Reference Signal (RS) Configuration for Mobility and Transmission from Serving and Neighbor Cells

Abstract

To provide methods and apparatus for mobility measurement procedures according to new radio (NR) technologies.SOLUTION: A method for wireless communications by user equipment comprises: receiving signaling of an indication of whether neighbor cells are synchronous or asynchronous with a serving cell of the UE; based on the indication, for the neighbor cells that are synchronous with the serving cell differently than in the neighbor cells that are asynchronous with the serving cell, deriving one or more indices of synchronous signal blocks (SSBs) transmitted by the neighbor cells; receiving signaling of one or more reference signal (RS) configurations; and monitoring one or more CSI-RSs or SSBs from the neighbor cells based on the one or more RS configurations.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] Cross-reference and priority claim to related applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 521,092, filed June 16, 2017, and U.S. Patent Application No. 16 / 005,739, filed June 12, 2018, both of which are incorporated herein by reference in their entireties.

[0002] The present disclosure relates generally to communication systems, and more particularly to a method and apparatus for mobility measurement procedures with New Radio (NR) technologies. [Background technology]

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include Long Term Evolution (LTE) systems, 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.

[0004] In some examples, a wireless multiple-access communication system may include several base stations, each simultaneously supporting communication for multiple communication devices, also known as user equipment (UE). In an LTE or LTE-A network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next-generation or 5G network), a wireless multiple-access communication system may include several distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit receive points (TRPs), etc.) that communicate with several aggregation units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), and the set of one or more distributed units that communicate with the aggregation units may define an access node (e.g., new radio base station (NR BS), new radio node-B (NR NB), network node, 5G NB, eNB, next-generation node-B (gNB), etc.). A base station or a DU may communicate with a set of UEs over a downlink channel (e.g., for transmission from the base station or to the UEs) and an uplink channel (e.g., for transmission from the UEs to the base station or distributed unit).

[0005] These multiple access technologies are being adopted in various telecommunications standards to provide common protocols that enable different wireless devices to communicate on a city, national, regional, or even global scale. One example of an emerging telecommunications standard is New Radio (NR), e.g., 5G radio access. NR is a set of extensions to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP®). It is designed to improve spectral efficiency, reduce costs, improve services, utilize new spectrum, and better support mobile broadband Internet access by better integrating with other open standards that use OFDMA with cyclic prefixes (CPs) on the downlink (DL) and uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. Summary of the Invention [Problem to be solved by the invention]

[0006] However, as demand for mobile broadband access continues to grow, further improvements in NR technology are desirable. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunications standards that use these technologies. [Means for solving the problem]

[0007] The systems, methods, and devices of the present disclosure each have several aspects, no single aspect of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the following claims, some features will now be briefly described. After considering this description, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide advantages, including improved communications between access points and stations in a wireless network.

[0008] Some aspects provide a method for wireless communication by a base station. The method generally includes determining whether a neighbor cell is synchronized or asynchronous with a serving cell based on a reported symbol timing difference between the serving cell and one or more neighbor cells, providing an indication of which neighbor cells are synchronized or asynchronous with the serving cell to one or more user equipments (UEs), using the symbol timing difference to determine a configuration for at least one of synchronization signal (SS) transmissions or channel state information reference signal (CSI-RS) transmissions in the neighbor cell such that CSI-RS or SS from the neighbor cell is transmitted within one measurement window, and providing the indication of the configuration to the one or more UEs.

[0009] Certain aspects provide a method for wireless communication by a user equipment (UE), the method generally including: receiving an indication of which neighbor cells are synchronized or asynchronous with a serving cell of the UE; and, based on the indication, performing channel state information reference signal (CSI-RS) measurements in cells synchronized with the serving cell differently than in cells asynchronous with the serving cell.

[0010] Aspects generally include methods, apparatus, systems, computer-readable media, and processing systems as fully described herein with reference to and illustrated by the accompanying drawings.

[0011] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of the various aspects may be employed, and the description is intended to include all such aspects and their equivalents.

[0012] So that the above-described features of the present disclosure may be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present description may lead to other equally effective embodiments, and that the accompanying drawings illustrate only some typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram conceptually illustrating an example telecommunications system in which aspects of the present disclosure may be implemented. [Figure 2] FIG. 1 is a block diagram illustrating an example logical architecture of a distributed RAN, in accordance with certain aspects of the present disclosure. [Figure 3] FIG. 1 illustrates an example physical architecture of a distributed RAN, in accordance with certain aspects of the present disclosure. [Figure 4] FIG. 1 is a block diagram conceptually illustrating an example BS and user equipment (UE) design in accordance with certain aspects of the present disclosure. [Figure 5] FIG. 1 illustrates an example for implementing a communication protocol stack in accordance with certain aspects of the present disclosure. [Figure 6] FIG. 1 illustrates an example of a frame format for a New Radio (NR) system in accordance with some aspects of the present disclosure. [Figure 7] FIG. 1 illustrates example operations for wireless communication by a base station according to aspects of the present disclosure. [Figure 8] FIG. 1 illustrates example operations for wireless communication by a user equipment (UE), according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] For ease of understanding, the same reference numbers have been used, where possible, to designate identical elements common to the figures. It is contemplated that elements disclosed in one embodiment may be advantageously utilized in other embodiments without specific recitation.

[0015] Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable media for New Radio (NR) (New Radio Access Technology or 5G Technology).

[0016] NR may support various wireless communication services, such as wide bandwidths (e.g., greater than 80 MHz) for enhanced mobile broadband (eMBB) targets, high carrier frequencies (e.g., 60 GHz) for millimeter wave (mmW) targets, non-backward compatible MTC techniques for massive MTC (mMTC) targets, and / or ultra reliable low latency communication (URLLC) for mission-critical targets. These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet their respective quality of service (QoS) requirements. In addition, these services may coexist in the same subframe.

[0017] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of the elements described without departing from the scope of the present disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects described herein. Additionally, the scope of the present disclosure is intended to encompass such apparatuses or methods practiced using other structure, functions, or structure and functions in addition to or other than the various aspects of the present disclosure described herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of a claim. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

[0018] The techniques described herein may be used for various wireless communication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network may implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). NR is an emerging wireless communications technology being developed with the 5G Technology Forum (5GTF). 3GPP® Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM® are described in documents by an organization named "3rd Generation Partnership Project" (3GPP®). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP®2). "LTE" generally refers to LTE and LTE-Advanced (LTE-A), LTE in unlicensed spectrum (LTE white space), etc. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies.For clarity, aspects may be described herein generally using terminology associated with 3G and / or 4G wireless technology, although aspects of the present disclosure may be applied in other generation-based communication systems, such as 5G and beyond, including NR technology.

