Method and wtru for receiving downlink transmissions

Abstract

Methods and systems for detecting an enhanced massive mobile broadband (eMBB) physical downlink control channel (PDCCH) in the presence of ultra-reliable low latency communications (URLLC) users are disclosed. An eMBB wireless transmit / receive unit (WTRU) can receive an eMBB control resource set (CORESET) configuration for a CORESET including a PDCCH preemption indicator. If PDCCH preemption is enabled based on the PDCCH preemption indicator, the eMBB WTRU can identify and remove pre-empted resource element groups (REGs) in the eMBB CORESET by comparing channel estimates for each REG bundle in the eMBB CORESET. The WTRU can perform channel estimation based on remaining REGs in the eMBB CORESET and detect a PDCCH by performing blind decoding on the remaining REGs in the eMBB CORESET based on a received signal.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201980007565.3, filed on January 9, 2019, entitled “Method for identifying resources of a new radio-physical downlink control channel that have been preempted by ultra-reliable low-latency communication”, the contents of which are incorporated herein by reference.

[0002] This application claims the benefits of U.S. Provisional Application No. 62 / 615,825, filed January 10, 2018, and U.S. Provisional Application No. 62 / 715,940, filed August 8, 2018, the contents of which are incorporated herein by reference. Background Technology

[0003] In the New Radio (NR) used in fifth-generation (5G) wireless systems, the Physical Downlink Control Channel (PDCCH) is structured and designed using two transmission modes: interleaved units and non-interleaved units called Resource Element Groups (REG bundles). Each REG bundle includes multiple REGs in time or frequency for joint channel estimation. Slot-based and non-slot-based transmission, as well as monitoring of different rates for the PDCCH, are also defined in NR for 5G wireless systems. Summary of the Invention

[0004] A method and system are disclosed for detecting the Enhanced Massive Mobile Broadband (eMBB) Physical Downlink Control Channel (PDCCH) in the presence of Ultra-Reliable Low-Latency Communication (URLLC) users or for URLLC users. The eMBB Radio Transmit / Receive Unit (WTRU) can receive an eMBB CORESET configuration for a Control Resource Set (CORESET), including a PDCCH preemption indicator. If PDCCH preemption is enabled based on the PDCCH preemption indicator, the eMBB WTRU can identify and remove preempted Resource Element Groups (REGs) in the eMBB CORESET by comparing channel estimates bundled with each REG in the eMBB CORESET. The WTRU can perform channel estimation based on the remaining REGs in the eMBB CORESET and detect the PDCCH by performing blind decoding on the remaining REGs in the eMBB CORESET based on received signals. If PDCCH preemption is not enabled, the WTRU can perform channel estimation for each REG bundle in the eMBB CORESET and detect the PDCCH by performing blind decoding on all REGs in the eMBB CORESET based on the received signal. Attached Figure Description

[0005] A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings, wherein the same reference numerals in the drawings denote the same elements, and wherein:

[0006] Figure 1A This is a system diagram illustrating an exemplary communication system in which one or more of the disclosed embodiments may be implemented.

[0007] Figure 1B This illustrates the possibility of implementation according to an embodiment. Figure 1A The diagram shows an exemplary wireless transmit / receive unit (WTRU) used within a communication system.

[0008] Figure 1C This illustrates the possibility of implementation according to an embodiment. Figure 1A The diagram shows an exemplary radio access network (RAN) and an exemplary core network (CN) used within the communication system.

[0009] Figure 1D This illustrates the possibility of implementation according to an embodiment. Figure 1A The system diagram shows another exemplary RAN and another exemplary CN used within the communication system shown.

[0010] Figure 2 This is a scheduling diagram of an exemplary scheduling method for partially preempting the Physical Downlink Control Channel (PDCCH) for Enhanced Massive Mobile Broadband (eMBB) WTRU in the presence of a PDCCH for an Ultra Reliable Low Latency Communication (URLLC) WTRU;

[0011] Figure 3 This is a flowchart of an example method for partially preempting a PDCCH used for eMBB when a PDCCH for URLLC exists;

[0012] Figure 4 This is another scheduling graph for an exemplary scheduling method of partially preempting the PDCCH for the eMBB WTRU in the presence of a PDCCH for the URLLC WTRU;

[0013] Figure 5 This is a scheduling graph of an example scheduling method for fully preempting the PDCCH used for the eMBB WTRU when the PDCCH used for the eMBB WTRU overlaps with the PDCCH used for the URLLC WTRU.

[0014] Figure 6 This is a scheduling graph of an example method for transmitting the same downlink control information (DCI) on two PDCCH candidates in two different search space sets on the same control resource set (CORESET); and

[0015] Figure 7 A flowchart of an example WTRU process is shown for PDCCH repetition through a multi-CORESET search space and soft combination for blind detection. Detailed Implementation

[0016] Figure 1A This is an illustration of an exemplary communication system 100 that can implement the disclosed embodiments. The communication system 100 can be a multiple access system providing voice, data, video, messaging, broadcasting, and other content 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 can use 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 DFT Extended OFDM (ZT UW DTS-sOFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtering OFDM, and Filter Bank Multicarrier (FBMC), etc.

[0017] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110, and other networks 112. However, it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network components. Each WTRU 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, any WTRU 102a, 102b, 102c, or 102d may be referred to as a “station” and / or “STA”, and may be configured to transmit and / or receive wireless signals. It may 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, and devices operating on commercial and / or industrial wireless networks, etc. Any of WTRU 102a, 102b, 102c, or 102d may be interchangeably referred to as a UE.

[0018] The communication system 100 may also include base stations 114a and / or 114b. Each base station 114a, 114b may be any type of device configured to enable its access to one or more communication networks (e.g., CN 106 / 115, Internet 110, and / or other networks 112) by wirelessly interfacing with at least one of WTRUs 102a, 102b, 102c, 102d. For example, base stations 114a, 114b may be base transceiver stations (BTS), node B, e-node B, home node B, home e-node B, gNB, NR node B, site controller, access point (AP), and wireless routers, etc. Although each base station 114a, 114b is described as a single component, it should be understood that base stations 114a, 114b may include any number of interconnected base stations and / or network components.

[0019] Base station 114a may be part of RAN 104 / 113, and the RAN may also include other base stations and / or network components (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies called cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide radio service coverage for a specific geographic area that is relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, that is, each transceiver corresponds to one sector of the cell. In embodiments, base station 114a may use multiple-input multiple-output (MIMO) technology and may use multiple transceivers for each sector of the cell. For example, by using beamforming, signals can be transmitted and / or received in a desired spatial direction.

[0020] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116, wherein the air interface can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 can be established using any suitable radio access technology (RAT).

[0021] More specifically, as described above, the communication system 100 can be a multiple access system and can use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, etc. For example, base station 114a in RAN 104 / 113 and WTRUs 102a, 102b, and 102c can implement a certain radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), wherein the technology can use Wideband CDMA (WCDMA) to establish air interfaces 115 / 116 / 117. 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 ​​UL Packet Access (HSUPA).

[0022] In an embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement a certain radio technology, such as Evolved UMTS Terrestrial Radio Access (E-UTRA), wherein the technology may use Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTA Pro (LTE-APro) to establish air interface 116.

