMRS across several resource blocks, where the precoder is constant, allowing the receiver to perform wideband channel estimation.

[0067] Specific DMRS options can be implemented through both higher-level configuration and dynamic (DCI-based) signaling, but there may also be cases where a default configuration exists. Figures 2A to 2D The illustration shows an example of DMRS mode on a symbol and a resource block of an NR using downlink antenna ports 1000-1003, where the NR has configuration type 1, mapping type A, and start symbol 3, and CDM packets span both the frequency and code domains. Once the DMRS setting is selected, the base station signals the selection to the terminal. The base station can signal the selection via RRC, MAC-CE, or PDCCH / DCI.

[0068] The terminal then utilizes DMRS for channel estimation and coherent demodulation of the corresponding physical channel. This is accomplished through a specific receiver filter implementation (e.g., least squares, minimum mean square error (MMSE), etc.) that broadly estimates the composite channel by mapping the transmitted layers to the receive antennas of the scheduled resource blocks.

[0069] Figure 3 This is a diagram illustrating the channel estimation and equalization process based on DMRS. Figure 3 As shown, at 302, the receiver can first determine their channel estimates based on the known positions of DMRS symbols in the received time slots, typically using an averaging window to minimize the effects of noise. At 304, the receiver can perform multidimensional interpolation and extrapolation operations, and then use the results to estimate missing values ​​associated with all other REs from the channel estimation grid. At 306, the receiver can perform noise power estimation to improve performance by comparing direct and average channel estimates. At 308, the terminal can utilize the channel and noise estimates to design an equalizer (e.g., MMSE), followed by coherent OFDM demodulation of the precoded / beamforming physical channel.

[0070] In conventional methods, channel estimation is required for equalization and demodulation of the data channel. The mobile terminal uses DMRS to estimate the effective (or pre-coded) channel response experienced by the receiver. This information is then used for equalization and demodulation. The performance of the equalization process, and ultimately, the channel / link performance, can be directly affected by the quality of the channel estimation. Achieving satisfactory channel estimation performance requires a large number of DMRS symbols, leading to high DMRS overhead and reduced spectral efficiency. RS overhead can be reduced by decreasing the number of DMRS symbols. However, system performance can be affected by poor channel estimation performance. Furthermore, for multi-layer transmission (SU- or MU-MIMO), the DMRS signals across various layers / users must be orthogonal. This further increases DMRS overhead, especially as the number of layers / co-scheduled users increases.

[0071] Furthermore, such methods are highly complex to implement because the channel estimator requires additional processing blocks, such as noise estimators, Doppler estimators, and interpolation and extrapolation of all REs in the assigned channel. Any loss of DMRS orthogonality results in poor channel estimation performance and ultimately degrades system performance.

[0072] The following description utilizes spatial diversity to enable DMRS-free equalization using CCA. The following description addresses at least the following issues: (1) how to achieve efficient multilayer and / or multi-user transmission under the proposed DMRS-free method (i.e., spatial CCA); (2) how to determine the spatial CCA parameters to optimize CCA performance; (3) how to enable dual-modulation transmission under the proposed framework; and (4) how to determine the appropriate PDSCH operating mode (e.g., with or without DMRS) and how to enable dynamic operation of different PDSCH modes.

[0073] The embodiments described below introduce a data channel structure that enables DMRS-free equalization and describe procedures for mobile terminals (e.g., WTRU, UE, STA, etc.) to determine and / or report one or more aspects associated with the transmission and reception of the DMRS-free data channel.

[0074] CCA can require two data views for proper operation. A CCA view can be defined as a group of data REs in a time-frequency grid with certain characteristics (e.g., forced structure) received by a multi-antenna signal. The number of REs in the two CCA views can be the same.

[0075] Time / frequency CCA can take data (e.g., symbols or samples) repeated in time and / or frequency, or both. Depending on the repetition type, WTRU can form two views in time or frequency. Most symbols (except phase RS) do not carry RS, but instead carry data. Each of the two light blue RE groups forms a CCA view, which will be used at the receiver to find the equalizer / combiner without channel estimation. The terms "time / frequency CCA" and "regular CCA" are used interchangeably.

[0076] Figure 4A The illustration shows an example of a DMRS-based PDSCH, where the DMRS configuration mode uses DMRS configuration type 1, mapping type A, and the DMRS length is 2.

[0077] Figure 4B An example of a conventional CCA PDSCH data structure is illustrated, where conventional CCA PDSCH data assumes the repetition of some data symbols in each RB, and said repetition may occur in time or frequency. Figure 4B The example illustration shows the repetition in time, where data symbols in OFDM symbols 2 and 3 are copied to OFDM symbols 10 and 11.

[0078] Due to spatial diversity, spatial CCA repetition can occur naturally. Assuming the receiver has at least two receive antennas, the WTRU can form two CCA views in the receive antenna domain by grouping two non-overlapping / disjoint subsets of the receive antenna ports to form two views.

[0079] Figure 4C An example of a spatial CCA PDSCH data structure is illustrated, in which a special region 402 (referred to as a spatial CCA region) is included. Symbols within region 402 may have certain properties (e.g., following a specific power allocation distribution of the layer being transmitted / multiplexed).

[0080] In a spatial CCA region, the time-frequency region can contain a RE corresponding to the CCA view formed by the WTRU. In the case of spatial CCA, the view is formed in the receive antenna domain. An example of a spatial CCA region is shown in... Figure 4C The area bounded by the red rectangle is shown in the diagram.

[0081] The dominant layer can be the layer with the highest allocated power and / or RE density in its assigned spatial CCA region (e.g., in the case of overlap).

[0082] PDSCH mode / format can refer to a PDSCH with a specific data structure. For example, a PDSCH mode can be DMRS, regular CCA, or spatial CCA. The terms PDSCH mode and format are used interchangeably.

[0083] PDSCH with spatial CCA transmission can refer to a PDSCH transmission mode that has a DMRS-free data structure and includes one or more spatial CCA zones in the transmission. For example, Figure 4C The data structure shown.

[0084] The potential benefits of the proposed PDSCH with spatial CCA transmission and processing may include, among other things, performance gains, reduced complexity, robustness to interference, power consumption, and recovery guarantees.

[0085] The benefits of the proposed PDSCH with spatial CCA transmission and processing can include performance gains. Compared to conventional methods (DMRS-based), spatial CCA can provide higher performance (e.g., throughput) gains.

[0086] The benefits of the proposed PDSCH with spatial CCA transmission and processing can include reduced complexity. Spatial CCA can reduce WTRU complexity because it only requires solving one or more SVD problems to obtain the desired signal(s) without channel or noise estimation.

[0087] The benefits of the proposed PDSCH with spatial CCA transmission and processing can include robustness to interference. Spatial CCA implicitly accounts for any unknown and / or intermittent interference. The CCA combiner / equalizer can project away any interference, as long as the interference across the two CCA views is different.

[0088] The benefits of the proposed PDSCH with spatial CCA transmission and processing can include power consumption and robustness to high noise. Spatial CCA can provide performance gains in the low SNR region and thus reduce power consumption at the transmitter side.

[0089] The benefits of the proposed PDSCH with spatial CCA transmission and processing can include recovery guarantees. Unlike legacy methods whose performance is affected by channel and noise estimation performance, spatial CCA can provide signal recovery guarantees without any channel knowledge.

[0090] Figure 5 The diagram illustrates an example of a PDSCH format with spatial CCA transmission. RE 502 represents normal PDSCH data RE. RE 504a and 504b represent CCA phase-corrected RS symbols. RE 506a to 506j represent PDSCH data symbols with certain characteristics / forced structures. Spatial CCA area 510 represents the spatial CCA area. Figure 5 As shown, the spatial CCA region 510 includes REs 504a and 504c and REs 506a to 506j. The overlap region 512 represents the overlap area between multiple MIMO layers within the spatial CCA region, wherein there is a predefined power variation between the MIMO layers transmitting in the overlap region. Figure 5 As shown, the overlapping region 512 includes RE506e, 506f, 506g, 506h, 506i and 506j.

[0091] The embodiments described herein apply to any physical channel with spatial CCA transmission. Unlike conventional physical channels that include DMRS for effective / precoded channel estimation, the data structure with spatial CCA transmission described below does not have DMRS. The WTRU is configured with parameters to enable a physical channel with spatial CCA transmission, wherein the parameters can be signaled or indicated to the WTRU via DCI format, RRC, or MAC CE. The configuration parameters may include one or more of the following: Configuration parameters may include a transmission mode / format. The transmission mode / format parameter can be used to distinguish between different transmission formats. The transmission mode / format parameter can indicate to the WTRU the transmission mode / format used for correct decoding (e.g., from the perspective of spatial CCA transmission or DMRS transmission). The transmission mode may include at least one of legacy (e.g., DMRS) and / or spatial CCA.

[0092] Configuration parameters may include one or more spatial CCA zone parameters. Spatial CCA zone parameters may include zone boundaries / geometry, which can indicate the boundary information of each spatial CCA zone.

[0093] Spatial CCA zone boundary information can be indicated by a direct indication of each spatial CCA zone boundary. This configuration can include a start RE index and an end RE index, where each index can be signaled using two indices: one for subcarrier indexing and another for OFDM symbol indexing. The configuration can also include the number of REs for spatial CCA transmissions within the spatial CCA zone; a frequency span / spatial CCA subband size indicating how many RBs each spatial CCA zone spans; a frequency density within the spatial CCA zone, which can indicate the RE density of the dominant layer in the spatial CCA zone (e.g., per N subcarriers, even-numbered subcarriers, odd-numbered subcarriers, etc.); a time span, which can indicate the time width of each spatial CCA zone; and / or a time density within the spatial CCA zone, which can indicate the temporal RE density (e.g., per OFDM symbol in the spatial CCA zone).

[0094] Spatial CCA zone boundary information can also be indicated through mappings between different layers(one or more) and formats(one or more). For example, a WTRU can be configured with a defined mapping between the number of layers and the associated number and location of CCA zones for each layer, where each configured layer has a predefined mapping to spatial CCA zones.

[0095] In one embodiment, the WTRU may be configured with one or more layers that transmit via a physical channel having spatial CCA transmission. In one example, the WTRU may be configured with layer-specific spatial CCA parameters, wherein the layer-specific configuration includes one or more spatial CCA regions characterized by region parameters (e.g., region boundaries / geometry) as described above. The WTRU may assume that the spatial CCA regions are non-overlapping, wherein the different sets of RE indices associated with different spatial CCA regions are disjoint.

[0096] The WTRU can be configured with one or more parameters associated with multi-layer transport in each spatial CCA area. In a spatial CCA area (e.g., Figure 5 Apart from any of the RE 502 in the space, all layers can be multiplexed and transmitted under normal operation, with equal power distribution possible across all configured layers. On the other hand, in any of the space CCA zones, multilayer transmission is performed differently to ensure proper CCA operation.

[0097] Configuration parameters may include dominant layer parameters. Each spatial CCA region can have one dominant layer. The dominant layer may have higher allocated power within its assigned spatial CCA region compared to one or more other transport layers (if any). The dominant layer may also have higher RE density within its assigned spatial CCA region. Dominant layer parameters may include the dominant layer index associated with each spatial CCA region.

[0098] Configuration parameters can include the multi-layer multiplexing mode in the spatial CCA area. This mode can indicate whether multiple layers are transmitted in the spatial CCA area or only the dominant layer is transmitted. If not indicated, WTRU can assume that the default mode is non-overlapping layers in the spatial CCA area (i.e., only the dominant layer is transmitted in its assigned spatial CCA area, and other layers are turned off).

[0099] In one embodiment, to improve transmission rate, the WTRU can be configured with multi-layer transmission within the spatial CCA area. Along with the dominant layer spanning the entire CCA area, the WTRU can be configured with one or more overlapping layers in some sub-areas of the spatial CCA area.

[0100] As mentioned above, Figure 5 The illustration shows an example PDSCH format with spatial CCA transmissions having overlapping layers within a spatial CCA region, wherein the dominant layer spans all REs 502a to 502i demarcated by lines 510a to 510c. An overlapping layer 512 spans REs 506e to 506j. The WTRU can be configured with one or more of the following parameters associated with the overlapping region: WTRU can be configured with default / initial settings. WTRU can be configured with one or more default / initial overlaps between the dominant layer and other transport layers.

[0101] WTRUs can be configured with region boundaries / geometry. Region boundary / geometry configurations can include start and end RE indices for the overlap layers, or they can be granular overlap configurations. For example, a set of possible overlap formats, where each format has its defined parameters (e.g., start RE, region size, and density).

[0102] WTRU can be configured with overlapping layer indexes.

[0103] The WTRU can be configured with phase symbol information that indicates the position of the phase symbol within the overlap region. In one embodiment, the phase symbol can be shared across all layers in the overlap region.

[0104] Unlike DMRS-based data structures, the proposed data structure described herein operates in a DMRS-free environment, but requires appropriate processing at the receiver side (e.g., using CCA). One embodiment may utilize spatial / receive diversity (i.e., reception of the same signal on multiple receive channels / antennas, coupled with CCA processing, for recovering the desired signal in the absence of channel or noise estimation).

