CN118044134A

CN118044134A - Method and base station for dynamic ss_pbch processing to mitigate high power narrowband interference

Info

Publication number: CN118044134A
Application number: CN202280066222.6A
Authority: CN
Inventors: 阿尔帕斯兰·德米尔; J·默里; S·帕塔尔; P·皮特拉斯基; 穆罕默德·费齐利; J·黄; T·埃尔考迪; P·卡布罗; P·拉塞尔
Original assignee: InterDigital Patent Holdings Inc
Current assignee: InterDigital Patent Holdings Inc
Priority date: 2021-08-28
Filing date: 2022-08-26
Publication date: 2024-05-14

Abstract

A system, apparatus, and method are provided for adapting transmission characteristics to mitigate adverse effects on a Wireless Transmit Receive Unit (WTRU) when a high power, narrowband transmitter is being used by the WTRU to propagate energy in a narrowband within a wider frequency band for communication in an advanced communication network. The system, apparatus and method include: detecting interference based on the presence of the interference; determining a Power Spectral Density (PSD) level from the interference; determining a Synchronization Signal Burst (SSB) frequency location to mitigate interference based on the PSD level exceeding a threshold; and transmitting the determined SSB frequency location to at least one WTRU served by the base station. In an example, after a preset period of time, the SSB frequency may be restored back to the original SSB frequency. In an example, when the detected interference dissipates, the SSB frequency may be restored back to the original SSB frequency.

Description

Method and base station for dynamic ss_pbch processing to mitigate high power narrowband interference

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional application No. 63/390,100 filed on 7.18 in 2022 and U.S. provisional application No. 63/238,150 filed on 8.28 in 2021, the contents of which are incorporated herein by reference.

Background

In order to use an advanced next generation network implementing a 5G NR standard including a 3gpp r15 standard specification, a wireless transmit/receive unit (WTRU), such as a mobile phone, a laptop computer, etc., performs an initial access procedure to attach to a cell of the network. Cell-defined Synchronization Signal Burst (SSB) and associated Master Information Block (MIB) and system information block 1 (SIB 1) are key to the WTRUs performing the initial access procedure. In wireless communication systems, particularly in 5G cellular deployments, corrupted SSB bursts due to overlapping high-power narrowband interference, such as RADAR, must be avoided. There is a need for a network, system, method, and apparatus that is capable of dynamically adapting network transmission characteristics in response to channel conditions and interference characteristics to mitigate the risk of negative impact on the network due to high power narrowband interference, as well as mitigate the impact of network transmissions on high power narrowband energy associated with RADAR.

Disclosure of Invention

Disclosed and described herein are systems, methods, and apparatus that may dynamically adapt their transmission characteristics to mitigate the negative impact on a WTRU when a high power, narrowband transmitter is being used by the WTRU to propagate energy in a narrowband within a wider frequency band for communication in an advanced communication network.

A system, apparatus, and method are provided for adapting transmission characteristics to mitigate adverse effects on a WTRU when a high power, narrowband transmitter is being used by the WTRU to propagate energy in a narrowband within a wider frequency band for communication in an advanced communication network. The system, apparatus and method include: detecting interference based on the presence of the interference; determining a Power Spectral Density (PSD) level from the interference; determining a Synchronization Signal Burst (SSB) frequency location to mitigate interference based on the PSD level exceeding a threshold; and transmitting the determined SSB frequency location to at least one Wireless Transmit Receive Unit (WTRU) served by the base station. The system, apparatus and method may operate in the event that the interference is RADAR. The system, apparatus and method may include: detecting the interference includes determining an interference characteristic of the interference. The systems, devices, and methods may also include comparing the determined interference characteristics of the interference to a bandwidth of an existing SSB block frequency domain location. The system, apparatus and method may include: the detecting includes measuring channel conditions including at least one of carrier frequency, bandwidth, periodicity, dwell time, and AoA. The system, apparatus and method may include: the detecting includes receiving channel condition measurements from at least one of a WTRU and a gNB within the network. The systems, devices, and methods may include a threshold based on characteristics of the interference affecting operation. The systems, devices, and methods may include that the determined SSB frequencies are different frequencies, i.e., lower frequencies or higher frequencies. The system, apparatus and method may further include: after a preset period of time, the SSB frequency is restored back to the original SSB frequency. The system, apparatus and method may further include: when the detected interference dissipates, the SSB frequency is restored back to the original SSB frequency.

Drawings

A more detailed understanding of the description may be derived from the following description, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements, and in which:

FIG. 1A is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented;

Fig. 1B is a system diagram illustrating an exemplary wireless transmit/receive unit (WTRU) that may be used within the communication system shown in fig. 1A according to one embodiment;

fig. 1C is a system diagram illustrating an exemplary Radio Access Network (RAN) and an exemplary Core Network (CN) that may be used within the communication system shown in fig. 1A according to one embodiment;

fig. 1D is a system diagram illustrating another exemplary RAN and another exemplary CN that may be used in the communication system shown in fig. 1A according to one embodiment;

FIG. 2A shows an SSB structure;

FIG. 2B shows SSB index locations in the time domain;

fig. 2C shows a cell defined frequency allocation;

Fig. 3A shows the mapping between Kssb (subcarrier offset) for FR1, PDCCH-ConfigSIB1 (determining BW for PDCCH/SIB);

Fig. 3B shows the mapping between Kssb and PDCCH-ConfiguSIB1 for FR 2;

Fig. 4 shows a depiction of multiple SSBs in a carrier wave;

FIG. 5 shows an example in which narrowband interference overlaps with an SSB block;

FIG. 6 illustrates a technique for moving SSB positions in a negative direction to mitigate interference;

FIG. 7 illustrates a method of moving a cell defining SSB frequency locations in connection with the system of FIG. 6;

FIG. 8 illustrates a method of moving a cell defining SSB frequency locations in connection with the system of FIG. 6;

FIG. 9 illustrates a method of moving a cell defining an SSB frequency location in connection with the system of FIG. 6;

FIG. 10 illustrates a method of moving a cell defining an SSB frequency location in connection with the system of FIG. 6;

FIG. 11 illustrates a method of moving a cell defining an SSB frequency location in connection with the system of FIG. 6;

FIG. 12 illustrates a method of moving a cell defining an SSB frequency location in connection with the system of FIG. 6;

fig. 13 illustrates a technique for moving a cell defining an SSB location in a forward direction to mitigate interference;

fig. 14 illustrates a technique for defining multiple cell-defined SSBs to mitigate interference; and

Fig. 15 shows an example of a spatial solution for interference of an affected SSB beam.

Detailed Description

Fig. 1A is a schematic diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messages, broadcasts, etc., to a plurality of wireless users. Communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), time Division Multiple Access (TDMA), frequency Division Multiple Access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero-tail unique word discrete fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filter OFDM, filter Bank Multicarrier (FBMC), and the like.

As shown in fig. 1A, the communication system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a Radio Access Network (RAN) 104, a Core Network (CN) 106, a Public Switched Telephone Network (PSTN) 108, the internet 110, and other networks 112, although it should 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. For example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a Station (STA), may be configured to transmit and/or receive wireless signals, and may include User Equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular telephones, personal Digital Assistants (PDAs), smartphones, laptop computers, netbooks, personal computers, wireless sensors, hot spot or Mi-Fi devices, internet of things (IoT) devices, watches or other wearable devices, head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in an industrial and/or automated processing chain environment), consumer electronic devices, devices operating on a commercial and/or industrial wireless network, and the like. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

Communication system 100 may also include base station 114a and/or 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 the CN 106, the internet 110, and/or the other networks 112. As an example, the base stations 114a, 114B may be Base Transceiver Stations (BTSs), node bs, evolved node bs (enbs), home node bs, home evolved node bs, next generation node bs, such as gNode B (gNB), new air interface (NR) node bs, site controllers, access Points (APs), wireless routers, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

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

The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio Frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable Radio Access Technology (RAT).

More specifically, as noted above, communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, or the like. For example, the base station 114a and WTRUs 102a, 102b, 102c in the RAN 104 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) terrestrial radio access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116.WCDMA may include communication protocols such as High Speed Packet Access (HSPA) and/or evolved HSPA (hspa+). HSPA may include high speed Downlink (DL) packet access (HSDPA) and/or high speed Uplink (UL) packet access (HSUPA).

In an 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 use Long Term Evolution (LTE) and/or LTE-advanced (LTE-a) and/or LTE-advanced Pro (LTE-a Pro) to establish the air interface 116.

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may use NR to establish the air interface 116.

In embodiments, 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 a Dual Connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., enbs and gnbs).

In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., wireless fidelity (WiFi)), IEEE 802.16 (i.e., worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000 1X, CDMA EV-DO, tentative standard 2000 (IS-2000), tentative standard 95 (IS-95), tentative standard 856 (IS-856), global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE), GSM EDGE (GERAN), and the like.

The base station 114B in fig. 1A may be, for example, a wireless router, home node B, home evolved node B, or access point, and may utilize any suitable RAT to facilitate wireless connections in local areas such as business, home, vehicle, campus, industrial facility, air corridor (e.g., for use by drones), road, etc. In an 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 an 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 yet another 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 a pico cell or femto cell. As shown in fig. 1A, the base station 114b may have a direct connection with the internet 110. Thus, the base station 114b may not need to access the internet 110 via the CN 106.

