WO2021128233A1

WO2021128233A1 - Directional synchronization and system information acquisition

Info

Publication number: WO2021128233A1
Application number: PCT/CN2019/128985
Authority: WO
Inventors: Yu Zhang; Chao Wei; Qiaoyu Li; Hao Xu; Hung Dinh LY; Liangming WU; Chenxi HAO; Wanshi Chen; Jian Li
Original assignee: Qualcomm Incorporated
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2021-07-01

Abstract

Methods, systems, and devices for wireless communications are described. The described techniques provide utilization of SSB repetition in one or more beam directions. Accordingly, during a beam sweep procedure, a base station may repeat transmission of the SSB on a beam before transitioning to transmission of the SSB on a next beam. A UE positioned in the beam direction associated with repetitive SSBs may have a better opportunity to receive the SSB and/or may be able to combine the SSB repetitions. The UE may monitor for the SSB transmitted by the base station on a beam and at a first frequency range and monitor for transmission of the SSB at a second frequency range on another beam. The second frequency range may be associated with repetitive transmission of the SSB in successive time slots. The UE may communicate with the base station upon receipt of the SSB.

Description

DIRECTIONAL SYNCHRONIZATION AND SYSTEM INFORMATION ACQUISITION

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to directional synchronization and system information acquisition.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

A wireless multiple-access communications system may include a number of base stations, transmission/reception points (TRPs) , or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) . In some wireless communications systems, wireless devices (such as a base station and UE) may communicate using directional beams. The utilization of directional beams may provide more reliable and enhanced communication. In some cases, a directional beam may be influenced by physical objects, such as buildings, trees, vehicles, etc., which may result in a coverage hole in the beam direction.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support directional synchronization and system information acquisition. Generally, the described techniques provide for repetitive synchronization signal block (SSB) transmission in one or more beam directions. Accordingly, during a beam sweep procedure, a base station may repeat transmission of the SSB on a beam before transitioning to transmission of the SSB on a next beam. A UE positioned in the beam direction where the SSB is repeated may have a better opportunity to receive the SSB and/or may be able to combine the SSB repetitions. The UE may monitor for the SSB transmitted by the base station at a first frequency range and on a first beam and monitor for transmission of the SSB at a second frequency range on another beam. The second frequency range may be associated with repetitive transmission of the SSB in successive time slots. The UE may communicate with the base station upon receipt of the SSB.

A method of wireless communications at a UE is described. The method may include monitoring, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitoring for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicating with the base station upon receipt of the synchronization signal block.

An apparatus for wireless communications at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicate with the base station upon receipt of the synchronization signal block.

Another apparatus for wireless communications at a UE is described. The apparatus may include means for monitoring, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitoring for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicating with the base station upon receipt of the synchronization signal block.

A non-transitory computer-readable medium storing code for wireless communications at a UE is described. The code may include instructions executable by a processor to monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicate with the base station upon receipt of the synchronization signal block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the first frequency range and the second frequency range in accordance with a synchronization raster, where the synchronization raster includes a set of first frequency ranges separated by a synchronization raster shift and a set of second frequency ranges separated by a multiple of the synchronization raster shift.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying that at least one of the set of first frequency ranges overlaps with at least one of the set of second frequency ranges, and monitoring only for the repetitive transmissions of the synchronization signal block in the successive time slots on the one of the set of beams for overlapping first frequency ranges and second frequency ranges.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying that a frequency position of the second frequency range may be based on a repetition level for the repetitive transmissions of the synchronization signal block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the first frequency range or the second frequency range based on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the synchronization signal block at the second frequency range in the at least two successive time slots, and combining at least a portion of the synchronization signal block from each of the at least two successive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the synchronization signal block in the at least two successive time slots may include operations, features, means, or instructions for receiving the synchronization signal block in each of at least two consecutive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the synchronization signal block in the at least two successive time slots may include operations, features, means, or instructions for receiving the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the synchronization signal block in the at least two successive time slots may include operations, features, means, or instructions for receiving the synchronization signal block in interleaved potential synchronization signal block transmission locations.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the synchronization signal block in the at least two successive time slots may include operations, features, means, or instructions for receiving the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the common synchronization signal block index based on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the common synchronization signal block index based on a scrambling sequence of a physical broadcast channel of the synchronization signal block.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the scrambling sequence of the physical broadcast channel of the synchronization signal block may be based on a number of least significant bits in a word representative of the common synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a number of most significant bits in the word not overlapping with the number of least significant bits of the word may be included in either a physical broadcast channel payload or a cyclic redundancy check mask.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the number of most significant bits in the word may be included as reserve bits in the physical broadcast channel payload.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the synchronization signal block in the at least two successive time slots may include operations, features, means, or instructions for receiving the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots, and receiving the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the synchronization signal block of the first format includes a physical broadcast channel and at least one synchronization signal, and the synchronization signal block of the second format includes the physical broadcast channel without the at least one synchronization signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the synchronization signal block in a first time slot of the at least two successive time slots, and identifying a location of the synchronization signal block in a second time slot of the at least two successive time slots based on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for monitoring for remaining system information on resources of a physical downlink control channel in association with the successive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, monitoring for the synchronization signal block at the second frequency range may include operations, features, means, or instructions for monitoring for the synchronization signal block at the second frequency range based on a failure to receive the synchronization signal block at the first frequency range.

A method of wireless communication at a base station is described. The method may include identifying a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmitting, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmitting the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for identifying a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmitting, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmitting the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block may include operations, features, means, or instructions for transmitting the synchronization signal block on one of the first set of beams at a first frequency range, where the first frequency range may be associated with repetitive transmissions of the synchronization signal block in the successive time slots, and transmitting the synchronization signal block on the second set of beams at a at a second frequency range.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the first frequency range and the second frequency range in accordance with a synchronization raster, where the synchronization raster includes a set of first frequency ranges separated by a multiple of a synchronization raster shift and a set of second frequency ranges separated by the synchronization raster shift.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying that at least one of the set of first frequency ranges overlaps with at least one of the set of second frequency ranges, and transmitting the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block in each of the at least two successive time slots may include operations, features, means, or instructions for transmitting the synchronization signal block in each of at least two consecutive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block in each of the at least two successive time slots may include operations, features, means, or instructions for transmitting the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block in each of the at least two successive time slots may include operations, features, means, or instructions for transmitting the synchronization signal block in interleaved potential synchronization signal block transmission locations.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block in each of the at least two successive time slots may include operations, features, means, or instructions for transmitting the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the synchronization signal block index based on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for embedding the common synchronization signal block index in a physical broadcast channel payload.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for encoding the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based on a number of possible synchronization signal block locations.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the synchronization signal block in each of the at least two successive time slots may include operations, features, means, or instructions for transmitting the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots, and transmitting the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of the at least two successive time slots.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first set of beams may be used for more repeated synchronization signal block transmissions than on the second set of beams.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a synchronization raster configuration that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a repetitive SSB transmission pattern that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a repetitive SSB transmission pattern that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a common SSB index configuration that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 7 illustrates an example of a repetitive SSB format configuration that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 8 illustrates an example of a physical broadcast channel transport process that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 9 illustrates an example of a process flow diagram that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIGs. 10 and 11 show block diagrams of devices that support directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a communications manager that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIGs. 14 and 15 show block diagrams of devices that support directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 16 shows a block diagram of a communications manager that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIG. 17 shows a diagram of a system including a device that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

FIGs. 18 and 19 show flowcharts illustrating methods that support directional synchronization and system information acquisition in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless networks, base stations and/or user equipments (UEs) may utilize directional beams to provide enhanced and more reliable coverage. A base station may perform a beam sweep procedure, in which a series of beams may be used to transmit a synchronization signal/physical broadcast channel (PBCH) block (SSB) . More particularly, the base station may transmit the SSBs in different beams in a time-division multiplexed (TDM) manner. A UE may utilize the aspects of the synchronization signal block, such as synchronization signals and a physical broadcast channel (PBCH) to acquire downlink synchronization information and system information. A UE located in a particular direction may detect or receive a single SSB and may not receive other SSBs transmitted from the cell. Accordingly, during the beam sweep procedure, a UE may have one opportunity per sweep to acquire information from the SSB for downlink signal acquisition.

In some cases, a particular beam or beam direction may be influenced by external factors, such as physical objects located in the beam direction. A physical object may cause blocking or fading on a beam, which may result in a coverage hole in the beam direction. For example, a base station may be positioned next to a building, which might affect coverage in one or more directions. In some cases, to resolve these coverage issues, an additional cell/base station or repeater may be added to fill the coverage hole. However, the addition of a new device may be expensive for a wireless network operator.

