Subband indication in downlink control information in a shared radio frequency spectrum band

Abstract

Methods, systems, and apparatus for wireless communications are described, wherein a system bandwidth within a shared radio frequency spectrum band may be divided into a plurality of subbands. A base station may provide a resource grant to a user equipment using a fallback downlink control information format, wherein the fallback downlink control information has a predetermined number of bits. To provide an indication of one or more subbands to be used for uplink communications when using the fallback downlink control information, an explicit or implicit indication may be provided. Such a subband indication may allow a user equipment to use a particular subband that may be used for transmission in a shared radio frequency spectrum band. The indication of the one or more subbands may be provided explicitly by a subband indication field in the fallback downlink control information, or implicitly by one or more downlink transmissions of the base station.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of Indian Provisional Patent Application No. 201941046919 filed on November 18, 2019 by Thyagarajan et al., titled “SUB-BAND INDICATION IN DOWNLINK CONTROL INFORMATION IN SHARED RADIO FREQUENCY SPECTRUMBAND,” which has been assigned to the present assignee. Background Art

[0003] The following relates generally to wireless communications, and more particularly, to sub-band indication in downlink control information in a shared radio frequency spectrum band.

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Aspects 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 use techniques 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 extended orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include several base stations or network access nodes, each of which supports the communication of multiple communication devices simultaneously, and these communication devices may be referred to as user equipment (UE).

[0005] In some deployments, a UE and a base station may use a portion of a radio frequency spectrum band, which may be referred to as a bandwidth portion (BWP), for communication. Additionally, in some cases, the BWP may be in a shared radio frequency spectrum band, where various different users may access the radio frequency spectrum band using contention-based access techniques, such as using a listen-before-talk (LBT) process. In some cases, the BWP may be divided into multiple sub-bands, and communication between the UE and the base station may use one or more sub-bands within the BWP. In situations where communication uses a shared radio frequency spectrum band, the specific sub-bands that may be used for communication may change at certain times. Therefore, efficient techniques for maintaining communication between the base station and the UE when the sub-bands change will help improve system operation and efficiency. Summary of the invention

[0006] The present disclosure relates to methods, systems, devices and apparatuses that support subband indications in downlink control information in a shared radio frequency spectrum band. Various aspects of the present disclosure provide subband indications when a base station uses fallback downlink control information (DCI) to provide a user equipment (UE) with an authorization for uplink or downlink resources. In some aspects, multiple DCI formats may be used to provide an indication of resource authorization for uplink communications from a UE to a base station (e.g., physical uplink shared channel (PUSCH) resources) or for downlink communications from a base station to a UE (e.g., physical downlink shared channel (PDSCH) resources). Such multiple DCI formats may include a fallback DCI format with a predetermined number of bits, and a non-fallback DCI format, where different instances of DCI may have different numbers of bits based on specific information to be provided in a specific authorization.

[0007] In some aspects of the present disclosure, the fallback DCI may include a subband indication field, which may explicitly indicate that one or more subbands will be used for associated uplink or downlink transmissions. In some cases, the fallback DCI may provide an uplink grant and may have a predetermined number of bits that is the same as the number of bits of the fallback DCI providing the downlink grant. This fallback DCI providing the uplink grant may include a subband indication field while still maintaining the same predetermined number of bits. In some aspects, the fallback DCI providing the downlink grant may have several padding bits, and when the subband indication field is included in the fallback DCI, the padding bits may reduce the number of bits of the subband indication field. Additionally or alternatively, the fallback DCI may provide a downlink grant and may include a subband indication field that identifies one or more subbands associated with the downlink grant for uplink control channel communication of the UE (e.g., confirmation feedback information sent by the UE).

[0008] In some aspects of the present disclosure, an implicit indication of a subband for transmitting uplink communications may be provided. In these aspects, the UE may monitor downlink transmissions from a base station, which may provide an indication of the subband to be used. In some cases, an indication of a subband may be provided by a physical uplink control channel (PUCCH) resource indicator (PRI) field of a fallback DCI, where the subband used for uplink communications may correspond to a subband of a PUCCH resource indicated by a table entry identified by the PRI field. In some cases, the subband may be based on a subband used to send a synchronization signal block (SSB), a subband indicated in a physical broadcast channel (PBCH), a subband indicated in a remaining minimum system information (RMSI) communication, a subband used to send a fallback DCI, or a lowest subband used to send a fallback DCI. In response to the fallback DCI, the UE may use the indicated subband to send uplink communications.

[0009] A method is described. The method may include receiving a fallback downlink control information communication from a base station that provides an uplink grant to a user equipment (UE) within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determining one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and transmitting the uplink communication to the base station via the determined one or more subbands.

[0010] An apparatus is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to receive a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, maintain the predetermined number of bits of the fallback downlink control information communication even if the subband information field is included in the fallback downlink control information communication, and send the uplink communication to the base station via the determined one or more subbands.

[0011] Another apparatus is described. The apparatus may include means for receiving a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, means for determining one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and means for transmitting the uplink communication to the base station via the determined one or more subbands.

[0012] A non-transitory computer-readable medium storing code is described. The code may include instructions executable by a processor to receive a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and send the uplink communication to the base station via the determined one or more subbands.

[0013] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the fallback downlink control information communication has a fallback downlink control information format, and the predetermined number of bits may be based on the length of a separate fallback downlink control information format for a downlink grant to the UE.

[0014] Some aspects of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving configuration information from a base station, the configuration information indicating whether a fallback downlink control information communication includes a subband information field.

[0015] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration information may be received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

[0016] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the subband information field may be adjacent to a frequency division multiplexing resource assignment field in a fallback downlink control information communication, or may be located after a last information field in the fallback downlink control information communication, and the last information field may be present in the absence of a subband information field in the fallback downlink control information communication.

[0017] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, when a subband information field may not be present in a fallback downlink control information communication, the subband information field occupies one or more bits that may be used as zero-filling bits.

[0018] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, a number of bits in the subband information field may be determined based on a number of subbands in a plurality of available subband sets.

[0019] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the number of bits in the subband information field corresponds to the number of subbands in the active bandwidth portion, the number of subbands in the initial bandwidth portion used to establish a connection between the UE and the base station, can be a predetermined number of subbands, can be based on a maximum number of subbands that can be supported in a maximum configurable bandwidth, or any combination thereof.

[0020] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the subband information field may be a bitmap having a bit length corresponding to the number of subbands of the available subband set.

[0021] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the subband information field may be a bit field, and different available values ​​of the bit field may be mapped to different sets of contiguous subbands.

[0022] A method is described. The method may include monitoring a subband indication from a base station, the subband indication indicating a first subband from a set of multiple available subbands in an active bandwidth portion for uplink communications from a UE to the base station within a shared radio frequency spectrum band, receiving a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, determining based on the monitored signaling from the base station that the first subband is to be used for uplink communications, and in response to receiving the uplink grant, sending uplink communications to the base station via the first subband.

[0023] An apparatus is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to monitor a subband indication from a base station, the subband indication indicating a first subband in a set of multiple available subbands in an active bandwidth portion for uplink communications from a UE to a base station within a shared radio frequency spectrum band, receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, determine based on the monitored signaling from the base station that the first subband is to be used for uplink communications, and in response to receiving the uplink grant, send uplink communications to the base station via the first subband.

[0024] Another apparatus is described. The apparatus may include means for monitoring a subband indication from a base station, the subband indication indicating a first subband from a set of multiple available subbands in an active bandwidth portion for uplink communications from a UE to the base station within a shared radio frequency spectrum band, means for receiving a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, means for determining that the first subband is to be used for uplink communications based on the monitored signaling from the base station, and means for transmitting uplink communications to the base station via the first subband in response to receiving the uplink grant.

[0025] A non-transitory computer-readable medium storing code is described. The code may include instructions executable by a processor to monitor a subband indication from a base station, the subband indication indicating a first subband from a set of multiple available subbands in an active bandwidth portion for uplink communications from a UE to the base station within a shared radio frequency spectrum band, receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, determine based on the monitored signaling from the base station that the first subband is to be used for uplink communications, and in response to receiving the uplink grant, send uplink communications to the base station via the first subband.

[0026] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the first subband can be the lowest subband of the active bandwidth portion, or a subband for receiving a synchronization signal block from a base station, or a subband indicated in a physical broadcast channel received from a base station, or a subband indicated in a remaining minimum system information communication received from a base station, or a subband for sending a fallback downlink control information communication, or a lowest subband for sending a fallback downlink control information communication, or a combination thereof.

[0027] A method is described. The method may include identifying one or more subbands from a set of multiple available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant, receiving a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant to a UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, receiving the first downlink communication from the base station, determining uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and transmitting the uplink control channel communication to the base station via the one or more subbands.

[0028] An apparatus is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to identify one or more subbands from a set of multiple available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant; receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant to a UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the one or more subbands.

[0029] Another apparatus is described. The apparatus may include means for identifying one or more subbands from a set of multiple available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant, means for receiving a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant to a UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, means for receiving the first downlink communication from the base station, means for determining uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and means for transmitting the uplink control channel communication to the base station via the one or more subbands.

[0030] A non-transitory computer-readable medium storing code is described. The code may include instructions executable by a processor to identify one or more subbands from a plurality of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant, receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant to a UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the one or more subbands.

[0031] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, identifying one or more subbands may include operations, features, components, or instructions for monitoring a subband indication from a base station, the subband indication indicating a first subband in a set of multiple available subbands in an active bandwidth portion for uplink control channel communications from a UE to the base station, where the first subband may be one of the one or more subbands.

[0032] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, identifying one or more subbands may include operations, features, components, or instructions for determining one or more subbands based on a subband information field having a fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication may be maintained even though the subband information field may be included in the fallback downlink control information communication.

[0033] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, configuration information and a physical uplink control channel resource indicator field in a fallback downlink control information communication may indicate one or more subbands.

[0034] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration information may be received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

[0035] Some aspects of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving configuration information from a base station, the configuration information including information for a subband indication from the base station.

[0036] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, a first subband of the one or more subbands may be a lowest subband of an active bandwidth portion, or a subband for receiving a synchronization signal block from a base station, or a subband indicated in a physical broadcast channel received from a base station, or a subband indicated in a remaining minimum system information communication received from a base station, or a subband for sending a fallback downlink control information communication, or a lowest subband for sending a fallback downlink control information communication, or a combination thereof.

[0037] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, a fallback downlink control information communication may have a fallback downlink control information format that may indicate that a UE may identify one or more subbands by monitoring a subband indication.

[0038] Some aspects of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving configuration information from a base station, the configuration information indicating that a fallback downlink control information communication includes a subband information field.

[0039] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration information indicates that a physical uplink control channel (PUCCH) resource indicator (PRI) field in a fallback downlink control information communication provides subband information.

[0040] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration information may be received in radio resource control (RRC) signaling, in remaining minimum system information (RMSI) signaling, in a physical broadcast (PBCH) transmission, or in any combination thereof.

[0041] Some aspects of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving configuration information from a base station, the configuration information indicating whether a fallback downlink control information communication includes a subband information field.

[0042] In some aspects of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration information may be received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Aspects of a system for wireless communications that supports sub-band indication in downlink control information in a shared radio frequency spectrum band are shown in accordance with aspects of the present disclosure.

[0044] Figure 2 Aspects of a portion of a wireless communication system supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown.

[0045] Figure 3 Aspects of a DCI format supporting sub-band indication in a shared radio frequency spectrum band according to aspects of the present disclosure are shown.

[0046] Figures 4 to 7 Aspects of a process flow for supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown.

[0047] Figure 8 and Fig. 9 A block diagram of an apparatus supporting sub-band indication in downlink control information in a shared radio frequency spectrum band is shown according to aspects of the present disclosure.

[0048] Fig.10 A block diagram of a communications manager supporting sub-band indication in downlink control information in a shared radio frequency spectrum band is shown according to aspects of the present disclosure.

[0049] Fig.11 A diagram of a system including a device supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure is shown.

[0050] Fig.12 and Fig.13 A block diagram of an apparatus supporting sub-band indication in downlink control information in a shared radio frequency spectrum band is shown according to aspects of the present disclosure.

[0051] Fig.14 A block diagram of a communications manager supporting sub-band indication in downlink control information in a shared radio frequency spectrum band is shown according to aspects of the present disclosure.

[0052] Fig.15 A diagram of a system including a device supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure is shown.

[0053] Figures 16 to 27 A flow chart illustrating a method of supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0054] Various aspects of the present disclosure provide techniques for subband indication in downlink control information in a shared radio frequency spectrum band. In some aspects, a base station and a user equipment (UE) may communicate information of a grant of uplink or downlink resources using a fallback downlink control information (DCI) format and a non-fallback DCI format. The fallback DCI format may have a predetermined number of bits for multiple instances of the DCI, while the non-fallback DCI format may have different numbers of bits across multiple instances of the DCI based on the specific information to be provided in a specific grant.

