WO2020019125A1

WO2020019125A1 - Channel state feedback handling for multi-subscriber identity module device

Info

Publication number: WO2020019125A1
Application number: PCT/CN2018/096674
Authority: WO
Inventors: Jiming Guo; Ling Xie; Cheol Hee Park; Reza Shahidi; Xichang WU; Lu Bai; Shaolin PENG; Hamidreza KHAZAEI; Aswin Pranav SANKAR; Qingxin Chen
Original assignee: Qualcomm Incorporated
Priority date: 2018-07-23
Filing date: 2018-07-23
Publication date: 2020-01-30

Abstract

Methods, systems, and devices for wireless communications are described. A multi-subscriber identity module (MSIM) user equipment (UE) may detect an inactive period associated with a first radio, the inactive period concurrent with an active period of a second radio of the MSIM UE. The MSIM UE may perform, based on detecting the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the MSIM UE was affected by the inactive period. The MSIM UE may determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback. The MSIM UE may then transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.

Description

CHANNEL STATE FEEDBACK HANDLING FOR MULTI-SUBSCRIBER IDENTITY MODULE DEVICE

BACKGROUND

The following relates generally to wireless communications, and more specifically to channel state feedback handling for multi-subscriber identity module device.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform-spread-OFDM (DFT-S-OFDM) . A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

In some cases, a multi-subscriber identity module (MSIM) UE may turn off or otherwise inactivate a first radio associated with a first SIM when using a second radio associated with a second SIM. The MSIM UE may be scheduled to transmit channel state feedback (CSF) for the first subscription shortly after switching back to the first subscription after an inactive period. However, the MSIM UE may have missed an initial uplink grant transmitted during the inactive period. After the inactive period, the MSIM UE may receive a retransmission of the initial uplink grant using the first subscription service, but the retransmitted uplink grant may not include all of the information required by the MSIM UE to transmit the CSF in a way that is expected by the scheduling base station. This may lead to interference or the base station being unable to decode transmissions carrying unexpected information.

SUMMARY

Some user equipment (UEs) may support communications with a network using multiple subscriptions associated with multiple subscriber identity modules (SIMs) at the UEs. Such UEs may be referred to as multi-subscriber identity module (MSIM) UEs. If an MSIM UE stops using a first subscription associated with a first SIM to use a second subscription associated with a second SIM, the MSIM UE may turn off or inactivate a radio for the first subscription to use a radio for the second subscription. The period during which the UE stops using the first subscription to use the second subscription may be referred to as an inactivity period or an inactivity interval or an inactive period or inactive gap for the first subscription. The MSIM may not perform channel measurements for the first subscription while in the inactive period.

In some cases, the MSIM UE may be scheduled to transmit channel state feedback (CSF) for the first subscription shortly after switching back to the first subscription after an inactive period. However, the MSIM UE may have missed an initial uplink grant transmitted during the inactive period. After the inactive period, the MSIM UE may receive a retransmission of the initial uplink grant using the first subscription service, but the retransmitted uplink grant may not include all of the information required by the MSIM UE to transmit the CSF in a way that is expected by the scheduling base station. Thus, the retransmitted uplink grant may be an invalid grant for the MSIM UE. An MSIM UE described herein may implement techniques to determine whether the uplink grant is valid or not.

The MSIM UE may check whether the uplink grant is valid within a check window. The MSIM UE may check whether the uplink grant is valid when determining physical uplink shared channel (PUSCH) parameters including a modulation order (Qm) , redundancy version (RV) , and transport block (TB) size (TBS) . The Qm, RV, and TBS may be determined based on a modulation and coding scheme (MCS) indicator included with the uplink grant. If, for example, any one of the PUSCH parameters is not determined, the MSIM UE may determine the uplink grant is invalid. If, for example, a new data indicator (NDI) is flipped and the MCS value (e.g., I _MCp) satisfies 29≤I _MCS≤31, but the uplink grant is not just for transmitting a CSI report, the MSIM UE may determine that the uplink grant is invalid. The MSIM UE may wait to transmit a CSF report until either the MSIM UE receives a valid grant or an effective duration of the uplink hybrid automatic repeat request (HARQ) process with the invalid uplink grant ends. If the effective duration of the uplink HARQ process ends without the MSIM UE having received a valid grant, the MSIM UE may refrain from transmitting the CSF report.

An MSIM gap or inactive period may also affect the MSIM UE’s ability to populate its CSF report with current CSF data. For example, an MSIM UE that is scheduled to provide periodic CSF transmissions may not be able to include current CSF data in those transmissions if an inactive period precedes and is too close in time to the scheduled periodic CSF transmissions. To that end, additional techniques are described for evaluating which information to include in the CSF. For example, the MSIM UE may store a database of CSF values. If the CSF report is transmitted within a threshold of time from the end of the inactive period, the MSIM UE may report a most recent CSF evaluation stored in the database. If the CSF report is triggered after the threshold of time expires, the MSIM UE may report more recently recorded CSF information.

A method of wireless communication is described. The method may include detecting an inactive period associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE, performing, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determining, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmitting an uplink message that includes portions of the channel state feedback in accordance with the determining.

An 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 executable by the processor to cause the apparatus to detect an inactive period associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE, perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.

Another apparatus for wireless communication is described. The apparatus may include means for detecting an inactive period associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE, performing, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determining, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmitting an uplink message that includes portions of the channel state feedback in accordance with the determining.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to detect an inactive period associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE, perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the uplink grant validity check may include operations, features, means, or instructions for identifying that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message, identifying that the uplink grant includes an RV indication, indicating that a TB size of the uplink message may be to be based on a previously indicated TB size, identifying that the uplink grant includes a RB size and CSI request bit setting, where the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report may be to be triggered and determining, based on the new data indication, the RV indication, the RB size, and the CSI request bit setting, that the uplink grant may be invalid.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that the uplink grant includes the new data indication may include operations, features, means, or instructions for identifying that the uplink grant includes a flipped NDI flag.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that the uplink grant includes the RV indication may include operations, features, means, or instructions for identifying that the uplink grant indicates a non-RV0 version and identifying that the uplink grant indicates one of an MCS index within a predefined range.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the predefined range includes MCS29, MCS30, and MCS31.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the uplink grant validity check may include operations, features, means, or instructions for performing the uplink grant validity check within a check window that begins at an end of the inactive period.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a duration of the check window may be based on a HARQ process round trip time (RTT) for the UE.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, at the UE, a new initial uplink grant during the check window and terminating the check window early based on receiving the new initial uplink grant.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that an uplink HARQ process associated with the uplink grant may be inactive and terminating the check window early based on determining that the uplink HARQ process may be inactive.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the uplink grant may be associated with uplink scheduling for one of a primary component carrier or a secondary component carrier.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the uplink grant may be a set of uplink grants, each associated with uplink scheduling for a respective primary component carrier or secondary component carrier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to transmit at least portions of the channel state feedback may include operations, features, means, or instructions for determining that the uplink grant may be invalid and refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the portions of the channel state feedback not included in the uplink message based on the uplink grant being invalid include a periodic rank indicator and a channel quality indicator.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid may include operations, features, means, or instructions for refraining from including the portions of the channel state feedback in the uplink message for a predetermined duration of time.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the predetermined duration of time begins at an end of the inactive period and may be based on a HARQ process round trip time (RTT) for the UE multiplied by one less than a maximum number of uplink transmission attempts associated with the HARQ process.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for terminating the predetermined duration of time early if a new initial uplink grant may be received during the predetermined duration of time.