Aspects described herein provide for utilization of SSB repetition in one or more beam directions. Accordingly, during a beam sweep procedure, a base station may repeat transmission of the SSB on a beam, which may be known to have a coverage issue, before transitioning to transmission of the SSB on a next beam. Accordingly, a UE positioned in the beam direction including the repetitive SSB may have a better opportunity to receive the SSB and/or may be able to combine the SSB repetitions. As a result, the UE may be able to acquire downlink (DL) synchronization information and communicate with a base station on a downlink channel.

To support SSB repetition on one or more directional beams, the UE may be configured to monitor various resources associated with SSB repetition to identify the SSB. In some cases, repetitive SSBs may be transmitted at particular frequency positions and/or at time positions. For example, a repetitive SSB may be transmitted on a sparse synchronization raster (relative to a normal synchronization raster) , such that the UE may search for the repetitive SSBs on particular subcarrier frequencies. Further, the repetitive SSBs may be transmitted with defined time domain patterns, such that the UE may be able to receive one of the repetitive SSBs and efficiently identify the location of the other repetitive SSBs in accordance with the time domain patterns.

In some cases, repetitive SSBs may be transmitted with common SSB indexes. In some examples, a common SSB index may be carried in a physical broadcast channel (PBCH) payload of an SSB, a PBCH scrambling sequence, or a combination thereof. The resources carrying a common SSB index may depend on the number of possible locations of an SSB on various resources. The number of SSB locations may be based at least in part on the number of beams for a particular serving cell. For example, a word including a number of bits may represent the common SSB index. The least significant bits of the word may be utilized as scrambling sequence for the PBCH, and the most significant bits may be reserve bits, common SSB index bits included in the PBCH payload, and/or bits for utilization in a cyclic redundancy check mask.

The described repetitive SSB techniques may be implemented to realize one or more advantages. The described techniques may support improvements in downlink signal acquisition, which may decrease signaling overhead and improve reliability, among other advantages. As such, supported techniques may include improved network operations and, in some examples, may promote network efficiencies, among other benefits. Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further described with respect to a synchronization raster configuration, various repetitive SSB transmission patterns, SSB index configurations, SSB formats, and a process flow diagram. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to directional synchronization and system information acquisition.

FIG. 1 illustrates an example of a wireless communications system 100 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.

The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) . The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN) ) and may be positioned according to a channel raster for discovery by the UEs 115. A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs 115 via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology) .

The communication links 125 shown in the wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode) .

A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz) ) . Devices of the wireless communications system 100 (e.g., the base stations 105, the UEs 115, or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include base stations 105 or UEs 115 that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth.

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE 115 may be restricted to one or more active BWPs.

The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s= 1/ Δf _max·N _f) seconds, where Δf _max may represent the maximum supported subcarrier spacing, and N _f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems 100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N _f) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

Each base station 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) , or others) . In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A base station 105 may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.

In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timings, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timings, and transmissions from different base stations 105 may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) . M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs 115 may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications) , or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs) ) within a carrier, within a guard-band of a carrier, or outside of a carrier.

The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions) . Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT) , mission critical video (MCVideo) , or mission critical data (MCData) . Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol) . One or more UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105. In some examples, groups of the UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs 115 without the involvement of a base station 105.

In some systems, the D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services 150. The operators IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) . Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) . Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .

The wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the base stations 105, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

The base stations 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords) . Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) , where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , where multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

A base station 105 or a UE 115 may use beam sweeping techniques as part of beam forming operations. For example, a base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the base station 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions and may report to the base station 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .

The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or a core network 130 supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels.

The UEs 115 and the base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions) . In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

As described herein, the wireless communications system 100 may utilize beamforming techniques to improve signal quality and reliability, among other benefits. To support communication one various beams having various beam directions, a base station may perform a beam sweep procedure, in which each beam of a different beam direction may be utilized to transmit a SSB carrying downlink signal acquisition information that may be used by a UE 115. In a beam sweep procedure, a beam may be used to transmit the SSB before transitioning to transmit an SSB on a next beam in a different direction. As such, a UE 115 located in a direction of one of the beams may have one opportunity to acquire the SSB. That is, the UE 115 may be able to receive only one of the SSBs, and may be unable to receive any other SSBs transmitted from the base station 105 by other beams corresponding to other directions.

In some cases, a beam/beam direction may be influenced by external factors, such as a physical object, which may cause penetration loss in the beam direction resulting in a coverage hole. As such, a UE 115 located in the beam direction may not be able to receive the SSB due to the physical object causing penetration loss. In some cases, a wireless provider may add a device such as a wireless repeater or another base station 105 to fill the coverage hole. However, the addition of a new device may be expensive to the wireless network provider.

To solve these problems, a base station 105 may be configured to introduce repetitive SSBs in some directions (e.g., on some beams) . More particularly, the base station may transmit, during a beam sweep procedure, repetitive SSBs in a direction before transitioning to the next beam/direction. Accordingly, a UE 115 located in the direction of the repetitive SSB may have an increased chance of receiving the SSB and/or may be able to combine repetitive SSBs, which may increase the likelihood of the UE 115 being able to acquire downlink channel information (e.g., based on the information included in the SSB) . Accordingly, the coverage issue in one or more directions may be solved without introducing new and expensive devices to a network.

Various techniques may be utilized to support repetitive SSBs. For example, the repetitive SSBs may be transmitted on designated frequency and/or time resources, such that the UE 115 may be able to efficiently identify resource locations for the repetitive SSBs. Further, the repetitive SSBs may be transmitted with common SSB indexes, with different SSB formats, and in conjunction with repetitive remaining system information (RMSI) . These and other techniques are described with respect to the following figures.

FIG. 2 illustrates an example of a wireless communications system 200 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communications system 100. The wireless communications system 200 includes a base station 105-a and UEs 115-a and 115-b. The base station 105-a and the UEs 115 may be configured to communicate using beamforming techniques. To establish a communication channel between base station 105-a and a UE 115, the base station 105-a may perform a beam sweep procedure. In accordance with the beam sweep procedure, the base station 105-a may transmit a SSB on each of a plurality of beams 210. For example, the base station 105-a may transmit a SSB on beam 210-a, then an SSB on beam 210-b, then beam 210-c, 210-d, and 210-e. A UE 115 positioned in a direction of a beam 210 may be able to identify only the SSB on the particular beam 210. That is, the UE 115 may not receive SSBs transmitted on other beams 210.

A UE 115 that receives an SSB on a beam 210 may utilize the information included in the SSB to identify a communication channel (e.g., a downlink channel) . For example, the SSB may include synchronization signals (SSs) , such as one or more primary synchronization signals (PSS) and one or more secondary synchronization signals (SSS) . For example, UE 115-a may receive an SSB on beam 210-b and utilize the SSB to establish a communication channel with the base station 105-a.

In some cases, external factors, such as a physical object 220 may interfere with communication on one or more beams 210 in one or more directions. For example, object 220 may interfere with communication on beam 210-d in the direction of the UE 115-b. The object 220 may cause high penetration loss for signal transmitted on beam 210-d. Accordingly, during the beam sweep procedure, UE 115-b may not be able to receive and/or decode the SSB transmitted on beam 210-d. Further, since the UE 115-b is positioned in the direction of the beam 210-d, the UE 115-b may not be able to receive or decode the SSBs transmitted on other beams, such as beam 210-c or 210-e. To increase the likelihood that the UE 115-b may receive an SSB transmitted on beam 210-d, the base station 105-a may transmit repetitive SSBs on the beam 210-d in the direction of the physical object 220. More particularly, the base station 105-a may be configured such that it transmits repetitive SSBs in directions where potential coverage issues have been identified before transitioning to a next beam 210 during a beam sweep procedure. In some cases, the UE 115-b may combine repetitive SSBs such as to acquire the information to establish the channel.

The base station 105-a may transmit the repetitive SSBs on some frequency and/or time resources such that the repetitive SSBs may be identified by the UE 115-b. For example, the repetitive SSBs may be transmitted on specific frequency positions, such as a sparse synchronization raster (e.g., relative to a full synchronization raster for a particular frequency band) . Further repetitive SSBs may be transmitted using particular time domain patterns. In one example, the repetitive SSBs are transmitted on successive time slots for beam 210-a before transmitting an SSB on another beam. The successive time slots may be consecutive time slots, interleaved time slots (e.g., every other time slot) , etc. As such, when the UE 115-b receives one of the SSBs, the UE 115-b may be able to efficiently identify the location of the corresponding repetitive SSBs based on the location of the received SSBs (e.g., based on the SSB transmission pattern) .

In some cases, the repetitive SSBs may utilize a common SSB index to support PBCH symbol level combining before demodulation and decoding. The common SSB index may be based on a location of a first SSB in a repetition set, and the number of bits representing the SSB index may be based at least in part on the number of possible SSB locations (e.g., the number of beams) . Further, in some examples, a first SSB in a SSB repetition set may include PSS/SSS and PBCH, but the subsequent SSB repetitions may include only PBCH.

