PRACH and SR transmissions for new radio in unlicensed spectrum

Uplink signaling in unlicensed or shared spectrum may be subject to listen before talk procedures resulting in failed signaling transmissions. A user equipment (UE) may perform uplink signaling using a configuration based on whether a base station has entered a channel occupancy time (COT) shared with the UE. A UE may determine that the UE has an uplink transmission for a base station. A UE may determine whether the base station has entered a channel occupancy time that is shared with the UE. A UE may determine configured random access or scheduling request transmission resources based on the channel occupancy time, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. A UE may transmit a random access message or the scheduling request on selected configured resources.

BACKGROUND

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to transmissions in unlicensed spectrum.

Introduction

For example, deployment of 5G NR in unlicensed spectrum may be desired to improve or replace existing wireless networks.

SUMMARY

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The method may include determining that a UE has an uplink transmission for a base station. The method may include determining whether the base station has entered a channel occupancy time that is shared with the UE. The method may include determining configured random access or scheduling request transmission resources based on the channel occupancy time, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The method may include transmitting a random access message or the scheduling request on selected configured resources.

In an aspect, the disclosure provides an apparatus for wireless communication including a memory; and at least one processor coupled to the memory. The processor may be configured to determine that a UE has an uplink transmission for a base station. The processor may be configured to determine whether the base station has entered a channel occupancy time that is shared with the UE. The processor may be configured to determine configured random access or scheduling request transmission resources based on the channel occupancy time, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The processor may be configured to transmit a random access message or the scheduling request on selected configured resources.

In an aspect, the disclosure provides an apparatus for wireless communication. The apparatus may include means for determining that a UE has an uplink transmission for a base station. The apparatus may include means for determining whether the base station has entered a channel occupancy time that is shared with the UE. The apparatus may include means for determining configured random access or scheduling request transmission resources based on the channel occupancy time, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The apparatus may include means for transmitting a random access message or the scheduling request on selected configured resources.

In an aspect, the disclosure provides a computer-readable medium storing computer executable code. The computer-readable medium may include code to determine that a UE has an uplink transmission for a base station. The computer-readable medium may include code to determine whether the base station has entered a channel occupancy time that is shared with the UE. The computer-readable medium may include code to determine configured random access or scheduling request transmission resources based on the channel occupancy time, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The computer-readable medium may include code to transmit a random access message or the scheduling request on selected configured resources.

In another aspect, the disclosure provides method of wireless communications that may be performed by a base station. The method may include signaling at least a first uplink signaling configuration to a UE, the first uplink signaling configuration for use outside of a channel occupancy time (COT). The method may include transmitting a downlink control channel indicating that a base station has entered the COT to be shared with the UE, the COT being associated with a second uplink signaling configuration, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The method may include receiving a scheduling request or random access message from the UE according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT at a time of the scheduling request or random access message.

In another aspect, the disclosure provides an apparatus for wireless communication including a memory and at least one processor coupled to the memory. The processor may be configured to signal at least a first uplink signaling configuration to a UE, the first uplink signaling configuration for use outside of a COT. The processor may be configured to transmit a downlink control channel indicating that a base station has entered the COT to be shared with the UE, the COT being associated with a second uplink signaling configuration, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The processor may be configured to receive a scheduling request or random access message from the UE according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT at a time of the scheduling request or random access message.

In another aspect, the disclosure provides an apparatus for wireless communication. The apparatus may include means for signaling at least a first uplink signaling configuration to a UE, the first uplink signaling configuration for use outside of a COT. The apparatus may include means for transmitting a downlink control channel indicating that a base station has entered the COT to be shared with the UE, the COT being associated with a second uplink signaling configuration, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The apparatus may include means for receiving a scheduling request or random access message from the UE according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT at a time of the scheduling request or random access message.

In another aspect, the disclosure provides a computer-readable medium storing computer executable code. The computer-readable medium may include code to signal at least a first uplink signaling configuration to a UE, the first uplink signaling configuration for use outside of a COT. The computer-readable medium may include code to transmit a downlink control channel indicating that a base station has entered the COT to be shared with the UE, the COT being associated with a second uplink signaling configuration, wherein a density of transmission opportunities is greater outside of the shared channel occupancy time than within the shared channel occupancy time. The computer-readable medium may include code to receive a scheduling request or random access message from the UE according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT at a time of the scheduling request or random access message.

