Method and apparatus for initial access with multiple prach transmissions

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method and an apparatus for initial access using a plurality of physical random access channel (PRACH) transmissions in a wireless communication system are provided. A method includes receiving a system information block (SIB) indicating a first number of a plurality of PRACH transmissions, a first PRACH occasion (RO) partition associated with the plurality of PRACH transmissions, a second RO partition associated with one PRACH transmission, and one or more first sets of a plurality of ROs associated with the first number of the plurality of PRACH transmissions. One or more first sets include ROs from a first RO partition and not from a second RO partition, the method further including determining a RO group from the one or more first sets of the plurality of ROs, determining a PRACH preamble for transmission in a first number of ROs of the RO group, and transmitting the PRACH preamble in the first number of ROs of the RO group.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to methods and apparatus for initial access with multiple physical random access channel (PRACH) transmissions in a wireless communication system. Background Art

[0002] 5G mobile communication technology defines a wide frequency band so that high transmission rates and new services are possible, and can be realized not only in "below 6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands called millimeter waves (mmWave) including 28 GHz and 39 GHz. In addition, implementation of 6G mobile communication technology (called super 5G system) in terahertz frequency bands (e.g., 95 GHz to 3 THz frequency bands) has been considered in order to achieve a transmission rate fifty times faster than 5G mobile communication technology and ultra-low latency one-tenth of 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC) and massive machine type communications (mMTC), there has been ongoing standardization on the following: beamforming and massive MIMO for mitigating radio wave path loss and increasing radio wave transmission distance in mmWave, parameter sets to support dynamic operation for efficient utilization of mmWave resources and time slot formats (e.g., operating multiple subcarrier spacings), initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods such as LDPC (low-density parity check) codes for large-volume data transmission and polar codes for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, there are ongoing discussions on the improvement and performance enhancement of initial 5G mobile communication technologies in view of the services to be supported by 5G mobile communication technologies, and there has been physical layer standardization on technologies such as: V2X (Vehicle-to-Everything) for assisting autonomous vehicles in making driving determinations based on information about the position and status of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) for system operation intended to comply with various regulation-related requirements in unlicensed bands, NR UE power saving, non-terrestrial network (NTN) as UE-satellite direct communication for providing coverage in areas where communication with terrestrial networks is unavailable, and positioning.

[0005] In addition, there is ongoing standardization of air interface architecture / protocols on technologies such as the Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access (two-step RACH for NR) for simplifying the random access procedure. There is also ongoing standardization of system architecture / services for 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software-defined networking (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] As 5G mobile communication systems are commercialized, the number of connected devices, which has been growing exponentially, will be connected to the communication network, and it is accordingly expected that enhanced functions and performance of the 5G mobile communication systems and integrated operations of the connected devices will be necessary. To this end, new research related to extended reality (XR) is arranged for effectively supporting AR (augmented reality), VR (virtual reality), MR (mixed reality), etc., improving 5G performance and reducing complexity by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a foundation not only for the development of new waveforms for providing terahertz band coverage for 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using OAM (orbital angular momentum), and high-dimensional spatial multiplexing technologies of RIS (reconfigurable smart surface), but also for the development of full-duplex technology for improving frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technology for achieving system optimization and internalizing end-to-end AI support functions by utilizing satellites and AI (artificial intelligence) from the design stage, and next-generation distributed computing technology for realizing services that exceed the level of sophistication of UEs by utilizing ultra-high-performance communication and computing resources. Summary of the invention

[0008] Technical issues

[0009] The present invention has been made to address at least the above problems and / or disadvantages and to provide at least the advantages described below. Accordingly, one aspect of the present invention provides a method and apparatus for initial access using multiple PRACHs.

[0010] Solution to the problem

[0011] The present disclosure relates to wireless communication systems, and more particularly, to initial access utilizing multiple PRACH transmissions in wireless communication systems.