Further, the RMSI monitoring window may correspond to the resources of the repetitive SSBs. In some aspects, the RMSI physical downlink control channel (PDCCH) monitoring window associated with one SSB (e.g., a single SSB transmission on a beam 210) may have a duration of two consecutive slots, such that the RMSI PDCCH monitoring windows for different SSBs may overlap in the time domain. The RMSI PDCCH monitoring window for repetitive SSBs may include the candidate slots associated with each SSB in the repetition set. For example, the repetitive SSBs may be transmitted on the candidate time location of one SSB, and the associated RMSI PDCCH monitoring slots for that SSB block may be used. As such, the number of PDCCH repetitions for RMSI may be implicitly determined according to the number of repetitive SSBs.

FIG. 3 illustrates an example of a synchronization raster 300 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, synchronization raster 300 may implement aspects of wireless communications system 100. The synchronization raster 300 may define a set of SSB frequency positions 305. Each SSB frequency position 305 may correspond to a particular frequency (e.g., a subcarrier frequency) on which an SSB may be transmitted. A UE 115 may monitor for SSB transmissions 310 on the SSB frequency positions 305 indicated by the synchronization raster 300, and a base station 105 may transmit SSB transmissions 310 in accordance with the synchronization raster 300.

The SSB transmission configuration may depend on one of the respective SSB frequency positions 305. For example, for transmission of SSBs one time on each band in accordance with a beam sweep procedure, the SSB transmissions 310 may occur once per band as illustrated by SSB frequency position 305-a. For SSB frequency positions corresponding to repetitive SSB transmission 310, the SSB transmissions 310 may occur in a repetitive manner on the same band, as illustrated by SSB frequency position 305-b. The frequency position for a frequency range corresponding to an SSB frequency position 305 may be identified based on the center frequency of the range or based on the synchronization raster shift.

The SSB frequency positions 305 may be separated by a synchronization raster shift 315. For normal SSB transmission 310 (e.g., once per beam) , the SSB frequency positions 305 may be separated by a synchronization raster shift 315-a. The SSB frequency positions 305-b and 305-e for repetitive SSB transmission 310 may be separated by a different synchronization raster shift 315-b (or multiples of the synchronization raster shift 315-a) . For example, each SSB frequency positions 305 for normal SSB transmission 310 may be separated by a 1200 kHz synchronization raster shift 315 (which may depend on the frequency band) . That is, a synchronization raster may be defined for each frequency band. The frequency position of an SSB for a band may be defined as SS _Ref with a corresponding number global synchronization channel number (GSCN) . Using these parameters, the UE 115 may identify the synchronization raster shift for a particular band and monitor for SSBs based on the identified synchronization raster. A formula for identifying the SSB frequency position 305-b (corresponding to repetitive SSBs) may also be configured at the UE 115. For example, the frequency position of the repetitive SSB may be defined as SS _REF-rep and the GSCN associated with SS _REF may be different (e.g., there may be different GSCN step sizes) . For example, each synchronization raster for repetitive SSB transmissions 310 may be separated by a 4800 kHz synchronization raster shift 315. Accordingly, the repetitive SSB transmission 310 may be transmitted on a sparser synchronization raster than that of singular SSB transmissions per band. For example, the SSB repetition may occur on a 2x, 4x, 16x, etc. the standard synchronization raster shift 315-a. Example formulas for synchronization raster shifts are represented in the following table 1 and table 2:

Table 1: GSCN parameters for SSB frequency position SS _REF

Table 2: GSCN parameters for repetitive SSB frequency position SS _REF-rep

In some cases, a normal SSB set (e.g., one SSB per beam) may be transmitted on the same SSB frequency positions 305 as the repetitive SSB transmissions 310. That is, normal SSB transmissions may occur on the SSB frequency positions 305 before or after (in time) the occasion for repetitive SSB transmissions. Further, the frequency position for SSB repetition may be dependent on the repetition level. More particularly, a UE 115 may assume that the SSBs with some repetition level (s) are transmitted on some frequency positions, but not all frequency positions on the synchronization raster. Further, multiple repetitive SSBs may also be frequency division multiplexed (FDMed) on different frequency positions. That is, different directional SSBs may be allocated to different bandwidth parts (BWPs) .

FIG. 4 illustrates an example of a repetitive SSB transmission pattern 400 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, repetitive SSB transmission pattern 400 may implement aspects of wireless communications system 100. The pattern 400 may be implemented by a base station 105 and received and detected by a UE 115. The utilization of transmission pattern 400 may reduce search complexity for identification of repetitive SSBs. The pattern 400 illustrates potential SSB transmission locations 420, valid SSB transmission 425, and invalid SSB transmission 430.

In the pattern 400, valid SSB transmissions 425 are transmitted in successive time slots. More particularly, valid SSB transmissions 425 are transmitted in consecutive potential SSB transmission locations 420. Options 410-a, 410-b, and 410-c illustrate valid transmission patterns. That is, for a valid SSB repetition, SSBs are transmitted in consecutive potential SSB transmission locations 420. The positioning of the potential SSB transmission locations 420 may be dependent on a subcarrier spacing. FIG. 4 illustrates the potential SSB transmission locations 420 for a 15 kHz subcarrier spacing. However, potential SSB transmission locations 420 for another subcarrier spacing (e.g., 30 kHz, 60 kHz, and 120 kHz) may be different. For example, in a 30 kHz subcarrier spacing, multiple potential SSB transmission locations may be positioned within the same time slot. That is, a slot may include two potential SSB transmission locations. As such, repetitive SSBs may be transmitted in each SSB location within a time slot. With a repetition level of four, the repetitive SSBs may be transmitted in the two SSB locations in two consecutive time slots.

The utilization of consecutive potential SSB transmission locations 420 may reduce the number of hypothesis for identifying the SSB transmissions. For example, for a repetition level of four (e.g., four repetitions of the SSB before transitioning to another beam) and no consecutive location constraints, the UE may test seventy hypotheses to identify an SSB transmission location. With the consecutive location constrains and the repetition level of four, there may be five hypotheses (e.g., starting from

slot

0, 1, 2, 3, or 4) . With a further constraint of starting on an even numbered slot, the number of hypotheses is further reduced to three, as illustrated by options 410-a, 410-b, and 410-c.

FIG. 5 illustrates an example of a repetitive SSB transmission pattern 500 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, repetitive SSB transmission pattern 500 may implement aspects of wireless communications system 100. The pattern 500 may be implemented by a base station 105 and received and detected by a UE 115. The utilization of transmission pattern 500 may reduce search complexity for identification of repetitive SSBs. The pattern 500 illustrates potential SSB transmission locations 520, valid SSB transmission 525, and invalid SSB transmission 530.

In the pattern 500, valid SSB transmission 525 are transmitted in corresponding time. More particularly, valid SSB transmissions 525 are transmitted in non-consecutive potential SSB transmission locations 520. Options 510-a, 510-b, and 510-c illustrate valid transmission patterns. That is, for a valid SSB repetition, SSBs are transmitted in every other potential SSB transmission locations 520 (e.g., a distributed or interleaved transmission pattern) . As described with respect to FIG. 4, the potential SSB transmission locations 520 may depend on the subcarrier spacing. In a 30 kHz subcarrier spacing, a slot may include two potential SSB locations. As such, according to pattern 500 (e.g., interleaved transmissions) , an SSB may be transmitted in a first or second potential SSB location in consecutive time slots.

The utilization of every other potential SSB transmission location 520 may reduce the number of hypothesis for identifying the SSB transmissions. For example, for a repetition level of four (e.g., four repetitions of the SSB before transitioning to another beam) and no distributed location constraints (e.g., every other potential SSB transmission location 520) , the UE may test seventy hypotheses to identify an SSB transmission location. With the distributed location constrains and the repetition level of four, there may be five hypotheses (e.g., starting from

slot

0, 1, 2, 3, or 4) . With a further constraint of starting on an even numbered slot, the number of hypotheses is further reduced to three, as illustrated by options 510-a, 510-b, and 510-c.

FIG. 6 illustrates an example of a common SSB index configuration 600 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, common SSB index configuration 600 may implement aspects of wireless communications system 100. According to the common SSB index configuration 600, repetitive SSB transmissions 625 may be transmitted with a common SSB index. In cases where one SSB is transmitted on a beam before transitioning to another beam (e.g., normal SSB transmission during a beam sweep) , the SSBs may be transmitted with an SSB index in accordance with the normal SSB index 615. That is, the SSB index for a single SSB transmission may be based on the location (e.g., time slot index) in a time occasion for SSB transmission. For example, an SSB transmitted in slot 2 of subframe 1 may have an SSB index of 2.

