WO2021129594A1

WO2021129594A1 - Determining whether an uplink switching gap is to be applied between changes in radio frequency status of a user equipment

Info

Publication number: WO2021129594A1
Application number: PCT/CN2020/138226
Authority: WO
Inventors: Bo Chen; Chenxi HAO; Yiqing Cao; Yu Zhang; Chao Wei; Yi Huang; Peter Gaal; Hao Xu
Original assignee: Qualcomm Incorporated
Priority date: 2019-12-23
Filing date: 2020-12-22
Publication date: 2021-07-01
Also published as: WO2021127835A1

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The UE may receive a grant scheduling an uplink transmission for the UE. The UE may determine, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission. The UE may perform the uplink transmission in accordance with the determining.

Description

DETERMINING WHETHER AN UPLINK SWITCHING GAP IS TO BE APPLIED BETWEEN CHANGES IN RADIO FREQUENCY STATUS OF A USER EQUIPMENT

CROSS-REFERENCE

The present Application for Patent claims the benefit of PCT Application No. PCT/CN2019/127374 by Chen et al., entitled “DETERMINING WHETHER AN UPLINK SWITCHING GAP IS TO BE APPLIED BETWEEN CHANGES IN RADIO FREQUENCY STATUS OF A USER EQUIPMENT” filed December 23, 2019, and assigned to the assignee hereof.

BACKGROUND

The following relates generally to wireless communications, and more specifically to determining whether an uplink switching gap is to be applied between changes in radio frequency (RF) status of a user equipment (UE) .

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 orthogonal frequency division multiplexing (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 UE.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support determining whether an uplink switching gap is to be applied between changes in radio frequency (RF) status of a user equipment (UE) . Generally, the described techniques provide for various rules adopted by a base station and UE to improve determinations of whether a switching gap will be applied by the UE before performing an uplink transmission. For example, the UE may be configured with two transmit chains. One transmit chain may be configured to perform or otherwise support uplink transmissions on a first carrier and a second carrier. The other transmit chain may be configured to perform or otherwise support uplink transmissions on the second carrier. Accordingly, the UE may inform the base station that it is configured with the two transmit chains, along with carrier/port configurations supported by the UE (e.g., on a per-transmit chain basis) . Subsequently, the base station may transmit a grant to the UE scheduling an uplink transmission. The base station and UE may apply the described rules, alone or in any combination, in determining whether the current RF status (e.g., how the first and/or second transmit chains are currently configured, which may also be referred to as the RF state of the UE) is to be reconfigured during a switching gap that is applied prior to performing the uplink transmission. In the situation where the switching gap is to be applied to reconfigure the current RF status, the UE may reconfigure the first and/or second transmit chains during the switching gap and begin the uplink transmission after reconfiguration. In the situation where the switching gap is not to be applied, the UE may simply begin performing the uplink transmission. Based on the rules described herein, the base station may know whether or not the switching gap was applied prior to the UE commencing the uplink transmission. This may improve reception of the uplink transmission by the base station due to increased time alignment/synchronization between the base station and UE with respect to the switching gap.

A method of wireless communication at a UE is described. The method may include identifying that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receiving a grant scheduling an uplink transmission for the UE, determining, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and performing the uplink transmission in accordance with the determining.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receive a grant scheduling an uplink transmission for the UE, determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and perform the uplink transmission in accordance with the determining.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receiving a grant scheduling an uplink transmission for the UE, determining, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and performing the uplink transmission in accordance with the determining.

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 a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receive a grant scheduling an uplink transmission for the UE, determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and perform the uplink transmission in accordance with the determining.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to apply the switching gap may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to apply the switching gap may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain may be configured for either a one-port transmission on the second carrier or for no transmission, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

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 transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 transmission includes a one-port transmission on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the UE refrains from transmitting during the switching gap.

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 transmission includes a one-port transmission on the first carrier, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the UE refrains from transmitting during the switching gap.

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 UE is configured for dual uplink transmissions on the first carrier and the second carrier, determining that the uplink transmission includes a two-port transmission on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and the current RF status does not support two-port transmissions on the second carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the UE refrains from transmitting during the switching gap.

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 UE is configured for dual uplink transmissions on the first carrier and the second carrier, determining that the uplink transmission includes a one-port transmission on the first carrier, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and the current RF status supports two-port transmissions on the second carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the UE refrains from transmitting during the switching gap.

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 transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the current RF status of the UE, whether the uplink transmission includes a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the uplink transmission may include operations, features, means, or instructions for determining the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier based on a preceding uplink transmission that involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining the uplink transmission includes a one-port transmission using both the first transmit chain and the second transmit chain on the second carrier based on the preceding uplink transmission that involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second 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, based on a received medium access control (MAC) message or a radio resource control (RRC) message, that the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a downlink control information (DCI) format 0_0, determining, based on the DCI format, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_1, where the uplink transmission may be a non-codebook-based uplink transmission, determining, based on the DCI format, that the uplink transmission includes a one-port or a two-port uplink transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does not configure an uplink full power transmit mode.

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 reference signal resources identifies a one-port reference signal configuration, determining, based on the one-port reference signal configuration, that the uplink transmission includes a one-port transmission using the second transmit chain on the second carrier; , determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does configure an uplink full power transmit mode.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the upper layer parameter configured uplink full power transmit mode, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the grant, that the uplink transmission includes at least one of a physical uplink control channel (PUCCH) transmission, or a physical random access channel (PRACH) transmission, or a combination thereof, and determining that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second 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, based on the grant, that the uplink transmission includes at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof, determining that the uplink transmission may be immediately subsequent to a preceding uplink transmission that includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier, and determining that the uplink transmission, without sounding reference signal or physical uplink shared channel transmission, includes a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to apply the switching gap may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain on the first carrier, determining that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to apply the switching gap to reconfigure the current RF status may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant does not involve the second transmit chain, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier, and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether to apply the switching gap may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

A method of wireless communication at a base station is described. The method may include identifying that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmitting a grant scheduling an uplink transmission for the UE, identifying that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determining, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receiving the uplink transmission from the UE based on the grant and the determining.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmit a grant scheduling an uplink transmission for the UE, identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receive the uplink transmission from the UE based on the grant and the determining.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for identifying that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmitting a grant scheduling an uplink transmission for the UE, identifying that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determining, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receiving the uplink transmission from the UE based on the grant and the determining.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmit a grant scheduling an uplink transmission for the UE, identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receive the uplink transmission from the UE based on the grant and the determining.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the switching gap may be applied may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the switching gap may be applied may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain may be configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a current RF status of the UE, whether the uplink transmission includes a one-port transmission using only first second transmit chain or both the first transmit chain and the second transmit chain on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or one-port transmission using only the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_0, determining, based on the DCI format, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_1, where the uplink transmission may be a non-codebook-based uplink transmission, determining, based on the DCI format, that the uplink transmission includes a one-port or a two-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 reference signal resources identifies a one-port reference signal configuration, determining, based on the one-port reference signal configuration, that the uplink transmission includes a one-port transmission using the first transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

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 grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, the uplink transmission being a codebook-based uplink transmission, and an upper layer parameter configures an uplink full power transmit mode.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the grant, that the uplink transmission includes at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof, and determining that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the switching gap may be applied may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain on the first carrier, determining that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission, and determining that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the switching gap may be applied may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant does not involve the second transmit chain, determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier, and determining that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the switching gap may be applied may include operations, features, means, or instructions for determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier, determining that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier, and determining that the switching gap to reconfigure the current RF status may be not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports determining whether an uplink switching gap is to be applied between changes in radio frequency (RF) status of a user equipment (UE) in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communication system that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a switching configuration that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a process that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIGs. 5 and 6 show block diagrams of devices that support determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 7 shows a block diagram of a communications manager that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 8 shows a diagram of a system including a device that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIGs. 9 and 10 show block diagrams of devices that support determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 11 shows a block diagram of a communications manager that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIG. 12 shows a diagram of a system including a device that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

FIGs. 13 through 16 show flowcharts illustrating methods that support determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

A user equipment (UE) may be limited to two transmit chains (e.g., due to thermal and/or power consumption limitations) . For inter-band carrier aggregation (CA) communications, the UE may typically utilize one transmit chain for transmissions on a first carrier and the other transmit chain for transmissions on a second carrier (e.g., in the same radio frequency spectrum band or in different bands) . To support such multi-carrier uplink transmissions, the UE may switch (e.g., reconfigure, retune, etc. ) at least one of the transmit chains between different carriers and/or port configuration between uplink transmissions. Scheduling such multi-carrier uplink transmissions may be problematic from the perspective of base station. For example, the base station may not know the current port status and/or transmit chain configuration of the UE. For example, the base station may not know which carrier the first and/or second transmit chains are tuned to, the port configuration status of the first and/or second transmit chains, or both, and consequently may not know whether the UE would need to reconfigure its transmit chain if scheduled for an uplink transmission.

