Synchronization signal block index scheme

Abstract

Aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may detect synchronization signal block (SSB) within a discovery reference signal (DRS) transmission window including more than 64 candidate SSB positions; determining an index value of the SSB based at least in part on an index scheme for the SSB included in the DRS transmission window, wherein the index scheme comprises one of a coherent index scheme or a non-coherent index scheme; and determining cell timing based at least in part on the index value. Numerous other aspects are described.

Description

[0001] This application is a divisional application of a patent application with an international filing date of January 21, 2021, an international application number of PCT / US2021 / 014383, a Chinese national filing date of January 21, 2021, an application number of 202180014452.3, and an invention title of "Synchronization Signal Block Indexing Scheme".

[0002] Cross - Reference to Related Applications

[0003] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 978,656, titled "SYNCHRONIZATION SIGNAL BLOCK INDEXING SCHEMES", filed on February 19, 2020, and U.S. Non - Provisional Patent Application No. 17 / 153,474, titled "SYNCHRONIZATION SIGNAL BLOCK INDEXING SCHEMES", filed on January 20, 2021, which are hereby incorporated by reference in their entirety.

[0004] Field of Disclosure

[0005] Aspects of the present disclosure generally relate to wireless communication and relate to techniques and apparatus for synchronization signal block indexing schemes.

[0006] Background

[0007] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ a multiple access technology capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single - Carrier Frequency Division Multiple Access (SC - FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD - SCDMA) systems, and Long Term Evolution (LTE). LTE / Advanced LTE is an enhanced set of the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0008] A wireless communication network may include several base stations (BSs) capable of supporting communication of several user equipments (UEs). The UEs may communicate with the BSs via a downlink and an uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, while the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, the BS may be referred to as a B node, gNB, access point (AP), radio head, transmission reception point (TRP), new radio (NR) BS, 5G B node, and so on.

[0009] The above multi-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipments to communicate at the urban, national, regional, and even global levels. NR (which may also be referred to as 5G) is an enhanced set of the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by using orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) (CP-OFDM) on the downlink (DL), CP-OFDM and / or SC-FDM (e.g., also referred to as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation to improve spectral efficiency, reduce costs, improve services, utilize new spectra, and better integrate with other open standards. However, as the demand for mobile broadband access continues to grow, there is a need for further improvement in LTE and NR technologies. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

[0010] Summary

[0011] In some aspects, a wireless communication method performed by a user equipment (UE) may include detecting a synchronization signal block (SSB) within a discovery reference signal (DRS) transmission window that includes more than 64 candidate SSB positions; determining an index value of the SSB at least in part based on an index scheme for the SSBs included in the DRS transmission window, where the index scheme includes one of the following: a coherent index scheme, where all SSBs are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non - coherent index scheme, where a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and determining cell timing at least in part based on the index value.

[0012] In some aspects, a wireless communication method performed by a base station may include: determining an index value of the SSBs included in a DRS transmission window that includes more than 64 candidate SSB positions at least in part based on an index scheme for the SSBs included in the DRS transmission window, where the index scheme includes one of the following: a coherent index scheme, where all SSBs are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non - coherent index scheme, where a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and transmitting the SSB and an indication of the index value at a candidate SSB position in the DRS transmission window.

[0013] In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: detect an SSB within a DRS transmission window that includes more than 64 candidate SSB positions; determine an index value of the SSB based at least in part on an indexing scheme for the SSBs included in the DRS transmission window, where the indexing scheme includes one of: a consecutive indexing scheme, where all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive indexing scheme, where a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and determine cell timing based at least in part on the index value.

[0014] In some aspects, a base station for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: determine an index value of the SSBs included in a DRS transmission window based at least in part on an indexing scheme for the SSBs included in the DRS transmission window that includes more than 64 candidate SSB positions, where the indexing scheme includes one of: a consecutive indexing scheme, where all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive indexing scheme, where a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and transmit the SSB and an indication of the index value at a candidate SSB position of the DRS transmission window.

[0015] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: detect an SSB within a DRS transmission window that includes more than 64 candidate SSB positions; determine an index value of the SSB at least in part based on an index scheme for the SSBs included in the DRS transmission window, wherein the index scheme includes one of the following: a consecutive index scheme, in which all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive index scheme, in which a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and determine cell timing at least in part based on the index value.

[0016] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to: determine an index value of the SSBs included in the DRS transmission window at least in part based on an index scheme for the SSBs included in a DRS transmission window that includes more than 64 candidate SSB positions, wherein the index scheme includes one of the following: a consecutive index scheme, in which all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive index scheme, in which a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and transmit the SSB and an indication of the index value at candidate SSB positions in the DRS transmission window.

[0017] In some aspects, an apparatus for wireless communication may include: means for detecting an SSB within a DRS transmission window that includes more than 64 candidate SSB positions; means for determining an index value of the SSB based at least in part on an indexing scheme for the SSBs included in the DRS transmission window, wherein the indexing scheme includes one of: a consecutive indexing scheme, wherein all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive indexing scheme, wherein a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and means for determining cell timing based at least in part on the index value.

[0018] In some aspects, an apparatus for wireless communication may include: means for determining an index value of the SSBs included in a DRS transmission window based at least in part on an indexing scheme for the SSBs included in the DRS transmission window that includes more than 64 candidate SSB positions, wherein the indexing scheme includes one of: a consecutive indexing scheme, wherein all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-consecutive indexing scheme, wherein a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and means for transmitting the SSB and an indication of the index value at the candidate SSB positions of the DRS transmission window.

[0019] Aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems substantially as described herein with reference to the figures and the specification and as illustrated in the figures and the specification.

[0020] The foregoing has outlined rather broadly the features and technical advantages of examples according to the present disclosure in an effort to enable the following detailed description to be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples can be readily used as a basis for modifying or designing other structures for carrying out the same purposes as the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both as to their organization and method of operation, as well as associated advantages, will be better understood by reference to the following description when considered in conjunction with the accompanying drawings. Each drawing is provided for purposes of illustration and description, and is not to be construed as limiting the scope of the claims. Brief Description of the Drawings

[0022] To gain a more detailed understanding of the features set forth above in connection with the present disclosure, reference may be made to the various aspects described in more specific detail below, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the present disclosure and should not be considered as limiting its scope, as the description may admit of other equally effective aspects. The same reference numerals in different drawings or in the same drawing may identify the same or similar elements.

[0023] Figure 1 is a block diagram illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0024] Figure 2 is a block diagram illustrating an example of a base station and a UE in communication in a wireless communication network in accordance with various aspects of the present disclosure.

[0025] Figure 3 is a diagram illustrating an example of a synchronization signal (SS) hierarchy in accordance with various aspects of the present disclosure.

[0026] Figure 4 is a diagram illustrating an example of candidate synchronization signal block (SSB) positions in an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure.

[0027] Figure 5 is a diagram illustrating an example of SSB positions in a licensed radio frequency spectrum band with a 120 kHz subcarrier spacing in accordance with various aspects of the present disclosure.

[0028] Figure 6 is a diagram illustrating an example of SSB positions in a licensed radio frequency spectrum band with a 240 kHz subcarrier spacing in accordance with various aspects of the present disclosure.

[0029] Figures 7 - 11 is a diagram illustrating an example of a synchronization signal block indexing scheme in accordance with various aspects of the present disclosure.

[0030] Figure 12FIG. is an illustration of an example process performed, for example, by a user equipment, in accordance with various aspects of the present disclosure.

[0031] Figure 13 FIG. is an illustration of an example process performed, for example, by a base station, in accordance with various aspects of the present disclosure.

[0032] Detailed Description

[0033] The various aspects of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art should appreciate that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the present disclosure. For example, any number of the aspects set forth herein may be used to implement an apparatus or practice a method. Additionally, the scope of the present disclosure is intended to cover such apparatus or methods practiced using other structures, functionality, or structures and functionality in addition to or as a supplement to the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of a claim.

[0034] Certain aspects of a telecommunications system will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in detail hereinafter and illustrated in the drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0035] Note that while aspects may be described herein using terminology typically associated with 3G and / or 4G wireless technologies, aspects of the present disclosure may be applied in communication systems based on other generations (such as 5G and later generations, including NR technologies).

