Timing Adjustment with a Mixed Parameter Set

Abstract

Certain aspects of the present disclosure relate to communication systems, and more specifically, certain aspects of the present disclosure relate to interpreting timing advance (TA) commands for members (such as different uplink component carriers and / or different bandwidth parts) of a timing advance group (TAG) having different parameter sets (such as different subcarrier spacings (SCS)). A method that may be performed by a user equipment (UE) includes receiving a TA command from a base station (BS). The UE interprets the TA command in different ways for different members of the same TAG associated with different parameter sets. The UE applies a timing adjustment when transmitting an uplink transmission to the BS based at least in part on the interpretation.

Description

[0001] This application is a divisional application of a patent application with an application date of February 26, 2019, an invention title of "Timing Adjustment with Hybrid Parameter Sets", and an application number of 201980015058.4.

[0002] Priority Claim

[0003] This application claims the benefit and priority of U.S. Provisional Patent Application Serial No. 62 / 636,026, filed on February 27, 2018; U.S. Provisional Patent Application Serial No. 62 / 654,182, filed on April 6, 2018; and U.S. Non-Provisional Patent Application Serial No. 16 / 284,045, filed on February 25, 2019. The entire contents of the above U.S. patent applications are incorporated herein by reference as if fully set forth below and for all applicable purposes. Technical Field

[0004] Aspects of the present disclosure relate to wireless communication, and more particularly, aspects of the present disclosure relate to techniques for timing advance (TA) commands for uplink communication with hybrid parameter sets. Background Art

[0005] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, etc. These wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access systems include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, the Advanced LTE (LTE-A) system, the Code Division Multiple Access (CDMA) system, the Time Division Multiple Access (TDMA) system, the Frequency Division Multiple Access (FDMA) system, the Orthogonal Frequency Division Multiple Access (OFDMA) system, the Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and the Time Division Synchronous Code Division Multiple Access (TD-SCDMA) system, among others.

[0006] In some examples, a wireless multi-access communication system can include multiple base stations (BSs), each capable of simultaneously supporting communication for multiple communication devices (also referred to as user equipment (UEs)). In an LTE or LTE-A network, a collection of one or more base stations can define an evolved Node B (eNB). In other examples (e.g., in a next-generation, new radio (NR) or 5G network), a wireless multi-access communication system can include multiple distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), intelligent radio heads (SRHs), transmit receive points (TRPs), etc.) communicating with multiple central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where a collection of one or more DUs communicating with a CU can define an access node (e.g., which can be referred to as a BS, 5G NB, next-generation Node B (gNB or gNodeB), transmit receive point (TRP), etc.). A BS or DU can communicate with a set of UEs on a downlink channel (e.g., for transmission from the BS or DU to the UE) and an uplink channel (e.g., for transmission from the UE to the BS or DU).

[0007] These multi-access techniques have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the city, national, regional, and even global levels. NR (e.g., new radio or 5G) is an example of an emerging telecommunication standard. NR is a collection of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, reducing cost, improving services, leveraging new spectrum, and using OFDMA with cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) to better integrate with other open standards. To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna techniques, and carrier aggregation.

[0008] However, as the demand for mobile broadband access continues to grow, there is a need for further improvement in NR and LTE technologies. Preferably, these improvements should be applicable to other multi-access techniques and telecommunication standards that employ these techniques. SUMMARY

[0009] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the claims below, some features will now be briefly described. After considering this description, and particularly after reading the section entitled "DETAILED DESCRIPTION," those skilled in the art will understand how the features of the present disclosure provide advantages, which include improved communication between access points and stations in a wireless network.

[0010] Certain aspects provide a method for wireless communication by a user equipment (UE). Generally speaking, the method includes: receiving a timing advance (TA) command from a base station (BS). Generally speaking, the method includes: interpreting the TA command in different ways for different members of the same timing advance group (TAG). The members of the TAG are associated with different parameter sets. Generally speaking, the method includes: applying a timing adjustment when transmitting an uplink transmission to the BS, at least in part based on the interpretation.

[0011] Certain aspects provide an apparatus for wireless communication. Generally speaking, the apparatus includes: a unit for receiving a TA command from another apparatus. Generally speaking, the apparatus includes: a unit for interpreting the TA command in different ways for different members of the same TAG. The members of the TAG are associated with different parameter sets. Generally speaking, the apparatus includes: a unit for applying a timing adjustment when transmitting an uplink transmission to the other apparatus, at least in part based on the interpretation.

[0012] Certain aspects provide an apparatus for wireless communication. Generally speaking, the apparatus includes a receiver configured to: receive a TA command from another apparatus. Generally speaking, the apparatus includes at least one processor coupled to a memory and configured to: interpret the TA command in different ways for different members of the same TAG. The members of the TAG are associated with different parameter sets. Generally speaking, the apparatus includes a transmitter configured to: apply a timing adjustment when transmitting an uplink transmission to the other apparatus, at least in part based on the interpretation.

[0013] Certain aspects provide a computer-readable medium having computer-executable code stored thereon for wireless communication. Generally speaking, the computer-readable medium includes: code for receiving a TA command from a BS. Generally speaking, the computer-readable medium includes: code for interpreting the TA command in different ways for different members of the same TAG. The members of the TAG are associated with different parameter sets. Generally speaking, the computer-readable medium includes: code for applying a timing adjustment when transmitting an uplink transmission to the BS, at least in part based on the interpretation.

[0014] To achieve the foregoing and related purposes, one or more aspects include the features that are fully described hereinafter and particularly pointed out in the claims. The following description and the drawings set forth in detail certain illustrative features of one or more aspects. However, these features are only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] By referring to some of the aspects shown in the accompanying drawings, there can be a more specific description as briefly outlined above, so that the manner in which the above features of the present disclosure can be understood in detail. However, it should be noted that the drawings only show certain typical aspects of the present disclosure and are therefore not considered to be a limitation of its scope, as the description can recognize other equally effective aspects.

[0016] Figure 1 is a block diagram conceptually showing an example telecommunications system according to certain aspects of the present disclosure.

[0017] Figure 2 is a block diagram showing an example logical architecture of a distributed radio access network (RAN) according to certain aspects of the present disclosure.

[0018] Figure 3 is a diagram showing an example physical architecture of a distributed RAN according to certain aspects of the present disclosure.

[0019] Figure 4 is a block diagram conceptually showing the design of an example base station (BS) and user equipment (UE) according to certain aspects of the present disclosure.

[0020] Figure 5 is a diagram showing an example for implementing a communication protocol stack according to certain aspects of the present disclosure.

[0021] Figure 6 Shows an example of the frame format of a new radio (NR) system according to certain aspects of the present disclosure.

[0022] Figure 7 Shows an example scenario with a supplementary uplink (SUL) component carrier according to certain aspects of the present disclosure.

[0023] Figure 8 is a table showing an example timing advance (TA) unit for different subcarrier spacings according to certain aspects of the present disclosure.

[0024] Figure 9 is a flowchart showing an example operation for wireless communication by a UE according to certain aspects of the present disclosure.

[0025] Figure 10 Shows a communication device according to aspects of the present disclosure that can include various components configured to perform operations for the techniques disclosed herein.

[0026] For ease of understanding, wherever possible, the same reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation. Detailed Description

[0027] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for timing adjustment with a hybrid set of parameters.

[0028] In certain systems (e.g., 5G NR systems), a base station (BS) issues a timing advance (TA) command to a user equipment (UE). The TA command can be determined to endeavor to ensure that uplink transmissions from the UE arrive at the BS synchronously and orthogonally to each other. In some examples, compared to a UE located far from the BS, a UL transmission from a UE located close to the BS can have a shorter round-trip time (RTT). The TA command can be determined to endeavor to enable the BS to receive and process UL signaling using a single fast Fourier transform (FFT) window.