[0019] Exemplary Wireless Communication System FIG. 1 illustrates an example wireless network 100, such as a New Radio (NR) or 5G network, in which aspects of the present disclosure may be implemented.

[0020] As shown in FIG. 1, the wireless network 100 may include several BSs 110 and other network entities. A BS may be a station that communicates with UEs. Each BS 110 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to the coverage area of ​​a Node B and / or a Node B subsystem serving that coverage area, depending on the context in which the term is used. In an NR system, terms such as “cell” and eNB, Node B, 5G NB, AP, NR BS, gNB, or TRP may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of ​​a cell may move according to the location of a mobile base station. In some examples, the base stations may be interconnected to each other and / or to one or more other base stations or network nodes (not shown) within the wireless network 100 through various types of backhaul interfaces, such as direct physical connections, virtual networks, etc., using any suitable transport network.

[0021] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may also be referred to as a carrier, frequency channel, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, an NR RAT network or a 5G RAT network may be deployed.

[0022] A BS may provide communication coverage for a macrocell, a picocell, a femtocell, and / or other types of cell. A macrocell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs with a service subscription. A picocell may cover a relatively small geographic area and may allow unrestricted access by UEs with a service subscription. A femtocell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs that have an association with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in the home, etc.). A BS for a macrocell may be referred to as a macroBS. A BS for a picocell may be referred to as a picoBS. A BS for a femtocell may be referred to as a femtoBS or a homeBS. In the example shown in FIG. 1, BSs 110a, 110b, and 110c may be macroBSs for macrocells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for a pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or multiple (e.g., three) cells.

[0023] Wireless network 100 may also include relay stations. A relay station is a station that receives data and / or other information transmissions from an upstream station (e.g., a BS or a UE) and sends data and / or other information transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. In the example shown in FIG. 1, relay station 110r may communicate with BS 110a and UE 120r to facilitate communication between BS 110a and UE 120r. A relay station may also be referred to as a relay BS, a relay, etc.

[0024] Wireless network 100 may be a heterogeneous network including different types of BSs, e.g., macro BSs, pico BSs, femto BSs, relays, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 20 watts), while a pico BS, femto BS, and relays may have a lower transmit power level (e.g., 1 watt).

[0025] Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, BSs may have different frame timing, and transmissions from different BSs may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operation.

[0026] Network controller 130 may couple to a set of BSs and provide coordination and control for these BSs. Network controller 130 may communicate with BSs 110 via a backhaul. BSs 110 may also communicate with each other, e.g., directly or indirectly via wireless or wired backhaul.

[0027] The UEs 120 (eg, 120x, 120y, etc.) may be dispersed throughout the wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, customer premises equipment (CPE), cellular phone, smartphone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet, camera, gaming device, netbook, smartbook, ultrabook, medical device or equipment, healthcare device, biometric sensor / device, wearable device such as smart watch, smart clothing, smart glasses, virtual reality goggles, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.), entertainment device (e.g., music device, video device, satellite radio, etc.), vehicle component or vehicle sensor, smart meter / sensor, robot, drone, industrial manufacturing equipment, positioning device (e.g., GPS, Beidou, terrestrial), or any other suitable device configured to communicate over a wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices, where an MTC device or eMTC device may include a remote device that may communicate with a base station, another remote device, or some other entity. Machine type communication (MTC) may refer to communication involving at least one remote device on at least one end of the communication and may include a form of data communication with one or more entities that does not necessarily require human interaction. MTC UEs may include UEs capable of MTC communication with an MTC server and / or other MTC devices over Public Land Mobile Networks (PLMNs), for example.MTC UEs and eMTC UEs may communicate with a BS, another device (e.g., a remote device), or some other entity, including, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a camera, a location tag, etc. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. MTC UEs as well as other UEs may be implemented as Internet of Things (IoT) devices, for example, narrowband IoT (NB-IoT) devices.

[0028] In Figure 1, a solid line with double arrows indicates a desired transmission between a UE and a serving BS, where the serving BS is a BS designated to serve the UE on the downlink and / or uplink. A dashed line with double arrows indicates an interfering transmission between a UE and a BS.

[0029] Certain wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Generally, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kHz, and the minimum resource allocation (called a "resource block") may be 12 subcarriers (or 180 kHz). As a result, the nominal FFT size may be equal to 128, 256, 512, 1024, or 2048 for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (e.g., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0030] Although example aspects described herein may be related to LTE technology, aspects of the present disclosure may be applicable to other wireless communication systems, such as NR. NR utilizes OFDM with CP on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD). A single component carrier bandwidth of 100 MHz may be supported. An NR resource block may span 12 subcarriers with a subcarrier bandwidth of 75 kHz for a duration of 0.1 ms. Each radio frame may consist of 50 subframes with a length (duration) of 10 ms. As a result, each subframe may have a length of 0.2 ms. In some cases, a subframe may have a length (duration) of 1 ms, and each subframe may be further divided into two slots of 0.5 ms each (e.g., each slot includes six or seven OFDM symbols depending on the cyclic prefix (CP) length). A slot may be further divided into minislots, each of which has a shorter duration (e.g., includes fewer symbols than a full slot). Each subframe may indicate a link direction (e.g., DL or UL) for data transmission, and the link direction for each subframe may be dynamically switched. Each subframe may include DL / UL data and DL / UL control data. Beamforming may be supported, and the beam direction may be dynamically configured. MIMO transmission with precoding may also be supported. MIMO configuration in the DL may support up to eight transmit antennas with multi-layer DL transmission with up to eight streams and up to two streams per UE. Multi-layer transmission with up to two streams per UE may be supported. Multiple cell aggregation with up to eight serving cells may be supported. Alternatively, NR may support different air interfaces other than OFDM-based. An NR network may include entities such as a CU and / or DU.

[0031] In some examples, access to the air interface may be scheduled, and a scheduling entity (e.g., a base station) allocates resources for communication among some or all devices and equipment within its coverage area or cell. Within this disclosure, as described further below, the scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entities utilize the resources allocated by the scheduling entity. A base station is not the only entity that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity that schedules resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE is functioning as the scheduling entity, and the other UEs utilize the resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In a mesh network example, UEs may communicate with the scheduling entity and, in some cases, directly with each other.