A method of wireless communication at a UE is described. The method may include identifying that the UE is operating in an MSIM mode, maintaining, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determining whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmitting a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

An apparatus for wireless communication at a UE 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 executable by the processor to cause the apparatus to identify that the UE is operating in an MSIM mode, maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying that the UE is operating in a multi-subscriber identity module (MSIM) mode, maintaining, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determining whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmitting a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to identify that the UE is operating in an MSIM mode, maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, maintaining the channel state feedback database may include operations, features, means, or instructions for including a latest reported periodic rank indicator in the channel state feedback database and including a latest reported periodic channel quality indicator and precoding-matrix indicator in the channel state feedback database.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, maintaining the channel state feedback database may include operations, features, means, or instructions for updating the channel state feedback database each time the UE triggers a periodic rank-indicator report over the air or each time the UE triggers a periodic channel quality indicator and precoding-matrix indicator report over the air.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the channel state feedback information in the channel state feedback database may be usable for periodic reporting may include operations, features, means, or instructions for identifying the channel state feedback information in the channel state feedback database as unusable based on the UE participating in a handover, a changing of a transmission mode of the UE, a changing of a channel quality indicator report mode of the UE, or a changing of a number of receive antennas for the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the channel state feedback information in the channel state feedback database may be usable for periodic reporting may include operations, features, means, or instructions for identifying the channel state feedback information in the channel state feedback database as usable based on the UE transmitting a periodic rank-indicator report or a periodic channel quality indicator and precoding-matrix indicator report.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the periodic channel state feedback report may include operations, features, means, or instructions for transmitting the periodic channel state feedback report using the channel state feedback database based further on an elapsed time after an inactive period associated with a first radio of the UE operating in the MSIM mode and concurrent with an active period of a second radio of the UE operating in the MSIM mode.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for comparing the elapsed time with a predetermined threshold time and determining whether the channel state feedback information in the channel state feedback database may be usable for periodic reporting based on the comparison of the elapsed time with the predetermined threshold time, where the periodic report may be transmitted using channel state feedback information from the channel state feedback database when the elapsed time may be less than or equal to the predetermined threshold time and where the periodic report may be transmitted using the more recent channel state feedback information when the elapsed time exceeds the predetermined threshold time.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication enabling or disabling the maintaining of the channel state feedback database.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of an uplink grant validity check timing that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a channel state feedback evaluation that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a process flow that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIGs. 7 and 8 show block diagrams of devices that support channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 9 shows a block diagram of a communications manager that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIG. 10 shows a diagram of a system including a device that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

FIGs. 11 through 13 show flowcharts illustrating methods that support channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Some user equipment (UEs) may support communications with a network using multiple subscriptions associated with multiple subscriber identity modules (SIMs) at the UEs. Such UEs may be referred to as multi-subscriber identity module (MSIM) UEs. An MSIM UE may communicate using a first subscription associated with a first SIM, then stop using the first subscription to use a second subscription associated with a second SIM. When the MSIM UE stops using the first subscription, the MSIM UE may not perform measurements on channels used for the first subscription, as a radio for the first subscription may be turned off or made otherwise inactive to use a radio for the second subscription. The period during which the UE stops using the first subscription to use the second subscription may be referred to as an inactivity period, inactive interval, or an inactive gap for the first subscription.

An MSIM UE may be scheduled to transmit channel state feedback (CSF) for the first subscription shortly after switching back to the first subscription after an inactive period. However, the MSIM UE may have missed an initial uplink grant transmitted during the inactive period. After the inactive period, the MSIM UE may receive a retransmission of the initial uplink grant using the first subscription service, but the retransmitted uplink grant may not include all of the information required by the MSIM UE to transmit the CSF in a way that is expected by the scheduling base station. This may be problematic, as the carrier or channel on which the MSIM UE is to transmit CSF is based on a set of rules triggered by whether various control or data channels have been scheduled on various carriers. Thus, following the rules, the MSIM UE may wrongfully assume a carrier or channel to transmit the CSF report based on an invalid grant, while the base station, also following the rules, anticipates receiving the CSF report on a different carrier or channel. For example, the base station may anticipate receiving a CSF report on a shared channel of a primary component carrier (PCC) while the MSIM UE determines to transmit the CSF report on a shared channel of a secondary component carrier (SCC) , which may lead to a decoding error of the SCC physical uplink shared channel (PUSCH) . Instead, a UE and a base station described herein may implement techniques to handle CSF reporting for MSIM UEs.

An MSIM UE may re-activate a first subscription after an inactive period. The MSIM UE may receive an uplink grant while active, and the MSIM UE may implement techniques to determine whether the uplink grant is valid or not. The MSIM UE may check whether the uplink grant is valid within a check window. The MSIM UE may check whether the uplink grant is valid based on the available grant information such as an indication of new data, the modulation and coding scheme (MCS) , the RB size and CSI request bit setting. If, for example, a new data indicator (NDI) is flipped while a rescheduling MCS index ranging from 29 to 31 is used but no CSI request included, the MSIM UE may determine that the uplink grant is invalid.

The MSIM UE may wait to transmit a CSF report until either the MSIM UE receives a valid grant or an effective duration of the uplink hybrid automatic repeat request (HARQ) process with the invalid uplink grant ends. If the effective duration of the uplink HARQ process ends without the MSIM UE having received a valid grant, the MSIM UE may refrain from transmitting the CSF report.

An MSIM gap or inactivity period may also affect the MSIM UE’s ability to populate its CSF report with current CSF data. For example, an MSIM UE that is scheduled to provide periodic CSF transmissions may not be able to include current CSF data in those transmissions, for example because the related channel may not be complete if an inactivity period precedes and is too close in time to the scheduled periodic CSF transmissions. To that end, additional techniques are described for evaluating which information to include in the CSF. For example, the MSIM UE may store a database of CSF values. If the CSF report is transmitted within a threshold of time from the end of the inactive period, the MSIM UE may report a most recent CSF evaluation stored in the database. If the CSF report is triggered after the threshold of time expires, the MSIM UE may report more recently recorded CSF information.

Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to channel state feedback handling for multi-subscriber identity module device.

FIG. 1 illustrates an example of a wireless communications system 100 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communications system 100 may 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, wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation Node B or giga-nodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or some other suitable terminology. Wireless communications system 100 may include base stations 105 of different types (e.g., macro or small cell base stations) . The UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may utilize one or more carriers. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions.

The geographic coverage area 110 for a base station 105 may be divided into sectors making up only a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may 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 station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term “cell” refers to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) , and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) ) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband Internet-of-Things (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of devices. In some cases, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client. A UE 115 may also be a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.

Some UEs 115, 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 station 105 without 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 UEs 115 may 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.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications) . In some cases, UEs 115 may be designed to support critical functions (e.g., mission critical functions) , and a wireless communications system 100 may be configured to provide ultra-reliable communications for these functions.

In some cases, a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol) . One or more of a group of UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105, or be otherwise unable to receive transmissions from a base station 105. In some cases, groups of UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group. In some cases, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between UEs 115 without the involvement of a base station 105.

Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1, N2, N3, or other interface) . Base stations 105 may communicate with one another over backhaul links 134 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) .

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may 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 UEs 115 served by base stations 105 associated 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.

At least some of the network devices, such as a base station 105, may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC) . Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP) . In some configurations, various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station 105) .

Wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

Wireless communications system 100 may 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 industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that can tolerate interference from other users.

Wireless communications system 100 may 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, wireless communications system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, 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 UE 115. 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 cases, wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations 105 and UEs 115 may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a CA configuration in conjunction with CCs operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) , or a combination of both.

In some examples, base station 105 or UE 115 may 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, wireless communications system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115) , 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 station 105 or a UE 115) 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 station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an 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 station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) , or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal) . The single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions) .

In some cases, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-based network that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may in some cases perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data. At the Physical (PHY) layer, transport channels may be mapped to physical channels.

In some cases, UEs 115 and base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions) . In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

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 T _s = 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 T _f = 307,200 T _s. 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 wireless communications system 100, and may be referred to as a transmission time interval (TTI) . In other cases, a smallest scheduling unit of the wireless communications system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs) .

In some wireless communications systems, a slot may further be divided into multiple mini-slots containing one or more symbols. In some instances, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. Each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation, for example. Further, some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots are aggregated together and used for communication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125. For example, a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN) ) , and may be positioned according to a channel raster for discovery by UEs 115. Carriers may be downlink or uplink (e.g., in an FDD mode) , or be configured to carry downlink and uplink communications (e.g., in a TDD mode) . In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as OFDM or DFT-s-OFDM) .

The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR, etc. ) . For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc. ) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces) .

A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz) . In some examples, each served UE 115 may be configured for operating over portions or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type) .

In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. In MIMO systems, a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers) , and the use of multiple spatial layers may further increase the data rate for communications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations 105 or UEs 115) 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 wireless communications system 100 may include base stations 105 and/or UEs 115 that can support simultaneous communications via carriers associated with more than one different carrier bandwidth.

Wireless communications system 100 may support communication with a UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A UE 115 may 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, wireless communications system 100 may 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 UEs 115 that 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 UE 115 or base station 105, 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 the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

In some cases, a UE 115, such as an MSIM UE, may be scheduled to transmit CSF for the first subscription shortly after switching back to the first subscription after an inactivity period. However, the UE 115 may have missed an initial uplink grant transmitted during the inactive period. After the inactive period, the UE 115 may receive a retransmission of the initial uplink grant using the first subscription service, but the retransmitted uplink grant may not include all of the information required by the UE 115 to transmit the CSF in a way that is expected by the scheduling base station. Thus, the retransmitted uplink grant may be an invalid grant for the UE 115.

