Modulation table determination and channel quality indicator reporting

Methods, systems, and devices for wireless communications are described. One method may include a user equipment (UE) determining a capability of the UE for at least one modulation order associated with a first transmission time interval (TTI) and a second TTI that is shorter than the first TTI, transmitting a UE capability message based on determining the UE capability, receiving a message including a parameter and a modulation coding scheme (MCS) index based on the UE capability message, and selecting a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI.

BACKGROUND

The following relates generally to wireless communication, and more specifically to modulation table determination and channel quality indicator (CQI) reporting.

A base station may communicate with a UE to allocate resources for transmission during a transmission time interval (TTI). A portion of the resources (e.g., time and frequency resources) may be designated for transmission of this information (e.g. resource allocation) during the TTI. The base station may also use different communication channels to provide information to the UE. For example, the base station may use a control channel to transmit control information to the UE, and a data channel to transmit data to the UE. In some cases, the TTI may be a shortened TTI (sTTI). Improving the efficiency of transmission for one or more sTTIs may provide reliability for a wireless communications system.

SUMMARY

The described techniques relate to improved methods, systems, devices, or apparatuses that support modulation table determination and channel quality indicator (CQI) reporting. Generally, the described techniques provide for modulation table determination for shortened physical downlink control channel (sPDCCH), shortened physical uplink shared channel (sPUSCH), and sTTI CQI reporting. A UE may determine a capability of the UE for at least one modulation order associated with one or more TTIs, which may include one or more TTIs, one or more sTTIs, or both. The UE may transmit a UE capability message to a base station. In some cases, the UE may provide one or more capabilities associated with the one or more TTIs, including any sTTIs, in a single UE capability message.

Alternatively, the UE may transmit separate UE capability messages for a TTI and an sTTI, respectively. In some cases, the capability may indicate an order of modulation or an associated modulation scheme (which may in turn be part of a modulation and coding scheme (MCS)) supported by the UE for one or each of the one or more TTIs and/or the one or more sTTIs. The base station may receive the UE capability message and configure a parameter that may be a higher layer parameter. The parameter may indicate an applicability of a CQI table among multiple potential CQI tables that the UE may use to provide CQI information (e.g., feedback) to the base station. The base station may transmit a message including the parameter and an MCS index to the UE. In some cases, the parameter may be configured for each cell and for a subset or all subframes. The UE may receive and select a modulation table for communicating a transmission associated with the one or more TTIs (which may include one or more sTTIs), and provide CQI feedback to the base station by selecting a CQI table based on the configured parameter.

A method for wireless communication by a UE. The method may include determining a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; transmitting a UE capability message based at least in part on determining the UE capability; receiving a message comprising a parameter and a MCS index based at least in part on the UE capability message; and selecting a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based at least in part on receiving the message.

An apparatus for wireless communication is described. The apparatus may include means for determining a capability of the apparatus for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; means for transmitting a UE capability message based at least in part on determining the UE capability; means for receiving a message comprising a parameter and a MCS index based at least in part on the UE capability message; and means for selecting a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based at least in part on receiving the message.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to determine a capability of the apparatus for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; transmit a UE capability message based at least in part on determining the UE capability; receive a message comprising a parameter and a MCS index based at least in part on the UE capability message; and select a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based at least in part on receiving the message.

A non-transitory computer-readable medium for wireless communication at a UE is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; transmit a UE capability message based at least in part on determining the UE capability; receive a message comprising a parameter and a MCS index based at least in part on the UE capability message; and select a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based at least in part on receiving the message.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining whether the parameter is enabled or disabled, wherein selecting the modulation table is based at least in part on determining whether the parameter is enabled.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving the message via a sPDCCH. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message further comprises an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the configuration information comprises a transmission configuration for the first TTI and the second TTI, and the CQI reporting is based at least in part on the configuration information.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a downlink control information (DCI) format associated with the sPDCCH; and determining that a cyclic redundancy check (CRC) associated with the sPDCCH is scrambled with a cell radio network temporary identifier (C-RNTI) of the UE.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining that the DCI format is an acceptable DCI format from a list of DCI formats based at least in part on determining that the parameter is enabled; determining that the CRC is scrambled with the C-RNTI of the UE; and determining a modulation order in the modulation table based at least in part on the MCS index. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the modulation table is based at least in part on determining that the parameter is enabled, or the DCI format is the acceptable DCI format, or that the CRC is scrambled with the C-RNTI, or any combination thereof.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a modulation order in the selected modulation table based at least in part on the MCS index. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the modulation table is based at least in part on determining that the parameter is disabled.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the second TTI is a sTTI.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting a second UE capability information message separate from the UE capability message indicating capability of the UE for the second TTI.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message comprises UE capability for both the first TTI and the second TTI.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the second TTI comprises a plurality of sTTIs.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message is associated with the plurality of sTTIs.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting a UE capability message for at least some sTTIs of the plurality of sTTIs. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the parameter and the MCS index is associated with the plurality of sTTIs or each sTTI is associated with a separate parameter and MCS index.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, at least a subset of the sTTIs comprise variable lengths.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE is configured with a default modulation table for the transmission associated with the first TTI and the second TTI.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a DCI comprising an information element (IE) field for a modulation table indicator; and identifying the modulation table based at least in part on a bit value of the IE field. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the modulation table is based at least in part on the identifying.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for monitoring a downlink control channel for a message comprising a C-RNTI associated with the UE. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the modulation table is further based at least in part on the message comprising the C-RNTI.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a modulation order in the selected modulation table based at least in part on the MCS index; and selecting a CQI table based at least in part on a CQI reporting configuration.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the CQI reporting configuration associated with CQI reporting indicates that the CQI table applies to the first TTI or the second TTI, or both.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the parameter comprises an indication of UE capability for a 64QAM, a 256QAM, or a 1024QAM.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the transmission is a downlink transmission or an uplink transmission.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the modulation table for the uplink transmission based at least in part on the received MCS index; and determining a modulation order in the selected modulation table for the uplink transmission based at least in part on the MCS index and a DCI format associated with the received message.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining the modulation order for the uplink transmission based at least in part on semi-persistent scheduling or a random access response grant.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the parameter is a higher layer parameter.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting a second UE capability message separate from the UE capability message. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message is for uplink and the second UE capability message is for downlink.

A method for wireless communication by a base station. The method may include receiving a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; configuring a parameter associated with a modulation table based at least in part on the UE capability message; determining a MCS index based at least in part on the UE capability message; and transmitting a message comprising the parameter and the MCS index.

An apparatus for wireless communication is described. The apparatus may include means for receiving a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; means for configuring a parameter associated with a modulation table based at least in part on the UE capability message; means for determining a MCS index based at least in part on the UE capability message; and means for transmitting a message comprising the parameter and the MCS index.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; configure a parameter associated with a modulation table based at least in part on the UE capability message; determine a MCS index based at least in part on the UE capability message; and transmit a message comprising the parameter and the MCS index.