[0036] Figure 1FIG. is an illustration of a wireless network 100 in which aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include several BSs 110 (shown as BS110a, BS110b, BS110c, and BS110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, B node, gNB, 5G B node (NB), access point, transmission reception point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the coverage area of a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0037] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., with a radius of several kilometers) and may allow unconstrained access by UEs having a service subscription. A pico cell may cover a relatively small geographic area and may allow unconstrained access by UEs having a service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow constrained access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 the example shown, BS110a may be a macro BS for macro cell 102a, BS110b may be a pico BS for pico cell 102b, and BS110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "B node", "5G NB", and "cell" may be used interchangeably herein.

[0038] In some aspects, a cell may not have to be stationary, and the geographic area of a cell may move according to the location of a mobile BS. In some aspects, BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces, such as direct physical connections, virtual networks, and / or analogs using any suitable transport network.

[0039] The wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send the transmission of the data to a downstream station (e.g., a UE or a BS). A relay station can also be a UE that can relay transmissions for other UEs. In Figure 1 the example shown in

[0040] the relay BS 110d can communicate with the macro BS 110a and the UE 120d to facilitate communication between the BS 110a and the UE 120d. The relay BS may also be referred to as a relay station, a relay base station, a relay, etc.

[0041] The network controller 130 may be coupled to the set of BSs and may provide coordination and control of these BSs. The network controller 130 may communicate with each BS via a backhaul. These BSs may also communicate with each other directly or indirectly, e.g., via a wireless or wired backhaul.

[0042] The UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, a ultrabook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0043] Some UEs may be considered machine type communication (MTC) UEs, or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or provide connectivity to the network, for example, via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, and / or may be implemented as narrowband IoT (NB-IoT) devices. Some UEs may be considered customer premise equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120, such as a processor component, a memory component, etc. In some aspects, the processor component and the memory component may be coupled together. For example, the processor component (e.g., one or more processors) and the memory component (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, electrically coupled, etc.

[0044] Generally, any number of wireless networks may be deployed in a given geographical area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. The RAT may also be referred to as a radio technology, an air interface, etc. The frequency may also be referred to as a carrier, a frequency channel, etc. Each frequency may support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs. In some cases, an NR or 5G RAT network may be deployed.

[0045] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., communicate with each other without using base station 110 as an intermediary). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), a mesh network, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by base station 110.

[0046] As indicated above, Figure 1 is provided as an example. Other examples may be different from the example regarding Figure 1 described.

[0047] Figure 2FIG. 200 is a block diagram of a design 200 of a base station 110 and a UE 120, where the base station 110 and the UE 120 can be Figure 1 one of the base stations and one of the UEs in. The base station 110 may be equipped with T antennas 234a to 234t, and the UE 120 may be equipped with R antennas 252a to 252r, where generally T≥1 and R≥1.

[0048] At the base station 110, a transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCSs) for the UE at least in part based on channel quality indicators (CQIs) received from each UE, process (e.g., encode and modulate) the data for the UE at least in part based on the MCSs selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRSs)) and synchronization signals (e.g., primary synchronization signals (PSSs) and secondary synchronization signals (SSSs)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, overhead symbols, and / or reference symbols when applicable, and provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 may process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from the modulators 232a to 232t may be transmitted via the T antennas 234a to 234t, respectively. According to various aspects described in more detail below, position coding may be utilized to generate synchronization signals to convey additional information.

[0049] At the UE 120, antennas 252a through 252r may receive downlink signals from the base station 110 and / or other base stations and may provide the received signals to demodulators (DEMOD) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, down-convert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 may obtain the received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols when applicable, and provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide the decoded data for the UE 120 to the data sink 260, and provide the decoded control information and system information to the controller / processor 280. The channel processor may determine the reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in a housing.

[0050] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 and control information from the controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 when applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, the uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 when applicable, and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and provide the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0051] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other component may perform one or more techniques associated with the synchronization signal block indexing scheme, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 any other component may perform or direct operations of, for example, Figure 12 procedure 1200, Figure 13 procedure 1300, and / or other procedures as described herein. Memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. In some aspects, memories 242 and / or memory 282 may include non-transitory computer-readable media storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station 110 and / or the UE 120 (e.g., executed directly, or after compilation, conversion, interpretation, etc.), may perform or direct operations of, for example, Figure 12 procedure 1200, Figure 13 procedure 1300, and / or other procedures as described herein. In some aspects, executing the instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, etc. The scheduler 246 may schedule the UE for data transmission on the downlink and / or uplink.

[0052] In some aspects, the UE 120 may include: means for detecting an SSB within a discovery reference signal (DRS) transmission window including more than 64 candidate SSB positions; means for determining an index value of the SSB based at least in part on an indexing scheme for the SSBs included in the DRS transmission window, where the indexing scheme includes one of the following: a coherent indexing scheme, where all SSBs are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-coherent indexing scheme, where a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; means for determining cell timing based at least in part on the index value, etc. In some aspects, such means may include one or more components of the UE 120 described in conjunction with Figure 2 such as the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the MOD 254, the antenna 252, the DEMOD 254, the MIMO detector 256, the receive processor 258, etc.

[0053] In some aspects, base station 110 may include: means for determining an index value of an SSB included in a DRS transmission window based at least in part on an index scheme for the SSBs included in a DRS transmission window that includes more than 64 candidate SSB positions, wherein the index scheme includes one of the following: a consecutive index scheme, wherein all SSBs are consecutively indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, or a non-consecutive index scheme, wherein a first subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; means for transmitting the SSB and an indication of the index value in a candidate SSB position of the DRS transmission window, and so on. In some aspects, such means may include one or more components of base station 110 described in conjunction with Figure 2 those described, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and so on.

[0054] As indicated above, Figure 2 is provided as an example. Other examples may differ from the example described with respect to Figure 2 those described.

[0055] Figure 3 is a diagram illustrating example 300 of a synchronization signal (SS) hierarchy in accordance with various aspects of the present disclosure. As Figure 3As shown, the SS tier may include SS burst sets 305 (e.g., SS burst sets 305a, 305b, etc.), which may include multiple SS bursts 310 (e.g., SS bursts 310a, 310b, 310c, etc.), shown as SS burst 0 to SS burst N-1, where N is the maximum number of repetitions of SS bursts 310 that can be transmitted by the base station. As further shown, each SS burst 310 may include one or more SS blocks (SSBs) 315 (e.g., SSBs 315a, 315b, 315c, 315x, 315y, 315z, etc.), shown as SSB 0 to SSB M-1, where M is the maximum number of SSBs 315 that can be carried by the SS burst 310. In some aspects, different SSBs 315 may be beamformed differently (e.g., transmitted using different beams), and may be used for beam management, beam selection, etc. (e.g., as part of an initial network access procedure). The SS burst set 305 may be transmitted periodically by a wireless node (e.g., base station 110), such as every X milliseconds, as Figure 3 shown in. In some aspects, the SS burst set 305 may have a fixed or dynamic length, shown as Y milliseconds in Figure 3 . In some cases, the SS burst set 305 or the SS burst 310 may be referred to as a discovery reference signal (DRS) transmission window, an SSB measurement time configuration (SMTC) window, etc.

[0056] In some aspects, the SSB 315 may include resources carrying a primary synchronization signal (PSS) 320 (e.g., PSS 320a, 320b, etc.), a secondary synchronization signal (SSS) 325 (e.g., SSS 325a, 325b, etc.), a physical broadcast channel (PBCH) 330 (e.g., PBCH330a, 330b, etc.), and so on. In some aspects, multiple SSBs 315 are included in the SS burst 310 (e.g., transmissions on different beams), and the PSS 320, SSS 325, and / or PBCH 330 may be the same across each SSB 315 of the SS burst 310. In some aspects, a single SSB 315 may be included in the SS burst 310. In some aspects, the SSB 315 may be at least four symbols (e.g., OFDM symbols) in length, where each symbol carries one or more of the PSS 320 (e.g., occupies one symbol), the SSS 325 (e.g., occupies one symbol), and / or the PBCH 330 (e.g., occupies two symbols). In some aspects, the SSB 315 may be referred to as an SS / PBCH block.

[0057] In some aspects, the symbols of the SSB 315 are contiguous, as Figure 3As shown. In some aspects, the symbols of the SSB 315 are non-coherent. Similarly, in some aspects, one or more SSBs 315 of the SS burst 310 can be transmitted in coherent radio resources (e.g., coherent symbols) during one or more time slots. Additionally or alternatively, one or more SSBs 315 of the SS burst 310 can be transmitted in non-coherent radio resources.