The UE 115 may check whether the uplink grant is valid within a check window. The UE 115 may check whether the uplink grant is valid based on an indication of new data and an RV indication in the uplink grant. If, for example, an NDI is flipped while a rescheduling MCS ranging from 29 to 31 is used, the UE 115 may determine that the uplink grant is invalid. The UE 115 may wait to transmit a CSF report until either the UE 115 receives a valid grant or an effective duration of the uplink HARQ process with the invalid uplink grant ends. If the effective duration of the uplink HARQ process ends without the UE 115 having received a valid grant, the UE 115 may refrain from transmitting the CSF report.

FIG. 2 illustrates an example of a wireless communications system 200 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communication system 100. Wireless communications system 200 may include UE 115-a, which may be an example of a UE 115 as described herein. UE 115-a may be an example of an MSIM UE described herein. Wireless communications system 200 may also include base station 105-a and base station 105-b, which may each be an example of a base station 105 as described herein.

UE 115-a may support communications with a network using multiple subscriptions associated with multiple SIMs. UE 115-a may be referred to as an MSIM UE. MSIM UEs may communicate using a first subscription associated with a first SIM, then stop using the first subscription to use a second subscription associated with a second SIM. For example, UE 115-a may communicate with base station 105-a on a first communication link 205 (e.g., a first subscriber link) and may communicate with base station 105-b on a second communication link 210 (e.g., a second subscriber link) . In some cases, to communicate using one subscription, UE 115-a may turn off a radio used to communicate using the other subscription. When a radio for a subscription is turned off, UE 115-a may have an inactive period 215 for that subscription. During the inactive period 215 for a subscription, UE 115-a may not monitor channel conditions or other factors UE 115-a would use to generate a CSF report 230. In some examples, a CSF report 230 may include a rank indicator (RI) and a channel quality indicator (CQI) .

In the illustrated example, UE 115-a may first communicate with base station 105-b using the second subscription on the communication link 210. UE 115-a may switch from using the second subscription to using the first subscription provided by base station 105-a on communication link 205. The second subscription may be in inactive period 215-a until UE 115-a begins using the subscription. Similarly, the inactive period 215-b for the second subscription may begin once UE 115-a starts using the first subscription.

The wireless communications system 200 may support carrier aggregation. For example, the communication link 205 for the first subscription may include a primary component carrier (PCC) and at least one secondary component carrier (SCC) . Base station 105-a may transmit downlink information (e.g., control or data) to UE 115-a on the PCC or the SCC. For example, base station 105-a may transmit uplink grants to UE 115-a scheduling transmission on the PCC or the SCC, and the uplink grants may further indicate resources (e.g., physical uplink control channel (PUCCH) or PUSCH resources) on one or both of the PCC and the SCC for UE 115-a to use for uplink transmissions.

An example of a set of “rules” for selecting a channel and carrier for transmitting a CSF report is shown in the table below.

PCC/SCC Scheduling	CSF Mapping
No/No	PCC PUCCH
Yes/No	PCC PUSCH
No/Yes	SCC PUSCH
Yes/Yes	PCC PUSCH

Table 1

As shown, if there is no scheduling on PCC or SCC, the CSF report may be transmitted in a PUCCH message on the PCC. If there is PCC scheduling, but no SCC scheduling, the CSF report may be transmitted in a PUSCH message on the PCC. If there is no PCC scheduling, but there is SCC scheduling, the CSF report may be transmitted in a PUSCH message on the SCC. If there is scheduling on both the PCC and the SCC, the CSF report may be transmitted in a PUSCH message on the PCC.

However, as explained below, there are times when a MIMO UE may not receive an initial uplink grant providing either PCC or SCC scheduling. Thus, in such situations, the base station, having transmitted an uplink grant providing a particular schedule, may expect to receive a CSF report on a given channel, as outlined in Table 1. However, because the UE has not received the uplink grant and is thus unaware of the correct scheduling, the MSIM UI may (following the rules of Table 1) elect to transmit its CSF report on a channel that differs from that on which the base station expects.

The below table illustrates mapping conflicts between UE 115-a and base station 105-a when an uplink grant is identified as invalid (due, for example, to the non-receipt of an initial grant during an inactivity period of a MSIM UE) . Table 2 illustrates the conflicts that occur if a grant scheduling resources is invalid when using the rules set by Table 1.

Table 2

As shown above, UE 115-a and base station 105-a may experience some conflict mapping when an uplink grant is invalid. For example, if the uplink grant scheduling the PCC for uplink is invalid, and if the SCC is not scheduled for uplink, UE 115-a may transmit the CSF report 230 on PCC PUCCH, while base station 105-a expects to receive the CSF report 230 on PCC PUSCH, which may lead to PUCCH interference.

If the uplink grant scheduling the PCC is invalid, while the SCC is scheduled with a valid grant, UE 115-a may transmit the CSF report 230 on SCC PUSCH while base station 105-a expects to receive the CSF report 230 on PCC PUSCH, which may lead to an SCC PUSCH decoding error.

If both the PCC and the SCC are scheduled for uplink transmission and both of the respective grants are invalid, UE 115-a may transmit the CSF report 230 on PCC PUCCH, while base station 105-a expects to receive the CSF report 230 on the PCC PUSCH. This may lead to PUCCH interference.

Further, if PCC uplink is not scheduled, but SCC uplink is scheduled with an invalid grant, UE 115-a may transmit the CSF report 230 on the PCC PUCCH while base station 105-a expects to receive the CSF report 230 on the SCC PUCCH, which may lead to PUCCH interference. Other scenarios (e.g., scheduling on PCC with a valid grant, scheduling on SCC with a valid grant, and no scheduling on either PCC or SCC) may not lead to a resource mapping mis-match.

The conflicts described in Table 2 may arise after an inactive period for an MSIM UE. For example, UE 115-a may re-activate the first subscription after the inactive period 215-a. When the inactive period 215-a ends, UE 115-a may monitor for a PCC or SCC uplink grant. Base station 105-a may transmit, and UE 115-a may receive, a retransmitted uplink grant 225 shortly after the inactive period 215-a ends (a retransmission of an initial grant that the UE 115-a would have received had it not been in an inactive period) . In some cases, UE 115-a may be scheduled to transmit a periodic CSF report 230, and the retransmitted uplink grant 225 may schedule resources for which the UE 115-a may apply the rules of Table 1 to transmit the CSF report 230. For CSF report transmission, UE 115-a may map the CSF report 230 to a PUSCH or PUCCH resource, on which base station 105-a expects to receive the CSF report 230.

Base station 105-a may still expect UE 115-a to map the CSF report 230 to a PUCCH or PUSCH resource even if UE 115-a discards a portion of an uplink transmission of an uplink HARQ process, for example if an initial uplink grant 220 is missing inside the inactive period 215-a. Thus, UE 115-a may initially be unaware that the retransmitted uplink grant 225 is a retransmission of the initial uplink grant 220, where treating the retransmitted uplink grant 225 as if it were not a retransmission may lead to conflicting resource mappings for the CSF report 230 between UE 115-a and base station 105-a. Thus, the retransmitted uplink grant 225 may be an invalid grant, but UE 115-a may initially be unaware that the retransmitted uplink grant 225 is an invalid grant.

To avoid a resource mapping mis-match, UE 115-a may check whether the retransmitted uplink grant 225 is valid. The validity check may be performed within an uplink HARQ process validity check window, referred to herein as a check window. The duration of the check window may be based on a HARQ round-trip time (RTT) (e.g., in milliseconds) after the end of the inactive period 215-a. For example, if UE 115-a missed the initial uplink grant 220, UE 115-a may not transmit an ACK or NACK for the initial uplink grant 220. Base station 105-a may determine that the initial uplink grant 220 was not received, and base station 105-a may attempt to re-transmit an uplink grant as part of a HARQ process. Thus, base station 105-a may repeatedly transmit re-transmissions of the uplink grant for the duration of an uplink HARQ process. Therefore, UE 115-a may monitor for the retransmitted uplink grant 225 within the HARQ RTT, as base station 105-a may continue to transmit re-transmissions of the initial uplink grant 220 during the uplink HARQ process. In some cases, if UE 115-a does not receive the retransmitted uplink grant 225, this may be an indication that either the UL HARQ process has ended, or base station 105-a did not transmit an initial uplink grant 220.