[0029] As the UE moves away from the BS, the RTT increases. Thus, the TA command from the BS may not ensure synchronization. In the presence of adjustments made by the UE, the time at which UL transmissions from the UE arrive at the BS may start to lag behind other UEs located closer to the BS. To compensate for the RTT difference, the BS sends a TA command to adjust the timing of the UE.

[0030] In certain systems (such as certain Long Term Evolution (LTE) systems), the TA has a fixed granularity that depends on the LTE subcarrier spacing (e.g., 15 kHz). Since LTE supports a single SCS, the fixed granularity can be considered constant. Other wireless communication systems (such as 5G NR systems) support a hybrid set of parameters for UL transmissions. As described herein, a parameter set refers to a collection of parameters that define the structure of time and frequency resources for communication. Such parameters can include, for example, subcarrier spacing, type of cyclic prefix (e.g., such as normal CP or extended CP), and transmission time interval (TTI) (e.g., such as subframe or slot duration). A single TA command can be applied to an entire timing adjustment group (TAG); however, members of the TAG can be associated with different parameter sets. Accordingly, the UE may not be able to apply the same TA granularity to all UL transmissions.

[0031] Aspects of the present disclosure provide techniques and apparatus for determining TA granularity (e.g., for received TA commands) between uplink carriers having mixed (e.g., different) UL parameter sets. As described above, for example, 5G NR can support mixed parameter sets across cells with carrier aggregation and across bandwidth parts (BWPs) or subbands within a cell. Using aspects given herein, a UE can determine the TA to be used for UL transmission based in part on the parameter set associated with one or more of the uplink carriers and / or the parameter set associated with one or more supported uplink bandwidth parts.

[0032] In some examples, in accordance with aspects described herein, a UE receives a TA command, interprets the TA command based on the parameter set associated with the UL transmission, and applies a timing adjustment when transmitting UL signaling to the BS based at least in part on the interpreted TA. The same TA command may have different effects on different members of a TAG. Advantageously, this allows UL signaling in a system with mixed parameter sets to reach the BS in a synchronized (e.g., time-aligned) manner by applying the same TA command.

[0033] The following description provides examples and is not a limitation on the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of the elements discussed without departing from the scope of the present disclosure. Each example may omit, substitute, or add various processes or components as appropriate. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with respect to some examples may be combined in some other examples. For instance, a device may be implemented or a method may be practiced using any number of aspects set forth herein. Moreover, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functions, or a combination of structures and functions in addition to or different from the aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of the claims. The word “exemplary” as used herein means “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0034] The techniques described herein can be used in various wireless communication technologies such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. Cdma2000 covers the IS-2000, IS-95, and IS-856 standards. A TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network may implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS).

[0035] New Radio (NR) is an emerging wireless communication technology under development that incorporates the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Enhanced LTE (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). Cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used in the wireless networks and radio technologies mentioned above and other wireless networks and radio technologies. For clarity, although aspects may be described herein using terms typically associated with 3G and / or 4G wireless technologies, aspects of the present disclosure can be applied to communication systems based on other generations (such as 5G and later technologies, including NR technologies).

[0036] Example Wireless Communication System

[0037] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a New Radio (NR) or 5G network. A UE 120 in the wireless communication network 100 may receive a Timing Advance (TA) command from a BS 110 in the wireless communication network 100. The UE 120 may interpret the TA command based on a set of parameters associated with the uplink transmission (or associated with the UE). For example, as Figure 1As shown, according to certain aspects of the present disclosure, UE 120a has a TA command determination module configured to interpret TA commands. The UE 120 may apply timing adjustment when transmitting uplink signaling to the BS 110. The timing adjustment applied by the UE 120 may be at least partially based on the interpreted TA. The same TA command may have different effects on different members of a timing advance group (TAG) (and may be interpreted in different ways).

[0038] As Figure 1 shown in FIG., the wireless network 100 may include multiple base stations (BSs) 110 and other network entities. A BS may be a station that communicates with a user equipment (UE). Each BS 110 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In an NR system, the terms "cell" and next-generation Node B (gNB or gNodeB), NR BS, 5G NB, access point (AP), transmit receive point (TRP) may be used interchangeably. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some examples, base stations may be interconnected with each other and / or with one or more other base stations or network nodes (not shown) in the wireless communication network 100 through various types of backhaul interfaces, such as direct physical connections, wireless connections, virtual networks, or interfaces using any suitable transport network.

[0039] Generally, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. The RAT may also be referred to as a radio technology, air interface, etc. The frequency may also be referred to as a carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks with different RATs. In some cases, an NR or 5G RAT network may be deployed.

[0040] The BS can provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell can cover a relatively large geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A pico cell can cover a relatively small geographical area and can allow unrestricted access by UEs with service subscriptions. A femto cell can cover a relatively small geographical area (e.g., a residence) and can allow restricted access by UEs associated with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in a residence, etc.). The BS for a macro cell can be referred to as a macro BS. The BS for a pico cell can be referred to as a pico BS. The BS for a femto cell can be referred to as a femto BS or a home BS. In Figure 1 the example shown in, BSs 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c respectively. BS110x can be a pico BS for pico cell 102x. BSs 110y and 110z can be femto BSs for femto cells 102y and 102z respectively. A BS can support one or more (e.g., three) cells.

[0041] The wireless communication network 100 can also include relay stations. A relay station is a station that receives the transmission of data and / or other information from an upstream station (e.g., a BS or a UE) and sends the transmission of data and / or other information to a downstream station (e.g., a UE or a BS). A relay station can also be a UE that relays transmissions for other UEs. In Figure 1 the example shown in, relay station 110r can communicate with BS 110a and UE 120r to facilitate communication between BS 110a and UE 120r. A relay station can also be referred to as a relay BS, a repeater, etc.

[0042] The wireless communication network 100 can be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, repeaters, etc.). These different types of BSs can have different transmit power levels, different coverage areas, and different impacts on interference in the wireless communication network 100. For example, a macro BS can have a high transmit power level (e.g., 20 watts), while pico BSs, femto BSs, and repeaters can have lower transmit power levels (e.g., 1 watt).

[0043] The wireless communication network 100 can support synchronous operation or asynchronous operation. For synchronous operation, the BSs can have similar frame timings, and transmissions from different BSs can be approximately aligned in time. For asynchronous operation, the BSs can have different frame timings, and transmissions from different BSs can be misaligned in time. The techniques described herein can be used for both synchronous operation and asynchronous operation.

[0044] The network controller 130 can be coupled to a set of BSs and provide coordination and control for these BSs. The network controller 130 can communicate with the BS 110 via a backhaul. The BSs 110 can also communicate with each other, for example, via a wireless or wired backhaul (e.g., directly or indirectly).

[0045] UEs 120 (e.g., 120x, 120y, etc.) can be spread throughout the wireless communication network 100, and each UE can be stationary or mobile. UEs can also be referred to as mobile stations, terminals, access terminals, user units, stations, customer premise equipment (CPE), cellular phones, smart phones, personal digital assistants (PDA), wireless modems, wireless communication devices, handheld devices, laptop computers, cordless phones, wireless local loop (WLL) stations, tablet computers, cameras, gaming devices, netbooks, smartbooks, ultrabooks, appliances, medical devices or medical apparatus, biometric sensors / devices, wearable devices (such as smart watches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets, etc.)), entertainment devices (e.g., music devices, video devices, satellite wireless units, etc.), in-vehicle components or sensors, smart meters / sensors, industrial manufacturing devices, global positioning system devices, or any other suitable devices configured to communicate via wireless or wired media. Some UEs can be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node can provide a connection to or from a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs can be considered Internet of Things (IoT) devices, which can be narrowband IoT (NB-IoT) devices.