[0012] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver configured to receive a system information block (SIB). The SIB indicates a first number of multiple physical random access channel (PRACH) transmissions, a first PRACH opportunity (RO) partition associated with the multiple PRACH transmissions, a second RO partition associated with one PRACH transmission, and one or more first sets of multiple ROs associated with the first number of multiple PRACH transmissions. The one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition. The UE also includes a processor operably coupled to the transceiver. The processor is configured to determine an RO group and a PRACH preamble for transmission in a first number of ROs in the RO group from one or more first sets of multiple ROs. The transceiver is also configured to send the PRACH preamble in the first number of ROs.

[0013] In another embodiment, a base station (BS) is provided. The BS includes a transceiver configured to send a SIB. The SIB indicates a first number of multiple PRACH receptions, a first RO partition associated with the multiple PRACH receptions, a second RO partition associated with one PRACH reception, and one or more first sets of multiple ROs associated with the first number of multiple PRACH receptions. The one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition. The BS also includes a processor operably coupled to the transceiver. The processor is configured to determine an RO group and a PRACH preamble code for receiving in a first number of ROs in the RO group from one or more first sets of multiple ROs. The transceiver is also configured to receive the PRACH preamble code in the first number of ROs.

[0014] In yet another embodiment, a method is provided. The method includes: receiving a SIB, the SIB indicating a first number of multiple PRACH transmissions, a first RO partition associated with the multiple PRACH transmissions, a second RO partition associated with one PRACH transmission, and one or more first sets of multiple ROs associated with the first number of multiple PRACH transmissions. The one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition. The method also includes: determining an RO group from the one or more first sets of multiple ROs, determining a PRACH preamble for transmission in a first number of ROs in the RO group, and sending the PRACH preamble in the first number of ROs in the RO group.

[0015] Other technical features may be apparent to those skilled in the art from the following drawings, descriptions and claims.

[0016] Before the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document. The term "coupling" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other. The terms "send", "receive" and "communication" and their derivatives cover both direct and indirect communication. The terms "include" and "comprise" and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with ... " and its derivatives mean including, included in ..., interconnected with ..., including, included in ..., connected to or with ..., connected to or with ..., coupled to or with ..., can communicate with ..., collaborate with ..., interlace, juxtapose, approach, bind to or with ..., bind, have, have the property of ..., have to or with ..., etc. The term "controller" means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The function associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one of" when used with a list of items means that different combinations of one or more of the listed items can be used, and that only one of the items in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0017] In addition, the various functions described below may be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or a portion thereof, suitable for implementation in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disk (DVD), or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and later rewritten, such as rewritable optical disks or erasable memory devices.

[0018] Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0019] Advantageous Effects of the Invention

[0020] The advantages and salient features of the present invention will become apparent to those skilled in the art through the following detailed description which discloses exemplary embodiments of the present invention in conjunction with the accompanying drawings.For a more enhanced communication system, a method and apparatus for initial access using multiple PRACHs is needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts:

[0022] Figure 1 An example of a wireless network according to an embodiment of the present disclosure is shown;

[0023] Figure 2 An example of a gNB according to an embodiment of the present disclosure is shown;

[0024] Figure 3 An example of a UE according to an embodiment of the present disclosure is shown;

[0025] Figure 4 shows examples of wireless transmit and receive paths according to the present disclosure;

[0026] Figure 5 shows examples of wireless transmit and receive paths according to the present disclosure;

[0027] Figure 6 An example of mapping between SS / PBCH blocks and RO according to an embodiment of the present disclosure is shown;

[0028] Figure 7 A flowchart showing the operation of a UE according to an embodiment of the present disclosure is shown;

[0029] Figure 8 shows an example of PRACH transmission with repetition according to an embodiment of the present disclosure; and

[0030] Fig. 9 An example of PRACH transmission with repetition according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0031] Before the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document. The term "coupling" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other. The terms "send", "receive" and "communication" and their derivatives cover both direct and indirect communication. The terms "include" and "comprise" and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with ... " and its derivatives mean including, included in ..., interconnected with ..., including, included in ..., connected to or with ..., connected to or with ..., coupled to or with ..., can communicate with ..., collaborate with ..., interlace, juxtapose, approach, bind to or with ..., bind, have, have the property of ..., have to or with ..., etc. The term "controller" means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The function associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one of" when used with a list of items means that different combinations of one or more of the listed items can be used, and that only one of the items in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0032] In addition, the various functions described below may be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or a portion thereof, suitable for implementation in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disk (DVD), or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and later rewritten, such as rewritable optical disks or erasable memory devices.