The RAN 104 may communicate with a CN 106, 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, 102 d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, delay requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 may provide call control, billing services, mobile location based services, prepaid calls, internet connections, video distribution, etc., and/or perform advanced security functions such as user authentication. Although not shown in fig. 1A, it should be appreciated that RAN 104 and/or CN 106 may communicate directly or indirectly with other RANs that employ the same RAT as RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104 that may utilize NR radio technology, the CN 106 may also communicate with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, wiMAX, E-UTRA, or WiFi radio technology.

The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the internet 110, and/or other networks 112.PSTN 108 may include circuit-switched telephone networks that provide Plain Old Telephone Services (POTS). The internet 110 may include a global system for interconnecting computer networks and devices using common communication protocols, such as Transmission Control Protocol (TCP), user Datagram Protocol (UDP), and/or Internet Protocol (IP) in the TCP/IP internet protocol suite. Network 112 may include wired and/or wireless communication networks owned and/or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 radio technology, and with a base station 114b, which may employ an IEEE 802 radio technology.

Fig. 1B is a system diagram illustrating an exemplary WTRU 102. As shown in fig. 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a Global Positioning System (GPS) chipset 136, and/or other peripheral devices 138, etc. It should be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs), any other type of Integrated Circuit (IC), a state machine, or the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to a transceiver 120, which may be coupled to a transmit/receive element 122. Although fig. 1B depicts the processor 118 and the transceiver 120 as separate components, it should be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

The transmit/receive element 122 may be configured to transmit signals to and receive signals from a base station (e.g., base station 114 a) 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 emit and/or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and/or receive RF and optical signals. It should be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

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

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

The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker/microphone 124, a keypad 126, and/or a display/touchpad 128, such as 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. Further, the processor 118 may access information from and store data in any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include Random Access Memory (RAM), read Only Memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a Subscriber Identity Module (SIM) card, a memory stick, a Secure Digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from a memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown), and store data in the memory.

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

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 base stations (e.g., base stations 114a, 114 b) over the air interface 116 and/or determine its location based on the timing of signals received from two or more nearby base stations. It should be appreciated that the WTRU 102 may acquire location information by any suitable location determination method while remaining consistent with an embodiment.

The processor 118 may also be coupled to other peripheral devices 138, which may include one or more software modules and/or hardware modules that provide additional features, functionality, and/or wired or wireless connections. For example, the number of the cells to be processed, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photographs and/or video), universal Serial Bus (USB) ports, vibrating devices, television transceivers, hands-free headsets, wireless communications devices, and the like,Modules, frequency Modulation (FM) radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and/or augmented reality (VR/AR) devices, activity trackers, and the like. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: gyroscopes, accelerometers, hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; geographic position sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, humidity sensors, and the like.

WTRU 102 may include a full duplex radio for which transmission and reception of some or all signals (e.g., associated with a particular subframe for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and/or simultaneous. The full duplex radio station may include an interference management unit for reducing and/or substantially eliminating self-interference via hardware (e.g., choke) or via signal processing by a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which some or all signals are transmitted and received (e.g., associated with a particular subframe for UL (e.g., for transmitting) or DL (e.g., for receiving).

Fig. 1C is a system diagram illustrating a RAN 104 and a CN 106 according to one embodiment. As noted above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using an E-UTRA radio technology. RAN 104 may also communicate with CN 106.

RAN 104 may include enode bs 160a, 160B, 160c, but it should be understood that RAN 104 may include any number of enode bs while remaining consistent with an embodiment. The enode bs 160a, 160B, 160c may each include one or more transceivers to communicate with the WTRUs 102a, 102B, 102c over the air interface 116. In an embodiment, the evolved node bs 160a, 160B, 160c may implement MIMO technology. Thus, the enode B160 a may use multiple antennas to transmit wireless signals to and/or receive wireless signals from the WTRU 102a, for example.

Each of the evolved node bs 160a, 160B, 160c 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 UL and/or DL, and the like. As shown in fig. 1C, the enode bs 160a, 160B, 160C may communicate with each other over an X2 interface.

The CN 106 shown in fig. 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be appreciated that any of these elements may be owned and/or operated by entities other than the CN operator.

The MME 162 may be connected to each of the evolved node bs 162a, 162B, 162c 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 the user of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, and the like. MME 162 may provide control plane functionality for switching between RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and/or WCDMA.

SGW 164 may be connected to each of the evolved node bs 160a, 160B, 160c in RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102 c. The SGW 164 may perform other functions such as anchoring user planes during inter-enode B handover, triggering paging when DL data is available to the WTRUs 102a, 102B, 102c, managing and storing the contexts of the WTRUs 102a, 102B, 102c, etc.

The SGW 164 may be connected to a PGW 166 that may provide the WTRUs 102a, 102b, 102c with access to a packet switched network, such as the internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to a circuit-switched network (such as the PSTN 108) to facilitate communications between the WTRUs 102a, 102b, 102c and legacy landline communication devices. For example, the CN 106 may include or may 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.

Although the WTRU is depicted in fig. 1A-1D as a wireless terminal, it is contemplated that in some representative embodiments such a terminal may use a wired communication interface with a communication network (e.g., temporarily or permanently).

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in an 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 to and/or from the BSS. Traffic originating outside the BSS and directed to the STA may arrive through the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may pass the traffic to the destination STA. Traffic between STAs within a BSS may be considered and/or referred to as point-to-point traffic. Point-to-point traffic may be sent between (e.g., directly between) the source and destination STAs using Direct Link Setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunnel DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

When using the 802.11ac infrastructure mode of operation or similar modes of operation, the AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20MHz wide bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative implementations, carrier sense multiple access/collision avoidance (CSMA/CA) may be implemented, for example, in an 802.11 system. For CSMA/CA, STAs (e.g., each STA), including the AP, may listen to the primary channel. If the primary channel is listened to/detected by a particular STA and/or determined to be busy, the particular STA may backoff. One STA (e.g., only one station) may transmit at any given time in a given BSS.

High Throughput (HT) STAs may communicate using 40MHz wide channels, for example, via a combination of a primary 20MHz channel with an adjacent or non-adjacent 20MHz channel to form a 40MHz wide channel.

Very High Throughput (VHT) STAs may support channels that are 20MHz, 40MHz, 80MHz, and/or 160MHz wide. 40MHz and/or 80MHz channels may be formed by combining consecutive 20MHz channels. The 160MHz channel may be formed by combining 8 consecutive 20MHz channels, or by combining two non-consecutive 80MHz channels (this may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, the data may pass through a segment parser that may split the data into two streams. An Inverse Fast Fourier Transform (IFFT) process and a time domain process may be performed on each stream separately. These streams may be mapped to two 80MHz channels and data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed and the combined data may be sent to a Medium Access Control (MAC).

The 802.11af and 802.11ah support modes of operation below 1 GHz. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11 ac. The 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the television white space (TVWS) spectrum, and the 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter type control/Machine Type Communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including supporting (e.g., supporting only) certain bandwidths and/or limited bandwidths. MTC devices may include batteries with battery lives above a threshold (e.g., to maintain very long battery lives).

WLAN systems that can support multiple channels, and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include channels that can be designated as primary channels. The 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 set and/or limited by STAs from all STAs operating in the BSS (which support a minimum bandwidth mode of operation). In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only) 1MHz mode, the primary channel may be 1MHz wide, even though the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and/or other channel bandwidth modes of operation. The carrier sense and/or Network Allocation Vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because the STA is transmitting to the AP (only supporting 1MHz mode of operation), all available frequency bands may be considered busy even if most available frequency bands remain idle.

The available frequency band for 802.11ah in the united states is 902MHz to 928MHz. In korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

Fig. 1D is a system diagram illustrating a RAN 104 and a CN 106 according to one embodiment. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. RAN 104 may also communicate with CN 106.

RAN 104 may include gnbs 180a, 180b, 180c, although it will be appreciated that RAN 104 may include any number of gnbs while remaining consistent with an embodiment. Each of the gnbs 180a, 180b, 180c may include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In an implementation, the gnbs 180a, 180b, 180c may implement MIMO technology. For example, gnbs 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from gnbs 180a, 180b, 180 c. Thus, the gNB 180a may use multiple antennas to transmit wireless signals to and/or receive wireless signals from the WTRU 102a, for example. In an embodiment, the gnbs 180a, 180b, 180c may implement carrier aggregation techniques. 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 the unlicensed spectrum while the remaining component carriers may be on the licensed spectrum. In embodiments, the gnbs 180a, 180b, 180c may implement coordinated multipoint (CoMP) techniques. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180 c).

The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using transmissions associated with the scalable parameter sets. For example, the OFDM symbol interval and/or OFDM subcarrier interval may vary from one transmission to another, from one cell to another, and/or from one portion of the wireless transmission spectrum to another. The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using various or scalable length subframes or Transmission Time Intervals (TTIs) (e.g., including different numbers of OFDM symbols and/or continuously varying absolute time lengths).

The gnbs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in an independent configuration and/or in a non-independent configuration. In a standalone configuration, the WTRUs 102a, 102B, 102c may communicate with the gnbs 180a, 180B, 180c while also not accessing other RANs (e.g., such as the enode bs 160a, 160B, 160 c). In an independent configuration, the WTRUs 102a, 102b, 102c may use one or more of the gnbs 180a, 180b, 180c as mobility anchor points. In an independent configuration, the WTRUs 102a, 102b, 102c may use signals in unlicensed frequency bands to communicate with the gnbs 180a, 180b, 180 c. In a non-standalone configuration, the WTRUs 102a, 102B, 102c may communicate or connect with the gnbs 180a, 180B, 180c, while also communicating or connecting with other RANs (such as the enode bs 160a, 160B, 160 c). 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 enode bs 160a, 160B, 160c may serve 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, 102 c.

