Method, architecture, apparatus and system for sidelink transmit power determination - Patents.com

Abstract

A first wireless transmit / receive unit (WTRU) detects at least one signal using a first receive beam in a first direction associated with an upcoming sidelink unicast transmission to a target WTRU and (2) a second receive beam in an opposite direction, determines from the detected signal(s) a scheduled transmission that interferes with an upcoming sidelink unicast transmission based on an overlap in time and frequency of the scheduled transmission with the upcoming sidelink unicast transmission, determines a transmit power to compensate for (1) a path loss and (2) an estimated interference of a scheduled transmission at the target WTRU that interferes with the upcoming sidelink unicast transmission and has a lower priority than the upcoming sidelink unicast transmission, where the estimated interference is based on a received signal strength of each of the detected signals, and transmits data to the target WTRU in the sidelink unicast transmission using the determined transmit power.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Patent Application No. 63 / 303,721, filed January 27, 2022, the entirety of which is incorporated by reference herein. [Background technology]

[0002] The present disclosure is generally directed to the fields of communications, software, and coding, including, for example, methods, architectures, apparatus, and systems directed to determining transmit power for sidelink transmissions. Summary of the Invention

[0003] Aspects of the present disclosure relate to methods, architectures, apparatuses, and systems directed to determining a sidelink transmit power. In one aspect of the present disclosure, a wireless transmit / receive unit (WTRU) detects at least one signal using a first receive beam in a first direction associated with an upcoming sidelink unicast transmission to a target WTRU and a second receive beam in a second direction opposite to the first direction, determines from the at least one detected signal a scheduled transmission that interferes with the upcoming sidelink unicast transmission based on an overlap in time and frequency of the scheduled transmission with the upcoming sidelink unicast transmission, determines a transmit power to compensate for a path loss to the target WTRU and an estimated interference of a scheduled transmission at the target WTRU that interferes with the upcoming sidelink unicast transmission and has a lower priority than the upcoming sidelink unicast transmission, where the estimated interference is based on a received signal strength of each of the at least one detected signal, and transmits data to the target WTRU in a sidelink unicast transmission using the determined transmit power. [Brief description of the drawings]

[0004] A more detailed understanding may be had from the following detailed description, taken by way of example in conjunction with the accompanying drawings. Such drawing figures, like the detailed description, are examples. Thus, the figures and detailed description should not be considered as limiting, as other equally effective examples are possible and likely. Moreover, like reference numerals ("references") in the figures indicate like elements. [Figure 1A] FIG. 1A is a system diagram illustrating an example communication system. [Figure 1B] FIG. 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A. [Figure 1C] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A. [Figure 1D] FIG. 1D is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communications system illustrated in FIG. 1A. [Diagram 2] FIG. 2 is a diagram illustrating different cases for a sidelink (SL) transmitter (Tx) where an interfering transmission is detected. [Diagram 3] FIG. 3 is a diagram illustrating two possibilities for the first case of FIG. [Figure 4] FIG. 4 is a diagram illustrating two possibilities for the second case of FIG. [Diagram 5] FIG. 5 is a diagram illustrating the results of an evaluation of the present principles. [Figure 6] FIG. 6 is a diagram illustrating transmit power determination in a first exemplary embodiment in accordance with the present principles. [Figure 7] FIG. 7 is a diagram illustrating a method for determining transmit power in accordance with a second exemplary embodiment of the present principles. [Figure 8] FIG. 8 is a diagram illustrating packet transmission in a second exemplary embodiment in accordance with the present principles. [Figure 9] FIG. 9 is a diagram illustrating packet transmission in a third exemplary embodiment of the present principles. [Figure 10] FIG. 10 is a diagram illustrating two exemplary transmission cases on a two-dimensional plane. [Figure 11] FIG. 11 is a diagram illustrating two further exemplary transmission cases on a two-dimensional plane. [Figure 12] FIG. 12 is a diagram illustrating one exemplary embodiment of a method for SL transmission with enhanced power control for unicast SL transmission in accordance with the present principles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the following description. Furthermore, embodiments and examples not specifically described herein may be practiced in place of or in combination with embodiments and other examples explicitly, implicitly and / or inherently (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which apparatus, systems, devices, etc. and / or any elements thereof perform operations, processes, algorithms, functions, etc. and / or any portions thereof, it should be understood that any embodiment described and / or claimed herein contemplates that any apparatus, system, device, etc. and / or any elements thereof are configured to perform any operations, processes, algorithms, functions, etc. and / or any portions thereof.

[0006] Exemplary Communication System The methods, apparatus, and systems provided herein are well suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with reference to Figures 1A-1D, in which various elements of a network may utilize, execute, be arranged in accordance with, and / or be adapted and / or configured for the methods, apparatus, and systems provided herein.

[0007] 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. Communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0008] 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or “STA,” may be configured to transmit and / or receive wireless signals and may include (or be) user equipment (UE), mobile station, fixed or mobile subscriber unit, subscription-based unit, pager, mobile phone, personal digital assistant (PDA), smartphone, laptop, netbook, personal computer, wireless sensor, hotspot or Mi-Fi device, Internet of Things (IoT) device, watch or other wearable, head-mounted display (HMD), vehicle, drone, medical device and application (e.g., remote surgery), industrial device and application (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronic device, device operating in commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0009] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as, for example, the CN 106 / 115, the Internet 110, and / or the network 112. By way of example, the base station 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0010] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0011] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0012] More specifically, as noted above, the communications system 100 may be a multiple access system, but may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a of the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communications protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink Packet Access (HSDPA) and / or High-Speed ​​Uplink Packet Access (HSUPA).

[0013] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0014] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0015] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to and from multiple types of base stations (e.g., eNBs and gNBs).

[0016] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0017] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as, for example, an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish either a small cell, a pico cell, or a femto cell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0018] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as, for example, different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, the CN 106 / 115, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, may communicate with another RAN (not shown) that employs any of GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technologies.

[0019] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), the user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may use the same RAT as the RANs 104 / 114 or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802 wireless technology.

[0021] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a Global Positioning System (GPS) chipset 136, and / or other elements / peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0022] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated into an electronic package or chip, for example.

[0023] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In one embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0024] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0025] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0026] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0027] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0028] 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) regarding the current location of the WTRU 102. In addition to, or in lieu of, information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0029] The processor 118 may be further coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functions, and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (e.g., for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The elements / peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0030] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe for both the uplink (e.g., for transmission) and downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference either through hardware (e.g., a choke) or signal processing via a processor (e.g., via a separate processor (not shown) or via processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either the uplink (e.g., for transmission) or downlink (e.g., for reception)).

[0031] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0032] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a may, for example, use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0033] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), etc. As shown in FIG 1C, the eNodeBs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0034] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although each of the foregoing elements is depicted as part of the CN 106, it will be understood that any one of these elements may be owned and / or operated by an entity other than the CN operator.

[0035] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0036] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions such as fixing the user plane during inter-eNodeB handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0037] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0038] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0039] Although the WTRU is illustrated in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may use a wired communications interface (e.g., temporarily or permanently) with the communications network.

[0040] In an exemplary embodiment, the other network 112 may be a WLAN.

[0041] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a distribution system (DS) or another type of wired / wireless network that carries traffic within and / or outside the BSS. Traffic originating outside the BSS to a STA may arrive through the AP and be sent to the STA. Traffic originating from a STA destined for a destination outside the BSS may be sent to the AP to be sent to the respective destination. Traffic between STAs in a BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, and the AP may send traffic to the destination STA. Traffic between STAs in a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) a source STA and a destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode is sometimes referred to herein as an "ad-hoc" communication mode.

[0042] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. With CSMA / CA, STAs (e.g., all STAs), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0043] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0044] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining multiple adjacent 20 MHz channels. A 160 MHz channel may be formed by combining eight consecutive 20 MHz channels or by combining two non-adjacent 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse fast fourier transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the above-mentioned operations for the 80+80 configuration may be reversed and the combined data may be transmitted to a medium access control (MAC) layer, entity, etc.

[0045] Sub-1 GHz operation modes are supported by 802.11af and 802.11ah. The channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter-type control / machine-type communication (MTC) such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for certain and / or limited bandwidths (e.g., only supporting these). The MTC device may include a battery that has a battery life above a threshold (eg, to maintain a very long battery life).

[0046] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be configured and / or limited by the STAs among all STAs operating in the BSS that support the minimum bandwidth operating mode. In an 802.11ah embodiment, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) setting may depend on the state of the primary channel. For example, if the primary channel is active due to a STA (that only supports the 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered active even though most of the frequency band may remain dormant and available.

[0047] In the United States, the available frequency bands that can be used by 802.11ah are 902MHz to 928MHz. In South Korea, the available frequency bands are 917.5MHz to 923.5MHz. In Japan, the available frequency bands are 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0048] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.

[0049] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0050] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may be different for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including varying numbers of OFDM symbols and / or varying lengths of absolute time durations).

[0051] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to a gNB 180a, 180b, 180c while also communicating with and connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0052] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0053] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. Although each of the foregoing elements is illustrated as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0054] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling different protocol data unit (PDU) sessions having different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service being utilized by the WTRUs 102a, 102b, 102c, for example. For example, different network slices may be established for various use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as Wi-Fi.

[0055] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session types may be IP-based, non-IP-based, Ethernet-based, etc.

[0056] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110, for example to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0057] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface with the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0058] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to any of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other element(s) / device(s) described herein may be performed by one or more emulation elements / devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0059] The emulation device may be designed to implement one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may use terrestrial wireless communication to implement the tests.

[0060] The one or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0061] Introduction Unless otherwise stated, SL Tx, SL Tx UE, Tx UE, Tx device, and Tx are used interchangeably herein.

[0062] Unless otherwise stated, SL Rx, SL Rx UE, Rx UE, Rx device, and Rx are used interchangeably herein.

[0063] Unless otherwise stated, primary direction, intended transmission direction, and primary transmission direction are used interchangeably herein.

[0064] Unless otherwise stated, UE and device are used interchangeably herein.

[0065] Device-to-device (D2D) communications has been of interest for a long time. 3GPP standardized the first version of D2D communications for proximity services in Release 12. Then, in Release 14, 3GPP standardized LTE V2X (Vehicle-to-Xtra and Vehicle-to-Infrastructure) based on the 4G LTE cellular standard. This was further enhanced in 3GPP Release 15.

[0066] In parallel, 3GPP standardized the baseline for the 5G cellular standard New Radio (NR) in Release 15. 5G NR is standardized with a very flexible and future-proof design. This entails many advanced features, such as flexible numerology, advanced design for control transmission, bandwidth portion, transmission configurability, and HARQ (Hybrid Automatic Repeat Request) related parameters. The first sidelink (SL) standard was provided in 3GPP Release 16, the so-called NR Sidelink, which builds over the basic features and framework of NR Uu. Here, sidelink refers to direct data communication between devices without data passing through the network. Sidelink resource allocation supports two different schemes, which respectively enable sidelink operation for devices in and out of the cell coverage.

[0067] 3GPP Technical Report (TR) 22.886 and Technical Specification (TS) 22.186 provide a comprehensive description of NR V2X use cases and requirements that will serve as the basis for NR SL studies in Rel-16. The use cases are divided into four groups: See TR 22.886 and MHG Garcia et al., "A Tutorial on 5G NR V2X Communications," In IEEE Communications Surveys & Tutorials, February 2021.

[0068] 1) Vehicle Platooning: Includes use cases related to dynamically forming and managing groups of vehicles in a platoon. Vehicles in the platoon periodically exchange data to ensure the platoon functions correctly. The distance between vehicles in the platoon may depend on the available QoS.

[0069] 2) Advanced Driving: Includes use cases that enable semi-autonomous or fully autonomous driving. Vehicles share data acquired from their local sensors with nearby surrounding vehicles. In addition, vehicles share their driving intent to adjust the vehicle's trajectory or maneuvering, leading to improved safety and traffic efficiency.

[0070] 3) Extended Sensors: Allows the exchange of either raw or processed sensor data collected through nearby sensors between vehicles, Roadside Units (RSUs), pedestrian devices, and V2X application servers, with the goal of improving the perception of the environment beyond the perception capabilities of the vehicle's own sensors.

[0071] 4) Remote Driving: Allows a remote driver or V2X application to operate the vehicle. Primary use cases target passengers who cannot drive themselves, vehicles located in harsh environments (e.g. construction zones or locations with poor weather conditions), and complex situations where autonomous vehicles cannot navigate safely.

[0072] The NR V2X SL physical layer structure is heavily based on the Rel.15 NR Uu design. In addition, the NR V2X SL physical layer procedures reuse some of the Rel.14 LTE V2X concepts, with additional procedures introduced to provide physical layer support for unicast and groupcast transmissions. Although both frequency ranges are supported in the NR V2X sidelink, the NR V2X sidelink design is primarily based on the lower frequencies of FR1. For the NR V2X sidelink, no special optimizations have been made in the higher frequency bands of FR2, except to address phase noise that is more pronounced in the higher frequency bands.

[0073] NR V2X SL transmissions use an Orthogonal Frequency Division Multiplexing (OFDM) waveform, including a Cyclic Prefix (CP). The sidelink frame structure is organized into radio frames (also simply referred to as frames), each with a duration of 10 ms. The radio frames are divided into 10 subframes, each with a duration of 1 ms. This physical structure is essentially consistent with the 5G NR Uu structure, standardized in Rel. 15.

[0074] 3GPP Release 16 provides two designs for sidelink resource allocation, see already mentioned "A Tutorial..." and TS 38.214. For devices within the coverage of a cell, SL resource allocation can be performed by the gNB, which is called Mode 1 based resource allocation. Furthermore, SL devices can also perform autonomous resource allocation based on themselves sensing which resources become available for SL communication. This autonomous SL resource allocation mode is called Mode 2 based resource allocation. In Mode 2, SL devices autonomously perform sidelink resource allocation for their transmissions.

[0075] In NR V2X, SL power control is supported for PSCCH, PSSCH, PSFCH, and S-SSB transmissions. Transmit power control (TPC) commands are not supported for NR SL, so the SL power control scheme is open loop. For SL power control, the maximum transmit power P_max is (pre-)configured in the Tx UE. See TS 38.214. SL power control is supported for unicast and groupcast transmissions in NR V2X.

[0076] For unicast transmission, PSSCH power control can be configured to use only DL path loss PL_DL (between gNB and Tx UE), only SL path loss PL_SL (between Tx UE and Rx UE), or both DL path loss PL_DL and SL path loss PLSL. PSSCH power control can be based on DL path loss PL_DL when Tx UE is in network coverage. This allows mitigating interference at gNB (for uplink reception) like SL power control in LTE V2X. If PSSCH power control is based only on DL path loss, Tx UEs close to gNB transmit with lower power over PSSCH than Tx UEs far from gNB. DL path loss based PSSCH power control can be enabled or disabled by gNB. DL path loss can be derived at Tx UE based on measurements of reference signals (such as channel state information reference signals, CSI-RS, or SSB) transmitted by gNB.