When SSBs are transmitted repetitively on the same beam, the repetitive SSBs may share a common SSB index. Utilization of a common SSB index may support PBCH symbol-level combining before demodulation and decoding. In accordance with common SSB index configuration 600, the common SSB index may be determined in accordance with the time location of the first SSB in the repetition set. More particularly, each SSB index of a set of repetitive SSBs may be based on the time location (e.g., slot index) of the first transmission of the repetitive SSBs. Options 610-a, 610-b, and 610-c illustrate potential configurations for common SSB indexes. With respect to option 2 610-a, the first SSB transmission 625 of the set is transmitted in slot 2 of subframe 1 and thus has an SSB index of 2. Accordingly, each subsequent repetitive transmission of the SSB has the same SSB index of 2.

The common SSB index configuration 600 is illustrated with the pattern 400 as illustrated with respect to FIG. 4. It should be understood that the common SSB index configuration 600 may be utilized with other SSB repetition timing patterns. For example, with respect to FIG. 5, the SSBs transmitted in accordance with option 510-b may share the SSB index of 1, which is the time slot index of the first SSB of the SSB repetition set.

FIG. 7 illustrates an example of a repetitive SSB format configuration 700 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, repetitive SSB format configuration 700 may implement aspects of wireless communications system 100. According to the SSB format configuration 700, a base station may transmit a first SSB transmission in an SSB repetition set using a first format 720 and the remaining SSB transmissions in an SSB repetition set using a second format 725 In some cases, the

formats

720 and 725 may be configured at a UE 115. The

formats

720 and 725 may also be configured using RRC signaling. In examples, the first format 720 may include a physical broadcast channel and one or more synchronization signals (e.g., primary synchronization signals and/or secondary synchronization signals) , and the second format 725 may include the physical broadcast channel and no synchronization signals. The resources that may be reserved for synchronization signals may be used for additional physical broadcast channel resources.

In some cases, time domain combining across multiple half-frames may be used for improving PSS/SSS performance, but combining may not be useful for PBCH as the PBCH payload may change periodically. For this reason, repetition of the PBCH in the second SSB format in a lower coding rate within a half-frame may be useful in that it provides a UE additional opportunities to successfully decode PBCHs within a half-frame. Accordingly, a PBCH transmission may be included in the repetition symbols of the SSBs (e.g., four symbols) . As such, there may be no timing ambiguity since the PSS/SSS may be transmitted only in the starting SSB in the repetition set. Options 710-a, 710-b and 710-c illustrate potential implementations of using

multiple SSB formats

720 and 725 for SSB repetition sets. It should be understood that the

multiple SSB formats

720 and 725 may be used with over repetition patterns, such as pattern 500 of FIG. 5.

FIG. 8 illustrates an example of an physical broadcast channel transport process 800 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, physical broadcast channel transport process 800 may implement aspects of wireless communications system 100. The transport process 800 may be implemented by a base station 105 in generating and transmitting a PBCH in a SSB. The transport process 800 may be utilized to transmit a common SSB index, as described with respect to FIG. 6. In some examples, CRC masking (e.g., at 810) may be performed and may depend on the bit-length of the common SSB index, as described herein.

In some cases, a common SSB index may be included in an PBCH payload, which may be generated at 805. Additionally or alternatively, the common SSB index may be carried by a PBCH scrambling sequence (generated at 815) and/or a cyclic redundancy check (CRC) mask (generated at 810) . In PBCH scrambling 815, the scrambling sequence for M _bit-PBCH is c (i + vM _bit) , where c (i) is a length-31 Gold sequence. The scrambling sequence may be initialized with

at the start of each SSB. For L _max = 4, v is the two least significant bits (LSBs) of the SSB index (two bits) , for L _max = 8, v is the three LSBs of the SSB index (three bits) , and for L _max = 64, v is the three LSBs of the SSB index (6-bit SSB index, the three most significant bits (MSBs) are in PBCH payload) . L _max may represent the number of candidate beams (or the number of possible SSB starting locations) . Thus, the SSB index for L _max = 4 or for L _max = 8 may be represented in a word that is used for the PBCH scrambling sequence, and the LSBs of the SSB index for L _max = 64 may be used for the PBCH scrambling sequence.

When repetitive SSBs are transmitted, for L _max = 4, v may be the two LSBs of the common SSB index (two bits) , for L _max = 8, v is the three LSBs of the common SSB index (three bits) , and for L _max = 64, v is the three LSBs of the SSB index (6-bit SSB index, the three MSBs are in PBCH payload) . However, because of the utilization of a repetitive SSB pattern (e.g., as described with respect to FIGs. 4 and 5) , the SSB index may be limited to a set of values. For example, if the starting location (e.g., starting time slot index) is limited to 0, 8, 16, etc., then the common SSB index may utilize three bits. Thus, three bits of the PBCH scrambling sequence may be used for the common SSB index, while the three MSBs of the SSB index may be used as reserved bits. If the starting location (e.g., the starting time slot index) is not as limited (e.g., 0, 4, 7, 16, etc. ) , then the common SSB index may utilize four bits. In such cases, the MSB of the four bits may be embedded in a CRC mask (e.g., at step 810) .

When the UE 115 receives the PBCH, the UE 115 may try each value of a scrambling sequence (according to the number of bits) to descramble the PBCH. When the descrambling is successful, the UE 115 may be able to identify the common SSB index (e.g., based on the scrambling sequence) . Further, because of the utilization of a sparser synchronization raster for the repetitive SSB transmissions, there may be fewer starting location of the SSB, and thus fewer bits needed for the indication of the common SSB index/starting location. Accordingly, when the UE 115 receives one of the repetitive SSBs and identifies the SSB index, the UE 115 may be able to efficiently identify the first SSB and other SSBs based on the SSB index (e.g., when the SSB index reflects the starting time slot index of the SSB) .

As discussed, the common SSB may use four bits (e.g., three LSBs for the scrambling sequence) with the MSB used for CRC masking. In such cases, when the MSB of the SSB index has a value of 0, then the CRC masking sequence may comprise a series of zeros (e.g., twenty-three zeros followed by a zero) . When the MSB of the SSB index has a value of 1, then the CRC masking sequence may comprise a series of zeros followed by a one (e.g., twenty-three zeros followed by a 1) . Thus, at 810, the masking sequence may be identified based on the MSB of the common SSB index. At 820, a CRC sequence is attached to a scrambled payload, and the output of CRC attachment may be b ₀, b ₁, b ₂, ..., b _B-1, where B = A + L (A is the number of the scrambled PBCH payload bits) and L is the number of the CRC parity bits. As such, (b ₀, b ₁, b ₂, ..., b _A-1) = (a′ ₀, a′ ₁, a′ ₂, ..., a′ _A-1 ) , and (b _A, b _A+1, b _A+2, ..., b _A+L-1) are the parity bits (L bits) . In the CRC masking technique described herein, b′ _k=b _k, for k = 0, 1, ..., A-1. b′ _k= (b _k+x _k-A) mod 2, for k = A, A+1, ..., A+L-1, where L = 24. The CRC masking sequence may have the value as indicated by table 3, below:

Table 3

FIG. 9 illustrates an example of a process flow diagram 900 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. In some examples, process flow diagram 900 may implement aspects of wireless communications system 100. The process flow diagram 900 includes base station 105-b and a UE 115-b, which may be examples of the corresponding devices as described with respect to FIGs. 2–8.

At 905, the base station 105-b identifies a plurality of beams to be used for synchronization signal block transmission. Each of the plurality of beams may be associated with a synchronization signal block index and a direction. At 910, the base station 105-b transmits, on a first set of beams of the plurality of beams, a synchronization signal block in each of at least two successive time slots. At 915, the base station 105-b may transmit the synchronization signal block on a second set of beams of the plurality of beams by using different beams during successive time slots. The operations at 910 and 915 may occur at the same or during overlapping time periods.

At 920, the UE 115-b monitors, at a first frequency range, for a synchronization signal block transmitted by the base station 105-b on a beam of a plurality of beams, each of the plurality of beams being associated with a synchronization signal block index and a direction. At 925, the UE 115-b monitors for the synchronization signal block at a second frequency range. In some cases, the monitoring for the synchronization signal block at the second frequency range may be based at least in part on a failure to receive the synchronization signal block at the first frequency range. The second frequency range may be associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the plurality of beams. In some cases, the first and/or second frequency range may be identified based on a synchronization raster. The synchronization raster may include a first plurality of first frequency ranges separated by a synchronization shift and a plurality of second frequency ranges separated by a multiple of the synchronization raster shift.

In some cases, the UE 115-b may receive SSBs at the second frequency range in successive time slots. For example, the UE 115-b may receive repetitive SSBs in consecutive time slots (e.g., consecutive potential SSB locations) . In other cases, the UE 115-b may receive repetitive SSBs in the interleaved SSB transmission locations (e.g., every other potential SSB location) , which may correspond to interleaved time slots (e.g., depending on the subcarrier spacing) . The received SSBs may share a common SSB index, which may be embedded in a PBCH channel payload of the SSB, the scrambling sequence of the PBCH, the CRC mask of the PBCH, or a combination of these.

