Patent Description:
The following relates generally to wireless communication and to joint determination of demodulation and channel state information reference signals.

Examples of such multiple-access systems include fourth generation (<NUM>) systems such as a Long Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, and fifth generation (<NUM>) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM). Relatedly, the documents 3GPP R1-<NUM>, 3GPP R1-<NUM> and 3GPP R1-<NUM> describe quasi-co-localization of reference signals, document <CIT> describes controlling of interference in wireless communication systems, document 3GPP R1-<NUM> describes CSI-RS and DMRS multiplexing and document 3GPP R1-<NUM> describes CSI-RS RE patterns.

The described techniques relate to improved methods, systems, devices, or apparatuses that support joint determination of demodulation and channel state information reference signals. Generally, the described techniques provide for mapping one or more demodulation reference signal (DMRS) patterns to one or more available channel state information reference signal (CSI-RS) resources. A UE receiving DMRS and CSI-RS signals may thus determine CSI-RS resource or reduce its search space for identification of CSI-RS transmissions based on a DMRS pattern for a transmission. In some cases, a base station may transmit DMRS patterns and a mapping between DMRS patterns and CSI-RS resources to a user equipment (UE). CSI-RS resources may be configured semi-statically or dynamically by a base station. In some cases, one or more null DMRS patterns may be configured and mapped to CSI-RS resources, and a base station may use a null DMRS pattern for one UE to transmit a DMRS to a different UE, and both UEs may measure channel state information based on an associated CSI-RS transmitted in mapped CSI-RS resources. In some other cases, one or more DMRS patterns may be precluded for DMRS transmissions, based in part on a CSI-RS configuration. In such cases, the mapping between the DMRS patterns and CSI-RS resources may indicate the constraints on DMRS.

In some wireless communication systems, a transmitter may transmit a demodulation reference signal (DMRS) that a receiver may use to demodulate other transmissions from the transmitter. In some systems, such DMRS transmissions may be transmitted using specified resources available for transmission (e.g., in a middle symbol of a transmission slot). In some next generation wireless communication systems (e.g., a <NUM> or NR system), various different DMRS patterns may be used for DMRS transmissions, in which different resources (i.e., DMRS resource elements) may be used within a wireless subframe or slot. In such cases, a base station may configure a particular DMRS pattern or DMRS patterns for data demodulation, which in some cases may support a front-loaded DMRS pattern in which a DMRS transmission is located relatively early in a transmission (e.g., in a first symbol following a control information symbol). Such variable or configurable resources for DMRS transmissions may have an impact on other reference signals, such as a channel state information reference signal (CSI-RS). Thus, a receiver such as a user equipment (UE), may need to be aware of both a DMRS configuration and a CSI-RS configuration in order to properly receive one or both reference signals.

Various techniques discussed herein provide for mapping one or more DMRS patterns to one or more available CSI-RS resources. A UE receiving DMRS and CSI-RS signals may thus determine CSI-RS resources, or reduce a search space for identification of CSI-RS transmissions, based on a DMRS pattern. In some cases, a base station may transmit DMRS patterns and a mapping between DMRS patterns and CSI-RS resources to a user equipment (UE). The base station may then transmit (e.g., in downlink control information (DCI) or radio resource control (RRC) signaling) an indication of a DMRS pattern and an indication of a selected CSI-RS resource (e.g., an index to a set of CSI-RS resources provided in the mapping) used for one or more transmissions. A UE may use the DMRS pattern, the indication of the selected CSI-RS resource, and the mapping, to determine CSI-RS resources. In some instances, instead of or in addition to an explicit mapping from the base station, the UE may determine an implicit mapping between the DMRS pattern transmitted by the base station and the CSI-RS resources. In some instances, for example, the UE may determine, based on a grant, the DMRS pattern that is to be transmitted and may implicitly determine which configured CSI-RS resources cannot also be transmitted. In certain instances, the UE may receive the implicit mapping through other signaling. Accordingly, there may be an implicit association between the DMRS and CSI-RS resources.

In some other cases, the base station may transmit a CSI-RS resource configuration, and a mapping between DMRS patterns and CSI-RS resources to a UE. In such cases, one or more DMRS patterns may be precluded from DMRS transmissions based in part on the CSI-RS configuration. Thus, DMRS and CSI-RS transmissions may be configured semi-statically or dynamically by a base station. In some cases, one or more null DMRS patterns may be configured and mapped to one or more CSI-RS resources, and a base station may use a null DMRS pattern for one UE to transmit a DMRS to a different UE, and both UEs may measure channel state information based on an associated CSI-RS transmitted in mapped CSI-RS resources.

Aspects of the disclosure are initially described in the context of a wireless communications system. Various examples of DMRS patterns, CSI-RS resources, and mappings between DMRS patterns and CSI-RS resources are then described. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to joint determination of demodulation and channel state information reference signals.

<FIG> illustrates an example of a wireless communications system <NUM> in accordance with various aspects of the present disclosure. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices. UEs <NUM> and base stations <NUM> may transmit one or more reference signals, in which resources of one reference signal may be mapped to another reference signal to allow joint determination of resources for both reference signals.

The wireless communications system <NUM> may include, for example, a heterogeneous LTE/LTE-A or NR network in which different types of base stations <NUM> provide coverage for various geographic coverage areas <NUM>.

For example, wireless communication system may use a transmission scheme between a transmitting device (e.g., a base station <NUM>) and a receiving device (e.g., a UE <NUM>), where the transmitting device is equipped with multiple antennas and the receiving devices are equipped with one or more antennas.

