WO2021012137A1 - Répétition de la transmission de séquences d'accès aléatoire - Google Patents

Répétition de la transmission de séquences d'accès aléatoire Download PDF

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Publication number
WO2021012137A1
WO2021012137A1 PCT/CN2019/096994 CN2019096994W WO2021012137A1 WO 2021012137 A1 WO2021012137 A1 WO 2021012137A1 CN 2019096994 W CN2019096994 W CN 2019096994W WO 2021012137 A1 WO2021012137 A1 WO 2021012137A1
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WO
WIPO (PCT)
Prior art keywords
random access
synchronization signal
preamble sequence
signal block
access preamble
Prior art date
Application number
PCT/CN2019/096994
Other languages
English (en)
Inventor
Qiaoyu Li
Chao Wei
Hao Xu
Yu Zhang
Liangming WU
Chenxi HAO
Yuwei REN
Changlong Xu
Min Huang
Wanshi Chen
Original Assignee
Qualcomm Incorporated
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Application filed by Qualcomm Incorporated filed Critical Qualcomm Incorporated
Priority to PCT/CN2019/096994 priority Critical patent/WO2021012137A1/fr
Priority to PCT/CN2020/103415 priority patent/WO2021013165A1/fr
Publication of WO2021012137A1 publication Critical patent/WO2021012137A1/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
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/08—Arrangements for detecting or preventing errors in the information received by repeating transmission, e.g. Verdan system
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/189—Transmission or retransmission of more than one copy of a message

Definitions

  • the following relates generally to wireless communications, and more specifically to repeating transmission of random access sequences.
  • Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) .
  • Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems.
  • 4G systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems
  • 5G systems which may be referred to as New Radio (NR) systems.
  • a wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .
  • UE user equipment
  • a UE may perform a random access procedure during initial access to connect to a base station.
  • the UE may receive synchronization signals from a base station and identify a random access occasion (RO) based on the synchronization signals.
  • the UE may then transmit a random access preamble sequence during the RO.
  • Conventional techniques for identifying the RO and performing the random access procedure may be improved.
  • the described techniques relate to improved methods, systems, devices, and apparatuses that support repeating transmission of random access sequences.
  • the described techniques provide for random access procedures for New Radio (NR) Light devices.
  • NR Light devices such as smart devices, wearable devices, smart sensors, etc.
  • MBB mobile broadband
  • a Light user equipment (UE) such as an NR- Light UE, may be configured to transmit with a reduced transmit power compared to non-Light devices. Based on the reduced transmit power, Light devices may transmit multiple repetitions of uplink signaling. Transmitting multiple repetitions may improve the likelihood of a base station receiving and successfully decoding transmissions from a Light UE.
  • a Light UE may transmit repetitions of a random access preamble of a random access procedure during initial access.
  • Techniques described herein support a UE, such as an NR-Light UE, to identify associations between a received synchronization signal block (SSB) and parameters for transmitting repetitions of a random access preamble sequence during a random access procedure.
  • SSB received synchronization signal block
  • a UE may receive a synchronization signal block (SSB) from a base station and identify a mapping between the received SSB and random access procedure occasions (ROs) for transmitting the repetitions of the random access preamble sequence.
  • the UE may transmit the random access procedure preamble sequence in ROs corresponding to the received SSB.
  • the UE may identify a repetition pattern or repetition scheme for transmitting repetitions of the random access preamble sequence.
  • the UE 115 may identify different configurations for how many repetitions of the random access preamble sequences to transmit within a single mapping association period, or how the repetitions of the random access preamble sequence are distributed across one or more mapping association periods.
  • the SSB-to-RO mappings, preamble configurations, and repetition patterns may either be configured for the UE (e.g., as dedicated configurations) , or the UE may interpret signaling for non-Light devices to determine parameters and configurations for the Light random access procedure. Additional techniques are described herein, such as determining a repetition scheme based on a SIB update cycle. Additionally, techniques for configuring different repetition schemes based on a repetition level of the device are described.
  • a method of wireless communications at a UE may include identifying a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmitting an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identifying a repetition scheme for repetitions of the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmitting the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory.
  • the instructions may be executable by the processor to cause the apparatus to identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for repetitions of the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the apparatus may include means for identifying a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmitting an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identifying a repetition scheme for repetitions of the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmitting the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • a non-transitory computer-readable medium storing code for wireless communications at a UE is described.
  • the code may include instructions executable by a processor to identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for repetitions of the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • each of the one or more mapping association periods includes at least one repetition period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting at least a set of repetitions of the initial random access preamble sequence within each of the one or more mapping association periods.
  • the initial random access preamble sequence may be transmitted in a first random access occasion, an Nth random access occasion, or a multiple of the Nth random access occasion, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting at least a portion of a set of repetitions of the initial random access procedure sequence in a mapping association period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the set of repetitions within a single association pattern period spanning a set of mapping association periods.
  • the initial random access preamble sequence may be transmitted in a first mapping association period, an Nth mapping association period, or a multiple of the Nth mapping association period, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a portion of a set of repetitions of the initial random access preamble sequence within each of one or more association pattern periods, where an association pattern period spans a set of mapping association periods.
  • the initial random access preamble sequence may be transmitted in a first association pattern period, an Nth association pattern period, or a multiple of the Nth association pattern period, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for applying a root sequence offset to a random access preamble root sequence, and generating the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the root sequence offset may be based on one or more of a cell identity (ID) of the base station, an index of the synchronization signal block, an index of a synchronization signal block-to-random access occasion mapping association period, an index of the random access occasion associated with the identified synchronization signal block within a synchronization signal block-to-random access occasion mapping association period, and the random access preamble root sequence.
  • ID cell identity
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the root sequence offset from the base station.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions across a set of mapping association periods, where the one or more additional random access occasions include one random access occasion per mapping association period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying an initial random access occasion index included by the initial random access preamble sequence for the random access occasion associated with the synchronization signal block, where each of the one or more additional random access occasions during the one or more mapping association periods corresponds to the initial random access occasion index.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a random access occasion hopping pattern for the one or more additional random access occasions, where the random access hopping pattern may be applied across the one or more mapping association periods, and where the random access hopping pattern may be associated with an initial random access occasion index included by the initial random access preamble sequence.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions during the one or more mapping association periods, where the one or more additional random access occasions include multiple random access occasions within each of the one or more mapping association periods.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication of a number of repetitions of the initial random access preamble sequence and a repetition pattern, where the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on a ratio of the repetition pattern to the number of repetitions.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence for the repetition pattern number of times per synchronization signal block-to-random access occasion cycle.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a pre-configured synchronization signal block-to-random access occasion mapping association period configuration, and determining the repetition scheme based on applying a synchronization signal block-to-random access occasion remapping factor to the pre-configured synchronization signal block-to-random access occasion mapping association period configuration, where the synchronization signal block-to-random access occasion remapping factor adjusts a number of synchronization signal blocks per random access occasion, a number of random access preambles per synchronization signal block, or both.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, the repetition scheme.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting the repetition scheme based on the synchronization signal block.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a SIB update cycle, and selecting the repetition scheme based on the SIB update cycle.
  • the one or more additional random access occasions occur after a first SIB update message and before a second SIB update message.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a repetition level setting of the UE including at least a number of repetitions of the initial random access preamble sequence, where the repetition scheme may be based on the determined repetition level setting of the UE.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where a configuration for the initial random access preamble sequence may be based on the determined repetition level setting of the UE.
  • the UE may be a New Radio (NR) -Light UE.
  • NR New Radio
  • a method of wireless communications at a base station may include transmitting a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receiving, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identifying a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitoring for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory.
  • the instructions may be executable by the processor to cause the apparatus to transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the apparatus may include means for transmitting a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receiving, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identifying a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitoring for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • a non-transitory computer-readable medium storing code for wireless communications at a base station is described.
  • the code may include instructions executable by a processor to transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • each of the one or more mapping association periods includes at least one repetition period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving at least a set of repetitions of the initial random access preamble sequence within each of the one or more mapping association periods.
  • the initial random access preamble sequence may be received in a first random access occasion, an Nth random access occasion, or a multiple of the Nth random access occasion, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving at least a portion of a set of repetitions of the initial random access procedure sequence in a mapping association period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the set of repetitions within a single association pattern period spanning a set of mapping association periods.
  • the initial random access preamble sequence may be received in a first mapping association period, an Nth mapping association period, or a multiple of the Nth mapping association period, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a portion of a set of repetitions of the initial random access preamble sequence within each of one or more association pattern periods, where an association pattern period spans a set of mapping association periods.
  • the initial random access preamble sequence may be received in a first mapping association period, an Nth mapping association period, or a multiple of the Nth association pattern period, and where N may be a number of repetitions of the initial random access preamble sequence to be transmitted.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for applying a root sequence offset to a random access preamble root sequence, and determining the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the root sequence offset may be based on one or more of a cell identity (ID) of the base station, an index of the synchronization signal block, an index of a synchronization signal block-to-random access occasion mapping association period, an index of the random access occasion associated with the identified synchronization signal block within a synchronization signal block-to-random access occasion mapping association period, and the random access preamble root sequence.
  • ID cell identity
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the root sequence offset to the UE.
  • the repetition scheme indicates to monitor for the repetitions of the initial random access preamble sequence during the one or more additional random access occasions across a set of mapping association periods, where the one or more additional random access occasions include one random access occasion per mapping association period.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying an initial random access occasion index included by the initial random access preamble sequence for the random access occasion associated with the synchronization signal block, where each of the one or more additional random access occasions during the one or more mapping association periods corresponds to the initial random access occasion index.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a random access occasion hopping pattern for the one or more additional random access occasions, where the random access hopping pattern may be applied across the one or more mapping association periods, and where the random access hopping pattern may be associated with an initial random access occasion index included by the initial random access preamble sequence.
  • the repetition scheme indicates to monitor for the repetitions of the initial random access preamble sequence during the one or more additional random access occasions during the one or more mapping association periods, where the one or more additional random access occasions include multiple random access occasions within each of the one or more mapping association periods.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an indication of a number of the repetitions of the initial random access preamble sequence and a repetition pattern, where the repetition scheme indicates to monitor for the initial random access preamble sequence during the one or more additional random access occasions based on a ratio of the repetition pattern to the number of the repetitions.