UE 115-a may check whether the retransmitted uplink grant 225 is valid based on the available grant information such as an indication of new data, the MCS, the RB size and CSI request bit setting. If, for example, an NDI is flipped while a rescheduling MCS index ranging from 29 to 31 is used but no CSI request included, UE 115-a may determine the retransmitted uplink grant 225 is invalid. If, for example, an NDI in the retransmitted uplink grant 225 is flipped while the RV version indicates to use a non-RV0 version, UE 115-a may determine that the retransmitted uplink grant 225 is invalid. In some cases, the uplink grant may indicate the TB size by an MCS indicator. If the MCS indicator is 29, 30, or 31, the MCS indicator may be indicating to use the previous TB size. In some cases, if the retransmitted uplink grant 225 includes a toggled NDI (e.g., NDI = ‘1’ ) and an MCS of 29, 30, or 31, UE 115-a may determine the retransmitted uplink grant 225 is not valid. If the retransmitted uplink grant 225 is not valid, the uplink HARQ process may be marked with an “invalid grant” flag.

In some cases, an NDI is not toggled and an MCS ranges from 29 to 31. In this case, an uplink grant may be a valid uplink grant, and UE 115-a can look up the table to check the RV and reuse the previous Qm in the initial grant. In another example, if the NDI is toggled and the MCS ranges from 29 to 31, then UE 115-a may further check the CSI bit and RB size to determine whether the corresponding grant is a CSI request. If the uplink grant is a CSI request, the uplink grant may be a valid uplink grant. However, if the NDI is toggled, the MCS ranges from 29 to 31, and the uplink grant is not for a CSI report, UE 115-a may determine the uplink grant is an invalid uplink grant.

The “invalid grant” flag for the uplink HARQ process may be cleared if UE 115-a receives another, valid grant. For example, if UE 115-a receives a new DCI0 grant, coming with an RV0 grant. The “invalid grant” flag may also be cleared if the uplink HARQ process is inactive or expires. If UE 115-a receives a valid grant before the end of the uplink HARQ process, UE 115-a may transmit according to the valid grant instead. For example, if UE 115-a receives another uplink grant with a toggled NDI, but the other uplink grant has a valid MCS (e.g., not value 29, 30, or 31) , UE 115-a may transmit according to the other uplink grant and reset the “invalid grant” flag for the uplink HARQ process. In some cases, if the NDI is flipped (e.g., toggled) while a rescheduling MCS index ranging from 29 to 31 is used, but no CSI request is included, the UE 115-c may determine that the retransmitted uplink grant 225 is invalid.

UE 115-a may identify an effective duration of the uplink HARQ process. UE 115-a may assume the retransmitted uplink grant 225 is the second transmission attempt (e.g., first re-transmission) of the initial uplink grant 220 and set the effective duration of the uplink HARQ process accordingly. For example, the effective duration of the uplink HARQ process, assuming the retransmitted uplink grant 225 is the second transmission attempt, may be equal to (maximum uplink transmission attemps-1) *HARQ RTT. The assumption made by UE 115-a may be configurable. For example, under other configurations, UE 115-a may assume the invalid uplink grant is the third transmission attempt (e.g., second retransmission) , which may result in a shorter effective duration of the HARQ process.

If UE 115-a is to transmit the CSF report 230 (e.g., based on a periodicity of the CSF reporting or otherwise) and there is an invalid PCC uplink grant, the CSF resource mapping may be modified. For example, if there is PCC uplink scheduling, but the grant scheduling the PCC uplink is invalid UE 115-a may drop transmission of the CSF report 230. For example, UE 115-a may drop transmission of the CSF report 230 if there is SCC uplink scheduling with a valid grant, if there is SCC uplink scheduling with an invalid grant, or if there is not SCC uplink scheduling. Similarly, UE 115-a may drop the CSF report if there is not PCC uplink scheduling, but there is SCC uplink scheduling with an invalid grant. Thus, UE 115-a may prevent a resource mapping mis-match.

If UE 115-a does transmit the CSF report 230, UE 115-a may evaluate which information to include in the CSF report 230. For example, due to turning off the radio used for the first subscription during the inactive period 215-a, UE 115-a may not have taken measurements for the first subscription during the inactive period 215-a. Thus, in some cases, UE 115-a may not have up-to-date measurements to include in the CSF report 230.

Still, UE 115-a may in some cases report channel quality information (CQI) (e.g., based on the latest reported RI) , PMI, and RI even if UE 115-a does not have enough measurement results after an inactive period 215. In some examples, UE 115-a may be required to transmit the CSF report 230 even if UE 115-a has insufficient measurements.

UE 115-a may maintain a CSF database 235, which may store a latest reported periodic RI, a latest reported CQI, and a latest reported PMI. In some cases, the latest reported RI may be stored as one entry, while latest reported CQI and PMI are stored as another entry. For periodic CSI reporting, the CQI and PMI reporting duty cycle may be less than the RI reporting duty cycle. For example, CQI and PMI may be reported every 20 ms, where RI is reported every 160 or 320 ms. Based on the reporting duty cycles, CQI and PMI may be reported more frequently than RI. As such, UE 115-a may, in some cases, store more up-to-date values for the CQI and the PMI separate from the less frequently reported RI. Aperiodic CSI may be triggered and reported on PUSCH.

When an inactive period 215 ends and UE 115-a is scheduled or requested to transmit a CSF report 230, UE 115-a may use the latest reported RI information in the CSF database 235 for CQI/PMI computation. In some cases, using the latest reported RI information in the CSF database 235 may be based on the latest reported RI information being usable. When an inactive period 215 ends and UE 115-a is scheduled to report periodic RI/CQI within X ms, UE 115-a may use the latest reported RI for the RI report if usable and use the latest reported CQI/PMI for the CQI/PMI report if usable.

In some cases, UE 115-a may determine whether to use the values stored in the CSF database 235 for the CSF report 230 based on the time elapsed since the inactive period 215 ended. For example, if the time elapsed is less than a threshold time, UE 115-a may use values stored in the CSF database 235. If the time elapsed is greater than the threshold time, UE 115-a may use more recent CSF information. In some cases, the threshold time may be based on a CSF reporting periodicity. For example, the threshold time may be set such that UE 115-a generates a CSF report within the threshold time. Therefore, in some cases, UE 115-a either reports CSF information generated since leaving the inactive period 215 or CSF information stored in the CSF database 235.

UE 115-a may update the stored values in the CSF database 235. When UE 115-a triggers a periodic RI report over the air, UE 115-a may update the latest reported RI in the CSF database 235 accordingly. When UE 115-a triggers a periodic CQI/PMI report over the air, UE 115-a may update the latest reported CQI and PMI information in the CSF database 235 accordingly. In some cases, UE 115-a may maintain the CSF database 235. For example, UE 115-a may store and recover the CSF database 235 before and after an inactive period 215.

In some cases, UE 115-a may maintain whether the information stored in the CSF database 235 is valid. UE 115-a may mark the information stored in the CSF database 235 as invalid if, for example, there is a change of a serving cell or absolute radio frequency number (ARFCN) , an adaptive receive diversity (ARD) state transition, or a change of transmission mode or CQI report mode. In some cases, the CSF information in the CSF database 235 may be marked as invalid if UE 115-a undergoes a handover. UE 115-a may mark the related field in the CSF database 235 as usable when a periodic RI report or a periodic CQI/PMI report is triggered.

The information included in the CSF report 230 may be based on a transmission mode of UE 115-a. For example, when operating according to transmission mode 3, UE 115-a may report CQI and RI. When operating according to transmission 4, UE 115-a may report CQI, RI, and PMI. Transmission mode 3 and 4 may be often used for time division duplexed (TDD) and frequency division duplex (FDD) wireless communication deployments. When operating according to transmission mode 8, UE 115-a may report CQI. In transmission mode 8, UE 115-a may also transmit RI, if configured, and PMI, if configured, as well. When operating according to transmission mode 9, UE 115-a may report CQI. UE 115-a may also report RI, if configured and the CSI RS port is greater than or equal to 2, and report, if configured, PMI as well. In some cases, UE 115-a may report a precoding type indicator (PTI) for transmission mode 9 as well.

FIG. 3 illustrates an example of an uplink grant validity check timing 300 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. In some examples, uplink grant validity check timing 300 may implement aspects of wireless communication system 100.

As described in FIG. 2, a UE 115, such as an MSIM UE described herein, may turn on a radio for a first subscription after being in an inactive period 305 for the first subscription. The UE 115 may have turned off the radio for the first subscription to use another radio for a second subscription, at which point the inactive period 305 for the first subscription started. The illustration shows the end of the inactive period 305 for the first subscription. A check window 310 and an effective duration 315 may begin at the end of the inactive period 305.

