USE OF PHYSICAL BROADCAST CHANNEL DEMODULATION REFERENCE SIGNAL TO SPEED UP NEIGHBOR CELL MEASUREMENT

In a wireless communication system, a user equipment (UE) may measure synchronization signal blocks (SSBs) to evaluate neighbor cells. A UE configured with multiple potential receive beams may conventionally measure one receive beam per SSB. A UE may improve the speed of receive beam measurements by performing measurements using demodulation reference signals (DMRS) of physical broadcast channel (PBCH) symbols, which occur twice per SSB. The UE may perform a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells. The UE may measure one or more receive beams using the DMRs of the PBCHs of SSBs received from the neighbor cells. Each receive beam may be measured during a beam switch time unit including a PBCH symbol from each of the neighbor cells according to the timing information.

BACKGROUND

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to use of physical broadcast channel (PBCH) demodulation reference signal (DMRS) to speed up neighbor cell measurement.

Introduction

SUMMARY

In an aspect of the disclosure, a method, a non-transitory computer-readable medium, and an apparatus for a user equipment (UE) are provided. The method includes performing a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells. The method includes measuring one or more receive beams using demodulation reference signals (DMRS) of physical broadcast channel (PBCH) symbols of synchronization signal blocks (SSBs) received from the neighbor cells, each receive beam measured during a beam switch time unit including a PBCH symbol from each of the neighbor cells according to the timing information.

The present disclosure also provides an apparatus (e.g., a UE) including a memory storing computer-executable instructions and at least one processor configured to execute the computer-executable instructions to perform the above method, an apparatus including means for performing the above method, and a non-transitory computer-readable medium storing computer-executable instructions for performing the above method.

DETAILED DESCRIPTION

In order to combat high propagation loss in high frequency bands such as millimeter wave (mmW) bands, 5G NR may utilize a pair of gNB beam and UE beam to form a beam pair link between the gNB and the UE, which carries control and data channels. The 5G NR Rel-15 specification provides a synchronization signal block (SSB) for the UE to conduct initial access as well as cell, gNB, and UE beam tracking. Typically, the SSBs are transmitted in an SSB burst including the SSB on different beams. An SSB burst may be transmitted at a default periodicity of 20 ms, but periodicities of 5 ms, 10 ms, or a multiples of 20 ms may be configured.

Each SSB consists of four symbols carrying a respective signal arranged in a mostly time division multiplexing (TDM) manner: primary synchronization signal (PSS), physical broadcast channel (PBCH), secondary synchronization signal (SSS), and PBCH. The PBCH is actually transmitted over the last three symbols of the SSB, but in the third symbol, most resource blocks (RBs) are for the SSS. The PBCH includes both resources used for a demodulation reference signal (DMRS) and resources used for traffic. The SSS is usually used for beam scanning and beam reporting. For serving cell and different neighbor cells, a UE may need to use different UE beams to form different beam pair links. In order to measure different cells, the UE needs to switch UE beams to point to different cells to assure signal quality or identify a beam pair with the best signal quality. As the number of potential beams and neighbor cells increases, the time for the UE to conduct a UE beam scan on both serving and neighbor cells solely based on the SSS symbol increases.

In a synchronous network, the frame timing is generally aligned between neighbor cells. However, a synchronous network may tolerate an offset between neighbor cells. That is, the timing of serving and neighbor cells may not be perfectly aligned. For a synchronous network, the timing offset may be +/−3 microseconds (μs) at the gNB side, and the UE may expect the maximum offset to be 3+1.7=4.7 μs, where the 1.7 μs covers the propagation delay.