DETAILED DESCRIPTION

A 5G NR system operating in unlicensed spectrum may share the unlicensed spectrum with other communications systems. A listen-before-talk (LBT) procedure may be used to prevent transmissions from interfering with ongoing communications of other systems. As discussed in further detail below, 5G NR may utilize frame structures to facilitate efficient communications. In order to implement frame structures in unlicensed spectrum, a base station (e.g., a gNB) may occupy a channel for a period of time by transmitting in a downlink direction and sharing the channel with user equipment (UE) for uplink transmissions. The period of time utilized by the base station may be referred to as a channel occupancy time (COT).

A UE may perform uplink transmissions either inside the COT or outside the COT. Uplink transmissions may be subject to LBT procedures. In an aspect, LBT procedures (e.g., LBT periods and/or energy detection thresholds) may be different inside and outside of the COT. Since the base station has reserved the channel during the COT, if the UE transmits using configured resources during the COT, the UE may generally experience higher LBT success rates (e.g., energy below an energy detection threshold) inside the COT. The higher success rate may apply when the same LBT type can be used for transmissions inside and outside of the COT. For example, control signaling such as physical random access channel (PRACH) transmissions and scheduling requests (SR) may occur either inside or outside the COT.

Uplink control signaling may be sensitive to latency. In particular, failure of an LBT procedure for control signaling may result in latency for an uplink transmission due to periodicity of uplink control signaling opportunities. One technique to reduce latency for control signaling is to reduce the periodicity of the uplink control signaling opportunities. Using a smaller periodicity for control signaling, however, may incur a larger overhead as resources are reserved for the control signaling. For example, supported periodicities for release 15 of 5G NR is listed in Table 1.

In an aspect, the present disclosure provides for multiple configurations of uplink control signaling opportunities. Generally, a higher density of control signaling opportunities may be utilized outside of a COT than inside the COT. Accordingly, a UE may transmit PRACH or SR outside of the COT, where LBT failure is more likely or more frequent, and overhead for uplink control signaling may be reduced within the COT. The higher density of control signaling opportunities may refer to a number of configured signaling opportunities per unit of time. The number of control signaling opportunities may be increased by configuring a smaller periodicity or by configuring a greater number of SR or PRACH resources per opportunity.

A UE may determine which configuration of uplink control resources to use based on whether the base station has entered a COT that is shared with the UE. For example, the base station may provide COT information in a group based physical downlink control channel (PDCCH) or a UE specific PDCCH when starting the COT. The COT information may indicate the uplink control signaling configuration. In an aspect, a PDCCH may indicate an uplink control signaling configuration without specific reference to COT information.

Referring again toFIG. 1, in certain aspects, the UE104may include an uplink signaling component142for determining an uplink signaling configuration and transmitting uplink signaling according to the determined uplink signaling configuration. For example, the uplink signaling component142may be included in or implemented by the modem140of UE104or by one or more processors of the UE104. Additionally, one or more base stations102may include a channel occupancy component148for occupying a channel in unlicensed or shared spectrum. The channel occupancy component148may also indicate when the base station102is occupying the channel and/or indicate an uplink signaling configuration to use.

Turning now toFIGS. 2A-9aspects are depicted with reference to one or more components and one or more methods that may perform the actions or operations described herein, where aspects in dashed line may be optional. Although the operations described below inFIGS. 7 and 8are presented in a particular order and/or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Moreover, it should be understood that the following actions, functions, and/or described components may be performed by a specially-programmed processor, a processor executing specially-programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component capable of performing the described actions or functions.

Referring toFIG. 3, one example of an implementation of UE104may include a variety of components, some of which have already been described above and are described further herein, including components such as one or more processors312and memory316and transceiver302in communication via one or more buses344, which may operate in conjunction with modem140and/or uplink signaling component142to enable one or more of the functions described herein related to uplink control signaling inside or outside of a COT.

In an aspect, the one or more processors312can include a modem140and/or can be part of the modem140that uses one or more modem processors. Thus, the various functions related to uplink signaling component142may be included in modem140and/or processors312and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors312may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver302. In other aspects, some of the features of the one or more processors312and/or modem140associated with uplink signaling component142may be performed by transceiver302.

Also, memory316may be configured to store data used herein and/or local versions of applications375or uplink signaling component142and/or one or more of its subcomponents being executed by at least one processor312. Memory316can include any type of computer-readable medium usable by a computer or at least one processor312, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory316may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining uplink signaling component142and/or one or more of its subcomponents, and/or data associated therewith, when UE104is operating at least one processor312to execute uplink signaling component142and/or one or more of its subcomponents.