  • the repetition scheme indicates to monitor for the initial random access preamble sequence for the repetition pattern number of times per synchronization signal block-to-random access occasion cycle.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a pre-configured synchronization signal block-to-random access occasion mapping association period configuration, where the repetition scheme may be identified based on applying a synchronization signal block-to-random access occasion remapping factor to the pre-configured synchronization signal block-to-random access occasion mapping association period configuration, and where the synchronization signal block-to-random access occasion remapping factor adjusts a number of synchronization signal blocks per random access occasion, a number of random access preambles per synchronization signal block, or both.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the UE, the repetition scheme.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a SIB update cycle, where the repetition scheme may be identified based on the SIB update cycle.
  • the one or more additional random access occasions occur after a first SIB update message and before a second SIB update message.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where the repetition scheme may be based on the determined repetition level setting of the UE.
  • Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where a configuration for the initial random access preamble sequence may be based on the repetition level setting of the UE.
  • the UE may be a New Radio (NR) -Light UE.
  • NR New Radio
  • FIG. 1 illustrates an example of a system for wireless communications that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 2 illustrates an example of a wireless communications system that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIGs. 3 and 4 illustrate examples of repetition pattern configurations that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 5 illustrates an example of a dedicated repetition pattern configuration that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 6 illustrates examples of mapping identification configurations that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 7 illustrates an example of a process flow that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIGs. 8 and 9 show block diagrams of devices that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 10 shows a block diagram of a communications manager that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 11 shows a diagram of a system including a device that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIGs. 12 and 13 show block diagrams of devices that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 14 shows a block diagram of a communications manager that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIG. 15 shows a diagram of a system including a device that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • FIGs. 16 through 21 show flowcharts illustrating methods that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • Light devices may support Light devices.
  • Light devices such as smart devices, wearable devices, smart sensors, etc.
  • MBB mobile broadband
  • a Light device may also be referred to as a low-tier device for which premium features may not be needed or useful.
  • premium New Radio (NR) services may include ultra-reliable low-latency communications (URLLC) devices or enhanced mobile broadband (eMBB) devices.
  • URLLC ultra-reliable low-latency communications
  • eMBB enhanced mobile broadband
  • Low tier devices in Long Term Evolution (LTE) wireless systems included low power wide area (LPWA) devices or massive machine type communications (mMTC) devices.
  • LPWA low power wide area
  • mMTC massive machine type communications
  • a Light device may encompass LPWA and mMTC devices
  • a Light device also may include sensors (for example, industrial sensors) , cameras (for example, video monitoring devices) , wearables, and low tier or relaxed Internet of Things (IoT) devices.
  • Light devices may be used in a variety of applications, including healthcare, smart cities, transportation and logistics, electricity distribution, process automation, and building automation, just to name a few.
  • a Light device may have a latency requirement of 10-30 ms, and a reliability requirement of a Light device may be in the order of 10 -3 , 10 -4 , or 10 -5 .
  • the data rate of a Light device may be 10 Mbps and lower, for example.
  • a Light user equipment such as an NR-Light UE, may be configured to transmit with a reduced transmit power compared to non-Light devices.
  • the uplink transmit power of an NR-Light UE may be at least 10 dB lower than that of an MBB UE.
  • Light devices may transmit multiple repetitions of uplink signaling. Transmitting multiple repetitions may improve the likelihood of a base station receiving and successfully decoding transmissions from a Light UE.
  • a Light UE may transmit repetitions of a random access preamble of a random access procedure during initial access. Techniques described herein support a UE to identify associations between a received synchronization signal block (SSB) and parameters for transmitting repetitions of a random access preamble sequence during a random access procedure.
  • SSB received synchronization signal block
  • a UE may receive an SSB from a base station and identify information to receive a system information block (SIB) .
  • SIB system information block
  • the UE may receive SIB1 and identify parameters for a random access procedure in SIB1.
  • SIB1 may carry dedicated random access procedure parameters for Light (e.g., NR-Light) random access procedures.
  • the UE may interpret parameters for the Light random access procedure based on the actual parameters in the SIB1, which may be for other devices such as MBB UEs.
  • the UE may identify a configuration for generating the random access preamble sequences.
  • the UE may use different random access preamble sequences than, for example, MBB UEs to indicate that the UE is performing a Light random access procedure and transmitting multiple repetitions of the random access preamble sequence.
  • the UE may identify a mapping between the received SSB and random access procedure occasions (ROs) . For example, different SSBs (e.g., with different indexes) may be mapped to different ROs.
  • the UE may transmit the random access procedure preamble sequence in ROs corresponding to the received SSB.
  • the UE may also identify a repetition pattern or repetition scheme for transmitting repetitions of the random access preamble sequence.
  • the UE 115 may identify different configurations for how many repetitions of the random access preamble sequences to transmit within a single mapping association period, or how the repetitions of the random access preamble sequence are distributed across one or more mapping association periods. Additional techniques are described herein, such as determining a repetition scheme based on a SIB update cycle. Additionally, techniques for configuring different repetition schemes based on a repetition level of the device are described.
  • aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to repeating transmission of random access sequences.
  • FIG. 1 illustrates an example of a wireless communications system 100 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the wireless communications system 100 includes base stations 105, UEs 115, and a core network 130.
  • the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network.
  • LTE Long Term Evolution
  • LTE-A LTE-Advanced
  • LTE-A Pro LTE-Advanced Pro
  • NR New Radio
  • wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.
  • ultra-reliable e.g., mission critical
  • Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas.
  • Base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or some other suitable terminology.
  • Wireless communications system 100 may include base stations 105 of different types (e.g., macro or small cell base stations) .
  • the UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.
  • Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may utilize one or more carriers. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions.
  • the geographic coverage area 110 for a base station 105 may be divided into sectors making up a portion of the geographic coverage area 110, and each sector may be associated with a cell.
  • each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof.
  • a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110.
  • different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105.
  • the wireless communications system 100 may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.
  • the term “cell” refers to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) , and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) ) operating via the same or a different carrier.
  • a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband Internet-of-Things (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of devices.
  • MTC machine-type communication
  • NB-IoT narrowband Internet-of-Things
  • eMBB enhanced mobile broadband
  • the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.
  • UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile.
  • a UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client.
  • a UE 115 may also be a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer.
  • PDA personal digital assistant
  • a UE 115 may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.
  • WLL wireless local loop
  • IoT Internet of Things
  • IoE Internet of Everything
  • MTC massive machine type communications
  • Some UEs 115 may be low cost or low complexity devices, and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) .
  • M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention.
  • M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application.
  • Some UEs 115 may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.
  • Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications) . In some cases, UEs 115 may be designed to support critical functions (e.g., mission critical functions) , and a wireless communications system 100 may be configured to provide ultra-reliable communications for these functions.
  • critical functions e.g., mission critical functions
  • a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol) .
  • P2P peer-to-peer
  • D2D device-to-device
  • One or more of a group of UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105.
  • Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105, or be otherwise unable to receive transmissions from a base station 105.
  • groups of UEs 115 communicating via D2D communications may utilize a one-to-many (1 ⁇ M) system in which each UE 115 transmits to every other UE 115 in the group.
  • a base station 105 facilitates the scheduling of resources for D2D communications.
  • D2D communications are carried out between UEs 115 without the involvement of a base
  • Base stations 105 may communicate with the core network 130 and with one another.
  • base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1, N2, N3, or other interface) .
  • Base stations 105 may communicate with one another over backhaul links 134 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) .
  • the core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions.
  • the core network 130 may be an evolved packet core (EPC) , which may include at least one mobility management entity (MME) , at least one serving gateway (S-GW) , and at least one Packet Data Network (PDN) gateway (P-GW) .
  • the MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC.
  • User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW.
  • the P-GW may provide IP address allocation as well as other functions.
  • the P-GW may be connected to the network operators IP services.
  • the operators IP services may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched (PS) Stream
  • At least some of the network devices may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC) .
  • Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP) .
  • TRP transmission/reception point
  • various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station 105) .
  • Wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) .
  • the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length.
  • UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.
  • HF high frequency
  • VHF very high frequency
  • Wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band.
  • SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that may be capable of tolerating interference from other users.
  • ISM bands 5 GHz industrial, scientific, and medical bands
  • Wireless communications system 100 may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band.
  • EHF extremely high frequency
  • wireless communications system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE 115.
  • mmW millimeter wave
  • the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.
  • wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands.
  • wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band.
  • LAA License Assisted Access
  • LTE-U LTE-Unlicensed
  • NR NR technology
  • an unlicensed band such as the 5 GHz ISM band.
  • wireless devices such as base stations 105 and UEs 115 may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data.
  • LBT listen-before-talk
  • operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) .
  • Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these.
  • Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) , or a combination of both.
  • FDD frequency division duplexing
  • TDD time division duplexing
  • base station 105 or UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming.
  • wireless communications system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115) , where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas.
  • MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing.
  • the multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas.
  • Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams.
  • Different spatial layers may be associated with different antenna ports used for channel measurement and reporting.
  • MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.
  • SU-MIMO single-user MIMO
  • MU-MIMO multiple-user MIMO
  • Beamforming which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device.
  • Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference.
  • the adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device.
  • the adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .
  • a base station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105.
  • some signals e.g. synchronization signals, reference signals, beam selection signals, or other control signals
  • Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105.
  • Some signals may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) .
  • the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions.
  • a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality.
  • a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) , or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .
  • a receiving device may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals.
  • a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions.
  • a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal) .
  • the single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions) .
  • the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming.
  • one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower.
  • antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations.
  • a base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115.
  • a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.
  • wireless communications system 100 may be a packet-based network that operate according to a layered protocol stack.
  • PDCP Packet Data Convergence Protocol
  • a Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels.
  • RLC Radio Link Control
  • a Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels.
  • the MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency.
  • HARQ hybrid automatic repeat request
  • the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data.
  • RRC Radio Resource Control
  • transport channels may be mapped to physical channels.
  • UEs 115 and base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully.
  • HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link 125.
  • HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) .
  • FEC forward error correction
  • ARQ automatic repeat request
  • HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions) .
  • a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.
  • the radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023.
  • SFN system frame number
  • Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms.
  • a subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods.
  • a subframe may be the smallest scheduling unit of the wireless communications system 100, and may be referred to as a transmission time interval (TTI) .
  • TTI transmission time interval
  • a smallest scheduling unit of the wireless communications system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs) .
  • a slot may further be divided into multiple mini-slots containing one or more symbols.
  • a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling.
  • Each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation, for example.
  • some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots are aggregated together and used for communication between a UE 115 and a base station 105.
  • carrier refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125.
  • a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology.
  • Each physical layer channel may carry user data, control information, or other signaling.
  • a carrier may be associated with a pre-defined frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN) ) , and may be positioned according to a channel raster for discovery by UEs 115.
