Methods for beam determination after beam pair link indication

Methods, systems, and devices for wireless communications are described that provide for signaling and switching of beam pair links (BPLs) for directional transmission beams between a base station and a user equipment (UE). A threshold value may be determined, which corresponds to an amount of time for a UE to receive and decode control information, and apply a different BPL than a current BPL that that is in use. The UE may maintain a BPL for data, which is used during data transmission time intervals (TTIs) until an indication is received to change the BPL for data. The UE and the base station may determine to change between BPLs based at least in part on the threshold value and a scheduling offset between a control channel transmission that allocates resources for a data TTI and a start of the data TTI.

BACKGROUND

The following relates generally to wireless communication, and more specifically to methods for beam determination after beam pair link indication.

In some cases, base stations and UEs may transmit using relatively high frequencies referred to as millimeter wave (mmW) frequencies, in which a base station and a UE may communicate via one or more directional beams. A transmitter (e.g. a base station) may engage in a beam sweeping procedure to establish an active beam pair with a receiver (e.g., a UE). An active beam pair may include an active transmit beam of the transmitter and a corresponding active receive beam of the receiver. The transmit beams and the receive beams in an active beam pair may be refined through, for example, beam refinement procedures. When the base station and UE identify a preferred beam, an active beam pair link (BPL) may be established for communications. In some cases, two or more BPLs may be identified, and a base station and UE may switch to different BPLs for transmissions based on channel conditions, for example. Techniques that may provide more efficient change of BPLs at a UE and base station may be desirable to help enhance network efficiency.

SUMMARY

The described techniques relate to improved methods, systems, devices, or apparatuses that support beam determination after beam pair link indication. Generally, the described techniques provide for signaling and switching of beam pair links (BPLs) for directional transmission beams between a base station and a user equipment (UE). In some cases, a threshold value may be determined, which corresponds to an amount of time for a UE to receive and decode control information, and apply a different BPL than a current BPL that is in use. In some cases, the UE may maintain a BPL for data, which is used during data TTIs until an indication is received to change the BPL for data. In some cases, the UE and the base station may determine to change between BPLs based at least in part on the threshold value and a scheduling offset between a control channel transmission that allocates resources for a data transmission time interval (TTI) and a start of the data TTI.

In some cases, if the scheduling offset is less than the threshold value, the UE is unable and is not expected to switch beams prior to the start of the data TTI. In some cases, if the scheduling offset is less than the threshold value, the UE may ignore a BPL indication provided in the control channel information and receive a data TTI using the BPL for data that was used in a prior data TTI. In other cases, if the scheduling offset is less than the threshold value, the UE may identify a BPL indication provided in the control information and verify that the BPL for data used for the corresponding data TTI matches the indicated BPL. In the event that the BPL indicated in the control information does not match the BPL for data used by the UE for the corresponding data TTI, the UE may determine that an error occurred in the receipt of a prior BPL indication (e.g., due to a failure to receive and decode a prior control information transmission), and the UE may enter a procedure to correct the error (e.g., via a random access request or control channel transmission on another carrier). In some cases, the procedure to correct the error may include identifying a BPL indication provided in the control information and change the BPL for data to the indicated BPL for data TTIs that start after the time of the control channel transmission plus the threshold value.

In some cases, if the scheduling offset is greater than the threshold value, the UE may switch the BPL for data to the BPL that is indicated in the control information at the start of the corresponding data TTI. The UE may apply the BPL for data for all subsequent TTIs until it receives another control information from which the UE may determine that it is to change its BPL for data.

In cases where the base station determines that the BPL for data communication is to be changed based on channel conditions, the base station may indicate the change in a subsequent control information transmission. In some cases, the base station may identify the threshold value at the UE that corresponds to the amount of time for the UE to decode an indication of a BPL switch and apply a different BPL. The base station may then provide an indication of a change in the BPL for data to the UE based on the scheduling offset, the time of the control information transmission, the threshold value, and the BPL indication. All this information indicates to the UE whether the BPL for data will change, a BPL change time, and the new value for the BPL for data.

A method of wireless communication is described. The method may include establishing, at a UE, a first connection with a base station using a first beam pair link (BPL), maintaining a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), identifying a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication, receiving a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication, determining, based at least in part on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch, and switching the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data.

An apparatus for wireless communication is described. The apparatus may include means for establishing, at a user equipment, a first connection with a base station using a first beam pair link (BPL), means for maintaining a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), means for identifying a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication, means for receiving a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication, means for determining, based at least in part on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch, and means for switching the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication, receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication, determine, based at least in part on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch, and switch the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication, receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication, determine, based at least in part on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch, and switch the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the determining comprises determining to switch the BPL for data based at least in part on determining that the scheduling offset may be greater than or equal to the threshold value, and to switch the BPL for data to the second BPL at the second time. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the determining comprises determining to maintain the first BPL as the BPL for data based on determining that the scheduling offset may be less than the threshold value.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying that an error in receiving a prior BPL indication has occurred based at least in part on determining that the scheduling offset is less than the threshold value, and the BPL indicated differs from the BPL for data at the second time. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for correcting, after the identifying the error in receiving the prior BPL indication, the BPL for data as maintained by the UE and using the corrected BPL for data after the first time plus the threshold value if it is not overwritten by any other signaled switch of the BPL for data occurring between the second time and the first time plus threshold value.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the determining comprises determining to switch the BPL for data to the second BPL, based at least in part on determining that the scheduling offset may be less than the threshold value, effective starting at the first time plus the threshold value. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the determining comprises determining to switch the BPL for data to the second BPL at the first time plus the threshold value irrespective of the scheduling offset. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

A method of wireless communication is described. The method may include establishing, at a base station, a first connection with a user equipment (UE) using a first beam pair link (BPL), maintaining a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), changing the BPL for data to a second BPL based at least on one or more channel conditions, identifying a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based at least in part on the indication, allocating resources for the UE for a first data TTI, determining a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI, and transmitting control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and wherein the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

An apparatus for wireless communication is described. The apparatus may include means for establishing, at a base station, a first connection with a user equipment (UE) using a first beam pair link (BPL), means for maintaining a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), means for changing the BPL for data to a second BPL based at least on one or more channel conditions, means for identifying a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based at least in part on the indication, means for allocating resources for the UE for a first data TTI, means for determining a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI, and means for transmitting control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and wherein the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to establish, at a base station, a first connection with a user equipment (UE) using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), change the BPL for data to a second BPL based at least on one or more channel conditions, identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based at least in part on the indication, allocate resources for the UE for a first data TTI, determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI, and transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and wherein the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to establish, at a base station, a first connection with a user equipment (UE) using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), change the BPL for data to a second BPL based at least on one or more channel conditions, identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based at least in part on the indication, allocate resources for the UE for a first data TTI, determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI, and transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and wherein the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, a change of the BPL for data for the first data TTI may be indicated by the scheduling offset being greater than or equal to the threshold value. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining not to convey a change of the BPL for data when the scheduling offset may be less than the threshold value.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above, when the scheduling offset may be less than the threshold value, the BPL indicated in the control information indicates the BPL used for the first data TTI. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, a change of the BPL for data may be indicated by the scheduling offset being less than the threshold value, and the BPL change time corresponds to the time of the control information transmission plus the threshold value.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, a change of the BPL for data may be indicated irrespective of the scheduling offset, and the BPL change time corresponds to the time of the control information transmission plus the threshold value. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

DETAILED DESCRIPTION

Various described techniques provide for signaling and switching of beam pair links (BPLs) for directional transmission beams between a base station and a user equipment (UE). In some cases, a threshold value may be determined, which corresponds to an amount of time for a UE to receive and decode control information, and apply a different BPL than a current BPL that is in use. In some cases, the UE may maintain a BPL for data, which is used during data TTIs until an indication is received to change the BPL for data. In some cases, the UE and the base station may determine to change between BPLs based at least in part on the threshold value and a scheduling offset between a control channel transmission that allocates resources for a data transmission time interval (TTI) and a start of the data TTI.

