WO2020014907A1 - Identification d'utilisateur dans une procédure de canal d'accès aléatoire en deux étapes - Google Patents

Identification d'utilisateur dans une procédure de canal d'accès aléatoire en deux étapes Download PDF

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Publication number
WO2020014907A1
WO2020014907A1 PCT/CN2018/096178 CN2018096178W WO2020014907A1 WO 2020014907 A1 WO2020014907 A1 WO 2020014907A1 CN 2018096178 W CN2018096178 W CN 2018096178W WO 2020014907 A1 WO2020014907 A1 WO 2020014907A1
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Prior art keywords
message
rnti
rntis
subframe
time
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PCT/CN2018/096178
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English (en)
Inventor
Chao Wei
Qiaoyu Li
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Qualcomm Incorporated
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Priority to PCT/CN2018/096178 priority Critical patent/WO2020014907A1/fr
Publication of WO2020014907A1 publication Critical patent/WO2020014907A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/002—Transmission of channel access control information
    • H04W74/006—Transmission of channel access control information in the downlink, i.e. towards the terminal

Definitions

  • aspects of the technology described below generally relate to wireless communication, and more particularly to techniques and apparatuses for user identification in a two-step random access channel procedure.
  • Some techniques and apparatuses described herein enable and provide wireless communication devices and systems configured for low latency and/or low power Internet of Things (IoT) devices.
  • IoT Internet of Things
  • Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts.
  • Typical 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, and/or the like) .
  • 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) .
  • UMTS Universal Mobile Telecommunications System
  • a wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) .
  • a user equipment (UE) may communicate with a base station (BS) via the downlink and uplink.
  • the downlink (or forward link) refers to the communication link from the BS to the UE
  • the uplink (or reverse link) refers to the communication link from the UE to the BS.
  • a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a new radio (NR) BS, a 5G Node B, and/or the like.
  • New radio 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 spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM 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.
  • OFDM orthogonal frequency division multiplexing
  • SC-FDM e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)
  • DFT-s-OFDM discrete Fourier transform spread OFDM
  • MIMO multiple-input multiple-output
  • a method of wireless communication may include receiving, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; selecting a GF-RNTI from the set of GF-RNTIs; and transmitting a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on the GF-RNTI.
  • RACH random access channel
  • a user equipment for wireless communication may include memory and one or more processors operatively coupled to the memory.
  • the memory and the one or more processors may be configured to receive, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; select a GF-RNTI from the set of GF-RNTIs; and transmit a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on the GF-RNTI.
  • RACH random access channel
  • a non-transitory computer-readable medium may store one or more instructions for wireless communication.
  • the one or more instructions when executed by one or more processors of a user equipment, may cause the one or more processors to receive, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; select a GF-RNTI from the set of GF-RNTIs; and transmit a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on the GF-RNTI.
  • RACH random access channel
  • an apparatus for wireless communication may include means for receiving, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; selecting a GF-RNTI from the set of GF-RNTIs; and transmitting a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on the GF-RNTI.
  • BS base station
  • GF-RNTIs grant free radio network temporary identifiers
  • RACH random access channel
  • a method of wireless communication may include transmitting, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; and receiving, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE.
  • RACH random access channel
  • a base station (BS) for wireless communication may include memory and one or more processors operatively coupled to the memory.
  • the memory and the one or more processors may be configured to transmit, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; and receive, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE.
  • RACH random access channel
  • a non-transitory computer-readable medium may store one or more instructions for wireless communication.
  • the one or more instructions when executed by one or more processors of a base station (BS) , may cause the one or more processors to transmit, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; and receive, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE.
  • RACH random access channel
  • an apparatus for wireless communication may include means for transmitting, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF-RNTIs) ; and receiving, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE.
  • RACH random access channel
  • Fig. 1 is a block diagram conceptually illustrating an example of a wireless communication network, in accordance with various aspects of the present disclosure.
  • Fig. 2 is a block diagram conceptually illustrating an example of a base station in communication with a user equipment (UE) in a wireless communication network, in accordance with various aspects of the present disclosure.
  • UE user equipment
  • Fig. 3A is a block diagram conceptually illustrating an example of a frame structure in a wireless communication network, in accordance with various aspects of the present disclosure.
  • Fig. 3B is a block diagram conceptually illustrating an example synchronization communication hierarchy in a wireless communication network, in accordance with various aspects of the present disclosure.
  • Fig. 4 is a diagram illustrating an example of user identification in a two-step random access channel procedure, in accordance with various aspects of the present disclosure.
  • Fig. 5 is a diagram illustrating an example of user identification in a two-step random access channel procedure, in accordance with various aspects of the present disclosure.
  • Fig. 6 is a diagram illustrating an example process performed, for example, by a user equipment, in accordance with various aspects of the present disclosure.
  • Fig. 7 is a diagram illustrating an example process performed, for example, by a base station, in accordance with various aspects of the present disclosure.
  • aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.
  • Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations.
  • devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments.
  • transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including one or more antennas, RF-chains, power amplifiers, modulators, buffers, processors, interleavers, adders/summers, and/or the like) .
  • innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.
  • Fig. 1 is a diagram illustrating a network 100 in which aspects of the present disclosure may be practiced.
  • the network 100 may be an LTE network or some other wireless network, such as a 5G or NR network.
  • Wireless network 100 may include a number 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 user equipment (UEs) and may also be referred to as a base station, a NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like.
  • Each BS may provide communication coverage for a particular geographic area.
  • the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.
  • 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 having association 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.
  • a BS 110a may be a macro BS for a macro cell 102a
  • a BS 110b may be a pico BS for a pico cell 102b
  • a BS 110c may be a femto BS for a femto cell 102c.
  • a BS may support one or multiple (e.g., three) cells.
  • eNB base station
  • NR BS NR BS
  • gNB gNode B
  • AP AP
  • node B node B
  • 5G NB 5G NB
  • cell may be used interchangeably herein.
  • a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS.
  • the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the access network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.
  • Wireless network 100 may also include relay stations.
  • a relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data 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.
  • a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d.
  • a relay station may also be referred to as a relay BS, a relay base station, a relay, and/or the like.
  • Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impact on interference in wireless network 100.
  • macro BSs may have a high transmit power level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 Watts) .
  • a network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs.
  • Network controller 130 may communicate with the BSs via a backhaul.
  • the BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.
  • UEs 120 may be dispersed throughout wireless network 100, and each UE may be stationary or mobile.
  • a UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like.
  • a UE may 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, medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.
  • PDA personal digital assistant
  • WLL wireless local loop
  • MTC and eMTC UEs include, for example, robots, drones, remote devices, such as sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity.
  • a wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link.
  • Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) .
  • UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like.
  • any number of wireless networks may be deployed in a given geographic area.
  • Each wireless network may support a particular RAT and may operate on one or more frequencies.
  • a RAT may also be referred to as a radio technology, an air interface, and/or the like.
  • a frequency may also be referred to as a carrier, a frequency channel, and/or the like.
  • Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.
  • NR or 5G RAT networks may be deployed.
  • two or more UEs 120 may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) .
  • the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, and/or the like) , a mesh network, and/or the like.
  • V2X vehicle-to-everything
  • the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.
  • Fig. 1 is provided merely as an example. Other examples are possible and may differ from what was described with regard to Fig. 1.
  • Fig. 2 shows a block diagram of a design 200 of base station 110 and UE 120, which may be one of the base stations and one of the UEs in Fig. 1.
  • Base station 110 may be equipped with T antennas 234a through 234t
  • UE 120 may be equipped with R antennas 252a through 252r, where in general T ⁇ 1 and R ⁇ 1.
  • a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols.
  • MCS modulation and coding schemes
  • Transmit processor 220 may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS) ) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) .
  • a transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream.
  • TX transmit
  • MIMO multiple-input multiple-output
  • Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream.
  • Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal.
  • T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively.
  • the synchronization signals can be generated with location encoding to convey additional information.
  • antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively.
  • Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples.
  • Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols.
  • a MIMO detector 256 may obtain received symbols from all R demodulators 254a through 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.
  • a channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , and/or the like.
  • RSRP reference signal received power
  • RSSI received signal strength indicator
  • RSRQ reference signal received quality
  • CQI channel quality indicator
  • one or more components of UE 120 may be included in a housing.
  • a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from 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, and/or the like) , and transmitted to base station 110.
  • modulators 254a through 254r e.g., for DFT-s-OFDM, CP-OFDM, and/or the like
  • the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120.
  • Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240.
  • Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244.
  • Network controller 130 may include communication unit 294, controller/processor 290, and memory 292.
  • Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with user identification in a two-step random access procedure, as described in more detail elsewhere herein.
  • controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 600 of Fig. 6, process 700 of Fig. 7, and/or other processes as described herein.
  • Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively.
  • a scheduler 246 may schedule UEs for data transmission on the downlink and/or uplink.
  • UE 120 may include means for receiving, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) , means for selecting a GF-RNTI from the set of GF-RNTIs, means for transmitting a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, means for randomly selecting the GF-RNTI from the set of GF-RNTIs; means for selecting the GF-RNTI from the set of GF-RNTIs based at least in part on the time-frequency resource, means for determining the time-frequency resource for the first message based at least in part on a cell-specific resource configuration associated with the BS, means for receiving, from the BS, a second message associated with the two-step RACH procedure based at least in part on transmitting the first message, means for performing a comparison of a first identifier included in the first message and a second identifie
  • base station 110 may include means for transmitting, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF-RNTIs) , means for receiving, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, means for transmitting, to the UE, a second message associated with the two-step RACH procedure based at least in part on receiving the first message, means for receiving, from the UE, an indication that the two-step RACH procedure was successful based at least in part on another uplink transmission scrambled by the C-RNTI, means for receiving the first message on a starting frame or subframe and one or more subsequent frames or subframes, means for, and/or the like.
  • such means may include one or more components of base station 110 described in connection with Fig. 2.
  • Fig. 2 is provided merely as an example. Other examples are possible and may differ from what was described with regard to Fig. 2.