[0058] In some aspects, the SS burst 310 can have a burst period, and the SSBs 315 of the SS burst 310 can be transmitted by a radio node (e.g., the base station 110) according to this burst period. In this case, these SSBs 315 can be repeated during each SS burst 310. In some aspects, the SS burst set 305 can have a burst set periodicity, whereby the SS bursts 310 of the SS burst set 305 are transmitted by a radio node according to a fixed burst set periodicity. In other words, the SS bursts 310 can be repeated during each SS burst set 305.

[0059] In some aspects, the SSB 315 can include an SSB index, which can correspond to the beam used to carry the SSB 315. The UE 120 can use different receive (Rx) beams to monitor and / or measure the SSB 315 during the initial network access procedure. At least partially based on this monitoring and / or measurement, the UE 120 can indicate to the base station 110 one or more SSBs 315 having the best signal parameters (e.g., reference signal received power (RSRP) parameter, etc.). The base station 110 and the UE 120 can use the indicated one or more SSBs 315 to select one or more beams for communication between the base station 110 and the UE 120 (e.g., for the random access channel (RACH) procedure, etc.). Additionally or alternatively, the UE 120 can use the SSB 315 and / or the SSB index to determine the cell timing of the cell (e.g., serving cell) via which the SSB 315 is received, as described in more detail below.

[0060] As indicated above, Figure 3 is provided as an example. Other examples can be different from the examples regarding Figure 3 described.

[0061] Figure 4 is a diagram illustrating an example 400 of candidate SSB positions in an unlicensed radio frequency spectrum band according to various aspects of the present disclosure. The unlicensed radio frequency spectrum band can be referred to herein as an unlicensed band and can include bands reserved for shared or unlicensed use, bands reserved for licensed use but operating in an unlicensed operation mode, etc.

[0062] As an example, unlicensed bands can include one or more radio frequencies (e.g., one or more radio frequency bands) included in the radio spectrum (e.g., the portion of the electromagnetic spectrum corresponding to radio frequencies, or frequencies below approximately 300 gigahertz (GHz)). In some aspects, an unlicensed band can include one or more bands that are open for shared use by any device compliant with the rules of a regulatory body (e.g., associated with a particular country) to communicate via the one or more bands. For example, an unlicensed band can include one or more radio frequencies between approximately 5 GHz and approximately 6 GHz. As a more specific example, an unlicensed band can include one or more radio frequencies between approximately 5.15 GHz and approximately 5.825 GHz.

[0063] As another example, an unlicensed band can include one or more bands defined by the Federal Communications Commission (FCC) of the United States as unlicensed national information infrastructure (U-NII) radio bands. The U-NII radio bands can include, for example, a first band between approximately 5.15 GHz and approximately 5.25 GHz (e.g., U-NII low band), a second band between approximately 5.25 GHz and approximately 5.35 GHz (e.g., U-NII mid band), a third band between approximately 5.47 GHz and approximately 5.725 GHz (e.g., U-NII global band), and / or a fourth band between approximately 5.725 GHz and approximately 5.825 GHz (e.g., U-NII higher band).

[0064] Devices operating in an unlicensed band (e.g., UE 120, base station 110, etc.) can contend for access to the unlicensed band (such as by performing a listen-before-talk (LBT) procedure) before obtaining access to the unlicensed band and / or communicating on the unlicensed band. The LBT procedure can include performing a clear channel assessment (CCA) procedure to determine whether the channel of the unlicensed band is available. When the device determines that the channel of the unlicensed band is not available (e.g., because another device is already using the channel), the CCA procedure can be performed on the channel again later. The CCA procedure can include detecting the energy level on the channel of the unlicensed band and determining whether the energy level meets a threshold. When the energy level does not meet (e.g., is less than, or less than or equal to) the threshold, the CCA procedure is successful and the contention for accessing the unlicensed band channel can be successful. When the energy level meets (e.g., is greater than, or greater than or equal to) the threshold, the CCA procedure is unsuccessful and the contention for accessing the unlicensed band channel may be unsuccessful. When the CCA procedure is successful, the device can transmit on the channel of the unlicensed band.

[0065] Since channel access is not guaranteed in the unlicensed band, a larger number of candidate SSB positions can be used in the unlicensed band compared to the licensed band. For example, the DRS transmission window in the licensed band may include 8 candidate SSB positions. A candidate SSB position is a position (e.g., in the time domain) where an SSB can be (e.g., permitted or allowed to be) transmitted (regardless of whether the SSB is actually transmitted at that position).

[0066] As shown by reference numeral 405, in the unlicensed band with a subcarrier spacing (SCS) of 30 kilohertz (kHz), compared to 8 candidate SSB positions in the licensed band with an SCS of 30 kHz, 20 candidate SSB positions may be present in a 5 millisecond DRS transmission window. In the unlicensed band, the SSB may have 8 possible SSB index values (e.g., from 0 to 7, shown in parentheses), and these index values may be repeated one or more times at different SSB candidate positions in the DRS transmission window. As shown, candidate SSB positions 0 to 7 may each carry an SSB with index values 0 to 7; candidate SSB positions 8 to 15 may each carry an SSB with index values 0 to 7; and candidate SSB positions 16 to 19 may each carry an SSB with index values 0 to 3. In this way, compared to the licensed band, for the unlicensed band, the number of opportunities for SSB transmission in the DRS transmission window is increased to mitigate the lower reliability of the unlicensed band (due to shared channel characteristics, access contention, etc.).

[0067] As shown by reference numeral 410, in the unlicensed band with an SCS of 15 kHz, compared to 8 candidate SSB positions in the licensed band with an SCS of 30 kHz, 10 candidate SSB positions may be present in a 5 millisecond DRS transmission window. In the unlicensed band, the SSB may have 8 possible SSB index values (e.g., from 0 to 7, shown in parentheses), and a portion of these index values may be repeated at different SSB candidate positions in the DRS transmission window. As shown, candidate SSB positions 0 to 7 may each carry an SSB with index values 0 to 7; and candidate SSB positions 8 and 9 may each carry an SSB with index values 0 and 1. In this way, compared to the licensed band, for the unlicensed band, the number of opportunities for SSB transmission in the DRS transmission window is increased to mitigate the lower reliability of the unlicensed band (due to shared channel characteristics, access contention, etc.).

[0068] In Example 400, the DRS transmission window has a duration of 5 milliseconds, which can be the maximum DRS transmission window duration. In some aspects, the DRS transmission window can have a duration such as 0.5 milliseconds, 1 millisecond, 2 milliseconds, 3 milliseconds, 4 milliseconds, or 5 milliseconds. In some aspects, UE 120 can assume that the DRS transmission window duration is 5 milliseconds unless UE 120 receives other indications. In Example 400, for 15 kHz SCS, the maximum number of candidate SSB positions within the DRS transmission window is 10, while for 30 kHz SCS, the maximum number of such candidate SSB positions is 20.

[0069] For 15 kHz or 30 kHz SCS, the 8 candidate SSB positions for the licensed band do not occupy the entire DRS transmission window, leaving room for additional candidate SSB positions in the unlicensed band (e.g., up to 12 additional candidate SSB positions for 30 kHz SCS and up to 2 additional candidate SSB positions for 15 kHz SCS). For 120 kHz SCS (described in more detail below Figure 5 ), 64 candidate SSB positions can be used in the licensed band and can occupy the entire DRS transmission window, leaving no room for additional candidate SSB positions in the unlicensed band according to the existing candidate SSB pattern. For 240 kHz SCS (described in more detail below Figure 6 ), 64 candidate SSB positions can be used in the licensed band and can occupy half of the DRS transmission window. Some of the techniques and apparatuses described herein allow for adding additional candidate SSB positions for the 120 kHz or 240 kHz unlicensed band by introducing a new design or pattern for the SSB candidate positions. Additionally, some of the techniques and apparatuses described herein introduce various indexing schemes for indexing the additional candidate SSB positions (e.g., assigning an SSB index to an additional candidate SSB position).

[0070] As indicated above, Figure 4 is provided as an example. Other examples may be different from the example described with respect to Figure 4 .