[0055] In some aspects of the present disclosure, when a fallback DCI is used, one or more subbands for associated uplink communications may be indicated to the UE. Such a subband indication may allow the UE to use a specific subband that may be used for transmission in a shared radio frequency spectrum band. As described above, in aspects of using a shared radio frequency spectrum band, various different users may access the radio frequency spectrum band using contention-based access techniques (e.g., using a listen-before-talk (LBT) process), and in such deployments the specific subbands available for communication may change at certain times. However, existing fallback DCI formats do not provide a subband indication for associated uplink transmissions, and in situations where the subband used for uplink communications may change (e.g., because one or more subbands in a bandwidth part (BWP) did not pass the LBT process), the UE may not be able to identify the subband used for uplink transmissions (e.g., for physical uplink control channel (PUCCH) transmissions, physical uplink shared channel (PUSCH) transmissions, or a combination thereof).

[0056] Furthermore, in some aspects, it may be beneficial for uplink communications to use staggered allocations so that the uplink communications occupy more BWPs or subbands than non-staggered or contiguous allocations (e.g., so as to use a minimum occupied channel bandwidth (OCB) in a shared radio frequency spectrum band). However, the fallback DCI format provides support for contiguous allocations of frequency resources, and providing non-contiguous allocations with fallback DCI may further require an indication of the subbands in which the uplink communications will be sent to avoid allocations that span subbands that have not yet been passed through the LBT process.

[0057] In some aspects, when fallback DCI is used, an indication of one or more subbands used for uplink communication allows one or more subbands used for uplink communication to be clearly determined at the UE. In some cases, the indication of one or more subbands may be an explicit indication provided in the fallback DCI, or may be an implicit indication based on one or more other downlink transmissions to the UE or an indication provided in the fallback DCI. In some cases, a fallback DCI (e.g., fallback DCI format 0_0) that provides an uplink grant to the UE may contain fewer information bits than a fallback DCI (e.g., fallback DCI format 1_0) that provides a downlink grant to the UE. In some cases, such fallback DCI may be used during initial access or during radio resource control (RRC) reconfiguration, or in a physical downlink control channel (PDCCH) grant to avoid ambiguity of a DCI size that is smaller than the fallback DCI.

[0058] In order to make the fallback DCI for uplink grant and the fallback DCI for downlink grant have the same total length, zero padding bits may be added to the fallback DCI for uplink grant. In some aspects, a separate subband indication field may be provided in the fallback DCI for uplink grant that explicitly indicates one or more subbands used for uplink communication, and the number of zero bits in the fallback DCI for uplink grant may be reduced by a size corresponding to the number of bits used to indicate the one or more subbands.

[0059] In other aspects, the UE may be configured to implicitly determine one or more subbands for uplink communication based on one or more downlink transmissions of the base station or other indications in the fallback DCI for downlink communication or uplink communication. In these aspects, the UE may monitor downlink transmissions from the base station, which may provide an indication of the subband to be used. In some cases, the indication of the subband may be provided by the PUCCH resource indicator (PRI) field of the fallback DCI, where the subband for uplink communication may correspond to the subband of the PUCCH resource indicated by the table entry identified by the PRI field. In some cases, the indication of the subband may be based on the subband used to send a synchronization signal block (SSB), the subband indicated in the physical broadcast channel (PBCH), the subband indicated in the remaining minimum system information (RMSI) communication, the subband used to send the fallback DCI, or the lowest subband used to send the fallback DCI. In response to the fallback DCI, the UE may use the indicated subband to send uplink communication.

[0060] Such techniques may provide consistent interpretation and size of a fallback DCI format that is independent of a particular radio resource control (RRC) configuration (e.g., there may be no ambiguity in the fallback DCI format in the event of an RRC reconfiguration). Thus, techniques according to various aspects may allow efficient and reliable use of a shared radio frequency spectrum band where available subbands for uplink communications may change.

[0061] Aspects of the present disclosure are initially described in the context of a wireless communication system. Various fallback DCI formats are then discussed in some aspects of the present disclosure. Aspects of the present disclosure are further illustrated and described by reference to apparatus diagrams, system diagrams, and flow charts related to subband indication in downlink control information in a shared radio frequency spectrum band.

[0062] Figure 1Aspects of a wireless communication system 100 that supports subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some aspects, the wireless communication system 100 can be a long term evolution (LTE) network, an LTE advanced (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some cases, the wireless communication system 100 can support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

[0063] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga-NodeB (any of which may be referred to as a gNB), a home NodeB, a home eNodeB, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network devices including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0064] Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 are supported. Each base station 105 may provide communications coverage for the respective geographic coverage area 110 via a communications link 125, and the communications link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communications link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0065] The geographic coverage area 110 of the base station 105 can be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector can be associated with a cell. In this example, each base station 105 can provide communication coverage for a macro cell, a small cell, a hotspot, or other type of cell, or various combinations thereof. In some aspects, the base station 105 can be mobile, thereby providing communication coverage for a mobile geographic coverage area 110. In some aspects, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. In some aspects, the wireless communication system 100 may include heterogeneous LTE / LTE-A / LTE-APro or NR networks in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0066] The term "cell" refers to a logical communication entity for communicating with a base station 105 (e.g., via a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) for distinguishing adjacent cells operating via the same or different carriers. In some aspects, 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 other) that may provide access to different types of devices. In some cases, the term "cell" may refer to a portion (e.g., a sector) of a geographic coverage area 110 on which the logical entity operates.

[0067] UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be stationary or mobile. UE 115 can 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 "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can 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 aspects, UE 115 can 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, etc., which can be implemented in various items such as household appliances, vehicles, meters, etc.

[0068] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automatic communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some aspects, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or capture information and relay the information to a central server or application that may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Some aspects of the application of 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.

[0069] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some aspects, half-duplex communication may be performed at a reduced peak rate. Other energy-saving techniques for UEs 115 include entering an energy-saving "deep sleep" mode when not participating in active communications or operating on 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 the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0070] In some cases, the UE 115 may also communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more of the group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105 or may not be able to receive transmissions from the base station 105. In some cases, the group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving the base station 105.

[0071] The base stations 105 may communicate with the core network 130 and with each other. In some aspects, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via an S1, N2, N3, or other interface). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) via a backhaul link 134 (e.g., via an X2, Xn, or other interface).

[0072] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connections, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC), which may include at least one mobile 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 UE 115 served by a base station 105 associated with the EPC. User IP packets may be transmitted through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to a network operator IP service. Operator IP services may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or a packet switched (PS) streaming service.

[0073] At least some network devices, such as base stations 105, may include subcomponents such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with UE 115 through several other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices, such as radio heads and access network controllers, or integrated into a single network device, such as base station 105.

[0074] The wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Typically, the region of 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is approximately 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features. However, these waves can penetrate structures enough to allow macro cells to serve UEs 115 indoors. Transmissions using UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 km) than transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum with frequencies less than 300 MHz.

[0075] The wireless communication system 100 may also operate in the Super High Frequency (SHF) region using frequency bands from 3 GHz to 30 GHz (also known as centimeter wave bands). The SHF region includes frequency bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) bands, which may be used by devices that can tolerate interference from other users.

[0076] The wireless communication system 100 can also operate in the extremely high frequency (EHF) region (e.g., from 30 GHz to 300 GHz), also referred to as the millimeter wave band. In some aspects, the wireless communication system 100 can support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antennas of each device can be smaller and closer than the UHF antennas. In some cases, this can facilitate the use of antenna arrays in the UE 115. However, the propagation of EHF transmissions may be subject to greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The technology disclosed herein can be used across transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions can be different due to countries or regulatory agencies.

[0077] In some cases, the wireless communication system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. In some aspects, the wireless communication system 100 can adopt license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5GHz ISM band. When operating in an unlicensed radio frequency spectrum band, wireless devices such as base stations 105 and UE 115 can use a listen-before-talk (LBT) process to ensure that the channel is idle before sending data. In some cases, operations in unlicensed bands can be based on carrier aggregation configurations and component carriers operating in licensed bands (e.g., LAA). Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0078] In some aspects, the base station 105 or UE 115 may be equipped with multiple antennas, which can be used to adopt technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication or beamforming. In some aspects, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may use multipath signal propagation to improve spectral efficiency by sending or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. In some aspects, multiple signals may be sent by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different antenna combinations. 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 for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are sent to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are sent to multiple devices.

[0079] 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 direct an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that signals propagating in a particular direction relative to the antenna array experience constructive interference while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying certain amplitude and phase offsets to signals carried via each antenna element associated with the device. The adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other direction).

[0080] In some cases, the wireless communication system 100 can be a packet-based network operating according to a layered protocol stack. In the user plane, the communication at the bearer or packet data aggregation protocol (PDCP) layer can be based on IP. The radio link control (RLC) layer can perform packet segmentation and reassembly to communicate on a logical channel. The medium access control (MAC) layer can perform priority processing and multiplex logical channels into transport channels. The MAC layer can 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 can provide the establishment, configuration and maintenance of the RRC connection between the base station 105 or the core network 130 that supports the radio bearer for user plane data. At the physical layer, the transport channel can be mapped to the physical channel.

[0081] In some cases, UE 115 and base station 105 may support retransmission of data to increase the possibility of successfully receiving data. HARQ feedback is a technique to increase the possibility of correctly receiving data through communication link 125. HARQ may include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC) and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput of the MAC layer under poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0082] Time intervals in LTE or NR may be expressed as multiples of a basic time unit. In some aspects, the basic time unit may be referred to as T s =1 / 30720000 second sampling period. The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be denoted as T f =307200T s. A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots, each slot 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 preceding each symbol period). In addition to the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe, or may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI), or in a component carrier selected using an sTTI).

[0083] In some wireless communication systems, a time slot may be further divided into a plurality of mini-slots containing one or more symbols. In some cases, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. In some aspects, the duration of each symbol may vary depending on the subcarrier spacing or the operating frequency band. In addition, some wireless communication systems may implement time slot aggregation, where multiple time slots or mini-slots are aggregated together and used for communication between UE 115 and base station 105.

[0084] The term "carrier" refers to a set of radio frequency spectrum resources with a defined physical layer structure for supporting communications on the communication link 125. In some aspects, the carrier of the communication link 125 may include a portion of a radio frequency spectrum band that operates according to a physical layer channel of 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 predefined frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel raster for discovery by a UE 115. A carrier may be a downlink or uplink (e.g., in FDD mode), or may be configured to carry downlink and uplink communications (e.g., in TDD mode). In some aspects, a signal waveform transmitted by a carrier may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0085] The organization structure of the carrier may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR). In some aspects, communications on the carrier can be organized based on TTIs or time slots, where each TTI or time slot can include user data and control information or signaling to support decoding of the user data. The carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate the operation of the carrier. In some aspects (e.g., in a carrier aggregation configuration), the carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers.

[0086] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, in some aspects using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some aspects, control information sent in a physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0087] A carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some aspects, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. In some aspects, the carrier bandwidth may be one of several predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some aspects, each serviced UE 115 may be configured to operate on part or all of the carrier bandwidth. In other aspects, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or resource blocks (RBs)) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0088] In a system using MCM technology, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the 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). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate may be for UE 115. In a MIMO system, wireless communication resources may refer to a combination of radio spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may further increase the data rate used to communicate with UE 115.

[0089] A device of the wireless communication system 100 (e.g., a base station 105 or a UE 115) may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configured to support communication on one of a set of carrier bandwidths. In some aspects, the wireless communication system 100 may include a base station 105 and / or a UE 115 that supports simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0090] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation or multi-carrier operation. The 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.

[0091] In some aspects, the system bandwidth may be divided into multiple subbands, and when fallback DCI is used, one or more subbands to be used for uplink communications may be indicated to the UE 115. Such subband indication may allow the UE 115 to use a specific subband that may be used for transmission in the shared radio frequency spectrum band. The indication of one or more subbands may be explicitly provided by a subband indication field in the fallback DCI, or may be implicitly provided by one or more downlink transmissions of the base station 105. In some cases, the UE 115 may be configured (e.g., via RRC signaling) to monitor for explicit or implicit indications of subbands to be used for uplink communications.

[0092] Figure 2 Aspects of a wireless communication system 200 that supports subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the wireless communication system 200 may implement aspects of the wireless communication system 100. The wireless communication system 200 may include a base station 105-a and a UE 115-a, which may be respective examples of the base station 105 and the UE 115 as described herein.

[0093] UE 115-a and base station 105-a can communicate via downlink carrier 205 and uplink carrier 210. In some cases, carriers 205 and 210 can be the same carrier. In some cases, carriers 205 and 210 can be component carriers (CCs), and multiple different CCs can be used for communication between UE 115-a and base station 105-a. In some cases, carriers 205 and 210 can use a shared radio frequency spectrum band. In this regard, base station 105-a can send configuration information 215 to UE 115-a. In some cases, such configuration information can be provided via RRC signaling. In some aspects, configuration information 215 can configure UE 115-a to monitor fallback DCI 220, and can further configure UE 115-a to monitor indications of one or more subbands to be used for uplink transmission 225.