In some cases, a base station 105 may have transmitted an initial uplink grant (e.g., similar to the initial uplink grant 220 of FIG. 2) to the UE 115 for the first subscription while the UE 115 was in the inactive period 305. The initial uplink grant may schedule resources for the UE 115 to transmit a CSF report. The UE 115, having the radio for the first subscription turned off, may have missed the initial uplink grant. If the UE 115 missed the initial uplink grant, the UE 115 may not transmit an ACK or NACK for the initial uplink grant. Based on not receiving an ACK or a NACK, base station 105 may determine that the initial uplink grant was not received, and the base station 105 may attempt to re-transmit an uplink grant as part of a HARQ process. Thus, the base station 105 may repeatedly transmit re-transmissions of the uplink grant for the duration of an uplink HARQ process. At some point during the check window 310, UE 115 may receive an uplink grant (e.g., similar to the retransmitted uplink grant 225 described in FIG. 2) , which may be a re-transmission of the initial uplink grant.

The UE 115 may check whether the uplink grant is valid. The uplink grant validity check may be performed within an uplink HARQ process validity check window. The check window 310 may be an example of an uplink HARQ process validity check window. The duration of the check window 310 may be based on a HARQ RTT (e.g., in milliseconds) after the end of the inactive period 305. The UE 115 may monitor for the uplink grant within the HARQ RTT, as the base station 105 may continue to transmit re-transmissions of the initial uplink grant during the uplink HARQ process. In some cases, if the UE 115 does not receive the uplink grant, this may be an indication that either the UL HARQ process has ended, or base station 105 did not transmit an initial uplink grant.

The UE 115 may check whether the uplink grant is valid based on the available grant information such as an indication of new data (e.g., the NDI) , the MCS, the RB size and CSI request bit setting. If, for example, the NDI is flipped while a rescheduling MCS index ranging from 29 to 31 is used, but no CSI request included, the UE 115 may determine the uplink grant is invalid. In some cases, the UE 115 may check whether the uplink grant is valid based on an indication of new data and an RV/MCS indication in the uplink grant. If, for example, an NDI in the uplink grant is flipped while MCS indicates that the RV version is not RV0, the UE 115 may determine that the uplink grant is invalid. For example, the indication of new data may contradict the indication to use a previously used TB size, and the UE 115 may determine the uplink grant is invalid based on the contradiction. In some cases, the uplink grant may indicate the TB size by an MCS indicator. If the MCS indicator is 29, 30, or 31, the MCS indicator may be indicating to use the previous TB size. Thus, if the uplink grant includes a toggled NDI (e.g., NDI = ‘1’ ) and an MCS of 29, 30, or 31, the UE 115 may determine the uplink grant is not valid. If the uplink grant is not valid, the uplink HARQ process may be marked with an “invalid grant” flag.

The “invalid grant” flag for the uplink HARQ process may be cleared if the UE 115 receives another, valid grant. For example, if the UE 115 receives a new DCI0 grant, coming with an RV0 grant. The “invalid grant” flag may also be cleared if the uplink HARQ process is inactive or expires. If the UE 115 receives a valid grant before the end of the uplink HARQ process, the UE 115 may transmit according to the valid grant instead. For example, if the UE 115 receives another uplink grant with a toggled NDI, but the other uplink grant has a valid MCS (e.g., not value 29, 30, or 31) , UE 115-a may transmit according to the other uplink grant and reset the “invalid grant” flag for the uplink HARQ process.

The UE 115 may identify an effective duration 315 of the uplink HARQ process. The UE 115 may assume the uplink grant is the second transmission attempt (e.g., first re- transmission) of the initial uplink grant and set the effective duration 315 of the uplink HARQ process accordingly. For example, the effective duration 315 of the uplink HARQ process, assuming the uplink grant is the second transmission attempt, may be equal to (maximum uplink transmission attemps-1) *HARQ RTT. The assumption made by the UE 115 may be configurable. For example, under other configurations, the UE 115 may assume the invalid uplink grant is the third transmission attempt (e.g., second retransmission) , which may result in a shorter effective duration of the HARQ process.

If the UE 115 is to transmit the CSF report (e.g., based on a periodicity of the CSF reporting or otherwise) and there is an invalid PCC uplink grant, the CSF resource mapping may be modified. For example, if there is PCC uplink scheduling, but the grant scheduling the PCC uplink is invalid, the UE 115 may drop transmission of the CSF report. For example, the UE 115 may drop transmission of the CSF report if there is SCC uplink scheduling with a valid grant, if there is SCC uplink scheduling with an invalid grant, or if there is not SCC uplink scheduling. Similarly, the UE 115 may drop the CSF report if there is not PCC uplink scheduling, but there is SCC uplink scheduling with an invalid grant. Thus, the UE 115 may prevent a resource mapping mis-match.

FIG. 4 illustrates an example of a channel state feedback evaluation 400 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. In some examples, channel state feedback evaluation 400 may implement aspects of wireless communication system 100.

As described in FIG. 2, UE 115-b, which may be an example of an MSIM UE described herein, may be capable of communicating using two different subscriptions using two different radios. UE 115-b may maintain a CSF database 430, in which UE 115-b stores CSF information. For example, the CSF database 430 may store a latest reported periodic RI, a latest reported CQI, and a latest reported PMI.

UE 115-b may update the CSF information stored in the CSF database. At 420, UE 115-b may be triggered to transmit a CSF report during the active period 405-a. For example, UE 115-b may transmit a periodic RI report over the air, and UE 115-b may update the latest reported RI in the CSF database 430 accordingly. Additionally, or alternatively, UE 115-b may trigger a periodic CQI/PMI report over the air at 420, and UE 115-b may update the latest reported CQI and PMI information in the CSF database 430 accordingly.

In some cases, for periodic CSI reporting, the CQI and PMI reporting duty cycle may be less than the RI reporting duty cycle. For example, CQI and PMI may be reported every 20 ms, where RI is reported every 160 or 320 ms. As such, UE 115-a may, in some cases, store more up-to-date values for the CQI and the PMI separate from the less frequently reported RI. Based on the reporting duty cycles, CQI and PMI may be reported more frequently than RI. Aperiodic CSI may be triggered and reported on PUSCH. In some cases, UE 115-b may store and recover the CSF database 430 before and after an inactive period 410.

UE 115-b may communicate using the first subscription during the active period 405-a, but then turn off the radio for the first subscription to use a second subscription. When UE 115-b turns off the radio for the first subscription, the first subscription may enter an inactive period 410. During the inactive period, UE 115-b may not monitor conditions of channels used for the first subscription. Thus, in some cases, UE 115-b may not record information which is used to report a CSF report for the inactive period 410. When UE 115-b leaves the inactive period 410, the active period 405-b may begin, and UE 115-b may be requested or scheduled to transmit a CSF report shortly after the active period 405-b begins. UE 115-b may determine whether to transmit a CSF report as described in FIG. 3.

If UE 115-b does decide to transmit a CSF report, UE 115-b may evaluate which information to include in the CSF report. Having turned off the radio used for the first subscription during the inactive period 410, UE 115-b may not have taken measurements for the first subscription during the inactive period 410. Thus, in some cases, UE 115-b may not have up-to-date measurements to include in the CSF report.

Still, UE 115-b may in some cases report CQI (e.g., based on the latest reported RI) , PMI, and RI even if UE 115-b did not take measurements during the inactive period 410. In some examples, UE 115-b may be required to transmit the CSF report even if UE 115-b has insufficient measurements.

When the inactive period 410 ends and UE 115-b is scheduled or requested to transmit a CSF report, UE 115-b may use the latest reported RI information in the CSF database 430 for CQI/PMI computation. In some cases, using the latest reported RI information in the CSF database 430 may be based on the latest reported RI information being usable. When an inactive period 410 ends and UE 115-b is scheduled to report periodic RI/CQI within X ms, UE 115-b may use the latest reported RI for the RI report if usable and use the latest reported CQI/PMI for the CQI/PMI report if usable.

In some cases, UE 115-b may determine whether to use the values stored in the CSF database 430 for the CSF report based on the time elapsed since the inactive period 215 ended. For example, if the time elapsed is less than a threshold time, shown as delta T 415, UE 115-b may use values stored in the CSF database 430. If UE 115-b makes the determination 425 at 435 (e.g., within delta T 415) , UE 115-b may generate a CSF report based on information stored in the CSF database 430. If UE 115-b makes the determination 425 at 440, UE 15-b may generate a CSF report based on a more recent CSF measurement.