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 UL and/or DL, support of network slices, interworking between DC, 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, and so on. As shown in fig. 1D, gnbs 180a, 180b, 180c may communicate with each other through an Xn interface.

The CN 106 shown in fig. 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 possibly a Data Network (DN) 185a, 185b. Although the foregoing elements are depicted as part of the CN 106, it should be appreciated that any of these elements may be owned and/or operated by entities other than the CN operator.

The AMFs 182a, 182b may be connected to one or more of the gnbs 180a, 180b, 180c in the RAN 104 via an N2 interface and may function as control nodes. For example, the AMFs 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slices (e.g., handling of different Protocol Data Unit (PDU) sessions with different requirements), selection of a particular SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The AMFs 182a, 182b may use network slices to customize CN support for the WTRUs 102a, 102b, 102c based on the type of service used by the WTRUs 102a, 102b, 102 c. For example, different network slices may be established for different use cases, such as services relying on ultra-high reliability low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for MTC access, and so on. The AMFs 182a, 182b may provide control plane functionality for switching between the RAN 104 and other RANs (not shown) employing other radio technologies, such as LTE, LTE-A, LTE-a Pro, and/or non-3 GPP access technologies, such as WiFi.

The SMFs 183a, 183b may be connected to AMFs 182a, 182b in the CN 106 via an N11 interface. The SMFs 183a, 183b may also be connected to UPFs 184a, 184b in the CN 106 via an N4 interface. SMFs 183a, 183b may select and control UPFs 184a, 184b and configure traffic routing through UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, etc. The PDU session type may be IP-based, non-IP-based, ethernet-based, etc.

The UPFs 184a, 184b may be connected to one or more of the gnbs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to a packet-switched network, such as the internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-host PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, and the like.

The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may 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. In one embodiment, the WTRUs 102a, 102b, 102c may connect to the DNs 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the local DNs 185a, 185b.

In view of fig. 1A-1D and the corresponding descriptions of fig. 1A-1D, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more emulation devices (not shown): the WTRUs 102a-d, base stations 114a-B, evolved node bs 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMFs 182a-B, UPFs 184a-B, SMFs 183a-B, DN 185a-B, and/or any other devices described herein. The emulated device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device may be used to test other devices and/or analog network and/or WTRU functions.

The simulation device may be designed to conduct one or more tests of other devices in a laboratory environment and/or an operator network environment. For example, the one or more emulation devices can perform one or more or all of the functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices can perform one or more functions or all functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device can be directly coupled to another device for testing purposes and/or perform testing using over-the-air wireless communications.

The one or more emulation devices can perform one or more (including all) functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the simulation device may be used in a test laboratory and/or a test scenario in a non-deployed (e.g., test) wired and/or wireless communication network in order to enable testing of one or more components. The one or more simulation devices may be test equipment. Direct RF coupling and/or wireless communication via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation device to transmit and/or receive data.

Cell-defined Synchronization Signal Burst (SSB) and associated Master Information Block (MIB) and system information block 1 (SIB 1) are key to the WTRUs performing the initial access procedure. There is a need in wireless communication systems to avoid corrupted SSB bursts due to overlapping interference, such as high power narrowband interference like RADAR in the time and frequency domains.

When narrowband high power interference includes initial BWP of SSB transmission, system information exchange, physical Random Access Channel (PRACH), and paging related signaling, the WTRU may not detect the synchronization signal and decode the system information, access network, and decode the paging signal. Not only is it difficult for a newly emerging WTRU to access the network when interference overlaps with the initial BWP, but the camped WTRU may not be able to read the system information update and paging messages and perform RACH on the initial BWP if needed.

As exemplified by the DoD spectrum sharing policy (i.e., doD instructions 4650.01), existing prior art techniques are not flexible and dynamic enough to meet future needs and requirements. For example, sharing the usage spectrum without detrimental degradation or interference in a manner that provides adequate regulatory protection to current and future users does not result in loss of access to the spectrum, and allowing use of spectrum for mutual usage without degradation or detrimental interference in a manner that provides adequate regulatory protection to current and future users does not result in loss of access to the spectrum.

Typically, SSB bursts transmitted by a cell node device are handled for WTRUs connected to a network cell. The WTRU initial timing synchronization procedure may include Primary Synchronization Sequence (PSS) detection. The PSS detects the identification symbol boundary. For example, symbol timing offset = PSS peak position-sequence length. MSP and FSP may be used to determine symbol timing offset. The WTRU initial timing synchronization procedure may include SSB index detection. The SSB index detects the reference frame boundary to identify the symbol offset. In an example, the SSB index is implicitly found by detecting a Physical Broadcast Channel (PBCH) demodulation reference symbol (DMRS) sequence. The WTRU initial timing synchronization procedure may include PBCH decoding. PBCH decoding enables frame timing to be determined by the WTRU based on knowledge of PSS symbol timing offset, SSB index position in the symbol, and half frame timing (0 or 5ms decoded from PBCH).

Fig. 2A shows an SSB structure 200. As shown in fig. 2A, SSB structure 200 includes 20 Resource Blocks (RBs), where each RB is 12 Resource Elements (REs) 220 over a symbol duration (also referred to as a single subcarrier). SSB structure 200 includes a Primary Synchronization Sequence (PSS) 205, PBCH 215, and Secondary Synchronization Sequence (SSS) 210 in correspondence with REs 220, and the distribution of OFDM symbols over PSS 205, PBCH 215, and SSS 210. SSB structure 200 includes PSS 205 in symbol 0 and SSS210 in symbol 2, which occupy the same 127 REs 220 while being located one symbol apart. Fig. 2A shows PBCH 215 spread over three consecutive symbols (i.e., symbols 1,2, and 3).

Fig. 2B shows SSB index positions in the time domain. SSB index positions as shown in the example of fig. 2B are provided for carrier frequencies between 3GHz and 6GHz, with subcarrier spacing (SCS) =30 kHz. In general, a frame may be divided into two half frames. Fig. 2B shows a half frame 240. Half frame 240 is divided into a plurality of subframes 250 including subframe 0 250 ₀, subframe 1250 ₁, subframe 2 250 ₂, subframe 3 250 ₃, and subframe 4 250 ₄, collectively referred to as subframes 250. Each subframe 250 is divided into two slots 255. For example, subframe 0 250 ₀ is divided into two slots slot 0 255 ₀ and slot 1 255 ₁, subframe 1250 ₁ is divided into two slots slot 2255 ₂ and slot 3 255 ₃, subframe 2 250 ₂ is divided into two slots slot 4 255 ₄ and slot 5 255 ₅, subframe 3 250 ₃ is divided into two slots slot 6 255 ₆ and slot7 255 ₇, and subframe 4 250 ₄ is divided into two slots slot 8 255 ₈ and slot 9 255 ₉, collectively referred to as slots 255. A given slot 255 may include two SIBs 245. For example, slot 0 255 ₀ includes SIB 0 245 ₀ and SIB 1 245 ₁, slot 1 255 ₁ includes SIB 2 245 ₂ and SIB 3 245 ₃, slot 2255 ₂ includes SIB 4 245 ₄ and SIB 5 245 ₅, and slot 3 255 ₃ includes SIB 6 245 ₆ and SIB 7245 ₇, collectively referred to as SIB 245.SSB index 245 may be transmitted in a predetermined symbol starting at subframe 0 250 ₀ or subframe 5 (not shown) to align SSB burst transmissions in the first half or second half of the frame. The first and fifth subframes are typically separated by 5ms.

Fig. 2C shows a cell defined frequency allocation 260. Cell-defined frequency allocation 260 includes AbsoluteFrequencyPointA 265,265, and the curve of cell-defined frequency allocation 260 increases with frequency and power from AbsoluteFrequencyPointA 265,265. offsetToCarrier 270,270 and carrier bandwidth 275 define a frequency allocation 260. The Common Resource Blocks (CRBs) may start at AbsoluteFrequencyPointA 265,265 with increasing increments until CRBs _n included in offsetToCarrier with Physical Resource Blocks (PRBs) increase in increments until the frequency allocation 260 ends. offsetToPointA 280 is provided from AbsoluteFrequencyPointA 265,265. From offsetToPointA to 280 using Kssb to 285, the SSB 290 may be located at AbsoluteFrequnecySSB to 295 using a central RE within the SSB.

In some examples, the network directs the WTRU to determine AbsoluteFrequencyPointA 265 (a pointer to the common resource block 0 (CRB 0) location in the frequency domain) after the WTRU completes PSS, SSS detection, and PBCH/MIB & SIB1 decoding. Once the WTRU detects PSS, absoluteFrequencySSB may be derived. After decoding the PBCH and reading the MIB parameters ssb-SubcarrierOffset, kssb 285 is known (for FR1, the 4 LSB bits of the Kssb value are determined in the MIB by ssb-SubcarrierOffset and the MSB bits are provided via bits within the PBCH Data; for FR2 the entire Kssb value can be determined via ssb SubcarrierOffset in the MIB). Kssb 285 provide information about the frequency offset between SSBs and Common Resource Block (CRB) grids. In addition, MIB provides controlResourceSetZero and searchSpaceZero in Physical DL Control Channel (PDCCH) -ConfigSIB IE. The control resource set (CORESET) #0 frequency location is determined by controlResourceSetZero parameter (by pointing to the offset parameter), while the searchSpaceZero parameter specifies the time-frequency multiplexing mode between SSB and CORESET #0/PDSCH. Specifically, ssb-SubcarrierOffset, controlResourceSetZero and searchSpaceZero are defined as follows:

After decoding the Type0-PDCCH for SIB1, the WTRU extracts SIB1 parameter offsetToPointA 280 in the cell defined frequency allocation 260.

