Methods and apparatus for global synchronization raster determination in wireless communication

Abstract

Methods and devices for establishing the SYNC rasters to be used in a cell search procedure. The number and profile of the SYNC rasters may be established based on different channel BW considerations to reduce connection time and save energy. Different approaches may be used to establish which SYNC raster profiles should be employed at the UE.

Description

TITLE: Methods and Apparatus for Global Synchronization Raster Determination inWireless CommunicationFIELD

[0001] The present application relates to wireless devices and wireless networks including devices, computer-readable media, and methods for determining synchronization rasters for cell searching by the wireless device.BACKGROUND

[0002] Wireless communication systems are rapidly growing in usage. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices now provide access to the internet, email, text messaging, and navigation using the global positioning system (GPS) and are capable of operating sophisticated applications that utilize these functionalities. Additionally, there exist numerous different wireless communication technologies and standards. Some examples of wireless communication standards include GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e g., IxRTT, IxEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH™, 5G New Radio (NR), etc.

[0003] The ever-increasing number of features and functionality introduced in wireless communication devices also creates a continuous need for improvement in both the wireless communications and the wireless communication devices.

[0004] During an initial cell search procedure, a wireless device scans for a synchronization signal block (SSB) and / or Physical Broadcast Channel (PBCH) block for synchronization. The synchronization rasters (i.e., SYNC rasters) define a set of allowed center frequencies forlooking for the SSB when each SSB has a bandwidth of 20 Resource Blocks (RBs) and is contained within a channel bandwidth (BW).

[0005] In current 5G NR designs, the SYNC rasters are established in view of a minimum channel BW for each frequency range (FR) to ensure that at least one SYNC raster is available for any two consecutive channel BWs. This can result in an unnecessarily dense SYNC raster.SUMMARY

[0006] In general, embodiments disclosed herein are directed to methods and devices for establishing the SYNC rasters to be used in a cell search procedure. The number and profile of the SYNC rasters may be established based on different channel BW considerations. Different approaches may be used to establish the SYNC rasters at the UE.

[0007] In one aspect, embodiments are directed to a cell search method performed by a User Equipment (UE) to acquire timing and frequency synchronization within a cell by searching for an SSB signal on a set of frequency positions defined by SYNC rasters over a frequency bandwidth. The method includes deriving a frequency spacing that is a distance between two consecutive SYNC rasters based on a channel bandwidth of the cell and a SSB bandwidth and determining frequency positions of the SYNC rasters in the frequency bandwidth based on the derived frequency spacing between two consecutive SYNC rasters. The method includes performing a frequency scan on the determined SYNC rasters that includes measuring for the SSB signal at each SYNC raster and detecting the SSB signal on a frequency position of one of the SYNC rasters in the frequency bandwidth based on the frequency scan. The UE acquires the time and frequency synchronization within the cell using the detected SSB on the one of the SYNC rasters.

[0008] In another aspect, embodiments are directed to a cell search method performed by a User Equipment (UE) to acquire timing and frequency synchronization within a cell by searching for a Synchronization Signal Block (SSB) on a set of frequency positions defined by synchronization (SYNC) rasters over a frequency bandwidth. The method includes determining a number of consecutive SYNC rasters for a given frequency range based on a channel bandwidth of the cell, a reference channel bandwidth, and a reference SYNC raster step size. The reference SYNC raster step size is associated with the reference channel bandwidth. The method includes the UE performing a frequency scan on the number of determined SYNC rasters for the frequency range that includes measuring for a SSB signal at each SYNC raster of the number of consecutive SYNC rasters over the frequency bandwidth and detecting the SSB signal on a frequency position of one of the SYNC rasters in the frequency bandwidth based on the frequency scan. The UE acquires time and frequency synchronization within the cell using the detected SSB on the SYNC raster.

[0009] The techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to cellular phones, wireless devices, tablet computers, wearable computing devices, portable media players, and any of various other computing devices.

[0010] This Summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it will be appreciated that the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims.BRIEF DESCRIPTION OF DRAWINGS

[0011] A better understanding of the present subject matter can be obtained when the following detailed description of various aspects is considered in conjunction with the following drawings.

[0012] Figure 1 illustrates an example wireless communication system, according to some aspects.

[0013] Figure 2 illustrates an example block diagram of a UE, according to some aspects.

[0014] Figure 3 illustrates a base station (BS) in communication with a UE device, according to some aspects.

[0015] Figure 4 illustrates a general method according to some aspects.

[0016] Figure 5 demonstrates a maximum step size based on a channel bandwidth according to some aspects.

[0017] Figure 6 illustrates different SYNC raster profiles for different BWs according to some aspects.

[0018] Figure 7 illustrates different SYNC raster profiles using a reference SYNC raster according to some aspects.

[0019] While the features described herein may be susceptible to various modifications and alternative forms, specific aspects thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to be limiting to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims.DETAILED DESCRIPTION

[0020] The SYNC rasters define a set of allowed center frequencies for looking for the SSB to acquire time and frequency synchronization within a cell. The SSB typically has a bandwidth of 20 RBs contained within a channel BW.

[0021] In current 5G NR designs, the SYNC rasters are established in view of a minimum channel BW for the frequency range (FR). Specifically, the SYNC rasters are spaced at and 50 MHz for FR2. This SYNC raster spacing ensures at least one SYNC raster is available for two consecutive channel BWs.

[0022] The 5 MHz for FR1 SYNC raster spacing is motivated by the assumption that an operator may utilize a 5 MHz channel BW in FR1, which is not widely used in practice. As an example, if an operator uses a minimum channel BW of 10 MHz, the current number of SYNC rasters used could be five times less and still provide at least one SSB in each of two adjacent channel BWs. Accordingly, embodiments disclosed herein determine and use an efficient number of SYNC rasters to scan for synchronization. Embodiments may help minimize delays in an initial cell search procedure, and embodiments further contribute to network energy savings for NR and future (6G) wireless networks.