At 930, the UE 115-b and the base station 105-communicate based on receipt of the synchronization signal block. Because the UE 115-b may receive the repetitive SSBs, the UE 115 may combine the received SSBs or may have a better chance of receiving one of the repetitive SSBs in a direction that may have coverage limitations.

FIG. 10 shows a block diagram 1000 of a device 1005 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a UE 115 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to directional synchronization and system information acquisition, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicate with the base station upon receipt of the synchronization signal block. The communications manager 1015 may be an example of aspects of the communications manager 1310 described herein.

The communications manager 1015, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1015, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 1015, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1015, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1015, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1020 may utilize a single antenna or a set of antennas.

In some examples, the communications manager 1015 may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 1010 and transmitter 1020 may be implemented as analog components (e.g., amplifiers, filters, antennas) coupled with the mobile device modem to enable wireless transmission and reception over one or more bands.

The communications manager 1015 as described herein may be implemented to realize one or more potential advantages. One implementation may allow the device 1005 to more efficiently establish communication parameters based on receipt of one or more repetitive SSBs. For example, the device 1005 may identify a frequency and/or time location of repetitive SSBs, receive one or more of the repetitive SSBs, and establish a communication channel based on the received repetitive SSBs.

Based on implementing the feedback mechanism techniques as described herein, a processor of a UE 115 (e.g., controlling the receiver 1010, the transmitter 1020, or the transceiver 1320 as described with reference to FIG. 13) may increase reliability and decrease signaling overhead in the establishment of a communication channel because the repetitive SSBs may be received by the UE 115.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a device 1005, or a UE 115 as described herein. The device 1105 may include a receiver 1110, a communications manager 1115, and a transmitter 1135. The device 1105 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to directional synchronization and system information acquisition, etc. ) . Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1110 may utilize a single antenna or a set of antennas.

The communications manager 1115 may be an example of aspects of the communications manager 1015 as described herein. The communications manager 1115 may include a SSB monitoring component 1120, a repetitive SSB component 1125, and a communication interface 1130. The communications manager 1115 may be an example of aspects of the communications manager 1310 described herein.

The SSB monitoring component 1120 may monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction.

The repetitive SSB component 1125 may monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams. The communication interface 1130 may communicate with the base station upon receipt of the synchronization signal block.

The transmitter 1135 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1135 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1135 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1135 may utilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a communications manager 1205 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The communications manager 1205 may be an example of aspects of a communications manager 1015, a communications manager 1115, or a communications manager 1310 described herein. The communications manager 1205 may include a SSB monitoring component 1210, a repetitive SSB component 1215, a communication interface 1220, a synchronization raster component 1225, a SSB combining component 1230, a common SSB index component 1235, a SSB identification component 1240, and a RMSI component 1245. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The SSB monitoring component 1210 may monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction.

The repetitive SSB component 1215 may monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block at the second frequency range in at least two successive time slots.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block in each of at least two consecutive time slots.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block in interleaved potential synchronization signal block transmission locations.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.

In some examples, the repetitive SSB component 1215 may receive the synchronization signal block in a first time slot of the at least two successive time slots.

In some cases, the synchronization signal block of the first format includes a physical broadcast channel and at least one synchronization signal.

In some cases, the synchronization signal block of the second format includes the physical broadcast channel without the at least one synchronization signal.

The communication interface 1220 may communicate with the base station upon receipt of the synchronization signal block.

The synchronization raster component 1225 may identify the first frequency range and the second frequency range in accordance with a synchronization raster, where the synchronization raster includes a set of first frequency ranges separated by a synchronization raster shift and a set of second frequency ranges separated by a multiple of the synchronization raster shift.

In some examples, the synchronization raster component 1225 may identify that at least one of the set of first frequency ranges overlaps with at least one of the set of second frequency ranges.

In some examples, the synchronization raster component 1225 may monitor only for repetitive transmissions of the synchronization signal block in the successive time slots on the one of the set of beams for overlapping first frequency ranges and second frequency ranges.

In some examples, the synchronization raster component 1225 may identify the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.

In some examples, the synchronization raster component 1225 may monitor for the synchronization signal block at the second frequency range based at least in part on a failure to receive the synchronization signal block at the first frequency range.

In some examples, the synchronization raster component 1225 may identify that a frequency position of the second frequency range is based on a repetition level for the repetitive transmissions of the synchronization signal block.

The SSB combining component 1230 may combine at least a portion of the synchronization signal block from each of the at least two successive time slots.

The common SSB index component 1235 may identify the common synchronization signal block index based on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.

In some examples, the common SSB index component 1235 may identify the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.

In some examples, the common SSB index component 1235 may identify the common synchronization signal block index based on a scrambling sequence of a physical broadcast channel of the synchronization signal block.

In some cases, the scrambling sequence of the physical broadcast channel of the synchronization signal block is based on a number of least significant bits in a word representative of the common synchronization signal block index.

In some cases, a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.

In some cases, the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.

The SSB identification component 1240 may identify a location of the synchronization signal block in a second time slot of the at least two successive time slots based on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.

The RMSI component 1245 may monitor for remaining system information on resources of a physical downlink control channel in association with the successive time slots.

FIG. 13 shows a diagram of a system 1300 including a device 1305 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1305 may be an example of or include the components of device 1005, device 1105, or a UE 115 as described herein. The device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1310, an I/O controller 1315, a transceiver 1320, an antenna 1325, memory 1330, and a processor 1340. These components may be in electronic communication via one or more buses (e.g., bus 1345) .

The communications manager 1310 may monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction, monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams, and communicate with the base station upon receipt of the synchronization signal block.

The I/O controller 1315 may manage input and output signals for the device 1305. The I/O controller 1315 may also manage peripherals not integrated into the device 1305. In some cases, the I/O controller 1315 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1315 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 1315 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1315 may be implemented as part of a processor. In some cases, a user may interact with the device 1305 via the I/O controller 1315 or via hardware components controlled by the I/O controller 1315.

The transceiver 1320 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1325. However, in some cases the device may have more than one antenna 1325, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1330 may include RAM and ROM. The memory 1330 may store computer-readable, computer-executable code 1335 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1330 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1340 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1340 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1330) to cause the device 1305 to perform various functions (e.g., functions or tasks supporting directional synchronization and system information acquisition) .

The code 1335 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1335 may not be directly executable by the processor 1340 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 14 shows a block diagram 1400 of a device 1405 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1405 may be an example of aspects of a base station 105 as described herein. The device 1405 may include a receiver 1410, a communications manager 1415, and a transmitter 1420. The device 1405 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1410 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to directional synchronization and system information acquisition, etc. ) . Information may be passed on to other components of the device 1405. The receiver 1410 may be an example of aspects of the transceiver 1720 described with reference to FIG. 17. The receiver 1410 may utilize a single antenna or a set of antennas.

The communications manager 1415 may identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots. The communications manager 1415 may be an example of aspects of the communications manager 1710 described herein.

The communications manager 1415, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1415, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 1415, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1415, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1415, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1420 may transmit signals generated by other components of the device 1405. In some examples, the transmitter 1420 may be collocated with a receiver 1410 in a transceiver module. For example, the transmitter 1420 may be an example of aspects of the transceiver 1720 described with reference to FIG. 17. The transmitter 1420 may utilize a single antenna or a set of antennas.

FIG. 15 shows a block diagram 1500 of a device 1505 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1505 may be an example of aspects of a device 1405, or a base station 105 as described herein. The device 1505 may include a receiver 1510, a communications manager 1515, and a transmitter 1535. The device 1505 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to directional synchronization and system information acquisition, etc. ) . Information may be passed on to other components of the device 1505. The receiver 1510 may be an example of aspects of the transceiver 1720 described with reference to FIG. 17. The receiver 1510 may utilize a single antenna or a set of antennas.

The communications manager 1515 may be an example of aspects of the communications manager 1415 as described herein. The communications manager 1515 may include a beam identification component 1520, a repetitive SSB component 1525, and a SSB component 1530. The communications manager 1515 may be an example of aspects of the communications manager 1710 described herein.

The beam identification component 1520 may identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction.

The repetitive SSB component 1525 may transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots.

The SSB component 1530 may transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

The transmitter 1535 may transmit signals generated by other components of the device 1505. In some examples, the transmitter 1535 may be collocated with a receiver 1510 in a transceiver module. For example, the transmitter 1535 may be an example of aspects of the transceiver 1720 described with reference to FIG. 17. The transmitter 1535 may utilize a single antenna or a set of antennas.