[0077] In the unicast case, the PSSCH power control may also be based on the SL path loss PL_SL between the Tx UE and the Rx UE. This allows for compensating for attenuation in the SL channel. For example, if the PSSCH power control is configured to use only DL path loss, a Tx UE that is far from the gNB may transmit over the PSSCH with more power than necessary. However, if the PSSCH power control also takes into account the SL path loss, this may prevent the Tx UE from transmitting with high power. The SL path loss-based PSSCH power control may be used when the Tx UE is in and out of network coverage. The SL path loss-based PSSCH power control may be enabled or disabled by (pre)configuration. For this power control scheme, the Tx UE needs an estimate of the SL path loss, which may be obtained from the feedback of the Rx UE. See TS 38.214. Based on the PSSCH DMRS (Demodulation Reference Signal) transmitted by the Tx UE, the Rx UE can obtain an average Reference Signal Received Power (RSRP) over several RSRP measurements to mitigate the fluctuation of the received power. See TS 38.215. Since the transmit power of the PSSCH DMRS is not indicated to the Rx UE, the Rx UE cannot derive the SL path loss based on the RSRP measurement. See "A Tutorial...". Therefore, the Rx UE feeds back the average RSRP to the Tx UE using higher layer signaling. The Tx UE can use the fed back average RSRP together with the average transmit power of the PSSCH DMRS to derive the sidelink path loss PL_SL (in dB) as follows: PL_SL = average Tx power PSSCH DMRS (in dBm) - average RSRP at Rx UE (in dBm)

[0078] If the PSSCH power control is configured to use both DL pathloss and SL pathloss, the transmit power for the PSSCH is determined at the Tx UE as follows (in dBm): P_pssch=min(P_max,P_plDL_Legacy,P_plSL_Legacy); P_plDL_Legacy=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL P_plSL_Legacy=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL where the second and third terms P_plDL_Legacy and P_plSL_Legacy of the min expression in the first expression are power values ​​due to DL and SL path losses, respectively. The power control parameters are configured separately (pre-) when considering DL and SL path losses, specifically, P_0 DL and a_DL are associated with DL path losses, and P_0 SL and a_SL are associated with SL path losses. u is the SCS configuration coefficient of the configured numerology. M_pssch is the number of PRBs for PSSCH (in symbols without PSCCH). If the sidelink power control is not based on DL or SL path losses, the second or third terms are not included in the min expression arguments, respectively. As mentioned above, SL path loss based PSSCH power control is only supported for unicast transmissions. If both DL pathloss and SL pathloss are disabled for PSCCH power control, the transmit power for the PSSCH is equal to the (pre-)configured maximum transmit power P_max.

[0079] In the case of transmission with two streams over PSSCH, the PSSCH transmit power is shared equally between the two streams. The formula in the above expression represents the PSSCH transmit power for a PSSCH symbol without PSCCH. In NR V2X, the Tx UE transmits with the same power spectral density over PSSCH and PSCCH (i.e., with the same power on PRBs) in all symbols with PSCCH, PSSCH, or PSCCH / PSSCH. With M_pscch PRBs used in transmission over PSCCH, there are M_pssch-M_pscch PRBs available for PSSCH in the PSCCH / PSSCH symbol. Based on this, the PSSCH transmit power P_pssch_i and the PSCCH transmit power P_pscch in the initial symbol carrying both PSCCH and PSSCH are given by (in dBm): P_pssch_i=P_pssch+10 * log10[(M_pssch-M_pscch) / M_pssch] P_pscch=P_pssch+10 * log10[M_pscch / M_pssch]

[0080] For groupcast transmission, PSSCH power control can be configured to use DL pathloss. SL pathloss-based PSSCH power control is not supported for groupcast in NR V2X. For groupcast PSSCH power control based on SL pathloss, Rx UEs need to feed back their RSRP to Tx UEs, which may lead to large overhead since all of the Rx UEs need to feed back RSRP to Tx UEs. This may reduce the gain or even the feedback overhead may exceed the benefit.

[0081] For a UE transmitting a PSFCH, if the UE is in network coverage, the PSFCH power control may be based on the path loss between the gNB and the UE (i.e., DL path loss). Using the SL path loss can avoid transmitting at more power than necessary, but SL path loss based PSFCH power control is not supported in NR V2X.

[0082] When a sidelink UE transmits a sidelink synchronization sequence block (S-SSB) and functions as a synchronization reference (SyncRef) UE, the S-SSB power control can be based on the path loss between the gNB and the SyncRef UE (i.e., DL path loss) when the SyncRef UE is in coverage. The S-SSB power control parameters related to the DL path loss are configured separately from the PSSCH or PSFCH power control parameters. When the SyncRef UE is out of network coverage, the SyncRef UE transmits the S-SSB with a (pre-)configured maximum transmit power P_max.

[0083] The primary / pairing sidelink control information (SCI) transmission / reception scheme includes an SCI transmission scheme and a sensing scheme for autonomous SL resource allocation, and by using these schemes in combination, it is possible to significantly improve performance compared to conventional schemes in which transmission and sensing are performed only in the transmit direction.

[0084] We now present two main features of the primary / pairing transmit / receive scheme:

[0085] TDMA Primary / Pairing SCI Transmit In this feature, when the SL Tx transmits over the SL, the SCI (e.g., first stage SCI) is transmitted in the intended transmission direction (0° transmission) and then in the opposite direction to the intended transmission direction (180° transmission). However, SL data transmission (e.g., over the PSSCH) is only performed in the intended transmission direction. In this specification, the terms "primary direction" and "pairing direction" are used for the intended transmission direction and the opposite direction to the intended transmission direction, respectively. The two transmissions are performed in a rotating manner when the SL device uses an antenna panel or set of antennas in different orientations for the two transmissions.

[0086] Furthermore, SCI sensing for resource allocation is neither omnidirectional (traditional SL design) nor only in the intended transmission direction. Rather, a potential transmitter performing autonomous resource allocation performs SCI sensing in (i) the intended transmission direction and (ii) the direction paired with the intended transmission direction. An SL device performing sensing will know the sequences for the primary SCI transmission and the pairing SCI transmission as described and will adapt its receive beam accordingly. It is assumed that an SL device can perform sensing in the primary and pairing directions simultaneously.

[0087] If the SL Tx performs sensing-based autonomous resource allocation for the next SL transmission and performs this sensing in the intended transmission direction and pairing direction, it may receive most of the transmissions for which this transmission may have a collision risk.

[0088] Parallel primary / pairing SCI transmission An important observation made in highly directional systems is that only (near) collinear transmissions can cause problems in terms of contention, and this needs to be taken into consideration while performing sensing for SL's autonomous resource allocation.

[0089] This feature requires that SCI (e.g., first stage SCI) transmissions in the primary and pairing directions are performed simultaneously and that the SL device is capable of such transmissions. As an example, this may be possible if the SL device is equipped with two or more antenna panels.

[0090] The detection of SCI for resource allocation is neither omnidirectional (traditional SL design) nor only in the intended transmission direction. Potential transmitters performing autonomous resource allocation perform SCI detection in the primary direction of transmission as well as in the pairing direction. This feature requires that the SL UE can receive SCI simultaneously in the pairing direction. As SL devices are typically mounted on vehicles, they can be equipped with multiple antenna panels and thus can easily meet this requirement.

[0091] If the SL Tx performs sensing-based autonomous resource allocation for the next SL transmission and performs this sensing in the intended transmission direction and pairing direction, it may receive most of the transmissions for which this transmission may have a collision risk.

[0092] However, for sidelink communications, there is no closed-loop power control, i.e. only open-loop power control is supported. Sidelink power control may be based on DL pathloss or pathloss estimation of sidelink pathloss. A sidelink Tx may be configured to use DL pathloss or SL pathloss or both to calculate its transmit power to a given SL Rx. In the absence of any SL or DL ​​based power control configuration, a SL Tx transmits at maximum SL power.

[0093] Conventional power control designs have some limitations. If SL or DL ​​path loss compensation is not configured, the SL Tx will transmit at maximum power, which will result in increased interference to others and less energy efficient transmission. If SL path loss is compensated, the SL transmission will not react to the potential interference level it will encounter, and thus the SL Rx may not be able to decode packets if there is interference on the overlapping subchannel (despite path loss compensation). If DL path loss is configured to be compensated, it is suboptimal since it does not fully understand the power required on the sidelink. This means that in some cases, the SL Tx may transmit at a high power that is not required to ensure detection at the SL Rx. In other cases, it may transmit at a low power dictated by the DL path loss, which may result in packet errors at the SL Rx.

[0094] Furthermore, the highly directional nature of at least some sidelink transmissions has a certain impact on signal propagation and needs to be incorporated into the power control mechanism for calculating signal and interference energies.

[0095] Another limitation of conventional sidelink power control is that there is no mechanism to prioritize higher priority sidelink transmissions when multiple transmissions use a given time-frequency resource. Furthermore, this may lead to interference situations that degrade the performance of higher priority sidelink transmissions, resulting in degradation of system operation.

[0096] Thus, it can be seen that it may be desirable for an SL power control mechanism to overcome at least some of the limitations of conventional solutions, for example, so that SL communications are more reliable and energy efficient. It may also be possible to have the SL system provide higher key performance indicators (KPIs) to higher priority sidelink transmissions, even when the SL system is highly loaded. The present principles overcome at least some of the limitations of conventional solutions.

[0097] Priority-aware and interference-aware power control for sidelink transmissions In this embodiment, we propose a power control procedure for sidelink transmissions that aims to address shortcomings in current power control designs. The proposed design considers the priority of the sidelink transmission, e.g., the data / traffic priority of the sidelink transmission, and is aware of the interference that the current transmission may experience at the target receiver. In this embodiment, we show how the SL Tx can prepare relevant interference measurements while operating under Mode 1 or Mode 2 based resource allocation, and then provide a design for priority-aware and interference-aware transmit power decision. We also outline the main solution variants and provide a configuration setup for the proposed power control.

[0098] In the case of directional transmission, the SL Tx transmits to its intended SL Rx. As already explained, the direction from the SL Tx to its intended SL Rx is called the "primary direction". Another set of directions is associated with a given primary direction at a given SL Tx, such that transmissions of other transmitting devices received from these directions may interfere with the SL Tx transmission in its primary direction to the SL Tx's target SL Rx. Such a set of directions is called the "pairing direction". A typical example of a pairing direction is the direction 180° opposite to the primary direction. However, due to location aspects such as variable beamwidth transmission, side lobes, back lobes, the presence of reflective surfaces at / around a given location, etc., the pairing direction may include additional directions.

[0099] basic principle According to this embodiment, the SL Tx transmits a SL transmission whose transmit power is determined in order to compensate for the path loss and the estimated interference at the target receiver. The key idea is to compensate for the estimated interference received by the intended SL Rx in order to increase the probability of successful detection. However, if all nearby devices increase their transmit power to compensate for the estimated interference, the noise and interference floor may rise, i.e. the SL receiver receives higher signal power and also higher interference power, which may lead to no effective improvement of the received signal-to-interference-and-noise ratio (SINR) and may even lead to a saturation level of the system. To avoid this detrimental phenomenon, further according to the embodiment, each SL Tx determines its transmit power to compensate for the path loss and only those interference sources that have a lower priority than its own transmission.

[0100] This priority-aware interference cancellation can be applied to D2D communications / systems in various operating regimes, which may operate in FR1 frequencies below 6 GHz, FR2 up to 52.6 GHz, FR2-2 up to 71 GHz, or future extensions that may target sub-THz or THz systems.

[0101] In addition to priority, an aspect is the determination of interference sources that will affect the intended receiver device(s). The determination of interfering transmissions is highly dependent on the operating frequency. As an example, a D2D system operating in FR1 (sub-6 GHz frequencies) may potentially use omnidirectional transmissions, and therefore all nearby transmissions using overlapping time-frequency resources will reach the target Rx device and increase its received interference. In such a system, the Tx device then considers all interfering transmissions, estimates their transmit power at the target Rx, and performs priority-based interference cancellation. As another example, for a system operating in FR2 and performing directional transmissions, the interfering transmissions need to be considered in conjunction with directional aspects that may incorporate direction, beamwidth, and even antenna radiation patterns. Such devices operating in FR2 may also utilize quasi-omnidirectional antenna patterns. In addition, the devices may be equipped with multiple antennas and antenna panels in different directions, thus providing each SL Tx reception of potentially interfering transmissions from several directions. In this example, while executing the proposed power control solution, the SL Tx will consider all estimated (e.g., measured) interfering transmissions from all directions and down-select a subset of the interfering transmissions to be received at the target Rx in future according to the Tx knowledge (e.g., measured by the Tx) of the directions of the interfering transmissions, the location of the target Rx, beam-related aspects including beam-width and antenna pattern etc. This is further explained below in "Obtaining Relevant Estimates in Mode 1" and "Obtaining Relevant Estimates in Mode 2".

[0102] After applying this aspect of knowledge to obtain a subset of interfering transmissions that the Rx will receive in the future, the SL Tx can apply priority-based interference cancellation.

[0103] For ease of understanding, this description is directed to vehicle devices, but it should be noted that the present principles are general and fully applicable to various devices involved in D2D communication. As an example, the present principles are fully applicable to portable devices such as smartphones, tablets, and human-wearable devices such as virtual reality headsets / head-mounted displays or glasses. For different categories of devices, the SL Tx may have additional knowledge about the device category, such as the number of antenna panels that such devices are typically equipped with and their typical radiation patterns. This information is then used by the SL Tx to determine the transmissions that will affect (i.e., hit) the target receiver, and the SL Tx further applies this knowledge to determine the interfering transmissions. Thus, for different natures of systems and devices, the relevant information may be different, but the present principles are still applicable and valid for the extended power control transmissions.

[0104] Preparation of relevant estimates for various SL operation modes Obtaining the relevant estimate in mode 1 In mode 1, the gNB performs resource allocation for SL Tx devices. However, the SL Tx decodes subchannels to decode transmissions that other UEs are sending to this SL Tx. The SL Tx can maintain a sliding window for detected reservations and an estimated power for such reservations. In addition to the interference sources after decoding, the SL Tx can also maintain a received signal strength indicator (RSSI) estimate. Strictly speaking, this sliding window for characterizing power control can only be maintained for resource pools that are configured as transmission resource pools for this SL Tx.

