CONTROL RESOURCE SET PRECODING INDICATION

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a configuration for a control resource set (CORESET) that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET. The precoder granularity unit may be greater than a resource element group bundle of the CORESET and less than contiguous resource blocks of the CORESET. The UE may monitor for one or more physical downlink control channel candidates according to the configuration. Numerous other aspects are provided.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for control resource set precoding indication.

BACKGROUND

SUMMARY

In some aspects, a method of wireless communication, performed by a user equipment (UE), may include receiving a configuration for a control resource set (CORESET) that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than a resource element group (REG) bundle of the CORESET and less than contiguous resource blocks of the CORESET; and monitoring for one or more physical downlink control channel (PDCCH) candidates according to the configuration.

In some aspects, a method of wireless communication, performed by a base station (BS), may include determining, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and transmitting, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration.

In some aspects, a BS for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and monitor for one or more PDCCH candidates according to the configuration.

In some aspects, a BS for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and transmit, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: receive a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and monitor for one or more PDCCH candidates according to the configuration.

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 BS, may cause the one or more processors to: determine, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and transmit, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration.

In some aspects, an apparatus for wireless communication may include means for receiving a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and means for monitoring for one or more PDCCH candidates according to the configuration.

In some aspects, an apparatus for wireless communication may include means for determining, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET; and means for transmitting, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration.

DETAILED DESCRIPTION

Controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG.2may perform one or more techniques associated with control resource set (CORESET) precoding indication, 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, process800ofFIG.8, process900ofFIG.9, and/or other processes as described herein. Memories242and282may store data and program codes for base station110and UE120, respectively. In some aspects, memory242and/or memory282may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station110and/or the UE120, may perform or direct operations of, for example, process800ofFIG.8, process900ofFIG.9, and/or other processes as described herein. A scheduler246may schedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE120may include means for receiving a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET, means for monitoring for one or more PDCCH candidates according to the configuration, and/or the like. In some aspects, such means may include one or more components of UE120described in connection withFIG.2, such as controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like.

In some aspects, base station110may include means for determining, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET, means for transmitting, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration, and/or the like. In some aspects, such means may include one or more components of base station110described in connection withFIG.2, such as antenna234, DEMOD232, MIMO detector236, receive processor238, controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, and/or the like.

FIG.3Aillustrates an example resource structure300for wireless communication, in accordance with various aspects of the present disclosure. Resource structure300shows an example of various groups of resources described herein. As shown, resource structure300may include a subframe305. Subframe305may include multiple slots310. While resource structure300is shown as including 2 slots per subframe, a different number of slots may be included in a subframe (e.g., 4 slots, 8 slots, 16 slots, 32 slots, and/or the like). In some aspects, different types of transmission time intervals (TTIs) may be used, other than subframes and/or slots. A slot310may include multiple symbols315, such as 7 symbols or 14 symbols per slot.

The potential control region of a slot310may be referred to as a CORESET320, and may be structured to support an efficient use of resources, such as by flexible configuration or reconfiguration of resources of the CORESET320for one or more physical downlink control channels (PDCCHs), one or more physical downlink shared channels (PDSCHs), and/or the like. In some aspects, the CORESET320may occupy the first symbol315of a slot310, the first two symbols315of a slot310, or the first three symbols315of a slot310. Thus, a CORESET320may include multiple resource blocks (RBs) in the frequency domain, and either one, two, or three symbols315in the time domain. In 5G, a quantity of resources included in the CORESET320may be flexibly configured, such as by using radio resource control (RRC) signaling to indicate a frequency domain region (e.g., a quantity of resource blocks) and/or a time domain region (e.g., a quantity of symbols) for the CORESET320.

As illustrated, a symbol315that includes CORESET320may include one or more control channel elements (CCEs)325, shown as two CCEs325as an example, that span a portion of the system bandwidth. A CCE325may include downlink control information (DCI) that is used to provide control information for wireless communication. A base station may transmit DCI during multiple CCEs325(as shown), where the quantity of CCEs325used for transmission of DCI represents the aggregation level (AL) used by the BS for the transmission of DCI. InFIG.3A, an aggregation level of two is shown as an example, corresponding to two CCEs325in a slot310. In some aspects, different aggregation levels may be used, such as 1, 4, 8, 16, and/or the like.