[0105] Figure 6An exemplary PDSCH format with spatial CCA transmission is illustrated. Figure 6 As shown, REs 604a, 604b, and 606a to 606j represent the transmitted REs. The received signals (labeled as) corresponding to the transmitted data REs (i.e., REs 604a, 604b, and 606a to 606j) ) can be expressed as: in It is the multi-antenna signal received at the receiver. It is an effective / precoded channel, and Indicates noise items. Parameter N can define the CCA view length / density, for example, in... Figure 6 In this context, N = 12. Hereinafter, N may be referred to as the CCA view length or density. To enable CCA processing, two CCA views can be created by constructing two signal / data views from different / disjoint sets of receive antenna ports, where the two sets can have different numbers of non-overlapping receive antenna ports. For example, one signal may come from the first half of the receive antenna, and the second signal may come from the second half of the receive antenna. Therefore, the two CCA views can be expressed as: in It is the signal associated with the i-th (for i=1,2) CCA view, and This is the noise term associated with each set of the receiving antenna ports. The effective channels can be different across the two views because the two sets are disjoint. Solving the CCA problem defined above using the two constructed views shows that the desired signal x can be recovered to a complex scaling ambiguity that can be resolved using several phase symbols (including RE 606a and 606b). Furthermore, from (i.e., and The resulting CCA equalizer / combiner can be used to combine the received signals from the remaining portion of the received physical channel.

[0106] One or more embodiments are described herein for any physical channel with spatial CCA transmission. For example, a physical channel may include PDSCH, PUSCH, PUCCH, PDCCH, PBCH, PRACH, or any sidelink channel. For example, some embodiments may be described using PDSCH as an example implementation, but these embodiments are equivalently applicable to any other physical channel. For example, some embodiments may be described using a WTRU as a receiver for spatial CCA transmission, but these embodiments are equivalently applicable to the case where the WTRU is a transmitter for spatial CCA transmission.

[0107] The embodiments described herein can be applied to physical channels (e.g., PDSCH) with spatial CCA transmission. Unlike conventional physical channels (e.g., PDSCH) that include DMRS for effective / precoding channel estimation and noise estimation, the proposed physical channel (e.g., PDSCH) does not have DMRS, but adds some features (e.g., forced structure) to the set of data REs, which will be utilized at the receiver to enable DMRS-free decoding of the physical channel (e.g., PDSCH). The terms PDSCH with spatial CCA transmission and / or spatial CCA PDSCH are used interchangeably to denote the described PDSCH format.

[0108] The described spatial CCA PDSCH format can reduce RS overhead compared to existing PDSCH (i.e., DMRS-based) while achieving better decoding performance. The spatial CCA PDSCH format can provide a significant reduction in complexity because the forced structure will be used directly for decoding PDSCH without the need for channel estimation and noise estimation.

[0109] Legacy PDSCH (i.e., DMRS) requires orthogonal DMRS sequences for use across all WTRUs in the transmitted MIMO layer. Spatial CCA PDSCH can require fewer constraints to support multi-layer transmission. In particular, to support multi-layer transmission with minimal overhead, the spatial CCA PDSCH format simply requires that each spatial CCA region (i.e., by...)... Figure 9 Partial overlap and power distribution between configured MIMO layers in the regions demarcated by lines 910a, 910b, and 910c.

[0110] The embodiments described herein apply to any physical channel with spatial CCA transmission. Unlike conventional physical channels that include DMRS for effective / precoded channel estimation, the data structure with spatial CCA transmission described below does not have DMRS. The WTRU is configured with parameters to enable a physical channel with spatial CCA transmission, wherein the parameters can be signaled or indicated to the WTRU via DCI format, RRC, or MAC CE. The configuration parameters may include one or more of the following: Configuration parameters may include a transmission mode / format. The transmission mode / format parameter can be used to distinguish between different transmission formats. The transmission mode / format parameter can indicate to the WTRU the transmission mode / format used for correct decoding (e.g., from the perspective of spatial CCA transmission or DMRS transmission). The transmission mode may include at least one of legacy (e.g., DMRS) and / or spatial CCA.

[0111] Configuration parameters may include one or more spatial CCA zone parameters. Spatial CCA zone parameters may include zone boundaries / geometry, which can indicate the boundary information of each spatial CCA zone.

[0112] Spatial CCA zone boundary information can be indicated by a direct indication of each spatial CCA zone boundary. This configuration can include a start RE index and an end RE index, where each index can be signaled using two indices: one for subcarrier indexing and another for OFDM symbol indexing. The configuration can also include the number of REs for spatial CCA transmissions within the spatial CCA zone; a frequency span indicating the size of the spatial CCA subband, which indicates how many RBs each spatial CCA zone spans; a frequency density within the spatial CCA zone, which can indicate the RE density of the dominant layer in the spatial CCA zone (e.g., per N subcarriers, even subcarriers, odd subcarriers, etc.); a time span indicating the time width of each spatial CCA zone; and / or a time density within the spatial CCA zone, which can indicate the time-varying RE density (e.g., per OFDM symbol in the spatial CCA zone).

[0113] Spatial CCA zone boundary information can also be indicated through mappings between different layers(one or more) and formats(one or more). For example, a WTRU can be configured with a defined mapping between the number of layers and the associated number and location of CCA zones for each layer, where each configured layer has a predefined mapping to spatial CCA zones.

[0114] In one embodiment, the WTRU may be configured with one or more layers that transmit via a physical channel having spatial CCA transmission. In one example, the WTRU may be configured with layer-specific spatial CCA parameters, wherein the layer-specific configuration includes one or more spatial CCA regions characterized by region parameters (e.g., region boundaries / geometry) as described above. The WTRU may assume that the spatial CCA regions are non-overlapping, wherein the different sets of RE indices associated with different spatial CCA regions are disjoint.

[0115] It can be configured with one or more parameters WTRU associated with multi-layer transport in each spatial CCA area. In a spatial CCA area (e.g., Figure 5 Apart from any of the RE 502 in the space, all layers can be multiplexed and transmitted under normal operation, possibly with equal power distribution across all configured layers. On the other hand, in any of the space CCA zones, multilayer transmission is performed differently to ensure proper CCA operation.

[0116] Configuration parameters may include dominant layer parameters. Each spatial CCA region can have one dominant layer. The dominant layer may have higher allocated power within its assigned spatial CCA region compared to one or more other transport layers (if any). The dominant layer may also have higher RE density within its assigned spatial CCA region. Dominant layer parameters may include the dominant layer index associated with each spatial CCA region.

[0117] Configuration parameters can include the multi-layer multiplexing mode in the spatial CCA area. This mode can indicate whether multiple layers are transmitted in the spatial CCA area or only the dominant layer is transmitted. If not indicated, WTRU can assume that the default mode is non-overlapping layers in the spatial CCA area (i.e., only the dominant layer is transmitted in its assigned spatial CCA area, while other layers are turned off).

[0118] In one embodiment, to improve transmission rate, the WTRU can be configured with multi-layer transmission within the spatial CCA area. Along with the dominant layer spanning the entire CCA area, the WTRU can be configured with one or more overlapping layers in some sub-areas of the spatial CCA area.

[0119] As mentioned above, Figure 5 An example PDSCH format with spatial CCA transmission is illustrated, the spatial CCA transmission having an overlap layer in the spatial CCA region, wherein the dominant layer spans REs 502a to 502i demarcated by lines 510a to 510c. An overlap layer 512 spans REs 506e to 506j. The WTRU can be configured with one or more of the following parameters associated with the overlap region: WTRU can be configured with a default / initial overlap ratio. WTRU can be configured with one or more default / initial overlaps between the dominant layer and other transport layers.

[0120] WTRUs can be configured with region boundaries / geometry. This region boundary / geometry configuration can include start and end RE indices for the overlapping layers, or it can be a granular overlap configuration. For example, a set of possible overlap formats, where each format has its defined parameters (e.g., start RE, region size, and density).

[0121] WTRU can be configured with overlapping indexes.

[0122] The WTRU can be configured with phase symbol information that indicates the position of the phase symbol within the overlap region. In one embodiment, the phase symbol can be shared across all layers in the overlap region.

[0123] In one embodiment, the WTRU can be configured and instructed to process and / or decode a spatial CCA PDSCH (e.g., a field in a DCI indicating a new PDSCH format with spatial CCA transmissions). Upon receiving a configuration associated with one or more configured spatial CCA areas, the WTRU can process and / or decode the received PDSCH with spatial CCA transmissions as follows: First, the WTRU can construct two spatial CCA views (as described above) in each configured spatial CCA region, one view constructed from a first set of receive antenna elements and the second view constructed from a second set of receive antenna elements. The two sets of receive antenna elements can be non-intersecting / non-overlapping. Next, the WTRU can derive a first CCA-based equalizer / combiner associated with the dominant layer in its assigned spatial CCA region.

[0124] The WTRU can then apply a first spatial CCA equalizer to decode the RE associated with the dominant layer in the assigned spatial CCA region and the surrounding data RE associated with the first layer. In another embodiment, the WTRU can derive additional CCA-based equalizers / combiners for each additional overlapping layer(s) in the spatial CCA region to decode the RE associated with any of the overlapping layers(s) in the spatial CCA region. Alternatively, the additional equalizers(s) can be used to compute interference-related measurements associated with the overlapping layers.

[0125] In one embodiment, the WTRU can be configured to indicate a spatial CCA feedback parameter associated with the decoding performance of a PDSCH with spatial CCA transmission. In one example, the parameter may include a performance indicator of decoding quality. For example, the WTRU can be configured to indicate the CCA correlation energy associated with each dominant layer in its assigned spatial CCA region. In another embodiment, the WTRU can be configured to indicate CCA correlation only when the measured correlation is below a specific configured CCA correlation threshold. The WTRU can indicate the feedback parameter in a UCI field, using a configured set of PUSCH resources, or as part of a HARQ (ACK / NACK) report.

[0126] The principles described in this paper for PDSCH transmission based on spatial CCA can be applied to PUSCH transmission. The WTRU can be configured with one or more parameters for UL spatial CCA transmission in the PUSCH.

[0127] The parameters transmitted in the UL spatial CCA in PUSCH can include PUSCH format / mode, including spatial CCA and / or DMRS.

[0128] Parameters for UL spatial CCA transfers in PUSCH can include layer-specific spatial CCA region configurations. Layer-specific spatial CCA region configurations can be predefined (i.e., func (number of layers)). Layer-specific spatial CCA region configurations can be based on a mapping between (one or more) view formats and (one or more) layers. Layer-specific spatial CCA region configurations can be based on the geometry / boundaries of each layer configuration in a RE group (e.g., starting RE, region size, and density). Layer-specific spatial CCA region configurations can be based on a dominant layer index that indicates a MIMO layer index with higher power and RE density within the assigned spatial CCA region. Layer-specific spatial CCA region configurations can be based on temporal density (additional location in time in the case of multiple CCA regions per layer in time). Layer-specific spatial CCA region configurations can be based on frequency density (additional location in frequency (e.g., per N RBs)).

[0129] Parameters for UL space CCA transmission on PUSCH can include configured overlap between layers. For each dominant layer, the overlap configuration can be a predefined configuration (i.e., func(number of layers and percentage of overlap)). The overlap configuration can also be a granular overlap configuration with a possible set of predefined overlap formats, where each format can be described, for example, the starting RE, the size of the region, and / or the density.

[0130] The parameters of the UL spatial CCA transmission on the PUSCH may include the CCA phase correction reference symbol format (e.g., number, position, modulation order) within the spatial CCA region.

[0131] In one embodiment, the WTRU can be configured to transmit a spatial CCA on the PUSCH based on an instruction from the network. For example, the WTRU can be configured with a spatial CCA configuration in RRC signaling. Subsequently, the WTRU can be instructed to perform a spatial CCA transmission on the PUSCH based on implicit or explicit instructions in the DCI bearer of the UL authorization. For example, a specific DCI format can be defined for the UL authorization associated with the spatial CCA transmission. In another example, the WTRU can determine the association of the UL authorization with the spatial CCA transmission based on the presence / absence and / or values ​​of fields in the DCI. For example, those fields can be associated with or indicate a spatial CCA transmission.

[0132] In another example, upon receiving a DCI indicating the PUSCH format associated with a spatial CCA transmission, the WTRU can determine that the spatial CCA should be applied to the UL PUSCH. In one embodiment, the WTRU can be configured with a semi-persistent UL resource having a PUSCH format associated with the spatial CCA transmission. For example, as part of the SPS configuration, the WTRU can be configured with spatial CCA parameters.

[0133] When determining the association between UL authorization and spatial CCA transport, the WTRU can perform transport on the PUSCH associated with the spatial CCA transport. For each layer, the spatial CCA transport can include a symbol set comprising four RE groups. The first RE group can carry data associated with the first layer. The second RE group can carry data from both the first and second layers, where the power difference between the first and second layers is greater than a threshold. The third RE group can carry CCA phase correction reference symbols. The fourth RE group can carry data from both the first and second layers, where the power of the first layer can be equal to the power of the second layer.

[0134] For example, the first three RE groups can correspond to the "spatial CCA area" of each layer. For example, the number of REs in the second group can be less than or equal to the configured overlap, relative to the sum of the REs in the first and second groups. For example, spatial CCA regions of different layers can be non-overlapping. For example, fields in DCI can indicate a new PDSCH format with spatial CCA transmission.

[0135] WTRU can be configured with one or more parameters associated with spatial CCA transport.

[0136] The configuration associated with spatial CCA transmissions may include a PDSCH format / mode. The PDSCH format / mode may indicate, for example, a spatial CCA format and / or a DMRS format.

[0137] Configurations associated with spatial CCA transport can include layer-specific spatial CCA region configurations. Layer-specific spatial CCA region configurations can be predefined (i.e., func (number of layers)). Layer-specific spatial CCA region configurations can be configured using one or more view formats and mappings between layers. Layer-specific spatial CCA region configurations can be configured with geometry / boundaries, where each layer has its own configuration for RE groups within the CCA region, and region boundaries can be defined using, for example, the starting RE, region size, and / or density. Layer-specific spatial CCA region configurations can be configured with a dominant layer index, which indicates the MIMO layer index with higher power and RE density within the assigned spatial CCA region. Layer-specific spatial CCA region configurations can be configured with temporal density, which can be additional temporal location in the case of multiple CCA regions per layer. Layer-specific spatial CCA region configurations can be configured with frequency density, which can be additional frequency location (e.g., per N RBs).