[0105] It will be explained later that it may be necessary to differentiate the RSRP estimates (and RSSI values ​​as energy / interference indicators) of the decoded SCI depending on whether such SCI is a primary SCI (e.g., simply an SCI in the case of 3GPP Release-16 based SL designs) or a paired SCI transmission [first stage SCI transmitted in a direction paired with the primary transmission direction as already explained]. Another difference is obtained based on whether the SL Tx receives through the same antenna / beam direction used for transmission to the intended SL Rx or whether the receive beam direction is paired with the primary beam direction (e.g., 180° opposite). The idea of ​​receiving through the same receive beam can be more precisely explained using the concept of beam correspondence. In that respect, receiving the SCI through the primary direction means that the SL Tx receives the SCI through a receive beam that has beam correspondence with the transmit beam used to transmit to the intended SL Rx of this transmission in the primary direction of transmission.

[0106] Devices using such highly directional sidelinks may be equipped with a variable number of antennas or antenna panels that may be fixed in different physical directions. In addition, a given SL Tx may be in communication with more than one SL Rx, so there may be a need to use interference sources as part of interference-aware power control. It therefore makes sense for the SL Tx to maintain orientation along with the decoded SCI that indicates future reservations.

[0107] Another way to maintain such directions may be to maintain these moving windows of decoded SCIs (along with the primary indicator and pair indicator used in pairing SCI transmit / receive based SL communication) for each receive direction. This receive direction can be associated with each receive antenna, each receive antenna panel, each receive beam, or each receive beam of each receive antenna panel. This can make the process simpler since when the SL Tx wants to transmit to the target Rx, it can extract useful interference reservations that are meaningful for the intended transmit direction.

[0108] Obtaining the relevant estimate in mode 2 In mode 2, the SL Tx can perform sensing-based resource allocation and maintain a sliding window of detected SCIs and their powers over its configured transmit resource pool. This is already required for the SL Tx to perform its resource allocation, but this data can be further processed to obtain appropriate parameters for interference compensation for its SL transmissions. The SL Tx can also maintain RSSI estimates over the subchannels in the sliding window used for resource allocation. This can help with interference compensation for transmissions.

[0109] Estimation of interference metrics at SL Tx As described, the SL Tx can estimate potential interference metrics reflecting future interference that the transmission will experience in several ways. The interference estimation then allows the SL Tx to use an appropriate amount of transmit power, increasing the chances of reliable detection at the target receiver(s). Some methods are direct, providing a reliable measure of interference, i.e., RSRP from the decoded SCI, along with an indication of future reservations that overlap with the selected resource. Some methods, i.e., RSSI estimates over the assigned subchannels, RSRP thresholds for resource allocations, and CBR, are indirect measures of interference, but these measures rise with increasing interference in the system. Thus, various measurements can be used individually or in appropriate combinations with appropriate weights to calculate transmit power, such as to compensate for interference at the SL Rx.

[0110] Direct interference metrics (e.g., RSRP from decoded SCI) The most accurate direct measurement of interference comes from the decoded SCI, which in this case provides an indication of a future reservation together with an indication of the time and frequency at which this future reservation will be transmitted.

[0111] There is a set of interference sources (and future reservations) for which the SL Tx can decode the SCIs. For those SCIs that indicate reservations on resources on which the SL Tx transmits, the decoded transmissions act as interference to the SL Tx transmissions. Since the SL Tx has decoded these reservations, it obtains an RSRP estimate for these transmissions.

[0112] Since a better estimation of the future interference that a given SL transmission will experience at a given SL Rx is possible at that SL Rx, the Tx's knowledge of potentially interfering transmissions can be improved by obtaining feedback from the target Rx. Various mechanisms enable this feedback from the intended Rx.

[0113] If the intended SL Rx knows the scheduled resources a priori, e.g., in case of periodic transmissions, it can estimate the interfering transmissions and their powers for the intended reception. In case of configured grant transmissions or future reservation indicated transmissions, there are scenarios where the SL Rx knows a priori the future SL resources that are the intended destinations for the SL transmissions. The SL Rx can then provide an indication of these interfering transmissions and their powers to its Tx. Such indications can be provided to the SL Tx through appropriate signaling, e.g., in the form of physical, MAC or RRC level signaling. The SL Tx can then use this information to apply appropriate power control to ensure reliable detection of the transmissions at the intended SL Rx.

[0114] Besides directly indicating the interference source, the SL Rx can provide useful indications that may help estimate the interference at the SL Rx. As an example, the number of receive antennas, receive beamforming parameters, ability to highly null out or cancel received interference, etc., can all be useful parameters that help the SL Tx select a suitable transmit power for this target SL Rx device when it experiences interference. Such signaling can be provided to the SL Tx, for example, during sidelink RRC_Active configuration between the SL Tx and the SL Rx. Such signaling can be part of the PSSCH configuration.

[0115] Tx power indication for SL transmission The SL Tx or SL Rx can also generate interference estimates as follows: The transmit power can be indicated as part of the SL control information. This indication then provides knowledge of the transmit power to all devices that decode this SCI. The transmit power indication can be appropriately quantized. The indication can be added to the first stage SCI or the second stage SCI. This knowledge can then be used to determine the path loss of this transmission, which in combination with angle estimation and beam measurement algorithms can allow for position determination of the transmitting device. This means that if each SL Tx indicates its current transmit power as part of the control information, devices that are able to decode this control information can process and estimate the position of the transmitting device. The estimation is more accurate for highly directional systems with strong line of sight and minimal multipath. Combining this knowledge of the location of the interfering Tx and the location of the target SL Rx, the interested SL Tx can determine the interference level that each interfering Tx causes to the target SL Rx. This helps the SL Tx to perform transmit power control to compensate for the interference that its transmission incurs (ie faces) at the target receiver.

[0116] Indirect interference metrics (e.g. RSSI, CBR, HARQ feedback) Usually, direct interference metrics provide an accurate view of future interfering transmissions with a given scheduled resource. However, this information is often not available. A possible reason is that transmissions can be made without an explicit indication of a reservation. Another possible reason is that the Tx cannot decode the reservation if it were transmitted, which can happen for many reasons, e.g. channel fade and directional aspects. It turns out that the SL Tx can estimate and maintain a number of indirect interference measurements that can provide valuable information about the situation of the target SL Rx. Some of these measurements are considered below.

[0117] RSSI across scheduled subchannels In the absence of decoded SCI, or as a supplement, the SL Tx can maintain RSSI estimates across subchannels. When it selects a set of subchannels for SL transmission (mode 2) or when the gNB assigns it (mode 1), it can check the (historical) RSSI estimates for the assigned subchannels as well as their relative RSSI values ​​compared to the RSSI of the resource pool. As an example, if the RSSI of the target subchannel is higher (e.g., much higher) than the average RSSI of the resource pool, this may indicate the presence of external noise or interference, which could potentially be a different RAT if operation is not over licensed carriers. The RSSI in the resource pool, and its relative strength, can be used to appropriately select the appropriate transmit power.

[0118] RSRP threshold from resource allocation procedure When the SL Tx is performing autonomous resource allocation, if there are not enough candidate resources available at the end of the resource identification phase, the SL Tx increases the RSRP threshold (associated with a given SL transmission priority and with each detected (potential interference source) transmission priority) and performs the resource identification phase again. The SL Tx keeps increasing the RSRP threshold as long as it does not find at least a configurable number of candidate resources. Increasing the RSRP threshold leads to ignoring transmissions / reservations, some of which will eventually act as interference sources to the target transmission. Thus, the increase in the RSRP threshold (the number of iterations taken to perform resource allocation) is a direct indicator of the interference level that the transmission from the SL Tx will face in the future. Thus, the increase in the RSRP threshold provides a direct indication of the expected interference power and can thus be used as a mechanism to control the SL transmission power to compensate for the expected interference.

[0119] Channel Busy Ratio (CBR) The SL Tx maintains and monitors the Channel Busy Ratio (CBR) as part of resource allocation over the sidelink. This measurement is used for autonomous congestion control purposes over the sidelink. This measurement provides an indication of the utilization of the subchannels over the sidelink. The higher the CBR, the higher the likelihood that a transmission will face interference. These measurements can therefore be incorporated as part of the SL transmit power control to overcome the negative effects of increased interference.

[0120] HARQ feedback from target SL Rx For SL transmissions with some form of HARQ feedback, whether ACK / NAK based or NAK only, the state of past HARQ feedback from a given SL Rx can be a useful indication to modulate the transmit power control for this SL Rx. If the SL Tx receives a NAK or a given number of consecutive NAKs from the SL Rx, this usually means that the SL Rx is not receiving enough signal energy to allow successful detection, and the transmit power needs to be increased so that the probability of successful detection goes up. On the other hand, if the SL Tx receives a given number of consecutive ACKs from a given SL Rx, this usually means that the SL Rx has correctly decoded the data, and there may be an opportunity to lower the transmit power while still maintaining successful detection at the SL Rx. Reducing the transmit power is useful for two reasons: it improves the energy efficiency of the SL transmission, and also increases the SL Tx battery life. At the network level, if some or all SL Tx adjust their transmit power, the overall noise and interference levels remain contained. In the absence of a mechanism to reduce transmit power, all Tx's will continue to increase their transmit power based on the increasing noise and interference floor to limit network interference.

[0121] Indirect measurement feedback from Target SL Rx The target SL Rx can provide an indication of estimates of indirect interference measurements made locally at this target SL Rx. These indirect measurements can be in the form of RSSI estimates as seen at the target Rx for scheduled subchannels, or average RSSI for a resource pool. Furthermore, this can include CBR or other indirect measurements estimated directly at the target Rx and sent back to the SL Tx in an appropriate format.

[0122] Hybrid Join Metrics In practice, the SL Tx may decode some, but not all, of the SCI. In this case, a single metric based only on the detected SCI or only on the RSSI does not have a picture of the entire interference at the target Rx. In that respect, a hybrid scheme can be applied to the SL Tx to estimate the interference that is actually compensated through the proposed power control.

[0123] An exemplary hybrid interference metric may be one in which the SL Tx considers the RSSI contribution from potential other interference sources (after resolving the contribution of the decoded SCI) taking into account the RSRP value from the decoded SCI. In addition, there may be a weighted consideration of the RSRP threshold and the RSRP from the detected SCI. These factors thus lead to selecting the transmit power such that the best knowledge of each interference level is incorporated as part of the transmit power control. Another example may be a combination of the RSRP from the decoded RSRP and the HARQ feedback value from the target SL Rx. Yet another example may be the RSRP from the decoded SCI, RSSI, and CBR with appropriate weights in the power control procedure. These weights are further detailed later in this embodiment. In another variation, the RSRP from the decoded SCI may be combined with the HARQ feedback value and the estimated CBR for the transmit power decision.

[0124] Calculation of SL interference measurements at target SL Rx We have described the main direct and indirect metrics for the SL Tx to locally estimate the interference its future transmissions will cause to the target receiver(s). However, detection performance usually depends on the interference seen at the SL Rx, not as seen by the SL Tx. We will now describe how the SL Tx can derive an interference estimate at the SL Rx using the locally available estimates and also using other information it may have, such as the location, orientation, or other parameters related to the SL Rx. Here, one of these methods incorporates direct feedback from the SL Rx, indicating the interference perceived / estimated at the SL Rx.

[0125] Projection of interference metrics on target SL Rx Apply Tx interference as is at SL Rx.

[0126] The basic method involves assuming that the estimated interference at the SL Tx is directly applicable at the intended SL Rx. This method can be useful when the SL Tx does not have a (reliable) estimate of the SL Rx location or direction, which makes it difficult to project the Tx perceived interference onto the Rx location.

[0127] Distance-Based Estimation If the SL Tx has an estimate of the distance of the SL Rx, the SL Tx can estimate whether the interference will increase or decrease at the SL Rx. It can therefore calculate an estimated interference value at the SL Rx for each interfering SL Tx that is decodable and indicates the reservation of overlapping SL resources. This is done individually since various interference sources may be located at different distances, directions and angles, and therefore the interference seen at the intended Rx undergoes a unique shift for each interfering Tx.

[0128] In some SL transmissions, the SL Tx adds zone identification information that aids in estimating its location. This can be useful for SL Txes that perform power control for interference compensation. The SL Tx can maintain zone identification information for SL Txes that it was able to decode, and can further use this information to make an estimate of the relative distance between the interfering device and the target SL Rx.

[0129] Estimation based on computation cones For each decoded SCI, the SL Tx can estimate the direction of the interference. Furthermore, the SL Tx also knows the direction of the intended SL Rx. Based on this knowledge, the SL Tx can prepare a calculation cone for the detected interference source and can further estimate whether the interference will increase or decrease at the SL Rx. This also takes into account the direction in which the SL Rx beamforms to receive from the SL Tx. It can therefore calculate an estimated interference value at the SL Rx for each interfering SL Tx that is decodable and indicates the reservation of overlapping SL resources. This is done individually, since various interference sources may be located at different distances, directions and angles, and therefore the interference seen at the intended Rx undergoes a unique shift for each interfering Tx.

[0130] Enhanced by intended feedback from SL Rx The future interference estimate that a given SL transmission will encounter at a given SL Rx can be improved by gaining knowledge of potential interfering transmissions from the Rx. This feedback can be provided in a variety of ways from the intended Rx.

[0131] If the intended SL Rx knows the scheduled resources a priori, e.g., in the case of periodic transmissions, it can estimate the interfering transmissions and their powers for the intended reception. In the case of configured grant transmissions or future reservation indicated transmissions, there are scenarios where the SL Rx knows a priori the future SL resources that are the intended destination for the SL transmission. The SL Rx can then provide an indication of these interfering transmissions and their powers to its Tx. The SL Tx can then use this information to apply appropriate power control to ensure reliable detection of the transmission at the intended SL Rx.

[0132] Besides directly indicating the interference source, the SL Rx can also provide useful indications that may help estimate the interference at the SL Rx. For example, one or more of the number of receive antennas, receive beamforming parameters, and ability to highly null out or cancel received interference may be useful parameters and may further help in selecting a suitable transmit power for this target SL Rx device when the SL Tx experiences interference.

[0133] Incorporating beam / directional aspects for interference estimation When sidelink systems operate over very high frequency carriers, SL devices (Tx and Rx) transmit and receive through very directional narrow beams. Narrow beam transmission / reception by beamforming from multiple antennas (antenna panels) is required in such systems to compensate for the reduction in the aperture area received by each antenna and the reduction in signal energy.

[0134] An important consequence of such highly directional transmissions is that a transmission between a pair of SL devices will only be hit by an interfering transmission if the other pair is (nearly) collinear with the first pair. This occurs because the SL Tx beamforms to its intended SL Rx, and the SL Rx receives through a narrow beam aligned with that SL Tx. Given this, it is possible to consider only interfering transmissions from collinear SL devices for compensation purposes. Other transmissions between non-collinear devices that the SL device may be receiving due to distributed antennas or antenna panels are irrelevant for compensation, since these transmissions are not being received through the same beam that the intended SL Rx uses to receive the target transmission from its SL Tx.

