Low power synchronization signal for LP-WUR

Abstract

A method of wireless communication at a UE includes performing one or more RRM measurements on an LP-RS of at least one cell. The method also includes selecting a cell on which to camp based on the one or more RRM measurements performed on the LP-RS.

Description

Technical Field

[0001] The present disclosure relates generally to communication systems and, more particularly, to wireless communications including synchronization. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at city, national, regional, and even global levels. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Certain aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. Further improvements to 5G NR technology are needed. In addition, these improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0004] A simplified summary of one or more aspects is presented below to provide a basic understanding of these aspects. This summary is not an extensive review of all contemplated aspects. This summary is neither intended to identify key or important elements of all aspects, nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description presented later.

[0005] In one aspect of the present disclosure, a method, computer readable medium, and apparatus for wireless communication at a user equipment (UE) are provided. The apparatus is configured to perform one or more radio resource management (RRM) measurements on a low power reference signal (LP-RS) of at least one cell and select a cell to camp on based on the one or more RRM measurements performed on the LP-RS.

[0006] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus for wireless communication at a network node are provided. The apparatus is configured to transmit a synchronization signal block (SSB) of a cell and transmit a low power reference signal (LP-RS) associated with the cell, the LP-RS being configured to be received at a lower power than the SSB.

[0007] To achieve the aforementioned and related purposes, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail some exemplary features of one or more aspects. However, these features are only indicative of only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0009] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0010] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0011] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0012] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0013] Figure 3 is a diagram illustrating an example of a base station and a UE in an access network.

[0014] Figure 4 is a diagram illustrating an example of a low power reference signal (LP-RS) according to a first configuration.

[0015] Figure 5 is a diagram illustrating an example of an LP-RS according to a second configuration.

[0016] Figure 6 is a diagram illustrating an example communication flow.

[0017] Figure 7 is a flow chart of a method of wireless communication.

[0018] Figure 8 is a flow chart of another method of wireless communication.

[0019] Fig. 9are diagrams illustrating examples of hardware implementations for example apparatuses and / or network entities.

[0020] Fig.10 is a diagram illustrating an example of a hardware implementation for an example network entity. DETAILED DESCRIPTION

[0021] The UE may be equipped with a low power wake-up radio (LP-WUR) that utilizes lower power than the main radio of the UE. In some aspects, the UE may use the LP-WUR to monitor the LP-WUS. The various aspects presented herein enable the UE to utilize the LP-WUR in different contexts (e.g., contexts for synchronization) in order to reduce UE power consumption. In order to address issues related to UE power consumption, this document describes enhancements to the UE synchronization procedure using LP-RS. In one example, the UE performs one or more RRM measurements (e.g., layer 3 reference signal received power (L3-RSRP) measurements) on the LP-RS of at least one cell and selects a cell to reside on based on the one or more RRM measurements performed on the LP-RS. Thus, the UE may use the LP-RS for cell selection / reselection purposes without having to continuously measure the SSB. Since measuring the LP-RS may consume less UE power than measuring the SSB, UE power consumption is reduced. According to some configurations, the UE uses the LP-RS for additional purposes such as cell barring, intra-frequency reselection, and / or system information changes.

[0022] The detailed description set forth below in conjunction with the accompanying drawings is a description of various configurations and does not represent the only configurations with which the concepts described herein can be practiced. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0023] Several aspects of the telecommunication system are also presented with reference to various apparatus and methods. These apparatus and methods are described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0024] As an example, an element or any part of an element or any combination of elements can be implemented as a "processing system", which includes one or more processors. The example of a processor includes a microprocessor, a microcontroller, a graphics processing unit (GPU), a central processing unit (CPU), an application processor, a digital signal processor (DSP), a reduced instruction set computing (RISC) processor, a system on a chip (SoC), a baseband processor, a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gate logic piece, a discrete hardware circuit and other suitable hardware configured to perform various functionalities described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language or other terms, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions or any combination thereof.

[0025] Therefore, in one or more example aspects, specific implementations and / or use cases, the described functions may be implemented with hardware, software, or any combination thereof. If implemented with software, the functions may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available medium that can be accessed by a computer. By way of example, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0026] Although various aspects, specific implementations and / or use cases are described in this application by the illustration of some examples, additional or different aspects, specific implementations and use cases may be generated in many different arrangements and scenarios. The various aspects, specific implementations and / or use cases described herein can be implemented across many different platform types, devices, systems, shapes, sizes and packaging arrangements. For example, aspects, specific implementations and / or use cases can be generated via integrated chip specific implementations and other devices based on non-module components (e.g., end-user equipment, vehicles, communication equipment, computing equipment, industrial equipment, retail / purchase equipment, medical equipment, artificial intelligence (AI) enabled devices, etc.). Although some examples may be specifically for use cases or applications, or may not be specifically for use cases or applications, the described examples may have a wide range of applicability. Aspects, specific implementations and / or use cases may be in the range from chip-level or modular components to non-modular, non-chip-level specific implementations, and further to the range of aggregated, distributed or original equipment manufacturer (OEM) devices or systems in conjunction with one or more technologies herein. In some practical environments, the equipment in conjunction with the various aspects and features described may also include additional components and features for implementing and practicing the various aspects claimed and described. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / accumulators, etc.) The techniques described herein can be practiced in a wide variety of devices of various sizes, shapes, and configurations, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc.

[0027] The deployment of a communication system (such as a 5G NR system) can be arranged in a variety of ways using various components or constituent parts. In a 5G NR system or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment (such as a base station (BS), or one or more units (or one or more components) that perform base station functionality can be implemented in an aggregated architecture or a decomposed architecture. For example, a BS (such as a Node B (NB), an evolved NB (eNB), an NR BS, a 5G NB (e.g., referred to as a gNB), an access point (AP), a transmit receive point (TRP), or a cell, etc.) can be implemented as an aggregated base station (also referred to as an independent BS or a monolithic BS) or a decomposed base station.

[0028] A converged base station may be configured to utilize a radio protocol stack physically or logically integrated within a single RAN node. A decomposed base station may be configured to utilize a protocol stack physically or logically distributed between two or more units, such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed in one or more other RAN nodes. A DU may be implemented to communicate with one or more RUs. Each of a CU, a DU, and a RU may be implemented as a virtual unit, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU).

[0029] Base station operation or network design may take into account the aggregated nature of base station functionality. For example, a disaggregated base station may be used in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (network configuration such as that initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)). Decomposition may include distributing functionality across two or more units at various physical locations, as well as virtually distributing functionality of at least one unit, which may enable flexibility in network design. Individual units of a disaggregated base station or disaggregated RAN architecture may be configured for wired or wireless communication with at least one other unit.

[0030] Figure 1 1 is a diagram 100 illustrating an example of a wireless communication system and an access network. The illustrated wireless communication system includes a disaggregated base station architecture. The disaggregated base station architecture may include one or more CUs 110 that may communicate directly with a core network 120 via a backhaul link, or indirectly with the core network 120 through one or more disaggregated base station units, such as a near real-time (near RT) RAN intelligent controller (RIC) 125 via an E2 link, or a non-real-time (non-RT) RIC 115 associated with a service management and orchestration (SMO) framework 105, or both. The CU 110 may communicate with one or more DUs 130 via corresponding midhaul links, such as an F1 interface. The DU 130 may communicate with one or more RUs 140 via corresponding fronthaul links. The RU 140 may communicate with corresponding UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 140.

[0031] Each of the units (i.e., CU 110, DU 130, RU 140, and near-RT RIC 125, non-RT RIC 115, and SMO framework 105) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to the communication interfaces of these units may be configured to communicate with one or more of the other units via a transmission medium. For example, these units may include a wired interface configured to receive or send signals to one or more of the other units on a wired transmission medium. Additionally, these units may include a wireless interface that may include a receiver, transmitter, or transceiver (such as an RF transceiver) configured to receive or send signals, or both, to one or more of the other units on a wireless transmission medium.

[0032] In some aspects, CU 110 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may be implemented using an interface that is configured to communicate signals with other control functions hosted by CU 110. CU110 may be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some specific implementations, CU 110 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 110 may be implemented to communicate with DU 130 for network control and signaling.

[0033] DU 130 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 140. In some aspects, DU 130 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) depending at least in part on a functional split (such as a functional split defined by 3GPP). In some aspects, DU 130 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 130 or with control functions hosted by CU 110.

