Techniques and apparatuses for signaling regarding control region size

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may receive at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region identify a location of a demodulation reference signal (DMRS), associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region; and communicate on the data channel based at least in part on the DMRS. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 national stage of PCT Application No. PCT/CN2018/090573 filed on Jun. 11, 2018, entitled “TECHNIQUES AND APPARATUSES FOR SIGNALING REGARDING CONTROL REGION SIZE,” which claims priority to PCT Application No. PCT/CN2017/087941 filed on Jun. 12, 2017, entitled “TECHNIQUES AND APPARATUSES FOR SIGNALING REGARDING BANDWIDTH DEPENDENT CONTROL SIZE,” all of which are incorporated by reference herein.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication, and more particularly to techniques and apparatuses for signaling regarding control region size.

BACKGROUND

SUMMARY

In some aspects, a method for wireless communication may include receiving at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region identifying a location of a demodulation reference signal (DMRS), associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region; and communicating on the data channel based at least in part on the DMRS.

In some aspects, a wireless communication device may include a memory and one or more processors coupled to the memory and configured to receive at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region; identify a location of a DMRS, associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region; and communicate on the data channel based at least in part on the DMRS.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a wireless communication device, may cause the one or more processors to receive at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region; identify a location of a DMRS, associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region; and communicate.

In some aspects, an apparatus for wireless communication may include means for receiving at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region; means for identifying a location of a DMRS, associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region; and means for communicating on the data channel based at least in part on the DMRS.

DETAILED DESCRIPTION

An access point (“AP”) may comprise, be implemented as, or known as NodeB, Radio Network Controller (“RNC”), eNodeB (eNB), Base Station Controller (“BSC”), Base Transceiver Station (“BTS”), Base Station (“BS”), Transceiver Function (“TF”), Radio Router, Radio Transceiver, Basic Service Set (“BSS”), Extended Service Set (“ESS”), Radio Base Station (“RBS”), Node B (NB), gNB, 5G NB, NR BS, Transmit Receive Point (TRP), or some other terminology.

An access terminal (“AT”) may comprise, be implemented as, or be known as an access terminal, a subscriber station, a subscriber unit, a mobile station, a remote station, a remote terminal, a user terminal, a user agent, a user device, user equipment (UE), a user station, a wireless node, or some other terminology. In some aspects, an access terminal may comprise a cellular telephone, a smart phone, a cordless telephone, a Session Initiation Protocol (“SIP”) phone, a wireless local loop (“WLL”) station, a personal digital assistant (“PDA”), a tablet, a netbook, a smartbook, an ultrabook, a handheld device having wireless connection capability, a Station (“STA”), or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone, a smart phone), a computer (e.g., a desktop), a portable communication device, a portable computing device (e.g., a laptop, a personal data assistant, a tablet, a netbook, a smartbook, an ultrabook), wearable device (e.g., smart watch, smart glasses, smart bracelet, smart wristband, smart ring, smart clothing, etc.), medical devices or equipment, biometric sensors/devices, an entertainment device (e.g., music device, video device, satellite radio, gaming device, etc.), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. In some aspects, the node is a wireless node. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered machine-type communication (MTC) UEs, which may include remote devices that may communicate with a base station, another remote device, or some other entity. Machine type communications (MTC) may refer to communication involving at least one remote device on at least one end of the communication and may include forms of data communication which involve one or more entities that do not necessarily need human interaction. MTC UEs may include UEs that are capable of MTC communications with MTC servers and/or other MTC devices through Public Land Mobile Networks (PLMN), for example. Examples of MTC devices include sensors, meters, location tags, monitors, drones, robots/robotic devices, etc. MTC UEs, as well as other types of UEs, may be implemented as NB-IoT (narrowband internet of things) devices.

UEs120(e.g.,120a,120b,120c) may be dispersed throughout wireless network100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, such as sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices. Some UEs may be considered a Customer Premises Equipment (CPE). UE120may be included inside a housing120′ that houses components of UE120, such as processor components, memory components, and/or the like.

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station) allocates resources for communication among some or all devices and equipment within the scheduling entity's service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity.

Base stations are not the only entities that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE is functioning as a scheduling entity, and other UEs utilize resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may optionally communicate directly with one another in addition to communicating with the scheduling entity.