[0135] Priority-aware and interference-aware power control for primary / pairing SCI transmit / receive based schemes The key objective of distributed SL power control is to find a trade-off between increasing the transmit power to compensate for the estimated interference (and SL path loss) at the target Rx and the interference increase that the transmission will generate in the future due to overlapping transmissions at neighboring devices. If every device tries to compensate for the estimated interference, over time every device will tend to overshoot to compensate for the interference increase. Eventually, the entire network will transmit at a saturated power level and each receiver will experience an interference-limited situation, possibly leading to an increase in erroneous packets and poor network efficiency.

[0136] One possibility is to compensate for SL path loss and then balance between power compensation (removing a detected interferer by increasing power) and interference reduction to neighboring devices (reducing its own transmit power to reduce interference to others). When the SL Tx performs the extended power control, it would be best to incorporate the priority of its own transmission, the priority of the estimated interfering transmission, and the priority of the transmissions that it interferes with. Two factors inhibit the knowledge of how other transmissions are affected by its own transmission. The first factor is the physical constraint that in a distributed system of devices, the SL Tx cannot know the receiver location / channel to estimate how its transmission will hit the receiver location / channel. The second factor is that if such interference compensation is incorporated at the neighboring receiver, this may require a reduction in its own transmit power, which may not be able to properly compensate for the path loss / interference, making correct decoding difficult, etc.

[0137] However, it is possible to apply power control to compensate for interference with respect to the relative SL priority of its own transmission to the priority of the interfering transmission. In particular, it is possible to compensate for interference received by the intended SL Rx to increase the probability of successful detection. As explained, if multiple devices in a given vicinity increase their transmission power to compensate for the estimated interference, this will raise the noise and interference floor. This may result in each SL Rx getting both higher signal power and higher interference power, without substantial improvement in the received SINR, bringing the system to saturation levels. To avoid this harmful phenomenon of devices systematically increasing their transmission power, we propose that each SL Tx increases its transmission power to compensate only for interference sources with lower priority than its own transmission priority.

[0138] As already mentioned, in the case of a highly directional system, the interfering transmissions are between a pair of devices that are (at least approximately) collinear with each other. This results in a system in which an increase in the power of a given SL Tx (Tx) to compensate for a transmission from another interfering SL Tx (Tx-I) may result in an increase in interference at the intended receivers of Tx-I, Rx-I. Thus, if both devices increase their power to compensate for each other's transmissions, the receivers will not see the effect in their effective SINR. To that end, interference-aware power control-based compensation that takes into account SL priority provides interference compensation only for higher priority transmissions, thus prioritizing the higher priority transmissions. A typical result is that the higher priority transmissions are decoded while the lower priority transmissions may not be successful. On the other hand, in a conventional system where no interference compensation is performed and power control is based only on path loss, both transmissions may fail due to the low SINR resulting from the presence of interference at the respective receivers. Similarly, if both SL devices compensate for the estimated interference independent of SL priority, both SL Txs will increase their transmit power, resulting in an increase in signal power and an increase in interference power for both receivers. Again, the net result of the increase in signal power and interference power is an insufficient SINR at each receiver. In such a case, both transmissions will generally fail, as in the conventional case where no interference compensation is performed.

[0139] The SL Tx is assumed to transmit SL SCIs (e.g., first stage SCIs) in a primary direction (towards the intended SL Rx, called the primary SCI) and in a pairing direction (which may be 180 degrees opposite the primary direction, called the pairing SCI). Pairing direction SCI transmission and reception serves to mitigate interfering transmissions that often occur between collinear SL devices to enable highly beamformed transmissions.

[0140] As explained, the interfering transmissions of concern are only from (near) collinear devices from which the intended SL Rx will receive energy while attempting to receive data from the intended SL Tx. Figure 2 illustrates different cases for a SL Tx where an interfering transmission is detected. A primary SCI is received through its primary direction (Case A) The primary SCI is received through that pairing direction (Case B) The pairing SCI is received through its primary direction (Case C) A pairing SCI is received through the pairing direction (Case D)

[0141] Note that for each primary SCI received from one direction, the Tx knows that the pairing direction is in the opposite direction. Similarly, for each interfering pairing SCI received in one direction, the Tx knows that the primary direction of the interfering transmission is in the opposite direction. Therefore, it can be concluded that case A (primary SCI received from the primary direction of transmission) is not harmful because the two transmissions are in opposite directions and the receiver beamforms to their intended Tx, so such transmissions are not harmed. This also applies to case D (pairing SCI received in pairing direction). The Tx of the interfering transmission transmits in the opposite direction to the direction of the target Tx / Rx pair. Therefore, for interference compensation purposes, both case A and case D can be excluded from power control considerations. Therefore, the main cases of interest are case B (primary SCI received through pairing direction) and case C (pairing SCI received through primary direction).

[0142] FIG. 3 illustrates two possibilities for Case C. In one possibility, Case CI, if the interfering Tx is far from Rx, Rx is not harmed when the interfering Tx transmits in its intended transmission direction, denoted as Tx-I. In another possibility, Case C-II, the transmitter of the interfering transmission is located in the middle of the target pair Tx and Rx. In this case, when the interfering device Tx-I transmits to its receiver, it generates interference at the intended receiver Rx. Although, Tx (the target transmitter) only receives a given amount of power, given channel fading and other perturbations, the exact location of the interfering transmitter cannot be estimated. Therefore, it cannot be reliably established whether the transmission of Tx-I (in the primary direction) will impair the reception at the intended Rx. On the other hand, increasing the transmission power of Tx to compensate for the interference power from Tx-I will harm the intended receiver of Tx-I. As can be seen, compensating for the interfering transmissions of case C is useful in some scenarios, but not in others from the point of view of the target receiver Rx. On the other hand, this compensation is always harmful from the point of view of the interfering pair. Therefore, in a variant, power compensation is not applied to the scenarios of case C.

[0143] Figure 4 shows two possibilities for case B where an interfering transmission is harmful to the intended receiver Rx. This is true regardless of how far or close the interfering transmitter is located to the left of Tx (in the figure). Depending on the distance, the interfering power is modulated but always harmful. Furthermore, case B can also be analyzed with respect to whether the receiver of the interfering transmitter Tx-I is located to the left of Tx (in the figure) or in the middle of the target pair Tx and Rx. Case BI shows a scenario where Rx-I is located between the target pair Tx and Rx. Transmissions from both Tx and Tx-I harm each other's receiver. In case B-II, Rx-I is located to the left of Tx. Then, Rx is harmed by the interference generated by Tx-I, but Rx-I does not receive any interference when Tx transmits in the primary direction to its intended receiver Rx. However, regardless of the location of Rx-I, Rx receives the interference generated by Tx-I, and therefore, for the purpose of priority-based interference compensation, this suggests that only interfering transmissions where the SL Tx receives the primary SCI in its pairing transmission direction are compensated.

[0144] SL data transmission power If an SL Tx is configured with a nominal SL Tx power of P_0 SL, transmitting using numerology "u", and intends to transmit over PSSCH using the M_pssch PRB, then the SL Tx configured to use at least the SL pathloss for power control can calculate its transmit power as follows: P_pssch=min(P_max,P_plDL_Legacy,P_plSL_Legacy); and P_plDL_Legacy=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL P_plSL_Legacy=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL where P_plDL_Legacy disappears if not configured to use DL PL for power control.

[0145] As proposed in this embodiment, for the proposed priority-aware and interference-aware power control, the SL Tx uses information of direct interference metrics (decoded SCI) and indirect interference metrics. Assume that the SL Tx intends to transmit a SL transmission with priority p_i to a SL Rx with a given primary direction. Following the above description, the SL Tx only considers interfering transmissions that receive the primary SCI through its pairing direction, which is opposite to the primary direction in which the SL Tx transmits to reach its target SL Rx. This represents case B in Fig. 2. From this set of direct interfering transmissions (SCIs decoded at the SL Tx or SCIs decoded at the Rx and fed back to the SL Tx), assume that the set PC-IA represents a subset of overlapping transmissions whose priority p_j is lower than the priority of its own transmission p_i. These interfering transmissions are then used in the proposed power control to be compensated in this SL Tx. Thus, the SL Tx calculates the power from the SL PL as follows: P_plSL=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL+10 * log_10 [SUM_j(bj * IF_SL_Dec_j)] where IF_SL_Dec_j ∈ PC-IA represents the set of low-priority primary SCIs detected in the pairing direction (Case B).

[0146] Next, by substituting this into the following equation, the transmission power of the PSSCH can be calculated. P_pssch=min(P_max,P_plDL_Legacy,P_plSL)

[0147] Each contribution in the first summation term with IF_SL_Dec_j is the interference power of the jth decoded interferer at the SL Tx, weighted by a coefficient bj to compensate for its interference contribution at the SL Rx, for the target transmission from the SL Tx. Thus, these are primarily RSRP values ​​for interferers whose primary SCI is decoded at this SL Tx in the pairing direction of the SL Tx with a future reservation indication that conflicts with the resource selected at the SL Tx, and whose priority is lower than its own transmission. The combined estimated interference contribution at the target Rx is converted from a linear scale to a dB scale to match the remaining terms in the formula.

[0148] The weighting factor bj can be selected for each interferer that can take into account knowledge about the interferer (e.g., location, beam direction, number of subchannels overlapping with the target transmission), SL Tx transmission parameters (transmit direction, beam width, target distance), and knowledge about the target SL Rx (e.g., location, direction, receive beamforming parameters). In this way, the weighting factor bj can also accommodate the translation of Tx local interference estimates to the target SL Rx. If Rx provides estimates of the interferers estimated by Rx, they appear here too with the appropriate weighting factor. There is no need to incorporate a projection factor from SL Tx to SL Rx, since the weighting factor for the Rx-indicated interferer is estimated directly in the SL Rx and indicated back to the SL Tx. In another example, the weighting factor bj can also take into account the priority of the jth interferer. For example, the lower the priority of the jth interferer, the higher the compensation (e.g., a higher value of bj) can be selected. The association / mapping between priority and compensation factor (e.g., contribution to bj) may be configured for the SL UE, e.g., by the network / serving gNB for in-coverage SL UEs, and may also be pre-configured for out-of-coverage SL UEs.

[0149] If the SL Tx is configured to use indirect interference metrics (either directly estimated and converted at the Tx or fed back from the target SL Rx) as part of its PC-IA power control algorithm, the transmit power resulting from the SL PL (and interference metrics) can be calculated as follows: P_plSL=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL+10 * log_10 [SUM_j(bj * IF_SL_Dec_j)+SUM_k(ck * IF_SL_NDec_k)] where IF_SL_NDec_k denotes the kth indirect (undetected SCI) measurement.

[0150] Each contribution in the last summation term, including IF_SL_NDec_k, is from one of the interference estimation methods and corresponds to an interferer that the SL Tx / Rx was not able to decode. These terms therefore capture indirect measurements such as RSSI estimates on the assigned subchannels. Other examples for considering this metric could be based on the CBR value for the resource pool or on an increase of the RSRP threshold from its default configured value as a result of iterations performed in the SL Tx as part of the resource allocation process. Note that when an RSSI value is measured and some of the strong interferers are decoded on the same subchannel, the contribution of the interferer after decoding should be subtracted from the estimated RSSI value. Otherwise, this would result in an overestimation of the interferer on the subchannel of interest. There is a source of uncertainty in the measurements on these interferers. Since the SL Tx was not able to decode them, future reservations or the possibility of future transmissions on them cannot be known with certainty. This uncertainty can be reflected in the power control equation by an appropriate choice of the weighting factor ck. Furthermore, the weighting factors can also be adapted depending on which or how many of these measurements are used to calculate the transmit power. As an example, the RSSI over subchannels and the increase in the RSRP threshold from resource allocation are directly related. Thus, if multiple indirect values ​​are used in the power calculation, the weighting factors can be adjusted (reduced) accordingly.

[0151] The transmit power calculation formula provided earlier ignores the explicit treatment of the noise power at the target receiver, which may be acceptable if the effective interference power significantly exceeds the receiver noise power. However, a more accurate transmit power determination adds the estimated noise at the target receiver to the estimated interference metric. If N_ref denotes the reference noise power at the intended SL Rx, the above formula can be written as follows: P_plSL=P_0SL+10 * log_10(2^u * M_pssch)+a_SL *PL_SL+10 * log_10[N_ref+SUM_j(bj * IF_SL_Dec_j)+SUM_k(ck * IF_SL_NDec_k)]

[0152] The reference noise power N_ref can be part of the power control configuration. Either a specific value of N_ref can be provided directly to the SL devices to be used, or a value of the reference noise figure can be provided to the SL devices. They can then use the reference noise figure together with other relevant parameters such as carrier frequency, bandwidth, etc. to calculate the value of the reference noise power to be used in the transmit power calculation. For the remaining transmit power decision calculations, the noise power is not explicitly shown, but may be added along with the interference as above to make the calculation more accurate.

[0153] Transmit power for SL data and control channels Considering that for the initial symbol of an SL slot, in which the SL Tx transmits the first stage of SCI in the form of a PSCCH and a PSSCH carrying data and a second stage SCI, the number of PRBs used for transmission via PSCCH is indicated by M_pscch, the power allocated to the PRB on which the PSSCH is transmitted can be determined as follows: P_pssch_i=P_pssch+10 * log_10([M_pssch-M_pscch] / M_pssch)

[0154] This formula actually maintains the same amount of power per symbol in the initial symbols carrying data via PSCCH / PSSCH as in the last symbol of the SL slot carrying only data via PSSCH. In addition, for symbols to which both PSCCH and PSSCH are mapped (e.g., used for transmission), they are both assigned the same power per PRB, and therefore each is assigned a split power in direct proportion to the fraction of PRBs used among the assigned PRBs. Thus, in effect, the power spectral density remains constant across resource blocks throughout the entire SL slot.

[0155] The transmit power for the PSCCH carrying the first stage SCI can be derived from the description and formula for PSSCH power. The power spectral density is kept the same between data and control, so a slight transformation of P_pssch_SL gives the power of the PSCCH as follows: P_pscch=P_pssch+10 * log_10(M_pscch / M_pssch)

[0156] In a pairing SCI transmission based scheme, different transmission powers can be selected for the primary SCI and the pairing SCI. For example, in an aggressive transmission scheme, the pairing SCI can be transmitted at a higher power to eliminate or reduce interference from other SL Txes, which may be to the left of the SL Tx (as seen in FIG. 4). A power offset between the pairing SCI transmission and the primary SCI transmission can be configured for the SL UE. The power offset can be associated with the transmission priority of the SL Tx, where the association between the priority and the corresponding value of the power offset can be configured for the SL UE. The configuration can be given to the SL UE by the network, for example, for in-coverage UEs, or can be pre-configured for out-of-coverage UEs.

