Event-triggered reference signal transmission

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a base station (BS) may configure a first resource and a second resource before sending a physical downlink shared channel communication. The BS may use the first resource to send a physical downlink shared channel communication. After sending the physical downlink shared channel communication, the BS may selectively use the second resource for the reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected. Many other aspects are provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 885,138, filed on August 9, 2019, entitled “EVENT TRIGGERED REFERENCESIGNAL TRANSMISSION,” and U.S. Non-Provisional Patent Application No. 16 / 947,070, filed on July 16, 2020, entitled “EVENT TRIGGERED REFERENCE SIGNAL TRANSMISSION,” which are expressly incorporated herein by reference. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications, and to techniques and apparatus for event-triggered reference signal transmission. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] A wireless communication network may include multiple base stations (BS) that can support communication of multiple user equipments (UEs). User equipments (UEs) may communicate with base stations (BSs) via downlinks and uplinks. Downlinks (or forward links) refer to communication links from BSs to UEs, and uplinks (or reverse links) refer to communication links from UEs to BSs. As will be described in more detail herein, BSs may be referred to as Node Bs, gNBs, Access Points (APs), Radio Heads, Transmit Receive Points (TRPs), New Radio (NR) BSs, 5G Node Bs, etc.

[0006] The above-mentioned multiple access technologies have been adopted by various telecommunication standards to provide a common protocol that enables different user devices to communicate at municipal, national, regional and even global levels. New Radio (NR), which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDMA) with cyclic prefix (CP) (CP-OFDMA) on the downlink (DL), using CP-OFDMA and / or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation. However, with the continuous increase in demand for mobile broadband access, there is a need to further improve LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0007] In some aspects, a wireless communication method performed by a base station (BS) may include: before sending a physical downlink shared channel communication, configuring a first resource and a second resource, wherein the first resource is used for the physical downlink shared channel communication in a current subband and the second resource is used for reference signal transmission; using the first resource to send the physical downlink shared channel communication; and after sending the physical downlink shared channel communication, selectively using the second resource used for the reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected.

[0008] In some aspects, a BS for wireless communication includes: a memory and one or more processors coupled to the memory. The memory and the one or more processors are configured to: before sending a physical downlink shared channel communication, configure a first resource and a second resource, wherein the first resource is used for the physical downlink shared channel communication in a current subband and the second resource is used for reference signal transmission; send the physical downlink shared channel communication using the first resource; and after sending the physical downlink shared channel communication, selectively use the second resource for the reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected.

[0009] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a BS, the one or more instructions may cause the one or more processors to: configure a first resource and a second resource before sending a physical downlink shared channel communication, wherein the first resource is used for the physical downlink shared channel communication in a current subband and the second resource is used for reference signal transmission; send the physical downlink shared channel communication using the first resource; and after sending the physical downlink shared channel communication, selectively use the second resource for the reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected.

[0010] In some aspects, an apparatus for wireless communication may include: a component for configuring first resources and second resources before sending a physical downlink shared channel communication, wherein the first resources are used for the physical downlink shared channel communication in a current subband and the second resources are used for reference signal transmission; a component for sending the physical downlink shared channel communication using the first resources; and a component for selectively using the second resources for the reference signal transmission for subband selection and beam selection after sending the physical downlink shared channel communication, at least in part based on whether a retransmission event is detected.

[0011] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems as generally described with reference to and illustrated by the figures and descriptions herein.

[0012] The above has been a rather broad overview of the features and technical advantages of examples according to the present disclosure so that the following detailed description may be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples may be readily used as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The features of the concepts disclosed herein, their organization and methods of operation, both together with the associated advantages, will be better understood from the following description when considered in conjunction with the accompanying drawings. Each figure is provided for the purpose of illustration and description and not as a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description briefly summarized above can be obtained by reference to various aspects, some of which are shown in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of the present disclosure and should not be considered as limiting the scope thereof, as the description may allow for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0014] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0015] Figure 2 is a block diagram conceptually illustrating an example of a base station communicating with a UE in a wireless communication network according to various aspects of the present disclosure.

[0016] Figure 3A-3D is a diagram illustrating an example of event-triggered reference signal transmission according to various aspects of the present disclosure.