A non-transitory computer-readable medium for wireless communication at a base station is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to receive a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI; configure a parameter associated with a modulation table based at least in part on the UE capability message; determine a MCS index based at least in part on the UE capability message; and transmit a message comprising the parameter and the MCS index.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for enabling the parameter based at least in part on the UE capability message, wherein configuring the parameter comprises the enabling.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for disabling the parameter based at least in part on the UE capability message, wherein configuring the parameter comprises the disabling.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the message via a sPDCCH, wherein the message further comprises an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the configuration information comprises a transmission configuration for the first TTI and a second TTI, and the CQI reporting is based at least in part on the configuration information.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the second TTI is an sTTI.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a second UE capability information message separate from the UE capability message indicating capability for the second TTI.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message comprises UE capability for both the first TTI and the second TTI.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the second TTI comprises a plurality of sTTIs.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message is associated with the plurality of sTTIs.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a second UE capability message separate from the UE capability message. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the UE capability message is for uplink and the second UE capability message is for downlink.

DETAILED DESCRIPTION

A user equipment (UE) may determine a capability of the UE for at least one modulation order associated with one or more TTIs. The modulation order may be associated with a modulation coding scheme (MCS), and thus may be associated with modulation scheme such as a 64QAM, a 256QAM, or a 1024QAM, among other possibilities. In some cases, some of the TTIs may be sTTIs. For example, a first TTI may have a 1 ms duration, while a second TTI may be an sTTI that has a duration less than 1 ms (e.g., 0.5 ms). Because of characteristics and operations related to the sTTIs, other systems and operations related to modulation order and transport block size (TB S) index determination may be insufficient or may not account for variations and differences based on sTTIs. There is a need for devices to configure various communication aspects such as modulation order and TBS index determinations to facilitate communications between a first device (e.g., a UE) and a second device (e.g., a base station) based on TTIs, sTTIs, or both. Moreover, there is a need for devices to be able to determine aspects related to different modulation orders (e.g., higher modulation orders such as 1024QAM), such as which TBS table or other parameters should be used.

The UE may transmit a UE capability message to a base station. In some examples, the UE may transmit different UE capability messages for uplink and downlink. In some cases, the UE may provide one or more capabilities associated with the one or more TTIs, including any sTTIs, in a single UE capability message. Alternatively, the UE may transmit separate UE capability messages for a TTI and an sTTI. In the example of a first TTI and a second TTI being an sTTI, the UE may indicate UE capability associated with the first TTI in a first UE capability message and UE capability associated with the second TTI in a second UE capability message. Additionally, in the case that the UE is scheduled for one or more transmissions during a number of sTTIs, the UE may provide separate indications of UE capability for each of the sTTI. In some cases, the capability may indicate an MCS supported by the UE for one or each of the TTI and/or sTTI. Each TTI and sTTI may be associated with downlink communications or uplink communications, or both.

Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to modulation table determination and CQI reporting.

FIG. 1illustrates an example of a wireless communications system100that supports modulation table determination and CQI reporting in accordance with various aspects of the present disclosure. The system100includes base stations105, UEs115, and a core network130. In some examples, the system100may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, the system100may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

The geographic coverage area110for a base station105may be divided into sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, each base station105may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station105may be movable and therefore provide communication coverage for a moving geographic coverage area110.

In some examples, different geographic coverage areas110associated with different technologies may overlap, and overlapping geographic coverage areas110associated with different technologies may be supported by the same base station105or by different base stations105. The system100may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations105provide coverage for various geographic coverage areas110.

Some UEs115, such as MTC or IoT devices, may be low cost or low complexity devices, and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station105without human intervention.

In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. Some UEs115may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network130may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW).

The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs115served by base stations105associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to the network operators IP services. The operators IP services may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

The system100may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz multiple industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that can tolerate interference from other users. The system100may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the system100may support millimeter wave (mmW) communications between UEs115and base stations105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE115.

However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

In some examples, base station105or UE115may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, the system100may use a transmission scheme between a transmitting device (e.g., a base station105) and a receiving device (e.g., a UE115), where the transmitting device is equipped with multiple antennas and the receiving devices are equipped with one or more antennas.

MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station105or a UE115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device.

Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation).

In one example, a base station105may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station105multiple 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 station105or a receiving device, such as a UE115) a beam direction for subsequent transmission and/or reception by the base station105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station105in a single beam direction (e.g., a direction associated with the receiving device, such as a UE115). 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 UE115may receive one or more of the signals transmitted by the base station105in different directions, and the UE115may report to the base station105an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station105, a UE115may 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 UE115), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

Time intervals in LTE or NR may be expressed in multiples of a basic time unit, which may, for example, refer to a sampling period of Ts=1/30,720,000 seconds. Time intervals of a communications resource may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as Tf=307,200 Ts. The radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms.

A subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases a subframe may be the smallest scheduling unit of the system100, and may be referred to as a TTI. In other cases, a smallest scheduling unit of the system100may be shorter than a subframe or may be dynamically selected (e.g., in bursts of sTTIs or in selected component carriers using sTTIs).

A UE115may determine a capability for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The second TTI may be an sTTI. The UE115may transmit to a base station105a UE capability message based on determining the UE115capability. In some cases, the UE capability message may include UE115capability for both the first TTI and the second TTI. The base station105may receive the UE capability message and configure a parameter associated with a modulation table based on the UE capability message. The base station105may also determine an MCS index based on the UE capability message. In some cases, the parameter may be configured for each cell (e.g., different base stations105) and for a subset or all subframes associated with a transmission (e.g., downlink and/or uplink transmission).

Upon configuring the parameter and determining the MCS index, the base station105may transmit a message including the parameter and the MCS index to the UE115. The UE115may receive the message, and select a modulation table for communicating a transmission associated with the first TTI and the second TTI. The UE115may receive the message via an sPDCCH. The message may include an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof. The configuration information may include a transmission configuration for the first TTI and the second TTI, and the CQI reporting may be based in part on the configuration information.

The UE115may determine whether the parameter is enabled or disabled. In some cases, selecting the modulation table may be based in part on determining whether the parameter is enabled. The UE115may also determine a DCI format associated with the sPDCCH, and determine that a CRC associated with the sPDCCH is scrambled with a C-RNTI of the UE115. In some cases, the UE115may determine that the DCI format is an acceptable DCI format from a list of DCI formats based in part on determining that the parameter is enabled, and determine that the CRC is scrambled with the C-RNTI of the UE, and determine a modulation order in the modulation table based in part on the MCS index. In some cases, selecting the modulation table may be based in part on determining that the parameter is enabled, or the DCI format is the acceptable DCI format, or that the CRC is scrambled with the C-RNTI, or any combination thereof. The UE115may determine a modulation order in the selected modulation table based in part on the MCS index.

Devices of the system100(e.g., base stations105or UEs115) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the system100may include base stations105and/or UEs that can support simultaneous communications via carriers associated with more than one different carrier bandwidth. The system100may support communication with a UE115on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A UE115may be configured with multiple downlink CCs and one or more uplink CCs according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

In some cases, the system100may utilize enhanced component carriers (eCCs). An eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link).

An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs115that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power). In some cases, an eCC may utilize a different symbol duration than other CCs, which may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE115or base station105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67 microseconds). A TTI in eCC may consist of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable.