[0157] It should be noted that in certain cases it may be advantageous to have different power levels for control and data in order to make the control information decodable over a wider area by increasing the power allocated to the control channel compared to the data channel.

[0158] Priority-aware and interference-aware power control for 3GPP Rel-16 / 17 SL design This applies the principles to the sidelink design standardized in 3 GPP Rel-16 / 17. Each SL Tx transmits SL SCI in a primary direction (towards the intended SL Rx). However, most SL devices may be equipped with multiple antennas (or antenna panels) to cover transmission / reception in multiple directions. Such antennas allow reception / detection of transmissions from these directions, increasing the SL device's knowledge of the network and ongoing transmissions. When a SL Tx intends to transmit in a given primary direction, there is a pairing direction associated with the primary direction of transmission. The pairing direction SCI reception serves to estimate interfering transmissions that frequently occur between collinear SL devices to enable highly beamformed transmissions.

[0159] As already explained, the only interfering transmissions of concern are from collinear devices from which the intended SL Rx will receive energy while attempting to receive data from the intended SL Tx. Thus, for cases A and B, the SL Tx will detect the following interfering transmissions: SCI received via the primary direction of the SL Tx (e.g., SCI transmitted in the primary direction) (Case A), and SCI received through the pairing direction of SL Tx (Case B).

[0160] The SL Tx can determine that case A (primary SCI received from the primary direction of transmission) is not harmful since the two transmissions are in opposite directions and the receiver beamforms to their intended Tx. The case of interest is then case B (SCI received through the pairing direction), which represents a scenario where an interfering transmission is harmful to the intended receiver Rx. This is true regardless of how far or close the interfering transmitter is located to the left of the Tx (in the figure). Therefore, for the purposes of priority-based interference compensation, we propose that only lower priority interfering transmissions, for which the SL Tx receives SCI in its pairing transmission direction, are compensated.

[0161] As proposed, for the proposed priority-aware and interference-aware power control, the SL Tx uses information of direct interference metrics (decoded SCI) and indirect interference metrics. Assume that the SL Tx intends to transmit an SL transmission with priority p_i to an SL Rx with a given primary direction. Following the previous explanation, the SL Tx only considers interfering transmissions that receive SCI through its pairing direction, which is opposite to the primary direction for the SL Tx to reach its target SL Rx. This represents case B. From this set of directly interfering transmissions (SCI decoded at the SL Tx or SCI decoded at the Rx and fed back to the SL Tx), assume that the set PC-IA represents the subset of overlapping transmissions whose priority p_j is lower than the priority of its own transmission p_i. These interfering transmissions are then used in the proposed power control solution to be compensated at this SL Tx. Thus, the SL Tx calculates the power from the SL PL as follows: P_plSL=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL+10 * log_10[SUM_j(bj * IF_SL_Dec_j)], IF_SL_Dec_j∈PC-IA represents the set of low priority SCIs detected in the pairing direction (Case B).

[0162] Next, by substituting this into the following equation, the transmission power of the PSSCH can be calculated. P_pssch=min(P_max,P_plDL_Legacy,P_plSL).

[0163] Each contribution in the summation term with IF_SL_Dec_j is the interference power of the jth decoded interferer at the SL Tx, weighted by a coefficient bj to compensate for its interference contribution at the SL Rx, for the target transmission from the SL Tx. Thus, these are primarily RSRP values ​​for interferers whose SCIs are decoded at this SL Tx in the pairing direction of the SL Tx with future reservation indications that collide with resources selected at the SL Tx, and whose priority is lower than their own transmission. The combined estimated interference contribution at the target Rx is converted from a linear scale to a dB scale to match the remaining terms in the formula.

[0164] The weighting factor bj can be selected for each interferer that can take into account knowledge about the interferer (e.g., location, beam direction, number of subchannels overlapping with the target transmission), SL Tx transmit parameters (transmit direction, beam width, target range), and knowledge about the target SL Rx (e.g., location, direction, receive beamforming parameters). In this way, the weighting factor bj can also accommodate the translation of Tx local interference estimates to the target SL Rx. If Rx provides estimates of the interferers estimated by Rx, they appear with the appropriate weighting factor. There is no need to incorporate a projection factor from SL Tx to SL Rx, since the weighting factor for the Rx-indicated interferer is estimated directly in the SL Rx and indicated back to the SL Tx. In another example, the weighting factor bj can also take into account the priority of the j-th interferer. For example, the lower the priority of the j-th interferer, the higher the compensation (e.g., a higher value of bj) can be selected. The association / mapping between priority and compensation factor (e.g., contribution to bj) may be configured for the SL UE, e.g., by the network / serving gNB for in-coverage SL UEs, and may also be pre-configured for out-of-coverage SL UEs.

[0165] In the 3GPP SL design, indirect interference measurements are configured to be used, and new variations on the power control decision depending on their availability can be derived by taking a direct example of the power control decision with the primary / pairing transmission scheme. Similarly, for the initial symbol of the SL slot, where the SL Tx transmits the first stage of SCI in the form of PSCCH and the PSSCH carrying data and second stage SCI, considering that the number of PRBs used for transmission via PSCCH is indicated by M_pscch, the power allocated to PSCCH and PSSCH is divided per symbol in direct proportion to the PRBs in the symbol. For systems where the transmission is quasi-omnidirectional, the SL Tx considers all received transmissions as potential interference at the target SL Rx and applies priority-based cancellation to determine its transmit power.

[0166] Enhanced Power Control Variations As explained, the principles allow power control where the SL Tx determines its transmission power depending on the transmission priority and interference awareness. The SL Tx monitors interference metrics, especially decoded control information from neighboring devices indicating future reservations over resources that overlap with selected (mode 2) or assigned (mode 1) sidelink resources. The SL Tx then performs interference compensation with the aim of compensating for interference generated at the target Rx by detected transmissions with an indicated priority lower than its own transmission. In this section, some variants are provided. The main schemes, or variants, can be configured by the network in special cases.

[0167] Compensation for a limited number of interference sources within the post-configuration power margin In a variant, the SL Tx compensates only the N strongest low priority interfering transmissions, and the maximum power raised for such compensation is limited to be within P_raise_limit dB. Such a limitation may be efficient from the network point of view, since a large increase in the power of the SL Tx may be beneficial to its target SL Rx in packet detection, but may increase interference for other SL Rxs, reducing their likelihood of packet decoding. Therefore, keeping the transmission power within certain limits is beneficial to better maintain system performance while keeping the priority perspective.

[0168] The number of interfering transmissions, N, and the power compensation limit, P_raise_limit_dB, are configuration parameters. In one design, the SL Tx may be configured with a value of N to 2 such that only the two strongest low priority interferers are compensated. Similarly, the additional power for interference compensation may be capped to be within 3 dB of the transmit power determined without interference compensation. The SL device may have preconfigured default values ​​for these parameters, or the network may configure preferred values. The values ​​may be part of the resource pool configuration. The values ​​may be configured differently for each priority level.

[0169] Compensates for high-priority interferers without affecting their quality In a variant, the SL Tx compensates only for low priority interfering transmissions and a subset of high priority interfering transmissions. The subset of high priority interfering transmissions includes high priority overlap detection transmissions for which the SL Tx can establish that their respective target receiving devices do not receive interference from this receiving device's transmission. This example is similar to case B-II illustrated in FIG. 4. In this case, if the SL Tx can establish the correct location of Rx-I, it knows that Rx-I does not receive any interference due to its location and directivity of transmission, regardless of its transmission power. Thus, the SL Tx can incorporate interference compensation for the interfering Tx-I in case B-II, even if the interfering transmission is indicated with a priority not lower than the SL Tx itself. Thus, the SL path loss based extended transmission power for PSSCH can be: P_plSL=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL+10 * log_10[SUM_j(bj * IF_SL_Dec_j)+ SUM_k(ck * IF_SL_NDec_k)+ / / Indirect (undetected SCIs) measurements SUM_m(dm * IF_SL_Dec_HighPRIOm) / / High priority interferer that does not affect the target receiver Where IF_SL_DEC_HighPriom indicates the mth high priority interferer whose SL Tx power is not harmful to the target receiver, dm is a weighting factor, and / / indicates the start of a comment as in MATLAB notation.

[0170] Compensating for a Proper Subset of Low Priority Interferers from Case C In one variant, the SL Tx compensates for only the low priority interfering transmissions of case B and the subset of low priority interfering transmissions of case C for which it can determine with high accuracy that the target receiver is affected by this interfering transmission. The subset of low priority interfering transmissions consists of low priority overlapping transmissions for which the SL Tx receives the pairing SCI in its primary direction of transmission and estimates that the interfering Tx is located in front of its intended Rx (e.g., between the SL Tx and the intended SL Rx). This example is similar to case C-II illustrated in Figure 3.

[0171] Priority-free interference-aware power control In a variant, all interfering transmissions are treated regardless of their priority. This does not limit the use of suitable coefficients, which may be functions of estimated power or other parameters. This variant may be suitable for other device-to-device communication systems, for example, where there is no supported physical layer priority indication.

[0172] This power control can be easily implemented in the SL Tx by skipping the above mentioned priority down selection step that is applied to the interfering transmissions after decoding.

[0173] Transmit power relaxation to avoid network saturation In priority independent interference aware power control, the SL Tx estimates and tries to compensate for interfering transmissions that its transmissions may face. If multiple or all devices are configured to perform similar compensation, this may result in a gradual increase in transmit power leading to transmissions at saturated transmit power, which is neither desirable nor effective from a system performance point of view. To avoid such overshoot of transmit power, it is possible to lower the transmit power of a given SL Rx if N transmissions of past transmissions to this SL Rx have been correctly received at this SL Rx.

[0174] For HARQ-based SL transmissions, the correct detection can be inferred from the HARQ ACK feedback received for these transmissions. This method can be very effective for HARQ-enabled transmissions to avoid saturation power levels. A suitable number N is part of the configuration to moderate the transmit power. The reduction of the transmit power due to N acknowledgments is also part of the configuration. As an example, the SL Tx can reduce its transmit power by 3 dB compared to the calculated value if it receives 5 consecutive ACKs from the target Rx. This is an example, and a suitable value can be configured as part of the power control algorithm.

[0175] In the case of HARQ-less SL transmission, other suitable techniques may be employed to overcome saturation transmission. The transmit power relaxation may be conditional on one or more of the RSSI, the estimate of the CBR, and the determined transmit power. As an example, if the past RSSI estimates over the selected subchannels show values ​​higher than a preconfigured threshold, this may indicate that many devices are transmitting over these subchannels at higher power. In this case, if the SL Tx's own calculated transmit power also exceeds another preconfigured threshold, the SL Tx may relax the final transmit power x-dB compared to the calculated power. The thresholds for the RSSI, own Tx power, and relaxation x-dB may be part of the power control configuration.

[0176] For example, transmit power mitigation using HARQ ACK / NAK history information may be combined with priority-aware and interference-aware power control solutions. The transmit power reduction with N configured HARQ ACKs may be configured as an association with the priority of the SL Tx's transmissions. For example, lower priority transmissions may be configured to reduce power by a larger amount compared to higher priority transmissions. The mapping between priority and power reduction factor may be configured for the SL UEs by the network / serving gNB for in-coverage SL UEs and may also be pre-configured for out-of-coverage SL UEs.

[0177] Configuring Advanced Power Control The SL Tx can be configured to perform the extended power control in various ways. One aspect of the extended power control algorithm relates to the configuration of the power control algorithm, and a second aspect relates to the selection of appropriate weights for the algorithm variants to be applied to the interference metrics to calculate the final transmit power for the SL transmission. Appropriate algorithm configurations and various ways to perform the weight determination are described in the following subsections.

[0178] Algorithm configuration The network can configure the SL device with an extended power control algorithm used to calculate the SL transmit power. This configuration can be part of the pre-configuration that the SL device is provided with through its initial configuration. This configuration can be part of the resource pool configuration. Thus, each resource pool configuration can have an indication on the type of power control algorithm that needs to be adopted for transmissions through that resource pool. As an example, the device can be configured to use only an interference-aware variant of power control, where the transmit power is independent of the relative priority of its own transmission and the priority of the interfering transmission. Another example is a configuration in which the resource pool is configured using a priority-aware interference-aware power control variant. Similarly, the device can be configured with the size of the window to be used for the interference metric. For devices operating in mode 2, a suitable configuration envisaged could be to use a window of the same size (history) for the interference metric as used in resource selection. This then simplifies the processing in the SL Tx, since the same window can be used in resource selection and power control processing. For devices operating in mode 1, the length of the window for estimating the interference metric can be equal to the resource selection window of mode 2. However, as Mode 1 devices are allocated resources by the gNB, shorter window sizes may be configured to facilitate transmit power control related processing.

[0179] While the gNB is performing resource allocation, for devices operating in mode 1 of resource allocation, the gNB may update the power control configuration.

[0180] Determining Coefficients for Interference Weighting In this description, we have provided a formula that allows the SL Tx to calculate the transmit power to compensate for the interference at the SL Rx. The weighting factors play a role in modulating the transmit power depending on the estimated interference source, or interference metric.

[0181] The weighting factors may be (pre)configured by the network as part of the power control parameters. This configuration may provide a combination of weights corresponding to interference sources and associated metrics to be utilized. In addition, this configuration may provide instructions on how to modify the weights depending on the number of available interference sources or interference metrics to be utilized in the power control formula. For example, when there are only two SCIs decoded with overlapping transmissions, the coefficients b1 and b2 may have pre-configured values. These values ​​may be configured to be different and smaller when there are five interference sources decoded with overlapping transmissions. Thus, the weighting factors b1, b2, b3, b4, and b5 will have different values ​​depending on the number of interference sources undergoing decoding.

[0182] The weighting factor may vary depending on the relative priority between one's own transmission and the interfering transmission.

[0183] Two (or multiple) sets of weighting factors can be configured by the network for the appropriate Rx type (interference possible or not). The SL Tx can select the appropriate weight depending on the intended SL Rx type.

[0184] For various strategies, different coefficients can be configured. The active strategy is configured as part of the configuration from one of the configured strategies. The network can update the active power control strategy and the SL Tx selects the appropriate method with the weights appropriately configured.

[0185] A set of weights or weight determination methods for various power control algorithm variants may also be provided as part of the initial configuration. One such variant may be configured as a default configuration, which may be different for various resource pools. The network may update and change the active power control configuration for any set of resource pools, and the device may use the weights and weight determination methods corresponding to the active configuration from the initial configuration in which all relevant details are configured for all possible algorithm variants.

[0186] Performance evaluation of the proposed method Simulation Settings For the evaluation, unicast SL communication, where SL UEs communicate in pairs, one UE acting as Tx and the other as Rx, was simulated using the "NR V2X Expressway" scenario, which is a special case of NR V2X Expressway recommended by 3GPP in TR 37.885. In this evaluation, a single lane of a 4 km long highway with 100 SL vehicle UEs (50 Tx-Rx pairs) was simulated. The vehicle positions and distances followed the guidelines specified by 3 GPP in TR 37.885. A Tx UE randomly selected a corresponding Rx UE from vehicles located within a distance of 150 m.