In some aspects, one or more components of UE120may be included in a housing. Controllers/processors240and280and/or any other component(s) inFIG. 2may direct the operation at base station110and UE120, respectively, to perform signaling regarding control region size, as described in more detail elsewhere herein. For example, controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG. 2may perform or direct operations of, for example, process900ofFIG. 9and/or other processes as described herein. In some aspects, one or more of the components shown inFIG. 2may be employed to perform example process900, and/or other processes for the techniques described herein. Memories242and282may store data and program codes for base station110and UE120, respectively. A scheduler246may schedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE120may include means for receiving at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region; means for identifying a location of a demodulation reference signal (DMRS), associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols comprising the downlink control region, means for communicating on the data channel based at least in part on the DMRS, and/or the like. In some aspects, such means may include one or more components of UE120described in connection withFIG. 2.

As indicated above,FIG. 2is provided merely as an example. Other examples are possible and may differ from what was described with regard toFIG. 2.

While aspects of the examples described herein may be associated with LTE technologies, aspects of the present disclosure may be applicable with other wireless communication systems, such as NR or 5G technologies.

A single component carrier bandwidth of 100 MHZ may be supported. NR resource blocks may span 12 sub-carriers with a sub-carrier bandwidth of 75 kilohertz (kHz) over a 0.1 ms duration. Each radio frame may include 50 subframes with a length of 10 ms. Consequently, each subframe may have a length of 0.2 ms. Each subframe may indicate a link direction (e.g., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be as described in more detail below with respect toFIGS. 5 and 6.

The RAN may include a central unit (CU) and distributed units (DUs). A NR BS (e.g., gNB, 5G Node B, Node B, transmit receive point (TRP), access point (AP)) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells). For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity, but not used for initial access, cell selection/reselection, or handover. In some cases, DCells may not transmit synchronization signals—in some case cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based at least in part on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and/or measurement based at least in part on the indicated cell type.

FIG. 3illustrates an example logical architecture of a distributed RAN300, according to aspects of the present disclosure. A 3G access node306may include an access node controller (ANC)302. The ANC may be a central unit (CU) of the distributed RAN300. The backhaul interface to the next generation core network (NG-CN)304may terminate at the ANC. The backhaul interface to neighboring next generation access nodes (NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs308(which may also be referred to as BSs, NR BSs, Node Bs, 3G NBs, APs, gNB, or some other term). As described above, a TRP may be used interchangeably with “cell.”

The architecture may share features and/or components with LTE. According to aspects, the next generation AN (NG-AN)310may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.

The architecture may enable cooperation between and among TRPs308. For example, cooperation may be preset within a TRP and/or across TRPs via the ANC302. According to aspects, no inter-TRP interface may be needed/present.

According to aspects, a dynamic configuration of split logical functions may be present within the architecture of RAN300. The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP.

According to certain aspects, a BS may include a central unit (CU) (e.g., ANC302) and/or one or more distributed units (e.g., one or more TRPs308).

As indicated above,FIG. 3is provided merely as an example. Other examples are possible and may differ from what was described with regard toFIG. 3.

FIG. 4illustrates an example physical architecture of a distributed RAN400, according to aspects of the present disclosure. A centralized core network unit (C-CU)402may host core network functions. The C-CU may be centrally deployed. C-CU functionality may be offloaded (e.g., to advanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU)404may host one or more ANC functions. Optionally, the C-RU may host core network functions locally. The C-RU may have distributed deployment. The C-RU may be closer to the network edge.

A distributed unit (DU)406may host one or more TRPs. The DU may be located at edges of the network with radio frequency (RF) functionality.

As indicated above,FIG. 4is provided merely as an example. Other examples are possible and may differ from what was described with regard toFIG. 4.

FIG. 5is a diagram500showing an example of a DL-centric subframe or wireless communication structure. The DL-centric subframe may include a control portion502. The control portion502may exist in the initial or beginning portion of the DL-centric subframe. The control portion502may include various scheduling information and/or control information corresponding to various portions of the DL-centric subframe. In some configurations, the control portion502may be a physical DL control channel (PDCCH), as indicated inFIG. 5. In some aspects, the control portion502may include legacy PDCCH information, shortened PDCCH (sPDCCH) information), a control format indicator (CFI) value (e.g., carried on a physical control format indicator channel (PCFICH)), one or more grants (e.g., downlink grants, uplink grants, etc.), and/or the like.