Transceiver302may include at least one receiver306and at least one transmitter308. Receiver306may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). Receiver306may be, for example, a radio frequency (RF) receiver. In an aspect, receiver306may receive signals transmitted by at least one base station102. Additionally, receiver306may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR), reference signal received power (RSRP), received signal strength indicator (RSSI), etc. Transmitter308may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). A suitable example of transmitter308may include, but is not limited to, an RF transmitter.

Moreover, in an aspect, UE104may include RF front end388, which may operate in communication with one or more antennas365and transceiver302for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one base station102or wireless transmissions transmitted by UE104. RF front end388may be connected to one or more antennas365and can include one or more low-noise amplifiers (LNAs)390, one or more switches392, one or more power amplifiers (PAs)398, and one or more filters396for transmitting and receiving RF signals.

In an aspect, LNA390can amplify a received signal at a desired output level. In an aspect, each LNA390may have a specified minimum and maximum gain values. In an aspect, RF front end388may use one or more switches392to select a particular LNA390and its specified gain value based on a desired gain value for a particular application.

Further, for example, one or more PA(s)398may be used by RF front end388to amplify a signal for an RF output at a desired output power level. In an aspect, each PA398may have specified minimum and maximum gain values. In an aspect, RF front end388may use one or more switches392to select a particular PA398and its specified gain value based on a desired gain value for a particular application.

Also, for example, one or more filters396can be used by RF front end388to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter396can be used to filter an output from a respective PA398to produce an output signal for transmission. In an aspect, each filter396can be connected to a specific LNA390and/or PA398. In an aspect, RF front end388can use one or more switches392to select a transmit or receive path using a specified filter396, LNA390, and/or PA398, based on a configuration as specified by transceiver302and/or processor312.

As such, transceiver302may be configured to transmit and receive wireless signals through one or more antennas365via RF front end388. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE104can communicate with, for example, one or more base stations102or one or more cells associated with one or more base stations102. In an aspect, for example, modem140can configure transceiver302to operate at a specified frequency and power level based on the UE configuration of the UE104and the communication protocol used by modem140.

In an aspect, modem140can be a multiband-multimode modem, which can process digital data and communicate with transceiver302such that the digital data is sent and received using transceiver302. In an aspect, modem140can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem140can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem140can control one or more components of UE104(e.g., RF front end388, transceiver302) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with UE104as provided by the network during cell selection and/or cell reselection.

In an aspect, uplink signaling component142may optionally include a configuration component350for determining at least two uplink signaling configurations. Each uplink signaling configuration may indicate a periodicity of configured uplink resources. The uplink signaling configuration may also indicate a number of uplink resources per uplink signaling opportunity. For example, a first uplink signaling configuration may be for uplink signaling outside a COT and a second uplink signaling configuration may be for uplink signaling inside a COT. Generally, the first uplink signaling configuration may have a greater density of uplink signaling opportunities. For example, the first uplink signaling configuration may have a smaller periodicity or a larger number of resources per uplink signaling opportunity than the second uplink signaling configuration. The uplink signaling configurations may be signaled by the network, for example, as radio resource control (RRC) layer signaling. The configuration component350may receive the signaled uplink signaling configurations and configure the uplink signaling component142with the received configurations.

In an aspect, uplink signaling component142may optionally include a COT component144for determining whether the base station102has entered a COT that is shared with the UE104. For example, the COT component144may control the receiver306to receive COT information transmitted by the base station102. The COT information may be included in a group based PDCCH such as a SFI or common PDCCH. The COT information may indicate that the base station102has entered a COT. The COT information may also include a duration of the COT. In an aspect, the COT component144may detect a medium reservation waveform. For example, a Wi-Fi preamble may include a short training field (STF), long training field (LTF), and/or a duration. A base station102may use a medium reservation waveform to occupy the channel. The COT component144may identify a medium reservation waveform and determine that the base station102has entered a COT.

The uplink signaling component142may optionally include a resource component146for determining one or more resources for an uplink transmission. The resource component146may determine the resources based on whether the base station102is in a COT. For example, the resource component146may determine the resources according to a first uplink signaling configuration when the base station102is outside of a COT and determine the resources according to the second uplink signaling configuration when the base station102is inside of the COT.