[0046] Some wireless networks (e.g., LTE) utilize Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single Carrier Frequency Division Multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are often also referred to as tones, frequency bands, etc. Each subcarrier can be modulated with data. Typically, OFDM is utilized in the frequency domain and SC-FDM is utilized in the time domain to transmit the modulated symbols. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz and the minimum resource allocation (referred to as a "resource block" (RB)) can be 12 subcarriers (or 180 kHz). Thus, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal Fast Fourier Transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be divided into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there can be 1, 2, 4, 8, or 16 subbands, respectively.

[0047] Although aspects of the examples described herein can be associated with LTE technology, aspects of the present disclosure can be applicable to other wireless communication systems (such as NR). NR can utilize OFDM with CP on both the uplink and downlink, and can include support for half-duplex operation using TDD. Beamforming can be supported and the beam direction can be configured dynamically. MIMO transmission with precoding can also be supported. The MIMO configuration in the DL can support up to 8 transmit antennas, where multi-layer DL transmission is up to 8 streams and up to 2 streams per UE. Multi-layer transmission with up to 2 streams per UE can be supported. Aggregation of multiple cells with up to 8 serving cells can be supported.

[0048] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all of the devices and apparatuses within its serving area or cell. The scheduling entity can be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for the scheduled communication, the subordinate entities utilize the resources allocated by the scheduling entity. A base station is not the only entity that can act as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs can utilize the resources scheduled by the UE for wireless communication. In some examples, a UE can act as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In the mesh network example, in addition to communicating with the scheduling entity, UEs can also communicate directly with each other.

[0049] In Figure 1 it, the solid line with double arrows indicates the desired transmission between the UE and the serving BS, which is the BS designated to serve the UE on the downlink and / or uplink. The thin dashed line with double arrows indicates the interfering transmission between the UE and the BS.

[0050] Figure 2 shows an example logical architecture of a distributed radio access network (RAN) 200 that can be implemented in the wireless communication network 100 shown in Figure 1 it. The 5G access node 206 can include an access node controller (ANC) 202. The ANC 202 can be the central unit (CU) of the distributed RAN 200. The backhaul interface to the next-generation core network (NG-CN) 204 can terminate at the ANC 202. The backhaul interface to an adjacent next-generation access node (NG-AN) 210 can terminate at the ANC 202. The ANC 202 can include one or more TRPs 208 (e.g., cells, BSs, gNBs, etc.).

[0051] The TRP 208 can be a distributed unit (DU). The TRP 208 can be connected to a single ANC (e.g., ANC 202) or more than one ANC (not shown). For example, for RAN sharing, radio as a service (RaaS), and service-specific AND deployments, the TRP 208 can be connected to more than one ANC. Each TRP 208 can include one or more antenna ports. The TRP 208 can be configured to serve traffic to the UE either individually (e.g., dynamic selection) or jointly (e.g., joint transmission).

[0052] The logical architecture of the distributed RAN 200 can support fronthaul solutions across different deployment types. For example, the logical architecture can be based on the transmitting network capabilities (e.g., bandwidth, latency, and / or jitter).

[0053] The logical architecture of the distributed RAN 200 can share features and / or components with LTE. For example, the next-generation access node (NG-AN) 210 can support dual connectivity with NR and can share a common fronthaul for LTE and NR.

[0054] The logical architecture of the distributed RAN 200 can enable cooperation between and among the TRPs 208, e.g., via the ANC202 within and / or across the TRPs. An inter-TRP interface may not be used.

[0055] The logical functions can be dynamically distributed in the logical architecture of the distributed RAN 200. As will be described in more detail with reference to Figure 5 the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer can be adaptively placed at the DU (e.g., the TRP 208) or the CU (e.g., the ANC202).

[0056] Figure 3 An example physical architecture of the distributed RAN 300 in accordance with aspects of the present disclosure is shown. The centralized core network unit (C-CU) 302 can host core network functions. The C-CU 302 can be centrally deployed. The C-CU 302 functions can be offloaded (e.g., to the advanced wireless service (AWS)) to handle peak capacity as much as possible.

[0057] The centralized RAN unit (C-RU) 304 can host one or more ANC functions. Optionally, the C-RU 304 can locally host core network functions. The C-RU 304 can have a distributed deployment. The C-RU 304 can be close to the network edge.

[0058] The DU 306 can host one or more TRPs (edge node (EN), edge unit (EU), radio head (RH), smart radio head (SRH), etc.). The DU can be located at the edge of the network with radio frequency (RF) capabilities.

[0059] Figure 4 BS 110 and UE 120 are shown (as in Figure 1Example components (depicted in [FIGURE REFERENCE]) that can be used to implement aspects of the present disclosure. For example, the antenna 452, processors 466, 458, 464, and / or controller / processor 480 of the UE 120, and / or the antenna 434, processors 420, 430, 438, and / or controller / processor 440 of the BS 110 can be used to perform the various techniques and methods described herein and referenced with Figure 9 shown. For example, as Figure 4 shown, according to certain aspects of the present disclosure, the controller / processor 480 has a TA command determination module configured to interpret TA commands.

[0060] At the BS 110, the transmit processor 420 can receive data from the data source 412 and control information from the controller / processor 440. The control information can be used for physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data can be used for physical downlink shared channel (PDSCH), etc. The processor 420 can process (e.g., encode and symbol map) the data and control information respectively to obtain data symbols and control symbols. The processor 420 can also generate reference symbols for, e.g., primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). The transmit (TX) multiple-input multiple-output (MIMO) processor 430 can perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols (if applicable), and can provide an output symbol stream to the modulators (MOD) 432a to 432t. Each modulator 432 can process the corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the modulators 432a to 432t can be transmitted via the antennas 434a to 434t respectively.

[0061] At the UE 120, antennas 452a through 452r may receive downlink signals from the base station 110 and may provide the received signals to demodulators (DEMOD) 454a through 454r in the transceiver, respectively. Each demodulator 454 may condition (e.g., filter, amplify, down-convert, and digitize) the respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 456 may obtain the received symbols from all the demodulators 454a through 454r, perform MIMO detection (if applicable) on the received symbols, and provide detected symbols. The receive processor 458 may process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide the decoded data for the UE 120 to the data sink 460, and provide the decoded control information to the controller / processor 480.

[0062] On the uplink, at the UE 120, the transmit processor 464 may receive and process data from the data source 462 (e.g., for the physical uplink shared channel (PUSCH)) and control information from the controller / processor 480 (e.g., for the physical uplink control channel (PUCCH)). The transmit processor 464 may also generate reference symbols for reference signals (e.g., for the sounding reference signal (SRS)). Symbols from the transmit processor 464 may be precoded by the TX MIMO processor 466 (if applicable), further processed by the demodulators 454a through 454r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the base station 110. At the BS 110, the uplink signal from the UE 120 may be received by the antenna 434, processed by the modulator 432, detected by the MIMO detector 436 (if applicable), and further processed by the receive processor 438 to obtain the decoded data and control information transmitted by the UE 120. The receive processor 438 may provide the decoded data to the data sink 439 and the decoded control information to the controller / processor 440.