[0023] Embodiments herein provide SYNC rasters using a channel BW dependent approach to indicate the frequency positions for an SSB that can be used by UE for system acquisition when explicit signaling is not present. Embodiments include establishing SYNC rasters in view of a given channel BW and establishing SYNC rasters in association with a reference BW. Embodiments allow a UE to conduct an efficient SSB frequency search in view of a more typical channel BW for a band or frequency range (FR). Embodiments also includetechniques for providing and establishing the information on the relevant BWs used for the embodied SYNC rasters searching procedure.

[0024] The following is a glossary of terms that may be used in this disclosure:

[0025] Memory Medium - Any of various types of non-transitory memory devices or storage devices. The term “memory medium” is intended to include an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of non-transitory memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term “memory medium” may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors.

[0026] Carrier Medium - a memory medium as described above, as well as a physical transmission medium, such as a bus, network, and / or other physical transmission medium that conveys signals such as electrical, electromagnetic, or digital signals.

[0027] Programmable Hardware Element - includes various hardware devices comprising multiple programmable function blocks connected via a programmable interconnect. Examples include FPGAs (Field Programmable Gate Arrays), PLDs(Programmable Logic Devices), FPOAs (Field Programmable Object Arrays), and CPLDs (Complex PLDs). The programmable function blocks may range from fine grained (combinatorial logic or look up tables) to coarse grained (arithmetic logic units or processor cores). A programmable hardware element may also be referred to as “reconfigurable logic.”

[0028] Computer System - any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combinations of devices. In general, the term “computer system” can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0029] User Equipment (UE) (also “User Device” or “UE Device”) - any of various types of computer systems or devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), laptops, wearable devices (e.g., smart watch, smart glasses), PDAs, portable Internet devices, music players, data storage devices, other handheld devices, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, an instrument cluster, head-up display (HUD) devices, onboard diagnostic (OBD) devices, dashtop mobile equipment (DME), mobile data terminals (MDTs), Electronic Engine Management System (EEMS), electronic / engine control units (ECUs), electronic / engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), networked or “smart” appliances, machine type communications (MTC) devices, machine-to-machine (M2M), internet of things (loT) devices, etc. In general, the term “UE” or “UE device” can be broadly defined to encompass any electronic, computing,and / or telecommunications device (or combination of devices) which is transportable by a user and capable of wireless communication.

[0030] Wireless Device - any of various types of computer systems or devices that perform wireless communications. A wireless device can be portable (or mobile) or may be stationary or fixed at a certain location. A UE is an example of a wireless device.

[0031] Communication Device - any of various types of computer systems or devices that perform communications, where the communications can be wired or wireless. A communication device can be portable (or mobile) or may be stationary or fixed at a certain location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0032] Base Station - The term “base station” or “wireless station” has the full breadth of its ordinary meaning, and at least includes a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system. For example, if the base station is implemented in the context of LTE, it may alternately be referred to as an ‘eNodeB’ or ‘eNB.’ If the base station is implemented in the context of 5GNR, it may alternately be referred to as a ‘gNodeB’ or ‘gNB’. Although certain aspects are described in the context of LTE or 5G NR, references to “eNB,” “gNB,” “nodeB,” “base station,” “NB,” etc., may refer to one or more wireless nodes that service a cell to provide a wireless connection between user devices and a wider network generally and that the concepts discussed are not limited to any particular wireless technology. Although certain aspects are described in the context of LTE or 5G NR, references to “eNB,” “gNB,” “nodeB,” “base station,” “NB,” etc., are not intended to limit the concepts discussed herein to any particular wireless technology and the concepts discussed may be applied in any wireless system.

[0033] Node - The term “node,” or “wireless node” as used herein, may refer to one moreapparatus associated with a cell that provide a wireless connection between user devices and a wired network generally.

[0034] Processing Element (or Processor) - refers to various elements or combinations of elements that are capable of performing a function in a device, such as a user equipment or a cellular network device. Processing elements may include, for example: processors and associated memory, portions or circuits of individual processor cores, entire processor cores, individual processors, processor arrays, circuits such as an ASIC (Application Specific Integrated Circuit), programmable hardware elements such as a field programmable gate array (FPGA), as well any of various combinations of the above.

[0035] Channel - a medium used to convey information from a sender (transmitter) to a receiver. It should be noted that since characteristics of the term “channel” may differ according to different wireless protocols, the term “channel” as used herein may be considered as being used in a manner that is consistent with the standard of the type of device with reference to which the term is used. In some standards, channel widths may be variable (e.g., depending on device capability, band conditions, etc.). For example, LTE may support scalable channel bandwidths from 1.4 MHz to 20MHz. In contrast, WLAN channels may be 22MHz wide while Bluetooth channels may be IMhz wide. Other protocols and standards may include different definitions of channels. Furthermore, some standards may define and use multiple types of channels, e.g., different channels for uplink or downlink and / or different channels for different uses such as data, control information, etc.

[0036] Band - The term “band” has the full breadth of its ordinary meaning, and at least includes a section of spectrum (e.g., radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0037] Automatically - refers to an action or operation performed by a computer system(e.g., software executed by the computer system) or device (e.g., circuitry, programmable hardware elements, ASICs, etc.), without user input directly specifying or performing the action or operation. Thus, the term “automatically” is in contrast to an operation being manually performed or specified by the user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by the user, but the subsequent actions that are performed “automatically” are not specified by the user, i.e., are not performed “manually,” where the user specifies each action to perform. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting check boxes, radio selections, etc.) is filling out the form manually, even though the computer system must update the form in response to the user actions. The form may be automatically filled out by the computer system where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills in the form without any user input specifying the answers to the fields. As indicated above, the user may invoke the automatic filling of the form but is not involved in the actual filling of the form (e.g., the user is not manually specifying answers to fields but rather they are being automatically completed). The present specification provides various examples of operations being automatically performed in response to actions the user has taken.