As indicated above, in mmW systems a base station and UE may communicate via one or more directional beams, and a base station may engage in a beam sweeping operation to establish an active transmit beam with a UE. A base station may also engage in beam tracking to maintain a connection with a UE. In some cases, the base station, as part of the beam sweep procedure, may perform a sector sweep with wide-formed, lower gain beams to establish a primary connection. Then, the base station may perform beam refinement using narrower, higher gain beams, and the UE and base station may identify one or more BPLs that are suitable for subsequent communications. Once the BPLs are identified, the base station may signal to the UE which BPL is to be used for data TTIs, which may include uplink data TTIs in which data is transmitted from the UE to the base station, downlink TTIs in which data is transmitted from the base station to the UE, or combinations thereof. The base station in some cases may perform a continuous beam tracking process to identify a preferred BPL for communications with the UE. For example, a first BPL may be the BPL for data, and the base station may determine that a second BPL has better channel conditions and should be used in subsequent transmissions (e.g., due to signal fading or blockage of the first BPL).

In order to switch between BPLs, various techniques such as described herein provide for dynamic switching of BPLs. For dynamic switching purposes, the BPL may be conveyed to the UE in the same control information message (e.g., downlink control information (DCI)) that contains the scheduling assignment of a data TTI (e.g., a physical downlink shared channel (PDSCH) transmission). For example, the DCI may contain a BPL indication (which may also be referred to as a spatial quasi colocation (QCL) indication), details of the TTI, and a scheduling offset. The scheduling offset indicates the time between the symbol that contains the DCI and the start of the associated data TTI. However, as indicated above, the UE may need a certain period of time to receive and decode an indication of a BPL switch and to perform the BPL switch, and such a time period is referred to herein as a threshold value. In the event that the base station determines to switch BPLs, the scheduling offset to indicate such a change that is implemented at the UE for a data TTI needs to be greater than or equal to the threshold value. Various aspects of the present disclosure provide techniques for indicating BPLs for data to a UE, and UE actions based on received indications of BPLs. Such techniques may provide for relatively fast switching between BPLs, and may also provide opportunities for UEs to identify if an error in one or more BPL indications has occurred. Such techniques may improve network efficiency through transmissions using favorable BPLs, which may support higher data rates, lower error rates, or combinations thereof.

Aspects of the disclosure are initially described in the context of a wireless communications system. Various examples of timings for indications of BPLs for data and associated data TTIs, and process flows are then described. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to methods for beam determination after beam pair link indication.

FIG. 1illustrates an example of a wireless communications system100in accordance with various aspects of the present disclosure. The wireless communications system100includes base stations105, UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE), LTE-Advanced (LTE-A) network (also referred to as a 4G network), or a New Radio (NR) network (also referred to as a 5G network). In some cases, wireless communications system100may support enhanced broadband communications, ultra-reliable (i.e., mission critical) communications, low latency communications, and communications with low-cost and low-complexity devices. Wireless communications system100may support mmW transmissions and beam switching techniques for switching BPLs, as discussed herein.

In some cases, wireless communications system100may use mmW communications between UEs115and base stations105, which may use beamforming techniques for transmitting and receiving transmissions. Devices operating in mmW or EHF bands may have multiple antennas to allow beamforming. That is, a base station105may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE115. Beamforming (which may also be referred to as spatial filtering or directional transmission) is a signal processing technique that may be used at a transmitter (e.g., a base station105) to shape and/or steer an overall antenna beam in the direction of a target receiver (e.g., a UE115). This may be achieved by combining elements in an antenna array in such a way that transmitted signals at particular angles experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation).

In some cases, wireless communications system100may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system100may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations105and UEs115may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a carrier aggregation (CA) configuration in conjunction with CCs operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both. In some cases, mmW transmissions may use an unlicensed high frequency band and a separate anchor carrier may be established in a lower band.

As indicated above, in some cases communications between a UE115and a base station105may be established using a first BPL having an associated uplink transmission beam and downlink transmission beam. The base station105, the UE115, or both, may periodically measure one or more channel conditions and may determine whether the first BPL, or a different second BPL, may be more suitable for subsequent transmissions. Upon determining that the second BPL should be used for subsequent transmissions at the base station105(e.g., through channel measurements or receiving signaling from the UE115with channel measurements), the second BPL may be indicated to the UE115in a control information transmission (e.g., a DCI transmission using a PDCCH). Depending upon the scheduling offset and the threshold value for receiving control information and changing BPLs at the UE115, the UE115may receive the control information and determine whether the BPL is to be changed. Such techniques may improve network efficiency through transmissions using favorable BPLs, which may support higher data rates, lower error rates, or combinations thereof.

FIG. 2illustrates an example of a wireless communication subsystem200that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. Wireless communication subsystem200may include a base station105-aand a UE115-a, which may be examples of the corresponding devices described with reference toFIG. 1. Base station105-aand UE115-amay communicate using one or more directional beams. In wireless communication system200, a transmitter (e.g., base station105-a) may engage in a beam sweeping operation to establish an active BPL with a receiver (e.g., UE115-a).

In some examples, the beam sweeping operation and any associated beam refinement procedures to establish an active BPL between UE115-aand the base station105-amay identify a number of suitable BPLs that may be used for mmW communications. In some examples, base station105-amay use a first port to transmit relatively wide-formed beams205(e.g., analog beams), that may be transmitted towards different sectors or geographic directions. In the example ofFIG. 2, a first wide-formed beam205-amay be transmitted in a first direction, a second wide-formed beam205-bmay be transmitted in a second direction, and a third wide-formed beam205-cmay be transmitted in a third direction. In some examples, the gain across a plurality of tones corresponding to wide-formed beams205may be close to equal.

In some cases, wide-formed beams205may not be narrow enough or have a high enough gain to be a preferred directional transmit beam for use in a BPL. Transmissions from UE115-amay be more clearly received and decoded if received via a highly directional and refined transmit beam. Therefore, it may be beneficial for base station105-ato use beam refinement to generate narrower beamformed signals of refined beams210, which may have a narrower coverage area but higher gain. UE115-amay identify which of the refined beams210is received at the highest gain, and may indicate one or more such beams to the base station105-awhich may be used to identify one or more BPLs that are suitable for communications between the UE115-aand the base station105-a. In some cases, the base station105-amay perform similar measurements on beams215transmitted from the UE115-ain order to determine one or more BPLs that are suitable for communications.