Each CCE325may include a fixed quantity of resource element groups (REGs)330, shown as 4 REGs330, or may include a variable quantity of REGs330. In some aspects, the quantity of REGs330included in a CCE325may be specified by an REG bundle size. An REG330may include one resource block, which may include 12 resource elements (REs)335within a symbol315. A resource element335may occupy one subcarrier in the frequency domain and one OFDM symbol in the time domain.

A CORESET320may include one or more search spaces, such as a UE-specific search space, a group-common search space, and/or a common search space. A search space may indicate a set of CCE locations where a UE may find PDCCHs that can potentially be used to transmit control information to the UE. The possible locations for a PDCCH may depend on whether the PDCCH is a UE-specific PDCCH (e.g., for a single UE) or a group-common PDCCH (e.g., for multiple UEs), an aggregation level being used, and/or the like. A possible location (e.g., in time and/or frequency) for a PDCCH may be referred to as a PDCCH candidate, and the set of all possible PDCCH locations may be referred to as a search space. For example, the set of all possible PDCCH locations for a particular UE may be referred to as a UE-specific search space. Similarly, the set of all possible PDCCH locations across all UEs may be referred to as a common search space. Similarly, the set of all possible PDCCH locations for a particular group of UEs may be referred to as a group-common search space.

A UE may perform channel estimation for one or more PDCCH candidates or CCEs325of the CORESET320. In some cases, the UE may aggregate, for channel estimation, frequency domain resources that use the same spatial precoding, thereby reducing a complexity of the channel estimation. The UE may be configured with a precoder granularity that identifies frequency domain resources over which the same precoding is used.

For example, the precoder granularity may indicate that REGs330of contiguous resource blocks of the CORESET320use the same precoding. However, such a precoder granularity may be too broad and limit BS performance because the CORESET320cannot be used to schedule multiple UEs that lack spatial alignment. As another example, the precoder granularity may indicate that REGs330of an REG bundle use the same precoding. However, such a precoder granularity may be too narrow and limit channel estimation performance of a UE by limiting frequency domain resources that can be aggregated for channel estimation. Moreover, this precoder granularity may be unsuitable for UEs with reduced capability.

In particular, different types of UEs may operate in a cell provided by a BS. For example, a BS may provide network service to a premium UE (which may be termed a legacy UE or a high-tier UE), an NR-Light (or NR-Lite) UE (which may be termed a low-tier UE), and/or the like. A premium UE may be a UE that is associated with a receive bandwidth capability in receiving downlink signals/channels that is above a particular threshold (for example, a bandwidth of greater than or equal to 100 megahertz (MHz)). In contrast, an NR-Light UE may be a UE with a bandwidth capability in receiving the downlink signals/channels that is below a particular threshold (for example, a bandwidth of less than 10 MHz, less than 5 MHz, or the like). Moreover, an NR-Light UE may have a lesser quantity of receive antennas or a lower computational or memory capacity than a premium UE. Accordingly, NR-Light UEs that have reduced capability (e.g., a lesser quantity of receive antennas) may experience reduced PDCCH coverage when an REG bundle is the unit of precoder granularity.

Some techniques and apparatuses described herein provide additional precoder granularities that may be used to improve frequency domain resource aggregation for channel estimation. In some aspects, a precoder granularity unit, over which the same precoding is used, may be greater than an REG bundle of a CORESET and less than contiguous resource blocks of the CORESET. For example, the precoder granularity unit may be a PDCCH candidate. In this way, channel estimation performance of UEs, such as NR-Light UEs, may be improved, while permitting a BS to schedule multiple UEs that are not spatially aligned in the same CORESET.

As indicated above,FIG.3Ais provided as an example. Other examples may differ from what is described with regard toFIG.3A.