[0063] The controller / processors 440 and 480 may direct operations at the BS 110 and UE 120, respectively. The processor 440 and / or other processors and modules at the base station 110 may execute or direct the execution of processes for the techniques described herein. The memories 442 and 482 may store data and program code for the BS 110 and UE 120, respectively. The scheduler 444 may schedule the UE for data transmission on the downlink and / or uplink.

[0064] Figure 5Aspects in accordance with the present disclosure illustrate FIG. 500 that depicts an example for implementing a communication protocol stack. The depicted communication protocol stack may be implemented by a device operating in a wireless communication system such as a 5G system (e.g., a system supporting uplink-based mobility). FIG. 500 depicts a communication protocol stack that includes an RRC layer 510, a PDCP layer 515, an RLC layer 520, a MAC layer 525, and a PHY layer 530. In various examples, the layers of the protocol stack may be implemented as separate software modules, parts of a processor or ASIC, parts of non-collocated devices connected by a communication link, or various combinations thereof. Collocated and non-collocated implementations may be used in, for example, the protocol stack for a network access device (e.g., an AN, a CU, and / or a DU) or a UE.

[0065] The first option 505-a depicts a split implementation of the protocol stack, where the implementation of the protocol stack is split between a centralized network access device (e.g., Figure 2 the ANC 202 in Figure 2 and a distributed network access device (e.g.,

[0066] the DU 208 in

[0067] In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by a central unit, and the RLC layer 520, the MAC layer 525, and the PHY layer 530 may be implemented by the DU. In various examples, the CU and the DU may be collocated or non-collocated. In macrocell, microcell, or picocell deployments, the first option 505-a may be useful.

[0068] In LTE, the basic Transmission Time Interval (TTI) or packet duration is a 1 ms subframe. In NR, the subframe is still 1 ms, but the basic TTI is called a slot. A subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16,... slots), which depends on the subcarrier spacing. An NR RB is 12 consecutive frequency subcarriers. NR can support a basic subcarrier spacing of 15 kHz, and other subcarrier spacings can be defined relative to the basic subcarrier spacing, e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. The symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing.

[0069] Figure 6 FIG. is an example showing the frame format 600 for NR. The transmission timeline for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes with indices 0 to 9, each subframe being 1 ms. Each subframe can include a variable number of slots, which depends on the subcarrier spacing. Each slot can include a variable number of symbol periods (e.g., 7 or 14 symbols), which depends on the subcarrier spacing. An index can be assigned to the symbol periods in each slot. A mini-slot (which can be referred to as a sub-slot structure) refers to a transmission time interval having a duration less than that of a slot (e.g., 2, 3, or 4 symbols).

[0070] Each symbol in a slot can indicate the link direction for data transmission (e.g., DL, UL, or flexible), and the link direction for each subframe can be switched dynamically. The link direction can be based on the slot format. Each slot can include DL / UL data and DL / UL control information.

[0071] In NR, a Synchronization Signal (SS) block is transmitted. The SS block includes the PSS, SSS, and a two-symbol PBCH. It can be in a fixed slot position (such as in Figure 6The SS blocks are transmitted using the symbols 0-3 shown. The PSS and SSS can be used by the UE for cell search and acquisition. The PSS can provide half-frame timing, and the SSS can provide the CP length and frame timing. The PSS and SSS can provide the cell identity. The PBCH carries certain basic system information, such as the downlink system bandwidth, timing information within the radio frame, the SS burst set period, the system frame number, etc. The SS blocks can be organized into SS bursts to support beam scanning. Additional system information, such as the remaining minimum system information (RMSI), system information block (SIB), other system information (OSI), can be transmitted on the physical downlink shared channel (PDSCH) in certain subframes. For mmW, the SS blocks can be transmitted up to sixty-four times, e.g., with up to sixty-four different beam directions. The transmission of up to sixty-four SS blocks is referred to as an SS burst set. The SS blocks within an SS burst set are transmitted in the same frequency region, while the SS blocks in different SS burst sets can be transmitted at different frequency positions.

[0072] In some cases, two or more secondary entities (e.g., UEs) can communicate with each other using sidelink signals. Real-world applications of such sidelink communication can include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communication, Internet of Everything (IoE) communication, IoT communication, mission-critical mesh, and / or various other suitable applications. Generally, a sidelink signal can refer to a signal transmitted from one secondary entity (e.g., UE1) to another secondary entity (e.g., UE2) without the need to relay the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity can be used for scheduling and / or control purposes. In some examples, licensed spectrum can be used to transmit sidelink signals (different from wireless local area networks which typically use unlicensed spectrum).

[0073] Example supplementary uplink

[0074] Some wireless communication system deployments utilize multiple downlink (DL) component carriers (CCs) as part of a carrier aggregation (CA) scheme. For example, in addition to the primary DL CC, one or more supplementary DL (SDL) CCs can be used to enhance data throughput and / or reliability.

[0075] As Figure 7 shown, for some systems (e.g., such as 5G NR), one or more supplementary UL (SUL) CCs can also be utilized. SUL generally can refer to a UL CC that does not have a corresponding DL CC in the cell (e.g., no paired DL). In other words, from the perspective of an NR device, SUL generally can refer to the situation when there are only UL resources available for a carrier. As Figure 7As shown, SUL can allow for scenarios where there is one DL CC and multiple UL CCs in a cell. In some cases, there can be a one-to-many relationship between DL and UL. When the cells are co-located, SUL and the primary UL (PUL) can belong to the same Timing Advance Group (TAG).

[0076] In NR, UE-specific RRC signaling can (re)configure the position of PUCCH on the SUL carrier in the SUL band combination or on a non-SUL UL carrier. The default position of PUSCH can be the same carrier used by PUCCH. Additionally, UE-specific RRC signaling can (de)configure PUSCH to be dynamically scheduled on another (i.e., non-PUCCH) carrier in the same cell as the SUL. In this case, the Carrier Indicator Field (CIF) in the UL grant can be used to indicate (e.g., dynamically) whether PUSCH is transmitted on the PUCCH carrier or on another carrier. There can be an active Bandwidth Part (BWP) on the SUL carrier and an active BWP on the non-SUL UL carrier.

[0077] RRC parameters related to SRS can be configured independently for SRS on the SUL carrier in the SUL band combination and SRS on the non-SUL UL carrier. For example, SRS can be configured on the SUL carrier and the non-SUL UL carrier regardless of the carrier configuration for PUSCH and PUCCH.

[0078] Example TA Granularity for UL with Different Parameter Sets

[0079] For uplink transmission, Timing Advance (TA) is typically used to ensure that signals from different UEs arrive at the base station (e.g., gNB) synchronously (e.g., orthogonally) to avoid performance degradation. Generally, the amount of TA (also referred to as the TA command) is signaled from the gNB to the UE. For example, the gNB can signal TA in the Medium Access Control (MAC) Control Element (CE) of the Random Access Response (RAR) during the random access procedure. After receiving the RAR, the UE can send the first uplink transmission based on the TA. For example, the UE applies timing adjustment to the uplink transmission based on the TA.

[0080] In NR, the TA granularity (e.g., the unit of the TA command) is typically based on one or more parameters associated with the parameter set of the uplink carrier. As used herein, the term parameter set generally refers to a set of parameters that define the structure of time and frequency resources for communication. Such parameters can include, for example, the Subcarrier Spacing (SCS), the type of cyclic prefix (e.g., such as normal CP or extended CP), and the Transmission Time Interval (TTI) (e.g., such as subframe or slot duration).

[0081] In Figure 8 a reference example shown in Table 800, the TA granularity (TA unit) is based on the subcarrier spacing of the first uplink transmission after RAR. As shown, for a single parameter set case (e.g., where one or more uplink carriers have the same parameter set), the unit of TA (e.g., TA granularity) scales with the subcarrier spacing (e.g., one aspect of the parameter set).