Wireless communications systems such as an NR system may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

FIG. 2illustrates an example of a wireless communications system200that supports modulation table determination and CQI reporting in accordance with various aspects of the present disclosure. In some examples, the wireless communications system200may implement aspects of the wireless communications system100. The wireless communications system200may include a base station205and a UE215, which may be examples of the corresponding devices described with reference toFIG. 1. In the example ofFIG. 2, the wireless communications system200may operate according to a radio access technology (RAT) such as a fourth generation (4G) LTE or LTE-A, although techniques described herein may be applied to any RAT and to wireless communications systems that may concurrently use two or more different RATs, for example, 4G LTE, LTE-A, and 5G NR.

The base station205may establish a connection (e.g., a bidirectional link220) with the UE215within a coverage area210. The base station205and the UE215may communicate one or more frames using the bidirectional link220. Each frame may include ten 1 ms subframes numbered from 0 to 9 (e.g., SF0through SF9). A subframe may be further divided into two 0.5 ms slots, each of which may contain 6 or 7 modulation symbol periods. In some cases, the subframe may be the smallest scheduling unit, also known as a TTI. In other cases, a TTI may be shorter than a subframe and may be referred to as an sTTI. For example, the base station205may communicate information (e.g., control information and data) during a TTI225or sTTI230, or both.

In some examples, the base station205and the UE215may establish the bidirectional link220by performing a connection procedure (e.g., a cell acquisition procedure, a random access channel (RACH) procedure, an RRC connection procedure, an RRC configuration procedure). In some cases, during the connection procedure the base station205may allocate resources (e.g., time and frequency resources) for the UE215. The resources may include a number of resource elements that span one modulation symbol period by one sub-carrier. Each resource element may carry two, four, or six physical channel bits depending on a modulation scheme (e.g., 16QAM, 64QAM). Additionally or alternatively, a higher order modulation scheme such as 1024QAM may be supported by the base station205and the UE215. The base station205may group resource elements into resource blocks (RBs), each RB may span 0.5 ms (i.e., one slot) by 180 kHz (i.e.,12sub-carriers). The base station205may use the RBs for frequency-dependent scheduling, by allocating modulation symbol periods and sub-carriers within each subframe in units of RBs.

The base station205may transmit a message including control information to the UE215via bidirectional link220. In an example, the message may be an RRC message, which the base station205may communicate to the UE215via RRC signaling. In another example, the base station205may transmit the control information in a DCI on a physical downlink control channel (PDCCH) or a sPDCCH. For example, for the TTI225the base station205may communicate a DCI on a PDCCH, while for the sTTI230-aor sTTI230-bthe base station205may communicate an sDCI on an sPDCCH. The base station205may use different formats to communicate different control information to the UE215. For example, a DCI format may include a DCI format 1, a DCI format 1B, a DCI format 1D, a DCI format 2, a DCI format 2A, a DCI format 2B, a DCI format 2C, and a DCI format 2D. An sDCI format may include an sDCI format 7-1B, an sDCI format 7-1C, an sDCI format 7-1D, an sDCI format 7-1E, an sDCI format 7-1F, and an sDCI format 7-1G. In some cases, the base station205may configure one or more sDCI formats for sTTI230, or modify preconfigured sDCI formats.

The message may be transmitted to the UE215during a portion of the TTI225or at least one of the sTTIs230, for example, during a control region. The control information in the message may indicate to the UE215forthcoming data transmission and information on how the data will be transmitted to the UE215, for example, configuration parameters such as an amount of data, allocated resources, CQI reporting configuration, and an MCS index. The base station205may transmit the message including the control information using a higher order modulation (e.g., 64QAM, 256QAM). A modulation scheme used by the base station205and the UE215may be static or dynamic. For example, the modulation scheme may vary across different sTTIs and/or TTIs based on channel conditions, etc.

The base station205may, in some cases, assign a unique C-RNTI to the UE215. Prior to transmitting control information to the UE215, the base station205may attach a CRC to the control information. For example, the base station205may append a CRC to an sDCI. In some examples, the CRC may be scrambled with a scramble bit sequence. The scramble bit sequence may include bits of the payload (e.g., an sDCI) and bits of an error detection code (e.g., one or more CRC bits). In some examples, the scrambling bit sequence may be different C-RNTIs. For example, the base station205may scramble the control information including the CRC using a C-RNTI scrambling bit sequence. The base station205may transmit the control information to the UE215on a downlink control channel (e.g., an sPDCCH).

The UE215may receive and demodulate control information received from the base station205. For example, the UE215may decode the control information to identify information included within e.g., upcoming data transmission on an sPDSCH and information on how the data will be transmitted. In some cases, upon receiving the control information, the UE215may perform a measurement (e.g., an SINR) to identify one or more metrics. The UE215may perform this measurement to identify a channel quality (e.g., of an sPDCCH transmission) related to the data channel. The UE215may determine a code rate for a subband of the downlink control channel (e.g., sPDCCH) based on the measurement. In some cases, the UE215may also determine an aggregation level based on the code rate. In other examples, the UE215may determine a CQI, a pre-coding matrix indicator (PMI), a precoding type indicator (PTI), or a rank indicator (RI) based on the measurement. In some examples, to determine the CQI the UE215may consult a CQI table, as described in further detail below. The UE215may generate and transmit channel quality feedback data (e.g., a CQI value) to the base station205.

The base station205may transmit data on a downlink physical channel such as an sPDSCH, which the UE215may be aware of (based on the received control information) and receive from the base station205. In some cases, the data may include one or two transport blocks, whose duration may span the TTI225or one or more of the sTTIs230. The UE215may receive the data and demodulate the transport blocks based on the MCS index and a modulation table (e.g., a modulation table that supports 64QAM, 256QAM, or 1024QAM). Additionally, the UE215may select a CQI index in a CQI table for reporting a CQI (or channel state information (CSI)) to the base station205. In some cases, the wireless communications system200may support multiple modulation tables used by the UE215to demodulate a transmission. A modulation table and a CQI table may be selected by the UE215based on UE capability.

In some cases, the UE215may determine a capability for supporting an MCS. For example, the UE215may determine whether it can support an MCS for one or more scheduled transmissions associated with a TTI or an sTTI. For example, the UE215may determine whether it can support a 64QAM or 256QAM for the TTI225and/or the sTTIs230. Additionally or alternatively, the UE215may be capable to support a higher MCS such as 1024QAM for a TTI or an sTTI. In some examples, the UE215may determine a capability for supporting an MCS for a transmission scheduled during an sTTI based on a length of the sTTI. For example, the UE215may determine that the sTTI230-ahas a length that supports a 256QAM, and that the sTTI230-bhas a length shorter than the sTTI230-aand supports a 64QAM. In some cases, the UE215may determine a capability for supporting an MCS for a transmission scheduled during an sTTI based on a length of the sTTI satisfying a threshold length.

The UE215may communicate, to the base station205, a UE capability message indicating the supported MCS. For example, the UE capability message may include an IE for indicating an MCS supported by the UE215. In addition, the UE capability message may be communicated to the base station205via RRC signaling. In some examples, a transmission scheduled and associated with an sTTI or a TTI may be for a downlink transmission or an uplink transmission, or both. The UE215may report UE capability associated with the sTTI or the TTI, separately or jointly. For example, the UE215may transmit a single UE capability message for the TTI225, the sTTI230-a, and the sTTI230-b.