[0032] Thus, in wireless communication networks with scheduled access to time-frequency resources and having cellular, P2P, and mesh configurations, a scheduling entity and one or more subordinate entities may communicate utilizing the scheduled resources.

[0033] As described above, the RAN may include a CU and a DU. An NR BS (e.g., eNB, 5G Node B, Node B, Transmit Reception Point (TRP), Access Point (AP)) may correspond to one or more BSs. An NR cell may be configured as an access cell (ACell) or a data-only cell (DCell). For example, a RAN (e.g., an aggregation unit or a distributed unit) may configure a cell. A DCell may be a cell used for carrier aggregation or dual connectivity but not used for initial access, cell selection / reselection, or handover. In some cases, a DCell may not transmit a synchronization signal, and in some cases, a DCell may transmit an SS. An NR BS may transmit a downlink signal indicating a cell type to a UE. Based on the cell type indication, the UE may communicate with an NR BS. For example, the UE may determine an NR BS to consider for cell selection, access, handover, and / or measurements based on the indicated cell type.

[0034] 2 illustrates an example logical architecture of a distributed radio access network (RAN) 200 that may be implemented within the wireless communication system illustrated in FIG. 1. A 5G access node 206 may include an access node controller (ANC) 202. The ANC may be an aggregation unit (CU) of the distributed RAN 200. A backhaul interface to a next generation core network (NG-CN) 204 may terminate at the ANC. A backhaul interface to a neighboring next generation access node (NG-AN) may terminate at the ANC. The ANC may include one or more TRPs 208 (which may also be referred to as a BS, NR BS, Node B, 5G NB, AP, gNB, or some other terminology). As explained above, TRP may be used interchangeably with “cell.”

[0035] The TRP 208 may be a DU. A TRP may be connected to one ANC (ANC 202) or to two or more ANCs (not shown). For example, for RAN sharing, radio as a service (RaaS), and service-specific ANC deployments, a TRP may be connected to two or more ANCs. A TRP may include one or more antenna ports. TRPs may be configured to serve traffic to UEs individually (e.g., dynamic selection) or jointly (e.g., joint transmission).

[0036] The local architecture 200 may be used to illustrate fronthaul definitions. Architectures may be defined that support fronthaul solutions across different deployment types. For example, the architectures may be based on transmission network capabilities (e.g., bandwidth, latency, and / or jitter).

[0037] The architecture may share features and / or components with LTE. According to an aspect, the Next Generation AN (NG-AN) 210 may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.

[0038] The architecture may enable cooperation between TRPs 208. For example, cooperation may be preset within the TRPs and / or across the TRPs via the ANC 202. According to aspects, an inter-TRP interface may not be required / existent.

[0039] According to aspects, there may be dynamic configuration of partitioned logical functions within architecture 200. As described in more detail with reference to FIG. 5, a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer may be adaptively disposed in DUs or CUs (e.g., TRPs or ANCs, respectively). According to some aspects, a BS may include a aggregation unit (CU) (e.g., ANC 202) and / or one or more distributed units (e.g., one or more TRPs 208).

[0040] 3 illustrates an example physical architecture of a distributed RAN 300 in accordance with certain aspects of the present disclosure. A centralized core network unit (C-CU) 302 may host core network functions. The C-CU may be centrally located. The C-CU functions may be offloaded (e.g., to Advanced Wireless Services (AWS)) to address peak capacity.

[0041] A centralized RAN unit (C-RU) 304 may host one or more ANC functions. In some cases, the C-RU may host core network functions locally. The C-RU may have a distributed location. The C-RU may be closer to the network edge.

[0042] The DU 306 may host one or more TRPs (Edge Nodes (EN), Edge Units (EU), Radio Heads (RH), Smart Radio Heads (SRH), etc.). The DU may be located at the edge of the network with radio frequency (RF) capabilities.

[0043] 4 illustrates example components of the BS 110 and the UE 120 shown in FIG. 1 that may be used to implement aspects of the present disclosure. As described above, the BS may include a TRP. One or more components of the BS 110 and the UE 120 may be used to practice aspects of the present disclosure. For example, the antenna 452, processors 466, 458, 464, and / or controller / processor 480 (used to implement a transceiver or a chain function between individual receivers and transmitters) of the UE 120, and / or the antenna 434, processors 430, 420, 438, and / or controller / processor 440 of the BS 110 may be used to perform the operations described herein and illustrated with reference to FIGS. 10 and 11.

[0044] 4 shows a block diagram of a design of a BS 110 and a UE 120, which may be one of the BSs and one of the UEs in FIG. 1. For a limited connectivity scenario, the base station 110 may be the macro BS 110c, and the UE 120 may be a UE 120y in FIG. 1. The base station 110 may also be some other type of base station. The base station 110 may be equipped with antennas 434a through 434t, and the UE 120 may be equipped with antennas 452a through 452r.

[0045] At the base station 110, the transmit processor 420 may receive data from the data source 412 and control information from the controller / processor 440. The control information may be for a Physical Broadcast Channel (PBCH), a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid ARQ Indicator Channel (PHICH), a Physical Downlink Control Channel (PDCCH), etc. The data may be for a Physical Downlink Shared Channel (PDSCH), etc. The processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The processor 420 may also generate reference symbols, e.g., for the PSS, SSS, and cell-specific reference signals. The transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 432a through 432t. For example, TX MIMO processor 430 may perform some aspects described herein for RS multiplexing. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 432 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 432a through 432t may be transmitted via antennas 434a through 434t, respectively.

[0046] At the UE 120, the antennas 452a through 452r may receive downlink signals from the base station 110 and may provide received signals to the demodulators (DEMODs) 454a through 454r, respectively. Each demodulator 454 may condition (e.g., filter, amplify, downconvert, and digitize) its respective received signal to obtain input samples. Each demodulator 454 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 456 may obtain the received symbols from all the demodulators 454a through 454r, perform MIMO detection on the received symbols, if applicable, and provide the detected symbols. For example, the MIMO detector 456 may provide the detected RS transmitted using the techniques described herein. A receive processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols and provide decoded data for the UE 120 to a data sink 460 and decoded control information to the controller / processor 480. According to one or more examples, CoMP aspects can include providing antennas as well as some Tx / Rx functions so that they reside in distributed units. For example, some Tx / Rx processing can occur in a central unit, while other processing can occur in distributed units. For example, according to one or more aspects shown in the figure, the BS modulator / demodulator 432 can be in a distributed unit.