Generally, the described techniques provide various mechanisms that support wireless communications in a wireless network. Broadly, aspects of the described techniques provide for various rules adopted by a base station and UE to improve determinations of whether a switching gap will be applied by the UE before performing an uplink transmission. For example, the UE may be configured with two transmit chains. One transmit chain may be configured to perform or otherwise support uplink transmissions on a first carrier and a second carrier. The other transmit chain may be configured to perform or otherwise support uplink transmissions on the second carrier. Accordingly, the UE may inform the base station that it is configured with the two transmit chains, along with carrier/port configurations supported by the UE (e.g., on a per-transmit chain basis) . Subsequently, the base station may transmit a grant to the UE scheduling an uplink transmission. The base station and UE may apply the described rules, alone or in any combination, in determining whether the current radio frequency (RF) status (e.g., how the first and/or second transmit chains are currently configured) is to be reconfigured during a switching gap that may be applied prior to performing the uplink transmission. In the situation where the switching gap is to be applied to reconfigure the current RF status, the UE may reconfigure the first and/or second transmit chains during the switching gap and begin the uplink transmission after reconfiguration. In the situation where the switching gap is not to be applied, the UE may simply begin performing the uplink transmission. Based on the rules described herein, the base station may know whether or not the switching gap was applied prior to the UE commencing the uplink transmission. This may improve reception of the uplink transmission by the base station due to increased time alignment and synchronization between the base station and the UE with respect to the switching gap.

Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to determining whether an uplink switching gap is to be applied between changes in RF status of a UE.

FIG. 1 illustrates an example of a wireless communications system 100 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE 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 NodeB 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 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 megahertz (MHz) to 300 gigahertz (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 may be capable of tolerating 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 carrier aggregation configuration in conjunction with component carriers 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 device is 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 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 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 evolved universal mobile telecommunication system terrestrial radio access (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 orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (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) . 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 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 or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers 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 component carriers, which may include use of a reduced symbol duration as compared with symbol durations of the other component carriers. 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 system 100 may be an NR system that 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.

A UE 115 may identify that a RF status of the UE 115 includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The UE 115 may receive a grant scheduling an uplink transmission for the UE 115. The UE 115 may determine, based at least in part on the grant and on a current RF status of the UE 115, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission. The UE 115 may perform the uplink transmission in accordance with the determining.

A base station 105 may identify that a RF status of a UE 115 includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The base station 105 may transmit a grant scheduling an uplink transmission for the UE 115. The base station 105 may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE 115. The base station 105 may determine, based at least in part on the grant and the current RF status of the UE 115, whether a switching gap to reconfigure the current RF status will be applied at the UE 115 prior to transmission of the uplink transmission. The base station 105 may receive the uplink transmission from the UE 115 based at least in part on the grant and the determining.

FIG. 2 illustrates an example of a wireless communication system 200 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. In some examples, wireless communication system 200 may implement aspects of wireless communication system 100. Wireless communication system 200 may include base station 205 and UE 210, which may be examples of the corresponding devices described herein.

In some configurations, a UE may have two transmit chains. One of the transmit chains may be configured to support communications on a first carrier (or carrier 1) and a second carrier (or carrier 2) . The second transmit chain may be configured to support communications on the second carrier. The UE supporting a maximum of two concurrent transmissions may support transmit chain switching between a first case (Case 1) where the first transmit chain is configured on carrier 1 and the second transmit chain is configured on carrier 2, and a second case (Case 2) where the first transmit chain and the second transmit chain are both configured on carrier 2. An uplink switching period (or gap) for the UE to retune its RF components (e.g., RF status) may be required between uplink transmissions. The RF status of the UE may refer to the configuration of the first transmit chain and/or the second transmit chain with respect to being tuned to carrier 1 and/or carrier 2. The RF status of the UE may refer to the configuration of the first transmit chain and/or the second transmit chain with respect to whether they are configured for a one-port and/or a two-port transmission on carrier 1 and/or carrier 2. In some aspects, the UE may be configured with dual uplink capabilities such that the UE may support a one-port transmission on carrier 1 and a one-port transmission on carrier 2 (e.g., UE 210 may be configured with dualUL by a parameter such as uplink TxSwitchingOption-r16) . Retuning or otherwise reconfiguring the RF status (e.g., the current RF status or RF state) of the UE may refer to retuning or reconfiguring at least one or both transmit chain (s) from the first carrier to the second carrier, or vice versa. Retuning or otherwise reconfiguring the RF status (e.g., the current RF status) of the UE may refer to retuning or reconfiguring the first transmit chain and/or the second transmit chain between a one-port transmission and a two-port transmission on the first carrier and/or the second carrier, or vice versa. In some aspects, a decision of whether to retune or otherwise reconfigure the RF status of the UE may be made, and the UE may continue communications according to the current RF status for a time period before performing the switch. The switching gap may generally refer to the time period in which the UE is retuning or otherwise reconfiguring its transmit chain (s) between carriers and/or port configurations, which may result in a delay in initiating the uplink transmission. The UE may refrain from transmitting for the duration of the switching gap (e.g., a duration such as N _TX1- _TX2) .

Some wireless communication systems may be configured such that the location of the switching gap is based on the deployment scenario. For example, in a E-UTRAN NR –Dual Connectivity (EN-DC) scenario, the switching period may be configured for the NR carrier. As another example, in an uplink CA and super-uplink (SUL) scenario, the switching period may be configured semi-statically by RRC on one carrier of the first and/or second carriers.

However, this may not always provide certainty from perspectives of the base station and UE regarding whether or not the switching period is required when switching between uplink transmissions. In some aspects, whether or not the switching period is needed may be based on whether the transmit chain switching occurs between carrier 1 and carrier 2, or vice versa, in adjacent slots. However, such techniques may raise ambiguity concerns because the network (e.g., base station) may not be aware of the number of transmit chains on carrier 2. For example, a UE may support transmissions on two transmit chains on carrier 2. Additionally or alternatively, the UE may support transmissions on one transmit chain on carrier 2. That is, only considering the transmission port on carrier 2 to determine whether the switching gap is needed, or not, may not provide clarity.

One approach to address this is that the switching period may only exist when the scheduled uplink transmissions are switched between a two-port (2P) transmission on carrier 2 and either a one-port (1P) transmission on carrier 1 or carrier 2 or a 1P transmission on both carrier 1 and carrier 2. This is illustrated in Table 1 below:

Table 1

However, in the 0P+1P scenario (e.g., PUCCH and PRACH) , the UE may use one transmit chain or both transmit chains for a 1P transmission (e.g., two transmit chains may be used for a one-port transmission on carrier 2) . If the number of transmit chains for the scheduled uplink transmission is changed in the following slot, the network may not know whether the switching gap is needed since the network does not know whether the number of transmit chain (s) is changed on carrier 2 from the UE side.

Accordingly, aspects of the described techniques provide various mechanisms (e.g., rules) that may be applied by base station 205 and UE 210 to ensure that both devices are in sync with regard to whether the switching gap is applied prior to performing an uplink transmission or not.

For example, UE 210 may be configured with a first transmit chain that supports communications on both carrier 1 and carrier 2 and a second transmit chain that supports communications on at least carrier 2. In the non-limiting example illustrated in wireless communication system 200, the first transmit chain may support communications on the first carrier 215 (carrier 1) and the second carrier 220 (carrier 2) and the second transmit chain may support communications on the second carrier 220.

When scheduling an uplink transmission for UE 210, base station 205 may transmit a DCI or RRC grant (e.g., a control signal) to UE 210 scheduling uplink resources for the uplink transmission. When the scheduled uplink transmission requires a switching gap, UE 210 may need additional time to prepare for the uplink transmission (e.g., to reconfigure the first and/or second transmit chains, prepare the uplink information for transmission, etc. ) . Aspects of the described techniques support mechanisms that improve performance of the uplink transmission by UE 210 in the situation where base station 205 may not know the transmit chains/port configuration of the first and/or second transmit chains of UE 210.

Accordingly, aspects of the described techniques support base station 205 and UE 210 identifying or otherwise determining that the RF status of UE 210 includes the first transmit chain that can be tuned or otherwise configured for communications on the first carrier 215 or the second carrier 220, and that the second transmit chain may be tuned or otherwise configured for communications on the second carrier 220. For example, this information may be identified based on the UE capability message, RRC signaling, and the like, exchanged between base station 205 and UE 210. The current RF status of UE 210 may also be identified based on a preceding uplink transmission (e.g., based on the information configured for the uplink transmission) .

Subsequently, base station 205 may determine that an uplink transmission is to be performed by UE 210 (e.g., based on receiving a scheduling request, a buffer status report, and the like, from UE 210) . Accordingly, base station 205 may transmit a grant to UE 210 scheduling the uplink transmission. For example, the grant may be a DCI grant (e.g., for dynamically allocated resources) and/or an RRC grant (e.g., for semi-statically configured resources) scheduling the uplink transmission. In some aspects, the grant may also identify time and/or frequency resources that UE 210 is to use for performing the uplink transmission. In some aspects, base station 205 and UE 210 may, according to the techniques described herein, determine whether a switching gap to reconfigure the current RF status of UE 210 will be applied prior to performing the uplink transmission. In this situation, the timing for the uplink transmission scheduled by the grant may be selected to account for the switching gap.