[0082] In some cases, NR may support a mixed parameter set across cells with carrier aggregation and / or across BWPs within a cell. In some examples, the PUL and SUL that may belong to the same TAG may have different parameter sets. In some examples, one or more UL BWPs of the carriers within a cell may have different parameter sets. In the case where the uplink within a cell has a mixed parameter set, the gNB (using conventional techniques) may not be able to accurately determine the TA granularity to be used for TA commands.

[0083] According to some aspects, the gNB may determine the TA configuration (e.g., TA granularity) for TA commands between uplink carriers associated with a mixed (different) UL parameter set. The BS shares the same TA command across uplink carriers (e.g., PUL and SUL) with different parameter sets.

[0084] In some aspects, the BS may determine the TA configuration to be used for TA commands based on the TA granularity for each uplink carrier in the uplink carriers. Assuming that the PUL and SUL are uplink carriers, the BS may determine the TA granularity of the PUL CC (e.g., based on the parameter set for the PUL CC), and determine the TA granularity of the SUL CC (e.g., based on the parameter set for the PUL CC). The BS may determine the TA granularity of the TA command based on the determined TA granularities of both the PUL CC and the SUL CC. For example, in one aspect, the BS may determine the TA granularity for the TA command based on the maximum or minimum of the TA granularity of the SUL TA and the TA granularity of the PUL TA.

[0085] In some aspects, the BS may determine the TA granularity of the TA command based on the parameter set of the PUCCH carrier. For example, the base station may determine which uplink carrier in the uplink carriers is associated with the PUCCH, and determine the TA granularity of the TA command based on the TA granularity of the determined uplink carrier associated with the PUCCH.

[0086] In some aspects, the BS may determine one uplink carrier associated with a specific carrier index (e.g., index zero, or the minimum or maximum among all uplink carrier indices, or a specific index indicated by RRC configuration) in the uplink carrier, and determine the TA granularity of the TA command based on the TA granularity of the determined uplink carrier. The index of each carrier itself may be configured or reconfigured, for example, via RRC signaling, and this may provide a way to change the TA granularity when needed.

[0087] In some aspects, the BS may determine the TA granularity based on a "reference" carrier explicitly configured by the network. For example, the base station may receive an indication of an uplink carrier for the TA granularity of the TA command in the uplink carrier, and determine the TA granularity of the TA command based on the TA granularity of the indicated uplink carrier.

[0088] As described above, NR may also support different parameter sets for different parts of the bandwidth (or BWP) within one or more carriers across a cell. That is, a cell including UL may be configured with multiple UL BWPs having different parameter sets. The BWP may be defined by a specific frequency range, center frequency, and / or parameter set. Although a CC may include multiple BWP configurations, there is typically a single BWP that is active at any given time. However, the active UL BWP may change dynamically (e.g., based on DCI).

[0089] Therefore, if the TA granularity is based on the parameter set of the currently active UL BWP, the TA granularity will also have to change dynamically at any time the currently active UL BWP changes. However, since the BWP switch command (for switching the active UL BWP) is based on DCI and the TA command is based on MAC CE, the base station may have to align the timing of the BWP switch command and the MAC CE command to ensure that the correct TA granularity is used for the currently active UL BWP.

[0090] According to certain aspects, the BS may implement timing alignment between the TA command (e.g., based on MAC-CE) and the BWP switch command (e.g., based on DCI).

[0091] In an illustrative example, BWP1 and BWP2 (for a single carrier) have different parameter sets. When a MAC-CE command is decoded (e.g., by a UE), the TA granularity depends on the BWP that is active at that moment. However, this may lead to timing ambiguity at that moment. For example, even if a MAC-CE command is sent assuming the TA granularity of BWP1, the command may not be successfully decoded in the first transmission and a HARQ retransmission may be required. However, before the retransmission is completed, the active BWP may switch from BWP1 to BWP2. In this case, the UE may not know how to interpret the TA granularity of the MAC-CE command (e.g., based on BWP1 or BWP2).

[0092] In some examples, the MAC-CE TA command ACK timing can be used to determine the BWP parameter set to be used. To avoid ambiguity, when a MAC-CE with a TA command is pending HARQ retransmission, the gNB can defer the BWP switch. If the HARQ retransmission is completed and there is still a NACK, this indicates that the TA command has still not passed. Therefore, the gNB can determine to restart the MAC-CE TA command transmission in BWP1 and continue to defer the switch to BWP2. Alternatively, after switching from BWP1 to BWP2, the gNB can determine to restart the MAC-CE TA command transmission in BWP2.

[0093] Dynamically changing the TA granularity in this way may be undesirable, partly because it is difficult to align the timing of the BWP switch command (based on DCI) and the TA command (based on MAC CE).

[0094] According to certain aspects, the BS can reliably determine the TA granularity for the TA command in the case where the active BWP changes dynamically.

[0095] In some examples, the BS can determine, for each uplink carrier among one or more uplink carriers, the parameter set associated with one or more configured BWPs of the uplink carrier. There may be multiple configured BWPs for each carrier, but there is one active BWP among the configured BWPs. Using PUL and SUL as reference examples, the PUL may include one or more configured BWPs with different parameter sets, and the SUL may include one or more configured BWPs with different parameter sets. Once determined, the base station can further determine the TA configuration for the TA command based on the parameter sets of each configured BWP.

[0096] In some examples, the BS may determine the TA granularity of the TA command based on the maximum TA granularity of the BWP or the minimum TA granularity of the BWP. This determination may be made in a semi-static manner since typically the UL BWP is configured for the cell by RRC. Thus, even if the BWP is changing dynamically, the BS may use the same determined TA granularity for the TA command.

[0097] In some aspects, the BS may specify (or select) one of the UL BWPs as a "reference" UL BWP. For example, in TDD, the specified UL BWP may be one UL BWP associated with the default DL BWP. In another example, the specified UL BWP may be one UL BWP associated with a specific BWP index (e.g., index zero, or the minimum or maximum among all uplink BWP indexes). The BS may determine the TA granularity of the TA command based on the TA granularity of the selected bandwidth part (determined according to the parameter set of the reference UL BWP). The index of each BWP may be configured or reconfigured, for example, by RRC signaling, such that the TA granularity can be changed / updated when needed. In addition, the BWPs may be indexed separately within each CC, or may be indexed jointly across all CCs. If separate indexing is used, multiple BWPs in different CCs may have the same index, and then the specified UL BWP may be one UL BWP associated with a specific BWP index within a specific carrier index.

[0098] Accordingly, the various aspects presented herein may be used to address the ambiguity problem regarding the TA granularity in a hybrid UL parameter set.

[0099] Example TA command interpretation for a TAG with a hybrid parameter set

[0100] As described above, for uplink transmissions, timing advance (TA) is used to ensure that signals from different user equipments (UEs) generally arrive at a base station (BS) in a synchronous manner (e.g., orthogonally) to avoid performance degradation. As described above, in some systems (e.g., such as 5G NR systems), the TA granularity (e.g., the unit of TA commands) is based on one or more parameters associated with a parameter set of an uplink carrier, and thus, can be different for different parameter sets. The term parameter set refers to a collection of parameters that define the structure of time and frequency resources for communication. Such parameters can include, for example, subcarrier spacing (SCS), type of cyclic prefix (e.g., such as normal CP or extended CP), and / or transmission time interval (TTI, e.g., such as subframe or slot duration). For example, a parameter set with a larger SCS can be associated with a shorter symbol duration and a control timing with a finer TA granularity (e.g., the ability for finer timing adjustment), and a parameter set with a smaller SCS can be associated with a longer symbol duration and a coarser timing adjustment (e.g., a larger timing adjustment compared to a parameter set with a larger SCS).