In one example, a base station <NUM> may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station <NUM> multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station <NUM> or a receiving device, such as a UE <NUM>) a beam direction for subsequent transmission and/or reception by the base station <NUM>. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station <NUM> in a single beam direction (e.g., a direction associated with the receiving device, such as a UE <NUM>). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE <NUM> may receive one or more of the signals transmitted by the base station <NUM> in different directions, and the UE <NUM> may report to the base station <NUM> an indication of the signal it received with a highest signal quality (e.g., based on measurements of one or more reference signals such as a CSI-RS), or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station <NUM>, a UE <NUM> may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE <NUM>), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

In some examples, a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal).

In other cases, a smallest scheduling unit of the wireless communications system <NUM> may be shorter than a subframe (e.g., a slot TTI) or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs).

In some instances, a symbol of a mini-slot, or a mini-slot may be the smallest unit of scheduling. Further, some wireless communications systems may implement slot aggregation in which multiple slots, or mini-slots are aggregated together and used for communication between a UE <NUM> and a base station <NUM>.

The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, NR, etc.). A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.), and control signaling that coordinates operation for the carrier.

As indicated above, in some cases, a transmitter such as a base station <NUM>, may transmit a DMRS that may be used by a receiver, such as a UE <NUM>, for channel estimation and coherent demodulation of data transmissions from the transmitter. Also, as indicated above, in some cases wireless resources for DMRS transmissions may be variable or configurable, and various different DMRS patterns may be employed depending upon the type and configuration of transmissions. The variable DMRS patterns may also impact resources used for other transmissions, such as CSI-RS transmissions, and various techniques discussed herein provide for mapping one or more DMRS patterns to one or more available CSI-RS resources. A UE receiving DMRS and CSI-RS signals may thus determine CSI-RS resources, or reduce a search space for identification of CSI-RS transmissions, based on a DMRS pattern. In some other cases, the available DMRS patterns from a set of DMRS patterns may be constrained based in part on a CSI-RS configuration. For example, one or more DMRS patterns from the set of DMRS patterns may be precluded for DMRS transmissions based on CSI-RS configured at the base station. Thus, the UE may utilize an implicit mapping scheme where the UE may implicitly determine which configured CSI-RS resources or DMRS patterns cannot also be transmitted based on the DMRS pattern or CSI-RS configuration, respectively.

<FIG> illustrates an example of a wireless communication system <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, wireless communication system <NUM> may implement aspects of wireless communication system <NUM>. Wireless communication system <NUM> may include a base station <NUM>-a and a UE <NUM>-a, which may be examples of the corresponding devices described with reference to <FIG>.

In some examples, base station <NUM>-a may be in communication with one or more UEs <NUM> within geographic coverage area <NUM>. For example, base station <NUM>-a may be in communication with UE <NUM>-a via bidirectional communication link <NUM>. Base station <NUM>-a may transmit one or more reference signals, such as a DMRS <NUM> or a CSI-RS <NUM>. In some cases, DMRS <NUM> may be transmitted using wireless resources at different locations within a transmission slot, and resources used for CSI-RS <NUM> may be modified based on the DMRS <NUM> resources. In some cases, for example, DMRS <NUM> may be transmitted in up to four OFDM symbols within a subframe, and a location of the DMRS <NUM> symbols may be different in different subframes. In some cases, CSI-RS <NUM> may not be multiplexed on any of the potential DMRS <NUM> OFDM symbol(s). However, in such cases, the locations of CSI-RS <NUM> may be relatively limited. In other cases, if DMRS <NUM> may be transmitted on a first number of symbols (e.g., up to four symbols), but is not transmitted on a subset of those symbols (e.g., DMRS is transmitted on only two symbols), CSI-RS <NUM> may be transmitted on the subset of the first number of symbols. In further cases, CSI-RS <NUM> may be multiplexed on all potential DMRS <NUM> OFDM symbol(s). As indicated above, various aspects of the present disclosure provide mappings between CSI-RS <NUM> resources and patterns of DMRS <NUM> transmissions. Thus, the CSI-RS <NUM> resources for a particular transmission or set of transmissions may be determined based on the DMRS <NUM> for that transmission or set of transmissions. In some cases, CSI-RS <NUM> resources may span <NUM>, <NUM>, or <NUM> OFDM symbols. If CSI-RS <NUM> resources span four OFDM symbols, for example, two pairs of adjacent OFDM symbols may be used for one CSI-RS <NUM> resource, where the two pairs can be adjacent or non-adjacent.

In some other cases, DMRS <NUM> may be constrained based on the configured CSI-RS <NUM>. For instance, base station <NUM>-a may transmit a mapping between CSI-RS <NUM> and DMRS <NUM>, along with a CSI-RS configuration (i.e., potential CSI-RS <NUM> OFDM symbol(s)). In such cases, one or more DMRS patterns may be precluded for DMRS <NUM> transmissions.

<FIG> illustrate several examples of potential DMRS patterns.

<FIG> illustrates examples of DMRS patterns <NUM> that support joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS patterns <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, a UE (e.g., a UE <NUM> of <FIG> or <FIG>), may be configured by higher layers with DMRS pattern either from a front-loaded DMRS Configuration type <NUM>, or from a front-loaded DMRS Configuration type <NUM> for downlink and uplink transmissions. DMRS patterns <NUM> illustrate example configuration type <NUM> patterns. In some aspects, a DMRS pattern may refer to one or more resource elements used for DMRS transmissions, DMRS resource elements, which may be located in certain time-frequency locations within a frame, subframe, slot, or other time interval according to a configuration by the network or base station. Such DMRS patterns may repeat at regular intervals for a slot, subframe, frame, or a number of frames, or another time interval.

