Patent Description:
In other examples (e.g., in a next generation, a new radio (NR), or <NUM> network), a wireless multiple access communication system may include a number of distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) in communication with a number of central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where a set of one or more DUs, in communication with a CU, may define an access node (e.g., which may be referred to as a BS, next generation NodeB (gNB or gNodeB), TRP, etc.). A BS or DU may communicate with a set of UEs on downlink channels (e.g., for transmissions from a BS or DU to a UE) and uplink channels (e.g., for transmissions from a UE to a BS or DU).

Relevant background art documents are described as follows:.

<CIT> discloses in paragraphs [<NUM>]-[<NUM>] a method in which a WB DMRS may be transmitted over a frequency range wider than the frequency range of the control resource set e.g., a wide band including the frequency range of the control resource set and that the wideband DMRS may be transmitted via the PRB to which the PDCCH is not allocated as well as the PRB to which the PDCCH is allocated.

3GPP draft: "<NPL> discusses in section <NUM>. that
a better channel estimation performance may be enabled by transmitting a wideband RS in a CORESET that is independent from the actual PDCCH transmission,.

Preferred embodiments of the invention are stipulated in the dependent claims. While several embodiments and/or examples have been disclosed in the description, the subject matter for which protection is sought is limited to those examples and/or embodiments which are encompassed by the scope of the appended claims. Embodiments and/or examples that do not fall under the scope of the claims are useful for understanding the invention.

The following drawings illustrate certain aspects of the disclosure:.

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for transmitting demodulation reference signals (DMRS) with control channels (e.g., physical downlink control channels (PDCCHs)) that enable receiving devices to bundle (e.g., coherently combine) the DMRS over time. In wireless communications systems, DMRS can be coherently transmitted over different time instants. At the receiver, estimates of the channel determined based on DMRS in different time instants can be coherently combined to enhance the channel estimation performance. DMRS bundling is straightforward for DMRS transmitted in association with physical downlink shared channels (PDSCHs), tracking reference signals (TRS) and channel state information (CSI) reference signals (CSI-RS). Bundling of DMRS in association with PDCCHs is not as straightforward, due to the allocation of control channel elements (CCEs) of each PDCCH across the downlink bandwidth to which a receiving user equipment (UE) is blind. That is, a UE is not aware that a CCE of a PDCCH for the UE is present in a bandwidth part (BWP) until the UE blindly detects the PDCCH, which implies that the UE does not whether a DMRS is present in the BWP unless the UE detects a PDCCH in that BWP.

According to previously known techniques, configuration of DMRS to be transmitted with PDCCHs is on a per control resource set (CORESET) basis. A configuration of DMRS may include whether the DMRS are narrowband or wideband (WB), with narrowband indicated by a precoderGranularity information element in a radio resource control (RRC) configuration and wideband indicated by the sameAsREG-bundle and allContiguousRBs IEs in an RRC CORESET configuration. Additionally, a scrambling identifier (ID) for generating a DMRS scrambling sequence may be configured by a pdcch-DMRS-ScramblingID IE. If a pdcch-DMRS-ScramblingID is not configured, then a UE may use the physical layer cell ID as a scrambling ID for receiving the PDCCH DMRS.

According to aspects of the present disclosure, PDCCH DMRS bundling may be more useful for WB DMRS than for narrowband DMRS.

The techniques described herein may be used for various wireless communication technologies, such as 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single-carrier frequency division multiple access (SC-FDMA), time division synchronous code division multiple access (TD-SCDMA), and other networks.

NR access (e.g., <NUM> NR) may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., <NUM> or beyond), millimeter wave (mmW) targeting high carrier frequency (e.g., <NUM> or beyond), massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC).

For example, as shown in <FIG>, the UE 120a has a DMRS combining module <NUM> that may be configured for detecting a portion of a physical downlink control channel (PDCCH) to the UE in at least one resource element group (REG), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE and the REG is during a first search space (SS) set occasion configured for the UE; and processing wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein the UE does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion. , according to aspects described herein. In another example, as shown in <FIG>, the BS 110a has a WB DMRS module <NUM> that may be configured for allocating at least one resource element group (REG) for transmission of a physical downlink control channel (PDCCH) to a user equipment (UE), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE and the REG is during a first search space (SS) set occasion configured for the UE; transmitting a portion of the PDCCH via the REG; and transmitting wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion. , according to aspects described herein.