[0094] In such an aspect, the base station 105-a may be configured with a system bandwidth or bandwidth part (BWP) spanning a number of subbands, which may include a first subband 230, a second subband 235, through an nth subband 240. Each subband 230 to 240 may have a separate associated LBT process for contention-based access in a shared radio frequency spectrum band. As discussed herein, in order to indicate to the UE 115-a which of the subbands 230 to 240 are to be used for uplink transmissions 225, the base station 105-a may provide, and the UE 115-a may monitor, one or more implicit indications, one or more explicit indications, or a combination thereof. Figure 2 In the illustration of , the second subband 235 can be used for uplink communication. In some cases, a single subband can be used for uplink transmission 225, while in other cases, two or more subbands can be used for uplink transmission 225.

[0095] In some aspects, one or more of the configuration information 215 or the fallback DCI 220 may provide an explicit indication of which subband may be used for uplink transmission 225. For some aspects that provide an explicit subband indication, see Figure 3A subband indication field in a fallback DCI 220 is discussed. In other aspects, the UE 115-a may determine which of the subbands 230 to 240 are to be used for uplink transmissions 225 by implicit indication. In some cases, the fallback DCI 220 may provide an uplink grant to the UE 115-a (e.g., the fallback DCI 220 has a DCI format 0_0), and the UE 115-a may use a single subband 235 for uplink transmissions 225. In various aspects, the UE 115-a may determine the single subband 235 based on the lowest subband configured in the system bandwidth, the subband used by the base station 105-a for SSB transmissions, the subband indicated in a physical broadcast channel (PBCH) transmission of the base station 105-a, the subband indicated in a remaining minimum system information (RMSI) transmission of the base station 105-a, the same subband as used to send the fallback DCI 220, or the lowest subband used to send the fallback DCI 220.

[0096] In some aspects, the fallback DCI 220 may provide a downlink grant to the UE 115-a (e.g., for a PDSCH or PDCCH transmission in accordance with DCI format 1_0), and the UE 115-a may determine a subband 235 for transmitting uplink control information (e.g., for HARQ ACK / NACK feedback for downlink communications provided in a PUCCH transmission). In some aspects, such a fallback DCI 220 for a downlink grant may include a PRI field that may identify a table entry of a PRI table for the corresponding PUCCH communication. In these aspects, the table entry of the PRI table indicated in the PRI field (e.g., an index value) may implicitly indicate which subband is to be used for uplink communications from the UE 115-a, and a separate subband indication field may not be provided in the fallback DCI 220. In some cases, the length of the fallback DCI 220 format for a downlink grant (e.g., DCI format 1_0) may already be longer than the length of the fallback DCI for an uplink grant (e.g., DCI format 0_0), and to maintain a predetermined bit length, the indication of the subband 235 used for the uplink transmission 225 may be implicitly indicated rather than explicitly indicated in a separate DCI field. Thus, in some aspects, the base station 105-a may include a subband indication in the resource configuration for the PUCCH (e.g., via an RRC configured or pre-assigned subband) such that the PRI already present in the fallback DCI 220 for the downlink grant automatically indicates the subband.

[0097] In other aspects, when fallback DCI 220 is used for downlink grants, a single subband can be allowed for uplink transmission 225, and the subband index can be selected from the same subband containing the fallback DCI 220, the same subband containing the PDSCH allocation if in a single subband, the lowest (or highest) subband in the PDSCH allocation if it spans multiple subbands, or the SSB subband if the fallback DCI 220 or PDCCH includes the subband (if the subband is not included, one of the other options can be used).

[0098] In further aspects, one or more bits may be added to the fallback DCI 220 to indicate the subband resources. In this case, a number of bits corresponding to the plurality of subbands 230 to 240 may be added to the fallback DCI 220 (e.g., to provide a bitmap of subbands to be used for uplink transmissions 225). In other cases, the number of bits added to the fallback DCI 220 may be determined as an upper bound of log2(N), where N is the number of subbands in the system bandwidth or the number of subbands in the initial BWP, or N is fixed to the number of subbands in the maximum supported system bandwidth. In these aspects, each potential value of the indication may be mapped to a different subband index. As indicated herein, in some aspects, the fallback DCI format may be used to provide resource grants to the UE 115-a, and Figure 3 Illustrations of some fallback DCI formats are provided.

[0099] Figure 3 Aspects of a DCI format 300 that supports subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the DCI format 300 can implement aspects of the wireless communication system 100 or 200. In this case, a downlink fallback DCI 305 (e.g., DCI format 1_0), an uplink fallback DCI 310 (e.g., DCI format 0_0), and an uplink fallback DCI (e.g., DCI format 0_0 for shared spectrum) for a shared spectrum 315 are shown.

[0100] exist Figure 3In the illustrated aspect, the downlink fallback DCI 305 may include several fields, including a downlink / uplink field 320 indicating whether the DCI 305 is a downlink or uplink DCI, a frequency division resource assignment (FDRA) field 325 indicating the frequency resources of the downlink grant (e.g., based on the RB index), a time division resource assignment (TDRA) field 330 indicating the time resources of the downlink grant, and a parameter field 335 indicating various parameters (such as a new data indicator (NDI), HARQ process information, a downlink assignment index (DAI), a transmit power control (TPC), a PUCCH resource indicator (PRI), feedback timing, and one or more other parameters). In addition, the downlink fallback DCI 305 may include one or more other fields that provide parameters, such as for resource mapping or modulation and coding. As shown in reference Figure 2 As discussed, in some aspects, the downlink fallback DCI 305 may provide an implicit indication of the subband for the associated PUCCH transmission (eg, based on a table entry of the PRI, or one or more other indications provided by the base station's downlink transmission).

[0101] like Figure 3 The illustrated uplink fallback DCI 310 may include several fields, including a downlink / uplink field 340 indicating whether the DCI 310 is a downlink or uplink DCI, a FDRA field 345 for uplink grants, a TDRA field 350 for uplink grants, and a parameter field 355 indicating various parameters, such as NDI, HARQ process information, DAI, TPC, and one or more other parameters. In addition, the uplink fallback DCI 310 may include one or more other fields (e.g., providing parameters such as for redundant versions, uplink or supplemental uplink indications, etc.). As discussed herein, the uplink fallback DCI 310 may include a plurality of zero padding bits 360 to provide a total DCI length corresponding to a predetermined number of bits 395, thereby providing the downlink fallback DCI 305 and the uplink fallback DCI 310 with the same bit length. In some aspects, such as with reference to Figure 2 As discussed, the uplink fallback DCI 310 may provide an implicit indication of the subband for the associated PUSCH transmission, for example, based on an indication provided by one or more downlink transmissions by the base station.

[0102] In some aspects, the uplink fallback DCI for the shared spectrum 315, such as Figure 3As shown in , an explicit indication of a subband may be provided for associated uplink communications. In one aspect, the uplink fallback DCI for the shared spectrum 315 may include multiple fields, including a downlink / uplink field 365 indicating whether the DCI for the shared spectrum 315 is a downlink or uplink DCI, an FDRA field 370 for uplink grants, a subband indication field 375 indicating one or more subbands for uplink communications, a TDRA field 380 for uplink grants, and a parameter field 385 indicating various parameters (e.g., NDI, HARQ process information, DAI, TPC, etc.). In addition, the uplink fallback DCI for the shared spectrum 315 may include one or more other fields (e.g., providing parameters, such as for redundancy versions, uplink or supplemental uplink indications, etc.). As discussed herein, the uplink fallback DCI for the shared spectrum 315 may include a reduced number of zero padding bits 390 relative to the zero padding bits 360 to provide a total DCI length corresponding to a predetermined number of bits 395, thereby providing all fallback DCIs 305, 310, and 315 with the same bit length.

[0103] In some cases, the number of bits in the subband indication field 375 may be included along with the bits of the FDRA field 370. In other cases, the subband indication field 375 may be provided at the end of the uplink fallback DCI for the shared spectrum 315, replacing some zero padding bits. In some cases, the number of bits of the subband indication field 375 may correspond to the number of subbands (N), and may provide a bitmap subband to be used for the corresponding uplink communication. In other cases, the subband indication field 375 may be a bit field that may indicate a subband of two or more subbands allocated contiguously based on an upper limit of (log2(N*(N+1) / 2), which is less than the number of available subbands. In other cases, a single subband may be indicated in the subband indication field 375, and the number of bits in the field may correspond to an upper limit of log2(N) to provide a subband index for the selected subband.

[0104] The number of subbands N can be the actual number of subbands in the BWP that the UE is monitoring, which can be the number of subbands in the initial BWP or the active BWP, depending on the common or UE-specific search space. In some aspects, when a connection is established between the base station and the UE, the initial BWP can be the active BWP. In some aspects, if the initial BWP or the active BWP contains one subband, then N = 1, and no additional bits are needed for subband indication. In other cases, N can correspond to the maximum number of subbands of the supported maximum system bandwidth, even if the actual BWP may be smaller (e.g., 4 bits are allocated fixed in the DCI). In this case, N is fixed, independent of the size of the current BWP, and is based on the maximum number of subbands in the system bandwidth. In some aspects, if the uplink system bandwidth is 80 MHz and the active uplink BWP is 40 MHz, then 4 bits are used for subband indication in the fallback DCI, while in the non-fallback DCI (e.g., DCI format 0_1), 2 bits can be used to refer to the subbands in the current BWP.

[0105] In some aspects, the bits of the subband indication field 375 can be selected to provide that the uplink fallback DCI of the shared spectrum 315 has a predetermined number of bits 395. In some cases, the number of zero-padding bits 360, referred to as "Z", can correspond to the bit length difference between the downlink fallback DCI 305 and the uplink fallback DCI 310 (before padding). Additionally, the value "S" can be the number of bits required for subband indication, and the value "M" can be the minimum margin bits reserved for future potential use. In some aspects, the value S can be the maximum number of subbands in the supported maximum system bandwidth (e.g., 5 bits for 100 MHz), or can be the actual number of subbands in the active / initial BWP. In some aspects, if Z ≥ M + S, then S bits can be used in the subband indication field 375 (e.g., to provide a bitmap of the subbands). In other aspects, if M < Z < S + M, then Z - M bits (< S) can be used in the subband indication field 375, and some combinations out of 2S combinations can be allowed (e.g., if for 4 subbands, S = 4 bits and Z - M = 2 bits, then the subband indication field 375 can indicate the lower 2 subbands). A special case of this situation is M = 0 (e.g., up to Z bits or min(S, Z) bits are used for subband indication).

[0106] Figure 4Aspects of a process flow 400 for supporting subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the process flow 400 can implement aspects of the wireless communication system 100 or 200. As described herein, the process flow 400 can be implemented by the UE 115-b and the base station 105-b. The following alternative aspects can be implemented, in which some of the steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0107] Optionally, at 405, the base station 105-b may send configuration information to the UE 115-b. In some cases, this configuration may configure the UE 115-b to monitor the subband indication of the uplink communication when the resource grant is provided to the UE 115-b using the fallback DCI. Optionally, at 410, the UE 115-b may determine to monitor the fallback DCI transmission including the subband indication field.

[0108] At 415, the base station 105-b may determine one or more subbands that the UE 115-b will use for uplink communications with the base station 105-b. In some cases, the base station 105-b may determine the number of subbands based on the one or more subbands for which a contention-based channel access procedure (e.g., an LBT procedure) has passed in the shared radio frequency spectrum band. In some cases, the base station 105-b may perform a contention-based channel access procedure, and the duration of the channel access may include sufficient time for downlink and uplink transmissions so that the UE 115-b may perform a simplified channel access procedure (e.g., a one-time LBT procedure) and have a high probability of obtaining channel access to the indicated one or more subbands.

[0109] At 420, the base station 105-b may format a fallback DCI for an uplink grant that includes a subband indication field. In some cases, the subband indication field may indicate the determined one or more subbands that the UE 115-b is to use for uplink communications. In some cases, the number of bits of the subband indication field may be configured by the base station 105-b in configuration information provided to the UE 115-b. At 425, the base station 105-b may send the fallback DCI to the UE 115-b.

[0110] At 430, UE 115-b may receive the fallback DCI and determine one or more subbands to use for uplink communications to base station 105-b. In some cases, UE 115-b may identify the subband based on a subband indication field of the fallback DCI. In some cases, the subband indication field may include a bitmap indicating which of a plurality of available subbands will be used by UE 115-b for uplink communications. In other cases, the subband indication field may provide a bit field in which the provided bit value may be mapped to one or more subband index values.

[0111] UE 115-b may format uplink communications for transmission to base station 105-b at 435. In some cases, uplink communications may be formatted according to information provided in the fallback DCI.

[0112] At 440, the base station 105-b may monitor uplink communications from the UE 115-b on the determined subbands. At 445, the UE 115-b may send uplink communications to the base station 105-b. The uplink communications may be sent on one or more subbands determined to be used for uplink communications based on the subband indication field in the fallback DCI.

[0113] Figure 5 Aspects of a process flow 500 for supporting subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the process flow 500 can implement aspects of the wireless communication system 100 or 200. As described herein, the process flow 500 can be implemented by a UE 115-c and a base station 105-c. The following alternative aspects can be implemented, in which some of the steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0114] Optionally, at 505, the base station 105-c may send configuration information to the UE 115-c. In some cases, such configuration information may configure the UE 115-c to monitor subband indications for uplink communications when a resource grant is provided to the UE 115-c using a fallback DCI. Optionally, at 510, the UE 115-c may determine to monitor for fallback DCI transmissions and subband indications from the base station 105-c.