  • E-UTRA evolved universal mobile telecommunication system terrestrial radio access
  • E-UTRA absolute radio frequency channel number
  • Carriers may be downlink or uplink (e.g., in an FDD mode) , or be configured to carry downlink and uplink communications (e.g., in a TDD mode) .
  • signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) .
  • MCM multi-carrier modulation
  • OFDM orthogonal frequency division multiplexing
  • DFT-S-OFDM discrete Fourier transform spread OFDM
  • the organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR) .
  • communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data.
  • a carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc. ) and control signaling that coordinates operation for the carrier.
  • acquisition signaling e.g., synchronization signals or system information, etc.
  • control signaling that coordinates operation for the carrier.
  • a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.
  • Physical channels may be multiplexed on a carrier according to various techniques.
  • a physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques.
  • control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces) .
  • a carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100.
  • the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz) .
  • each served UE 115 may be configured for operating over portions or all of the carrier bandwidth.
  • some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type) .
  • a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type) .
  • a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related.
  • the number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme) .
  • the more resource elements that a UE 115 receives and the higher the order of the modulation scheme the higher the data rate may be for the UE 115.
  • a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers) , and the use of multiple spatial layers may further increase the data rate for communications with a UE 115.
  • a spatial resource e.g., spatial layers
  • Devices of the wireless communications system 100 may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths.
  • the wireless communications system 100 may include base stations 105 and/or UEs 115 that support simultaneous communications via carriers associated with more than one different carrier bandwidth.
  • Wireless communications system 100 may support communication with a UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation or multi-carrier operation.
  • a UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration.
  • Carrier aggregation may be used with both FDD and TDD component carriers.
  • wireless communications system 100 may utilize enhanced component carriers (eCCs) .
  • eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration.
  • an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link) .
  • An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum) .
  • An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs 115 that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power) .
  • an eCC may utilize a different symbol duration than other component carriers, which may include use of a reduced symbol duration as compared with symbol durations of the other component carriers.
  • a shorter symbol duration may be associated with increased spacing between adjacent subcarriers.
  • a device such as a UE 115 or base station 105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc. ) at reduced symbol durations (e.g., 16.67 microseconds) .
  • a TTI in eCC may consist of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable.
  • Wireless communications system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others.
  • the flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums.
  • NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.
  • Some UEs 115 may be examples of Light devices, such as smart devices, wearable devices, smart sensors, etc. Light devices may communicate with a base station 105 and operate in the same cell as other, non-Light devices, such as mobile broadband (MBB) devices.
  • a Light UE 115 such as an NR-Light UE 115, may be configured to transmit with a reduced transmit power compared to non-Light devices. Based on the reduced transmit power, Light devices may transmit multiple repetitions of uplink signaling. Transmitting multiple repetitions may improve the likelihood of a base station receiving and successfully decoding transmissions from a Light UE 115. For example, a Light UE 115 may transmit repetitions of a random access preamble of a random access procedure during initial access. Techniques described herein support a UE 115, such as an NR-Light UE 115, to identify associations between a received SSB and parameters for transmitting repetitions of a random access preamble sequence during a random access procedure.
  • a UE 115 may receive an SSB from a base station and identify a mapping between the received SSB and ROs for transmitting the repetitions of the random access preamble sequence.
  • the UE 115 may transmit the random access procedure preamble sequence in ROs corresponding to the received SSB.
  • the UE 115 may identify a repetition pattern or repetition scheme for transmitting repetitions of the random access preamble sequence.
  • the UE 115 may identify different configurations for how many repetitions of the random access preamble sequences to transmit within a single mapping association period, or how the repetitions of the random access preamble sequence are distributed across one or more mapping association periods. Additional techniques are described herein, such as determining a repetition scheme based on a SIB update cycle. Additionally, techniques for configuring different repetition schemes based on a repetition level of the device are described.
  • FIG. 2 illustrates an example of a wireless communications system 200 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • wireless communications system 200 may implement aspects of wireless communication system 100.
  • the wireless communications system 200 may include UE 115-a and base station 105-a, which may be respective examples of a UE 115 and a base station 105.
  • Base station 105-a and UE 115-a may support beamformed communications. For example, base station 105-a may transmit to UE 115-aon a base station beam 205, and UE 115-a may monitor for the transmissions using UE beams 210. Or, UE 115-a may transmit using the UE beams 210, and base station 105-a may monitor using the base station beams 205.
  • UE 115-a may perform a random access procedure to attach to base station 105-a.
  • UE 115-a may monitor for synchronization signals, transmitted in a synchronization signal block (SSB) 215 by base station 105-a.
  • An SSB 215 may include, for example, a primary synchronization signal (PSS) , a secondary synchronization signal (SSS) , and two physical broadcast channels (PBCHs) .
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • PBCHs physical broadcast channels
  • Base station 105-a may transmit a master information block (MIB) in the PBCH, which may carry information for how UE 115-a can find system information blocks (SIBs) .
  • SIB such as a first SIB or SIB1, may carry information (e.g., parameters) related to random access procedures.
  • UE 115-a may determine random access channel parameters based on the parameters carried in SIB1. For example, UE 115-a may determine a set of preambles to transmit during the random access procedure. In some cases, UE 115-a may identify up to 64 preambles.
  • the preambles may be determined by a preamble root sequence parameter (e.g., “prach-RootSequenceIndex” ) , a parameter indicating a set restriction for the preambles (e.g., “restrictedSetConfig” ) , a zero correlation zone parameter (e.g., “zeroCorrelationZoneConfig” ) , a parameter indicating a total number of random access preambles ( “totalNumberOfRA-Preambles” ) , or any combination thereof.
  • a preamble root sequence parameter e.g., “prach-RootSequenceIndex”
  • a parameter indicating a set restriction for the preambles e.g., “restrictedSetConfig”
  • a zero correlation zone parameter e.g., “zeroCorrelationZoneConfig”
  • a parameter indicating a total number of random access preambles “totalNumberOf
  • UE 115-a may also determine when to transmit a random access preamble. For example, UE 115-a may identify random access occasions (ROs) based on the information conveyed in the SIB1. In some cases, UE 115-a may determine which format of random access preamble that UE 115-a can transmit. UE 115-a may identify a number of frequency division multiplexed ROs at each RO instance (e.g., in the time domain) , which may be determined based on a parameter such as “msg1-FDM. ” UE 115-a may also identify a starting frequency of the ROs, which may be determined based on a parameter such as “msg1-FrequencyStart.
  • ROs random access occasions
  • UE 115-a may also determine an association between an index of the received SSB and ROs. For example, UE 115-a may determine how a transmitted preamble or a chosen RO can be associated with an SSB index, such as for beam management. The association may be determined based on an SSB-to-RO association parameter such as “ssb-perRACH-OccasionAndCB-PreamblesPerSSB. ”
  • the SSB-to-RO association parameter may indicate both a number of SSBs per RO. For example, there may be 1/8, 1/4, 1/2, 1, 2, 4, 8, or 16 SSBs per RO.
  • the SSB-to-RO association parameter may indicate a number of contention- based random access preambles per SSB.
  • the number of contention-based random access preambles per SSB may be based on a number of SSBs per RO.
  • the total number of random access preambles may correspond to the number of contention-based random access preambles per SSB and the number of SSBs per RO. In some cases, mapping may follow one of four different orders.
  • the first order may be preamble indexes within a single RO.
  • the second order may be FDM index for the same time-domain RO instance.
  • the third order may be time division multiplexed random access index within a random access channel slot.
  • the fourth order may be the random access channel slot index.
  • UE 115-a may be an example of a Light device.
  • UE 115-a may be an example of a Light UE, such as NR-Light UE or an NR-Light device.
  • an NR-Light UE may be referred to as a Low-Tier NR UE 115.
  • Light devices may be, for example, smart devices, wearable devices, sensors, such as industrial sensors or video surveillance sensors, or other types of devices. Light devices may have a reduced transmit power compared to other types of NR devices.
  • the uplink transmit power of a Light UE may be at least 10 dB lower than an MBB or eMBB UE 115.
  • Light UEs may have a reduced transmit/receive bandwidth.
  • a Light UE may be configured with 5 MHz bandwidth or 10MHz bandwidth, or some amount between, for both transmitting and receiving.
  • a Light UE may have a reduced number of receive antennas.
  • a Light UE may use one receive antenna, which may correspond to a lower equivalent receive SNR.
  • the Light UEs may support generally reduced computation complexity.
  • the Light UEs may be low power devices, where increased complexity and processing may lead to higher power usage.
  • Light devices such as UE 115-a, may operate in the same cell as other UEs 115 which are not Light devices. In some cases, based on the reduced transmit power of the Light devices, Light devices may repeat uplink transmissions. For example, UE 115-a may transmit repetitions for random access channel transmissions, reference signals, uplink control channel transmissions, uplink shared channel transmissions, or any combination thereof. This may assist base station 105-a in successfully detecting and decoding the uplink signals from UE 115-a. Without transmitting repetitions, base station 105-a may not be able to detect the uplink signaling from UE 115-a, as the uplink transmissions with lower transmit power may be more susceptible to interference.
  • a Light UE may transmit repetitions of random access preambles during initial access.
  • Techniques described herein support a UE 115, such as a Light UE like UE 115-a, to identify associations between a received SSB 215 and parameters for a random access procedure which supports repeated transmissions of a random access preamble.
  • UE 115-a may identify an SSB-to-RO mapping, a configuration for random access preambles for Light random access procedures, a configuration for a repetition scheme to transmit repetitions of the random access preamble, or any combination thereof.
  • UE 115-a may identify these associations based on interpreting a random access channel configuration for other UEs 115 (e.g., legacy NR UEs or eMBB UEs) , which may be signaled in SIB1.
  • UE 115-a may identify the associations based on dedicated configurations for Light UEs.
  • the dedicated configurations may be signaled in SIB1.
  • the repetitions may be retransmissions of the initial random access preamble sequence.
  • UE 115-a may use different random access preambles than a non-Light device.
  • UE 115-a may be configured with dedicated random access preambles, and the dedicated random access preambles may be indicated in a SIB1. If dedicated preambles are not configured, UE 115-a may still use different preamble sequences than those used by non-Light devices. If UE 115-a used the same preamble sequences, base station 105-a may not be able to distinguish the NR-Light transmission repetitions across ROs, and base station 105-a would not carry out combining the repetitions. Therefore, UE 115-a may apply an interpretation to the random access configuration carried in the SIB1 for other UEs 115.