For example, base station 205 and UE 210 may identify or otherwise determine that the uplink transmission scheduled by the grant would include a reconfiguration of the current RF status of UE 210. Based on the grant and the current RF status of UE 210, base station 205 and UE 210 may both determine whether the switching gap to reconfigure the current RF status of UE 210 will be applied prior to performing the uplink transmission. Aspects of the described techniques provide various rules that may be implemented at base station 205 and UE 210 to determine whether the switching gap will be applied. It is to be understood that the rules discussed herein, or any sub-rule associated with a rule, may be implemented individually or in any combination.

One rule may include the switching gap being applied any time scheduled uplink transmissions are switched between a two-port (2P) transmission on the second carrier 220 (e.g., 0P+2P) and either a one-port (1P) transmission on the first carrier 215 (e.g., 1P+0P of Case 1) or a one-port transmission on both the first carrier 215 and the second carrier 220 (e.g., 1P+1P) . For example, the UE capability message may indicate that UE 210 supports a one-port transmission on the second carrier 220 using either the first transmit chain or both the first transmit chain and the second transmit chain. Accordingly, base station 205 and UE 210 may determine that the switching gap is applied prior to performing the uplink transmission if the conditions for this rule are satisfied. In some aspects, this rule may be applied on top of any of the rules described herein (e.g., the rule may serve as a base rule when determining whether the switching gap is applied) .

Another rule may define a preference for application of the switching gap for a one-port uplink transmission on the second carrier 220 (e.g., 0P+1P) . In some aspects, this rule may introduce 0P+1P_A and 0P+1P_B for Case 1 and Case 2, respectively, according to Table 2 below:

Table 2

0P+1P_A may generally refer to a single transmit chain being used for a scheduled uplink transmission on the second carrier 220. In some aspects, there may be no switching gap applied when switching between 1P+0P or 1P+1P and 0P+1P_A. 0P+1P_B may generally refer to both transmit chains being used for a scheduled uplink transmission on the second carrier 220. In some aspects, there may be no switching gap applied when switching between 0P+2P and 0P+1P_B, and UE 210 may transmit uplink transmissions without interruption for uplink switching. UE 210 may report (e.g., in the UE capability report) its support for 0P+1P_A and 0P+1P_B. In some aspects, support for 0P+1P_B may implicitly indicate support for 0P+1P_A, or vice versa. In some aspects, UE 210 may be in an operation state in which two-port transmission may not be supported on the same uplink carrier. For example, UE 210 may support using one transmit chain for a scheduled uplink transmission on the second carrier 220, but UE 210 may not support using two transmit chains for a scheduled uplink transmission on the second carrier 220 (e.g., UE 210 may support 0P+1P_A but UE 210 may not support 0P+1P_B or 0P+2P) . Additionally or alternatively, UE 210 may be in an operation state in which two-port transmission can be supported on the same uplink carrier, and UE 210 may support using two transmit chains on the second carrier 220 (e.g., 0P+1P_B or 0P+2P) .

For UE 210 reporting support for 0P+1P_A capability, UE 210 may be expected to apply the switching gap for any new 0P+1P_A uplink transmission from 0P+2P. For UE 210 reporting support for 0P+1P_B capability, two alternatives may be provided in this rule. In alternative one, UE 210 may be expected to apply the switching gap for any new 0P+1P_B uplink transmission from 1P+1P or 1P+0P, or vice versa. As discussed, UE 210 may not be expected to apply the switching gap for any new scheduled 0P+1P_B uplink transmission from 0P+2P. In alternative two, UE 210 may not be expected to apply the switching gap for any new 0P+1P_A or 0P+1P_B scheduled uplink transmission. Whether a single transmit chain or dual transmit chains are used for a one-port transmission may depend on the available number of transmit chain (s) on the second carrier 220. That is, if UE 210 is in Case 1 (e.g., the current RF status of UE 210 is in Case 1) , a single transmit chain may be used (0P+1P_A) . If UE 210 is in Case 2 (e.g., the current RF status of UE 210 is in Case 2) , dual transmit chains may be used for 0P+1P_B. In some aspects, the application of the switching gap may be based on the operation state of UE 210, such as whether UE 210 is in an operation state (e.g., an RF state) that supports dual transmit chains for a transmission on a single carrier or not.

In one example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain or the second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine that the current RF status (e.g., based on a preceding uplink transmission) involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission.

In another example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain or the second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine that the current RF status (e.g., based on the preceding uplink transmission) involves the first transmit chain configured for a one-port transmission on the first carrier 215 and the second transmission chain configured for either a one-port transmission on the second carrier 220 or for no transmission. Accordingly, this may indicate that the switching gap to reconfigure the current RF status is not applied prior to performing the uplink transmission.

In another example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine that the current RF status (e.g., based on the preceding uplink transmission) involves the first transmit chain configured for a one-port transmission on the first carrier 215 and the second transmit chain configured for either a one-port transmission on the second carrier 220 or for no transmission. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission (e.g., UE 210 may not be expected to transmit for a duration of N _TX1-TX2 on carrier 1 and carrier 2) .

In another example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine (e.g., based on a preceding uplink transmission) that the current RF status involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier 220 (e.g., 0P+2P) . Accordingly, this may indicate that the switching gap to reconfigure the current RF status is not applied prior to performing the uplink transmission, and UE 210 may transmit uplink transmissions without interruption for uplink switching.

In another example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine that the current RF status (e.g., based on the preceding uplink transmission) involves the first transmit chain configured for a one-port transmission on the second carrier 220 and the second transmit chain configured for a one-port transmission on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status is not applied prior to performing the uplink transmission.

In another example, application of this rule may include base station 205 and UE 210 determining that the uplink transmission scheduled by the grant is a one-port transmission using the first transmit chain or second transmit chain on the second carrier 220. Base station 205 and UE 210 may determine that the current RF status (e.g., based on the preceding uplink transmission) involves the first transmit chain or the second transmit chain configured for a one-port transmission on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status is not applied prior to performing the uplink transmission.

In another example, base station 205 and UE 210 may determine that the scheduled uplink transmission is a two-port transmission on the second carrier 220 (e.g., 0P+2P) . Base station 205 and UE 210 may determine that a preceding uplink transmission is a one-port transmission on the first carrier 215 (e.g., 1P+0P) . Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission, and UE 210 may refrain from transmitting for the duration of the switching gap (e.g., N _TX1-TX2) on any of the first carrier 215 and the second carrier 220.

In another example, base station 205 and UE 210 may determine that the scheduled uplink transmission is a one-port transmission on the first carrier 215 and a preceding uplink transmission is a two-port transmission on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission, and UE 210 may refrain from transmitting for the duration of the switching gap on the first carrier 215 and the second carrier 220.

In another example, UE 210 may be configured to support dual uplink transmissions on the first carrier 215 and the second carrier 220 (e.g., UE 210 may be configured with dualUL to support 1P+1P) . UE 210 and base station 205 may determine that the scheduled uplink transmission is a two-port transmission on the second carrier 220 (e.g., 0P+2P) , and a preceding uplink transmission is a one-port transmission on the second carrier 220 (e.g., 1P+1P or 0P+1P_A) . Base station 205 and UE 210 may determine that UE 210 is under an operation state in which UE 210 may not support two-port transmissions on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission, and UE 210 may refrain from transmitting for the duration of the switching gap on the first carrier 215 and the second carrier 220 (e.g., UE 210 may switch from 1P+1P or 1P+1P_A to 0P+2P during the switching gap) .

In another example, UE 210 may be configured to support dual uplink transmissions on the first carrier 215 and the second carrier 220. UE 210 and base station 205 may determine that the scheduled uplink transmission is a one-port transmission on the first carrier 215 (e.g., 1P+0P or 1P+1P) and that a preceding uplink transmission is a one-port transmission on the second carrier 220 (e.g., 0P+1P_B) . Base station 205 and UE 210 may determine that UE 210 is under an operation state in which UE 210 may support two-port transmissions on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission, and UE 210 may refrain from transmitting for the duration of the switching gap on the first carrier 215 and the second carrier 220 (e.g., UE 210 may switch between 0P+1P_B and 1P+0P or 1P+1P during the switching gap) .

Another rule may be a MAC based rule. That is, application of the switching gap to reconfigure the current RF status of UE 210 may be implemented according to a MAC control element (CE) configuration based solution. Accordingly, additional configuration information (e.g., a MAC CE) may define the preference for application of the switching gap for a one-port uplink transmission on the second carrier 220 (e.g., the 0P+1P scenario) . According to the MAC CE configuration, the 0P+1P scenario may be semi-statically configured in either Case 1 or Case 2. That is, the MAC CE may semi-statically configure the 0P+1P_A scenario for Case 1 and/or the 0P+1P_B scenario for Case 2.

Accordingly, application of this rule may include base station 205 transmitting a MAC message to UE 210 indicating whether the switching gap to reconfigure the current RF status of UE 210 is to be applied prior to performing the uplink transmission. That is, the MAC message may configure UE 210 for an uplink transmission in the 0P+1P_A or the 0P+1P_B scenario, which may then be used to determine whether or not to apply the switching gap to reconfigure the current RF status of UE 210. In some aspects, the MAC message may indicate the time period associated with the switching gap.

