Phase tracking reference signal transmission

Abstract

A system, method, and apparatus for ensuring that a number of phase tracking reference signals (PT-RSs) remains the same across multiple slots. A wireless transmit / receive unit (WTRU) can receive control information including a number of scheduled resource blocks (RBs), and can then determine a PT-RS density based on the number of scheduled RBs. The WTRU can determine a RB offset value for the WTRU based on a modulo of a WTRU-ID and a maximum RB offset value, where a maximum value of the RB offset value can be based on at least one of the number of scheduled RBs and the PT-RS density. The WTRU can then transmit or receive a signal with PT-RSs based on the RB offset value.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201880073849.8, filed on November 14, 2018, entitled “Phase Tracking Reference Signal Transmission”, the contents of which are incorporated herein by reference.

[0002] Cross-references to related applications

[0003] This application claims the benefit of Provisional U.S. Application 62 / 586,642, filed November 15, 2017, and U.S. Application 62 / 720,614, filed August 21, 2018, the contents of which are incorporated herein by reference. Background Technology

[0004] In advanced wireless systems, there is a high demand for data in the spectrum above 6 GHz in order to utilize the greater available bandwidth. One challenge in using these frequencies is the significant propagation loss due to the higher free-space path loss at these higher frequencies (especially in outdoor environments). These problems can be addressed by using systems, methods, and devices. Summary of the Invention

[0005] A system, method, and apparatus for ensuring that the number of Phase Tracking Reference Signals (PT-RS) remains the same across multiple time slots. A Wireless Transmit / Receive Unit (WTRU) can receive control information including the number of scheduled Resource Blocks (RBs), and then determine the PT-RS density based on the number of scheduled RBs. The WTRU can determine its RB offset value based on the modulus of its WTRU-ID and a maximum RB offset value, wherein the maximum RB offset value can be based on at least one of the number of scheduled RBs and the PT-RS density. The WTRU can then transmit or receive signals with PT-RS based on the RB offset value. Attached Figure Description

[0006] A more detailed understanding can be obtained from the following description given with reference to the accompanying drawings, wherein the same reference numerals in the drawings indicate the same parts, and wherein:

[0007] Figure 1A This is a system diagram illustrating an exemplary communication system that can implement one or more embodiments disclosed;

[0008] Figure 1B This illustrates a method according to one embodiment. Figure 1A The system diagram shown illustrates an example wireless transmit / receive unit (WTRU) used internally within a communication system.

[0009] Figure 1C This illustrates a method according to one embodiment. Figure 1A The diagram shows an example radio access network (RAN) and an example core network (CN) used within the communication system.

[0010] Figure 1D This illustrates a method according to one embodiment. Figure 1A The system diagram shown illustrates another example of a RAN and another example of a CN used internally in the communication system.

[0011] Figure 2 This is an example graph showing the PT-RS time density.

[0012] Figure 3 This is a diagram of a block-based PT-RS that precedes DFT, used as an example of DFT-s-OFDM with N blocks;

[0013] Figure 4 This is a diagram illustrating a normal cyclic prefix (CP);

[0014] Figure 5 This is a diagram illustrating an extended CP (virtual CP);

[0015] Figure 6 It is a set of illustrations of ordinary UW and CP combinations;

[0016] Figure 7 This is a diagram illustrating an example of a perturbation method;

[0017] Figure 8 This is a diagram illustrating an example dynamic method for DFT-s-OFDM;

[0018] Figure 9 This is a diagram illustrating an example dynamic method for DFT-s-OFDM;

[0019] Figure 10 This is a diagram illustrating an example of PT-RS frequency density;

[0020] Figure 11A This is an illustration of an example of RB offset values;

[0021] Figure 11B This is a diagram illustrating an example of a process used to maintain the same number of PT-RS for the scheduled bandwidth;

[0022] Figure 12 This is a diagram illustrating an example of a cyclic shift of an RB containing PT-RS;

[0023] Figure 13 This is an illustration of an example of PT-RS mapping for 7 RBs with different RB offset values;

[0024] Figure 14This is a diagram illustrating PT-RS mappings used for scheduling processing with widths of 7 RBs and 13 RBs;

[0025] Figure 15 This is a diagram illustrating an example PT-RS mapping for 7 RBs with dynamic RB offset values;

[0026] Figure 16 This is an illustration of an example of PT-RS mapping for transmission of 13 RBs with dynamic RB offset values;

[0027] Figure 17 This is a diagram illustrating the PT-RS frequency position based on the symbol position;

[0028] Figure 18 This is a diagram illustrating the PT-RS frequency density based on RBG;

[0029] Figure 19 This is an illustration of an example PT-RS generation process used for pi / 2BPSK data modulation;

[0030] Figure 20 This is an illustration of PT-RS generation processing used for pi / 2BPSK data modulation and OCC;

[0031] Figure 21 This is a diagram illustrating an example of looping through Objective-C;

[0032] Figure 22 This is an example constellation diagram related to pi / 2BPSK and QPSK constellations;

[0033] Figure 23 This is an illustration of a public PT-RS design example;

[0034] Figure 24 This is a diagram illustrating an example of an OCC application;

[0035] Figure 25 This is a diagram illustrating an example of an OCC application;

[0036] Figure 26 This is an example constellation diagram of the alternative pi / 2BPSK constellations;

[0037] Figure 27 This is an illustration of an example of using a CP extender block and generating a CP extended RS based on a predefined RS;

[0038] Figure 28 This is a diagram illustrating an example signal structure for implementing a virtual CP using a CP expander block;

[0039] Figure 29 This is a diagram illustrating the partitions of the waveform matrix used to derive the CP expander block;

[0040] Figure 30 This is a transmission diagram with an example NR value configuration featuring a virtual CP;

[0041] Figure 31 This is a signal diagram with an example NR numerical configuration featuring a virtual CP;

[0042] Figure 32 This is a diagram illustrating a double CP extension with an example of CP extension RS.

[0043] Figure 33 This is a diagram illustrating an example of a CP extended PT-RS design;

[0044] Figure 34 This is a diagram illustrating an example signal structure for a virtual CP with a CP expander block; and

[0045] Figure 35 This is a diagram illustrating an example of waveform matrix partitioning used to derive the CP extender block for a complete PT-RS. Detailed Implementation

[0046] Figure 1A This is an illustration of an exemplary communication system 100 that can implement one or more of 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.

[0047] 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. WTRU 102a, 102b, 102c, or 102d may be interchangeably referred to as UE.

[0048] 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., CN106 / 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.

[0049] As described herein, a wireless device can be any node that performs wireless communication on a network, such as a WTRU or base station as described herein.

[0050] 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 one embodiment, 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.

[0051] 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, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 can be established using any suitable radio access technology (RAT).

[0052] 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).

[0053] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may use some kind of 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-A Pro) to establish air interface 116.

[0054] In one 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 an air interface 116.

[0055] 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 (e.g., using the dual connectivity (DC) principle). Thus, the air interface used 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).

[0056] 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.

[0057] Figure 1ABase station 114b can be, for example, 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 a radio technology such as IEEE 802.11. In one embodiment, base station 114b and WTRUs 102c, 102d can establish a wireless personal area network (WPAN) by implementing a 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.

[0058] RAN 104 / 113 can communicate with CN 106 / 115, 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 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 RAN 104 / 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.

[0059] 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.

[0060] 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 using cellular-based radio technology, and with base station 114b using IEEE 802 radio technology.

[0061] 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 numeric keypad 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. It should be understood that, while remaining consistent with the embodiments, WTRU 102 may also include any sub-combination of the foregoing components.

[0062] 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.

[0063] 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 another embodiment, transmit / receive component 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, transmit / receive component 122 may be configured to transmit and receive both 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.

[0064] Although Figure 1B While the transmit / receive component 122 is described as a single component, the WTRU 102 may include any number of transmit / receive components 122. More specifically, the WTRU 102 may use MIMO technology. Thus, in one 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.

[0065] 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).

[0066] The processor 118 of WTRU 102 can be coupled to a speaker / microphone 124, a numeric keypad 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, the numeric keypad 126, and / or the 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, a memory stick, a secure digital card (SD card), etc. In other embodiments, processor 118 may access information from and store data in memories that are not actually located in WTRU 102, such as those memories located in a server or home computer (not shown).

[0067] 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.

[0068] 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.

[0069] 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.

[0070] WTRU 102 may include a full-duplex wireless device, wherein the reception and 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 one embodiment, 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)).

[0071] 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 using E-UTRA radio technology on air interface 116. RAN 104 can also communicate with CN 106.

[0072] 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.

[0073] 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.

[0074] Figure 1C The CN 106 shown may include a Mobility Management Gateway (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.

[0075] MME 162 can connect to each eNode B160a, 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).

[0076] The SGW 164 can connect to each eNodeB160a, 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.

[0077] SGW 164 can be connected to PGW 146, which can provide packet-switched network (e.g., Internet 110) access for WTRUs 102a, 102b, and 102c to facilitate communication between WTRUs 102a, 102b, and 102c and IP-enabled devices.

[0078] 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.

[0079] 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.

[0080] In a typical embodiment, the other network 112 may be a WLAN.

[0081] 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 types of wired / wireless networks that send 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, where a source STA can send traffic to the AP and the AP can deliver 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 Tunneled DLS (TDLS). For example, a WLAN using 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. Here, the IBSS communication mode is sometimes referred to as a "self-organizing" communication mode.

[0082] 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, carrier-sense multiple access with collision avoidance (CSMA / CA) can be implemented (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. In a given BSS, at any given time, there is only one STA (e.g., only one station) transmitting.

[0083] 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).

[0084] 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 is 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).

[0085] 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 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).

[0086] For WLAN systems that can support multiple channels and channel bandwidths (e.g., 802.11n, 802.11ac, 802.11af, and 802.11ah), these systems include 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 single STA, which is derived from all STAs operating in the BSS supporting 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.

[0087] 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.

[0088] Figure 1D This is a system diagram illustrating RAN 113 and CN 115 according to one 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.

[0089] 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 160a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers (not shown) to WTR 102a. A subset of these component carriers may be in unlicensed spectrum, while the remaining component carriers may be in licensed spectrum. In one embodiment, 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).

[0090] 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 varying absolute durations).

[0091] 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.

[0092] 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 Xn interface.

[0093] 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.

[0094] 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. As an example, different network slices can be established for different use cases, such as services relying on Ultra Reliable Low Latency (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.

[0095] 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 WTRU 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.

[0096] UPF 184a and 184b can be connected to one or more gNB 180a, 180b, and 180c in CN 113 via the N3 interface, thus providing packet-switched network (e.g., Internet 110) access for WTRU 102a, 102b, and 102c 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.

[0097] 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 DNs 185a and 185b via the N3 interface connected to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and local data networks (DNs) 185a and 185b.

[0098] 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, DN185a-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.

[0099] 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.

[0100] 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).

[0101] Typically, in LTE, Orthogonal Frequency Division Multiplexing (OFDM) can be used for downlink (DL) transmission, while Discrete Fourier Transform (DFT)-s-OFDM can be used for uplink (UL) transmission. In conventional Cyclic Prefix (CP) DFT-s-OFDM (sometimes also called Single Carrier Frequency Division Multiple Access with Multiple Access (SC-FDMA)), data symbols can be expanded with DFT blocks and then mapped to the corresponding inputs of IDFT blocks. CP can be prepended at the beginning of symbols to avoid inter-symbol interference (ISI) and to allow single-tap frequency domain equalization (FDE) to be performed at the receiver.

[0102] In downlink transmission, reference symbols can be distributed across specific subcarriers (that is, one OFDM symbol can load data and reference symbols onto multiple subcarriers). Common reference symbols can be transmitted on subcarriers distributed across the system bandwidth, while WTRU-specific reference signals can be distributed on subbands allocated to a specific WTRU.

[0103] 3GPP has proposed an advanced wireless communication system called New Radio (NR). NR applications can be broadly categorized into several types: Enhanced Mobile Broadband (eMBB), Massive Machine-Type Communication (mMTC), and Ultra-Reliable Low-Latency Communication (URLLC). Within each category, there are numerous applications that can be considered for different needs and deployment scenarios with specific performance requirements. For example, mMTC and URLLC applications can range from automotive to healthcare, agriculture, utilities, and logistics industries.