[0017] Figure 4 is a diagram illustrating example processes performed, for example, by a base station according to various aspects of the present disclosure.

[0018] Figure 5 is a conceptual data flow diagram illustrating an example of the flow of data between different modules / components / components in an example apparatus.

[0019] Figure 6 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system. DETAILED DESCRIPTION

[0020] Various aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms and should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. Instead, these aspects are provided so that the present disclosure will be comprehensive and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings herein, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method: the device or method uses other structures, functions, or structures and functions other than or different from the various aspects of the present disclosure set forth herein to practice. It should be understood that any aspect of the present disclosure disclosed herein can be embodied by one or more elements of the claims.

[0021] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0022] Figure 1 is a diagram showing a wireless network 100 in which various aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a plurality of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0023] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown, BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "Node B", "5G NB", and "cell" may be used interchangeably herein.

[0024] In some aspects, the cell may not necessarily be fixed, and the geographic area of ​​the cell may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces (such as direct physical connections, virtual networks, etc.) using any suitable transport network.

[0025] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and send data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown, a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like.

[0026] The wireless network 100 may be a heterogeneous network including different types of BSs, such as a macro BS, a pico BS, a femto BS, a relay BS, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a higher transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0027] A network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other directly or indirectly, for example, via a wireless or wired backhaul.

[0028] UE 120 (e.g., 120a, 120b, 120c, 120d, 120e) can be dispersed throughout the wireless network 100, and each UE can be fixed or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biosensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle-mounted component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0029] Some UEs may be considered machine type communication (MTC), or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a base station, another device (e.g., a remote device), or some other entity. For example, a wireless node may provide a connection to a network (e.g., a wide area network such as the Internet or a cellular network) or to the network via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered customer premises equipment (CPE). UE 120 may be included in a housing that houses components of UE 120, such as a processor component, a memory component, etc.

[0030] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific RAT and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0031] In certain aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using base station 110 as an intermediary to communicate with each other) using one or more sidelink channels. For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), mesh networks, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations performed by base station 110 as described elsewhere herein.

[0032] As noted above, providing Figure 1 As an example. Other examples can be related to Figure 1 Different than described.

[0033] Figure 2 A block diagram of a design 200 of a base station 110 and a UE 120 is shown, which may be Figure 1 Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≥1 and R≥1.

[0034] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the (one or more) MCS selected for the UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). If applicable, the transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, and can provide T output symbol streams to T modulators (MOD) 232a to 232t. Each modulator 232 can process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t, respectively. According to various aspects described in more detail below, position coding can be used to generate synchronization signals to convey additional information.

[0035] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 and / or other base stations, and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0036] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by MIMO detectors 236 (if applicable), and further processed by receive processors 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0037] Controller / processor 240 of base station 110, controller / processor 280 of UE 120, and / or Figure 2Any other components of the base station 110 may perform one or more techniques associated with event-triggered reference signal transmission, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component(s) of may perform or direct e.g. Figure 4 400 and / or other processes described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, when executed by one or more processors of base station 110 and / or UE 120, the one or more instructions may perform or direct, for example, Figure 4 The operations of process 400 and / or other processes described herein. Scheduler 246 may schedule UEs to transmit data on the downlink and / or uplink.

[0038] In some aspects, the base station 110 may include: a component for configuring the first resource and the second resource before sending a physical downlink shared channel communication; a component for sending the physical downlink shared channel communication using the first resource; a component for selectively using the second resource for reference signal transmission for subband selection and beam selection after sending the physical downlink shared channel communication, based at least in part on whether a retransmission event is detected, etc. In some aspects, such a component may include a combination of Figure 2 One or more components of base station 110 are depicted, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and the like.

[0039] As noted above, providing Figure 2 As an example. Other examples can be related to Figure 2 Different than described.

[0040] In some communication systems, the BS may be deployed with multiple panels including multiple antennas. The BS may use multiple panels and multiple antennas for multi-panel frequency division multiplexing (FDM) transmission operations. In some cases, the BS may also perform multi-user, multiple-input, multiple-output (MU-MIMO) operations based on analog beamforming when performing multi-panel FDM transmission. In this way, the BS may communicate with multiple UEs simultaneously across multiple subbands.