[0187] The carrier frequency of the simulated system was 28 GHz and a slot time of 0.25 ms was used, indicating a subcarrier spacing (SCS) of 60 kHz. In the frequency domain, a maximum of 10 subchannels available for SL and a subchannel size of 10 Physical Resource Blocks (PRBs) were considered. A periodic traffic model was used, where a new packet arrives at each UE every X ms. The simulation provides results for X={5,4,3,2,1} ms. The packet size at each Tx UE was uniformly distributed between 1 and 10 subchannels. In only one simulation run, the packet size for a given Tx UE remained constant.

[0188] For directional transmission and reception of data (PSSCH), directional antennas with beamwidth 300 are assumed for both Tx UE and Rx UE. For directional sensing and directional transmission of SCI (PSCCH), beamwidth was taken as 300. For both Tx UE and Rx UE, directional antenna gain was assumed equal to 5 dB. Primary / pairing SCI transmit / receive based SL communication strategy was simulated. No antenna gain was assumed for omnidirectional transmission and reception.

[0189] Packet detection and decoding is based on the received SINR. For the data channel, the SINR threshold for reliable reception of data was set to 10 dB, as evaluated in R1-1908900 [LG Electronics, "R1-1908900: Discussion on Physical Layer Structure for NR Sidelink," 3GPP TSG-RAN WG1 Meeting 98, August 2019]. For the control channel, a 5 dB SINR threshold was used to decode the received SCI. The same 5 dB threshold was applied in this resource allocation procedure, considering the set of received SCI. The maximum power limit of the SL TX was fixed at 26 dBm.

[0190] performance results In this section, the performance of the proposed power control scheme is compared with the 3GPP standardized power control that performs path loss compensation.

[0191] 3GPP-based power control scheme: We assume that SL Tx UEs have a distance estimate to their intended Rx UEs, which can be calculated through NR SL supported measurements. Knowing the distance, each SL Tx UE selects the minimum power that results in a signal-to-noise ratio (SNR) equal to the data decoding threshold (10 dB). We add an interference margin of 5 dB to account for neighboring transmissions that are not known a priori.

[0192] In the scheme according to the present principles, a scheme was used in which the SL Tx compensates for the interference caused by all lower priority transmissions received through its pairing direction.

[0193] Simulation results were averaged over 100 different distributions of SL UE for the highway deployment scenario.

[0194] Results are presented from two aspects: system level performance results in terms of Packet Reception Ratio (PRR) average across all devices, as well as 10th percentile performance results focusing on devices with higher interference. The 10th percentile performance is similar to the analysis of cell edge user performance in cellular wireless communication systems, where the goal is to investigate the impact of new solutions on users that are worst affected by interference.

[0195] Figure 5 illustrates the results of the evaluation of the present principles. The average packet reception rate (PRR) is plotted on the y-axis against the traffic intensity, indicated using the traffic arrival interval on the x-axis. PRR is the percentage of packets that are successfully received without decoding errors at the intended SL Rx. For the average performance of the whole system at a packet arrival interval of 1 ms, the PRR of the proposed power control scheme is 97% compared to the 3GPP power control solution, which results in a PRR of 90.5%. For the 10th percentile results, the improvement in PRR when using the proposed power control solution can be clearly seen. For the 10th percentile performance at a packet arrival interval of 1 ms, where the system is heavily loaded, the PRR of the proposed power control scheme is 81% compared to the 3GPP power control solution, which results in a PRR of 61%.

[0196] The results demonstrate clear technical advantages of the proposed power control solution over conventional solutions.

[0197] Exemplary embodiments In the following subsections, three exemplary embodiments are described: the first exemplary embodiment provides the general principles proposed for determining the SL transmit power, and the next two embodiments describe the SL transmit power decision in the context of a directional SL system with Tx UEs operating in Mode 2 and Mode 1 based resource allocation, respectively.

[0198] General priority-based power control 6 illustrates a first exemplary embodiment in accordance with the present principles describing a method performed by a SL Tx to perform SL transmissions with enhanced power control for unicast SL transmissions. The SL Tx is configured to use at least the SL path loss for power control of the PSSCH with appropriate parameters.

[0199] The SL Tx obtains a packet for transmission over the sidelink from higher layers and the appropriate transmission resources for that SL transmission according to the configured resource allocation mode.

[0200] In step S610, the SL Tx identifies interfering transmissions that have resources that overlap with its transmission resources.

[0201] In step S620, the SL Tx downselects the interfering transmission that is to be received at the target SL Rx.

[0202] In step S630, the SL Tx further downselects the interfering transmission whose indicated transmission priority is lower than the priority of its own transmission.

[0203] In step S640, the SL Tx determines the SL transmit powers for PSSCH and PSCCH in different symbols of the SL slot according to the formulas provided in this embodiment together with the weights configured as part of the power control configuration.

[0204] In step S650, the SL Tx transmits via the transmission resource the PSCCH and the PSSCH with the determined transmission power.

[0205] The SL Tx may transmit on PSCCH and PSSCH in the primary direction only if it operates according to 3GPP Rel-16 / 17 designs.

[0206] The SL Tx may transmit via PSCCH in the primary and pairing directions, and also via PSSCH in the primary direction only if it is configured to operate under the primary / pairing transmission scheme.

[0207] The SL Tx can track resources in its transmit resource pool and maintain the RSSI and RSRP of the decoded SCI.

[0208] The SCI used to derive the interference may be the primary SCI, the pairing SCI, or both.

[0209] The SL Tx can use knowledge of the system operating frequency, the default transmission mode, the nature of the transmission being omnidirectional or directional, knowledge of the antenna panel configuration for devices equipped with an antenna panel, as well as the antenna radiation pattern to determine interfering transmissions that would hit the intended SL Rx.

[0210] The SL Tx can apply appropriate weights to interference compensation based on knowledge of the interferer (location, beam direction, number of subchannels overlapping with the target transmission, etc.), SL Tx transmission parameters (transmit direction, beam width, target distance), knowledge of the target SL Rx (location, direction, receive beamforming parameters, etc.), and / or the relative priority of the interferer.

[0211] The SL Tx can estimate how the locally made interference estimate is projected to the SL Rx.

[0212] The SL Tx can use the computation cone and the direction from which it received the SCI (reserved) to measure the interference at the SL Rx.

[0213] The SL Tx can receive feedback from the SL Rx to calculate the interference estimate. The feedback may include a finite set of strongest interferers on the assigned subchannels. It may also include aspects related to the direction from which the SL Rx is receiving interference, the receive beam width, etc.

[0214] The SL Tx may reduce its power by a configured amount (based on priority) if at least N configured HARQ ACKs are received from the target SL Rx.

[0215] Figure 6 illustrates the steps that the Tx UE performs to determine the transmit power. The determined transmit power is then provided to the appropriate block in the WTRU responsible for the actual transmission. As part of the proposed power control solution, the SL Tx performs multiple down-selections on the detected transmissions (potentially through the decoded SCI). One down-selection is to find transmissions that overlap in time and frequency with the resources selected for its own transmission. Another down-selection is to select only those transmissions that the SL Tx estimates will hit the intended SL Rx. Yet another down-selection is to select only those interfering transmissions whose indicated priority is lower than that of its own transmission. Note that while the figure shows the down-selection steps in a given order, the steps can be performed in any order, possibly even in a single step. The goal is to arrive at a final set of interfering transmissions that are compensated with appropriate weights to determine the final transmit power.

[0216] Power Control in Mode 2 Based Resource Allocation In a second exemplary embodiment according to the present principles, a method performed by a SL Tx to perform SL transmission with enhanced power control for unicast SL transmissions is described.

[0217] Configure SL Tx to use at least the SL pathloss for power control of PSSCH with appropriate parameters.

[0218] The SL Tx obtains packets for transmission over the sidelink from higher layers. The SL Tx performs autonomous resource allocation by preparing a sensing window and a resource allocation window, and selects suitable resources for SL transmission according to a resource selection procedure.

[0219] FIG. 7 illustrates a method for determining transmit power in accordance with a second exemplary embodiment of the present principles.

[0220] In step S710, the SL Tx identifies interference decoded SCIs indicating future reservations having resources that overlap with scheduled resources.

[0221] In step S720, the SL Tx down-selects an interference-decoded primary SCI received through a pairing direction of the SL Tx, where the pairing direction is associated with the primary transmission direction to the target SL Rx.

[0222] In step S730, the SL Tx further down-selects the received pairing interference decoding primary SCI whose indicated transmission priority is lower than the priority of its own transmission.

[0223] In step S740, the SL Tx uses the SL path loss and the finally selected overlapping interference weighted with the weight configured as part of the power control configuration to determine the SL transmit power for PSSCH and PSCCH in different symbols of the SL slot according to the formula provided in this embodiment.

[0224] In step S750, the SL Tx transmits the first stage SCI via the PSCCH and the SL data (together with the second stage SCI) via the PSSCH via the selected transmission resource with the determined transmission power.

[0225] A primary SCI can be an SCI (first stage, second stage, or both).

[0226] The SL Tx may transmit via PSCCH and PSSCH in the primary direction only if it operates according to 3GPP Rel-16 / 17 designs.

[0227] The SL Tx may transmit via PSCCH in the primary and pairing directions, and also via PSSCH in the primary direction only if it is configured to operate under the primary / pairing transmission scheme.

[0228] The SL Tx can track resources in its transmit resource pool and maintain the RSSI and RSRP of the decoded SCI.

[0229] The SL Tx may compute an interference estimate over its assigned resources from the detected SCIs indicating a reservation over the same resources as those assigned to the SL Tx.

[0230] The SL Tx can apply appropriate weights to interference compensation based on knowledge of the interferer (e.g., location, beam direction, number of subchannels overlapping with the target transmission, etc.), SL Tx transmission parameters (e.g., transmit direction, beam width, target distance), knowledge of the target SL Rx (e.g., location, direction, receive beamforming parameters, etc.), and / or the relative priority of the interferer.

[0231] The SL Tx can apply appropriate weights depending on the RSSI over the assigned sub-channel.

[0232] The SL Tx can estimate how the locally made interference estimate is projected to the SL Rx.

[0233] The SL Tx can use the computation cone and the direction from which it received the SCI (reserved) to measure the interference at the SL Rx.

[0234] The SL Tx can receive feedback from the SL Rx to calculate the interference estimate. The feedback may include a finite set of strongest interferers on the assigned subchannels. It may also include aspects related to the direction from which the SL Rx is receiving interference, the receive beam width, etc.

[0235] The SL Tx may reduce its power by a configured amount (based on priority) if at least N configured HARQ ACKs are received from the target SL Rx.

[0236] For a primary / pairing SCI transmit / receive based scheme, the SL Tx can apply separate processing for the primary SCI and the pairing SCI. The pairing SCI can be transmitted at a higher power compared to the primary SCI, where the power margin is selected based on the transmission priority.

[0237] As mentioned above, in Fig. 7 we illustrate the steps that the UE can perform to calculate the transmit power. The determined transmit power is then provided to the appropriate block in the WTRU responsible for the actual transmission. As part of the proposed power control solution, the SL Tx performs multiple down-selections for the detected SCI. One down-selection is to find transmissions that overlap in time and frequency with the resources selected for its own transmission. Another down-selection is to select only those transmissions for which the SL Tx has received a primary SCI through its pairing direction, which is relative to the primary direction towards the target SL Rx. Yet another down-selection is to select only those interfering transmissions whose indicated priority is lower than that of its own transmission. It should be noted that although Fig. 7 shows these down-selection steps in a given order, the steps can be performed in any order, possibly even in a single step. The goal is to arrive at a final set of interfering transmissions that are compensated with appropriate weights to determine the final transmit power according to this embodiment.

[0238] 8 illustrates a transmission method of a second exemplary embodiment of the present principles. The transmission is performed over the sidelink while operating in an autonomous mode of resource allocation, so-called Mode 2 based resource allocation.

[0239] In step S810, the SL Tx receives configuration information regarding the resource pool along with instructions for PC-IA power control related parameters, such as algorithms and weighting factors.

[0240] Then the SL Tx operates in mode 2.

[0241] In step S820, the SL Tx monitors the SCI on the configured resource pool to find a suitable transmission and to perform resource allocation. The SL Tx also monitors parameters such as RSSI and CBR.

[0242] After receiving a packet from upper layer, in step S830, the SL Tx performs mode 2 based resource allocation to find a suitable resource for its transmission.

[0243] In step S840, the SL Tx performs priority-aware and interference-aware power control to determine the transmission power.

[0244] In step S850, the SL Tx transmits the packet on the selected resource with the determined transmit power.

[0245] Power Control in Mode 1 Based Resource Allocation 9 illustrates a packet transmission in a third exemplary embodiment of the present principles. This method is executed by a SL Tx to perform SL transmission with enhanced power control for unicast SL transmission.

[0246] Configure SL Tx to use at least the SL pathloss for power control of PSSCH with appropriate parameters.

[0247] The SL Tx obtains packets from higher layers for transmission over the sidelink. The SL Tx sends scheduling requests to the gNB to obtain resources allocated over the SL and also receives grants (SL allocations) from the gNB providing the resources allocated over the sidelink.

[0248] The SL Tx identifies interference decoded SCIs from the monitoring performed on the sidelink resource pool indicating future reservations having resources overlapping with scheduled resources, down-selects paired received interference decoded primary SCIs received through the pairing direction associated with the primary direction of transmission to the target SL Rx, and further down-selects paired received interference decoded primary SCIs whose indicated transmission priority is lower than its own transmission priority, and determines the SL transmit powers of PSSCH and PSCCH in various symbols of the SL slot according to the formulas provided in this embodiment using weights configured as part of the power control configuration.

[0249] The SL Tx transmits the first stage SCI via PSCCH and the SL data (together with the second stage SCI) via PSSCH via the transmission resources allocated by the gNB using the determined transmission power.

[0250] A primary SCI can be an SCI (first stage, second stage, or both).

[0251] The SL Tx may transmit via PSCCH and PSSCH in the primary direction only if it operates according to 3GPP Rel-16 / 17 designs.

[0252] The SL Tx may transmit via PSCCH in the primary and pairing directions, and also via PSSCH in the primary direction only if it is configured to operate under the primary / pairing transmission scheme.

[0253] The SL Tx can track resources in its transmit resource pool and maintain the RSSI and RSRP of the decoded SCI.

[0254] The SL Tx may compute an interference estimate over its assigned resources from the detected SCIs indicating a reservation over the same resources as those assigned to the SL Tx.

[0255] The SL Tx can apply appropriate weights depending on the RSSI over the assigned sub-channel.