The DL-centric subframe may also include a DL data portion504. The DL data portion504may sometimes be referred to as the payload of the DL-centric subframe. The DL data portion504may include the communication resources utilized to communicate DL data from the scheduling entity (e.g., UE or BS) to the subordinate entity (e.g., UE). In some configurations, the DL data portion504may be a physical DL shared channel (PDSCH).

The DL-centric subframe may also include an UL short burst portion506. The UL short burst portion506may sometimes be referred to as an UL burst, an UL burst portion, a common UL burst, a short burst, an UL short burst, a common UL short burst, a common UL short burst portion, and/or various other suitable terms. In some aspects, the UL short burst portion506may include one or more reference signals. Additionally, or alternatively, the UL short burst portion506may include feedback information corresponding to various other portions of the DL-centric subframe. For example, the UL short burst portion506may include feedback information corresponding to the control portion502and/or the data portion504. Non-limiting examples of information that may be included in the UL short burst portion506include an ACK signal (e.g., a PUCCH ACK, a PUSCH ACK, an immediate ACK), a NACK signal (e.g., a PUCCH NACK, a PUSCH NACK, an immediate NACK), a scheduling request (SR), a buffer status report (BSR), a HARQ indicator, a channel state indication (CSI), a channel quality indicator (CQI), a sounding reference signal (SRS), a demodulation reference signal (DMRS), PUSCH data, and/or various other suitable types of information. The UL short burst portion506may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests, and various other suitable types of information.

As illustrated inFIG. 5, the end of the DL data portion504may be separated in time from the beginning of the UL short burst portion506. This time separation may sometimes be referred to as a gap, a guard period, a guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the subordinate entity (e.g., UE)) to UL communication (e.g., transmission by the subordinate entity (e.g., UE)). The foregoing is merely one example of a DL-centric wireless communication structure, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

As indicated above,FIG. 5is provided merely as an example. Other examples are possible and may differ from what was described with regard toFIG. 5.

FIG. 6is a diagram600showing an example of an UL-centric subframe or wireless communication structure. The UL-centric subframe may include a control portion602. The control portion602may exist in the initial or beginning portion of the UL-centric subframe. The control portion602inFIG. 6may be similar to the control portion502described above with reference toFIG. 5. The UL-centric subframe may also include an UL long burst portion604. The UL long burst portion604may sometimes be referred to as the payload of the UL-centric subframe. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, the control portion602may be a physical DL control channel (PDCCH).

As illustrated inFIG. 6, the end of the control portion602may be separated in time from the beginning of the UL long burst portion604. This time separation may sometimes be referred to as a gap, guard period, guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the scheduling entity) to UL communication (e.g., transmission by the scheduling entity).

The UL-centric subframe may also include an UL short burst portion606. The UL short burst portion606inFIG. 6may be similar to the UL short burst portion506described above with reference toFIG. 5, and may include any of the information described above in connection withFIG. 5. The foregoing is merely one example of an UL-centric wireless communication structure, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

In one example, a wireless communication structure, such as a frame, may include both UL-centric subframes and DL-centric subframes. In this example, the ratio of UL-centric subframes to DL-centric subframes in a frame may be dynamically adjusted based at least in part on the amount of UL data and the amount of DL data that are transmitted. For example, if there is more UL data, then the ratio of UL-centric subframes to DL-centric subframes may be increased. Conversely, if there is more DL data, then the ratio of UL-centric subframes to DL-centric subframes may be decreased.

As indicated above,FIG. 6is provided merely as an example. Other examples are possible and may differ from what was described with regard toFIG. 6.

FIG. 7illustrates an example700of control region sizes, in accordance with aspects of the present disclosure. Reference number702illustrates an example system having a wider system bandwidth as compared to the narrower system bandwidth shown by reference number704. In one aspect, the narrower system bandwidth may be associated with a bandwidth of approximately 5 MHz, and the wider system bandwidth may be associated with a bandwidth of at least approximately 10 MHz.

As shown by reference number706, in some aspects, the wider system bandwidth702may include a control region comprising two downlink control symbols. For example, the wider system bandwidth702can be used to simultaneously convey a greater amount of information than the narrower system bandwidth704, so fewer symbols in the time domain may be needed to convey downlink control information. In some aspects, the size of the control region (e.g., a particular set of control symbols comprising a potential search space for UE120) may be selected from a plurality of possible sizes (e.g., a plurality of sets of control symbols), and such selection may not depend on the system bandwidth. For example, BS110may select the size of the control region to be two downlink control symbols (e.g., rather than three downlink control symbols) even when a narrower system bandwidth is to be used for downlink communications, in some aspects.