[0138] The configuration associated with spatial CCA transport may also include configured overlap between layers. For each dominant layer, the overlap configuration can be predefined (i.e., func(number of layers and percentage of overlap)). The overlap configuration can also be a granular overlap configuration configured with a predefined set of possible overlap formats, where each format can be described, for example, the starting RE, the size of the region, and / or the density.

[0139] This configuration may also include the CCA phase correction reference symbol format (number, position, modulation order, etc.) within the spatial CCA area.

[0140] The WTRU can receive PDSCH associated with a spatial CCA transmission (e.g., in a new PDSCH format). For each layer, a spatial CCA transmission may include a symbol set comprising four RE groups: a first RE group carrying data associated with the first layer; a second RE group carrying data from both the first and second layers—where the transmission power difference between the first and second layers is greater than a threshold; a third RE group carrying CCA phase correction reference symbols; and a fourth RE group carrying data from both the first and second layers—where the transmission power of the first layer may be equal to that of the second layer.

[0141] For example, the first three RE groups can correspond to the "spatial CCA area" of each layer. For example, the number of REs in the second group can be less than or equal to the configured overlap, relative to the sum of the REs in the first and second groups. For example, spatial CCA regions of different layers can be non-overlapping. For example, fields in DCI can indicate a new PDSCH format with spatial CCA transmission.

[0142] The WTRU can construct two spatial CCA views in the receive antenna domain of each configured spatial CCA region (e.g., the first three RE groups), one view being constructed from a first set of receive antenna elements and the second view being constructed from a second set of receive antenna elements, wherein the two sets of receive antenna elements should be non-intersecting / non-overlapping and each of the two sets should contain at least one receive antenna element.

[0143] The WTRU can process CCA views for use in decoding the first, second, and fourth RE groups in spatial CCA transmissions, and use the third RE group for phase correction.

[0144] WTRU can indicate successful decoding associated with spatial CCA transmissions (e.g., CCA correlation coefficients associated with the first and second RE groups). This indication can be found in the HARQ feedback.

[0145] Figure 7 This is a flowchart illustrating an exemplary procedure 700 executed by the WTRU. At 702, the WTRU can receive a PDSCH associated with a CCA transmission, wherein the spatial CCA transmission includes groups of REs, including a first group, a second group, a third group, and a fourth group. The first RE group can carry data associated with the first layer. The second RE group can carry data from the first layer and the second layer, wherein the transmission power difference between the first layer and the second layer is greater than a threshold. The third RE group can carry CCA phase correction reference symbols. The fourth RE group can carry data from the first layer and data from the second layer, wherein the transmission power of the first layer is equal to the transmission power of the second layer. At 704, the WTRU can construct a first spatial CCA view and a second spatial CCA view in the receive antenna domain within the spatial CCA region. At 706, the WTRU can decode the first RE group, the second RE group, and the fourth RE group in the spatial CCA transmission.

[0146] In one embodiment, to further improve the transmission rate, the WTRU can be configured with multiple layers transmitting within a spatial CCA region. For example, along with a dominant layer spanning the entire spatial CCA region, the WTRU can be configured with one or more overlapping layers in some sub-regions of the spatial CCA region. For example, as described above, Figure 5 The diagram illustrates the overlapping layers in the spatial CCA region, where the dominant layer spans RE 506a to 506j, demarcated by lines 510a and 510c, while other overlapping layers span RE 506e to 506j, demarcated by rectangle 512. The degree of overlap between the dominant layer and other layers is a key parameter affecting the quality of the CCA equalizer.

[0147] WTRU can be configured with one or more of the following parameters associated with the overlapping area: WTRU can be configured with default / initial, minimum and / or maximum overlap. WTRU can be configured with initial overlap and the range of allowed overlap between layers (e.g., minimum and maximum values).

[0148] WTRUs can be configured with region boundaries / geometry. This can include start and end RE indices for the overlap layers, or it can be a granular overlap configuration, such as a set of possible overlap formats, where each format has its defined parameters (e.g., start RE, region size and / or density).

[0149] The WTRU can be configured with an overlap layer index. The WTRU can also be configured with phase symbol information, which indicates the position of the phase symbol within the overlap region. The phase symbol can be shared across all layers in the overlap region.

[0150] The WTRU can be configured with performance metric thresholds to help it determine one or more parameters associated with spatial CCA transport. For example, the WTRU can be configured with CCA-based performance metrics. These metrics could be, for instance, CCA-related thresholds (i.e., The range is between 0 and 1, where higher correlation implies better detection / decoding performance. WTRU can be configured to indicate the CCA correlation difference / gap between the dominant layer and the second interfering layer. In another example, WTRU can be configured based on a correlation CCA interference metric threshold (e.g., the ratio of dominant layer correlation to the sum of interfering layer correlations (DCIR)).

[0151] The WTRU can be configured to indicate one or more parameters associated with spatial CCA. The WTRU can be configured to report one or more spatial CCA parameters periodically, semi-persistently, non-periodically, or upon fulfillment of a trigger condition. For example, the trigger condition could be a percentage change in overlap. The trigger condition could be based on performance degradation relative to a pre-configured CCA performance threshold. In another embodiment, the WTRU can be configured to indicate interference measurements within the spatial CCA region. For example, the WTRU can be configured to indicate interference-related measurements based on the measured CCA correlation coefficients of the dominant layer and other overlap layers. The WTRU can indicate one or more CCA parameters via UCI, in PUSCH resource transfer, or in MAC CE.

[0152] WTRU can be configured to determine the parameters necessary for a specified resource grid on which spatial CCA-based transport / computation needs to be performed.

[0153] A CCA region can be located anywhere across the resource grid. A CCA region can be a set of REs that are closed and occupy all REs within the outline, or a set of REs that are expanded across the grid.

[0154] The location of regions can be based on similarity information about REs within a grid. If most REs observe similar channels, then a CCA region can be defined as a subset of these majority REs. For example, this can be implemented as an RE clustering framework where REs are clustered based on some performance criterion or loss function (e.g., the NMSE / SGCS value of estimated channels on the REs, e.g., using CSI-RS), and the subset of the largest clusters of REs can be selected as CCA regions. In another example, CCA regions can be selected by solving an optimization problem that aims to minimize the variance between some metrics on the REs (e.g., the magnitude of channel values ​​on the REs, the phase of the channels, etc.) to identify sets of similar REs. Furthermore, subsets of these similar and low-variance REs can define CCA regions.

[0155] In another embodiment, the CCA region can depend on channel-related derived values. For example, the location and extension of the CCA region can depend on a trade-off between Doppler (WTRU rate) and delay spread. For example, depending on the trade-off between these values, the CCA region extension can span rows or columns. For example, if the ratio of delay spread to Doppler is low, the CCA region extension can be column-spanning rather than row-spanning. Alternatively, when the ratio is high, the extension can be row-spanning rather than column-spanning.

[0156] In another embodiment, the trained ML model (e.g., a neural network) can take some derived metrics about the channel (e.g., Doppler, rank, delay spread, and / or any other extractable metrics that indicate information about the channel) as input, or it can take the raw channel (from current or past channel estimates) as input to identify the WTRU set to be used for CCA.

[0157] As a default configuration, without any explicitly defined procedure, the CCA zone can be positioned toward the geometric center of the resource grid to ensure the similarity variability of each RE with respect to the CCA-based equalizer.

[0158] In settings where channels change significantly across resource grids, multiple CCA zones can be further utilized to capture variability for efficient equalization.

[0159] For example, in a setup with high WTRU speeds (e.g., high Doppler)—where variability in the CSI across OFDM symbols is high—multiple CCA zones can be defined, where these zones are separated across different OFDM symbols. For instance, in a setup with two zones, the first zone could be in the left half of the grid, and the second zone could be in the right half. Therefore, the equalizer obtained from these zones can be applied only to the left and right halves, respectively, or interpolation can be utilized.

[0160] For example, in a setup with high latency spread—where CSI variability is high across frequency / subcarrier / subband / RB—multiple CCA zones can be defined, where these zones are separated across the subcarrier dimension. For instance, in a setup with two zones, the first zone could be from the upper half of the grid, and the second zone could be from the lower half. The equalizers obtained from these zones can be applied only to the upper and lower halves, respectively, or interpolation can be utilized.

[0161] In embodiments where the WTRU utilizes spatial CCA-based equalization / combination, the WTRU can be configured to determine the location and number of phase symbols required to resolve phase ambiguity in the CCA.

[0162] The RE set used as a phase symbol can be inside or outside the CCA region.

[0163] In one embodiment, the number of REs required for phase ambiguity can be modified by the WTRU based on the channel or any channel-related metric.

[0164] For example, a WTRU can utilize handcrafted or machine learning functions of channel parameters to predict and / or estimate the number of phase symbols, their location, and the modulation type associated with the phase symbols. Handcrafted / machine learning functions can, for example, utilize raw channel values ​​or derived metrics such as signal strength (RSRP, RSRQ, etc.), SNR level, and power levels associated with the entire channel or a specific layer. Alternatively, the function can utilize correlation coefficients associated with a given layer.

[0165] In another embodiment, the number of phase symbols can be inversely proportional to the SNR. Therefore, as the SNR decreases, the number of phase symbols will increase in a linear or non-linear manner (and vice versa).

[0166] In another example, WTRU can use optimization-based formulas to explicitly optimize for the number of phase symbols, their positions in the grid, and the corresponding modulation type.

[0167] In embodiments corresponding to multi-layer transmission, multiple non-overlapping CCA regions can be utilized. Therefore, the method described above for the single-layer case can be directly used to identify the CCA regions associated with each multi-layer case while ensuring that the non-overlapping constraint is met.

[0168] In one embodiment, to ensure a non-overlapping set, the above method can be performed in a prioritized manner, such that the WTRU prioritizes the layer corresponding to the highest power to determine the CCA region first. Then, the CCA region selected for the first layer can be removed from the mesh before selecting CCA regions for the remaining layers.

[0169] In one embodiment, the CCA region is identified based on either optimization or machine learning. Additional set partitioning constraints can be introduced into the formula to ensure that non-overlapping sets can be utilized in the optimization formula to guarantee non-overlapping regions.

[0170] In another embodiment, different phase symbols can be used to resolve the phase ambiguity for each layer. As an example, the symbol corresponding to the layer with the highest power can be transmitted with the highest power, and the same applies to the other layers.

[0171] In one embodiment, a common phase symbol can be utilized across all layers.

[0172] In one embodiment, where WTRU transfers are configured to occur across multiple layers, the WTRU can be configured to utilize overlapping sets of REs for spatial CCA computations across multiple layers. To enable the WTRU to use overlapping sets of REs for spatial CCA computations across multiple layers, the WTRU can be configured with one or more procedures for selecting associated parameters. The WTRU can be configured to identify segments within the CCA region suitable for overlapping across different layers, and more specifically, to identify the number and location of REs within the CCA region used for overlapping across multiple layers.

[0173] For example, the degree of overlap can depend on the power difference between layers as measured by WTRU. If the power difference is large, large segments of the CCA region can be reused across said layers.

[0174] In another example, given a specific performance criterion based on throughput or bit error rate, the overlap can be adjusted to ensure that the performance criterion is met across each of the layers, or for a specific layer or for the dominant layer. Such calculations can utilize pre-computed metrics or lookup tables that associate performance criteria with overlap.

[0175] In another example, the power associated with symbols transmitting within a CCA region can be adjusted across different layers. Thus, some symbols in the dominant layer (from overlapping CCA regions) can utilize higher power transmission, while for other layers, symbols from the same overlap region can utilize lower power transmission. Specific power levels for each layer can be estimated based on pre-computed metrics or a lookup table that associates performance criteria with power differences.

[0176] The degree of overlap can depend on the number of symbols required for CCA computation. For example, if a large number of symbols / REs are required to perform spatial CCA computations for each layer, the number of overlapping elements can increase.

[0177] In another embodiment, a function can be constructed (as a machine learning-based embodiment, which can be trained using a variation of the gradient based on a non-gradient-based learning strategy, or can be hand-designed based on observations) that takes the following as inputs: the required performance metric (e.g., BER, throughput, etc.), the power associated with each layer, the correlation coefficient of each layer, and / or any other input, and outputs the required degree of overlap and the optimal position of the RE suitable for overlapping transmission.

[0178] In one embodiment, the WTRU can be configured to determine one or more interference-related parameters associated with the reception of a spatial CCA PDSCH. The CCA correlation coefficient is a parameter that can be used to infer the interference intensity on the dominant layer within the assigned spatial CCA region from an overlapping (e.g., partially overlapping) layer. The CCA correlation coefficient associated with the dominant layer can be defined as...

[0179] in and It is the CCA equalizer / combiner required to recover the signal associated with the dominant layer in the assigned spatial CCA region from the two receiving antennas, and This is the correlation coefficient ranging from 0 to 1. A higher correlation may imply better recovery of the dominant layer signal in the spatial CCA region. For each additional layer that overlaps with the dominant layer (e.g., partially overlaps), the additional correlation coefficient can be calculated as:

[0180] in, and It is the CCA combiner / equalizer associated with the i-th overlap layer, and That is the corresponding correlation coefficient, for and To ensure acceptable detection / recovery performance of the dominant layer in its assigned spatial CCA region, the dominant layer CCA correlation coefficient is... It may need to be sufficiently larger than the correlation associated with the overlapping layer. ,for WTRU can determine and / or report one or more interference-related parameters based on the measured CCA correlation coefficients of the dominant layer and overlapping / interfering layers.