In the examples of <FIG>, a first DMRS pattern <NUM> and a second DMRS pattern <NUM> are one-symbol DMRS patterns that are front loaded in a first slot of a subframe. The one-symbol patterns may be used for DMRS transmissions on up to four antenna ports, with the first DMRS pattern providing DMRS for antenna ports <NUM> and <NUM>, and the second DMRS pattern providing DMRS for antenna ports <NUM> and <NUM>. The one-symbol DMRS patterns may use a comb pattern with every other tone having a DMRS for a different antenna port.

DMRS patterns <NUM> may also include two-symbol DMRS patterns that include a third DMRS pattern <NUM>, a fourth DMRS pattern <NUM>, a fifth DMRS pattern <NUM>, and a sixth DMRS pattern <NUM>, in which DMRS for up to eight antenna ports may be provided. In the illustrated example DMRS patterns <NUM> through <NUM>, a comb pattern may be used along with a time domain orthogonal cover code (TD-OCC) (e.g., {<NUM><NUM>} and {<NUM> -<NUM>} for adjacent symbols), and may provide DMRS for up to <NUM> antenna ports. In other examples, DMRS patterns may be used that provide DMRS for up to four antenna ports without using both TD-OCC {<NUM>,<NUM>} and {<NUM>,-<NUM>}.

<FIG> illustrates examples of DMRS patterns <NUM> that support joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS patterns <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, a UE (e.g., a UE <NUM> of <FIG> or <FIG>), may again be configured from a front-loaded DMRS Configuration type <NUM> or from a front-loaded DMRS Configuration type <NUM> for downlink and uplink transmissions. DMRS patterns <NUM> illustrate example configuration type <NUM> patterns.

In the examples of <FIG>, a first DMRS pattern <NUM> and a second DMRS pattern <NUM> are one-symbol DMRS patterns that are front loaded in a first slot of a subframe. The one-symbol patterns may be used for DMRS transmissions on up to six antenna ports, with the first DMRS pattern <NUM> providing DMRS for antenna ports <NUM>, <NUM>, and <NUM>, and the second DMRS pattern <NUM> providing DMRS for antenna ports <NUM>, <NUM>, and <NUM>. The one-symbol DMRS patterns may use a frequency division (FD) OCC (e.g., {<NUM><NUM>} and {<NUM> -<NUM>}) for adjacent REs in the frequency domain, to provide DMRS for up to <NUM> antenna ports.

DMRS patterns <NUM> may also include two-symbol DMRS patterns that include a third DMRS pattern <NUM>, a fourth DMRS pattern <NUM>, a fifth DMRS pattern <NUM>, and a sixth DMRS pattern <NUM>, in which DMRS for up to <NUM> antenna ports may be provided. In the illustrated example DMRS patterns <NUM> through <NUM>, FD-OCC may be applied across adjacent REs in the frequency domain, and TD-OCC (e.g., {<NUM>,<NUM>} and {<NUM>,-<NUM>}) applied across adjacent REs in the time domain. The DMRS signal sequence design for downlink and uplink CP-OFDM is a known QPSK sequence that is transmitted by each port in the corresponding resource elements.

<FIG> illustrates further examples of DMRS patterns <NUM> that support joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS patterns <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, some subframes may include both a downlink portion and an uplink burst portion, and some subframes may include only downlink transmissions. Depending upon which symbols are configured for downlink or uplink transmissions, other symbols may be configured for DMRS to provide enhanced DMRS for each subframe.

In the examples of <FIG>, a number of DMRS patterns may be used for subframes with no uplink burst portions, including first DMRS pattern <NUM> with four spaced DMRS symbols, a second DMRS pattern <NUM> with three spaced DMRS symbols, a third DMRS pattern <NUM> with two spaced DMRS symbols, and a fourth DMRS pattern <NUM> with four DMRS symbols that are located in pairs of symbols, with different pairs spread across the subframe. In cases where a two-symbol uplink burst is present, a fifth DMRS pattern <NUM> may include three spaced DMRS symbols, a sixth DMRS pattern <NUM> with two spaced DMRS symbols, and a seventh DMRS pattern <NUM> with two front-loaded DMRS symbols and a third spaced DMRS symbol.

In cases where a three-symbol uplink burst is present, an eighth DMRS pattern <NUM> may include three spaces DMRS symbols, a ninth DMRS pattern <NUM> may include two spaced DMRS symbols, and a tenth DMRS pattern <NUM> may include four DMRS symbols arranged as pairs of adjacent DMRS symbols with different pairs spread across the downlink symbols. In cases where a five-symbol uplink burst is present, an eleventh DMRS pattern <NUM> may have two spaced DMRS symbols spread across the downlink symbols.

<FIG> illustrates further examples of DMRS patterns <NUM> that support joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS patterns <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example again, some subframes may include both a downlink portion and an uplink burst portion, and some subframes may include only downlink transmissions. Depending upon which symbols are configured for downlink or uplink transmissions, other symbols may be configured for DMRS to provide enhanced DMRS for each subframe. In the examples of <FIG>, DMRS symbols may be located at the same symbols within a subframe irrespective of a number of uplink symbols, with uplink symbols replacing DMRS symbols in the event that the DMRS symbol is located in the uplink burst.

In the examples of <FIG>, a number of DMRS patterns may be used for subframes with no uplink burst portions, including first DMRS pattern <NUM> with four spaced DMRS symbols, a second DMRS pattern <NUM> with three spaced DMRS symbols, a third DMRS pattern <NUM> with four DMRS symbols that are located in pairs of symbols with different pairs spread across the subframe, and a fourth DMRS pattern <NUM> with two spaced DMRS symbols. In cases where a two-symbol uplink burst is present, a fifth DMRS pattern <NUM> may include three spaced DMRS symbols, a sixth DMRS pattern <NUM> with two spaced DMRS symbols, and a seventh DMRS pattern <NUM> with two front-loaded DMRS symbols and a third spaced DMRS symbol.