In an aspect, the present disclosure provides techniques for a UE to use the DMRS of the PBCH symbols to speed up the UE beam scan for parallel measurements on both serving and neighbor cells. As there are two PBCH symbols per SSB, the use of the DMRS of the PBCH can effectively increase the speed of a beam scan by 2 times. The use of DMRS may provide more measurement opportunities and better support of mobility. The use of DMRS may be able to support parallel measurement on both serving and neighbor cells. For a UE to perform beam measurements on the DMRS of PBCH symbols of different cells of a Synchronous Network, the offset may determine how often the UE is able to switch UE beams for measurement. The UE may obtain timing information for detected cells based on a cell search for neighbor cells that determines a number of neighbor cells and timing information for each of the neighbor cells (e.g., based on the PSS and SSS symbols of the SSBs). Based on the timing information, the UE may determine a maximum relative timing offset between the neighbor cells. The UE may perform measurements for one or more receive beams using the DMRS of PBCH symbols of the SSBs during a beam switch time unit including a PBCH symbol from each of the neighbor cells. The beam switch time unit may be based on the maximum relative timing offset between neighbor cells. For example, the beam switch time unit may be at least a sum of the maximum timing offset and a length of a symbol according to a subcarrier spacing. In some implementations, a beam switch time unit with a duration of two symbols may be used unless the maximum relative timing offset is greater than one symbol.

One or more of the UEs104may include a beam measurement component140that measures beams for the serving cell and neighbor cells. The beam measurement component140may include a search component142configured to perform a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells. The beam measurement component140may include PBCH measurement component144configured to measure one or more receive beams using DMRS of PBCH symbols of a SSB received from the neighbor cells. Each receive beam may be measured during a beam switch time unit including a PBCH symbol from each of the neighbor cells according to the timing information. In some implementations, the beam measurement component140may optionally include a report component146configured to transmit a beam measurement report including measurements of each of the receive beams to a serving cell. In some implementations, the beam measurement component140may optionally include a scheduling component148configured to schedule measurements of a plurality of receive beams over one or more SSBs based on the beam switch time unit.

In an aspect, one or more of the base stations102may include a synchronized network component120that synchronizes the base station with other base station in the synchronized network. For example, the synchronized network component120may maintain a timing difference of less than 3 μs between the base station102/180and other base stations.

A base station102, whether a small cell102′ or a large cell (e.g., macro base station), may include an eNB, gNodeB (gNB), or other type of base station. Some base stations, such as gNB180may operate in one or more frequency bands within the electromagnetic spectrum.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band. Communications using the mmW radio frequency band have extremely high path loss and a short range. The mmW base station180may utilize beamforming182with the UE104to compensate for the path loss and short range.

The base station180may transmit a beamformed signal to the UE104one or more transmit beams182′. The UE104may receive the beamformed signal from the base station180on one or more receive beams182″. The UE104may also transmit a beamformed signal to the base station180in one or more transmit directions. The base station180may receive the beamformed signal from the UE104in one or more receive directions. The base station180/UE104may perform beam training to determine the best receive and transmit directions for each of the base station180/UE104. The transmit and receive directions for the base station180may or may not be the same. The transmit and receive directions for the UE104may or may not be the same. In the case of a synchronous network, cells from base stations180may be generally aligned. A different receive beam182″ may provide the best performance for each cell. A UE may perform a neighbor cell search and beam measurements to identify the best receive beam182″ for each cell.

FIG.2Billustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) may be within symbol 2 (e.g., a PSS symbol242) of particular subframes of a frame. The PSS is used by a UE104to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4(e.g., a SSS symbol246) of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DMRS202. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block, also referred to as an SSB232. The PBCH may be transmitted over symbols 3-5 of a subframe, with symbols 3 and 5, for example, being referred to as PBCH symbols244,248because those symbols include mostly RBs for the PBCH. The DMRS202may be interleaved with the RBs for the PBCH (e.g., every fourth RB) to allow decoding of the PBCH. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages.

At least one of the Tx processor368, the Rx processor356, and the controller/processor359may be configured to perform aspects in connection with the beam measurement component140ofFIG.1.

At least one of the Tx processor316, the Rx processor370, and the controller/processor375may be configured to perform aspects in connection with the synchronized network component120ofFIG.1.