[0038] Approximately - refers to a value that is almost correct or exact. For example, approximately may refer to a value that is within 1 to 10 percent of the exact (or desired) value. It should be noted, however, that the actual threshold value (or tolerance) may be application dependent. For example, in some aspects, “approximately” may mean within 0.1% of some specified or desired value, while in various other aspects, the threshold may be, for example, 2%, 3%, 5%, and so forth, as desired, or as required by the particular application.

[0039] Concurrent - refers to parallel execution or performance, where tasks, processes,or programs are performed in an at least partially overlapping manner. For example, concurrency may be implemented using “strong” or strict parallelism, where tasks are performed (at least partially) in parallel on respective computational elements, or using “weak parallelism,” where the tasks are performed in an interleaved manner, e.g., by time multiplexing of execution threads.

[0040] Configured to - Various components may be described as “configured to” perform a task or tasks. In such contexts, “configured to” is a broad recitation generally meaning “having structure that” performs the task or tasks during operation. As such, the component can be configured to perform the task even when the component is not currently performing that task (e.g., a set of electrical conductors may be configured to electrically connect a module to another module, even when the two modules are not connected). In some contexts, “configured to” may be a broad recitation of structure generally meaning “having circuitry that” performs the task or tasks during operation. As such, the component can be configured to perform the task even when the component is not currently on. In general, the circuitry that forms the structure corresponding to “configured to” may include hardware circuits.

[0041] Various components may be described as performing a task or tasks, for convenience in the description. Such descriptions should be interpreted as including the phrase “configured to.” Reciting a component that is configured to perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation for that component.

[0042] Example Wireless Communication System

[0043] Turning now to Figure 1, a simplified example of a wireless communication system is illustrated, according to some aspects. It is noted that the system of Figure 1 is a non-limiting example of a possible system, and that features of this disclosure may be implemented in any of various systems, as desired.

[0044] As shown, the example wireless communication system includes a base station102A, which communicates over a transmission medium with one or more user devices 106A and 106B, through 106Z. Each of the user devices may be referred to herein as a “user equipment” (UE). Thus, the user devices 106 are referred to as UEs or UE devices.

[0045] The base station (BS) 102A may be a base transceiver station (BTS) or cell site (e.g., a “cellular base station”) and may include hardware that enables wireless communication with the UEs 106A through 106Z.

[0046] The communication area (or coverage area) of the base station may be referred to as a “cell.” The base station 102A and the UEs 106 may be configured to communicate over the transmission medium using any of various radio access technologies (RATs), also referred to as wireless communication technologies, or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000. Note that if the base station 102A is implemented in the context of LTE, it may alternately be referred to as an ‘eNodeB’ or ‘eNB’. Note that if the base station 102A is implemented in the context of 5G NR, it may alternately be referred to as a ‘gNodeB’ or ‘gNB’.

[0047] In some aspects, the UEs 106 may be loT UEs, which may comprise a network access layer designed for low-power loT applications utilizing short-lived UE connections. An loT UE may utilize technologies such as M2M or MTC for exchanging data with an MTC server or device via a public land mobile network (PLMN), proximity service (ProSe) or device-to-device (D2D) communication, sensor networks, or loT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An loT network describes interconnecting loT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. As an example,vehicles to everything (V2X) may utilize ProSe features using a PC5 interface for direct communications between devices. The loT UEs may also execute background applications (e.g., keep-alive messages, status updates, and the like) to facilitate the connections of the loT network.

[0048] As shown in Figure 1, the UEs 106, such as UE 106A and UE 106B, may directly exchange communication data via a PC5 interface 108 A. Also, the UEs 106C, 106N, and 106Z, may collectively exchange communication data via a PC5 interfaces 108B, 108C, and 108D. In general, such PC5 interfaces are referred to as SL connections.

[0049] The PC5 interface 108 may comprise one or more physical channels, including but not limited to a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Broadcast Channel (PSBCH), and a Physical Sidelink Feedback Channel (PSFCH). The PC5 interface 108 may be responsible for direct communication between devices (unicast), group messaging among select devices (groupcast), and broadcast messaging in accordance with embodiments disclosed herein.

[0050] In V2X scenarios, one or more of the base stations 102 may be or act as Road Side Units (RSUs). The term RSU may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable wireless node or a stationary (or relatively stationary) UE, where an RSU implemented in or by a UE , eNB, or by a gNB. For example, an RSU is a computing device coupled with radio frequency circuitry located on a roadside that provides connectivity support to passing vehicle UEs.

[0051] As shown, the base station 102A may also be equipped to communicate with a network 100 (e.g., a core network of a cellular service provider, a telecommunication network such as a public switched telephone network (PSTN), and / or the Internet, among various possibilities). Thus, the base station 102A may facilitate communication between the userdevices and / or between the user devices and the network 100. In particular, the cellular base station 102 A may provide UEs 106 with various telecommunication capabilities, such as voice, SMS and / or data services.

[0052] Base station 102 A and other similar base stations (such as base stations 102B through 102N) operating according to the same or a different cellular communication standard may thus be provided as a network of cells, which may provide continuous or nearly continuous overlapping service to UEs 106A-106Z and similar devices over a geographic area via one or more cellular communication standards.

[0053] Thus, while base station 102 A may act as a “serving cell” for UEs 106A-106Z as illustrated in Figure 1, each UE 106 may also be capable of receiving signals from (and possibly within communication range of) one or more other cells (which may be provided by base stations 102B-102Z and / or any other base stations), which may be referred to as “neighboring cells.” Such cells may also be capable of facilitating communication between user devices and / or between user devices and the network 100. Such cells may include “macro” cells, “micro” cells, “pico” cells, and / or cells which provide any of various other granularities of service area size. For example, base stations 102A and 102B illustrated in Figure 1 may be macro cells, while base station 102Z may be a micro cell. Other configurations are also possible.