[0041] When performing analog beamforming-based MU-MIMO with multi-panel FDM transmissions, the BS may use a semi-persistent scheduling mode for the UE. However, an initial transmission based on semi-persistent scheduling may fail when the quality of the current subband on which the BS is scheduling transmissions degrades, which may trigger a retransmission in a new subband. The conflict candidates for the initial transmission may be different from the conflict candidates for the retransmission. As a result, the static configuration may not provide the flexibility to schedule retransmissions using beams and / or subbands that avoid conflicts and increase the likelihood of success of the retransmission relative to the initial transmission.

[0042] Some aspects described herein enable event-triggered reference signal transmission for subband and beam selection. For example, the BS may detect a failure of an initial transmission and may use preconfigured resources in different subbands for reference signal transmission to identify resources for retransmission. In this manner, the BS ensures that retransmissions may be dynamically configured based at least in part on the results of the reference signal transmission. Moreover, if the failure of the initial transmission does not occur, the BS may make the preconfigured resources available for other transmissions, thereby reducing utilization of network resources. In this manner, when performing analog beamforming-based MU-MIMO with multi-panel FDM transmissions, the BS may reduce the likelihood of failed retransmissions, thereby improving network performance and reducing network resource utilization associated with subsequent retransmissions.

[0043] Figure 3A-3D 300-303 are diagrams illustrating examples of event-triggered reference signal transmission according to various aspects of the present disclosure. Figure 3A-3D As shown, examples 300 - 303 may include a BS 110 and one or more UEs 120 .

[0044] like Figure 3A As shown and in example 300, in a first transmission period (e.g., having a particular length, such as 1 millisecond (ms)), BS 110 may configure resources 320 for a physical downlink shared channel (PDSCH) on a first subband and resources 322 for reference signal transmissions on a first subband and / or a second subband. As indicated by reference numeral 324, BS 110 may transmit a PDSCH transmission and may receive a negative acknowledgement (NACK) feedback message from UE 120. In this case, based at least in part on the received NACK feedback message, BS 110 may determine that a retransmission event has occurred.

[0045] like Figure 3AAs further shown in FIG. 1 and by reference numeral 326, based at least in part on determining that a retransmission event has occurred, the BS 110 may use resources 322 for reference signal transmission. For example, the BS 110 may receive a sounding reference signal (SRS) on a particular subband. In this case, the BS 110 may use the SRS to select a subband (e.g., a first subband or a second subband) and / or a beam for retransmitting the PDSCH. In this manner, by using a NACK feedback message to trigger reference signal transmission, the BS 110 reduces overhead relative to enabling reference signal transmission using downlink control information (DCI) and a scheduling offset.

[0046] In some aspects, BS 110 may activate resources 322 based at least in part on determining that a retransmission event has occurred. For example, BS 110 may indicate to UE 120 that UE 120 will transmit a reference signal and that resources 322 are reserved and not used for other transmissions. In some aspects, BS 110 may receive a reference signal on a first subband to enable BS 110 to identify a better beam (e.g., compared to a beam used for an initial PDSCH transmission) for PDSCH retransmission on the first subband. In this case, the better beam may be determined based at least in part on, for example, reference signal received power (RSRP), reference signal received quality (RSRQ), signal to interference and noise ratio (SINR), etc. relative to a current beam used for an initial PDSCH transmission. In some aspects, BS 110 may receive a reference signal on the second subband to enable BS 110 to identify a better beam and / or a better subband for PDSCH retransmission (e.g., relative to the first subband and in terms of RSRP, RSRQ, SINR, etc. of the beam of the second subband). In some aspects, BS 110 may receive a reference signal on both the first subband and the second subband. In some aspects, BS 110 may receive a reference signal on one or more other subbands.

[0047] like Figure 3A As further shown in FIG. 1 and by reference numeral 328, based at least in part on receiving reference signals on the first subband and the second subband, the BS 110 may select a beam of the second subband for retransmission. Based at least in part on selecting the beam of the second subband, the BS 110 may send a physical downlink control channel (PDCCH) and an associated PDSCH retransmission on the second subband.