Fig. 3A shows a mapping 300 between Kssb (subcarrier offset) for FR1, PDCCH-ConfigSIB1 (BW determined for PDCCH/SIB), and fig. 3B shows a mapping 350 between Kssb and PDCCH-ConfiguSIB1 for FR 2. Fig. 3A shows the mapping between k _SSB (frequency domain offset), PDCCH-ConfigSIB1 (determining BW for PDCCH/SIB) and NGSCNOffset. The WTRU may monitor for the presence of Type0-PDCCH for SIB 1. SIB1 parameters may be extracted for initial access. The parameter that controls whether or not the SSB is considered to define the cell of the SSB is the K _SSB parameter in the MIB. K _SSB may provide the frequency domain offset between SSB and the common resource block grid in the number of subcarriers (scs=15 kHz). In some examples, the K _SSB field may indicate that the cell does not provide SIB1 and that CORESET #0 is not configured in the MIB.

According to an example, after decoding the MIB, the WTRU may perform the following procedure to decode SIB1 parameters. If Kssb.ltoreq.23 for FR1 or Kssb.ltoreq.11 for FR2, SIB1 may be transmitted in the same initial bandwidth portion (BWP) where SSB is detected.

If SIB1 information is not present for FR1, 24.ltoreq. kSSB.ltoreq.29 or 12.ltoreq. Kssb.ltoreq.13 for FR2, the WTRU may find an SSB grating with SIB1 information. The target SSB grating position is given by equation 1:

for FR1, kssb =30, and for FR2, kssb =14.

If for FR1 Kssb =31 or for FR2 Kssb =15, there is no SSB with an associated Type0-PDCCH CSS set within GSCN as defined in equation 2:

The subcarrier spacing for the target SSB grating position in the above equation is 15kHz for FR1 and 60kHz for FR2, regardless of the SSB subcarrier spacing. Thus, the maximum offset between the non-cell-defining SSB and the cell-defining SSB may be maximum at Kssb =26 for FR1 (301) and Kssb =29 for FR1 (303), and maximum at Kssb =12 for FR2 (330) and Kssb =13 for FR2 (340). The corresponding maximum offset between the non-cell-defining SSB and the cell-defining SSB is ± 11.52MHz for FR1 and ± 15.36MHz for FR 2.

Fig. 4 shows a depiction 400 of multiple SSBs in a carrier. Specifically, fig. 4 shows the frequency domain (increasing right movement in depiction 400) placement of multiple SSBs 410, 420, 425, 430 within carrier 470. For WTRUs in the rrc_connected state, the BWP 450 ₁、460₁、465₁ configured by the serving cell may overlap in the frequency domain with the BWP 450 ₃、460₃、465₃ configured for other WTRUs of other cells within the carrier. BWP 450 ₁、460₁、465₁ of WRTU 1 and BWP 450 ₂、460₂ of WRTU 2 are BWP of different WTRUs within the same cell (i.e., cell 5 where NCGI =5). Multiple SSBs may also be transmitted within the frequency span of the carrier used by the serving cell. From the WTRU's perspective, each serving cell is associated with at most a single SSB.

Fig. 4 shows a scenario where there are multiple SSBs 410, 420, 425, 430 within carrier 470, identifying two different cells 405, 415 associated with SSB 1410 (NCGI =5 (referred to as cell 5) associated with SSB 1410 and NCGI =6 415 (referred to as cell 6) associated with SSB3 420). An overlapping BWP of cell 5 450 ₁、460₁、465₁;450₂、460₂ is shown; and BWP of cell 6 450 ₃、460₃、465₃. RRM measurements may be performed by the WTRU on each of the available SSBs 410, 420, 425, 430, namely SSB1, SSB2, 425, SSB3420, and SSB4 430. There is a single cell-defined SSB per cell, e.g., SSB 1410 for cell 5 405 and SSB3420 for cell 6 415. The cell-defined SSB can only be in the initial BWP 450 ₁、450₂ for cell 5 and the initial BWP 450 ₃ for cell 6. Each cell has only one initial BWP:450 ₁ (configured to WTRU 1) and 450 ₂ (configured to WTRU 2) are initial BWP for cell 5 and 450 ₃ (configured to WTRU 3) is initial BWP for cell 6. Two different initial BWP IDs 450 ₁ and 450 ₂ in fig. 4 are shown from the WRTU perspective, while they are the same initial BWP from the cell perspective. The cell definition SSB is defined by an association with RMSI. Thus, SSB 1410 and SSB3420 are cell-defined SSBs. The initial BWP is used for initial access. On the other hand, 460 ₁、465₁ (configured to WTRU 1 from cell 5), 460 ₂ (configured to WTRU 2 from cell 5), 460 ₃、465₃ (configured to WTRU 3 from cell 6) are dedicated BWP for data transmission. After successful initial access via the initial BWP, the dedicated BWP may be configured to the WTRUs 435, 440, 445.

Fig. 5 shows an example 500 in which narrowband interference 550 overlaps SSB block 590. Similar to the cell-defined frequency allocation of fig. 2C, example 500 includes a cell-defined frequency allocation including AbsoluteFrequencyPointA565, from which AbsoluteFrequencyPointA565, the curve of the cell-defined frequency allocation increases with frequency and power. offsetToCarrier 570 and carrier bandwidth 575 define a frequency allocation. The Common Resource Blocks (CRBs) may start at AbsoluteFrequencyPointA565 with increasing increments until CRBs _n included in offsetToCarrier 570 with Primary Resource Blocks (PRBs) increase in increments until the frequency allocation ends. offsetToPointA 580 is provided from AbsoluteFrequencyPointA 565. From offsetToPointA 580 using Kssb585, SSB 590 may be located at AbsoluteFrequnecySSB 595 using a central RE within the SSB. In this example 500, there is interference 550 that interferes with SSB 590. This interference 550 is shown as being approximately centered on SSB 590, although as will be appreciated, this is merely an example configuration, as interference may also occur in the event of misalignment. The interference 550 may be a narrowband high power interference, such as RADAR. The interference may overlap in some way (interference) with the cell-defining SSB 590 blocks in the frequency domain. Disclosed herein are systems, apparatuses, and methods by which a network is dynamically reconfigured to mitigate adverse effects that may occur in a scenario like this, thereby facilitating coexistence of advanced networks such as 5G NR and narrowband interference such as RADAR.

Fig. 6 illustrates a technique for moving SSB positions in a negative direction to mitigate interference. Although fig. 6 depicts movement of the SSB position in a negative direction to mitigate interference, the present description contemplates movement of the SSB position in any direction to be away from interference, and negative direction movement is merely an example.

Fig. 6 shows an example 600 in which narrowband interference 650 overlaps SSB blocks 690. Similar to the cell-defined frequency allocation of fig. 5, example 600 includes a cell-defined frequency allocation including AbsoluteFrequencyPointA 665, from which AbsoluteFrequencyPointA 565, the curve of the cell-defined frequency allocation increases with frequency and power. offsetToCarrier 670 and carrier bandwidth 675 define the frequency allocation. The Common Resource Blocks (CRBs) may start at AbsoluteFrequencyPointA 665 with increasing increments until CRBs _n included in offsetToCarrier 670 with Primary Resource Blocks (PRBs) increase with increments until the frequency allocation ends. offsetToPointA 680 is provided from AbsoluteFrequencyPointA 665. From offsetToPointA 680 using Kssb685, SSB 690 may be located at AbsoluteFrequnecySSB 695 using a central RE within the SSB. In this example 600, there is interference 650 that interferes with SSB 690. This disturbance 650 is shown as being approximately centered on SSB 690, although as will be appreciated, this is merely an example configuration, as disturbances may also occur in the event of misalignment. As described with respect to interference 550 of fig. 5, interference 650 may be a narrowband high power interference such as RADAR. The interference may overlap in some way (interference) with the cell-defining SSB 690 blocks in the frequency domain.

As shown in fig. 6, disclosed herein are systems, apparatuses, and methods by which a network is dynamically reconfigured to mitigate adverse effects that may occur in a scenario like this, thereby facilitating coexistence of advanced networks such as 5G NR and narrowband interference such as RADAR. New offsetToPointA _new680 ₁ and SSB_new690 ₁ at AbsoluteFrequencySSB _new 695 ₁ use Kssb _new685 ₁. As shown in fig. 6, ssb_new690 ₁ is shifted from interference 650 to mitigate interference with interference 650. The cell-defined SSB frequency locations are moved to mitigate narrowband interference when the interference level triggers the detection of a threshold crossing event. This process is triggered by a narrowband high power interference level from interference 650 that passes a predefined threshold. The narrowband high power interference 650 triggering procedure may be implemented by an external node independently determining interference characteristics (such as interference level, range, aoA) or by observing cellular domain protocol stack measurements provided by the WTRU or determined by the network node (i.e., gNBs). Upon detecting the presence of interference 650, the network creates a new cell definition SSB 690 ₁, which new cell definition 690 ₁ is located in the carrier spectrum of the selected location where interference may not affect SSB block processing of the newly emerging WTRUs for synchronization and initial access procedures such as PSS, SSS detection, extracting MIB and SIB1 parameters, and performing RACH procedures. A WTRU that is already camped on the cell may perform RACH procedure and decode the paging message by using the new SSB 690 ₁ if needed.