In some cases, the base station105-aand the UE115-amay operate in a non-standalone configuration, in which mmW communications have an associated low-band carrier or anchor carrier. In some cases, some or all control information may be transmitted between the UE115-aand the base station105-ausing such a low-band carrier, and data TTIs may refer to TTIs that are used to transmit data using high-band mmW BPLs. In some cases, as will be discussed in more detail below, the base station105-amay provide indications in control information, such as in DCI transmissions to the UE115-a, of a BPL and a scheduling offset for a data TTI, and the BPL indication indicates to the UE115-awhether the BPL for a data TTI will change, a BPL change time, and the associated BPL. In other cases, a standalone configuration may be used in which all control and data transmissions are transmitted using high-band mmW carriers.

FIG. 3illustrates an example of timings between control information transmissions and associated data TTIs300that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, timings between control information transmissions and associated data TTIs300may be used to implement aspects of wireless communication system100.

In the example ofFIG. 3, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments310or resource allocations for corresponding data TTIs305. In some cases, the scheduling assignments310may be transmitted on a control channel (e.g., a PDCCH) in DCI. In some cases, the scheduling assignments310may be transmitted using a low-band anchor carrier and the data TTIs305may use high-band mmW carriers. In other cases scheduling assignments310and the data TTIs305may both use high-band mmW carriers. The data TTIs305may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

In some examples, the DCI may contain the BPL indication (also referred to as a spatial quasi colocation (QCL) indication), details of the TTI (e.g., uplink or downlink resources, etc.), and a scheduling offset (si). The scheduling offset indicates, in some cases, the time between the symbol that contains the DCI and the start of the associated data TTI. In the example ofFIG. 3, a first scheduling assignment315may include an assignment for a first data TTI340(TTI0) and may indicate a first scheduling offset s0corresponding to a time difference between the start time t0of the first scheduling assignment315and the start time of the first data TTI340. In this example, a second scheduling assignment320may include an assignment for a second data TTI345(TTI1) and may indicate a second scheduling offset s1corresponding to a time difference between the start time t1of the second scheduling assignment320and the start time of the second data TTI345, with similar scheduling assignments for a third scheduling assignment325, fourth scheduling assignment330, and fifth scheduling assignment335that schedule corresponding third data TTI350(TTI2), fourth data TTI355(TTI3), and fifth data TTI360(TTI4).

As indicated in the example ofFIG. 3the scheduling offsets can be vary in length and therefore the order of the TTIs does not have to match the order of the associated DCIs with the scheduling assignments. In the example ofFIG. 3, for example, the third data TTI350(TTI2) is preceded by fourth data TTI355(TTI3). As discussed, scheduling assignments310may include a BPL or QCL indication, referred to as bi, and a UE (e.g., a UE115ofFIG. 1 or 2) may use a beam compatible with biduring the associated data TTIi. However, as indicated above, a UE may require some time t0decode a DCI and scheduling assignment, extract the BPL or QCL indication, and prepare the associated beam to be ready when data TTIistarts. In some cases, a threshold value, referred to as time K, may be an upper bound to the time the UE requires to decode a DCI and prepare a beam corresponding to the indicated BPL. In some cases, both the base station and the UE may be aware of the threshold value K, and various beam scheduling rules may be implemented that depend on K. In some cases, the threshold value K may either be part of the air-link specification or can be established after the UE or several UEs have signaled to the base station their individual threshold values K between DCI receipt and beam readiness. The base station may use one value of K for each individual UE or one value K for a group of UEs, or one value K for all UEs.

In cases where the scheduling offset siis larger or equal to K, the UE has enough time to prepare a beam compatible with bi, and in the remaining case si<K this is not possible. Various aspects of the present disclosure provide techniques for determining a BPL to use for a TTI based on the value of K, the scheduling offset, and the BPL or QCL indicated in the scheduling assignment, that may provide a scheduler at a base station with relatively high flexibility with relatively small scheduling offsets. Such techniques may enable the base station to provide low latency for certain packets.

FIG. 4illustrates another example of timings between control information transmissions and associated data TTIs as well as associated BPLs400that support methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, timings between control information transmissions and associated data TTIs as well as associated BPLs400may implement aspects of wireless communication system100.

In the example ofFIG. 4, similarly as discussed with respect toFIG. 3, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments410or resource allocations for corresponding data TTIs405. Scheduling assignments410may be transmitted on a control channel (e.g., a PDCCH) in DCI, as discussed above. In some cases, the scheduling assignments410may be transmitted using a low-band anchor carrier and the data TTIs405may use high-band mmW carriers. In other cases scheduling assignments410and the data TTIs may both use high-band mmW carriers. The data TTIs405may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

As indicated above, the DCI may contain the BPL indication (also referred to as a spatial quasi colocation (QCL) indication), details of the TTI (e.g., uplink or downlink resources, etc.), and a scheduling offset (si). In this example, some of the scheduling assignments410may include a BPL indication bi(or QCL indication). The scheduling offset indicates, in some cases, the time between the symbol that contains the DCI and the start of the associated data TTI. In the example ofFIG. 4, similarly as discussed inFIG. 3, a first scheduling assignment415may include an assignment for a first data TTI440(TTI0) and may indicate a first scheduling offset s0corresponding to a time difference between the start time t0of the first scheduling assignment415and the start time of the first data TTI440. In this example, a second scheduling assignment420may include an assignment for a second data TTI445(TTI1) and may indicate a second scheduling offset s1corresponding to a time difference between the start time t1of the second scheduling assignment420and the start time of the second data TTI445, with similar scheduling assignments for a third scheduling assignment425, fourth scheduling assignment430, and fifth scheduling assignment435that schedule corresponding third data TTI450(TTI2), fourth data TTI455(TTI3), and fifth data TTI460(TTI4).

In the example ofFIG. 4, the base station may use relatively large scheduling offsets to signal BPL changes to the UE. In this example, TTIs between BPL changes can be scheduled with small scheduling offsets and a rule may be established that states that those TTIs scheduled with small offsets use the same BPL as the most recent TTI scheduled with a large offset. In the example ofFIG. 4, a BPL change may be indicated at the start of TTI0440to change from a prior BPL to b0, and another change at the start of TTI2450to change from b0to b1. In this case, the intermediate TTIs (namely TTI1445and TTI3455) are scheduled with small offsets, and data TTIs with such small offsets (e.g., a scheduling offset of si<K) may be transmitted by the base station using the same BPL as the most recent data TTI, and the UE may assume the same BPL as the most recent TTI scheduled with a large offset is used. In such a case, in the example ofFIG. 4, the first TTI440(TTI0) may be transmitted using a first BPL465(i.e., b0), and the second TTI445(TTI1) and fourth TTI (TTI3) may have scheduling offsets (s1and s3) that are less than K, and in this example the first BPL465is used for each. The third data TTI450(TTI2), which in this example is after the fourth TTI455due to the associated scheduling offset, may switch to a second BPL470.