Alternatively, the UE215may transmit separate UE capability message for sTTIs and TTIs. For example, the UE215may transmit a first UE capability message associated with the TTI225and a second UE capability message, different from the first UE capability message, associated with the sTTI230-aor the sTTI230-b. The UE215may transmit separate UE capability messages for different sTTIs (e.g., the sTTI230-aand the sTTI230-b). Alternatively, the UE215may transmit a combined UE capability message for multiple sTTIs (e.g., the sTTI230-aand the sTTI230-b), regardless of whether the sTTIs have a same or different length (e.g., duration). In some examples, the TTI225may be associated with downlink communications, and the sTTI230-aor the sTTI230-bmay be associated with uplink communications. Alternatively, the TTI225may be associated with uplink communications, and the sTTI230-aor the sTTI230-bmay be associated with downlink communications. In these examples, the UE215may transmit separate UE capability messages for downlink and uplink. The UE capability message may, in some examples, provide an indication of a modulation scheme supported by the UE215in downlink or uplink, or both. For example, a field in the UE capability message (e.g., dl-1024QAM-Slot-r15, dl-1024QAM-SubslotTA-r15, dl-1024QAM-SubslotTA-2-r15) may provide an indication that the UE215supports 1024QAM for downlink on a frequency spectrum band for slot TTI operation, or for subslot TTI operation. Additionally, or alternatively, a field in the UE capability message (e.g., ul-256QAM-Slot-r15, ul-256QAM-Subslot-r15) may provide an indication that the UE215support 256QAM for uplink on a frequency spectrum band for slot TTI operation or for subslot TTI operation, or both.

The UE215receive data on a downlink physical channel such as a PDSCH or an sPDSCH. The data may include one or two transport blocks, whose duration may span the TTI225or the sTTIs230. As part of receiving the data, the UE215may demodulate the transport blocks based on the MCS index and a modulation table (e.g., a modulation table the supports 64QAM or 256QAM). With reference to the example above relating to the control information, the base station205may transmit an MCS index based on the capability provided in the UE capability message. The base station205may also configure a higher layer parameter such as an RRC parameter (e.g., altCQI-Table-STTI-r15) based on the capability received in the UE capability message from the UE215. A higher layer parameter, such as an RRC parameter may be referred to as an altCQI-Table-STTI-15, altCQI-Table-1024QAM, tbsIndexAlt-STTI, tbsIndexAlt2-STTI, tbsIndexAlt3-STTI. Although an RRC parameter may be referred to by different terms (e.g., an altCQI-Table-STTI-15, tbsIndexAlt-STTI, tbslndexAlt2-STTI, tbsIndexAlt3-STTI), it should be understood that the different terms defining an RRC parameter may have same or similar functions and operations associated with it. In some cases, the parameter may be configured for each cell (e.g., a serving base station and neighboring base station) and for a subset or all subframes associated with a transmission (e.g., downlink and/or uplink transmission).

In some examples, the parameter may indicate an applicability of TBS index (or TBS table) that the UE215may use to provide CQI feedback to the base station205. For example, a higher layer parameter (e.g., tbsIndexAlt-STTI) may indicate an applicability of a TBS index for one or more slots subslots, sTTIs, TTIs scheduled by a first DCI format (e.g., a DCI format 7-1F, a DCI form 7-1G). Here, a TBS index may be 33 based in part on the configured higher layer parameter, for example. In some examples, a higher layer parameter (e.g., tbsIndexAlt2-STTI) may indicate an applicability of a TBS index for one or more slots subslots, sTTIs, TTIs scheduled by a second DCI format (e.g., a DCI format 7-1B, a DCI format 7-1C, a DCI form 7-1D). Here, a TBS index may be 33/B based in part on the configured higher layer parameter, for example. In other examples, a higher layer parameter (e.g., tbsIndexAlt3-STTI) may indicate an applicability of a TBS index for one or more slots subslots, sTTIs, TTIs scheduled by a third DCI format (e.g., a DCI format 7-1B, a DCI format 7-1C, a DCI form 7-1D). Here, a TBS index may be 37A//B based in part on the configured higher layer parameter, for example The TBS index may be part of a CQI table. In some examples, if the higher layer parameter is not configured, the UE215may use a default TBS (e.g., preconfigured TBS).

The parameter may indicate an applicability of a CQI table that the UE215may use to provide CQI feedback to the base station205. In addition, the parameter may include the applicability of the CQI table for both aperiodic and periodic CSI reporting for the UE215(and the concerned serving cell associated with the base station205). The higher layer parameter may additionally, or alternatively, include a modulation table indicator that may indicate a modulation table (e.g., supporting up to 64QAM, 256QAM, or 1024QAM) for the UE215to use in demodulating a transmission from the base station205, or modulating a transmission to the base station205during the TTI225and/or at least one of the sTTI230. In some cases, the base station205may configure the higher layer parameter based on the UE capability (i.e., information for supporting a particular MCS) provided by the UE215. The base station205may configure the higher layer parameter separately or jointly. For example, the base station205may configure a higher layer parameter for the TTI225and the sTTIs230mutually, or separately for the TTI225and each of the sTTIs230.

The higher layer parameter may also be configured with at least one sub-parameter from a set of sub-parameters by the base station205. For example, the set of sub-parameters may include {allSubframes, csi-SubframesSet1, csi-SubframeSet2, spare1}. The UE215may select a CQI table, subsequently to selecting a modulation table, based on the sub-parameter assigned. In some cases, the sub-parameter may be configured for different sTTIs such as the sTTI230-aand the sTTI230-b. That is, a same configuration may apply for both sTTIs230, or a first configuration may apply to the sTTI230-aand a second configuration may apply to the sTTI230-bbased on the sub-parameter for the CQI configuration.

For example, the configured parameter may include a set of sub-parameters for configuring the CQI feedback. The set may include {allSubframes, csi-SubframeSet1, csi-SubframeSet2, spare1}. The UE215may provide aperiodic or periodic CQI reporting for the base station205based on at least one of the sub-parameters of the set. The sub-parameter may be configured by the base station205. In an example, if the sub-parameter is set to allSubframes, the CQI table may apply to all subframes (or sTTIs, TTIs). Alternatively, if the sub-parameter is set to csi-SubframeSet1, the CQI table may apply to CSI subframe set 1, or if the sub-parameter is set to csi-SubframeSet2, the CQI table may apply to SSI subframe set 2.

In some cases, the UE215may select a CQI table for CQI reporting based on the UE capability supporting a particular MCS, and determining that the higher layer parameter is configured, and that the sDCI format is an acceptable DCI format from a list of DCI formats. For example, selection of the CQI table may be based on the UE215determining that an sPDSCH is assigned by a sPDCCH with a specific sDCI format (e.g., an sDCI format 7-1B, an sDCI format 7-1C, an sDCI format 7-1D, an sDCI format 7-1E, an sDCI format 7-1F, and/or an sDCI format 7-1G), and that the sPDCCH is scrambled with a C-RNTI. The base station205may scramble the sDCI including a CRC using a C-RNTI scrambling bit sequence.

As such, selection of a modulation table for a transmission associated with an sTTI may be based on determining that the higher layer parameter is configured (e.g., enabled), or that the DCI format is an acceptable DCI format, or that the CRC is scrambled with the C-RNTI, or any combination thereof. The UE215may be configured with a default modulation table for the transmission associated the TTI225and/or the sTTIs230. Alternatively, the UE215may select a modulation table based on a modulation table indicator provided in an IE field carried in a DCI or sDCI. For example, the UE215may identify the modulation table based on a bit value of the IE field.