[0033] Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0034] The following description particularly describes and defines the nature of the present invention and the manner in which the present invention is practiced:

[0035] Discussed below Figures 1 to 9 The various embodiments used to describe the principles of the present disclosure in this patent document are illustrative only and should not be interpreted in any way to limit the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any appropriately arranged system or device.

[0036] In order to meet the demand for wireless data services that have increased since the deployment of 4G communication systems and to realize various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are considered to be implemented in higher frequency (millimeter wave) bands (e.g., 28 GHz or 60 GHz bands) to achieve higher data rates, or in lower frequency bands (e.g., 6 GHz) to achieve robust coverage and mobility support. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are discussed in 5G / NR communication systems.

[0037] In addition, in 5G / NR communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RANs) ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), receiving-side interference cancellation, etc.

[0038] The discussion of 5G systems and frequency bands associated therewith is for reference, as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems or frequency bands associated therewith, and embodiments of the present disclosure may be used in conjunction with any frequency band. For example, aspects of the present disclosure may also be applied to the deployment of 5G communication systems, 6G, or even later versions that may use terahertz (THz) frequency bands.

[0039] The following Figures 1 to 3 Various embodiments are described that are implemented in a wireless communication system and utilizing Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) communication techniques. Figure 1-3 The description is not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably arranged communications system.

[0040] Figure 1 An example wireless network according to an embodiment of the present disclosure is shown. Figure 1 The embodiment of the wireless network shown is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0041] like Figure 1 As shown, the wireless network includes gNB 101 (e.g., base station, BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130 such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0042] gNB 102 provides wireless broadband access to network 130 for a first plurality of user equipment (UE) within coverage area 120 of gNB 102. The first plurality of UEs include UE 111, which may be located in a small business; UE 112, which may be located in an enterprise; UE 113, which may be a WiFi hotspot; UE 114, which may be located in a first residence; UE 115, which may be located in a second residence; and UE 116, which may be a mobile device such as a cellular phone, a wireless laptop, a wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within coverage area 125 of gNB 103. The second plurality of UEs include UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, Long Term Evolution (LTE), Long Term Evolution-Advanced (LTE-A), WiMAX, WiFi, or other wireless communication technologies.

[0043] Depending on the network type, the term "base station" or "BS" may refer to any component (or collection of components) configured to provide wireless access to a network, such as a transmission point (TP), a transmission-reception point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro cell, a femto cell, a WiFi access point (AP), or other wireless enabling devices. A base station may provide wireless access according to one or more wireless communication protocols (e.g., 5G / NR Third Generation Partnership Project (3GPP) NR, Long Term Evolution (LTE), LTE Advanced (LTE-A), High Speed ​​Packet Access (HSPA), Wi-Fi 802.11 a / b / g / n / ac, etc.). For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to a network infrastructure component that provides wireless access to a remote terminal. In addition, depending on the network type, the term "user equipment" or "UE" may refer to any component, such as a "mobile station", "subscriber station", "remote terminal", "wireless terminal", "reception point", or "user equipment". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to a remote wireless device that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer or vending machine).

[0044] Dashed lines illustrate the approximate extents of coverage areas 120 and 125, which are shown as approximately circular for purposes of illustration and explanation only. It should be clearly understood that coverage areas associated with gNBs, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0045] As described in more detail below, one or more of the UEs 111-116 include circuitry, programming, or a combination thereof for supporting initial access utilizing multiple PRACH transmissions in a wireless communication system. In certain embodiments, one or more of the gNBs 101-103 include circuitry, programming, or a combination thereof for supporting initial access utilizing multiple PRACH transmissions in a wireless communication system.