In connection with the description of fig. 6, a method for coexistence of a cellular network with narrowband high power interference (such as RADAR) is disclosed and described herein. With the techniques disclosed herein, the network takes responsive actions, including but not limited to shifting the affected channels in the frequency and/or time domains, or reducing the power level of the associated beams to force the WTRU to move to other beams in the same cell or even to other cells to avoid interference.

Fig. 7 illustrates a method 700 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. The method 700 includes detecting an interference characteristic of an interference at 710. At 720, method 700 includes determining a Power Spectral Density (PSD) level from the detected interference characteristics. In the event that the PSD level exceeds the threshold, at 730, method 700 includes determining a new SSB frequency location. At 740, the method 700 includes transmitting the new SSB frequency location to the WTRU currently being served by the base station.

Fig. 8 illustrates a method 800 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. The method 800 includes triggering an interference level that passes a predefined threshold at 810. The method 800 includes creating a cell defined SSB in a carrier spectrum at 820. At 830, method 800 can include selecting SSB frequency locations that are less affected by interference from interference identified by passing a threshold. At 840, method 800 may include performing a RACH procedure using CORESET # and RACH resources associated with the created SSB. At 850, method 800 can include decoding the paging message using CORESET # and RACH resources associated with the created SSB.

Fig. 9 illustrates a method 900 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. Method 900 includes moving a cell-defined SSB frequency location to mitigate high power narrowband interference when an interference level triggers an event that a PSD threshold crossing has been detected. The method 900 includes detecting an interference characteristic of an interference at 910. The external nodes of the network may determine interference characteristics such as carrier frequency, bandwidth, periodicity, dwell time, aoA, and PSD. These measurements may also be determined within the wireless network by observing measurements associated with the WTRUs and gNBs.

At 920, method 900 includes triggering an interference characteristic that passes a threshold to determine a new SSB location. For example, a PSD level passing a predefined threshold triggers an event.

At 930, the method 900 may include using the new SIB1 parameter absoluteFrequencySSB to indicate the new cell-defined SSB location frequency to the WTRU. For example, upon event triggering, the network determines a new SSB location in the frequency and uses the new SIB1 parameter absoluteFrequencySSB to indicate to the WTRU that the new cell in the frequency defines the SSB location.

At 940, method 900 may include setting Kssb to 30 (FR 1)/14 (FR 2). At 950, the method 900 includes notifying the WTRU of SI modification using a paging short message. At 960, method 900 includes transmitting two SSBs during a transient time to allow for understanding of a new SSB location before the first SSB location is removed.

In some examples, interference characteristics such as periodicity, dwell time, power Spectral Density (PSD), and AoA are determined. In some examples, the characteristics are determined by nodes or components operating independently or outside the network and are communicated from the external nodes to the network. In other examples, the interference characteristics are determined by components of the network (i.e., the cellular system itself) through measurements taken by devices operating in the network to provide cellular system-related measurements.

In some examples, referring to fig. 6, upon detection of interference, the cell-defined SSB frequency location moves from a first location taken upon interference detection to a second location, wherein the second location avoids narrowband interference to mitigate narrowband interference.

In an example of a method, the method starts when interference is indicated. For example, the method may be triggered by detecting a narrowband high power interference level that passes a predefined threshold. In some examples, the narrowband high power interference (e.g., RADAR) event triggering procedure or method may be performed by an external node that independently determines RADAR characteristics (such as interference level, range, aoA) or by observing cellular domain protocol stack measurements provided by the WTRU or determined by a network node (i.e., gNBs). In some examples, an external or independent node cooperates with one or more network nodes (e.g., a gNB), including, for example, an external node (i.e., a gNB) that implements synchronization with the network. In some examples, RADAR event triggering advantageously occurs while RADAR-induced interference is still low enough to have negligible impact on ongoing communications with the WTRU and is detected early enough so that the system can take necessary action in advance to avoid serious adverse consequences, such as a complete network disaster if high power RADAR interference is not detected. In this case, RADAR interference may completely block the cell-defined SSB signal.

In some examples, upon detecting the presence of RADAR, the network creates a new cell-defined SSB that is located in the carrier spectrum at the selected location such that RADAR interference may not affect SSB block processing of the newly emerging WTRUs for synchronization and initial access procedures such as PSS, SSS detection, extracting MIB and SIB1 parameters, and performing RACH procedures. In some examples, a WTRU that has camped on a cell may perform RACH procedures appropriately and may also decode paging messages using a new SSB.

In some examples, a WTRU in rrc_idle or rrc_inactive monitors for a System Information (SI) change indication in its own paging occasion every DRX cycle. If the WTRU is provided with a common search space on active BWP to monitor paging, the WTRU in RRC_CONNECTED monitors the SI change indication in any paging occasion at least once per modification period.

The WTRU may receive an indication of SI modification using a short message transmitted in DCI format 1_0 with a P-RNTI in systemInfoModification bits. For short message reception in paging occasions, the WTRU may monitor PDCCH monitoring occasions for paging. If the WTRU receives a short message with systemInfoModification bits set to 1, the WTRU applies SI acquisition procedures known to those skilled in the art from the next modification period. The updated SI message is broadcast in a modification period subsequent to the modification period in which the SI change indication is transmitted. The modification period boundary is defined by the SFN value for which SFN mod m=0, where m is the number of radio frames comprising the modification period. The modification period is configured by modificationPeriodCoeff parameters in the BCCH-Config IE and defaultPagingCycle parameters in the PCCH-Config IE as described below. Further, repetition of the SI change indication may occur within the previous modification period.

ModificationPeriodCoeff refers to the actual modification period, expressed in the number of radio frames m= modificationPeriodCoeff × defaultPagingCycle. n2 corresponds to a value of 2, n4 corresponds to a value of 4, and so on.

Upon triggering the RADAR presence indication, the network may be informed of RADAR parameters such as carrier location, interference bandwidth, aoA, PSD. The network then evaluates by comparing the RADAR carrier and bandwidth to the existing SSB block frequency domain locations. In the event that the network decides that RADAR interference may interrupt SSB-related channel detection and MIB and SIB1 decoding, the network may create a timer and notify all WTRUs of SI modification while configuring and immediately activating new cell-defined SSB locations that are far from RADAR interference in the carrier band. Some examples may be implemented using an overlap timer such that SSB locations affected by RADAR interference remain available long enough such that interfering legacy WTRUs, which only know the cell-defined SSB time and frequency locations, have an opportunity to read updated SI information at least once. During the transition period, the network may set Kssb on the old SSB to 30 for FR1 and 14 for FR2 via MIB parameters SSB-SubcarrierOffset and the related PBCH bits (the latter only for FR 1) to indicate that the current cell-defining SSB is being removed and that the two cell-defining SSBs (the old SSB and the new SSB) overlap until the overlap timer expires. An additional field "absoluteFrequencySSB" may be used to indicate in the FrequencyInfoDL-SIB IE that the "target" cell defines the absolute frequency location of the SSB. Specifically, the Kssb parameters in the MIB (i.e., ssb-SubcarrierOffset) and the newly introduced absoluteFrequencySSB (which is also part of DownlinkConfigCommonSIB IE) in the FrequencyInfoDL-SIB IE are described as follows:

alternatively, a frequency offset between the old SSB and the new SSB may be provided to point to the new SSB frequency location.

The WTRU may still receive SI modification notification even if there is RADAR interference in the case where the RADAR bandwidth overlaps with the SSB/CORESET #0 bandwidth. The impact on NR downlink reception may be tolerable if RADAR interference is detected by the network or an external sensor early enough. Furthermore, interference from RADAR may be highly directional and highly dynamic, as RADAR beams may be scanned in azimuth and elevation directions. When RADAR beams are directed toward the NR system, NR downlink reception may be significantly affected. When the RADAR beam is pointing far (which may be most of the time), the WTRU may be able to receive paging short messages.

Fig. 10 illustrates a method 1000 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. If the WTRU is able to acquire MIB at 1010 and SIB1 at 1020 regardless of RADAR interference (this may be due to the SSB WTRU attempting to acquire MIB/SIB1 that is not in the operating RADAR frequency bandwidth, or because SSB/CORESET #0 is not subject to significant RADAR interference when the WTRU attempts to acquire MIB/SIB1, even though SSB/CORESET #0 bandwidth still falls in the operating RADAR frequency bandwidth), and retrieving SIB1 information, method 1000 may occur.

If Kssb =30 for FR1 or Kssb =14 for FR2 (cell-defining SSB is removed), at 1030 the method 1000 compares whether the absolute frequency on the synchronization grating of the currently detected SSB matches absoluteFrequencySSB information in the FrequencyInfoDL-SIB IE. If the currently detected SSB absolute frequency matches absoluteFrequencySSB, at 1040, the method 1000 proceeds with initial access based on RACH information provided by SIB 1. Method 1000 includes, at 1050, reading MIB and SIB1 information associated with the SSB indicated by absoluteFrequencySSB. If the currently detected SSB absolute frequency does not match absoluteFrequencySSB, then at 1040, an initial access procedure is conducted based on RACH information provided by the new SIB1 associated with absoluteFrequencySSB indicated in the current SIB1, provided that the absolute frequency on the synchronization grating of the new SSB matches absoluteFrequencySSB indicated in the new SIB 1. If there is still a mismatch between the new SSB absolute frequency and absoluteFrequencySSB indicated in the new SIB1, the WTRU may consider the cell barred, and if the field intra freqreselection in the MIB message is set to "allowed", the WTRU may select another cell on the same frequency if the selection criteria is met; and/or the WTRU will exclude barred cells as candidates for cell selection/reselection within 300 seconds. If the condition for FR1, kssb =30, or Kssb =14 (cell-defined SSB removed) is not met, the WTRU ignores absoluteFrequencySSB based on the RACH information provided by SIB1 and proceeds with the initial access procedure.