  • the SIB1 may include a root sequence, which UEs 115 (e.g., eMBB UEs 115) use to determine random access preambles.
  • An NR-Light UE such as UE 115-a, may apply a root sequence offset to the root sequence in the SIB1.
  • the root sequence offset may be associated with the root sequence in the SIB1, a cell ID of base station 105-a, and an SSB index for the received SSB 215.
  • UE 115-a may then use the modified root sequence to identify random access preamble sequences.
  • UE 115-a may transmit one or more of the random access preamble sequences generated from the modified root sequence during a random access procedure.
  • Base station 105-a may receive the random access preamble sequence from UE 115-a, determine that it corresponds to an NR-Light UE, and determine that there may be repetitions of the random access preamble sequence in following ROs. Base station 105-a may then monitor following ROs for the repetitions based on the random access preamble sequence corresponding to NR-Light UEs 115.
  • Some techniques for identifying repetition patterns and SSB-to-RO mappings are described herein. Some example techniques for identifying repetition patterns are described with reference to FIGs. 3 through 5. Some examples techniques for identifying SSB-to-RO mappings are described with reference to FIG. 6.
  • base station 105-a may transmit a SIB1 with updated information from a previously transmitted SIB1. If UE 115-a is re-using resource elements of non-NR-Light UEs 115, then arbitrarily allocating repetitions may lead to repetitions crossing from one random access cycle with a first SIB1 configuration to a second random access cycle with a second, updated SIB1 configuration. This may cause some issues, such as if resource element allocations for random access procedures change across the random access cycles. Therefore, UE 115-a may avoid a repetition pattern or repetition scheme which would lead to repetitions across SIB update cycles.
  • UE 115-a may be aware of when SIB updates occur, and UE 115-a may select a repetition scheme which avoids transmitting repetitions of a random access preamble sequence across SIB cycles. For example, UE 115-a may transmit an initial random access preamble sequence and each repetition of the random access preamble sequence within one SIB update cycle.
  • NR-Light UEs 115 may have different configurations.
  • UE 115-a may have a repetition level.
  • UEs 115 with different repetition levels may identify different configurations.
  • UE 115-a may identify a configuration of preambles, a configuration of repetition patterns, or both, based on the repetition level of UE 115-a.
  • the configuration of preambles may correspond to a repetition-level specific root sequence offset.
  • an NR-Light UE 115 may identify a root sequence offset for determining random access sequence preambles based on its repetition level. which may correspond to a number of repetitions UE 115-a performs.
  • UEs 115 with different repetition levels may identify different ROs that may be supported to start repetitions or transmit preamble repetitions.
  • repetition pattern identification as described at least with reference to FIGs. 3 through 6, may be based on a repetition level of the UE 115 performing the identifying.
  • a repetition level may be based on hardware of the corresponding device. Additionally, or alternatively, the repetition level may be configurable.
  • each SSB-to-RO association period may include at last one repetition period.
  • UE 115-a may be able to finish at least one set of repetitions within a single SSB-to-RO association period.
  • the starting random access occasion index used to transmit the initial random access preamble sequence in this first example may be the 0th random access occasion, the Nth random access occasion, or a multiple of the Nth random access occasion (e.g., 2*Nth, 3*Nth, etc. ) , where N is the number of repetitions of the initial random access preamble sequence UE 115-a is to transmit.
  • UE 115-a may be able to repeat a part of the repetitions within a single SSB-to-RO mapping association period.
  • the full set of repetitions may be finished within a single SSB-to-RO association pattern period across multiple SSB-to-RO mapping association periods.
  • the second example may occur when the first example cannot be met.
  • the SSB-to-RO mapping association periods may be mapped within at most 160ms. For multiple rounds, the 160ms may be referred to as an SSB-to-RO association pattern period.
  • UE 115-a may start the transmission of the initial random access preamble sequence in the 0th mapping association period, the Nth mapping association period, or a multiple of the Nth mapping association period (e.g., 2*Nth, 3*Nth, etc. ) , where N is the number of repetitions of the initial random access preamble sequence UE 115-a is to transmit.
  • the repetition of PRACH sequences may be transmitted across multiple SSB-to-RO association pattern periods.
  • the third example may occur when the first example and the second example cannot be met.
  • UE 115-a may start transmission with the initial random access preamble sequence in the 0th association pattern period, the Nth association pattern period, or a multiple of the Nth association pattern period (e.g., 2*Nth, 3*Nth, etc. ) , where N is the number of repetitions of the initial random access preamble sequence UE 115-a is to transmit.
  • FIG. 3 illustrates an example of repetition pattern configurations 300 and 301 that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the repetition pattern configurations 300 and 301 may implement aspects of wireless communication system 100.
  • Some UEs 115 may transmit repetitions of uplink signaling based on having a lower uplink transmit power.
  • a receiving device e.g., a base station 105
  • the techniques described herein provide for transmitting repetitions of random access preamble sequences, such as during initial access.
  • a UE 115 may receive an SSB and identify associations between the received SSB and one or more configurations for the random access procedure. The UE 115 may then transmit an initial random access preamble sequence and repetitions of the initial random access preamble sequence based on the identified configurations.
  • a UE 115 may identify a repetition pattern for transmitting repetitions of the initial random access preamble sequence.
  • the repetition pattern may be an example of, or may be an aspect of, a repetition scheme identified by the UE 115.
  • the repetition pattern configurations 300 and 301 show SSB-to-RO mapping configurations, which indicate how SSBs 310 map to ROs 305, and which preambles 315 are supported for transmission in which ROs 305.
  • an SSB 310 with index #1 may correspond to ROs 310 with indexes #4, #5, #6, and #7, and there may be 64 contention-based preambles 315 per SSB 310.
  • the UE 115 may transmit the repetitions across SSB-to-RO mapping association periods 320, or SSB-to-RO mapping cycles 320.
  • the UE 115 may determine which ROs 305 to use for transmitting repetitions of the initial random access preamble sequence in subsequent SSB-to-RO mapping association periods based on a repetition scheme.
  • the UE 115 may interpret configuration information included in a SIB (e.g., for non-NR-Light UEs) to determine a repetition scheme such as the repetition pattern configurations 300 and 301.
  • repetition schemes like the repetition pattern configurations 300 and 301 may be configured for the UE 115 and may, in some cases, be explicitly indicated in system information.
  • the UE 115 may randomly choose one RO 305 (e.g., a selected RO 325) associated with the index of the received SSB 310 (e.g., the identified SSB index) .
  • the UE 115 may transmit a preamble 315 associated with the SSB index in the selected RO 325.
  • the preamble may be transmitted for a number of repetitions in a same number of following SSB-to-RO mapping association periods 320.
  • the selected ROs 325 in the following SSB-to-RO mapping association periods 320 may be determined based on the RO 305 chosen in the initial SSB-to-RO mapping association period 320.
  • the number of repetitions may be determined based on, for example, information transmitted in a SIB (e.g., SIB1) .
  • SIB1 information transmitted in a SIB
  • a UE 115 may transmit four repetitions of an initial random access preamble sequence.
  • a UE 115 may receive an SSB 310 with index 1.
  • the UE 115 may select an RO 305 (e.g., a selected RO 325) corresponding to RO #5 to transmit an initial random access preamble sequence.
  • the selected RO 325 may correspond to a second RO of first SSB-to-RO mapping association period 320.
  • the UE 115 may transmit a repetition of the initial random access preamble sequence in the second RO.
  • the UE 115 may transmit a repetition of the initial random access preamble sequence in the second RO in each of second SSB-to-RO mapping association period 320-b, third SSB-to-RO mapping association period 320-c, and fourth SSB-to-RO mapping association period 320-d.
  • a UE 115 may receive an SSB 310 with index 1 and select an RO 305 (e.g., a selected RO 325) corresponding to RO #5 to transmit an initial random access preamble sequence.
  • the selected RO 325 may correspond to a second RO of first SSB-to-RO mapping association period 320.
  • the UE 115 may transmit a repetition of the initial random access preamble sequence based on an RO choosing pattern.
  • the selected RO 325 for each SSB-to-RO mapping association period 320 may change.
  • the UE 115 may transmit a repetition of the initial random access preamble sequence in the third RO 305 of second SSB-to-RO mapping association period 320-b, the fourth RO 305 of third SSB-to-RO mapping association period 320-c, and the first RO 305 of fourth SSB-to-RO mapping association period 320-d. If a random access preamble sequence is mapped to RO N in a first SSB-to-RO mapping association period 320, a repetition of the random access preamble sequence may be mapped to RO N+1 in a following SSB-to-RO mapping association period 320. In other examples, other RO choosing patterns may be applied (e.g., N-1, etc. ) .
  • a UE 115 may start an initial preamble transmission in an SSB-to-RO mapping association period 320 which is based on a number of repetitions. For example, a UE 115 may start the initial preamble transmission in an SSB-to-RO mapping association period 320 with index 0 or an index which is equal to a multiple of the number of repetitions.
  • FIG. 4 illustrates an example of a repetition pattern configuration 400 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • repetition pattern configuration 400 may implement aspects of wireless communication system 100.
  • a UE 115 may transmit repetitions of uplink signaling, such as random access preamble sequences during a random access procedure.
  • the UE 115 may identify a repetition scheme for transmitting repetitions of an initial random access preamble sequence.
  • the repetition scheme may include, for example, a repetition pattern.
  • the repetition pattern may indicate how the UE 115 is to transmit the repetitions in one or more SSB-to-RO mapping association periods 420, or SSB-to-RO mapping cycles 420.
  • the repetition pattern configuration 400 shows an SSB-to-RO mapping configuration, which indicate how SSBs 410 map to ROs 405, and which preambles 415 can be transmitted in which ROs 405.
  • the UE 115 may determine which ROs 405 to use for transmitting repetitions of the initial random access preamble sequence based on an identified repetition scheme (e.g., including a repetition pattern) .
  • the repetition pattern configuration 400 may show an example repetition pattern where repetitions may be transmitted in time division multiplexed ROs 405 which are associated with the same identified SSB. For example, starting from a first RO 405 within an SSB-to-RO mapping association period 420 which is associated with the identified SSB, a UE 115 may transmit a number of preamble repetitions in a consecutive number of ROs 405 that are associated with the identified SSB index.
  • a first UE 115 may receive an SSB 410 with index 1. There may be four ROs 405 associated with each SSB 410 per SSB-to-RO mapping association period 420.
  • the first UE 115 may be configured to transmit eight repetitions of an initial random access preamble sequence. Therefore, the first UE 115 may transmit all eight repetitions in selected ROs 425 across two SSB-to-RO mapping association periods 420.