[0071] Figure 5 is a diagram illustrating Example 500 of SSB positions in a licensed radio frequency spectrum band with a 120 kHz subcarrier spacing in accordance with various aspects of the present disclosure.

[0072] As shown by reference numeral 505, in a configuration where each time slot for 120 kHz SCS in a licensed frequency band includes 14 orthogonal frequency division multiplexing (OFDM) symbols, up to 4 SSBs can be transmitted across two consecutive time slots. As shown by reference numeral 510, for 120 kHz SCS, a time slot can have a duration of 0.125 milliseconds. As shown by reference numeral 515, a DRS transmission window with a duration of 5 milliseconds in a frequency band with 120 kHz SCS can be configured with double time slot gaps (e.g., having a length of 0.25 milliseconds) after every 8 time slots (e.g., 1 millisecond) including an SSB, for a total of four gaps (covering 8 time slots). Thus, the DRS transmission window can include up to 64 SSBs.

[0073] As indicated above, according to existing SSB patterns (such as the pattern shown in Figure 5 ), this configuration does not leave room for additional candidate SSB positions in the unlicensed frequency band. Some of the techniques and apparatuses described herein allow for adding additional candidate SSB positions for the 120 kHz unlicensed frequency band by introducing a new design or pattern for candidate SSB positions. Additionally, some of the techniques and apparatuses described herein introduce various indexing schemes for indexing additional candidate SSB positions (e.g., assigning an SSB index to an additional candidate SSB position) and processing SSBs at least partially based on the indexing scheme.

[0074] As indicated above, Figure 5 is provided as an example. Other examples may be different from the example described with respect to Figure 5

[0075] Figure 6 is a diagram illustrating example 600 of SSB positions in a licensed radio frequency spectrum band with a 240 kHz subcarrier spacing in accordance with various aspects of the present disclosure.

[0076] ​As shown by reference numeral 605, in a configuration where each time slot for 240 kHz SCS in a licensed band includes 14 OFDM symbols, up to 8 SSBs can be transmitted across four consecutive time slots. As shown by reference numeral 610, for 240 kHz SCS, a time slot can have a duration of 0.0625 milliseconds. As shown by reference numeral 615, a DRS transmission window having a duration of 5 milliseconds on a band with 240 kHz SCS can be configured with a four-time-slot gap (e.g., having a length of 0.25 milliseconds) after the first 16 time slots (e.g., 1 millisecond) including the SSB. Further, as shown by reference numeral 620, for 240 kHz SCS, the SSB can occupy only the first half (e.g., the first 2.25 milliseconds) of the DRS transmission window. Thus, the DRS transmission window can include up to 64 SSBs. With this configuration, the SSB positions for 240 kHz SCS can be time-aligned with the SSB positions for 120 kHz SCS (at least in the first half of the DRS transmission window for 240 kHz).

[0077] As indicated above, according to existing SSB patterns (such as the pattern shown in Figure 6 ), this configuration does not leave room for additional candidate SSB positions in the unlicensed band (at least in the first half of the DRS transmission window). Some of the techniques and apparatuses described herein permit adding additional candidate SSB positions for the 240 kHz unlicensed band by introducing a new design or pattern for candidate SSB positions. In addition, some of the techniques and apparatuses described herein introduce various indexing schemes for indexing additional candidate SSB positions (e.g., assigning an SSB index to an additional candidate SSB position) and processing SSBs at least partially based on the indexing scheme.

[0078] As indicated above, Figure 6 is provided as an example. Other examples may be different from the example described with respect to Figure 6 .

[0079] Figure 7 is a diagram illustrating example 700 of an SSB indexing scheme in accordance with various aspects of the present disclosure. As shown in Figure 7 , base station 110 and UE 120 can communicate with each other.

[0080] As shown by reference numeral 705, base station 110 may determine an SSB index value for an SSB (or a set of SSB index values corresponding to an SSB set) at least in part based on an SSB index scheme. The SSB may be included in a DRS transmission window. In some aspects, the DRS transmission window may include more than 64 candidate SSB positions. Additionally or alternatively, the DRS transmission window may have a duration of 5 milliseconds. In some aspects, base station 110 may determine an SSB index value for SSB transmission on an unlicensed frequency band.

[0081] In some aspects, the SSB index scheme is a scheme in which a first subset of SSBs in the SSB set included in the DRS transmission window is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs in the SSB set included in the DRS transmission window is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and the earliest SSB included in the second SSB subset occurs before at least one SSB in the first SSB subset and has an index value higher than all SSBs in the first SSB subset. This is referred to herein as a "non-coherent index scheme" and is described in more detail below in conjunction with Figure 8 more detail.

[0082] In some aspects, the SSB index scheme is a scheme in which all SSBs included in the DRS transmission window are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window. This is referred to herein as a "coherent index scheme" and is described in more detail below in conjunction with Figure 9 more detail.

[0083] As shown by reference numeral 710, base station 110 may transmit an SSB (e.g., in an unlicensed frequency band), which may include an indication of the SSB index value determined by base station 110 according to an index scheme (e.g., a coherent index scheme or a non-coherent index scheme). Base station 110 may transmit the SSB at a candidate SSB position in the DRS transmission window (e.g., one of more than 64 candidate SSB positions in the DRS transmission window). In some aspects, the SSB index value may be indicated at least in part based on a PBCH demodulation reference signal (DMRS) sequence index, the subcarrier spacing (SCS) of the frequency band on which the SSB is transmitted, the PBCH payload, etc. In some aspects, base station 110 may transmit the SSB at all candidate SSB positions. In some aspects, base station 110 may transmit the SSB at fewer than all candidate SSB positions, such as when fewer than all candidate SSB positions are configured or used by base station 110 for actual SSB transmission, when base station 110 cannot obtain channel access to the unlicensed frequency band in a portion of the DRS transmission window, etc.

[0084] As shown by reference numeral 715, the UE 120 may detect an SSB within a DRS transmission window on an unlicensed frequency band and may determine an SSB index value for the SSB based at least in part on an SSB index scheme. As described above, the DRS transmission window may include more than 64 candidate SSB positions, and the UE 120 may search (e.g., monitor) the candidate SSB positions within the DRS transmission window to obtain an SSB. As described above, the index scheme may be a coherent index scheme or a non - coherent index scheme. In some aspects, a wireless communication standard may specify whether to use a coherent index scheme or a non - coherent index scheme.

[0085] As shown by reference numeral 720, the UE 120 may determine cell timing based at least in part on the SSB index value. For example, an SSB with a particular index value may be located (e.g., in the time domain) at a particular candidate SSB position fixed according to a wireless communication standard. After determining the SSB index value, the UE 120 may identify a known position where the SSB with that index value will be located and may adjust the cell timing accordingly (e.g., by adjusting the timing of a slot boundary, the timing of a symbol boundary, etc.).

[0086] As shown by reference numeral 725, the UE 120 and the base station 110 may communicate based at least in part on the cell timing. For example, the UE 120 may use the determined cell timing to synchronize communication with the base station 110 (e.g., to transmit uplink communication in a proper time slot and / or symbol aligned with the base station 110, to receive downlink communication in a proper time slot and / or symbol aligned with the base station 100, etc.).

[0087] Using more than 64 candidate SSB positions in a DRS transmission window on an unlicensed frequency band may enable the base station 110 to transmit an SSB in the DRS transmission window (e.g., in a later part of the window), even if the base station 110 is unable to access the unlicensed frequency band due to conflicts and / or contentions on the unlicensed frequency band (e.g., in an earlier part of the window). This may reduce the waiting time compared to waiting for the next DRS transmission window to attempt an SSB transmission. Additionally, this may improve reliability by enabling the UE 120 to combine multiple SSBs within the same DRS transmission window (e.g., for decoding purposes).

[0088] As indicated above, Figure 7 is provided as an example. Other examples may be different from the example regarding Figure 7 described.

[0089] Figure 8 is a diagram illustrating an example 800 of an SSB index scheme in accordance with various aspects of the present disclosure. Figure 8Shows example candidate SSB positions and corresponding SSB index values in the unlicensed radio frequency spectrum band with 120 kHz SCS.