As illustrated in <FIG>, the wireless communication network <NUM> may include a number of base stations (BSs) <NUM> and other network entities. A BS may be a station that communicates with user equipments (UEs). Each BS <NUM> may provide communication coverage for a particular geographic area. In some examples, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in wireless communication network <NUM> through various types of backhaul interfaces, such as a direct physical connection, a wireless connection, a virtual network, or the like using any suitable transport network.

A finely dashed line with double arrows indicates potentially interfering transmissions between a UE and a BS.

<FIG> illustrates example components of BS <NUM> and UE <NUM> (e.g., in the wireless communication network <NUM> of <FIG>), which may be used to implement aspects of the present disclosure. For example, antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the UE <NUM> and/or antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the BS <NUM> may be used to perform the various techniques and methods described herein. For example, as shown in <FIG>, the controller/processor <NUM> of the BS <NUM> has a WB DMRS module <NUM> that may be configured for allocating at least one resource element group (REG) for transmission of a physical downlink control channel (PDCCH) to a user equipment (UE), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE and the REG is during a first search space (SS) set occasion configured for the UE; transmitting a portion of the PDCCH via the REG; and transmitting wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion, according to aspects described herein. For example, as shown in <FIG>, the controller/processor <NUM> of the UE <NUM> has a DMRS combining module <NUM> that may be configured for detecting a portion of a physical downlink control channel (PDCCH) to the UE in at least one resource element group (REG), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE and the REG is during a first search space (SS) set occasion configured for the UE; and processing wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein the UE does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion, according to aspects described herein.

The transmit processor <NUM> may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a-232t. Downlink signals from modulators 232a-232t may be transmitted via the antennas 234a-234t, respectively.

At the UE <NUM>, the antennas 252a-252r may receive the downlink signals from the BS <NUM> and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. A MIMO detector <NUM> may obtain received symbols from all the demodulators 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols.

The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the demodulators in transceivers 254a-254r (e.g., for SC-FDM, etc.), and transmitted to the base station <NUM>.

The controllers/processors <NUM> and <NUM> may direct the operation at the BS <NUM> and the UE <NUM>, respectively. The controller/processor <NUM> and/or other processors and modules at the BS <NUM> may perform or direct the execution of processes for the techniques described herein.

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for transmitting demodulation reference signals (DMRS) with control channels (e.g., physical downlink control channels (PDCCHs)) that enable receiving devices to bundle (e.g., coherently combine) the DMRS over time. In wireless communications systems, DMRS can be coherently transmitted over different time instants. At the receiver, estimates of the channel determined based on DMRS in different time instants can be coherently combined to enhance the channel estimation performance. DMRS bundling is straightforward for DMRS transmitted in association with physical downlink shared channels (PDSCHs), tracking reference signals (TRS) and channel state information (CSI) reference signals (CSI-RS). Bundling of DMRS in association with PDCCHs is not as straightforward, due to the allocation of control channel elements (CCEs) of each PDCCH across the downlink bandwidth to which a receiving user equipment (UE) is blind. That is, a UE is not aware that a CCE of a PDCCH for the UE is present in a bandwidth part (BWP) until the UE blindly detects the PDCCH, which implies that the UE does not have information regarding whether a DMRS is present in the BWP unless the UE detects a PDCCH in that BWP.

It is desirable to develop resolutions to two issues in order to enable PDCCH WB DMRS bundling in time domain. One issue is that in previously known techniques, WB PDCCH DMRS are transmitted by a network entity (e.g., a BS) in a segment (e.g., a group of contiguous resource blocks (RBs) in a BWP) to a UE for the UE to use to demodulate the PDCCH, if at least one REG of the PDCCH is transmitted to the UE in the segment. Thus, the network may not transmit DMRS in a segment to the UE, if no REG of the PDCCH is transmitted to the UE in that segment. The network entity may, for example, prefer to not transmit DMRS in the segment without the PDCCH to reduce interference to other devices and/or to save power. Another issue is that, according to previously known techniques, when a network entity (e.g., a BS) transmits WB DMRS in two adjacent PDCCH monitoring occasions, the network entity may not transmit the WB DMRS using a same precoding in the corresponding segment of the two PDCCH monitoring occasions. Thus, in these previously known techniques, a UE may not coherently combine the WB DMRS that are transmitted using different precodings.