[0181] In one embodiment, the WTRU may be configured or instructed to determine and / or report one of the following interference metrics: WTRU can be configured or indicated to determine and / or report the number of strong interferences in each spatial CCA region (N_I). For i>1, if the associated correlation coefficient... If a specific configured threshold is exceeded, WTRU can count the i-th overlap layer as strong. In another example, if the correlation difference... or related ratio If the value is below a certain configured threshold, the WTRU can count the i-th overlapping layer as strong. The WTRU can be configured to indicate... Does it exceed a specific configured threshold, where the threshold can represent the number of configured overlapping layers within a spatial CCA region?

[0182] The WTRU can be configured or instructed to determine and / or report interference metrics based on CCA relevance. Interference metrics may include one or more of the following: Interference metrics may include the dominant layer correlation relative to the sum-of-interference-layers ratio (DCIR), where DCIR can be defined as: in And I is the number of interfering / overlapping layers in the spatial CCA region. The WTRU can be configured to measure and indicate the DCIR if the measured value exceeds a certain threshold. For example, the WTRU can be configured or indicated to measure the DCIR associated with a specific configured number of interferences (I). For example, the WTRU can be indicated to measure interference based on the strongest interfering layer (i.e., I = 2).

[0183] Interference metrics can include correlation difference (CD), which represents the CCA correlation difference between the dominant layer and each interfering layer, where CD can be defined as:

[0184] The WTRU can be configured to determine and / or report the correlation difference between the dominant layer correlation coefficient and the i-th interfering layer. In one embodiment, the WTRU can be configured to report the correlation difference if it exceeds a specific configured threshold.

[0185] In another embodiment, the WTRU can be configured to perform and / or report power measurements associated with the dominant layer and overlapping layer in each spatial CCA region. In one example, the WTRU can report the ratio between the received power of the dominant layer and the sum of the power of the overlapping layers in each spatial CCA region. In another example, the WTRU can be configured to report a power difference or ratio if the measured value is below a configured threshold.

[0186] The WTRU can be configured to indicate one or more parameters associated with interference measurements in one or more configured spatial CCA zones. The WTRU can indicate interference feedback parameters when a trigger condition is met (e.g., DCIR exceeds a configured threshold). Alternatively, the WTRU can indicate one or more interference parameters based on time events (e.g., periodic or semi-persistent). If configured to indicate one of the parameters, the WTRU can indicate the interference parameter in a UCI field or using a configured set of PUSCH values ​​from the resources.

[0187] The WTRU can be configured to receive spatial CCA transmissions based on configured spatial CCA parameters.

[0188] In one embodiment, the WTRU can be configured to determine preferred spatial CCA parameters based on pre-configured criteria. In one embodiment, different criteria can be configured to determine preferred values ​​for different CCA parameters. These criteria may include measurements of received spatial CCA transmissions and / or spatial CCA configurations. In one embodiment, the WTRU can be configured with trigger conditions to report preferred CCA parameters. The WTRU can report one or more preferred spatial CCA parameters based on pre-configured trigger conditions. In one embodiment, different reporting trigger conditions can be configured for different CCA parameters. The WTRU can trigger spatial CCA parameter reporting when the difference between the configured spatial CCA parameter and the preferred spatial CCA parameter exceeds a pre-configured threshold. Different thresholds can be configured for different parameters. The threshold can be a function of the spatial CCA parameter type.

[0189] The WTRU can receive spatial CCA transmissions according to a spatial CCA configuration. In one embodiment, the spatial CCA configuration may include a spatial CCA region configuration. The spatial CCA region configuration may include an initial RE, the region size, the temporal density of the RE—the number of symbols within the spatial CCA region, the frequency density of the RE—the number of subcarriers per RB, etc. The WTRU can be configured to determine preferred spatial CCA region parameters—based on pre-configured conditions. For example, the WTRU can determine a preferred spatial CCA region configuration such that the smallest spatial CCA region results in the lowest correlation between layers within the spatial CCA region. For example, the WTRU can determine a preferred spatial CCA region configuration such that the smallest spatial CCA region results in a target bit error rate (BER). The WTRU can be configured to report the preferred spatial CCA configuration if the change in BER and / or correlation exceeds a pre-configured threshold compared to the currently configured spatial CCA configuration. The WTRU can be configured to report the preferred spatial CCA configuration if the change in the spatial CCA region size exceeds a pre-configured threshold. In one embodiment, the WTRU can be configured with n spatial CCA regions, where each spatial CCA region is associated with a specific layer. WTRU can be configured to report the preferred spatial region configuration for each layer.

[0190] In one embodiment, the trigger for reporting spatial CCA parameters can be a function of the overlap between layers in the spatial CCA region. For example, the overlap can be associated with the size of a second RE group within the spatial CCA region. For example, in transmission, a pre-configured RE group (the second RE group herein) within the spatial CCA region can carry data from both the first and second layers, where the transmission power difference between the first and second layers is greater than a pre-configured threshold. The size of this RE group can correspond to the amount of overlap between the first and second layers. The WTRU can be configured with overlap parameters (configured overlap) for spatial CCA transmission. In one embodiment, the WTRU can be configured to determine overlap parameters (preferred overlap) that satisfy criteria. For example, the WTRU can determine preferred overlap parameters that maximize the size of the second RE group. For example, the WTRU can determine preferred overlap parameters that maximize the size of the second RE group and maximize throughput / SNR. For example, the WTRU can determine preferred overlap parameters that maximize the size of the second RE group and minimize inter-layer interference and / or BER.

[0191] In one embodiment, the WTRU can be configured to report the size of the overlap in terms of the number of REs, the starting RE, the time span in terms of OFDM symbols, and / or the frequency space in terms of the number of subcarriers per RB.

[0192] In one embodiment, the WTRU may be pre-configured with overlap patterns / configuration sets. Each pre-configured overlap pattern may be associated with a logical ID. The WTRU may be configured to determine an overlap pattern that maximizes throughput / SNR / SINR and / or minimizes inter-layer interference and / or BER / BLER. When the preferred overlap pattern differs from the configured overlap pattern, the WTRU may trigger a report including spatial CCA parameters. In one embodiment, the WTRU may report an index of the preferred overlap pattern as part of the spatial CCA parameters.

[0193] In one embodiment, the WTRU can be configured to report the overlap ratio in terms of the number of REs from the first layer to the second layer within the overlap area. In one embodiment, the ratio can be expressed as a percentage. The WTRU can report the overlap ratio or percentage when the ratio or overlap changes to a pre-configured threshold.

[0194] In one or more embodiments, the WTRU may be pre-configured with minimum and maximum overlap parameters. By default, the minimum overlap parameter can be zero. The WTRU may be configured to report overlap parameters within this pre-configured range.

[0195] In one embodiment, the WTRU can be configured to determine the difference between the currently configured overlap and the preferred overlap (referred to herein as "incremental overlap"). The WTRU can be configured to determine the magnitude and label of the incremental overlap. For example, if the preferred overlap is greater than the configured overlap, the WTRU can determine a positive incremental overlap. For example, if the preferred overlap is less than the configured overlap, the WTRU can determine a negative incremental overlap.

[0196] The WTRU can be configured with one or more spatial CCA regions. Within each spatial CCA region, the WTRU can be configured with a dominant layer and n non-dominant layers. In one embodiment, the WTRU can be configured to measure the received power difference between the n layers in the spatial CCA region. In another embodiment, the WTRU can be configured to measure the difference between the received power in the dominant layer and the sum of the received power in the remaining non-dominant layers in the spatial CCA region. The WTRU can be configured to measure the power difference between the dominant and non-dominant layers for each configured spatial CCA region. In one embodiment, the WTRU can be configured to trigger a spatial CCA parameter reporting when the received power difference between the dominant and non-dominant layers exceeds a pre-configured threshold. In one embodiment, the WTRU can be configured to determine the power difference between layers based on BER and / or throughput. For example, for a given overlap configuration, the WTRU can determine the preferred power difference that results in the lowest BER / highest throughput.

[0197] In one embodiment, the WTRU can be configured to report the number of strong interference sources in each CCA area. In another embodiment, the WTRU can be configured to report the layer with the largest number of interference sources. In yet another embodiment, the WTRU can be configured to report the top n layers with the highest number of interference sources. The WTRU can trigger such a report when the number of strong interference sources exceeds a threshold. In another embodiment, the WTRU can be configured to report the DCIR for each CCA area. The WTRU can be configured to report the DCIR when it exceeds a threshold. The WTRU can trigger the report when the layer with the largest DCIR and / or the largest number of interference sources differs from a previous report.

[0198] In one embodiment, the WTRU can be used as a function of measured interference within the spatial CCA region to determine one or more preferred spatial CCA configurations. In one embodiment, the WTRU can be configured as a function of the number of interfering layers in the spatial CCA region to determine one or more of the preferred spatial CCA region size, overlap ratio, and power difference. In another embodiment, the WTRU can be configured as a function of the DCIR and / or correlation difference between the dominant and interfering layers in the spatial CCA region to determine one or more of the preferred spatial CCA region size, overlap ratio, and power difference. In yet another embodiment, the WTRU can be configured to determine one or more preferred spatial CCA parameters, wherein these parameters may include one or more of the following: region size, overlap ratio between transmitted MIMO layers within the spatial CCA region, and / or power difference between transmitted MIMO layers within the spatial CCA region, wherein the power difference is determined to maximize throughput / SNR / SINR and / or minimize inter-layer interference and / or BER and / or BLER.

[0199] In one embodiment, the WTRU can be configured to trigger the reporting of preferred CCA parameters based on one or more measurements associated with spatial CCA region conditions or changes. For example, this could include changes in channel rank, SNR, SINR, RSRP, RSRQ, Doppler spread, delay spread, and / or BLER.

[0200] In one embodiment, the WTRU can be configured to trigger the reporting of preferred CCA parameters based on one or more measurements associated with channel conditions or changes thereof. For example, this could include changes in channel rank, SNR, SINR, RSRP, RSRQ, Doppler spread, delay spread, and / or BLER.

[0201] In one embodiment, the WTRU can be configured to periodically report preferred space CCA parameters. For example, the WTRU can be configured with periodic / semi-permanent UL resources to report space CCA parameters. The WTRU can be configured with PUCCH resources for reporting. In one embodiment, the WTRU can be configured to report preferred space CCA parameters as part of a CSI feedback report. For example, the WTRU can include CSI feedback in a first part of the CSI report and preferred space CCA parameters in a second part of the CSI report.

[0202] In one embodiment, the WTRU can be configured to report preferred spatial CCA parameters based on one or more conditions. For example, the WTRU can be pre-configured with a set of spatial CCA parameters indexed using logical IDs. The WTRU can report preferred spatial CCA parameters by selecting and / or indicating one of the pre-configured spatial CCA parameters from the pre-configured set. In one embodiment, the WTRU can transmit a MAC CE carrying an index to one of the pre-configured sets of spatial CCA parameters. In another embodiment, the WTRU can transmit predefined code points in the PUCCH, wherein the code points are mapped to one of the pre-configured sets of spatial CCA parameters.

[0203] In one embodiment, the WTRU can be configured to report preferred spatial CCA parameters in response to an explicit request from the network. For example, the WTRU can be configured with a CSI report format associated with the spatial CCA parameters. For example, the WTRU can receive aperiodic CSI report triggers from the NW. For example, in response, the WTRU can transmit preferred spatial CCA parameters. In one embodiment, the aperiodic request trigger can indicate which spatial CCA parameters can be indicated in the report.

[0204] In one embodiment, the WTRU can be configured to implicitly or explicitly report preferred spatial CCA parameters as part of the HARQ feedback. In one embodiment, the WTRU can be configured with a Spatial CCA-Aware HARQ Codebook (SAHC). For example, the SAHC can include one or more HARQ feedback code points, where each code point can indicate two types of information. A first type of information can indicate whether transport block decoding was successful, and a second type of information can indicate the preferred spatial CCA configuration. For example, the WTRU can have an SAHC codebook that may have the following code points: ACK, NACK + spatial CCA parameter 1, and / or NACK + spatial CCA parameter 2.

[0205] When decoding of a transport block is successful, the WTRU can transmit an ACK. When decoding of a transport block fails, the WTRU can determine code points based on preferred spatial CCA parameters. For example, when spatial CCA parameter 1 is preferred, the WTRU can transmit code points associated with NACK + spatial CCA parameter 1. For example, when spatial CCA parameter 2 is preferred, the WTRU can transmit code points associated with NACK + spatial CCA parameter 2. In one embodiment, spatial CCA parameter 1 may correspond to positive incremental overlap, and spatial CCA parameter 2 may correspond to negative incremental overlap. This embodiment can be extended to support feedback from different combinations of spatial CCA parameters and HARQ codebooks.

[0206] In one embodiment, for example during RRC reconfiguration, RRC establishment, and / or RRC recovery, the WTRU may receive configuration of spatial CCA parameters via RRC signaling. In another embodiment, the WTRU may be pre-configured with multiple sets of spatial CCA parameters, each associated with a logical ID. In one embodiment, the WTRU may receive a MAC CE indicating which specific spatial CCA parameter should be activated or deactivated. In one embodiment, the WTRU may receive a DCI with DL permission, wherein the DCI may indicate spatial CCA parameters associated with PDSCH transmissions.

[0207] In one embodiment, multiple PDSCH formats can be defined, each of which can be associated with a specific spatial CCA parameterization. The WTRU can receive DCI indications for new PDSCH formats, where the PDSCH format can implicitly indicate the spatial CCA parameterization.

[0208] In one embodiment, the WTRU can be pre-configured with default spatial CCA parameters. Subsequently, MAC CE-based signaling or DCI-based signaling can instruct incremental configuration to the default spatial CCA parameters.