[0090] As described above in connection with Figure 5 In the configuration where each time slot for 120 kHz SCS on the licensed frequency band includes 14 OFDM symbols, up to 4 SSBs can be transmitted across two consecutive time slots. As indicated by reference numeral 805, for 120 kHz SCS, a time slot can have a duration of 0.125 milliseconds. As indicated by reference numeral 810, a DRS transmission window with a duration of 5 milliseconds on a frequency band with 120 kHz SCS may not be configured with a double-time-slot gap after every 8 time slots including an SSB. For example, four candidate SSB positions can be included in the ninth and tenth time slots in the DRS transmission window (e.g., between 1 millisecond and 1.25 milliseconds), in the nineteenth and twentieth time slots in the DRS transmission window (e.g., between 2.25 milliseconds and 2.50 milliseconds), in the twenty-ninth and thirtieth time slots in the DRS transmission window (e.g., between 3.5 milliseconds and 3.75 milliseconds), and / or in the thirty-ninth and fortieth time slots in the DRS transmission window (e.g., between 4.75 milliseconds and 5 milliseconds).

[0091] In some aspects, the DRS transmission window can include at least one candidate SSB position in each time slot of the DRS transmission window. Additionally or alternatively, the DRS transmission window can include a set of candidate SSB positions (e.g., up to four candidate SSB positions) in every 0.25 millisecond period (e.g., every two time slots) of the DRS transmission window. With this candidate SSB pattern, the DRS transmission window can include up to 80 candidate SSB positions (e.g., 64 candidate SSB positions also included in the licensed frequency band plus 16 additional candidate SSB positions in the four double-time-slot gaps used in the licensed frequency band). In this way, additional candidate SSB positions can be added for the 120 kHz unlicensed frequency band by introducing a new design or pattern for SSB candidate positions. Using the additional candidate SSB positions in the DRS transmission window on the unlicensed frequency band can enable the base station 110 to transmit an SSB in the DRS transmission window (e.g., in the later part of the window), even if the base station 110 is unable to access the unlicensed frequency band (e.g., the earlier part of the window) due to conflicts and / or contentions on the unlicensed frequency band. This can reduce the waiting time compared to waiting for the next DRS transmission window to attempt an SSB transmission. Additionally, this can improve reliability by enabling the UE 120 to combine multiple SSBs within the same DRS transmission window (e.g., for decoding purposes).

[0092] As Figure 8As shown, in some aspects, the SSBs can be indexed according to a non - coherent indexing scheme. In this scheme, a first SSB subset of the set of SSBs included in the DRS transmission window (a part of which is shown by reference numeral 815) is indexed in ascending order from an earlier position to a later position in the DRS transmission window. In addition, a second SSB subset of the set of SSBs included in the DRS transmission window (a part of which is shown by reference numeral 820) is indexed in ascending order from an earlier position to a later position in the DRS transmission window. Further, the earliest SSB 825 included in the second SSB subset occurs before at least one of the SSBs in the first SSB subset and has an index value higher than all of the SSBs in the first SSB subset (e.g., shown as index value 64).

[0093] In example 800, the first SSB subset occurs in the first through eighth time slots of the DRS transmission window (e.g., between 0 ms and 1 ms), in the eleventh through eighteenth time slots of the DRS transmission window (e.g., between 1.25 ms and 2.25 ms), in the twenty - first through twenty - eighth time slots of the DRS transmission window (e.g., between 2.5 ms and 3.5 ms), and in the thirty - first through thirty - eighth time slots of the DRS transmission window (e.g., between 3.75 ms and 4.75 ms). The SSBs in the first SSB subset are indexed from 0 to 63 in the order in which these SSBs occur in the time domain within the DRS transmission window (64 SSBs in total).

[0094] Also in Example 800, the second SSB subset occurs in the ninth and tenth time slots of the DRS transmission window (e.g., between 1 ms and 1.25 ms), in the nineteenth and twentieth time slots of the DRS transmission window (e.g., between 2.25 ms and 2.50 ms), in the twenty-ninth and thirtieth time slots of the DRS transmission window (e.g., between 3.5 ms and 3.75 ms), and in the thirty-ninth and fortieth time slots of the DRS transmission window (e.g., between 4.75 ms and 5 ms). The SSBs in the second SSB subset are indexed from 64 to 79 in the order in which these SSBs occur in the time domain within the DRS transmission window (a total of 16 SSBs). This results in the entire set of SSBs included in the DRS transmission window being non-coherently indexed from the start to the end of the DRS transmission window. For example, the first 16 SSBs will be indexed from 0 - 15, the next 4 SSBs will be indexed from 64 - 67, the next 16 SSBs will be indexed from 16 - 31, the next 4 SSBs will be indexed from 68 - 71, the next 16 SSBs will be indexed from 32 - 47, the next 4 SSBs will be indexed from 72 - 75, the next 16 SSBs will be indexed from 48 - 63, and the last 4 SSBs will be indexed from 76 - 79.

[0095] This non-coherent indexing scheme enables backward compatibility, where the legacy SSB indexing scheme can be reused for SSB indices 0 to 63. In this way, cell timing determination can be performed by legacy UEs without introducing additional complexity.

[0096] As indicated above, Figure 8 is provided as an example. Other examples may be different from the example Figure 8 described.

[0097] Figure 9 is a diagram illustrating Example 900 of an SSB indexing scheme in accordance with various aspects of the present disclosure. Figure 9 Shows the same example candidate SSB locations described above in connection with Figure 8 . In Figure 9 , a coherent indexing scheme is shown.

[0098] As Figure 9As shown, in some aspects, SSBs can be indexed according to a consecutive indexing scheme. In this scheme, all SSBs included in the DRS transmission window are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window. For example, for 80 candidate SSB positions, the 80 SSBs will be indexed from 0 to 79 in ascending order from the start to the end of the DRS transmission window. Compared with a non-consecutive indexing scheme, this consecutive indexing scheme enables the UE 120 to perform PBCH combining across different candidate SSB positions with reduced complexity, thereby saving UE resources (e.g., processing resources, memory resources, etc.).

[0099] As indicated above, Figure 9 is provided as an example. Other examples may be different from the example regarding Figure 9 described.

[0100] Figure 10 is a diagram illustrating Example 1000 of an SSB indexing scheme according to various aspects of the present disclosure. Figure 10 Shows example candidate SSB positions in an unlicensed radio frequency spectrum band with 240 kHz SCS.

[0101] As described above in connection with Figure 6 In a configuration where each time slot for 240 kHz SCS in a licensed frequency band includes 14 OFDM symbols, up to 8 SSBs can be transmitted across four consecutive time slots. As indicated by reference numeral 1005, for a 240 kHz SCS, a time slot can have a duration of 0.0625 milliseconds. As shown, the DRS transmission window for the unlicensed frequency band can include a first half 1010 (e.g., from 0 milliseconds to 2.25 milliseconds of the window, up to 64 SSBs) that carries SSBs in the window and a second part 1015 (e.g., in the window from 2.25 milliseconds to 5 milliseconds, up to 64 SSBs) that also carries SSBs in the window. With this configuration, the DRS transmission window can have up to 128 candidate SSB positions.

[0102] As indicated by reference numeral 1020, in some aspects, the DRS transmission window can include a four-time-slot gap (e.g., having a length of 0.25 milliseconds) after every 16 time slots (e.g., 1 millisecond) that include SSBs. For example, the DRS transmission window can not include candidate SSB positions (e.g., can include gaps in candidate SSB positions) in the seventeenth to twentieth time slots (e.g., between 1 millisecond and 1.25 milliseconds), in the thirty-seventh to fortieth time slots (e.g., between 2.25 milliseconds and 2.50 milliseconds), in the fifty-seventh to sixtieth time slots (e.g., between 3.5 milliseconds and 3.75 milliseconds), and / or in the seventy-seventh to eightieth time slots (e.g., between 4.75 milliseconds and 5 milliseconds).

[0103] In some aspects, the SSBs may be indexed according to a consecutive indexing scheme. In this scheme, all the SSBs included in the DRS transmission window are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window. For example, for 128 candidate SSB positions, the 128 SSBs will be indexed from 0 to 127 in ascending order from the start of the DRS transmission window towards the end of the DRS transmission window. Compared with a non-consecutive indexing scheme, this consecutive indexing scheme enables the UE 120 to perform PBCH combining across different candidate SSB positions with reduced complexity, thereby saving UE resources (e.g., processing resources, memory resources, etc.). In addition, this indexing scheme achieves backward compatibility, where the legacy SSB indexing scheme can be reused for SSB indexes 0 to 63. In this way, cell timing determination can be performed by legacy UEs without introducing additional complexity.