[0104] To meet high data rate requirements, spectrum above 6 GHz can be used to utilize its large bandwidth. One challenge of using these higher frequencies is the significant propagation loss due to the higher free-space path loss at these frequencies (especially in outdoor environments).

[0105] Because beamforming can compensate for path loss without increasing transmission power, it is a solution for addressing significant path loss at higher frequencies. When using beamforming to compensate for path loss, all downlink and uplink channels can be beam-based.

[0106] In one scenario, device-to-device (D2D) and / or vehicle-to-everything (V2X) communication can utilize LTE. One or more of the following physical channels may be used for sidelink transmission and / or reception: SPSS (Sidelink Primary Synchronization Signal) and / or SSSS (Sidelink Secondary Synchronization Signal); PSBCH (Physical Sidelink Broadcast Channel); PSCCH (Physical Sidelink Control Channel); PSSCH (Physical Sidelink Shared Channel); and / or PSDCH (Physical Sidelink Discovery Channel).

[0107] Sidelinks can support one or more modes (e.g., up to four modes). First and / or second modes (e.g., mode 1 and / or mode 2) can be used for D2D communication. D2D communication may require reliable transmission with energy efficiency. D2D communication can tolerate latency and / or can be used for low mobility. Mode 1 can be based on or can utilize eNB scheduling to perform sidelink transmissions, where resources for sidelink transmissions can be scheduled by the eNB using DCI. Mode 2 can be based on or can utilize WTRU resource selection within a configurable resource pool (e.g., autonomous resource selection). Mode 1 can be used when the WTRU performing the sidelink transmission is located below or within the eNB's coverage area, enabling the WTRU to receive control signals from the eNB. Mode 2 can be used when the WTRU for sidelink transmission is outside and / or within the eNB's coverage area.

[0108] Third and / or fourth modes (e.g., mode 3 and / or mode 4) can be used for V2X communication (e.g., to support high mobility and / or low latency). Mode 3 can use eNB scheduling to perform sidelink resource determination. Mode 4 can use WTRU resource selection (e.g., autonomous resource selection).

[0109] For modes using scheduling (e.g., mode 1 and / or mode 3), the sidelink WTRU can receive resource grants for sidelink transmissions. The WTRU can monitor (e.g., obtain by monitoring) resource grants within the search space configured for the Uu interface.

[0110] In one or more embodiments, phase noise can be compensated before demodulating the Physical Downlink Shared Channel (PDSCH) and / or Physical Uplink Shared Channel (PUSCH) by using a phase tracking reference signal (PT-RS) to measure, track, and / or estimate phase noise. The PT-RS can be interchanged with a phase noise reference signal (PNRS) and a reference signal (RS).

[0111] PT-RS can be transmitted within the scheduling bandwidth used for PDSCH or PUSCH. Nodes (e.g., gNBs) can enable / disable PT-RS transmissions within the scheduling bandwidth used for PDSCH or PUSCH using higher-layer signaling. If PT-RS transmission is enabled in the scheduling bandwidth, the presence and / or density (e.g., time and / or frequency) of PT-RS in the scheduling bandwidth used for PDSCH or PUSCH can be determined based on one or more of the following: the number of scheduling resource blocks (RBs) (which, as an example, are also called scheduling bandwidth and / or physical resource blocks (PRBs)); the indicated modulation and coding scheme (MCS) level for the scheduled PDSCH and / or PUSCH; numerical configurations (e.g., subcarrier spacing, slot length, etc.); WTRU capabilities (e.g., whether PT-RS is supported); the density of demodulation reference signals (DM-RS) available for demodulation; the number of layers scheduled (e.g., the transmission rank of PDSCH or PUSCH); and / or the presence of UCI in the PUSCH and the associated UCI type (e.g., HARQ-ACK or CSI).

[0112] When a PT-RS exists in the scheduling bandwidth used for PDSCH or PUSCH, a subset of the scheduled RBs may include, contain, or transmit the PT-RS. This subset of PT-RS RBs may be determined based on one or more of the RB offsets or scheduling bandwidths.

[0113] For RB offsets, within the scheduling bandwidth, a subset of RBs with PT-RS can be located every K-1 RBs, where, regardless of whether the scheduled RBs are contiguous or distributed, the RBs are indexed from the lowest RB index within the scheduled RBs to RBs with higher indices. The RB offset can be the starting RB index containing the PT-RS. As described herein, RB offset, PRB offset, starting RB offset, and starting RB index are interchangeable.

[0114] Based on the scheduling bandwidth, the number of RBs that can include, contain, or transmit PT-RS can be determined. If the scheduling bandwidth is less than a first threshold, then a first number of RBs can contain PT-RS; and if the scheduling bandwidth is equal to or greater than the first threshold and less than a second threshold, then a second number of RBs can contain PT-RS. And so on. This subset can include cases where all scheduled RBs (or multiple RBs) can contain, include, or transmit PT-RS.

[0115] When PT-RS is present in the scheduling bandwidth used for PDSCH or PUSCH, the PT-RS can be contained within a subset of symbols (e.g., CP-OFDM symbols or DFT-s-OFDM symbols). The presence of PT-RS in a symbol can be determined based on one or more of the following: the MCS level (or modulation order) of the scheduled PDSCH or PUSCH; the presence of DM-RS in the symbol (for example, if a symbol contains DM-RS, then PT-RS will not be transmitted in that symbol); and / or the PT-RS density determined based on one or more scheduling parameters. The PT-RS density, time / frequency position, and / or the use of DFT precoding can depend on the waveform used.

[0116] In one scenario, when using CP-OFDM waveforms, PT-RS can be used for PDSCH or PUSCH transmission. One or more subcarriers in the RB can be used for PT-RS transmission; alternatively, the same subcarrier positions on consecutive OFDM symbols determined for PT-RS transmission can also be used.

[0117] Figure 2Several examples of PT-RS temporal density are shown. In the three exemplary grids 202, 204, and 206, the horizontal axis 201 of each grid can be an OFDM symbol, and the vertical axis 203 is a subcarrier. Each example has a resource element (RE) grid, where shaded blocks can represent REs containing PT-RS. Looking from left to right, in example 202, PT-RS can be located in every symbol (e.g., an OFDM symbol); in example 204, there is one PT-RS every other symbol; and / or in example 206, there is one PT-RS every three symbols. The PT-RS temporal density can be determined based on an MCS threshold, with relevant examples shown in Table 1 below. MCS The MCS level can be used for PUSCH or PDSCH, determined, or indicated in the associated DCI. PT-RSthMCS1, PT-RSthMCS2, PT-RSthMCS3, and PT-RSthMCS4 can be configured using higher-layer signaling or DCI and can be referred to as thresholds used to determine the temporal density of PT-RS. If no configuration or indication is provided, then the default configuration (e.g., per symbol) can be used.

[0118]

[0119] Table 1: Indicative time density of PT-RS as a function of the scheduled MCS

[0120] For CP-OFDM and DFT-s-OFDM, when PT-RS is present, the PT-RS mapping pattern can begin with the first symbol in the time slot containing PDSCH / PUSCH, and then be mapped to every L_{PT-RS} symbol. The PT-RS mapping pattern can restart at each symbol containing DMRS, and then be mapped to every L_{PT-RS} symbol opposite the symbol containing PT-RS. For two adjacent DMRS symbols, the second of the two DMRS symbols can be used as a reference to restart the PT-RS pattern. When the PT-RS time density is less than 1, the symbol immediately following the preceding DMRS and the symbol immediately following the additional DMRS (if any) will not contain PT-RS. According to this mapping pattern, PT-RS will not be transmitted in OFDM symbols containing PDSCH / PUSCHDMRS. According to this mapping pattern, PT-RS will not be transmitted in resource elements (REs) overlapping with the configured control channel resource set (CORESET).

[0121] The PT-RS frequency density can be determined based on the number of scheduled RBs shown in Table 2 below. RBThis can be the number of RBs to be scheduled. PT-RSthRB0, PT-RSthRB1, PT-RSthRB2, PT-RSthRB3, and PT-RSthRB4 can be thresholds used to determine the frequency density of PT-RS, and can be configured via RRC signaling or indicated in the associated DCI. If not configured or indicated, the default configuration (e.g., the second RB) can be used.

[0122] Scheduled bandwidth Frequency density (every K-1 RB) <![CDATA[N RB <PT-RSthRB0]]> PT-RS does not exist <![CDATA[PT-RSthRB0<=N RB <PT-RSthRB1]]> PT-RS exists on each RB <![CDATA[PT-RSthRB1<=N RB <PT-RSthRB2]]> There is a PT-RS every other RB <![CDATA[PT-RSthRB2<=N RB <PT-RSthRB3]]> There is a PT-RS every three RBs. <![CDATA[PT-RSthRB3<=N RB <PT-RSthRB4]]> There is a PT-RS every seven RBs.

[0123] Table 2: Frequency density of PT-RS as a function of scheduling bandwidth

[0124] Figure 3 An illustrative process for generating DFT-s-OFDM waveforms using block-based, DFT-preceding PT-RS insertion processing is shown. PT-RS input / output 322 is shown with arrows and gray shading, and data input / output 321 is shown with black arrows. Typically, in LTE, the waveform formation process may include initially expanding data symbols 302 with DFT block 304 and then mapping them to the corresponding inputs of IDFT block 306. CP 308 can be prepended at the beginning of a symbol, thereby avoiding inter-symbol interference (ISI) and allowing single-tap frequency domain equalization (FDE) to be performed at the receiver.

[0125] The PT-RS pattern (e.g., a block-based PT-RS pattern preceding the DFT) can be determined based on the number of blocks (X) 310, the block size (V) 312, and the position of the blocks. X PT-RS blocks 310, such as PT-RS block #1311, can be inserted before the DFT block 304. The PT-RS blocks and data proceed along the same process as described above for forming the waveform. A block includes tones, and for each block, its size can be V PT-RS tones. For each block, there are V PT-RS tones before the DFT input; Figure 3 In the example, as shown by the three long dashed arrows for each PT-RS block, the block size can be V=3; this is also shown in the final waveform of DFT-S-OFDM symbol 313, where PT-RS block #1311 is in the first three shaded blocks and PT-RS block #X is at the end.

[0126] The position of the blocks in the DFT output can be determined based on the scheduled RB, the block size (V) 312, and / or the number of blocks (X) 310. For example, two values ​​of V, V1 and V2, can be used, and the position of the blocks can be determined based on the value of V as follows: when V = V1, the samples in the DFT domain can be divided into X intervals, and the blocks can be located at the head (first V samples), middle (middle V samples), or tail (last V samples) of each interval; when V = V2, the samples in the DFT domain are divided into X intervals, where in the first interval, the blocks are placed at the head (first V samples), in the last interval, the blocks are placed at the tail (last V samples), and in the remaining intervals, the blocks are placed in the middle of each of the two intervals.

[0127] PT-RS patterns can be determined based on scheduling bandwidth (BW), where each BWP has a set of thresholds N. RBn n = 0, 1, 2, 3, 4, which indicates the X and V values ​​that the WTRU should use according to Table 3 below and the scheduled BW. Y represents any value. In one example, the value of Y could be 8.