According to aspects of the present disclosure, a CORESET configuration may indicate a set of frequency domain resources for PDCCH transmission based on a bitmap named frequencyDomainResources. In the bitmap, a bit that is set to <NUM> indicates that a group of <NUM> contiguous resource blocks (RBs) is included in frequency domain resources of this CORESET. The CORESET configuration may also indicate a number of contiguous OFDM symbols in which a PDCCH can be transmitted.

In aspects of the present disclosure, a CORESET may contain more than one segment of contiguous RBs. Gaps between segments correspond to zero bits in the bitmap.

According to aspects of the present disclosure, a maximum of <NUM> segments can be configured by a network entity (e.g., a BS) for WB DMRS in a CORESET. That is, a BS may configure a CORESET to include <NUM>, <NUM>, <NUM>, or <NUM> segments of contiguous RBs in a BWP.

<FIG> illustrates an exemplary bandwidth part <NUM> having segments <NUM>, <NUM>, and <NUM> configured as the frequency domain resources for an exemplary CORESET, according to aspects of the present disclosure. An exemplary bitmap [<NUM>,. <NUM>, <NUM>, <NUM>,. <NUM>, <NUM>, <NUM>,. <NUM>, <NUM>, <NUM>,. <NUM>, <NUM>, <NUM>,. <NUM>,<NUM>, <NUM>,. <NUM>, <NUM>, <NUM>,. <NUM>, <NUM>] (e.g., a bitmap named frequencyDomainResources) may be transmitted by a base station (e.g., BS <NUM>, illustrated in <FIG> and <FIG>) configuring the CORESET to indicate that segments <NUM>, <NUM>, and <NUM> are included in frequency domain resources of the CORESET. As mentioned above, bits set to <NUM> in the exemplary bitmap correspond to RBs included in the segments (e.g., segments <NUM>, <NUM>, and <NUM>) of the CORESET, while bits set to <NUM> correspond to gaps (e.g., RBs) between the segments that are not included in the exemplary CORESET.

According to previously known techniques, when no resource element group (REG) of a PDCCH is transmitted in a segment, then a network entity (e.g., a BS) may not transmit a DMRS (e.g., a DMRS associated with the PDCCH) in that segment.

In aspects of the present disclosure, a REG is equivalent to one RB of frequency resources (e.g., twelve subcarriers) during one OFDM symbol. A PDCCH is assigned an integer number of REGs (that is, the PDCCH is transmitted via transmission resources of an integer number of REGs), and these REGs may not be adjacent in a time frequency resource grid, due to interleaving, for example. For example, a BS may interleave REGs from a plurality of PDCCHs in a set of frequency resources, and thus REGs from a first PDCCH may be interleaved with REGs of a second PDCCH, such that one or more REGs of the first PDCCH are not all adjacent to other REGs of the first PDCCH. Accordingly, in previously known techniques, a UE is not expected to obtain any meaningful information from DMRS locations (on a time frequency resource grid) in a segment where no REG of a PDCCH directed to the UE is detected.

According to aspects of the present disclosure, a search space (SS) set configuration indicates a time domain pattern in which a UE monitors transmission resources (e.g., a CORESET) for PDCCH(s) directed to the UE.

In aspects of the present disclosure, a CORESET defines a building block (e.g., a set of RB allocations in the frequency domain and a number of OFDM symbols in the time domain, such as <NUM> to <NUM> symbols) of a control region for a UE to monitor for PDCCHs directed to the UE. Each such building block (i.e., the CORESET at a particular time) may be referred to as a SS set occasion.