FIG.3Bis a diagram illustrating an example350of interleaving of a CORESET, in accordance with various aspects of the present disclosure. In particular, example350may illustrate an example of interleaving a CORESET that is in three or fewer symbols (e.g., one symbol, two symbols, or three symbols). As shown inFIG.3B, an REG bundle352may be configured to include two REGs351(i.e., the REG bundle352may be configured to have a size of two REGs351). That is, the REG bundle352may have an REG bundle shape that includes two REGs351in a frequency domain and one symbol in a time domain (e.g., for a CORESET356in one symbol).

As shown by reference number353, the REG bundles352may be written into a matrix354according to an interleaving configuration. For example, the interleaving configuration may indicate a quantity of rows that are to be used for interleaving. As shown, the quantity of rows may be three (e.g., the matrix354may include three rows). The REG bundles352may be written into the matrix354by row, such that the REG bundles352are written to a first row of the matrix354first, a second row of the matrix354second, and so forth.

As shown by reference number355, the REG bundles352may be read out of the matrix354, in REG bundle units, and mapped to a plurality of CCEs (CCE1, CCE2, CCE3, and CCE4) of a CORESET356. For example, the REG bundles352may be read out of the matrix354, by column, and mapped to the plurality of CCEs. As an example, REG bundles352in a first column of the matrix354are mapped to the plurality of CCEs first, REG bundles352in a second column are mapped to the plurality of CCEs second, and so forth. A CCE may include six REGs351(i.e., three REG bundles352of two REGs351).

As shown by reference number357, the mapping of the REG bundles352to the plurality of CCEs of the CORESET356may result in an interleaving of the REG bundles352in the plurality of CCEs of the CORESET356.

As indicated above,FIG.3Bis provided as an example. Other examples may differ from what is described with respect toFIG.3B.

FIG.3Cis a diagram illustrating an example360of interleaving of a CORESET, in accordance with various aspects of the present disclosure. In particular, example360may illustrate an example of interleaving a CORESET that is in three or fewer symbols. As shown inFIG.3C, an REG bundle362may be configured to include two REGs361. That is, the REG bundle362may have an REG bundle shape that includes two REGs361in two symbols in the time domain (e.g., for a CORESET366in two symbols).

As shown by reference number363, the REG bundles362may be written into a matrix364according to an interleaving configuration, as described above in connection withFIG.3B. For example, the interleaving configuration may indicate a quantity of rows that are to be used for interleaving. As shown, the quantity of rows may be six (e.g., the matrix364may include six rows).

As shown by reference number365, the REG bundles362may be read out of the matrix364, in REG bundle units, and mapped to a plurality of CCEs (CCE1-CCE8) of a CORESET366, as described above in connection withFIG.3B.

As shown by reference number367, the mapping of the REG bundles362to the plurality of CCEs of the CORESET366may result in an interleaving of the REG bundles362in the plurality of CCEs of the CORESET366.

As indicated above,FIG.3Cis provided as an example. Other examples may differ from what is described with respect toFIG.3C.

FIG.3Dis a diagram illustrating an example370of interleaving of a CORESET, in accordance with various aspects of the present disclosure. In particular, example370may illustrate an example of interleaving a CORESET that is in three or fewer symbols. As shown inFIG.3D, an REG bundle372may be configured to include six REGs371. That is, the REG bundle372may have an REG bundle shape that includes two REGs371in the frequency domain in three symbols in the time domain (e.g., for a CORESET376in three symbols).

As shown by reference number373, the REG bundles372may be written into a matrix374according to an interleaving configuration, as described above in connection withFIG.3B. For example, the interleaving configuration may indicate a quantity of rows that are to be used for interleaving. As shown, the quantity of rows may be six (e.g., the matrix374may include six rows).

As shown by reference number375, the REG bundles372may be read out of the matrix374, in REG bundle units, and mapped to a plurality of CCEs (CCE1-CCE12) of a CORESET376, as described above in connection withFIG.3B.