In cases as discussed with respect toFIG. 4, if BPL indications of scheduling assignments410are provided when the scheduling offset is less than the threshold value, a UE may ignore the BPL indication. In some cases, however, if a UE misses a scheduling assignment410that indicates a changed BPL, then the UE may apply the wrong beam for subsequent data TTIs. In case ofFIG. 4, if the UE fails to receive and decode the first scheduling assignment415, then TTI0440, TTI1445, and TTI3455would be lost. In some cases, as will be discussed with respect toFIG. 5, a UE may verify a BPL indication in scheduling assignments410that have a scheduling offset that is less than the threshold value.

FIG. 5illustrates another example of timings between control information transmissions and associated data TTIs as well as associated BPLs500that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, control information transmissions and associated data TTIs as well as associated BPLs500may implement aspects of wireless communication system100.

In the example ofFIG. 5, similarly as discussed with respect toFIGS. 3 and 4, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments510or resource allocations for corresponding data TTIs505. Scheduling assignments510may be transmitted on a control channel (e.g., a PDCCH) in DCI, as discussed above. In some cases, the scheduling assignments510may be transmitted using a low-band anchor carrier and the data TTIs505may use high-band mmW carriers. In other cases scheduling assignments510and the data TTIs may both use high-band mmW carriers. The data TTIs505may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

As indicated above, the DCI may contain the BPL indication (also referred to as a spatial quasi colocation (QCL) indication), details of the TTI (e.g., uplink or downlink resources, etc.), and a scheduling offset (si). In this example, each of the scheduling assignments510also include a BPL indication bi(or QCL indication). The scheduling offset indicates, in some cases, the time between the symbol that contains the DCI and the start of the associated data TTI. In the example ofFIG. 5, similarly as discussed inFIGS. 3 and 4, a first scheduling assignment515may include an assignment for a first data TTI540(TTI0) and may indicate a first scheduling offset s0corresponding to a time difference between the start time t0of the first scheduling assignment515and the start time of the first data TTI540. In this example, a second scheduling assignment520may include an assignment for a second data TTI545(TTI1) and may indicate a second scheduling offset s1corresponding to a time difference between the start time t1of the second scheduling assignment520and the start time of the second data TTI545, with similar scheduling assignments for a third scheduling assignment525, fourth scheduling assignment530, and fifth scheduling assignment535that schedule corresponding third data TTI550(TTI2), fourth data TTI555(TTI3), and fifth data TTI560(TTI4).

In the example ofFIG. 5, in order to limit potential error propagation that may result from a missed scheduling assignment, the base station may provide a BPL indication bifor scheduling assignments410even in cases where the scheduling offset is less than the threshold value. The UE can use this information to verify that it has used or is about to use the correct beam for the scheduled TTI. If not, the UE may take corrective action and apply the beam compatible with bifor a TTI that starts at ti+K, where tiis the start of the symbol that carries the scheduling assignment DCI. In the example ofFIG. 5, the second scheduling assignment520and the fourth scheduling assignment530may carry a BPL indication of b0to indicate to the UE that BPL b0565is used for the associated TTIs. Likewise after a switch to a second BPL b1570, if any scheduling assignments are provided in which the scheduling offset is less than the threshold value, the base station may indicate b1in such scheduling assignments, which the UE may use to confirm the BPL.

Likewise, if the UE does not successfully receive and decode the first scheduling assignment515, it will miss TTI0540and apply the wrong beam for TTI1545. In this example, the second scheduling assignment520contains the QCL indication b0and the UE will likely decode this information (e.g., via a low-band anchor carrier) while it is receiving/transmitting TTI1545. At that time, the UE may realize that the wrong BPL is being used due to a missed DCI. As a corrective action the UE may, for example, prepare a beam compatible with the BPL b0565which can be ready for use after time t1+K, well ahead of TTI3555, and the UE will receive/transmit TTI3555using the correct BPL. Similarly, if the UE were to miss third scheduling assignment525, a correction could be made to the BPL upon receipt of a subsequent scheduling assignment irrespective of whether the associated scheduling offset is less than or greater than the threshold value K.

FIG. 6illustrates another example of timings between control information transmissions and associated data TTIs as well as associated BPLs600that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, control information transmissions and associated data TTIs as well as associated BPLs600may implement aspects of wireless communication system100.

In the example ofFIG. 6, similarly as discussed with respect toFIGS. 3 through 5, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments610or resource allocations for corresponding data TTIs605. Scheduling assignments610may be transmitted on a control channel (e.g., a PDCCH) in DCI, as discussed above. In some cases, the scheduling assignments610may be transmitted using a low-band anchor carrier and the data TTIs605may use high-band mmW carriers. In other cases scheduling assignments610and the data TTIs may both use high-band mmW carriers. The data TTIs605may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

As indicated above, the DCI may contain the BPL indication (also referred to as a spatial quasi colocation (QCL) indication), details of the TTI (e.g., uplink or downlink resources, etc.), and a scheduling offset (si). In this example, each of the scheduling assignments610also include a BPL indication bi(or QCL indication). The scheduling offset indicates, in some cases, the time between the symbol that contains the DCI and the start of the associated data TTI. In the example ofFIG. 6, similarly as discussed inFIGS. 3 through 5, a first scheduling assignment615may include an assignment for a first data TTI640(TTI0) and may indicate a first scheduling offset s0corresponding to a time difference between the start time t0of the first scheduling assignment615and the start time of the first data TTI640. In this example, a second scheduling assignment620may include an assignment for a second data TTI645(TTI1) and may indicate a second scheduling offset s1corresponding to a time difference between the start time t1of the second scheduling assignment620and the start time of the second data TTI645, with similar scheduling assignments for a third scheduling assignment625, fourth scheduling assignment630, and fifth scheduling assignment635that schedule corresponding third data TTI650(TTI2), fourth data TTI655(TTI3), and fifth data TTI660(TTI4).

In the example ofFIG. 6, another technique is provided which may limit potential error propagation that may result from a missed scheduling assignment. Here, the base station may provide a BPL indication bifor scheduling assignments410in which the indicated BPL is to be effective at a starting time of the symbol used to transmit the scheduling assignment plus the threshold value K. Thus, such a technique provides a rule that for si<K the BPL indication biwill be effective at the time ti+K, where tiis the start of the symbol that carries the DCI for the scheduling assignment. In such cases, the BPL indication remains effective until it is overwritten by a new BPL indication. In contrast to the technique discussed above with respect toFIG. 5, the BPL indication will be effective independent of any TTI starting between tiand ti+K. In the example ofFIG. 6, in the event that the UE does not successfully receive and decode the first scheduling assignment615, the UE will use the wrong BPL for TTI1645but will have the correct beam for TTI3655, because the starting time for TTI3is greater than t1+K. In this particular example, both the third scheduling assignment625and the fourth scheduling assignment630create an effective QCL indication for TTI2650which reduces the probability that the UE uses the wrong BPL for TTI2650, since both DCIs need to be lost in order for such an error to occur.