According to aspects of the present disclosure, an SS set configuration may indicate a periodicity (measured in a number of slots) for monitoring of PDCCHs to a UE. The SS set configuration may also indicate which slots, in each set of slots for the periodicity, for monitoring of PDCCHs to the UE.

In aspects of the present disclosure, more than one SS set occasion of the same SS set may be configured in a slot.

According to aspects of the present disclosure, SS set occasions within a slot may be configured by a symbol level bitmap in the SS set configuration.

<FIG> illustrates an exemplary SS set <NUM>, according to aspects of the present disclosure. An exemplary CORESET <NUM> indicates a set of frequency resources to be monitored by a UE for control channels. An exemplary time domain pattern <NUM>, based on an SS set configuration, shows two SS set occasions of a SS set configured in each of two slots <NUM> and <NUM>. However, the figure does not necessarily show a complete period of an SS set configuration. Instead, the figure may display two slots of an SS set configuration that is valid for a longer number of slots (and therefore would have a periodicity longer than two slots). In aspects of the present disclosure, a symbol level bitmap corresponding to the SS set configuration contains <NUM> non-zero bits, for example, each non-zero bit corresponding to one of the CORESETs in each of the slots <NUM> and <NUM>.

In aspects of the present disclosure, a UE may be configured with up to <NUM> CORESETs and <NUM> SS sets in each BWP. As described above, a CORESET and a SS set jointly specify a set of time and frequency resources for a UE to monitor for a PDCCH directed to the UE.

According to aspects of the present disclosure, a CORESET can be associated to multiple SS sets, but a SS set can be associated to only one CORESET.

<FIG> is an exemplary transmission timeline <NUM> in which a network entity (e.g., a BS, such as BS <NUM>, shown in <FIG> and <FIG>) transmits PDCCHs to a UE (e.g., UE <NUM>, shown in <FIG> and <FIG>), according to previously known techniques. The network entity transmits PDCCHs to the UE in three adjacent SS set occasions <NUM>, <NUM>, and <NUM> in different segments <NUM>, <NUM>, and <NUM>. According to previously known techniques, a BS transmitting a PDCCH transmits wideband DMRS associated with the PDCCH only in segment(s) that contain at least one REG of the PDCCH (e.g., segments <NUM>, <NUM>, and <NUM>) and thus, only the segment(s) that contain at least one REG of the PDCCH have a wideband DMRS associated with the PDCCH. Thus, a UE cannot coherently combine DMRS over multiple occasions in any segment because the DMRS are transmitted in a different segment (i.e., at different frequencies) in each SS set occasion. While the example shows REGs of the PDCCH are transmitted in a single segment in each SS set occasion, the present disclosure is not so limited, and REGs of a PDCCH may fall in multiple segments. For example, a BS may randomize resource allocation to a PDCCH, such that REGs conveying a PDCCH may fall in any segment. In addition, REGs conveying a PDCCH may fall in multiple segments.

In previously known techniques, WB PDCCH DMRS are transmitted by a network entity (e.g., a BS) in a segment to a UE for the UE to use to demodulate the PDCCH, if at least one REG of the PDCCH is transmitted to the UE in the segment. Thus, the network entigy does not transmit DMRS in a segment to the UE if no REG of the PDCCH is transmitted to the UE in that segment. The network entity may prefer to not transmit DMRS to reduce interference and/or to save power.

According to aspects of the present disclosure, a network (e.g., a network entity, such as BS <NUM> or a scheduler in a BS) may allocate a different set of resources to transmit a PDCCH to a UE via PDCCH monitoring occasions associated with the same CORESET. The network may select any PDCCH candidate, from the set of PDCCH candidates configured for the UE, to transmit the PDCCH.

In aspects of the present disclosure, a network entity (e.g., a BS) may transmit WB DMRS in all segments in all SS set occasions configured for the UE, regardless of whether any REG of a PDCCH is transmitted in each of the segments. The UE may be enabled to bundle the WB DMRS of each segment over the time domain.