[0209] According to the above embodiments, when a spatial CCA-based PDSCH transmission is received, the WTRU can determine the associated spatial CCA parameterization and process the received PDSCH, which receives the spatial CCA parameter configuration and the corresponding PDSCH transmission. For example, the WTRU can construct two spatial CCA views in each configured spatial CCA region, one view constructed from a first set of receiving antenna elements and the second view constructed from a second set of receiving antenna elements, wherein the two sets of receiving antenna elements may be non-intersecting / non-overlapping. Second, the WTRU can derive a first CCA-based equalizer / combiner associated with the dominant layer in its assigned spatial CCA region. The WTRU can then apply the first spatial CCA equalizer to decode the RE associated with the dominant layer in the assigned spatial CCA region and the surrounding data RE associated with the first layer. In another embodiment, the WTRU can derive additional CCA-based equalizers / combiners for each (one or more) additional overlapping layers in the spatial CCA region to decode the RE associated with (one or more) overlapping layers in any of the spatial CCA regions. Additional equalizers can be used to calculate interference-related measurements associated with the overlapping layer.

[0210] In one embodiment, there may be ambiguity regarding the preferred spatial CCA parameter indication from the WTRU. For example, when the spatial CCA parameter is signaled as incremental overlap, the reference spatial CCA parameter may be associated with a previous PDSCH transmission. However, if a transmission error occurs (e.g., the WTRU fails to detect the DCI associated with the PDSCH transmission), there may be a mismatch with the reference spatial CCA parameter. In one embodiment, the WTRU may be configured to transmit incremental feedback associated with a pre-configured reference transmission. For example, the reference transmission may be a hypothetical transmission with pre-configured parameters. In another example, the reference transmission may be explicitly signaled by the NW. For example, the reference transmission may be associated with a transmission for which it has received a successful ACK from the WTRU.

[0211] To illustrate the effect of spatial CCA parameters (e.g., overlap percentage and power difference), in Figure 8 The BER performance was evaluated and illustrated. Figure 8 The diagram illustrates the effects of overlap and power difference on space CCA performance. Figure 8 The diagram illustrates a downlink scenario with a single transmitter-receiver pair. Figure 8The following simulation parameters were used: the number of receive antennas was set to 4, the modulation scheme was BPSK, the SNR was set to 10 dB, and the number of CCA phase symbols was set to 2. The number of symbols in the spatial CCA region was set to 100. The overlap between the first / dominant layer and the second layer varied between 0% and 100% on the x-axis. Furthermore, BER performance was evaluated for different power differences in the overlap region between the first and second layers.

[0212] like Figure 8 As shown, for a fixed power difference, increasing the overlap between the dominant layer / first and second layers in the spatial CCA region degrades the detection performance of the first layer for that fixed power difference, highlighting the need for careful selection of the overlap percentage. For a fixed overlap percentage, BER performance is improved by increasing the power difference between the two layers in the overlap region. Appropriate power control between the two layers in the overlap region can improve system performance under spatial CCA transmission.

[0213] In one embodiment, the WTRU can be configured with one or more CCA configurations. Each CCA configuration can include a layer-specific spatial CCA region configuration. The layer-specific spatial CCA region can be predefined (e.g., func (number of layers)). The layer-specific spatial CCA region can be configured using one or more view formats and mappings between layers. The layer-specific spatial CCA region configuration can be configured with geometry / boundaries, where each layer has its own configuration for the RE group within the CCA region, and the region boundary can be defined using, for example, the starting RE, the size of the region, and / or the density.

[0214] Each CCA configuration can include the default / initial, minimum and / or maximum overlap percentage between layers. For each dominant layer, the overlap configuration can be predefined (e.g., func(number of layers and percentage of overlap)). For each dominant layer, the overlap configuration can be configured using granular overlap configuration, including a set of possible overlap formats for each format (e.g., starting RE, region size, and density).

[0215] Each CCA configuration may include performance metric thresholds (e.g., CCA correlation difference / gap threshold). Each CCA configuration may include CCA phase symbol format (e.g., number, location, modulation order, etc.). Each CCA configuration may include spatial CCA feedback configuration, including triggers and UL resources.

[0216] The WTRU can receive the PDSCH associated with the spatial CCA configuration (e.g., a field in the DCI indicating a new PDSCH format with spatial CCA transmission). For each layer, the spatial CCA transmission may include a symbol set comprising four RE groups: (1) a first RE group carrying data associated with the first layer; (2) a second RE group carrying data from both the first and second layers—where the transmission power difference between the first and second layers is greater than a threshold, and the number of REs in the second group is less than or equal to the configured overlap percentage relative to the sum of the REs in the first and second groups. (3) A third RE group carrying CCA phase correction reference symbols; and / or (4) a fourth RE group carrying data from both the first and second layers, wherein the transmission power of the first layer may be equal to the transmission power of the second layer.

[0217] For example, the first three RE groups can correspond to the spatial CCA area of ​​each layer. For example, the number of REs in the second group, relative to the sum of the REs in the first and second groups, can be less than or equal to the configured overlap percentage. For example, spatial CCA regions of different layers can be non-overlapping. For example, fields in DCI can indicate a new PDSCH format with spatial CCA transmission.

[0218] The WTRU can determine one or more spatial CCA feedback parameters based on pre-configured conditions that are at least partially associated with correlation and / or power differences between the layers. For example, the WTRU can determine parameters based on one or more of the following conditions: size, time / frequency span, permissible overlap per layer, or incremental overlap. (1) The measured CCA correlation associated with the target layer within the spatial CCA region (e.g., based on the correlation difference between different layers transmitting within the same region), wherein the WTRU may increment / decrement the overlap based on a configured correlation threshold; (2) The received power difference between the dominant layer and the second strongest layer or the sum of the remaining transmission layers; and / or (3) The measured SNR and channel quality metrics (e.g., L1-RSRP, RSRQ) for each layer in the spatial CCA region.

[0219] In one example, WTRU can determine the number of strong interference sources in one or more dominant layers in one or more spatial CCA regions based on a configured correlation threshold (e.g., based on the measured CCA correlation gap between the first component and each of the other components, such as counting a component as a strong interference source if the associated measured gap exceeds the configured threshold).

[0220] In one example, if a trigger condition is met for the CCA parameters of the reporting space, the WTRU can transmit feedback on a pre-configured / assigned UL resource. The trigger condition can be periodic and / or non-periodic, for example, including whether one or more of the following parameters change a pre-configured threshold. The trigger condition can be a relevant threshold.

[0221] Feedback on pre-configured / assigned UL resources may include overlap information. Overlap information may include incremental overlap (i.e., the number of REs in the second RE group relative to the sum of the number of REs in the first and second groups). (Ratio). For example, a negative increment can provide an indication to reduce overlap between layers (e.g., reduce the number of REs in the second group). Within configured minimum and maximum values, a positive increment can provide an indication to increase overlap between layers. Another example could be feeding the index back to one of a pre-configured overlap configuration, one or more overlap boundary regions (e.g., the starting RE).

[0222] Feedback regarding pre-configured / assigned UL resources may include the difference in received power between the dominant layer and the second non-dominant layer or the sum of the remaining non-dominant layers in one or more spatial CCA zones.

[0223] Feedback on pre-configured / assigned UL resources may include spatial CCA zone parameters (e.g., size, time / frequency span).

[0224] Feedback regarding pre-configured / assigned UL resources may include interference measurements. For example, interference measurements could indicate significant interference in each dominant layer within its assigned spatial CCA area. Interference measurements may include interference metrics, which could be based on a correlation (e.g., a dominant layer correlation relative to the sum-of-interference-layers ratio (DCIR)). DCIR can be used with spatial CCAs to assist gNB in ​​MU scheduling.

[0225] The WTRU can receive configuration information for new spatial CCA parameters, where, for example, the configuration may include one or more of the parameters mentioned above (e.g., overlap, number of overlap layers). The WTRU can receive PDSCHs with updated CCA configurations (e.g., an indication that a DCI bearer with DL authorization has a PDSCH with a new CCA format). The WTRU can process the received PDSCHs using the updated spatial CCA configuration.

[0226] The WTRU can be configured with one or more layers via PDSCH transmission with spatial CCA transmission, wherein the configuration includes one or more parameters associated with the spatial CCA region (e.g., the spatial CCA region boundary), as defined above. Because the REs associated with the dominant layer in its assigned spatial CCA region have special characteristics (e.g., higher density, minimal channel variation, and lower interference), further increasing the transmission rate within the spatial CCA region and surrounding REs can be beneficial. In one embodiment, the WTRU can be configured with a dual-modulation transmission mode, wherein this mode enables different transmission rates (e.g., different modulation orders) within the same transmission that may be in different regions of the time-frequency resource grid. In the embodiments described herein, the dual-modulation transmission mode is not limited to changes in the modulation scheme but can also include changes in the modulation scheme and / or target code rate and / or transport block size.

[0227] Figure 9 The diagram illustrates an example dual-modulation transmission mode for PDSCH based on spatial CCA. RE 902 represents the normal PDSCH data RE. RE 904a and 904b represent CCA phase-corrected RS symbols. RE 906a to 906j represent PDSCH data symbols with some characteristics / forced structures. Spatial CCA area 810 represents the spatial CCA area. Figure 9 As shown, the spatial CCA region 910 includes REs 904a and 904c and REs 906a to 906j. Boundary 912 represents the interval between REs transmitted at a first transmission rate and REs transmitted at a second transmission rate.

[0228] The dual-modulation transmission mode configuration can include dual-modulation transmission mode parameters. One bit can indicate whether the mode is enabled. If not configured, the WTRU can assume that the entire transmission comprises a fixed transmission rate across the entire time-frequency grid (i.e., a single modulation mode).

[0229] The dual-modulation transmission mode configuration may include dual-modulation boundary information parameters. The dual-modulation boundary distinguishes between a first RE group transmitted at a first transmission rate and a second RE group transmitted at a second transmission rate. The first RE group may be referred to as the first zone, and the second RE group may be referred to as the second zone. Figure 9 In this context, the first RE group includes all REs within boundary 912, and the second RE group includes all REs outside boundary 912.

[0230] Boundary information may include parameters. For example, boundary information may include a spatial CCA area boundary flag, where a bit in the scheduling DCI indicates that the dual modulation boundary is different from the spatial CCA area boundary. If not configured, the WTRU may assume that the spatial CCA area and the dual modulation boundary are aligned. Boundary information may include boundary geometry, which may indicate the geometry of the boundary (e.g., start RE, end RE, predefined format for signaling / configuration via index).

[0231] Dual modulation transmission mode configuration may include a dual modulation granularity parameter indicating the level at which the dual modulation mode is used. In one embodiment, the dual modulation mode can be activated or deactivated across all layers transmitted to a particular WTRU. In one embodiment, the dual modulation mode can be used for each layer across the entire time-frequency grid (i.e., the dual modulation mode is used for the first layer, while a single modulation mode is used for other layers). In one embodiment, the dual modulation mode can be applied at the sub-band level, where the same layer can use either dual or single modulation modes in different zones of the time-frequency grid.

[0232] The dual-modulation transmission mode configuration may include a performance threshold parameter, which indicates one or more performance conditions that can be used to assist the WTRU in determining boundary information. In one example, the performance threshold may be the CCA correlation coefficient associated with detection in the first zone (e.g., reducing the zone size if the measured correlation is below the threshold). In another example, the performance threshold may indicate the permissible amount of channel variation within the first zone (e.g., based on CSI-RS).

[0233] In another embodiment, the WTRU may be configured with another CSI quantity that defines the data transmission rate used in the first RE group (i.e., the first zone). The CSI quantity associated with the first zone may be referred to as a Precoded Channel Quality Indicator (PCQI) or an Effective Channel Quality Indicator (eCQI), and may be defined as a portion of a PDSCH transport block—having a combination of modulation scheme, target code rate, and transport block size corresponding to the PCQI index, and occupying a group of downlink physical resource blocks associated with spatial CCA transmissions—that may be received with a transport block error probability not exceeding 0.1. The PCQI may be derived based on the quality of the precoded / effective channel, while the CQI may be based on a CSI-RS-based channel. In one embodiment, the PCQI may be used in conjunction with a legacy CQI, where the PCQI indicates the transmission rate in the first zone, while the CQI is used in the second zone. In one embodiment, the PCQI may be used to indicate the transmission rates in both zones.

[0234] The WTRU can be configured to indicate feedback associated with a dual-modulation transmission mode. For example, the WTRU can be configured to indicate PCQI associated with one or more zones. In one embodiment, the WTRU can be configured to indicate both CQI and PCQI associated with said two zones.

[0235] WTRU can use dual modulation modes to receive transmissions (e.g., PDSCH) or perform transmissions (e.g., PUSCH). In dual modulation modes, a single transmission can consist of zones, each zone having one or more zone-specific modulation orders, or code rates, or transport block sizes, or code block group sizes, or code block sizes, or transmission power. A zone can be defined or parameterized by at least one of the following: RE set; subcarrier set; symbol set; RB set; transport layer; Rx or Tx beam; and / or TCI state.

[0236] Dual modulation mode transmission can be configured with a set of parameters.

[0237] The dual modulation mode transmission parameter set may include a number of regions. For example, the transmission may include one or more of the following: a first region that overlaps with and includes the CCA symbol set (e.g., overlaps with and includes all CCA symbols); a second region that does not overlap with and does not include the CCA symbol set (e.g., does not overlap with and does not include any CCA symbols); or a third region that overlaps with and includes the phase symbols (e.g., overlaps with and includes only the phase symbols). Herein, CCA symbols may be used to indicate symbols carried by the RE of any of the spatial CCA regions. The regions of the dual modulation mode transmission may cover all resources of the transmission. The regions of the dual modulation mode transmission may be orthogonal to each other (i.e., the regions do not overlap in the same resources).