Another rule may be a DCI based rule. That is, the described techniques may introduce a per-carrier definition for the preference of whether the switching gap is applied to reconfigure the current RF status for a one-port uplink transmission on the second carrier 220.

One application of this rule may be for a one-port physical uplink shared channel (PUSCH) transmission when the grant is a DCI grant using DCI format 0_0 in Case 2 (e.g., 0P+1P_PUSCH) . That is, base station 205 and UE 210 may determine that the grant scheduling the uplink transmission is a DCI format 0_0 grant. Base station 205 and UE 210 may determine that, based on the DCI format, the uplink transmission is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier 220.

Another application of this rule may be for a PUSCH transmission granted by a DCI format 0_1. For example, if a sounding reference signal (SRS) resource indicated by SRS resource indicator (SRI) in a DCI grant using DCI format 0_1 is a one-port uplink configuration, this may signal that the PUSCH transmission is in Case 1 (0P+1P_PUSCH_DCI0_1_SRI_singleport) . If a SRS resource indicated by the SRI in a DCI grant using DCI format 0_1 is a two-port configuration, this may signal that the PUSCH transmission is in case 2 (0P+1P_PUSCH_DCI0_1_SRI_twoports) .

Application of this rule may include base station 205 and UE 210 determining that the grant scheduling the uplink transmission is a DCI format 0_1 (e.g., a non-codebook-based uplink transmission) . Accordingly, base station 205 and UE 210 may determine that the uplink transmission is a one-port or a two-port uplink transmission using the first transmit chain and the second transmit chain on the second carrier 220.

Application of this rule may include base station 205 and UE 210 determining that the grant scheduling the uplink transmission is a DCI format 0_1 (e.g., a codebook-based uplink transmission) . In this situation, base station 205 and UE 210 may determine that the reference signal resources (e.g., SRS resource) identifies a one-port reference signal configuration and, therefore, that the uplink transmission comprises a one-port transmission using the first transmit chain on the second carrier 220. In this situation, base station 205 and UE 210 may determine that the reference signal resources identifies a two-port reference signal configuration and, therefore, that the uplink transmission comprises a two-port transmission using the first transmit chain and the second transmit chain on the second carrier 220.

Another application of this rule may be based on a one-port uplink transmission of PUCCH/PRACH. In one alternative, this may include any PUCCH/PRACH uplink transmission being in Case 2. For example, base station 205 and UE 210 may determine that the uplink transmission is a PUCCH transmission and/or a PRACH transmission and, therefore, that the uplink transmission is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier 220.

Another application of this rule may include, for the case where there is PUCCH/PRACH transmission only on carrier 2 immediately after an uplink transmission in Case 1, the PUCCH/PRACH uplink transmission (without SRS or PUSCH) is recognized as Case 1 to avoid carrier switching. For all other cases, PUCCH/PRACH may all be considered in Case 2. For example, base station 205 and UE 210 may determine that the uplink transmission is a PUCCH/PRACH transmission, and that the preceding uplink transmission is a one-port transmission using the first transmit chain or the second transmit chain on the second carrier 220. Accordingly, base station 205 and UE 210 may determine that the uplink transmission (without SRS or PUSCH transmission) is a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier 220.

In another example, base station 205 and UE 210 may determine that the uplink transmission is a PUCCH transmission and/or a PRACH transmission and that the uplink transmission is immediately subsequent to a preceding uplink transmission that is a one-port transmission using the first transmit chain or the second transmit chain on the second carrier 220. In this example, base station 205 and UE 210 may determine that the uplink transmission, without SRS or PUSCH, is a one-port uplink transmission using either the first transmit chain or the second transmit chain on the second carrier 220.

Another rule may be a number of ports on the first carrier 215 based solution. That is, the presence of the switching gap may depend on whether a transmission using one transmit chain as requested on a carrier supporting only one transmit chain. For inter-band uplink CA, the condition of the existence of the switching gap may depend on whether the UE 210 can be scheduled on the first carrier 215 for Case 1. This is illustrated in Table 3 below.

Table 3

The switching gap may only exist when the scheduled uplink transmissions are switched between a one-port transmission on the first carrier 215 and a zero port transmission and the second carrier 220. For Case 1, a one-port transmission on the first carrier 215 and a one-port transmission on both the first carrier 215 and the second carrier 220 may be supported. For Case 2, both a one-port and a two-port transmission on the second carrier 220 may be supported.

Accordingly, application of this rule may include base station 205 and UE 210 determining that the uplink transmissions is a one-port transmission using the first transmit chain on the first carrier 215 and that the current RF status (e.g., based on a preceding uplink transmission) involves the second transmit chain configured for no transmission. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission.

Another application of this rule may include base station 205 and UE 210 determining that the uplink transmission does not involve the second transmit chain. Base station 205 and UE 210 may determine that the current RF status (e.g., based on a preceding uplink transmission) involves a one-port transmission using the first transmit chain on the first carrier. Accordingly, this may indicate that the switching gap to reconfigure the current RF status may be applied prior to performing the uplink transmission.

Another application of this rule may include base station 205 and UE 210 determining that the uplink transmission is a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. Base station 205 and UE 210 may determine (e.g., based on a preceding uplink transmission) that the current RF status involves either the first transmit chain configured for a one-port transmission on the second carrier 220 or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier 220. Accordingly, this may indicate that the switching gap to reconfigure the current RF status is not applied prior to performing the uplink transmission.

Accordingly, the techniques described herein may be applied by base station 205 and UE 210 when scheduling an uplink transmission. That is, base station 205 may transmit the grant to UE scheduling the uplink transmission and determine whether or not the switching gap is applied by UE 210 prior to performing the uplink transmission based on any of the rules discussed above, alone or in any combination. Accordingly, base station 205 and UE 210 may perform the uplink transmission from UE 210 based on the grant and the determination of whether or not the switching gap was applied to reconfigure the current RF status of UE 210.

FIG. 3 illustrates an example of a switching configuration 300 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. In some examples, switching configuration 300 may implement aspects of wireless communication systems 100 and/or 200. Aspects of switching configuration 300 may be implemented by a base station and/or UE, which may be examples of the corresponding devices described herein.

Broadly, switching configuration 300 illustrates one example of a subframe 305 including the plurality of slots on a first carrier and the second carrier. In some aspects, the first carrier and the second carrier may be in different radio frequency spectrum bands or may be in the same band. The first carrier and second carrier may be configured such that the duration of the slots on carrier 1 is different than the duration of the slots on carrier 2 (e.g., based on the bandwidth supported on each carrier) . For example, slots 310 in carrier one (e.g., slots 310-a through 310-f) may have a duration that is twice as long as the duration of slots 315 on carrier 2 (e.g., slots 315-a, 315-b, 315-c, 315-d, 315-e, 315-f, 315-g, 315-h, 315-i, 315-j, 315-k, and 315-l) . However, it is to be understood that the described techniques are not at all limited to carriers having slots of the same or different durations.

As discussed above, the base station and UE may be configured to support application of the rules described herein, alone or in any combination, to determine whether a switching gap 320 is applied to reconfigure the current RF status of the UE prior to performing an uplink transmission. For example, the base station the UE may determine that the RF status of the UE includes a first transmit chain that can be configured for communications on the first carrier or the second carrier and a second transmit chain configured for communications on the second carrier. The base station may transmit a grant to the UE scheduling an uplink transmission for the UE to perform. The base station and UE may determine, based on the grant and the current RF status of the UE, whether to apply the switching gap 320 to reconfigure the current RF status prior to performing the uplink transmission. The UE may perform the uplink transmission to the base station in accordance with the grant and the determination of whether to apply the switching gap 320.

Switching configuration 300 illustrates various examples of where the switching gap 320 may be applied, or not. For example, initially the first transmit chain may be configured for communications on the second carrier (not shown) , which means that during the beginning of slot 310-a the UE may apply the switching gap to reconfigure the current RF status of the UE prior to performing the uplink transmission during slots 310-a and 310-b. However, as the uplink transmission in the first carrier occurs during adjacent slots 310-a and 310-b, the UE may not need to apply the switching gap 320 to reconfigure the current RF status of the UE prior to continuing the uplink transmission on the first carrier (as indicated by the dashed-circle) .

At the end of the uplink transmission on the first carrier during slot 310-b and during slot 315-d of the second carrier, the UE may reconfigure the current RF status from the first carrier to the second carrier for an uplink transmission on the second carrier. Accordingly, during slot 315-d of the second carrier, the UE may reconfigure the current status to apply the switching gap 320 prior to performing the uplink transmission on the second carrier. Again, the UE may not apply the switching gap 320 to reconfigure the current RF status of the UE between uplink transmissions in adjacent slots 315-d and 315-e on the second carrier.

During slot 310-c on the first carrier, the UE may again apply the switching gap 320 to reconfigure the current RF status prior to performing an uplink transmission on the first carrier. Again, the UE may not apply the switching gap 320 to reconfigure the current RF status of the UE between uplink transmissions in adjacent slots 310-c and 310-d on the first carrier, nor again between uplink transmissions in adjacent slots 310-d and 310-e of the first carrier.