FIG.4shows a diagram illustrating an example disaggregated base station400architecture. The disaggregated base station400architecture may include one or more central units (CUs)410that can communicate directly with a core network420via a backhaul link, or indirectly with the core network420through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (MC)425via an E2 link, or a Non-Real Time (Non-RT) RIC415associated with a Service Management and Orchestration (SMO) Framework405, or both). A CU410may communicate with one or more distributed units (DUs)430via respective midhaul links, such as an F1 interface. The DUs430may communicate with one or more radio units (RUs)440via respective fronthaul links. The RUs440may communicate with respective UEs104via one or more radio frequency (RF) access links. In some implementations, the UE104may be simultaneously served by multiple RUs440.

Each of the units, i.e., the CUs410, the DUs430, the RUs440, as well as the Near-RT RICs425, the Non-RT RICs415and the SMO Framework405, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

The DU430may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs440. In some aspects, the DU430may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP). In some aspects, the DU430may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU430, or with the control functions hosted by the CU410.

Lower-layer functionality can be implemented by one or more RUs440. In some deployments, an RU440, controlled by a DU430, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s)440can be implemented to handle over the air (OTA) communication with one or more UEs104. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU(s)440can be controlled by the corresponding DU430. In some scenarios, this configuration can enable the DU(s)430and the CU410to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework405may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework405may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO Framework405may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud)490) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements can include, but are not limited to, CUs410, DUs430, RUs440and Near-RT RICs425. In some implementations, the SMO Framework405can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB)411, via an O1 interface. Additionally, in some implementations, the SMO Framework405can communicate directly with one or more RUs440via an O1 interface. The SMO Framework405also may include a Non-RT RIC415configured to support functionality of the SMO Framework405.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC425, the Non-RT RIC415may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC425and may be received at the SMO Framework405or the Non-RT MC415from non-network data sources or from network functions. In some examples, the Non-RT MC415or the Near-RT MC425may be configured to tune RAN behavior or performance. For example, the Non-RT MC415may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework405(such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies).

FIG.5is a diagram of SSBs received at a UE104from different cells in a synchronized network. For example, a slot is illustrated for each of three cells510,520,530. The synchronized network may be configured with a subcarrier spacing of 120 kHz. As illustrated, each slot may include a burst of two SSBs. The timing of the slots may differ due to timing differences of the cells and/or different propagation delays to a UE. The UE104may obtain the timing information of each cell by performing a cell search based on the PSS and SSS signals. For instance, the UE104may determine a maximum timing offset540between the cells510,520,530. The UE may monitor the SSBs of the cells using different receive beams. The UE may perform measurements on the DMRS of the PBCH symbols during a beam switch time unit550. The beam switch time unit550may be based on the timing information of the cells such as the maximum timing offset540. The duration of the beam switch time unit550may be selected such that each beam switch time unit550includes a PBCH symbol for each cell510,520,530. For example, the duration of the beam switch time unit550may be at least a duration of a symbol plus the maximum timing offset540. In some implementations, the duration of the beam switch time unit550may be selected such that the beam switch time units550occur consecutively. In some implementations, the beam switch time units550may be spaced apart by a gap (not shown).

FIG.6is a diagram of SSBs received at a UE104from different cells in another synchronized network. For example, a slot is illustrated for each of three cells610,620,630. The synchronized network may be configured with a subcarrier spacing of 240 kHz. Each slot may include a burst of four SSBs. The UE104may determine a maximum timing offset640between the cells610,620,630. As noted above, the UE expects a maximum timing offset of no more than 4.7 μs. At 240 kHz, the duration of a symbol may be approximately 4.5 μs. InFIG.6, the maximum timing offset640is illustrated as less than 4.5 μs. Accordingly, a duration of the beam switch time unit650may be set such that each beam switch time unit650includes a PBCH symbol for each cell610,620,630.

FIG.7is a diagram of SSBs received at a UE104from different cells in another synchronized network with a maximum timing offset740greater than a duration of a symbol. For example, the maximum timing offset740may be 4.6 μs, which may satisfy requirements based on differences at the base station and propagation delays. However, a beam switch time unit750that is at least the maximum timing offset740plus a symbol length would be greater than a duration of two symbols. Accordingly, a longer beam switch time unit750may be selected to ensure that at least one PBCH symbol included within the beam switch time unit750for each cell710,720,730. For example, the beam switch time unit750may have a duration of four symbols. The beam switch time unit750may also include an SSS symbol for each cell, so the beam measurement may alternatively or additionally be based on the SSS symbol.