In some cases, delta T 415 may be based on a CSF reporting periodicity. For example, the threshold time may be set such that UE 115-b generates a CSF report within delta T 415 (not shown) . Therefore, in some cases, UE 115-b may either report CSF information generated since leaving the inactive period 410 or CSF information stored in the CSF database 430.

In some cases, UE 115-b may maintain whether the information stored in the CSF database 430 is valid. UE 115-b may mark the information stored in the CSF database 430 as invalid if, for example, there is a change of a serving cell or ARFCN, an ARD state transition, or a change of transmission mode or CQI report mode. In some cases, the CSF information in the CSF database 430 may be marked as invalid if UE 115-b undergoes a handover. UE 115-b may mark the related field in the CSF database 430 as usable when a periodic RI report is triggered or a periodic CQI/PMI report is triggered.

The information included in the CSF report may be based on a transmission mode of UE 115-b. For example, when operating according to transmission mode 3, UE 115-b may report CQI and RI. When operating according to transmission 4, UE 115-b may report CQI, RI, and PMI. Transmission mode 3 and 4 may be often used for TDD and FDD wireless communication deployments. When operating according to transmission mode 8, UE 115-b may report CQI. In transmission mode 8, UE 115-b may also transmit RI, if configured, and PMI, if configured, as well. When operating according to transmission mode 9, UE 115-b may report CQI. UE 115-b may also report RI, if configured and the CSI RS port is greater than or equal to 2, and report, if configured, PMI as well. In some cases, UE 115-b may report a PTI for transmission mode 9 as well.

FIG. 5 illustrates an example of a process flow 500 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. In some examples, process flow 500 may implement aspects of wireless communication system 100. The process flow 500 may include UE 115-c and base station 105-c, which may be respective examples of a UE 115 and a base station 105 as described herein. UE 115-c may be an example of an MSIM UE as described herein.

UE 115-c may be in an inactive period 505 for a first subscription provided by base station 105-c. During the inactive period 505, base station 105-c transmits an initial uplink grant to UE 115-c at 510. UE 115-c, being in the inactive period 505 for the first subscription, may miss the initial uplink grant 510, as radios for the first subscription may be turned off.

At 515, UE 115-c may detect the inactive period 505 associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE. In some cases, 515 may be performed during an active period 520, shortly after the end of the inactive period 505. At 535, base station 105-c may transmit a retransmission of the uplink grant transmitted at 510. In some cases, retransmitted uplink grant may not include all of the information required by UE 115-c to transmit the CSF in a way that is expected by the scheduling base station. In other words, the retransmitted uplink grant may be an invalid grant.

At 540, UE 115-c may perform, based on detection of the inactive period 505, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by UE 115-c was affected by the inactive period 505. For example, UE 115-c may perform the uplink grant validity check on the retransmitted uplink grant, which was transmitted at 535. In some cases, performing the uplink grant validity check includes identifying that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message. Performing the uplink grant validity check may also include identifying that the uplink grant includes an RV indication, indicating that a TB size of the uplink message is to be based on a previously indicated TB size.

In some cases, UE 115-c may identify that the uplink grant includes an RB size and CSI request bit setting, where the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report (e.g., an aperiodic CSI report) is to be triggered. In some examples, the indication for the aperiodic report may be based on a setting of one or more of the RB size, CSI request bit, NDI indication, and RV indication. For example, given a certain RB size, CSI request bit, and RV indication setting, UE 115-c may determine that an aperiodic CSI report is triggered. Performing the uplink grant validity check may also include determining, based on the new data indication, the RV indication, the RB size, and the CSI request bit setting, that the uplink grant is invalid. UE 115-c may perform the uplink validity check within a check window 525 that starts at the end of the inactive period 505.

In some cases, identifying that the uplink grant includes the new data indication includes identifying that the uplink grant includes a flipped NDI flag. In some examples, identifying that the uplink grant includes the RV indication includes identifying that the uplink grant indicates one of an MCS index within a predefined range. For example, the predefined range may include MCS29, MCS30, and MCS31.

UE 115-c may determine, based on whether the uplink grant (e.g., the retransmitted uplink grant) is valid, whether to transmit at least portions of channel state feedback. In some cases, determining whether to transmit at least portions of the channel state feedback includes determining that the uplink grant is invalid and refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid.

UE 115-c may refrain from including the portions of the channel state feedback in the uplink message for a predetermined duration of time. The effective duration 530 may be an example of the predetermine duration of time. In some cases, the predetermined duration of time may begin at an end of the inactive period 505 and be based on a HARQ process RTT for UE 115-c multiplied by one less than a maximum number of uplink transmission attempts associated with the HARQ process.

At 550, UE 115-c may transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. In some cases, the uplink message may include a CSF report.

FIG. 6 illustrates an example of a process flow 600 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. In some examples, process flow 600 may implement aspects of wireless communication system 100. Process flow 600 includes UE 115-d and base station 105-d, which may be respective examples of a UE 115 and a base station 105 as described herein. UE 115-d may be an example of an MSIM UE as described herein.

At 605, UE 115-d may identify it is operating in an MSIM mode. At 610, UE 115-d may maintain, based on operating in MSIM mode, a CSF database that includes CSF information for periodic reporting. In some cases, maintaining the CSF database includes including a latest reported periodic rank indicator in the CSF database and including a latest reported periodic CQI and PMI in the CSF database.

In some examples, maintaining the CSF database includes updating the CSF database each time UE 115-d triggers a periodic RI report over the air or each time the UE triggers a periodic CQI indicator and PMI indicator over the air.

At 615, UE 115-d may determine whether the CSF information in the CSF database is usable for periodic reporting. In some cases, determining whether the CSF information in the CSF database is usable for periodic reporting includes identifying the CSF information in the CSF database as usable based on UE 115-d transmitting a periodic RI report or a periodic CQI and PMI report.

At 620, UE 115-d may transmit a periodic CSF report using either the CSF information in the CSF database or more recent CSF information based on whether the CSF information in the CSF database is usable. In some cases, transmitting the periodic CSF report includes transmitting the periodic CSF report using the CSF database based further on an elapsed time after an inactive period associated with a first radio of UE 115-d operating in the MSIM mode and concurrent with an active period of a second radio of UE 115-d operating in the MSIM mode.

FIG. 7 shows a block diagram 700 of a device 705 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a communications manager 715, and a transmitter 720. The device 705 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to channel state feedback handling for multi-subscriber identity module device, etc. ) . Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 710 may utilize a single antenna or a set of antennas.

The communications manager 715 may detect an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) UE and concurrent with an active period of a second radio of the MSIM UE, perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. The communications manager 715 may also identify that the UE is operating in a multi-subscriber identity module (MSIM) mode, maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable. The communications manager 715 may be an example of aspects of the communications manager 1010 described herein.

The communications manager 715, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 715, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 715, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 715, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 715, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 720 may transmit signals generated by other components of the device 705. In some examples, the transmitter 720 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 720 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 720 may utilize a single antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a device 805 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The device 805 may be an example of aspects of a device 705 or a UE 115 as described herein. The device 805 may include a receiver 810, a communications manager 815, and a transmitter 860. The device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to channel state feedback handling for multi-subscriber identity module device, etc. ) . Information may be passed on to other components of the device 805. The receiver 810 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 810 may utilize a single antenna or a set of antennas.

The communications manager 815 may be an example of aspects of the communications manager 715 as described herein. The communications manager 815 may include an inactive period detection component 820, an uplink grant validity check component 825, a CSF transmission determining component 830, an uplink message transmitting component 835, a MSIM mode identifying component 840, a CSF database maintaining component 845, a CSF database use determining component 850, and a periodic CSF transmitting component 855. The communications manager 815 may be an example of aspects of the communications manager 1010 described herein.

The inactive period detection component 820 may detect an inactive period associated with a first radio of an MSIM UE and concurrent with an active period of a second radio of the MSIM UE. The uplink grant validity check component 825 may perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period. The CSF transmission determining component 830 may determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback. The uplink message transmitting component 835 may transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.

The MSIM mode identifying component 840 may identify that the UE is operating in an MSIM mode. The CSF database maintaining component 845 may maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting. The CSF database use determining component 850 may determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting. The periodic CSF transmitting component 855 may transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

The transmitter 860 may transmit signals generated by other components of the device 805. In some examples, the transmitter 860 may be collocated with a receiver 810 in a transceiver module. For example, the transmitter 860 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 860 may utilize a single antenna or a set of antennas.