[0023] In an embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement a certain radio technology, such as NR radio access, wherein the radio technology may use a novel radio (NR) to establish air interface 116.

[0024] In this embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement various radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access (e.g., using the dual connectivity (DC) principle). Therefore, the air interface used by WTRUs 102a, 102b, and 102c can be characterized by various types of radio access technologies and / or transmissions sent to / from various types of base stations (e.g., eNBs and gNBs).

[0025] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement the following radio technologies, such as IEEE 802.11 (i.e., WiFi), IEEE 802.16 (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 for GSM Evolution (EDGE), and GSM EDGE (GERAN), etc.

[0026] Figure 1ABase station 114b can be a wireless router, home node B, home e node B, or access point, and can use any suitable RAT to facilitate wireless connectivity in a local area, such as a business premises, residence, vehicle, campus, industrial facility, air corridor (e.g., for use by drones), and road, etc. In one embodiment, base station 114b and WTRUs 102c, 102d can establish a wireless local area network (WLAN) by implementing radio technology such as IEEE 802.11. In another embodiment, base station 114b and WTRUs 102c, 102d can establish a wireless personal area network (WPAN) by implementing radio technology such as IEEE 802.15. In yet another embodiment, base station 114b and WTRUs 102c, 102d can establish a picocell or femtocell by using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). Figure 1A As shown, base station 114b can be directly connected to the Internet 110. Therefore, base station 114b does not need to access the Internet 110 via CN 106 / 115.

[0027] RAN 104 / 113 can communicate with CN 106 / 115, where CN can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more WTRUs 102a, 102b, 102c, 102d. This data can have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements, etc. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or can perform advanced security functions such as user authentication. Although in Figure 1A While not shown, it should be understood that RAN104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that use the same RAT or a different RAT as RAN 104 / 113. For example, in addition to connecting to RAN 104 / 113 which uses NR radio technology, CN 106 / 115 can also communicate with other RANs (not shown) that use GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technologies.

[0028] CN 106 / 115 may also act as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Simple Old-Style Telephone Service (POTS). The Internet 110 may include a global network of interconnected computer equipment systems 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, wherein the one or more RANs may use the same RAT or a different RAT as RAN 104 / 113.

[0029] 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 communicating with different wireless networks on different wireless links). For example... Figure 1A The WTRU 102c shown can be configured to communicate with base station 114a, which can use cellular-based radio technology, and with base station 114b, which can use IEEE 802 radio technology.

[0030] Figure 1B This is a system diagram illustrating an example of WTRU 102. (See diagram below.) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive unit 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 other peripheral devices 138. It should be understood that, while remaining consistent with the embodiments, WTRU 102 may also include any sub-combination of the foregoing components.

[0031] Processor 118 can 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) circuit, any other type of integrated circuit (IC), and a state machine, etc. Processor 118 can perform signal encoding, data processing, power control, input / output processing, and / or any other function that enables WTRU 102 to operate in a wireless environment. Processor 118 can be coupled to transceiver 120, and transceiver 120 can be coupled to transmitting / receiving unit 122. Although Figure 1B While the processor 118 and transceiver 120 are described as separate components, it should be understood that the processor 118 and transceiver 120 can also be integrated into a single electronic component or chip.

[0032] Transmit / receive component 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmit / receive component 122 may be an antenna configured to transmit and / or receive RF signals. As an example, in an embodiment, transmit / receive component 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In an embodiment, transmit / receive component 122 may be configured to transmit and / or receive RF and optical signals. It should be understood that transmit / receive component 122 may be configured to transmit and / or receive any combination of wireless signals.

[0033] Although Figure 1B The transmit / receive component 122 is described as a single component, but the WTRU 102 may include any number of transmit / receive components 122. More specifically, the WTRU 102 may use MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit / receive components 122 (e.g., multiple antennas) that transmit and receive radio signals via the air interface 116.

[0034] Transceiver 120 can be configured to modulate signals to be transmitted by transmitter / receiver 122 and demodulate signals received by transmitter / receiver 122. As described above, WTRU 102 can have multimode capability. Therefore, transceiver 120 can include multiple transceivers that allow WTRU 102 to communicate using various RATs (e.g., NR and IEEE 802.11).

[0035] The processor 118 of WTRU 102 can be coupled to 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) and can receive user input data from these components. 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 and store information from any suitable memory, such as non-removable memory 130 and / or removable memory 132. Non-removable memory 130 can include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 can include a subscriber identity module (SIM) card, memory stick, secure digital card (SD) memory card, etc. In other embodiments, the processor 118 can access and store information from memory that is not actually located in WTRU 102; for example, such memory could be located in a server or home computer (not shown).

[0036] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control power for other components in the WTRU 102. The power supply 134 can be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cell battery packs (such as nickel-cadmium (Ni-Cd), nickel-zinc (Ni-Zn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, and fuel cells, etc.

[0037] 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) related to the current location of the WTRU 102. As a supplement or replacement to the information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via the air interface 116, and / or determine its location based on signal timing received from two or more nearby base stations. It should be understood that, while remaining consistent with the embodiments, the WTRU 102 may acquire location information using any suitable positioning method.

[0038] The processor 118 can also be 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 video), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, etc. Modules, FM radio units, digital music players, media players, video game console modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, and activity trackers, etc. Peripheral devices 138 may include one or more sensors, which 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, gesture sensors, biometric sensors, and / or humidity sensors.

[0039] WTRU 102 may include a full-duplex wireless device, wherein the reception or transmission of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous for the wireless device. The full-duplex wireless device may include an interference management unit 139 that reduces and / or substantially eliminates self-interference by means of hardware (e.g., choke coils) or by means of a processor (e.g., a separate processor (not shown) or by means of processor 118) for signal processing. In embodiments, WTRU 102 may include a half-duplex wireless device that transmits and receives some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception).

[0040] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to an embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c using E-UTRA radio technology on air interface 116. RAN 104 can also communicate with CN 106.

[0041] RAN 104 may include eNodeBs 160a, 160b, and 160c; however, it should be understood that RAN 104 may include any number of eNodeBs while remaining consistent with the embodiments. Each eNodeB 160a, 160b, and 160c may include one or more transceivers communicating with WTRUs 102a, 102b, and 102c on air interface 116. In one embodiment, eNodeBs 160a, 160b, and 160c may implement MIMO technology. Thus, for example, eNodeB 160a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a.

[0042] Each eNodeB 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 UL and / or DL, etc. For example... Figure 1C As shown, nodes B160a, 160b, and 160c can communicate with each other via the X2 interface.

[0043] 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 (or PGW) 166. While each of the foregoing components is described as part of the CN 106, it should be understood that any of these components may be owned and / or operated by an entity other than the CN operator.

[0044] MME 162 can connect to each eNodeB 160a, 160b, and 160c in RAN 104 via the S1 interface and can act as a control node. For example, MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, performing bearer activation / deactivation processes, and selecting a specific serving gateway during the initial attach process of WTRUs 102a, 102b, and 102c, etc. MME 162 can also provide control plane functionality for handover between RAN 104 and other RANs (not shown) using other radio technologies (such as GSM and / or WCDMA).