[0046] although Figure 1 An example of a wireless network is shown, but Figure 1 Various changes may be made. For example, the wireless network may include any number of gNBs and any number of UEs in any suitable arrangement. In addition, gNB 101 may communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 may communicate directly with network 130 and provide the UEs with direct wireless broadband access to network 130. In addition, gNBs 101, 102, and / or 103 may provide access to other or additional external networks, such as an external telephone network or other type of data network.

[0047] Figure 2 An example gNB 102 is shown according to an embodiment of the present disclosure. Figure 2 The embodiment of the gNB 102 shown in FIG. is for illustration only, and Figure 1 gNBs 101 and 103 may have the same or similar configurations. However, gNBs have a variety of configurations, and Figure 2 The scope of the present disclosure is not limited to any particular implementation of the gNB.

[0048] like Figure 2 As shown, the gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0049] The transceivers 210a-210n receive incoming RF signals from the antennas 205a-205n, such as signals transmitted by UEs in the network 100. The transceivers 210a-210n downconvert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuits in the transceivers 210a-210n and / or the controller / processor 225, which generate processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0050] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or the controller / processor 225 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from the controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceivers 210a-210n up-convert the baseband or IF signal to an RF signal that is transmitted via the antennas 205a-205n.

[0051] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 may control the reception of UL channel signals and the transmission of DL channel signals by the transceivers 210a-210n according to well-known principles. The controller / processor 225 may also support additional functionality, such as more advanced wireless communication functionality. For example, the controller / processor 225 may support beamforming or directional routing operations, in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively direct the outgoing signals in a desired direction. The controller / processor 225 may support any of a wide variety of other functionality in the gNB 102.

[0052] The controller / processor 225 is also capable of executing programs and other processes, such as an OS, that reside in the memory 230. The controller / processor 225 may move data into or out of the memory 230 as required by the executing process. The controller / processor 225 is also capable of executing programs and other processes that reside in the memory 230, such as a process for supporting initial access with multiple PRACH transmissions in a wireless communication system.

[0053] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 235 may support communication over any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G / NR, LTE, or LTE-A), the interface 235 may allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 may allow the gNB 102 to communicate with a larger network (such as the Internet) over a wired or wireless local area network or over a wired or wireless connection. The interface 235 includes any suitable structure that supports communication over a wired or wireless connection, such as Ethernet or a transceiver.

[0054] Memory 230 is coupled to controller / processor 225. A portion of memory 230 may include RAM, and another portion of memory 230 may include flash memory or other ROM.

[0055] although Figure 2 An example of a gNB 102 is shown, but the Figure 2 For example, gNB 102 may include any number of Figure 2 Each component shown in . In addition, Figure 2 The various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs.

[0056] Figure 3 An example UE 116 is shown in accordance with an embodiment of the present disclosure. Figure 3 The embodiment of UE 116 shown is for illustration only, and Figure 1 UEs 111-115 may have the same or similar configurations. However, UEs have a variety of configurations, and Figure 3 The scope of the present disclosure is not limited to any particular implementation of the UE.

[0057] like Figure 3 As shown, UE 116 includes antenna 305, transceiver 310, and microphone 320. UE 116 also includes speaker 330, processor 340, input / output (I / O) interface (IF) 345, input 350, display 355, and memory 360. Memory 360 includes operating system (OS) 361 and one or more applications 362.

[0058] The transceiver 310 receives incoming RF signals from the antenna 305 transmitted by the gNB of the network 100. The transceiver(s) 310 downconvert the incoming RF signals to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in the transceiver 310 and / or the processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry transmits the processed baseband signal to the speaker 330 (such as for voice data) or is processed by the processor 340 (such as for web browsing data).

[0059] The TX processing circuitry in the transceiver(s) 310 and / or processor 340 receives analog or digital voice data from the microphone 320, or receives other outgoing baseband data (such as web data, email, or interactive video game data) from the processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 305.