[0115] At 515, the base station 105-c may determine one or more subbands that the UE 115-c will use for uplink communications with the base station 105-c. In some cases, the base station 105-c may determine the number of subbands based on one or more subbands for which a contention-based channel access process (e.g., an LBT process) has passed in the shared radio frequency spectrum band.

[0116] At 520, the base station 105-c may send a downlink transmission that may be used to indicate the selected subband for uplink communications from the UE 115-c. In some cases, the downlink transmission may be an SSB transmission on the selected subband, a PBCH transmission indicating the selected subband or sent on the selected subband, an RMSI communication indicating the selected subband or sent on the selected subband, or any combination thereof. In some cases, the subband used to send the fallback DCI or the lowest subband used to send the fallback DCI may be used to indicate the selected subband.

[0117] The UE 115-c may determine one or more subbands to use for uplink communications to the base station 105-c at 525. The UE 115-c may make such a determination based on any of the various techniques discussed herein that provide for implicit indication of subbands.

[0118] At 530, the base station 105-c may format a fallback DCI for the uplink grant. At 535, the base station 105-c may send the fallback DCI to the UE 115-c.

[0119] At 540, the UE 115-c may receive the fallback DCI and format uplink communications for transmission to the base station 105-c. In some cases, the uplink communications may be formatted according to information provided in the fallback DCI and may be formatted to be sent in the subband determined for the uplink communications.

[0120] The base station 105-c may monitor for uplink communications from the UE 115-c on the determined subbands at 545. The UE 115-c may send uplink communications to the base station 105-c at 545. The uplink communications may be sent on one or more subbands determined to be used for uplink communications based on the implicit subband indication provided by the base station 105-c.

[0121] Figure 6 Aspects of a process flow 600 for supporting subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the process flow 600 can implement aspects of the wireless communication system 100 or 200. As described herein, the process flow 600 can be implemented by the UE 115-d and the base station 105-d. The following alternative aspects can be implemented, in which some of the steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0122] Optionally, at 605, the base station 105-d may send configuration information to the UE 115-d. In some cases, such configuration information may configure the UE 115-d to monitor subband indications for uplink communications when a resource grant is provided to the UE 115-d using a fallback DCI. Optionally, at 610, the UE 115-d may determine to monitor for fallback DCI transmissions and subband indications from the base station 105-d.

[0123] At 615, base station 105-c may determine one or more subbands that UE 115-d will use to communicate with the uplink control channel of base station 105-d. In some cases, base station 105-d may determine the number of subbands based on one or more subbands for which a contention-based channel access procedure (e.g., an LBT procedure) has been passed in the shared radio frequency spectrum band.

[0124] At 620, the base station 105-d may send a downlink transmission that may be used to indicate a selected subband for uplink control channel communications from the UE 115-d, such as a control channel transmission for providing HARQ ACK / NACK feedback transmissions. In some cases, the downlink transmission may be an SSB transmission on the selected subband, a PBCH transmission indicating the selected subband or sent on the selected subband, an RMSI communication indicating the selected subband or sent on the selected subband, or any combination thereof. In some cases, the subband used to send the fallback DCI or the lowest subband used to send the fallback DCI may be used to indicate the selected subband. In some cases, the fallback DCI may provide a downlink resource grant to the UE 115-d, and an indication of the selected subband may be provided by a PRI field of the fallback DCI, where the subband used for uplink communications may correspond to a subband of a PUCCH resource indicated from a table entry identified by the PRI field. In some cases, the table may be pre-configured by RRC signaling. In other cases, the table may be a pre-specified table defined in the specification. In some cases, such a table may include multiple entries that are indexed and mapped to the value of the PRI field. In some cases, one or more table entries may indicate more than one subband, so the PRI field in the fallback DCI may identify one or more subbands for transmitting the PUCCH.

[0125] At 625, the UE 115-d may determine one or more subbands to use for uplink communications to the base station 105-d. The UE 115-d may make such a determination based on any of the various techniques discussed herein that provide for implicit indication of subbands.

[0126] At 630, the base station 105-d may format a fallback DCI for an uplink grant. At 635, the base station 105-d may send the fallback DCI to the UE 115-d. At 640, the UE 115-d may determine a downlink grant based on the fallback DCI.

[0127] At 645, the base station 105-d may send the downlink communication to the UE 115-d. At 650, the UE 115-d may determine ACK / NACK feedback associated with the downlink communication for transmission in the control channel communication.

[0128] The base station 105-d may monitor for uplink control channel communications from the UE 115-d on the determined subbands at 655. The UE 115-d may send uplink control channel communications to the base station 105-d at 660. The uplink communications may be sent on one or more subbands determined to be used for uplink control channel communications based on the implicit subband indication provided by the base station 105-d.

[0129] Figure 7 Aspects of a process flow 700 for supporting subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure are shown. In some aspects, the process flow 700 can implement aspects of the wireless communication system 100 or 200. As described herein, the process flow 700 can be implemented by a UE 115-e and a base station 105-e. The following alternative aspects can be implemented, in which some of the steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0130] Optionally, at 705, the base station 105-e may send configuration information to the UE 115-e. In some cases, such configuration may configure the UE 115-e to monitor subband indications for uplink communications when a resource grant is provided to the UE 115-e using a fallback DCI. Optionally, at 710, the UE 115-e may determine to monitor for fallback DCI transmissions from the base station 105-e.

[0131] At 715, the base station 105-e may determine one or more subbands that the UE 115-e will use to communicate with the uplink control channel of the base station 105-e. In some cases, the base station 105-e may determine the number of subbands based on one or more subbands for which a contention-based channel access process (e.g., an LBT process) has been passed in the shared radio frequency spectrum band.

[0132] At 720, the base station 105-e may format a fallback DCI for a downlink grant that includes a subband indication field. In some cases, the subband indication field may indicate the determined subband or subbands that the UE 115-e is to use for uplink control channel communications. In some cases, the number of bits of the subband indication field may be configured by the base station 105-e in configuration information provided to the UE 115-e. At 725, the base station 105-e may send the fallback DCI to the UE 115-e.

[0133] At 730, the UE 115-e may receive the fallback DCI and determine one or more subbands to use for uplink control channel communications to the base station 105-e. In some cases, the UE 115-e may identify the subband based on a subband indication field of the fallback DCI. In some cases, the subband indication field may include a bitmap indicating which of a plurality of available subbands will be used by the UE 115-e for uplink communications. In other cases, the subband indication field may provide a bit field, wherein the provided bit value may be mapped to one or more subband index values.

[0134] At 735, the base station 105-e may send the downlink communication to the UE 115-e. At 740, the UE 115-e may determine ACK / NACK feedback associated with the downlink communication for transmission in the control channel communication.

[0135] The base station 105-e may monitor for uplink control channel communications from the UE 115-e on the determined subbands at 745. The UE 115-e may send uplink control channel communications to the base station 105-e at 750. The uplink communications may be sent on one or more subbands determined to be used for uplink control channel communications based on an explicit subband indication provided by the base station 105-e in the subband indication field.

[0136] Figure 8 A block diagram 800 of a device 805 supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The device 805 may be an example of aspects of a UE 115 as described herein. The device 805 may include a receiver 810, a communication manager 815, and a transmitter 820. The device 805 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0137] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to subband indications in downlink control information in a shared radio frequency spectrum, etc.). The information may be passed to other components of the device 805. The receiver 810 may be a reference Fig.11 Examples of aspects of the transceiver 1120 are described. The receiver 810 may utilize a single antenna or a collection of antennas.

[0138] In some aspects, the communication manager 815 can receive a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and send the uplink communication to the base station via the determined one or more subbands.

[0139] In some aspects, the communication manager 815 may monitor a subband indication from a base station that indicates a first subband in a set of available subbands in an active bandwidth portion for uplink communications from the UE to the base station within a shared radio frequency spectrum band, determine that the first subband is to be used for uplink communications based on signaling monitored from the base station, receive a fallback downlink control information communication from the base station that provides an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, and in response to receiving the uplink grant, send uplink communications to the base station via the first subband.

[0140] In some aspects, the communication manager 815 may monitor a subband indication from a base station that indicates a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE to a base station within a shared radio frequency spectrum band, receive a fallback downlink control information communication from the base station that provides a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the first subband.

[0141] In some aspects, the communication manager 815 can receive a fallback downlink control information communication from a base station that provides a downlink grant to a UE for a first downlink communication within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink control channel communications associated with the downlink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the determined one or more subbands. The communication manager 815 can be an example of aspects of the communication manager 1110 described herein.

[0142] The actions performed by the communication manager 815 as described herein may be implemented to achieve one or more potential advantages. One implementation may allow the UE 115 to save power and increase battery life by maintaining a predetermined number of bits for fallback downlink control information communications, even if the subband information field is included in the fallback downlink control information communications. Additionally or alternatively, the UE 115 may further improve reliability when communicating with the base station 105 using a shared radio frequency spectrum band, where the available subbands for uplink communications may vary. Another implementation may provide improved quality at the UE 115 because latency may be reduced.

[0143] The communication manager 815 or its subcomponents may be implemented by 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 communication manager 815 or its subcomponents may be performed 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.

[0144] The communication manager 815 or its subcomponents can be physically located in various locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some aspects, the communication manager 815 or its subcomponents can be independent and distinct components according to various aspects of the present disclosure. In some aspects, the communication manager 815 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in the present disclosure, or combinations thereof according to various aspects of the present disclosure.

[0145] The transmitter 820 can transmit signals generated by other components of the device 805. In some aspects, the transmitter 820 can be collocated with the receiver 810 in the transceiver module. In some aspects, the transmitter 820 can be a reference Fig.11 Examples of aspects of the transceiver 1120 are described. The transmitter 820 may utilize a single antenna or a collection of antennas.

[0146] Fig. 9 A block diagram 900 of a device 905 supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The device 905 may be an example of aspects of the device 805 or UE 115 as described herein. The device 905 may include a receiver 910, a communication manager 915, and a transmitter 945. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0147] 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 subband indications in downlink control information in a shared radio frequency spectrum, etc.). The information may be passed to other components of the device 905. The receiver 910 may be a reference Fig.11 Examples of aspects of the transceiver 1120 are described. The receiver 910 may utilize a single antenna or a collection of antennas.

[0148] The communication manager 915 may be an example of aspects of the communication manager 815 as described herein. The communication manager 915 may include a DCI manager 920, a subband manager 925, an uplink transmission manager 930, a downlink transmission manager 935, and an acknowledgement feedback manager 940. The communication manager 915 may be an example of aspects of the communication manager 1110 described herein.

[0149] In some aspects, the DCI manager 920 may receive a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The subband manager 925 may determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The uplink transmission manager 930 may send an uplink communication to the base station via the determined one or more subbands.

[0150] In some aspects, the subband manager 925 may monitor a subband indication from a base station indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communications from a UE to a base station within a shared radio frequency spectrum band, and determine based on the monitored signaling from the base station that the first subband will be used for uplink communications. The DCI manager 920 may receive a fallback downlink control information communication from the base station that provides an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits. The uplink transmission manager 930 may, in response to receiving the uplink grant, send an uplink communication to the base station via the first subband.

[0151] In some aspects, the subband manager 925 may monitor a subband indication from a base station, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE to a base station within a shared radio frequency spectrum band. The DCI manager 920 may receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The downlink transmission manager 935 may receive the first downlink communication from the base station. The acknowledgment feedback manager 940 may determine the uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication. The uplink transmission manager 930 may send the uplink control channel communication to the base station via the first subband.

[0152] In some aspects, the DCI manager 920 may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant for a first downlink communication to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The subband manager 925 may determine one or more subbands in a set of available subbands in an active bandwidth portion of an uplink control channel communication associated with the downlink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The downlink transmission manager 935 may receive a first downlink communication from a base station. The confirmation feedback manager 940 may determine the uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication. The uplink transmission manager 930 may send the uplink control channel communication to the base station via the determined one or more subbands.

[0153] The transmitter 945 can transmit signals generated by other components of the device 905. In some aspects, the transmitter 945 can be collocated with the receiver 910 in the transceiver module. In some aspects, the transmitter 945 can be a reference Fig.11 Examples of aspects of the transceiver 1120 are described. The transmitter 945 may utilize a single antenna or a collection of antennas.

[0154] Fig.10 A block diagram 1000 of a communication manager 1005 supporting subband indication in downlink control information in a shared radio frequency spectrum is shown according to aspects of the present disclosure. The communication manager 1005 may be an example of aspects of the communication manager 815, the communication manager 915, or the communication manager 1110 described herein. The communication manager 1005 may include a DCI manager 1010, a subband manager 1015, an uplink transmission manager 1020, a configuration manager 1025, a downlink transmission manager 1030, an acknowledgment feedback manager 1035, and a PRI manager 1040. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0155] The DCI manager 1010 may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. In some aspects, the DCI manager 1010 may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant for a first downlink communication to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits.

[0156] In some cases, the fallback downlink control information communication has a fallback downlink control information format, and wherein the predetermined number of bits is based on the length of a separate fallback downlink control information format for a downlink grant to the UE.