As shown by reference number377, the mapping of the REG bundles372to the plurality of CCEs of the CORESET376may result in an interleaving of the REG bundles372in the plurality of CCEs of the CORESET376.

As indicated above,FIG.3Dis provided as an example. Other examples may differ from what is described with respect toFIG.3D.

FIG.4is a diagram illustrating an example400of CORESET precoding indication, in accordance with various aspects of the present disclosure. As shown inFIG.4, a BS110may communicate with a UE120in connection with a PDCCH communication. In some aspects, the UE120may be an NR-Light UE, such as a wearable device, an Internet of Things (IoT) device, a sensor, a camera, and/or the like, that is associated with a limited bandwidth, power capacity, transmission range, and/or the like. For example, the UE120may have a quantity of receive antennas that satisfies (e.g., is below) a threshold value and/or a bandwidth capability that satisfies (e.g., is below) a threshold value.

As shown inFIG.4, and by reference number405, the BS110may determine a precoder granularity unit that the UE120is to use to monitor for PDCCH candidates associated with a CORESET. The precoder granularity unit may indicate resources (e.g., frequency domain resources) of the CORESET over which the same precoding is used.

In some aspects, the precoder granularity unit may be an REG bundle of the CORESET (e.g., an REG bundle of a size that is configured for the CORESET). In this case, REGs of an REG bundle may use the same precoding. In some aspects, the precoder granularity unit may be contiguous resource blocks of the CORESET. In this case, REGs of contiguous resource blocks of the CORESET may use the same precoding.

In some aspects, the precoder granularity unit may be greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET. For example, the precoder granularity unit may be a PDCCH candidate associated with a particular aggregation level (as described in connection withFIG.5), a PDCCH candidate associated with a lowest aggregation level, of one or more aggregation levels that are configured for a search space set of the CORESET, having a non-zero quantity of PDCCH candidates (as described in connection withFIG.6), resource block groups that are contiguously identified for the CORESET (as described in connection withFIG.7), and/or the like.

As shown by reference number410, the BS110may transmit, and the UE120may receive, a configuration that indicates the precoder granularity unit that is determined. For example, the configuration may be a PDCCH configuration, a CORESET configuration, and/or the like. The BS110may transmit the configuration by RRC signaling. In some aspects, the precoder granularity unit may be indicated in a field of the configuration, such as a precoderGranularity field.

As shown by reference number415, the UE120may monitor for one or more PDCCH candidates according to the configuration. For example, the UE120may perform channel estimation, when monitoring for the one or more PDCCH candidates, according to the configuration. In this case, the UE120may aggregate REG bundles according to the precoder granularity unit that is indicated by the configuration, and may determine that each set of aggregated REG bundles uses a respective precoding. For example, the UE120may determine that one or more aggregated REG bundles of a first set use a first precoding and one or more aggregated REG bundles of a second set use a second precoding. Accordingly, the UE120may perform channel estimation for a set of aggregated REG bundles, thereby improving channel estimation efficiency.

FIG.5is a diagram illustrating an example500of CORESET precoding indication, in accordance with various aspects of the present disclosure.FIG.5shows a plurality of CCEs510(CCE1, CCE2, CCE3, and CCE4) that are mapped to a CORESET505in an interleaved manner (e.g., according to an interleaving described in connection withFIGS.3B-3D). The CCEs510are interleaved for illustration of example500, and in some aspects, the CCEs510may not be interleaved.

A PDCCH candidate may include one or more (e.g., 1, 2, 4, 8, 16, or the like) CCEs510according to an aggregation level that is configured for a search space set associated with the CORESET505. A CCE510may include a quantity (e.g., 6) of REGs515, and multiple (e.g., 2, 3, 6, or the like) REGs515may be aggregated in an REG bundle520(shown as 2 REGs515in an REG bundle520).