In general, a beam switch time unit of two symbols may be used when the maximum timing offset is less than a duration of a symbol and a beam switch time unit of four symbols may be used when the maximum timing offset is greater than a duration of a symbol. The following table provides example configuration of the beam switch time unit.

In an aspect, the beam switch time unit may be dynamic because the maximum timing offset may vary based on timing drift and propagation delay. For instance, if the UE moves closer to one neighbor cell and further from another neighbor cell, the difference in propagation delay may increase the maximum timing offset beyond the1symbol threshold. Accordingly, the UE may determine the maximum timing offset based on the neighbor cell search and schedule measurements based on the DMRS of the PBCH symbols according to the maximum timing offset.

FIG.8is a message diagram800illustrating example messages for beam measurement. A UE104may be connected to a serving cell810and may be in a coverage area of neighbor cells812and814. The cells810,812,814may be part of a synchronized network. As such, the cells810,812,814may transmit respective SSBs820,822,824at approximately the same time (e.g., within 3 μs of each other).

At block830, the UE104may perform a cell search. For example, the UE104may identify each of the cells810,812,814based on the PSS and SSS symbols of the SSBs820,822,824. The UE104may also determine timing information for each cell810,812,814.

At block840, the UE may determine the maximum timing offset832between the SSBs820,822,824. For example, the UE may determine a difference in timing between an earliest one of the neighbor cells and a latest one of the neighbor cells.

The cells810,812,814may transmit the SSBs820,822,824again based on an SSB burst periodicity850. The SSB burst periodicity850may be significantly greater than the maximum timing offset832. For example, the SSB burst periodicity850may be 20 ms or a multiple thereof. The UE104may schedule measurements of a plurality of receive beams over one or more SSBs based on the beam switch time unit. For example, the UE104may schedule a beam measurement on each of the PBCH symbols when the beam switch time unit is two symbols or less. The UE may schedule measurements of the receive beam for each cell based on the respective SSB820,822,824in parallel.

At block860, the UE104may measure the SSBs820,822,824based on the DMRS of the PBCH symbols within each SSB. Because the UE104may perform multiple measurements per SSB, the UE104may measure a configured set of receive beams more quickly than if only the SSS is used for beam measurements. Accordingly, the UE104may transmit a beam measurement report870including the beam measurements.

FIG.9is a conceptual data flow diagram900illustrating the data flow between different means/components in an example UE904, which may be an example of the UE104and include the beam measurement component140. As discussed with respect toFIG.1, the beam measurement component140may include the search component142and the PBCH measurement component144. The beam measurement component140may optionally include the report component146, the scheduling component148, and the timing component149.

The UE104also may include a receiver component970and a transmitter component972. The receiver component970may include, for example, a RF receiver for receiving the signals described herein. The transmitter component972may include for example, an RF transmitter for transmitting the signals described herein. In some implementations, the receiver component970and the transmitter component972may be co-located in a transceiver such as the Tx/Rx354inFIG.3.

The receiver component970may receive downlink signals such as the SSBs820,822,824. The receiver component970may provide the SSBs820,822,824to the search component142and/or the PBCH measurement component144.

The search component142may be configured to perform a cell search for neighbor cells available to the UE in a synchronized network. The search component142may receive the SSBs via the receiver component970. The search component142may process the PSS and SSS portions of the SSBs to determine a cell identifier and timing information for each of the neighbor cells. The search component142may determine a number of the neighbor cells and timing information for each of the neighbor cells. In some implementations, the search component142may provide the number of neighbor cells and timing information to the timing component149. In other implementations, the search component142may perform the functions of the timing component149, or provide the number of cells and timing information directly to the PBCH measurement component144.