[0157] In some cases, the subband information field is adjacent to a frequency division multiplexing resource assignment field in a fallback downlink control information communication, or is located after a last information field in the fallback downlink control information communication, which last information field is present when the subband information field is not present in the fallback downlink control information communication. In some cases, when the subband information field is not present in the fallback downlink control information communication, the subband information field occupies one or more bits that are used as zero padding bits. In some cases, the fallback downlink control information communication has a fallback downlink control information format, and wherein the monitoring of the subband indication is based on the fallback downlink control information format.

[0158] The subband manager 1015 can determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with an uplink grant based on a subband information field within a fallback downlink control information communication, wherein a predetermined number of bits for the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication.

[0159] In some aspects, the subband manager 1015 may monitor a subband indication from a base station indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communications from a UE to a base station within a shared radio frequency spectrum band. In some aspects, the subband manager 1015 may determine that the first subband is to be used for uplink communications based on the monitored signaling from the base station.

[0160] In some aspects, the subband manager 1015 may monitor a subband indication from a base station indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE to a base station within a shared radio frequency spectrum band. In some aspects, the subband manager 1015 may determine one or more subbands in the set of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant based on a subband information field within a fallback downlink control information communication, wherein a predetermined number of bits for the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. In some cases, the number of bits in the subband information field is determined based on the number of subbands in the set of available subbands. In some cases, the number of bits in the subband information field corresponds to the number of subbands in the active bandwidth portion, the number of subbands in the initial bandwidth portion for establishing a connection between the UE and the base station, is a predetermined number of subbands, is based on the maximum number of subbands supported in the maximum configurable bandwidth, or any combination thereof. In some cases, the subband information field is a bitmap whose bit length corresponds to the number of subbands in the set of available subbands. In some cases, the subband information field is a bit field, and wherein different available values ​​of the bit field are mapped to different sets of contiguous subbands. In some cases, the subband information field is a bit field, and wherein different available values ​​of the bit field are mapped to different individual subbands of the set of available subbands.

[0161] In some cases, the number of subbands of the available subband set is based on the actual number of subbands in the active bandwidth portion, or the maximum number of subbands of the maximum configurable bandwidth. In some cases, the first subband is one of the lowest subband of the active bandwidth portion, a subband used to receive SSBs from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send fallback downlink control information communications, or a lowest subband used to send fallback downlink control information communications.

[0162] In some cases, a PRI field in the fallback downlink control information communication provides a subband indication. In some cases, the first subband is one of a lowest subband of the active bandwidth portion, a subband used to receive SSBs from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send the fallback downlink control information communication, or a lowest subband used to send the fallback downlink control information communication. In some cases, the subband information field occupies one or more bits appended to the downlink control information and is otherwise provided when the subband information field is not present in the fallback downlink control information communication.

[0163] In some cases, the number of bits in the subband information field corresponds to the number of subbands in the available subband set. In some cases, the number of bits in the subband information field is based on the different number of subbands in the available subband set in the active bandwidth portion or the initial bandwidth portion. In some cases, the number of bits in the subband information field is configured by the base station based on the different number of subbands of the maximum supported system bandwidth.

[0164] The uplink transmission manager 1020 may send an uplink communication to the base station via the determined one or more subbands. The downlink transmission manager 1030 may receive a first downlink communication from the base station. The acknowledgment feedback manager 1035 may determine uplink control channel information to be provided in an uplink control channel communication based on the first downlink communication.

[0165] The configuration manager 1025 may receive configuration information from a base station indicating whether the fallback downlink control information communication includes a subband information field. In some aspects, the configuration manager 1025 may receive configuration information from a base station indicating whether to monitor a subband indication.

[0166] In some cases, the configuration information is received in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0167] The PRI manager 1040 may identify the PRI provided by the base station and a corresponding PRI table with corresponding parameters for uplink control channel resources. In some cases, the configuration information indicates that the PRI field in the fallback downlink control information communication provides subband information.

[0168] Fig.11 A diagram of a system 1100 including a device 1105 supporting subband indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure is shown. The device 1105 may be an example of or include components of a device 805, a device 905, or a UE 115 as described herein. The device 1105 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 1110, an I / O controller 1115, a transceiver 1120, an antenna 1125, a memory 1130, and a processor 1140. These components may be in electronic communication via one or more buses (e.g., bus 1145).

[0169] In some aspects, the communication manager 1110 may receive a fallback downlink control information communication from a base station that provides an uplink grant to a UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and send the uplink communication to the base station via the determined one or more subbands.

[0170] In some aspects, the communication manager 1110 may monitor a subband indication from a base station that indicates a first subband in a set of available subbands in an active bandwidth portion for uplink communications from a UE to a base station within a shared radio frequency spectrum band, determine that the first subband is to be used for uplink communications based on signaling monitored from the base station, receive a fallback downlink control information communication from the base station that provides an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, and in response to receiving the uplink grant, send uplink communications to the base station via the first subband.

[0171] In some aspects, the communication manager 1110 may monitor a subband indication from a base station that indicates a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE to a base station within a shared radio frequency spectrum band, receive a fallback downlink control information communication from the base station that provides a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the first subband.

[0172] In some aspects, the communication manager 1110 can receive a fallback downlink control information communication from a base station, which provides a downlink grant to the UE for a first downlink communication within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits, determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink control channel communications associated with the downlink grant based on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, receive the first downlink communication from the base station, determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication, and send the uplink control channel communication to the base station via the determined one or more subbands.

[0173] Based on receiving a fallback downlink control information communication from the base station 105, the fallback downlink control information communication provides a downlink grant to the UE for a first downlink communication within the shared radio frequency spectrum band, the processor of the UE 115 (e.g., controls the receiver 910, the transmitter 945, as described in reference Fig. 9 The UE 115 may be configured to receive a downlink grant and to receive a control channel associated with the downlink grant. The UE 115 may be configured to receive a control channel associated with the ...

[0174] I / O controller 1115 can manage input and output signals for device 1105. I / O controller 1115 can also manage peripheral devices that are not integrated into device 1105. In some cases, I / O controller 1115 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1115 can utilize a computer such as a MS- MS- OS / Or another known operating system. In other cases, I / O controller 1115 can be represented or interacted with by a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1115 can be implemented as part of a processor. In some cases, a user can interact with device 1105 via I / O controller 1115 or via hardware components controlled by I / O controller 1115.

[0175] The transceiver 1120 may communicate bidirectionally via one or more antennas, wired or wireless links as described herein. In some aspects, the transceiver 1120 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1120 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating packets received from an antenna.

[0176] In some cases, a wireless device may include a single antenna 1125. However, in some cases, a device may have more than one antenna 1125, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously.

[0177] The memory 1130 may include random access memory (RAM) and read-only memory (ROM). The memory 1130 may store computer-readable computer executable code 1135, which includes instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1130 may contain a basic I / O system (BIOS), etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0178] Processor 1140 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1140 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 1140. Processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1130) to cause device 1105 to perform various functions (e.g., functions or tasks to support subband indication in downlink control information in a shared radio spectrum).

[0179] The code 1135 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1135 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some cases, the code 1135 may not be directly executed by the processor 1140, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0180] Fig.12 A block diagram 1200 of a device 1205 supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The device 1205 may be an example of aspects of a base station 105 as described herein. The device 1205 may include a receiver 1210, a communication manager 1215, and a transmitter 1220. The device 1205 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0181] The receiver 1210 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 subband indications in downlink control information in a shared radio frequency spectrum, etc.). The information may be passed to other components of the device 1205. The receiver 1210 may be a reference Fig.15 Examples of aspects of the transceiver 1520 are described. The receiver 1210 may utilize a single antenna or a collection of antennas.

[0182] In some aspects, the communication manager 1215 may identify one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications from a UE within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE that provides an uplink authorization for uplink communications and indicates the one or more subbands, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and monitor the one or more subbands used for uplink communications from the base station.

[0183] In some aspects, the communications manager 1215 may send a subband indication to the UE that indicates a first subband in a set of available subbands in an active bandwidth portion for uplink communications from the UE to a base station within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE that provides an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, and monitor the first subband for uplink communications from the UE.

[0184] In some aspects, the communications manager 1215 may send a subband indication to the UE, the subband indication indicating a first subband in a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to a base station within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing the UE with a downlink grant for the first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, send the first downlink communication to the UE based on the downlink grant, and monitor the first subband for uplink control channel communications from the UE.

[0185] In some aspects, the communications manager 1215 may identify one or more subbands in a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, send the first downlink communication to the UE, and monitor the one or more subbands for uplink control channel communications from the UE. The communications manager 1215 may be an example of aspects of the communications manager 1510 described herein.

[0186] The actions performed by the communication manager 1215 as described herein may be implemented to achieve one or more potential advantages. One implementation may allow the UE 115 to save power and increase battery life by maintaining a predetermined number of bits for fallback downlink control information communications, even if the subband information field is included in the fallback downlink control information communications. Additionally or alternatively, the base station 105 may further improve reliability when communicating with the UE 115 using a shared radio frequency spectrum band, where the available subbands for uplink communications may vary. Another implementation may provide improved quality at the base station 105 because latency may be reduced.

[0187] The communication manager 1215 or its subcomponents may be implemented by 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 communication manager 1215 or its subcomponents may be performed by a general purpose processor, DSP, ASIC, 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.

[0188] The communication manager 1215 or its subcomponents can be physically located in a variety of locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some aspects, the communication manager 1215 or its subcomponents can be independent and distinct components according to various aspects of the present disclosure. In some aspects, the communication manager 1215 or its subcomponents can be combined with one or more other hardware components, including but not limited to I / O components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof according to various aspects of the present disclosure.

[0189] The transmitter 1220 can transmit signals generated by other components of the device 1205. In some aspects, the transmitter 1220 can be collocated with the receiver 1210 in the transceiver module. In some aspects, the transmitter 1220 can be a reference Fig.15 Examples of aspects of the transceiver 1520 are described. The transmitter 1220 may utilize a single antenna or a collection of antennas.

[0190] Fig.13 A block diagram 1300 of a device 1305 supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The device 1305 may be an example of aspects of the device 1205 or base station 105 as described herein. The device 1305 may include a receiver 1310, a communication manager 1315, and a transmitter 1340. The device 1305 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0191] The receiver 1310 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 subband indications in downlink control information in a shared radio frequency spectrum, etc.). The information may be passed to other components of the device 1305. The receiver 1310 may be a reference Fig.15 Examples of aspects of transceiver 1520 are described. Receiver 1310 may utilize a single antenna or a collection of antennas.

[0192] The communication manager 1315 may be an example of aspects of the communication manager 1215 as described herein. The communication manager 1315 may include a subband manager 1320, a DCI manager 1325, an uplink transmission manager 1330, and a downlink transmission manager 1335. The communication manager 1315 may be an example of aspects of the communication manager 1510 as described herein.

[0193] In some aspects, the subband manager 1320 may identify one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications from a UE within a shared radio frequency spectrum band. The DCI manager 1325 may send a fallback downlink control information communication to the UE that provides an uplink grant for uplink communications and indicates one or more subbands, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The uplink transmission manager 1330 may monitor the one or more subbands used for uplink communications from the base station.

[0194] In some aspects, the subband manager 1320 may send a subband indication to the UE indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communications from the UE to the base station within the shared radio frequency spectrum band. The DCI manager 1325 may send a fallback downlink control information communication to the UE that provides an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits. The uplink transmission manager 1330 may monitor the first subband for uplink communications from the UE.

[0195] In some aspects, the subband manager 1320 may send a subband indication to the UE indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to the base station within a shared radio frequency spectrum band. The DCI manager 1325 may send a fallback downlink control information communication to the UE that provides a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The downlink transmission manager 1335 may send the first downlink communication to the UE based on the downlink grant. The uplink transmission manager 1330 may monitor the first subband for uplink control channel communications from the UE.

[0196] In some aspects, the subband manager 1320 may identify one or more subbands in a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE within a shared radio frequency spectrum band. The DCI manager 1325 may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The downlink transmission manager 1335 may send the first downlink communication to the UE. The uplink transmission manager 1330 may monitor the one or more subbands used for uplink control channel communications from the UE.

[0197] The transmitter 1340 can transmit signals generated by other components of the device 1305. In some aspects, the transmitter 1340 can be collocated with the receiver 1310 in the transceiver module. In some aspects, the transmitter 1340 can be a reference Fig.15 Examples of aspects of the transceiver 1520 are described. The transmitter 1340 may utilize a single antenna or a collection of antennas.

[0198] Fig.14 A block diagram 1400 of a communication manager 1405 supporting subband indication in downlink control information in a shared radio frequency spectrum is shown according to aspects of the present disclosure. The communication manager 1405 may be an example of aspects of the communication manager 1215, the communication manager 1315, or the communication manager 1510 described herein. The communication manager 1405 may include a subband manager 1410, a DCI manager 1415, an uplink transmission manager 1420, a configuration manager 1425, and a downlink transmission manager 1430. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0199] The subband manager 1410 may identify one or more subbands in a set of available subbands in an active bandwidth portion for uplink communications from a UE within a shared radio frequency spectrum band. In some aspects, the subband manager 1410 may send a subband indication to the UE indicating a first subband of the set of available subbands in the active bandwidth portion for uplink communications from the UE to a base station within the shared radio frequency spectrum band. In some aspects, the subband manager 1410 may send a subband indication to the UE indicating a first subband of the set of available subbands in the active bandwidth portion for uplink control channel communications from the UE to the base station within the shared radio frequency spectrum band.