  • the first UE 115 may transmit an initial random access preamble sequence in a first RO 405 associated with the SSB in SSB-to-RO mapping association period 420-a.
  • the first UE 115 may then transmit repetitions of the random access preamble sequence in the following three ROs 405, which may each be associated with SSB #1.
  • the first UE 115 may transmit repetitions of the random access preamble sequence in the four ROs 405 which are associated with SSB #1.
  • a second UE 115 may receive an SSB 410 with index 1 (e.g., SSB #1) .
  • the second UE 115 may be configured to transmit eight repetitions of an initial random access preamble sequence.
  • the second UE 115 may transmit all eight repetitions in selected ROs 425 across two SSB-to-RO mapping association periods 420.
  • the second UE 115 may transmit an initial random access preamble sequence in a first RO 405 associated with SSB #1 in SSB-to-RO mapping association period 420-c.
  • the second UE 115 may then transmit repetitions of the random access preamble sequence in the following three ROs 405, which may each be associated with SSB #1.
  • the second UE 115 may transmit repetitions of the random access preamble sequence in the four ROs 405 which are associated with SSB #1.
  • the repetitions may be associated with the same or different frequency division multiplexed ROs. If the repetitions are associated with different frequency division multiplexed ROs, the association may be based on a random patter associated with an index of the initially chosen frequency division multiplexed RO.
  • the UE 115 may start the initial preamble transmission on an SSB-to-RO mapping association period 420 with an index may be based on the number of configured repetitions and a number of ROs per SSB per cycle. For example, the initial SSB-to-RO mapping association period 420 may have an index equal to a multiple of the number of repetitions over the number of ROs per SSB per cycle. In an example, the UE 115 may be configured to transmit 8 repetitions per random access procedure. There may be 4 ROs per SSB within an SSB-to-RO mapping association period 420. Then, the initial SSB-to-RO mapping association period 420 for starting transmission of random access preamble repetitions may be 0, 2, 4, etc.
  • FIG. 5 illustrates an example of a dedicated repetition pattern configuration 500 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the dedicated repetition pattern configuration 500 may implement aspects of wireless communication system 100.
  • a UE 115 may be configured with a dedicated repetition pattern for identifying ROs to transmit repetitions of a random access preamble sequence.
  • the UE 115 may be configured with a number of repetitions, R, and a repetition pattern value P.
  • the repetition pattern value P may be a portion of the number of repetitions. For example, P may be 25%of R, 50%of R, 100%of R, etc.
  • a UE 115 may be configured to transmit 8 repetitions of a random access preamble sequence for an NR-Light random access procedure.
  • the UE 115 may also be configured with a repetition pattern value, P, via a SIB. Using the above examples of 25%, 50%, and 100%, P may then be 2, 4, or 8, respectively.
  • the UE 115 may map P consecutive repetitions in a first SSB-to-RO mapping association period 525 starting from a first RO associated with the received SSB. For example, the UE 115 may map until all SSBs 510 in the SSB-to-RO mapping association period 525 are mapped. This mapping pattern may continue in following SSB-to-RO mapping association periods 525 until each SSB is repeated R times, corresponding to R repetitions of the random access preamble sequence. This mapping may occur within a repetition pattern mapping association period 530, which may span multiple SSB-to-RO mapping association periods 525.
  • each SSB-to-RO mapping association period 525 may have eight ROs 505, where each RO 505 is mapped to an SSB index 510.
  • the SSB-per-RACH-occasion parameter may be 1
  • the msg1-FDM may be 1.
  • the UE 115 may receive an SSB with index #1 and identify a repetition mapping scheme based on the SSB. Then, starting at initial SSB-to-RO cycle 525-a, the UE 115 transmits P random access preamble sequences in a selected RO 515 to SSB index #1.
  • the UE 115 transmits one random access preamble sequence per SSB-to-RO cycle 525. After transmitting an initial random access preamble sequence in initial SSB-to-RO cycle 525-a, the UE 115 transmits a repetition of the initial random access preamble sequence once in each of the following seven SSB-to-RO mapping association periods 525 at selected ROs 515 corresponding to SSB index #1.
  • Repetition pattern mapping association period 530-a may span R SSB-to-RO mapping association periods 525-a in this example.
  • the dedicated repetition pattern configuration 500 may be referred to as a per SSB-burst based repetition pattern.
  • each SSB-to-RO mapping association period 525 may have 64 ROs 505, where each SSB index 510 is mapped to eight different ROs 505.
  • the SSB-per-RACH-occasion parameter may be 1/8, and the msg1-FDM may be 1.
  • the UE 115 may receive an SSB with index #1 and identify a repetition mapping scheme based on the SSB. In the repetition pattern mapping association period 530-b, the UE 115 then transmits P random access preamble sequences in ROs 505 mapped to SSB index #1 (e.g., selected ROs 515) .
  • the UE 115 transmits eight random access preamble sequence per SSB-to-RO mapping association period 525, which may span the same number of ROs 505 as the repetition pattern mapping association period 530-b.
  • the repetition pattern mapping association period 530-b may be finished after one SSB-to-RO mapping association period 525.
  • the UE 115 may transmit eight consecutive repetitions of a random access preamble sequence in eight consecutive ROs 505 which map to SSB #1.
  • the dedicated repetition pattern configuration 500 may be referred to as a per repetition level based repetition pattern.
  • each SSB-to-RO mapping association period 525 may have 32 ROs 505, where each SSB 510 is mapped to four consecutive ROs 505.
  • the SSB-per-RACH-occasion parameter may be 1/4, and the msg1-FDM may be 1.
  • the UE 115 may receive an SSB with index #1 and identify a repetition mapping scheme based on the SSB.
  • the UE 115 transmits P (e.g., 4) random access preamble sequences in ROs 505 mapped to SSB index #1 (e.g., the selected ROs 515) . Then, in second SSB-to-RO mapping association period 525-d, the UE 115 may transmit four random access preamble sequences in the ROs 505 mapped to SSB index #1. In this example, the UE 115 transmits four random access preamble sequence per SSB-to-RO mapping association period 525, and the repetition pattern mapping association period 530-b may span two SSB-to-RO mapping association periods 525. In some cases, the dedicated repetition pattern configuration 500 may be referred to as a half repetition level based repetition pattern.
  • the mapping of repetitions for the initial SSB indexes may start from the frequency division multiplexed RO groups associated with the same SSB index. For example, the mapping of repetitions may start from the first RO group and continued for P ROs. Then, repetitions for the multiple SSB indexes may start from the (P+1) th RO and continue for the next P ROs. Repetitions for the next SSB indexes may start from
  • FIG. 6 illustrates examples of mapping identification configurations 600 that support repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the mapping identification configuration 600 may implement aspects of wireless communication system 100.
  • a UE 115 such as an NR-Light UE 115, may implement techniques to identify SSB-to-RO mapping configurations. The UE 115 may then select ROs to transmit repetitions of a random access preamble sequence for an NR-Light random access procedure based on a repetition scheme.
  • a base station 105 may transmit some SSB-to-RO mapping information in a SIB.
  • the SSB-to-RO mapping information transmitted in the SIB may indicate SSB-to-RO mapping configurations for eMBB, or non-NR-Light, devices. Therefore, an NR-Light UE 115 may interpret the SSB-to-RO mapping information in the SIB to identify an SSB-to-RO mapping configuration for NR-Light random access procedure.
  • the UE 115 may identify a new SSB-to-RO mapping by multiplying the value of the SSB-per-RACH-occasion parameter indicated in the SIB.
  • the UE 115 may also update the value of the CB-preambles-per-SSB indicated in the SIB based on the updated SSB-per-RACH-occasion value.
  • an updated mapping identification configuration such as a mapping identification configuration 601 or 602, may be used for the SSB-to-RO repetition pattern identification techniques described in FIGs. 3 through 5.
  • the mapping identification configuration 600 may correspond to the SSB-to-RO mapping configuration for eMBB devices as indicated in a SIB.
  • the mapping identification configuration 600 may have an SSB-per-RACH-occasion value of 1/4 and a CB-preambles-per-SSB value of 64. Therefore, each SSB 610 may correspond to four ROs 605, with 64 available preambles 615 per SSB 610.
  • a UE 115 such as an NR-Light UE 115, may receive the SIB indicating these parameters and apply a scaling factor or interpretation rule to determine an SSB-to-RO mapping configuration for NR-Light random access procedures.
  • the updated SSB-per-RACH-occasion value may be equal to 1.
  • the SSB-per-RACH-occasion parameter indicated by the SIB may be multiplied 4 times to determine the updated SSB-per-RACH-occasion value for NR-Light random access procedures.
  • the UE 115 may still use the value of 64 CB-preambles-per-SSB as indicated for eMBB devices.
  • the updated SSB-per-RACH-occasion value may be equal to 4.
  • the SSB-per-RACH-occasion parameter indicated by the SIB may be multiplied 16 times to determine the updated SSB-per-RACH-occasion value for NR-Light random access procedures.
  • the UE 115 may re-calculate the value of CB-preambles-per-SSB to support 4 ROs 605 per SSB 610. Therefore, there may be 16 preambles 615 per SSB 610, with a CB-preambles-per-SSB value of 16.
  • FIG. 7 illustrates an example of a process flow 700 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • process flow 700 may implement aspects of wireless communication system 100.
  • Process flow 700 may include UE 115-b and base station 105-b, which may be respective examples of a UE 115 and a base station 105.
  • UE 115-b may be an example of an NR-Light device as described herein.
  • UE 115-b may have a lower transmit power than other (e.g., eMBB) devices. Therefore, UE 115-b may transmit repetitions of uplink signaling, which base station 105-b may then combine to improve the likelihood of successful reception and decoding.
  • the process flow 700 may describe UE 115-b performing a random access procedure (e.g., during initial access) based on NR-Light configurations.
  • base station 105-b may transmit an SSB associated with a transmit beam of base station 105-b, the SSB being one of a set of SSBs that are each associated with a respective transmit beam of base station 105-b.
  • UE 115-b may receive the SSB and, in some cases, identify information for decoding SIBs, such as SIB1, from the SSB.
  • base station 105-b may transmit SIB1.
  • SIB1 may include parameters for random access procedures.
  • SIB1 may indicate SSB-to-RO mapping configurations, which preambles can be used for random access procedures, and scheduling information (e.g., time and frequency information) for ROs, among other parameters.
  • the SIB1 may include parameters for NR-Light random access procedures.