FIG. 9 shows a block diagram 900 of a communications manager 905 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The communications manager 905 may be an example of aspects of a communications manager 715, a communications manager 815, or a communications manager 1010 described herein. The communications manager 905 may include an inactive period detection component 910, an uplink grant validity check component 915, a CSF transmission determining component 920, an uplink message transmitting component 925, a check window updating component 930, a HARQ component 935, a MSIM mode identifying component 940, a CSF database maintaining component 945, a CSF database use determining component 950, and a periodic CSF transmitting component 955. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The inactive period detection component 910 may detect an inactive period associated with a first radio of a MSIM UE and concurrent with an active period of a second radio of the MSIM UE. The uplink grant validity check component 915 may perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period. In some examples, the uplink grant validity check component 915 may identify that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message. In some examples, the uplink grant validity check component 915 may identify that the uplink grant includes a RV indication, indicating that the TB size of the uplink message is to be based on a previously indicated TB size.

In some examples, the uplink grant validity check component 915 may identify that the uplink grant includes an RB size and CSI request bit setting, where the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report is to be triggered.

In some examples, the uplink grant validity check component 915 may determine, based on the new data indication and the RV indication, the RB size, and the CSI request bit setting, that the uplink grant is invalid. In some examples, the uplink grant validity check component 915 may identify that the uplink grant includes a flipped NDI flag.

In some examples, the uplink grant validity check component 915 may identify that the uplink grant indicates a non-RV0 version. In some examples, the uplink grant validity check component 915 may identify that the uplink grant indicates one of a MCS index within a predefined range. In some cases, the predefined range includes MCS29, MCS30, and MCS31.

In some examples, the uplink grant validity check component 915 may perform the uplink grant validity check within a check window that begins at an end of the inactive period. In some cases, a duration of the check window is based on a HARQ process round trip time (RTT) for the UE.

In some examples, the uplink grant validity check component 915 may determine that the uplink grant is associated with uplink scheduling for one of a primary component carrier or a secondary component carrier.

In some examples, the uplink grant validity check component 915 may determine that the uplink grant is a set of uplink grants, each associated with uplink scheduling for a respective primary component carrier or secondary component carrier.

The CSF transmission determining component 920 may determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback. In some examples, the CSF transmission determining component 920 may determine that the uplink grant is invalid. In some examples, the CSF transmission determining component 920 may refrain from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid.

In some examples, the CSF transmission determining component 920 may refrain from including the portions of the channel state feedback in the uplink message for a predetermined duration of time. In some examples, the CSF transmission determining component 920 may terminate the predetermined duration of time early if a new initial uplink grant is received during the predetermined duration of time. In some cases, the portions of the channel state feedback not included in the uplink message based on the uplink grant being invalid include a periodic rank indicator and a channel quality indicator. In some cases, the predetermined duration of time begins at an end of the inactive period and is based on a HARQ process RTT for the UE multiplied by one less than a maximum number of uplink transmission attempts associated with the HARQ process.

The uplink message transmitting component 925 may transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. The check window updating component 930 may receive, at the UE, a new initial uplink grant during the check window. In some examples, the check window updating component 930 may terminate the check window early based on receiving the new initial uplink grant.

The HARQ component 935 may determine that an uplink HARQ process associated with the uplink grant is inactive. In some examples, the HARQ component 935 may terminate the check window early based on determining that the uplink HARQ process is inactive.

The MSIM mode identifying component 940 may identify that the UE is operating in an MSIM mode. The CSF database maintaining component 945 may maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting. In some examples, the CSF database maintaining component 945 may include a latest reported periodic rank indicator in the channel state feedback database.

In some examples, the CSF database maintaining component 945 may include a latest reported periodic channel quality indicator and precoding-matrix indicator in the channel state feedback database. In some examples, the CSF database maintaining component 945 may update the channel state feedback database each time the UE triggers a periodic rank-indicator report over the air or each time the UE triggers a periodic channel quality indicator and precoding-matrix indicator report over the air.

The CSF database use determining component 950 may determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting. In some examples, the CSF database use determining component 950 may identify the channel state feedback information in the channel state feedback database as unusable based on the UE participating in a handover, a changing of a transmission mode of the UE, a changing of a channel quality indicator report mode of the UE, or a changing of a number of receive antennas for the UE. In some examples, the CSF database use determining component 950 may identify the channel state feedback information in the channel state feedback database as usable based on the UE transmitting a periodic rank-indicator report or a periodic channel quality indicator and precoding-matrix indicator report.

The periodic CSF transmitting component 955 may transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

In some examples, the periodic CSF transmitting component 955 may transmit the periodic channel state feedback report using the channel state feedback database based further on an elapsed time after an inactive period associated with a first radio of the UE operating in the MSIM mode and concurrent with an active period of a second radio of the UE operating in the MSIM mode.

In some examples, the periodic CSF transmitting component 955 may compare the elapsed time with a predetermined threshold time. In some examples, the periodic CSF transmitting component 955 may determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting based on the comparison of the elapsed time with the predetermined threshold time, where the periodic report is transmitted using channel state feedback information from the channel state feedback database when the elapsed time is less than or equal to the predetermined threshold time and where the periodic report is transmitted using the more recent channel state feedback information when the elapsed time exceeds the predetermined threshold time.

FIG. 10 shows a diagram of a system 1000 including a device 1005 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The device 1005 may be an example of or include the components of device 705, device 805, or a UE 115 as described herein. The device 1005 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1010, an I/O controller 1015, a transceiver 1020, an antenna 1025, memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., bus 1045) .

The communications manager 1010 may detect an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) UE and concurrent with an active period of a second radio of the MSIM UE, perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period, determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback, and transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. The communications manager 1010 may also identify that the UE is operating in a multi-subscriber identity module (MSIM) mode, maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting, determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting, and transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable.

The I/O controller 1015 may manage input and output signals for the device 1005. The I/O controller 1015 may also manage peripherals not integrated into the device 1005. In some cases, the I/O controller 1015 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1015 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 1015 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1015 may be implemented as part of a processor. In some cases, a user may interact with the device 1005 via the I/O controller 1015 or via hardware components controlled by the I/O controller 1015.

The transceiver 1020 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1020 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1025. However, in some cases the device may have more than one antenna 1025, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1030 may include RAM and ROM. The memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1030 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1040 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1040 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks supporting channel state feedback handling for multi-subscriber identity module device) .

The code 1035 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1035 may not be directly executable by the processor 1040 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 11 shows a flowchart illustrating a method 1100 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a UE 115 or its components as described herein. In some cases, the UE 115 may be an example of an MSIM UE as described herein. For example, the operations of method 1100 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1105, the UE may detect an inactive period associated with a first radio of the UE and concurrent with an active period of a second radio of the MSIM UE. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be performed by an inactive period detection component as described with reference to FIGs. 7 through 10.

At 1110, the UE may perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period. The operations of 1110 may be performed according to the methods described herein. In some examples, aspects of the operations of 1110 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1115, the UE may determine, based on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be performed by a CSF transmission determining component as described with reference to FIGs. 7 through 10.

At 1120, the UE may transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be performed by an uplink message transmitting component as described with reference to FIGs. 7 through 10.

FIG. 12 shows a flowchart illustrating a method 1200 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The operations of method 1200 may be implemented by a UE 115 or its components as described herein. In some cases, the UE 115 may be an example of an MSIM UE as described herein. For example, the operations of method 1200 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1205, the UE may detect an inactive period associated with a first radio of the UE and concurrent with an active period of a second radio of the MSIM UE. The operations of 1205 may be performed according to the methods described herein. In some examples, aspects of the operations of 1205 may be performed by an inactive period detection component as described with reference to FIGs. 7 through 10.

At 1210, the UE may perform, based on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period. The operations of 1210 may be performed according to the methods described herein. In some examples, aspects of the operations of 1210 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1215, the UE may identify that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message. The operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1220, the UE may identify that the uplink grant includes an RV indication, indicating that a TB size of the uplink message is to be based on a previously indicated TB size. The operations of 1220 may be performed according to the methods described herein. In some examples, aspects of the operations of 1220 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1225, the UE may identify that the uplink grant includes an RB size and CSI request bit setting, where the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report is to be triggered. The operations of 1225 may be performed according to the methods described herein. In some examples, aspects of the operations of 1225 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1230, the UE may determine, based on the new data indication and the RV indication, that the uplink grant is invalid. The operations of 1230 may be performed according to the methods described herein. In some examples, aspects of the operations of 1230 may be performed by an uplink grant validity check component as described with reference to FIGs. 7 through 10.