The optional timing component149may be configured to determine the beam switch time unit based on a maximum timing offset between the neighbor cells. The timing component149may receive the number of cells and timing information from the search component142. The timing component149may determine the pair of cells with the greatest timing offset among the neighbor cells and set the greatest timing offset as the maximum timing offset. The timing component149may determine the beam switch time unit based on the above table1, for example. The timing component149may provide the beam switch time unit to the scheduling component148.

The scheduling component148may be configured to schedule beam measurements on PBCH symbols of the SSBs. The scheduling component148may receive the beam switch time unit from the timing component149. The scheduling component148may determine at least one PBCH symbol for each cell within the beam switch time unit. The scheduling component148may configure the PBCH measurement component144to measure the DMRS during the respective PBCH symbol for each cell. The scheduling component148may configure the PBCH measurement component144to switch receive beams between beam switch time units.

The PBCH measurement component144may be configured to measure one or more receive beams using DMRS of PBCH symbols of SSBs received from the neighbor cells. The PBCH measurement component144may measure each receive beam during the beam switch time unit including the PBCH symbol from each of the neighbor cells. The PBCH measurement component144may receive the SSBs via the receiver component970. The PBCH measurement component144may receive the timing information from the search component142, timing component149, and/or the scheduling component148. The PBCH measurement component144may determine a transmitted sequence for the DMRS for each cell based on the cell ID, SSB index, and timing information. The PBCH measurement component144may then measure properties of the DMRS such as the signal to noise ratio (SNR) or signal to noise plus interference ratio (SINR). The measurements may correspond to a particular receive beam and particular cell. The PBCH measurement component144may measure a different receive beam for each cell during the next beam switch time unit. The PBCH measurement component144may provide the measurements to the report component146.

The report component146may be configured to transmit a beam measurement report including measurements of each of the receive beams to a serving cell. The report component146may receive the measurements from the PBCH measurement component144. The report component146may generate the beam measurement report, for example, as a RRC message. The report component146may transmit the beam measurement report via the transmitter component972.

FIG.10is a flowchart of an example method1000for a UE to perform beam measurements on PBCH symbols. The method1000may be performed by a UE (such as the UE104, which may include the memory360and which may be the entire UE104or a component of the UE104such as the beam measurement component140, Tx processor368, the Rx processor356, or the controller/processor359). The method1000may be performed by the beam measurement component140in communication with the synchronized network component120of one or more base stations102. Optional blocks are shown with dashed lines.

At block1010, the method1000performing a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells. In some implementations, for example, the UE104, the Rx processor356, or the controller/processor359may execute the beam measurement component140or the search component142to perform a cell search for neighbor cells812,814bavailable to the UE104in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells. Accordingly, the UE104, the Rx processor356, or the controller/processor359executing the beam measurement component140or the search component142may provide means for performing a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells.

At block1020, the method1000optionally includes determining the beam switch time unit based on a maximum timing offset between the neighbor cells. In some implementations, for example, the UE104, the Rx processor356, or the controller/processor359may execute the beam measurement component140or the timing component149to determine the beam switch time unit550,650,750based on a maximum timing offset540,640,740between the neighbor cells. Accordingly, the UE104, the Rx processor356, or the controller/processor359executing the beam measurement component140or the timing component149may provide means for determining the beam switch time unit based on a maximum timing offset between the neighbor cells.

At block1030, the method1000may optionally include scheduling measurements of a plurality of receive beams over one or more SSBs based on the beam switch time unit. In some implementations, for example, the UE104, the Rx processor356, or the controller/processor359may execute the beam measurement component140or the scheduling component148to schedule measurements of a plurality of receive beams182″ over one or more SSBs based on the beam switch time unit. Accordingly, the UE104, the Rx processor356, or the controller/processor359executing the beam measurement component140or the scheduling component148may provide means for scheduling measurements of a plurality of receive beams over one or more SSBs based on the beam switch time unit.