[0048] like Figure 3AAs further shown in , in the second transmission period, BS 110 can preconfigure resources for another PDSCH transmission and another reference signal transmission. As shown in the figure numerals 330, 332 and 334, BS 110 can successfully transmit the PDSCH, receive an acknowledgment (ACK) feedback message, and can determine not to use the preconfigured resources for reference signal transmission. In this case, BS 110 can, for example, send an indication that reference signal transmission will not occur. In this way, relative to receiving the reference signal in the second transmission period according to the static configuration, BS 110 can reduce the utilization of network resources, reduce interference, etc.

[0049] like Figure 3B As shown, in example 301, and in the first transmission cycle, BS 110 may preconfigure resources 340 and 342, which are statically reserved for PDSCH transmission and reference signal transmission. For example, unlike preconfiguring reference signal resources that are dynamically activated by NACK feedback messages in example 300, BS 110 may preconfigure resources 342 that are statically activated but triggered by receiving a NACK feedback message. In this way, the offset between the resource in which the NACK feedback message is to be received and the occurrence of the reference signal resource can be reduced relative to the dynamically activated reference signal resource.

[0050] like Figure 3B As further shown, and by reference numerals 344 and 346, BS 110 may transmit a PDSCH in resource 340, and may receive a NACK feedback message from UE 120 indicating a transmission failure. Additionally or alternatively, BS 110 may determine a transmission failure based at least in part on another indicator. For example, BS 110 may use resource 342 to receive a discontinuous transmission (DTX) of an SRS, which may indicate an ACK feedback message, and may determine that a successful transmission has occurred. Conversely, when BS 110 receives a continuous transmission of an SRS using resource 342, BS 110 may determine that a transmission failure has occurred. In this way, BS 110 uses statically configured reference signal resources to reduce network utilization relative to using explicit ACK feedback messages or NACK feedback messages.

[0051] like Figure 3B As further shown in and by reference numeral 348, BS 110 may select a beam and / or subband for retransmitting a PDSCH using the SRS received in the first subband and the second subband, and may retransmit the PDSCH. For example, BS 110 may send a PDCCH and an associated PDSCH retransmission in the second subband.

[0052] like Figure 3BAs further shown in FIG. 1 , in the second transmission period, BS 110 may configure a first resource for transmitting PDSCH and a second resource for reference signal transmission. In this case, as shown by reference numerals 350 and 352, BS 110 may transmit PDSCH and receive an ACK feedback message indicating successful transmission of PDSCH from UE 120. As a result, as shown by reference numeral 354, BS 110 may abandon the use of resource 352 to receive reference signals, thereby reducing interference associated with receiving reference signals when PDSCH transmission has been completed.

[0053] like Figure 3C As shown, in example 302, and in the first transmission cycle, BS 110 may preconfigure resources 360 and 362 reserved for PDSCH transmission and reference signal transmission. In this case, BS 110 may preconfigure resources 362 that are statically activated but triggered by the occurrence of another type of event rather than by receiving a NACK feedback message. For example, when the component carrier channel quality metric is below a measurement threshold, BS 110 may preconfigure resources 362 for SRS transmission. In this case, as shown by reference numerals 364 and 366, BS 110 may transmit PDSCH in resource 360, and may receive an ACK feedback message from UE 120 indicating successful transmission. However, based at least in part on the ACK feedback message, BS 110 and / or UE 120 may determine that a retransmission event is detected based at least in part on RSRP, RSRQ, SINR, log likelihood ratio (LLR), etc. of the PDSCH and / or the ACK feedback message being below a threshold.

[0054] like Figure 3C As further shown in FIG. 1 and by reference numeral 346, BS 110 may receive a reference signal (e.g., SRS) in the first subband and the second subband using resource 362 to select a beam and / or subband for retransmission of the PDSCH. As shown by reference numeral 368, BS 110 may transmit the PDCCH and associated PDSCH retransmissions in the second subband based at least in part on the reference signal.

[0055] like Figure 3C As further shown in FIG. 1 , in the second transmission period, BS 110 may configure a first resource for transmitting the PDSCH and a second resource for reference signal transmission. As shown in reference numerals 370 and 372, BS 110 may transmit the PDSCH and receive an ACK feedback message indicating successful transmission of the PDSCH from UE 120. In this case, based at least in part on receiving the ACK feedback message, BS 110 may determine that no retransmission event has occurred (e.g., the measurement is greater than or equal to the measurement threshold), and may abandon reference signal transmission and PDSCH retransmission.