In some examples, the UE215may select a first CQI table (e.g., supporting up to 256QAM) to transmit CQI reporting, based on determining that the higher layer parameter is configured and is set to allSubframes. For example, if at least one sub-parameter (e.g., allSubframes) from a set of sub-parameters of a higher layer parameter (e.g., altCQI-TableSTTI-r15) is configured/set, and when aperiodic CSI is triggered based in part on a specific DCI format (e.g., DCI format 7-0A or 7-0B), the UE215may select an appropriate CQI table for CQI reporting. Alternatively, if at least one sub-parameter (e.g., allSubframes) from a set of sub-parameters of the higher layer parameter (e.g., altCQI-Table 1024QAM-STTI-r15) is configured/set, and when aperiodic CSI is triggered based in part on a specific DCI format (e.g., DCI format 7-0A or 7-0B), the UE215may select a different CQI table for CQI reporting

Alternatively, the UE215may select the first CQI table based on the higher layer parameter being configured and set to csi-SubframeSet1 or csi-SubframeSet2. In this case, the UE215may transmit CQI reporting according to the first CQI table and corresponding to the subframes configured by the higher layer parameter (e.g., csi-SubframeSet1 or csi-SubframeSet2), or the UE215may transmit the CQI reporting according to a second CQI table (e.g., supporting up to 64QAM) for the other set (i.e., csi-SubframeSet1 or csi-SubframeSet2). For example, if at least one sub-parameter (e.g., csi-SubframeSet1 or csi-SubframeSet2) from a set of sub-parameters of a higher layer parameter (e.g., altCQI-TableSTTI-r15) is configured/set, and when aperiodic CSI is triggered based in part on a DCI format (e.g., DCI format 7-0A or 7-0B), the UE215may select an appropriate CQI table for CQI reporting for corresponding CSI subframes configured by the higher layer parameter (e.g., altCQI-TableSTTI-r15). Alternatively, if at least one sub-parameter (e.g., csi-SubframeSet1 or csi-SubframeSet2) from a set of sub-parameters of a higher layer parameter (e.g., altCQI-Table 1024QAM-STTI-r15) is configured/set, and when aperiodic CSI is triggered based in part on a DCI format (e.g., DCI format 7-0A or 7-0B), the UE215may select an appropriate CQI table for CQI reporting for corresponding CSI subframes configured by the higher layer parameter (e.g., altCQI-Table1024QAM-STTI-r15). In this example, the UE215may report CQI for the other CSI subframe set according to a different CQI table.

In some examples, the UE215may select an appropriate CQI table for CQI reporting for corresponding CSI subframes configured by the higher layer parameter without basing the selection on a DCI format. For example, if at least one sub-parameter (e.g., allSubframes) from a set of sub-parameters of a higher layer parameter (e.g., altCQI-Table-r12) is configured/set, the UE215may select an appropriate CQI table for CQI reporting for corresponding CSI subframes configured by the higher layer parameter (e.g., altCQI-Table-r12). In other examples, if at least one sub-parameter (e.g., allSubframes) from a set of sub-parameters of a higher layer parameter (e.g., altCQI-Table-1024QAM-r15) is configured/set, the UE215may select an appropriate CQI table for CQI reporting for corresponding CSI subframes configured by the higher layer parameter (e.g., altCQI-Table-r12).

In some cases, if the UE215determines that the higher layer parameter is not configured (e.g., disabled), the UE215may be configured to transmit CQI reporting according to a default CQI table (e.g., a CQI table supporting up to 64QAM). The base station205may receive CQI reporting from the UE215, and is some cases adjust an MCS for the UE215based on the CQI reporting

The UE215may select a modulation table for uplink communication (e.g., modulating or demodulation transport blocks) to the base station205, a transmission associated with the TTI225and/or the sTTIs230based on the higher layer parameter and the determined capability of the UE215. For example, the UE215may select a modulation table that supports 256QAM based at least in part on a UE capability and the higher layer parameter being configured (e.g., enabled or disabled). The UE215may determine a modulation order in the selected modulation table based on the received MCS index. Alternatively, the UE215may select a modulation table that supports 64QAM, to determine a modulation order used for demodulation transport blocks in the PDSCH, based on determining that a sDCI format is an unacceptable format, and that a sDCI is not scrambled with a C-RNTI.

The UE215may also transmit uplink data to the base station205including uplink control information (UCI) on a sPUSCH or PUSCH. In some cases, the UE215may provide other various control signaling on a PUCCH such as, scheduling requests, downlink data acknowledgment and non-acknowledgment (ACK/NACK) (e.g., Hybrid ARQ (HARD) feedback), and a CQI. In some examples, the feedback may be an ACK if the UE215determined data intended for it on the PDSCH and the UE215did not detect any transmission error on the PDSCH data. Alternatively, the UE215may transmit a NACK if the UE215recognized data intended for it on the PDSCH, but the UE215detected some transmission error on the PDSCH data.

The UE215may also determine a modulation order for an uplink transmission associated with the TTI225and/or the sTTIs230. The modulation order for the uplink transmission may be determined in a modulation table selected based on a UE capability (e.g., whether the UE215supports 64QAM or 256QAM), a transport block transmission (e.g., whether a transport block was initially transmitted with a grant according to a new or preconfigured DCI format (e.g., an sDCI format 7-1B, an sDCI format 7-1C, an sDCI format 7-1D, an sDCI format 7-1E, an sDCI format 7-1F, and/or an sDCI format 7-1G, or a DCI format 0/4)), or a PUSCH transmission (e.g., whether the PUSCH transmission is initiated by a grant received during a RACH procedure), or any combination thereof. In some cases, the UE215may determine a modulation order based on a recent semi-persistent scheduling assignment received (e.g. in a PDCCH or an enhanced ePDCCH), when an initial PUSCH for a same transport block is semi-persistently scheduled. The UE215may alternatively, determine a modulation order based on a RACH response grant for the same transport block, when the PUSCH is initiated by the RACH response grant.

FIG. 3illustrates an example of a process flow300that supports modulation table determination and CQI reporting in accordance with various aspects of the present disclosure. In some examples, process flow300may implement aspects of the wireless communications systems100and200. The operations of the process flow300may be implemented by a UE or a base station or its components as described herein. For example, the operations of the process flow300may be implemented by a base station305and a UE315. In some examples, the base station305and the UE315may execute a set of codes to control the functional elements of the base station305and the UE315. The base station305and the UE315may be examples of the corresponding devices described with reference toFIGS. 1 and 2.

In the following description of the process flow300, the operations between the base station305and the UE315may be transmitted in a different order than the exemplary order shown, or the operations performed by the base station305and the UE315may be performed in different orders or at different times. Certain operations may also be left out of the process flow300, or other operations may be added to the process flow300.

In some examples, the process flow300may commence with the base station305establishing a connection with the UE315(e.g., performing a cell acquisition procedure, random access procedure, RRC connection procedure, RRC configuration procedure).