[0034] The lower layer functionality may be implemented by one or more RUs 140. In some deployments, the RUs 140 controlled by the DUs 130 may correspond to logical nodes that host RF processing functions or low PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on functional splitting (such as lower layer functional splitting). In such an architecture, the RUs 140 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control plane and user plane communications with the RUs 140 may be controlled by the corresponding DUs 130. In some scenarios, this configuration may enable the implementation of the DUs 130 and CUs 110 in a cloud-based RAN architecture (such as a vRAN architecture).

[0035] The SMO framework 105 may be configured to support RAN deployment and provisioning of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 105 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 105 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 190) to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 110, DU 130, RU 140, and near-RT RIC 125. In some specific implementations, the SMO framework 105 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 111) via the O1 interface. Additionally, in some specific implementations, the SMO framework 105 may communicate directly with one or more RUs 140 via the O1 interface. The SMO framework 105 may also include a non-RT RIC 115 configured to support the functionality of the SMO framework 105 .

[0036] The non-RT RIC 115 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence (AI) / machine learning (ML) (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 125. The non-RT RIC 115 may be coupled to or communicate with the near-RT RIC 125 (such as via an A1 interface). The near-RT RIC 125 may be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 110, one or more DUs 130, or both, and O-eNBs with the near-RT RIC 125.

[0037] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 125, the non-RT RIC 115 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 125 and may be received from a non-network data source or from a network function at the SMO framework 105 or the non-RT RIC 115. In some examples, the non-RT RIC 115 or the near-RT RIC 125 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 115 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 105 (such as via reconfiguration of O1) or via creation of RAN management policies (such as A1 policies).

[0038] At least one of the CU 110, the DU 130, and the RU 140 may be referred to as a base station 102. Therefore, the base station 102 may include one or more of the CU 110, the DU 130, and the RU 140 (each component is indicated by a dotted line to indicate that each component may be included in the base station 102, or may not be included in the base station). The base station 102 provides an access point to the core network 120 for the UE 104. The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). Small cells include femto cells, pico cells, and micro cells. A network including both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG). The communication link between RU 140 and UE 104 may include uplink (UL) (also known as reverse link) transmission from UE 104 to RU 140 and / or downlink (DL) (also known as forward link) transmission from RU 140 to UE 104. The communication link may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmission diversity. The communication link may be through one or more carriers. For each carrier allocated in a carrier aggregation of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz, etc.) bandwidth. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

[0039] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL wireless wide area network (WWAN) spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, Bluetooth, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0040] The wireless communication system may also include a Wi-Fi AP 150 that communicates with a UE 104 (also referred to as a Wi-Fi station (STA)) via a communication link 154, for example, in a 5 GHz unlicensed spectrum, etc. When communicating in an unlicensed spectrum, the UE 104 / AP 150 may perform a clear channel assessment (CCA) to determine whether a channel is available prior to communication.

[0041] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz–7.125 GHz) and FR2 (24.25 GHz–52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the “sub-6 GHz” band in various documents and articles. A similar naming issue sometimes occurs with respect to FR2, which is often (interchangeably) referred to as the “millimeter wave” band in documents and articles, although distinct from the extremely high frequency (EHF) band (30 GHz–300 GHz) identified as the “millimeter wave” band by the International Telecommunication Union (ITU).

[0042] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125GHz–24.25GHz). The bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and therefore the features of FR1 and / or FR2 can be effectively extended to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to more than 52.6GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6GHz–71GHz), FR4 (71GHz–114.25GHz), and FR5 (114.25GHz–300GHz). Each of these higher frequency bands falls within the EHF band.

[0043] In view of the above, unless otherwise specified, if the term "6 GHz or less" is used in this document, it can broadly refer to frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specified, if the term "millimeter wave" is used in this document, it can broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2 and / or FR5, or may be within the EHF band.

[0044] The base station 102 and the UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming. The base station 102 may send a beamformed signal 182 to the UE 104 in one or more transmit directions. The UE 104 may receive the beamformed signal from the base station 102 in one or more receive directions. The UE 104 may also send a beamformed signal 184 to the base station 102 in one or more transmit directions. The base station 102 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 102 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 102 / UE 104. The transmit direction and receive direction of the base station 102 may be the same or different. The transmit direction and receive direction of the UE 104 may be the same or different.

[0045] The base station 102 may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), a network node, a network entity, a network equipment, or some other suitable term. The base station 102 may be implemented as an integrated access backhaul (IAB) node, a relay node, a sidelink node, an aggregated (monolithic) base station with a baseband unit (BBU) (including a CU and a DU) and a RU, or as a disaggregated base station including one or more of a CU, a DU, and / or a RU. A set of base stations that may include disaggregated base stations and / or aggregated base stations may be referred to as a next generation (NG) RAN (NG-RAN).

[0046] The core network 120 may include an access and mobility management function (AMF) 161, a session management function (SMF) 162, a user plane function (UPF) 163, a unified data management (UDM) 164, one or more location servers 168, and other functional entities. AMF 161 is a control node that handles signaling between UE 104 and core network 120. AMF 161 supports registration management, connection management, mobility management, and other functions. SMF 162 supports session management and other functions. UPF 163 supports packet routing, packet forwarding, and other functions. UDM 164 supports the generation of authentication and key agreement (AKA) credentials, user identity handling, access authorization, and subscription management. One or more location servers 168 are illustrated as including a gateway mobile location center (GMLC) 165 and a location management function (LMF) 166. However, in general, the one or more location servers 168 may include one or more location / positioning servers, which may include one or more of the GMLC 165, the LMF 166, the positioning determination entity (PDE), the serving mobile location center (SMLC), the mobile positioning center (MPC), etc. The GMLC 165 and the LMF 166 support UE location services. The GMLC 165 provides an interface for clients / applications (e.g., emergency services) to access UE positioning information. The LMF 166 receives measurement results and assistance information from the NG-RAN and the UE 104 via the AMF 161 to calculate the positioning of the UE 104. The NG-RAN may determine the positioning of the UE 104 using one or more positioning methods. Positioning the UE 104 may involve signal measurements, positioning estimates, and optional speed calculations based on these measurements. Signal measurements may be performed by the UE 104 and / or the serving base station 102. The measured signals may be based on a satellite positioning system (SPS) 170 (e.g., one or more of a global navigation satellite system (GNSS), a global positioning system (GPS), a non-terrestrial network (NTN), or other satellite positioning / location systems), LTE signals, wireless local area network (WLAN) signals, Bluetooth signals, a terrestrial beacon system (TBS), sensor-based information (e.g., an atmospheric pressure sensor, a motion sensor), an NR enhanced cell ID (NR E-CID) method, NR signals (e.g., multi-round trip time (multi-RTT), DL angle of departure (DL-AoD), DL time difference of arrival (DL-TDOA), UL time difference of arrival (UL-TDOA), and UL angle of arrival (UL-AoA) positioning), and / or one or more of other systems / signals / sensors.

[0047] Examples of UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet computers, smart devices, wearable devices, vehicles, electric meters, gas pumps, large or small kitchen appliances, healthcare equipment, implants, sensors / actuators, displays, or any other similarly functional devices. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as stations, mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, mobile phones, user agents, mobile clients, clients, or some other suitable terminology. In some scenarios, the term UE may also be applied to one or more supporting devices, such as in a device cluster arrangement. One or more of these devices may access the network collectively and / or individually.

[0048] Refer again Figure 1 In some aspects, the UE 104 may include an LP synchronization component configured to perform one or more RRM measurements on the LP-RS of at least one cell and select a cell to camp on based on the one or more RRM measurements performed on the LP-RS. In some aspects, the base station 102 includes an LP synchronization signaling component 199 configured to transmit an SSB of a cell and transmit an LP-RS associated with the cell, the LP-RS configured to be received at a lower power than the SSB. Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar fields, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0049] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2DFIG280 is a diagram illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL, or may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , Figure 2C In the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28, respectively, any particular subframe may be configured with any of the various available slot formats 0 to 61. Slot formats 0 and 1 are both DL and both UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. The slot format is configured for the UE via a received slot format indicator (SFI) (dynamically configured via DL control information (DCI) or semi-statically / statically configured via radio resource control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure as TDD.