FIG. 7illustrates another example of timings between control information transmissions and associated data TTIs as well as associated BPLs700that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, control information transmissions and associated data TTIs as well as associated BPLs700may implement aspects of wireless communication system100.

In the example ofFIG. 7, similarly as discussed with respect toFIGS. 3 through 6, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments710or resource allocations for corresponding data TTIs705. Scheduling assignments710may be transmitted on a control channel (e.g., a PDCCH) in DCI, as discussed above. In some cases, the scheduling assignments710may be transmitted using a low-band anchor carrier and the data TTIs705may use high-band mmW carriers. In other cases scheduling assignments710and the data TTIs may both use high-band mmW carriers. The data TTIs705may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

As indicated above, the DCI may contain the BPL indication (also referred to as a spatial quasi colocation (QCL) indication), details of the TTI (e.g., uplink or downlink resources, etc.), and a scheduling offset (si). In this example, each of the scheduling assignments710also include a BPL indication bi(or QCL indication). The scheduling offset indicates, in some cases, the time between the symbol that contains the DCI and the start of the associated data TTI. In the example ofFIG. 7, similarly as discussed inFIGS. 3 through 6, a first scheduling assignment715may include an assignment for a first data TTI740(TTI0) and may indicate a first scheduling offset s0corresponding to a time difference between the start time t0of the first scheduling assignment715and the start time of the first data TTI740. In this example, a second scheduling assignment720may include an assignment for a second data TTI745(TTI1) and may indicate a second scheduling offset s1corresponding to a time difference between the start time t1of the second scheduling assignment720and the start time of the second data TTI745, with similar scheduling assignments for a third scheduling assignment725, fourth scheduling assignment730, and fifth scheduling assignment735that schedule corresponding third data TTI750(TTI2), fourth data TTI755(TTI3), and fifth data TTI760(TTI4).

In the example ofFIG. 7, another technique is provided which may provide that a BPL is switched relatively quickly after a determination is made to switch BPLs. For example, a base station may detect fading in a first BPL765and determine to switch to a second BPL770. In this example, a rule may be provided that, independent of the scheduling offset, the QCL indication biis effective at time ti+K. This also allows a change of the BPL for TTIs that have already been scheduled with a large scheduling offset. For example, the base station may determine at time t3that the second BPL770is better than the first BPL765. At that point TTI2750is already scheduled with the third scheduling assignment725that indicates the first BPL765. In this case, due to the fourth scheduling assignment730being provided the threshold value K in advance of the start of TTI2750, the UE will still use a beam compatible with the new BPL indication for the second BPL770. For this technique, similarly with the techniques described forFIGS. 5 and 6, error propagation due to lost scheduling assignments may be mitigated.

FIG. 8illustrates another example of timings between control information transmissions and associated data TTIs as well as associated BPLs800that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, control information transmissions and associated data TTIs as well as associated BPLs800may implement aspects of wireless communication system100.

In the example ofFIG. 8, similarly as discussed with respect toFIGS. 3 through 7, a base station (e.g., a base station105ofFIG. 1 or 2) may transmit scheduling assignments810or resource allocations for corresponding data TTIs805. Scheduling assignments810may be transmitted on a control channel (e.g., a PDCCH) in DCI, as discussed above. In some cases, the scheduling assignments810may be transmitted using a low-band anchor carrier and the data TTIs805may use high-band mmW carriers. In other cases scheduling assignments810and the data TTIs may both use high-band mmW carriers. The data TTIs805may be uplink TTIs, downlink TTIs, or combinations thereof, that may include physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmissions in which data may be transmitted.

In the example ofFIG. 8, BPLs may be determined based on a function of the scheduling offsets and threshold values according to the various techniques described above. Table 1 shows the BPL indication birelated interpretations for the different techniques ofFIGS. 4 through 7.

For each technique, a scheduling assignment indicates that a UE is to prepare a beam compatible with the BPL indication either unconditionally, as in the examples ofFIGS. 6 and 7, or if a certain condition is met as in the examples ofFIGS. 4 and 5. Both situations may be formally covered in a unified manner through a function ƒ(si, K). Table 2 shows the function f for the different described techniques.

In each case, the UE has to prepare beams only, if ƒ(si, K)≥0. If the UE has to prepare a beam, it may apply the beam starting from the time ti+g(si, K) until a time when the UE is instructed by the same mechanism to use a potentially new beam. Table 2 shows the function g for each technique.

In the example ofFIG. 8, which may apply to each of the discussed techniques, a scheduling assignment815occurring at time timay contain a scheduling offset sisuch that f(si, K)≥0. Then the UE prepares a beam compatible with the BPL indication bi845for use of a beam for data starting with time ti+g(si, K). From all scheduling assignments810(DCIn) with
f(sn,K)≥0  i.
tn+g(sn,K)≥ti+g(si,K).  ii.
Further, let DCIjbe the one with the earliest beam start time tj+g(sj, K). In other words there is no scheduling assignment DCI with a beam start time that falls between ti+g(si, K) and tj+g(sj, K). Then the UE uses the beam compatible with bifor all TTIs starting within the time interval [ti+g(si, K), tj+g(sj, K)].

In the example ofFIG. 8, the UE applies the beam compatible with bi845for TTIi830(scheduled by scheduling assignment815) and also for TTIm835as this is scheduled by a scheduling assignment820that does not fulfill the condition f(sm, K)≥0. Another example for such a TTIm835could be one with a beam start time of tm+g(sm, K) occurring before ti+g(si, K). The BPL bj850may be used after scheduling assignment825, for TTIj840, in this example.

With respect to scheduling assignment810timing,FIG. 8does not show the full scope of possibilities as will be readily recognized, and it is noted that there can be many or no scheduling assignments between scheduling assignment815and scheduling assignment825. It is also possible that scheduling assignment825occurs before scheduling assignment815. Further g(si, K) can be smaller or larger than sidepending on the desired technique to be employed. However, g(si, K), in each case, must always be larger or equal to threshold value K such that the UE has enough time to prepare a beam consistent with the BPL indication of the scheduling assignment.

FIG. 9illustrates an example of a process flow900that supports methods for beam determination after beam pair link indication in accordance with various aspects of the present disclosure. In some examples, process flow900may implement aspects of wireless communication system100. Process flow900may include a base station105-b, and a UE115-b, which may be examples of the corresponding devices ofFIG. 1 or 2.

Initially, at905, the UE115-band the base station105-bmay establish a connection. In some cases, the connection may be a mmW connection using a first BPL that is established between the base station105-band the UE115-b. In some cases, a low-band connection may be established, or another high-band connection may be established which may be used to convey control information.

At910, the base station105-bmay allocate a data TTI to the UE115-band select a BPL for the data TTI. In some cases, the allocation may be made based on data that is to be transmitted between the UE115-band the base station105-b. In some cases, the base station105-bmay measure one or more channel quality parameters associated with one or more BPLs that may have been established during the connection establishment or afterward, and select the BPL based on the measurements. Additionally or alternatively, the UE115-bmay provide one or more measurement reports that the base station105-bmay use in determining a BPL to use for the data TTI. Channel quality measurements may be made according to established techniques, such as measurements based on one or more reference signal transmissions of the base station105-band the UE115-b. The base station105-bmay transmit DCI915to the UE115-bthat indicates the allocated resources for the data TTI. As discussed above, the DCI915may also indicate a scheduling offset and a BPL indication. In some cases, the base station105-bmay indicate the BPL for the data TTI based on one of the techniques as discussed above.