  • Fig. 3A shows an example frame structure 300 for FDD in a telecommunications system (e.g., NR) .
  • the transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames (sometimes referred to as frames) .
  • Each radio frame may have a predetermined duration (e.g., 10 milliseconds (ms) ) and may be partitioned into a set of Z (Z ⁇ 1) subframes (e.g., with indices of 0 through Z-1) .
  • Each subframe may have a predetermined duration (e.g., 1ms) and may include a set of slots (e.g., 2 m slots per subframe are shown in Fig.
  • Each slot may include a set of L symbol periods.
  • each slot may include fourteen symbol periods (e.g., as shown in Fig. 3A) , seven symbol periods, or another number of symbol periods.
  • the subframe may include 2L symbol periods, where the 2L symbol periods in each subframe may be assigned indices of 0 through 2L-1.
  • a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, and/or the like.
  • a wireless communication structure may refer to a periodic time-bounded communication unit defined by a wireless communication standard and/or protocol. Additionally, or alternatively, different configurations of wireless communication structures than those shown in Fig. 3A may be used.
  • a base station may transmit synchronization signals.
  • a base station may transmit a primary synchronization signal (PSS) , a secondary synchronization signal (SSS) , and/or the like, on the downlink for each cell supported by the base station.
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • the PSS and SSS may be used by UEs for cell search and acquisition.
  • the PSS may be used by UEs to determine symbol timing
  • the SSS may be used by UEs to determine a physical cell identifier, associated with the base station, and frame timing.
  • the base station may also transmit a physical broadcast channel (PBCH) .
  • the PBCH may carry some system information, such as system information that supports initial access by UEs.
  • the base station may transmit the PSS, the SSS, and/or the PBCH in accordance with a synchronization communication hierarchy (e.g., a synchronization signal (SS) hierarchy) including multiple synchronization communications (e.g., SS blocks) , as described below in connection with Fig. 3B.
  • a synchronization communication hierarchy e.g., a synchronization signal (SS) hierarchy
  • multiple synchronization communications e.g., SS blocks
  • Fig. 3B is a block diagram conceptually illustrating an example SS hierarchy, which is an example of a synchronization communication hierarchy.
  • the SS hierarchy may include an SS burst set, which may include a plurality of SS bursts (identified as SS burst 0 through SS burst B-1, where B is a maximum number of repetitions of the SS burst that may be transmitted by the base station) .
  • each SS burst may include one or more SS blocks (identified as SS block 0 through SS block (b max_SS-1 ) , where b max_SS-1 is a maximum number of SS blocks that can be carried by an SS burst) .
  • An SS burst set may be periodically transmitted by a wireless node, such as every X milliseconds, as shown in Fig. 3B.
  • an SS burst set may have a fixed or dynamic length, shown as Y milliseconds in Fig. 3B.
  • the SS burst set shown in Fig. 3B is an example of a synchronization communication set, and other synchronization communication sets may be used in connection with the techniques described herein.
  • the SS block shown in Fig. 3B is an example of a synchronization communication, and other synchronization communications may be used in connection with the techniques described herein.
  • an SS block includes resources that carry the PSS, the SSS, the PBCH, and/or other synchronization signals (e.g., a tertiary synchronization signal (TSS) ) and/or synchronization channels.
  • synchronization signals e.g., a tertiary synchronization signal (TSS)
  • multiple SS blocks are included in an SS burst, and the PSS, the SSS, and/or the PBCH may be the same across each SS block of the SS burst.
  • a single SS block may be included in an SS burst.
  • the SS block may be at least four symbol periods in length, where each symbol carries one or more of the PSS (e.g., occupying one symbol) , the SSS (e.g., occupying one symbol) , and/or the PBCH (e.g., occupying two symbols) .
  • the symbols of an SS block are consecutive, as shown in Fig. 3B. In some aspects, the symbols of an SS block are non-consecutive. Similarly, in some aspects, one or more SS blocks of the SS burst may be transmitted in consecutive radio resources (e.g., consecutive symbol periods) during one or more slots. Additionally, or alternatively, one or more SS blocks of the SS burst may be transmitted in non-consecutive radio resources.
  • the SS bursts may have a burst period, whereby the SS blocks of the SS burst are transmitted by the base station according to the burst period. In other words, the SS blocks may be repeated during each SS burst.
  • the SS burst set may have a burst set periodicity, whereby the SS bursts of the SS burst set are transmitted by the base station according to the fixed burst set periodicity. In other words, the SS bursts may be repeated during each SS burst set.
  • the base station may transmit system information, such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain slots.
  • SIBs system information blocks
  • the base station may transmit control information/data on a physical downlink control channel (PDCCH) in C symbol periods of a slot, where B may be configurable for each slot.
  • the base station may transmit traffic data and/or other data on the PDSCH in the remaining symbol periods of each slot.
  • Figs. 3A and 3B are provided as examples. Other examples are possible and may differ from what was described with regard to Figs. 3A and 3B.
  • a two-step random access channel (RACH) procedure two messages may be exchanged between a UE and a BS.
  • the UE may transmit, to the BS, a first message of the RACH procedure that includes a physical random access channel (PRACH) preamble, a RACH message, and/or a demodulation reference signal (DMRS) .