In some aspects, the precoder granularity unit, described in connection withFIG.4, may be a PDCCH candidate associated with a particular aggregation level (which may be designated as PerPDCCH-AnyAL in the precoderGranularity field of the configuration described in connection withFIG.4). In other words, a search space of the CORESET505may include PDCCH candidates of various aggregation levels, and the precoder granularity unit may indicate that REG bundles520associated with a particular PDCCH candidate, regardless of an aggregation level of the particular PDCCH candidate, are to use the same precoding.

For example, if an aggregation level is one (1) for several PDCCH candidates (i.e., a PDCCH candidate includes one CCE), then REG bundles520of CCE1may use a first precoding, REG bundles520of CCE2may use a second precoding, and so forth. As another example, if an aggregation level for several PDCCH candidates is two (2) (i.e., a PDCCH candidate includes two CCEs), then REG bundles520of CCE1and CCE2may use a first precoding, REG bundles520of CCE3and CCE4may use a second precoding, and so forth.

In other words, REG bundles520of a first PDCCH candidate associated with a particular aggregation level (e.g., 4 CCEs510) may use a first precoding and REG bundles520of a second PDCCH candidate associated with the same particular aggregation level (e.g., 4 CCEs510) may use a second precoding. In addition, REG bundles520of a first PDCCH candidate associated with a first aggregation level (e.g., 4 CCEs510) may use a first precoding and REG bundles520of a second PDCCH candidate associated with a second aggregation level (e.g., 8 CCEs510) may use a second precoding. In this way, the UE120may perform a single channel estimation for REG bundles520that use the same precoding. This may be useful when the CORESET505includes a Type0 search space or a random access search space.

In some aspects, a single REG bundle520may be associated with multiple PDCCH candidates of different aggregation levels. For example, the single REG bundle520may be associated with a first PDCCH candidate associated with a first aggregation level (e.g., 4 CCEs510) and a second PDCCH candidate associated with a second aggregation level (e.g., 8 CCEs510). In this case, the single REG bundle520may use a first precoding with respect to the first PDCCH candidate and a second precoding with respect to the second PDCCH candidate. Thus, the UE120may perform multiple channel estimations for the single REG bundle520with respect to the multiple PDCCH candidates.

In some aspects, REG bundles520associated with a PDCCH candidate may use the same precoding based at least in part on a frequency adjacency or separation of the REG bundles520. For example, REG bundles520may use the same precoding when the REG bundles520are adjacent in the frequency domain. As another example, REG bundles520may use the same precoding when the REG bundles520have frequency separations that satisfy a threshold value (e.g., a threshold value that is RRC configured for the UE120). Accordingly, a first REG bundle520of a PDCCH candidate may use a first precoding, and a second REG bundle520of the PDCCH candidate may use a second precoding, when the first REG bundle520and the second REG bundle are not adjacent in the frequency domain and/or have a frequency separation that does not satisfy the threshold value.

In some aspects, the UE120may determine that the frequency adjacency or separation of REG bundles520is to be used to determine a precoding used by the REG bundles520when the REG bundles520are configured with a cyclic shift. That is, the frequency adjacency or separation criteria for determining precoding of REG bundles520, as described above, may be activated when the REG bundles520are configured with a cyclic shift. The configuration (described in connection withFIG.4) may set a ShiftIndex field to a non-zero value to indicate that the REG bundles520are to be cyclic shifted.

FIG.6is a diagram illustrating an example600of CORESET precoding indication, in accordance with various aspects of the present disclosure.FIG.6shows a plurality of CCEs610(CCE1, CCE2, CCE3, and CCE4) that are mapped to a CORESET605in a non-interleaved manner. The CCEs610are non-interleaved for illustration of example600, and in some aspects, the CCEs610may be interleaved (e.g., according to an interleaving described in connection withFIGS.3B-3D).

A PDCCH candidate may include one or more CCEs610according to an aggregation level that is configured for a search space set associated with the CORESET605, as described above. A CCE610may include a quantity of REGs615, and multiple REGs615may be aggregated in an REG bundle620, as described above. As shown inFIG.6, a PDCCH candidate625may have an aggregation level of 2 (including CCE1and CCE2), a PDCCH candidate630may have an aggregation level of 2 (including CCE3and CCE4), and a PDCCH candidate635may have an aggregation level of 4 (including CCE1, CCE2, CCE3, and CCE4).