At block1040, the method1000includes measuring one or more receive beams using

DMRS of PBCH symbols of SSBs received from the neighbor cells. In some implementations, for example, the UE104, the Rx processor356, or the controller/processor359may execute the beam measurement component140or the PBCH measurement component144to measure one or more receive beams182″ using DMRS202of PBCH symbols244,248of SSBs820,822,824received from the neighbor cells. In some implementations, at sub-block1042, the block1040optionally includes measuring at least two receive beams during each SSB when the maximum timing offset is less than a length of a symbol according to a subcarrier spacing. For example, the PBCH measurement component144may measure the DMRS202of a first PBCH symbol244, the receiver component970may change the receive beam, and the PBCH measurement component144may measure the DMRS202of a second PBCH symbol248of an SSB. In some implementations, at sub-block1044, the block1040optionally includes measuring one receive beam during each SSB when the maximum timing offset is greater than or equal to a length of a symbol according to a subcarrier spacing. Accordingly, the UE104, the Rx processor356, or the controller/processor359executing the beam measurement component140or the PBCH measurement component144may provide means for measuring one or more receive beams using DMRS of PBCH symbols of SSBs received from the neighbor cells.

At block1050, the method1000optionally includes transmitting a beam measurement report including measurements of each of the receive beams to a serving cell. In some implementations, for example, the UE104, the Tx processor368, or the controller/processor359may execute the beam measurement component140or the report component146to transmit the beam measurement report870including measurements of each of the receive beams to the serving cell810. Accordingly, the UE104, the Tx processor368, or the controller/processor359executing the beam measurement component140or the report component146may provide means for transmitting a beam measurement report including measurements of each of the receive beams to a serving cell

Aspect 1: A method of wireless communication for a user equipment (UE), comprising: performing a cell search for neighbor cells available to the UE in a synchronized network to determine a number of the neighbor cells and timing information for each of the neighbor cells; and measuring one or more receive beams using demodulation reference signals (DMRS) of physical broadcast channel (PBCH) symbols of synchronization signal blocks (SSBs) received from the neighbor cells, each receive beam measured during a beam switch time unit including a PBCH symbol from each of the neighbor cells according to the timing information.

Aspect 2: The method of Aspect 1, further comprising transmitting a beam measurement report including measurements of each of the receive beams to a serving cell.

Aspect 3: The method of Aspect 1 or 2, further comprising scheduling measurements of a plurality of receive beams over one or more of the SSBs based on the beam switch time unit.

Aspect 4: The method of any of Aspects 1-3, further comprising determining the beam switch time unit based on a maximum timing offset between the neighbor cells.

Aspect 5: The method of Aspect 4, wherein measuring the one or more receive beams includes measuring at least two beams during one of the SSBs when the maximum timing offset is less than a length of a symbol according to a subcarrier spacing.

Aspect 6: The method of Aspect 4 or 5, wherein the maximum timing offset includes a maximum synchronization offset and a maximum propagation delay offset.

Aspect 7: The method of Aspect 4, wherein measuring the one or more receive beams includes measuring one receive beam during one of the SSBs when the maximum timing offset is greater than or equal to a length of a symbol according to a subcarrier spacing.

Aspect 8: The method of Aspect 7, further comprising measuring the one or more receive beams using a secondary synchronization signal of the SSBs.

Aspect 9: The method of any of Aspects 4-8, wherein the maximum timing offset is a difference in timing between an earliest one of the neighbor cells and a latest one of the neighbor cells.

Aspect 10: The method of any of Aspects 4-8, wherein the beam switch time unit is at least a sum of the maximum timing offset and a length of a symbol according to a subcarrier spacing.

Aspect 11: An apparatus for wireless communication for a user equipment (UE), comprising: a memory storing computer-executable instructions; and at least one processor coupled to the memory and configured to execute the computer-executable instructions to perform the method of any of Aspects 1-10.

Aspect 12: A apparatus for wireless communication for a user equipment (UE), comprising: means for performing the method of any of Aspects 1-10.

Aspect 13: A non-transitory computer-readable medium storing computer executable code, the code when executed by a processor of a user equipment (UE) causes the processor to perform the method of any of Aspects 1-10.