[0045] The SGW 164 can connect to each eNodeB 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 typically routes and forwards user data packets to / from WTRUs 102a, 102b, and 102c. Furthermore, the SGW 164 can perform other functions, such as anchoring the user plane during handover between eNBs, triggering paging processes when DL data is available to WTRUs 102a, 102b, and 102c, and managing and storing the context of WTRUs 102a, 102b, and 102c, etc.

[0046] SGW 164 can be connected to PGW 166, which can provide packet-switched network (e.g., Internet 110) access for WTRU 102a, 102b, 102c to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0047] CN 106 can facilitate communication with other networks. For example, CN 106 can provide circuit-switched network (e.g., PSTN 108) access for WTRUs 102a, 102b, and 102c to facilitate communication between WTRUs 102a, 102b, and 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), and the IP gateway may act 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.

[0048] Although Figure 1A-1D The WTRU is described as a wireless terminal; however, it should be understood that in some typical embodiments, such a terminal may use a wired communication interface (e.g., temporary or permanent) with the communication network.

[0049] In a typical embodiment, the other network 112 may be a WLAN.

[0050] A WLAN employing an Infrastructure Basic Services Set (BSS) model may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may access or interface with a distributed system (DS) or other type of wired / wireless network that sends traffic into and / or out of the BSS. Traffic originating outside the BSS and destined for a STA can be delivered to the STA via the AP. Traffic originating from a STA and destined for a destination outside the BSS can be sent to the AP for delivery to the appropriate destination. Traffic between STAs within the BSS can be sent via the AP; for example, a source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic can be sent between the source and destination STAs (e.g., directly therebetween) using Direct Link Establishment (DLS). In some typical embodiments, the DLS may use 802.11e DLS or 802.11z Channelized DLS (TDLS). A WLAN using the Independent BSS (IBSS) mode may not have an access point (AP), and STAs (STAs) within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. Here, the IBSS communication mode is sometimes referred to as a "self-organizing" communication mode.

[0051] When operating in 802.11ac infrastructure mode or a similar mode, the AP can transmit beacons on a fixed channel (e.g., the primary channel). The primary channel can have a fixed width (e.g., a 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish connections with the AP. In some typical embodiments, this can be implemented as Carrier-Sense Multiple Access with Collision Avoidance (CSMA / CA) (e.g., in an 802.11 system). For CSMA / CA, STAs, including the AP (e.g., each STA), can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, that particular STA can fall back. Within a given BSS, at any given time, only one STA (e.g., only one station) can be transmitting.

[0052] High-throughput (HT) STAs can communicate using a 40MHz wide channel (e.g., by combining a 20MHz wide main channel with adjacent or non-adjacent 20MHz wide channels to form a 40MHz wide channel).

[0053] Very High Throughput (VHT) STAs can support channels with widths of 20MHz, 40MHz, 80MHz, and / or 160MHz. 40MHz and / or 80MHz channels can be formed by combining consecutive 20MHz channels. A 160MHz channel can be formed by combining eight consecutive 20MHz channels or by combining two non-consecutive 80MHz channels (this combination may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, data is transmitted and passed through a segmented parser that splits the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed individually on each stream. The streams can be mapped onto two 80MHz channels, and the data can be transmitted by the STA performing the transmission. On the receiver of the STA performing the reception, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0054] 802.11af and 802.11ah support sub-1 GHz operating modes. Compared to 802.11n and 802.11ac, the channel operating bandwidth and carrier used in 802.11af and 802.11ah are reduced. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to some typical embodiments, 802.11ah can support instrument-type control / machine-type communication (e.g., MTC devices in macro coverage areas). MTCs may have certain capabilities, such as limited capabilities including support (e.g., only support) certain and / or limited bandwidths. MTC devices may include a battery with a battery life exceeding a threshold (e.g., for maintaining a very long battery life).

[0055] For WLAN systems that can support multiple channels and channel bandwidths (e.g., 802.11n, 802.11ac, 802.11af, and 802.11ah), the WLAN system includes a channel that can be designated as the primary channel. The bandwidth of the primary channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by a particular STA, which is derived from all STAs operating in the BSS that support the minimum bandwidth operating mode. In the example of 802.11ah, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes, the width of the primary channel can be 1MHz for STAs that support (e.g., only support) the 1MHz mode (e.g., MTC type devices). Carrier sensing and / or Network Allocation Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy (e.g., because an STA (which only supports the 1MHz operating mode) is transmitting to the AP), then the entire available band can be considered busy even if most of the band remains open and available.

[0056] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. Depending on the country code, the total bandwidth available for 802.11ah is 6MHz to 26MHz.

[0057] Figure 1DThis is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, and 102c using NR radio technology on air interface 116. RAN 113 can also communicate with CN 115.

[0058] RAN 113 may include gNBs 180a, 180b, and 180c; however, it should be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. Each gNB 180a, 180b, and 180c may 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 180b may use beamforming to transmit and / or receive signals to and / or from gNBs 180a, 180b, and 180c. Thus, for example, gNB 180a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In an embodiment, gNBs 180a, 180b, and 180c may 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 embodiments, gNBs 180a, 180b, and 180c may implement Cooperative Multipoint (CoMP) technology. For example, WTRU 102a can receive cooperative transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0059] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable parameter configurations. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can be different for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0060] 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 accessing other RANs (e.g., eNodeBs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can use one or more of gNBs 180a, 180b, and 180c as mobile anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can use signals in unlicensed frequency bands to communicate with gNBs 180a, 180b, and 180c. In a non-standalone configuration, WTRUs 102a, 102b, and 102c communicate / connect with gNBs 180a, 180b, and 180c simultaneously with other RANs (e.g., eNodeBs 160a, 160b, and 160c). For example, WTRUs 102a, 102b, and 102c can communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c, as well as one or more eNodeBs 160a, 160b, and 160c, by implementing DC principles. In a non-standalone configuration, eNodeBs 160a, 160b, and 160c can act as mobile anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput to service WTRUs 102a, 102b, and 102c.

[0061] Each gNB 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, support network slicing, implement dual connectivity, implement interoperability processing between NR and E-UTRA, route user plane data to User Plane Functions (UPF) 184a and 184b, and route control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, etc. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other via the X2 interface.

[0062] Figure 1DThe CN 115 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 may include data network (DN) 185a, 185b. While each of the foregoing components is described as part of CN 115, it should be understood that any of these components may be owned and / or operated by an entity other than the CN operator.

[0063] AMF 182a and 182b can connect to one or more gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can act 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 PDU sessions with different needs), selecting specific SMF 183a and 183b, managing registration areas, terminating NAS signaling, and mobility management, etc. AMF 182a and 1823b can use network slicing to customize the CN support provided to WTRU 102a, 102b, and 102c based on the service types used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services relying on Ultra Reliable Low Latency Communication (URLLC) access, services relying on Enhanced Massive Mobile Broadband (eMBB) access, and / or services for Machine Type Communication (MTC) access, etc. AMF 162 can provide control plane functions for switching between RAN 113 and other RANs (not shown) using other radio technologies (such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi).