[0238] The dual modulation mode transmission parameter set may include the boundaries of the one or more zones. For example, the two zones may be defined by the boundary where each zone meets.

[0239] The dual-modulation mode transmission parameter set may include transmission parameters associated with a zone. For example, each zone of the transmission may be associated with a transmission parameter set. Transmission parameters may include at least one of modulation order, code rate, transport block size, code block group size, code block size, and transmission power. In scheduling and allocation, transmission parameters may be indicated via TBS. In the feedback report of dual-modulation mode transmission, transmission parameters may be indicated via CSI (e.g., CQI).

[0240] The dual modulation mode transmission parameter set may include a transmission layer. For example, the dual modulation mode transmission parameter set may be associated with a specific transmission layer.

[0241] The WTRU can receive or transmit a first transmission using a dual modulation mode. The first transmission can use a first parameter set, including at least one of the following: a CCA symbol configured using a first CCA, a phase symbol configured using a first phase symbol, a first transmission area set, a first transmission area boundary, and a DMRS symbol configured using a first DMRS. The WTRU can determine the desired dual modulation mode parameter set based on the reception of the first transmission or measurements performed on the first transmission.

[0242] WTRU can determine that a transmission is the first transmission based on whether the transmission is the first in a burst (i.e., it can determine the transmission of the desired dual modulation mode parameter set from it).

[0243] The WTRU can determine whether a transmission is the first transmission based on time. For example, the WTRU can be configured to allow a transmission to be used as a first transmission for a specific time instance, slot, symbol, or subframe. In another example, the WTRU can be configured to determine the maximum duration, maximum number of slots, maximum number of symbols, or maximum number of subframes between two first transmissions. When the maximum duration has elapsed or the maximum number of slots / symbols / subframes has been exceeded, the WTRU can consider a subsequent transmission as the first transmission.

[0244] WTRU can determine that a transmission is the first transmission based on indications in the scheduling and dispatching. For example, WTRU can indicate in the DCI that a transmission will be the first transmission.

[0245] The WTRU can determine that a transmission is the first transmission based on associated measurements that are above or below a threshold. For example, the WTRU can measure the transmission or the resources associated with the transmission (e.g., DMRS, CCA, CSI-RS) to identify the transmission as the first transmission.

[0246] The WTRU can determine the performance of the first dual-modulation mode transmission parameter set based on the reception of the first transmission. The WTRU can also determine the performance of the first dual-modulation mode transmission parameter set based on the reception of feedback associated with the transmitted first transmission.

[0247] The WTRU can determine the performance of the first dual-mode transmission parameter set based on HARQ-ACK determination. For example, the WTRU can determine one or more HARQ-ACK values ​​for each configured zone.

[0248] The WTRU can determine the performance of the first dual-mode transmission parameter set based on the correlation of CCA symbols or resource elements. For example, the WTRU can determine the correlation of decoded CCA symbols or resource elements.

[0249] WTRU can determine the performance of the first dual-mode transmission parameter set based on DMRS measurements.

[0250] The WTRU can determine the performance of the first dual-mode transmission parameter set based on CSI-RS measurements. For example, the WTRU can determine the performance of the first dual-modulation mode transmission parameter set based on CSI-RS received in the resource set associated with the first transmission.

[0251] The WTRU can determine the performance of the first dual-mode transmission parameter set based on the determined CSI. For example, the WTRU can determine the CSI based on CCA, DMRS, or CSI-RS measurements.

[0252] WTRU can compare performance measurements against one or more thresholds to determine whether performance is above or below an acceptable level. These thresholds(s) can be configurable.

[0253] The WTRU can determine the desired set of dual modulation mode parameters based on the performance of the first transmission and associated performance requirements. Performance requirements may include at least one of the following: BLER; CCA correlation value; HARQ-NACK or HARQ-ACK rate; minimum, maximum, or fixed CQI difference between the two zones; maximum throughput (e.g., the requirement may be the maximum throughput that meets the BLER target); and / or minimum or maximum zone size of at least one zone.

[0254] Performance requirements can be determined based on transmission priority. For example, a first-priority transmission might require a first CCA-related value, and a second-priority transmission might require a second CCA-related value. Performance requirements can also be determined based on transmission type. For example, requirements can depend on whether the transmission is in the control plane or data plane, and whether it is broadcast, multicast, or unicast. Performance requirements can also be determined based on indications. For example, a WTRU might receive indications of performance requirements in an RRC message, MAC CE, or DCI.

[0255] WTRU can determine the desired set of dual modulation mode parameters, as described above.

[0256] The desired set of dual modulation mode parameters can be indicated using absolute feedback from one or more zones. For example, the feedback can include the absolute CQI, RI, or PMI of the zone.

[0257] The desired set of dual modulation mode parameters can be indicated using relative feedback from one or more zones. For example, the feedback can include relative CQI, RI, or PMI of a zone, where the value is relative to another zone.

[0258] An offset value between two zones can be used to indicate a desired set of dual modulation mode parameters. For example, feedback may include an offset value of the CQI between two zones. The offset value may be valid over a time period or in multiple subsequent feedback reports. The WTRU may report a single value in subsequent feedback reports (e.g., associated with the first zone), and the actual value of the second zone can be determined based on the reported value of the first zone and the reported offset.

[0259] The transmission of performance metrics can be used to indicate a desired set of dual modulation mode parameters. For example, the WTRU can report performance metrics (e.g., CCA correlation) and can report a first parameter value associated with the first region. The WTRU can be used as a function of the performance metric value to determine whether to report a first parameter value associated with the second region.

[0260] Resources can be provided to the WTRU to report the desired dual-modulation transmission parameter set. The WTRU can be configured to report the desired dual-modulation transmission parameter set periodically. In another approach, the WTRU can determine when to report the dual-modulation transmission parameter set.

[0261] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on changes compared to a previously reported set. For example, if the WTRU determines that the set of desired areas or boundaries has changed compared to a previously reported set of areas or boundaries, the WTRU can report a new set of desired dual-modulation transmission parameters.

[0262] The WTRU can be triggered to determine or report a dual-modulation transmission parameter set based on performance metrics determined from a first transmission using the first dual-modulation transmission parameter set. For example, if performance falls below performance requirements (e.g., below a threshold), the WTRU can be triggered to report a new desired dual-modulation transmission parameter set.

[0263] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on performance metrics determined from multiple transmissions using one or more sets of dual-modulation transmission parameters. For example, the WTRU can determine the HARQ-NACK rate, and if that rate exceeds a threshold, the WTRU can be triggered to determine or report a new desired set of dual-modulation transmission parameters.

[0264] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on changes in measured performance metrics, such as changes greater than a threshold. For example, if the CCA correlation changes more than a threshold compared to a previously determined CCA correlation, the WTRU can be triggered to determine or report a new desired set of dual-modulation transmission parameters.

[0265] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on a request from the gNB. For example, when an aperiodic request is received from the gNB, the WTRU can be requested to transmit the desired set of dual-modulation transmission parameters.

[0266] The WTRU can be triggered to determine or report the dual-modulation transmission parameter set based on DMRS reception or transmission using DMRS.

[0267] The WTRU can be triggered to determine or report the set of dual-modulation transmission parameters based on the priority of the transmission. For example, the WTRU can be triggered upon receiving a transmission of a specific priority to determine or report the desired set of dual-modulation transmission parameters.

[0268] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on the feedback resource payload. For example, the WTRU can be triggered to report the desired set of dual-modulation transmission parameters when the feedback resource payload is greater than a threshold; where the threshold can be configurable and can depend on the size of the dual-modulation transmission parameters to be reported.

[0269] WTRU can be triggered to determine or report the dual-modulation transmission parameter set based on the TCI state or a change in the TCI state.

[0270] The WTRU can be triggered to determine or report a set of dual-modulation transmission parameters based on the transmission type. For example, the WTRU can report the expected set of dual-modulation transmission parameters upon completion of the RA procedure.

[0271] WTRU can determine and report the expected set of dual-modulation transmission parameters.

[0272] The WTRU can report the desired set using UCI transmissions in PUCCH or PUSCH. For example, the WTRU can be configured with periodic, aperiodic, or semi-persistent resources to report the desired dual-modulation transmission parameter set. Note that for aperiodic transmissions, the WTRU can be triggered by the gNB or can be triggered autonomously. For WTRU-triggered aperiodic transmissions, the WTRU can be configured with reporting resources (e.g., conditional reporting resources). In another approach, for WTRU-triggered aperiodic transmissions, the WTRU can request reporting resources when triggered to report the desired set. For example, the WTRU can multiplex the desired dual-modulation transmission parameter set with one or more of CSI, SR, or HARQ-ACK.

[0273] WTRU can use HARQ-ACK feedback to report desired sets. For example, WTRU can report enhanced HARQ acknowledgment feedback. Enhanced HARQ acknowledgment feedback can provide per-region feedback. Enhanced HARQ-ACK feedback can indicate whether the coding rate of one or more regions should be changed. Enhanced HARQ-ACK feedback can indicate whether to increase or decrease the coding rate of one or more regions. Enhanced HARQ-ACK feedback can indicate one or more new regions or boundaries.

[0274] WTRU can use MAC CE to report the expected set.

[0275] WTRU can use RRC to report the expected set.

[0276] The WTRU can receive indications of the dual-modulation transmission parameter set used in DL transmissions or intended for UL transmissions.

[0277] The WTRU can receive an indication of the dual-modulation transmission parameter set from the DCI. For example, the DCI can be enhanced to include new information elements indicating the dual-modulation transmission parameter set or its index. The DCI may include new TBS mapping rules. The WTRU can be configured with one or more TBS mapping rules, for example, each TBS mapping rule associated with a different dual-modulation transmission parameter set. The WTRU can determine the TBS value of one or more zones as a function of the received one or more TBS indices and the dual-modulation transmission parameter set in the DCI. In another approach, the WTRU can determine the TBS value of one or more zones as a function of the received one or more TBS indices and one or more offsets associated with one or more zones. One or more offsets can be included in the DCI.

[0278] The WTRU can receive an indication of a dual-modulation transmission parameter set from a region-specific DCI. For example, the WTRU can receive multiple DCI-scheduled transmissions in the corresponding region of the transmission.

[0279] The WTRU can receive an indication of the dual-modulation transmission parameter set from the CCA configuration. For example, the WTRU can determine the dual-modulation transmission parameter set from the CCA configuration.

[0280] The WTRU can be (re)configured from the RRC with an indication of receiving a dual-modulation transmission parameter set.

[0281] The WTRU can receive instructions on the dual-modulation transmission parameter set from the MAC CE transmission.

[0282] The WTRU can implicitly receive indications of the dual-modulation transmission parameter set. For example, parameters of the DCI can be reused to indicate the dual-modulation transmission parameter set.

[0283] The WTRU can receive an indication of the dual modulation transmission parameter set based on the dual modulation transmission parameter set used for other potentially associated transmissions.

[0284] In one embodiment, the WTRU can be configured to determine the transport block size of the physical channel associated with a spatial CCA transmission based on pre-configured rules. In one embodiment, the WTRU can receive spatial CCA transmissions with dual modulation (e.g., a first modulation and a second modulation). In one embodiment, the WTRU can receive two MCS indices associated with a single PDSCH transmission. For example, the first MCS index can be associated with a RE in a first region (e.g., the spatial CCA region and optionally its neighborhood), and the second MCS index can be associated with a RE in a second region. For example, the WTRU can be pre-configured with two MCS tables—where the first table maps the first MCS index to a first code rate, and the second table maps the second MCS index to a second code rate. The WTRU can calculate the transport block size as a function of one or more of the following: the first code rate, the second code rate, the size of the first region, the size of the second region, the number of layers associated with the spatial region, etc.

[0285] The WTRU can be configured with one or more spatial CCA configurations with dual modulation transmission modes.

[0286] CCA configuration can include layer-specific spatial CCA region configuration. Layer-specific spatial CCA regions can also be predefined (i.e., func (number of layers)). One or more options can be used to configure layer-specific spatial CCA regions: (1) mapping between (one or more) view formats and (one or more) layers; (2) geometry / boundaries—per-layer configuration for the following: starting RE, region size, and density; and / or modulation order (e.g., PCQI) used for the spatial CCA region RE. CCA configuration may include a boundary associated with dual modulation transmission, wherein the boundary is distinguished by a first RE group (i.e., the first zone) modulated with a first modulation order and a second RE group (i.e., the second zone) modulated with a second modulation order, the boundary being configured using one or more of the following: (1) a spatial CCA zone boundary marker (if the boundary is the same as the spatial CCA zone boundary) and / or (2) boundary information (e.g., starting RE, zone size).

[0287] CCA configuration can include phase symbol format (position, modulation order, etc.).

[0288] CCA configuration can include performance metrics associated with the dominant layer (e.g., one or more CCA-related thresholds). The WTRU can receive (e.g., initial) PDSCH associated with a spatial CCA configuration that has dual-modulation transmission (e.g., a field in DCI).

[0289] For each layer, a spatial CCA PDSCH with dual-modulation transmission can include a symbol set comprising five RE groups: a first RE group carrying data associated with the first layer; a second RE group carrying data from both the first and second layers, wherein the transmission power difference between the first and second layers is greater than a threshold, and the number of REs in the second group is less than or equal to the configured overlap relative to the sum of the REs in the first and second groups. The third RE group carrying CCA phase correction reference symbols; the fourth RE group carrying data from both the first and second layers—where the transmission power of the first layer may be equal to that of the second layer; and / or the fifth RE group carrying data from both the first and second layers—which may have equal power distribution across the first and second layers, and the fifth RE group is adjacent to the first three RE groups (e.g., across one or more of adjacent OFDM symbols and / or subcarriers).

[0290] For example, the first three RE groups can correspond to the "spatial CCA area" of each layer.