[0054] In some aspects, base station 102 A may be a next generation base station, (e.g., a 5GNew Radio (5GNR) base station, or “gNB”). In some aspects, a gNB may be connected to a legacy evolved packet core (EPC) network and / or to a NR core (NRC) / 5G core (5GC) network. In addition, a gNB cell may include one or more transition and reception points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs. For example, it may be possible that that the basestation 102A and one or more other base stations 102 support joint transmission, such that UE 106 may be able to receive transmissions from multiple base stations (and / or multiple TRPs provided by the same base station). For example, as illustrated in Figure 1, both base station 102 A and base station 102C are shown as serving UE 106 A.

[0055] Note that a UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using a wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fi peer-to-peer, and the like) in addition to some of the cellular communication protocols discussed herein. The UE 106 may also or alternatively be configured to communicate using one or more global navigational satellite systems (GNSS) (e.g., GPS or GLONASS), one or more mobile television broadcasting standards (e.g., ATSC-M / H), and / or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0056] In one or more embodiments, the UE 106 may be a device with cellular communication capability such as a mobile phone, a hand-held device, a computer, a laptop, a tablet, a smart watch, or other wearable device, or virtually any type of wireless device.

[0057] The UE 106 may include a processor (processing element) that is configured to execute program instructions stored in memory. The UE 106 may perform any of the method aspects described herein by executing such stored instructions. Alternatively, or in addition, the UE 106 may include a programmable hardware element such as an FPGA (field- programmable gate array), an integrated circuit, and / or any of various other possible hardware components that are configured to perform (e.g., individually or in combination) any of the method aspects described herein, or any portion of any of the method aspects described herein.

[0058] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some aspects, the UE 106 may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As additional possibilities, the UE 106 could be configured to communicate using CDMA2000 (IxRTT / IxEV-DO / HRPD / eHRPD) or LTE using a single shared radio and / or GSM or LTE using the single shared radio. The shared radio may couple to a single antenna, or may couple to multiple antennas (e.g., for a multiple-input multiple output (MIMO) configuration) for performing wireless communications. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, and the like), or digital processing circuitry (e.g., for digital modulation as well as other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE 106 may share one or more parts of a receive and / or transmit chain between multiple wireless communication technologies, such as those discussed above.

[0059] In some aspects, the UE 106 may include separate transmit and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As a further possibility, the UE 106 may include one or more radios which are shared between multiple wireless communication protocols, and one or more radios which are used exclusively by a single wireless communication protocol. For example, the UE 106 might include a shared radio for communicating using either of LTE or 5GNR (or either of LTE or IxRTT, or either of LTE or GSM, among various possibilities), and separate radios for communicating using each of WiFi and Bluetooth. Other configurations are also possible.

[0060] In some aspects, a downlink resource grid may be used for downlink transmissionsfrom any of the base stations 102 to the UEs 106, while uplink transmissions may utilize similar techniques. The grid may be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a timefrequency plane representation is a common practice for Orthogonal Frequency Division Multiplexing (OFDM) systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid may comprise a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a set of resource elements. There are several different physical downlink channels that are conveyed using such resource blocks.

[0061] One such channel is the physical downlink shared channel (PDSCH) that may carry user data and higher layer signaling to the UEs 106. The PDCCH may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs 106 about the transport format, resource allocation, and HARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE 102 within a cell) may be performed at any of the base stations 102 based on channel quality information fed back from any of the UEs 106. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs.

[0062] The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex- valued symbols may first be organized into quadruplets, which may then be permuted using a sub-blockinterleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH may be transmitted using one or more CCEs, depending on the size of the Downlink Control Information (DCI) and the channel condition. There may be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=l, 2, 4, or 8).

[0063] Example Communication Device

[0064] Figure 2 illustrates user equipment 106 (e.g., one of the devices 106A through 106N) in communication with a base station 102 or other user equipment 106, according to some aspects. The UE 106 may be a device with cellular communication capability such as a mobile phone, a hand-held device, a computer, a laptop, a tablet, a smart watch, or other wearable device, or virtually any type of wireless device.

[0065] The UE 106 may include a processor (processing element) that is configured to execute program instructions stored in memory. The UE 106 may perform any of the method aspects described herein by executing such stored instructions. Alternatively, or in addition, the UE 106 may include a programmable hardware element such as an FPGA (field- programmable gate array), an integrated circuit, and / or any of various other possible hardware components that are configured to perform (e.g., individually or in combination) any of the method aspects described herein, or any portion of any of the method aspects described herein.

[0066] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some aspects, the UE 106 may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As additional possibilities, the UE 106 could be configured to communicate usingCDMA2000 (IxRTT / IxEV-DO / HRPD / eHRPD) or LTE using a single shared radio and / or GSM or LTE using the single shared radio. The shared radio may couple to a single antenna, or may couple to multiple antennas (e.g., for MIMO) for performing wireless communications. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation as well as other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE 106 may share one or more parts of a receive and / or transmit chain between multiple wireless communication technologies, such as those discussed above.

[0067] In some aspects, the UE 106 may include separate transmit and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As a further possibility, the UE 106 may include one or more radios which are shared between multiple wireless communication protocols, and one or more radios which are used exclusively by a single wireless communication protocol. For example, the UE 106 might include a shared radio for communicating using either of LTE or 5GNR (or either of LTE or IxRTT, or either of LTE or GSM, among various possibilities), and separate radios for communicating using each of WiFi and Bluetooth. Other configurations are also possible.

[0068] In some aspects, a downlink resource grid can be used for downlink transmissions from any of the base stations 102 to the UEs 106, while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a timefrequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource gridcorresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid may comprise a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements. There are several different physical downlink channels that are conveyed using such resource blocks.