[0101] In some examples, a timing adjustment group (TAG) includes members or components associated with different parameter sets (e.g., different SCSs, where SCS can be referred to as tone spacing). The members of a TAG are associated with bandwidth parts (BWPs) and / or component carriers (CCs) that do not all share a common SCS. A single TA command is used for all members in the members of a TAG (e.g., all BWPs and CCs). Different from systems (such as long term evolution (LTE) systems) where the SCS is fixed (e.g., at 15 kHz), some systems (such as 5G NR systems) support UL transmissions with different SCSs (i.e., hybrid parameter sets). Thus, due to the different parameter sets associated with a TAG, the TA commands for the TAG may not ensure synchronous (e.g., orthogonal) reception at the BS.

[0102] Aspects of the present disclosure provide methods and apparatuses for members of a TAG with different parameter sets to interpret the same TA command. In an example, for all members of a TAG, the command can be interpreted as the same TA. Alternatively, and as described in more detail herein, the TA can be interpreted differently based on the parameter set associated with the members of the TAG. For example, the TA command can be interpreted differently based on the SCS associated with the corresponding members of the TAG.

[0103] As described above, the components or members of a TAG may have different tone intervals (i.e., different SCSs). In some examples, the TA command granularity (e.g., the unit of the TA command) for a TAG is bound to or associated with a specific SCS, which is referred to as the "TAG SCS". The TAG SCS may be signaled to a UE (e.g., a member of the TAG). In some examples, the TAG SCS may be signaled to the UE via RRC signaling. Accordingly, the TA command may indicate the TA granularity (e.g., the unit of TA) bound to the TAG SCS.

[0104] According to some aspects, when a TAG is configured, all the CCs and BWPs associated with the TAG and the TAG SCS to be used for determining the TA granularity may be identified. In some examples, the TAG SCS is based on the minimum / minimum SCS associated with the members of the TAG. Thus, the TA granularity for the TAG is bound to the minimum SCS for the members of the TAG. The minimum SCS is associated with the maximum OFDM symbol duration and the coarsest timing adjustment. Thus, if the TA command granularity is associated with the minimum SCS, all the members in the group will be able to apply the same TA command (no member will apply a fractional TA). This is because the minimum SCS is associated with the coarsest timing adjustment, which is a multiple of finer granularity adjustments. In this case, UL transmissions associated with an SCS larger than the minimum SCS of the TAG can control timing with a finer granularity but may not do so because they are restricted by the coarser granularity indicated in the TA command.

[0105] Associating the TA command with the minimum SCS for the members of the TAG may be applied in a supplementary UL (SUL) scenario, where a single DL carrier is assigned to two UL carriers and each of the UL carriers has different parameter sets. Similarly, the TA command associated with the minimum SCS may be applied to different CCs within a band or different BWPs within a system bandwidth, where the different CCs or BWPs have different parameter sets.

[0106] According to some aspects, the TA command granularity may be associated with an SCS other than the minimum SCS of the TAG (e.g., the maximum SCS such as the TAG). Applying the granularity associated with a larger TAG SCS to members of a TAG having an SCS smaller than the indicated TAG SCS may be challenging. For example, applying a TA command to a member of a TAG having an SCS smaller than the indicated TAG SCS may require a timing adjustment that is a fraction of the natural TA granularity associated with that member (e.g., a fraction of the CC or BWP associated with the TAG member). Thus, members of a TAG associated with an SCS smaller than the TAG SCS can naturally support a timing adjustment with a coarser granularity compared to a finer TAG command granularity.

[0107] According to some aspects, when the TA command granularity (larger TAG SCS) is finer than the coarser granularity supported by a member (having a smaller SCS), the UE may round the TA command granularity to the natural TA granularity supported by the member. For example, for a CC or BWP of a TAG having an SCS smaller than the TAG SCS, the UE may round the granularity to the coarsest TA granularity supported by the CC or BWP. In some examples, the UE applies the rounded TA to all members of the TAG. This may have the same effect as using the SCS of the CC or BWP (smaller than the indicated TAG SCS) as the TAG SCS or using the minimum SCS of all CC / BWPs in the TAG to define the TA granularity applicable to all members of the TAG.

[0108] According to other aspects, for different members of a TAG, the TA command may be interpreted in different ways. In some examples, for members of a TAG having an SCS smaller than the TAG SCS, the UE may apply a rounded TA, e.g., to try to avoid applying a fraction of the natural TA granularity associated with the CC or BWP. Thus, for members of a TAG having a smaller SCS (e.g., CC / BWP), the UE may interpret the TA command as a rounded TA command. The finer granularity associated with the TA command can be preserved and used / applied by members of the TAG having an SCS equal to or larger than the TAG SCS. Thus, for different members of a TAG having different parameter sets, the same TA command may be interpreted in different ways, and any member may be avoided from applying a fractional part of the natural TA granularity of that member.

[0109] For members of a TAG with an SCS smaller than the TAG SCS, additional actions can be taken to help maintain synchronization of received UL transmissions at the BS. According to some aspects, the UE can track the rounding error between the TA command granularity and the (rounded) TA applied to the member. For example, instead of simply processing future TA commands, the rounding error or difference can be applied to future UL transmissions. In some examples, the UE can recognize that a quantized version of the TA command is applied to the member, determine the error due to quantization, and accumulate the quantization error with the next command or the next UL transmission to try to avoid errors from accumulation. Tracking the difference and applying it to future UL transmissions helps keep UL transmissions from the TAG time-aligned. In some examples, the UE can apply the difference to the next or later received TA command. In some examples, the UE predominantly applies the difference based on a determined change in the DL timing at the UE. For example, a change in the DL timing at the UE can occur when the UE is moving away from or towards the BS. Predominantly applying refers to the UE applying the error to subsequent UL transmissions without receiving an explicit TA command.

[0110] According to some aspects, the error or difference can be included or excluded in the calculation of adjusting the UE's UL adjustment based on DL timing (e.g., limits on per-instant adjustment and adjustment rate over time). The UE may be able to make a limited number of per-instant adjustments or a limited number of adjustments within a given time window. The application of the accumulated error may or may not contribute to these limits.

[0111] Certain events can reset the tracking of the rounding error (difference). In some examples, the accumulated rounding error can be reset based on a triggering event. In some examples, since the difference between the TA command granularity and the applied TA is based on the SCS, reconfiguration of the BWP and / or CC or a change in the SCS can trigger resetting the accumulation of the difference. In some examples, a change in the TAG SCS can trigger resetting the error. In some examples, an explicit reset command sent via RRC signaling or MAC-CE can force the reset of the error. The expiration of the TA timer can indicate a link failure. In some examples, the UE can start a RACH procedure or make a limited transmission when the TA timer expires, and the UE can reset the error when the TA timer expires.

[0112] According to some aspects, the options for interpreting TA commands described herein can depend on the UE's capabilities and RRC configuration.

[0113] Figure 9 Aspects in accordance with the present disclosure illustrate an example operation 900 that can be performed by a UE. The UE can include Figure 4One or more components shown. Operation 900 may be implemented as a software component that executes and runs on one or more processors (e.g., Figure 4 processor 480). In addition, the transmission and reception of signals by the UE in operation 900 may be implemented, for example, via one or more antennas (e.g., Figure 4 antenna 452). In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface that obtains and / or outputs signals via one or more processors (e.g., processor 480).