[0050] FIG. 2A to FIG. 2D The frame structure is illustrated, and various aspects of the present disclosure may be applicable to other wireless communication technologies that may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes of the same size (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is conventional or extended. For a conventional CP, each time slot may include 14 symbols, and for an extended CP, each time slot may include 12 symbols. The symbol on the DL may be a CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the CP and parameter set. The parameter set defines the subcarrier spacing (SCS) and effectively defines the symbol length / duration, which is equal to 1 / SCS.

[0051]

[0052] For normal CP (14 symbols / slot), different parameter sets μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For extended CP, parameter set 2 allows 4 slots per subframe. Accordingly, for normal CP and parameter set μ, there are 14 symbols / slot and 2 μ timeslots / subframe. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is parameter set 0 to 4. Therefore, the subcarrier spacing for parameter set μ=0 is 15kHz, and the subcarrier spacing for parameter set μ=4 is 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIG. 2A to FIG. 2D An example of a parameter set μ=2 with a normal CP of 14 symbols per slot and 4 slots per subframe is provided. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is about 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP may have a specific parameter set and CP (normal or extended).

[0053] A resource grid may be used to represent a frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0054] like Figure 2A As illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0055] Figure 2BExamples of various DL channels within a subframe of a frame are illustrated. A physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies on the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identity (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the system frame number (SFN) and the number of RBs in the system bandwidth. The physical downlink shared channel (PDSCH) carries user data, broadcast system information such as system information blocks (SIBs) that are not sent via the PBCH, and paging messages.

[0056] like Figure 2C As illustrated, some of the REs carry DM-RS (indicated as R for a particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may send a DM-RS for a physical uplink control channel (PUCCH) and a DM-RS for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first or first two symbols of the PUSCH. Depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used, the PUCCH DM-RS may be sent in different configurations. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The SRS may be used by the base station for channel quality estimation to achieve frequency-dependent scheduling of the UL.

[0057] Figure 2DExamples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located at a position as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACKs and / or negative ACKs (NACKs)). The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0058] Figure 3 3 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, Internet Protocol (IP) packets may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with delivery of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0059] The transmit (TX) processor 316 and receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-order phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols can then be divided into parallel streams. Subsequently, each stream can be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time domain and / or frequency domain, and then combined using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially pre-coded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived from reference signals and / or channel state feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318Tx. Each transmitter 318Tx may modulate a radio frequency (RF) carrier for transmission using a corresponding spatial stream.

[0060] At the UE 350, each receiver 354Rx receives a signal through its corresponding antenna 352. Each receiver 354Rx recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be merged into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.

[0061] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0062] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with delivery of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0063] The TX processor 368 may use channel estimates derived by the channel estimator 358 from a reference signal or feedback sent by the base station 310 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via corresponding transmitters 354Tx. Each transmitter 354Tx may modulate an RF carrier with a corresponding spatial stream for transmission.

[0064] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318Rx receives a signal through its respective antenna 320. Each receiver 318Rx recovers information modulated onto an RF carrier and provides the information to the RX processor 370.

[0065] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0066] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to combine Figure 1 The LP synchronization component 198 is used to perform various aspects.

[0067] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to combine Figure 1 The LP synchronization signaling component 199 is used to perform various aspects.

[0068] In RRC idle and inactive states, radio resource management (RRM) and paging may consume significant UE power. In one example, in RRM, the UE periodically performs layer 3 reference signal received power (L3-RSRP) measurements on SBSs transmitted by the UE's serving cell and the UE's neighboring cells. Such L3-RSPRP measurements consume power at the UE. In another example, in paging, the UE may periodically monitor paging occasions (POs) during each idle discontinuous reception (I-DRX) cycle.

[0069] The UE may be configured with resources for monitoring a wake-up signal (WUS). When configured, the UE wakes up a configurable amount of time before the start of a long discontinuous reception (DRX) cycle. The UE then checks for the WUS. If the UE does not receive the WUS, the UE will return to sleep and enter the next long DRX cycle. The WUS can reduce the power consumption of the UE. In some configurations, the WUS can be sent via the PDCCH (such a wake-up signal may be referred to as a PDCCH-WUS).

[0070] In some configurations, the UE may be equipped with a low power wake-up radio (LP-WUR) that utilizes lower power than the UE's main radio. In one example, the LP-WUR may utilize less than 1 mA. The LP-WUR may be configured to receive a low power wake-up signal (LP-WUS). A UE that wakes up using the LP-WUS may consume less power than a UE that wakes up using the PDCCH-WUS. The LP-WUR may utilize an on-off keying (OOK) modulation scheme. The OOK modulation scheme may limit the payload size of the LP-WUS. The LP-WUR may need to be utilized in different contexts (e.g., contexts for synchronization) in order to reduce UE power consumption.

[0071] Various aspects presented herein achieve further reduction in UE power consumption by using LP-RS and LP-WUR for synchronization or RRM. The base station may send the LP-RS and the UE may receive the LP-RS using the LP-WUR. In some aspects, the location of the LP-RS may be defined or configured for the synchronization raster, or may be provided in signaling such as remaining minimum system information (RMSI).

[0072] The UE may perform measurements (e.g., L3-RSRP measurements) on the LP-RS. Using LP-RS and LP-WUR to perform measurements may help the UE reduce the power to perform such measurements. The UE may also perform measurements on the LP-RS received by the LP-WUR from neighboring cells. In some aspects, the UE may use RSRP measurements performed on the LP-RS to derive equivalent RSRP measurement values ​​for corresponding measurements performed on the SSB. The UE may utilize equivalent RSRP measurements performed on the SSB in cell selection / reselection. When the LP-WUR receives the LP-RS (as opposed to the UE's main radio component receiving the SSB), the UE may be able to perform cell selection / reselection using less power than cell selection / reselection performed using the SSB. According to some configurations, the UE may use the LP-RS for additional purposes such as cell barring, intra-frequency reselection, and / or system information changes.

[0073] In one example, the UE performs one or more RRM measurements on the LP-RS of at least one cell and selects a cell to camp on based on the one or more RRM measurements performed on the LP-RS. Thus, the UE can use the LP-RS for cell selection / reselection purposes without having to measure the SSB, which may consume more power at the UE. Since measuring the LP-RS consumes less UE power than measuring the SSB, UE power consumption is reduced.

[0074] Figure 4 4 is a diagram illustrating example aspects of an LP-RS. Diagram 400 includes an SSB 402 and an LP-RS 404. A base station (e.g., base station 102, base station 310, base station 604, network entity 902, etc.) may transmit the SSB 402 and the LP-RS 404. A UE (e.g., 102, UE 350, UE 602, device 904, etc.) may receive the LP-RS using a different receiver or radio (e.g., LP-WUR) than that used to receive the SSB. The LP-WUR may use less power at the UE than other receivers or radios (e.g., which may be referred to as higher power receivers or radios) used by the UE to receive the SSB.

[0075] The LP-RS may be configured such that the UE uses less power to receive the LP-RS than the SSB. The LP-RS may include a different waveform than the SSB and / or a different modulation than the SSB, and the waveform or modulation of the LP-RS may be received using lower power than the waveform / modulation of the SSB. In some aspects, the waveform and / or modulation of the LP-RS may be the same as the waveform or modulation used for the LP-WUS. Figure 4As illustrated, the LP-RS 404 may span fewer frequency resources than the SSB 402. For example, the base station may transmit the LP-RS 404 in a narrower frequency band for a longer period of time than the SSB 402. In some aspects, the LP-RS 404 may include a defined sequence transmitted by a serving cell. The defined sequence of the LP-RS 404 may be scrambled by the PCI, or the payload of the LP-RS may carry the PCI for cell identification.