[0047] On the uplink, at the UE 120, a transmit processor 464 may receive and process data (e.g., for the Physical Uplink Shared Channel (PUSCH)) from a data source 462 and control information (e.g., for the Physical Uplink Control Channel (PUCCH)) from a controller / processor 480. The transmit processor 464 may also generate reference symbols for a reference signal. The symbols from the transmit processor 464 may be precoded by a TX MIMO processor 466 if applicable, further processed by demodulators 454a through 454r (e.g., for SC-FDM, etc.), and transmitted to the base station 110. At the BS 110, uplink signals from the UE 120 may be received by the antennas 434, processed by a modulator 432, detected by a MIMO detector 436 if applicable, and further processed by a receive processor 438 to obtain decoded data and control information sent by the UE 120. The receive processor 438 may provide the decoded data to a data sink 439 and the decoded control information to a controller / processor 440 .

[0048] The controllers / processors 440 and 480 may direct operation at the base station 110 and the UE 120, respectively. The processor 440 and / or other processors and modules at the base station 110 may perform or direct processes for the techniques described herein. The processor 480 and / or other processors and modules at the UE 120 may also perform or direct processes for the techniques described herein. The memories 442 and 482 may store data and program codes for the BS 110 and the UE 120, respectively. The scheduler 444 may schedule UEs for data transmission on the downlink and / or uplink.

[0049] FIG. 5 illustrates a diagram 500 illustrating an example for implementing a communications protocol stack according to aspects of the present disclosure. The illustrated communications protocol stack may be implemented by a device operating within a 5G system (e.g., a system supporting uplink-based mobility). Diagram 500 illustrates a communications protocol stack including a Radio Resource Control (RRC) layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a Radio Link Control (RLC) layer 520, a Medium Access Control (MAC) layer 525, and a Physical (PHY) layer 530. In various examples, the layers of the protocol stack may be implemented as separate modules of software, portions of a processor or ASIC, portions of non-colocated devices connected by a communications link, or various combinations thereof. Co-located and non-co-located implementations may be used, for example, in a protocol stack for a network access device (e.g., an AN, a CU, and / or a DU) or a UE.

[0050] The first option 505-a illustrates a split implementation of the protocol stack in which the implementation of the protocol stack is split between a centralized network access device (e.g., the ANC 202 in FIG. 2 ) and a distributed network access device (e.g., the DU 208 in FIG. 2 ). In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by an aggregation unit, and the RLC layer 520, the MAC layer 525, and the PHY layer 530 may be implemented by the DU. In various examples, the CU and DU may or may not be co-located. The first option 505-a may be useful in a macrocell deployment, a microcell deployment, or a picocell deployment.

[0051] The second option 505-b illustrates an integrated implementation of the protocol stack in which the protocol stack is implemented within a single network access device (e.g., an Access Node (AN), a New Radio Base Station (NB BS), a New Radio Node B (NR NB), a Network Node (NN), etc.). In the second option, the RRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525, and the PHY layer 530 may each be implemented by the AN. The second option 505-b may be useful in femtocell deployments.

[0052] Regardless of whether the network access device implements some or all of the protocol stack, the UE may implement the entire protocol stack (e.g., RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530).

[0053] FIG. 6 illustrates an example of a frame format 600 for NR. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each 1 ms long and indexed from 0 to 9. Each subframe may include a variable number of slots depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the subcarrier spacing. The symbol periods within each slot may be assigned an index. A minislot, sometimes referred to as a subslot structure, refers to a transmission time interval having a duration shorter than one slot (e.g., 2, 3, or 4 symbols).

[0054] Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction per subframe may be dynamically switched. The link direction may be based on the slot format. Each slot may contain DL / UL data as well as DL / UL control information.

[0055] In NR, a synchronization signal (SS) block is transmitted. The SS block includes a PSS, SSS, and a two-symbol PBCH. The SS block may be transmitted within a fixed slot location, such as symbols 0 through 3, as shown in Figure 6. The PSS and SSS may be used by the UE for cell search and cell acquisition. The PSS may provide half-frame timing, and the SS may provide CP length and frame timing. The PSS and SSS may provide cell identity information. The PBCH carries some basic system information, such as the downlink system bandwidth, timing information within the radio frame, SS burst set period, and system frame number. The SS block may be configured within the SS burst to support beam sweeping. Further system information, such as remaining minimum system information (RMSI), system information block (SIB), and other system information (OSI), may be transmitted on the physical downlink shared channel (PDSCH) within some subframes.

[0056] A UE may operate in various radio resource configurations, including a configuration associated with transmitting pilots using a dedicated set of resources (e.g., a Radio Resource Control (RRC) dedicated state, etc.) or a configuration associated with transmitting pilots using a common set of resources (e.g., an RRC common state, etc.). When operating in an RRC dedicated state, the UE may select a dedicated set of resources to transmit pilot signals to the network. When operating in an RRC common state, the UE may select a common set of resources to transmit pilot signals to the network. In either case, the pilot signals transmitted by the UE may be received by one or more network access devices, such as an AN or DU, or portions thereof. Each receiving network access device may be configured to receive and measure pilot signals transmitted on the common set of resources as well as receive and measure pilot signals transmitted on dedicated sets of resources allocated to UEs for which the network access device is a member of a monitoring set of network access devices for the UE. One or more of the receiving network access devices, or a CU to which the receiving network access device transmits pilot signal measurements, may use the measurements to identify a serving cell for the UE or to initiate a serving cell change for one or more of the UEs.

[0057] RS Configuration for Exemplary Mobility and Transmissions from Serving and Neighbor Cells In accordance with one or more aspects of the embodiments disclosed herein, techniques are provided for assisting mobility measurement procedures based on reference signals (RS).

[0058] In some cases, such assistance may be provided in the form of a network entity (such as a base station of the serving cell), which may inform the UE which neighbor cells are synchronized with the serving cell (and may provide separate CSI-RS configurations for synchronized and asynchronous cells). Furthermore, RS from synchronized cells may be transmitted aligned during one measurement window, while asynchronous transmissions may be sent via a different measurement window. UE RS measurement processing in different windows may be different. Thus, providing configuration information to the UE may result in more efficient processing (and reduced power consumption) at the UE. For example, the UE does not need to decode the PBCH (to determine the CSI-RS configuration), at least for synchronized cells. For asynchronous cells, the network may provide configuration so that the UE can avoid decoding the PBCH.