[0069] The PDSCH may carry user data and higher layer signaling to the UEs 106. The PDCCH may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs 106 about the transport format, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE 102 within a cell) may be performed at any of the base stations 102 based on channel quality information fed back from any of the UEs 106. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs.

[0070] The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex- valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g.,aggregation level, L=l, 2, 4, or 8).

[0071] Figure 2 illustrates an example simplified block diagram of a communication device 106, according to some aspects. It is noted that the block diagram of the communication device of Figure 2 is only one example of a possible communication device. According to aspects, communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet, and / or a combination of devices, among other devices. As shown, the communication device 106 may include a set of components 200 configured to perform core functions. For example, this set of components may be implemented as a system on chip (SOC), which may include portions for various purposes. Alternatively, this set of components 200 may be implemented as separate components or groups of components for the various purposes. The set of components 200 may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device 106.

[0072] For example, the communication device 106 may include various types of memory (e.g., including NAND flash 210), an input / output interface such as connector I / F 220 (e.g., for connecting to a computer system; dock; charging station; input devices, such as a microphone, camera, keyboard; output devices, such as speakers; etc.), the display 260, which may be integrated with or external to the communication device 106, and wireless communication circuitry 230 (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some aspects, communication device 106 may include wired communication circuitry (not shown), such as a network interface card, e.g., for Ethernet.

[0073] The wireless communication circuitry 230 may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antenna(s) 335 as shown. The wirelesscommunication circuitry 230 may include cellular communication circuitry and / or short to medium range wireless communication circuitry and may include multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration.

[0074] In some aspects, as further described below, cellular communication circuitry 230 may include one or more receive chains (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radios) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for 5G NR). In addition, in some aspects, cellular communication circuitry 230 may include a single transmit chain that may be switched between radios dedicated to specific RATs. For example, a first radio may be dedicated to a first RAT, e.g., LTE, and may be in communication with a dedicated receive chain and a transmit chain shared with a second radio. The second radio may be dedicated to a second RAT, e.g., 5G NR, and may be in communication with a dedicated receive chain and the shared transmit chain. In some aspects, the second RAT may operate at mmWave frequencies. As mmWave systems operate in higher frequencies than typically found in LTE systems, signals in the mmWave frequency range are heavily attenuated by environmental factors. To help address this attenuating, mmWave systems often utilize beamforming and include more antennas as compared LTE systems. These antennas may be organized into antenna arrays or panels made up of individual antenna elements. These antenna arrays may be coupled to the radio chains.

[0075] The communication device 106 may also include and / or be configured for use with one or more user interface elements. The user interface elements may include any of various elements, such as display 260 (which may be a touchscreen display), a keyboard (which may be a discrete keyboard or may be implemented as part of a touchscreen display), a mouse, amicrophone and / or speakers, one or more cameras, one or more buttons, and / or any of various other elements capable of providing information to a user and / or receiving or interpreting user input.

[0076] The communication device 106 may further include one or more smart cards 245 that include SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards 245.

[0077] As shown, the SOC 200 may include processor(s) 202, which may execute program instructions for the communication device 106 and display circuitry 204, which may perform graphics processing and provide display signals to the display 260. The processor(s) 202 may also be coupled to memory management unit (MMU) 240, which may be configured to receive addresses from the processor(s) 202 and translate those addresses to locations in memory (e.g., memory 206, read only memory (ROM) 250, NAND flash memory 210) and / or to other circuits or devices, such as the display circuitry 204, wireless communication circuitry 230, connector I / F 220, and / or display 260. The MMU 240 may be configured to perform memory protection and page table translation or set up. In some aspects, the MMU 240 may be included as a portion of the processor(s) 202.

[0078] As noted above, the communication device 106 may be configured to communicate using wireless and / or wired communication circuitry. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and techniques described herein. The processor 202 of the communication device 106 may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer- readable memory medium). Alternatively (or in addition), processor 202 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or asan ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor 202 of the communication device 106, in conjunction with one or more of the other components 200, 204, 206, 210, 220, 230, 240, 245, 250, 260 may be configured to implement part or all of the features described herein.

[0079] In addition, as described herein, processor 202 may include one or more processing elements. Thus, processor 202 may include one or more integrated circuits (ICs) that are configured to perform the functions of processor 202. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processor(s) 202.

[0080] Further, as described herein, wireless communication circuitry 230 may include one or more processing elements. In other words, one or more processing elements may be included in wireless communication circuitry 230. Thus, wireless communication circuitry 230 may include one or more integrated circuits (ICs) that are configured to perform the functions of wireless communication circuitry 230. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of wireless communication circuitry 230.

[0081] Example Base Station

[0082] Figure 3 illustrates an example block diagram of a base station 102, according to some aspects. It is noted that the base station of Figure 3 is merely one example of a possible base station. As shown, the base station 102 may include processor(s) 304 which may execute program instructions for the base station 102. The processor(s) 304 may also be coupled to memory management unit (MMU) 340, which may be configured to receive addresses from the processor(s) 304 and translate those addresses to locations in memory (e.g., memory 360 and read only memory (ROM) 350) or to other circuits or devices.

[0083] The base station 102 may include at least one network port 370. The network port 370 may be configured to couple to a telephone network and provide a plurality of devices, such as UE devices 106, access to the telephone network as described above in Figures 1 and 2.

[0084] The network port 370 (or an additional network port) may also or alternatively be configured to couple to a cellular network, e.g., a core network of a cellular service provider. The core network may provide mobility related services and / or other services to a plurality of devices, such as UE devices 106. In some cases, the network port 370 may couple to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., among other UE devices serviced by the cellular service provider).

[0085] In some aspects, base station 102 may be a next generation base station, e.g., a 5G New Radio (5GNR) base station, or “gNB.” In such aspects, base station 102 may be connected to a legacy evolved packet core (EPC) network and / or to a NR core (NRC) / 5G core (5GC) network. In addition, base station 102 may be considered a 5G NR cell and may include one or more transition and reception points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs.