[0076] Figure 6 Diagram 600 is included including an example of a base station 604 broadcasting a LP-RS at 606. A UE may include multiple receivers or multiple radio components. Figure 6 A UE having a low power radio 601 (which may be referred to as a low power receiver, a low power transceiver, or a LP-WUR) and an additional radio 603 (which may be referred to as a higher power radio, a higher power receiver, a higher power transceiver, etc.) is illustrated, and the additional radio may use more power at the UE than the radio 601. A UE 602 (such as a UE in an RRC idle or inactive state) may receive an LP-RS using the LP-WUR. A base station (e.g., base station 102, base station 310, base station 604, network entity 902, etc.) may send an LP-RS 404 (e.g., 102, UE 350, UE 602, device 904, etc.) using the same waveform and modulation as that of the LP-WUS. In one example, the base station may send the LP-RS 404 using an OOK modulation scheme. In another example, the base station may send the LP-RS 404 using an OFDMA modulation scheme. The LP-WUR (e.g., 601) of the UE may receive the LP-RS. The LP-WUR utilizes lower power than the primary radio (e.g., 603) of the UE 602. Therefore, measurements performed by the UE on the LP-WUS (e.g., L3-RSRP measurements) consume less UE power than measurements performed by the UE on the SSB (which are received by the primary radio).

[0077] Figure 4The diagram 400 in shows the location of the LP-RS 404 defined based on the time offset 406 and the frequency offset 408 for the synchronization raster. The synchronization raster defines the known location of the transmission location of the SSB. By using the synchronization raster, the UE knows the location of the SSB. Since the UE knows the time and frequency location of the SSB 402 through the synchronization raster, the UE can determine or know the time and frequency location of the LP-RS 404. Since RRM measurements are performed in idle mode DRX or extended DRX, the base station can use a longer periodicity to send LP-RS than SSB. For example, the UE may not need to measure the LP-RS at the same rate as the SSB, which is typically sent every 20ms. By using repetitions, the LP-RS 404 can have similar or the same coverage as the SSB 402. The base station can configure the number of repetitions of the LP-RS.

[0078] In one aspect, the UE may determine the time and frequency location of the SSB 402 based on the synchronization raster. The UE may determine the location of the LP-RS 404 based on the time and frequency location of the SSB 402.

[0079] Figure 5 5 is a diagram illustrating various aspects of an LP-RS. Diagram 500 includes an SSB 502 and an LP-RS 504. The modulation and / or waveform of the LP-RS may include a combination of Figure 4 Aspects described. In one example, the base station may use OOK modulation to send the LP-RS 504. In another example, the base station may use OFDMA modulation to send the LP-RS 504. SSB 502 and LP-RS 504 may be similar to SSB 402 and LP-RS 404. However, unlike LP-RS 404, the location and other configuration information of LP-RS 504 may be sent by the base station. For example, the location of the LP-RS and / or other configurations of the LP-RS may be included in RMSI 506. RMSI 506 may be referred to as SIB1. SSB 502 may carry information for the UE to receive RMSI. RMSI 506 includes system information for the UE to access the RAN, such as information required for the UE to perform initial random access. The base station periodically broadcasts RMSI 506 within a cell area. For example, referring to Figure 6 At 620, the base station 604 broadcasts the SIB (which may include the RMSI 506) to the UE 602 and the UE 602 receives the SIB.

[0080] In some aspects, the UE may utilize LP-RS 404 or LP-RS 504 in cell selection and / or reselection. Utilizing LP-RS 404 or LP-RS 504 instead of SSB 402 or SSB 502 for cell selection and / or reselection may reduce the amount of time the UE wakes up the primary radio (unless the UE receives a page or short message). Using LP-RS for cell selection / reselection may reduce power consumption of the UE by reducing the use of the primary radio.

[0081] In one aspect, the UE utilizes LP-RS 404 or LP-RS 504 to perform serving cell measurements. Figure 6 , at 608, when UE 602 first selects a cell associated with base station 604, base station 604 broadcasts an SSB to UE 602. UE 602 receives the SSB at the primary radio component. Subsequently, at 606, base station 604 broadcasts an LP-RS to UE 602. UE 602 receives the LP-RS at the LP-WR. At 610, UE 602 measures the SSB (e.g., using L3-RSRP to measure). In one example, UE 602 may measure the SSB using a high power (HP) radio component 603. At 612, UE 602 measures the LP-RS (e.g., using L3-RSRP to measure). In one example, UE 602 may measure the LP-RS using a low power (LP) radio component 601. At 614, UE 602 selects a cell to camp on based on the measurements performed on the SSB and / or LP-RS. At 616, for subsequent serving cell measurements occurring after the first cell measurement, base station 604 broadcasts LP-RS for subsequent measurements by UE 602. UE 602 receives LP-RS at LP-WR. At 618, UE 602 measures LP-RS instead of SSB.

[0082] In one aspect, the UE utilizes LP-RS to perform neighbor cell measurements. Figure 6 In the embodiment of the present invention, at 620, base station 604 sends a SIB (e.g., SIB3 / 4 / 5) to UE 602. The SIB may include system information of a set of neighboring cells to be measured. UE 602 receives the SIB (e.g., at a primary radio component). At 622, UE 602 uses the above-mentioned Figure 4 and Figure 5The relationship between SSB and LP-RS described in (e.g., using a synchronization raster) is used to derive the time and frequency location of the neighboring LP-RS broadcasted by the neighboring BS 622 (i.e., the neighboring cell). At 624, the neighboring base station 626 broadcasts the neighboring LP-RS to the UE 602. The UE 602 receives the neighboring LP-RS at the LP-WUR. At 628, the UE 602 uses the neighboring LP-RS (e.g., using L3-RSRP measurement) to measure the neighboring cell associated with the neighboring base station 626 without having to measure its corresponding SSB. At 630, the UE 602 selects a neighboring cell or a cell associated with the base station to camp on based on the corresponding measurements of the neighboring cell or the cell associated with the base station 604.

[0083] In one aspect, the UE utilizes the L3-RSRP measurement performed on the LP-RS to derive an equivalent L3-RSRP measurement performed on the SSB. The UE may then compare the derived equivalent measurement with a threshold / cell selection or reselection parameter for the SSB and / or with other measurements of the SSB. For example, Figure 6 , at 632, the UE 602 may use the L3-RSRP measurement performed on the LP-RS to derive the L3-RSRP measurement performed on the SSB by applying the offset to the L3-RSRP measurement performed on the LP-RS. The UE 602 may derive the offset from its own measurements (e.g., measurements performed on the initial SSB), or the offset may be provided to the UE 602 by the network. The UE 602 may periodically measure the SSB to determine whether the derived offset is still valid and / or whether the derived offset needs to be adjusted. For example, at 634, the base station 604 may broadcast the offset to the UE 602. At 632, the UE 602 receives the offset and applies the offset. Thus, the UE 602 may perform cell selection / reselection using the equivalent L3-RSRP measurement performed on the SSB and the traditional cell selection / reselection criteria. Therefore, after deriving the equivalent L3-RSRP measurement performed on SSB, UE 602 can utilize existing cell selection / reselection procedures without having to utilize new LP-RS cell selection criteria. On the other hand, UE 602 utilizes reference signal received quality (RSRQ) measurements performed on LP-RS to derive equivalent RSRQ measurements performed on SSB.

[0084] In some aspects, the network may configure a separate set of measurements and cell selection / reselection parameters for LP-RS. The UE may then compare the LP-RS measurements to the corresponding thresholds / cell selection (reselection) parameters instead of deriving the corresponding SSB measurements. Figure 6, at 634, the base station 604 may broadcast parameters to the UE 602. The UE 602 may receive the parameters. The parameters may include selection criteria (Scriteria), such as Qrxlevmin / Qqualmin, Qrxlevminoffset / Qqualminoffset, Pcompensation, and / or Qoffsettemp. The parameters may also include thresholds for performing neighboring cell RRM measurements, such as SIntraSearchP, SIntraSearchQ, SnonIntraSearchP, and / or SnonIntraSearchQ. At 632, the UE 602 may utilize the parameters to perform cell selection / reselection.

[0085] In one aspect, LP-RS 404 or LP-RS 504 may include a cell barring indication, an intra-frequency reselection indication, and / or a system information (SI) change notification. Figure 6 In the example, at 606 and 616, the base station 604 may send an LP-RS including a cell barring indication, an intra-frequency reselection indication, and / or an SI change notification. The cell barring indication is used by the network to notify the UE whether a new UE is being accepted. The intra-frequency reselection indication notifies the UE that if cell barring occurs on a frequency, all cells on the same frequency are also barred. The SI change notification notifies the UE of a system information change. The cell barring indication, the intra-frequency reselection indication, and / or the SI change notification in the LP-RS 404 or LP-RS 504 may enable the UE 602 to obtain the barring status of a neighboring cell without having to wake up the main radio component to periodically check the MIB / SIB1 of the neighboring cell.