[0059] Various RSs may be used for various purposes, such as making mobility decisions (e.g., when switching from one cell to another). For example, for cell-level mobility in RRC CONNECTED mode, the CSI-RS may be used in addition to the IDLE mode RS (e.g., New Radio Synchronization Signal or NR-SS, which is used to enable some mobility when in IDLE mode). Neighbor cell detection for measurements is based on the NR-SS (e.g., with the PSS and SSS used for timing and to detect cell IDs).

[0060] For RRC CONNECTED mode mobility with NR-SS, the UE typically needs to know the NR-SS configuration for measuring NR-SS transmissions from the serving cell and neighbor cells. The NR-SS configuration typically includes at least a timing configuration, including time offsets and periods, and configurable time / frequency / port resources.

[0061] For RRC CONNECTED mode mobility with CSI-RS, the UE requires a CSI-RS configuration to measure CSI-RS transmissions from the serving cell and neighbor cells. The CSI-RS configuration typically includes at least the NR cell ID, timing configuration including time offset and periodicity, number of antenna ports, configurable time / frequency resources to indicate RE mapping, configurable transmission / measurement bandwidth, parameters for sequence generation, configurable numerology, and spatial quasi-co-location (QCL) assumptions (e.g., QCL between SS blocks and CSI-RS). As used herein, signals may be considered quasi-co-located if they are expected to experience similar channel conditions.

[0062] RS transmission (e.g., NR-SS / CSI-RS transmission) for Layer 3 (L3) mobility may aim to ensure that UE throughput and battery life are not adversely affected during measurements. To illustrate this, two options may be considered, in which CSI-RS transmission from a serving cell and a neighbor cell on a carrier frequency occurs in non-cooperative or cooperative transmission of CSI-RS: In the case of non-cooperative transmission, the serving cell and the neighbor cell transmit CSI-RS within different time periods (e.g., slots or minislots, which refer to intervals that are a fraction of a subframe). In the case of cooperative transmission, the serving cell and the neighbor cell transmit CSI-RS cooperatively to minimize UE wake-up for measurements (by allowing the UE to measure CSI-RS from both the serving cell and the neighbor cell within one measurement window during a single awake period).

[0063] If CSI-RS transmissions from the serving cell and neighbor cells are not coordinated between gNBs, the UE may require multiple measurement windows to measure the RS from both the serving cell and the neighbor cell. The problem is exacerbated as the number of measurement windows increases with the number of neighbors. This may have a negative impact on user rates due to scheduling limitations, and may also affect the UE's battery life as it must wake up multiple times to measure the serving and neighbor cells.

[0064] On the other hand, if CSI-RS transmissions from the serving cell and neighbor cell occur in a coordinated manner, the UE may measure the CSI-RS from the serving cell and neighbor cell within one measurement window. Therefore, the coordinated approach may limit the impact on the UE's throughput. Furthermore, the battery life of the UE may be improved due to fewer wake-ups for measuring the serving cell and neighbor cell.

[0065] Aspects of the present disclosure may assist in further improving cooperative CSI-RS transmission by providing information regarding whether neighbor cells are synchronized or asynchronous with the serving cell (e.g., an indication of which neighbor cells are synchronized and / or not). As described in more detail below, this information may be used to assist in cooperative CSI-RS transmission and, in some cases, may enable a UE to adjust CSI-RS measurements based on the information (e.g., avoiding the need to measure NR-SS and / or decode the PBCH in a synchronized cell before measuring CSI-RS).

[0066] The techniques provided herein may be applied to intra-frequency measurements as well as inter-frequency measurements (eg, with switching between frequencies performed during measurement gaps).

[0067] Returning now to the drawings, FIG. 7 illustrates operations 700 for wireless communication by a network entity (e.g., a source base station / gNB of a serving cell) according to aspects of the present disclosure that may be implemented to address one or more of the situations and / or features described above.

[0068] The operations 700 begin by determining, at 702, whether a neighbor cell is synchronized or asynchronous with a serving cell. In some cases, this determination may be made based on a symbol timing difference between the serving cell and one or more neighbor cells (e.g., as reported by one or more UEs).

[0069] At 704, the network entity provides an indication to one or more user equipments (UEs) of whether the neighbor cells are synchronized or asynchronous with the serving cell (and possibly which neighbor cells are synchronized or asynchronous with the serving cell). Indicating which neighbor cells are synchronized or asynchronous with the serving cell may enable the UE to determine whether it can derive neighbor cell RS timing (e.g., SS block index) based on the serving cell timing.

[0070] At 706, the network entity determines a configuration (e.g., based on a symbol timing difference) for at least one of synchronization signal (SS) transmissions or channel state information reference signal (CSI-RS) transmissions in the neighbor cell such that CSI-RS or SS from the neighbor cell are transmitted within one measurement window. At 708, the network entity provides an indication of the configuration to one or more UEs.

[0071] 8 illustrates operations 800 for wireless communication by a user equipment (UE) according to an aspect of the present disclosure. For example, the UE may utilize information provided by the network according to operations 800 of FIG. 8 described above.

[0072] The operations 800 begin by receiving an indication of whether neighbor cells are synchronized or asynchronous with the UE's serving cell (and possibly which neighbor cells are synchronized or asynchronous with the UE's serving cell) at 802. Based on the indication, the UE performs channel state information reference signal (CSI-RS) measurements in cells that are synchronized with the serving cell differently than in cells that are asynchronous with the serving cell at 804.

[0073] On the network side, the network can determine whether a neighbor cell is synchronized or asynchronous and send an indication to the UE. As mentioned above, in some cases, the determination may be based on measurement reports received from the UE. For example, the network may configure one or more UEs to measure and report timing differences (e.g., symbol timing differences) between the serving cell and one or more neighbor cells.

[0074] Thus, the network may obtain (derive) the symbol timing difference from one or more UEs, and after obtaining the symbol timing difference, derive an estimate of the symbol timing difference between the cell and its neighbors. The network may then provide a list of synchronized CELL-IDs to the cells, for example, via broadcast (SI) or via a dedicated message to the UE. The network may also provide a list of unsynchronized CELL-IDs to the cells, also via broadcast (SI) or via a dedicated message to the UE.