In cases where a three-symbol uplink burst is present, an eighth DMRS pattern <NUM> may include three spaced DMRS symbols, a ninth DMRS pattern <NUM> may include two spaced DMRS symbols, and a tenth DMRS pattern <NUM> may include four DMRS symbols arranged as pairs of adjacent DMRS symbols with different pairs spread across the downlink symbols. In cases where a five-symbol uplink burst is present, an eleventh DMRS pattern <NUM> may have two spaced DMRS symbols spread across the downlink symbols.

As indicated above, various techniques discussed herein provide for mapping one or more DMRS patterns to one or more available CSI-RS resources. In some cases, a base station may transmit DMRS patterns and a mapping between DMRS patterns and CSI-RS resources to a UE, and subsequently transmit (e.g., in downlink control information (DCI) or radio resource control (RRC) signaling) an indication of a DMRS pattern and an indication of a selected CSI-RS resource (e.g., an indication of the CSI-RS resource or an index to a set of CSI-RS resources provided in the mapping) used for one or more transmissions. A UE may use the DMRS pattern, the indication of the selected CSI-RS resource, and the mapping, to determine CSI-RS resources. In some other cases, the base station may transmit a CSI-RS configuration, and a mapping between DMRS patterns and CSI-RS resources to a UE. In some aspects, the mapping may be used to indicate that one or more DMRS patterns may be precluded for DMRS transmissions, based on the CSI-RS configuration. Thus, the UE may use the CSI-RS configuration, and the mapping to determine DMRS resources.

In some other cases, the UE may determine an implicit mapping between the DMRS pattern and CSI-RS resources, based on the DMRS pattern transmitted by the base station. For instance, the UE may determine, based on a grant, the DMRS pattern that is to be transmitted and may implicitly determine which configured CSI-RS resources may not be used for transmission of CSI-RS. In other cases, the UE may deduce the implicit mapping based on signaling other than a grant.

In some examples, and as further illustrated in <FIG>, resources selected for CSI-RS and DMRS transmissions may not overlap based on the mapping between CSI-RS resources and DMRS patterns. For instance, in some cases, DMRS patterns and CSI-RS resources may overlap by configuration, but the mapping may allow non-overlapping resources to be used during scheduling. Thus, in some aspects, one or more DMRS patterns, or CSI-RS resources may be precluded for RS transmissions based on the DCI and mapping (e.g., implicit or explicit).

<FIG> illustrates an example of a mapping <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, mapping <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, a base station (e.g. a base station <NUM> of <FIG> or <FIG>) may semi-statically signal (e.g., through RRC signaling) a UE (e.g., a UE <NUM> of <FIG> or <FIG>) a subset of possible DMRS patterns/configurations that are likely to be used for that specific UE. In this example, the base station may signal that DMRS pattern <NUM><NUM>, DMRS pattern <NUM><NUM>, DMRS pattern <NUM><NUM>, or a null DMRS pattern <NUM>, will be used for transmissions with the UE. Other DMRS patterns may also be indicated, and the example of <FIG> is provided for illustration and discussion purposes with the understanding that more of fewer DMRS patterns may be configured at the UE.

The base station may also signal, such as through semi-static signaling (e.g., RRC signaling) the possible CSI-RS resources that may be configured to the UE. In this example, for DMRS pattern <NUM><NUM>, three different CSI-RS resources may be configured to the UE, including CSI-RS resource <NUM><NUM>, CSI-RS resource <NUM><NUM>, and CSI-RS resource <NUM><NUM>. For DMRS pattern <NUM><NUM>, two different CSI-RS resources may be configured to the UE, including CSI-RS resource <NUM><NUM>, and CSI-RS resource <NUM><NUM>. For DMRS pattern <NUM><NUM>, two different CSI-RS resources may be configured to the UE, including CSI-RS resource <NUM><NUM>, and CSI-RS resource <NUM><NUM>. Similarly, for null DMRS pattern <NUM>, three different CSI-RS resources may be configured to the UE, including CSI-RS resource <NUM><NUM>, CSI-RS resource <NUM><NUM>, and CSI-RS resource <NUM><NUM>.

Such a mapping <NUM> CSI-RS resources and DMRS configurations provides that, when a specific DMRS configuration is enabled, only a subset of the available CSI-RS resources may be enabled. In some cases, the DMRS pattern and CSI-RS resources may be indicated in DCI provided to a UE for a particular transmission or set of transmissions. For example, a base station may transmit a first set of bits that indicate which DMRS pattern is used, which may be indexed to a DMRS pattern from the mapping <NUM>, along with a second set of bits that indicate the particular CSI-RS resource for the transmission, which may be indexed to the particular CSI-RS resources associated with the signaled DMRS pattern. In some examples, when no DMRS is transmitted to a UE in a slot, CSI-RS may still be transmitted in that slot, and the null DMRS pattern <NUM> may be indicated along with an indication of which of the CSI-RS resource <NUM><NUM>, CSI-RS resource <NUM><NUM>, or CSI-RS resource <NUM><NUM> is used for CSI-RS transmission. In some cases, there may be multiple "Null DMRS" options configured to a UE, so that the base station has the flexibility to change the DMRS pattern of the other UEs. The "Null DMRS" option may correspond to a specified/reference DMRS, such as a front-load DMRS configuration, a specified/reference DMRS that may be cell-specifically configured to all the UEs, or combinations thereof. In some cases, one or more zero power (ZP) CSI-RS resources may be configured to the UE that may not need to depend on the DMRS configuration, and may be configured independently of non-zero-power CSI-RS resources.