At920, the UE115-dmay determine a threshold value (K) for BPL switching. In some cases, the threshold value may be exchanged during connection establishment. As discussed above, the threshold value may correspond to a time that the UE115-bmay take to receive and decode DCI, and prepare a changed beam.

At block930, the UE115-bmay determine a BPL for the data TTI, and potentially for one or more subsequent data TTIs, based on f(si,K)≥0, g(si,K)≥K, as discussed above with respect toFIG. 8. The base station105-bmay transmit the data TTI transmission935using the BPL that is determined. In this example, the data TTI transmission935is a downlink transmission, although in other cases it may be an uplink transmission. At940, the UE115-bmay receive the data TTI transmission based on the identified BPL.

FIG. 10shows a block diagram1000of a wireless device1005that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Wireless device1005may be an example of aspects of a user equipment (UE)115as described herein. Wireless device1005may include receiver1010, UE communications manager1015, and transmitter1020. Wireless device1005may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1010may 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 methods for beam determination after beam pair link indication, etc.). Information may be passed on to other components of the device. The receiver1010may be an example of aspects of the transceiver1335described with reference toFIG. 13. The receiver1010may utilize a single antenna or a set of antennas.

UE communications manager1015may be an example of aspects of the UE communications manager1315described with reference toFIG. 13.

UE communications manager1015may establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based on the indication, receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication, determine, based on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch, and switch the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data.

FIG. 11shows a block diagram1100of a wireless device1105that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Wireless device1105may be an example of aspects of a wireless device1005or a UE115as described with reference toFIG. 10. Wireless device1105may include receiver1110, UE communications manager1115, and transmitter1120. Wireless device1105may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1110may 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 methods for beam determination after beam pair link indication, etc.). Information may be passed on to other components of the device. The receiver1110may be an example of aspects of the transceiver1335described with reference toFIG. 13. The receiver1110may utilize a single antenna or a set of antennas.

UE communications manager1115may be an example of aspects of the UE communications manager1315described with reference toFIG. 13. UE communications manager1115may also include connection establishment component1125, BPL manager1130, threshold identification component1135, and downlink control information (DCI) component1140.

Connection establishment component1125may establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL) for transmission of data TTIs. In some cases, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

BPL manager1130may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). In some cases, the BPL may be determined based on a threshold value and scheduling offset, and the BPL manager1130may determine whether to switch the BPL for data and a switching time for making the switch. In cases where BPL manager1130determines to switch the BPL, it may switch the BPL for data to a second BPL at the switching time. In some cases, the determining includes determining to switch the BPL for data based on determining that the scheduling offset is greater than or equal to the threshold value, and to switch the BPL for data to the second BPL at the second time. In some cases, the determining includes determining to maintain the first BPL as the BPL for data based on determining that the scheduling offset is less than the threshold value. In some cases, the determining includes determining to switch the BPL for data to the second BPL, based on determining that the scheduling offset is less than the threshold value, effective starting at the first time plus the threshold value. In some cases, the determining includes determining to switch the BPL for data to the second BPL at the first time plus the threshold value irrespective of the scheduling offset.

Threshold identification component1135may identify the threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based on the indication.

DCI component1140may receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication.

FIG. 12shows a block diagram1200of a UE communications manager1215that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. The UE communications manager1215may be an example of aspects of a UE communications manager1015, a UE communications manager1115, or a UE communications manager1315described with reference toFIGS. 10, 11, and 13. The UE communications manager1215may include connection establishment component1220, BPL manager1225, threshold identification component1230, DCI component1235, and error detection component1240. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Connection establishment component1220may establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL) for transmission of data TTIs. In some cases, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

BPL manager1225may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). In some cases, the BPL may be determined based on a threshold value and scheduling offset, and the BPL manager1225may determine whether to switch the BPL for data and a switching time for making the switch. In cases where BPL manager1225determines to switch the BPL, it may switch the BPL for data to a second BPL at the switching time. In some cases, the determining includes determining to switch the BPL for data based on determining that the scheduling offset is greater than or equal to the threshold value, and to switch the BPL for data to the second BPL at the second time. In some cases, the determining includes determining to maintain the first BPL as the BPL for data based on determining that the scheduling offset is less than the threshold value. In some cases, the determining includes determining to switch the BPL for data to the second BPL, based on determining that the scheduling offset is less than the threshold value, effective starting at the first time plus the threshold value. In some cases, the determining includes determining to switch the BPL for data to the second BPL at the first time plus the threshold value irrespective of the scheduling offset.

Threshold identification component1230may identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based on the indication.

DCI component1235may receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication.

Error detection component1240may identify that an error in receiving a prior BPL indication has occurred based on determining that the scheduling offset is less than the threshold value, and the BPL indicated in the first control information transmission indicates the BPL used by the base station for the first data TTI differs from the first BPL and correct the BPL for data as maintained by the UE and using the corrected BPL for data after the first time plus the threshold value.

FIG. 13shows a diagram of a system1300including a device1305that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Device1305may be an example of or include the components of wireless device1005, wireless device1105, or a UE115as described above, e.g., with reference toFIGS. 10 and 11. Device1305may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager1315, processor1320, memory1325, software1330, transceiver1335, antenna1340, and I/O controller1345. These components may be in electronic communication via one or more buses (e.g., bus1310). Device1305may communicate wirelessly with one or more base stations105.

Memory1325may include random access memory (RAM) and read only memory (ROM). The memory1325may store computer-readable, computer-executable software1330including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1325may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software1330may include code to implement aspects of the present disclosure, including code to support methods for beam determination after beam pair link indication. Software1330may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software1330may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

In some cases, the wireless device may include a single antenna1340. However, in some cases the device may have more than one antenna1340, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

I/O controller1345may manage input and output signals for device1305. I/O controller1345may also manage peripherals not integrated into device1305. In some cases, I/O controller1345may represent a physical connection or port to an external peripheral. In some cases, I/O controller1345may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, I/O controller1345may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller1345may be implemented as part of a processor. In some cases, a user may interact with device1305via I/O controller1345or via hardware components controlled by I/O controller1345.

FIG. 14shows a block diagram1400of a wireless device1405that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Wireless device1405may be an example of aspects of a base station105as described herein. Wireless device1405may include receiver1410, base station communications manager1415, and transmitter1420. Wireless device1405may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1410may 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 methods for beam determination after beam pair link indication, etc.). Information may be passed on to other components of the device. The receiver1410may be an example of aspects of the transceiver1735described with reference toFIG. 17. The receiver1410may utilize a single antenna or a set of antennas.

Base station communications manager1415may be an example of aspects of the base station communications manager1715described with reference toFIG. 17.