[0291] For example, the number of REs in the second group is less than or equal to the configured overlap relative to the sum of REs in the first and second groups. For example, the first three groups, along with the fifth RE group, correspond to the first region and can be modulated using the first modulation order. For example, the fourth RE group corresponds to the second region and can be modulated using the second modulation order, which can be lower than the first modulation order. For example, the spatial CCA regions of different layers are non-overlapping. For example, fields in the DCI indicate a new PDSCH format with spatial CCA transmission.

[0292] The WTRU can determine one or more parameters supporting dual-modulation transmissions associated with the first and second zones. For example, the WTRU can determine a precoded channel quality indicator (PCQI) for one or more configured spatial CCA zones. The WTRU can determine the PCQI based on the dominant layer detection performance in the assigned spatial CCA zone (e.g., incrementing the PCQI if the measured CCA correlation exceeds a specific configured threshold, otherwise using the same CQI or decrementing the CQI). In another embodiment, the WTRU can select a PCQI index based on the measured correlation and a predefined mapping between correlation and modulation order.

[0293] A single PDSCH transport block, having a combination of modulation scheme, target code rate, and transport block size corresponding to a PCQI index, and occupying a group of downlink physical resource blocks associated with spatial CCA transmission, can be received with a transport block error probability not exceeding a threshold. WTRU can determine boundary information between different modulation zones (zone 1 and zone 2) based on one or more of the following conditions: for example, a binary flag indicating whether the modulation boundary is aligned with the boundary of the spatial CCA zone; if not aligned, the starting RE of the new zone; and the PCQI associated with the new zone (e.g., ...). PCQI: (1) The spatial CCA-related specific measured in the first zone exceeds a specific threshold; (2) The measured change of the estimated channel (e.g., using CSI-RS) in the first zone may be below a configured threshold; and / or (3) The measured change of the combiner / equalizer domain in the first zone may be below a configured threshold.

[0294] When triggering conditions for reporting dual-modulation transmission mode parameters are met (e.g., changes in PCQI or boundaries between zones, relevant thresholds, time events (predefined periodicities)), the WTRU transmits feedback on pre-configured / assigned UL resources.

[0295] For example, WTRU can transmit PCQI indexes based on the measured changes in the correlation or precoding channel or the BLER associated with the higher-order modulation region.

[0296] For example, the WTRU can transmit boundary information between the first and second resource sets (i.e., the first and second zones). Optionally, a binary flag indicates whether the modulation boundary between the first and second zones is aligned with the spatial CCA zone boundary (i.e., the fifth RE group is empty).

[0297] The WTRU can be configured with updated dual-modulation transmission parameters (e.g., the configuration aspect may include one or more of the parameters in step 1 (e.g., PCQI, updated boundary information)).

[0298] WTRU can receive PDSCHs with updated spatial CCAs in dual-modulation transmission mode (e.g., an indication of a PDSCH with a new CCA format or its dual-modulation transmission model from a DCI bearer with DL authorization). WTRU can utilize dual-modulation transmission to process the received spatial CCA PDSCH.

[0299] One or more channel estimation schemes can be used for demodulation or CSI measurements, wherein the channel estimation scheme may include at least one of DMRS, time-domain CCA, frequency-domain CCA, and spatial / space-domain CCA, as well as combinations of one or more of the channel estimation schemes. The operating mode of a data channel (e.g., PDSCH or PUSCH) can be defined or determined based on the associated channel estimation scheme.

[0300] The channel estimation schemes presented in this paper can be referred to as reference resource transmission and / or reception methods. For example, a DMRS-based channel estimation scheme can be a channel estimation scheme based on transmission / reception DMRS; a time-domain CCA-based channel estimation scheme can be a channel estimation scheme based on repetitive data symbols in the time domain; a frequency-domain CAA-based channel estimation scheme can be a channel estimation scheme based on repetitive data symbols in the frequency domain; a conventional CCA-based channel estimation scheme can be referred to as a channel estimation scheme based on repetitive data symbols in time and / or frequency; and a spatial (or spatial) domain CCA-based channel estimation scheme can be a channel estimation scheme based on repetitive data symbols in the spatial domain.

[0301] Operating modes can be defined or used, whereby the operating mode can be determined based on the associated channel estimation scheme. For example, a mode associated with DMRS-based channel estimation can be called a legacy mode; a mode associated with conventional CCA-based channel estimation can be called a conventional CCA mode; a mode associated with spatial CCA-based channel estimation can be called a spatial CCA mode; and a mode associated with one or more modes (or channel estimation schemes) can be called a hybrid mode, where the hybrid mode can be associated with a combination of DMRS, conventional CCA, and spatial CCA.

[0302] If a mode is associated with PDSCH transmission / reception, it can be called PDSCH mode; if a mode is associated with PUSCH transmission / reception, it can be called PUSCH mode; if a mode is associated with CSI, it can be called CSI mode.

[0303] In one embodiment, PDSCH RE mapping can be determined based on the determined PDSCH mode. For example, if a first PDSCH mode (e.g., legacy mode) is used, configured, or determined, the PDSCH RE set can be mapped sequentially in time-priority or frequency-priority among the allocated PDSCH resources, excluding some types of RS (e.g., DMRS, periodic CSI-RS); if a second PDSCH mode (e.g., regular CCA mode) is used, configured, or determined, the PDSCH RE set can be mapped sequentially in time-priority or frequency-priority among the allocated PDSCH resources, excluding some types of RS and resources reserved for CCA mode transmissions.

[0304] In one embodiment, for PDSCH transmission, the WTRU can be configured with one or more PDSCH modes. For example, a first PDSCH mode can be configured, determined, or used for a first type of PDSCH data symbols, and a second PDSCH mode can be configured, determined, or used for a second type of PDSCH data symbols.

[0305] The first and second types of PDSCH data symbols can be determined based on the number of layers. For example, data symbols associated with the first layer of PDSCH can be configured, determined, or identified as first type PDSCH data symbols, and data symbols associated with the second layer of PDSCH can be configured, determined, or identified as second type PDSCH data symbols.

[0306] The first and second types of PDSCH data symbols can be determined based on symbol location. For example, data symbols located in OFDM symbols close to the DMRS can be configured, determined, or identified as first type PDSCH data symbols (e.g., legacy PDSCH mode), and the remaining data symbols can be configured, determined, or identified as second type PDSCH data symbols.

[0307] First and second types of PDSCH data symbols can be determined based on priority. For example, when services of different priorities are multiplexed for PDSCH transmission and / or reception, data symbols associated with the first service type (or priority) can be configured, determined, or identified as first-type PDSCH data symbols (e.g., using DMRS-based channel estimation), and data symbols associated with the second service type (or priority) can be configured, determined, or identified as second-type PDSCH data symbols (e.g., using CCA-based channel estimation). The first and second types of PDSCH data symbols can be determined based on the channel type; when different types of channels are multiplexed in PDSCH transmission, data symbols associated with the first channel in PDSCH (e.g., control information) can be configured, determined, or identified as first type of PDSCH data symbols, and data symbols associated with the second channel in PDSCH (e.g., data information) can be configured, determined, or identified as second type of PDSCH data symbols.

[0308] The first and second types of PDSCH data symbols can be determined based on the target purpose. If one or more PDSCH data symbols are used only for data transmission, they can be configured, determined, or identified as first-type PDSCH data symbols (e.g., using DMRS-based channel estimation); if one or more PDSCH data symbols are used for both data transmission and measurement (e.g., phase noise, CSI measurement, time / frequency tracking), they can be configured, determined, or identified as second-type PDSCH data symbols (e.g., using CCA-based channel estimation), wherein second-type PDSCH data symbols can be repeated in time / frequency / space.

[0309] The first and second types of PDSCH data symbols can be determined based on the frequency band (or RB position).

[0310] The first and second types of PDSCH data symbols can be determined based on time location (e.g., OFDM symbol).

[0311] In this document, the PDSCH mode can be used as an example to describe the proposed embodiments. However, the proposed embodiments can be applied to other data transmissions (e.g., PUSCH, PSSCH, PDCCH, PSCCH) and / or signal transmissions (e.g., CSI-RS, TRS, PRS, SRS, DRS) without any limitation. Thereafter, PDSCH can be used interchangeably with PUSCH, PSSCH, PDCCH, and PSCCH, but still consistent with the disclosed embodiments.

[0312] In one embodiment, the WTRU may report auxiliary information to determine the operating mode (e.g., PDSCH mode). The auxiliary information may include the preferred operating mode (e.g., PDSCH, PUSCH, PSSCH) for the RE set (all or a subset) in the data transmission.

[0313] Ancillary information may include one or more conditions that can be used to determine the operating mode. WTRU speed-related information (e.g., Doppler frequency, WTRU speed, time-domain correlation) can be reported; if the WTRU speed is above a threshold, the gNB can determine the time-domain CCA; otherwise, the gNB can determine the frequency-domain CCA. Spatial correlation-related information (e.g., antenna correlation, channel covariance matrix, etc.) can also be reported. When the spatial correlation is below a threshold, a spatial CCA mode can be used or determined; otherwise, a regular CCA mode can be used.

[0314] Auxiliary information may include channel estimation performance-related information. For a given operating mode, the WTRU may report channel estimation performance-related information (e.g., MSE) in a periodic, semi-persistent, or aperiodic manner, wherein in the semi-persistent or aperiodic case, reporting may be triggered when one or more predetermined conditions are met (e.g., channel estimation performance is below a threshold).

[0315] In one embodiment, the PDSCH mode for PDSCH transmission can be indicated to the WTRU. One or more of the following may be applicable: The bit field (or code point) in the scheduling DCI of PDSCH transmission can be used to indicate the PDSCH mode of the PDSCH transmission.

[0316] The PDSCH mode can be determined based on the associated scheduling DCI format. For example, when using DCI format 1-1, a first PDSCH mode can be used; otherwise, a second PDSCH mode can be used. Alternatively, when using fallback DCI (e.g., DCI format 1-0), the first PDSCH mode can be used, and when using non-fallback DCI, the second PDSCH mode can be used, wherein the first PDSCH mode can be predetermined (e.g., legacy mode), and the second PDSCH mode can be configured (e.g., legacy mode, regular CCA mode, and spatial CCA mode).

[0317] The PDSCH mode can be determined based on the RNTI scrambled on the CRC used for scheduling DCI. For example, a first RNTI can be associated with a first PDSCH mode, and a second RNTI can be associated with a second PDSCH mode.

[0318] Dynamic PDSCH mode indication (or adaptation) is only allowed when the PDSCH scheduling offset (Kmin) is greater than a threshold (e.g., Kmin>1). For example, dynamic PDSCH mode indication / adaptation is not allowed for the same time slot scheduling case (i.e., PDCCH and PDSCH are in the same time slot) to avoid making WTRU processing time longer.

[0319] Whether using dynamic or semi-static PDSCH mode, the required minimum WTRU processing time can be determined. For example, if the PDSCH mode is configured or determined via higher-level signaling (e.g., RRC, MAC-CE), a first minimum WTRU processing time can be applied; if the PDSCH mode is dynamically indicated or determined via DCI signaling, a second minimum WTRU processing time can be applied; wherein the first minimum WTRU processing time can be shorter than the second minimum WTRU processing time.

[0320] In another embodiment, one or more PDSCH modes of the PDSCH transport can be used to indicate the WTRU. For example, a first subset of PDSCH REs can be configured or determined to be associated with a first PDSCH mode (e.g., legacy mode), and a second subset of PDSCH REs can be dynamically indicated (e.g., in the DCI) of which PDSCH mode to use for demodulation (e.g., legacy mode, regular CCA mode, spatial CCA mode), wherein the actual transport block size can be determined based on the determined PDSCH mode. The PDSCH mode can be indicated in the DCI associated with the PDSCH transport (e.g., for dynamic authorization). The PDSCH mode can be indicated in a common DCI shared by one or more WTRUs.

[0321] In one embodiment, the WTRU can determine the PUSCH mode based on one or more conditions, wherein the WTRU can be configured with a set of PUSCH modes, within which the WTRU can determine the PUSCH mode used for PUSCH transmission.

[0322] One or more of the following conditions may be used to determine the PUSCH: WTRU speed; the determined or used transmission power; the determined or used waveform; scheduling parameters (e.g., rank, MCS, DMRS mode, number of symbols, etc.); multiplexing conditions (e.g., UCI, PTRS, SRS, etc.); time slot type (e.g., UL-only time slot, flexible time slot, special time slot, SBFD time slot); service type (e.g., eMBB, URLLC, mMTC); and channel conditions (e.g., SINR). For configured authorization, the WTRU can be configured with PUSCH mode. The WTRU can determine the PUSCH mode.

[0323] The WTRU can indicate a determined PUSCH mode based on one or more of the following: it can multiplex a UCI (e.g., the first symbol of the PUSCH) that indicates the determined PUSCH mode within the PUSCH; it can define or configure one or more DMRS sequences, each of which can be associated with a PUSCH mode (the WTRU can determine the DMRS sequences based on the determined PUSCH mode); it can configure, determine, or use one or more PUSCH resources (e.g., PUSCH resources are time / frequency separated), where each PUSCH resource can be associated with a PUSCH mode. The WTRU can transmit PUSCHs within the determined PUSCH resources associated with the determined PUSCH mode.

[0324] A WTRU that supports several operating modes (e.g., PDSCH mode such as regular CCA, spatial CCA, DMRS mode) can be configured to operate using a first operating mode. The WTRU can be triggered to determine and / or report auxiliary information about the parameters of the first operating mode, or to determine a second operating mode, wherein the triggering can be event-based, time-based, or NW-based.