[0060] The processor 340 may include one or more processors or other processing devices and executes the OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, the processor 340 may control the reception of DL channel signals and the transmission of UL channel signals by the transceiver(s) 310 according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0061] The processor 340 is also capable of executing other processes and programs resident in the memory 360, such as processes for supporting initial access with multiple PRACH transmissions in a wireless communication system. The processor 340 can move data into or out of the memory 360 as needed for the execution process. In some embodiments, the processor 340 is configured to execute the application 362 based on the OS 361 or in response to a signal received from the gNB or operator. The processor 340 is also coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices such as laptops and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0062] Processor 340 is also coupled to input 350 including, for example, a touch screen, a keyboard, etc., and display 355. An operator of UE 116 may use input 350 to enter data into UE 116. Display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of presenting text and / or at least limited graphics, such as from a website.

[0063] Memory 360 is coupled to processor 340. A portion of memory 360 may include random access memory (RAM), and another portion of memory 360 may include flash memory or other read-only memory (ROM).

[0064] although Figure 3 An example of UE 116 is shown, but the Figure 3 For example, they can be combined, further subdivided, or omitted Figure 3 , and additional components may be added as needed. As a specific example, processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, transceiver(s) 310 may include any number of transceivers and signal processing chains and may be connected to any number of antennas. In addition, although Figure 3 The UE 116 is shown configured as a mobile phone or smart phone, but the UE may be configured to operate as other types of mobile or stationary devices.

[0065] Figure 4 and Figure 5 Example wireless transmit and receive paths according to the present disclosure are shown. In the following description, transmit path 400 may be described as being implemented in a gNB (such as gNB 102) and receive path 500 may be described as being implemented in a UE (such as UE 116). However, it is understood that receive path 500 may be implemented in a gNB and transmit path 400 may be implemented in a UE. In some embodiments, receive path 500 is configured to support initial access with multiple PRACH transmissions in a wireless communication system.

[0066] like Figure 4 The transmit path 400 shown includes a channel coding and modulation block 405, a serial to parallel (S to P) block 410, an inverse fast Fourier transform (IFFT) block of size N 415, a parallel to serial (P to S) block 420, an add cyclic prefix block 425, and an upconverter (UC) 430. Figure 5 The illustrated receive path 500 includes a downconverter (DC) 555 , a remove cyclic prefix block 560 , a serial to parallel (S to P) block 565 , a size-N fast Fourier transform (FFT) block 570 , a parallel to serial (P to S) block 575 , and a channel decoding and demodulation block 580 .

[0067] like Figure 4As shown, channel coding and modulation block 405 receives a set of information bits, applies coding (such as low-density parity check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols.

[0068] The serial-to-parallel block 410 converts (e.g., demultiplexes) the serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and the UE 116. The size-N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate a time domain output signal. The parallel-to-serial block 420 converts (e.g., multiplexes) the parallel time domain output symbols from the size-N IFFT block 415 to generate a serial time domain signal. The add cyclic prefix block 425 inserts a cyclic prefix to the time domain signal. The up-converter 430 modulates (e.g., up-converts) the output of the add cyclic prefix block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

[0069] The RF signal transmitted from gNB 102 reaches UE 116 after passing through the wireless channel, and an operation opposite to that at gNB 102 is performed at UE 116.

[0070] like Figure 5 As shown, the down converter 555 down-converts the received signal to the baseband frequency, and the cyclic prefix removal block 560 removes the cyclic prefix to generate a serial time domain baseband signal. The serial to parallel block 565 converts the time domain baseband signal into a parallel time domain signal. The size N FFT block 570 performs an FFT algorithm to generate N parallel frequency domain signals. The parallel to serial block 575 converts the parallel frequency domain signals into a modulated data symbol sequence. The channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0071] Each of gNBs 101-103 may implement Figure 4 The transmission path 400 shown is similar to the transmission to UE 111-116 in the downlink and can be implemented as follows Figure 5 Receive path 500 is shown, which is similar to receiving from UE 111-116 in the uplink. Similarly, each of UE 111-116 can implement transmit path 400 for transmitting to gNB 101-103 in the uplink, and can implement receive path 500 for receiving from gNB 101-103 in the downlink.