Base station communications manager1415may establish, at a base station, a first connection with a UE using a first beam pair link (BPL), maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs), change the BPL for data to a second BPL based at least on one or more channel conditions, identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based on the indication, allocate resources for the UE for a first data TTI, determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI, and transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and where the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

Transmitter1420may transmit signals generated by other components of the device. In some examples, the transmitter1420may be collocated with a receiver1410in a transceiver module. For example, the transmitter1420may be an example of aspects of the transceiver1735described with reference toFIG. 17. The transmitter1420may utilize a single antenna or a set of antennas.

FIG. 15shows a block diagram1500of a wireless device1505that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Wireless device1505may be an example of aspects of a wireless device1405or a base station105as described with reference toFIG. 14. Wireless device1505may include receiver1510, base station communications manager1515, and transmitter1520. Wireless device1505may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver1510may 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 methods for beam determination after beam pair link indication, etc.). Information may be passed on to other components of the device. The receiver1510may be an example of aspects of the transceiver1735described with reference toFIG. 17. The receiver1510may utilize a single antenna or a set of antennas.

Base station communications manager1515may be an example of aspects of the base station communications manager1715described with reference toFIG. 17. Base station communications manager1515may also include connection establishment component1525, BPL manager1530, channel condition component1535, resource allocation component1540, and DCI component1545.

Connection establishment component1525may establish, at a base station, a first connection with a UE using a first beam pair link (BPL) for transmission of data TTIs. In some cases, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

BPL manager1530may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). In some cases, BPL manager1530may identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based on the indication. In some cases, BPL manager1530may determine not to convey a change of the BPL for data when the scheduling offset is less than the threshold value, and when the scheduling offset is less than the threshold value, the BPL indicated in the control information indicates the BPL used for the first data TTI. In some cases, a change of the BPL for data for the first data TTI is indicated by the scheduling offset being greater than or equal to the threshold value. In some cases, a change of the BPL for data is indicated by the scheduling offset being less than the threshold value, and the BPL change time corresponds to the time of the control information transmission plus the threshold value. In some cases, a change of the BPL for data is indicated irrespective of the scheduling offset, and the BPL change time corresponds to the time of the control information transmission plus the threshold value.

Channel condition component1535may change the BPL for data to a second BPL based at least on one or more channel conditions. Resource allocation component1540may allocate resources for the UE for a first data TTI.

DCI component1545may determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI and transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and where the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

Transmitter1520may transmit signals generated by other components of the device. In some examples, the transmitter1520may be collocated with a receiver1510in a transceiver module. For example, the transmitter1520may be an example of aspects of the transceiver1735described with reference toFIG. 17. The transmitter1520may utilize a single antenna or a set of antennas.

FIG. 16shows a block diagram1600of a base station communications manager1615that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. The base station communications manager1615may be an example of aspects of a base station communications manager1715described with reference toFIGS. 14, 15, and 17. The base station communications manager1615may include connection establishment component1620, BPL manager1625, channel condition component1630, resource allocation component1635, and DCI component1640. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Connection establishment component1620may establish, at a base station, a first connection with a UE using a first beam pair link (BPL) for transmission of data TTIs. In some cases, the data TTIs include uplink data TTIs, downlink data TTIs, or combinations thereof.

BPL manager1625may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). In some cases, BPL manager1625may identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based on the indication. In some cases, BPL manager1625may determine not to convey a change of the BPL for data when the scheduling offset is less than the threshold value, and when the scheduling offset is less than the threshold value, the BPL indicated in the control information indicates the BPL used for the first data TTI. In some cases, a change of the BPL for data for the first data TTI is indicated by the scheduling offset being greater than or equal to the threshold value. In some cases, a change of the BPL for data is indicated by the scheduling offset being less than the threshold value, and the BPL change time corresponds to the time of the control information transmission plus the threshold value. In some cases, a change of the BPL for data is indicated irrespective of the scheduling offset, and the BPL change time corresponds to the time of the control information transmission plus the threshold value.

Channel condition component1630may change the BPL for data to a second BPL based at least on one or more channel conditions.

Resource allocation component1635may allocate resources for the UE for a first data TTI.

DCI component1640may determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI and transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and where the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time.

FIG. 17shows a diagram of a system1700including a device1705that supports methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. Device1705may be an example of or include the components of base station105as described above, e.g., with reference toFIG. 1. Device1705may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager1715, processor1720, memory1725, software1730, transceiver1735, antenna1740, network communications manager1745, and inter-station communications manager1750. These components may be in electronic communication via one or more buses (e.g., bus1710). Device1705may communicate wirelessly with one or more UEs115.

Memory1725may include RAM and ROM. The memory1725may store computer-readable, computer-executable software1730including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1725may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software1730may include code to implement aspects of the present disclosure, including code to support methods for beam determination after beam pair link indication. Software1730may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software1730may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

In some cases, the wireless device may include a single antenna1740. However, in some cases the device may have more than one antenna1740, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

Network communications manager1745may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager1745may manage the transfer of data communications for client devices, such as one or more UEs115.

FIG. 18shows a flowchart illustrating a method1800for methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. The operations of method1800may be implemented by a UE115or its components as described herein. For example, the operations of method1800may be performed by a UE communications manager as described with reference toFIGS. 10 through 13. In some examples, a UE115may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE115may perform aspects of the functions described below using special-purpose hardware.

At1805the UE115may establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL). The operations of1805may be performed according to the methods described herein. In certain examples, aspects of the operations of1805may be performed by a connection establishment component as described with reference toFIGS. 10 through 13.

At1810the UE115may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). The operations of1810may be performed according to the methods described herein. In certain examples, aspects of the operations of1810may be performed by a BPL manager as described with reference toFIGS. 10 through 13.

At1815the UE115may identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication. The operations of1815may be performed according to the methods described herein. In certain examples, aspects of the operations of1815may be performed by a threshold identification component as described with reference toFIGS. 10 through 13.

At1820the UE115may receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication. The operations of1820may be performed according to the methods described herein. In certain examples, aspects of the operations of1820may be performed by a DCI component as described with reference toFIGS. 10 through 13.

At1825the UE115may determine, based at least in part on the threshold value and the scheduling offset, whether to switch the BPL for data and a switching time for making the switch. The operations of1825may be performed according to the methods described herein. In certain examples, aspects of the operations of1825may be performed by a BPL manager as described with reference toFIGS. 10 through 13. In some cases, the determining comprises determining to switch the BPL for data to the second BPL, based at least in part on determining that the scheduling offset is less than the threshold value, effective starting at the first time plus the threshold value. In some cases, the determining comprises determining to switch the BPL for data to the second BPL at the first time plus the threshold value irrespective of the scheduling offset.

At1830the UE115may switch the BPL for data to a second BPL at the switching time responsive to determining to switch the BPL for data. The operations of1830may be performed according to the methods described herein. In certain examples, aspects of the operations of1830may be performed by a BPL manager as described with reference toFIGS. 10 through 13.