At the end of the uplink transmission on the first carrier in slot 310-e, the UE may be scheduled for an uplink transmission on the second carrier, and therefore apply the switching gap 320 to reconfigure the current RF status of the UE prior to performing the uplink transmission during slots 315-j, 315-k, and 315-l on the second carrier. Again, the UE may not need to apply the switching gap to reconfigure the current RF status of the UE before continuing the uplink transmission during adjacent slots 315-j, 315-k, and 315-l on the second carrier.

FIG. 4 illustrates an example of a process 400 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. In some examples, process 400 may implement aspects of wireless communication systems 100 and/or 200 and/or switching configuration 300. Aspects of process 400 may be implemented by UE 405 and/or base station 410, which may be examples of corresponding devices described herein.

At 415, UE 405 may identify that the RF status of UE 405 includes a first transmit chain changeably configured for communications on a first carrier or a second carrier, and a second transmit chain configured for communications on the second carrier. Similarly and at 420, base station 410 may identify that the RF status of UE 405 includes the first transmit chain changeably configurable for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. In some aspects, this identifying may be based on UE capability signaling, based on RRC configuration/reconfiguration signaling, and the like. In some aspects, this identifying may be based on a preceding uplink transmission configured for UE 405 by base station 410. For example, the preceding uplink transmission may be configured by base station 410 and performed by UE 405 such that UE 405 and base station 410 know, at least to some degree, what the current RF status of UE 405 is.

At 425, base station 410 may transmit (and UE 405 may receive) a grant scheduling an uplink transmission for UE 405. The grant may be a DCI grant (e.g., scheduling dynamic resources for the uplink transmission) and/or an RRC grant (e.g., scheduling semi-statically configured resources for the uplink transmissions) . The grant may be transmitted on a control channel, such as a PUCCH/PDCCH.

At 430, base station 410 may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of the current RF status of UE 405. For example, the grant scheduling the uplink transmission may indicate that the uplink transmission is scheduled on a first carrier whereas the preceding uplink transmission was scheduled on the second carrier, or vice versa. As another example, the grant scheduling the uplink transmission may indicate that the uplink transmission is scheduled as a one-port transmission whereas the preceding uplink transmission was scheduled as a two-port transmission.

At 435, UE 405 may determine, based on the grant and the current RF status, whether to apply switching gap to reconfigure the current RF status prior to performing the uplink transmission. Similarly and at 440, base station 410 may determine, based on the grant and the current RF status of the UE 405, whether the switching gap to reconfigure the current RF status will be applied at UE 405 prior to transmission of the uplink transmission. For example, UE 405 and base station 410 may determine whether the switching gap to reconfigure the current RF status of UE 405 will be applied based on any of the rules discussed above, alone or in any combination.

At 445, UE 405 may transmit (and base station 410 may receive) the uplink transmission according to the grant and the determination of whether the switching gap to reconfigure the current RF status of UE 405 has been applied. Accordingly, the techniques discussed herein provide rules implemented at UE 405 and/or base station 410 that, when applied, provide increased certainty that both devices are in sync with regards to whether the switching gap has been applied by UE 405.

FIG. 5 shows a block diagram 500 of a device 505 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a communications manager 515, and a transmitter 520. The device 505 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 510 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 determining whether an uplink switching gap is to be applied between changes in RF status of a UE, etc. ) . Information may be passed on to other components of the device 505. The receiver 510 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 510 may utilize a single antenna or a set of antennas.

The communications manager 515 may identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receive a grant scheduling an uplink transmission for the UE, determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and perform the uplink transmission in accordance with the determining. The communications manager 515 may be an example of aspects of the communications manager 810 described herein.

The communications manager 515, 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 515, or its sub-components may be executed by 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, 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 515, 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 515, 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 515, 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 communications manager 515 as described herein may be implemented to realize one or more potential advantages. One implementation may provide for reduced latency for communications via one or more uplink carriers. For example, the device 505 (e.g., a UE 115) may transmit one or more uplink transmissions via two or more carriers. In some cases, the device 505 may perform RF retuning to switch between the uplink carriers. The device 505 may determine whether a switching period is needed for RF retuning based on one or more parameters associated with the communications, as described herein. If a switching period is not needed, the device 505 may continue transmitting without interruption. The described methods for determining whether to continue uplink transmissions or to perform retuning during a switching period thereby reduce latency during communications by reducing a number of switching periods during uplink transmissions.

A processor of the device 505 (e.g., a processor controlling the receiver 510, the communications manager 515, the transmitter 520, etc. ) may reduce processing latency and processing resources used for communications. For example, if the device 505 determines that a switching period is not needed, the processor may refrain from reconfiguring the device 505 or performing RF retuning, which may save processing resources and reduce processing overhead. The device 505 may thereby perform uplink transmissions more efficiently if the device 505 determines whether a switching period is necessary or not.

The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 520 may utilize a single antenna or a set of antennas.

FIG. 6 shows a block diagram 600 of a device 605 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a device 505, or a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 640. The device 605 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 610 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 determining whether an uplink switching gap is to be applied between changes in RF status of a UE, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may be an example of aspects of the communications manager 515 as described herein. The communications manager 615 may include a RF status manager 620, a grant manager 625, a switching gap manager 630, and a transmission manager 635. The communications manager 615 may be an example of aspects of the communications manager 810 described herein.

The RF status manager 620 may identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier.

The grant manager 625 may receive a grant scheduling an uplink transmission for the UE.

The switching gap manager 630 may determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission.

The transmission manager 635 may perform the uplink transmission in accordance with the determining.

The transmitter 640 may transmit signals generated by other components of the device 605. In some examples, the transmitter 640 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 640 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 640 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a communications manager 705 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The communications manager 705 may be an example of aspects of a communications manager 515, a communications manager 615, or a communications manager 810 described herein. The communications manager 705 may include a RF status manager 710, a grant manager 715, a switching gap manager 720, a transmission manager 725, a UE capability manager 730, a port-based switching gap manager 735, a MAC-based switching gap manager 740, a DCI- based switching gap manager 745, and a carrier-based switching gap manager 750. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The RF status manager 710 may identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier.

The grant manager 715 may receive a grant scheduling an uplink transmission for the UE.

The switching gap manager 720 may determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission.

The transmission manager 725 may perform the uplink transmission in accordance with the determining.

The UE capability manager 730 may transmit a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

The port-based switching gap manager 735 may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier.

In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the port-based switching gap manager 735 may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the port-based switching gap manager 735 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain may be configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a two-port transmission on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier. In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some cases, the UE may refrain from transmitting during the switching gap.

In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a one-port transmission on the first carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves a two-port transmission on the second carrier. In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some cases, the UE may refrain from transmitting during the switching gap.

In some examples, the port-based switching gap manager 735 may determine that the UE is configured for dual uplink transmissions on the first carrier and the second carrier. In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a two-port transmission on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status does not support two-port transmissions on the second carrier. In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some cases, the UE may refrain from transmitting during the switching gap.

In some examples, the port-based switching gap manager 735 may determine that the UE is configured for dual uplink transmissions on the first carrier and the second carrier. In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a one-port transmission on the first carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status supports two-port transmissions on the second carrier. In some examples, the port-based switching gap manager 735 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status. In some cases, the UE may refrain from transmitting during the switching gap.

In some examples, the port-based switching gap manager 735 may determine that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 735 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier.

In some examples, the port-based switching gap manager 735 may determine, based on the current RF status of the UE, whether the uplink transmission includes a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain on the second carrier. In some examples, determining whether the uplink transmission includes a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain includes determining the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier based on a preceding uplink transmission that involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission, and determining the uplink transmission includes a one-port transmission using both the first transmit chain and the second transmit chain on the second carrier based on the preceding uplink transmission that involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier.

The MAC-based switching gap manager 740 may determine, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier. In some examples, the MAC-based switching gap manager 740 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier. In some examples, the MAC-based switching gap manager 740 may determine that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the MAC-based switching gap manager 740 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the MAC-based switching gap manager 740 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the MAC-based switching gap manager 740 may determine, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier. In some examples, the MAC-based switching gap manager 740 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the MAC-based switching gap manager 740 may determine that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based on the grant and the current RF status.

The DCI-based switching gap manager 745 may determine that the grant scheduling the uplink transmission includes a DCI format 0_0. In some examples, determining, based on the DCI format, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 745 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission.

In some examples, the DCI-based switching gap manager 745 may determine that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, determining that the grant scheduling the uplink transmission includes a DCI format 0_1, where the uplink transmission is a non-codebook-based uplink transmission. In some examples, determining, based on the DCI format, that the uplink transmission includes a one-port or a two-port uplink transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, determining that the grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does not configure an uplink full power transmit mode. In some examples, the DCI-based switching gap manager 745 may determine that the reference signal resources identifies a one-port reference signal configuration. In some examples, determining, based on the one-port reference signal configuration, that the uplink transmission includes a one-port transmission using the second transmit chain on the second carrier.