  • base station 105-b may indicate dedicated configurations for SSB-to-RO mapping association periods, repetition patterns, preamble configurations, or any combination thereof. In some cases, there may not be dedicated configurations for NR-Light devices.
  • the random access parameters indicated in the SIB1 may be for non-NR-Light devices, such as eMBB UEs. Therefore, to distinguish the random access procedures and random access transmissions of NR-Light devices from eMBB devices, the NR-Light devices may interpret different configurations for parameters indicated in the SIB1.
  • UE 115-b may identify random access parameters for transmitting an initial random access preamble sequence.
  • UE 115-b may transmit an initial random access preamble sequence during an RO associated with the SSB.
  • the SSB received at 705 may have an SSB index of 2 (e.g., SSB #2) .
  • UE 115-b may transmit the initial random access preamble sequence in an RO to which SSB #2 is mapped.
  • the SSB-to-RO mapping information used to identify the RO may be for NR-Light devices.
  • UE 115-b may determine an updated SSB-to-RO mapping configuration from the parameters indicated in the SIB1 as described with reference to FIG. 6.
  • UE 115-b may identify a pre-configured synchronization signal block-to-random access occasion mapping association period configuration.
  • the pre-configured SSB-to-RO mapping association period configuration may be indicated in the SIB1.
  • UE 115-b may determine the repetition scheme based at on applying a synchronization signal block-to-random access occasion remapping factor to the pre-configured synchronization signal block-to-random access occasion mapping association period configuration, where the synchronization signal block-to-random access occasion remapping factor adjusts a number of synchronization signal blocks per random access occasion, a number of random access preambles per synchronization signal block, or both. Examples of applying an SSB-to-RO remapping factor of 4 and 16 are described with reference to FIG. 6.
  • the initial random access preamble sequence may correspond to NR-Light devices.
  • UE 115-b may apply a root sequence offset to a root sequence and generate the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • base station 105-b may be able to determine that the random access preamble sequence is transmitted by an NR-Light device, and base station 105-b may combine the repetitions of the initial random access preamble sequence.
  • UE 115-b may identify a repetition scheme for transmitting repetitions of the initial random access preamble sequence during one or more additional ROs associated with the SSB during one or more mapping association periods of an SSB-to-RO mapping.
  • base station 105-b may identify the repetition scheme.
  • the repetition scheme may include, for example, a repetition pattern for transmitting repetitions of the initial random access preamble sequence.
  • the repetition scheme indicates to transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions across a set of mapping association periods, where the one or more additional random access occasions include one random access occasion per mapping association period.
  • This first example may correspond to repetition pattern configurations as described with reference to FIG. 3.
  • the repetition scheme indicates to transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions during the one or more mapping association periods, where the one or more additional random access occasions include multiple random access occasions within each of the one or more mapping association periods.
  • This example may correspond to a repetition pattern configuration as described with reference to FIG. 4.
  • UE 115-b may receive an indication of a number of repetitions for the initial random access preamble sequence and a repetition pattern, where the repetition scheme indicates to transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on a ratio of the repetition pattern to the number of repetitions.
  • the indication of the number of repetitions may be R
  • the repetition pattern may be P as described with reference to FIG. 6.
  • the repetition scheme may indicate to transmit the initial random access preamble sequence for the repetition pattern number of times per SSB-to-RO mapping association period.
  • UE 115-a may transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • base station 105-b may combine the initial random access preamble sequence and the repetitions of the initial random access preamble sequence. Based on the initial random access preamble sequence, base station 105-b may determine that UE 115-b is an NR-Light UE performing an NR-Light random access procedure. Due to the lower transmit power of these types of devices, UE 115-b may transmit the repetitions of the initial sequence to improve the likelihood of successful reception and decoding at base station 105-b. Therefore, base station 105-b may receive the initial random access preamble sequence, determine it’s used for NR-Light random access procedures based on the selected sequence (e.g., sequence number) , and attempt to combine the initial transmission and the repetitions. Base station 105-b may monitor for the repetitions based on identifying the repetition scheme at 720-b.
  • FIG. 8 shows a block diagram 800 of a device 805 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 805 may be an example of aspects of a UE 115 as described herein.
  • the device 805 may include a receiver 810, a communications manager 815, and a transmitter 820.
  • the device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to repeating transmission of random access sequences, etc. ) . Information may be passed on to other components of the device 805.
  • the receiver 810 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the receiver 810 may utilize a single antenna or a set of antennas.
  • the communications manager 815 may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for repetitions of the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the communications manager 815 may be an example of aspects of the communications manager 1110 described herein.
  • the communications manager 815 may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 815, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.
  • code e.g., software or firmware
  • ASIC application-specific integrated circuit
  • the communications manager 815 may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components.
  • the communications manager 815, or its sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure.
  • the communications manager 815, or its sub-components may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.
  • I/O input/output
  • the actions performed by the UE communications manager 815 as described herein may be implemented to realize one or more potential advantages.
  • One implementation may allow a UE 115 to increase the likelihood of successful uplink transmissions.
  • uplink transmissions from Light devices e.g., Light UEs 115
  • Light devices e.g., Light UEs 115
  • the techniques described herein may also assist a base station 105 in detecting that the UE 115 is a Light device, such that the base station 105 can determine to combine the repetitions of the random access preamble sequence.
  • the transmitter 820 may transmit signals generated by other components of the device 805.
  • the transmitter 820 may be collocated with a receiver 810 in a transceiver module.
  • the transmitter 820 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the transmitter 820 may utilize a single antenna or a set of antennas.
  • FIG. 9 shows a block diagram 900 of a device 905 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 905 may be an example of aspects of a device 805, or a UE 115 as described herein.
  • the device 905 may include a receiver 910, a communications manager 915, and a transmitter 940.
  • the device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to repeating transmission of random access sequences, etc. ) . Information may be passed on to other components of the device 905.
  • the receiver 910 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the receiver 910 may utilize a single antenna or a set of antennas.
  • the communications manager 915 may be an example of aspects of the communications manager 815 as described herein.
  • the communications manager 915 may include a SSB identifying component 920, an initial transmission component 925, a repetition scheme identifying component 930, and a repetition component 935.
  • the communications manager 915 may be an example of aspects of the communications manager 1110 described herein.
  • the SSB identifying component 920 may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the initial transmission component 925 may transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the repetition scheme identifying component 930 may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the repetition component 935 may transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the transmitter 940 may transmit signals generated by other components of the device 905.
  • the transmitter 940 may be collocated with a receiver 910 in a transceiver module.
  • the transmitter 940 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11.
  • the transmitter 940 may utilize a single antenna or a set of antennas.
  • a processor of a Light UE 115 may efficiently transmit repetitions of a random access preamble sequence during a random access procedure.
  • the random access procedure may be performed during initial access, which may result in the Light UE 115 attaching to a cell faster. Without transmitting repetitions of the random access preambles sequence, the transmissions of the UE 115 with a lower uplink transmit power may not be successfully received by a base station 105. This may lead the UE 115 being unable to attach to the base station 105 and using significant power and energy to perform random access procedures.
  • the UE 115 may successfully perform a random access procedure quickly, which may let the UE 115 enter a low power mode instead of continuing to attempt random access procedures.
  • FIG. 10 shows a block diagram 1000 of a communications manager 1005 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the communications manager 1005 may be an example of aspects of a communications manager 815, a communications manager 915, or a communications manager 1110 described herein.
  • the communications manager 1005 may include a SSB identifying component 1010, an initial transmission component 1015, a repetition scheme identifying component 1020, a repetition component 1025, a preamble root sequence component 1030, a SIB update cycle component 1035, and a repetition level component 1040. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
  • the SSB identifying component 1010 may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the UE is an NR-Light UE.
  • the initial transmission component 1015 may transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the repetition scheme identifying component 1020 may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the repetition scheme identifying component 1020 may identify an initial random access occasion index included by the initial random access preamble sequence for the random access occasion associated with the synchronization signal block, where each of the one or more additional random access occasions during the one or more mapping association periods corresponds to the initial random access occasion index.
  • the repetition scheme identifying component 1020 may identify a random access occasion hopping pattern for the one or more additional random access occasions, where the random access hopping pattern is applied across the one or more mapping association periods, and where the random access hopping pattern is associated with an initial random access occasion index included by the initial random access preamble sequence.
  • the repetition scheme identifying component 1020 may receive an indication of a number of repetitions for the initial random access preamble sequence and a repetition pattern, where the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on a ratio of the repetition pattern to the number of repetitions.
  • the repetition scheme identifying component 1020 may identify a pre-configured synchronization signal block-to-random access occasion mapping association period configuration.
  • the repetition scheme identifying component 1020 may determine the repetition scheme based on applying a synchronization signal block-to-random access occasion remapping factor to the pre-configured synchronization signal block-to-random access occasion mapping association period configuration, where the synchronization signal block-to-random access occasion remapping factor adjusts a number of synchronization signal blocks per random access occasion, a number of random access preambles per synchronization signal block, or both.
  • the repetition scheme identifying component 1020 may receive, from the base station, the repetition scheme.
  • the repetition scheme identifying component 1020 may select the repetition scheme based on the synchronization signal block.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions across a set of mapping association periods, where the one or more additional random access occasions include one random access occasion per mapping association period.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions during the one or more mapping association periods, where the one or more additional random access occasions include multiple random access occasions within each of the one or more mapping association periods.
  • the repetition scheme indicates to transmit the repetitions of the initial random access preamble sequence for the repetition pattern number of times per synchronization signal block-to-random access occasion cycle.
  • the repetition component 1025 may transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • each of the one or more mapping association periods includes at least one repetition period.
  • the repetition component 1025 may transmit at least a set of repetitions of the initial random access preamble sequence within each of the one or more mapping association periods.
  • the initial random access preamble sequence is transmitted in a first random access occasion, an Nth random access occasion, or a multiple of the Nth random access occasion, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • the repetition component 1025 may transmit at least a portion of a set of repetitions of the initial random access procedure sequence in a mapping association period. In some cases, the repetition component 1025 may transmit the set of repetitions within a single association pattern period spanning a set of mapping association periods. In some examples, the initial random access preamble sequence is transmitted in a first mapping association period, an Nth mapping association period, or a multiple of the Nth mapping association period, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • the repetition component 1025 may transmit a portion of a set of repetitions of the initial random access preamble sequence within each of one or more mapping association periods, where an association pattern period spans a plurality of mapping association periods.
  • the initial random access preamble sequence is transmitted in a first association pattern period, an Nth association pattern period, or a multiple of the Nth association pattern period, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • a synchronization signal block-to-random access occasion association pattern period spans the one or more mapping association periods of the synchronization signal block-to-random access occasion mapping.