[0056] like Figure 3D As shown, and in example 303, BS 110 may configure resources 380 for PDSCH on the first subband and resources 382 for reference signal transmission on the first subband and / or the second subband. In this case, BS 110 may configure resources 382 for channel state information (CSI-RS) transmission on the downlink instead of SRS transmission on the uplink. As shown by reference numeral 384, BS 110 may transmit a PDSCH transmission and may receive a NACK feedback message from UE 120. In this case, based at least in part on receiving the NACK feedback message, BS 110 may determine that a retransmission event has occurred.

[0057] like Figure 3D As further shown in FIG. 1 and by reference numeral 386, based at least in part on determining that a retransmission event has occurred, the BS 110 may transmit the CSI-RS using resource 322 on a first subband, on a second subband, on a first subband and a second subband, etc. As shown by reference numeral 388, based at least in part on transmitting the CSI-RS, the BS 110 may receive a quality report (e.g., transmitted via a physical uplink control channel (PUCCH)) from the UE 120. In some aspects, the BS 110 may preconfigure another resource for the PUCCH transmission to convey the quality report. In this case, when the BS 110 does not detect a retransmission event, the BS 110 may deactivate the resource 382 for CSI-RS transmission and / or the resource for PUCCH transmission of the quality report to reduce resource utilization and / or interference levels. As shown by reference numerals 390 and 392, based at least in part on the quality report, the BS 110 may select a subband and a beam, and may use the selected subband and beam to transmit the PDCCH and associated PDSCH retransmissions.

[0058] As noted above, providing Figure 3A-3D As an example. Other examples may differ from the Figure 3A-3D As described.

[0059] Figure 4 is a diagram illustrating an example process 400, performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process 400 is an example of operations in which a BS (eg, BS 110, etc.) performs events associated with reference signal transmission.

[0060] like Figure 4As shown, in some aspects, process 400 may include configuring first resources and second resources before transmitting physical downlink shared channel communications, wherein the first resources are used for physical downlink shared channel communications in the current subband and the second resources are used for reference signal transmission (block 410). For example, the BS (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may configure the first resources and the second resources before transmitting physical downlink shared channel communications, as described above in conjunction with Figure 3A-3D In some aspects, the first resources are used for physical downlink shared channel communication in the current subband and the second resources are used for reference signal transmission.

[0061] In the first aspect, the second resource is in the current subband.

[0062] In a second aspect, alone or in combination with the first aspect, the second resource is in a subband different from the current subband.

[0063] In a third aspect, alone or in combination with one or more of the first and second aspects, the second resource is used for a first reference signal transmission in a current subband and a second reference signal transmission in a subband different from the current subband.

[0064] In a fourth aspect, alone or in combination with one or more of the first to third aspects, a first time position for a first reference signal transmission in a current subband is offset from a second time position for a second reference signal transmission in the different subband.

[0065] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, a second resource is reserved at a time position offset from a time when a retransmission event is to occur.

[0066] like Figure 4 As further shown in FIG. 4 , in some aspects, process 400 may include sending a physical downlink shared channel communication using a first resource (block 420). For example, a BS (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may send a physical downlink shared channel communication using a first resource, as described above in conjunction with Figure 3A-3D as described.

[0067] like Figure 4As further shown in FIG. 4 , in some aspects, process 400 may include, after transmitting the physical downlink shared channel communication, selectively using the second resource for reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected (block 430). For example, the BS (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may, after transmitting the physical downlink shared channel communication, selectively using the second resource for reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected, as described above in conjunction with Figure 3A-3D as described.

[0068] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the retransmission event is reception of a negative acknowledgement message on an uplink of the sub-band.

[0069] In a seventh aspect, alone or in combination with the first to sixth aspects, the second resource is activated based at least in part on detecting a retransmission event.

[0070] In an eighth aspect, alone or in combination with one or more of the first and seventh aspects, the second resource is cancelled based at least in part on not detecting a retransmission event.