[0072] Figure 4 and Figure 5Each component in may be implemented using hardware only or a combination of hardware and software / firmware. As a specific example, Figure 4 and Figure 5 At least some components in can be implemented in software, while other components can be implemented by configurable hardware or a mixture of software and configurable hardware. For example, FFT block 570 and IFFT block 415 can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation.

[0073] In addition, although described as using FFT and IFFT, this is by way of illustration only and may not be construed as limiting the scope of the present disclosure. Other types of transforms may be used, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions. It will be appreciated that for DFT and IDFT functions, the value of variable N may be any integer (e.g., 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N may be any integer that is a power of two (e.g., 1, 2, 4, 8, 16, etc.).

[0074] although Figure 4 and Figure 5 An example of a wireless transmit and receive path is shown, but the Figure 4 and Figure 5 For example, they can be combined, further subdivided, or omitted Figure 4 and Figure 5 There are various components in it, and additional components can be added according to specific needs. In addition, Figure 4 and Figure 5 It is intended to illustrate examples of the types of transmit and receive paths that may be used in a wireless network. Any other suitable architecture may be used to support wireless communications in a wireless network.

[0075] The present disclosure provides that a gNB may not be able to successfully receive a PRACH transmission made by a UE under poor coverage conditions. One way to improve PRACH reception is for the UE to repeat the PRACH transmission multiple times, and the gNB combines the corresponding multiple PRACH receptions. In order to enable the gNB to combine multiple PRACH receptions, it is necessary to provide a means for the gNB to determine PRACH receptions associated with the same UE. It is also necessary to provide a signaling mechanism for the UE to determine the PRACH resources for multiple PRACH transmissions.

[0076] The present disclosure relates to a random access (RA) procedure for a UE to establish an RRC connection with a serving gNB, wherein the random access procedure includes multiple PRACH transmissions from the UE. The present disclosure relates to determining a number of repetitions of a PRACH transmission. The present disclosure also relates to determining time and frequency resources and a PRACH preamble index for multiple PRACH transmissions. The present disclosure also relates to calculating a RA-RNTI associated with a RO for multiple PRACH transmissions.

[0077] Throughout this disclosure, terms such as random access resources or PRACH resources or RACH resources may be used interchangeably to indicate resources used for a random access procedure, and these resources may be associated with one or more UE characteristics.

[0078] The embodiments described in this disclosure for multiple PRACH transmissions with the same beam are also applicable to multiple PRACH transmissions with different beams, and vice versa.

[0079] The RA procedure may be initiated by the Radio Resource Control (RRC) for a System Information (SI) request (if the System Information Block 1 (SIB1) includes scheduling information for an on-demand SI request), by the Medium Access Control (MAC), or by a Physical Downlink Control Channel (PDCCH) command. The RA procedure may be initiated due to various triggers or purposes.

[0080] For example, the RA procedure may be initiated for initial access to establish an RRC connection, where the user equipment (UE) transitions from the RRC_IDLE state to the RRC_CONNECTED state, to reestablish an RRC connection after a radio link failure (RLF), for an on-demand SI request or for handover. In addition, the RA procedure may be initiated for purposes such as uplink (UL) synchronization, scheduling request (SR), positioning, or link recovery (referred to herein as beam failure recovery (BFR)).

[0081] RA can operate in at least two modes. The first mode is contention-based random access (CBRA), where UEs transmitting to the same serving cell can share the same RA resources, and therefore, there is a possibility of collision between RA attempts from different UEs. The second mode is contention-free random access (CFRA), where the UE has dedicated RA resources indicated by the serving gNB and may not be shared with other UEs so that RA collisions can be avoided. The four-step RA procedure, also known as the Type 1 (L1) random access procedure, includes the transmission of a physical random access channel (PRACH) preamble (Msg1), an attempt to receive a random access response (RAR or Msg2), the transmission of a contention resolution message (Msg3), and an attempt to receive a contention resolution message (Msg4).