[0128] Scheduled BW XxV <![CDATA[N RB0 <N RB ≤N RB1 ]]> 2x2 <![CDATA[N RB1 <N RB ≤N RB2 ]]> 2x4 <![CDATA[N RB2 <N RB ≤N RB3 ]]> 4x2 <![CDATA[N RB3 <N RB ≤N RB4 ]]> 4x4 <![CDATA[N RB >N RB4 ]]> Yx4

[0129] Table 3: PT-RS patterns (X,V) prior to DFT based on the scheduled BW

[0130] Figure 4A diagram of a signal with a normal cyclic prefix (CP) is shown. Time 401 is displayed on the horizontal axis. For any of the figures discussed here, each portion of any designated symbol shown in the time-domain signal diagram can be patterned to indicate similarity. As shown, a signal has two symbols (i.e., DFT-s-OFDM, OFDM), namely symbols 402 and 403 with CP406 and CP407 respectively. In normal CP operation, the size of each CP can be G, and the Inverse Discrete Fourier Transform (IDFT) output can be extended by a copy of the last portion of the preceding IDFT output: CP 406 and CP407 can be copied at the end and can be followed by N-IDFT outputs 404 and 405 respectively, where the last portions are 413 and 415 respectively, and are indicated by arrows 410 and 411 respectively. On the receiver side, the DFT window can be located at the first symbol and will not capture samples from subsequent symbols: each N-IDFT output 404, 405 can be within the receiver (RX) DFT window 408, 409, respectively. However, if the CP size G is not less than the number of taps in the multipath channel, the receiver may encounter ISI. In some cases, the normal CP size may be insufficient. For example, if the communication environment is outdoors or a link is established on a non-line-of-sight (LOS) path, the maximum excess delay of the multipath channel may be significantly increased. In these cases, the duration of the CP may be insufficient to handle the channel delay spread, and an insufficient CP size may lead to inter-symbol interference (ISI).

[0131] Figure 5 An illustration of a signal with extended CP (e.g., virtual CP) is shown. Time 501 is displayed on the horizontal axis. As shown, the signal has a symbol 502 with CP 506, which can be extended to length 523. It should be noted that a second symbol 503 with N-IDFT output 505 and CP 507 is shown to provide context related to where the extension originates relative to the entire signal. CP extension (also known as virtual CP) can be used to address the problem of insufficient CP size. The goal of virtual CP can be to increase the effective CP length of block-based symbols (e.g., DFT-s-OFDM, OFDM) to improve their robustness relative to multipath channels. Figure 5 In the example shown, a CP of length G, 506, can be extended by H samples, resulting in a total extended CP length of 523. Figure 4Similar to the example shown, the N-IDFT output 504 of the IDFT can be extended by a copy 522 of the last part of the preceding N-IDFT output 504; however, due to the special structure of the IDFT output, the extended CP region will be forced to be the same. It should also be noted that the RX DFT window 508 can be shifted by H samples.

[0132] Since this approach does not change the basic receiver operation, maintaining the hardware complexity on the receiver side is also highly beneficial. Because sampling in the RX DFT window should be continuous in order to decode symbols without interference, two consecutive symbols must also be consecutive. Due to this fact, another benefit of the virtual CP is reduced out-of-band emission (OOBE).

[0133] Figure 6 An example of a combination of a common unique word (UW) and a cyclic prefix (CP) is shown. In one approach, UW and CP can be combined as shown in the figure. Observing the transmission (TX) block diagram 601, PT-RS 602a and 602b can be mapped to both ends of M-DFT 604 (denoted by DM) to output N-IDFT 606 (denoted by DM). This indicates that (·) H It is the Hermitian conjugate operation, and FN is the timely generation of the head portion 612 and the tail portion 614 on the N-DFT. Without any special design of the reference symbol, if the CP 611 with duration G is smaller than the tail 614 with duration T, then the indicated portions can become approximately the same and can be considered as extended CP durations.

[0134] As an example, examine frame 630 of the generated time-domain signal, which has a length G. e The extended CP 620 can have the previous symbol 631 i-1 The tail of the symbol 631 i The cascading of the CP and header portions. While this approach appears to achieve the goal of the virtual / extended CP 620, the receiver (RX) may be affected because the size of the RX DFT window 621 changes from N to N+G. Consequently, the receiver architecture is affected by receiving the extended CP, which is undesirable. Since the current symbol 631 is used without any special design... i The tail and the next symbol 631 i+1 The transitions between CP symbols can be discontinuous, thus affecting the receiver; consequently, data symbols (e.g., 613) may be interfered with. Therefore, the receiver may need to perform additional operations to recover the data, which is not ideal.

[0135] Figure 7 An example of a perturbation method is shown. In this method, each OFDM symbol can be perturbed by a certain perturbation vector to achieve continuity between adjacent symbols (that is, it also achieves CP spread). Figure 7 In the example shown, the transmitter diagram 701 and the corresponding time-domain signal 730 of the proposed method are shown on the left and right sides, respectively. As with other transmission processes discussed herein, data can be fed into an IDFT block (using...). (Represented by) 716, which produces a symbol of length N. The symbol can be perturbed by block 722, and / or a delay can be introduced in block 720. CP can be added at block 708, thus obtaining a symbol of length N+G. CP can be added at block 708 to obtain a symbol of length N+G.

[0136] For illustrative purposes, the generated signal 730 may have the preceding symbol 731. i-1 Current symbol 731 i And the next symbol 731 i+1 It should be noted that each portion of any designated symbol displayed in the time-domain signal 730 can be pattern-masked to indicate similarity. Furthermore, for each symbol, three TX IDFTs exist separately. b i It can be the undisturbed signal X to be operated on. i Part of it. Element 760 can be used with a i-1 Replace b i The output of the perturbation vector generator. In 731a, the previous perturbation OFDM symbol The head can be represented as a i-1 In order to maintain the previous one (i.e., TX IDFT) )) and the current symbol (TX IDFT) The continuity between ) can also be that the header of the CP of the current or i-th perturbation OFDM symbol is a i-1 As shown in 731b. Since CP is the symbol TX IDFT The last part of the copy, therefore, vector This may include the a at the corresponding position at the tail of 731bc. i-1 For this purpose, the IDFT 706 output (i.e., ) can be used as the (i-1)th perturbation OFDM symbol a i-1 The function is used to perturb.

[0137] This method can be applied to any CP duration, but it also has some potential problems. One problem is that it is a dynamic method (i.e., the perturbation depends on the data), and therefore may require calculations for each individual OFDM symbol, which could require significant processing. Furthermore, because it is a dynamic method, it may be incompatible with the reference signal (RS). Another problem is that the perturbation signal cannot be used as the RS. Yet another problem is that the perturbation vector follows an arbitrary structure, and therefore the receiver may need to perform additional operations to eliminate the interference caused by the perturbation vector.

[0138] Figure 8 An example of a dynamic method for DFT-s-OFDM is shown. The illustrated transmitter diagram 801 and the corresponding time-domain signal 830 can be seen on the left and right sides of the diagram, respectively. In this method, the single-carrier structure of DFT-s-OFDM can be used, and CP spreading can be achieved by moving the positions of data symbols based on a certain rule for a given CP length and DFT spread size, and by reusing these data symbols in the previous and next DFT-s-OFDM symbols. Similar to other transmission processes discussed here, transmitter diagram 801 sequentially executes a process involving block D... M (DFT)802, M f 804 The processes of (IDFT)806 and CP 808. M f 804 can be D M 802 output mapped to Subcarrier mapping operation of the input of 806. In this method, the symbols s at the input of DFT-s-OFDM block 802 k It can be sorted in the following way:

[0139]

[0140] in as well as Here, k is the data symbol, k is the DFT-s-OFDM symbol index, and the CP length should be set to...

[0141] For illustrative purposes, the preceding symbol 831 may exist in the generated time-domain signal 830. i-1 Current symbol 831 i and the next symbol 831 i+1 It should be noted that each portion of any designated symbol displayed in the time-domain signal 830 can be pattern-masked to indicate similarity. In the example shown, if it is a kFor symbol 831 i If k=2, then b k-1 It is b1, and the same applies to the other inputs located at the beginning of transmitter diagram 801. Then, for each element in the symbol, there can be a corresponding input, for example, in the case of still using the example of k=2, It is the current symbol 831 i The head (H). As shown, this method can achieve an extended CP 833, which shows that the CP length (G) plus the tail (T) and (H) will result in a G taken from the other end 832. e (Note the similar patterns in extended CP 833 and the other end 832); this process can be implemented without any complex operations on the transmitter and receiver; however, it may also introduce unintended constraints on the CP size G. Therefore, this method may only be compatible with certain numerical configurations. Another potential problem with this method is that the CP extension may be generated based on data symbols. Therefore, this method may only be compatible with certain PT-RS structures.

[0142] Figure 9 An example of a static method for DFT-s-OFDM is shown. On the left and right sides of the figure, an illustrative transmitter diagram 901 and its corresponding time-domain signal 930 can be seen, respectively. As with other transmission processes discussed here, transmitter diagram 801 sequentially executes the block D... M (DFT)902, M f 904 and The process of (IDFT)906. In this method, the single-carrier structure of DFT-s-OFDM can be used, and in the transmitter, by using Using such a fixed RS to replace the input data symbol, the CP extension shown in the signal diagram 901 can be implemented using a CP block.

[0143] For illustrative purposes, the preceding symbol 931 may be present in the generated time-domain signal 830. i-1 Current symbol 931 i and the next symbol 931 i+1 It should be noted that each portion of any designated symbol displayed in the time-domain signal 930 can be patterned to indicate similarity. As... Figure 8 As shown in the example, this method can implement an extended CP 933, where it is shown that adding the CP length (G) to the tail (T) and (H) will result in a G taken from the other end 932. e(Note the similar patterns in extended CP 933 and the other end 932). While this static method solves the PT-RS design, it may suffer from the drawbacks of dynamic methods, such as the need to set the CP length to...

[0144] Figure 10 An example of how the PT-RS frequency density (K) can work with different bandwidth scheduling is shown. Specifically, the PT-RS frequency density can be based on the number of RBs scheduled when the RB offset is "0" (i.e., starting from the first scheduled RB), and the following thresholds are configured: {PT-RSthRB0 = 2, PT-RSthRB1 = 6, PT-RSthRB2 = 12, PT-RSthRB3 = 16}. The RB index 1001 at the bottom shows the RB number where the PT-RS 1010 resides for any given configuration. Three example scenarios with different PT-RS densities are shown: one PT-RS for every RB 1010 (i.e., K = 1); one PT-RS for every other RB 1020 (i.e., K = 2); and one PT-RS for every three RBs 1030 (i.e., K = 4). The PT-RS frequency density does not increase linearly with the number of scheduled RBs. Furthermore, the PT-RS frequency density can vary based on the RB offset. For example, for a WTRU with RB offset = 0 and another WTRU with RB offset = 1, although the number of RBs scheduled for these two WTRUs may be the same, the total number of PT-RS may be different.

[0145] RB offsets (e.g., starting RB index) can be used to randomize PT-RS interference from co-scheduled WTRUs (e.g., due to collisions between PT-RS). RB offsets can be determined based on one or more WTRU-specific parameters. One such parameter can be a WTRU-ID (e.g., temporary C-RNTI, C-RNTI, IMSI), and one or more of these WTRU-IDs can be used. For example, when the WTRU is in RRC idle mode, IMSI can be used as the WTRU-ID, while when the WTRU is in RRC connected mode, C-RNTI can be used. Temporary C-RNTIs can be used to determine RB offsets for transmission / reception of RACH messages 2, 3, and / or 4, and can be used after the WTRU receives a C-RNTI configuration.

[0146] Similarly / alternatively, the RB offset can be determined based on the WTRU-specific parameter scrambling ID (e.g., a scrambling ID configured or indicated for DM-RS), wherein the scrambling ID can be configured in the WTRU-specific RRC signaling or indicated in the relevant DCI used for PDSCH or PUSCH scheduling.

[0147] Similarly / alternatively, the RB offset can be determined based on the WTRU-specific parameter cell ID (e.g., physical cell ID), which can be determined either during initial access or detected from the synchronization signal (SS).

[0148] Similarly / alternatively, the RB offset can be determined based on the WTRU-specific parameter SS block time index (e.g., SS / PBCH block index), where the SS block index can be determined during the initial access process; as described herein, the SS block index, SS block time index, SS / PBCH block index, and SS / PBCH block time index are interchangeable.

[0149] Similarly / alternatively, the RB offset can be determined based on the WTRU-specific parameter bandwidth portion (BWP) index, for example, where the WTRU can be configured to have one or more BWPs and a subset of the configured BWPs is active at a time. This index can be used to determine the RB offset value for the active BWP index that the WTRU can be configured or indicated to transmit and / or receive PDSCH or PUSCH. As described herein, BWPs and carriers are interchangeable.