  • the preamble root sequence component 1030 may apply a root sequence offset to a random access preamble root sequence.
  • the preamble root sequence component 1030 may generate the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the preamble root sequence component 1030 may receive the root sequence offset from the base station.
  • the root sequence offset is based on one or more of a cell identity (ID) of the base station, an index of the synchronization signal block, an index of a synchronization signal block-to-random access occasion mapping association period, an index of the random access occasion associated with the identified synchronization signal block within a synchronization signal block-to-random access occasion mapping association period, and the random access preamble root sequence.
  • ID cell identity
  • the SIB update cycle component 1035 may identify a SIB update cycle.
  • the SIB update cycle component 1035 may select the repetition scheme based on the SIB update cycle.
  • the one or more additional random access occasions occur after a first SIB update message and before a second SIB update message.
  • the repetition level component 1040 may determine a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where the repetition scheme is based on the determined repetition level setting of the UE.
  • the repetition level component 1040 may determine a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where a configuration for the initial random access preamble sequence is based on the determined repetition level setting of the UE.
  • FIG. 11 shows a diagram of a system 1100 including a device 1105 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 1105 may be an example of or include the components of device 805, device 905, or a UE 115 as described herein.
  • the device 1105 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1110, an I/O controller 1115, a transceiver 1120, an antenna 1125, memory 1130, and a processor 1140. These components may be in electronic communication via one or more buses (e.g., bus 1145) .
  • buses e.g., bus 1145
  • the communications manager 1110 may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and transmit the repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the I/O controller 1115 may manage input and output signals for the device 1105.
  • the I/O controller 1115 may also manage peripherals not integrated into the device 1105.
  • the I/O controller 1115 may represent a physical connection or port to an external peripheral.
  • the I/O controller 1115 may utilize an operating system such as or another known operating system.
  • the I/O controller 1115 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device.
  • the I/O controller 1115 may be implemented as part of a processor.
  • a user may interact with the device 1105 via the I/O controller 1115 or via hardware components controlled by the I/O controller 1115.
  • the transceiver 1120 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above.
  • the transceiver 1120 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver.
  • the transceiver 1120 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.
  • the wireless device may include a single antenna 1125. However, in some cases the device may have more than one antenna 1125, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.
  • the memory 1130 may include RAM and ROM.
  • the memory 1130 may store computer-readable, computer-executable code 1135 including instructions that, when executed, cause the processor to perform various functions described herein.
  • the memory 1130 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.
  • the processor 1140 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) .
  • the processor 1140 may be configured to operate a memory array using a memory controller.
  • a memory controller may be integrated into the processor 1140.
  • the processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting repeating transmission of random access sequences) .
  • the code 1135 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications.
  • the code 1135 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1135 may not be directly executable by the processor 1140 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.
  • FIG. 12 shows a block diagram 1200 of a device 1205 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 1205 may be an example of aspects of a base station 105 as described herein.
  • the device 1205 may include a receiver 1210, a communications manager 1215, and a transmitter 1220.
  • the device 1205 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to repeating transmission of random access sequences, etc. ) . Information may be passed on to other components of the device 1205.
  • the receiver 1210 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15.
  • the receiver 1210 may utilize a single antenna or a set of antennas.
  • the communications manager 1215 may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the communications manager 1215 may be an example of aspects of the communications manager 1510 described herein.
  • the communications manager 1215 may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1215, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.
  • code e.g., software or firmware
  • ASIC application-specific integrated circuit
  • the communications manager 1215 may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components.
  • the communications manager 1215, or its sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure.
  • the communications manager 1215, or its sub-components may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.
  • I/O input/output
  • the transmitter 1220 may transmit signals generated by other components of the device 1205.
  • the transmitter 1220 may be collocated with a receiver 1210 in a transceiver module.
  • the transmitter 1220 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15.
  • the transmitter 1220 may utilize a single antenna or a set of antennas.
  • FIG. 13 shows a block diagram 1300 of a device 1305 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 1305 may be an example of aspects of a device 1205, or a base station 105 as described herein.
  • the device 1305 may include a receiver 1310, a communications manager 1315, and a transmitter 1340.
  • the device 1305 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .
  • the receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to repeating transmission of random access sequences, etc. ) . Information may be passed on to other components of the device 1305.
  • the receiver 1310 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15.
  • the receiver 1310 may utilize a single antenna or a set of antennas.
  • the communications manager 1315 may be an example of aspects of the communications manager 1215 as described herein.
  • the communications manager 1315 may include a SSB transmission component 1320, an initial random access preamble sequence component 1325, a repetition scheme component 1330, and a repetition monitoring component 1335.
  • the communications manager 1315 may be an example of aspects of the communications manager 1510 described herein.
  • the SSB transmission component 1320 may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the initial random access preamble sequence component 1325 may receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the repetition scheme component 1330 may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the repetition monitoring component 1335 may monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the transmitter 1340 may transmit signals generated by other components of the device 1305.
  • the transmitter 1340 may be collocated with a receiver 1310 in a transceiver module.
  • the transmitter 1340 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15.
  • the transmitter 1340 may utilize a single antenna or a set of antennas.
  • FIG. 14 shows a block diagram 1400 of a communications manager 1405 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the communications manager 1405 may be an example of aspects of a communications manager 1215, a communications manager 1315, or a communications manager 1510 described herein.
  • the communications manager 1405 may include a SSB transmission component 1410, an initial random access preamble sequence component 1415, a repetition scheme component 1420, a repetition monitoring component 1425, a preamble root sequence component 1430, a SIB update cycle component 1435, and a repetition level component 1440.
  • Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
  • the SSB transmission component 1410 may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the UE is a New Radio (NR) -Light UE.
  • NR New Radio
  • the initial random access preamble sequence component 1415 may receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the repetition scheme component 1420 may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the repetition scheme component 1420 may identify an initial random access occasion index included by the initial random access preamble sequence for the random access occasion associated with the synchronization signal block, where each of the one or more additional random access occasions during the one or more mapping association periods corresponds to the initial random access occasion index.
  • the repetition scheme component 1420 may identify a random access occasion hopping pattern for the one or more additional random access occasions, where the random access hopping pattern is applied across the one or more mapping association periods, and where the random access hopping pattern is associated with an initial random access occasion index included by the initial random access preamble sequence.
  • the repetition scheme component 1420 may transmit an indication of a number of the repetitions of the initial random access preamble sequence and a repetition pattern, where the repetition scheme indicates to monitor for the initial random access preamble sequence during the one or more additional random access occasions based on a ratio of the repetition pattern to the number of the repetitions.
  • the repetition scheme component 1420 may identify a pre-configured synchronization signal block-to-random access occasion mapping association period configuration, where the repetition scheme is identified based on applying a synchronization signal block-to-random access occasion remapping factor to the pre-configured synchronization signal block-to-random access occasion mapping association period configuration, and where the synchronization signal block-to-random access occasion remapping factor adjusts a number of synchronization signal blocks per random access occasion, a number of random access preambles per synchronization signal block, or both.
  • the repetition scheme component 1420 may transmit, to the UE, the repetition scheme.
  • the repetition scheme indicates to monitor for the repetitions of the initial random access preamble sequence during the one or more additional random access occasions across a set of mapping association periods, where the one or more additional random access occasions include one random access occasion per mapping association period.
  • the repetition scheme indicates to monitor for the repetitions of the initial random access preamble sequence during the one or more additional random access occasions during the one or more mapping association periods, where the one or more additional random access occasions include multiple random access occasions within each of the one or more mapping association periods. In some cases, the repetition scheme indicates to monitor for the initial random access preamble sequence for the repetition pattern number of times per synchronization signal block-to-random access occasion cycle.
  • the repetition monitoring component 1425 may monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • each of the one or more mapping association periods includes at least one repetition period.
  • the repetition monitoring component 1425 may receive at least a set of repetitions of the initial random access preamble sequence within each of the one or more mapping association periods.
  • the initial random access preamble sequence is received in a first random access occasion, an Nth random access occasion, or a multiple of the Nth random access occasion, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • the repetition monitoring component 1425 may receive at least a portion of a set of repetitions of the initial random access procedure sequence in a mapping association period. In some cases, the repetition monitoring component 1425 may receive the set of repetitions within a single association pattern period spanning a set of mapping association periods. In some examples, the initial random access preamble sequence is received in a first mapping association period, an Nth mapping association period, or a multiple of the Nth mapping association period, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • a synchronization signal block-to-random access occasion association pattern period spans the one or more mapping association periods of the synchronization signal block-to-random access occasion mapping.
  • the repetition monitoring component 1425 may receive a portion of a set of repetitions of the initial random access preamble sequence within each of the one or more mapping association periods, where an association pattern period spans a plurality of mapping association periods.
  • the initial random access preamble sequence is received in a first mapping association period, an Nth mapping association period, or a multiple of the Nth association pattern period, and where N is a number of repetitions of the initial random access preamble sequence to be transmitted.
  • the preamble root sequence component 1430 may apply a root sequence offset to a random access preamble root sequence.
  • the preamble root sequence component 1430 may determine the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the preamble root sequence component 1430 may transmit the root sequence offset to the UE.
  • the root sequence offset is based on one or more of a cell identity (ID) of the base station, an index of the synchronization signal block, an index of a synchronization signal block-to-random access occasion mapping association period, an index of the random access occasion associated with the identified synchronization signal block within a synchronization signal block-to-random access occasion mapping association period, and the random access preamble root sequence.
  • ID cell identity
  • the SIB update cycle component 1435 may identify a SIB update cycle, where the repetition scheme is identified based on the SIB update cycle.
  • the one or more additional random access occasions occur after a first SIB update message and before a second SIB update message.
  • the repetition level component 1440 may determine a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where the repetition scheme is based on the determined repetition level setting of the UE.
  • the repetition level component 1440 may determine a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where a configuration for the initial random access preamble sequence is based on the repetition level setting of the UE.
  • FIG. 15 shows a diagram of a system 1500 including a device 1505 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the device 1505 may be an example of or include the components of device 1205, device 1305, or a base station 105 as described herein.
  • the device 1505 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1510, a network communications manager 1515, a transceiver 1520, an antenna 1525, memory 1530, a processor 1540, and an inter-station communications manager 1545. These components may be in electronic communication via one or more buses (e.g., bus 1550) .
  • buses e.g., bus 1550
  • the communications manager 1510 may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station, receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block, identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping, and monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the network communications manager 1515 may manage communications with the core network (e.g., via one or more wired backhaul links) .