In some examples, the DCI-based switching gap manager 745 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the DCI-based switching gap manager 745 may determine that the grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does configure an uplink full power transmit mode. In some examples, the DCI-based switching gap manager 745 may determine, based on the upper layer parameter configured uplink full power transmit mode, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 745 may determine, based on the grant, that the uplink transmission includes at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof. In some examples, the DCI-based switching gap manager 745 may determine that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, determining that the uplink transmission is immediately subsequent to a preceding uplink transmission that includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier.

In some examples, the DCI-based switching gap manager 745 may determine that the uplink transmission, without sounding reference signal or physical uplink shared channel transmission, includes a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier. In some examples, determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain on the first carrier.

In some examples, the DCI-based switching gap manager 745 may determine that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission. In some examples, the DCI-based switching gap manager 745 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

The carrier-based switching gap manager 750 may determine that the uplink transmission scheduled by the grant does not involve the second transmit chain. In some examples, the carrier-based switching gap manager 750 may determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier. In some examples, the carrier-based switching gap manager 750 may apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the carrier-based switching gap manager 750 may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the carrier-based switching gap manager 750 may determine that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier. In some examples, the carrier-based switching gap manager 750 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

FIG. 8 shows a diagram of a system 800 including a device 805 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 805 may be an example of or include the components of device 505, device 605, or a UE 115 as described herein. The device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 810, an I/O controller 815, a transceiver 820, an antenna 825, memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., bus 845) .

The communications manager 810 may identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, receive a grant scheduling an uplink transmission for the UE, determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission, and perform the uplink transmission in accordance with the determining.

The I/O controller 815 may manage input and output signals for the device 805. The I/O controller 815 may also manage peripherals not integrated into the device 805. In some cases, the I/O controller 815 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 815 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 815 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 815 may be implemented as part of a processor. In some cases, a user may interact with the device 805 via the I/O controller 815 or via hardware components controlled by the I/O controller 815.

The transceiver 820 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 820 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 825. However, in some cases the device may have more than one antenna 825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 830 may include random access memory (RAM) and read-only memory (ROM) . The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 830 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 840 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU) , a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting determining whether an uplink switching gap is to be applied between changes in RF status of a UE) .

The code 835 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 835 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 835 may not be directly executable by the processor 840 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 9 shows a block diagram 900 of a device 905 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 905 may be an example of aspects of a base station 105 as described herein. The device 905 may include a receiver 910, a communications manager 915, and a transmitter 920. The device 905 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 910 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 determining whether an uplink switching gap is to be applied between changes in RF status of a UE, etc. ) . Information may be passed on to other components of the device 905. The receiver 910 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The receiver 910 may utilize a single antenna or a set of antennas.

The communications manager 915 may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmit a grant scheduling an uplink transmission for the UE, identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receive the uplink transmission from the UE based on the grant and the determining. The communications manager 915 may be an example of aspects of the communications manager 1210 described herein.

The communications manager 915, 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 915, or its sub-components may be executed by a general-purpose processor, a DSP, an 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 915, 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 915, 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 915, or its sub-components, may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 920 may transmit signals generated by other components of the device 905. In some examples, the transmitter 920 may be collocated with a receiver 910 in a transceiver module. For example, the transmitter 920 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The transmitter 920 may utilize a single antenna or a set of antennas.

FIG. 10 shows a block diagram 1000 of a device 1005 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a device 905, or a base station 105 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1040. The device 1005 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 1010 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 determining whether an uplink switching gap is to be applied between changes in RF status of a UE, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may be an example of aspects of the communications manager 915 as described herein. The communications manager 1015 may include a RF status manager 1020, a grant manager 1025, a switching gap manager 1030, and a transmission manager 1035. The communications manager 1015 may be an example of aspects of the communications manager 1210 described herein.

The RF status manager 1020 may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier.

The grant manager 1025 may transmit a grant scheduling an uplink transmission for the UE.

The switching gap manager 1030 may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE and determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission.

The transmission manager 1035 may receive the uplink transmission from the UE based on the grant and the determining.

The transmitter 1040 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1040 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1040 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The transmitter 1040 may utilize a single antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a communications manager 1105 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The communications manager 1105 may be an example of aspects of a communications manager 915, a communications manager 1015, or a communications manager 1210 described herein. The communications manager 1105 may include a RF status manager 1110, a grant manager 1115, a switching gap manager 1120, a transmission manager 1125, a UE capability manager 1130, a port-based switching gap manager 1135, a MAC-based switching gap manager 1140, a DCI-based switching gap manager 1145, and a carrier-based switching gap manager 1150. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The RF status manager 1110 may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier.

The grant manager 1115 may transmit a grant scheduling an uplink transmission for the UE.

The switching gap manager 1120 may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE. In some examples, the switching gap manager 1120 may determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission.

The transmission manager 1125 may receive the uplink transmission from the UE based on the grant and the determining.

The UE capability manager 1130 may receive a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

The port-based switching gap manager 1135 may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 1135 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier. In some examples, the port-based switching gap manager 1135 may determine that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier.

In some examples, the port-based switching gap manager 1135 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the port-based switching gap manager 1135 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, determining that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

In some examples, the port-based switching gap manager 1135 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the port-based switching gap manager 1135 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier.

In some examples, the port-based switching gap manager 1135 may determine, based on a current RF status of the UE, whether the uplink transmission includes a one-port transmission using only first second transmit chain or both the first transmit chain and the second transmit chain on the second carrier. In some examples, the port-based switching gap manager 1135 may determine the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier based on a preceding uplink transmission that involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the port-based switching gap manager 1135 may determine the uplink transmission includes a one-port transmission using both the first transmit chain and the second transmit chain on the second carrier based on the preceding uplink transmission that involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier.

The MAC-based switching gap manager 1140 may determine, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using only the second transmit chain on the second carrier. In some examples, the MAC-based switching gap manager 1140 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier.

In some examples, the MAC-based switching gap manager 1140 may determine that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the MAC-based switching gap manager 1140 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission. In some examples, the MAC-based switching gap manager 1140 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the MAC-based switching gap manager 1140 may determine, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier. In some examples, the MAC-based switching gap manager 1140 may determine, based on a received MAC message or a RRC message, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or one-port transmission using only the second transmit chain on the second carrier.

The DCI-based switching gap manager 1145 may determine that the grant scheduling the uplink transmission includes a DCI format 0_0. In some examples, determining, based on the DCI format, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 1145 may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission.

In some examples, the DCI-based switching gap manager 1145 may determine that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, determining that the grant scheduling the uplink transmission includes a DCI format 0_1, where the uplink transmission is a non-codebook-based uplink transmission. In some examples, the DCI-based switching gap manager 1145 may determine, based on the DCI format, that the uplink transmission includes a one-port or a two-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 1145 may determine that the grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does not configure an uplink full power transmit mode.

In some examples, the DCI-based switching gap manager 1145 may determine that the reference signal resources identifies a one-port reference signal configuration. In some examples, determining, based on the one-port reference signal configuration, that the uplink transmission includes a one-port transmission using the first transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 1145 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

In some examples, the DCI-based switching gap manager 1145 may determine that the grant scheduling the uplink transmission includes a DCI format 0_1, the grant identifying a reference signal resource, the uplink transmission being a codebook-based uplink transmission, and an upper layer parameter configures an uplink full power transmit mode. In some examples, the DCI-based switching gap manager 1145 may determine, based on the upper layer parameter configured uplink full power transmit mode, that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

In some examples, the DCI-based switching gap manager 1145 may determine, based on the grant, that the uplink transmission includes at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof. In some examples, determining that the uplink transmission includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 1145 may determine that the uplink transmission is immediately subsequent to a preceding uplink transmission that includes a one-port transmission using the first transmit chain or the second transmit chain on the second carrier. In some examples, the DCI-based switching gap manager 1145 may determine that the uplink transmission, without sounding reference signal or physical uplink shared channel transmission, includes a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier.

The carrier-based switching gap manager 1150 may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain on the first carrier. In some examples, the carrier-based switching gap manager 1150 may determine that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission. In some examples, the carrier-based switching gap manager 1150 may determine that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based on the grant and the current RF status. In some examples, the carrier-based switching gap manager 1150 may determine that the uplink transmission scheduled by the grant does not involve the second transmit chain. In some examples, the carrier-based switching gap manager 1150 may determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier. In some examples, determining that the uplink transmission scheduled by the grant includes a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

In some examples, the carrier-based switching gap manager 1150 may determine that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier. In some examples, the carrier-based switching gap manager 1150 may determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based on the grant and the current RF status.

FIG. 12 shows a diagram of a system 1200 including a device 1205 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The device 1205 may be an example of or include the components of device 905, device 1005, or a base station 105 as described herein. The device 1205 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1210, a network communications manager 1215, a transceiver 1220, an antenna 1225, memory 1230, a processor 1240, and an inter-station communications manager 1245. These components may be in electronic communication via one or more buses (e.g., bus 1250) .