[0075] In some cases, the network may use the symbol timing difference between the serving cell and neighbor cells for NR-SS, CSI-RS configuration, and transmission coordination. To coordinate with neighbor cells, the network may provide the CSI-RS configuration of one or more neighbor cells.

[0076] In some cases, the network may provide separate (different) configurations for SYNC cells (cells synchronized with the serving cell) and ASYNC cells (cells not synchronized with the serving cell). In some cases, a subset of parameters may be different for SYNC cells and ASYNC cells (and only that subset needs to be signaled). For example, timing parameters such as slot offset or periodicity may be different for SYNC cells and ASYNC cells. For example, (a) the slot offset or periodicity may be the same for all SYNC cells and (b) may be different for ASYNC cells.

[0077] Further to this example, among SYNC cells, the symbol / slot offset of one or more cells may be provided such that RS from one or more cells arrive (1) in the same slot / minislot or (2) one after another (back to back), while among ASYNC cells, the symbol / slot offset of one or more cells may be provided such that RS from one or more cells arrive (1) in approximately the same slot / minislot or (2) one after another (back to back).

[0078] The network may provide / adjust the CSI-RS configuration such that the CSI-RS of the (serving and neighbor) cells arrive within a single measurement time window (symbol / slot / minislot). In some cases, the slot offset for CSI-RS transmission may be a function of CELL-ID, NR-PSS, or NR-SSS. To coordinate CSI-RS transmission from neighbor cells, the network may notify the neighbor cells to transmit CSI-RS (at a coordinated time determined based on the serving or neighbor cell timing).

[0079] In this way, the network may coordinate RS (e.g., NR-SS or CSI-RS) transmissions from one or more cells so that RSs from different cells arrive within one measurement window. For example, RS transmissions may be coordinated to arrive (1) in the same slot / minislot or (2) one after the other (back to back).

[0080] As described above, from the UE's perspective, the UE may receive information about which neighbor cells are synchronized (SYNC) or not synchronized (ASYNC) with the serving cell and perform CSI measurements accordingly. In other words, the UE may perform CSI measurements for SYNC cells differently from those for ASYNC cells. As an example, the UE may perform CSI-RS measurements in SYNC cells without needing to monitor NR-SS (e.g., obtain cell timing). In other words, the UE may derive neighbor cell RS timing (e.g., SS block index) for a SYNC cell based on the serving cell timing. On the other hand, for an ASYNC cell, the UE may need to first detect NR-SS (e.g., obtain cell timing and CSI-RS configuration) and, in some cases, decode the PBCH after detecting NR-SS before performing CSI-RS measurements. By only having to detect NR-SS when necessary, the UE can reduce power (e.g., simultaneously stay in a low power state longer).

[0081] Using the techniques presented herein, for intra-frequency measurements, the UE may use the serving cell timing to derive the SSB index of a neighbor cell in the same frequency layer. For inter-frequency measurements, the UE may use the timing of any detected cell in the target frequency layer to derive the SSB index of a neighbor cell of the target frequency layer. Cells in different frequency layers are not considered to be aligned half-radio frames.

[0082] In some cases, the UE may determine whether to use a directional antenna configuration or an omnidirectional antenna configuration to receive (monitor) CSI-RS based on CSI-RS configuration information. For example, after waking up and operating, the UE may monitor CSI-RS using an omnidirectional setting if CSI-RS from multiple cells are configured to arrive simultaneously (or within a narrow timing window). On the other hand, if the CSI-RS arrives one after the other (e.g., in subsequent symbols, slots, or minislots), the UE may monitor CSI-RS using either the omnidirectional setting or the directional setting.

[0083] As described herein, with respect to assistance information (e.g., in the form of an indication of which neighbor cells are synchronized or asynchronous with the serving cell), a UE can optimize its RS measurement processing. For example, a UE can wake up and make measurements of RSs in different cells within a single measurement window to determine whether to decode a PBCH, which may result in enhanced mobility decisions and reduced power consumption.

[0084] The methods disclosed herein include one or more steps or actions for achieving the described method. Method steps and / or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0085] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to include a, b, c, ab, ac, bc, and abc, as well as any combination having multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other order of a, b, and c). As used herein, including within the claims, the term "and / or," when used in a list of two or more items, means that any one of the listed items can be taken alone, or any combination of two or more of the listed items can be taken. For example, if a composition is described as containing components A, B, and / or C, the composition can include only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0086] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, etc. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Also, "determining" may include resolving, selecting, electing, establishing, etc.

[0087] The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications of these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments. Accordingly, the claims are not limited to the embodiments set forth herein but are to be accorded all scope consistent with the claim language, and references to elements in the singular shall mean "one or more" rather than "one and only one" unless expressly stated otherwise. For example, the articles "a" and "an" as used in this application and the appended claims shall be generally construed to mean "one or more" unless otherwise specified or unless it is clear from the context that a singular form is intended. Unless otherwise specified, the term "some" refers to one or more. Furthermore, the term "or" shall mean an inclusive "or" rather than an exclusive "or." That is, for example, unless otherwise specified or clear from the context, a phrase such as "X employs A or B" shall mean any of the natural inclusive permutations. That is, for example, the phrase "X employs A or B" is satisfied by any of the following examples: X employs A, X employs B, or X employs both A and B. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known, or that later become known, to those of skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is made public, regardless of whether such disclosure is expressly recited in the claims. Claim elements are not to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase "means for," or, in the case of a method claim, unless the element is recited using the phrase "step for."

[0088] The various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and / or software components and / or modules, including, but not limited to, circuits, application specific integrated circuits (ASICs), or processors. For example, operations 700 and 800 in Figures 7 and 8 may be performed by various processors shown in Figure 4. In general, where there are operations shown in figures, those operations may have means-plus-functions of corresponding counterparts.

[0089] The various example logic blocks, modules, and circuits described in connection with this disclosure may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0090] When implemented in hardware, an exemplary hardware configuration may include a processing system within a wireless node. The processing system may be implemented using a bus architecture. The bus may include any number of interconnected buses and bridges, depending on the particular application and overall design constraints of the processing system. The bus may link various circuits together, including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter to the processing system via the bus, among other things. The network adapter may be used to implement PHY layer signal processing functions. In the case of a user terminal 120 (see FIG. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may be connected to the bus. The bus may link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well-known in the art and therefore will not be described further. The processor may be implemented using one or more general-purpose and / or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how to best implement the above functionality for a processing system depending on the particular application and the overall design constraints imposed on the overall system.