[0150] A default RB offset may be used before an RRC connection is established or before the WTRU can be configured with WTRU-specific parameters. The default RB offset may be determined by at least one of the following: a fixed RB offset (e.g., RB offset = 0); and / or an RB offset determined based on one or more cell-specific parameters (e.g., physical cell ID).

[0151] To determine the RB offset value, a maximum RB offset value can be determined, used, configured, or predefined. For example, if WTRU-ID is used to determine the RB offset value, then a modulo operation (mod) can be performed between WTRU-ID and the maximum RB offset value (max_RB_offset) (where mod represents the modulus after division). As described here, the modulo operation produces a remainder, where the modulo operation between A and B is performed with A as the dividend and B as the divisor, and can be commutatively represented as Amod B, (A)mod B, and / or mod(A, B).

[0152] As an example, RB offset value = (n RNTI mod max_RB_offset, where nRNTI It can be C-RNTI or temporary C-RNTI, or as a replacement, n RNTI It can be the most significant bit (MSB) or least significant bit (LSB) of the C-RNTI or temporary C-RNTI. In either case, max_RB_offset can be the maximum RB offset value. In some cases, the max_RB_offset value can be implicitly determined based on one or more of the following: the scheduled BW (e.g., the number of scheduled RBs); the PT-RS frequency density (e.g., PT-RS within every K RBs), where K can be related to the following as discussed here: Use interchangeably; and / or WTRU-specific parameters. In some cases, the max_RB_offset value configured at a higher level can override the implicitly determined max_RB_offset value.

[0153] The RB offset values ​​may be limited to a set of configurable, determinable, or usable RB offsets. Furthermore, a subset of the RB offset set may be determined or used based on at least one of the scheduled BW, frequency density, and / or WTRU-specific parameters. The RB offsets may be limited to a set / subset and may be determined and / or configured using one or more methods discussed herein.

[0154] In one approach, the RB offset set can be defined, determined, or used based on the max_RB_offset value. For example, the RB offset set can be {0,1,...,max_RB_offset}, which constitutes the complete set of possible values. In one example, max_RB_offset can be the frequency density K, where max_RB_offset = K, thereby producing the RB offset set {0,1,...,K}.

[0155] In another approach, the set and / or subset of RB offsets can be based on the scheduling bandwidth N. RB The first subset is determined by the PT-RS frequency density K. In one example, if the first condition is satisfied, then the first subset can be {0}, where the first condition is (N... RB +1)mod K=0. In another example, if the second condition is satisfied, then the second subset {0,1} can be used, where the second condition is (N RB +2)mod K=0. In another example, if the third condition is met, then the RB offset set (i.e., all RB offsets) {0,1,...,max_RB_offset} can be used, where the third condition is (N RB )mod K=0.

[0156] In another method, the RB offset value can be based on RB offset value = (n RNTI The value is determined by mod max_RB_offset_S, where max_RB_offset_S can be the number of RB offset values ​​within the subset.

[0157] In another approach, a subset of the RB offset set can be configured using higher-layer signaling. For example, a subset of the RB offset set can be indicated using a bitmap.

[0158] In another approach to limiting RB offset values, the max_RB_offset value of the RB offset set can be determined based on the number of RBs that do not contain PT-RS after the last RB containing PT-RS (RB offset = 0), where the RB offset set is the entire set of values ​​{0, 1, ..., max_RB_offset}. For an example, refer back to... Figure 10 In scenario 1030, 16 RBs are scheduled, where the max_RB_offset value can be 3 because all RBs after the last RB 12 (i.e., RBs 13, 14, and 15) do not contain PT-RS. In another example shown in scenario 1030, when scheduling 15 RBs, the max_RB_offset value can be 2 because this value represents the number of RBs (RBs 13 and 14) that do not contain PT-RS after the 12th RB. One approach in this method is to determine max_RB_offset as max_RB_offset = KN. RB mod K-1, where K can be determined based on frequency density (e.g., PT-RS can be located in every K RBs), and / or N RB This can be the number of scheduled RBs. In another method, the RB offset value = (n RNTI )mod max_RB_offset.

[0159] Figure 11A An example is shown where the max_RB_offset value (or limit / constraint) is determined based on the scheduled RB and PT-RS frequency densities. As... Figure 10 As shown in the diagram, shaded blocks can represent PT-RS within an RB. In scene 1120, there can be 8 RBs, and every other RB has one PT-RS (i.e., K=2): as shown in line 1121, when the offset is 0, the total number of PT-RS can be 4; and as shown in line 1122, when the offset is 1, the number of PT-RS may still be 4. It should be noted that in scene 1120, the PT-RS density is divisible by the number of scheduled RBs without a remainder (i.e., N). RBmod K = 0), which results in max_RB_offset equal to the PT-RS density K = 2; in other words, when K = 2, the RB offset will be the first two possible values, where the values ​​start from 0, so the set of values ​​will be {0, 1}. More generally, this can be rewritten as when N RB When mod K = 0, max_RB_offset = K.

[0160] In scenario 1110, there can be 7 RBs and a PT-RS density of one PT-RS for every other RB (i.e., K=2). It should be noted that the PT-RS density is not divisible by the number of scheduled RBs (i.e., N). RB (mod K≠0). Therefore, when the RB offset is 0, as shown in line 1111, the total number of PT-RS can be 4; when the offset is 1, the total number of PT-RS will decrease to 3 (that is, the RB offset value limits the number of PT-RS).

[0161] In some cases, it is best if the number of PT-RS used for scheduling bandwidth is the same to avoid WTRU performance degradation. Therefore, it may be desirable to avoid a situation where, as shown in line 1112, the number of PT-RS used for the same scheduling bandwidth varies. To ensure that the number of PT-RS remains constant, it is necessary to limit the maximum possible set of RB offset values, max_RB_offset. For example, if, as described here, the RB offset can be based on WTRU-ID (i.e., n... RNTI If we mod max_RB_offset), then by limiting max_RB_offset, we can enable the ability to keep the number of PT-RS the same across a specified number of scheduled RBs. As shown in scenario 1120, this only applies when the PT-RS density is not divisible by the number of scheduled RBs (i.e., N). RBWhen mod K ≠ 0, limiting max_RB_offset is necessary. In scenario 1110, max_RB_offset can be limited to a function of the PT-RS density and the number of scheduled RBs; specifically, max_RB_offset can be limited to the remainder of the PT-RS density divided by the number of scheduled RBs, which will be 7 mod 2, resulting in 1. As mentioned above, a value of max_RB_offset (e.g., 1) will result in a finite set (i.e., a subset) of RB offset values, where any RB offset value will start from 0. Then, if max_RB_offset is limited to 1, the subset of max_RB_offset will be {0}, meaning that any RB offset greater than 0 (as shown in line 1112 with RB offset values ​​{0,1}) will result in a different total number of PT-RS. More generally, this can be rewritten as when N RB When mod K≠0, max_RB_offset=N RB mod K.

[0162] Figure 11B An exemplary process is shown to ensure that the PT-RS density K remains the same by sending PT-RS transmissions, thereby solving the control problem. Figure 11A The potential problems discussed. In the first step 1151, the PT-RS density K and the number of scheduled RBs N are determined. RB In one scenario, a device (e.g., a WTRU) can schedule a certain bandwidth (i.e., receive control information on the control channel). The WTRU can determine the PT-RS density K based on the scheduled bandwidth. In step 1152, if the PT-RS density K is divisible by the number of scheduled RBs N... RB In step 1152, max_RB_offset can be equal to the PT-RS density, or if not, max_RB_offset can be a function of the PT-RS density and the number of scheduled RBs. In step 1154, the RB offset value can be determined based on the result of step 1153. In step 1155, once the RB offset is determined, this information can be used to transmit and / or receive transmissions with PT-RS.

[0163] In another approach to limiting RB offset values, if the max_RB_offset value is less than K, then one or more methods may be applicable to the interference of randomization with the restricted / limited set of RB offset values. One or more methods will follow the aforementioned approach.

[0164] In one approach, the RE position or subframe position of the PT-RS within the RB can be determined based on one or more WTRU-specific parameters. For example, when the RB offset value is constrained / limited, the RE position of the PT-RS within the RB can be determined based on WTRU-specific parameters, and when the RB offset value is not constrained / limited (e.g., max_RB_offset = K), the RE position of the PT-RS within the RB can be determined based on non-WTRU-specific parameters (e.g., fixed, predefined, cell-specific parameters).

[0165] In another approach, the PT-RS scrambling sequence can be determined based on one or more WTRU-specific parameters. For example, when the RB offset is unconstrained, the PT-RS scrambling sequence can be initialized based on non-WTRU-specific parameters, while when the RB offset is constrained, the PT-RS scrambling sequence can be initialized based on one or more WTRU-specific parameters.

[0166] In another approach, the PT-RS time position can be determined based on one or more WTRU-specific parameters (e.g., the start symbol index). For example, when the RB offset value is unconstrained, a first symbol index can be used as the start symbol for the PT-RS transmission, and when the RB offset value is constrained, a second symbol index can be used as the start symbol for the PT-RS transmission. The first symbol index can be fixed, configured, and / or predefined, and the second symbol index can be determined based on one or more WTRU-specific parameters.

[0167] Figure 12An example of cyclic shifting of RBs containing PT-RS is shown. In this method, the set of RB offsets can be defined, determined, or used with the set {0,1,...,max_RB_offset}, where max_RB_offset can be K (e.g., PT-RS density); the RBs containing PT-RS can be cyclically shifted based on the RB offset value. Regardless of the RB offset value, the number of RBs containing PT-RS can be the same. Scenario 1210 shows several instances with a slot having 7 RBs, where every other RB has a PT-RS. In one instance 1211, the RBs containing PT-RS can be uniformly distributed, where the RB offset is 0, resulting in a PT-RS density of 4. In another instance 1212, the RB offset can be 1, and the RBs containing PT-RS are not uniformly distributed, where one PT-RS RB 1202 is shifted and adjacent to another PT-RS RB, but the PT-RS density remains 4. Furthermore, the cyclic shift value can be determined based on one or more WTRU-specific parameters. For example, a PT-RS that is not assigned to an RB due to an RB offset value may be located in an RB that does not contain a PT-RS, wherein the location of the RB may be determined based on WTRU-ID (e.g., C-RNTI).

[0168] In some cases, the reference position of the RB containing the PT-RS can be based on an RB offset of 0, wherein the number of RBs containing the PT-RS can be the same as in the case of an RB offset of 0, regardless of the determined RB offset value, and the PT-RS density can be 4.

[0169] In one approach, if the number of RBs used for RB offset in the PT-RS is relatively small compared to the reference RB offset, then a power boost PT-RS can be used. For example, the reference RB offset can be defined, configured, or used when the RB offset is equal to 0, and the number of RBs used for the PT-RS when the RB offset is equal to 0 can be K. p If, for a given RB offset, the number of RBs used for PT-RS is less than K. p Then, PT-RS power boosting can be used. In this method, for the first RB offset value, when the number of RBs containing PT-RS is equal to K... p At the same time, the first power level can be used for PT-RS; for the second RB offset value, when the number of RBs including PT-RS is less than K. p At this time, a second power level (e.g., higher than the first power level) can be used for PT-RS. The second power level can be based on the number of RBs including PT-RS for a specific RB offset value and K. p The ratio between them is used to determine this.

[0170] Furthermore, in this method, constellation points can be correlated with offset values. For the first RB offset value, when the number of RBs containing PT-RS is related to K... p Similarly, the first constellation point (e.g., a QPSK constellation) can be used for the PT-RS sequence. For the second RB offset value, when the number of RBs containing PT-RS is less than K... p In this case, a second constellation point (e.g., the outermost constellation point of 16QAM, 64QAM, or 256QAM) can be used. The modulation order used for the outermost constellation point (e.g., 16QAM, 64QAM, or 256QAM) can be based on the number of RBs (K0, K0, K0) that contain the PT-RS for a given RB offset value. a ) and K p The ratio between them determines this. For example, if K... a / K p If the value is greater than a predefined threshold, then the first modulation order (e.g., 16QAM) can be used; if K a / K p If the value is less than a predefined threshold, then a second modulation order (e.g., 64QAM) can be used. The modulation order used for the outermost constellation point can be determined based on the modulation order indicated, determined, or scheduled for the associated data channel (e.g., PDSCH or PUSCH).