[0104] As indicated above, Figure 10 is provided as an example. Other examples may be different from the example regarding Figure 10 described.

[0105] Figure 11 is a diagram illustrating Example 1100 of an SSB indexing scheme according to various aspects of the present disclosure. Figure 11 Shows example candidate SSB positions in an unlicensed radio frequency spectrum band with 240 kHz SCS.

[0106] As described above in connection with Figure 6 In a configuration where each time slot includes 14 OFDM symbols for 240 kHz SCS in a licensed frequency band, up to 8 SSBs can be transmitted across four consecutive time slots. As indicated by reference numeral 1105, for a 240 kHz SCS, a time slot may have a duration of 0.0625 milliseconds. As shown, the DRS transmission window for the unlicensed frequency band may include a first half 1110 (e.g., from 0 milliseconds to 2.25 milliseconds of the window, up to 64 SSBs) in the window that carries SSBs and a second part 1115 (e.g., in the window from 2.25 milliseconds to 5 milliseconds, up to 64 SSBs) in the window that also carries SSBs, as described above in connection with Figure 10 described.

[0107] Additionally or alternatively, a DRS transmission window having a duration of 5 milliseconds on a band with 240 kHz SCS may not be configured with a four-slot gap (e.g., having a length of 0.25 milliseconds) after every 16 time slots (e.g., 1 millisecond) including an SSB. For example, eight candidate SSB positions may be included in the seventeenth to twentieth time slots (e.g., between 1 millisecond and 1.25 milliseconds) in the DRS transmission window, in the thirty-seventh to fortieth time slots (e.g., between 2.25 milliseconds and 2.50 milliseconds) in the DRS transmission window, in the fifty-seventh to sixtieth time slots (e.g., between 3.5 milliseconds and 3.75 milliseconds) in the DRS transmission window, and / or in the seventy-seventh to eightieth time slots (e.g., between 4.75 milliseconds and 5 milliseconds) in the DRS transmission window.

[0108] In some aspects, a DRS transmission window may include at least one candidate SSB position in each time slot in the DRS transmission window. Additionally or alternatively, a DRS transmission window may include a set of candidate SSB positions (e.g., up to eight candidate SSB positions) in every 0.25 millisecond period (e.g., every four time slots) of the DRS transmission window. With this candidate SSB pattern, a DRS transmission window may include up to 160 candidate SSB positions (e.g., 64 candidate SSB positions that are also included in the licensed band plus 96 additional candidate SSB positions in the second half of the window plus four four-slot gaps used in the licensed band). In this way, additional candidate SSB positions may be added for the 240 kHz unlicensed band by introducing a new design or pattern for SSB candidate positions. Using additional candidate SSB positions in the DRS transmission window on the unlicensed band may enable the base station 110 to transmit an SSB in the DRS transmission window (e.g., in a later part of the window), even if the base station 110 is unable to access the unlicensed band (e.g., an earlier part of the window) due to conflicts and / or contentions on the unlicensed band. This may reduce the waiting time compared to waiting for the next DRS transmission window to attempt an SSB transmission. Additionally, this may improve reliability by enabling the UE 120 to combine multiple SSBs within the same DRS transmission window (e.g., for decoding purposes).

[0109] In some aspects, the SSBs in the DRS transmission window can be indexed according to a coherent indexing scheme. In this scheme, all the SSBs included in the DRS transmission window are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window. For example, for 160 candidate SSB positions, the 160 SSBs will be indexed from 0 to 159 in ascending order from the start to the end of the DRS transmission window. Compared with a non - coherent indexing scheme, this coherent indexing scheme enables the UE120 to perform PBCH combining across different candidate SSB positions with reduced complexity, thereby saving UE resources (e.g., processing resources, memory resources, etc.). In addition, this indexing scheme achieves backward compatibility, where the legacy SSB indexing scheme can be reused for SSB indices 0 to 63. In this way, cell timing determination can be performed by legacy UEs without introducing additional complexity.

[0110] In some aspects, the SSBs in the DRS transmission window can be indexed according to a non - coherent indexing scheme. In this scheme, a first SSB subset of the set of SSBs included in the DRS transmission window is indexed in ascending order from an earlier position to a later position in the DRS transmission window. In addition, a second SSB subset of the set of SSBs included in the DRS transmission window is indexed in ascending order from an earlier position to a later position in the DRS transmission window. Further, the earliest SSB included in the second SSB subset occurs before at least one SSB in the first SSB subset and has a higher index value than one or more SSBs (e.g., the first 64 SSBs, the first 128 SSBs, or all SSBs) included in the first SSB subset. In some aspects, the earliest SSB included in the second SSB subset has an SSB index value of 64. In some aspects, the earliest SSB included in the second SSB subset has an SSB index value of 128.

[0111] In example 1100, the first SSB subset can occur in the first to sixteenth time slots (e.g., between 0 ms and 1 ms) of the DRS transmission window, in the twenty - first to thirty - sixth time slots (e.g., between 1.25 ms and 2.25 ms) of the DRS transmission window, in the forty - first to fifty - sixth time slots (e.g., between 2.5 ms and 3.5 ms) of the DRS transmission window, and in the sixty - first to seventy - sixth time slots (e.g., between 3.75 ms and 4.75 ms) of the DRS transmission window. The SSBs in the first SSB subset are indexed from 0 to 127 in the order in which these SSBs occur in the time domain within the DRS transmission window (a total of 128 SSBs).

[0112] Also in Example 1100, the second SSB subset occurs in the seventeenth to twentieth time slots of the DRS transmission window (e.g., between 1 millisecond and 1.25 milliseconds), in the thirty-seventh to fortieth time slots of the DRS transmission window (e.g., between 2.25 milliseconds and 2.50 milliseconds), in the fifty-seventh to sixtieth time slots of the DRS transmission window (e.g., between 3.5 milliseconds and 3.75 milliseconds), and in the seventy-seventh to eightieth time slots of the DRS transmission window (e.g., between 4.75 milliseconds and 5 milliseconds). The SSBs in the second SSB subset are indexed from 128 to 159 in the order in which these SSBs occur in the time domain within the DRS transmission window (32 SSBs in total). This results in the entire set of SSBs included in the DRS transmission window being indexed non-consecutively from the start to the end of the DRS transmission window. For example, the first 32 SSBs will be indexed from 0 - 31, the next 8 SSBs will be indexed from 128 - 135, the next 32 SSBs will be indexed from 32 - 63, the next 8 SSBs will be indexed from 136 - 143, the next 32 SSBs will be indexed from 64 - 95, the next 8 SSBs will be indexed from 144 - 151, the next 32 SSBs will be indexed from 96 - 127, and the last 8 SSBs will be indexed from 152 - 159.

[0113] This non-consecutive indexing scheme enables backward compatibility, where the legacy SSB indexing scheme can be reused for SSB indices 0 to 63. In this way, cell timing determination can be performed by legacy UEs without introducing additional complexity.

[0114] As indicated above, Figure 11 is provided as an example. Other examples may be different from the examples described with respect to Figure 11 above.

[0115] Figure 12 is a diagram illustrating an example process 1200, such as may be performed by a UE, in accordance with various aspects of the present disclosure. Example process 1200 is an example where a UE (e.g., UE 120, etc.) performs operations associated with an SSB indexing scheme.

[0116] As shown in Figure 12 in some aspects, process 1200 may include detecting an SSB within a DRS transmission window that includes more than 64 candidate SSB positions (block 1210). For example, a UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may detect an SSB within a DRS transmission window that includes more than 64 candidate SSB positions, as described above.

[0117] As Figure 12As further shown, in some aspects, process 1200 may include determining an index value of an SSB (block 1220) at least in part based on an indexing scheme for the SSBs included in the DRS transmission window. For example, a UE (e.g., using the receiving processor 258, the controller / processor 280, the memory 282, etc.) may determine the index value of the SSB at least in part based on the indexing scheme for the SSBs included in the DRS transmission window, as described above. In some aspects, the indexing scheme includes a coherent indexing scheme, where all SSBs are coherently indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window. In some aspects, the indexing scheme includes a non - coherent indexing scheme, where a first subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset.

[0118] As Figure 12 As further shown, in some aspects, process 1200 may include determining cell timing (block 1230) at least in part based on the index value. For example, a UE (e.g., using the receiving processor 258, the controller / processor 280, the memory 282, etc.) may determine cell timing at least in part based on the index value, as described above.