At325, the UE315may determine a capability of the UE315for at least one modulation order associated with one or more TTIs. The modulation order may be associated with an MCS such as 64QAM, a 256QAM, or a 1024QAM. In some cases, some of the TTIs may be sTTIs. For example, a first TTI may have a 1 ms duration while a second TTI may be an sTTI that has a duration less than 1 ms (e.g., 0.5 ms). After the UE315determines the capability, the UE315may generate a UE capability message indicating the capability of the UE315.

At330, the UE315may transmit the UE capability message to the base station305. In some examples, the UE capability message may be for downlink or uplink, or both. In some cases, the UE315may provide capability associated with the one or more TTIs including any sTTIs in a single UE capability message. Alternatively, the UE315may transmit separate UE capability messages for a TTI and an sTTI. In the example of a first TTI and a second TTI being an sTTI, the UE315may indicate UE capability associated with the first TTI in a first UE capability message and UE capability associated with the second TTI in a second UE capability message. Additionally, in the case that the UE315is scheduled for one or more transmissions during a number of sTTIs, the UE315may provide separate indications of UE capability for each of the sTTI. In some cases, the capability may indicate an MCS supported by the UE for one or each of the TTI and/or sTTI.

At335, the base station305may configure a parameter associated with a modulation order based on the UE capability message. In some cases, the parameter may be a higher layer parameter (e.g., altCQI-Table-STTI-r15). The parameter may indicate an applicability of a CQI table that the UE315may use to provide CQI feedback to the base station305. In addition, the parameter may include the applicability of the CQI table for both aperiodic and periodic CSI reporting for the UE315. In some cases, configuring the parameter may include enabling or disabling a field in a configuration message. For example, the parameter may be part of an RRC configuration message. The base station305may enable or disable the parameter via a bit value. As such, based on the bit value the UE315may be capable to determine if the parameter is configured.

At340, the base station305may determine an MCS index based on information provided in the UE capability message, for example, such as current channel conditions, a supporting MCS. At345, the base station305may transmit a configuration message. The configuration message may, for example, include the parameter and the MCS index.

At350, the UE315may select a modulation table for communicating a transmission associated with the one or more TTIs. The UE315may determine a modulation order in the selected modulation table based on the MCS index. Additionally, the UE315may provide CQI feedback to the base station305by selecting a CQI table based on the configured parameter. For example, the configured parameter may include a set of sub-parameters for configuring the CQI feedback. The set may include {allSubframes, csi-SubframeSet1, csi-SubframeSet2, spare1}. The UE315may provide aperiodic or periodic CQI reporting for the base station305based on at least one of the sub-parameters of the set. The sub-parameter may be configured by the base station305. In an example, if the sub-parameter is set to allSubframes, the CQI table may apply to all subframes (or sTTIs, TTIs). Alternatively, if the sub-parameter is set to csi-SubframeSet1, the CQI table may apply to CSI subframe set 1, or if the sub-parameter is set to csi-SubframeSet2, the CQI table may apply to SSI subframe set 2. In some cases, the applicability of the CQI table may be based on the UE capability (e.g., whether the UE315supports a certain MCS), whether the parameter is configured (e.g., enabled or disabled), and/or based on a DCI format used to schedule the transmission (e.g., a sPDSCH) associated with the one or more sTTIs and/or TTIs. As such, the UE315may communicate the transmission associated with the one or more TTIs including CQI feedback using the communication link355.

FIG. 4shows a block diagram400of a wireless device405that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Wireless device405may be an example of aspects of a UE115as described herein. Wireless device405may include receiver410, UE communications manager415, and transmitter420. Wireless device405may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver410may 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 modulation table determination and CQI reporting, etc.). Information may be passed on to other components of the device. The receiver410may be an example of aspects of the transceiver735described with reference toFIG. 7. The receiver410may utilize a single antenna or a set of antennas.

Receiver410may receive a message including a parameter and an MCS index based on the UE capability message and receive the message via a sPDCCH. In some cases, the message may also include an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof. In some cases, the configuration information includes a transmission configuration for the first TTI and the second TTI, and the CQI reporting is based on the configuration information. In some cases, the parameter includes an indication of UE capability for a 64QAM, a 256QAM, or a 1024QAM. In some cases, the parameter is a higher layer parameter.

UE communications manager415may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI and select a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based on receiving the message.

Transmitter420may transmit signals generated by other components of the device. In some examples, the transmitter420may be collocated with a receiver410in a transceiver module. For example, the transmitter420may be an example of aspects of the transceiver735described with reference toFIG. 7. The transmitter420may utilize a single antenna or a set of antennas.

Transmitter420may transmit a UE capability message based on determining the UE capability. The transmitter420may transmit a second UE capability information message separate from the UE capability message indicating capability of the UE for the second TTI. The transmitter420may transmit a UE capability message for at least some sTTIs of the set of sTTIs. The parameter and the MCS index may be associated with the set of sTTIs or each sTTI is associated with a separate parameter and MCS index. In some cases, the UE capability message is associated with the set of sTTIs. In some examples, the transmitter420may transmit a second UE capability message separate from the UE capability message. In some examples, the UE capability message may be for uplink and the second UE capability message may be for downlink, or vice versa.

FIG. 5shows a block diagram500of a wireless device505that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Wireless device505may be an example of aspects of a wireless device405or a UE115as described with reference toFIG. 4. Wireless device505may include receiver510, UE communications manager515, and transmitter520. Wireless device505may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver510may 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 modulation table determination and CQI reporting, etc.). Information may be passed on to other components of the device. The receiver510may be an example of aspects of the transceiver735described with reference toFIG. 7. The receiver510may utilize a single antenna or a set of antennas.

UE communications manager515may be an example of aspects of the UE communications manager715described with reference toFIG. 7. UE communications manager515may also include capability component525and selection component530.

The capability component525may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. In some cases, the second TTI is an sTTI. In some cases, the UE capability message includes UE capability for both the first TTI and the second TTI. In some cases, the second TTI includes a set of sTTIs. In some cases, at least a subset of the sTTIs include variable lengths.

The selection component530may select a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based on receiving the message. The selection component530may determine whether the parameter is enabled or disabled. In some examples, selecting the modulation table is based on determining whether the parameter is enabled. The selection component530may identify the modulation table based on a bit value of the IE field. In some examples, selecting the modulation table is based on the identifying.

The selection component530may monitor a downlink control channel for a message including a C-RNTI associated with the UE. In some examples, selecting the modulation table is further based on the message including the C-RNTI. The selection component530may select the modulation table for the uplink transmission based on the received MCS index. In some cases, the UE is configured with a default modulation table for the transmission associated with the first TTI and the second TTI. In some cases, the transmission is a downlink transmission or an uplink transmission.

Transmitter520may transmit signals generated by other components of the device. In some examples, the transmitter520may be collocated with a receiver510in a transceiver module. For example, the transmitter520may be an example of aspects of the transceiver735described with reference toFIG. 7. The transmitter520may utilize a single antenna or a set of antennas.

FIG. 6shows a block diagram600of a UE communications manager615that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. The UE communications manager615may be an example of aspects of a UE communications manager415, a UE communications manager515, or a UE communications manager715described with reference toFIGS. 4, 5, and 7. The UE communications manager615may include capability component620, selection component625, DCI format component630, CRC component635, modulation order component640, DCI component645, and CQI component650. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Capability component620may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. In some cases, the second TTI is an sTTI. In some cases, the UE capability message includes UE capability for both the first TTI and the second TTI. In some cases, the second TTI includes a number of sTTIs. In some cases, at least a subset of the sTTIs may be variable lengths.