As indicated above, in some cases the base station may signal possible CSI-RS resources that may be configured to a UE. For each CSI-RS resource, depending on the DMRS configurations, some parameters may change of that specific CSI-RS resource. For example, the same CSI-RS resource may have more than one set of parameters that define it, depending on the DMRS configuration. Such parameters may include, for example, CSI-RS location (symbols, tones, REs, etc.), CDM options for the configured ports due to the CSI-RS location change, CSI-RS transmission size, or combinations thereof. For example, a CSI-RS resource may have four symbols and <NUM> ports. If the configured DMRS is a first DMRS pattern, then CSI-RS is transmitted in four consecutive symbols, otherwise if the configured DMRS is a second DMRS pattern, CSI-RS is transmitted in two groups of two adjacent symbols.

<FIG> illustrates an example of CSI-RS settings, resource sets, and associated resources of a mapping <NUM> that support joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, mapping <NUM> may implement aspects of wireless communication system <NUM> or <NUM>.

In the example of <FIG>, a CSI-RS setting <NUM> may have a number of CSI-RS sets <NUM> associated therewith, and each CSI-RS set <NUM> may have a number of CSI-RS resources <NUM> associated therewith. In such examples, depending on the DMRS configuration, a different CSI-RS set <NUM> is enabled, and the CSI-RS resources <NUM> may be enabled based on the CSI-RS set <NUM>. In some cases, the CSI-RS set <NUM> may be indicated with a first set of bits and the CSI-RS resources may be indicated with a second set of bits.

Furthermore, a configured CSI-RS resource (or equivalently the parameters of a CSI-RS resource) may change for different front-load DMRS configuration (e.g., config-<NUM> or config-<NUM> as discussed above with respect to <FIG>). For example, DMRS configuration <NUM> uses a comb-<NUM> solution, whereas DMRS configuration <NUM> uses a <NUM>-by-<NUM> boxes (FD-OCC and TD-OCC). So, if CSI-RS and DMRS appear on the same symbol, (either NZP or ZP CSIRS), then the CSI-RS pattern may need to change accordingly.

In some other cases, DMRS pattern may change based in part on the CSI-RS and DMRS appearing on the same symbol. For instance, a mapping (either implicit or explicit) between CSI-RS resources and DMRS patterns provides that, when a specific CSI-RS configuration is enabled, only a subset of the available DMRS patterns may be enabled.

<FIG> illustrates an example of DMRS and CSI-RS resources <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS and CSI-RS resources <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, a UE may be configured with DMRS pattern <NUM><NUM> that includes two spaced DMRS symbols. In this case, CSI-RS resources may be configured to span four OFDM symbols, and may be located around the DMRS symbols, according to pattern <NUM>. Similarly, DMRS pattern <NUM><NUM> may have one front-loaded DMRS symbol, and the corresponding DMRS and CSI-RS pattern <NUM> may have four adjacent OFDM symbols configured for CSI-RS.

<FIG> illustrates an example of a DMRS and CSI-RS resources <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, DMRS and CSI-RS resources <NUM> may implement aspects of wireless communication system <NUM> or <NUM>. In this example, a first DMRS pattern <NUM> may have DMRS resources that use the same tones in different OFDM symbols. A second DMRS pattern <NUM> may have DMRS resources that are frequency staggered across OFDM symbols. In such cases, CSI-RS resources may be associated with the different DMRS patterns. Thus, the CSI-RS parameter in such a case would be changed when the DMRS configuration changes from the non-staggered to the staggered configuration.

<FIG> illustrates an example of a process flow <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with various aspects of the present disclosure. In some examples, process flow <NUM> may implement aspects of wireless communication system <NUM>. Process flow <NUM> may include a base station <NUM>-b, and a UE <NUM>-b, which may be examples of the corresponding devices described with reference to <FIG>. The base station <NUM>-b and the UE <NUM>-b may establish a connection <NUM> according to established connection establishment techniques for the wireless communications system.

At <NUM>, the base station <NUM>-b may identify DMRS patterns and a set of available CSI-RS resources that may be used for reference signal transmissions. The DMRS patterns may be identified, for example, as one or more available DMRS patterns that may be configured at the UE <NUM>-b. The DMRS patterns may be, for example, different patterns of OFDM symbols that may include DMRS transmissions, a number of adjacent REs that may be used for DMRS for a particular antenna port, an OCC applied to adjacent REs, or any combination thereof. In some examples, the base station <NUM>-b may identify potential DMRS patterns for the UE <NUM>-b based at least in part on one or more services that may be enabled at the UE <NUM>-b (e.g., a ultra-reliable low latency (URLLC) or enhanced mobile broadband (eMBB) service) and configurations for uplink and downlink transmissions associated therewith (e.g., transmissions using slot TTIs or <NUM> TTIs). CSI-RS resources may be identified based on, for example, a number of symbols that may be available for CSI-RS transmissions, multiplexing available for multiplexing CSI-RS and DMRS transmissions, frequency staggering of DMRS transmissions across symbols, or any combination thereof.

At <NUM>, the base station <NUM>-b may determine a mapping between the DMRS patterns and CSI-RS resources for UEs. In some cases, the base station may identify a first number of potential DMRS patterns for the UE <NUM>-b, and may then identify a second number of potential CSI-RS resources associated with each DMRS pattern. The base station <NUM>-b may map the potential CSI-RS resources to the corresponding potential DMRS pattern, and provide the mapping to the UE <NUM>-b through a configuration <NUM> transmission. In some cases, the configuration <NUM> may be transmitted using RRC signaling, and the potential DMRS patterns and associated CSI-RS resources may be semi-statically configured at the UE <NUM>-b.