[0119] Process 1200 may include additional aspects, such as any individual aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0120] In a first aspect, the DRS transmission window includes a set of SSBs within each 0.25 - millisecond time period of the DRS transmission window.

[0121] In a second aspect, alone or in combination with the first aspect, the SSB is located within a DRS transmission window having a sub - carrier spacing of 120 kHz.

[0122] In a third aspect, alone or in combination with one or more of the first and second aspects, the DRS transmission window has a duration of 5 milliseconds.

[0123] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the DRS transmission window includes 80 candidate SSB positions.

[0124] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the earliest SSB included in the second subset has an index value of 64.

[0125] In a sixth aspect, either alone or in combination with one or more of the first to fifth aspects, the earliest SSB included in the second subset has an index value of 128.

[0126] In a seventh aspect, either alone or in combination with one or more of the first to sixth aspects, the SSB is located within a DRS transmission window having a subcarrier spacing of 240 kHz.

[0127] In an eighth aspect, either alone or in combination with one or more of the first to seventh aspects, a part of the SSB is located in the second half of the DRS transmission window.

[0128] In a ninth aspect, either alone or in combination with one or more of the first to eighth aspects, the DRS transmission window includes 128 candidate SSB positions.

[0129] In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, the DRS transmission window includes 160 candidate SSB positions.

[0130] Although Figure 12 illustrates example blocks of process 1200, in some aspects, process 1200 may include additional blocks, fewer blocks, different blocks, or blocks arranged differently compared to the blocks depicted in Figure 12 . Additionally or alternatively, two or more blocks of process 1200 may be executed in parallel.

[0131] Figure 13 is a diagram illustrating an example process 1300, such as performed by a base station, in accordance with various aspects of the present disclosure. Example process 1300 is an example in which a base station (e.g., base station 110, etc.) performs operations associated with an SSB indexing scheme.

[0132] As Figure 13As shown, in some aspects, process 1300 may include determining an index value for an SSB included in a DRS transmission window (block 1310) based at least in part on an index scheme for the SSBs included in a DRS transmission window that includes more than 64 candidate SSB positions. For example, a base station (e.g., using receive processor 238, controller / processor 240, memory 242, etc.) may determine an index value for an SSB included in a DRS transmission window based at least in part on an index scheme for the SSBs included in a DRS transmission window that includes more than 64 candidate SSB positions, as described above. In some aspects, the index scheme is a coherent index scheme, where all SSBs are coherently indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window. In some aspects, the index scheme is a non - coherent index scheme, where a first subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, where the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset.

[0133] As Figure 13 As further shown, in some aspects, process 1300 may include transmitting an SSB and an indication of the index value in a candidate SSB position of the DRS transmission window (block 1320). For example, a base station (e.g., using transmit processor 220, controller / processor 240, memory 242, etc.) may transmit an SSB and an indication of the index value in a candidate SSB position of the DRS transmission window, as described above.

[0134] Process 1300 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere in this document.

[0135] In a first aspect, the DRS transmission window includes a set of SSBs in each 0.25 - millisecond time period of the DRS transmission window.

[0136] In a second aspect, either alone or in combination with the first aspect, the SSB is located within a DRS transmission window having a sub - carrier spacing of 120 kHz.

[0137] In a third aspect, either alone or in combination with one or more of the first and second aspects, the DRS transmission window has a duration of 5 milliseconds.

[0138] In a fourth aspect, either alone or in combination with one or more of the first through third aspects, the DRS transmission window includes 80 candidate SSB positions.

[0139] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the earliest SSB included in the second subset has an index value of 64.

[0140] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the earliest SSB included in the second subset has an index value of 128.

[0141] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the SSB is located within a DRS transmission window having a subcarrier spacing of 240 kHz.

[0142] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, a portion of the SSB is located in the second half of the DRS transmission window.

[0143] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the DRS transmission window includes 128 candidate SSB positions.

[0144] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the DRS transmission window includes 160 candidate SSB positions.

[0145] Although Figure 13 example blocks of process 1300 are shown, in some aspects, process 1300 may include additional blocks, fewer blocks, different blocks, or blocks arranged differently than those depicted in Figure 13 . Additionally or alternatively, two or more blocks of process 1300 may be executed in parallel.

[0146] An overview of some aspects of the present disclosure is provided below:

[0147] Aspect 1: A wireless communication method performed by a user equipment (UE), comprising: detecting a synchronization signal block (SSB) within a discovery reference signal (DRS) transmission window including more than 64 candidate SSB positions; determining an index value of the SSB at least in part based on an index scheme for the SSBs included in the DRS transmission window, wherein the index scheme includes one of the following: a coherent index scheme, wherein all SSBs are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non-coherent index scheme, wherein a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and determining cell timing at least in part based on the index value.

[0148] Aspect 2: The method of Aspect 1, wherein the DRS transmission window includes a set of SSBs within each 0.25 millisecond time period of the DRS transmission window.

[0149] Aspect 3: The method of any of the preceding aspects, wherein the DRS transmission window has a duration of 5 milliseconds.

[0150] Aspect 4: The method of any of the preceding aspects, wherein the SSB is located within a DRS transmission window having a subcarrier spacing of 120 kHz.

[0151] Aspect 5: The method of any of the preceding aspects, wherein the DRS transmission window includes 80 candidate SSB positions.

[0152] Aspect 6: The method of any of the preceding aspects, wherein the earliest SSB included in the second subset has an index value of 64.

[0153] Aspect 7: The method of any of Aspects 1-5, wherein the earliest SSB included in the second subset has an index value of 128.

[0154] Aspect 8: The method of any of Aspects 1-3, wherein the SSB is located within a DRS transmission window having a subcarrier spacing of 240 kHz.

[0155] Aspect 9: The method of Aspect 8, wherein a portion of the SSB is located in the second half of the DRS transmission window.

[0156] Aspect 10: The method of any of Aspects 1-9, wherein the DRS transmission window includes 128 candidate SSB positions.

[0157] Aspect 11: A method as in any one of Aspects 1-9, wherein the DRS transmission window includes 160 candidate SSB positions.

[0158] Aspect 12: A wireless communication method performed by a base station, comprising: determining an index value of an SSB included in a discovery reference signal (DRS) transmission window for including more than 64 candidate synchronization signal block (SSB) positions, at least in part based on an index scheme for the SSB included in the DRS transmission window, wherein the index scheme includes one of the following: a coherent index scheme, wherein all SSBs are coherently indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, or a non-coherent index scheme, wherein a first SSB subset is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, and a second SSB subset is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset occurs before at least one SSB in the first subset and has an index value higher than all SSBs in the first subset; and transmitting the SSB and an indication of the index value at a candidate SSB position in the DRS transmission window.

[0159] Aspect 13: The method as in Aspect 12, wherein the DRS transmission window includes an SSB set within each 0.25 millisecond time period of the DRS transmission window.

[0160] Aspect 14: The method as in any one of Aspects 12-13, wherein the DRS transmission window has a duration of 5 milliseconds.

[0161] Aspect 15: The method as in any one of Aspects 12-14, wherein the SSB is located within a DRS transmission window having a subcarrier spacing of 120 kHz.

[0162] Aspect 16: The method as in any one of Aspects 12-15, wherein the DRS transmission window includes 80 candidate SSB positions.

[0163] Aspect 17: The method as in any one of Aspects 12-16, wherein the earliest SSB included in the second subset has an index value of 64.

[0164] Aspect 18: The method as in any one of Aspects 12-16, wherein the earliest SSB included in the second subset has an index value of 128.

[0165] Aspect 19: The method as in any one of Aspects 12-14, wherein the SSB is located within a DRS transmission window having a subcarrier spacing of 240 kHz.

[0166] Aspect 20: The method as in aspect 19, wherein a part of the SSB is located in the second half of the DRS transmission window.

[0167] Aspect 21: The method as in any one of aspects 12 - 20, wherein the DRS transmission window includes 128 candidate SSB positions.

[0168] Aspect 22: The method as in any one of aspects 12 - 20, wherein the DRS transmission window includes 160 candidate SSB positions.

[0169] Aspect 23: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the device to perform the method of one or more of aspects 1 - 11.

[0170] Aspect 24: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors being configured to perform the method of one or more of aspects 1 - 11.