FIG. 16 shows a block diagram 1600 of a communications manager 1605 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The communications manager 1605 may be an example of aspects of a communications manager 1415, a communications manager 1515, or a communications manager 1710 described herein. The communications manager 1605 may include a beam identification component 1610, a repetitive SSB component 1615, a SSB component 1620, a synchronization raster component 1625, a common SSB index component 1630, and a RMSI component 1635. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The beam identification component 1610 may identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction.

The repetitive SSB component 1615 may transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block on one of the first set of beams at a first frequency range, where the first frequency range is associated with repetitive transmissions of the synchronization signal block in the successive time slots.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block in each of at least two consecutive time slots.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block in each of the at least two consecutive potential synchronization signal block transmission locations.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block in interleaved potential synchronization signal block transmission locations.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots.

In some examples, the repetitive SSB component 1615 may transmit the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.

The SSB component 1620 may transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

In some examples, the SSB component 1620 may transmit the synchronization signal block on the second set of beams at a at a second frequency range.

In some examples, the SSB component 1620 may transmit the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.

In some cases, the first set of beams is used for more repeated synchronization signal block transmissions than on the second set of beams.

The synchronization raster component 1625 may identify the first frequency range and the second frequency range in accordance with a synchronization raster, where the synchronization raster includes a set of first frequency ranges separated by a multiple of a synchronization raster shift and a set of second frequency ranges separated by the synchronization raster shift.

In some examples, the synchronization raster component 1625 may identify that at least one of the set of first frequency ranges overlaps with at least one of the set of second frequency ranges.

In some examples, the synchronization raster component 1625 may identify the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.

In some examples, the synchronization raster component 1625 may transmit the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.

In some examples, the synchronization raster component 1625 may identify that a frequency position of the second frequency range is based on a repetition level for the repetitive transmissions of the synchronization signal block.

The common SSB index component 1630 may transmit the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.

In some examples, the common SSB index component 1630 may determine the synchronization signal block index based on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.

In some examples, the common SSB index component 1630 may embed the common synchronization signal block index in a physical broadcast channel payload.

In some examples, the common SSB index component 1630 may encode the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based on a number of possible synchronization signal block locations.

The RMSI component 1635 may transmit remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of at least two successive time slots.

FIG. 17 shows a diagram of a system 1700 including a device 1705 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The device 1705 may be an example of or include the components of device 1405, device 1505, or a base station 105 as described herein. The device 1705 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1710, a network communications manager 1715, a transceiver 1720, an antenna 1725, memory 1730, a processor 1740, and an inter-station communications manager 1745. These components may be in electronic communication via one or more buses (e.g., bus 1750) .

The communications manager 1710 may identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction, transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots, and transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots.

The network communications manager 1715 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1715 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1720 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1720 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1720 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1725. However, in some cases the device may have more than one antenna 1725, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1730 may include RAM, ROM, or a combination thereof. The memory 1730 may store computer-readable code 1735 including instructions that, when executed by a processor (e.g., the processor 1740) cause the device to perform various functions described herein. In some cases, the memory 1730 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1740 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1740 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1740. The processor 1740 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1730) to cause the device 1705 to perform various functions (e.g., functions or tasks supporting directional synchronization and system information acquisition) .

The inter-station communications manager 1745 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1745 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1745 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1735 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1735 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1735 may not be directly executable by the processor 1740 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 18 shows a flowchart illustrating a method 1800 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The operations of method 1800 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1800 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1805, the UE may monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a set of beams, each of the set of beams being associated with a synchronization signal block index and a direction. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a SSB monitoring component as described with reference to FIGs. 10 through 13.

At 1810, the UE may monitor for the synchronization signal block at a second frequency range, where the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the set of beams. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by a repetitive SSB component as described with reference to FIGs. 10 through 13.

At 1815, the UE may communicate with the base station upon receipt of the synchronization signal block. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by a communication interface as described with reference to FIGs. 10 through 13.

FIG. 19 shows a flowchart illustrating a method 1900 that supports directional synchronization and system information acquisition in accordance with aspects of the present disclosure. The operations of method 1900 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1900 may be performed by a communications manager as described with reference to FIGs. 14 through 17. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1905, the base station may identify a set of beams to be used for synchronization signal block transmission, each of the set of beams being associated with a synchronization signal block index and a direction. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a beam identification component as described with reference to FIGs. 14 through 17.

At 1910, the base station may transmit, on a first set of beams of the set of beams, a synchronization signal block in each of at least two successive time slots. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by a repetitive SSB component as described with reference to FIGs. 14 through 17.

At 1915, the base station may transmit the synchronization signal block on a second set of beams of the set of beams by using different beams during successive time slots. The operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by a SSB component as described with reference to FIGs. 14 through 17.

It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communications at a user equipment (UE) , comprising:

monitoring, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a plurality of beams, each of the plurality of beams being associated with a synchronization signal block index and a direction;

monitoring for the synchronization signal block at a second frequency range, wherein the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the plurality of beams; and

communicating with the base station upon receipt of the synchronization signal block.
The method of claim 1, further comprising:

identifying the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a synchronization raster shift and a plurality of second frequency ranges separated by a multiple of the synchronization raster shift.
The method of claim 2, further comprising:

identifying that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

monitoring only for the repetitive transmissions of the synchronization signal block in the successive time slots on the one of the plurality of beams for overlapping first frequency ranges and second frequency ranges.
The method of claim 2, further comprising:

identifying that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The method of claim 2, further comprising:

identifying the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The method of claim 1, further comprising:

receiving the synchronization signal block at the second frequency range in the at least two successive time slots; and

combining at least a portion of the synchronization signal block from each of the at least two successive time slots.
The method of claim 6, wherein receiving the synchronization signal block in the at least two successive time slots comprises:

receiving the synchronization signal block in each of at least two consecutive time slots.
The method of claim 6, wherein receiving the synchronization signal block in the at least two successive time slots comprises:

receiving the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The method of claim 6, wherein receiving the synchronization signal block in the at least two successive time slots comprises:

receiving the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The method of claim 6, wherein receiving the synchronization signal block in the at least two successive time slots comprises:

receiving the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The method of claim 10, further comprising:

identifying the common synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.
The method of claim 10, further comprising:

identifying the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.
The method of claim 10, further comprising:

identifying the common synchronization signal block index based at least in part on a scrambling sequence of a physical broadcast channel of the synchronization signal block.
The method of claim 13, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The method of claim 14, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The method of claim 15, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The method of claim 6, wherein receiving the synchronization signal block in the at least two successive time slots comprises:

receiving the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

receiving the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The method of claim 17, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The method of claim 6, further comprising:

receiving the synchronization signal block in a first time slot of the at least two successive time slots; and

identifying a location of the synchronization signal block in a second time slot of the at least two successive time slots based at least in part on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.
The method of claim 1, further comprising:

monitoring for remaining system information on resources of a physical downlink control channel in association with the successive time slots.
The method of claim 1, wherein monitoring for the synchronization signal block at the second frequency range comprises:

monitoring for the synchronization signal block at the second frequency range based at least in part on a failure to receive the synchronization signal block at the first frequency range.
A method for wireless communication at a base station, comprising:

identifying a plurality of beams to be used for synchronization signal block transmission, each of the plurality of beams being associated with a synchronization signal block index and a direction;

transmitting, on a first set of beams of the plurality of beams, a synchronization signal block in each of at least two successive time slots; and

transmitting the synchronization signal block on a second set of beams of the plurality of beams by using different beams during successive time slots.
The method of claim 22, wherein transmitting the synchronization signal block comprises:

transmitting the synchronization signal block on one of the first set of beams at a first frequency range, wherein the first frequency range is associated with repetitive transmissions of the synchronization signal block in the successive time slots; and

transmitting the synchronization signal block on the second set of beams at a at a second frequency range.
The method of claim 23, further comprising:

identifying the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a multiple of a synchronization raster shift and a plurality of second frequency ranges separated by the synchronization raster shift.
The method of claim 24, further comprising:

identifying that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

transmitting the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.
The method of claim 24, further comprising:

identifying that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The method of claim 24, further comprising:

identifying the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The method of claim 23, further comprising:

transmitting the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.
The method of claim 22, wherein transmitting the synchronization signal block in each of the at least two successive time slots comprises:

transmitting the synchronization signal block in each of at least two consecutive time slots.
The method of claim 22, wherein transmitting the synchronization signal block in each of the at least two successive time slots comprises:

transmitting the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The method of claim 22, wherein transmitting the synchronization signal block in each of the at least two successive time slots comprises:

transmitting the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The method of claim 22, wherein transmitting the synchronization signal block in each of the at least two successive time slots comprises:

transmitting the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The method of claim 32, further comprising:

determining the synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.
The method of claim 32, further comprising:

embedding the common synchronization signal block index in a physical broadcast channel payload.
The method of claim 32, further comprising:

encoding the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based at least in part on a number of possible synchronization signal block locations.
The method of claim 35, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The method of claim 36, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The method of claim 37, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The method of claim 22, wherein transmitting the synchronization signal block in each of the at least two successive time slots comprises:

transmitting the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

transmitting the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The method of claim 39, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The method of claim 22, further comprising:

transmitting remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of the at least two successive time slots.
The method of claim 22, wherein the first set of beams is used for more repeated synchronization signal block transmissions than on the second set of beams.
An apparatus for wireless communications at a user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a plurality of beams, each of the plurality of beams being associated with a synchronization signal block index and a direction;

monitor for the synchronization signal block at a second frequency range, wherein the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the plurality of beams; and

communicate with the base station upon receipt of the synchronization signal block.
The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a synchronization raster shift and a plurality of second frequency ranges separated by a multiple of the synchronization raster shift.
The apparatus of claim 44, wherein the instructions are further executable by the processor to cause the apparatus to:

identify that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

monitor only for the repetitive transmissions of the synchronization signal block in the successive time slots on the one of the plurality of beams for overlapping first frequency ranges and second frequency ranges.
The apparatus of claim 44, wherein the instructions are further executable by the processor to cause the apparatus to:

identify that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The apparatus of claim 44, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to:

receive the synchronization signal block at the second frequency range in at least two successive time slots; and

combine at least a portion of the synchronization signal block from each of the at least two successive time slots.
The apparatus of claim 48, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable by the processor to cause the apparatus to:

receive the synchronization signal block in each of at least two consecutive time slots.
The apparatus of claim 48, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable by the processor to cause the apparatus to:

receive the synchronization signal block in each of at least two consecutive time slots of at least two consecutive subframes.
The apparatus of claim 48, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable by the processor to cause the apparatus to:

receiving the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The apparatus of claim 48, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable by the processor to cause the apparatus to:

receiving the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The apparatus of claim 52, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the common synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.
The apparatus of claim 52, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.
The apparatus of claim 52, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the common synchronization signal block index based at least in part on a scrambling sequence of a physical broadcast channel of the synchronization signal block.
The apparatus of claim 55, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The apparatus of claim 56, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The apparatus of claim 57, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The apparatus of claim 48, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable by the processor to cause the apparatus to:

receive the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

receive the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The apparatus of claim 59, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The apparatus of claim 48, wherein the instructions are further executable by the processor to cause the apparatus to:

receive the synchronization signal block in a first time slot of the at least two successive time slots; and

identify a location of the synchronization signal block in a second time slot of the at least two successive time slots based at least in part on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.
The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to:

monitor for remaining system information on resources of a physical downlink control channel in association with the successive time slots.
The apparatus of claim 43, wherein the instructions to monitor for the synchronization signal block at the second frequency range are further executable by the processor to cause the apparatus to:

monitoring for the synchronization signal block at the second frequency range based at least in part on a failure to receive the synchronization signal block at the first frequency range.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify a plurality of beams to be used for synchronization signal block transmission, each of the plurality of beams being associated with a synchronization signal block index and a direction;

transmit, on a first set of beams of the plurality of beams, a synchronization signal block in each of at least two successive time slots; and

transmit the synchronization signal block on a second set of beams of the plurality of beams by using different beams during successive time slots.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block are executable by the processor to cause the apparatus to:

transmit the synchronization signal block on one of the first set of beams at a first frequency range, wherein the first frequency range is associated with repetitive transmissions of the synchronization signal block in the successive time slots; and

transmit the synchronization signal block on the second set of beams at a at a second frequency range.
The apparatus of claim 65, wherein the instructions are further executable by the processor to cause the apparatus to:

identify the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a multiple of a synchronization raster shift and a plurality of second frequency ranges separated by the synchronization raster shift.
The apparatus of claim 66, wherein the instructions are further executable by the processor to cause the apparatus to:

identify that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

transmit the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.
The apparatus of claim 66, wherein the instructions are further executable by the processor to cause the apparatus to:

identify that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The apparatus of claim 66, wherein the instructions are further executable by the processor to cause the apparatus to:

identifying the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The apparatus of claim 65, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable by the processor to cause the apparatus to:

transmit the synchronization signal block in each of at least two consecutive time slots.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable by the processor to cause the apparatus to:

transmit the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable by the processor to cause the apparatus to:

transmit the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable by the processor to cause the apparatus to:

transmit the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The apparatus of claim 74, wherein the instructions are further executable by the processor to cause the apparatus to:

determine the synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.
The apparatus of claim 74, wherein the instructions are further executable by the processor to cause the apparatus to:

embed the common synchronization signal block index in a physical broadcast channel payload.
The apparatus of claim 74, wherein the instructions are further executable by the processor to cause the apparatus to:

encode the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based at least in part on a number of possible synchronization signal block locations.
The apparatus of claim 77, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The apparatus of claim 78, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The apparatus of claim 79, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The apparatus of claim 64, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable by the processor to cause the apparatus to:

transmit the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

transmit the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The apparatus of claim 81, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The apparatus of claim 64, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of the at least two successive time slots.
The apparatus of claim 64, wherein the first set of beams is used for more repeated synchronization signal block transmissions than on the second set of beams.
An apparatus for wireless communications at a user equipment (UE) , comprising:

means for monitoring, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a plurality of beams, each of the plurality of beams being associated with a synchronization signal block index and a direction;

means for monitoring for the synchronization signal block at a second frequency range, wherein the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the plurality of beams; and

means for communicating with the base station upon receipt of the synchronization signal block.
The apparatus of claim 85, further comprising:

means for identifying the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a synchronization raster shift and a plurality of second frequency ranges separated by a multiple of the synchronization raster shift.
The apparatus of claim 86, further comprising:

means for identifying that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

means for monitoring only for the repetitive transmissions of the synchronization signal block in the successive time slots on the one of the plurality of beams for overlapping first frequency ranges and second frequency ranges.
The apparatus of claim 86, further comprising:

means for identifying that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The apparatus of claim 86, further comprising:

means for identifying the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The apparatus of claim 85, further comprising:

means for receiving the synchronization signal block at the second frequency range in the at least two successive time slots; and

means for combining at least a portion of the synchronization signal block from each of the at least two successive time slots.
The apparatus of claim 90, wherein the means for receiving the synchronization signal block in the at least two successive time slots comprises:

means for receiving the synchronization signal block in each of at least two consecutive time slots.
The apparatus of claim 90, wherein the means for receiving the synchronization signal block in the at least two successive time slots comprises:

means for receiving the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The apparatus of claim 90, wherein the means for receiving the synchronization signal block in the at least two successive time slots comprises:

means for receiving the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The apparatus of claim 90, wherein the means for receiving the synchronization signal block in the at least two successive time slots comprises:

means for receiving the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The apparatus of claim 94, further comprising:

means for identifying the common synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.
The apparatus of claim 94, further comprising:

means for identifying the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.
The apparatus of claim 94, further comprising:

means for identifying the common synchronization signal block index based at least in part on a scrambling sequence of a physical broadcast channel of the synchronization signal block.
The apparatus of claim 97, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The apparatus of claim 98, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The apparatus of claim 99, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The apparatus of claim 90, wherein the means for receiving the synchronization signal block in the at least two successive time slots comprises:

means for receiving the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

means for receiving the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The apparatus of claim 101, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The apparatus of claim 90, further comprising:

means for receiving the synchronization signal block in a first time slot of the at least two successive time slots; and

means for identifying a location of the synchronization signal block in a second time slot of the at least two successive time slots based at least in part on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.
The apparatus of claim 85, further comprising:

means for monitoring for remaining system information on resources of a physical downlink control channel in association with the successive time slots.
The apparatus of claim 85, wherein the means for monitoring for the synchronization signal block at the second frequency range comprises:

means for monitoring for the synchronization signal block at the second frequency range based at least in part on a failure to receive the synchronization signal block at the first frequency range.
An apparatus for wireless communication at a base station, comprising:

means for identifying a plurality of beams to be used for synchronization signal block transmission, each of the plurality of beams being associated with a synchronization signal block index and a direction;

means for transmitting, on a first set of beams of the plurality of beams, a synchronization signal block in each of at least two successive time slots; and

means for transmitting the synchronization signal block on a second set of beams of the plurality of beams by using different beams during successive time slots.
The apparatus of claim 106, wherein the means for transmitting the synchronization signal block comprises:

means for transmitting the synchronization signal block on one of the first set of beams at a first frequency range, wherein the first frequency range is associated with repetitive transmissions of the synchronization signal block in the successive time slots; and

means for transmitting the synchronization signal block on the second set of beams at a at a second frequency range.
The apparatus of claim 107, further comprising:

means for identifying the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a multiple of a synchronization raster shift and a plurality of second frequency ranges separated by the synchronization raster shift.
The apparatus of claim 108, further comprising:

means for identifying that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

means for transmitting the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.
The apparatus of claim 108, further comprising:

means for identifying that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The apparatus of claim 108, further comprising:

means for identifying the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The apparatus of claim 107, further comprising:

means for transmitting the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.
The apparatus of claim 106, wherein the means for transmitting the synchronization signal block in each of the at least two successive time slots comprises:

means for transmitting the synchronization signal block in each of at least two consecutive time slots.
The apparatus of claim 106, wherein the means for transmitting the synchronization signal block in each of the at least two successive time slots comprises:

means for transmitting the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The apparatus of claim 114, further comprising:

means for determining the synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.
The apparatus of claim 114, further comprising:

means for embedding the common synchronization signal block index in a physical broadcast channel payload.
The apparatus of claim 114, further comprising:

means for encoding the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based at least in part on a number of possible synchronization signal block locations.
The apparatus of claim 117, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The apparatus of claim 118, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The apparatus of claim 119, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The apparatus of claim 106, wherein the means for transmitting the synchronization signal block in each of the at least two successive time slots comprises:

means for transmitting the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

means for transmitting the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The apparatus of claim 121, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The apparatus of claim 106, further comprising:

means for transmitting remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of the at least two successive time slots.
The apparatus of claim 106, wherein the first set of beams is used for more repeated synchronization signal block transmissions than on the second set of beams.
A non-transitory computer-readable medium storing code for wireless communications at a user equipment (UE) , the code comprising instructions executable by a processor to:

monitor, at a first frequency range, for at least a synchronization signal block transmitted by a base station on a beam of a plurality of beams, each of the plurality of beams being associated with a synchronization signal block index and a direction;

monitor for the synchronization signal block at a second frequency range, wherein the second frequency range is associated with repetitive transmissions of the synchronization signal block in successive time slots on one of the plurality of beams; and

communicate with the base station upon receipt of the synchronization signal block.
The non-transitory computer-readable medium of claim 125, wherein the instructions are further executable to:

identify the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a synchronization raster shift and a plurality of second frequency ranges separated by a multiple of the synchronization raster shift.
The non-transitory computer-readable medium of claim 126, wherein the instructions are further executable to:

identify that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

monitor only for the repetitive transmissions of the synchronization signal block in the successive time slots on the one of the plurality of beams for overlapping first frequency ranges and second frequency ranges.
The non-transitory computer-readable medium of claim 126, wherein the instructions are further executable to:

identify that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The non-transitory computer-readable medium of claim 126, wherein the instructions are further executable to:

identify the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The non-transitory computer-readable medium of claim 125, wherein the instructions are further executable to:

receive the synchronization signal block at the second frequency range in the at least two successive time slots; and

combine at least a portion of the synchronization signal block from each of the at least two successive time slots.
The non-transitory computer-readable medium of claim 130, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable to:

receive the synchronization signal block in each of at least two consecutive time slots.
The non-transitory computer-readable medium of claim 130, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable to:

receive the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The non-transitory computer-readable medium of claim 130, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable to:

receive the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The non-transitory computer-readable medium of claim 130, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable to:

receive the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The non-transitory computer-readable medium of claim 134, wherein the instructions are further executable to:

identify the common synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including the synchronization signal block.
The non-transitory computer-readable medium of claim 134, wherein the instructions are further executable to:

identify the common synchronization signal block index from a physical broadcast channel payload of the synchronization signal block.
The non-transitory computer-readable medium of claim 134, wherein the instructions are further executable to:

identify the common synchronization signal block index based at least in part on a scrambling sequence of a physical broadcast channel of the synchronization signal block.
The non-transitory computer-readable medium of claim 137, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The non-transitory computer-readable medium of claim 138, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The non-transitory computer-readable medium of claim 139, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The non-transitory computer-readable medium of claim 130, wherein the instructions to receive the synchronization signal block in the at least two successive time slots are executable to:

receive the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

receive the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The non-transitory computer-readable medium of claim 141, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The non-transitory computer-readable medium of claim 130, wherein the instructions are further executable to:

receive the synchronization signal block in a first time slot of the at least two successive time slots; and

identify a location of the synchronization signal block in a second time slot of the at least two successive time slots based at least in part on a slot index of the first time slot, a synchronization signal block index of the synchronization signal block received in the first time slot, or both.
The non-transitory computer-readable medium of claim 125, wherein the instructions are further executable to:

monitor for remaining system information on resources of a physical downlink control channel in association with the successive time slots.
The non-transitory computer-readable medium of claim 125, wherein the instructions to monitor for the synchronization block at the second frequency range are further executable to:

monitor for the synchronization signal block at the second frequency range based at least in part on a failure to receive the synchronization signal block at the first frequency range.
A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to:

identify a plurality of beams to be used for synchronization signal block transmission, each of the plurality of beams being associated with a synchronization signal block index and a direction;

transmit, on a first set of beams of the plurality of beams, a synchronization signal block in each of at least two successive time slots; and

transmit the synchronization signal block on a second set of beams of the plurality of beams by using different beams during successive time slots.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block are executable to:

transmit the synchronization signal block on one of the first set of beams at a first frequency range, wherein the first frequency range is associated with repetitive transmissions of the synchronization signal block in the successive time slots; and

transmit the synchronization signal block on the second set of beams at a at a second frequency range.
The non-transitory computer-readable medium of claim 147, wherein the instructions are further executable to:

identify the first frequency range and the second frequency range in accordance with a synchronization raster, wherein the synchronization raster includes a plurality of first frequency ranges separated by a multiple of a synchronization raster shift and a plurality of second frequency ranges separated by the synchronization raster shift.
The non-transitory computer-readable medium of claim 148, wherein the instructions are further executable to:

identify that at least one of the plurality of first frequency ranges overlaps with at least one of the plurality of second frequency ranges; and

transmit the synchronization signal block in the successive time slots on one of the first set of beams for overlapping first frequency ranges and second frequency ranges.
The non-transitory computer-readable medium of claim 148, wherein the instructions are further executable to:

identify that a frequency position of the second frequency range is based at least in part on a repetition level for the repetitive transmissions of the synchronization signal block.
The non-transitory computer-readable medium of claim 148, wherein the instructions are further executable to:

identify the first frequency range or the second frequency range based at least in part on a center frequency of the first frequency range or the second frequency range, a bandwidth of the synchronization signal block, or a combination thereof.
The non-transitory computer-readable medium of claim 147, wherein the instructions are further executable to:

transmit the synchronization signal block on the second set of beams at the first frequency range after transmitting the synchronization signal block on the one of the first set of beams at the first frequency range.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable to:

transmit the synchronization signal block in each of at least two consecutive time slots.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable to:

transmit the synchronization signal block in each of at least two consecutive potential synchronization signal block transmission locations.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable to:

transmit the synchronization signal block in interleaved potential synchronization signal block transmission locations.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable to:

transmit the synchronization signal block in each of the at least two successive time slots with a common synchronization signal block index.
The non-transitory computer-readable medium of claim 156, wherein the instructions are further executable to:

determine the synchronization signal block index based at least in part on a slot index of a first time slot of the at least two successive time slots including a transmission of the synchronization signal block.
The non-transitory computer-readable medium of claim 156, wherein the instructions are further executable to:

embed the common synchronization signal block index in a physical broadcast channel payload.
The non-transitory computer-readable medium of claim 156, wherein the instructions are further executable to:

encode the common synchronization signal block index in a scrambling sequence of a physical broadcast channel based at least in part on a number of possible synchronization signal block locations.
The non-transitory computer-readable medium of claim 159, wherein the scrambling sequence of the physical broadcast channel of the synchronization signal block is based at least in part on a number of least significant bits in a word representative of the common synchronization signal block index.
The non-transitory computer-readable medium of claim 160, wherein a number of most significant bits in the word not overlapping with the number of least significant bits of the word are included in either a physical broadcast channel payload or a cyclic redundancy check mask.
The non-transitory computer-readable medium of claim 161, wherein the number of most significant bits in the word are included as reserve bits in the physical broadcast channel payload.
The non-transitory computer-readable medium of claim 146, wherein the instructions to transmit the synchronization signal block in each of the at least two successive time slots are executable to:

transmit the synchronization signal block having a first format in at least a first time slot of the at least two successive time slots; and

transmit the synchronization signal block having a second format in one or more remaining time slots of the at least two successive time slots.
The non-transitory computer-readable medium of claim 163, wherein:

the synchronization signal block of the first format comprises a physical broadcast channel and at least one synchronization signal; and

the synchronization signal block of the second format comprises the physical broadcast channel without the at least one synchronization signal.
The non-transitory computer-readable medium of claim 146, wherein the instructions are further executable to:

transmit remaining system information on resources of a physical downlink control channel associated with the transmitting of the synchronization signal block in each of the at least two successive time slots.
The non-transitory computer-readable medium of claim 146, wherein the first set of beams is used for more repeated synchronization signal block transmissions than on the second set of beams.