At 1235, the UE may transmit an uplink message that includes portions of the channel state feedback in accordance with the determining. The operations of 1235 may be performed according to the methods described herein. In some examples, aspects of the operations of 1235 may be performed by an uplink message transmitting component as described with reference to FIGs. 7 through 10.

FIG. 13 shows a flowchart illustrating a method 1300 that supports channel state feedback handling for multi-subscriber identity module device in accordance with aspects of the present disclosure. The operations of method 1300 may be implemented by a UE 115 or its components as described herein. In some cases, the UE 115 may be an example of an MSIM UE as described herein. For example, the operations of method 1300 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1305, the UE may identify that the UE is operating in an MSIM mode. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed by a MSIM mode identifying component as described with reference to FIGs. 7 through 10.

At 1310, the UE may maintain, based on the UE operating in MSIM mode, a channel state feedback database that includes channel state feedback information for periodic reporting. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed by a CSF database maintaining component as described with reference to FIGs. 7 through 10.

At 1315, the UE may determine whether the channel state feedback information in the channel state feedback database is usable for periodic reporting. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed by a CSF database use determining component as described with reference to FIGs. 7 through 10.

At 1320, the UE may transmit a periodic channel state feedback report using either the channel state feedback information in the channel state feedback database or more recent channel state feedback information based on whether the channel state feedback information in the channel state feedback database is usable. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed by a periodic CSF transmitting component as described with reference to FIGs. 7 through 10.

It should be noted that the methods described above describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single carrier frequency division multiple access (SC-FDMA) , and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .

An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS) . LTE, LTE-A, and LTE-A Pro are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs 115 having an association with the femto cell (e.g., UEs 115 in a closed subscriber group (CSG) , UEs 115 for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells, and may also support communications using one or multiple component carriers.

The wireless communications system 100 or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication, comprising:

detecting an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) user equipment (UE) and concurrent with an active period of a second radio of the MSIM UE;

performing, based at least in part on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period;

determining, based at least in part on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback; and

transmitting an uplink message that includes portions of the channel state feedback in accordance with the determining.
The method of claim 1, wherein performing the uplink grant validity check comprises:

identifying that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message;

identifying that the uplink grant includes a redundancy version (RV) indication, indicating that a transport block (TB) size of the uplink message is to be based on a previously indicated TB size

identifying that the uplink grant includes a resource block (RB) size and channel state information (CSI) request bit setting, wherein the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report is to be triggered; and

determining, based at least in part on the new data indication, the RV indication, the RB size, and the CSI request bit setting, that the uplink grant is invalid.
The method of claim 2, wherein identifying that the uplink grant includes the new data indication comprises:

identifying that the uplink grant includes a flipped new data indicator (NDI) flag.
The method of claim 2, wherein identifying that the uplink grant includes the RV indication comprises:

identifying that the uplink grant indicates a non-RV0 version; and

identifying that the uplink grant indicates one of a modulation and coding scheme (MCS) index within a predefined range.
The method of claim 4, wherein the predefined range includes MCS29, MCS30, and MCS31.
The method of claim 1, wherein performing the uplink grant validity check comprises:

performing the uplink grant validity check within a check window that begins at an end of the inactive period.
The method of claim 6, wherein a duration of the check window is based at least in part on a hybrid automatic repeat request (HARQ) process round trip time (RTT) for the UE.
The method of claim 6, further comprising:

receiving, at the UE, a new initial uplink grant during the check window; and

terminating the check window early based on receiving the new initial uplink grant.
The method of claim 6, further comprising:

determining that an uplink hybrid automatic repeat request (HARQ) process associated with the uplink grant is inactive; and

terminating the check window early based on determining that the uplink HARQ process is inactive.
The method of claim 1, further comprising:

determining that the uplink grant is associated with uplink scheduling for one of a primary component carrier or a secondary component carrier.
The method of claim 1, further comprising:

determining that the uplink grant is a plurality of uplink grants, each associated with uplink scheduling for a respective primary component carrier or secondary component carrier.
The method of claim 1, wherein determining whether to transmit at least portions of the channel state feedback comprises:

determining that the uplink grant is invalid; and

refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid.
The method of claim 12, wherein the portions of the channel state feedback not included in the uplink message based on the uplink grant being invalid include a periodic rank indicator and a channel quality indicator.
The method of claim 12, wherein refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid comprises:

refraining from including the portions of the channel state feedback in the uplink message for a predetermined duration of time.
The method of claim 14, wherein the predetermined duration of time begins at an end of the inactive period and is based at least in part on a hybrid automatic repeat request (HARQ) process round trip time (RTT) for the UE multiplied by one less than a maximum number of uplink transmission attempts associated with the HARQ process.
The method of claim 14, further comprising:

terminating the predetermined duration of time early if a new initial uplink grant is received during the predetermined duration of time.
An apparatus for wireless communication, comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

detect an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) user equipment (UE) and concurrent with an active period of a second radio of the MSIM UE;

perform, based at least in part on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period;

determine, based at least in part on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback; and

transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.
An apparatus for wireless communication, comprising:

means for detecting an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) user equipment (UE) and concurrent with an active period of a second radio of the MSIM UE;

means for performing, based at least in part on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period;

means for determining, based at least in part on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback; and

means for transmitting an uplink message that includes portions of the channel state feedback in accordance with the determining.
The apparatus of claim 18, wherein the means for performing the uplink grant validity check comprises:

means for identifying that the uplink grant includes a new data indication, indicating that the uplink grant pertains to a first transmission of the uplink message;

means for identifying that the uplink grant includes a redundancy version (RV) indication, indicating that a transport block (TB) size of the uplink message is to be based on a previously indicated TB size

means for identifying that the uplink grant includes a resource block (RB) size and channel state information (CSI) request bit setting, wherein the RV indication, the RB size, and the CSI request bit setting indicate that an aperiodic report is to be triggered; and

means for determining, based at least in part on the new data indication, the RV indication, the RB size, and the CSI request bit setting, that the uplink grant is invalid.
The apparatus of claim 19, wherein the means for identifying that the uplink grant includes the new data indication comprises:

means for identifying that the uplink grant includes a flipped new data indicator (NDI) flag.
The apparatus of claim 19, wherein the means for identifying that the uplink grant includes the RV indication comprises:

identifying that the uplink grant indicates a non-RV0 version; and

means for identifying that the uplink grant indicates one of a modulation and coding scheme (MCS) index within a predefined range.
The apparatus of claim 18, wherein the means for performing the uplink grant validity check comprises:

means for performing the uplink grant validity check within a check window that begins at an end of the inactive period.
The apparatus of claim 22, wherein a duration of the check window is based at least in part on a hybrid automatic repeat request (HARQ) process round trip time (RTT) for the UE.
The apparatus of claim 22, further comprising:

means for receiving, at the UE, a new initial uplink grant during the check window; and

means for terminating the check window early based on receiving the new initial uplink grant.
The apparatus of claim 22, further comprising:

means for determining that an uplink hybrid automatic repeat request (HARQ) process associated with the uplink grant is inactive; and

means for terminating the check window early based on determining that the uplink HARQ process is inactive.
The apparatus of claim 18, further comprising:

means for determining that the uplink grant is associated with uplink scheduling for one of a primary component carrier or a secondary component carrier.
The apparatus of claim 18, wherein the means for determining whether to transmit at least portions of the channel state feedback comprises:

means for determining that the uplink grant is invalid; and

means for refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid.
The apparatus of claim 27, wherein the portions of the channel state feedback not included in the uplink message based on the uplink grant being invalid include a periodic rank indicator and a channel quality indicator.
The apparatus of claim 27, wherein the means for refraining from including in the uplink message portions of the channel state feedback based on the uplink grant being invalid comprises:

means for refraining from including the portions of the channel state feedback in the uplink message for a predetermined duration of time.
A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

detect an inactive period associated with a first radio of a multi-subscriber identity module (MSIM) user equipment (UE) and concurrent with an active period of a second radio of the MSIM UE;

perform, based at least in part on detection of the inactive period, an uplink grant validity check to determine whether an uplink grant is invalid due to the uplink grant being a retransmission of an initial uplink grant whose receipt by the UE was affected by the inactive period;

determine, based at least in part on whether the uplink grant is invalid, whether to transmit at least portions of channel state feedback; and

transmit an uplink message that includes portions of the channel state feedback in accordance with the determining.