<FIG> is an exemplary transmission timeline <NUM> of a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmitting WB DMRS in all segments in all SS set occasions configured for a UE (e.g., UE <NUM>, shown in <FIG> and <FIG>), according to aspects of the present disclosure. The network entity transmits PDCCHs to the UE in three adjacent SS set occasions <NUM>, <NUM>, and <NUM> in different segments <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. The BS transmitting the PDCCHs transmits wideband DMRS associated with the PDCCHs in the segments that contain at least one REG of each PDCCH (i.e., segments <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) and the segments that do not contain at least one REG of the PDCCH (i.e., segments <NUM>, <NUM>, <NUM>, and <NUM>). All of the segments of the CORESET and the SS set have wideband DMRS associated with the PDCCH. Thus, a UE can coherently combine DMRS over multiple SS set occasions in any segment because there are DMRS transmitted in each segment in each of the SS set occasions. In particular, the DMRS in the box <NUM> can be coherently combined. Similarly the DMRS in the box <NUM> can be coherently combined, and the DMRS in the box <NUM> can be coherently combined.

According to aspects of the present disclosure, if a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmits at least one REG in a segment in a SS set occasion, then the network entity transmits WB DMRS in the segment in one or more following occasions, until RRC reconfigures the CORESET to a different set of frequency resources (e.g., by changing the frequencyDomainResources information element).

In aspects of the present disclosure, if a network entity does not transmit an REG of a PDCCH in a segment in a SS set occasion, then the network entity does not transmit DMRS in the segment in the SS set occasion or any previous SS set occasion.

<FIG> is an exemplary transmission timeline <NUM> of a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmitting WB DMRS in segments in which the network entity transmits at least one REG of a PDCCH and in the segments in one or more following occasions, according to aspects of the present disclosure. The network entity transmits PDCCHs to the UE in two adjacent SS set occasions <NUM> and <NUM> in different segments <NUM> and <NUM>. The network entity transmitting the PDCCHs transmits wideband DMRS associated with the PDCCHs in the segment(s) that contain at least one REG of the PDCCHs (i.e., segments <NUM> and <NUM>) and in the segment(s) in later SS set occasions that do not contain at least one REG of the PDCCH (i.e., segments <NUM>, <NUM>, and <NUM>). The network entity does not transmit DMRS in the segments <NUM>, <NUM>, and <NUM> in which the network entity does not transmit an REG of the PDCCH. The network entity also does not transmit DMRS in the segment <NUM> in SS set occasion <NUM>. Segments of the CORESET and the SS set that have at least one REG of the PDCCH also have wideband DMRS associated with the PDCCH, as do the segments in succeeding SS set occasions. Thus, a UE can coherently combine DMRS over multiple occasions in the segments <NUM>, <NUM>, and <NUM>, because there are DMRS transmitted in the segment in each of those SS set occasions. In particular, the DMRS in the box <NUM> can be coherently combined. Similarly the DMRS in the segments <NUM> and <NUM> in the box <NUM> can be coherently combined.

According to aspects of the present disclosure, if a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmits at least one REG of a control channel (e.g., a PDCCH) in a segment in a SS set occasion, then the network entity also transmits WB DMRS in the segment in the SS set occasion and in a number, N, of adjacent SS set occasions that contains the SS set occasion.

In aspects of the present disclosure, if a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmits at least one REG of a control channel (e.g., a PDCCH) in a segment in a SS set occasion, then the network entity also transmits WB DMRS in all SS set occasions within a certain time duration that contains the SS set occasion.

In aspects of the present disclosure, the duration for transmission of DMRS in segments without at least one REG of a control channel can be one period of an SS set configuration periodicity. For example, if a network entity transmits a REG of a control channel in any SS set occasion in a slot associated with a CORESET, then the network entity transmits WB DMRS in all SS set occasions that are associated with the CORESET of the slot.