[0071] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the retransmission event relates to at least one of: a feedback message, discontinuous transmission, a type of received reference signal, or content of a physical uplink control channel.

[0072] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the retransmission event is a component carrier channel quality measurement satisfying a measurement threshold.

[0073] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the component carrier channel quality measurement is at least one of: a signal to interference and noise ratio measurement, a reference signal received power measurement, or a log-likelihood ratio measurement.

[0074] In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the reference signal transmission is a sounding reference signal transmission received from a user equipment, or a channel state information reference signal transmission sent to a user equipment.

[0075] In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, a third resource for uplink quality reporting is configured before sending a physical downlink shared channel communication and is activated at least in part based on whether a retransmission event is detected.

[0076] In a fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, the third resource is cancelled based at least in part on non-detection of a retransmission event.

[0077] Process 400 may include additional aspects, such as any single aspect or any combination of aspects described above and / or in connection with one or more other processes described elsewhere herein.

[0078] although Figure 4 An example block diagram of process 400 is shown. In some aspects, process 400 may include Figure 4 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those described in . Additionally or alternatively, two or more blocks of process 400 may be performed in parallel.

[0079] Figure 5 5 is a conceptual data flow diagram of an example 500 illustrating the flow of data between different modules / components / components in an example apparatus 502. The apparatus 502 may include, for example, a BS (e.g., BS 110). In some aspects, the apparatus 502 includes a receiving module 504, a configuring module 506, a utilizing module 508, and a transmitting module 510.

[0080] In some aspects, the receiving module 504 may receive a transmission sent to the apparatus 502. For example, the receiving module 504 may receive a PUCCH conveying a NACK feedback message, an ACK feedback message, etc., as described above in conjunction with Figure 3A-3D Additionally or alternatively, the receiving module 504 may receive a reference signal, such as the one described above with respect to Figure 3A-3D The sounding reference signal described.

[0081] In some aspects, the configuration module 506 may configure resources. For example, the configuration module 506 may configure resources for receiving a reference signal, resources for sending a reference signal, resources for receiving a quality report in response to a reference signal, etc., as described above with respect to Figure 3A-3D As described.

[0082] In some aspects, the utilization module 508 can cause the transmission module 510 and / or the reception module 504 to use the reserved resources. For example, based at least in part on detecting a retransmission event, the utilization module 508 can cause the reception module 504 to receive a reference signal from the UE, or cause the transmission module 510 to send a reference signal to the UE, as described above with respect to Figure 3A and Figure 3B As described.

[0083] In some aspects, the apparatus 502 may include performing the aforementioned Figure 4Each block of the algorithm in the flowchart is an additional module. Figure 4 Each block in the flowchart of can be performed by a module, and the device 502 may include one or more of those modules. A module can be one or more hardware components that are specifically configured to implement the described process / algorithm, implemented by a processor configured to execute the described process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0084] supply Figure 5 The number and arrangement of modules shown in the figure are examples. In practice, Figure 5 There may be additional modules, fewer modules, different modules, or differently arranged modules than those shown. Figure 5 Two or more of the modules shown in may be implemented in a single module, or Figure 5 The single module shown in can be implemented as multiple distributed modules. Additionally or alternatively, Figure 5 A set of modules (eg, one or more modules) shown in FIG. 1 may perform operations described as follows: Figure 5 Another set of modules shown in the figure performs one or more functions.

[0085] Figure 6 is a diagram showing an apparatus for using a processing system 602 (e.g., the above combined Figure 5 6 is a diagram of an example hardware implementation 600 of the described apparatus 502). The apparatus 502' may include, for example, a UE (eg, UE 120).

[0086] The processing system 602 may be implemented with a bus architecture, generally represented by bus 604. Bus 604 may include any number of interconnecting buses and bridges, depending on the specific application and overall design constraints of the processing system 602. Bus 604 links together various circuits including one or more processors and / or hardware modules represented by processor 606, modules 504, 506, 508, and / or 510, and computer readable media / memory 608. Bus 604 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further.

[0087] The processing system 602 may be coupled to a transceiver 610. The transceiver 610 is coupled to one or more antennas 612. The transceiver 610 provides components for communicating with various other devices over a transmission medium. The transceiver 610 receives signals from the one or more antennas 612, extracts information from the received signals, and provides the extracted information to the processing system 602. In addition, the transceiver 610 receives information from the processing system 602 and generates signals to be applied to the one or more antennas 612 based at least in part on the received information.