  • the first message may include information that would be included in both messages from a UE if the UE was performing a 4-step RACH procedure.
  • the BS may transmit, to the UE, a second message of the RACH procedure (e.g., that includes a random access response and/or that is to be used for contention resolution) .
  • a second message of the RACH procedure e.g., that includes a random access response and/or that is to be used for contention resolution
  • the BS may transmit the second message using PDCCH and/or PDSCH.
  • the second message may include information that would be included in both messages from the BS if the BS was performing a 4-step RACH procedure.
  • the second message may include a detected RACH preamble, an RS identifier, a UE identifier, a timing advance, a back-off indicator, a contention resolution message, and/or the like.
  • the two-step RACH procedure may be associated with grant-free uplink transmissions, and can use orthogonal multiple access (OMA) and/or non-orthogonal multiple access (NOMA) schemes (e.g., by implementing different user multiplexing schemes for RACH messages) .
  • OMA orthogonal multiple access
  • NOMA non-orthogonal multiple access
  • the two-step RACH procedure may reduce latency related to a RACH procedure, may conserve processing resources of a UE and/or a BS related to a RACH procedure, may conserve network bandwidth, and/or the like relative to a four-step RACH procedure
  • UE identification during the two-step RACH procedure may be difficult or impossible due to lack of an uplink grant. This difficulty may be increased in scenarios where the UE is in an idle state and/or is not associated with a valid cell radio network temporary identifier (C-RNTI) and/or a temporary cell radio network temporary identifier (TC-RNTI) .
  • C-RNTI cell radio network temporary identifie
  • Some aspects described herein provide a UE and/or a BS that are capable of utilizing a two-step RACH procedure with information that facilitates identification of the UE. For example, prior to transmitting a message associated with the two-step RACH procedure, the UE may randomly select a GF-RNTI from a set of GF-RNTIs provided by the BS that is to be used to identify the UE in communications between the UE and the BS. This facilitates UE identification during a two-step RACH procedure, thereby improving the two-step RACH procedure. In addition, this reduces or eliminates consumption of processing resources that would otherwise be consumed as a result of failing to identify the UE during a two-step RACH procedure. Further, this reduces or eliminates latency that would otherwise result from failing to identify a UE during a two-step RACH procedure, thereby improving the two-step RACH procedure.
  • Fig. 4 is a diagram illustrating an example 400 of user identification in a two-step random access channel procedure, in accordance with various aspects of the present disclosure.
  • example 400 includes a BS (e.g., BS 110) and a UE (e.g., UE 120) .
  • BS e.g., BS 110
  • UE e.g., UE 120
  • the BS may transmit, and the UE may receive, a set of GF-RNTIs.
  • the BS may transmit a set of GF-RNTIs that includes multiple GF-RNTIs from which the UE is to select a GF-RNTI that is to be used in association with communications between the UE and the BS, as described in more detail elsewhere herein.
  • the BS may transit the set of GF-RNTIs in association with system information.
  • the BS may transmit the set of GF-RNTIs in association with system information that is to be used for a grant-free uplink transmission from the UE, such as when the UE is in an idle state.
  • the UE may select a GF-RNTI from the set of GF-RNTIs. For example, the UE may select a single GF-RNTI from multiple GF-RNTIs included in the set of GF-RNTIs. In some aspects, the UE may randomly select the GF-RNTI. For example, the UE may randomly generate a number using a random number generator and may select the GF-RNTI from an index position within a data structure that matches the randomly generated number.
  • the UE may select the GF-RNTI based at least in part on a time-frequency resource at which a first message associated with the two-step RACH procedure is to be transmitted. For example, GF-RNTIs included in the set of GF-RNTIs may be mapped to transmission occasions for the first message (e.g., a first GF-RNTI may be mapped to a first transmission occasion of the first message, a second GF-RNTI may be mapped to a second transmission occasion of the first message, etc. ) . In this case, an index of the GF-RNTI to be used may be determined by the formula:
  • mod () is a modulo operation
  • k is the transmission occasion of the first message
  • N is a quantity of GF-RNTIs included in the set of GF-RNTIs. For example, if k equals 2, and N equals 4, then mod (2, 4) equals 2, which would be the index value in a data structure of the GF-RNTI that the UE is to select. This may reduce a receiver complexity at the BS by reducing or eliminating a need for the BS to detect the transmitted GF-RNTI in the first message, thereby conserving processing resource of the BS.
  • the selected GF-RNTI may be used to identify the UE in communications between the UE and the BS during a two-step RACH procedure.
  • the UE may select the GF-RNTI when the UE is in an idle state. For example, the UE may select the GF-RNTI from the set of GF-RNTIs when operating in the idle state. Additionally, or alternatively, the UE may select the GF-RNTI when the UE is operating in a particular mode, such as a connected mode. Additionally, or alternatively, the UE may select the GF-RNTI when performing a random access attempt using a two-step RACH process. For example, the UE may determine to not select a GF-RNTI from the set of GF-RNTIs if the UE is using a four-step RACH procedure, and/or the like.