As shown by reference number708, when the control region includes two downlink control symbols, a first downlink reference signal of the data channel (e.g., DMRS associated with a data channel, such as a PDSCH, a PUSCH and/or the like) is included after the maximum possible number of symbols of the downlink control channel. For example, the first downlink reference signal may be included after a last symbol of the maximum possible number of symbols, irrespective of whether all of the downlink control channel symbols are used to convey control information. This reduces complexity of signaling, implementing and processing the first DMRS. Furthermore, providing the first DMRS as soon as possible after the downlink control information enables more expedient decoding or demodulation of the downlink data information (shown by reference number710). As further shown, in some aspects, the first DMRS may be multiplexed with downlink data information.

As shown by reference number712, in some aspects, the narrower system bandwidth704may include a control region including three downlink control symbols in the downlink control information. For example, since the narrower system bandwidth704is associated with a narrower bandwidth than the wider system bandwidth702, more downlink control symbols in the time domain may be needed to convey downlink control information. In some aspects, the size of the control region may be selected from a plurality of possible sizes, and such selection may not depend on the system bandwidth. For example, BS110may select the size of the control region to be three downlink control symbols (e.g., rather than two downlink control symbols) even when the wider system bandwidth is to be used for downlink communications, in some aspects.

As shown by reference number714, when the control region includes three downlink control symbols, the first DMRS of the data channel (e.g., the DMRS associated with the data channel) may occur after the third downlink control symbol. For example, the first DMRS may be provided as soon as possible after the downlink control information so that the downlink data can be decoded or demodulated in a timely fashion. However, there may be a higher maximum possible number of downlink control symbols when three control symbols are used than when two control symbols are used, so the first DMRS may be provided later (in time) for cases in which three control symbols are used.

As indicated above,FIG. 7is provided as an example. Other examples are possible and may differ from what was described with respect toFIG. 7.

A UE may communicate based at least in part on a control channel and a downlink reference signal (e.g., a DMRS). For example, the control channel may include a control region comprising a physical downlink control channel (PDCCH) and/or the like. In some cases, a BS may provide control information for multiple, different UEs on the PDCCH. For example, the BS may provide a cell that covers a group of UEs, and may provide control channel elements (CCEs) for each UE, of the group of UEs, on the PDCCH (e.g., in a common search space and/or in one or more UE-specific search spaces). A set of CCEs (whether common or UE-specific) for a particular UE is referred to herein as a control resource set, or coreset. The particular UE may listen to a first time and/or frequency resource, associated with one or more control channels, to identify the coreset, and may listen to a second time and/or frequency resource to identify the downlink reference signal. The particular UE may use the coreset to identify downlink data relevant to the particular UE, and may decode the downlink data using the downlink reference signal. The particular UE may need to identify the first time and/or frequency resource and the second time and/or frequency resource to identify the control channel and the downlink reference signal, respectively.

However, as described above, the control channel may be of different time domain sizes among different slots, subframes, and/or the like and, thus, a first downlink reference signal of the data channel may be in different time domain locations. Therefore, it may be difficult for a UE to identify which time domain resources to monitor for the control channel and the first downlink reference signal, since the control channel is used to convey information that identifies a set of control symbols that carry PDCCH.

Techniques and apparatuses, described herein, provide signaling of at least one bit that identifies a particular set of control symbols, of a plurality of sets of control symbols, that comprise a downlink control region (e.g., using a physical broadcast channel (PBCH) and/or the like). The UE may determine a time domain location of a control channel and a downlink reference signal of the UE based at least in part on the at least one bit. For example, when the at least one bit indicates a first particular set of control symbols (e.g., a set of two symbols for a control region size of two symbols), the UE may identify a first two symbols as the control channel and a third symbol as a location of the downlink reference signal. When the at least one bit indicates a second particular set of control symbols (e.g., a set of three symbols for a control region size of three symbols), the UE may identify a first three symbols as the control channel and a fourth symbol as a location of the downlink reference signal. As used herein, “system bandwidth” is intended to be synonymous with “channel bandwidth.”