[0064] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and can configure traffic routing 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, and providing downlink data notifications, etc. PDU session types can be IP-based, non-IP-based, and Ethernet-based, etc.

[0065] UPF 184a and 184b can be connected to one or more gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface, thus providing WTRU 102a, 102b, and 102c with access to a packet-switched network (e.g., Internet 110) to facilitate communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184 and 184b can perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring processing, etc.

[0066] CN 115 can facilitate communication with other networks. For example, CN 115 may include or can communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 115 and PSTN 108. Furthermore, CN 115 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 can be connected to local data networks (DNs) 185a and 185b via the N3 interface connected to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and DNs 185a and 185b.

[0067] In view of Figure 1A-1D And about Figure 1A-1D The corresponding descriptions herein refer to one or more of the functions described below, which can be performed by one or more emulation devices (not shown): WTRU 102a-d, Base Station 114a-b, eNodeB 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other devices (one or more) described herein. These emulation devices can be one or more devices configured to simulate one or more of the functions described herein. For example, these emulation devices can be used to test other devices and / or simulate network and / or WTRU functions.

[0068] The simulation device can be designed to perform one or more tests on other devices in a laboratory environment and / or a carrier network environment. For example, the one or more simulation devices can perform one or more functions while being implemented and / or deployed, wholly or partially, as part of a wired and / or wireless communication network, to test other devices within the communication network. The 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. The simulation device can be directly coupled to other devices to perform tests, and / or can use over-the-air wireless communication to perform tests.

[0069] The one or more simulation devices can perform one or more functions, including all functionalities, without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation devices can be used in test laboratories and / or test scenarios where wired and / or wireless communication networks are not deployed (e.g., under test) to perform tests on one or more components. The one or more simulation devices can be test equipment. The simulation devices can transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (which, as an example, may include one or more antennas).

[0070] WTRU, UE, and user can be used interchangeably in this document.

[0071] In NR used in 5G wireless systems, ultra-reliable low-latency communication (URLLC) systems require mechanisms to increase the reliability of control channels (e.g., PDCCH) by reducing block error rate (BER) and the likelihood of congestion.

[0072] As used herein, a reference symbol may include a symbol (e.g., which may be represented as a complex number) that is fixed and known and used as a pilot symbol. A reference signal may include a time-domain signal generated by processing the reference symbol. For example, in OFDM, the reference symbol may be a complex number fed into n inverse discrete Fourier transform (IDFT) blocks, and the reference signal may be the output of said IDFT blocks. Downlink control information (DCI) may include a set of bits that are transmitted via a PDCCH carrying control information for a WTRU (user) or a set of WTRUs (users).

[0073] A resource element (RE) can include an OFDM symbol on a subcarrier. A resource element group (REG) can include a set of REs used as building blocks for control channel elements (CCEs), where the CCEs assign resource elements to WTRUs. REG bundles are REGs that are adjacent in time or frequency and are combined with the same associated precoder. NR-REG, NR-CCE, and NR-PDCCH can be used to refer to REGs, CCEs, and PDCCHs used for NR in 5G radio systems.

[0074] In 5G NR, a REG can be the smallest building block of a PDCCH. For example, each REG can consist of a resource block (RB) in frequency and 12 REs in time on an OFDM symbol. Within each REG, 9 REs can be used for control information, and 3 REs can be used for demodulation reference signals (DMRS). Multiple REGs that are adjacent in time or frequency (e.g., 2, 3, or 6) can form a REG bundle that is used with the same precoder and has a DMRS used together for channel estimation. Six REGs (e.g., in the format of a bundle of 1, 2, or 3 REGs) can form a CCE for a PDCCH. Each PDCCH can consist of one or more CCEs (e.g., 1, 2, 4, 8, or 16 CCEs), and the number of CCEs in a PDCCH can be referred to as the aggregation level (AL) of the PDCCH.

[0075] The mapping of REG bundles can include the following modes: interleaved and non-interleaved modes. In a non-interleaved mapping, consecutive REG bundles (i.e., frequency-adjacent) form a CCE, and frequency-adjacent CCEs form a PDCCH. In an interleaved mapping, REGs are interleaved (or permuted) before being mapped to a CCE, which may result in some (or all) non-adjacent REG bundles in a CCE and some (or all) non-adjacent CCEs in a PDCCH.

[0076] A control resource set (CORESET) can be configured by its frequency assignment (e.g., in blocks of 6 RBs), time length (1-3 OFDM symbols), REG bundle type, and the type of mapping from REG bundles to CCE (i.e., interleaved or non-interleaved). In one example, up to 3 CORESETs can exist in each bandwidth portion (BWP) (12 CORESETs in all 4 possible bandwidth portions).

[0077] A set of PDCCH candidates can be assigned to the WTRU for monitoring during blind detection of the PDCCH; this set is referred to as a search space or search space set (e.g., for multiple ALs). Each search space set can be configured by its associated CORESET, the number of candidates for each AL, and the monitoring timing. The monitoring timing can be determined by the monitoring period (e.g., in terms of time slots), the monitoring offset, and the monitoring mode (corresponding to 14 bits of all possible symbol patterns within a time slot).

[0078] Example methods for providing sufficient resources for downlink control channel transmission for URLLC WTRUs may include preempting eMBB control channels (one or more) in the presence of URLLC channels (one or more). In the example, resources can be assigned to downlink control channel transmissions available for the eMBB WTRU. Downlink control channels for URLLC WTRUs can receive higher priority than those for eMBB WTRUs. For example, the presence of a PDCCH for a URLLC WTRU can preempt or partially preempt the transmission of PDCCHs scheduled for the eMBB WTRU.

[0079] To reduce the probability of locking the PDCCH of a URLLC WTRU, the URLLC WTRU can be given higher priority than the eMBB WTRU on the PDCCH. In the example, when scheduling PDCCHs for different WTRUs based on their search space, the gNB can schedule the PDCCH for the URLLC WTRU first. Then, the gNB can schedule the PDCCH for the eMBB WTRU by removing PDCCH candidates that have been fully or partially used for the URLLC WTRU from the search space corresponding to the active eMBB WTRU. By allowing more resources to be used, enabling eMBB PDCCH preemption can reduce or eliminate blocking and increase the reliability of the URLLC WTRU's PDCCH.

[0080] An exemplary method can be used to partially preempt a PDCCH for an eMBB WTRU when a PDCCH for a URLLC WTRU is available. Two different overlapping cores can be assigned to the PDCCH for the eMBB WTRU and the PDCCH for the URLLC WTRU, respectively. The different overlapping cores can have different REG bundling types and / or transmission modes (i.e., interleaved and non-interleaved). To reduce latency for the URLLC WTRU, the cores assigned to the PDCCH for the URLLC WTRU can be allocated on the first OFDM symbol of the time slot, and the cores assigned to the PDCCH for the eMBB WTRU can be multi-symbol. When scheduling PDCCH candidates in the URLLC core, transmission of the eMBB PDCCH can be preempted on REGs shared with the transmitted URLLC PDCCH. When preemption occurs on shared REGs, rate matching can be employed to match the code rate of the eMBB PDCCH based on the remaining available REGs of the PDCCH. Figure 2 This is a scheduling diagram for an exemplary scheduling method 200 for partially preempting a PDCCH for an eMBB WTRU in the presence of a PDCCH for a URLLC WTRU. PDCCH 204 is scheduled for the URLLC WTRU on the first OFDM symbol 201 and partially preempts the transmission of PDCCH 210 for the eMBB WTRU on the dual-symbol CORESET 206 (across symbols 201 and 202). Data 208 can be sent after the transmission of PDCCH 204 and 210.