[0256] The SL Tx may estimate how the locally made interference estimate is projected to the SL Rx, which may follow the power control configuration information received from the gNB.

[0257] The SL Tx can use the computation cone and the direction from which it received the SCI (reserved) to measure the interference at the SL Rx.

[0258] The SL Tx can receive feedback from the SL Rx to calculate the interference estimate. The feedback may include a finite set of strongest interferers on the assigned subchannels. It may also include aspects related to the direction from which the SL Rx is receiving interference, the receive beam width, etc.

[0259] The pairing SCI may be transmitted at a higher power compared to the primary SCI, where the power margin is selected based on the transmission priority.

[0260] In Fig. 9, a UE transmission method for sidelink transmissions is illustrated when operating under Mode 1 based resource allocation where the base station performs resource allocation for that sidelink transmission. The SL Tx keeps monitoring its configured Tx resource pool and maintains a history of future reservations and other parameters related to the configured power control solution. As an example, these parameters may include subchannel and resource pool based RSSI and CBR. The duration over which averaging is performed over such parameters is part of the power control configuration information. An exemplary duration may be equal to the duration of the sensing window that a Mode 2 based user employs to perform resource allocation. In this way, power control solution parameters can be harmonized between SL UEs, regardless of whether they are operating under Mode 1 or Mode 2 based resource allocation.

[0261] In step S910, the SL Tx receives configuration information regarding the resource pool along with instructions for PC-IA power control related parameters, such as algorithms and weighting factors.

[0262] Then the SL Tx operates in mode 1.

[0263] In step S920, the SL Tx monitors the SCI on the configured Tx resource pool to find suitable transmissions and also to perform power control. The SL Tx also monitors parameters such as RSSI and CBR.

[0264] After receiving the packet from the upper layer, in step S930, the SL Tx sends a scheduling request to the base station to receive the SL resource for transmission.

[0265] In step S940, the SL Tx performs priority-aware and interference-aware power control to determine the transmission power.

[0266] In step S950, the SL Tx transmits the packet on the base station allocated resources with the determined transmission power.

[0267] Optimized DL path loss in SL beam-based transmit power control for PSSCH with respect to DL path loss When the Tx device is in network coverage, the legacy SL device may be configured to perform power control of sidelink transmissions based on DL path loss. The SL Tx estimates the path loss to the serving base station (gNB) and uses this in its power control calculations. If the PSSCH power control is configured to use at least the DL path loss, the transmit power for the PSSCH is determined at the Tx UE as follows (in dBm): P_pssch=min(P_max,P_plDL_Legacy,P_plSL_Legacy); P_plDL_Legacy=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL P_plSL_Legacy=P_0SL+10 * log_10(2^u * M_pssch)+a_SL * PL_SL In the formula, the second term P_plDL_Legacy and the third term P_plSL_Legacy of the argument of the min formula in the first formula are the power values ​​due to the DL path loss and the SL path loss, respectively.

[0268] For this calculation, SL Tx is configured with a nominal Tx power of P_0DL to be used in conjunction with DL pathloss based power control, and is intended to transmit using numerology "u" and also to transmit via PSSCH via the M_pssch PRB. a_DL is the parameter configured for split power control based on DL pathloss, and PL_DL denotes the estimate of DL pathloss at the Tx UE.

[0269] DL PL based power control tries to contain interference to uplink transmissions at the gNB. This is important when SL and UL operate in the same band and SL transmissions create interference to UL transmissions, preventing correct reception at the base station. DL PL based power control is very restrictive for sidelink transmissions. If the SL Tx is located close to the gNB, the DL path loss will be smaller and therefore the SL transmissions of the SL Tx will be transmitted at a lower transmit power. If the target SL Rx of such SL Tx is at a larger relative distance compared to the gNB from the SL Tx, the path loss will be larger and the power control applied by the SL Tx will limit correct reception at the target SL Rx. On the other hand, if the SL Tx is close to the cell edge, the DL path loss may be larger and it will transmit at a higher SL power. If the SL Rx for such SL Tx is located nearby and the relative distance and path loss is much less compared to the gNB, the SL Tx does not need to transmit at such a higher power to reach this Rx located very close. In this case, this transmission may be very power inefficient.

[0270] Moreover, this calculation of power control may be suitable for (near) omnidirectional transmission, although for directional transmission, which is the de facto mode of operation at high carrier frequencies, power control based on this formula is usually suboptimal.

[0271] The focus of this embodiment is to provide a sidelink transmit power calculation with respect to DL pathloss for directional sidelink transmissions, which in turn allows a more accurate SL transmit power calculation without disturbing the base station reception of other uplink transmissions. However, it may make sense to use SL pathloss-based power control for sidelink transmissions and use the DL pathloss-based transmit power as an upper limit and limit the actual transmit power if the SL pathloss-based power control exceeds this upper limit.

[0272] For SL transmissions not targeted to the gNB, it does not make sense to apply power control considering DL path loss without considering the directional aspects. We propose to impose real constraints in the form of power received at the gNB, taking into account the directional nature of the transmission.

[0273] If the SL Tx is configured to take DL path loss into account for SL power control and further configured with appropriate parameters related to applying DL path loss to calculate SL power, in addition to those parameters, the SL Tx uses the directivity of the SL Tx's transmission to calculate the SL transmit power. The directivity incorporates the intended transmit direction of the SL Tx and the direction of the gNB from the SL Tx. Also, the transmit pattern, beam width, and main lobe and side lobe information can be used if such information is available.

[0274] As an example, the SL Tx applies the following formula to calculate the SL transmit power with respect to the DL path loss: P_plDL=F(P_0DL+10 * log_10[2^u * M_pssch]+a_DL * PL_DL) where F is a transformation incorporating the directivity of transmission and the direction of the gNB from the SL Tx.

[0275] The direction can be incorporated in various ways. Typically, the direction to the target Rx and the serving gNB is known at the potential Tx, so the angle between these directions can be known. For example, the angle between the selected UE Tx / Rx beam used to communicate with the serving gNB and the selected UE Tx beam used to communicate with the target SL Rx can be derived. The angle can be derived in both azimuth and elevation directions.

[0276] FIG. 10 illustrates two exemplary transmission cases for a two-dimensional plane (e.g., the elevation angle between the two directions is 0). For case 1, the SL Tx intends to transmit to the SL Rx. Given the angle (e.g., azimuth) between the intended transmission direction and the gNB is β, and given the beamwidth at which the transmit power is received at the gNB, the received power at the gNB is cos(β) times smaller than the power transmitted by the SL Tx in the direction of the SL Rx. Thus, taking this reduction into account, the SL Tx can calculate the transmit power based on the DL path loss as follows: P_plDL=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL+10 * log_10(g * cosβ).

[0277] In this equation, g denotes a factor that may provide additional flexibility by weighting or lightening the cos β term. The value of the weighting factor g may be configured for the UE, for example, by the network or by the serving gNB.

[0278] In the three-dimensional plane, assuming an azimuth angle β between the direction towards the target SL Rx and the direction towards the serving gNB, and an elevation angle φ, the SL Tx can calculate the transmit power based on the DL path loss as follows: P_plDL=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL+10 * log_10(g * cosβ * cosφ).

[0279] In this formula, different weighting factors can be configured for the proportion of azimuth and elevation power, for example, g1 is the weight assigned to the azimuth power proportion and g2 is the weight assigned to the elevation power proportion, as in the following formula: P_plDL=P_0DL+10 * log_10(2^u * M_pssch)+a_DL * PL_DL+10 * log_10(g1 * cosβ * g2 * cosφ).

[0280] Case 2 keeps the same Tx, Rx and gNB locations as Case 1. This highlights a scenario where the transmission from the SL Tx is very directional and the beam to the intended SL Rx is very narrow. Note that such very narrow beam transmissions are common at very high frequencies where there are very few paths to carry the signal power. By knowing its own beamwidth, the SL Tx can determine that in fact no power is received at the gNB and therefore for all practical purposes can ignore the constraints of SL interference as seen at the gNB for its intended transmission.

[0281] FIG. 11 is a diagram illustrating two further exemplary transmission cases for a two-dimensional plane. This exemplary case illustrates a possible improvement that can be used to calculate SL transmit power based on DL path loss to limit interference seen at the gNB. Case 1 shows a deployment of an SL Tx, SL Rx, and a gNB with the SL Tx configured to use at least DL-based power calculation. Using knowledge of the intended transmit direction to the SL Rx, the beam width, and the location of the gNB, the SL Tx determines that power is not effectively directed to the gNB and therefore does not need to consider gNB interference in its SL transmit power decision. Depending on the configuration, it can either transmit at maximum transmit power or use an enhanced version of SL power control using SL path loss based power calculation or SL priority and interference nulling at the SL Rx.

[0282] Case 2 uses the same example deployment as Case 1, but shows a new and improved method for SL power calculation based on DL path loss. In Case 2, the SL Tx is shown to gain detailed knowledge of its antenna pattern. Using knowledge of the gNB location and its own antenna radiation pattern, the SL Tx determines that its transmission to the target SL Rx will result in a backlobe and a sidelobe, such that the gNB will receive its signal energy from one of the backlobes. The SL Tx can then determine the split power that will leak in the direction of the gNB. This split power can then be multiplied by 10 * log_10(g * cosβ), or 10 * log_10(g * cosβ * cosφ) term needs to be substituted into the above equation.

[0283] Power control for sidelink feedback channel - Patents.com The feedback channel on the SL PSFCH can also be configured to be subject to power control based on DL path loss. Although the parameters to be used in the power control calculation for the PSFCH are configured separately from the PSSCH parameters, the operation and formulas are very similar to those used for a PSSCH configured to operate on DL path loss. Therefore, all of the discussion above regarding power control based on DL path loss made in the context of the PSSCH is also applicable to power control of the SL PSFCH.

[0284] Power Control for Sidelink Synchronization Sequence Block (S-SSB) In conventional solutions, the S-SSB power is calculated based on the DL path loss when the SL device transmits S-SSB in mode 1. This limitation is related to the same constraint of avoiding interference at the gNB in ​​uplink reception. A SL UE configured to transmit S-SSB can be configured to use the DL path loss for power control as follows:

[0285] [Table 1] where P_max is the maximum power configured for the SL UE, P_0DLSSB is the nominal power for S-SSB, u is the numerology for S-SSB transmission, M_sssb is the number of PRBs used for S-SSB transmission, which is fixed at 11 in the current standard, and a_DLSSSB is a coefficient applied to the downlink path loss PL_DL.

[0286] As discussed above, the directivity aspect significantly impacts how the base station (gNB) sees interference from a particular transmission. Thus, an S-SSB transmission that is not aligned with the direction of the gNB from the transmitting SL device has little impact on the gNB's reception of the uplink transmission. In view of this, the power control for the S-SSB can be based on the proposal of this embodiment, which incorporates the directivity of the transmission from which the SL UE intends to transmit this S-SSB. Thus, the DL path loss based S-SSB transmit power calculation can be updated with respect to the directivity of the S-SSB transmission and the direction of the gNB. An example is as follows:

[0287] [Table 2] where β is the azimuth angle, and φ is the elevation angle at SL Tx between the S-SSB transmission direction and the direction of the gNB. Furthermore, g1 and g2 are weights configured for the power ratios in the azimuth and elevation angles.

[0288] Other improvements proposed for DL ​​path-loss based power calculation for PSSCH are namely incorporating beam width, antenna radiation pattern, etc., all of which apply to power control of S-SSB transmissions to compensate for DL ​​path-loss. In the extreme case, for beams not directed to the gNB, where the gNB does not receive any signal energy from S-SSB transmissions, the DL path-loss limit disappears and the SL UE may transmit S-SSB at the configured maximum power to increase the UE's coverage, indirectly using the gNB as a synchronization reference. In this way, these improvements can now positively impact the system in at least two ways: First, with accurate control, no interference is generated by the S-SSB transmissions above the nominal value configured through the power control parameters. Second, a more accurate calculation of the directional aspect allows to use a higher power for S-SSB transmissions, which leads to having more SL devices aware of this synchronization reference UE directly attached to the gNB.

[0289] Exemplary embodiment - Power control of SL channel with respect to DL path loss In an exemplary embodiment of the present principles illustrated in FIG. 12, the SL Tx implements the SL transmission method with enhanced power control for unicast SL transmissions.

[0290] In step S1210, the SL Tx is configured to use at least the SL path loss for power control of the PSSCH with appropriate parameters, for which the SL Tx receives resource pool configuration information together with parameters for DL ​​PL-based extended power control, e.g., algorithm identifiers and coefficients.

[0291] In step S1220, the SL Tx obtains packets for transmission over the sidelink from higher layers.

[0292] In step S1230, the SL Tx transmits a scheduling request to the gNB to obtain the allocated resources over the SL. In response, the SL Tx then receives a grant (SL allocation) from the gNB providing the allocated resources over the sidelink.

[0293] In step S1240, the SL Tx determines the intended transmission direction to the target SL Rx, determines the direction of the gNB, calculates the angle between the intended transmission direction and the direction of the gNB, and further determines the SL transmit power for PSSCH and PSCCH in various symbols of the SL slot using weights configured as part of the power control configuration according to the equations provided in this embodiment.

[0294] In step S1250, the SL Tx transmits the first stage SCI via PSCCH and the SL data (along with the second stage SCI) via PSSCH via transmission resources allocated by the gNB with the determined transmit power. The SL Tx can transmit via PSCCH and PSSCH in the primary direction only if it operates according to the 3GPP Rel-16 / 17 design.

[0295] The SL Tx may transmit via PSCCH in the primary and pairing directions, and also via PSSCH in the primary direction only if it is configured to operate under the primary / pairing transmission scheme.

[0296] The SL Tx may transmit the PSFCH using the power determined for the proposed DL pathloss based approach when receiving a transmission via a PSFCH resource determined relative to the PSSCH resource.

[0297] The SL Tx may be configured / instructed to transmit the S-SSB and to determine the transmit power for the S-SSB using the described method.

[0298] The SL Tx can use the transmit beamwidth information to further improve the estimated interference at the gNB.

[0299] The SL Tx can use its antenna radiation pattern to calculate the interference seen at the gNB.

[0300] The SL Tx can use knowledge / location of multiple TRPs and multiple gNBs in its vicinity and apply a directivity based power transmission decision procedure to its known TRPs / gNBs and further select the minimum transmit power from these determined transmit power values.

[0301] It should be noted that the division of transmit power between PSSCH and PSCCH is not detailed but can be done using a simple division on the number of PRBs used by each physical channel.

[0302] conclusion Although features and elements are provided above in specific combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. The present disclosure is not limited in terms of the specific embodiments described in this application, which are intended as illustrations of various aspects. As will be apparent to those skilled in the art, many modifications and variations may be made without departing from the spirit and scope of the present invention. No element, operation, or instruction used in the description of this application should be construed as critical or essential to the invention unless expressly set forth as such. In addition to those enumerated herein, functionally equivalent methods and apparatuses within the scope of the present disclosure will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that the present disclosure is not limited to any particular method or system.