Selection component625may select a modulation table for communicating, to a base station, a transmission associated with the first TTI and the second TTI based on receiving the message. The selection component625may determine whether the parameter is enabled or disabled. In some examples, selecting the modulation table is based on determining whether the parameter is enabled. The selection component625may identify the modulation table based on a bit value of the IE field. In some examples, selecting the modulation table is based on the identifying. The selection component625may monitor a downlink control channel for a message including a C-RNTI associated with the UE. In some examples, selecting the modulation table is further based on the message including the C-RNTI. The selection component625may select the modulation table for the uplink transmission based on the received MCS index. In some cases, the UE is configured with a default modulation table for the transmission associated with the first TTI and the second TTI. In some cases, the transmission is a downlink transmission or an uplink transmission.

DCI format component630may determine a DCI format associated with the sPDCCH and determine that the DCI format is an acceptable DCI format from a list of DCI formats based on determining that the parameter is enabled. CRC component635may determine that a CRC associated with the sPDCCH is scrambled with a C-RNTI of the UE and determine that the CRC is scrambled with the C-RNTI of the UE.

Modulation order component640may determine a modulation order in the modulation table based on the MCS index. In some examples, selecting the modulation table is based on determining that the parameter is enabled, or the DCI format is the acceptable DCI format, or that the CRC is scrambled with the C-RNTI, or any combination thereof. The modulation order component640may determine a modulation order in the selected modulation table based on the MCS index. In some examples, selecting the modulation table is based on determining that the parameter is disabled. The modulation order component640may determine a modulation order in the selected modulation table based on the MCS index. The modulation order component640may determine a modulation order in the selected modulation table for the uplink transmission based on the MCS index and a DCI format associated with the received message. The modulation order component640may determine the modulation order for the uplink transmission based on semi-persistent scheduling or a random access response grant.

DCI component645may receive a DCI including an IE field for a modulation table indicator. CQI component650may select a CQI table based on a CQI reporting configuration. In some cases, the CQI reporting configuration associated with CQI reporting indicates that the CQI table applies to the first TTI or the second TTI, or both.

FIG. 7shows a diagram of a system700including a device705that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Device705may be an example of or include the components of wireless device405, wireless device505, or a UE115as described above, e.g., with reference toFIGS. 4 and 5. Device705may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager715, processor720, memory725, software730, transceiver735, antenna740, and I/O controller745. These components may be in electronic communication via one or more buses (e.g., bus710). Device705may communicate wirelessly with one or more base stations105.

Memory725may include random access memory (RAM) and read only memory (ROM). The memory725may store computer-readable, computer-executable software730including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory725may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software730may include code to implement aspects of the present disclosure, including code to support modulation table determination and CQI reporting. Software730may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software730may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

I/O controller745may manage input and output signals for device705. I/O controller745may also manage peripherals not integrated into device705. In some cases, I/O controller745may represent a physical connection or port to an external peripheral. In some cases, I/O controller745may utilize an operating system such as iOS, ANDROID, MS-DOS, MS-WINDOWS, OS/2, UNIX, LINUX, or another known operating system. In other cases, I/O controller745may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller745may be implemented as part of a processor. In some cases, a user may interact with device705via I/O controller745or via hardware components controlled by I/O controller745.

FIG. 8shows a block diagram800of a wireless device805that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Wireless device805may be an example of aspects of a base station105as described herein. Wireless device805may include receiver810, base station communications manager815, and transmitter820. Wireless device805may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver810may receive a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The receiver810may receive a second UE capability information message separate from the UE capability message indicating capability for the second TTI. In some cases, the second TTI is an sTTI. In some cases, the UE capability message includes UE capability for both the first TTI and the second TTI. In some cases, the second TTI includes a set of sTTIs. In some cases, the UE capability message is associated with the set of sTTIs. In some examples, the receiver810may receive a second UE capability message separate from the UE capability message. In some examples, the UE capability message may be for uplink and the second UE capability message may be for downlink, or vice versa.

Base station communications manager815may configure a parameter associated with a modulation table based on the UE capability message and determine an MCS index based on the UE capability message.

Transmitter820may transmit signals generated by other components of the device. In some examples, the transmitter820may be collocated with a receiver810in a transceiver module. For example, the transmitter820may be an example of aspects of the transceiver1035described with reference toFIG. 10. The transmitter820may utilize a single antenna or a set of antennas.

Transmitter820may transmit a message including the parameter and the MCS index and transmit the message via a sPDCCH. In some cases, the message further includes an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof. In some cases, the configuration information includes a transmission configuration for the first TTI and a second TTI, and the CQI reporting is based on the configuration information.

FIG. 9shows a block diagram900of a wireless device905that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Wireless device905may be an example of aspects of a wireless device805or a base station105as described with reference toFIG. 8. Wireless device905may include receiver910, base station communications manager915, and transmitter920. Wireless device905may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver910may 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 modulation table determination and CQI reporting, etc.). Information may be passed on to other components of the device. The receiver910may be an example of aspects of the transceiver1035described with reference toFIG. 10. The receiver910may utilize a single antenna or a set of antennas.

Base station communications manager915may be an example of aspects of the base station communications manager1015described with reference toFIG. 10. Base station communications manager915may also include configuration component925and MCS component930.

Configuration component925may configure a parameter associated with a modulation table based on the UE capability message. The configuration component925may enable the parameter based on the UE capability message. In some examples, configuring the parameter includes enabling or disabling the parameter based on the UE capability message. MCS component930may determine an MCS index based on the UE capability message.

Transmitter920may transmit signals generated by other components of the device. In some examples, the transmitter920may be collocated with a receiver910in a transceiver module. For example, the transmitter920may be an example of aspects of the transceiver1035described with reference toFIG. 10. The transmitter920may utilize a single antenna or a set of antennas.

FIG. 10shows a diagram of a system1000including a device1005that supports modulation table determination and CQI reporting in accordance with aspects of the present disclosure. Device1005may be an example of or include the components of base station105as described above, e.g., with reference toFIG. 1. Device1005may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager1015, processor1020, memory1025, software1030, transceiver1035, antenna1040, network communications manager1045, and inter-station communications manager1050. These components may be in electronic communication via one or more buses (e.g., bus1010). Device1005may communicate wirelessly with one or more UEs115.

Memory1025may include RAM and ROM. The memory1025may store computer-readable, computer-executable software1030including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1025may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

At1105the UE115may determine a capability of the UE115for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1105may be performed according to the methods described herein. In certain examples, aspects of the operations of1105may be performed by a capability component as described with reference toFIGS. 4 through 7.

At1110the UE115may transmit a UE capability message based on determining the UE capability. The operations of1110may be performed according to the methods described herein. In certain examples, aspects of the operations of1110may be performed by a transmitter as described with reference toFIGS. 4 through 7.

At1115the UE115may receive a message including a parameter and an MCS index based on the UE capability message. In some examples, the parameter may be a higher layer parameter. The operations of1115may be performed according to the methods described herein. In certain examples, aspects of the operations of1115may be performed by a receiver as described with reference toFIGS. 4 through 7.