In an aspect, the uplink signaling component142and/or resource component146may include an LBT component352for performing an LBT procedure prior to a transmission. For example, the LBT component352may perform an LBT procedure on resources selected by the resource component146to determine whether the transmission should occur. For instance, the LBT component352may sense the selected resource for an LBT duration prior to the transmission and determine whether sensed energy exceeds an energy detection threshold. If the sensed energy exceeds the energy detection threshold, the LBT component352may block the transmission, and the transmission may be considered an LBT failure. If the sensed energy is less than the energy detection threshold, the LBT component352may allow the transmission to occur.

In an aspect, the uplink signaling component142and/or resource component146may include a priority component354. Transmissions may be associated with logical channels based on a type or source of data to be transmitted. Each logical channel may be associated with a priority. Uplink signaling resources may also be associated with a priority corresponding to a logical channel. The resource component146may utilize the priority component354to select uplink signaling resources that correspond to a priority of a logical channel associated with the transmission. In an aspect, when a transmission experiences an LBT failure, the priority component354may identify another uplink signaling resource associated with a lower priority that may be used for the transmission. Accordingly, a high priority transmission may utilize lower priority resources if a transmission attempt fails. In contrast, a transmission associated with a lower priority logical channel may not utilize higher priority resources in the event of an LBT failure.

In an aspect, uplink signaling component142may optionally include a transmitting component356for transmitting uplink signaling such as an SR or PRACH on selected configured resources. The transmitting component356may control the transmitter308to transmit the uplink signaling. In an aspect, the transmitting component may transmit different content for the uplink signaling depending on whether the transmission occurs during the COT. Transmissions within the COT may be more reliable (e.g., less likelihood of LBT failure), so the transmitting component356may generally include additional content because resources may not be needed for multiple transmission opportunities. Additionally, the resources may be reserved by the base station and may not be used for a downlink transmission. For example, a SR transmission outside of the COT may only include an indication that the UE has data to transmit to the base station. In contrast, an SR transmission inside the COT may include a payload such as a buffer status report (BSR). As another example, a PRACH transmission outside of the COT may include only a preamble. In contrast, a PRACH transmission inside of the COT may include the preamble and a payload such as a UE identifier, C-RNTI, or small message.

Referring toFIG. 4, one example of an implementation of a base station102may include a variety of components, some of which have already been described above, but including components such as one or more processors412and memory416and transceiver402in communication via one or more buses444, which may operate in conjunction with modem460and channel occupancy component148to indicate to one or more UEs104whether the base station102is occupying a channel and sharing the COT with the UEs104, or indicate an uplink signaling configuration for the UEs104to use.

The transceiver402, receiver406, transmitter408, one or more processors412, memory416, applications475, buses444, RF front end488, LNAs490, switches492, filters496, PAs498, and one or more antennas465may be the same as or similar to the corresponding components of the UE104, as described above, but configured or otherwise programmed for base station operations as opposed to UE operations.

FIG. 5is a resource diagram showing a first example500of different uplink signaling configurations based on a COT502. A first uplink signaling configuration may be used outside of the COT502. The first uplink signaling configuration may have a periodicity of 7 symbols. One resource may be used for uplink signaling in each period. In this example, each slot may include 14 symbols, so an uplink signaling opportunity may occur twice each slot. In contrast, a second uplink configuration may be used inside of the COT502. Again, one resource may be used for uplink signaling per period. The second uplink signaling configuration may have a periodicity of 2 slots. Accordingly, an uplink signaling opportunity may occur once every 2 slots or 28 symbols. Therefore, the first uplink signaling configuration may have a greater density of uplink signaling opportunities.

FIG. 6is another resource diagram showing a second example600of different uplink signaling configurations based on a COT502. A first uplink signaling configuration may be used outside of the COT502. The first uplink signaling configuration may have a periodicity of 1 slot. Three resources (e.g., combinations of resource blocks and OFDM symbols) may be used for uplink signaling during each period, so there may be three uplink signaling opportunities per slot. In contrast, a second uplink configuration may be used inside of the COT502. The second uplink signaling configuration may have a periodicity of 2 slots. One resource may be used for uplink signaling per period. Accordingly, an uplink signaling opportunity may occur once every 2 slots. Again, the first uplink signaling configuration may have a greater density of uplink signaling opportunities.

FIG. 7is a flowchart of a method700of wireless communication. The method may be performed by an UE (e.g., the UE104) including an uplink signaling component142in communication with a base station102, which may include a channel occupancy component148.