[0088] The processing system 602 includes a processor 606 coupled to a computer-readable medium / memory 608. The processor 606 is responsible for general processing, including executing software stored on the computer-readable medium / memory 608. The software, when executed by the processor 606, causes the processing system 602 to perform the various functions described above for any particular device. The computer-readable medium / memory 608 may also be used to store data that is manipulated by the processor 606 when executing the software. The processing system also includes at least one of the modules 504, 506, 508, and / or 510. A module may be a software module that runs in the processor 606, resides / stored in the computer-readable medium / memory 608, one or more hardware modules coupled to the processor 606, or some combination thereof.

[0089] In some aspects, the apparatus 502 for wireless communication includes: a component for configuring the first resource and the second resource before sending a physical downlink shared channel communication; a component for sending the physical downlink shared channel communication using the first resource; a component for selectively using the second resource for reference signal transmission for subband selection and beam selection based at least in part on whether a retransmission event is detected after sending the physical downlink shared channel communication, etc. The aforementioned components may be one or more of the aforementioned modules of the apparatus 502 and / or the processing system 602 of the apparatus 502 configured to perform the functions recited by the aforementioned components.

[0090] As noted above, providing Figure 6 As an example. Other examples can be related to Figure 6 Different than described.

[0091] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of these aspects.

[0092] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0093] As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0094] It will be apparent that the systems and / or methods described herein may be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit these aspects. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code - it is understood that software and hardware can be designed to implement the systems and / or methods based at least in part on the description herein.

[0095] Although specific combinations of features are recorded in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically recorded in the claims and / or not specifically disclosed in the specification. Although each dependent claim listed below can be directly subordinate to only one claim, the disclosure of various aspects includes that each dependent claim is combined with each other claim in the claim set. The phrase "at least one" mentioned in the list of items refers to any combination of these items, including single members. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b and c).

[0096] Elements, actions or instructions used herein should not be interpreted as critical or essential unless explicitly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more items and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and can be used interchangeably with "one or more". In the case of only one item being meant, the phrase "only one" or similar language is used. In addition, as used herein, the terms "has", "have", "having" etc. are intended to be open terms. In addition, unless otherwise expressly stated, the phrase "based on" is intended to mean "based at least in part on".

Claims

1. A wireless communication method performed by a base station, comprising: Before sending a physical downlink shared channel communication, configuring a first resource of a current subband, a second resource of the current subband, and a third resource of a second subband, wherein the first resource is used to send the physical downlink shared channel communication in a current subband, and wherein the second resource is used to receive a first reference signal transmission in a current subband, and wherein the third resource is used to receive a second reference signal transmission in a second subband; sending the physical downlink shared channel communication using the first resource; and After transmitting the physical downlink shared channel communication, based at least in part on whether a retransmission event is detected, selectively using the second resource of the current subband and the third resource of the second subband for: receiving a first reference signal transmission on a current subband and a second reference signal transmission on a second subband, and selecting a beam associated with the current subband or a second subband, If the retransmission event is not detected, the second resource and the third resource are used for other transmissions.

2. The method according to claim 1, wherein: The retransmission event is receiving a negative acknowledgement message on the uplink of the current sub-band.

3. The method according to claim 1, wherein: At least one of the second resource and the third resource is activated based at least in part on detecting the retransmission event.

4. The method according to claim 1, wherein: A first time position in the current subband for sending the first reference signal is offset from a second time position in the second subband for sending the second reference signal.

5. The method according to claim 1, wherein: At least one of the second resource and the third resource is reserved at a time position that is offset from a time when the retransmission event is to occur.

6. The method according to claim 1, wherein: The retransmission event involves at least one of the following: Feedback message, Discontinuous sending, The type of reference signal received, or Contents of the physical uplink control channel.

7. The method according to claim 1, wherein: The retransmission event is a component carrier channel quality measurement that meets a measurement threshold.

8. The method according to claim 7, wherein: The component carrier channel quality measurement is at least one of the following: Signal to Interference and Noise Ratio measurement, Reference signal received power measurement, or Log-likelihood ratio measure.