Thus, a scheduling entity (e.g., a BS and/or the like) can provide downlink reference signals sooner for control regions having a comparatively smaller size than for control regions having a comparatively larger size by signaling a set of control symbols, which improves demodulation performance for UEs. In some aspects, information identifying the particular set of control symbols that comprise the potential search space (e.g., a size of the control region) may be provided in association with information identifying particular control symbols to be used by a BS to convey control information (e.g., a subset of the particular set of control symbols), which saves resources of the UE that would otherwise be used to scan the entirety of the control region.

FIG. 8is a diagram of an example800of signaling for control region size, in accordance with certain aspects of the present disclosure.

As shown inFIG. 8, and by reference number802, a BS110may determine to schedule communications with a UE120(e.g., using a wide system bandwidth or a narrow system bandwidth). As shown by reference number804, the BS110may determine that a control channel is to be provided on symbols0and1(e.g., a first two symbols) of a subframe or slot (e.g., the subframe or slot described in connection withFIGS. 5, 6, and/or7, above). For example, the BS110may select a size of the control region (e.g., a size of a PDCCH) from a plurality of possible control region sizes (e.g., the BS110may select a size of two control symbols or a size of three control symbols). In this example, the BS110selects the size of the control region to be two control symbols and, therefore, determines that the control channel is to be provided on symbols0and1since the associated maximum possible number of control symbols is two control symbols. In some aspects, the BS110may determine that fewer than the maximum possible number of control symbols are to be used, and may accordingly schedule a control channel of the UE120on fewer than the maximum possible number of control symbols (e.g., on symbol0, on symbol1, and/or the like).

As shown by reference number806, the BS110may generate and transmit a physical broadcast channel (PBCH) to indicate a control region (e.g., a particular set of control symbols that correspond to the selected control region size, where the particular set of control symbols comprise a potential search space for the UE120) and a control channel allocation of the UE120. For example, the BS110may indicate the control region (e.g., the particular set of control symbols) so that the UE120can determine the maximum possible number of control symbols. When the UE120knows the maximum possible number of control symbols, the UE120may identify a DMRS location based at least in part on the maximum possible number of control symbols. Further, the BS110may indicate a control channel allocation, which may identify particular control symbols that are used to carry a control channel of the UE120.

As shown by reference number808, the BS110may transmit the PBCH. As shown by reference number810, the PBCH may indicate a control region of 1. InFIG. 8, the control region of 1 corresponds to a control region comprising two control symbols. In some aspects, the information indicating the particular set of control symbols that form the potential search space (i.e., the downlink control region) may be conveyed by at least one bit. For example, inFIG. 8, a single bit with a value of 1 indicates that two control symbols are included in the control region. Conversely, if the single bit were a value of 0, this may indicate that three control symbols are included in the control region. In some aspects, more than a single bit may be used to convey the information indicating the particular set of control symbols that form the potential search space.

As shown by reference number812, in some aspects, the PBCH may indicate a control channel allocation. The control channel allocation may identify a location of a search space (e.g., a common search space or a UE-specific search space) or a coreset in a time domain. InFIG. 8, the PBCH indicates a control channel allocation of 01. For example, in some aspects, the control channel allocation may be identified by two bits. As one possible aspect, when the size of the control region is two control symbols, the two bits may indicate whether the UE120is to use a first, second, or third control channel allocation (e.g., symbol0, symbol1, or symbols0and1). This approach may be more flexible than using a single bit to indicate the control channel allocation. For example, the single bit may indicate whether the UE120is to use a first control channel allocation or a second control channel allocation (e.g., symbol0or symbols0and1).

As another possible aspect, when the size of the control region is three control symbols, the two bits may indicate whether the UE120is to use a first, second, or third control channel allocation (e.g., symbols0and1, symbols1and2, or symbols0,1, and2). This approach may be more flexible than using a single bit to indicate the control channel allocation. For example, the single bit may indicate whether the UE120is to use a first control channel allocation or a second control channel allocation (e.g., symbols0and1or symbols0,1, and2).

In some aspects, the PBCH may provide information associated with the downlink control region (e.g., information that identifies a potential search space or a coreset) time domain location in another fashion. For example, the PBCH may indicate a start symbol and an end symbol of the search space or the coreset.

In some aspects, the BS110may provide information indicating a time domain location of the DMRS. For example, the BS110may provide the information indicating the time location of the DMRS in the PBCH. Additionally, or alternatively, the BS110may provide the information indicating the time domain location of the DMRS on a downlink control channel in the common search space (e.g., as part of the DCI).