[0086] In one aspect, LP-RS 404 or LP-RS 504 may be used as a reference signal for tracking the timing of a serving cell of a UE. Figure 6 In the example embodiment, at 636, UE 602 uses LP-RS to track the timing of the serving cell.

[0087] In one aspect, the UE selects the SSB or LP-RS to be measured based on one or more conditions. Figure 6 At 638, the UE 602 selects an SSB or LP-RS based on a condition. The one or more conditions may include an RSRP of a downlink reference signal of the UE satisfying a threshold, a location of the UE within a cell, and / or a mobility condition of the UE.

[0088] Figure 7700 is a flow chart of a method of wireless communication. The method may be performed by a UE (e.g., UE 104, UE 350, UE 602, device 904). In one example, the method (including various configurations described below) may be performed by LP synchronization component 198. The method may be associated with various advantages of the UE, such as reduced UE power consumption.

[0089] At 702, the UE performs one or more RRM measurements on the LP-RS of at least one cell. Figure 6 At 612, UE 602 measures the LP-RS broadcasted by base station 604. In another example, referring to Figure 4 , depicting LP-RS 404. In yet another example, referring to Figure 5 , depicting LP-RS 504.

[0090] At 704, the UE selects a cell to camp on based on the one or more RRM measurements performed on the LP-RS. Figure 6 At 614 , UE 602 selects a cell to camp on based on the measurements performed on the LP-RS performed at 612 .

[0091] In one configuration, the LP-RS may be configured to be received at a reduced power relative to receiving the SSB of at least one cell. Figure 6 , at 608 and 606, UE 602 may receive SSB and LP-RS and the LP-RS may be configured for reception at a reduced power compared to the SSB.

[0092] In one configuration, the UE may include a first receiver and a second receiver, the second receiver operating at a lower power than the first receiver, and wherein the one or more RRM measurements are performed on the LP-RS using the second receiver of the UE. Figure 1 , the LP synchronization component 198 may include a first receiver and a second receiver, the second receiver operating with lower power than the first receiver, and the UE may use the second receiver to perform RRM measurements on the LP-RS. Figure 6 , the LP synchronization component 198 can perform RRM measurements via the LP radio component 601.

[0093] In one configuration, the UE may receive an SSB associated with the serving cell before receiving an LP-RS associated with the serving cell. Figure 6At 608, UE 602 may receive a broadcasted SSB associated with base station 604. In such a configuration, the UE may obtain information about the LP-RS based on the SSB or from the RMSI associated with the SSB. Figure 4 , the UE may obtain information about the LP-RS 404 based on the SSB 402. In another example, referring to Figure 5 , the UE may obtain information about the LP-RS 504 based on the RMSI 506.

[0094] In one configuration, before receiving the LP-RS associated with the serving cell, the UE may determine the time and frequency location of the SSB associated with the serving cell based on the synchronization raster. Figure 4 , the UE may use the synchronization raster to determine the time and frequency position of the SSB 402. In such a configuration, the UE may determine the position of the LP-RS based on the time and frequency position of the SSB associated with the serving cell. For example, referring to Figure 4 , the UE can determine the location of the LP-RS 404 based on the SSB 402.

[0095] In one configuration, the LP-RS may be transmitted at a first periodicity and the SSB may be transmitted at a second periodicity. Figure 4 , LP-RS 404 is transmitted with a first periodicity and SSB 402 is transmitted with a second periodicity. Figure 5 , LP-RS 504 is transmitted with a first periodicity and SSB 502 is transmitted with a second periodicity.

[0096] In one configuration, the UE may be in an RRC idle or inactive state. Figure 6 , at 612 and 614, when UE 602 measures the LP-RS and selects a cell based on the measured LP-RS, UE 602 may be in an RRC idle or inactive state.

[0097] In one configuration, the LP-RS may be identified by the PCI of the serving cell. Figure 6 At 606 , the broadcast LP-RS may be identified by a PCI associated with the base station 604 .

[0098] In one configuration, the LP-RS may include a payload carrying the PCI. Figure 6 , at 606, the broadcast LP-RS may carry the PCI in the payload.

[0099] In one configuration, the LP-RS may include a payload including at least one of: a cell barring indication, an intra-frequency reselection indication, or a system information change notification. Figure 6 At 606, the LP-RS may include a cell barring indication, an intra-frequency reselection indication, and / or an SI change notification.

[0100] In one configuration, the LP-RS may include an OOK modulation scheme or an OFDMA modulation scheme. Figure 4 , LP-RS404 may include an OOK modulation scheme or an OFDMA modulation scheme. In another example, referring to Figure 5 , the LP-RS 504 may include an OOK modulation scheme or an OFDMA modulation scheme.

[0101] In one configuration, the one or more RRM measurements may include L3-RSRP measurements. Figure 6 At 612, UE 602 may perform L3-RSRP measurements on the LP-RS. For example, UE 602 may use LP radio component 601 to perform measurements on the LP-RS.

[0102] In one configuration, the UE may perform a first measurement on the SSB associated with the serving cell before receiving the LP-RS associated with the serving cell. Figure 6 At 610, UE 602 may perform measurements on SSBs associated with base station 604. For example, UE 602 may use HP radio 603 to perform measurements on SSBs.

[0103] In one configuration, the UE may perform cell reselection based on the one or more RRM measurements performed on the LP-RS of the cell and the second one or more RRM measurements performed on the second LP-RS of at least one neighboring cell. Figure 6 At 612 and 628, UE 602 may perform measurements on the LP-RS transmitted by base station 604 and the LP-RS transmitted by neighboring base station 626, and at 630, UE 602 may perform cell reselection based on the corresponding measurements.

[0104] In one configuration, the UE may derive the time and frequency position of the LP-RS associated with at least one neighboring cell indicated in the system information. Figure 6 At 620, the UE 602 may receive the broadcasted SIB, and at 622, the UE may derive the time and frequency location of the LP-RS broadcasted by the neighboring base station 626. In such configurations, performing the one or more RRM measurements on at least one cell includes performing a second one or more RRM measurements on the LP-RS of at least one neighboring cell. Figure 6 At 628 , UE 602 may measure the LP-RS associated with neighboring base station 626 .

[0105] In one configuration, the UE may derive an estimated RSRP for the corresponding SSB based on the offset and the one or more RRM measurements performed on the LP-RS. Figure 6 At 632, the UE 602 may derive an RSRP measurement performed on the SSB based on the offset and the measurement performed on the LP-RS performed at 612. In such a configuration, the UE may select a cell based on a threshold and an estimated RSRP of the corresponding SSB. Figure 6 At 632, UE 602 may perform cell selection or reselection based on the derived RSRP measurements performed on the SSB.

[0106] In one configuration, the UE may estimate the offset based on a difference between the one or more RRM measurements performed on the LP-RS and a corresponding RRM measurement performed on the corresponding SSB. Figure 6 , at 632, the UE may estimate the offset.

[0107] In one configuration, the UE may receive an offset from a network node. Figure 6 , at 634 , UE 602 may receive an offset from base station 604 .

[0108] In one configuration, the UE may receive an LP-RS cell selection parameter from a network entity, the LP-RS cell selection parameter being different from the SSB cell selection parameter, wherein selecting a cell is also based on the LP-RS cell selection parameter. Figure 6 At 634 , UE 602 may receive cell selection parameters from base station 604 .

[0109] In one configuration, the UE may select the LP-RS based on at least one condition before performing the one or more measurements on the LP-RS of at least one cell. Figure 6 , at 638, the UE may select the SSB based on the conditions.

[0110] In one configuration, the LP-RS may be selected from the group consisting of an LP-RS and an SSB. Figure 6 At 638, the LP-RS may be selected from the group consisting of SSB and LP-RS.

[0111] Figure 8800 is a flow chart of a method of wireless communication. The method may be performed by a network entity (e.g., base station 102, base station 310, base station 604, network entity 902). In one example, the method (including various configurations described below) may be performed by LP synchronization signaling component 199. At 802, the network node sends an SSB of a cell. For example, referring to Figure 6 , at 608, the base station 604 broadcasts the SSB. In another example, referring to Figure 4 , the base station sends SSB 402. In yet another example, referring to Figure 5 , the base station sends SSB 502.