[0200] In some cases, the subband information field is adjacent to the frequency division multiplexing resource assignment field in the fallback downlink control information communication, or is located after the last information field in the fallback downlink control information communication, which is present when the subband information field is not present in the fallback downlink control information communication. In some cases, when the subband information field is not present in the fallback downlink control information communication, the subband information field occupies one or more bits, which are used as zero padding bits. In some cases, the number of bits in the subband information field is determined based on the number of subbands in the available subband set. In some cases, the number of bits in the subband information field corresponds to the number of subbands in the active bandwidth part, the number of subbands in the initial bandwidth part for establishing a connection between the UE and the base station, is a predetermined number of subbands, is based on the maximum number of subbands supported in the maximum configurable bandwidth, or any combination thereof. In some cases, the subband information field is a bitmap with a bit length corresponding to the number of subbands in the available subband set. In some cases, the subband information field is a bit field, and different available values ​​of the bit field are mapped to different sets of consecutive subbands. In some cases, the subband information field is a bit field, and wherein different available values ​​of the bit field are mapped to different individual subbands of the available subband set. In some cases, the number of subbands of the available subband set is based on the actual number of subbands in the active bandwidth portion, or the maximum number of subbands for the maximum configurable bandwidth.

[0201] In some cases, the first subband is one of a lowest subband of the active bandwidth portion, a subband used to receive SSB from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send fallback downlink control information communications, or a lowest subband used to send fallback downlink control information communications. In some cases, a PRI field in the fallback downlink control information communication provides a subband indication.

[0202] In some cases, the first subband is one of a lowest subband of the active bandwidth portion, a subband used to receive SSB from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send fallback downlink control information communications, or a lowest subband used to send fallback downlink control information communications. In some cases, the subband information field occupies one or more bits appended to the downlink control information and is otherwise provided when the subband information field is not present in the fallback downlink control information communication.

[0203] The DCI manager 1415 may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing an uplink grant for uplink communication and indicating one or more subbands, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. In some aspects, the DCI manager 1415 may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing an uplink grant for uplink communication to the UE, wherein the fallback downlink control information communication has a predetermined number of bits. In some aspects, the DCI manager 1415 may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing a downlink grant for a first downlink communication to the UE, wherein the fallback downlink control information communication has a predetermined number of bits.

[0204] In some aspects, the DCI manager 1415 may send a fallback downlink control information communication to the UE that provides a downlink grant to the UE for a first downlink communication, wherein the fallback downlink control information communication includes a subband information field indicating one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even though the subband information field is included in the fallback downlink control information communication. In some cases, the fallback downlink control information communication has a fallback downlink control information format, and wherein the predetermined number of bits is based on a length of a separate downlink control information format for the downlink grant to the UE.

[0205] The uplink transmission manager 1420 may monitor one or more subbands for uplink communications from the base station. The downlink transmission manager 1430 may send a first downlink communication to the UE based on the downlink grant. In some aspects, the downlink transmission manager 1430 may send the first downlink communication to the UE.

[0206] The configuration manager 1425 may send configuration information to the UE indicating whether the fallback downlink control information communication includes a subband information field. In some aspects, the configuration manager 1425 may send configuration information to the UE indicating whether to monitor the subband indication. In some aspects, the configuration manager 1425 may send configuration information to the UE indicating whether to monitor the subband indication from the base station. In some cases, the configuration information is sent in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0207] Fig.15 A diagram of a system 1500 including a device 1505 supporting sub-band indication in downlink control information in a shared radio frequency spectrum band according to aspects of the present disclosure is shown. The device 1505 may be an example of or include components of the device 1205, device 1305, or base station 105 as described herein. The device 1505 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 1510, a network communication manager 1515, a transceiver 1520, an antenna 1525, a memory 1530, a processor 1540, and an inter-station communication manager 1545. These components may be in electronic communication via one or more buses (e.g., bus 1550).

[0208] In some aspects, the communications manager 1510 may identify one or more subbands from a set of available subbands in an active bandwidth portion for uplink communications from a UE within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE that provides an uplink authorization for uplink communications and indicates the one or more subbands, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, and monitor the one or more subbands used for uplink communications from the base station.

[0209] In some aspects, the communications manager 1510 may send a subband indication to the UE, the subband indication indicating a first subband in a set of available subbands in an active bandwidth portion for uplink communications from the UE to a base station within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing an uplink grant to the UE for uplink communications, wherein the fallback downlink control information communication has a predetermined number of bits, and monitor the first subband for uplink communications from the UE.

[0210] In some aspects, the communications manager 1510 may send a subband indication to the UE, the subband indication indicating a first subband in a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to a base station within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing the UE with a downlink grant for the first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits, send the first downlink communication to the UE based on the downlink grant, and monitor the first subband for uplink control channel communications from the UE.

[0211] In some aspects, the communications manager 1510 may identify one or more subbands from a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE within a shared radio frequency spectrum band, send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing the UE with a downlink grant for a first downlink communication, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication, send the first downlink communication to the UE and monitor the one or more subbands for uplink control channel communications from the UE.

[0212] Based on sending a fallback downlink control information communication to UE 115, the fallback downlink control information communication provides a downlink grant to UE 115 for a first downlink communication within the shared radio frequency spectrum band, a processor of the base station (e.g., controls receiver 1410, transmitter 1340, as described in reference to Fig.13 The or transceiver 1520) can effectively transmit the first downlink communication to the UE. In addition, the processor of the UE115 can send an uplink control channel communication via the determined one or more sub-bands. The processor of the base station 105 can turn on one or more processing units for sending the first downlink communication to the UE, increase the processing clock, or a similar mechanism within the UE 115. In this way, when sending the first downlink communication, the processor can be ready to respond more effectively by reducing the increase in processing power.

[0213] The network communications manager 1515 may manage communications with the core network (eg, via one or more wired backhaul links). In some aspects, the network communications manager 1515 may manage the delivery of data communications for client devices such as one or more UEs 115 .

[0214] The transceiver 1520 may communicate bidirectionally via one or more antennas, wired or wireless links as described herein. In some aspects, the transceiver 1520 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1520 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating packets received from an antenna.

[0215] In some cases, a wireless device may include a single antenna 1525. However, in some cases, a device may have more than one antenna 1525, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously.

[0216] Memory 1530 may include RAM, ROM, or a combination thereof. Memory 1530 may store computer readable code 1535, which includes instructions that, when executed by a processor (e.g., processor 1540), cause the device to perform various functions described herein. In some cases, memory 1530 may include BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0217] Processor 1540 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1540 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1540. Processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1530) to cause device 1505 to perform various functions (e.g., functions or tasks to support subband indication in downlink control information in a shared radio spectrum).

[0218] The inter-site communication manager 1545 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in coordination with other base stations 105. In some aspects, the inter-site communication manager 1545 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques such as beamforming or joint transmissions. In some aspects, the inter-site communication manager 1545 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0219] The code 1535 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1535 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some cases, the code 1535 may not be directly executed by the processor 1540, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0220] Fig.16 A flow chart illustrating a method 1600 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. In some aspects, the operations of the method 1600 may be implemented by the UE 115 as described in reference to Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0221] At 1605, the UE may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 1605 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1605 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0222] At 1610, the UE may determine one or more subbands in a set of available subbands in an active bandwidth portion for uplink communications associated with an uplink grant based on a subband information field within a fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 1610 may be performed in accordance with the methods described herein. In some aspects, aspects of the operations of 1610 may be performed with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0223] At 1615, the UE may send an uplink communication to the base station via the determined one or more subbands. The operations of 1615 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1615 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0224] Fig.17A flow chart illustrating a method 1700 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by the UE 115 or components thereof, as described herein. In some aspects, the operations of the method 1700 may be implemented by the UE 115 or components thereof, as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0225] At 1705, the UE may receive configuration information from the base station, the configuration information indicating whether the fallback downlink control information communication includes a subband information field. The operations of 1705 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1705 may be described with reference to Figures 8 to 11 In some cases, the configuration information is received in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0226] At 1710, the UE may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 1710 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1710 may be described with reference to Figures 8 to 11 In some cases, the fallback downlink control information communication has a fallback downlink control information format, and wherein the predetermined number of bits is based on a length of a separate fallback downlink control information format for a downlink grant to the UE.

[0227] At 1715, the UE may determine one or more subbands in a set of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based on a subband information field within the fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 1715 may be performed in accordance with the methods described herein. In some aspects, aspects of the operations of 1715 may be performed with reference to Figures 8 to 11The subband information field is performed by the subband manager described in the fallback downlink control information communication. In some cases, the subband information field is adjacent to the frequency division multiplexing resource assignment field in the fallback downlink control information communication, or is located after the last information field in the fallback downlink control information communication, which last information field exists when the subband information field does not exist in the fallback downlink control information communication. In some cases, when the subband information field does not exist in the fallback downlink control information communication, the subband information field occupies one or more bits, which are used as zero padding bits.

[0228] At 1720, the UE may send an uplink communication to the base station via the determined one or more subbands. The operations of 1720 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1720 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0229] Fig.18 A flow chart illustrating a method 1800 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by the UE 115 or components thereof, as described herein. In some aspects, the operations of the method 1800 may be implemented by the UE 115 or components thereof, as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0230] At 1805, the UE may monitor a subband indication from the base station, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communications from the UE to the base station within a shared radio frequency spectrum band. The operations of 1805 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1805 may be described with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0231] At 1810, the UE may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to the UE for uplink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 1810 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1810 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0232] At 1815, the UE may determine, based on signaling monitored from the base station, that the first subband is to be used for uplink communication. The operations of 1815 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1815 may be described with reference to Figures 8 to 11 In some cases, the first subband is one of a lowest subband of the active bandwidth portion, a subband used to receive SSB from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send fallback downlink control information communications, or a lowest subband used to send fallback downlink control information communications.

[0233] At 1820, the UE may, in response to receiving the uplink grant, send an uplink communication to the base station via the first subband. The operations of 1820 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1820 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0234] Fig.19 A flow chart illustrating a method 1900 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 1900 may be implemented by a UE 115 or a component thereof as described herein. In some aspects, the operations of the method 1900 may be implemented by a UE 115 or a component thereof as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0235] At 1905, the UE may receive configuration information from the base station indicating whether to monitor the subband indication. The operation of 1905 may be performed according to the method described herein. In some aspects, aspects of the operation of 1905 may be referred to as Figures 8 to 11 In some cases, the configuration information is received in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0236] At 1910, the UE may monitor a subband indication from a base station, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communications from the UE to the base station within a shared radio frequency spectrum band. The operations of 1910 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1910 may be described with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0237] At 1915, the UE may receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing the UE with an uplink grant for uplink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 1915 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1915 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0238] At 1920, the UE may determine, based on signaling monitored from the base station, that the first subband is to be used for uplink communication. The operations of 1920 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1920 may be described with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0239] At 1925, the UE may, in response to receiving the uplink grant, send an uplink communication to the base station via the first subband. The operations of 1925 may be performed according to the methods described herein. In some aspects, aspects of the operations of 1925 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0240] Fig. 20 A flow chart illustrating a method 2000 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2000 may be implemented by the UE 115 or components thereof, as described herein. In some aspects, the operations of the method 2000 may be implemented by the UE 115 or components thereof, as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0241] At 2005, the UE may monitor a subband indication from the base station, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to the base station within a shared radio frequency spectrum band. The operations of 2005 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2005 may be described with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0242] At 2010, the UE may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing the UE with a downlink grant for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations at 2010 may be performed according to the methods described herein. In some aspects, aspects of the operations at 2010 may be described with reference to Figures 8 to 11The DCI manager is used to perform the above operations.

[0243] At 2015, the UE may receive a first downlink communication from the base station. The operations at 2015 may be performed according to the methods described herein. In some aspects, aspects of the operations at 2015 may be described with reference to Figures 8 to 11 The downlink transmission manager is executed.

[0244] At 2020, the UE may determine, based on the first downlink communication, uplink control channel information to be provided in the uplink control channel communication. The operations at 2020 may be performed according to the methods described herein. In some aspects, aspects of the operations at 2020 may be described with reference to Figures 8 to 11 The confirmation feedback manager is used to perform the above operation.

[0245] At 2025, the UE may send an uplink control channel communication to the base station via the first subband. The operations of 2025 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2025 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0246] Fig.21 A flow chart illustrating a method 2100 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2100 may be implemented by a UE 115 or a component thereof as described herein. In some aspects, the operations of the method 2100 may be implemented by a UE 115 or a component thereof as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0247] At 2105, the UE may receive configuration information from the base station indicating monitoring of the subband indication from the base station. The operation of 2105 may be performed according to the method described herein. In some aspects, aspects of the operation of 2105 may be referred to as Figures 8 to 11 In some cases, the configuration information is received in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0248] At 2110, the UE may monitor a subband indication from the base station, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to the base station within a shared radio frequency spectrum band. The operations of 2110 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2110 may be described with reference to Figures 8 to 11In some cases, the first subband is one of a lowest subband of the active bandwidth portion, a subband used to receive SSB from the base station, a subband indicated in a PBCH received from the base station, a subband indicated in an RMSI communication received from the base station, a subband used to send fallback downlink control information communications, or a lowest subband used to send fallback downlink control information communications.