Fig. 11 illustrates a method 1100 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. If the WTRU is able to acquire MIB at 1110 but unable to acquire SIB1 at 1120, if for FR1 Kssb =30 or for FR2 Kssb =14 (cell definition SSB is removed), and if the field intrafreqselection in MIB message is set to "allowed" at 1130, method 1100 includes scanning the synchronization grating at 1140 to select another cell definition SSB on the same cell or another cell on the same frequency, whichever gives stronger SSB measurements. If the field interFreqReselection in the MIB message is not set to "allowed" at 1130, the method 1100 includes scanning the synchronization grating to find another cell-defined SBS on the same cell only at 1150.

If the condition for FR1, kssb =30, or Kssb =14 for FR2 (cell-defined SSB removed) is not met, the method 1100WTRU may consider the cell to be barred and follow the procedure described in the prior art. If the field interFreqReselection in the MIB message is set to "allowed," the WTRU may select another cell on the same frequency if the reselection criteria are met, and the WTRU will exclude forbidden cells as candidates for cell selection/reselection within 300 seconds.

The camped WTRU may receive SIB1 because it should already know the subcarrier offset between SSB and common source grid, while the newly emerging WTRU may not be able to receive SIB1 because Kssb has been set to 30 (FR 1)/14 (FR 2).

Fig. 12 illustrates a method 1200 of moving a cell defining an SSB frequency location in connection with the system of fig. 6. If the WTRU is unable to acquire the MIB at 1210, the method 1200 includes treating the cell as barred and performing barred as if the intra freqreselection is set to allowed, and following the procedure described in the art. The WTRU may exclude forbidden cells as candidates for cell selection/reselection within 300 seconds. At 1230, method 1200 includes selecting another cell on the same frequency if the selection criterion is met.

For RRC connected WTRUs, beam switching/recovery and mobility management may be performed on the latest SSB from which the WTRU retrieves MIB and SIB1 system information. The network may dynamically signal the RRC connected WTRU via dedicated RRC signaling to switch SSB frequency locations. As shown in the message diagram below, absoluteFrequencySSB in FrequencyInfoDL IE (which is part of DownlinkConfigCommon IE in ServingCellConfigCommon IE) may be used to indicate the new SSB frequency location to the WTRU. Different signaling methods, such as MAC-CE, may also be used to signal SSB frequency switching.

In other examples, the overlay timer may be configured to implement one or more rules based on RADAR interference levels set by the measured RADAR interference PSD. If the PSD is greater than a predefined threshold, the overlap period of the new cell-defining SSB transmission and the old cell-defining SSB transmission may be shortened, e.g., set to 0 in some cases. If RADAR interference is relatively low, the overlap period may be set to a predefined maximum. In another example, the overlap period is set to be proportional, e.g., proportional, to the RADAR PSD.

During the old and new SSB transmission overlap periods, the old SSB may inform the WTRU that the associated SIB1 is not present for further processing to obtain SIB1 parameter extraction during initial access. The WTRU cannot read RACH related parameters by using the old cell-defined SSB. Kssb in the K _SSB mapping technique shown in fig. 3A may be used to indicate the location of a new cell-defined SSB with all relevant accesses to extract parameters in SIB 1. For example, if Kssb map entry 30 for the reserved field is used to indicate a positive frequency offset between the old SSB and the new SSB, the map may be extended to add entry 31, which entry 31 may be used to indicate a corresponding negative frequency offset.

In some examples, when a larger offset is desired, large positive and negative offset settings for Kssb of SCS with 30kHz may be sufficient to avoid high power RADAR interference. For example, if RADAR interference is measured to have a 30MHz bandwidth, the new SSB location is selected to be greater than 30MHz to minimize interference impact on the system.

The SSB offset, as depicted in fig. 6, although shown in the negative direction, may be in the positive or negative direction, depending on the initial BWP size and how the new cell definition SSB is allocated or may be allocated in the carrier bandwidth. Fig. 6 depicts an example of a negative frequency offset. After removing or reducing the interference caused by the interference, the SSB may be shifted back to the previous position, but this return is not necessary. That is, when the interference is removed, the SSB may be moved back. Alternatively, the new SSB may continue to be used indefinitely.

The current SSB may be moved if the new cell-defined SSB is later interfered, such as by interference including RADAR signals. The movement may be moved again in a negative direction as shown in fig. 6, or may be moved in a positive direction with an offset. This offset may be opposite to that which occurs in fig. 6, although such a matching offset is not required.

Fig. 13 illustrates a technique for moving a cell defining an SSB location in a forward direction to mitigate interference. Fig. 13 shows the shift SSB in the positive direction with a positive shift. According to an embodiment, the method may take the above-described action in the opposite direction to move the cell-defined SSB location to its original frequency location, e.g. in case inter-cell interference is minimized as part of the initial network deployment scenario, or to a new location in the positive direction.

Fig. 13 shows an example 1300 in which narrowband interference 1350 overlaps SSB block 1390. Similar to the cell-defined frequency allocation of fig. 6, example 1300 includes a cell-defined frequency allocation including AbsoluteFrequencyPointA1365, from which AbsoluteFrequencyPointA 565, the curve of the cell-defined frequency allocation increases with frequency and power. offsetToCarrier 1370 and carrier bandwidth 1375 define a frequency allocation. The Common Resource Block (CRB) may start at AbsoluteFrequencyPointA1365 in increments of increase until CRB _n included in offsetToCarrier 1370 with Physical Resource Blocks (PRBs) increases in increments until the frequency allocation ends. offsetToPointA 1380 is provided from AbsoluteFrequencyPointA 1365. From offsetToPointA 1380 using Kssb 1385, SSB 1390 may be located at AbsoluteFrequnecySSB 1395 using a central RE within the SSB. In this example 1300, there is interference 1350 that interferes with SSB 1390. This interference 1350 is shown as being approximately centered on SSB 1390, although as will be appreciated, this is merely an example configuration, as interference may also occur in the event of misalignment. As described with respect to interference 650 of fig. 6, interference 1350 may be narrowband high power interference such as RADAR. The interference may overlap (interfere) in some way with the cell-defining SSB 1390 in the frequency domain.

As shown in fig. 13, disclosed herein are systems, apparatuses, and methods by which a network is dynamically reconfigured to mitigate adverse effects that may occur in a scenario like this, thereby facilitating coexistence of advanced networks such as 5G NR and narrowband interference such as RADAR. New offsetTo PointA _new 1380 ₁ and SSB_new 1390 ₁ at AbsoluteFrequencySSB _new 1395 ₁ use Kssb _new 1385 ₁. As shown in fig. 13, ssb_new 1390 ₁ is shifted from interference 1350 to mitigate interference with interference 1350. In fig. 13, the shift is in the positive direction and SSB 1390 ₁ can be moved back to the original position of SSB 690 in fig. 6 or to another predefined or currently determined position.

As described with respect to fig. 6, the cell-defined SSB frequency locations are moved to mitigate narrowband interference when the interference level triggers the detection of a threshold crossing event. This process is triggered by a narrowband high power interference level from interference 1350 that passes a predefined threshold. The narrowband high power interference 1350 triggering procedure may be implemented by an external node independently determining interference characteristics (such as interference level, range, aoA) or by observing cellular domain protocol stack measurements provided by the WTRU or determined by the network node (i.e., gNBs). Upon detecting the presence of interference 1350, the network creates a new cell definition SSB 13901, which is located 6901 in the carrier spectrum of the selected location where interference may not affect the SSB block processing of the newly emerging WTRUs for synchronization and initial access procedures such as PSS, SSS detection, extracting MIB and SIB1 parameters, and performing RACH procedures. A WTRU that is already camping on a cell may need to be informed about the SSB change by the SI and then find a new SSB frequency location by reading the AbsoluteFrequencySSB parameters introduced in the original SIB1 before using the new SSB.

In some examples, including those described in fig. 6 and 13, selecting a plurality of cell-defining SSB candidates. Cell-defined SSBs are important for newly emerging WTRUs to access the network and for WTRUs already present in the network to monitor and extract SI information updates and related paging messages. Examples in which selecting only one cell defines SSB alternatives may not sufficiently mitigate the possibility of adverse effects, such as total system failure for both newly emerging and already attached WTRUs, where high power narrowband interference (such as RADAR) overlaps with the SSB transmission in both the time and frequency domains.

Fig. 14 shows an alternative example 1400 in which two cells are selected to define SSB locations to mitigate the effects of interference. Although this example illustrates the use of two cell-defined SSB locations, more than two simultaneous cell-defined SSBs may be selected in various frequency locations, as two are used herein for clarity of understanding. The use of two or more cell-defined SSB locations may increase the probability of initial access for a newly emerging WTRU as well as connectivity for an existing WTRU in the network. Once the newly emerging WTRU detects and decodes one of the cell-defining SSBs, the WTRU extracts the necessary information about the other cell-defining SSB location and its system parameters. In some examples, SIB1 may be extended with a field to indicate an offset of the cell-defined SSB relative to the current SSB block. For example, if a newly emerging WTRU enters the system via SSB1 detection and MIB and SIB1 reading related to SSB1, the WTRU may extract a cell-defined SSB in the resource grid that is offset to the SSB2 frequency location, as described herein. Similarly, if the WTRU first detects SSB2 and performs related MIB and SIB1 parameter extraction, the WTRU is informed about SIB1 position in the resource grid by defining SSB using cells offset along with reference SSB 2.