[0081] At the receiver, the eMBB WTRU can detect preempted REGs in a PDCCH candidate by comparing channel estimates from the DMRS of a REG bundle. For example, in the case of a REG bundle completed in time for the eMBB CORESET and the URLLC CORESET only covering the first symbol of the slot, if the eMBB WTRU observes a significant difference between the channel estimate of the REG on the first symbol and the channel estimates for the other REGs in that bundle, the eMBB WTRU can assume that the URLLC WTRU used the REG on the first symbol and can identify it as a preempted REG. The eMBB WTRU can remove the preempted REG from the REG set used for channel estimation (and PDCCH detection), and the channel estimation process can be completed by joint channel estimation for the remaining REGs in each REG bundle. The eMBB WTRU can perform blind decoding on the remaining REGs based on the channel estimate and the received signal, and apply rate matching associated with the number of remaining REGs.

[0082] The quality of channel estimation and consequently the quality of soft decisions based on those REGs for the received coded bits can vary depending on the number of remaining REGs in each REG bundle. Therefore, the eMBB WTRU can use information about the REGs removed from each bundle (and related information such as the number of DMRSs used for channel estimation of the REG bundles) for the decoding process. For example, the number of DMRSs used for channel estimation can affect the quality of the channel estimation, and this can be taken into account when calculating the log-likelihood ratio (LLR) of the received coded bits during decoding (i.e., the quality of soft decisions during decoding).

[0083] After decoding, similar to conventional blind detection of PDCCH, the eMBB WTRU can check the Cyclic Redundancy Code (CRC) to determine if the decoded data is correct and if it is associated with the eMBB's Radio Network Temporary Identifier (RNTI). Indications for the blind detection process's requirements (i.e., the existence of a possible overlapping URLLC PDCCH on a portion of the eMBB CORESET) and / or additional parameters that may be useful during blind detection can be included or excluded from the eMBB CORESET configuration provided by the gNB Radio Resource Control (RRC) layer. These additional parameters may include information such as the overlapping resource areas of the overlapping URLLC CORESET (e.g., represented according to OFDM symbol indexes and RBs, for example, with a granularity of 6 RBs for CORESET frequency configuration in 5G NR) and / or transmission modes. If the indication of the blind detection process's requirements is not included in the CORESET configuration received from the gNB, the WTRU can implicitly derive the overlapping portion of the CORESET based on some predefined pattern. For example, assuming the eMBB WTRU is configured with a relatively wideband coreset (e.g., a single-symbol coreset as wide as the bandwidth portion) and a narrowband multi-symbol coreset overlapping the single-symbol coreset (e.g., the multi-symbol coreset is much smaller than the bandwidth portion) on the first OFDM symbol, the eMBB WTRU can assume that the REG on the first OFDM symbol is preempted according to a previously known pattern. This method can be useful when the URLLC coreset is a single symbol and the eMBB coreset is a multi-symbol coreset, and it can also be applied when two coresets cover the same symbol but have different transmission patterns (e.g., one is interleaved while the other is not).

[0084] Figure 3This is a flowchart of an example method 300 for partial preemption of the PDCCH for the eMBB in the presence of a PDCCH for the URLLC. This example method 300 can be executed by the WTRU of the eMBB user. For example, example method 300 can be executed when the URLLC CORESET is single-symbol and the eMBB CORESET is multi-symbol. At 302, the eMBB WTRU can obtain the CORESET configuration for the eMBB CORESET and search space parameters (e.g., via RRC signaling). This CORESET configuration may include preemption indication parameters (PDCCH preemption indicator). At 304, the eMBB WTRU can determine whether the eMBB CORESET configuration includes an indication of possible (partial) preemption (i.e., an indication to enable PDCCH preemption). If the preemption indicator is not used, the eMBB WTRU can implicitly derive the overlapping portion of the CORESET to determine the likelihood of preemption as described above. If the indication of potential preemption is detected, at 306, the eMBB WTRU can examine each REG bundle and check the consistency of the channel estimation to identify the preempted REG. At 308, the eMBB WTRU can remove the preempted REG from the REG set used for channel estimation (and PDCCH detection) of the REG bundle, and perform channel estimation based on the remaining REGs (e.g., their DMRS) of each REG bundle. At 310, the eMBB WTRU can perform PDCCH detection by performing blind decoding (and avoiding the preempted REG) on the remaining REGs of each REG bundle based on the received signal, and perform rate matching associated with the number of remaining REGs in each REG bundle. At 312, the eMBB WTRU can check the CRC of the data decoded from the remaining REGs to detect errors and can receive the PDCCH (e.g., by checking the RNTI, etc., to determine if the PDCCH is used by the eMBB WTRU). If no indication of potential partial preemption is detected, at 314, the eMBB WTRU can perform joint channel estimation for each REG bundle. At 316, the eMBB can perform blind decoding of the PDCCH candidate using all REGs for each PDCCH candidate. At 318, the eMBB WTRU can check the CRC of the data decoded from all REGs to detect errors and can receive the PDCCH (e.g., by checking the RNTI, etc., to determine if the PDCCH is used by the eMBB WTRU).

[0085] The example method can be used for complete preemption of the eMBB WTRU's PDCCH when the PDCCH for the eMBB WTRU overlaps with the PDCCH for the URLLC WTRU. In the example, draft scheduling of the PDCCH for the eMBB WTRU can be done independently of scheduling of the PDCCH for the URLLC WTRU. Transmission of the scheduled PDCCH for the eMBB WTRU can be preempted when the URLLC WTRU's PDCCH requires an eMBB PDCCH candidate or when the eMBB PDCCH candidate overlaps with a PDCCH scheduled for the URLLC. This method of completely preempting the eMBB user's PDCCH can lead to a high probability of blocking for the eMBB WTRU. To avoid a high probability of blocking, a small number of additional spare PDCCH candidates can be allocated on the same CORESET or another CORESET for the eMBB WTRU to monitor when it cannot find and decode its expected PDCCH in its default search space.

[0086] Figure 4 This is another scheduling diagram for an exemplary scheduling method 400 used to partially preempt a PDCCH for an eMBB WTRU in the presence of a PDCCH for a URLLC WTRU. URLLC CORESET 404 (for URLLC WTRU PDCCH search) occupies OFDM symbol 401 (across all frequencies), and eMBB CORESET 406 (for eMBB WTRU PDCCH search) occupies a subset of frequencies on OFDM symbols 401 and 402, thus partially overlapping with URLLC CORESET 504 on certain carrier frequencies of OFDM symbol 401. According to... Figure 4 For example, multiple REG bundles 408 for the URLLC PDCCH are scheduled in OFDM symbol 401, and multiple REG bundles 410 are scheduled in OFDM symbols 401 and 402, such that the eMBB PDCCH is preempted by the URLLC PDCCH on REG 412 due to CORESET overlap. After the PDCCH is transmitted on OFDM symbols 401 and 402, data (e.g., Physical Downlink Shared Channel (PDSCH) 414) can be transmitted.