  • the UE may select the GF-RNTI based at least in part on receiving the set of GF-RNTIs, determining to perform a random access attempt using a two-step RACH procedure, receiving a set of instructions from the BS to select the GF-RNTI, and/or the like.
  • the UE may transmit, and the BS may receive, a first message of a two-step RACH procedure.
  • the UE may transmit the first message after selecting the GF-RNTI, based at least in part on initiating a two-step RACH procedure, and/or the like.
  • the UE may transmit the first message at a time and/or frequency resource (time-frequency resource) on at least one subframe (e.g., at a starting frame and/or subframe, on one or more subsequent frames and/or subframes after the starting frame and/or subframe, and/or the like) .
  • time-frequency resource time-frequency resource
  • the first message may include a PRACH preamble, a DMRS, a RACH message, and/or the like.
  • the first message may include information that would otherwise be included in both messages that the UE would transmit in a four-step RACH procedure (e.g., the first message and the third message of the four-step RACH procedure) .
  • the first message may include the GF-RNTI.
  • the first message may include a unique identifier for the UE to be used for contention resolution.
  • the unique identifier may include a system architecture evolution temporary mobile subscriber identity (S-TMSI) , a random value that the UE generated, and/or the like.
  • S-TMSI system architecture evolution temporary mobile subscriber identity
  • the first message may be scrambled.
  • the UE may scramble the first message using a sequence associated with the UE.
  • the sequence may be based at least in part on the GF-RNTI.
  • the UE may determine a time and/or frequency resource (time-frequency resource) at which the UE is to transmit the first message. For example, the UE may determine the time-frequency resource based at least in part on a cell-specific resource configuration associated with the BS (e.g., received from the BS) .
  • an index of the starting frame and/or subframe of the first message and/or an index of a frequency location of the first message may be used to identify the UE for contention resolution.
  • the first message may be scrambled based at least in part on the index of the starting frame and/or subframe and/or the index of the frequency location.
  • the UE when determining the time-frequency resource for the first message, may determine a starting frame and/or subframe for the first message (e.g., prior to transmitting the first message) . For example, the UE may determine the starting frame and/or subframe for the first message (e.g., a grant-free transmission) when in an idle state.
  • the cell-specific configuration associated with the BS includes a time domain resource and an offset (e.g., if the cell-specific configuration identifies a periodicity of a time-domain resource and an offset of the time-domain resource)
  • the UE may determine the starting frame and/or subframe according to the formula:
  • nf is a frame index of the first message
  • floor () is a floor function
  • ns is a subframe index of the first message
  • mod is a modulo operation
  • T is a periodicity of the time-domain resource for the first message
  • N start time is an offset of the time-domain resource for the first message.
  • the UE may determine the starting frame and/or subframe for the first message in a manner different from that described above. For example, the UE may determine the starting frame and/or subframe based at least in part on a cell-specific configuration associated with the BS identifying a valid frame and/or subframe configuration (e.g., where a set of frames and/or subframes based at least in part on the valid frame and/or subframe configuration is not used for another uplink communication from the UE) .
  • the UE may allocate one or more subframes for the first message within a time interval for the first message (e.g., as indicated in the cell-specific configuration associated with the BS) .
  • the UE may allocate the one or more subframes within a 1024 frame interval (e.g., 10.24 seconds) based at least in part on the valid subframe configuration.
  • the time interval may differ in other aspects from 10.24 seconds.
  • the UE may enumerate the subframes within a time interval for the first message as:
  • the periodicity of the allowed starting subframes of the time interval may be based at least in part on a configured maximum quantity of transmission subframes or repetitions for the first message (e.g., represented by ) and/or a configured starting subframe periodicity.
  • the allowed starting subframes defined over may be determined based at least in part on the formula:
  • the starting subframe periodicity may be provided by a higher layer associated with the BS, then the starting frame periodicity of allowed starting subframes (e.g., in terms of subframes allowed for the first message) may be based at least in part on an offset associated with a time-domain resource (e.g., represented by N satrt time ) .
  • the allowed starting subframes defined over may be determined based at least in part on the formula:
  • determining the starting frame and/or subframe in this manner when the cell-specific configuration includes a valid frame and/or subframe configuration may provide backward compatibility based at least in part on the valid subframes for the first message being configurable as invalid for the other UL transmission, thereby facilitating time division multiplexing (TDM) resource multiplexing of the grant-free UL transmission and the grant-based UL transmission.
  • TDM time division multiplexing
  • the UE may receive, and the BS may transmit a second message of the two-step RACH procedure.
  • the second message may be associated with a random access response and/or contention resolution.
  • the second message may include a detected RACH preamble, an RS identifier for an RS, a UE identifier for the UE, a timing advance, a back-off indicator, a contention resolution message, and/or the like.
  • the second message may include information that would otherwise be included in both messages from the BS if the BS were implementing a four-step RACH procedure (e.g., the second and the fourth message of the four-step RACH procedure) .
  • the BS may have transmitted the second message using PDCCH and/or PDSCH.
  • the PDCCH and/or the PDSCH for the second message may be addressed to the GF-RNTI that the UE selected from the set of GF-RNTIs.