As shown by reference number814, the UE120may receive the PBCH. As further shown, the UE120may determine that a communication is inbound (e.g., based at least in part on receiving the PBCH). As shown by reference number816, the UE120may identify a DMRS location of the communication. In some aspects, the UE120may identify the DMRS location based at least in part on the at least one bit indicating the particular set of control symbols comprising the control region. For example, the DMRS may be located after a last symbol of the control region (e.g., a last symbol after the maximum possible number of control symbols of the communication). Here, the UE120may determine the maximum possible number of control symbols associated with the control region (e.g., two, corresponding to control symbols0and1) based at least in part on the at least one bit indicating the particular set of control symbols, and may determine that the DMRS is located at symbol2.

As shown by reference number818, the UE120may identify a control channel allocation using the control channel allocation information included in the PBCH. Here, the UE120identifies control symbols0and1(e.g., the maximum possible number of control symbols). As shown by reference number820, the UE120may scan control symbols0and1to identify a control channel of the UE120(e.g., a coreset and/or the like), and may scan symbol2(e.g., a first symbol after the maximum possible number of control symbols) to identify the DMRS. In some aspects, the UE may communicate on the data channel based at least in part on the DMRS. For example, the UE may use the DMRS in order to decode a PDSCH transmission received from the BS110.

The example ofFIG. 8was described in the context of a control region comprising two control symbols. In some aspects, the UE120may operate with a control region of another size. For example, the UE120may receive information indicating another particular set of control symbols (e.g., a set of three control symbols) is included in the control region (e.g., rather than two control symbols) and identify a location of the DMRS based at least in part on the indication, accordingly.

As indicated above,FIG. 8is provided as an example. Other examples are possible and may differ from what is described in connection withFIG. 8.

FIG. 9is a diagram illustrating an example process900performed, for example, by a wireless communication device, in accordance with various aspects of the present disclosure. Example process900is an example where a wireless communication device (e.g., UE120) communicates based at least in part on signaling for control region size.

As shown inFIG. 9, in some aspects, process900may include receiving at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region (block910). For example, the wireless communication device (e.g., UE120, using antenna252, DEMOD254, receive processor258, controller/processor280, and/or the like) may receive at least one bit indicating a particular set of control symbols, of a plurality of sets of control symbols, comprising a downlink control region, as described above.

As shown inFIG. 9, in some aspects, process900may include identifying a location of a DMRS, associated with a data channel, based at least in part on the at least one bit indicating the particular set of control symbols (block920). For example, the wireless communication device (e.g., UE120, using receive processor258, controller/processor280, and/or the like) may identify a location of a DMRS, associated with a data channel (e.g., a PDSCH, a PUSCH, and/or the like), based at least in part on the at least one bit indicating the particular set of control symbols, as described above.

As shown inFIG. 9, in some aspects, process900may include communicating on the data channel based at least in part on the DMRS (block930). For example, the wireless communication device (e.g., UE120, using antenna252, receive processor258, controller/processor280, and/or the like) may communicate on the data channel based at least in part on the DMRS, as described above. Process900may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In some aspects, the particular set of control symbols identifies a maximum length of a physical downlink control channel (PDCCH), wherein the location of the DMRS is identified based at least in part on the maximum length of the PDCCH.

In some aspects, the at least one bit is a single bit and a value of the single bit indicates whether the particular set of control symbols is a first set of control symbols, of the plurality of sets of control symbols, or a second set of control symbols of the plurality of sets of control symbols. In some aspects, the first set of control symbols includes two control symbols and the second set of control symbols includes three control symbols.

In some aspects, the at least one bit includes two bits and values of the two bits indicate whether the particular set of control symbols is a first set of control symbols of the plurality of sets of control symbols, a second set of control symbols of the plurality of sets of control symbols, or a third set of control symbols of the plurality of sets of control symbols.

In some aspects, the at least one bit identifies a start symbol of the particular set of control symbols and an end symbol of the particular set of control symbols.

In some aspects, the at least one bit is received in a physical broadcast channel (PBCH). In some aspects, the downlink control region includes a common search space. In some aspects, the downlink control region includes a user equipment (UE)-specific search space.

In some aspects, the data channel is a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH).

AlthoughFIG. 9shows example blocks of process900, in some aspects, process900may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG. 9. Additionally, or alternatively, two or more of the blocks of process900may be performed in parallel.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term component is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software.