[0087] Figure 5 This is a scheduling graph for an exemplary scheduling method 500 used to fully preempt the PDCCH used for the eMBB WTRU when the PDCCH used for the eMBB WTRU overlaps with the PDCCH used for the URLLC WTRU. (See example...) Figure 5As shown, the large CORESET 504 or primary CORESET 504 for eMBB and URLLCWTRU can be configured on the first OFDM symbol 501 of the time slot (e.g., symbol 0, if they are numbered starting from zero), while the smaller (alternate) CORESET 506 can be configured on the second (and / or third) OFDM symbol 502 of the time slot, which contains a small number of PDCCH candidates for eMBB WTRU (in case their expected PDCCH is preempted on the primary CORESET 504). For example, the structure of the smaller CORESET 506 containing the alternative PDCCH candidates, as well as the number and size (aggregation level) of those alternative PDCCH candidates, can be configured by RRC. The positions of alternative PDCCH candidates with different aggregation levels within the alternative CORESET 506 can be fixed or obtained by a hash function defined for the search space. All active eMBB WTRUs can have the same search space within the alternative CORESET 506, or their corresponding search spaces can be different. Data 508 can be sent after the PDCCH is transmitted in CORESET 504 and / or 506.

[0088] The methods described herein for preempting the PDCCH of an eMBB WTRU may not affect the behavior of a URLLC WTRU, but may affect the behavior of an eMBB WTRU. For example, an eMBB WTRU may be explicitly or implicitly configured by a gNB (e.g., using RRC signaling) to blindly decode its PDCCH candidates in a standby CORESET or standby search space only if blind decoding of its PDCCH candidates in the primary CORESET or its primary search space set is unsuccessful. This implicit configuration of the eMBB WTRU behavior for the standby CORESET may be accomplished during CORESET configuration by including indications of the standby state of the standby CORESET and / or the index of the primary CORESET associated with the standby CORESET.

[0089] Several methods can be used by the gNB to transmit URLLC DCI on multiple PDCCHs, and various corresponding methods can be used for receiving URLLC WTRUs to increase the reliability of DCI transmission for URLLC WTRUs. In the example, the reliability of DCI transmission for URLLC can be increased by adding redundancy to the PDCCH of the URLLC user. For example, the same DCI can be transmitted on two or more PDCCHs for the URLLC WTRU, or a combined redundancy of multiple DCIs for the URLLC WTRU can be transmitted by the gNB.

[0090] In an example used to enhance the reliability of the URLLC control channel, the same DCI content can be transmitted repeatedly on multiple PDCCHs. PDCCH transmissions can be repeated at the same rate and / or the same transmission mode (e.g., by repeating the same PDCCH at two different locations), or they can be repeated at different rates (e.g., using PDCCHs with different aggregation levels) and / or different transmission modes (e.g., using interleaved and non-interleaved modes).

[0091] In one example, the same DCI can be sent on two or more PDCCH candidates within the same search space. In this example, the gNB can simultaneously use two or more PDCCH candidates (with the same or different aggregation levels) to send a DCI to a WTRU (e.g., a URLLC WTRU). The number or maximum number of simultaneous PDCCHs scheduled for a WTRU can be indicated in the WTRU's search space configuration (e.g., using RRC signaling), and / or can be indicated in the CORESET configuration for all associated WTRUs.

[0092] In another example, the same DCI can be sent on two or more PDCCH candidates in different search spaces on the same CORESET. In this example, two or more search space sets (e.g., each search space set may contain several candidates with different aggregation levels) can be assigned to WTRU. WTRU can anticipate and monitor the scheduled PDCCHs on each assigned search space set. RRC configuration can indicate whether the aggregation levels of multiple PDCCHs carrying the same DCI are the same or different.

[0093] When multiple PDCCHs have the same aggregation level, a one-to-one correspondence can exist between candidates in the search space set, such as... Figure 6 As shown. Figure 6 This is a scheduling graph for an example method 600 for transmitting the same DCI on two PDCCH candidates (REG bundle 606 and REG bundle 608) on two different search space sets 601 and 602, respectively, on the same CORESET 604. In this case, the scheduling of corresponding candidates (REG bundle 606 and REG bundle 608) in different search space sets 601 and 602 can be linked to each other (i.e., corresponding candidates can be scheduled simultaneously), and this correspondence can be explicitly or implicitly indicated in the RRC configuration for CORESET 604 and / or search space sets 601 and 602. This correspondence helps the WTRU simplify blind detection of PDCCHs received on REG bundles 606 and 608. Figure 6In the example, each of the two or more search space sets 601 and 602 is on a single OFDM symbol within the multi-symbol CORESET 604 and can be associated with different beams.

[0094] In the example above, a one-to-one correspondence between PDCCH candidates from two or more different search space sets can be achieved by using the following parameters as hash functions for two or more search space sets: the same RNTI, the same set of aggregation levels, and the number of candidates for each aggregation level. When the set of aggregation levels and the number of candidates for each aggregation level are the same for two or more search space sets, the one-to-one correspondence can be based on the candidate index for each aggregation level. Additionally, rules for the one-to-one correspondence can be pre-specified or configured by the gNB (e.g., using RRC signaling). This one-to-one correspondence between PDCCH candidates from two or more different search space sets can exist within a single CORESET, or between two or more different search space sets from different CORESETs and / or different monitoring times.

[0095] At the receiver, the WTRU can independently perform a blind search of all search space sets for the DCI by checking the RNTI separately through CRC check for each PDCCH candidate. In one example, if there is a one-to-one correspondence between PDCCH candidates in two or more different search space sets, the WTRU can first perform channel estimation separately for each PDCCH candidate, and then either add the received symbols of the corresponding PDCCH candidate together, or combine the soft decoding information of the corresponding PDCCH candidate, and then decode and CRC check the corresponding PDCCH candidate together. This method of combining soft decoding information can be used if the bit set transmitted through the corresponding PDCCH is the same (which is the case if the DCI is the same for the corresponding PDCCH and the channel coding and CRC are the same for the corresponding PDCCH).

[0096] In another example, the same DCI can be transmitted on two or more PDCCHs on different CORESETs. In this case, the same DCI can be transmitted via two or more PDCCHs on different CORESETs used for WTRU. Indications regarding possible redundant transmissions can be included in the CORESET configuration or the configuration regarding the search space (e.g., via RRC signaling) or the Physical Broadcast Channel (PBCH). Multiple CORESETs containing multiple PDCCHs transmitting the same DCI can be on the same or different BWPs.

[0097] In another example, multiple cores containing multiple PDCCHs transmitting the same DCI can be on different OFDM symbols. In this case, the core and the PDCCH candidates carrying the DCI can be associated with different beams. Furthermore, cores containing the PDCCHs can have different or the same transmission modes (e.g., interleaved and non-interleaved).