At <NUM>, the UE <NUM>-b may identify the DMRS patterns and the mapping for the CSI-RS resources. The UE <NUM>-b may identify the DMRS patterns and the mapping based on the configuration <NUM> transmission. In some cases, the base station <NUM>-b may explicitly indicate each enabled DMRS pattern and each of a number of associated CSI-RS resources for each DMRS pattern. In other cases, the UE <NUM>-b may be configured with a superset of available DMRS patterns and available CSI-RS resources, and the configuration <NUM> may indicate that one or more subsets of DMRS patterns, and one or more subsets of CSI-RS resources that are associated with each DMRS pattern are enabled. In some other cases, the UE <NUM>-b may be configured with a CSI-RS resource configuration, and the configuration <NUM> may indicate one or more subsets of CSI-RS resources that are enabled.

The base station <NUM>-b may allocate resources for a transmission, and transmit DCI <NUM> to the UE <NUM>-b that contains an indication of the allocated resources. The DCI <NUM> may also include information for which DMRS pattern of the enabled DMRS patterns is to be used for the transmission, and which CSI-RS resource associated with the selected DMRS pattern is to be used for the transmission. In some other cases, the DCI <NUM> may provide an indication of only one of the CSI-RS resource or DMRS pattern. In such cases, the UE may use an implicit scheme for determining the other one of the DMRS pattern or the CSI-RS resource, respectively.

The UE <NUM>-b, at <NUM>, may determine the DMRS pattern and the CSI-RS resources based at least in part on the information from the DCI, the enabled DMRS patterns, and the mapping between the DMRS patterns and CSI-RS resources. In some examples, DMRS patterns may be constrained for transmissions based on the configured CSI-RS resource configuration. For instance, the mapping between DMRS patterns and CSI-RS resources may be used to determine one or more DMRS patterns that are precluded, which may allow non-overlapping resources to be used for DMRS and CSI-RS transmissions. In such cases, the UE may determine an implicit mapping between the DMRS pattern and the CSI-RS resources, based on an indication of one of the DMRS pattern or the CSI-RS resources. In some instances, the UE <NUM>-b may determine, based on the DCI <NUM>, the selected CSI-RS resources, and may implicitly determine which DMRS patterns may not be used for transmission of DMRS. Accordingly, there may be an implicit association between the DMRS and CSI-RS resources.

In cases where different subsets of CSI-RS resources are associated with a DMRS pattern, the DCI may include an indication of the selected DMRS pattern (e.g., a first index into a list of enabled DMRS patterns) and an indication of the selected CSI-RS resources (e.g., a second index into a list of CSI-RS resources associated with the DMRS pattern).

The base station <NUM>-b may then transmit a downlink transmission <NUM> (e.g., a PDSCH transmission) having associated control, DMRS, and CSI-RS transmissions. At block <NUM>, the UE <NUM>-b may then receive the DMRS and CSI-RS according to the DMRS pattern and CSI-RS resources that were used for the downlink transmission <NUM>. The UE <NUM>-b may use the DMRS for channel estimation and coherent demodulation of data transmitted in the downlink transmission <NUM>. The UE <NUM>-b may also perform measurements of the CSI-RS transmissions and may provide such measurements to the base station <NUM>-b as part of channel state information that may be transmitted to the base station.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a UE <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, UE communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver <NUM> may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to joint determination of demodulation and channel state information reference signals, etc.). Information may be passed on to other components of the device. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>. The receiver <NUM> may utilize a single antenna or a set of antennas.

UE communications manager <NUM> may be an example of aspects of the UE communications manager <NUM> described with reference to <FIG>.

UE communications manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the UE communications manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in the present disclosure. The UE communications manager <NUM> and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, UE communications manager <NUM> and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, UE communications manager <NUM> and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

UE communications manager <NUM> may identify a set of DMRS patterns for use at a UE and a set of available CSI-RS resources, receive downlink control information (DCI) indicating one or more of the DMRS patterns based at least in part on a mapping between one or more of the set of DMRS patterns and one or more of the set of available CSI-RS resources that are associated with the one or more DMRS patterns, and receive one or more of a DMRS or a CSI-RS based at least in part on the received DCI and the mapping.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a UE <NUM> as described with reference to <FIG>. Wireless device <NUM> may include receiver <NUM>, UE communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

UE communications manager <NUM> may be an example of aspects of the UE communications manager <NUM> described with reference to <FIG>. UE communications manager <NUM> may also include reference signal manager <NUM>, mapping manager <NUM>, and reference signal receiver <NUM>.

Reference signal manager <NUM> may identify a set of DMRS patterns for use at a UE and a set of available CSI-RS resources. Reference signal manager <NUM> may also receive an indication of a first DMRS pattern for a first downlink transmission, and receive an indication of one or more ZP CSI-RS resources that are configured independently of the DMRS patterns. In some cases, the set of DMRS patterns includes a null DMRS pattern mapped to one or more CSI-RS resources. In some cases, the set of null DMRS patterns are received in a cell-specific configuration of all UEs within a cell.

Mapping manager <NUM> may receive DCI indicating one or more of the DMRS patterns based at least in part on a mapping between one or more of the set of DMRS patterns and one or more of the set of available CSI-RS resources that are associated with the one or more DMRS patterns. In some cases, such a mapping may be used by mapping manager <NUM> to identify a first subset of CSI-RS resources that are mapped to the first DMRS pattern. Alternatively, such a mapping may be used to identify a first subset of DMRS patterns which may be precluded from DMRS transmissions, based in part on a CSI-RS configuration.