[0091] If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. A processor may be responsible for managing buses and general processing, including the execution of software modules stored on the machine-readable storage medium. A computer-readable storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. By way of example, machine-readable media may include a transmission line, a carrier wave modulated by data, and / or a computer-readable storage medium on which instructions are stored separate from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or additionally, the machine-readable medium, or any portion thereof, may be integrated into the processor, such as a cache and / or general-purpose register file. Examples of machine-readable storage media may be, by way of example, RAM (random access memory), flash memory, phase-change memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

[0092] A software module may include a single instruction or many instructions and may be distributed across several different code segments, among different programs, and across multiple storage media. A computer-readable medium may include several software modules. The software modules include instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. The software modules may include a transmitting module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. As an example, a software module may be loaded into RAM from a hard drive when a trigger event occurs. During execution of a software module, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general-purpose register file for execution by the processor. When referring below to the functionality of a software module, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.

[0093] Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of medium. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy discs, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Thus, in some aspects computer-readable medium may include non-transitory computer-readable medium (e.g., tangible media). The phrase computer-readable medium does not refer to a transitory, propagating signal. In addition, in other aspects, computer-readable medium may include a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

[0094] Accordingly, some aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having stored thereon (and / or encoded thereon) instructions executable by one or more processors to perform the operations described herein. For example, instructions for performing the operations described herein and illustrated in the accompanying figures.

[0095] Furthermore, it should be understood that modules and / or other suitable means for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by a user terminal and / or base station, where applicable. For example, such devices may be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein may be provided via a storage means such that the user terminal and / or base station can obtain the various methods upon coupling or providing the storage means (e.g., RAM, ROM, physical storage medium such as a compact disc (CD) or floppy disk, etc.) to the device. Furthermore, any other suitable technique for providing the methods and techniques described herein to a device may be utilized.

[0096] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims. [Explanation of symbols]

[0097] 100 Wireless Networks 102a Macrocell 102b Macrocell 102c Macrocell 102x picocell 102y Femtocell 102z Femtocell 110 Base station (BS) 110a BS 110b BS 110c BS, Macro BS 110r relay station 110x BS 110y BS 110z BS 120 UE, user equipment, user terminal 120r UE 120x UE 120y UE 130 Network Controller 200 Distributed Radio Access Network (RAN), Local Architecture, Architecture 202 Access Node Controller (ANC) 204 Next Generation Core Network (NG-CN) 206 5G access nodes 208 TRP, DU 210 Next generation AN (NG-AN) 300 Distributed RAN 302 Centralized Core Network Unit (C-CU) 304 Centralized RAN Unit (C-RU) 306 DU 412 Data Source 420 Processor, Transmit Processor 430 processor, transmit (TX) multiple-input multiple-output (MIMO) processor, TX MIMO processor 432 Modulator, BS Modulator / Demodulator 432a~432t Modulator (MOD) 434 Antenna 434a~434t antenna 436 MIMO detector 438 Processor, Receiving Processor 439 Data Sink 440 Controller / Processor, Processor 442 memory 444 Scheduler 452 Antenna 452a~452r antenna 454 Demodulator 454a~454r Demodulator (DEMOD) 456 MIMO detector 458 processor, receiving processor 462 Data Sources 464 processor, transmit processor 466 processor, TX MIMO processor 480 Controller / Processor, Processor 500 Figures 505-a First Option 505-b Second Option 510 Radio Resource Control (RRC) Layer 515 Packet Data Convergence Protocol (PDCP) Layer 520 Radio Link Control (RLC) Layer 525 Medium Access Control (MAC) Layer 530 Physical (PHY) Layer 600 Frame Format 700 operations 800 operations

Claims

1. 1. A method for wireless communication by a user equipment (UE), comprising: receiving signaling indicating whether a neighbor cell is synchronized or asynchronous with a serving cell of the UE; deriving one or more indices of synchronization signal blocks (SSBs) transmitted by the neighbor cell based on the indication; deriving the one or more indices for neighbor cells that are synchronized with the serving cell to be different from the one or more indices for neighbor cells that are asynchronous with the serving cell; receiving signaling of one or more reference signal (RS) configurations associated with the one or more indexes; The one or more RS configurations configure a channel state information reference signal (CSI-RS) or SSB from the neighbor cell within one subframe during a measurement time window; monitoring one or more CSI-RS or SSBs from the neighbor cell based on the one or more RS configurations; A method comprising:

2. The step of deriving the one or more indices of the SSBs transmitted by the neighbor cell comprises: When the indication indicates that the neighbor cell is synchronized with the serving cell, deriving the one or more indices of SSBs transmitted by the neighbor cell based on the timing of the serving cell; when the indication indicates that the neighbor cell is asynchronous with the serving cell, deriving the one or more indices of the SSBs transmitted by the neighbor cell based on a detected timing of the neighbor cell; 2. The method of claim 1, comprising:

3. The method of claim 1 , further comprising measuring the one or more SSBs based on the derived one or more indexes.

4. The method of claim 1 , wherein the indication comprises dedicated signaling to the UE.

5. The method of claim 1 , wherein the one or more RS configurations include one or more SSB configurations that configure SSBs from the neighbor cells within the one subframe during the measurement time window.

6. The method of claim 1 , wherein the indication further indicates which neighbor cells are synchronized or asynchronous with the serving cell.

7. The method of claim 5 , wherein one or more SSB configurations for SSB transmissions by neighbor cells that are synchronized with the serving cell are different from one or more SSB configurations for SSB transmissions by neighbor cells that are asynchronous with the serving cell.