<FIG> is an exemplary transmission timeline <NUM> of a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) transmitting WB DMRS in segments in which the network entity transmits at least one REG of a PDCCH and in adjacent SS set occasions, according to aspects of the present disclosure. The network entity transmits PDCCHs to the UE in two adjacent SS set occasions <NUM> and <NUM> in different segments <NUM> and <NUM>. The network entity transmitting the PDCCHs transmits wideband DMRS associated with the PDCCH in the segments that contain at least one REG of the PDCCH (i.e., segments <NUM> and <NUM>) and in the segments in adjacent SS set occasions that do not contain at least one REG of the PDCCH (i.e., segments <NUM>, <NUM>, <NUM>, and <NUM>). The network entity does not transmit DMRS in the segments <NUM>, <NUM>, and <NUM> in which the network entity does not transmit an REG of the PDCCH. Segments of the CORESET and the SS set that have at least one REG of the PDCCH also have wideband DMRS associated with the PDCCH, as do the segments in adjacent SS set occasions. Thus, a UE can coherently combine DMRS over multiple occasions in the segments <NUM>, <NUM>, and <NUM>, because there are DMRS transmitted in the segment in each of those SS set occasions. In particular, the DMRS in the box <NUM> can be coherently combined. Similarly the DMRS in the box <NUM> can be coherently combined.

According to previously known techniques, when a network entity (e.g., a BS) transmits WB DMRS in two adjacent PDCCH monitoring occasions (i.e., the network entity transmits a PDCCH in each SS set occasion), the network entity does not necessarily transmit the WB DMRS using a same precoding in the corresponding segment of the two occasions. Thus, in these previously known techniques, a UE cannot necessarily coherently combine the WB DMRS, because the WB DMRS may be transmitted using different precodings.

In aspects of the present disclosure, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) that configures WB DMRS for a CORESET maintains either a same precoding matrix for transmitting the WB DMRS or maintains phase continuity of a precoding matrix over time, so UEs can benefit from coherent combining of DMRS bundling.

According to aspects of the present disclosure, maintaining of the precoding matrix or phase continuity of the precoding matrix can be applied by a network entity in all SS set occasions for a CORESET (e.g., similar to the technique shown in <FIG>), within a number of succeeding SS set occasions (e.g., similar to the technique shown in <FIG>), or in a duration (e.g., for a slot) that contains the occasion where at least one REG is transmitted (e.g., similar to the technique shown in <FIG>).

In aspects of the present disclosure, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may configure PDCCH DMRS bundling by adding an indication in a CORESET configuration that indicates the network entity is transmitting additional WB DMRS to enable WB DMRS bundling, as discussed above with references to <FIG>. According to these aspects of the present disclosure, this is a CORESET level PDCCH DMRS bundling.

In aspects of the present disclosure, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may implicitly configure WB DMRS bundling (i.e., implicitly indicating that the network entity is transmitting additional WB DMRS to enable WB DMRS bundling, as discussed above with references to <FIG>) whenever WB DMRS is configured for a CORESET. Thus, if WB DMRS is configured for a CORESET, then DMRS bundling is enabled for this CORESET. According to aspects of the present disclosure, implicitly configuring of WB DMRS bundling may be backward compatible for UEs. That is, a UE operating according to previously known techniques (and therefore not attempting to coherently combine WB DMRS) may be able to receive PDCCHs and other control channels from the network entity.

In aspects of the present disclosure, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may configure WB DMRS bundling (i.e., indicating that the network entity is transmitting additional WB DMRS to enable WB DMRS bundling, as discussed above with references to <FIG>) for a search space associated with a CORESET whenever WB DMRS is configured for the CORESET. According to aspects of the present disclosure, configuring WB DMRS bundling for a search space is SS set level PDCCH DMRS bundling.

According to aspects of the present disclosure, all PDCCH monitoring occasions for all search space sets associated with a same CORESET may be bundled. Thus, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may transmit WB DMRS in all SS set occasions of all search spaces associated with a CORESET, and a UE (e.g., UE <NUM>, shown in <FIG> and <FIG>) configured with the CORESET may coherently combine WB DMRS from all of the SS set occasions of a search space associated with the CORESET.

In aspects of the present disclosure, all PDCCH monitoring occasions associated with the same search space sets may be bundled. Thus, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may transmit WB DMRS in all SS set occasions of a search space associated with a CORESET, and a UE (e.g., UE <NUM>, shown in <FIG> and <FIG>) configured with the CORESET and the search space may coherently combine WB DMRS from all of the SS set occasions of the search space associated with the CORESET.