[0249] At 2115, the UE may receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing the UE with a downlink grant for the first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 2115 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2115 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0250] At 2120, the UE may receive a first downlink communication from the base station. The operations at 2120 may be performed according to the methods described herein. In some aspects, aspects of the operations at 2120 may be described with reference to Figures 8 to 11 The downlink transmission manager is executed.

[0251] At 2125, the UE may determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication. The operations of 2125 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2125 may be described with reference to Figures 8 to 11 The confirmation feedback manager is used to perform the above operation.

[0252] At 2130, the UE may send an uplink control channel communication to the base station via the first subband. The operations of 2130 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2130 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0253] Fig. 22 A flow chart illustrating a method 2200 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2200 may be implemented by a UE 115 or a component thereof as described herein. In some aspects, the operations of the method 2200 may be implemented by a UE 115 or a component thereof as described herein. Figures 8 to 11 The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0254] At 2205, the UE may receive a fallback downlink control information communication from the base station, the fallback downlink control information communication providing the UE with a downlink grant for a first downlink communication within the shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 2205 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2205 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0255] At 2210, the UE may determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant based on a subband information field within a fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 2210 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2210 may be performed with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0256] At 2215, the UE may receive a first downlink communication from the base station. The operations of 2215 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2215 may be described with reference to Figures 8 to 11 The downlink transmission manager is executed.

[0257] At 2220, the UE may determine uplink control channel information to be provided in an uplink control channel communication based on the first downlink communication. The operations of 2220 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2220 may be described with reference to Figures 8 to 11 The confirmation feedback manager is used to perform the above operation.

[0258] At 2225, the UE may send an uplink control channel communication to the base station via the determined one or more subbands. The operations of 2225 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2225 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0259] Fig.23 A flow chart illustrating a method 2300 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2300 may be implemented by a UE 115 or a component thereof as described herein. In some aspects, the operations of the method 2300 may be implemented by a UE 115 or a component thereof as described herein. Figures 8 to 11The communication manager described herein performs. In some aspects, the UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0260] At 2305, the UE may receive configuration information from a base station, the configuration information indicating that the fallback downlink control information communication includes a subband information field. The operations of 2305 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2305 may be described with reference to Figures 8 to 11 In some cases, the configuration information indicates that a PUCCH resource indicator (PRI) field in a fallback downlink control information communication provides subband information. In some cases, the configuration information is received in RRC signaling, RMSI signaling, PBCH transmission, or any combination thereof.

[0261] At 2310, the UE may receive a fallback downlink control information communication from a base station, the fallback downlink control information communication providing a downlink grant for a first downlink communication to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 2310 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2310 may be described with reference to Figures 8 to 11 The DCI manager is used to perform the above operations.

[0262] At 2315, the UE may determine one or more subbands from a set of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant based on a subband information field within the fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 2315 may be performed in accordance with the methods described herein. In some aspects, aspects of the operations of 2315 may be performed with reference to Figures 8 to 11 The sub-band manager is used to perform the above operations.

[0263] At 2320, the UE may receive a first downlink communication from the base station. The operations of 2320 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2320 may be described with reference to Figures 8 to 11 The downlink transmission manager is executed.

[0264] At 2325, the UE may determine uplink control channel information to be provided in the uplink control channel communication based on the first downlink communication. The operations of 2325 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2325 may be described with reference to Figures 8 to 11The confirmation feedback manager is used to perform the above operation.

[0265] At 2330, the UE may send an uplink control channel communication to the base station via the determined one or more subbands. The operations of 2330 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2330 may be described with reference to Figures 8 to 11 The uplink transmission manager is used to perform the above operation.

[0266] Fig.24 A flow chart illustrating a method 2400 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2400 may be implemented by the base station 105 or components thereof, as described herein. In some aspects, the operations of the method 2400 may be implemented by the base station 105 or components thereof, as described herein. Figure 12 to Figure 15 The communication manager described herein performs. In some aspects, the base station may execute a set of instructions to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described herein.

[0267] At 2405, the base station may identify one or more subbands in a set of available subbands in an active bandwidth portion for uplink communications from a UE within a shared radio frequency spectrum band. The operations of 2405 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2405 may be described with reference to Figures 12 to 15 The sub-band manager is used to perform the above operations.

[0268] At 2410, a base station may send a fallback downlink control information communication to a UE, the fallback downlink control information communication providing an uplink grant for uplink communication and indicating one or more subbands, wherein the fallback downlink control information communication includes a subband information field indicating the one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 2410 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2410 may be performed with reference to Figures 12 to 15 The DCI manager is used to perform the above operations.

[0269] At 2415, the base station may monitor one or more subbands for uplink communications from the base station. The operations of 2415 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2415 may be described with reference to Figures 12 to 15 The uplink transmission manager is used to perform the above operation.

[0270] Fig.25A flow chart illustrating a method 2500 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2500 may be implemented by the base station 105 or components thereof, as described herein. In some aspects, the operations of the method 2500 may be implemented by the base station 105 or components thereof, as described herein. Figure 12 to Figure 15 The communication manager described herein performs. In some aspects, the base station may execute a set of instructions to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described herein.

[0271] At 2505, the base station may send a subband indication to the UE, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink communication from the UE to the base station within a shared radio frequency spectrum band. The operations of 2505 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2505 may be described with reference to Figures 12 to 15 The sub-band manager is used to perform the above operations.

[0272] At 2510, the base station may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing the UE with an uplink grant for uplink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 2510 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2510 may be described with reference to Figures 12 to 15 The DCI manager is used to perform the above operations.

[0273] At 2515, the base station may monitor a first subband for uplink communications from the UE. The operations of 2515 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2515 may be described with reference to Figures 12 to 15 The uplink transmission manager is used to perform the above operation.

[0274] Fig.26 A flow chart illustrating a method 2600 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2600 may be implemented by the base station 105 or components thereof, as described herein. In some aspects, the operations of the method 2600 may be implemented by the base station 105 or components thereof, as described herein. Figure 12 to Figure 15 The communication manager described herein performs. In some aspects, the base station may execute a set of instructions to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described herein.

[0275] At 2605, the base station may send a subband indication to the UE, the subband indication indicating a first subband of a set of available subbands in an active bandwidth portion for uplink control channel communications from the UE to the base station within a shared radio frequency spectrum band. The operations of 2605 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2605 may be described with reference to Figures 12 to 15 The sub-band manager is used to perform the above operations.

[0276] At 2610, the base station may send a fallback downlink control information communication to the UE, the fallback downlink control information communication providing the UE with a downlink grant for the first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits. The operations of 2610 may be performed in accordance with the methods described herein. In some aspects, aspects of the operations of 2610 may be described with reference to Figures 12 to 15 The DCI manager is used to perform the above operations.

[0277] At 2615, the base station may send a first downlink communication to the UE based on the downlink grant. The operations of 2615 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2615 may be described with reference to Figures 12 to 15 The downlink transmission manager is executed.

[0278] At 2620, the base station may monitor a first subband for uplink control channel communications from the UE. The operations of 2620 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2620 may be described with reference to Figures 12 to 15 The uplink transmission manager is used to perform the above operation.

[0279] Fig. 27 A flow chart illustrating a method 2700 for supporting subband indication in downlink control information in a shared radio frequency spectrum according to aspects of the present disclosure is shown. The operations of the method 2700 may be implemented by the base station 105 or components thereof, as described herein. In some aspects, the operations of the method 2700 may be implemented by the base station 105 or components thereof, as described herein. Figure 12 to Figure 15 The communication manager described herein performs. In some aspects, the base station may execute a set of instructions to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described herein.

[0280] At 2705, the base station may identify one or more subbands in a set of available subbands in an active bandwidth portion for uplink control channel communications from a UE within a shared radio frequency spectrum band. The operations of 2705 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2705 may be described with reference to Figures 12 to 15 The sub-band manager is used to perform the above operations.

[0281] At 2710, a base station may send a fallback downlink control information communication to a UE, the fallback downlink control information communication providing the UE with a downlink grant for a first downlink communication, wherein the fallback downlink control information communication includes a subband information field indicating one or more subbands, and wherein the fallback downlink control information communication has a predetermined number of bits, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication. The operations of 2710 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2710 may be performed with reference to Figures 12 to 15 The DCI manager is used to perform the above operations.

[0282] At 2715, the base station may send a first downlink communication to the UE. The operations of 2715 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2715 may be described with reference to Figures 12 to 15 The downlink transmission manager is executed.

[0283] At 2720, the base station may monitor one or more subbands for uplink control channel communications from the UE. The operations of 2720 may be performed according to the methods described herein. In some aspects, aspects of the operations of 2720 may be described with reference to Figures 12 to 15 The uplink transmission manager is used to perform the above operation.

[0284] It should be noted that the methods described herein describe possible implementations, and that operations and steps may be rearranged or otherwise modified, and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0285] The following provides an overview of aspects of the present disclosure:

[0286] Aspect 1: A wireless communication method implemented by a UE, comprising: receiving a fallback downlink control information communication from a base station that provides an uplink authorization to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits; determining one or more subbands of a plurality of available subbands in an active bandwidth portion for uplink communications associated with the uplink authorization based at least in part on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication; and sending the uplink communication to the base station via the determined one or more subbands.

[0287] Aspect 2: The method according to aspect 1, wherein the fallback downlink control information communication has a fallback downlink control information format, and the predetermined number of bits is based at least in part on the length of a separate fallback downlink control information format for a downlink grant to the UE.

[0288] Aspect 3: The method according to aspect 2 further includes: receiving configuration information from a base station, the configuration information indicating whether the fallback downlink control information communication includes a subband information field.

[0289] Aspect 4: The method according to aspect 2, wherein the configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in physical broadcast channel transmission, or in any combination thereof.

[0290] Aspect 5: A method according to any one of Aspects 3 to 4, wherein the subband information field is adjacent to the frequency division multiplexing resource allocation field in the fallback downlink control information communication, or is located after the last information field in the fallback downlink control information communication, and the last information field exists when the subband information field does not exist in the fallback downlink control information communication.

[0291] Aspect 6: The method according to any one of aspects 3 to 5, wherein when the subband information field does not exist in the fallback downlink control information communication, the subband information field occupies one or more bits, which are used as zero filling bits.

[0292] Aspect 7: The method according to any one of aspects 1 to 6, wherein the number of bits in the subband information field is determined based at least in part on the number of subbands of the plurality of available subbands.

[0293] Aspect 8: A method according to Aspect 7, wherein the number of bits in the subband information field corresponds to the number of subbands in the active bandwidth part, the number of subbands in the initial bandwidth part used to establish a connection between the UE and the base station, a predetermined number of subbands, a maximum number of subbands supported in the maximum configurable bandwidth based at least in part, or any combination thereof.

[0294] Aspect 9: The method according to any one of aspects 1 to 8, wherein the subband information field is a bitmap having a bit length corresponding to the number of subbands of the plurality of available subbands.

[0295] Aspect 10: The method according to any one of aspects 1 to 9, wherein the subband information field is a bit field, and different available values ​​of the bit field are mapped to different sets of consecutive subbands.

[0296] Aspect 11: A method of wireless communication implemented by a UE, comprising: monitoring a subband indication from a base station, the subband indication indicating a first subband of a plurality of available subbands in an active bandwidth portion for uplink communication from the UE to the base station within a shared radio frequency spectrum band; receiving a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink authorization for uplink communication to the UE, wherein the fallback downlink control information communication has a predetermined number of bits; determining that a first subband will be used for uplink communication based at least in part on signaling monitored from the base station; and in response to receiving the uplink authorization, sending uplink communication to the base station via the first subband.

[0297] Aspect 12: A method according to Aspect 11, wherein the first subband is the lowest subband of the active bandwidth portion, or is a subband for receiving a synchronization signal block from a base station, or is a subband indicated in a physical broadcast channel received from a base station, or is a subband indicated in a remaining minimum system information communication received from a base station, or is a subband for sending fallback downlink control information communication, or is the lowest subband for sending fallback downlink control information communication, or a combination thereof.

[0298] Aspect 13: A method of wireless communication implemented by a UE, comprising: identifying one or more subbands of a plurality of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant; receiving a fallback downlink control information communication from a base station, the fallback downlink control information communication providing the UE with a downlink grant for a first downlink communication, wherein the fallback downlink control information communication has a predetermined number of bits; receiving the first downlink communication from the base station; determining, based at least in part on the first downlink communication, uplink control channel information to be provided in the uplink control channel communication; and sending the uplink control channel communication to the base station via one or more subbands.