[0303] The foregoing embodiments are discussed with respect to the terminology and structure of infrared-enabled devices (i.e., infrared emitters and receivers) for simplicity, however, the discussed embodiments are not limited to these systems and may also be applied to other systems that use other forms of electromagnetic waves, or non-electromagnetic waves such as acoustic waves.

[0304] It should also be understood that the terms used herein are for purposes of describing particular embodiments only and are not intended to be limiting. As used herein, the term "video" or "image" may mean either a snapshot, a single image, and / or multiple images displayed over time. As another example, the term "user equipment" and its abbreviation "UE", the term "remote", and / or the term "head mounted display" and its abbreviation "HMD" as referred to herein may mean or include (i) a wireless transmitting and / or receiving unit (WTRU), (ii) any of several embodiments of a WTRU, (iii) a wireless-enabled and / or wired-enabled (e.g., tetherable) device specifically configured to have some or all of the structure and functionality of a WTRU, (iii) a wireless-enabled and / or wired-enabled device configured to have less than all of the structure and functionality of a WTRU, or (iv) the like. Details of an exemplary WTRU that may represent any WTRU listed herein are provided herein with respect to FIGS. 1A-1D. As another example, various embodiments disclosed herein above and below are described as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than a head-mounted display may be utilized and that the present disclosure and any or all of the various disclosed embodiments may be modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an adaptive reality experience.

[0305] In addition, the methods provided herein may be implemented in a computer program, software, or firmware embodied in a computer readable medium for execution by a computer or processor. Examples of computer readable media include electronic signals (transmitted over wired or wireless connections) and computer readable storage media. Examples of computer readable storage media include, but are not limited to, read only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0306] Modifications of the methods, apparatus, and systems provided above are possible without departing from the scope of the present invention. In view of the wide variety of embodiments that may be applied, it should be understood that the illustrated embodiments are merely examples and should not be construed as limiting the scope of the following claims. For example, the embodiments provided herein include a portable device, which may include or be utilized with any suitable voltage source, such as a battery providing any suitable voltage.

[0307] Further, in the above embodiments, it should be noted that processing platforms, computing systems, controllers, and other devices including processors. These devices may include at least one central processing unit (CPU) and memory. In accordance with the practices of those skilled in the art of computer programming, references to operations and symbolic representations of operations or instructions may be performed by various CPUs and memories. Such operations and operations or instructions may be referred to as being "executed," "computer executed," or "CPU executed."

[0308] Those skilled in the art will appreciate that the operations and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. The electrical system represents data bits that may cause a resultant transformation or reduction of the electrical signals, and maintains the data bits in memory locations of the memory system, thereby reconfiguring or otherwise altering the operation of the CPU and the processing of other signals. The memory locations in which the data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be appreciated that the embodiments are not limited to the platforms or CPUs mentioned above, and that other platforms and CPUs may support the methods provided.

[0309] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read only memory (ROM)) mass storage system readable by a CPU. The computer readable medium may include computer readable media that resides exclusively on a processing system, or distributed, cooperative or interconnected among multiple interconnected processing systems that may be local or remote to a processing system. It should be understood that the embodiments are not limited to the memories mentioned above and that other platforms and memories may support the methods provided.

[0310] In an example embodiment, any of the operations, processes, etc. described herein may be implemented as computer readable instructions stored on a computer readable medium. The computer readable instructions may be executed by a processor of a mobile, a network element, and / or any other computing device.

[0311] There is little distinction between hardware and software implementations of aspects of the system. Whether to use hardware or software is generally a design choice that represents a cost vs. efficiency tradeoff (although in some circumstances the choice between hardware and software may be important). There may be a variety of vehicles (e.g., hardware, software, and / or firmware) in which the processes and / or systems and / or other techniques described herein may be effective, and the preferred vehicle may vary depending on the context in which the processes and / or systems and / or other techniques are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may select a primarily hardware and / or firmware vehicle. If flexibility is paramount, the implementer may select a primarily software implementation. Alternatively, the implementer may select some combination of hardware, software, and / or firmware.

[0312] The foregoing detailed description has illustrated various embodiments of devices and / or processes through the use of block diagrams, flow charts, and / or examples. To the extent that such block diagrams, flow charts, and / or examples include one or more functions and / or operations, it will be appreciated by those skilled in the art that each function and / or operation within such block diagrams, flow charts, or examples may be individually and / or collectively implemented by a wide range of hardware, software, firmware, or substantially any combination thereof. In one embodiment, some portions of the subject matter described herein may be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integrated forms. However, those skilled in the art will recognize that certain aspects of the embodiments disclosed herein may be equivalently implemented, in whole or in part, in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as substantially any combination thereof, and that designing circuitry and / or writing software and / or firmware code is within the skill of those skilled in the art in light of this disclosure. In addition, those skilled in the art will recognize that the subject matter described herein may be distributed as a program product in a variety of forms, and that representative embodiments of the subject matter described herein apply regardless of the particular type of signal-bearing medium used to actually effect the distribution. Examples of signal bearing media include, but are not limited to, recordable type media such as floppy disks, hard disk drives, CDs, DVDs, digital tape, computer memory, and transmission type media such as digital and / or analog communications media (e.g., fiber optic cables, wave guides, wired communications links, wireless communications links, etc.).

[0313] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner described herein and then use engineering techniques to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, memory such as volatile and non-volatile memory, a processor such as a microprocessor and a digital signal processor, computing entities such as an operating system, drivers, graphical user interfaces, and application programs, one or more interactive devices such as a touchpad or screen, and / or a control system including feedback loops and control motors (e.g., feedback to sense position and / or velocity, control motors to move and / or adjust components and / or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing / communication systems and / or network computing / communication systems.

[0314] The subject matter described herein may illustrate different components that are included within or connected to different other components. It should be understood that such depicted architectures are merely examples, and that in fact many other architectures that achieve the same functionality may be implemented. Conceptually, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Thus, any two components herein that are combined to achieve a particular functionality may be considered to be "associated" with one another such that the desired functionality is achieved, regardless of the architecture or intervening components. Similarly, any two components so associated may be considered to be "operably connected" or "operably coupled" with one another to achieve the desired functionality, and any two components that can be associated in this way may be considered to be "operably couplable" with one another to achieve the desired functionality. Examples of operably coupleable include, but are not limited to, physically matable and / or physically interacting components, and / or wirelessly interactable and / or wirelessly interacting components, and / or logically interactable and / or logically interacting components.

[0315] With respect to the use of substantially any plural and / or singular term herein, those of skill in the art may convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. For purposes of clarity, various singular / plural permutations may be expressly set forth herein.

[0316] In general, those skilled in the art will understand that the terms used in this specification, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," and the term "includes" should be interpreted as "includes but is not limited to"). Furthermore, those skilled in the art will understand that where a specific number of recitations of an introduced claim are intended, such intention is expressly set forth in the claim, and in the absence of such recitation, no such intention exists. For example, where only one item is intended, the term "single" or similar language may be used. To aid in understanding, the following appended claims and / or the description of this specification may include the use of the introductory phrases "at least one" and "one or more" to introduce the claim recitations. However, the use of such phrases should not be construed to mean that the introduction of a claim recitation with the indefinite article "a" or "an" limits any particular claim that includes such an introduced claim recitation to embodiments that include only that one recitation, even if the same claim also contains the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"). The same applies to the use of definite articles used to introduce claim recitations.In addition, even if a particular number of recitations in an introduced claim is explicitly recited, those of skill in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the simple recitation "two recitations" without other modifiers means at least two recitations, or more than two recitations). Furthermore, when a notation similar to "at least one of A, B, and C, etc." is used, such a structure is generally intended as a person of skill in the art would understand the notation (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). When a notation similar to "at least one of A, B, or C, etc." is used, such a structure is generally intended as one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). Those of ordinary skill in the art will further appreciate that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B" or "A and B."Additionally, as used herein, the term "any of" followed by a list of items and / or a list of categories of items is intended to include "any of," "any combination of," "any more than one of," and / or "any more than one combination of" the items and / or categories of items, individually or in combination with other items and / or other categories of items. Additionally, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. Also, as used herein, the term "multiple" is intended to be synonymous with "a plurality."

[0317] In addition, where features or aspects of the disclosure are described in terms of a Markush group, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual members or subgroups of members of the Markush group.

[0318] As will be appreciated by those skilled in the art, for all purposes, including in terms of providing a written description, all ranges disclosed herein also encompass any possible subranges and combinations of subranges thereof. Any recited range can be readily recognized as fully descriptive and allowing the same range to be broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, a middle third, an upper third, etc. As will also be appreciated by those skilled in the art, all words such as "up to," "at least," "greater than," "less than" and the like refer to ranges that include the recited numbers and that can be further broken down into subranges as discussed above. Finally, as will be appreciated by those skilled in the art, a range includes each individual element. Thus, for example, a group having 1 to 3 cells refers to a group having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so on.

[0319] Moreover, the claims should not be read as limited to the provided order or to the provided elements unless specifically so stated. In addition, the use of the term "means for" in any claim is intended to invoke 35 U.S.C. ...

[0320] The following references may have been mentioned above and are incorporated herein by reference in their entireties: [1] 3GPP, "TR 22.886: Study on enhancement of 3GPP Support for 5G V2X Services (v16.2.0, Release 16)", 3GPP, Tech. Rep., December 2018. [2] 3GPP, "TS 22.186 Service requirements for enhanced V2X scenarios (v16.2.0, Release 16)", 3GPP, Tech. Spec., June 2019. [3] M.H.C. Garcia et al., "A Tutorial on 5G NR V2X Communications", in IEEE Communications Surveys & Tutorials, February 2021. [4] 3GPP, "TS 38.214 Physical layer procedures for data (Release 16)", V16.1.0, March 2020. [5] 3GPP, "TS 38.331 Radio Resource Control (RRC) protocol specification (Release 16)", V16.0.0, March 2020. [6] 3GPP, "TS 38.215 Physical layer measurements (Release 16)", V16.3.0, September 2020. [7] 3GPP, "TR 37.885 Study on evaluation methodology of new Vehicle-to-Everything (V2X) use cases for LTE and NR", June 2019, v15.3.0. [8] LG Electronics, "R1-1908900: Discussion on physical layer structure for NR sidelink", 3GPP TSG-RAN WG1 Meeting 98, August 2019.

Claims

1. 1. A method performed by a first wireless transmit / receive unit (WTRU), comprising: detecting, by a detection means in the first WTRU, at least one signal using a first signal strength of a first receive beam in a first direction associated with an upcoming sidelink unicast transmission to the target WTRU and a second signal strength of a second receive beam in a second direction opposite the first direction; determining, by the interference determination means, from the at least one detected signal, a scheduled transmission that interferes with the upcoming sidelink unicast transmission based on the scheduled transmission overlapping in time and frequency with the upcoming sidelink unicast transmission and having a lower priority than the upcoming sidelink unicast transmission; determining, by a transmit power determination means within the first WTRU, a transmit power that compensates for a path loss to the target WTRU and an estimated interference of the scheduled transmission at the target WTRU, the estimated interference being based on a received signal strength of each of the at least one detected signal; transmitting, by a transmitting means in the first WTRU, data to the target WTRU in the sidelink unicast transmission using the determined transmit power; A method comprising:

2. 10. The method of claim 1, wherein the detected at least one signal carries sidelink control information.

3. 3. The method of claim 2, wherein the sidelink control information includes information indicating reservation of resources to be used by a transmitter of the detected signal for scheduled transmissions.

4. The method of claim 3 , wherein the reservation includes information indicating a time and frequency for the corresponding scheduled transmission.

5. The method of claim 3 , wherein the reservation includes information indicating a transmit power for the corresponding scheduled transmission.

6. The method of claim 1 , wherein the estimated interference at the target WTRU is further based on information received from the target WTRU.

7. The method of claim 1 , wherein the estimated interference is further based on a measurement of distance between the first WTRU and the target WTRU.

8. 2. The method of claim 1, wherein the estimated interference at the target WTRU is compensated only for scheduled transmissions corresponding to detection signals transmitted in a primary direction by a corresponding transmitter, the detection signals being received using the second receive beam.

9. 1. A wireless transmit / receive unit (WTRU), comprising: a memory for storing processor-executable program instructions; detecting, by the WTRU, at least one signal using a first signal strength of a first receive beam in a first direction associated with an upcoming sidelink unicast transmission to a target WTRU and a second signal strength of a second receive beam in a second direction opposite the first direction; determining, from the at least one detected signal, a scheduled transmission that interferes with the upcoming sidelink unicast transmission based on the scheduled transmission overlapping in time and frequency with the upcoming sidelink unicast transmission and having a lower priority than the upcoming sidelink unicast transmission; determining, by the WTRU, a transmit power that compensates for a path loss to the target WTRU and an estimated interference of the scheduled transmission at the target WTRU, the estimated interference being based on a received signal strength of each of the at least one detected signal; transmitting, by the WTRU, data to the target WTRU in the sidelink unicast transmission using the determined transmit power. at least one hardware processor configured to execute the program instructions so as to The WTRU includes:

10. The WTRU of claim 9 , wherein the detected at least one signal carries sidelink control information.

11. The WTRU of claim 10 , wherein the sidelink control information includes information indicating reservation of resources to be used by a transmitter of the detected signal for scheduled transmissions.

12. The WTRU of claim 11 , wherein the reservation includes information indicating a time and frequency for the corresponding scheduled transmission.

13. The WTRU of claim 11 , wherein the reservation includes information indicating a transmit power for the corresponding scheduled transmission.

14. The WTRU of claim 9 , wherein the estimated interference at the target WTRU is further based on information received from the target WTRU.

15. The WTRU of claim 9 , wherein the estimated interference is further based on a measurement of distance between the WTRU and the target WTRU.

16. The WTRU of claim 9, wherein the at least one hardware processor is further configured to execute the program instructions to compensate for the estimated interference at the target WTRU only for scheduled transmissions corresponding to detection signals transmitted in a primary direction by the WTRU's corresponding transmitter, the detection signals being received using the second receive beam.

17. The WTRU of claim 9 , wherein the at least one hardware processor executes the program instructions to further compensate for estimated interference at the target WTRU of only N strongest scheduled transmissions.

18. The WTRU of claim 9 , wherein the WTRU is configured to be at least one of: located in a vehicle; and worn by a person.

19. The WTRU of claim 9 , wherein the WTRU is one of a smartphone, a tablet, a virtual reality headset, a head-mounted display, and glasses.

20. 9. A non-transitory computer-readable storage medium storing instructions that, when executed, cause at least one hardware processor to perform the method of any one of claims 1 to 8.

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