[0082] An alternative RA procedure may consist of only two steps, referred to herein as a two-step RACH or type 2 L1 random access procedure. In a two-step RACH, Msg1 and Msg3 are combined into MsgA for transmission, and Msg2 and Msg4 above are combined into MsgB for reception. MsgA combines a PRACH preamble transmission in a RACH opportunity (RO) with a PUSCH transmission in a so-called PUSCH opportunity (PO). The mapping between RO and PO can be one-to-one, many-to-one, or one-to-many.

[0083] The gNB transmits SS / PBCH blocks using downlink beams in order to cover the corresponding area on the cell. Typically, there is a coverage imbalance between DL reception and UL transmission due to the imbalance in the maximum power that can be used for the respective transmissions of the gNB and the UE. To compensate for this coverage imbalance, the UE can send multiple PRACH transmissions using the same spatial filter for all PRACH transmissions. The UE can select the received SS / PBCH block based on the quality of the SS / PBCH block reception and can send a number of PRACH repetitions so that the gNB can combine the corresponding multiple PRACH receptions. The UE is also able to send multiple PRACH transmissions by scanning multiple spatial filters.

[0084] For example, the gNB may transmit a number of SS / PBCH blocks using different narrow downlink beams, and the UE may transmit multiple PRACHs using different spatial filters associated with the reception of different SS / PBCH blocks. A combination of multiple PRACH transmissions with different spatial filters and multiple PRACH transmissions for each of the different spatial settings is also possible. The gNB may be able to detect one or more of the UE transmissions, and based on the configuration of the PRACH transmissions, the gNB may send one or more RARs to the UE.

[0085] If the UE does not receive the RAR, either because the gNB did not detect the PRACH preamble from the UE, for example because the corresponding spatial filter used by the UE does not provide a sufficiently large SINR, or because the UE did not receive the RAR, for example because the corresponding spatial filter used by the gNB does not provide a sufficiently large SINR, although the gNB has successfully detected the PRACH preamble from the UE and has sent the RAR to the UE, the UE may restart the RA procedure. If the UE successfully receives the RAR, the UE sends Msg3.

[0086] The gNB typically sends multiple SS / PBCH block transmissions, where each SS / PBCH block transmission can be associated with an SS / PBCH block index corresponding to a downlink beam. The mapping between the SS / PBCH block index and the RACH opportunity (RO) and / or preamble makes it possible to establish beam pairing, for example, during initial access. For example, the gNB sends an SS / PBCH block with index i corresponding to downlink beam i, the UE receives the SS / PBCH block with index i, and sends a PRACH preamble in RO j associated with the SS / PBCH block with index i. The association between the SS / PBCH block and the RO and / or PRACH preamble can be a 1-to-1 mapping or a many-to-one mapping or a one-to-many mapping.

[0087] Figure 6 A mapping example between SS / PBCH blocks and RO 600 according to an embodiment of the present disclosure is shown. Figure 6 The illustrated embodiment of mapping between SS / PBCH blocks and RO 600 is for illustration only.

[0088] like Figure 6 As shown, in one example, the mapping is a 1-to-1 mapping of SS / PBCH blocks and PRACH opportunities 610. The association of SS / PBCH block index i with RO j provided by the PRACH configuration allows the gNB to understand the beam in which the UE is located, so that the gNB can use the downlink beam i that transmits the SS / PBCH block with index i to send the RAR corresponding to the PRACH transmission of the UE in RO j. Each RO can be associated with a single PRACH preamble or multiple PRACH preambles, and the configuration provides the number of PRACH preambles associated with one RO.

[0089] In one example, the mapping is a 1 to M mapping of SS / PBCH blocks and PRACH opportunities 620. Each of the M ROs corresponds to a single SS / PBCH block index, and the transmission by the UE in the RO is an indication of the SS / PBCH block index. Thus, the association of the SS / PBCH block index with the RO provided by the PRACH configuration allows the gNB to understand the beam in which the UE is located. Each RO can be associated with a single PRACH preamble or multiple PRACH preambles, and the configuration provides the number of PRACH preambles associated with one RO.