[0086] The base station 102 may include at least one antenna 334, and possibly multiple antennas. The at least one antenna 334 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE devices 106 via radio 330. The antenna 334 communicates with the radio 330 via communication chain 332. Communication chain 332 may be a receive chain, a transmit chain or both. The radio 330 may be configured to communicate via various wireless communication standards, including, but not limited to, 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0087] The base station 102 may be configured to communicate wirelessly using multiplewireless communication standards. In some instances, the base station 102 may include multiple radios, which may enable the base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, the base station 102 may include an LTE radio for performing communication according to LTE as well as a 5G NR radio for performing communication according to 5G NR. In such a case, the base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. When the base station 102 supports mmWave, the 5G NR radio may be coupled to one or more mmWave antenna arrays or panels. As another possibility, the base station 102 may include a multi-mode radio, which is capable of performing communications according to any of multiple wireless communication technologies (e.g., 5GNR and LTE, 5GNR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0088] As described further subsequently herein, the BS 102 may include hardware and software components for implementing or supporting implementation of features described herein. The processor 304 of the base station 102 may be configured to implement or support implementation of part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer readable memory medium). Alternatively, the processor 304 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. Alternatively (or in addition) the processor 304 of the BS 102, in conjunction with one or more of the other components 330, 332, 334, 340, 350, 360, 370 may be configured to implement or support implementation of part or all of the features described herein.

[0089] In addition, as described herein, processor(s) 304 may include one or more processing elements. Thus, processor(s) 304 may include one or more integrated circuits (ICs)that are configured to perform the functions of processor(s) 304. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processor(s) 304.

[0090] Further, as described herein, radio 330 may include one or more processing elements. Thus, radio 330 may include one or more integrated circuits (ICs) that are configured to perform the functions of radio 330. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of radio 330.

[0091] Global SYNC Raster Determination Using a Channel Bandwidth-Dependent Approach

[0092] Embodiments herein provide SYNC rasters using a channel BW dependent approach to indicate the frequency positions for an SSB that can be used by the UE for system acquisition. Figure 4 illustrates a general cell search method 400 according to some aspects. A UE performs the method of Figure 4 to acquire timing and frequency synchronization within a cell. In Step 410, the UE determines a number of SYNC rasters for a given frequency range.

[0093] In some embodiments, the UE determines the number of SYNC rasters by deriving a frequency spacing based on the channel BW and the SSB BW of the cell. The UE derives a maximum distance between two consecutive SYNC rasters using the channel bandwidth, SSB bandwidth, and a channel raster gap.

[0094] Figure 5 demonstrates an example 500 of a maximum SYNC raster step size based on a channel bandwidth according to some aspects. In Figure 5, the channel BW 510 is shown with a SYNC raster 520 and a consecutive SYNC raster 530 for two consecutive channel positions. Each SYNC raster 520, 530 is shown with a potential SSB bandwidth 540 shown as the shaded region. That is, for two consecutive channel positions, it is possible to configure anSSB shown by the shaded regions. Figure 5 also illustrates a channel raster gap 550 between the SYNC raster 520 and the consecutive SYNC raster 530. In this configuration, a maximum SYNC raster gap 560 would be located between the centers of each SSB BW.

[0095] In view of Figure 5, in some embodiments, the maximum offset between two consecutive SYNC rasters may be determined based on Equation (1):

[0096] wherein F ™teris the maximum spacing, BWchanneiis the channel bandwidth, BWSSBis the bandwidth of the SSB, and &Fr££™elis the space between two consecutive RF channel positions.

[0097] In other embodiments, the maximum offset may be derived using Equation (2):where AF^^ter is the maximum spacing, BWchanneiis the channel bandwidth, BWSSBis the bandwidth of the SSB, and ^F^terelis the space between two consecutive channel positions. In Equation (2), the [x] represents a floor function that maps the value of ‘x’ to the greatest integer less than ‘x’. This ensures that the step size is an integer number of MHz.

[0098] Table 1 summarizes the maximum offset (i.e., the SYNC raster step size) for different combinations of channel BW and SSB BW for FR1 in accordance with the above embodiments assuming a 15 kHz subcarrier spacing (SCS). Table 1 includes the number of Resource Blocks (RBs) for the given channel bandwidth.Table 1:

[0099] Figure 6 illustrates an example 600 of the different SYNC raster profiles for different BWs according to the embodiments above. The top SYNC raster profile 601 shown in Figure 6 represents the current SYNC raster profile that is used in 5G NR that assumes a 5 MHz BW with a 1 MHz SYNC raster step size. The remaining SYNC raster profiles 602, 604, 606, 608, and 610 show different SYNC raster profiles with different bandwidths in accordance with embodiments herein. The determined SYNC raster step size according to Equation (2) is shown for each SYNC raster profile shown in Figure 6.

[0100] As can be seen from Table 1 and Figure 6, compared to current 5G NR designs, the number of SYNC rasters that UE has to blindly search may be reduced by a factor of 5, 10, 15, 20 and 45 in raster profiles 602, 604, 606, 608, and 610 for the cases where the channel BW is 10, 15, 20, 25, and 50 MHz, respectively. As such, embodiments can reduce the time and energy needed to find the network SSB.

[0101] In some embodiments, in Step 410, the UE determines a set of reference SYNC rasters based on a channel bandwidth of the cell, a reference channel bandwidth, and a reference SYNC raster step size. In these embodiments, the standard 5GNR SYNC rasters may be used to determine the set of reference SYNC rasters. More specifically, the standard 5 MHz channel BW in FR1 (and equivalently 50 MHz for FR2) may be used as a reference channel BW to determine a set of reference SYNC rasters.