In some cases, mapping manager <NUM> may determine first CSI-RS resources associated with the first downlink transmission based on the first subset of CSI-RS resources, determine a configuration of the CSI-RS resources based on an associated DMRS pattern, and determine frequency resources of the CSI-RS resources based on associated DMRS frequency resources. In some cases, the receiving the mapping further includes receiving one or more parameters for a same subset of CSI-RS resources for two or more DMRS patterns, at least one of the one or more parameters being different for different DMRS patterns. In some cases, the one or more parameters include one or more of a CSI-RS location, a CDM configuration for one or more antenna ports, a CSI-RS transmission size, or any combination thereof.

Reference signal receiver <NUM> may receive one or more of a DMRS or CSI-RS based on the mapping. In some cases, the receiving the one or more of the DMRS or CSI-RS includes receiving a CSI-RS in a downlink transmission over the one or more CSI-RS resources mapped to the null DMRS configuration, and where a DMRS is not received in the downlink transmission.

<FIG> shows a block diagram <NUM> of a UE communications manager <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. The UE communications manager <NUM> may be an example of aspects of a UE communications manager <NUM>, a UE communications manager <NUM>, or a UE communications manager <NUM> described with reference to <FIG>, <FIG>, and <FIG>. The UE communications manager <NUM> may include reference signal manager <NUM>, mapping manager <NUM>, reference signal receiver <NUM>, control information manager <NUM>, and RRC component <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Reference signal receiver <NUM> may receive one or more of a DMRS or CSI-RS based on the received DCI and the mapping. In some cases, the receiving the one or more of the DMRS or CSI-RS includes receiving a CSI-RS in a downlink transmission over the one or more CSI-RS resources mapped to the null DMRS configuration, and where a DMRS is not received in the downlink transmission.

Control information manager <NUM> may receive an indication of the first CSI-RS resources within the first subset of CSI-RS resources in control information associated with the first downlink transmission. In some cases, the indication of the first CSI-RS resources is received dynamically in DCI associated with a downlink transmission.

RRC component <NUM> may transmit and receive RRC signaling. In some cases, RRC component <NUM> may semi-statically receive configuration information including the set of DMRS patterns and the set of available CSI-RS resources. In some cases, the configuration information is received in RRC signaling.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of wireless device <NUM>, wireless device <NUM>, or a UE <NUM> as described above, e.g., with reference to <FIG> and <FIG>. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, and I/O controller <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more base stations <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting joint determination of demodulation and channel state information reference signals).

Software <NUM> may include code to implement aspects of the present disclosure, including code to support joint determination of demodulation and channel state information reference signals. Software <NUM> may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

However, in some cases, the device may have more than one antenna <NUM>, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a base station <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, base station communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Base station communications manager <NUM> may be an example of aspects of the base station communications manager <NUM> described with reference to <FIG>.

Base station communications manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the base station communications manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in the present disclosure.

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

Base station communications manager <NUM> may identify a set of DMRS patterns for a UE and a set of available CSI-RS resources for the UE, determine a mapping between one or more of the DMRS patterns and one or more of the available CSI-RS resources, transmit DCI indicating one or more of the DMRS patterns based at least in part on the determined mapping, and transmit one or more of a DMRS or CSI-RS based on the transmitted DCI and the determined mapping.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a base station <NUM> as described with reference to <FIG>. Wireless device <NUM> may include receiver <NUM>, base station communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Base station communications manager <NUM> may be an example of aspects of the base station communications manager <NUM> described with reference to <FIG>. Base station communications manager <NUM> may also include reference signal manager <NUM>, mapping manager <NUM>, and configuration manager <NUM>.

Reference signal manager <NUM> may identify a set of DMRS patterns for a UE and a set of available CSI-RS resources for the UE, transmit an indication of a first DMRS pattern for a first downlink transmission, transmit an indication of the first CSI-RS resource, and transmit one or more of a DMRS or CSI-RS based on the transmitted DCI and the determined mapping. In some cases, reference signal manager <NUM> may transmit a CSI-RS in a downlink transmission over the one or more CSI-RS resources mapped to a null DMRS pattern, and where a DMRS is not transmitted in the downlink transmission. In some cases, reference signal manager <NUM> may determine a configuration of the CSI-RS based on an associated DMRS pattern, and determine frequency resources of the CSI-RS resources based on associated DMRS frequency resources. In some cases, the set of DMRS patterns includes a null DMRS pattern mapped to one or more CSI-RS resources. In some cases, the set of DMRS patterns includes a set of null DMRS patterns that are configured at a set of UEs in a cell-specific configuration.

Mapping manager <NUM> may determine a mapping between one or more of the DMRS patterns and one or more of the available CSI-RS resources, identify a first subset of CSI-RS resources that are mapped to the first DMRS pattern, and select a first CSI-RS resource based on the first subset of CSI-RS resources that are mapped to the first DMRS pattern. In some cases, the determining the mapping between the one or more DMRS patterns and the subset of the CSI-RS resources further includes configuring one or more parameters for a same subset of CSI-RS resources for two or more DMRS patterns, at least one of the one or more parameters being different for different DMRS patterns. In some cases, the one or more parameters include one or more of a CSI-RS location, a CDM configuration for one or more antenna ports, a CSI-RS transmission size, or any combination thereof.

Configuration manager <NUM> may transmit DCI indicating one or more of the DMRS patterns based at least in part on the determined mapping, and configure one or more ZP CSI-RS resources at the UE independently of the DMRS patterns.