According to aspects of the present disclosure, DMRS transmitted in some search space sets associated with the same CORESET can be bundled together. Thus, a network entity (e.g., BS <NUM>, shown in <FIG> and <FIG>) may transmit WB DMRS in all SS set occasions of a selected search space associated with a CORESET, and a UE (e.g., UE <NUM>, shown in <FIG> and <FIG>) configured with the CORESET and that search space may coherently combine WB DMRS from all of the SS set occasions of the search space associated with the CORESET.

In aspects of the present disclosure, a set of search space sets for which WB DMRS bundling is configured may be based on DCI formats configured for a UE monitoring a search space set in the set of search space sets.

According to aspects of the present disclosure, the set of search space sets for which WB DMRS bundling is configured may be based on the configured SS type, i.e., common search space (CSS) or UE specific search space (USS). That is, a network entity may configure WB DMRS bundling in a CSS and in a USS specific for a first UE, while the network entity does not configure WB DMRS bundling for a USS specific for a second UE.

In aspects of the present disclosure, the set of search space sets for which WB DMRS bundling is configured may be based on a configured SS index. That is, a network entity may configure WB DMRS bundling for search spaces having SS indices from a set (e.g., indices that are even), while the network entity does not configure WB DMRS bundling for search spaces having SS indices that are not in the set (e.g., indices that are odd).

<FIG> is a flow diagram illustrating example operations <NUM> for wireless communication, in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by a BS (e.g., such as BS <NUM> shown in the <FIG> and <FIG>). Operations <NUM> may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor <NUM> of <FIG>). Further, the transmission and reception of signals by the BS in operations <NUM> may be enabled, for example, by one or more antennas (e.g., antennas <NUM> of <FIG>). In certain aspects, the transmission and/or reception of signals by the BS may be implemented via a bus interface of one or more processors (e.g., controller/processor <NUM>) obtaining and/or outputting signals.

The operations <NUM> may begin, at block <NUM>, by the BS allocating at least one resource element group (REG) for transmission of a physical downlink control channel (PDCCH) to a user equipment (UE) or a group of UEs, wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or the group of UEs and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs. For example, BS 110a (see <FIG>) allocates a set of REGs in a segment at <NUM> (see <FIG>) for transmission of a PDCCH to UE 120a, wherein the segment at <NUM> is a segment of a CORESET configured for the UE and the REG is during a first SS set occasion <NUM> configured for the UE.

At block <NUM>, operations <NUM> continue with the BS transmitting a portion of the PDCCH via the REG. Continuing the example from above, the BS 110a transmits a portion of the PDCCH via the REG in the segment at <NUM>.

The operations <NUM> continue at block <NUM> with the BS transmitting wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion. Continuing the example from above, the BS 110a transmits WB DMRS in the segment at <NUM> during the first SS set occasion <NUM> and in the segment at <NUM> (see <FIG>) during the second SS set occasion <NUM>, wherein no resources in the segment at <NUM> are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion.

<FIG> is a flow diagram illustrating example operations <NUM> for wireless communication, in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by UE (e.g., such as UE <NUM>, shown in <FIG> and <FIG>). The operations <NUM> may be complimentary operations by the UE to the operations <NUM> performed by the BS. Operations <NUM> may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor <NUM> of <FIG>). Further, the transmission and reception of signals by the UE in operations <NUM> may be enabled, for example, by one or more antennas (e.g., antennas <NUM> of <FIG>). In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor <NUM>) obtaining and/or outputting signals.

The operations <NUM> may begin, at block <NUM>, by the UE detecting a portion of a physical downlink control channel (PDCCH) to the UE in at least one resource element group (REG), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or a group of UEs including the UE and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs. For example, UE 120a detects a portion of a PDCCH to the UE in at least one REG, wherein the REG is in a segment at <NUM> (see <FIG>) of a CORESET configured for the UE and the REG is during a first SS set occasion <NUM> configured for the UE.

At block <NUM>, operations <NUM> continue with the UE processing wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein the UE does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion. Continuing the example from above, the UE 120a processes WB DMRS in the segment at <NUM> during the first SS set occasion <NUM> and in the segment at <NUM> during the second SS set occasion <NUM>, wherein the UD does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion.