  • the PDCCH and/or the PDSCH may be scrambled.
  • the PDCCH and/or the PDSCH may be scrambled based at least in part on an index of the time-frequency resource for the first message.
  • the second message that the BS transmits may include a C-RNTI that is different than the GF-RNTI that the UE selected.
  • the second message may include a C-RNTI that is to replace the GF-RNTI in subsequent communications between the UE and the BS (e.g., the UE and the BS may use the C-RNTI, rather than the GF-RNTI when communicating with each other) .
  • the UE may decode the second message after receiving the second message. For example, the UE may decode the PDCCH and/or the PDSCH associated with the second message. In some aspects, to be capable of decoding the second message, the UE may need to have selected the GF-RNTI and/or determined the starting time-frequency resource for the first message. In some aspects, the UE may perform a comparison of one or more identifiers for the UE included in the second message and one or more other identifiers for the UE included in the first message to determine whether the identifiers match.
  • the UE may dynamically determine whether the two-step RACH procedure is successful (e.g., based at least in part on a result of the comparison indicating a match, based at least in part on the UE detecting the PDCCH associated with the second message, and/or the like) or is unsuccessful (e.g., based at least in part on a result of the comparison indicating a mismatch, based at least in part on the UE failing to detect the PDCCH associated with the second message, and/or the like) .
  • the UE may transmit, to the BS, information that identifies whether the two-step RACH procedure was successful. Additionally, or alternatively, the BS may determine whether the two-step RACH procedure was successful based at least in part on failing to receive information that identifies that the two-step RACH procedure was successful within a threshold amount of time after transmitting the second message.
  • the UE may perform a retransmission of the first message.
  • the retransmission and another first message from another UE on a same staring frame and/or subframe may be detectable based at least in part on being associated with different GF-RNTIs.
  • a retransmission GF-RNTI for the retransmission of the first message may be the same GF-RNTI used for the initial transmission of the first message.
  • the UE may randomly select a retransmission GF-RNTI for the retransmission of the first message from the set of GF-RNTIs or another set of GF-RNTIs that is different than the set of GF-RNTIs. For example, the other set of GF-RNTIs may be reserved for retransmissions.
  • the BS may transmit, to the UE, a retransmission GF-RNTI to be used for a retransmission of the first message (e.g., included in the second message) .
  • Fig. 4 is provided as an example. Other examples are possible and may differ from what was described with respect to Fig. 4.
  • Fig. 5 is a diagram illustrating an example 500 of user identification in a two-step random access channel procedure, in accordance with various aspects of the present disclosure.
  • example 500 includes multiple UEs (e.g., UEs 120) transmitting various first messages associated with a two-step RACH procedure.
  • UE1 and UE2 may use a same GF-RNTI for first messages associated with a two-step RACH procedure based at least in part on transmitting the first messages in association with different transmission occasions (e.g., different starting frames and/or subframes) .
  • UE1 and UE3 may use different GF-RNTIs for first messages associated with a two-step RACH process based at least in part on transmitting the first messages on a same starting frame and/or subframe. This facilitates detectability of the first messages by the BS.
  • a first message transmitted by UE3 and a first message transmitted by UE2 may partially overlap.
  • both first messages may be detectable based at least in part on UE2 and UE3 using different GF-RNTIs, based at least in part on UE-specific scrambling used by UE2 and UE3 for the first messages (e.g., which may be based at least in part on a respective GF-RNTI used by UE2 and UE3 and/or a respective index of the starting time and/or frequency location for the first messages) , and/or the like. This facilitates detectability of the first messages by the BS.
  • the retransmission (ReTx) of a first message by UE1 may collide with a first message transmitted by UE4.
  • both first messages may be detectable by the BS based at least in part on UE1 and UE4 using different GF-RNTIs.
  • Fig. 5 is provided as an example. Other examples are possible and may differ from what was described with respect to Fig. 5.
  • Fig. 6 is a diagram illustrating an example process 600 performed, for example, by a UE, in accordance with various aspects of the present disclosure.
  • Example process 600 is an example where a UE (e.g., UE 120) performs user identification in a two-step RACH procedure.
  • a UE e.g., UE 120
  • process 600 may include receiving, from a base station (BS) , a set of grant free radio network temporary identifiers (GF-RNTIs) (block 610) .
  • the UE e.g., UE 120 using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller/processor 280, and/or the like
  • process 600 may include selecting a GF-RNTI from the set of GF-RNTIs (block 620) .
  • the UE e.g., UE 120 using controller/processor 280 and/or the like
  • process 600 may include transmitting a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on the GF-RNTI (block 630) .
  • RACH random access channel
  • the UE may transmit a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, in a manner that is the same as or similar to that described with regard to Figs. 4 and 5.
  • RACH random access channel
  • the first message may be scrambled by a sequence associated with the UE.
  • the sequence may be based at least in part on the GF-RNTI.
  • Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.
  • the set of GF-RNTIs may be received in association with system information that is to be used for a grant-free uplink transmission from the UE.
  • the UE may randomly select the GF-RNTI from the set of GF-RNTIs.