[0171] In one scenario, the RB offset value can be used to shift the PT-RS from the default RB location to a different RB (e.g., an RB a fixed number of units away from the default RB location), thereby avoiding intra-cell or inter-cell interference sources from other PT-RS transmitters located at the same RB location. If significant PT-RS-based interference exists, the time and frequency of the PT-RS density can be modified or changed to avoid or reduce the interference level. For example, Table 4 below shows possible combinations of RB offsets and PT-RS frequency densities assuming that both transmitters use a PT-RS time density of 1 (e.g., transmitting PT-RS on every symbol).

[0172]

[0173] Table 4: Examples of PT-RS time / frequency density based on RB offset

[0174] In this scenario, higher-layer signaling or L1 signaling (such as DCI) can be used to indicate the frequency density of one or more interference sources (such as co-scheduled WTRUs or neighboring cells) to the WTRU. One or more methods can be applied for this indication to the WTRU.

[0175] In one approach, the WTRU may receive the frequency density of interfering PT-RS in the relevant DCI used for data scheduling, and the PT-RS density of the WTRU (e.g., the time and / or frequency density of the serving PT-RS) may be determined based on the frequency density of the interfering PT-RS. If the density of interfering PT-RS increases, then the serving PT-RS density will also increase. Alternatively, if the density of interfering PT-RS increases, then the serving PT-RS density may decrease.

[0176] In another approach, a set of RB offset values ​​can be limited based on the PT-RS density that generates interference. For example, if the PT-RS density that generates interference is low, a smaller set of RB offset values ​​can be used, and if the PT-RS density that generates interference is high, a larger set of RB offset values ​​can be used. In another example, if the PT-RS density that generates interference is very low (e.g., 1), a first subset of RB offset values ​​(e.g., {0}) can be used, and if the PT-RS density that generates interference is medium (e.g., 2), a second subset of RB offset values ​​(e.g., {0,1}) can be used; and if the PT-RS density that generates interference is very high (e.g., 4), a third subset of RB offset values ​​(e.g., {0,1,2,3}) can be used.

[0177] In another approach, the set of RB offset values ​​can be limited based on the PT-RS density that generates the interference and the service PT-RS density.

[0178] If either transmitter uses a PT-RS time density less than 1 (e.g., OFDM symbol offset), then similar options for RB offset would be possible. Furthermore, OFDM symbol offset might also be needed to handle DM-RS-based interference against PT-RS. Another possibility is to use subcarrier offset for PT-RS within the RB.

[0179] Figure 13 An example of PT-RS mapping for seven RBs with different RB offset values ​​is shown. In this method, the RB offset can be determined based on C-RNTI and / or subframe / slot number or index. See back for an example. Figure 2 The diagram shows different PT-RS densities. And the PT-RS mapping of the 4 RBs; since there is one PT-RS in the initial scheduling RB position, it can be assumed that the RB offset is 0 because there is a PT-RS RB in the first index. Therefore, for With any configuration, the PT-RS density per slot can be changed based on the RB offset value. Now view Figure 13 The example shown in the image shows that if NRB With 7 Restricted Bases (RBs), each RB has a PT-RS mapping, where each mapping has a different RB offset value: 0 RBs in scenario 1310 and 1 RB in scenario 1320. In scenario 1310, there is one PT-RS every other RB with an RB offset of 0, resulting in a PT-RS density of 4. In scenario 1320, there is one PT-RS every other RB with an RB offset of 1, resulting in a PT-RS density of 3. As shown, compared to the case where the RB offset is 0, the total number of PT-RS is smaller in the configuration where the RB offset is 1, leading to some performance degradation.

[0180] Figure 14 Examples of PT-RS mappings with different RB scheduling widths are shown. Scenario 1410 has 7 RBs, with one PT-RS every other RB, resulting in a density of 4. Scenario 1420 has 13 RBs, with one PT-RS every 3 RBs, resulting in a density of 4; such a configuration could potentially have a greater impact on performance due to the dispersed scheduling.

[0181] Figure 15 An example PT-RS mapping for 7 dynamic RB offset values ​​is shown. In this method, the RB offset values ​​can be dynamically adjusted or determined based on a time index to ensure equal PT-RS averages for the transmission duration. For scenario 1510, there are 7 RBs, and one PT-RS is provided for every other RB. The time index can be the frame number (n... Frame ), time slot number (n Slot ) or symbol number (n Sym At least one of the following. As an example, the initial RB offset can be determined based on C-RNTI, and then based on n Slot To apply the additional RB offset, where n Slot This is the slot number corresponding to the current transmission. Scenario 1510 shows an exemplary implementation based on an offset value setting, where the offset value setting is based on an odd / even slot number that causes slot increments (i.e., slot n, slot n+1, slot n+2, ... slot n+k), which causes the RB offset value to alternate, and this also affects the PT-RS density (that is, the density will alternate between 4 and 3 based on offset values ​​0 and 1, respectively). The slot number can be a slot number within a radio frame or an absolute value. In an alternative example, the RB offset value can be jointly defined based on C-RNTI and time index, etc. In another example, the RB offset adjustment can be applied only to configurations that exhibit unequal distribution, or universally applied to all configurations, regardless of the effect of the offset value.

[0182] Figure 16 An example of PT-RS mapping with 13 RBs per time slot and dynamic RB offset values ​​is shown. In this example, the RB offset values ​​can be dynamically adjusted based on the time index to counteract the effects of frequency-selective fading. In this way, the RB offsets can be dynamically changed for all configurations regardless of the impact of the PT-RS density, thus avoiding long fading. Scenario 1610 shows 13 RBs per time slot, with one PT-RSRB every three RBs (that is, where...). Time indexes can be based on n. Frame , n Slot or n Sym And so on, or combinations thereof. For example, the initial RB offset can be determined based on C-RNTI, and then an additional RB offset can be applied to move the position of the PT-RS RB according to the time slot or based on the time slot number. The RB offset can be based on n Slot and To determine, the additional offset can be defined as As shown, the RB offset increases with each slot number; therefore, the RB offset is 0 in slot n, 1 in slot n+1, 2 in slot n+2, and 3 in slot n+3. It should be noted that once the RB offset is 3, then in the next slot n+4, since the PT-RS density is only 4, and without a PT-RS density of at least 5 (which is not conceivable in this example), it will not be possible to have an RB offset of size 4; therefore, the RB offset will return to 0.

[0183] In one embodiment, the PT-RS density can depend on the frequency resource allocation type. Modulated information symbols can sometimes be mapped to time and frequency resources before transmission. Multiple information symbols can be mapped to discrete, continuous time and frequency blocks. In LTE and NR, modulated information symbols can be mapped to time and frequency units called resource elements (REs). An RE can contain one subcarrier within an OFDM symbol. A block of REs contains 12 consecutive subcarriers (i.e., in frequency) across 7 OFDM symbols (i.e., one time slot can contain one RB). When single or multiple RBs are mapped continuously or discontinuously in time and frequency, they are considered to have centralized or distributed resource allocation types, respectively. Since PT-RS can be mapped within allocated RBs with centralized or distributed resource allocation types, the PT-RS density in time and frequency can depend on the type. Therefore, in at least some cases, it is necessary for the PT-RS time and frequency density to depend on whether a centralized or distributed resource allocation type is used.

[0184] Figure 17 An example of PT-RS frequency location based on symbol location is shown. Figure 2 As in the diagram, the horizontal axis 1704 represents the symbol (i.e., OFDM), and the vertical axis 1705 represents the subcarrier. Regardless of whether NR resource allocation types 0 and 1 indicate a need for centralized or distributed allocation, PT-RS time and frequency density can be maintained. Figure 17 As shown, if the Resource Blocks (RBs) are distributed temporally within the transmission interval, then the PT-RS time density (which can be applied to centralized allocation in some cases) can be applied individually to each time region. If the RBs are distributed frequency-wise within the transmission interval, then the PT-RS frequency density (which can be applied to centralized allocation in some cases) can be applied individually to each frequency region (i.e., the portion of the carrier bandwidth used) with consecutively allocated Resource Blocks or Resource Block Groups (RBGs). For example, in 1701, each symbol can have one PT-RS, which does not exhibit any variation. In 1702, there is one PT-RS every other symbol (i.e., every second symbol), which can be activated when the frequency changes due to a different frequency region starting midway at 1712. In 1703, there is one PT-RS symbol every three symbols, which can be restarted when the frequency changes due to a different frequency region starting midway at 1713.

[0185] Figure 18 An example of PT-RS frequency density based on RBG is shown. This frequency density can be determined based on the configured or determined RBG size, and Figure 18Each scenario can have a different RBG. In scenario 1810, each RB has a PT-RS, and its density is one PT-RS per RB. For scenario 1820, it is possible to have different RBGs with different densities every other RB. For scenario 1830, it is also possible to have different RBGs with different densities every three RBs.

[0186] In one embodiment, within an RB containing a PT-RS, the RE location (e.g., subcarrier location, RE offset) of the PT-RS can be determined based on at least one of the following: physical cell ID, WTRU-ID (e.g., C-RNTI, temporary C-RNTI, or IMSI), PT-RS frequency density, PT-RS time density, and a max_RB_offset value. For example, if the max_RB_offset value is the first value (e.g., 0), then the RE location (or RE offset) can be determined based on the WTRU-ID, and if the max_RB_offset value is the second value (e.g., greater than 0), then the RE location (or RE offset) can be determined based on the cell ID. Alternatively, if the max_RB_offset value is the first value, then the RE location (or RE offset) can be determined based on the PT-RS frequency density, and if the max_RB_offset value is the second value, then the RE location (or RE offset) can be determined based on the cell ID.

[0187] Figure 19 An example of PT-RS generation processing for π / 2-BPSK data modulation is shown. For Binary Phase Shift Keying (BPSK) modulation 1912, the bit sequence b(n) can be mapped to the complex-valued modulation symbol x based on the following equation:

[0188]

[0189] For π / 2-BPSK modulation 1914, the bit sequence b(n), (where n is the index (i.e., position)) can be mapped to the complex-valued modulation symbol x based on the following equation:

[0190]

[0191] in

[0192] As stated here, π and pi are interchangeable. Figure 19As can be seen, there exists a PT-RS sequence design where the modulation order of the associated data (e.g., PDSCH or PUSCH) can be pi / 2BPSK. PT-RS bits consisting of 0s and 1s can be multiplexed with data bits 1910 according to a predetermined pattern. The resulting multiplexed bits b 1902 can undergo BPSK modulation 1912 to obtain d 1904, and then undergo pi / 2 modulation 1914 to obtain c 1906. Decoupling BPSK and pi / 2 modulation would be beneficial if orthogonal overlay codes (OCC) were applied to the PT-RS bits. After pi / 2 modulation 1914, the resulting symbols can be processed by DFT block 1916 and optional frequency domain spectral shaping (FDSS) 1918 (which can be performed either after or before DFT 1916). The shaped symbols can then be mapped 1920 to the assigned subcarriers and will be processed by IDFT block 1922 in preparation for transmission in OFDM symbols.

[0193] Figure 19 This can be further illustrated by the following example: Assume the DFT size is set to N=12 due to the allocated resources (e.g., the total number of data and PT-RS bits), and the PT-RS bits are inserted into two blocks at the beginning and end of sequence b 1902, with each block consisting of 2 bits; thus, the multiplexed vector of data and PT-RS 1910 can be written as b = [X, X, 8 data bits, Y, Y], where X, Y, and the data bits are 0 or 1. It should be noted that the PT-RS bits in each block do not necessarily have to be the same, and therefore, in this example, they can be values ​​X1, X2, Y1, and Y2, where different X and Y values ​​exist. For illustrative purposes, the value b = [1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 11] can exist, and after BPSK modulation 1912 of b 1902, as shown in Table 5 below, the modulated sequence can become d 1904, where the following notes will be used:

[0194] -0.7071-0.7071i -0.7071-0.7071i 0.7071+0.7071i 0.7071+0.7071i -0.7071-0.7071i -0.7071-0.7071i 0.7071+0.7071i -0.7071-0.7071i 0.7071+0.7071i -0.7071-0.7071i -0.7071-0.7071i -0.7071-0.7071i

[0195] Table 5: Examples of data and PT-RS bits after BPSK modulation

[0196] Then, sequence d 1904 will be element-wise compared with vector Multiply (Hadamard product) to perform pi / 2 modulation 1914, thus producing c 1906. It should be noted that p(n) can be written in a slightly different way as long as it represents pi / 2 modulation. Examples of calculated values ​​for p(n) are given in Table 6 below.