9. The method according to claim 1, wherein: Each of the first reference signal transmission and the second reference signal transmission is a sounding reference signal transmission received from a user equipment.

10. A base station for wireless communication, comprising: Memory; as well as one or more processors coupled to the memory, the one or more processors configured to: Before sending a physical downlink shared channel communication, configuring a first resource of a current subband, a second resource of the current subband, and a third resource of a second subband, wherein the first resource is used to send the physical downlink shared channel communication in a current subband, and wherein the second resource is used to receive a first reference signal transmission in a current subband, and wherein the third resource is used to receive a second reference signal transmission in a second subband; sending the physical downlink shared channel communication using the first resource; and After transmitting the physical downlink shared channel communication, based at least in part on whether a retransmission event is detected, selectively using the second resource of the current subband and the third resource of the second subband for: receiving a first reference signal transmission on a current subband and a second reference signal transmission on a second subband, and selecting a beam associated with the current subband or a second subband, If the retransmission event is not detected, the second resource and the third resource are used for other transmissions.

11. The base station according to claim 10, wherein: The retransmission event is receiving a negative acknowledgement message on the uplink of the current sub-band.

12. The base station according to claim 10, wherein: At least one of the second resource and the third resource is activated based at least in part on detecting the retransmission event.

13. The base station according to claim 10, wherein: A first time position in the current subband for sending the first reference signal is offset from a second time position in the second subband for sending the second reference signal.

14. The base station according to claim 10, wherein: At least one of the second resource and the third resource is reserved at a time position that is offset from a time when the retransmission event is to occur.

15. The base station according to claim 10, wherein: The retransmission event involves at least one of the following: Feedback message, Discontinuous sending, The type of reference signal received, or Contents of the physical uplink control channel.

16. The base station according to claim 10, wherein: The retransmission event is a component carrier channel quality measurement that meets a measurement threshold.

17. The base station according to claim 16, wherein: The component carrier channel quality measurement is at least one of the following: Signal to Interference and Noise Ratio measurement, Reference signal received power measurement, or Log-likelihood ratio measure.

18. The base station according to claim 10, wherein: Each of the first reference signal transmission and the second reference signal transmission is a sounding reference signal transmission received from a user equipment.

19. A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising: One or more instructions which, when executed by one or more processors of a base station, cause the base station to: Before sending a physical downlink shared channel communication, configuring a first resource of a current subband, a second resource of the current subband, and a third resource of a second subband, wherein the first resource is used to send the physical downlink shared channel communication in a current subband, and wherein the second resource is used to receive a first reference signal transmission in a current subband, and wherein the third resource is used to receive a second reference signal transmission in a second subband; sending the physical downlink shared channel communication using the first resource; and After transmitting the physical downlink shared channel communication, based at least in part on whether a retransmission event is detected, selectively using the second resource of the current subband and the third resource of the second subband for: receiving a first reference signal transmission on a current subband and a second reference signal transmission on a second subband, and selecting a beam associated with the current subband or a second subband, If the retransmission event is not detected, the second resource and the third resource are used for other transmissions.

20. The non-transitory computer readable medium of claim 19, wherein: At least one of the second resource and the third resource is activated based at least in part on detecting the retransmission event.

21. An apparatus for wireless communication, comprising: means for configuring a first resource of a current subband, a second resource of the current subband and a third resource of a second subband before sending a physical downlink shared channel communication, wherein the first resource is used to send the physical downlink shared channel communication in a current subband, and wherein the second resource is used to receive a first reference signal transmission in a current subband, and wherein the third resource is used to receive a second reference signal transmission in a second subband; means for transmitting the physical downlink shared channel communication using the first resource; and means for selectively using the second resource of the current subband and the third resource of the second subband for the following operations based at least in part on whether a retransmission event is detected after transmitting the physical downlink shared channel communication: receiving a first reference signal transmission on a current subband and a second reference signal transmission on a second subband, and selecting a beam associated with the current subband or a second subband, If the retransmission event is not detected, the second resource and the third resource are used for other transmissions.

22. The device according to claim 21, wherein At least one of the second resource and the third resource is activated based at least in part on detecting the retransmission event.

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