Fig. 14 illustrates a technique for selecting two cell-defined SSBs to mitigate the impact of interference that interferes with one location. Fig. 14 shows an example 1400 in which narrowband interference 1450 overlaps with SSB blocks 1490 ₁. Similar to the cell-defined frequency allocations of fig. 6 and 13, example 1400 includes a cell-defined frequency allocation that includes AbsoluteFrequencyPointA 1465 from which AbsoluteFrequencyPointA 565 the curve of the cell-defined frequency allocation increases with frequency and power. offsetToCarrier 1470 and carrier bandwidth 1475 define the frequency allocation. The Common Resource Block (CRB) may start at AbsoluteFrequencyPointA 1465 in incremental increments until CRB _n included in offsetToCarrier 1470 with Physical Resource Blocks (PRBs) increases in incremental increments until the frequency allocation ends. offsetToPointA1 1480 ₁ and offsetToPointA21480 ₂ are provided from AbsoluteFrequencyPointA 1465. The center RE within the SSB may be located at AbsoluteFrequnecySSB 1495 ₁ according to offsetToPointA1 1480 ₁,SSB1 1490₁ using Kssb1 1485 ₁. The center RE within the SSB may be located at AbsoluteFrequnecySSB 1495 ₂ according to offsetToPointA21480 ₂,SSB2 1490₂ using Kssb2 1485 ₂.

In this example 1400, there is an interference 1450 that interferes with SSB1 1390 ₁. This disturbance 1450 is shown as being approximately centered on SSB1 1490 ₁, although as will be appreciated, this is merely an example configuration, as disturbances may also occur in the event of misalignment. As described with respect to interference 650 of fig. 6, interference 1450 may be a narrowband high power interference such as RADAR. The interference may overlap in some way (interference) with the cell-defining SSB1 1490 ₁ block in the frequency domain. In this configuration, and somewhat different from the configuration described with respect to fig. 6 in which a new SSB is defined, SSB21490 ₂ is readily available in order to avoid interference with respect to interference 1450. In the case where two cells define SSB, both SSB1 1490 ₁ and SSB21490 ₂ are used simultaneously. Under normal operating conditions, some WTRUs may synchronize with a cell via SSB1 1490 ₁ during an initial synchronization raster search, and other WTRUs may synchronize with a cell via SSB21490 ₂. In the event SSB1 1490 ₁ is affected by a disturbance, the system may shut down SSB1 1490 ₁. Thus, all WTRUs may need to go through SSB21490 ₂.

As shown in fig. 14, disclosed herein are systems, apparatuses, and methods by which a network is dynamically reconfigured to mitigate adverse effects that may occur in a scenario like this, thereby facilitating coexistence of advanced networks such as 5G NR and narrowband interference such as RADAR. The predefined SSB2 1490 ₂ may be used to mitigate interference from the interference 1450.

As described above, FIG. 14 illustrates a technique of defining multiple SSBs to mitigate RADAR interference. In some embodiments, simultaneous multi-cell defined SSB transmissions are implemented using multiple initial BWPs. Multiple initial BWP may be deployed such that if narrowband interference such as RADAR exists, at least one of the initial BWP may be used to ensure that the newly emerging WTRU performs initial access and guaranteed connection to the existing WTRUs in the system. Each initial BWP is assumed to have its own cell definition SSB.

Fig. 15 shows an example 1500 of a spatial solution for interference of an affected SSB beam. As shown in fig. 15, gNB 1510 may include a plurality of SSB locations 1590. In the illustration of fig. 15, SSB positions 1590 include SSB position 0 1590 ₀, SSB position 1 1590 ₁, SSB position 2 1590 ₂, SSB position 3 1590 ₃, SSB position 4 1590 ₄, SSB position 5 1590 ₅, SSB position 6 1590 ₆, SSB position 7 1590 ₇ (collectively SSB positions 1590). Interference 1550 may radiate energy in the direction of an SSB 1590 beam radiated by a gcb 1510 (node) of the network. As shown, the jammer 1550 may affect the SSB 1590 ₂ and in response to the jammer 1550, the SSB1 5092 may not be used, power reduced, or even turned off. Similarly, as shown, the interference 1550 may also affect one or more SSBs 1590, including for example SSBs 1509 ₁ and SSBs 1590 ₃, neighbors of the affected SSBs 1590 ₂. In this example, one of SSBs 1590 ₁ and 1590 ₃ may not be used, powered down, or even turned off in response to interference from interference 1550.

In some examples, a method of mitigating the effects of interference 1550, such as high-power narrowband interference, includes the act of gradually reducing the transmit power in the index of the potentially or actually affected SSB beam 1590. For example, when narrowband high power interference 1550, such as RADAR, is detected and the AoA and PSD levels of the interference 1550 are also provided, network 1510 may identify an affected SSB beam 1590 index that overlaps the interference 1550 by comparing the AoA and SSB beam 1590 index directions. In some examples, network 1510 may have a priori knowledge of the direction and orientation of SSB beam 1590 index, e.g., by acquiring and storing this information when network 1510 is first implemented or initially established. In some examples, it is assumed that the antenna orientation is fixed, e.g., according to a deployment scenario. In such an example, if an AoA that interferes 1550 is known or understood, a corresponding SSB index 1590 for that AoA may be identified. Such identification is performed as part of a method according to an example.

Some examples include detection of interference 1550. Upon detecting the interference 1550 and the identified SSB index 1590 that overlaps with the interfering AoA, the network 1510 gradually reduces the transmit power level of the affected SSB index 1590 such that WTRUs (not shown) connected to the network via the affected SSB index 1590 are forced to select other SSB indices 1590 that are not affected by the interference 1550. This procedure may lead to a new beam selection procedure or even initiate a handover.

In some examples, the network 1510, or one or more components thereof, indicates a reference power level change when reducing interference affecting the SSB 1590. For example, if the amount of power reduction in the interference-affected SSB beam 1590 totals more than a predefined threshold (e.g., 3 dB), the network 1510 may inform the WTRU about the changed transmit power level by using SIB 1. The gradual power reduction in the interference affected SSB index 1590 may be set to an incremental offset (e.g., 0.5dB per SSB transmission) such that the impact on the connected WTRUs is minimized. The abrupt removal of SSB beam 1590 within the coverage area may cause call interruption and out of sync problems for WTRUs connected in network 1510.

Fig. 15 illustrates a scenario in which interference 1550 radiates energy in the direction of SSB beam 1590 radiated by the gNB (node) 1510 of the network. The interference 1550 as shown in fig. 15 directly affects SSB2 beam 1590 ₂ coverage. In this example, it may be desirable to force the newly emerging WTRU to find and select other SSB indices 1590, and possibly other cells. The existing WTRU also moves to another beam or cell in order to minimize network interference to the SSB2 1590 ₂ receiver. The network may gradually decrease the SSB2 1590 ₂ transmit power.

In some examples, the second event may occur when the interference 1550 no longer affects the network 1510. When the occurrence of such an event is detected, or when some other indication is received that the interference 1550 is no longer affecting the network 1510 (i.e., the interference is no longer present), the transmit power levels associated with the SSB beam indices 1590 may be restored to their original settings, i.e., the settings in place before the interference 1550 arrives.

In some examples, network 1510 dynamically responds to changes in the characteristics of interference 1550, or changes in the interference 1550 or related channel conditions. For example, where narrowband interference 1550 has periodic transmissions, its time domain characteristics, such as transmission period and dwell time, may be determined. The network 1510 may schedule important physical channels, such as SSB blocks, based on the determination to avoid overlapping time domains with the interference 1550.

In some examples, the synchronization and broadcast channel combination (ss_pbch) burst period may be set to one of the entries {5,10,20,40,80 and 160ms } to meet the 3GPP standards. Network 1510 may change SSB burst positions in time so as not to overlap with interference 1550 without changing SSB burst periods by using field timing updates. SSB bursts may be transmitted at the beginning of the first half or the second half of the frame. MIB reading identifies whether the detected SSB burst is in the first half frame or the second half frame so that the WTRU may determine full initial downlink synchronization.

In some examples, in conjunction with half-frame time shifting (i.e., 5 ms), network 1510 may use different SSB burst periods to avoid interference. For example, if the interference 1550 occurs every 100ms with a dwell time of 2ms, the network 1510 may change the SSB burst period to 40ms and transmit the SSB bursts until a minimum common factor in time is observed, as the periodic SSB bursts and the periodic interference eventually overlap. The network 1510 may modify the SSB burst transmission by using a field time shift or SSB burst period update to avoid the occurrence of the next overlap. The time domain interference avoidance process continues as long as the interference 1550 exists with measurable characteristics (e.g., periodicity and dwell time).

Triggering of the beam failure mechanism may be prevented by the connected WTRU when the network takes the necessary action to avoid periodic high power narrowband interference 1550. The network may modify system parameters so that the WTRU does not declare a beam failure or a loss of synchronization event during interference. In one example, the beam fault count is increased in the presence of interference 1550. An increased SSB burst period cannot adversely lead to beam failure triggering.