Utilizing techniques such as method1800, the base station105, the UE115, or both, may periodically measure one or more channel conditions and may determine whether the first BPL, or a different second BPL, may be more suitable for subsequent transmissions. Upon determining that the second BPL should be used for subsequent transmissions at the base station105(e.g., through channel measurements or receiving signaling from the UE115with channel measurements), the second BPL may be indicated to the UE115in a control information transmission (e.g., a DCI transmission using a PDCCH). Depending upon the scheduling offset and the threshold value for receiving control information and changing BPLs at the UE115, the UE115may receive the control information and determine whether the BPL is to be changed. Such techniques may improve network efficiency through transmissions using favorable BPLs, which may support higher data rates, lower error rates, or combinations thereof.

FIG. 19shows a flowchart illustrating a method1900for methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. The operations of method1900may be implemented by a UE115or its components as described herein. For example, the operations of method1900may be performed by a UE communications manager as described with reference toFIGS. 10 through 13. In some examples, a UE115may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE115may perform aspects of the functions described below using special-purpose hardware.

At1905the UE115may establish, at a user equipment, a first connection with a base station using a first beam pair link (BPL). The operations of1905may be performed according to the methods described herein. In certain examples, aspects of the operations of1905may be performed by a connection establishment component as described with reference toFIGS. 10 through 13.

At1910the UE115may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). The operations of1910may be performed according to the methods described herein. In certain examples, aspects of the operations of1910may be performed by a BPL manager as described with reference toFIGS. 10 through 13.

At1915the UE115may identify a threshold value corresponding to an amount of time needed by the UE to decode an indication of a BPL switch and apply a different BPL than the first BPL based at least in part on the indication. The operations of1915may be performed according to the methods described herein. In certain examples, aspects of the operations of1915may be performed by a threshold identification component as described with reference toFIGS. 10 through 13.

At1920the UE115may receive a first control information transmission at a first time, the first control information transmission including a scheduling offset, an assignment for a first data TTI that starts at a second time corresponding to the first time plus the scheduling offset, and a BPL indication. The operations of1920may be performed according to the methods described herein. In certain examples, aspects of the operations of1920may be performed by a DCI component as described with reference toFIGS. 10 through 13.

At1925the UE115may identify that an error in receiving a prior BPL indication has occurred based at least in part on determining that the scheduling offset is less than the threshold value, and the BPL indicated in the first control information transmission indicates the BPL used by the base station for the first data TTI differs from the first BPL. The operations of1925may be performed according to the methods described herein. In certain examples, aspects of the operations of1925may be performed by an error detection component as described with reference toFIGS. 10 through 13.

At1930the UE115may correct the BPL for data as maintained by the UE and using the corrected BPL for data after the first time plus the threshold value. The operations of1930may be performed according to the methods described herein. In certain examples, aspects of the operations of1930may be performed by an error detection component as described with reference toFIGS. 10 through 13.

Utilizing techniques such as method1900, the base station105, the UE115, or both, may periodically measure one or more channel conditions and may determine whether the first BPL, or a different second BPL, may be more suitable for subsequent transmissions. Upon determining that the second BPL should be used for subsequent transmissions at the base station105(e.g., through channel measurements or receiving signaling from the UE115with channel measurements), the second BPL may be indicated to the UE115in a control information transmission (e.g., a DCI transmission using a PDCCH). Depending upon the scheduling offset and the threshold value for receiving control information and changing BPLs at the UE115, the UE115may receive the control information and determine whether the BPL is to be changed. Such techniques may improve network efficiency through transmissions using favorable BPLs, which may support higher data rates, lower error rates, or combinations thereof.

FIG. 20shows a flowchart illustrating a method2000for methods for beam determination after beam pair link indication in accordance with aspects of the present disclosure. The operations of method2000may be implemented by a base station105or its components as described herein. For example, the operations of method2000may be performed by a base station communications manager as described with reference toFIGS. 14 through 17. In some examples, a base station105may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station105may perform aspects of the functions described below using special-purpose hardware.

At2005the base station105may establish, at a base station, a first connection with a user equipment (UE) using a first beam pair link (BPL). The operations of2005may be performed according to the methods described herein. In certain examples, aspects of the operations of2005may be performed by a connection establishment component as described with reference toFIGS. 14 through 17.

At2010the base station105may maintain a BPL for data, which is initialized with the first BPL and is used during data transmission time intervals (TTIs). The operations of2010may be performed according to the methods described herein. In certain examples, aspects of the operations of2010may be performed by a BPL manager as described with reference toFIGS. 14 through 17.

At2015the base station105may change the BPL for data to a second BPL based at least on one or more channel conditions. The operations of2015may be performed according to the methods described herein. In certain examples, aspects of the operations of2015may be performed by a channel condition component as described with reference toFIGS. 14 through 17.

At2020the base station105may identify a threshold value corresponding to an amount of time for the UE to decode an indication of a BPL switch and apply a different BPL based at least in part on the indication. The operations of2020may be performed according to the methods described herein. In certain examples, aspects of the operations of2020may be performed by a BPL manager as described with reference toFIGS. 14 through 17.

At2025the base station105may allocate resources for the UE for a first data TTI. The operations of2025may be performed according to the methods described herein. In certain examples, aspects of the operations of2025may be performed by a resource allocation component as described with reference toFIGS. 14 through 17.

At2030the base station105may determine a scheduling offset between a control information transmission indicating the allocated resources and a start of the first data TTI. The operations of2030may be performed according to the methods described herein. In certain examples, aspects of the operations of2030may be performed by a DCI component as described with reference toFIGS. 14 through 17.

At2035the base station105may transmit control information to the UE, the control information including the scheduling offset, an assignment for the first data TTI, and a BPL indication, and wherein the scheduling offset, a time of the control information transmission, the threshold value, and the BPL indication indicates to the UE whether the BPL for data will change and a BPL change time. The operations of2035may be performed according to the methods described herein. In certain examples, aspects of the operations of2035may be performed by a DCI component as described with reference toFIGS. 14 through 17. In some cases, the base station may determine not to convey a change of the BPL for data when the scheduling offset is less than the threshold value. In other cases, when the scheduling offset is less than the threshold value, the BPL indicated in the control information indicates the BPL used for the first data TTI. In some cases, a change of the BPL for data is indicated by the scheduling offset being less than the threshold value, and the BPL change time corresponds to the time of the control information transmission plus the threshold value. In some cases, a change of the BPL for data is indicated irrespective of the scheduling offset, and the BPL change time corresponds to the time of the control information transmission plus the threshold value.

Utilizing techniques such as method2000, the base station105, the UE115, or both, may periodically measure one or more channel conditions and may determine whether the first BPL, or a different second BPL, may be more suitable for subsequent transmissions. Upon determining that the second BPL should be used for subsequent transmissions at the base station105(e.g., through channel measurements or receiving signaling from the UE115with channel measurements), the second BPL may be indicated to the UE115in a control information transmission (e.g., a DCI transmission using a PDCCH). Depending upon the scheduling offset and the threshold value for receiving control information and changing BPLs at the UE115, the UE115may receive the control information and determine whether the BPL is to be changed. Such techniques may improve network efficiency through transmissions using favorable BPLs, which may support higher data rates, lower error rates, or combinations thereof.