[0197] 1.0000+0.0000i 0.0000+1.0000i -1.0000+0.0000i -0.0000-1.0000i 1.0000-0.0000i 0.0000+1.0000i -1.0000+0.0000i -0.0000-1.0000i 1.0000-0.0000i 0.0000+1.0000i -1.0000+0.0000i -0.0000-1.0000i

[0198] Table 6: Examples of p(n)

[0199] Then, as shown in Table 7 below, we will obtain

[0200]

[0201]

[0202] Table 7: Examples of PT-RS / data bits modulated by pi / 2BPSK

[0203] Figure 20 An example of PT-RS generation processing for pi / 2BPSK data modulation and OCC is shown. As described here, if some elements use the same last two digits (such as in...), Figure 19 and 20 If (in Chinese), then it can be interpreted as similar. Furthermore, Figure 20 Can be with Figure 19 Similarly, however, when transmitting PT-RS bits within a block, an orthogonal overlay code (OCC) can be applied to the PT-RS bits within that block. It should be noted that the bits multiplied by the OCC can be the same. In such a scenario, the OCC is applied to the PT-RS bits after BPSK modulation but before pi / 2 modulation 2013 (i.e., on sequence d 2004), resulting in an OCC-enhanced PT-RS bit e 2005 (i.e., vector e). It should be noted that applying OCC after pi / 2 modulation will disrupt the phase continuity of the signal and result in a signal with a large peak-to-average power ratio.

[0204] To illustrate further, consider an example where the block size is 2 and the OCCs to be applied are

[11] and [1-1]. In d 2004, the two PT-RS bits in each block can be multiplied by one of these OCCs 2013. Continuing with this example, if the OCC is

[11] , then the vector e 2005 would be as shown in Table 8 below.

[0205]

[0206]

[0207] Table 8: Examples of applying

[11] OCC to PT-RS bits after BPSK modulation

[0208] If OCC is [1-1], then vector e 2005 will be as shown in Table 9 below.

[0209] (-0.7071-0.7071i)x1 (-0.7071-0.7071i)x-1 0.7071+0.7071i 0.7071+0.7071i -0.7071-0.7071i -0.7071-0.7071i 0.7071+0.7071i -0.7071-0.7071i 0.7071+0.7071i -0.7071-0.7071i (-0.7071-0.7071i)x1 (-0.7071-0.7071i)x-1

[0210] Table 9: Examples of applying [1-1]OCC on PT-RS bits after BPSK modulation

[0211] For the OCC applied to each PT-RS bit block by the specified WTRU, the OCC can be the same for all blocks or different for one or more blocks. Taking two blocks and two bits as an example, the OCC code applied by the WTRU can be {

[11] ,

[11] or {[1-1], [1-1]} or {

[11] , [1-1]} or {[1-1],

[11] }.

[0212] If the same OCC is applied to all blocks, then another parameter (e.g., WTRU ID) can be used to implicitly signal or determine the index of the code. For example, mod(WTRU ID, 2) can determine one of two OCCs, while mod(WTRU ID, 4) can determine one of four OCCs. Typically, mod(WTRU ID, k) can determine one of k OCCs.

[0213] The index of the OCC applied on a block can be determined by some rule (e.g., by repeating the code in a loop). For example, suppose there are 4 blocks and each block has 2 PT-RS bits. Then the WTRU can apply the following codes to these four blocks in a specified order: {

[11] , [1-1],

[11] , [1-1]} or {[1-1],

[11] , [1-1],

[11] }. The index of the first code can be implicitly announced or determined by signaling, for example, by the WTRU ID.

[0214] Figure 21 An example of a repeating loop OCC is shown. This loop operation can be performed in a clockwise direction 2101 or a counterclockwise direction 2102, where the index of OCC is placed on the circle. As an example, OCC#1 =

[1111] ; OCC#2 = [11-1-1]; OCC#3 = [1-11-1]; OCC#4 = [1-1-11].

[0215] In one approach, the OCC can be used for a reference signal sequence (e.g., within a block) based on the modulation order of the reference signal (e.g., PT-RS). For example, if a first modulation order (e.g., pi / 2BPSK) is used for the reference signal, then the OCC will not be used (as an example, an OCC with all '1' entries could be used); if a second modulation order (e.g., QPSK) is used for the reference, then the OCC can be used, and the OCC can be determined based on one or more of the following: one or more WTRU-specific parameters (e.g., WTRU-ID (e.g., C-RNTI), scrambling ID, etc.); parameters configured at higher layers; layer (e.g., transport layer); layer number; one or more cell-specific parameters (e.g., cell ID); and / or the use of a specific OCC (e.g., all '1' entries) can be referred to as not using the OCC.

[0216] For a universal PT-RS design for all modulation types (e.g., QPSK modulation), the pairing of bits b(n) and b(n+1) can be mapped to the complex-valued modulation symbol x according to the following equation:

[0217]

[0218] Figure 22 Examples of pi / 2BPSK and QPSK constellations are shown. It should be noted that both pi / 2BPSK modulation and QPSK modulation, as described above, can have... Figure 22 The same constellation diagram is shown. The horizontal axis measures the real number 2201, and the vertical axis measures the imaginary number 2202. Given that pi / 2BPSK and QPSK share the same constellation, it would be ideal to have a PT-RS sequence design that is universal for all data modulation types, including pi / 2BPSK, QPSK, 16QAM, etc. In this way, the number of bits required for PT-RS in a DFT-s-OFDM symbol can be equal to V*X (V multiplied by X), where V is the block size and X is the number of blocks.

[0219] Figure 23 A general PT-RS design sample is shown. In this example, PT-RS bits 2310 can have values ​​of p(0), p(1), p(2), and p(3). Once processed by BPSK modulation 2302, the PT-RS sequence can be generated according to the following equation shown in 2303:

[0220]

[0221] And n is the index of the DFT 2304 input (n = 0, 1, ..., N-1), where the i-th PT-RS bit p(i) will be inserted.

[0222] As an example, if the DFT size is 12 and PT-RS is inserted into the DFT 2304 inputs n = 0, 1 (head) and n = 10, 11 (tail); then the PT-RS inserted into these DFT 2304 inputs can be written as:

[0223]

[0224]

[0225]

[0226]

[0227] Figure 24 An example of an OCC application for a PT-RS design used for the lowest n in the group is shown. Figure 25 The same situation is shown, except that it applies to the largest n in the group. It should be noted that, as in the comparison... Figure 21 As explained, if OCC is to be applied to the PT-RS bits in a block, and if the data modulation type is pi / 2BPSK, then OCC can be applied after BPSK modulation but before pi / 2 modulation. The same method can be used when the data modulation type is not pi / 2BPSK. Alternatively, as... Figure 24 As shown in the example, when the data modulation type is not pi / 2BPSK, OCC can be applied to the PT-RS bits modulated by pi / 2BPSK. Figure 24 In this context, O1 and O22405 can represent OCC bits (e.g., [O1 O2] =

[11] ; or [1-1]).

[0228] With OCC, the number of PT-RS bits 2410 required could be (X*V) / L, where L is the length of the OCC. After BPSK modulation 2402 on these bits, each bit can be repeated L times and mapped to the corresponding input of DFT 2404. Figure 24 The example in the example uses L=2. Then, the bits in each group of size L can be multiplied by the same coefficient e. jmπ / 2 2403, where m can be determined based on the index of the input to DFT 2404 corresponding to a group of size L. For example, m could be... Figure 24 The lowest n (that is, e) in the group shown jmπ / 2 It will switch to e j(0)π / 2 and e j(N-1)π / 2 ) or Figure 25 The largest n (that is, e) in the group shown jmπ / 2It will switch to e j(1)π / 2 and e j(N )π / 2 Besides the value of n, the comparison Figure 24 The described processing can be with Figure 25 Similarly. Alternatively, m can be set to equal i (PT-RS bit index, i = 0, 1, ..., (X*K) / L).

[0229] The PT-RS bit p(i) can be generated using a pseudo-random number generator (such as the Gold sequence generator used in LTE).

[0230] In one scenario, the OCC can depend on the data modulation order. For pi / 2BPSK modulation of data bits, a default OCC vector (e.g., an all-1 vector, such as

[11] or

[1111] ) can be applied to the PT-RS block.

[0231] If pi / 2BPSK modulation is defined as follows:

[0232]

[0233] So, the constellations will become like this Figure 26 The example is shown in the form where the horizontal axis displays the real number 2601, and the vertical axis displays the imaginary number 2602. In this case, the PT-RS symbol is multiplied by e^(jπ / 4) to create... Figure 26 Following the constellation shown, if the data modulation is QPSK or higher-order QAM modulation, then PT-RS modulated with pi / 2BPSK can be used.

[0234] In another scenario, the first RS sequence may be based on pi / 2BPSK, and the second RS sequence may be a phase-shifted version of the first RS sequence. In such a scenario, one or more of the following may be applied: when the modulation order of the data channel associated with the first RS sequence is a first-order modulation order (e.g., pi / 2BPSK), the first RS sequence can be used; and / or when the modulation or its associated data channel is a second-order modulation order (e.g., a modulation order higher than pi / 2BPSK), a phase-shifted version of the first RS sequence (e.g., the second RS sequence) can be used, wherein the phase shift value may be predefined, pre-configured, or determined based on the constellation of pi / 2BPSK and QPSK.

[0235] In one embodiment, PT-RS for a virtual CP (i.e., extended CP) in NR can be considered, wherein the waveform and frame structure can be normalized: CP DFT-s-OFDM and CP OFDM can be waveforms in the uplink direction; PT-RS prior to DFT can be used for DFT-s-OFDM; and multiple numerical configurations can have Δf = 2. μ • Subcarrier spacing of 15 [kHz], which are tabulated in Table 10 below. For different subcarrier spacings, the CP size can be based on the formula given by the following equation:

[0236]

[0237]

[0238]

[0239]

[0240] Table 10: Examples of subcarrier spacing in NR

[0241] Based on these considerations, if the subcarrier spacing in NR is large, the CP size will decrease exponentially. This means that if the subcarrier spacing is high, OFDM or DFT-s-OFDM symbols will be easily affected by multipath delay spread, and in some cases (e.g., outdoor scenarios or scenarios with NLOS links), the receiver may encounter ISI if the subcarrier spacing is high. Existing solutions may increase the complexity of the transmitter and receiver (e.g., UW and CP combination, perturbation methods), and may be incompatible with the numerical configurations used by NR (i.e., the dynamic and static methods used for DFT-s-OFDM). For example, the static method, which inherently allows PT-RS prior to DFT, can indicate the CP length as... However, this approach may not be feasible with one or more possible numerical configurations for NR. Therefore, it would be highly beneficial to consider a virtual CP solution that allows CP scaling while remaining compatible with possible constraints regarding CP size (e.g., regarding NR).