At1120the UE115may select a modulation table for communicating, to a base station105, a transmission associated with the first TTI and the second TTI based on receiving the message. The operations of1120may be performed according to the methods described herein. In certain examples, aspects of the operations of1120may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1205the UE115may determine a capability of the UE115for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1205may be performed according to the methods described herein. In certain examples, aspects of the operations of1205may be performed by a capability component as described with reference toFIGS. 4 through 7.

At1210the UE115may transmit a UE capability message based on determining the UE capability. The operations of1210may be performed according to the methods described herein. In certain examples, aspects of the operations of1210may be performed by a transmitter as described with reference toFIGS. 4 through 7.

At1215the UE115may receive a message via sPDCCH including a parameter and an MCS index based on the UE capability message. In some examples, the message further include an allocation of resources, or configuration information for one or more physical channels, or CQI reporting, or any combination thereof. The operations of1215may be performed according to the methods described herein. In certain examples, aspects of the operations of1215may be performed by a receiver as described with reference toFIGS. 4 through 7.

At1220the UE115may determine a DCI format associated with the sPDCCH. The operations of1220may be performed according to the methods described herein. In certain examples, aspects of the operations of1220may be performed by a DCI format component as described with reference toFIGS. 4 through 7.

At1225the UE115may determine that a CRC associated with the sPDCCH is scrambled with a C-RNTI of the UE115. The operations of1225may be performed according to the methods described herein. In certain examples, aspects of the operations of1225may be performed by a CRC component as described with reference toFIGS. 4 through 7.

At1230the UE115may determine that the DCI format is an acceptable DCI format from a list of DCI formats based on determining that the parameter is enabled. The operations of1230may be performed according to the methods described herein. In certain examples, aspects of the operations of1230may be performed by a DCI format component as described with reference toFIGS. 4 through 7.

At1235the UE115may select a modulation table for communicating, to a base station105, a transmission associated with the first TTI and the second TTI based on determining that the parameter is enabled, or the DCI format is the acceptable DCI format, or that the CRC is scrambled with the C-RNTI, or any combination thereof. The operations of1235may be performed according to the methods described herein. In certain examples, aspects of the operations of1235may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1305the UE115may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1305may be performed according to the methods described herein. In certain examples, aspects of the operations of1305may be performed by a capability component as described with reference toFIGS. 4 through 7.

At1310the UE115may transmit a UE capability message based on determining the UE capability. The operations of1310may be performed according to the methods described herein. In certain examples, aspects of the operations of1310may be performed by a transmitter as described with reference toFIGS. 4 through 7.

At1315the UE115may receive a message including a parameter and an MCS index based on the UE capability message. In some examples, the parameter may be a higher layer parameter (e.g., RRC configuration parameter). The operations of1315may be performed according to the methods described herein. In certain examples, aspects of the operations of1315may be performed by a receiver as described with reference toFIGS. 4 through 7.

At1320the UE115may receive a DCI including an IE field for a modulation table indicator. The operations of1320may be performed according to the methods described herein. In certain examples, aspects of the operations of1320may be performed by a DCI component as described with reference toFIGS. 4 through 7.

At1325the UE115may identify the modulation table based on a bit value of the IE field. The operations of1325may be performed according to the methods described herein. In certain examples, aspects of the operations of1325may be performed by a selection component as described with reference toFIGS. 4 through 7

At1330the UE115may select a modulation table for communicating, to a base station105, a transmission associated with the first TTI and the second TTI based on the identifying. The operations of1330may be performed according to the methods described herein. In certain examples, aspects of the operations of1330may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1405the UE115may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1405may be performed according to the methods described herein. In certain examples, aspects of the operations of1405may be performed by a capability component as described with reference toFIGS. 4 through 7.

At1410the UE115may transmit a UE capability message based on determining the UE capability. The operations of1410may be performed according to the methods described herein. In certain examples, aspects of the operations of1410may be performed by a transmitter as described with reference toFIGS. 4 through 7.

At1415the UE115may receive a message including a parameter and an MCS index based at least in part on the UE capability message. In some examples, the parameter may be a higher layer parameter. The operations of1415may be performed according to the methods described herein. In certain examples, aspects of the operations of1415may be performed by a receiver as described with reference toFIGS. 4 through 7.

At1420the UE115may monitor a downlink control channel for a message including a C-RNTI associated with the UE115. The operations of1420may be performed according to the methods described herein. In certain examples, aspects of the operations of1420may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1425the UE115may select a modulation table for communicating, to a base station105, a transmission associated with the first TTI and the second TTI based on the message including the C-RNTI. The operations of1425may be performed according to the methods described herein. In certain examples, aspects of the operations of1425may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1505the UE115may determine a capability of the UE for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1505may be performed according to the methods described herein. In certain examples, aspects of the operations of1505may be performed by a capability component as described with reference toFIGS. 4 through 7.

At1510the UE115may transmit a UE capability message based on determining the UE capability. The operations of1510may be performed according to the methods described herein. In certain examples, aspects of the operations of1510may be performed by a transmitter as described with reference toFIGS. 4 through 7.

At1515the UE115may receive a message including a parameter and an MCS index based on the UE capability message. In some examples, the parameter may be a higher layer parameter. The operations of1515may be performed according to the methods described herein. In certain examples, aspects of the operations of1515may be performed by a receiver as described with reference toFIGS. 4 through 7.

At1520the UE115may select a modulation table for communicating, to a base station105, a transmission associated with the first TTI and the second TTI based on receiving the message. The operations of1520may be performed according to the methods described herein. In certain examples, aspects of the operations of1520may be performed by a selection component as described with reference toFIGS. 4 through 7.

At1525the UE115may determine a modulation order in the selected modulation table based on the MCS index. The operations of1525may be performed according to the methods described herein. In certain examples, aspects of the operations of1525may be performed by a modulation order component as described with reference toFIGS. 4 through 7.

At1530the UE115may select a CQI table based on a CQI reporting configuration. The operations of1530may be performed according to the methods described herein. In certain examples, aspects of the operations of1530may be performed by a CQI component as described with reference toFIGS. 4 through 7.

At1605the base station105may receive a UE capability message for at least one modulation order associated with a first TTI and a second TTI that is shorter than the first TTI. The operations of1605may be performed according to the methods described herein. In certain examples, aspects of the operations of1605may be performed by a receiver as described with reference toFIGS. 8 through 10.

At1610the base station105may configure a parameter associated with a modulation table based on the UE capability message. In some examples, the parameter may be a higher layer parameter. For example, the parameter may be an RRC configuration parameter. The operations of1610may be performed according to the methods described herein. In certain examples, aspects of the operations of1610may be performed by a configuration component as described with reference toFIGS. 8 through 10.

At1615the base station105may determine an MCS index based on the UE capability message. The operations of1615may be performed according to the methods described herein. In certain examples, aspects of the operations of1615may be performed by an MCS component as described with reference toFIGS. 8 through 10.

At1620the base station105may transmit a message including the parameter and the MCS index. The operations of1620may be performed according to the methods described herein. In certain examples, aspects of the operations of1620may be performed by a transmitter as described with reference toFIGS. 8 through 10.