[0102] In some embodiments, for a channel BW BWchannei, the SYNC raster may be limited to 1 out of “K” reference SYNC rasters as defined by Equation (3):reference SYNC raster step size applied for the reference configurationhannei reference channel bandwidth. For example,= 1 andID g fB ^channel=MHz may be used for FR1. In this example, a value of K = 5, 10. . .45 may be used for BWchanne{= 10, 15...50, respectively.

[0103] Figure 7 illustrates an example 700 of different SYNC raster profiles using a reference SYNC raster according to some aspects. Like Figure 6, the top SYNC raster profile 701 represents the current SYNC raster profile that is used in 5G NR that assumes a 5 MHz BW. The remaining SYNC raster profiles 702, 704, and 706 in Figure 7 illustrate embodiments of the SYNC raster profile for 10, 15, and 20 MHz channel BWs and a corresponding value of “K” that may be used. Compared to current 5G NR designs, the number of SYNC rasters that a UE has to blindly search may be reduced to save time and power.

[0104] In some embodiments, the value of K may be pre-established (as associated with a potential channel BW) and encoded into the wireless standards for performing cell searches.

[0105] Returning to Figure 4, after determining the number of SYNC rasters and SYNC raster profile to be used for the frequency range in Step 410, the UE performs a frequency scan over the frequency range based on the SYNC rasters in Step 420. Ideally, the UE detects an SSB signal using one of the SYNC rasters (YES in Step 430). The UE then acquires the timing and frequency synchronization with the cell in Step 440.

[0106] However, given the channel bandwidth or value of “K” used in the above embodiments, if the UE does not detect the SSB signal after scanning the SYNC raster profile(No in Step 430), the process may return to repeat Steps 410 and 420 to determine an updated number of SYNC rasters and perform an updated frequency scan. This cycle may be repeated as necessary until the SSB signal is detected. In some embodiments, once a specific SYNC raster has been scanned in Step 420, a SYNC raster at the same frequency location may be skipped in future scans. That is, a scan at a specific SYNC raster is not repeated in any subsequent frequency scans. This may further contribute to time and energy savings.

[0107] For example, referring to Figure 6, in some embodiments, a UE may first conduct a scan with profile 610 corresponding to a 50 MHz channel BW with a 45 MHz SYNC raster step size as shown in the bottom SYNC raster profile. If the SSB is not detected in the scan, the UE may then conduct a second scan using a SYNC raster profile corresponding to a smaller channel BW. Specifically, the UE may use the SYNC raster profile 608 corresponding to a 25 MHz channel BW with the 20 MHz SYNC raster step size; followed by the raster profile 606 corresponding to a 20 MHz channel BW with the 15 MHz SYNC raster step size; followed by the raster profile 604 corresponding to a 15 MHz channel BW with the 15 MHz SYNC raster step size; and so on until the SSB is detected.

[0108] In the above example, the specific SYNC raster 605a is scanned in the first frequency scan based on the 50 MHz channel BW profile 610. Accordingly, the specific SYNC raster 605b in the subsequent scan based on the 20 MHz channel BW profile 606 may be skipped.

[0109] Thus, embodiments may perform multiple frequency scans using different SYNC raster profiles based on decreasing channel BWs / values of “K ” In this manner, a UE may scan for an SSB based on channel BW, and step through smaller channel BW options until the SSB is found. Such embodiments will still likely reduce the number of SYNC rasters for the UE to investigate compared to the currently used 5G NR SYNC rasters.

[0110] A variety of approaches may be used to provide information on the channel BWs or “K” values to be used by the UE for the above embodiments. In some embodiments, a channel BW or “K” value may be associated with different operating bands as encoded in the wireless standards. For example, Table 2 demonstrates associating a channel BW and “K” value for a SYNC raster profile with the 6G Radio operating band.Table 2:

[0111] One of ordinary skill in the art will appreciate that Table 2 could be similarly configured using a SYNC raster step size, or channel BW in combination with a SYNC raster step size.

[0112] In some embodiments, multiple channel BWs or values of “K” may be associated with the different operating bands. Such embodiments may provide operators with more flexibility for deployment. For example, Table 3 demonstrates associating multiple “K” values with different 6G Radio operating bands.Table 3:

[0113] In such embodiments, the UE may only perform the SYNC scan using the indicated ‘K’ values for a given band.

[0114] In embodiments, a SYNC raster step size, F- a^erel, may be associated with and a channel BW, BWchannei. For example, Table 4 demonstrates an association between a channel BW and SYNC raster step size that may be established for the UE.Table 4:

[0115] In the embodiments associated with Table 4, a larger SYNC raster step size is defined for larger channel BWs.

[0116] Embodiments disclosed herein advantageously provide methods and devices for saving time and energy when frequency scanning for an SSB for timing / synchronization. Embodiments reduce the number of SYNC rasters to be scanned, which saves power at the UE and shortens the time needed to connect the UE.

[0117] Aspects of the present disclosure may be realized in any of various forms. For example, some aspects may be realized as a computer-implemented method, a computer- readable memory medium, or a computer system. Other aspects may be realized using one or more custom-designed hardware devices such as ASICs. Still other aspects may be realized using one or more programmable hardware elements such as FPGAs.

[0118] In some aspects, a non-transitory computer-readable memory medium may be configured so that it stores program instructions and / or data, where the program instructions, if executed by a computer system, cause the computer system to perform a method, e.g., any of a method aspects described herein, or, any combination of the method aspects described herein, or, any subset of any of the method aspects described herein, or, any combination of such subsets.

[0119] In some aspects, a device (e.g., a UE 106, a BS 102) may be configured to include a processor (or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method aspects described herein (or, any combination of the method aspects described herein, or, any subset of any of the method aspects described herein, or, any combination of such subsets). The device may be realized in any of various forms.