[0242] Figure 27 An exemplary method for generating extended CP RS using a CP extender block and based on a predetermined RS is shown. In this method, the extended CP RS can be calculated based on other predetermined RS by using CP extender block 2708 and extending the normal CP duration through input mapped to DFT-s-OFDM. Figure 27The example diagram shown illustrates a detailed transmitter block diagram for this method, along with the corresponding time-domain symbols (i.e., three consecutive DFT-s-OFDM symbols 2731i-1, 2731i, and 2731). i+1 In TX block diagram 271, It is a data vector containing receipt symbols. and It can contain a vector that includes a predefined RS or PT-RS, and and It can contain vectors of CP-extended RS generated by CP extender block 2708. The input to the CP extender block can be a size and (that is, R) h and R t ), the extension in the time domain (i.e., T and H), the predetermined RS or PT-RS (i.e., h and t), the normal CP size G, and / or the vectors d, h, t, as well as Mapped to M-point DFT matrix D M The input symbol mapping matrix

[0243] Check Figure 27 The CP extender block 2708 can generate vectors based on a minimization criterion. and This is to enable virtual CP. Since CP extender block 2708 operates on a fixed value in this method, the output of CP extender block 270 can be calculated offline and stored in the transmitter's memory (not shown). During generation... and Then, using the symbol mapping matrix M t 2710, can be used to represent d, h, t, and Mapped to the input of the M-DFT. Then the mapped vectors d, h, t, ... can be computed. and The M-DFT. In subsequent steps, D M 2712 will result in a DFT (M-DFT) output of size M, which can be achieved by... The frequency domain mapping matrix is ​​mapped to subcarriers, and the N-IFDT of the mapped M-DFT output can be obtained through the IDFT matrix. This calculation will yield the time-domain signal vector. Then, the last G samples of x are pre-stressed on the signal vector x, and the resulting vector can be transmitted, thereby generating the time-domain signal (Figure 2730).

[0244] The overall operation that generates vector x can be expressed as:

[0245]

[0246] in From vectors d, h, t, and The waveform matrix of vector x is generated.

[0247] Figure 28 An example of a signal structure designed to implement a virtual CP using a CP extender block is shown. For illustrative purposes, the derivation of the CP extension part can be based on a predetermined RS (e.g., PT-RS). A signal structure with a CP part G can be used to implement a CP extension in a data vector M. d The virtual CP displayed when set to zero vector. This is for a specified CP length G, h, t, and mapping matrix M. t CP extender blocks can generate and Therefore, the last T samples (denoted by x1) and the first H samples (denoted by x4) shown in signal diagram 2830 are approximately equal to the T samples (denoted by x2) before the (N-G+1)th sample of x and the H samples (denoted by x3) starting from the (N-G+1)th sample of x, respectively. as well as CP can be used through operands and This is then virtually expanded. To achieve this, we can partition the waveform matrix A.

[0248] Figure 29 An example of partitioning the waveform matrix A used to derive the CP extension block is shown. Figure 29 Variables that can be discussed here (e.g., controls) Figure 27 and 28 Read in the context of (as described above). A submatrix can be defined as:

[0249] A H11 =A(1:H,[1:M) d +M t +M h ])

[0250] A H12 =A(1:H,M) d +M t +M h +[1:M])

[0251] A H21 =A(N-G+[1:H],[1:M d +Mt +M h ])

[0252] A H22 =A(N-G+[1:H],M d +M t +M h +[1:M])

[0253] A T11 =A(NG-T+[1:T],[1:M d +M t +M h ])

[0254] A T12 =A(NG-T+[1:T],M d +M t +M h +[1:M])

[0255] A T21 =A(N-T+[1:T],[1:M d +M t +M h ])

[0256] A T22 =A(N-T+[1:T],M d +M t +M h +[1:M])

[0257] Where A(X+[A1:A2],Y+[B1:B2]) gives a submatrix derived from A, consisting of rows from X+A1 to X+A2 and columns from Y+B1 to Y+B2.

[0258] By using the submatrices described above, vectors x1, x2, x3, and x4 can be expressed as follows:

[0259]

[0260]

[0261]

[0262] as well as

[0263]

[0264] Since the target can be as well as Therefore, by reordering these submatrices, the objective function in the CP expander block can be written as:

[0265]

[0266] obey

[0267]

[0268] Where α is a non-negative value that limits the energy of the CP-extended RS. An equivalent method for specifying α can be obtained in the closed form of the following formula (1).

[0269]

[0270] Where λ is a non-negative intrinsic parameter of the CP extender block.

[0271] Figure 30 An example transmission (TX) block diagram with assumed values ​​is shown to further illustrate the concepts associated with the CP extender block. Figure 30 Variables and processes that can be discussed here (e.g., joining) Figure 27 , 28 Read in the context of (as described in 29).

[0272] Figure 31 It shows the result of Figure 30 The example signal generated by the assumed value of the transmission block shown. Figure 31 Variables and processes that can be discussed here (e.g., joining) Figure 27 , 28 Read in the context of (as described in 29).

[0273] refer to Figure 30 Assuming M = 96 (which is 6 RBs, since there may be 96 subcarriers in NR), N = 512, G = 36, and the CP size is expanded to G e =G+18=54 (e.g., H=18 and T=0) samples, thereby improving the robustness of DFT-s-OFDM symbols against multipath channel interference. For this example, assume the independent RS length is M h =1 and M t =1 is given, and their values ​​are set to 1 (M) h It should be greater than M h ≥G / N×M, thus avoiding data symbol leakage). For this mapping, we can assume M d1 =86 and M d2 =1. The size of the attached RS can be set to R. h =3 and R t =2. The internal λ can be set to 0.0001. In view of these parameters, refer to... Figure 31The resulting signal can be displayed in the time domain, with the amplitude displayed on the vertical axis 3102 and the sample displayed on the horizontal axis 3101. With these settings, the CP extender block will produce the following CP extended RS:

[0274]

[0275] As can be seen from the time-domain signal, the extended CP portion 3114 appears substantially the same in 3110a and 3110b. Therefore, this example demonstrates how the robustness of DFT-s-OFDM against multipath can be improved using the methods disclosed herein.

[0276] Figure 32 An example of doubling the CP extension by extending RS is shown. For this example, H+T can be equal to G. To reduce the error in equation (1), the symbol mapping matrix M can be modified. t Optimize it. For example, the mapping matrix M t It can interface with CP extended RS and pre-defined RS.

[0277] Figure 33 An example of a CP-extended PT-RS design is shown. In one embodiment, by using CP extender block 3308, all RS or PT-RS with energy constraints can be computed, and said RS or PT-RS can be mapped to the input of DFT-s-OFDM. Detailed transmitter block diagram 3301 and corresponding time-domain symbols 3330 (i.e., three consecutive DFT-s-OFDM symbols 3331) are shown. i-1 3331 i and 3331 i+1 As shown in the figure, the CP extender block 3308 can generate vectors based on a minimization criterion. and This is to enable virtual CP. The output of the CP extender block can be computed offline and stored in the transmitter's memory. During generation... and Then, through the symbol mapping matrix M t d can be and Mapped to the input of the M-DFT. The overall operation of generating vector x can be represented as:

[0278]

[0279] in From vector d, and The waveform matrix of vector x is generated in the middle.

[0280] Figure 34An example of a signal structure for implementing a virtual CP using a CP extender block is shown. This is illustrated in the data vector M. d When set to zero vector, it has a signal structure 3430 for implementing the CP extension portion of the virtual CP. For a given CP length G and mapping matrix M... t In other words, CP extender blocks can generate and Therefore, the last T samples (denoted by x4) and the first H samples (denoted by x1) of vector x can be approximately equal to the T samples (denoted by x2) before the (N-G+1)th sample of x and the H samples (denoted by x3) starting from the (N-G+1)th sample of x, respectively. In other words, as well as CP can be used through operands and This is then virtually expanded. To achieve this, we can partition the waveform matrix A.

[0281] Figure 35 The waveform matrix A used to derive the CP extender block for the complete PT-RS is shown. The submatrix can be defined as follows:

[0282] A H11 =A(1:H,[1:M) d ])

[0283] A H12 =A(1:H,M) d +[1:M])

[0284] A H21 =A(N-G+[1:H],[1:M d ])

[0285] A H22 =A(N-G+[1:H],M d +[1:M])

[0286] A T11 =A(NG-T+[1:T],[1:M d ])

[0287] A T12 =A(NG-T+[1:T],M d +[1:M])

[0288] A T21 =A(N-T+[1:T],[1:M d ])

[0289] A T22 =A(N-T+[1:T],Md +[1:M])

[0290] Where A(X+[A1:A2],Y+[B1:B2]) gives the submatrix of A derived from the rows from X+A1 to X+A2 and the columns from Y+B1 to Y+B2.

[0291] By using the submatrices described above, vectors x1, x2, x3, and x4 can be expressed as follows:

[0292]

[0293]

[0294]

[0295] as well as

[0296]

[0297] Because a goal can be as well as Therefore, by reordering these submatrices, the objective function in the CP expander block can be written as:

[0298]

[0299] in

[0300]

[0301] Here, α is a nonnegative value for avoiding trivial solutions. Since this problem is convex, it can be solved using any convex optimization toolbox.

[0302] In another approach, elements and The value can be quantified by introducing another constraint.

[0303] In one embodiment, PT-RS can be used for sidelink transmission or sidelink channel, or in combination with it. The sidelink channel can be a channel used between WTRUs.

[0304] PT-RS is a non-limiting example of an available RS. In the embodiments and examples described herein, other RSs (e.g., DM-RS) may replace PT-RS and still conform to this disclosure. For example, solutions for determining the presence, density, and / or location of PT-RS are equally applicable to determining the presence, density, and / or location of other RSs (e.g., DM-RS) for a given channel (e.g., a sidelink channel).

[0305] A sidelink channel or transport is a non-limiting example of a channel or transport available for communication between WTRUs (which may be of the same or different types). For example, a backhaul channel or transport may replace the sidelink channel or transport in the examples and embodiments described herein, and still be consistent with this disclosure. A backhaul channel or transport may be between a gNB, a trunk and gNB (e.g., a donor gNB), an integrated access backhaul (IAB) node, a gNB and / or an IAB node, etc.

[0306] In one approach, the PSCCH and PSSCH can use the same structure (e.g., DM-RS RE position and data RE position within an RB or a scheduled RB). Sidelink transmissions may include the PSCCH and its associated PSSCH, where the PSCCH can provide scheduling information about the PSSCH.

[0307] The presence (e.g., transmission) of PT-RS in PSCCH can be determined based on the presence of PT-RS in PSSCH. For example, when PT-RS exists in an associated PSSCH (e.g., a PSSCH scheduled by PSCCH), PT-RS will also exist (e.g., be transmitted) in PSCCH.

[0308] The presence of PT-RS in the PSCCH can be determined based on the presence of PT-RS in the associated PSSCH and the time position of the associated PSCCH. For example, if the PSCCH and its associated PSSCH (e.g., a PSSCH scheduled by the PSCCH) are located in the same time slot or at the same time position, and the associated PSSCH contains PT-RS, then the PSSCH will contain PT-RS. If the PSCCH and its associated PSSCH are located in different time slots or at different time positions, then the PSCCH will not contain PT-RS.

[0309] The presence of PT-RS in PSSCH can be determined based on at least one of the following: the frequency range (e.g., FR1, FR2) of the carrier or bandwidth portion used for sidelink transmission (e.g., for PSSCH); the subcarrier spacing of the carrier or BWP used for PSSCH transmission, or the subcarrier spacing that can be used for PSSCH transmission; the MCS level and / or scheduling bandwidth indicated or used for PSSCH; the Doppler frequency (or the relative speed between two WTRUs); and / or higher layer configuration.

[0310] The density of PT-RS used for PSCCH (e.g., time and / or frequency density) can be determined based on the density of PT-RS used for associated PSSCH. Alternatively, the density of PT-RS used for PSCCH can be the same as the density of PT-RS used for associated PSSCH. Alternatively, the density of PT-RS used for associated PSSCH can be determined based on higher-layer configuration. Alternatively, the density of PT-RS used for associated PSSCH can be determined based on the distance or proximity between two WTRUs, where the WTRU can be informed of its distance or proximity information to a gNB that can grant sidelink resources. Alternatively, the density of PT-RS used for associated PSSCH can be determined based on one or more scheduling parameters (e.g., MCS level, scheduling bandwidth).

[0311] For one or more scheduling parameters of a PSSCH that can determine the PT-RS density of the PSSCH and / or PSCCH, these parameters may be configured (e.g., pre-configured) or indicated before the WTRU sends the PSCCH. For example, a PDCCH (e.g., a PDCCH that licenses one or more sidelink resources) can provide or indicate one or more pieces of information about the PSSCH that can determine or be used to determine the PT-RS density of the PSCCH and / or PSSCH.