8. 1. An apparatus for wireless communication, comprising: at least one processor; a memory coupled to said at least one processor; and the memory includes: receiving signaling indicating whether a neighbor cell is synchronized or asynchronous with a serving cell of the device; deriving one or more indices of synchronization signal blocks (SSBs) transmitted by the neighbor cell based on the indication; deriving, wherein the one or more indices for neighbor cells that are synchronized with the serving cell are derived differently from the one or more indices for neighbor cells that are asynchronous with the serving cell; receiving signaling of one or more reference signal (RS) configurations associated with the one or more indexes; receiving, within one subframe during a measurement time window, a channel state information reference signal (CSI-RS) or an SSB from the neighbor cell; monitoring one or more CSI-RS or SSBs from the neighboring cells based on the one or more RS configurations; and code executable by the at least one processor to cause the at least one processor to perform the steps of:

9. The at least one processor-executable code for causing the apparatus to derive the one or more indices of the SSBs transmitted by the neighbor cell may further include causing the apparatus to: When the indication indicates that the neighbor cell is synchronized with the serving cell, deriving the one or more indices of SSBs transmitted by the neighbor cell based on the timing of the serving cell; when the indication indicates that the neighbor cell is asynchronous with the serving cell, deriving the one or more indices of the SSBs transmitted by the neighbor cell based on the detected timing of the neighbor cell; 10. The apparatus of claim 8, further comprising code executable by the at least one processor to cause the at least one processor to:

10. 9. The apparatus of claim 8, wherein the memory further includes code executable by the at least one processor to cause the apparatus to measure the one or more SSBs based on the derived one or more indexes.

11. The device of claim 8 , wherein the indication comprises dedicated signaling to the device.

12. 10. The apparatus of claim 8, wherein the one or more RS configurations include one or more SSB configurations that configure SSBs from the neighbor cells within the one subframe during the measurement time window.

13. The apparatus of claim 8 , wherein the indication further indicates which neighbor cells are synchronized or asynchronous with the serving cell.

14. The apparatus of claim 12 , wherein one or more SSB configurations for SSB transmissions by neighbor cells that are synchronized with the serving cell are different from one or more SSB configurations for SSB transmissions by neighbor cells that are asynchronous with the serving cell.

15. 1. An apparatus for wireless communication, comprising: means for receiving signaling indicating whether a neighbor cell is synchronized or asynchronous with a serving cell of the device; means for deriving one or more indices of synchronization signal blocks (SSBs) transmitted by the neighbor cell based on the indication, means for deriving the one or more indices for neighbor cells that are synchronized with the serving cell to be different from the one or more indices for neighbor cells that are asynchronous with the serving cell; means for receiving signaling of one or more reference signal (RS) configurations associated with the one or more indexes, The one or more RS configurations configure a channel state information reference signal (CSI-RS) or SSB from the neighbor cell within one subframe during a measurement time window; means for monitoring one or more CSI-RS or SSBs from the neighbor cell based on the one or more RS configurations; 1. An apparatus comprising:

16. The means for deriving the one or more indices of the SSBs transmitted by the neighbor cell comprises: means for deriving the one or more indices of SSBs transmitted by the neighbor cell based on a timing of the serving cell when the indication indicates that the neighbor cell is synchronized with the serving cell; and means for deriving the one or more indices of the SSBs transmitted by the neighbor cell based on detected timing of the neighbor cell when the indication indicates that the neighbor cell is asynchronous with the serving cell; 16. The apparatus of claim 15, comprising:

17. 16. The apparatus of claim 15, further comprising: means for measuring the one or more SSBs based on the derived one or more indexes.

18. The device of claim 15 , wherein the indication comprises dedicated signaling to the device.

19. 16. The apparatus of claim 15, wherein the one or more RS configurations include one or more SSB configurations that configure SSBs from the neighbor cells within the one subframe during the measurement time window.

20. 16. The apparatus of claim 15, wherein the indication further indicates which neighbor cells are synchronized or asynchronous with the serving cell.

21. 20. The apparatus of claim 19, wherein one or more SSB configurations for SSB transmissions by neighbor cells that are synchronized with the serving cell are different from one or more SSB configurations for SSB transmissions by neighbor cells that are asynchronous with the serving cell.

22. A non-transitory computer-readable recording medium having stored thereon computer-executable code for wireless communication, the non-transitory computer-readable recording medium comprising: code for receiving signaling indicating whether a neighbor cell is synchronized or asynchronous with a serving cell of a user equipment (UE); code for deriving one or more indices of synchronization signal blocks (SSBs) transmitted by the neighbor cell based on the indication, the one or more indices for neighbor cells that are synchronized with the serving cell are derived differently than the one or more indices for neighbor cells that are asynchronous with the serving cell; Code for receiving signaling of one or more reference signal (RS) configurations associated with the one or more indexes, comprising: the one or more RS configurations configure a channel state information reference signal (CSI-RS) or SSB from the neighbor cell within one subframe during a measurement time window; and code for monitoring one or more CSI-RS or SSBs from the neighbor cell based on the one or more RS configurations; A non-transitory computer-readable recording medium comprising:

23. The code for deriving the one or more indices of the SSBs transmitted by the neighbor cell comprises: code for deriving the one or more indices of SSBs transmitted by the neighbor cell based on timing of the serving cell when the indication indicates that the neighbor cell is synchronized with the serving cell; and code for deriving the one or more indices of the SSBs transmitted by the neighbor cell based on detected timing of the neighbor cell when the indication indicates that the neighbor cell is asynchronous with the serving cell; and 23. The non-transitory computer-readable storage medium of claim 22, comprising:

24. 23. The non-transitory computer-readable storage medium of claim 22, further comprising code for measuring the one or more SSBs based on the derived one or more indexes.

25. 23. The non-transitory computer-readable medium of claim 22, wherein the indication comprises dedicated signaling to the UE.

26. 23. The non-transitory computer-readable storage medium of claim 22, wherein the one or more RS configurations include one or more SSB configurations that configure SSBs from the neighbor cells within the one subframe during the measurement time window.

27. 23. The non-transitory computer-readable medium of claim 22, wherein the indication further indicates which neighbor cells are synchronized or asynchronous with the serving cell.

28. 27. The non-transitory computer-readable storage medium of claim 26, wherein one or more SSB configurations for SSB transmissions by neighbor cells that are synchronized with the serving cell are different from one or more SSB configurations for SSB transmissions by neighbor cells that are asynchronous with the serving cell.

29. 2. The method of claim 1, wherein the one or more RS configurations configure the CSI-RS or SSB from the neighbor cell within the same symbol, slot, or subslot within the one subframe.

30. the one or more RS configurations such that the CSI-RS or SSB arrives at the UE within the one subframe during the measurement time window; configuring the CSI-RS or SSB from one or more neighbor cells synchronized with the serving cell with the same time offset, respectively; 10. The method of claim 1, further comprising: configuring the CSI-RS or SSB from one or more neighbor cells that are asynchronous with the serving cell with different time offsets.

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