The communications manager 1210 may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier, transmit a grant scheduling an uplink transmission for the UE, identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE, determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission, and receive the uplink transmission from the UE based on the grant and the determining.

The network communications manager 1215 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1215 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1220 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1220 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1220 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 1225. However, in some cases the device may have more than one antenna 1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1230 may include RAM, ROM, or a combination thereof. The memory 1230 may store computer-readable code 1235 including instructions that, when executed by a processor (e.g., the processor 1240) cause the device to perform various functions described herein. In some cases, the memory 1230 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 1240 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 1240 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1240. The processor 1240 may be configured to execute computer- readable instructions stored in a memory (e.g., the memory 1230) to cause the device 1205 to perform various functions (e.g., functions or tasks supporting determining whether an uplink switching gap is to be applied between changes in RF status of a UE) .

The inter-station communications manager 1245 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1245 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1245 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1235 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1235 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1235 may not be directly executable by the processor 1240 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 13 shows a flowchart illustrating a method 1300 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE 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. For example, the operations of method 1300 may be performed by a communications manager as described with reference to FIGs. 5 through 8. 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 a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. 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 RF status manager as described with reference to FIGs. 5 through 8.

At 1310, the UE may receive a grant scheduling an uplink transmission for the UE. 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 grant manager as described with reference to FIGs. 5 through 8.

At 1315, the UE may determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission. 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 switching gap manager as described with reference to FIGs. 5 through 8.

At 1320, the UE may perform the uplink transmission in accordance with the determining. 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 transmission manager as described with reference to FIGs. 5 through 8.

FIG. 14 shows a flowchart illustrating a method 1400 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communications manager as described with reference to FIGs. 5 through 8. 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 1405, the UE may transmit a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a UE capability manager as described with reference to FIGs. 5 through 8.

At 1410, the UE may identify that a RF status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a RF status manager as described with reference to FIGs. 5 through 8.

At 1415, the UE may receive a grant scheduling an uplink transmission for the UE. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by a grant manager as described with reference to FIGs. 5 through 8.

At 1420, the UE may determine, based on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed by a switching gap manager as described with reference to FIGs. 5 through 8.

At 1425, the UE may perform the uplink transmission in accordance with the determining. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed by a transmission manager as described with reference to FIGs. 5 through 8.

FIG. 15 shows a flowchart illustrating a method 1500 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1505, the base station may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a RF status manager as described with reference to FIGs. 9 through 12.

At 1510, the base station may transmit a grant scheduling an uplink transmission for the UE. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a grant manager as described with reference to FIGs. 9 through 12.

At 1515, the base station may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by a switching gap manager as described with reference to FIGs. 9 through 12.

At 1520, the base station may determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by a switching gap manager as described with reference to FIGs. 9 through 12.

At 1525, the base station may receive the uplink transmission from the UE based on the grant and the determining. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by a transmission manager as described with reference to FIGs. 9 through 12.

FIG. 16 shows a flowchart illustrating a method 1600 that supports determining whether an uplink switching gap is to be applied between changes in RF status of a UE in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1605, the base station may identify that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a RF status manager as described with reference to FIGs. 9 through 12.

At 1610, the base station may transmit a grant scheduling an uplink transmission for the UE. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a grant manager as described with reference to FIGs. 9 through 12.

At 1615, the base station may identify that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a switching gap manager as described with reference to FIGs. 9 through 12.

At 1620, the base station may determine, based on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a switching gap manager as described with reference to FIGs. 9 through 12.

At 1625, the base station may determine that the uplink transmission scheduled by the grant includes a one-port transmission using the second transmit chain on the second carrier. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed by a port-based switching gap manager as described with reference to FIGs. 9 through 12.

At 1630, the base station may determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed by a port-based switching gap manager as described with reference to FIGs. 9 through 12.

At 1635, the base station may determine that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based on the grant and the current RF status. The operations of 1635 may be performed according to the methods described herein. In some examples, aspects of the operations of 1635 may be performed by a port-based switching gap manager as described with reference to FIGs. 9 through 12.

At 1640, the base station may receive the uplink transmission from the UE based on the grant and the determining. The operations of 1640 may be performed according to the methods described herein. In some examples, aspects of the operations of 1640 may be performed by a transmission manager as described with reference to FIGs. 9 through 12.

It should be noted that the methods described herein 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.

SUMMARY OF ASPECTS

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communication at a user equipment (UE) , comprising: identifying that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier; receiving a grant scheduling an uplink transmission for the UE; determining, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission; and performing the uplink transmission in accordance with the determining.

Aspect 2: The method of aspect 1, further comprising: transmitting a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

Aspect 3: The method of any of aspects 1 through 2, wherein determining whether to apply the switching gap comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 4: The method of any of aspects 1 through 2, wherein determining whether to apply the switching gap comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 5: The method of any of aspects 1 through 2, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 6: The method of any of aspects 1 through 2, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 7: The method of any of aspects 1 through 2, further comprising: determining that the uplink transmission comprises a two-port transmission on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.

Aspect 8: The method of any of aspects 1 through 2, further comprising: determining that the uplink transmission comprises a one-port transmission on the first carrier; determining that the current RF status, based on a preceding uplink transmission, involves a two-port transmission on the second carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.

Aspect 9: The method of any of aspects 1 through 2, further comprising: determining that the UE is configured for dual uplink transmissions on the first carrier and the second carrier; determining that the uplink transmission comprises a two-port transmission on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status does not support two-port transmissions on the second carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.

Aspect 10: The method of any of aspects 1 through 2, further comprising: determining that the UE is configured for dual uplink transmissions on the first carrier and the second carrier; determining that the uplink transmission comprises a one-port transmission on the first carrier; determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status supports two-port transmissions on the second carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.

Aspect 11: The method of any of aspects 1 through 2, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 12: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on the current RF status of the UE, whether the uplink transmission comprises a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 13: The method of aspect 12, wherein determining whether the uplink transmission comprises a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain comprises: determining the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier based at least in part on a preceding uplink transmission that involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining the uplink transmission comprises a one-port transmission using both the first transmit chain and the second transmit chain on the second carrier based on the preceding uplink transmission that involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier.

Aspect 14: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on a received medium access control (MAC) message or a radio resource control (RRC) message, that the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 15: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on a received MAC message or an RRC message, that the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 16: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on a received MAC message or a RRC message, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 17: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on a received MAC message or a RRC message, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 18: The method of any of aspects 1 through 2, further comprising: determining that the grant scheduling the uplink transmission comprises a downlink control information (DCI) format 0_0; determining, based at least in part on the DCI format, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 19: The method of any of aspects 1 through 2, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, wherein the uplink transmission is a non-codebook-based uplink transmission; determining, based at least in part on the DCI format, that the uplink transmission comprises a one-port or a two-port uplink transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 20: The method of any of aspects 1 through 2, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does not configure an uplink full power transmit mode.

Aspect 21: The method of aspect 20, further comprising: determining that the reference signal resources identifies a one-port reference signal configuration; determining, based at least in part on the one-port reference signal configuration, that the uplink transmission comprises a one-port transmission using the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 22: The method of any of aspects 1 through 2, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does configure an uplink full power transmit mode.

Aspect 23: The method of aspect 22, further comprising: determining, based at least in part on the upper layer parameter configured uplink full power transmit mode, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 24: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on the grant, that the uplink transmission comprises at least one of a physical uplink control channel (PUCCH) transmission, or a physical random access channel (PRACH) transmission, or a combination thereof; and determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

Aspect 25: The method of any of aspects 1 through 2, further comprising: determining, based at least in part on the grant, that the uplink transmission comprises at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof; determining that the uplink transmission is immediately subsequent to a preceding uplink transmission that comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier; and determining that the uplink transmission, without sounding reference signal or physical uplink shared channel transmission, comprises a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier.

Aspect 26: The method of any of aspects 1 through 2, wherein determining whether to apply the switching gap comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain on the first carrier; determining that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 27: The method of any of aspects 1 through 2, wherein determining whether to apply the switching gap to reconfigure the current RF status comprises: determining that the uplink transmission scheduled by the grant does not involve the second transmit chain; determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier; and applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 28: The method of any of aspects 1 through 2, wherein determining whether to apply the switching gap comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 29: A method for wireless communication at a base station, comprising: identifying that a RF status of a UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier; transmitting a grant scheduling an uplink transmission for the UE; identifying that the uplink transmission scheduled by the grant will result in a reconfiguration of a current RF status at the UE; determining, based at least in part on the grant and the current RF status of the UE, whether a switching gap to reconfigure the current RF status will be applied at the UE prior to transmission of the uplink transmission; and receiving the uplink transmission from the UE based at least in part on the grant and the determining.

Aspect 30: The method of aspect 29, further comprising: receiving a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.