  • the network communications manager 1515 may manage the transfer of data communications for client devices, such as one or more UEs 115.
  • the transceiver 1520 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above.
  • the transceiver 1520 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver.
  • the transceiver 1520 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.
  • the wireless device may include a single antenna 1525. However, in some cases the device may have more than one antenna 1525, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.
  • the memory 1530 may include RAM, ROM, or a combination thereof.
  • the memory 1530 may store computer-readable code 1535 including instructions that, when executed by a processor (e.g., the processor 1540) cause the device to perform various functions described herein.
  • a processor e.g., the processor 1540
  • the memory 1530 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.
  • the processor 1540 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) .
  • the processor 1540 may be configured to operate a memory array using a memory controller.
  • a memory controller may be integrated into processor 1540.
  • the processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1530) to cause the device 1505 to perform various functions (e.g., functions or tasks supporting repeating transmission of random access sequences) .
  • the inter-station communications manager 1545 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1545 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1545 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.
  • the code 1535 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications.
  • the code 1535 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1535 may not be directly executable by the processor 1540 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.
  • FIG. 16 shows a flowchart illustrating a method 1600 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 1600 may be implemented by a UE 115 or its components as described herein.
  • the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 8 through 11.
  • a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.
  • the UE may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a SSB identifying component as described with reference to FIGs. 8 through 11.
  • the UE may transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by an initial transmission component as described with reference to FIGs. 8 through 11.
  • the UE may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a repetition scheme identifying component as described with reference to FIGs. 8 through 11.
  • the UE may transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a repetition component as described with reference to FIGs. 8 through 11.
  • FIG. 17 shows a flowchart illustrating a method 1700 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 1700 may be implemented by a UE 115 or its components as described herein.
  • the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 8 through 11.
  • a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.
  • the UE may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a SSB identifying component as described with reference to FIGs. 8 through 11.
  • the UE may apply a root sequence offset to a random access preamble root sequence.
  • the operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a preamble root sequence component as described with reference to FIGs. 8 through 11.
  • the UE may generate the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a preamble root sequence component as described with reference to FIGs. 8 through 11.
  • the UE may transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by an initial transmission component as described with reference to FIGs. 8 through 11.
  • the UE may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed by a repetition scheme identifying component as described with reference to FIGs. 8 through 11.
  • the UE may transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 1730 may be performed according to the methods described herein. In some examples, aspects of the operations of 1730 may be performed by a repetition component as described with reference to FIGs. 8 through 11.
  • FIG. 18 shows a flowchart illustrating a method 1800 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 1800 may be implemented by a UE 115 or its components as described herein.
  • the operations of method 1800 may be performed by a communications manager as described with reference to FIGs. 8 through 11.
  • a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.
  • the UE may identify a synchronization signal block associated with a transmit beam of a base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a SSB identifying component as described with reference to FIGs. 8 through 11.
  • the UE may transmit an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by an initial transmission component as described with reference to FIGs. 8 through 11.
  • the UE may identify a SIB update cycle.
  • the operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by a SIB update cycle component as described with reference to FIGs. 8 through 11.
  • the UE may select the repetition scheme based on the SIB update cycle.
  • the operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by a SIB update cycle component as described with reference to FIGs. 8 through 11.
  • the UE may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be performed by a repetition scheme identifying component as described with reference to FIGs. 8 through 11.
  • the UE may transmit repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 1830 may be performed according to the methods described herein. In some examples, aspects of the operations of 1830 may be performed by a repetition component as described with reference to FIGs. 8 through 11.
  • FIG. 19 shows a flowchart illustrating a method 1900 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 1900 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 1900 may be performed by a communications manager as described with reference to FIGs. 12 through 15.
  • a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.
  • the base station may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a SSB transmission component as described with reference to FIGs. 12 through 15.
  • the base station may receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by an initial random access preamble sequence component as described with reference to FIGs. 12 through 15.
  • the base station may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by a repetition scheme component as described with reference to FIGs. 12 through 15.
  • the base station may monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be performed by a repetition monitoring component as described with reference to FIGs. 12 through 15.
  • FIG. 20 shows a flowchart illustrating a method 2000 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 2000 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 2000 may be performed by a communications manager as described with reference to FIGs. 12 through 15.
  • a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.
  • the base station may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed by a SSB transmission component as described with reference to FIGs. 12 through 15.
  • the base station may apply a root sequence offset to a random access preamble root sequence.
  • the operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed by a preamble root sequence component as described with reference to FIGs. 12 through 15.
  • the base station may determine the initial random access preamble sequence based on the root sequence offset and the random access preamble root sequence.
  • the operations of 2015 may be performed according to the methods described herein. In some examples, aspects of the operations of 2015 may be performed by a preamble root sequence component as described with reference to FIGs. 12 through 15.
  • the base station may receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 2020 may be performed according to the methods described herein. In some examples, aspects of the operations of 2020 may be performed by an initial random access preamble sequence component as described with reference to FIGs. 12 through 15.
  • the base station may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 2025 may be performed according to the methods described herein. In some examples, aspects of the operations of 2025 may be performed by a repetition scheme component as described with reference to FIGs. 12 through 15.
  • the base station may monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 2030 may be performed according to the methods described herein. In some examples, aspects of the operations of 2030 may be performed by a repetition monitoring component as described with reference to FIGs. 12 through 15.
  • FIG. 21 shows a flowchart illustrating a method 2100 that supports repeating transmission of random access sequences in accordance with aspects of the present disclosure.
  • the operations of method 2100 may be implemented by a base station 105 or its components as described herein.
  • the operations of method 2100 may be performed by a communications manager as described with reference to FIGs. 12 through 15.
  • a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.
  • the base station may transmit a synchronization signal block associated with a transmit beam of the base station, the synchronization signal block being one of a set of synchronization signal blocks that are each associated with a respective transmit beam of the base station.
  • the operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be performed by a SSB transmission component as described with reference to FIGs. 12 through 15.
  • the base station may receive, from a UE, an initial random access preamble sequence during a random access occasion associated with the synchronization signal block.
  • the operations of 2110 may be performed according to the methods described herein. In some examples, aspects of the operations of 2110 may be performed by an initial random access preamble sequence component as described with reference to FIGs. 12 through 15.
  • the base station may determine a repetition level setting of the UE including at least a number of repetitions for the initial random access preamble sequence, where the repetition scheme is based on the determined repetition level setting of the UE.
  • the operations of 2115 may be performed according to the methods described herein. In some examples, aspects of the operations of 2115 may be performed by a repetition level component as described with reference to FIGs. 12 through 15.
  • the base station may identify a repetition scheme for the initial random access preamble sequence during one or more additional random access occasions associated with the synchronization signal block during one or more mapping association periods of a synchronization signal block-to-random access occasion mapping.
  • the operations of 2120 may be performed according to the methods described herein. In some examples, aspects of the operations of 2120 may be performed by a repetition scheme component as described with reference to FIGs. 12 through 15.
  • the base station may monitor for repetitions of the initial random access preamble sequence during the one or more additional random access occasions based on the repetition scheme.
  • the operations of 2125 may be performed according to the methods described herein. In some examples, aspects of the operations of 2125 may be performed by a repetition monitoring component as described with reference to FIGs. 12 through 15.
  • CDMA code division multiple access
  • TDMA time division multiple access
  • FDMA frequency division multiple access
  • OFDMA orthogonal frequency division multiple access
  • SC-FDMA single carrier frequency division multiple access
  • a CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc.
  • CDMA2000 covers IS-2000, IS-95, and IS-856 standards.
  • IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc.
  • IS-856 TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc.
  • UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA.
  • a TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .
  • GSM Global System for Mobile Communications
  • An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc.
  • UMB Ultra Mobile Broadband
  • E-UTRA Evolved UTRA
  • IEEE Institute of Electrical and Electronics Engineers
  • Wi-Fi Institute of Electrical and Electronics Engineers
  • IEEE 802.16 WiMAX
  • IEEE 802.20 Flash-OFDM
  • UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS) .
  • LTE, LTE-A, and LTE-A Pro are releases of UMTS that use E-UTRA.
  • UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from the organization named “3rd Generation Partnership Project” (3GP
  • CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) .
  • 3GPP2 3rd Generation Partnership Project 2
  • the techniques described herein may be used for the systems and radio technologies mentioned herein as well as other systems and radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.
  • a macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider.
  • a small cell may be associated with a lower-powered base station, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells.
  • Small cells may include pico cells, femto cells, and micro cells according to various examples.
  • a pico cell for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider.
  • a femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) .
  • An eNB for a macro cell may be referred to as a macro eNB.
  • An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB.
  • An eNB may support one or multiple (e.g., two, three, four, and the like) cells, and may also support communications using one or multiple component carriers.
  • the wireless communications systems described herein may support synchronous or asynchronous operation.
  • the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time.
  • the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time.
  • the techniques described herein may be used for either synchronous or asynchronous operations.
  • Information and signals described herein may be represented using any of a variety of different technologies and techniques.
  • data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
  • a general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
  • a 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) .
  • the functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
  • Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
  • a non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer.
  • non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.
  • RAM random-access memory
  • ROM read-only memory
  • EEPROM electrically erasable programmable ROM
  • flash memory compact disk (CD) ROM or other optical disk storage
  • magnetic disk storage or other magnetic storage devices
  • any connection is properly termed a computer-readable medium.
  • the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave
  • the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
  • Disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

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Abstract

L'invention concerne des procédés, des systèmes et des dispositifs destinés aux communications sans fil. Un équipement utilisateur (UE) peut identifier un bloc de signal de synchronisation (BSS) associé à un faisceau d'émission d'une station de base, le BSS étant l'un d'un ensemble de BSS qui sont chacun associés à un faisceau d'émission respectif de la station de base. L'UE peut transmettre une séquence de préambule d'accès aléatoire initiale pendant une occasion d'accès aléatoire (RO) associée au bloc de signal de synchronisation. L'UE peut identifier un schéma de répétition pour la séquence de préambule d'accès aléatoire initiale pendant un ou plusieurs RO supplémentaires associés à la BSS pendant une ou plusieurs périodes d'association de mappage d'une cartographie BSS-à-RO. L'UE peut ensuite transmettre des répétitions de la séquence de préambule d'accès aléatoire initiale pendant le ou les ROs supplémentaires sur la base du schéma de répétition.
PCT/CN2019/096994 2019-07-22 2019-07-22 Répétition de la transmission de séquences d'accès aléatoire WO2021012137A1 (fr)

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