[0120] Although the aspects above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

Claims

CLAIMSWhat is claimed is:

1. A cell search method performed by a User Equipment (UE) to acquire timing and frequency synchronization within a cell by searching for a Synchronization Signal Block (SSB) signal on a set of frequency positions defined by synchronization (SYNC) rasters over a frequency bandwidth, the method comprising: deriving a frequency spacing that is a distance between two consecutive SYNC rasters based on a channel bandwidth of the cell and a SSB bandwidth; determining frequency positions of the SYNC rasters in the frequency bandwidth based on the derived frequency spacing between two consecutive SYNC rasters; and performing a frequency scan on the determined SYNC rasters comprising: measuring for the SSB signal at each SYNC raster; detecting the SSB signal on a frequency position of one of the SYNC rasters in the frequency bandwidth based on the frequency scan; and acquiring time and frequency synchronization within the cell using the detected SSB on the one of the SYNC rasters.

2. The method of claim 1, wherein the frequency spacing between consecutive SYNC rasters to acquire timing and frequency synchronization with a cell is derived using the following formula:A USYNC R]A7 _ RIA7 i A ^ChannelL rrasterD vvChannelD VVSSB ”r L rrasterwherein ^F^sNtgris the frequency spacing, BWchannelis the channel bandwidth of the cell, BWSSBis the bandwidth of the SSB, and ^F^terelis afrequency space between two consecutive channel positions of the cell.

3. The method of claim 1, wherein the frequency spacing between consecutive SYNC rasters to acquire timing and frequency synchronization with a cell is derived using the following formula:Wherein ^F^sNtgris the frequency spacing, BWchanneiis the channel bandwidth of the cell,is the bandwidth of the SSB, andis a frequency space between two consecutive channel positions of a cell, [xj represents a floor function that maps ‘x’ to the greatest integer less than ‘x’.

4. The method of claim 1, wherein determining the frequency spacing between consecutive SYNC rasters to acquire timing and frequency synchronization with the cell is further based on a reference channel bandwidth and the frequency spacing between two consecutive SYNC rasters derived for the reference channel bandwidth in a given frequency range.

5. A cell search method performed by a User Equipment (UE) to acquire timing and frequency synchronization within a cell by searching for a Synchronization Signal Block (SSB) on a set of frequency positions defined by synchronization (SYNC) rasters over a frequency bandwidth, the method comprising: determining a number of consecutive SYNC rasters for a given frequency range based on a channel bandwidth of the cell, a reference channel bandwidth, and areference SYNC raster step size, wherein the reference SYNC raster step size is associated with the reference channel bandwidth; performing a frequency scan on the number of determined SYNC rasters for the frequency range comprising: measuring for a SSB signal at each SYNC raster of the number of consecutive SYNC rasters over the frequency bandwidth; detecting the SSB signal on a frequency position of one of the SYNC rasters in the frequency bandwidth based on the frequency scan; and acquiring time and frequency synchronization within the cell using the detected SSB on the SYNC raster.

6. The method of claim 5, wherein determining the number of consecutive SYNC rasters to acquire timing and frequency synchronization with a cell is determined based on the difference between the channel bandwidth of the cell and the reference channel bandwidth divided by the reference SYNC raster step size.

7. The method of claim 6 further comprising: determining a number of reference SYNC rasters in the frequency range based on the reference SYNC raster step size; and selecting 1 out of ‘ / C reference SYNC rasters to be used as the SYNC rasters for the cell,ID g f where BWchanneirepresents the channel bandwidth of the cell, BWch^nnelrepresents the reference channel bandwidth andrepresents the reference SYNC raster step size, and [xj represents floor function that maps ‘x’ to the greatest integer less than ‘x’.

8. The method of claim 7, wherein a set of ‘ / C values are pre-defined for a channel bandwidth of the cell (BWchannei) in the frequency range and different values correspond to different channel bandwidths of the cell.

9. The method of claim 5, wherein the reference channel bandwidth is 5 MHz for Frequency Range 1 (FR1).

10. The method of claim 5, wherein the reference channel bandwidth is 50 MHz for Frequency Range 2 (FR2).

11. The method of claim 5, further comprising: determining a second number of consecutive SYNC rasters to acquire timing and frequency synchronization within the cell for the frequency range based on a second channel bandwidth of the cell, a second reference channel bandwidth, and the reference SYNC raster step size based on a second reference channel bandwidth; performing a second frequency scan on the second number of determined SYNC rasters comprising: measuring for the SSB signal at each SYNC raster of the second number of consecutive SYNC rasters over the frequency bandwidth; and failing to detect the SSB signal on the frequency position of the SYNC rasters in the bandwidth in the second frequency scan.

12. The method of claim 11, wherein a SYNC raster that is measured in the second frequency scan is not measured in the frequency scan on the number of determined SYNC rasters.

13. The method claims 1 or 5, wherein the channel bandwidth is determined based on an association of the channel bandwidth with a radio operating band in the frequency range.

14. The method of claim 13, wherein the radio operating band is associated with a plurality of channel bandwidths.

15. The method of claim 7, wherein the number of consecutive SYNC rasters and ‘ / C values are determined based on an association of the number of consecutive SYNC rasters or ‘ / C values with a radio operating band in the frequency range.

16. The method of claim 15, wherein the radio operating band is associated with a plurality of ‘ / C values that are used for determination of the number of consecutive SYNC rasters.

17. The method of claims 1 or 5, wherein the frequency spacing between two consecutive SYNC rasters is determined based on an association of the frequency spacing between the two consecutive SYNC rasters with a radio operating band in the frequency range.

18. The method of claim 17, wherein the radio operating band is associated with a plurality of frequency spacings between two consecutive SYNC rasters.

19. The method of claims 1 or 5, wherein the channel bandwidth is associated with a plurality of frequency spaces between two consecutive channel positions.

20. A wireless device that performs the methods of any of claims 1-19 for a cell search and acquires timing and frequency synchronization within a cell.

21. A non-transitory computer readable medium configured to store and execute instructions to perform the methods of any of claims 1-19.

22. A baseband processor configured to execute instructions to cause a wireless device to perform the methods of any of claims 1-19.

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