  • the GF-RNTI may be used as an identifier for the UE for contention resolution.
  • the UE may select the GF-RNTI from the set of GF-RNTIs based at least in part on the time-frequency resource.
  • the UE may determine the time-frequency resource for the first message based at least in part on a cell-specific resource configuration associated with the BS.
  • an identifier of the UE to be used for contention resolution may be based at least in part on an index of at least one of a starting frame or subframe of the first message associated with the time-frequency resource, or a frequency location of the first message associated with the time-frequency resource.
  • the first message may be scrambled based at least in part on the index.
  • the first message may include a unique identifier for the UE to be used for contention resolution.
  • the unique identifier may include a system architecture evolution temporary mobile subscriber identity (S-TMSI) , or a random value.
  • the UE may receive, from the BS, a second message associated with the two-step RACH procedure based at least in part on transmitting the first message.
  • the second message may be associated with contention resolution.
  • a physical downlink control channel (PDCCH) for the second message may be addressed to the GF-RNTI.
  • the PDCCH may be scrambled based at least in part on an index of the time-frequency resource for the first message.
  • the PDCCH may be decoded by the UE based at least in part on at least one of the GF-RNTI for the first message, or information regarding the time-frequency resource.
  • the UE may perform a comparison of a first identifier included in the first message and a second identifier included in the second message, and may determine whether the comparison indicates a match between the first identifier and the second identifier based at least in part on performing the comparison.
  • the UE may dynamically determine that the two-step RACH procedure is successful based at least in part on determining that the comparison indicates the match, or may determine that the two-step RACH procedure is unsuccessful based at least in part on determining that the comparison does not indicate the match.
  • the second message may include a cell radio network temporary identifier (C-RNTI) .
  • the C-RNTI may replace the GF-RNTI in subsequent communications between the UE and the BS.
  • the UE may determine that the two-step RACH procedure is unsuccessful based at least in part on failing to detect the PDCCH for the second message.
  • the UE may determine a starting frame or subframe for the first message, and may transmit the first message in one or more subsequent frames or subframes after the starting frame or subframe.
  • the UE may determine the starting frame or subframe based at least in part on a cell-specific configuration associated with the BS identifying a periodicity of a time-domain resource and an offset of the time-domain resource.
  • the UE may determine the starting frame or subframe based at least in part on a cell-specific configuration associated with the BS identifying a valid subframe configuration for the first message. In some aspects, a set of frames or subframes based at least in part on the valid subframe configuration may not be used for another uplink transmission.
  • the UE may allocate one or more subframes for the first message within a time interval based at least in part on the valid subframe configuration.
  • a periodicity of allowed starting subframes of the time interval for the first message may be based at least in part on a configured maximum quantity of transmission subframes or repetitions for the first message, or a configured starting subframe periodicity for the first message.
  • the UE and another UE may be associated with the GF-RNTI and may be associated with different starting frames or subframes.
  • another first message from the other UE may be detectable based at least in part on scrambling used for the first message or the other first message, the GF-RNTI, or the time-frequency resource.
  • the UE and another UE may be associated with different GF-RNTIs and may be associated with the starting frame or subframe.
  • another first message from the other UE may be detectable based at least in part on scrambling used for the first message or the other first message, the GF-RNTI, or the time-frequency resource.
  • a retransmission of the first message from the UE and a transmission of another first message from another UE on a same starting frame or subframe may be detectable based at least in part on being associated with different GF-RNTIs.
  • a retransmission GF-RNTI for a retransmission of the first message may be the GF-RNTI.
  • a retransmission GF-RNTI for a retransmission of the first message may be randomly selected from the set of GF-RNTIs or another set of GF-RNTIs.
  • the other set of GF-RNTIs may be different than the set of GF-RNTIs.
  • a retransmission GF-RNTI for a retransmission of the first message may be included in a second message, of the two-step RACH procedure, received from the BS.
  • process 600 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 6. Additionally, or alternatively, two or more of the blocks of process 600 may be performed in parallel.
  • Fig. 7 is a diagram illustrating an example process 700 performed, for example, by a BS, in accordance with various aspects of the present disclosure.
  • Example process 700 is an example where a BS (e.g., BS 110) performs user identification in a two-step RACH procedure.
  • a BS e.g., BS 110
  • process 700 may include transmitting, to a user equipment (UE) , a set of grant free radio network temporary identifiers (GF- RNTIs) (block 710) .
  • the BS e.g., BS 110 using controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like
  • process 700 may include receiving, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, wherein the first message is scrambled by a sequence associated with the UE, wherein the sequence is based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE (block 720) .
  • RACH random access channel
  • the BS may receive, from the UE, a first message of a two-step random access channel (RACH) procedure at a time and/or frequency resource (time-frequency resource) on at least one subframe, in a manner that is the same as or similar to that described with regard to Figs. 4 and 5.
  • RACH random access channel
  • the first message may be scrambled by a sequence associated with the UE.
  • the sequence may be based at least in part on a GF-RNTI, of the set of GF-RNTIs, selected by the UE.
  • Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.
  • the set of GF-RNTIs may be transmitted in association with system information that is to be used for a grant-free uplink transmission from the UE.