[0098] When transmitting the same DCI over multiple PDCCHs on the same CORESET, the WTRU may assume that the DMRS antenna ports associated with the multiple PDCCHs are quasi-co-bit in terms of delay spread, Doppler spread, Doppler shift, average delay, and / or spatial reception (Rx) parameters. When transmitting multiple PDCCHs on different CORESETs, the WTRU may not assume that the DMRS antenna ports associated with the multiple PDCCHs are quasi-co-bit in terms of delay spread, Doppler spread, Doppler shift, average delay, and / or spatial Rx parameters. In the latter case, the WTRU may perform channel estimation independently on each PDCCH.

[0099] When the WTRU receives the same DCI on multiple PDCCHs (e.g., the same downlink allocation or uplink grant), the WTRU can monitor a set of PDCCH candidates within the same or multiple search spaces. If a CRC scrambled by the cell RNTI (C-RNTI) is checked for one of the PDCCH candidates, the WTRU can continue monitoring other PDCCH candidates with CRCs scrambled by the same WTRU-specific C-RNTI. In this case, the WTRU can use the detected DCIs on multiple PDCCHs with the same C-RNTI to improve control channel detection reliability. Even when the same DCI is transmitted on multiple PDCCHs, and the CRCs of multiple PDCCHs are scrambled by the same WTRU-specific C-RNTI, the WTRU can receive one PDCCH in the common search space and another PDCCH in the WTRU-specific search space.

[0100] In another example, PDCCH repetition can be achieved through a multi-coreset search space. For example, to facilitate the scheduling and blind detection of repeated DCIs, the WTRU can be configured with search spaces associated with multiple coresets. The search space can be semi-statically configured via higher-level signaling (e.g., RRC) using a set of parameters (e.g., associated coresets). In the example approach, multiple coresets can be associated with a search space (or a set of search spaces), and each index of the corresponding hash function can be associated with multiple PDCCH candidates (e.g., one PDCCH candidate from each coreset). The linked PDCCH candidates (on different coresets) can be used to repeat the same control information (DCI). At the receiver, the WTRU can blindly detect its PDCCH by first combining the linked PDCCH candidates from different coresets (based on their search space or set of search spaces), then decoding the linked PDCCH candidates and verifying the CRC. In the example, the WTRU can decode each PDCCH candidate individually (and verify the CRC of each candidate separately). Individual decoding of the corresponding PDCCH candidate can provide enhanced reliability through multiple trials.

[0101] In PDCCH repetitions across multiple CORESET search spaces, the CORESET-related bit field of the search space configuration can indicate a combination of CORESETs (e.g., instead of a single CORESET). An example of indicating a combination of CORESETs is using 12 bits to indicate the association of a subset of configured CORESETs with a search space (or a set of search spaces), for example, replacing the current parameter ControlResourceSetId (or “CORESET-ID”) in 5G NR. The mapping of the CORESET-related bits in the search space configuration to subsets of CORESETs can be pre-specified as a table in the standard specification, or it can be indicated by including / excluding the i-th CORESET using 0 or 1 as the index (i from 0 to 11) of the i-th bit in the CORESET-related bit field of the search space configuration.

[0102] In another example, the undefined case of CORESET ID can be used to define combinations of multiple CORESETs. For example, when a maximum of 12 CORESETs (0-11) are defined in the search space configuration and 4 bits are used to indicate the ControlResourceSetId (or "CORESET-ID"), the last four values ​​(12-15) can be used to represent CORESET pairs, as shown in Table 1.

[0103]

[0104] Table 1: Examples of the ControlResourceSetID parameter, which includes multiple CORESET options for search space configuration.

[0105] Figure 7 A flowchart of an example WTRU procedure 700 for PDCCH repetition via a multi-CORESET search space and soft combination for blind detection is shown. After receiving the search space (SS) configuration 702 (e.g., via RRC or other higher-level signaling), the WTRU can determine at 704 whether the configured search space is a single CORESET or multiple CORESETs. For example, the WTRU can determine this based on received flag (indicator) bits (e.g., received in the search space configuration) or implicitly based on the number of CORESET-related bits in the search space configuration (e.g., the default could be a single CORESET search space).

[0106] If the WTRU identifies a multi-CORESET search space, then at 706, the WTRU can determine the associated CORESET based on the CORESET-related bits configured in the search space and a pre-specified mapping (e.g., based on a standard specification). At 708, the WTRU can determine the corresponding pairs (or tuples) of PDCCH candidates that should carry the same DCI (one DCI per CORESET) by determining the PDCCH candidate set associated with each CORESET and the one-to-one correspondence between the PDCCH candidates in these sets. For blind detection, at 710, the WTRU can perform channel estimation for each REG bundle of the PDCCH candidates separately. At 712, the WTRU can perform blind detection for each corresponding pair (or tuple) of PDCCH candidates by combining the symbols of the PDCCH candidates belonging to the pair (or tuple) (or soft-decoding information from the symbols), decoding each pair (or tuple), and checking the CRC.

[0107] If the WTRU identifies a single CORESET search space, then at 714, the WTRU can determine the associated CORESET using the CORESET-related bit field in the SS configuration. At 716, the WTRU can determine the PDCCH candidate set for each monitoring time based on the SS configuration parameters. At 718, the WTRU can perform blind detection by performing channel estimation and decoding each PDCCH candidate and verifying the CRC.

[0108] Joint redundancy can be used for multiple DCIs intended for use with a URLLC WTRU. As discussed in the examples above, multiple DCIs corresponding to multiple streams or data layers can be used for the same WTRU. In this case, in addition to repeating each DCI on multiple PDCCHs or as an alternative, joint redundancy of multiple DCIs can be used to achieve enhanced reliability through redundancy. To achieve joint redundancy, network coding schemes can be used to enhance reliability. For example, if two DCIs A and B have the same size and DCI A is sent to the WTRU by the first PDCCH and DCI B is sent to the WTRU by the second PDCCH, then DCI + DCI B (e.g., added as an XOR operation) can be sent to the same WTRU by the third PDCCH to increase reliability.

[0109] Drop rules can be designed to meet the blind decoding constraints of the WTRU. In 5G NR and LTE, a limit on the maximum number of blind decodes in a time slot can be assumed for the WTRU. To limit the complexity of channel estimation for the WTRU, the number of CCEs covered by the PDCCH candidates that the WTRU can blindly decode in a time slot can be limited. The inherent randomness of the hash function specifying the WTRU's search space set can make the number of covered CCEs (or the number of CCEs in the footprint of the WTRU's search space set) variable. Different types of PDCCHs with different possible monitoring rates can cause fluctuations in the number of PDCCH candidates to be blindly decoded. Therefore, limiting the parameters of the search space set to keep the number of blind decodes and the number of covered CCEs within appropriate ranges under all conditions may be too stringent.