[0112] At 804, the network node transmits an LP-RS associated with the cell, the LP-RS configured to be received at a lower power than the SSB. Figure 6 At 606, the base station 604 broadcasts the LP-RS. In another example, referring to Figure 4 , the base station sends LP-RS 404. In yet another example, referring to Figure 5 , the base station sends LP-RS 504.

[0113] In one configuration, the LP-RS may be broadcast with a first periodicity and the SSB may be broadcast with a second periodicity. Figure 4 , the base station broadcasts LP-RS 404 with a first periodicity and broadcasts SSB 402 with a second periodicity. In another example, referring to Figure 5 , the base station broadcasts LP-RS 504 with a first periodicity and broadcasts SSB 502 with a second periodicity.

[0114] In one configuration, the LP-RS may be identified by the PCI of the cell. Figure 6 At 606 , the broadcast LP-RS may be identified by a PCI associated with the base station 604 .

[0115] In one configuration, the LP-RS may include a payload carrying the PCI. Figure 6 , at 606, the broadcast LP-RS may carry the PCI in the payload.

[0116] In one configuration, the LP-RS may include an OOK modulation scheme or an OFDMA modulation scheme. Figure 4 , LP-RS404 may include an OOK modulation scheme or an OFDMA modulation scheme. In another example, referring to Figure 5 , the LP-RS 504 may include an OOK modulation scheme or an OFDMA modulation scheme.

[0117] In one configuration, LP-RS may be transmitted for L3-RSRP measurement associated with a cell. Figure 6 At 606, the base station 604 may broadcast an LP-RS for L3-RSRP measurement associated with the cell associated with the base station 604.

[0118] In one configuration, the network node may send an RMSI associated with the SSB and indicating the location of the LP-RS in at least one of time or frequency. Figure 6 At 620, the base station 604 may transmit a SIB including a RMSI associated with the SSB, wherein the RMSI includes a location of the LP-RS in at least one of time or frequency.

[0119] In one configuration, the network node may indicate a cell selection parameter based on the LP-RS, the cell selection parameter being different from the SSB cell selection parameter. Figure 6 At 634, the base station 604 may indicate the cell selection parameters.

[0120] Fig. 9900 is an example of a hardware implementation of an example device 904. The device 904 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the device 904 may include a cellular baseband processor 924 (also referred to as a modem) coupled to one or more transceivers 922 (e.g., a cellular RF transceiver). The cellular baseband processor 924 may include on-chip memory 924'. In some aspects, the device 904 may also include one or more subscriber identity module (SIM) cards 920 and an application processor 906 coupled to a secure digital (SD) card 908 and a screen 910. The application processor 906 may include on-chip memory 906'. In some aspects, the device 904 may also include a Bluetooth module 912, a WLAN module 914, an SPS module 916 (e.g., a GNSS module), one or more sensor modules 918 (e.g., an atmospheric pressure sensor / altimeter); motion sensors such as an inertial measurement unit (IMU), a gyroscope, and / or an accelerometer; light detection and ranging (LIDAR), radio-aided detection and ranging (RADAR), sound navigation and ranging (SONAR), magnetometers, audio, and / or other technologies for positioning), additional memory modules 926, a power source 930, and / or a camera 932. The Bluetooth module 912, the WLAN module 914, and the SPS module 916 may include an on-chip transceiver (TRX) (or in some cases, only a receiver (RX)). The Bluetooth module 912, the WLAN module 914, and the SPS module 916 may include their own dedicated antennas and / or communicate using an antenna 980. The cellular baseband processor 924 communicates with the UE 104 and / or with the RU associated with the network entity 902 through the transceivers 921 and 922 via one or more antennas 980. For example, as described in conjunction with Figure 6As described, the device may include a low-power transceiver 921 that uses lower power than the transceiver 922. The cellular baseband processor 924 and the application processor 906 may each include a computer-readable medium / memory 924', 906', respectively. The additional memory module 926 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory 924', 906', 926 may be non-transitory. The cellular baseband processor 924 and the application processor 906 are each responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the cellular baseband processor 924 / application processor 906, enables the cellular baseband processor 924 / application processor 906 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 924 / application processor 906 when executing the software. The cellular baseband processor 924 / application processor 906 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the device 904 may be a processor chip (modem and / or application) and include only the cellular baseband processor 924 and / or the application processor 906, while in another configuration, the device 904 may be the entire UE (e.g., see Figure 3 350) and includes additional modules of device 904.

[0121] As discussed above, the LP synchronization component 198 is configured to perform one or more RRM measurements on the LP-RS of at least one cell and select a cell to camp on based on the one or more RRM measurements performed on the LP-RS. The LP synchronization component 198 may be further configured to perform in conjunction with Figure 7 Described and / or by Figure 6Any of the aspects performed by the UE in . The LP synchronization component 198 may be within the cellular baseband processor 924, the application processor 906, or within both the cellular baseband processor 924 and the application processor 906. The LP synchronization component 198 may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination of the foregoing. As shown, the device 904 may include multiple components configured for various functions. In one configuration, the device 904 (particularly the cellular baseband processor 924 and / or the application processor 906) includes a component for performing one or more RRM measurements on the LP-RS of at least one cell and a component for selecting a cell to reside on based on the one or more RRM measurements performed on the LP-RS. The device 904 may also include a component for performing a combined Figure 7 Described and / or by Figure 6 The means may be a LP synchronization component 198 of the apparatus 904 configured to perform the functions recited by the means. As described above, the apparatus 904 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Thus, in one configuration, the means may be a TX processor 368, an RX processor 356, and / or a controller / processor 359 configured to perform the functions recited by the means.

[0122] Fig.101000 is a diagram illustrating an example of a hardware implementation for a network entity 1002. The network entity 1002 may be a BS, a component of a BS, or may implement BS functionality. The network entity 1002 may include at least one of a CU 1010, a DU 1030, or a RU 1040. For example, depending on the layer functionality handled by the LP synchronization signaling component 199, the network entity 1002 may include a CU 1010; both a CU 1010 and a DU 1030; each of the CU 1010, the DU 1030, and the RU 1040; the DU 1030; both a DU 1030 and a RU 1040; or a RU 1040. The CU 1010 may include a CU processor 1012. The CU processor 1012 may include an on-chip memory 1012'. In some aspects, the CU 1010 may also include an additional memory module 1014 and a communication interface 1018. CU1010 communicates with DU 1030 via a midhaul link (such as an F1 interface). DU 1030 may include a DU processor 1032. DU processor 1032 may include on-chip memory 1032'. In some aspects, DU 1030 may also include additional memory modules 1034 and communication interfaces 1038. DU 1030 communicates with RU 1040 via a fronthaul link. RU 1040 may include a RU processor 1042. RU processor 1042 may include on-chip memory 1042'. In some aspects, RU 1040 may also include additional memory modules 1044, one or more transceivers 1046, antennas 1080, and communication interfaces 1048. RU 1040 communicates with UE 104. On-chip memories 1012', 1032', 1042' and additional memory modules 1014, 1034, 1044 may each be considered a computer-readable medium / memory. Each computer readable medium / memory may be non-transitory. Each of the processors 1012, 1032, 1042 is responsible for general processing, including executing software stored on the computer readable medium / memory. The software, when executed by the corresponding processor, causes the processor to perform the various functions described above. The computer readable medium / memory may also be used to store data manipulated by the processor when executing the software.

[0123] As discussed above, the LP synchronization signaling component 199 is configured to transmit the SSB of the cell and transmit the LP-RS associated with the cell, the LP-RS configured to be received at a lower power than the SSB. The LP synchronization signaling component 199 may be further configured to perform a combined Figure 8 Described and / or by Figure 6Any of the aspects performed by the base station in. The LP synchronization signaling component 199 may be within one or more processors of one or more of the CU 1010, the DU 1030, and the RU 1040. The LP synchronization signaling component 199 may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination of the above. The network entity 1002 may include a variety of components configured for various functions. In one configuration, the network entity 1002 includes a component for transmitting an SSB of a cell and a component for transmitting an LP-RS associated with the cell, the LP-RS being configured to be received at a lower power than the SSB. The network entity may also include a component for performing a combined Figure 8 Described and / or by Figure 6 Any of the aspects performed by the base station in the. The means may be the LP synchronization signaling component 199 of the network entity 1002 configured to perform the functions recited by the means. As described above, the network entity 1002 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, the means may be the TX processor 316, the RX processor 370, and / or the controller / processor 375 configured to perform the functions recited by the means.