Aspect 31: The method of any of aspects 29 through 30, wherein determining whether the switching gap is applied comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 32: The method of any of aspects 29 through 30, wherein determining whether the switching gap is applied comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 33: The method of any of aspects 29 through 30, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 34: The method of any of aspects 29 through 30, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 35: The method of any of aspects 29 through 30, further comprising: determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 36: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on a current RF status of the UE, whether the uplink transmission comprises a one-port transmission using only first second transmit chain or both the first transmit chain and the second transmit chain on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 37: The method of aspect 36, wherein determining whether the uplink transmission comprises a one-port transmission using only the second transmit chain or both the first transmit chain and the second transmit chain on the second carrier comprises: determining the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier based at least in part on a preceding uplink transmission that involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining the uplink transmission comprises a one-port transmission using both the first transmit chain and the second transmit chain on the second carrier based on the preceding uplink transmission that involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier.

Aspect 38: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on a received MAC message or an RRC message, that the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 39: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on a received MAC message or an RRC message, that the uplink transmission comprises a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 40: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on a received MAC message or an RRC message, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or a one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 41: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on a received MAC message or an RRC message, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier or one-port transmission using only the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the second carrier and the second transmit chain configured for a one-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 42: The method of any of aspects 29 through 30, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_0; determining, based at least in part on the DCI format, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 43: The method of any of aspects 29 through 30, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, wherein the uplink transmission is a non-codebook-based uplink transmission; determining, based at least in part on the DCI format, that the uplink transmission comprises a one-port or a two-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 44: The method of any of aspects 29 through 30, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, the grant identifying a reference signal resource, and the uplink transmission being a codebook-based uplink transmission and an upper layer parameter does not configure an uplink full power transmit mode.

Aspect 45: The method of aspect 44, further comprising: determining that the reference signal resources identifies a one-port reference signal configuration; determining, based at least in part on the one-port reference signal configuration, that the uplink transmission comprises a one-port transmission using the first transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 46: The method of any of aspects 29 through 30, further comprising: determining that the grant scheduling the uplink transmission comprises a DCI format 0_1, the grant identifying a reference signal resource, the uplink transmission being a codebook- based uplink transmission, and an upper layer parameter configures an uplink full power transmit mode.

Aspect 47: The method of aspect 46, further comprising: determining, based at least in part on the upper layer parameter configured uplink full power transmit mode, that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 48: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on the grant, that the uplink transmission comprises at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof; and determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier.

Aspect 49: The method of any of aspects 29 through 30, further comprising: determining, based at least in part on the grant, that the uplink transmission comprises at least one of a PUCCH transmission, or a PRACH transmission, or a combination thereof; determining that the uplink transmission is immediately subsequent to a preceding uplink transmission that comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier; and determining that the uplink transmission, without sounding reference signal or physical uplink shared channel transmission, comprises a one-port transmission using either the first transmit chain or the second transmit chain on the second carrier.

Aspect 50: The method of any of aspects 29 through 30, wherein determining whether the switching gap is applied comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain on the first carrier; determining that the current RF status, based on a preceding uplink transmission, involves the second transmit chain configured for no transmission; and determining that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 51: The method of any of aspects 29 through 30, wherein determining whether the switching gap is applied comprises: determining that the uplink transmission scheduled by the grant does not involve the second transmit chain; determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission using the first transmit chain on the first carrier; and determining that the switching gap to reconfigure the current RF status is applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 52: The method of any of aspects 29 through 30, wherein determining whether the switching gap is applied comprises: determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier; determining that the current RF status, based on a preceding uplink transmission, involves either the first transmit chain configured for a one-port transmission on the second carrier or the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.

Aspect 53: An apparatus for wireless communication at a UE comprising a processor and memory coupled to the processor, the processor and memory configured to perform a method of any of aspects 1 through 28.

Aspect 54: An apparatus for wireless communication at a UE comprising at least one means for performing a method of any of aspects 1 through 28.

Aspect 55: A non-transitory computer-readable medium storing code for wireless communication at a UE the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 28.

Aspect 56: An apparatus for wireless communication at a base station comprising a processor and memory coupled to the processor, the processor and memory configured to perform a method of any of aspects 29 through 52.

Aspect 57: An apparatus for wireless communication at a base station comprising at least one means for performing a method of any of aspects 29 through 52.

Aspect 58: A non-transitory computer-readable medium storing code for wireless communication at a base station the code comprising instructions executable by a processor to perform a method of any of aspects 29 through 52.

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 herein 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 with service subscriptions with the network provider. A small cell may be associated with a lower-powered base station, 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 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 having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs 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 systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations 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 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 DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described 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 herein 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 RAM, ROM, electrically erasable programmable ROM (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 at a user equipment (UE) , comprising:

identifying that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier;

receiving a grant scheduling an uplink transmission for the UE;

determining, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission; and

performing the uplink transmission in accordance with the determining.
The method of claim 1, further comprising:

transmitting a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.
The method of claim 1, wherein determining whether to apply the switching gap comprises:

determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The method of claim 1, wherein determining whether to apply the switching gap comprises:

determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and

determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The method of claim 1, further comprising:

determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The method of claim 1, further comprising:

determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The method of claim 1, further comprising:

determining that the uplink transmission comprises a two-port transmission on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The method of claim 1, further comprising:

determining that the uplink transmission comprises a one-port transmission on the first carrier;

determining that the current RF status, based on a preceding uplink transmission, involves a two-port transmission on the second carrier; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The method of claim 1, further comprising:

determining that the UE is configured for dual uplink transmissions on the first carrier and the second carrier;

determining that the uplink transmission comprises a two-port transmission on the second carrier;

determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status does not support two-port transmissions on the second carrier; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The method of claim 1, further comprising:

determining that the UE is configured for dual uplink transmissions on the first carrier and the second carrier;

determining that the uplink transmission comprises a one-port transmission on the first carrier;

determining that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status supports two-port transmissions on the second carrier; and

applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

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

identify that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier;

receive a grant scheduling an uplink transmission for the UE;

determine, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission; and

perform the uplink transmission in accordance with the determining.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.
The apparatus of claim 11, wherein the instructions to determine whether to apply the switching gap are executable by the processor to cause the apparatus to:

determine that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 11, wherein the instructions to determine whether to apply the switching gap are executable by the processor to cause the apparatus to:

determine that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and

determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the uplink transmission comprises a two-port transmission on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the uplink transmission comprises a one-port transmission on the first carrier;

determine that the current RF status, based on a preceding uplink transmission, involves a two-port transmission on the second carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the UE is configured for dual uplink transmissions on the first carrier and the second carrier;

determine that the uplink transmission comprises a two-port transmission on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the second carrier and that the current RF status does not support two-port transmissions on the second carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
The apparatus of claim 11, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the UE is configured for dual uplink transmissions on the first carrier and the second carrier;

determine that the uplink transmission comprises a one-port transmission on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves a one-port transmission on the first carrier and that the current RF status supports two-port transmissions on the second carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status, wherein the UE refrains from transmitting during the switching gap.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for identifying that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier;

means for receiving a grant scheduling an uplink transmission for the UE;

means for determining, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission; and

means for performing the uplink transmission in accordance with the determining.
The apparatus of claim 21, further comprising:

means for transmitting a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.
The apparatus of claim 21, wherein the means for determining whether to apply the switching gap comprises:

means for determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier;

means for determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

means for applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 21, wherein the means for determining whether to apply the switching gap comprises:

means for determining that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier;

means for determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and

means for determining that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The apparatus of claim 21, further comprising:

means for determining that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

means for determining that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and

means for applying the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

identify that a radio frequency (RF) status of the UE includes a first transmit chain changeably configured for communication on a first carrier or a second carrier, and a second transmit chain configured for communication on the second carrier;

receive a grant scheduling an uplink transmission for the UE;

determine, based at least in part on the grant and on a current RF status of the UE, whether to apply a switching gap to reconfigure the current RF status prior to performing the uplink transmission; and

perform the uplink transmission in accordance with the determining.
The non-transitory computer-readable medium of claim 26, wherein the instructions are further executable to:

transmit a UE capability message indicating that the UE supports a UE capability for a one-port transmission on the second carrier using only the second transmit chain or both the first transmit chain and the second transmit chain.
The non-transitory computer-readable medium of claim 26, wherein the instructions to determine whether to apply the switching gap are executable to:

determine that the uplink transmission scheduled by the grant comprises a one-port transmission using the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain and the second transmit chain configured for a two-port transmission on the second carrier; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The non-transitory computer-readable medium of claim 26, wherein the instructions to determine whether to apply the switching gap are executable to:

determine that the uplink transmission scheduled by the grant comprises a one-port transmission using the first transmit chain or the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain configured for either a one-port transmission on the second carrier or for no transmission; and

determine that the switching gap to reconfigure the current RF status is not to be applied prior to performing the uplink transmission based at least in part on the grant and the current RF status.
The non-transitory computer-readable medium of claim 26, wherein the instructions are further executable to:

determine that the uplink transmission comprises a one-port transmission using the first transmit chain and the second transmit chain on the second carrier;

determine that the current RF status, based on a preceding uplink transmission, involves the first transmit chain configured for a one-port transmission on the first carrier and the second transmit chain is configured for either a one-port transmission on the second carrier or for no transmission; and

apply the switching gap to reconfigure the current RF status prior to performing the uplink transmission based at least in part on the grant and the current RF status.