[0299] Aspect 14: A method according to Aspect 13, wherein identifying one or more subbands further comprises: monitoring a subband indication from a base station, the subband indication indicating a first subband among a plurality of available subbands in an active bandwidth portion for uplink control channel communication from a UE to a base station, wherein the first subband is one of the one or more subbands.

[0300] Aspect 15: A method according to any one of Aspects 13 to 14, wherein identifying one or more subbands further comprises: determining one or more subbands based at least in part on a subband information field having a fallback downlink control information communication, wherein a predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication.

[0301] Aspect 16: The method according to any one of aspects 13 to 15, wherein the configuration information and the physical uplink control channel resource indicator field in the fallback downlink control information communication indicate one or more subbands.

[0302] Aspect 17: The method according to Aspect 16, wherein the configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

[0303] Aspect 18: The method according to any one of Aspects 13 to 17, further comprising: receiving configuration information from a base station, the configuration information comprising information of a subband indication from the base station.

[0304] Aspect 19: A method according to any one of Aspects 13 to 18, wherein the first subband of the one or more subbands is the lowest subband of the active bandwidth portion, or is a subband for receiving a synchronization signal block from a base station, or is a subband indicated in a physical broadcast channel received from a base station, or is a subband indicated in a remaining minimum system information communication received from a base station, or is a subband for sending fallback downlink control information communication, or is the lowest subband for sending fallback downlink control information communication, or a combination thereof.

[0305] Aspect 20: The method according to any one of aspects 13 to 19, wherein the fallback downlink control information communication has a fallback downlink control information format, and the fallback downlink control information format indicates that the UE is to identify one or more subbands by monitoring the subband indication.

[0306] Aspect 21: The method according to any one of aspects 13 to 20 further comprises: receiving configuration information from a base station, the configuration information indicating that the fallback downlink control information communication includes a subband information field.

[0307] Aspect 22: The method according to aspect 21, wherein the configuration information indicates that a PUCCH resource indicator (PRI) field in the fallback downlink control information communication provides subband information.

[0308] Aspect 23: The method according to Aspect 22, wherein the configuration information is received in RRC signaling, in Remaining Minimum System Information (RMSI) signaling, in Physical Broadcast CH (PBCH) transmission, or in any combination thereof.

[0309] Aspect 24: The method according to any one of aspects 13 to 23, further comprising: receiving configuration information from a base station, the configuration information indicating whether the fallback downlink control information communication includes a subband information field.

[0310] Aspect 25: The method according to Aspect 24, wherein the configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

[0311] Aspect 26: An apparatus comprising a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 1 to 10.

[0312] Aspect 27: An apparatus comprising at least one component for performing the method of any one of aspects 1 to 10.

[0313] Aspect 28: A non-transitory computer-readable medium storing code, the code comprising instructions executable by a processor to perform the method of any one of aspects 1 to 10.

[0314] Aspect 29: An apparatus comprising a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 11 to 12.

[0315] Aspect 30: An apparatus comprising at least one component for performing the method of any one of aspects 11 to 12.

[0316] Aspect 31: A non-transitory computer-readable medium storing code, the code comprising instructions executable by a processor to perform the method of any one of aspects 11 to 12.

[0317] Aspect 32: An apparatus comprising a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 13 to 25.

[0318] Aspect 33: An apparatus comprising at least one component for performing the method of any one of aspects 13 to 25.

[0319] Aspect 34: A non-transitory computer-readable medium storing code, the code comprising instructions executable by a processor to perform the method of any one of aspects 13 to 25.

[0320] The technology described herein can be used for various wireless communication 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. CDMA systems can implement radio technologies, such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions can be generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, high speed packet data (HRPD), etc. UTRA includes broadband CDMA (WCDMA) and other variants of CDMA. TDMA systems can implement radio technologies, such as global system for mobile communications (GSM).

[0321] OFDMA systems can implement radio technologies 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 versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an 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 technology described herein can be used for the systems and radio technologies mentioned herein as well as other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable to applications other than LTE, LTE-A, LTE-A Pro, or NR applications.

[0322] A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access to a UE through a service subscription with a network provider. Compared to a macro cell, a small cell may be associated with a base station with lower power, and the small cell may operate in the same or different (e.g., authorized, unauthorized, etc.) frequency band as a macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. In some aspects, a pico cell may cover a small geographic area and may allow unrestricted access to a UE through a service subscription with a network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access through a UE associated with a femto cell (e.g., a UE in a closed subscriber group (CSG), a UE for a user in a home, etc.). 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 more (e.g., two, three, four, etc.) cells and may also support communications using one or more component carriers.

[0323] The wireless communication 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 synchronous or asynchronous operation.

[0324] The information and signals described herein may be represented using any of a variety of different technologies and techniques. In some aspects, the 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.

[0325] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed using 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 an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

[0326] 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 as one or more instructions or codes on a computer-readable medium or transmitted thereon. Other examples and implementations are within the scope of the present disclosure and the appended claims. In some aspects, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented in different physical locations.

[0327] Computer readable medium includes both non-transitory computer storage medium and communication medium, and computer storage medium and communication medium include any medium that helps to transfer computer program from one place to another place.Non-transitory storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transitory computer readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, CD (CD) ROM or other optical disk storage, disk storage or other magnetic storage device or can be used for carrying or storing required program code mode in the form of instruction or data structure and can be accessed by general or special-purpose computer or general or special-purpose processor Any other non-transitory medium.In addition, any connection is appropriately referred to as computer readable medium.In some respects, if coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology (such as infrared, radio and microwave) are used to send software from website, server or other remote source, coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology (such as infrared, radio and microwave) are included in the definition of medium. Disk and disc, as used herein, includes 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.

[0328] As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items preceded by a phrase such as "at least one" or "one or more"), indicates an included list, such that in some aspects, 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). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. In some aspects, an exemplary step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0329] In the drawings, similar components or features may have the same reference label. In addition, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes between similar components. If only the first reference label is used in the specification, the specification applies to any one similar component having the same first reference label, regardless of the second reference label or other subsequent reference labels.

[0330] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "superior to other examples." For the purpose of providing an understanding of the described technology, the detailed description includes specific details. However, the technologies may be practiced without these specific details. In some cases, in order to avoid obscuring the concepts of the described examples, known structures and devices are shown in block diagram form.

[0331] The description provided herein enables those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but conforms to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication implemented by a user equipment (UE), comprising: receiving a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits; determining one or more subbands of a plurality of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based at least in part on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even though the subband information field is included in the fallback downlink control information communication; and The uplink communication is sent to the base station via the determined one or more subbands.

2. The method according to claim 1, wherein: The fallback downlink control information communication has a fallback downlink control information format, and wherein the predetermined number of bits is based at least in part on a length of a separate fallback downlink control information format for a downlink grant to the UE.

3. The method according to claim 2, further comprising: Configuration information is received from the base station, the configuration information indicating whether the fallback downlink control information communication includes the subband information field.

4. The method according to claim 3, wherein: The configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

5. The method according to claim 3, wherein: The subband information field is adjacent to a frequency division multiplexing resource assignment field in the fallback downlink control information communication, or is located after a last information field in the fallback downlink control information communication, and the last information field exists when the subband information field does not exist in the fallback downlink control information communication.

6. The method according to claim 3, wherein: When the subband information field does not exist in the fallback downlink control information communication, the subband information field occupies one or more bits used as zero padding bits.

7. The method according to claim 1, wherein: The number of bits in the subband information field is determined based at least in part on a number of subbands of the plurality of available subbands.

8. The method according to claim 7, wherein: The number of bits in the subband information field corresponds to the number of subbands in the active bandwidth portion, the number of subbands in the initial bandwidth portion used to establish a connection between the UE and the base station, a predetermined number of subbands, a maximum number of subbands supported in a maximum configurable bandwidth based at least in part, or any combination thereof.

9. The method according to claim 1, wherein: The subband information field is a bitmap having a bit length corresponding to the number of subbands of the plurality of available subbands.

10. The method according to claim 1, wherein: The subband information field is a bit field, and wherein different available values ​​of the bit field are mapped to different sets of consecutive subbands.

11. A method of wireless communication implemented by a user equipment (UE), comprising: monitoring a subband indication from a base station, the subband indication indicating a first subband of a plurality of available subbands in an active bandwidth portion for uplink communications from the UE to the base station within a shared radio frequency spectrum band; receiving a fallback downlink control information communication from the base station, the fallback downlink control information communication providing an uplink grant to the UE for the uplink communication, wherein the fallback downlink control information communication has a predetermined number of bits; determining, based at least in part on monitored signaling from the base station, that the first subband is to be used for the uplink communication; as well as In response to receiving the uplink grant, the uplink communication is sent to the base station via the first subband.

12. The method according to claim 11, wherein: The first subband is the lowest subband of the active bandwidth portion, or is a subband for receiving a synchronization signal block from the base station, or is a subband indicated in a physical broadcast channel received from the base station, or is a subband indicated in a remaining minimum system information communication received from the base station, or is a subband for sending the fallback downlink control information communication, or is the lowest subband for sending the fallback downlink control information communication, or a combination thereof.

13. A method of wireless communication implemented by a user equipment (UE), comprising: identifying one or more subbands of a plurality of available subbands in an active bandwidth portion for uplink control channel communications associated with a downlink grant; receiving, from a base station, a fallback downlink control information communication providing the downlink grant for a first downlink communication to the UE, wherein the fallback downlink control information communication has a predetermined number of bits; receiving the first downlink communication from the base station; determining, based at least in part on the first downlink communication, uplink control channel information to be provided in the uplink control channel communication; as well as The uplink control channel communication is sent to the base station via the one or more subbands.

14. The method according to claim 13, wherein: Identifying the one or more sub-bands further comprises: Monitoring a subband indication from the base station, the subband indication indicating a first subband of the plurality of available subbands in the active bandwidth portion for use for the uplink control channel communication from the UE to the base station, wherein the first subband is one of the one or more subbands.

15. The method according to claim 13, wherein: Identifying the one or more sub-bands further comprises: The one or more subbands are determined based at least in part on a subband information field having the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even if the subband information field is included in the fallback downlink control information communication.

16. The method according to claim 13, wherein: The configuration information and the physical uplink control channel resource indicator field in the fallback downlink control information communication indicate the one or more subbands.

17. The method according to claim 13, further comprising: Configuration information is received from the base station, the configuration information including information of a subband indication from the base station.

18. The method according to claim 17, wherein: The configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

19. The method according to claim 13, wherein: The first subband of the one or more subbands is the lowest subband of the active bandwidth portion, or is a subband for receiving a synchronization signal block from the base station, or is a subband indicated in a physical broadcast channel received from the base station, or is a subband indicated in a remaining minimum system information communication received from the base station, or is a subband for sending the fallback downlink control information communication, or is the lowest subband for sending the fallback downlink control information communication, or a combination thereof.

20. The method according to claim 13, wherein: The fallback downlink control information communication has a fallback downlink control information format, and the fallback downlink control information format indicates that the UE is to identify the one or more subbands by monitoring subband indications.

21. The method of claim 13, further comprising: Configuration information is received from the base station, the configuration information indicating that the fallback downlink control information communication includes a subband information field.

22. The method according to claim 21, wherein: The configuration information indicates that a physical uplink control channel (PUCCH) resource indicator (PRI) field in the fallback downlink control information communication provides subband information.

23. The method according to claim 22, wherein: The configuration information is received in radio resource control (RRC) signaling, in residual minimum system information (RMSI) signaling, in a physical broadcast cross-connect (PBCH) transmission, or in any combination thereof.

24. The method of claim 13, further comprising: Configuration information is received from the base station, the configuration information indicating whether the fallback downlink control information communication includes a subband information field.

25. The method according to claim 24, wherein: The configuration information is received in radio resource control signaling, in remaining minimum system information signaling, in a physical broadcast channel transmission, or in any combination thereof.

26. An apparatus for wireless communication at a user equipment (UE), comprising: processor, a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the device to: receiving a fallback downlink control information communication from a base station, the fallback downlink control information communication providing an uplink grant to the UE within a shared radio frequency spectrum band, wherein the fallback downlink control information communication has a predetermined number of bits; determining one or more subbands of a plurality of available subbands in an active bandwidth portion for uplink communications associated with the uplink grant based at least in part on a subband information field within the fallback downlink control information communication, wherein the predetermined number of bits of the fallback downlink control information communication is maintained even though the subband information field is included in the fallback downlink control information communication; and The uplink communication is sent to the base station via the determined one or more subbands.

27. The device according to claim 26, wherein: The fallback downlink control information communication has a fallback downlink control information format, and wherein the predetermined number of bits is based at least in part on a length of a separate fallback downlink control information format for a downlink grant to the UE.

28. The device according to claim 27, wherein The instructions are further executable by the processor to cause the apparatus to: Configuration information is received from the base station, the configuration information indicating whether the fallback downlink control information communication includes the subband information field.

29. The device according to claim 28, wherein The subband information field is adjacent to a frequency division multiplexing resource assignment field in the fallback downlink control information communication, or is located after a last information field in the fallback downlink control information communication, and the last information field exists when the subband information field does not exist in the fallback downlink control information communication.

30. The device according to claim 28, wherein When the subband information field does not exist in the fallback downlink control information communication, the subband information field occupies one or more bits used as zero padding bits.

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