[0114] At 905, the UE may receive a TA command from the BS. As described above, the TA granularity of the TA command is associated with the SCS. The TA granularity is defined by any combination of predetermined rules (e.g., agreed upon in a standard) and / or RRC signaling. As an example, the granularity may be hardwired into the UE (e.g., defined in the technical standard supported by the UE). The formula may be a function based on a parameter set such as the SCS.

[0115] At 910, the UE may interpret the TA command in different ways for different members of the same TAG, where the members of the TAG are associated with different parameter sets. In some examples, the parameter sets may be associated with different SCSs. Based on the member's SCS and the received TAG SCS, the UE may round the TA granularity in the received TA command. The UE may compare the member's SCS with the SCS associated with the TA granularity (e.g., TAG SCS). Based on this comparison, the UE may interpret the TA command. The members of the TAG may include one or more CCs and / or one or more BWPs.

[0116] At 906, the UE may apply a timing adjustment when transmitting an uplink transmission to the BS at least partially based on this interpretation. In some examples, the UE may apply the determined timing adjustment to the member, or apply the TA granularity as indicated in the command.

[0117] The UE may apply the timing adjustment by applying the TA command in different ways based on the SCS associated with the corresponding member of the TAG. For example, when the SCS is less than the indicated SCS of the TA granularity, the UE may apply the rounded granularity of the TA command. The rounded granularity may be a nominal coarse TA that is greater than the TA associated with the TA command. In another example, when the SCS of the member of the TAG is not an integer multiple of the indicated SCS of the TA granularity, the UE may apply the rounded granularity of the TA command.

[0118] On the other hand, when the SCS of a member of the TAG is greater than or equal to the indicated SCS of the TA granularity, the UE may apply the TA granularity indicated in the TA command (e.g., without rounding). In another example, when the SCS of a member of the TAG is an integer multiple of the indicated SCS of the TA granularity, the UE may apply the TA granularity indicated in the TA command without rounding.

[0119] When the UE applies a rounded TA granularity, the UE may track the difference between the TA granularity associated with the indicated subcarrier SCS and the applied nominal coarse TA granularity. This difference may be applied to subsequent TA commands. This difference may be applied autonomously by the UE. The accumulated difference may be reset, for example, when reconfiguring a member of the TAG, when the indicated SCS changes, when receiving a command from the BS, and / or when the TA timer expires.

[0120] As described herein, components (e.g., members) of the TAG may be associated with different parameter sets. To maintain synchronization of the received signal at the BS, members of the TAG may apply different interpretations of the TA command. This interpretation may be at least partially based on the parameter set associated with each member and the TAG SCS associated with the TA granularity for the TAG.

[0121] For simplicity, the above examples discuss that rounding of the TA command is performed for CCs and / or BWPs with an SCS less than the TAG SCS and otherwise no rounding is performed. However, the above concepts are not limited to these examples and are readily extensible to other examples with or without rounding. For example, the UE may even apply TA commands without rounding and / or with rounding error accumulation to certain CCs and / or BWPs with an SCS less than the TAG SCS. In some examples, for instance, as part of the UE capability signaling, a set of CCs and / or BWPs to which the UE can directly apply TA commands may be signaled to the BS, and the UE may be allowed to apply TA commands without rounding to the CCs or BWPs in this set. In some examples, rounding may be performed for an SCS that is not a multiple of all smaller allowed SCSs (i.e., the ratio of any two SCSs is not necessarily a power of 2), even for BWPs and / or CCs whose SCS is equal to or greater than the TAG SCS (e.g., the SCS is not a multiple of the TAG SCS).

[0122] According to some aspects, rounding may include rounding the TA command down (e.g., truncating), rounding the TA command up (e.g., ceiling), or rounding the TA command to the nearest supported granularity. The TA may be rounded such that the rounded TA is an integer multiple of the TA granularity associated with the SCS of a member of the TAG.

[0123] In some examples, the TA command before rounding can be equally close to the closest supported granularity obtained by rounding down or rounding up. The UE can round down, round up, or be configured regarding how to round the received TA command (TA granularity). The UE can randomly determine whether it will round up or round down the TA granularity for each TA command. The UE can select whether it will round up or round down via a deterministic pattern across multiple received TA commands (e.g., multiple consecutively received TA commands). For example, the UE can alternate between rounding up or rounding down the granularity to be applied.

[0124] The choice between the various possible rounding behaviors described above can also depend on whether the UE accumulates its rounding error and / or UE capabilities.

[0125] According to certain aspects, the BS can perform operations complementary to those that can be performed by the UE in operation 900.

[0126] Figure 10 A communication device 1000 is shown, which can include various components (e.g., corresponding to functional module components) configured to perform operations for the techniques disclosed herein, such as Figure 9 the operations shown. The communication device 1000 includes a processing system 1002 coupled to a transceiver 1008. The transceiver 1008 is configured to transmit and receive signals for the communication device 1000 via an antenna 1010, such as the various signals described herein. The processing system 1002 can be configured to perform processing functions for the communication device 1000, including processing signals received and / or to be transmitted by the communication device 1000.

[0127] The processing system 1002 includes a processor 1004 coupled to a computer-readable medium / memory 1012 via a bus 1006. In certain aspects, the computer-readable medium / memory 1012 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1004, cause the processor 1004 to perform Figure 9The operations shown or other operations for performing the various techniques discussed herein for TA adjustment for a set of hybrid parameters. In some aspects, the computer-readable medium / memory 1012 stores: code 1014 for receiving a TA command; code 1016 for interpreting the TA command based on the set of parameters; and code 1018 for applying a timing adjustment to an uplink transmission based on the interpreted TA command. In some aspects, the processor 1004 has circuitry configured to implement the code stored in the computer-readable medium / memory 1012. The processor 1004 includes: circuitry 1020 for receiving a TA command; circuitry 1022 for interpreting the TA command based on the set of parameters; and circuitry 1024 for applying a timing adjustment to an uplink transmission based on the interpreted TA command.

[0128] The methods disclosed herein include one or more steps or acts for implementing the methods. Without departing from the scope of the claims, these method steps and / or acts may be interchanged with one another. In other words, unless a specific order of the steps or acts is specified, the order and / or use of specific steps and / or acts may be modified without departing from the scope of the claims.

[0129] As used herein, the phrase referring to “at least one” of a list of items refers to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination of multiples of the same elements (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c or any other ordering of a, b, and c).

[0130] As used herein, the term “determine” includes a wide variety of actions. For example, “determine” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, database, or another data structure), inferring, etc. Additionally, “determine” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Additionally, “determine” may include parsing, selecting, picking, establishing, etc.

[0131] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein the use of the singular form of an element is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." The term "some," unless specifically stated otherwise, refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is expressly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the phrase "step for."

[0132] The various operations of the methods described above can be performed by any suitable unit capable of performing the corresponding functions. The unit may include various hardware and / or software components and / or modules, including but not limited to: circuits, application specific integrated circuits (ASICs), or processors. Generally, where there are operations shown in the figures, those operations may have corresponding paired functional module components with similar numbers.

[0133] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure can be implemented or performed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0134] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, machine-readable media, and a bus interface. The bus interface may also be used to connect, via the bus, a network adapter, etc. to the processing system. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of user terminal 120 (see Figure 1 ), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as a timing source, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and will thus not be described any further. The processor may be implemented using one or more general-purpose and / or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how best to implement the functions described for the processing system depends on the specific application and overall design constraints imposed on the overall system.