In some aspects, the precoder granularity unit, described in connection withFIG.4, may be a PDCCH candidate associated with a lowest aggregation level having a non-zero quantity of PDCCH candidates (which may be designated as PerPDCCH-LowestAL in the precoderGranularity field of the configuration described in connection withFIG.4). A lowest aggregation level having a non-zero quantity of PDCCH candidates may be referred to herein as a lowest utilized aggregation level. A lowest utilized aggregation level may be one of one or more aggregation levels that are configured for a search space set of the CORESET605. For example, a configuration received by the UE120(e.g., a search space configuration) may indicate respective quantities of PDCCH candidates that are configured for multiple aggregation levels (e.g., for aggregation levels of 1, 2, 4, 8, and 16) of a search space set, and the precoder granularity unit may be a lowest aggregation level for which the indicated quantity of PDCCH candidates is a non-zero value. Accordingly, in some cases, there may be one or more aggregation levels, having zero PDCCH candidates, that are lower than the lowest utilized aggregation level.

As an example in which a lowest utilized aggregation level is two, REG bundles620associated with PDCCH candidate625(i.e., the REG bundles620of CCE1and CCE2) may use a first precoding and REG bundles620associated with PDCCH candidate630(i.e., the REG bundles620of CCE3and CCE4) may use a second precoding. In other words, REG bundles620of a first PDCCH candidate associated with the lowest utilized aggregation level may use a first precoding and REG bundles620of a second PDCCH candidate associated with the lowest utilized aggregation level may use a second precoding. In this way, the UE120may perform a single channel estimation for REG bundles620that use the same precoding.

However, REG bundles620of a PDCCH candidate associated with a higher aggregation level than the lowest utilized aggregation level may not use the same precoding. As an example in which a lowest utilized aggregation level is two, REG bundles620of the PDCCH candidate635(associated with an aggregation level of four) may not use the same precoding. In particular, REG bundles620of the PDCCH candidate635may use a first precoding associated with the PDCCH candidate625(which is associated with the lowest utilized aggregation level) and a second precoding associated with the PDCCH candidate630(which is associated with the lowest utilized aggregation level). In such cases, the UE120may determine that channel estimation for REG bundles620of a PDCCH candidate associated with a higher aggregation level than the lowest utilized aggregation level is not to be performed (e.g., because channel estimation for the REG bundles620is performed in connection with the PDCCH candidates associated with the lowest aggregation level).

In some aspects, the UE120may not be configured to monitor all PDCCH candidates of a lowest utilized aggregation level. For example, the UE120may be configured to monitor the PDCCH candidate625and may not be configured to monitor the PDCCH candidate630. Furthermore, if the UE120is configured to monitor a PDCCH candidate of a higher aggregation level (e.g., PDCCH candidate635) that shares REG bundles620with an unmonitored PDCCH candidate of the lowest aggregation level (e.g., PDCCH candidate630), the UE120may perform channel estimation for the REG bundles620of the unmonitored PDCCH candidate (e.g., PDCCH candidate630). In this case, the UE120may determine a maximum quantity of PDCCH candidates that may be configured at the lowest utilized aggregation level in order to identify unmonitored PDCCH candidates that may be used for channel estimation of a monitored PDCCH candidate of a higher aggregation level.

In some aspects, REG bundles620associated with a PDCCH candidate may use the same precoding based at least in part on a frequency adjacency or separation of the REG bundles620, as described in connection withFIG.5.

FIG.7is a diagram illustrating an example700of CORESET precoding indication, in accordance with various aspects of the present disclosure.FIG.7shows a frequency domain resources bitmap705for a CORESET (which may be indicated in a frequencyDomainResources field of the configuration described in connection withFIG.4). The bitmap705may include a plurality of bits710. A bit710may identify a resource block group that includes a quantity (e.g., 6) of physical resource blocks. A set bit710of the bitmap705(e.g., set to a value of 1) may indicate that a resource block group associated with the set bit710is used by the CORESET.