  • the GF-RNTI may be randomly selected from the set of GF-RNTIs.
  • the GF-RNTI may be used as an identifier for the UE for contention resolution.
  • the GF-RNTI may be selected from the set of GF-RNTIs based at least in part on the time-frequency resource.
  • the first message may include an identifier of the UE to be used for contention resolution.
  • the identifier may be based at least in part on an index of at least one of a starting frame or subframe of the first message associated with the time-frequency resource, or a frequency location of the first message associated with the time-frequency resource.
  • the first message may be scrambled based at least in part on the index.
  • the first message may include a unique identifier for the UE to be used for contention resolution.
  • the unique identifier may include a system architecture evolution temporary mobile subscriber identity (S-TMSI) , or a random value.
  • the BS may transmit, to the UE, a second message associated with the two-step RACH procedure based at least in part on receiving the first message.
  • the second message may be associated with contention resolution.
  • a physical downlink control channel (PDCCH) for the second message may be addressed to the GF-RNTI.
  • the PDCCH may be scrambled based at least in part on an index of the time-frequency resource for the first message.
  • the PDCCH may be decodable by the UE based at least in part on at least one of the UE having used the GF-RNTI for the first message, or the UE having transmitted the first message on the time-frequency resource.
  • the second message may include a cell radio network temporary identifier (C-RNTI) .
  • C-RNTI may replace the GF-RNTI in subsequent communications between the UE and the BS.
  • the BS may receive, from the UE, an indication that the two-step RACH procedure was successful based at least in part on another uplink transmission scrambled by the C- RNTI.
  • the BS may receive the first message on a starting frame or subframe and one or more subsequent frames or subframes.
  • the starting frame or subframe may be based at least in part on a cell-specific configuration associated with the BS identifying a periodicity of a time-domain resource and an offset of the time-domain resource.
  • the starting frame or subframe may be based at least in part on a cell-specific configuration associated with the BS identifying a valid subframe configuration for the first message.
  • one or more subframes for the first message may be within a time interval based at least in part on the valid subframe configuration. In some aspects, a set of subframes based at least in part on the valid subframe configuration may not be used for another uplink transmission. In some aspects, a periodicity of allowed starting subframes of the time interval for the first message may be based at least in part on a configured maximum quantity of transmission subframes or repetitions for the first message, or a configured starting subframe periodicity for the first message.
  • the UE and another UE may be associated with the GF-RNTI and may be associated with different starting frames or subframes.
  • another first message from the other UE may be detectable based at least in part on scrambling used for the first message or the other first message, the GF-RNTI, or the time-frequency resource.
  • the UE and another UE may be associated with different GF-RNTIs and may be associated with the starting frame or subframe.
  • another first message from the other UE may be detectable based at least in part on scrambling used for the first message or the other first message, the GF-RNTI, or the time-frequency resource.
  • a retransmission of the first message from the UE and a transmission of another first message from another UE on a same starting frame or subframe may be detectable based at least in part on being associated with different GF-RNTIs.
  • a retransmission GF-RNTI for a retransmission of the first message may be the GF-RNTI.
  • a retransmission GF-RNTI for a retransmission of the first message may be randomly selected from the set of GF-RNTIs or another set of GF-RNTIs.
  • the other set of GF-RNTIs may be different than the set of GF-RNTIs.
  • a retransmission GF-RNTI for a retransmission of the first message may be included in a second message, of the two-step RACH procedure, transmitted by the BS.
  • process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two or more of the blocks of process 700 may be performed in parallel.
  • the term component is intended to be broadly construed as hardware, firmware, or a combination of hardware and software.
  • a processor is implemented in hardware, firmware, or a combination of hardware and software.
  • satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.
  • “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 with multiples of the same element (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) .

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  • Mobile Radio Communication Systems (AREA)

Abstract

Divers aspects de la présente invention concernent de manière générale la communication sans fil. Selon certains aspects, un équipement utilisateur peut recevoir, d'une station de base (BS), un ensemble d'identifiants temporaires de réseau radio sans autorisation (GF-RNTI). L'équipement utilisateur peut sélectionner un GF-RNTI à partir de l'ensemble de GF-RNTI. L'équipement utilisateur peut transmettre un premier message d'une procédure de canal d'accès aléatoire en deux étapes (RACH) à une ressource temporelle et/ou fréquentielle (ressource temps-fréquence) sur au moins une sous-trame. Selon certains aspects, le premier message peut être embrouillé par une séquence associée à l'UE. Selon certains aspects, la séquence peut être basée au moins en partie sur le GF-RNTI. L'invention concerne également de nombreux autres aspects.
PCT/CN2018/096178 2018-07-18 2018-07-18 Identification d'utilisateur dans une procédure de canal d'accès aléatoire en deux étapes WO2020014907A1 (fr)

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US20220416993A1 (en) * 2021-06-23 2022-12-29 Qualcomm Incorporated Demodulator configuration based on user equipment signaling
US11997185B2 (en) * 2021-06-23 2024-05-28 Qualcomm Incorporated Demodulator configuration based on user equipment signaling

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