[0135] If implemented in software, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be construed broadly to mean instructions, data, or any combination thereof. A computer-readable medium includes both computer storage media and communication media, and the communication media includes any medium that facilitates the transfer of a computer program from one place to another. A processor may be responsible for managing the bus and general processing, which includes executing software modules stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor such that the processor can read information from and write information to the storage medium. In an alternative, the storage medium may be integrated into the processor. For example, a machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium storing instructions separate from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or additionally, a machine-readable medium or any part thereof may be integrated into the processor, such as may be the case with a cache and / or a general register file. For example, examples of a machine-readable medium may include RAM (Random Access Memory), flash memory, ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. A machine-readable medium may be embodied in a computer program product.

[0136] Software modules may include a single instruction or many instructions, and may be distributed over several different code segments, distributed among different programs, and spread across multiple storage media. A computer-readable medium may include multiple software modules. Software modules include instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. Software modules may include a sending module and a receiving module. Each software module may be located in a single storage device or distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During the execution of a software module, the processor may load some of the instructions into a cache to increase access speed. Then one or more cache lines may be loaded into the general register file for execution by the processor. It will be understood that when the functions of a software module are referred to hereinafter, such functions are implemented by the processor when executing the instructions from the software module.

[0137] In addition, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technology such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology such as infrared, radio, and microwave is included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and optical disc, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects, a computer-readable medium may include a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, for other aspects, a computer-readable medium may include a transitory computer-readable medium (e.g., a signal). The above combinations should also be included within the scope of computer-readable media.

[0138] Accordingly, some aspects may include a computer program product for performing the operations given herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon that are executable by one or more processors to perform the operations described herein. For example, instructions for performing the operations described and shown in Figure 9 are provided.

[0139] Furthermore, it should be appreciated that modules and / or other suitable units for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by a user terminal and / or a base station, where applicable. For example, such a device may be coupled to a server to facilitate the transfer of units for performing the methods described herein. Alternatively, the various methods described herein may be provided via a storage unit (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.) such that, when the storage unit is coupled to or provided to the device, the user terminal and / or the base station may obtain the various methods. Additionally, any other suitable technique for providing the methods and techniques described herein to a device may be utilized.

[0140] It is to be understood that the claims are not limited to the exact configurations and components shown above. Various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatuses described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a user equipment UE, comprising: receiving a timing advance TA command from a base station BS; rounding the TA command to a TA granularity for a member of a timing advance group TAG, wherein the TA granularity of the TA command is associated with a subcarrier spacing SCS, and members of the TAG associated with different parameter sets include one or more members associated with different SCSs, and wherein rounding the TA command to the TA granularity includes rounding the TA command based on the SCS associated with the member of the TAG and rounding the TA command up or down to the closest supported granularity; and applying a timing adjustment when transmitting an uplink transmission to the BS based at least in part on the rounded TA command.

2. The method according to claim 1, wherein, the SCS is the maximum SCS in the TAG.

3. The method according to claim 1, wherein, the members of the TAG include one or more component carriers or one or more bandwidth parts.

4. The method according to claim 1, wherein, applying the timing adjustment includes: applying the TA command in a different manner based on the SCS associated with each member of the TAG.

5. The method according to claim 1, wherein, rounding the TA command includes: determining a TA based on the indicated maximum SCS of the TAG, and rounding a first TA to a second TA.

6. The method according to claim 1, wherein: the SCS of a first member of the TAG is not an integer multiple of the SCS of the TA granularity, and rounding the TA command to the TA granularity includes: rounding the granularity applied to the first member to a nominal coarser TA granularity larger than the TA granularity.

7. The method according to claim 6, further comprising: tracking a difference between the TA granularity associated with the SCS and the nominal coarser TA granularity applied to the first member of the TAG.

8. The method according to claim 7, further comprising: applying the difference to a future TA command.

9. The method according to claim 7, further comprising: determining a change in downlink timing at the UE; and applying the difference to UL transmissions to the BS based at least in part on the determination from the host.

10. The method according to claim 7, further comprising: resetting the difference based on at least one of: reconfiguration of a member of the TAG, a change in the SCS, a command received from the BS, or expiration of a TA timer.

11. The method according to claim 1, wherein: the SCS of a second member of the TAG is an integer multiple of the SCS of the TA granularity; and applying the timing adjustment includes: applying the TA granularity to the second member.

12. The method according to claim 1, wherein, The members of the TAG associated with different parameter sets include at least one of the following: component carriers CC or bandwidth parts BWP with different SCSs.

13. An apparatus for wireless communication, comprising: a unit for receiving a timing advance TA command from another apparatus; a unit for rounding the TA command to a TA granularity for a member of a timing advance group TAG, wherein the TA granularity of the TA command is associated with a subcarrier spacing SCS, and the members of the TAG associated with different parameter sets include one or more members associated with different SCSs, and wherein rounding the TA command to the TA granularity includes rounding the TA command based on the SCS associated with the member of the TAG and rounding the TA command up or down to the closest supported granularity; and a unit for applying a timing adjustment when transmitting an uplink transmission to the another apparatus based at least in part on the rounded TA command.

14. The apparatus according to claim 13, wherein, the SCS is the maximum SCS in the TAG.

15. The apparatus according to claim 13, wherein, the members of the TAG include one or more component carriers or one or more bandwidth parts.

16. The apparatus according to claim 13, wherein, applying the timing adjustment includes: applying the TA command in a different manner based on the SCS associated with each member of the TAG.

17. The apparatus according to claim 13, wherein, rounding the TA command includes: determining a TA based on the indicated maximum SCS of the TAG, and rounding a first TA to a second TA.

18. The apparatus according to claim 13, wherein, the SCS of the first member of the TAG is not an integer multiple of the SCS of the TA granularity, and rounding the TA command to the TA granularity includes: rounding the granularity applied to the first member to a nominal coarser TA granularity that is greater than the TA granularity of the TA command.

19. The apparatus according to claim 18, further comprising: a unit for tracking a difference between the TA granularity associated with the SCS and the nominal coarser TA granularity applied to the first member of the TAG.

20. The apparatus according to claim 19, further comprising: a unit for applying the difference to future TA commands.

21. The apparatus according to claim 13, wherein: the SCS of the second member of the TAG is an integer multiple of the SCS of the TA granularity; and applying the timing adjustment includes: applying the TA granularity to the second member.

22. An apparatus for wireless communication, comprising: a receiver configured to: receive a timing advance TA command from another apparatus; at least one processor coupled to a memory and configured to: Round the TA command to a TA granularity for a member of a timing advance group (TAG), wherein the TA granularity of the TA command is associated with a subcarrier spacing (SCS), and members of the TAG associated with different parameter sets include one or more members associated with different SCSs, and wherein rounding the TA command to the TA granularity includes rounding the TA command based on the SCS associated with the member of the TAG and rounding the TA command up or down to the closest supported granularity; and Apply a timing adjustment when transmitting an uplink transmission to the other device, at least in part based on the rounded TA command.

23. A non-transitory computer-readable medium having computer-executable code stored thereon for wireless communication, comprising:[[]] code for receiving a timing advance (TA) command from a device; code for rounding the TA command to a TA granularity for a member of a timing advance group (TAG), wherein the TA granularity of the TA command is associated with a subcarrier spacing (SCS), and members of the TAG associated with different parameter sets include one or more members associated with different SCSs, and wherein rounding the TA command to the TA granularity includes rounding the TA command based on the SCS associated with the member of the TAG and rounding the TA command up or down to the closest supported granularity; and code for applying a timing adjustment when transmitting an uplink transmission to the device, at least in part based on the rounded TA command.

Images