<FIG> illustrates a communications device <NUM> that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein for transmitting demodulation reference signals (DMRS) with control channels (e.g., physical downlink control channels (PDCCHs)) that enable receiving devices to bundle (e.g., coherently combine) the DMRS over time, such as the operations illustrated in <FIG>.

The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium/memory <NUM> via a bus <NUM>. In certain aspects, the computer-readable medium/memory <NUM> is configured to store instructions (e.g., computer-executable code) that when executed by the processor <NUM>, cause the processor <NUM> to perform the operations illustrated in <FIG> or other operations for transmitting DMRS with control channels (e.g., PDCCHs) that enable receiving devices to bundle (e.g., coherently combine) the DMRS over time. In certain aspects, computer-readable medium/memory <NUM> stores code <NUM> for allocating at least one resource element group (REG) for transmission of a physical downlink control channel (PDCCH) to a user equipment (UE) or a group of UEs, wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or the group of UEs and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs; code <NUM> for transmitting a portion of the PDCCH via the REG; and code <NUM> for transmitting wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion. In certain aspects, the processor <NUM> has circuitry configured to implement the code stored in the computer-readable medium/memory <NUM>. The processor <NUM> includes circuitry <NUM> for allocating at least one resource element group (REG) for transmission of a physical downlink control channel (PDCCH) to a user equipment (UE) or a group of UEs, wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or the group of UEs and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs; circuitry <NUM> for transmitting a portion of the PDCCH via the REG; and circuitry <NUM> for transmitting wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion.

<FIG> illustrates a communications device <NUM> that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein for bundling (e.g., coherently combining) DMRS over time, such as the operations illustrated in <FIG>.

The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium/memory <NUM> via a bus <NUM>. In certain aspects, the computer-readable medium/memory <NUM> is configured to store instructions (e.g., computer-executable code) that when executed by the processor <NUM>, cause the processor <NUM> to perform the operations illustrated in <FIG> or other operations for bundling (e.g., coherently combining) DMRS over time. In certain aspects, computer-readable medium/memory <NUM> stores code <NUM> for detecting a portion of a physical downlink control channel (PDCCH) to the UE in at least one resource element group (REG), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or a group of UEs including the UE and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs; and code <NUM> for processing wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein the UE does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion. In certain aspects, the processor <NUM> has circuitry configured to implement the code stored in the computer-readable medium/memory <NUM>. The processor <NUM> includes circuitry <NUM> for detecting a portion of a physical downlink control channel (PDCCH) to the UE in at least one resource element group (REG), wherein the REG is in a segment of a control resource set (CORESET) configured for the UE or a group of UEs including the UE and the REG is during a first search space (SS) set occasion configured for the UE or the group of UEs; and circuitry <NUM> for processing wideband (WB) demodulation reference signals (DMRS) in the segment during the first SS set occasion and in the segment during at least one second SS set occasion, wherein the UE does not detect another portion of the PDCCH or another PDCCH during the second SS set occasion.

In other jurisdictions, there are requirements for "essential elements" in the claims. Good practice to address this includes using multiple dependent claims, and providing solid description of various different combinations and alternatives. Ex: Invention includes ABCDEFG, the Claim is ABC. If the claim is amended to ABCG, the foreign Examiner may require inclusion of DEF as "essential steps", so if we can describe ABC, ABCD, ABCE, ABCDE, etc., we have support for all combinations.

Claim 1:
A method for wireless communications performed by a base station, comprising:
allocating (<NUM>) at least one resource element group, REG, for transmission of a physical downlink control channel, PDCCH, to a user equipment, UE, or a group of UEs, wherein the REG is in a segment of a control resource set, CORESET, configured for the UE or the group of UEs and the REG is during a first search space, SS, set occasion configured for the UE or the group of UEs;
transmitting (<NUM>) a portion of the PDCCH via the REG; and
transmitting (<NUM>) wideband, WB, demodulation reference signals, DMRS, in the segment during the first SS set occasion and in the segment during at least one second SS set occasion which is different to the first SS set occasion, and wherein no resources in the segment are allocated to transmitting the PDCCH or another PDCCH during the second SS set occasion.