At block710, the method700may include receiving a configuration of two or more uplink signaling configurations. In an aspect, for example, the UE104, the processor312, the RX processor956, and/or the controller/processor959may execute the uplink signaling component142and/or the configuration component350to receive the configuration of two or more uplink signaling configurations. For instance, the configuration component350may receive the two or more uplink signaling configurations via RRC signaling. Accordingly, the UE104, the processor312, the RX processor956, and/or the controller/processor959executing the uplink signaling component142and/or the configuration component350may provide means for receiving a configuration of two or more uplink signaling configurations.

At block720, the method700may include determining that a UE has an uplink transmission for a base station. In an aspect, for example, the UE104, the processor312, the TX processor968, and/or the controller/processor959may execute the uplink signaling component142to determine that the UE104has an uplink transmission for a base station102. For example, the uplink signaling component142may check a status of an uplink buffer or receive an indication of the uplink transmission from an application375. Accordingly, the UE104, the processor312, the TX processor968, and/or the controller/processor959executing the uplink signaling component142may provide means for determining that a UE has an uplink transmission for a base station.

At block730, the method700may include determining whether the base station has entered a channel occupancy time that is shared with the UE. In an aspect, for example, the UE104, the processor312, the RX processor956, and/or the controller/processor959may execute the uplink signaling component142and/or the COT component144to determine whether the base station102has entered the COT502that is shared with the UE104. For example, in block732, determining whether the base station has entered the COT502may include receiving a physical downlink control channel (PDCCH) from the base station indicating the channel occupancy time. For example, the COT component144may decode a PDCCH to determine whether the PDCCH indicates a channel occupancy time. The COT component144may also determine whether the base station102is sharing the COT by configuring uplink resources for the UE104. In an aspect, the PDCCH may be a group PDCCH such as an SFI or a common PDCCH. In another aspect, a base station102may indicate a COT by transmitting a medium reservation waveform. Accordingly, the UE104, the processor312, the RX processor956, and/or the controller/processor959executing the uplink signaling component142and/or the COT component144may provide means for determining whether the base station has entered a channel occupancy time that is shared with the UE.

At block740, the method700may include determining configured random access or scheduling request transmission resources based on the channel occupancy time. In an aspect, for example, the UE104, the processor312, the RX processor956, and/or the controller/processor959may execute the uplink signaling component142and/or the resource component146to determine configured random access or scheduling request transmission resources based on the COT502. For example, if the base station102is outside of the COT502(e.g., no COT indicated by the base station), the resource component146may determine the configured random access or scheduling request transmission resources based on a first uplink signaling configuration. In contrast, if the base station102is inside of the COT502, the resource component146may determine the configured random access or scheduling request transmission resources based on a second uplink signaling configuration, or based on resources indicated within the PDCCH indicating the COT502. In an aspect, where the transmission is associated with a logical channel and/or priority, the resource component146may select available random access or scheduling request transmission resources with a corresponding priority. Accordingly, the UE104, the processor312, the RX processor956, and/or the controller/processor959executing the uplink signaling component142and/or the resource component146may provide means for determining configured random access or scheduling request transmission resources based on the channel occupancy time.

At block750, the method700may include performing a listen before talk procedure prior to transmitting. In an aspect, for example, the UE104, the processor312, the RX processor956, and/or the controller/processor959may execute the uplink signaling component142and/or the LBT component352to perform the listen before talk procedure prior to transmitting. For example, the listen before talk procedure may include sensing the configured resources, determining an energy level, and comparing the energy level to an energy detection threshold to determine whether the configured resources are occupied. If the resources are unoccupied (e.g., the detected energy is less than the energy detection threshold, the method700may proceed to block760. In sub-block752, performing the listen before talk procedure may include determining that the selected resources are unavailable. For example, the LBT component352may determine that the detected energy level exceeds the energy detection threshold and determine that the selected resources are occupied. Accordingly, the UE104, the processor312, the RX processor956, and/or the controller/processor959executing the uplink signaling component142and/or the LBT component352may provide means for performing a listen before talk procedure prior to transmitting. The method700may proceed to block770in response to determining that the selected resources are occupied.

At block760, the method700may include transmitting a random access message or the scheduling request on selected configured resources. In an aspect, for example, the UE104, the processor312, the TX processor968, and/or the controller/processor959may execute the uplink signaling component142and/or the transmitting component356to transmit the random access message or the scheduling request on the selected configured resources. In an aspect, a SR transmission outside of the COT may only include an indication that the UE has data to transmit to the base station. In contrast, an SR transmission inside the COT may include a payload such as a BSR. As another example, a PRACH transmission outside of the COT may include only a preamble. In contrast, a PRACH transmission inside of the COT may include the preamble and a payload such as a UE identifier, C-RNTI, or small message. Accordingly, the UE104, the processor312, the TX processor968, and/or the controller/processor959executing the uplink signaling component142and/or the transmitting component356may provide means for transmitting a random access message or the scheduling request on selected configured resources.