One or more of the resource block groups mapped by the bitmap705may be associated with a particular bandwidth part (BWP). For example, one or more first resource block groups mapped by the bitmap705may be associated with a BWP715and one or more second resource block groups mapped by the bitmap705may be associated with another BWP.

In some aspects, the precoder granularity unit, described in connection withFIG.4, may be resource block groups that are contiguously identified for the CORESET (which may be designated as ContiguousRBGroups in the precoderGranularity field of the configuration described in connection withFIG.4). Resource block groups may be contiguously identified for the CORESET when consecutive bits710of the bitmap705are set (e.g., have a value of 1). For example, a first set720of resource block groups that are contiguously identified for the CORESET may use a first precoding, a second set725of resource block groups that are contiguously identified for the CORESET may use a second precoding, and a third set730of resource block groups that are contiguously identified for the CORESET may use a third precoding.

As shown inFIG.7, the third set730of resource block groups may not include contiguously-identified resource block groups that are not associated with the BWP715. In other words, the precoder granularity unit may be resource block groups, within a particular BWP, that are contiguously identified for the CORESET.

In some aspects, REG bundles of a PDCCH candidate, that are associated with resource block groups that are contiguously identified for the CORESET, may use the same precoding. For example, REG bundles of the PDCCH candidate that are associated with the first set720of resource block groups that are contiguously identified for the CORESET may use a first precoding, REG bundles of the PDCCH candidate that are associated with the second set725of resource block groups that are contiguously identified for the CORESET may use a second precoding, and so forth.

In some aspects, resource block groups that are contiguously identified for the CORESET may use the same precoding based at least in part on a frequency adjacency or separation of the resource block groups, as described in connection withFIG.5.

FIG.8is a diagram illustrating an example process800performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process800is an example where the UE (e.g., UE120, and/or the like) performs operations associated with CORESET precoding indication.

As shown inFIG.8, in some aspects, process800may include receiving a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET (block810). For example, the UE (e.g., using antenna252, DEMOD254, MIMO detector256, receive processor258, controller/processor280, and/or the like) may receive a configuration for a CORESET that indicates a precoder granularity unit over which a same precoding is used for resources of the CORESET, as described above. In some aspects, the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET.

As further shown inFIG.8, in some aspects, process800may include monitoring for one or more PDCCH candidates according to the configuration (block820). For example, the UE (e.g., using antenna252, DEMOD254, MIMO detector256, receive processor258, controller/processor280, and/or the like) may monitor for one or more PDCCH candidates according to the configuration, as described above.

In a first aspect, the precoder granularity unit is a PDCCH candidate associated with a particular aggregation level. In a second aspect, alone or in combination with the first aspect, one or more REG bundles of a first PDCCH candidate associated with the particular aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with the particular aggregation level use a second precoding. In a third aspect, alone or in combination with one or more of the first and second aspects, one or more REG bundles of a first PDCCH candidate associated with a first aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with a second aggregation level use a second precoding.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the precoder granularity unit is a PDCCH candidate associated with a lowest aggregation level, of one or more aggregation levels that are configured for a search space set of the CORESET, having a non-zero quantity of PDCCH candidates. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process800includes determining one or more REG bundles, for which channel estimation is to be performed, based at least in part on the precoder granularity unit and a maximum quantity of PDCCH candidates that can be configured for the CORESET.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, one or more REG bundles of a first PDCCH candidate associated with the lowest aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with the lowest aggregation level use a second precoding. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, a plurality of REG bundles of a PDCCH candidate, associated with a higher aggregation level than the lowest aggregation level, do not use the same precoding. In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the plurality of REG bundles include a first set of REG bundles that are associated with a first PDCCH candidate associated with the lowest aggregation level, and a second set of REG bundles that are associated with a second PDCCH candidate associated with the lowest aggregation level.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the precoder granularity unit is resource block groups, within a particular bandwidth part, that are contiguously identified for the CORESET. In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the resource block groups are contiguously identified for the CORESET when consecutive bits, of a frequency domain resources bitmap for the CORESET, are set. In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, a first set of resource block groups that are contiguously identified for the CORESET use a first precoding and a second set of resource block groups that are contiguously identified for the CORESET use a second precoding.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, one or more REG bundles, of a PDCCH candidate, associated with a first set of resource block groups that are contiguously identified for the CORESET, use a first precoding, and one or more REG bundles, of the PDCCH candidate, associated with a second set of resource block groups that are contiguously identified for the CORESET, use a second precoding.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, one or more REG bundles of a PDCCH candidate use the same precoding when the one or more REG bundles are adjacent in a frequency domain or have frequency separations that satisfy a threshold value. In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the one or more REG bundles of the PDCCH candidate use the same precoding when the one or more REG bundles are configured with a cyclic shift.