[0325] Event-based triggering can include changes in channel conditions, such as Doppler or delay spread. In one embodiment, the WTRU can measure channel conditions (e.g., based on received CSI-RS). The WTRU can be triggered to determine updated parameters for a second or first operating mode (e.g., PDSCH mode) when the difference (or relative change) between the current and previous (e.g., those reported for a previous operating mode) channel conditions exceeds a configuration threshold for multiple (e.g., consecutive) measurement periods (e.g., time slots, TTIs). The WTRU can make this determination as a function of the channel conditions, the current operating mode, and the changes in parameters.

[0326] For example, if the measured Doppler is high (in the case of a time-selective channel) and the first (e.g., current) operating mode is spatial CCA, the WTRU can determine the second operating mode as temporal CCA; if the first operating mode is temporal CCA, the WTRU can (e.g., can only) determine the update parameters of the temporal CCA operating mode, or the WTRU can determine the PDSCH mode as the second operating mode. In another example, if the measured Doppler is low and the first operating mode is temporal CCA, the WTRU can determine the second operating mode, for example, as spatial CCA, or a hybrid mode (spatial CCA for one layer / layer set, and regular CCA for other layers).

[0327] For example, if the measured delay spread is high (as in the case of a frequency-selective channel) and the first (e.g., current) operating mode is spatial CCA, the WTRU can determine the second operating mode as frequency CCA; in another example, if the first operating mode is frequency CCA, the WTRU can determine (e.g., determine only the frequency CCA update parameters), or the second operating mode can be determined as a hybrid mode (e.g., frequency CCA for one layer / layer set, and spatial CCA for other layers).

[0328] Event-based triggering can include a change in the rank (e.g., RI) determined by the WTRU. For example, when the WTRU determines, based on CSI-RS measurements, that the rank (regarding a previous TTI or previous configuration of the operating mode) has changed, the WTRU can be triggered to determine a new (e.g., a second) operating mode (e.g., PDSCH mode). The WTRU can determine the second operating mode based on the measured rank, a configured rank threshold, and the current (e.g., first) operating mode. For example, if the measured rank is below a configured threshold, the WTRU can determine the spatial CCA as the second operating mode.

[0329] Event-based triggering can include changes to layer indicators (e.g., the LI or index of the strongest layer) determined by the WTRU. For example, when the WTRU detects a change in the index of the strongest layer based on channel measurements (e.g., CSI-RS), the WTRU can be triggered to determine a new (e.g., a second) operating mode or to determine updated parameters. For example, if the new strongest layer is configured for either regular CCA or DMRS operating modes, the second operating mode could be a hybrid mode where the strongest layer uses spatial CCA operation and the other layers use regular CCA operation.

[0330] Event-based triggering can include CCA-related measurements. In one embodiment, the WTRU can be triggered to determine parameters of a second operating mode and / or a first operating mode as a function of the first operating mode, the number of layers, and CCA-related measurements (measured on the data channel). Using CCA-related measurements to determine the operating mode can reduce feedback latency (because CCA correlation can be performed at TTI granularity, which can be lower than the granularity of CSI-RS-based channel measurements). In another embodiment, the WTRU can recommend spatial CCA if the CCA correlation difference between the sums of correlations of the dominant and non-dominant layers exceeds a specific configured correlation threshold.

[0331] Event-based triggering can include performance measurements (e.g., SNR, RSRP, RSRQ, BLER, correlation between rx antennas). In one embodiment, the WTRU can be configured with an SNR range and an Rx antenna correlation range to determine the operating mode. For example, when operating under low SNR and high correlation between Rx antennas, the WTRU can determine the DMRS mode as the second operating mode (see throughput in Figure 16), while when operating under low SNR and low Rx antenna correlation, the WTRU can determine the spatial CCA as the second operating mode.

[0332] Event-based triggering can include the WTRU being triggered to report parameters of a second or first operating mode, if different from the previous report. The WTRU can skip reporting if no change in operating mode / parameters is found in the previous report.

[0333] Examples of time-based triggering can include WTRU configurations for periodic or non-periodic reporting of operating modes. For instance, the WTRU can be configured to report operating modes (e.g., preferred operating modes, or preferred parameters of the current operating mode) as part of a configured CSI report (periodic or semi-persistent). In another example, the WTRU can use HARQ feedback to signal to the NW an indication (e.g., 1 bit) of a change in preferred mode or operating or preferred parameters. In yet another example, the WTRU can be configured with periodic resources for reporting operating modes (e.g., dedicated data channel grants, new PUCCH formats).

[0334] NW-based triggering can include at least one of the following: BWP change; beam failure detection; RLF detection; reconfiguration based on RRC received from NW; handover to another cell; and / or TRP change; When any of the above changes / events occur, the WTRU can be triggered to determine a second operating mode and / or the parameters of that operating mode; the WTRU can be triggered to report the second operating mode / parameters, for example, when it determines that a change in the operating mode / parameters has occurred compared to a previous report.

[0335] WTRU can be configured to report operating modes (e.g., PDSCH mode) and / or parameters of the operating mode.

[0336] The report may include auxiliary information for determining the operating mode (e.g., second mode) / parameters. For example, the report may include measured channel conditions such as: Doppler spread, delay spread, AoA, channel rank, index of the strongest layer, SNR, RSRP, RSRQ, channel-dependent bandwidth, channel-dependent time, and / or correlation between Rx antennas (spatial correlation).

[0337] The report may include CCA-related measurements, such as CCA correlation for each layer, CCA correlation for each subband, and average CCA correlation. The report may include preferred (e.g., second) operating modes, such as conventional CCA, spatial CCA, or DMRS mode. The report may include view parameters (e.g., for conventional CCA mode). The report may include spatial CCA view parameters, such as CCA region boundaries and the number of REs within the CCA region.

[0338] When the WTRU determines that the preferred operating mode has changed, it can report the operating mode. The WTRU can indicate this change using a first report (e.g., with a small payload size), such as a 1-bit flag multiplexed with HARQ feedback. The WTRU can indicate the determined parameters using a second report, which can be multiplexed with a CSI report, such as an aperiodic CSI report on the PUSCH.

[0339] To demonstrate the effectiveness of the proposed PDSCH format and show the benefits of dynamically switching or multiplexing different PDSCH formats, end-to-end throughput performance of different PDSCH modes was evaluated on a 3GPP testbed and is shown in Figure 16. The following simulation parameters were used: a transmitter with 16 antennas, a receiver with 4 antennas, a CDL-C channel model, a 4 GHz carrier frequency, a 52 RBs bandwidth, a 30 ns delay spread, a 5 km / hr WTRU speed, and single-layer transmission. The CCA problem was resolved once every two RBs. For regular CCA, time repetition was used, where for each RB, data was repeated from OFDM symbol 3 to OFDM symbol 10 only for even-numbered subcarriers, thus ensuring that the number of reserved REs for each RB was equal to 6. Similarly, the DMRS configuration used six reference symbols per RB.

[0340] It can be seen that, under the considered parameters, spatial CCA provides a considerable throughput gain compared to DMRS and conventional CCA at different SNR regions. It can also be seen that conventional CCA outperforms DMRS in most SNR regions, while the latter is slightly better in low SNR regions. It is anticipated that, under different overlap and power difference settings, the performance of spatial CCA may slightly degrade when the number of layers exceeds a certain threshold. This indicates that different PDSCH modes can have different performance under different settings, and therefore, it spurs the need for multiplexing different PDSCH modes or enabling dynamic switching between different modes. Figure 10 This is a graph illustrating the end-to-end performance of different PDSCH modes.

[0341] Different CCA modes and DMRS have different performance trade-offs under different conditions. This solution describes methods and processes for dynamic adaptation between multiple PDSCH formats / transmissions / modes (e.g., DMRS, regular CCA, spatial CCA). An exemplary process for multiplexing different formats (e.g., DMRS, spatial CCA, regular CCA) within a single transmission for optimized performance is described below.

[0342] The WTRU can be configured with dynamic PDSCH transmission, which includes one or more multiplexed PDSCH modes (e.g., DMRS, spatial CCA, conventional CCA). This configuration can include PDSCH modes (and their parameters), including legacy modes: DMRS, conventional CCA, spatial CCA, and hybrid modes (e.g., layer-specific or subband-specific configurations). Hybrid modes can include DMRS+conventional CCA, DMRS+spatial CCA, conventional + spatial CCA, and DMRS+spatial + conventional CCA.

[0343] This configuration may include feedback configuration, including conditions / parameters for enabling dynamic adaptation (e.g., spatial CCA feedback independent of PDSCH mode).

[0344] The WTRU can receive PDSCH with a first mode (e.g., DMRS, regular, spatial CCA, or hybrid).

[0345] The WTRU can determine the preferred PDSCH pattern (per layer and / or per subband) based on measurements based on WTRU measurements (e.g., channel measurements (Doppler, SNR, CQI), interference measurements, RI). For example, the WTRU can recommend spatial CCA based on RI or the number of configured layers, e.g., if the RI is below a certain configured threshold. In another solution, the WTRU can recommend spatial CCA if the CCA correlation difference between the sums of correlations of the dominant and non-dominant layers exceeds a certain configured correlation threshold. Under specific channel conditions, such as in high-Doppler scenarios, for example, if the estimated Doppler exceeds a certain threshold, the WTRU can recommend DMRS.

[0346] WTRU can indicate layer-specific preferred PDSCH operating modes and related parameters (e.g., in UCI or MAC CE).

[0347] The WTRU can implicitly determine the layer-specific PDSCH operating mode (e.g., DMRS vs. spatial CCA vs. regular CCA) based on other information such as MCS indication, rank, waveform, retransmission, etc. Based on the waveform, the WTRU can be pre-configured with rules for DMRS vs. CCA type transmissions. For example, if the waveform is OFDM, the WTRU can assume all PDSCH modes are applicable; otherwise, if the waveform is DFT-s-OFDM, the WTRU can assume DMRS. The WTRU can be configured with a mapping between retransmission indices and PDSCH modes (e.g., initial transmissions using spatial or regular CCA and retransmissions using DMRS). The WTRU can also determine the layer-specific PDSCH operating mode (e.g., DMRS vs. spatial CCA vs. regular CCA) based on explicit indications in the DCI (e.g., a bitmap indicating the PDSCH mode).

[0348] WTRU can process received PDSCH corresponding to one or more modes.

[0349] Although features and elements have been described above in specific combinations, those skilled in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. Furthermore, the methods described herein 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 via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor storage devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROMs and digital multifunction discs (DVDs). The processor associated with the software can be used to implement a radio frequency transceiver for use in a UE, WTRU, terminal, base station, RNC, or any host.

Claims

1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: receiving a physical downlink shared channel (PDSCH) associated with a spatial canonical correlation analysis (CCA) transmission, wherein the spatial CCA transmission comprises resource element (RE) groups, including: a first RE group for carrying data associated with a first layer; a second RE group for carrying data from a first layer and a second layer, wherein a difference in transmission power between the first layer and the second layer is greater than a threshold value; a third RE group for carrying a CCA phase correction reference symbol; and a fourth RE group for carrying data from the first layer and data from the second layer, wherein a transmission power of the first layer is equal to a transmission power of the second layer; constructing a first spatial CCA view and a second spatial CCA view in a receive antenna domain in a spatial CCA region; and decoding the first RE group, the second RE group, and the fourth RE group in the spatial CCA transmission.

2. The method of claim 1, further comprising: receiving configuration information associated with the spatial CCA transmission.

3. The method of claim 2, wherein the configuration information comprises a PDSCH format.

4. The method of claim 2, wherein the configuration information comprises a layer-specific spatial CCA region configuration.

5. The method of claim 2, wherein the configuration information comprises an overlap percentage between the first layer and the second layer.

6. The method of claim 1, further comprising: performing phase correction using the third RE group.

7. The method of claim 1, wherein the spatial CCA region comprises the first RE group, the second RE group, and the third RE group.

8. The method of claim 1, wherein the first spatial CCA view is constructed from a first set of receive antenna elements and the second spatial CCA view is constructed from a second set of receive antenna elements.

9. The method of claim 8, wherein the first set of receive antenna elements does not overlap with the second set of receive antenna elements.

10. A wireless transmit / receive unit (WTRU), comprising: a transceiver; and a processor; wherein the transceiver and the processor are configured to: receive a physical downlink shared channel (PDSCH) associated with a spatial canonical correlation analysis (CCA) transmission, wherein the spatial CCA transmission comprises resource element (RE) groups, including: a first RE group for carrying data associated with a first layer; a second RE group for carrying data from a first layer and a second layer, wherein a difference in transmission power between the first layer and the second layer is greater than a threshold value; a third RE group for carrying a CCA phase correction reference symbol; and a fourth RE group for carrying data from the first layer and data from the second layer, wherein a transmission power of the first layer is equal to a transmission power of the second layer; construct a first spatial CCA view and a second spatial CCA view in a receive antenna domain in a spatial CCA region; and decode the first RE group, the second RE group, and the fourth RE group in the spatial CCA transmission.

11. The WTRU of claim 10, further comprising: receiving configuration information associated with the spatial CCA transmission.

12. The WTRU of claim 11, wherein the configuration information includes a PDSCH format.

13. The WTRU of claim 11, wherein the configuration information includes layer-specific space CCA area configuration.

14. The WTRU of claim 11, wherein the configuration information includes the percentage of overlap between the first layer and the second layer.

15. The WTRU of claim 10, further comprising: Phase correction is performed using the third RE group.

16. The WTRU of claim 10, wherein the spatial CCA region comprises a first RE group, a second RE group, and a third RE group.

17. The WTRU of claim 10, wherein the first spatial CCA view is constructed from the first set of receiving antenna elements, and the second spatial CCA view is constructed from the second set of receiving antenna elements.

18. The WTRU of claim 17, wherein the first set of receiving antenna elements does not overlap with the second set of receiving antenna elements.

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