If interference from the interferer 1550 is no longer present, the network application facilitates the WTRU to expedite the setting of the SSB burst period for recovery within the network. After a predefined period has elapsed or the number of PRACH attempts observed is determined, the network may return to default parameters optimized for the deployment scenario. Further details of the embodiments are disclosed and described below.

As described above, in response to an interference event or trigger, the network management component may change the cell-defined SSB frequency location (e.g., in fig. 6 and 13) in order to mitigate high power narrowband interference, such as when an interference level triggers an event that has detected a PSD threshold crossing. In some embodiments, an external node of the network may determine interference characteristics such as carrier frequency, bandwidth, periodicity, dwell time, aoA, and PSD. In some examples, the measurement results may be determined within the wireless network by observing measurement results associated with the WTRUs and gNBs.

PSD levels passing a predefined threshold trigger event. Upon event triggering, the network determines a new SSB location in the frequency and uses the new SIB1 parameter absoluteFrequencySSB to indicate to the WTRU that the new cell in the frequency defines the SSB location and sets Kssb to 30 (FR 1)/14 (FR 2). The network uses paging short messages to inform the WTRU about SI modification. The network transmits two SSBs during the transient time so that the WTRU has at least an opportunity to learn about the new SSB location before the first SSB location is completely removed.

If the WTRU is able to acquire MIB and SIB1 regardless of RADAR interference, and if for FR1, kssb =30 or for FR2, kssb =14 (cell-defined SSB is removed), the WTRU compares whether the absolute frequencies on the synchronization grating of the currently detected SSB match absoluteFrequencySSB. If the currently detected SSB absolute frequency matches absoluteFrequencySSB, the WTRU proceeds with the initial access procedure based on the RACH information provided by SIB 1. If a mismatch is detected, the WTRU continues to read the MIB and SIB1 information associated with the SSB indicated by absoluteFrequencySSB. The WTRU then proceeds with the initial access procedure based on the RACH information provided by the new SIB 1. If the condition for FR1, kssb =30, or Kssb =14 (cell-defined SSB removed) is not met, the WTRU ignores absoluteFrequencySSB based on the RACH information provided by SIB1 and proceeds with the initial access procedure.

If the WTRU is able to acquire MIB but unable to acquire SIB1, and if for FR1, kssb =30 or for FR2, kssb =14 (cell definition SSB is removed), and if the field interfreqreselection in MIB message is set to "allowed", the WTRU scans the synchronization grating to select another cell definition SSB on the same cell or another cell on the same frequency, whichever gives stronger beam measurement. Otherwise, the WTRU scans the synchronization grating to find another cell-defined SSB on the same cell only. If the condition for FR1, kssb =30, or for FR2, kssb =14 (cell-defined SSB is removed) is not met, the WTRU will consider the cell to be barred and follow the procedure described in the current technology. If the field interFreqReselection in the MIB message is set to "allowed", the WTRU may select another cell on the same frequency if the reselection criteria are met; and/or the WTRU will exclude barred cells as candidates for cell selection/reselection within 300 seconds.

If the WTRU is unable to acquire the MIB, the WTRU may consider the cell to be barred and perform the barred as if the intra freqreselection was set to allowed according to current standard operation, including the WTRU may exclude the barred cell as a candidate for cell selection/reselection within 300 seconds, and/or the WTRU may select another cell on the same frequency if the selection criteria are met.

For RRC connected WTRUs, beam switching/recovery and mobility management is performed on the latest SSB from which the WTRU retrieves MIB and SIB1 system information. In addition, the network may dynamically signal the RRC connected WTRU via dedicated RRC signaling to switch SSB frequency locations. absoluteFrequencySSB in FrequencyInfoDL IE may be used to indicate the new SSB frequency location to the WTRU. Different signaling methods, such as MAC-CE, may also be considered to signal SSB frequency switching.

In some examples, high power narrowband interference based on transmissions may occur in multiple cell defined blocks. In an example, two or more cell-defined SSB locations may be allocated to be far apart in the carrier band. Thus, if one of the cell-defining SSBs is corrupted by high power narrowband interference, the other is unlikely to be affected.

Some examples perform a gradual decrease in transmit power level in the affected SSB beam index. The purpose of this is to force the WTRU to select other beams. The beams may be selected from the same or neighboring cells. In some examples, a node (which may be a network node or an external node of the network in some embodiments) determines interference characteristics such as carrier frequency, bandwidth, periodicity, dwell time, aoA, and PSD. The measurements may be determined by an internal node, WTRU, or other device within the wireless network that obtains and/or observes those measurements related to both the WTRU and the gNB.

In an example, detection of a PSD level passing a predefined threshold triggers an event. Once an event is triggered, the network or node or component thereof recognizes the affected SSB index and begins to gradually decrease the transmit power level. In some embodiments, when the accumulated power exceeds a predefined threshold, the network reflects the changed SSB power level in SIB1 and sends SI update messages to all WTRUs.

Once the interference is no longer present (e.g., as detected or indicated by the node detector), the network may take action to restore or return to the pre-event or original power setting. In some examples, one method includes dynamically changing SS/PBCH locations in time by shifting field timing or SSB periodicity or a combination of both methods to avoid time overlapping of SSBs with interfering transmissions. For example, a node (which may be an external node of the network) determines interference characteristics such as carrier frequency, bandwidth, periodicity, dwell time, aoA, and PSD. These measurements may also be determined within the wireless network by observing measurements associated with the WTRUs and gNBs. The determined PSD level passing the predefined threshold is defined as an event. The occurrence of this event triggers a responsive action of the network.

Upon detecting the occurrence of this event, the network (or one or more nodes or components thereof) may act to shift the field timing and set the bit fields in the MIB accordingly to avoid interference in the time domain. In some examples, the network (or one or more nodes or components thereof) changes the SSB burst period with or without field time shifting to avoid interference in the time domain. In some examples, the network (or one or more components thereof) may act to increase beam failure detection timing so that the WTRU is not adversely affected by the introduced timing change.

In some examples, an interference presence indicator is used to indicate the occurrence of a condition or event that indicates the presence of interference. Detecting an indicator set to indicate that interference is present triggers activation of the time-frequency collision avoidance process. When interference is no longer present, the network adjusts the operating parameters and settings for the WTRUs to reestablish synchronization, initial access, and beam selection themselves, as indicated by the presence indicator settings. This may be accomplished, for example, by increasing the SSB periodicity and the number of associated RACH events and increasing the associated beam transmit power within a predetermined transition period. After the end of the transition period, the cellular network may default back to the original deployment scenario parameter setting when the interference is no longer present or its impact is negligible. Alternatively, the cellular network may maintain the mitigated deployment scenario indefinitely.

Although the features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. Furthermore, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer readable medium for execution by a computer or processor. Examples of computer readable media include electronic signals (transmitted over a wired or wireless connection) 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 associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method performed by a base station, the method comprising:

Detecting interference based on the presence of the interference;

determining a Power Spectral Density (PSD) level from the interference;

Determining a Synchronization Signal Burst (SSB) frequency location to mitigate the interference based on the PSD level exceeding a threshold; and

Transmitting a signal to at least one Wireless Transmit Receive Unit (WTRU) served by the base station at the determined SSB frequency location.

2. The method of claim 1, wherein the interference is RADAR.

3. The method of claim 1, wherein detecting interference comprises determining an interference characteristic of the interference.

4. A method according to claim 3, the method further comprising:

The determined interference characteristics of the interference are compared to the bandwidth of the existing SSB block frequency locations.

5. The method of claim 1, wherein detecting comprises measuring channel conditions including at least one of carrier frequency, bandwidth, period, dwell time, and angle of arrival (AoA).

6. The method of claim 1 wherein the detecting comprises receiving channel condition measurements from at least one of a WTRU and a gNB within a network.

7. The method of claim 1, wherein the threshold is based on the following level: interference exceeding the level affects operation of the base station.

8. The method of claim 1, wherein the determined SSB frequency is a lower frequency than a previous SSB frequency.

9. The method of claim 1, the method further comprising:

After a preset period of time, the determined SSB frequency location is restored back to the original SSB frequency location.

10. The method of claim 1, the method further comprising:

when the detected interference dissipates, the determined SSB frequency location is restored back to the original SSB frequency location.

11. A base station, the base station comprising:

a processor; and

A transceiver communicatively coupled to the processor, the processor and transceiver cooperatively operating to:

Detecting interference based on the presence of the interference;

determining a Power Spectral Density (PSD) level from the interference;

12. The base station of claim 11, wherein the interference is RADAR.

13. The base station of claim 11, wherein the processor and transceiver operate to determine an interference characteristic of the interference.

14. The base station of claim 13, the processor and transceiver further comprising operations to compare the determined interference characteristics of the interference to bandwidths of existing SSB block frequency locations.

15. The base station of claim 11, wherein the detecting comprises measuring channel conditions including at least one of carrier frequency, bandwidth, period, dwell time, and angle of arrival (AoA).

16. The base station of claim 11, wherein the detecting comprises receiving channel condition measurements from at least one of a WTRU and a gNB within the network.

17. The base station of claim 11, wherein the threshold is based on the following level: interference exceeding the level affects operation of the base station.

18. The base station of claim 11, wherein the determined SSB frequency is a lower frequency than a previous SSB frequency.

19. The base station of claim 11, further comprising: after a preset period of time, the processor and transceiver operate to restore the determined SSB frequency location back to the original SSB frequency location.

20. The base station of claim 11, further comprising: when the detected interference dissipates, the processor and transceiver operate to restore the original SSB frequency location back to the original SSB frequency location.