In block770, the method700may include transmitting the scheduling request on resources for a lower priority logical channel. In an aspect, for example, the UE104, the processor312, the TX processor968, and/or the controller/processor959may execute the uplink signaling component142and/or the transmitting component356to transmit the scheduling request on resources for a lower priority logical channel. That is, the resources for the lower priority logical channel may be preempted for a higher priority logical channel. If no lower priority logical channel resources are available, however, the transmitting component356may wait for a next transmission opportunity for transmission at the priority level. Accordingly, the UE104, the processor312, the TX processor968, and/or the controller/processor959executing the uplink signaling component142and/or the transmitting component356may provide means for transmitting the scheduling request on resources for a lower priority logical channel.

FIG. 8is a flowchart of a method800of wireless communication. The method may be performed by a base station (e.g., the base station102) including a channel occupancy component148in communication with a UE104, which may include an uplink signaling component142.

In block810, the method800may include signaling at least a first uplink signaling configuration to a UE, the first uplink signaling configuration for use outside of a channel occupancy time (COT). In an aspect, for example, the base station102, the processor412, the TX processor916, and/or the controller/processor975may execute the channel occupancy component148to control the transmitter408to signal at least a first uplink signaling configuration to a UE104, the first uplink signaling configuration for use outside of the COT502. For example, the channel occupancy component148may signal the uplink signaling configuration using RRC signaling.

In block820, the method800may include transmitting a downlink control channel indicating that a base station has entered the COT to be shared with the UE. In an aspect, the base station102, the processor412, the TX processor916, and/or the controller/processor975may execute the channel occupancy component148to control the transmitter408to transmit a downlink control channel indicating that a base station has entered the COT502to be shared with the UE104. The COT may be associated with a second uplink signaling configuration. A density of transmission opportunities may be greater outside of the shared channel occupancy time than within the shared channel occupancy time.

In block830, the method800may include receiving a scheduling request or random access message from the UE according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT at a time of the scheduling request or random access message. In an aspect, for example, the base station102, the processor412, the RX processor970, and/or the controller/processor975may execute the channel occupancy component148to control the receiver406to receive a scheduling request or random access message from the UE104according to one of the first uplink signaling configuration or the second uplink signaling configuration based on whether the base station is in the COT502at a time of the scheduling request or random access message.

FIG. 9is a block diagram of a base station910in communication with a UE950in an access network. The base station910may be an example of the base station102including a channel occupancy component148. The UE950may be an example of the UE104including the uplink signaling component142. In the DL, IP packets from the EPC160may be provided to a controller/processor975. The controller/processor975implements layer3and layer2functionality. Layer3includes a radio resource control (RRC) layer, and layer2includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor975provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

At the UE950, each receiver954RX receives a signal through its respective antenna952. Each receiver954RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor956. The TX processor968and the RX processor956implement layer1functionality associated with various signal processing functions. The RX processor956may perform spatial processing on the information to recover any spatial streams destined for the UE950. If multiple spatial streams are destined for the UE950, they may be combined by the RX processor956into a single OFDM symbol stream. The RX processor956then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station910. These soft decisions may be based on channel estimates computed by the channel estimator958. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station910on the physical channel. The data and control signals are then provided to the controller/processor959, which implements layer3and layer2functionality.

The controller/processor959can be associated with a memory960that stores program codes and data. The memory960may be referred to as a computer-readable medium. In the UL, the controller/processor959provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC160. The controller/processor959is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Channel estimates derived by a channel estimator958from a reference signal or feedback transmitted by the base station910may be used by the TX processor968to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor968may be provided to different antenna952via separate transmitters954TX. Each transmitter954TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station910in a manner similar to that described in connection with the receiver function at the UE950. Each receiver918RX receives a signal through its respective antenna920. Each receiver918RX recovers information modulated onto an RF carrier and provides the information to a RX processor970.

The controller/processor975can be associated with a memory976that stores program codes and data. The memory976may be referred to as a computer-readable medium. In the UL, the controller/processor975provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE950. IP packets from the controller/processor975may be provided to the EPC160. The controller/processor975is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.