<FIG> shows a block diagram <NUM> of a base station communications manager <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. The base station communications manager <NUM> may be an example of aspects of a base station communications manager <NUM> described with reference to <FIG>, <FIG>, and <FIG>. The base station communications manager <NUM> may include reference signal manager <NUM>, mapping manager <NUM>, configuration manager <NUM>, control information manager <NUM>, and RRC component <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Reference signal manager <NUM> may identify a set of DMRS patterns for a UE and a set of available CSI-RS resources for the UE, transmit an indication of a first DMRS pattern for a first downlink transmission, transmit an indication of the first CSI-RS resource, and transmit one or more of a DMRS or CSI-RS based on the transmitted DCI and the determined mapping. In some cases, reference signal manager <NUM> may transmit a CSI-RS in a downlink transmission over the one or more CSI-RS resources mapped to a null DMRS pattern, and where a DMRS is not transmitted in the downlink transmission. In some cases, reference signal manager <NUM> may determine a configuration of the CSI-RS resources based on an associated DMRS pattern, and determine frequency resources of the CSI-RS resources based on associated DMRS frequency resources. In some cases, the set of DMRS patterns includes a null DMRS pattern mapped to one or more CSI-RS resources. In some cases, the set of DMRS patterns includes a set of null DMRS patterns that are configured at a set of UEs in a cell-specific configuration.

Control information manager <NUM> may configure and transmit control information to one or more UEs. In some cases, the indication of the first CSI-RS resource is transmitted dynamically in DCI associated with the first downlink transmission.

RRC component <NUM> may configure and transmit RRC signaling to one or more UEs. In some cases, the RRC component <NUM> may semi-statically transmit in RRC signaling configuration information including the set of DMRS patterns and the set of available CSI-RS resources.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of base station <NUM> as described above, e.g., with reference to <FIG>. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, network communications manager <NUM>, and inter-station communications manager <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more UEs <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting joint determination of demodulation and channel state information reference signals).

Inter-station communications manager <NUM> may manage communications with other base station <NUM>, and may include a controller or scheduler for controlling communications with UEs <NUM> in cooperation with other base stations <NUM>. In some examples, inter-station communications manager <NUM> may provide an X2 interface within an Long Term Evolution (LTE)/LTE-A wireless communication network technology to provide communication between base stations <NUM>.

<FIG> shows a flowchart illustrating a method <NUM> for joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a UE communications manager as described with reference to <FIG>. In some examples, a UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware.

At <NUM>, the UE <NUM> identifies a set of DMRS patterns for use at the UE and a set of available CSI-RS resources. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> may receive DCI indicating one or more of the DMRS patterns based at least in part on a mapping between one or more of the set of DMRS patterns and one or more of the set of available CSI-RS resources that are associated with the one or more DMRS patterns. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> receives one or more of a DMRS or CSI-RS based at least in part on the received DCI and the mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal receiver as described with reference to <FIG>.

At <NUM>, the UE <NUM> may identify a set of DMRS patterns for use at the UE and a set of available CSI-RS resources. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> may receive an indication of a first DMRS pattern for a first downlink transmission. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> may identify a first subset of CSI-RS resources that are mapped to the first DMRS pattern. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> may determine first CSI-RS resources associated with the first downlink transmission based at least in part on the first subset of CSI-RS resources. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the UE <NUM> may receive one or more of a DMRS or CSI-RS based at least in part on the received DCI and the mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal receiver as described with reference to <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for joint determination of demodulation and channel state information reference signals in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a base station <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a base station communications manager as described with reference to <FIG>. In some examples, a base station <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station <NUM> may perform aspects of the functions described below using special-purpose hardware.

At <NUM>, the base station <NUM> identifes a set of DMRS patterns for a UE and a set of available CSI-RS resources for the UE. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> determines a mapping between one or more of the DMRS patterns and one or more of the available CSI-RS resources. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> transmits DCI indicating one or more of the DMRS patterns based at least in part on the determined mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> transmits one or more of a DMRS or CSI-RS based at least in part on the transmitted DCI and the determined mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may identify a set of DMRS patterns for a UE and a set of available CSI-RS resources for the UE. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may determine a mapping between one or more of the DMRS patterns and one or more of the available CSI-RS resources. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may transmit DCI indicating one or more of the DMRS patterns based at least in part on the determined mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may transmit an indication of a first DMRS pattern for a first downlink transmission. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may identify a first subset of CSI-RS resources that are mapped to the first DMRS pattern. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may select a first CSI-RS resource based at least in part on the first subset of CSI-RS resources that are mapped to the first DMRS pattern. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a mapping manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may transmit an indication of the first CSI-RS resource. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

At <NUM>, the base station <NUM> may transmit one or more of a DMRS or CSI-RS based at least in part on the transmitted DCI and the determined mapping. The operations at <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations at <NUM> may be performed by a reference signal manager as described with reference to <FIG>.

Claim 1:
A method for wireless communication at a user equipment, comprising:
semi-statically receiving configuration information including a set of demodulation reference signal, DMRS, patterns and a set of channel state information reference signal, CSI-RS, resources, wherein the set of CSI-RS resources comprises at least one non-zero-power, NZP, resource;
identifying (<NUM>) the set of DMRS patterns, the set of CSI-RS resources, and a mapping between the set of DMRS patterns and the set of CSI-RS resources that are associated with the set of DMRS patterns;
receiving (<NUM>) downlink control information, DCI, indicating one or more DMRS patterns of the set of DMRS patterns;
determining, based at least in part on the mapping and the indicated one or more DMRS patterns, one or more CSI-RS resources of the set of CSI-RS resources; and
receiving (<NUM>) a DMRS and a CSI-RS based at least in part on the one or more DMRS patterns indicated by the received DCI and the determined one or more CSI-RS resources, wherein the resources selected for CSI-RS and DMRS transmissions do not overlap based on the mapping between the set of DMRS patterns and the set of CSI-RS resources.