FIG.9is a diagram illustrating an example process900performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process900is an example where the BS (e.g., BS110, and/or the like) performs operations associated with CORESET precoding indication.

As shown inFIG.9, in some aspects, process900may include determining, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, wherein the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET (block910). For example, the BS (e.g., using controller/processor240and/or the like) may determine, for a CORESET, a precoder granularity unit over which a same precoding is used for resources of the CORESET, as described above. In some aspects, the precoder granularity unit is greater than an REG bundle of the CORESET and less than contiguous resource blocks of the CORESET.

As further shown inFIG.9, in some aspects, process900may include transmitting, to a UE, a configuration that indicates the precoder granularity unit, to enable the UE to monitor for one or more PDCCH candidates according to the configuration (block920). For example, the BS (e.g., using controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, and/or the like) may transmit, to a UE, a configuration that indicates the precoder granularity unit to enable the UE to monitor for one or more PDCCH candidates according to the configuration, as described above.

In a first aspect, the precoder granularity unit is a PDCCH candidate associated with a particular aggregation level. In a second aspect, alone or in combination with the first aspect, one or more REG bundles of a first PDCCH candidate associated with the particular aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with the particular aggregation level use a second precoding. In a third aspect, alone or in combination with one or more of the first and second aspects, one or more REG bundles of a first PDCCH candidate associated with a first aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with a second aggregation level use a second precoding.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the precoder granularity unit is a PDCCH candidate associated with a lowest aggregation level, of one or more aggregation levels that are configured for a search space set of the CORESET, having a non-zero quantity of PDCCH candidates. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, one or more REG bundles of a first PDCCH candidate associated with the lowest aggregation level use a first precoding and one or more REG bundles of a second PDCCH candidate associated with the lowest aggregation level use a second precoding.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, a plurality of REG bundles of a PDCCH candidate associated with a higher aggregation level than the lowest aggregation level do not use the same precoding. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the plurality of REG bundles include a first set of REG bundles that are associated with a first PDCCH candidate associated with the lowest aggregation level, and a second set of REG bundles that are associated with a second PDCCH candidate associated with the lowest aggregation level.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the precoder granularity unit is resource block groups, within a particular bandwidth part, that are contiguously identified for the CORESET. In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the resource block groups are contiguously identified for the CORESET when consecutive bits, of a frequency domain resources bitmap for the CORESET, are set. In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, a first set of resource block groups that are contiguously identified for the CORESET use a first precoding and a second set of resource block groups that are contiguously identified for the CORESET use a second precoding.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, one or more REG bundles, of a PDCCH candidate, associated with a first set of resource block groups that are contiguously identified for the CORESET, use a first precoding, and one or more REG bundles, of the PDCCH candidate, associated with a second set of resource block groups that are contiguously identified for the CORESET, use a second precoding.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, one or more REG bundles of a PDCCH candidate use the same precoding when the one or more REG bundles are adjacent in a frequency domain or have frequency separations that satisfy a threshold value. In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the one or more REG bundles of the PDCCH candidate use the same precoding when the one or more REG bundles are configured with a cyclic shift.