[0312] One or more PSCCHs may be associated with a PSSCH, wherein the side link control information (SCI) scheduling the PSSCH may be split into one or more PSCCHs. For example, a first subset of the SCI may be transmitted in a first PSCCH, and a second subset of the SCI may be transmitted in a second PSCCH, and so on. The first PSCCH may include PT-RS. The density and / or location of the PT-RS of the first PSCCH may be configured or predetermined. Alternatively, the first PSCCH may not contain PT-RS. As a supplement / alternative, the first PSCCH may include one or more scheduling information about the PSSCH, wherein the information may determine or be used to determine the PT-RS density and / or PT-RS location of the PSSCH. One or more scheduling information included in a PSCCH (e.g., the first PSCCH) may determine or be used to determine the PT-RS density and / or PT-RS location of another PSCCH (e.g., one or more (e.g., all) remaining PSCCHs).

[0313] The presence and / or density of PT-RS for PSCCH can be determined or predetermined based on PSCCH configuration. The presence and / or density of PT-RS for PSSCH can be determined based on scheduling parameters provided by the associated PSCCH.

[0314] In one scenario, when using PSCCH to schedule PSSCH, the scheduling parameters of PSSCH (e.g., MCS or scheduling bandwidth) are not known (e.g., until after the PSCCH is received). The maximum or minimum values ​​of the scheduling parameters (e.g. for PSSCH) can be configured and / or used to determine the presence and / or density of PT-RS with respect to PSCCH.

[0315] In one approach, PSCCH and / or PSSCH resources may be determined, indicated, and / or authorized by PDCCH. The existence and / or density of PT-RS regarding PSCCH may be determined based on information provided by the associated PDCCH. The existence and / or density of PT-RS regarding PSSCH may be determined based on information provided by the associated PSCCH.

[0316] A PDCCH (e.g., DCI) used for PSCCH resource allocation or licensing may include one or more of the following: the time / frequency location of one or more PSCCHs; the number of RBs used for PSCCH transmission; DM-RS configuration information (e.g., DM-RS density of PSCCH, DM-RS location within PSCCH, etc.); and / or PT-RS configuration information (e.g., PT-RS presence, PT-RS density, PT-RS location including RB offset, and subcarrier location).

[0317] The PSCCH used for PSSCH scheduling may include one or more of the following: the time / frequency location of the scheduled PSSCH; the number of RBs used for the scheduled PSSCH; DM-RS configuration information (e.g., DM-RS density of the PSSCH, DM-RS locations within the PSSCH, etc.); PT-RS configuration information (e.g., PT-RS presence, PT-RS density, PT-RS locations including RB offsets, and subcarrier locations); and / or, if the associated PSCCH does not provide PT-RS configuration information, then the PT-RS configuration may be the same as that used for the PSCCH.

[0318] Sidelinks can use one or more operating modes. In a first sidelink mode (e.g., SL mode-1), resources for PSCCH and / or PSSCH can be dynamically licensed by the gNB (e.g., using PDCCH). In a second sidelink mode (e.g., SL mode-2), one or more resources for PSCCH and / or PSCCH can be configured (e.g., pre-configured), and the WTRU can determine and / or use one of the configured resources.

[0319] In the examples and embodiments described herein, the first mode may be a mode with dynamically licensed resources (e.g., SL mode-1), and the second mode may be a mode with resources selected by WTRU from a configuration pool or set (e.g., SL mode-2), and vice versa.

[0320] In one solution, the presence, density, and / or location of PT-RS for sidelink channels (e.g., PSCCH and / or PSSCH) can be determined based on the sidelink operating mode. For example, the presence of PT-RS in a sidelink channel can be determined based on the sidelink operating mode. PT-RS may exist in a sidelink channel in a first sidelink mode but will not exist in a sidelink channel in a second sidelink mode.

[0321] The density and / or location of PT-RS used for sidelink channels can be configured (e.g., with the aid of higher-layer signaling) or determined in a manner described in the examples here (e.g., based on one or more transmission parameters, such as frequency range, subcarrier spacing, MCS level, or scheduling bandwidth, etc.).

[0322] The means used to determine the PT-RS density and / or location of a sidelink channel (e.g., which means to use for determination) can be determined based on the sidelink mode. This means can be explicit, such as configuration or signaling (e.g., configuration or signaling regarding density and / or location). It can also be implicit, such as a determination based on one or more parameters (e.g., not explicitly representing density and / or location). As an example, the PT-RS density and / or location of a sidelink channel can be configured (e.g., via higher-layer signaling) for a first sidelink mode. For a second sidelink mode, the PT-RS density and / or location of the sidelink channel can be determined based on one or more transmission parameters, such as frequency range, subcarrier spacing, MCS, and scheduling bandwidth, etc.

[0323] In one solution, the presence, density, and / or location of PT-RS for sidelink channels (e.g., PSCCH and / or PSSCH) can be determined based on one or more of the following transmission parameters: relative speed between WTRUs; coverage level (e.g., proximity) between WTRUs; geographical location of WTRUs (e.g., Tx WTRUs) within the cell; number of symbols used for the sidelink channel; frequency range; time / frequency location or index or identifier of the determined sidelink resource, wherein the sidelink resource can be determined based on scheduling, configuration, and / or selection; DM-RS density (e.g., number of symbols used for DM-RS); and / or search space used for the channel or associated channels (e.g., search space of the associated PSCCH channel when PT-RS is transmitted in the PSSCH or when PT-RS is transmitted with the PSSCH).

[0324] In one example, one or more sidelink resources can be configured (e.g., pre-configured), and each sidelink resource can be associated with a sidelink resource identifier (e.g., SL-id). The WTRU can determine the sidelink resources used for transmission or reception. The presence, density, and / or location of PT-RS for sidelink channels (e.g., PSCCH, PSSCH) can be determined based on the determined sidelink resource identifier.

[0325] The location of a PT-RS may include one or more RB locations and / or one or more subcarrier locations.

[0326] In one solution, the presence, density, and / or location of PT-RS for sidelink channels (e.g., PSCCH and / or PSSCH) can be determined based on DM-RS density (e.g., the number of symbols used by DM-RS). In one example, if the DM-RS density of a sidelink channel is below a threshold, then no PT-RS will exist in that sidelink channel; otherwise, PT-RS will exist in that sidelink channel. In another example, if the DM-RS density of a sidelink channel is below a threshold, then a first PT-RS density can be used for that sidelink channel; otherwise, a second PT-RS density can be used for that sidelink channel. The DM-RS density of the sidelink channel can be indicated in the associated PDCCH (e.g., SL mode-1) used for sidelink channel resource allocation.

[0327] In one solution, the RB offset of the PT-RS for the sidelink channel can be determined based on the WTRU identifier (WTRU-id) of the transmitter WTRU or receiver WTRU. Alternatively, the RB offset of the PT-RS for the sidelink channel can be determined based on the destination identifier, which can be the group ID (e.g., ProSe group ID) to which the transmitted sidelink channel is targeted. The WTRU-id can be an RNTI (e.g., C-RNTI, SL-RNTI) assigned to the WTRU (i.e., transmitter WTRU or receiver WTRU). The WTRU-id and / or group ID can be provided in the resource grant (e.g., from the PDCCH) used for sidelink transmission.

[0328] In another solution, the RB offset of the PT-RS for a channel (e.g., a sidelink channel) can be determined based on at least one of the following: a scrambling code or sequence that can be used for channel transmission (e.g., an index or identifier of the scrambling code or sequence); a DM-RS that can be transmitted with the channel (e.g., an index or identifier of the DM-RS, such as an index or identifier of a DM-RS sequence); and / or a search space for use by the channel or associated channels (e.g., the search space of the associated PSCCH channel when the PT-RS is transmitted in the PSSCH or when the PT-RS is transmitted with the PSSCH).

[0329] While features and elements in specific combinations have been described above, those skilled in the art will recognize 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 computer programs, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electrical 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 storage devices, magnetic media (e.g., internal hard disks and removable disks), magneto-optical media, and optical media (e.g., CD-ROM discs and digital multipurpose discs (DVDs)). The processor associated with the software can be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any computer host.

Claims

1. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: Receive control information indicating that one or more phase tracking reference signals (PT-RS) should be included in the transmission of the Physical Uplink Shared Channel (PUSCH); Generate a PT-RS sequence for the one or more PT-RS, wherein the phase shift of the PT-RS bits applied to the PT-RS sequence is based on one or more indices associated with one or more inputs of the Discrete Fourier Transform (DFT) for processing the one or more PT-RS; as well as Send the PUSCH transmission including the one or more PT-RS.

2. The method according to claim 1, wherein, The PUSCH transmission is sent as a DFT extended orthogonal frequency division multiplexing (DFT-s-OFDM) waveform.

3. The method according to claim 1, wherein, The PT-RS bits are modulated using binary phase shift keying (BPSK) modulation.

4. The method according to claim 3, wherein, Before applying an orthogonal cover code (OCC) to the BPSK-modulated PT-RS bit, the PT-RS bit is modulated using BPSK modulation, and after the OCC is applied to the BPSK-modulated PT-RS bit, pi / 2 modulation is applied to the BPSK-modulated PT-RS bit.

5. The method of claim 4, wherein the OCC applied to the BPSK-modulated PT-RS bits is determined based on the WTRU ID of the WTRU.

6. The method according to claim 1, wherein, The PT-RS bits are modulated using pi / 2 binary phase shift keying (BPSK) modulation, and the data included in the PUSCH transmission is modulated using quadrature phase shift keying (QPSK) modulation.

7. The method according to claim 1, wherein, The PT-RS density in the frequency domain of the one or more PT-RSs depends on the number of scheduling resource blocks (RBs) used for the PUSCH transmission.

8. The method according to claim 1, wherein, The phase shift applied to the PT-RS bits corresponds to the constellation of the pi / 2 modulation scheme.

9. The method of claim 1, wherein the control information indicating that the one or more PT-RSs are to be included in the PUSCH transmission is received in a Radio Resource Control (RRC) message.

10. The method of claim 1, further comprising: receiving downlink control information (DCI), the DCI containing scheduling information for the PUSCH transmission.

11. The method according to claim 1, wherein, The phase shift applied to the PT-RS bit is by To indicate, among which n The one or more indices represent the one or more inputs associated with the DFT used to process the PT-RS bits.

12. The method of claim 1, wherein the PT-RS sequence is generated based on a pseudo-random sequence generator.

13. A wireless transmit / receive unit (WTRU), the WTRU comprising: The processor is configured as follows: Receive control information indicating that one or more phase tracking reference signals (PT-RS) should be included in the transmission of the Physical Uplink Shared Channel (PUSCH); Generate a PT-RS sequence for the one or more PT-RS, wherein the phase shift of the PT-RS bits applied to the PT-RS sequence is based on one or more indices associated with one or more inputs of the Discrete Fourier Transform (DFT) used to process the one or more PT-RS; and Send the PUSCH transmission including the one or more PT-RS.

14. The WTRU of claim 13, wherein the PUSCH transmission is transmitted as a DFT extended orthogonal frequency division multiplexing (DFT-s-OFDM) waveform.

15. The WTRU of claim 13, wherein the PT-RS bits are modulated using binary phase shift keying (BPSK) modulation, wherein the PT-RS bits are modulated by BPSK modulation before an orthogonal cover code (OCC) is applied to the BPSK-modulated PT-RS bits, and wherein after the OCC is applied to the BPSK-modulated PT-RS bits, pi / 2 modulation is applied to the BPSK-modulated PT-RS bits.

16. The WTRU of claim 15, wherein the OCC applied to the BPSK-modulated PT-RS bits is determined based on the WTRU ID of the WTRU.

17. The WTRU of claim 13, wherein the control information indicating that the one or more PT-RS should be included in the PUSCH transmission is received in a Radio Resource Control (RRC) message.

18. The WTRU of claim 13, wherein the phase shift applied to the PT-RS bit is determined by... To indicate, among which n The one or more indices represent the one or more inputs associated with the DFT used to process the PT-RS bits.

19. The WTRU of claim 13, wherein the PT-RS sequence is generated based on a pseudo-random sequence generator.

20. The WTRU of claim 13, wherein the phase shift applied to the PT-RS bit corresponds to the constellation of the pi / 2 modulation scheme.

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