[0171] Aspect 25: A device for wireless communication, comprising at least one means for performing the method of one or more of aspects 1 - 11.

[0172] Aspect 26: A non - transient computer - readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method of one or more of aspects 1 - 11.

[0173] Aspect 27: A non - transient computer - readable medium storing a set of instructions for wireless communication, the set of instructions including one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of aspects 1 - 11.

[0174] Aspect 28: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the device to perform the method of one or more of aspects 12 - 22.

[0175] Aspect 29: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors being configured to perform the method of one or more of aspects 12 - 22.

[0176] Aspect 30: A device for wireless communication, comprising at least one means for performing the method of one or more of aspects 12 - 22.

[0177] Aspect 31: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform a method as in one or more of Aspects 12 - 22.

[0178] Aspect 32: A non-transitory computer-readable medium storing an instruction set for wireless communication, the instruction set including one or more instructions that, when executed by one or more processors of a device, cause the device to perform a method as in one or more of Aspects 12 - 22.

[0179] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations can be made in light of the above disclosure or can be obtained by practicing the aspects.

[0180] As used herein, the term "component" is intended to be broadly construed as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented with hardware, firmware, and / or a combination of hardware and software.

[0181] As used herein, depending on the context, meeting a threshold can mean a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0182] It will be apparent that the systems and / or methods described herein can be implemented in different forms of hardware, firmware, and / or a combination of hardware and software. The actual special control hardware or software code used to implement these systems and / or methods does not limit the aspects. Thus, the operation and behavior of these systems and / or methods are described herein without reference to specific software code - understanding that software and hardware can be designed to implement these systems and / or methods at least in part based on the description herein.

[0183] Although specific feature combinations are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and / or not disclosed in the specification. Although each of the dependent claims listed below may directly depend on only one claim, the disclosure of the various aspects includes each dependent claim in combination with every other claim in this group of claims. A phrase that recites "at least one of" a list of items refers to any combination of those items, including a single member. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination having multiple of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c, or any other ordering of a, b, and c).

[0184] Elements, acts, or instructions used herein should not be construed as critical or essential, unless expressly described as such. Also, as used herein, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more." Additionally, as used herein, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and may be used interchangeably with "one or more." Where only one item is intended, the phrase "only one" or similar language is used. Also, as used herein, the terms "having," "containing," "including," etc. are intended to be open-ended terms. Additionally, the phrase "based on" is intended to mean "at least partially based on," unless otherwise expressly stated.

Claims

1. A base station for wireless communication, comprising: one or more memories; and one or more processors coupled to the one or more memories, the one or more processors being configured to: determine an index value of a Synchronization Signal Block (SSB) included in a Discovery Reference Signal (DRS) transmission window based at least in part on an index scheme of the SSBs included in the DRS transmission window for including more than 64 candidate SSB positions, wherein the index scheme includes one of the following: a consecutive index scheme, wherein all SSBs are consecutively indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non - consecutive index scheme, wherein a first subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset of SSBs occurs before at least one SSB in the first subset of SSBs and has an index value higher than all SSBs in the first subset of SSBs; and transmit the SSB and an indication of the index value at candidate SSB positions in the DRS transmission window.

2. The base station according to claim 1, wherein the DRS transmission window includes a set of SSBs in each 0.25 - millisecond time period of the DRS transmission window.

3. The base station according to claim 1, wherein the DRS transmission window has a duration of 5 milliseconds.

4. The base station according to claim 1, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 120 kHz.

5. The base station according to claim 1, wherein the DRS transmission window includes 80 candidate SSB positions.

6. The base station according to claim 1, wherein the earliest SSB included in the second subset of SSBs has an index value of 64.

7. The base station according to claim 1, wherein the earliest SSB included in the second subset of SSBs has an index value of 128.

8. The base station according to claim 1, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 240 kHz.

9. The base station according to claim 8, wherein a portion of the SSB is located in the second half of the DRS transmission window.

10. The base station according to claim 1, wherein the DRS transmission window includes 128 candidate SSB positions.

11. The base station according to claim 1, wherein the DRS transmission window includes 160 candidate SSB positions.

12. A method for a base station to perform wireless communication, comprising: determine an index value of a Synchronization Signal Block (SSB) included in a Discovery Reference Signal (DRS) transmission window based at least in part on an index scheme of the SSBs included in the DRS transmission window for including more than 64 candidate SSB positions, wherein the index scheme includes one of the following: A coherent indexing scheme, in which all SSBs are coherently indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, or A non - coherent indexing scheme, in which a first subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, and a second subset of SSBs is indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, wherein the earliest SSB included in the second subset of SSBs occurs before at least one SSB in the first subset of SSBs and has an index value higher than all SSBs in the first subset of SSBs; And Transmit the SSB and an indication of the index value at candidate SSB positions in the DRS transmission window.

13. The method according to claim 12, wherein the DRS transmission window includes a set of SSBs in each 0.25 - millisecond time period of the DRS transmission window.

14. The method according to claim 12, wherein the DRS transmission window has a duration of 5 milliseconds.

15. The method according to claim 12, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 120 kHz.

16. The method according to claim 12, wherein the DRS transmission window includes 80 candidate SSB positions.

17. The method according to claim 12, wherein the earliest SSB included in the second subset of SSBs has an index value of 64.

18. The method according to claim 12, wherein the earliest SSB included in the second subset of SSBs has an index value of 128.

19. The method according to claim 12, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 240 kHz.

20. The method according to claim 19, wherein a portion of the SSB is located in the second half of the DRS transmission window.

21. The method according to claim 12, wherein the DRS transmission window includes 128 candidate SSB positions.

22. The method according to claim 12, wherein the DRS transmission window includes 160 candidate SSB positions.

23. A non - transitory computer - readable medium storing a set of instructions for wireless communication, the set of instructions including: One or more instructions that, when executed by one or more processors of a base station, cause the base station to perform the following operations: Determine index values of SSBs included in a discovery reference signal (DRS) transmission window based at least in part on an indexing scheme for SSBs included in the DRS transmission window that includes more than 64 candidate synchronization signal blocks (SSB) positions, wherein the indexing scheme includes one of the following: A coherent indexing scheme, in which all SSBs are coherently indexed in ascending order from an earlier position in the DRS transmission window to a later position in the DRS transmission window, or A non - coherent indexing scheme, wherein a first SSB subset is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second SSB subset is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second SSB subset occurs before at least one SSB in the first SSB subset and has an index value higher than all SSBs in the first SSB subset; and transmit the SSB and an indication of the index value in candidate SSB positions of the DRS transmission window.

24. The non - transient computer - readable medium of claim 23, wherein the DRS transmission window includes a set of SSBs in each 0.25 - millisecond time period of the DRS transmission window.

25. The non - transient computer - readable medium of claim 23, wherein the DRS transmission window has a duration of 5 milliseconds.

26. The non - transient computer - readable medium of claim 23, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 120 kHz.

27. The non - transient computer - readable medium of claim 23, wherein the DRS transmission window includes 80 candidate SSB positions.

28. The non - transient computer - readable medium of claim 23, wherein the earliest SSB included in the second SSB subset has an index value of 64.

29. The non - transient computer - readable medium of claim 23, wherein the earliest SSB included in the second SSB subset has an index value of 128.

30. The non - transient computer - readable medium of claim 23, wherein the SSB is located within the DRS transmission window having a sub - carrier spacing of 240 kHz.

31. An apparatus for wireless communication, comprising: means for determining an index value of an SSB included in a discovery reference signal (DRS) transmission window based at least in part on an indexing scheme for the SSB included in the DRS transmission window that includes more than 64 candidate synchronization signal block (SSB) positions, wherein the indexing scheme includes one of the following: a coherent indexing scheme, wherein all SSBs are coherently indexed in ascending order from an earlier position to a later position in the DRS transmission window, or a non - coherent indexing scheme, wherein a first SSB subset is indexed in ascending order from an earlier position to a later position in the DRS transmission window, and a second SSB subset is indexed in ascending order from an earlier position to a later position in the DRS transmission window, wherein the earliest SSB included in the second SSB subset occurs before at least one SSB in the first SSB subset and has an index value higher than all SSBs in the first SSB subset; and means for transmitting the SSB and an indication of the index value in candidate SSB positions of the DRS transmission window.

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