[0124] The UE may be configured with a wake-up signal (WUS). In some configurations, the UE may be equipped with a low-power wake-up radio (LP-WUR) that utilizes lower power than the main radio of the UE. It is necessary to utilize the LP-WUR in different contexts (e.g., contexts for synchronization) in order to reduce UE power consumption. In order to address issues related to UE power consumption, this document describes enhancements to the UE synchronization procedure using LP-RS. The base station may send an LP-RS to the LP-WUR of the UE, where the position of the LP-RS is predefined based on a synchronization raster or based on the remaining minimum system information (RMSI). The UE may perform measurements (e.g., L3-RSRP measurements) on the LP-RS. The UE may also perform measurements on the LP-RS received by the LP-WUR from neighboring cells. The UE may use RSRP measurements performed on the LP-RS to derive equivalent RSRP measurements performed on the SSB. The UE may utilize equivalent RSRP measurements performed on the SSB in cell selection / reselection. When the LP-WUR receives LP-RS (as opposed to the UE's main radio receiving SSB), the UE is able to perform cell selection / reselection using less power than cell selection / reselection performed using SSB. According to some configurations, the UE uses LP-RS for additional purposes such as cell barring, intra-frequency reselection, and / or system information changes.

[0125] In one example, the UE performs one or more RRM measurements on the LP-RS of at least one cell and selects a cell to camp on based on the one or more RRM measurements performed on the LP-RS. Thus, the UE may use the LP-RS for cell selection / reselection purposes without having to continuously measure the SSB. Since measuring the LP-RS may consume less UE power than measuring the SSB, UE power consumption is reduced.

[0126] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is only an illustration of the exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged based on design preferences. In addition, some blocks can be combined or omitted. The attached method claims provide the elements of each block in a sample order, but are not limited to the specific order or hierarchy provided.

[0127] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not limited to the various aspects described herein, but should be given the full scope consistent with the language claims. Unless otherwise specified, reference to an element in the singular form does not mean "one and only one", but "one or more". Terms such as "if", "when ..." and "at ..." do not mean a direct temporal relationship or reaction. That is, these phrases, such as "when ...", do not mean an instant action in response to the occurrence of an action or during the occurrence of an action, but only mean that if the condition is met, the action will occur without a specific or instantaneous time constraint to make the action occur. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or having an advantage over other aspects. Unless otherwise specified, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination may contain one or more members of A, B, or C. A set should be interpreted as a set of elements, where the number of elements is one or more. Thus, for a set of X, X will include one or more elements. If the first device receives data from the second device or sends data to the second device, data may be directly received / sent between the first device and the second device, or indirectly received / sent between the first device and the second device through a collection of devices. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure that are known or will later be known to a person of ordinary skill in the art are expressly incorporated herein by reference and are covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. Words such as "module", "mechanism", "element", "device", etc. cannot replace the word "component". Therefore, no claim element will be understood as a component plus function unless the element is explicitly stated using the phrase "component for..."

[0128] As used herein, the phrase "based on" should not be interpreted as referring to a closed set of information, one or more conditions, one or more factors, etc. In other words, the phrase "based on A" (where "A" can be information, a condition, a factor, etc.) should be interpreted as "based at least on A" unless specifically stated differently.

[0129] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0130] Aspect 1 is a method of wireless communication at a user equipment (UE), the method comprising: performing one or more radio resource management (RRM) measurements on a low power reference signal (LP-RS) of at least one cell; and selecting a cell to camp on based on the one or more RRM measurements performed on the LP-RS.

[0131] Aspect 2 is a method according to aspect 1, wherein the LP-RS is configured to be received at a reduced power relative to receiving a synchronization signal block (SSB) of the at least one cell.

[0132] Aspect 3 is a method according to any one of aspects 1 to 2, wherein the one or more RRM measurements are performed on the LP-RS using a second receiver, the second receiver operating using lower power than the first receiver.

[0133] Aspect 4 is a method according to any one of Aspects 1 to 3, the method further comprising: receiving a synchronization signal block (SSB) associated with the serving cell before receiving the LP-RS associated with the serving cell; and obtaining information about the LP-RS based on the SSB or from residual system information (RMSI) associated with the SSB.

[0134] Aspect 5 is a method according to any one of Aspects 1 to 4, the method further comprising: determining the time and frequency position of a synchronization signal block (SSB) associated with the service cell based on a synchronization raster before receiving the LP-RS associated with the service cell; and determining the position of the LP-RS based on the time and frequency position of the SSB associated with the service cell.

[0135] Aspect 6 is a method according to aspect 5, wherein the LP-RS is transmitted with a first periodicity and the SSB is transmitted with a second periodicity.

[0136] Aspect 7 is a method according to any one of aspects 1 to 6, wherein the UE is in a radio resource control (RRC) idle or inactive state.

[0137] Aspect 8 is a method according to any one of aspects 1 to 7, wherein the LP-RS is identified by a physical cell identity (PCI) of a serving cell.

[0138] Aspect 9 is a method according to aspect 8, wherein the LP-RS includes a payload carrying the PCI.

[0139] Aspect 10 is a method according to any one of aspects 1 to 9, wherein the LP-RS includes a payload, the payload including at least one of the following: a cell barring indication, an intra-frequency reselection indication, or a system information change notification.

[0140] Aspect 11 is a method according to any one of aspects 1 to 10, wherein the LP-RS includes an on-off keying (OOK) modulation scheme or an orthogonal frequency division multiple access (OFDMA) modulation scheme.

[0141] Aspect 12 is a method according to any one of aspects 1 to 11, wherein the one or more RRM measurements include layer 3 reference signal received power (L3-RSRP) measurements.

[0142] Aspect 13 is a method according to any one of aspects 1 to 12, the method further comprising: performing a first measurement on a synchronization signal block (SSB) associated with the serving cell before receiving the LP-RS associated with the serving cell.

[0143] Aspect 14 is a method according to any one of Aspects 1 to 13, the method further comprising: performing cell reselection based on the one or more RRM measurements performed on the LP-RS of the cell and the second one or more RRM measurements performed on the second LP-RS of at least one neighboring cell.

[0144] Aspect 15 is a method according to any one of Aspects 1 to 14, the method further comprising: deriving the time and frequency position of the LP-RS associated with at least one neighboring cell indicated in the system information, wherein performing the one or more RRM measurements comprises: performing a second one or more RRM measurements on the LP-RS of the at least one neighboring cell.

[0145] Aspect 16 is a method according to any one of Aspects 1 to 15, the method further comprising: deriving an estimated reference signal received power (RSRP) of a corresponding synchronization signal block (SSB) based on an offset and the one or more RRM measurements performed on the LP-RS; and selecting the cell based on a threshold and the estimated RSRP of the corresponding SSB.

[0146] Aspect 17 is a method according to aspect 16, the method further comprising estimating the offset based on a difference between the one or more RRM measurements performed on the LP-RS and a corresponding RRM measurement performed on the corresponding SSB.

[0147] Aspect 18 is the method according to aspect 16, the method further comprising: receiving the offset from a network entity.

[0148] Aspect 19 is a method according to any one of aspects 1 to 18, the method further comprising: receiving an LP-RS cell selection parameter from a network entity, the LP-RS cell selection parameter being different from the SSB cell selection parameter, wherein selecting the cell is also based on the LP-RS cell selection parameter.

[0149] Aspect 20 is a method according to any one of aspects 1 to 19, the method further comprising: before performing the one or more measurements on the LP-RS of the at least one cell, selecting the LP-RS based on at least one condition.

[0150] Aspect 21 is a method according to aspect 20, wherein the LP-RS is selected from the group consisting of the LP-RS and a synchronization signal block (SSB).

[0151] Aspect 22 is an apparatus for wireless communication at a user equipment (UE), the apparatus comprising a memory and at least one processor, the at least one processor being coupled to the memory and configured to perform the method according to any one of aspects 1 to 21.

[0152] Aspect 23 is an apparatus for wireless communication, the apparatus comprising means for performing the method according to any one of aspects 1 to 21.