[0110] In one example, the search space parameters can be designed to satisfy the constraints on the number of candidates and the number of CCEs covered with a high probability. For low-probability cases exceeding the constraints, rules can be set to discard some PDCCH candidates from the blind decoding process to meet hard constraints. The discarding rules can be based on many factors and variables. For example, discarding rules can be fixed rules specified by technical specifications and / or semi-static rules configured by higher-level signaling (e.g., RRC). The discarding rules can be based on the priority level of different types of PDCCHs, monitoring timing, and / or other parameters. The rules for discarding PDCCH candidates from blind decoding can be based on the aggregation level of the PDCCH candidates (e.g., having the lowest priority compared to other PDCCH candidates). The discarding rules and associated priority order can be based on a combination of different attributes, such as those discussed above. The WTRU and / or gNB can be aware of the discarding rules to prevent the WTRU from blindly searching for discarded PDCCH candidates and / or the gNB from scheduling discarded PDCCH candidates. In the example, a fixed set of drop rules can be used, and / or multiple sets of drop rules can be used, allowing a drop rule set to be semi-statically selected or configured by the gNB, and the WTRU to be notified of the selected drop rule set via a mechanism such as CORESET or RRC configuration of the search space.

[0111] Example hierarchy of priorities for different CORESETs and different PDCCH candidates with different aggregation levels within each CORESET can be as follows: (1) all PDCCH candidates on a single-symbol CORESET on the first OFDM symbol of the time slot; (2) all PDCCH candidates on a single-symbol CORESET on other OFDM symbols of the time slot; (3) PDCCH candidates on a multi-symbol CORESET with smaller candidates (with smaller aggregation levels) and higher priorities.

[0112] In one example, the rule for discarding PDCCH candidates from the blind search could be based on the number of CCEs that do not overlap with the CCEs of other PDCCH candidates in the search space set. In other words, one or more PDCCH candidates could be selectively removed from the blind search such that their removal would result in the removal of a maximum number of CCEs from the pool used for channel estimation. When multiple PDCCH candidates with the same metric are identified, their indices in the search space can indicate their priority.

[0113] Although features and elements have been described above in specific combinations, those skilled in the art will understand that each feature or element can be used alone or in arbitrary 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, buffer memory, semiconductor memory devices, magnetic media (e.g., internal hard disks and removable disks), magneto-optical media, and optical media (e.g., CD-ROMs and Digital Universal Discs (DVDs)). A processor associated with the software can be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), the WTRU comprising: processor; as well as Transceiver; The processor and the transceiver are configured to receive configuration information defining a first search space set and a second search space set, the first search space set including a first plurality of physical downlink control channel (PDCCH) candidates, the second search space set including a second plurality of PDCCH candidates, wherein the configuration information includes information indicating that the first search space set and the second search space set are linked, and wherein the number of the first plurality of PDCCH candidates is the same as the number of the second plurality of PDCCH candidates. as well as The processor and the transceiver are configured to receive downlink control information (DCI) by: Based on the received configuration information, at least one of the first plurality of PDCCH candidates is used to monitor the first transmission of the DCI; Based on the received configuration information, at least one of the second plurality of PDCCH candidates is used to monitor the second transmission of the DCI; as well as The DCI is decoded using either the first transmission or the second transmission.

2. The WTRU of claim 1, wherein the processor and the transceiver are further configured to decode the DCI using both the first transmission and the second transmission.

3. The WTRU of claim 2, wherein the processor and the transceiver are further configured to receive the DCI by combining the first transmitted information with the second transmitted information.

4. The WTRU according to claim 1, wherein: The first search space set is associated with an aggregation level, and The second search space set is associated with an aggregation level that corresponds to the aggregation level associated with the first search space set.

5. The WTRU of claim 1, wherein the configuration information indicates that each of the first plurality of PDCCH candidates is linked to a corresponding PDCCH candidate in the second plurality of PDCCH candidates.

6. The WTRU of claim 1, wherein the first search space set is associated with a first control resource set (CORESET), and the second search space set is associated with a second CORESET.

7. The WTRU of claim 6, wherein the first transmission and the second transmission are received using different beams.

8. A method for receiving downlink transmissions with increased reliability, performed by a wireless transmit / receive unit (WTRU), the method comprising: Receive configuration information defining a first search space set and a second search space set, wherein the first search space set includes a first plurality of physical downlink control channel (PDCCH) candidates, and the second search space set includes a second plurality of PDCCH candidates, wherein the configuration information includes information indicating that the first search space set and the second search space set are linked, and wherein the number of the first plurality of PDCCH candidates is the same as the number of the second plurality of PDCCH candidates; as well as Receive downlink control information (DCI) through the following steps: Based on the received configuration information, at least one of the first plurality of PDCCH candidates is used to monitor the first transmission of the DCI; Based on the received configuration information, at least one of the second plurality of PDCCH candidates is used to monitor the second transmission of the DCI; as well as The DCI is decoded using either the first transmission or the second transmission.

9. The method according to claim 8, wherein, Decoding the DCI using either the first transmission or the second transmission includes decoding the DCI using both the first transmission and the second transmission.

10. The method according to claim 9, wherein, Receiving the DCI further includes: receiving the DCI by combining the information transmitted in the first transmission with the information transmitted in the second transmission.

11. The method of claim 8, wherein: The first search space set is associated with an aggregation level, and The second search space set is associated with an aggregation level that corresponds to the aggregation level associated with the first search space set.

12. The method according to claim 8, wherein, The configuration information indicates that each of the first plurality of PDCCH candidates is linked to a corresponding one of the second plurality of PDCCH candidates.

13. The method according to claim 8, wherein, The first search space set is associated with the first control resource set (CORESET), and the second search space set is associated with the second CORESET.

14. The method according to claim 8, wherein, The first transmission and the second transmission are received using different beams.

15. A base station, comprising: processor; as well as Transceiver; The processor and the transceiver are configured to transmit configuration information defining a first search space set and a second search space set, the first search space set including a first plurality of physical downlink control channel (PDCCH) candidates, the second search space set including a second plurality of PDCCH candidates, wherein the configuration information includes information indicating that the first search space set and the second search space set are linked, and wherein the number of the first plurality of PDCCH candidates is the same as the number of the second plurality of PDCCH candidates; as well as The processor and the transceiver are configured to transmit downlink control information (DCI) by: The first transmission of the DCI is transmitted using at least one of the first plurality of PDCCH candidates; and The second transmission of the DCI is transmitted using at least one of the second plurality of PDCCH candidates, wherein the first transmission of the DCI includes control information and the second transmission of the DCI includes the control information according to the configuration information indicating that the first search space set and the second search space set are linked.

16. The base station according to claim 15, wherein: The first search space set is associated with an aggregation level, and The second search space set is associated with an aggregation level that corresponds to the aggregation level associated with the first search space set.

17. The base station according to claim 15, wherein, The configuration information indicates that each of the first plurality of PDCCH candidates is linked to a corresponding one of the second plurality of PDCCH candidates.

18. The base station according to claim 15, wherein, The first search space set is associated with the first control resource set (CORESET), and the second search space set is associated with the second CORESET.

19. The base station according to claim 15, wherein, The first transmission and the second transmission are sent using different beams.

20. The base station according to claim 15, wherein, The first transmission and the second transmission are transmitted using different orthogonal frequency division multiplexing (OFDM) symbols.

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