[0153] Aspect 24 is an apparatus according to aspect 22 or 23, wherein the apparatus also includes a first receiver and a second receiver, wherein the second receiver operates using lower power than the first receiver, and wherein the second receiver is configured to perform the one or more RRM measurements on the LP-RS.

[0154] Aspect 25 is a non-transitory computer-readable medium comprising instructions which, when executed by a device, cause the device to perform the method according to any one of aspects 1 to 21.

[0155] Aspect 26 is a method for wireless communication at a network node, the method comprising: sending a synchronization signal block (SSB) of a cell; and sending a low power reference signal (LP-RS) associated with the cell, the LP-RS being configured to be received at a lower power than the SSB.

[0156] Aspect 27 is a method according to aspect 26, wherein the LP-RS is broadcast with a first periodicity and the SSB is broadcast with a second periodicity.

[0157] Aspect 28 is a method according to any one of aspects 26 to 27, wherein the LP-RS is identified by a physical cell identity (PCI) of the cell.

[0158] Aspect 29 is a method according to any one of aspects 26 to 28, wherein the LP-RS comprises an on-off keying (OOK) modulation scheme or an orthogonal frequency division multiple access (OFDMA) modulation scheme.

[0159] Aspect 30 is a method according to any one of aspects 26 to 29, wherein the LP-RS is transmitted for layer 3 reference signal received power (L3-RSRP) measurement associated with the cell.

[0160] Aspect 31 is a method according to any one of aspects 26 to 30, the method further comprising: sending remaining minimum system information (RMSI) associated with the SSB and indicating the position of the LP-RS in at least one of time or frequency.

[0161] Aspect 32 is a method according to any one of aspects 26 to 31, the method further comprising: indicating a cell selection parameter based on the LP-RS, the cell selection parameter being different from an SSB cell selection parameter.

[0162] Aspect 33 is an apparatus for wireless communication at a network node, the apparatus comprising a memory and at least one processor, the at least one processor being coupled to the memory and configured to perform the method according to any one of aspects 26 to 32.

[0163] Aspect 34 is an apparatus for wireless communication, the apparatus comprising means for performing a method according to any one of aspects 26 to 32.

[0164] Aspect 35 is a non-transitory computer-readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform the method according to any one of aspects 26 to 32.

[0165] Aspect 36 is an apparatus according to aspect 33 or 34, the apparatus further comprising at least one transceiver configured to transmit the SSB and transmit the LP-RS.

Claims

1. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: Memory; and at least one processor coupled to the memory and based at least in part on the stored information stored in the memory, the at least one processor is configured to: performing one or more radio resource management (RRM) measurements on a low power reference signal (LP-RS) of at least one cell; and A cell to camp on is selected based on the one or more RRM measurements performed on the LP-RS.

2. The apparatus of claim 1, wherein the LP-RS is configured to be received at a reduced power relative to receiving a synchronization signal block (SSB) of the at least one cell.

3. The device according to claim 1, further comprising: a first receiver; and a second receiver, wherein the second receiver operates using lower power than the first receiver, and wherein the one or more RRM measurements are performed on the LP-RS using the second receiver.

4. The apparatus of claim 1 , wherein the at least one processor is further configured to: Prior to receiving the LP-RS associated with a serving cell: receiving a synchronization signal block (SSB) associated with the serving cell; and Information about the LP-RS is acquired based on the SSB or from residual system information (RMSI) associated with the SSB.

5. The apparatus of claim 1 , wherein the at least one processor is further configured to: Prior to receiving the LP-RS associated with a serving cell: determining a time and frequency position of a synchronization signal block (SSB) associated with the serving cell based on a synchronization raster; and The location of the LP-RS is determined based on the time and frequency location of the SSB associated with the serving cell.

6. The apparatus of claim 5, wherein the LP-RS is transmitted with a first periodicity and the SSB is transmitted with a second periodicity.

7. The apparatus of claim 1, wherein the UE is in a radio resource control (RRC) idle or inactive state.

8. The apparatus of claim 1, wherein the LP-RS is identified by a physical cell identity (PCI) of a serving cell.

9. The apparatus of claim 8, wherein the LP-RS includes a payload carrying the PCI.

10. The apparatus of claim 1, wherein the LP-RS comprises a payload, the payload comprising at least one of: The community prohibits instructions, Intra-frequency reselection indication, or Notification of system information changes.

11. The apparatus of claim 1, wherein the LP-RS comprises an on-off keying (OOK) modulation scheme or an orthogonal frequency division multiple access (OFDMA) modulation scheme.

12. The apparatus of claim 1, wherein the one or more RRM measurements comprise a Layer 3 Reference Signal Received Power (L3-RSRP) measurement.

13. The apparatus of claim 1, wherein the at least one processor is further configured to: Prior to receiving the LP-RS associated with a serving cell, a first measurement is performed on a synchronization signal block (SSB) associated with the serving cell.

14. The apparatus of claim 1, wherein the at least one processor is further configured to: Cell reselection is performed based on the one or more RRM measurements performed on the LP-RS of the cell and second one or more RRM measurements performed on a second LP-RS of at least one neighboring cell.

15. The apparatus of claim 1, wherein the at least one processor is further configured to: and deriving a time and frequency position of an LP-RS associated with at least one neighboring cell indicated in system information, wherein performing the one or more RRM measurements comprises: A second one or more RRM measurements are performed on the LP-RS of the at least one neighboring cell.

16. The apparatus of claim 1, wherein the at least one processor is further configured to: deriving an estimated reference signal received power (RSRP) of a corresponding synchronization signal block (SSB) based on an offset and the one or more RRM measurements performed on the LP-RS; and The cell is selected based on a threshold and the estimated RSRP of the corresponding SSB.

17. The apparatus of claim 16, wherein the at least one processor is further configured to: The offset is estimated based on a difference between the one or more RRM measurements performed on the LP-RS and a corresponding RRM measurement performed on the corresponding SSB.

18. The apparatus of claim 16, wherein the at least one processor is further configured to: The offset is received from a network entity.

19. The apparatus of claim 1, wherein the at least one processor is further configured to: An LP-RS cell selection parameter is received from a network entity, the LP-RS cell selection parameter being different from the SSB cell selection parameter, wherein selecting the cell is further based on the LP-RS cell selection parameter.

20. The apparatus of claim 1, wherein the at least one processor is further configured to: Prior to performing the one or more measurements on the LP-RS of the at least one cell, the LP-RS is selected based on at least one condition.

21. The apparatus of claim 20, wherein the LP-RS is selected from the group consisting of the LP-RS and a synchronization signal block (SSB).

22. A method of wireless communication at a user equipment (UE), the method comprising: performing one or more radio resource management (RRM) measurements on a low power reference signal (LP-RS) of at least one cell; as well as A cell to camp on is selected based on the one or more RRM measurements performed on the LP-RS.

23. An apparatus for wireless communication at a network node, the apparatus comprising: Memory; and at least one processor coupled to the memory and based at least in part on the information stored in the memory, the at least one processor configured to: Transmitting the cell's synchronization signal block (SSB); and A low power reference signal (LP-RS) associated with the cell is transmitted, the LP-RS being configured to be received at a lower power than the SSB.

24. The apparatus of claim 23, wherein the LP-RS is broadcast with a first periodicity and the SSB is broadcast with a second periodicity.

25. The apparatus of claim 23, wherein the LP-RS is identified by a physical cell identity (PCI) of the cell.

26. The apparatus of claim 23, wherein the LP-RS comprises an on-off keying (OOK) modulation scheme or an orthogonal frequency division multiple access (OFDMA) modulation scheme.

27. The apparatus of claim 23, wherein the LP-RS is transmitted for a layer 3 reference signal received power (L3-RSRP) measurement associated with the cell.

28. The apparatus of claim 23, wherein the at least one processor is further configured to: Remaining minimum system information (RMSI) associated with the SSB and indicating a location of the LP-RS in at least one of time or frequency is transmitted.

29. The apparatus of claim 23, wherein the at least one processor is further configured to: A cell selection parameter is indicated based on the LP-RS, the cell selection parameter being different from an SSB cell selection parameter.

30. A method for wireless communication at a network node, the method comprising: Sending cell synchronization signal block (SSB); as well as A low power reference signal (LP-RS) associated with the cell is transmitted, the LP-RS being configured to be received at a lower power than the SSB.

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