[0090] In one example, the mapping is an N to 1 mapping of SS / PBCH blocks and PRACH opportunities 630. A RO is associated with multiple SS / PBCH indices, and transmissions by the UE in the RO do not indicate a single SS / PBCH index. Therefore, the association of the SS / PBCH block index with the RO provided by the PRACH configuration does not allow the gNB to understand in which beam of the N beams the UE is located. Different SS / PBCH block indices need to be associated with different sets of PRACH preambles.

[0091] In one example, the mapping is an N to M mapping of SS / PBCH blocks and PRACH opportunities 640. A RO is associated with multiple SS / PBCH indices, and any SS / PBCH index can be associated with multiple ROs. Therefore, the association of the SS / PBCH block index with the RO provided by the RACH configuration does not allow the gNB to understand in which beam of the N beams the UE is located. Different SS / PBCH block indices need to be associated with different sets of PRACH preambles.

[0092] In the present disclosure, determining the number of repetitions of a PRACH transmission is provided.

[0093] Before initiating the physical random access procedure, the UE is provided with the details of the PRACH transmission. Layer 1 receives a set of SS / PBCH block indices mapped to valid PRACH opportunities from higher layers (for example, provided by ssb-PositionsInBurst in SIB1 or ssb-PositionsInBurst in ServingCellConfigCommon or by NonCellDefiningSSB). Layer 1 also receives the configuration of PRACH transmission parameters from higher layers, including the PRACH preamble format, time resources and frequency resources used for PRACH transmission, and parameters for determining the root sequence and its cyclic shift in the PRACH preamble set. Through ssb-perRACH-OccasionAndCB-PreamblesPerSSB, the UE is also provided with the number N of SS / PBCH block indices associated with one PRACH opportunity and the number R of contention-based preambles for each SS / PBCH block index per valid PRACH opportunity. The PRACH configuration may also include at least one parameter p indicating the number of repetitions of the PRACH transmission.

[0094] A UE that is capable of sending PRACH with repetitions and is provided with a value P for parameter p may send PRACH with P repetitions. Whether the UE sends PRACH without repetitions or sends PRACH with P repetitions may depend on RSRP measurements based on the received SS / PBCH blocks. In addition, it may also depend on a configured threshold, such as rsrp-ThresholdSSB-r18, which is an L1-RSRP threshold for determining whether a PRACH transmission associated with an SS / PBCH block index is sent in a repeated or non-repeated manner, or generally with a first number of repetitions or a second number of repetitions.

[0095] The RSRP threshold used to determine the number of PRACH repetitions may be the same as the threshold provided by rsrp-ThresholdSSB, which is used to select SS blocks and corresponding PRACH resources for path loss estimation and (re)transmission based on SS blocks that meet the threshold, or the RSRP threshold may be the same as the threshold provided by rsrp-ThresholdMsg3, which is used to determine whether Msg3 repetitions are applicable to the random access procedure. In one example, the configured threshold may be provided by a higher layer.

[0096] The PRACH configuration may provide more than one repetition number value, such as (2, 4) or (2, 4, 8) or (2, 3,4) or (2, 3, 4, 8), and the UE determines the repetition number by selecting one of the configured values ​​based on the RSRP measurement of the received SS / PBCH block. When the PRACH configuration provides a single value P, the UE sends PRACH with P repetitions based on the RSRP measurement being above a threshold, otherwise the UE sends PRACH with no repetitions. When the PRACH configuration provides two PRACH repetition values ​​(P 1 , P 2 ), based on RSRP measurement being higher than the threshold, the UE sends a signal with P 1 Repeat or P 2 When the PRACH configuration provides more than 2 values, the UE can still determine the number of PRACH repetitions based on RSRP measurements, and in addition, multiple thresholds can be provided to the UE.

[0097] The configuration of the number of PRACH repetitions may include a value of 1, such as (1, 2, 4) or (1, 2, 4, 8). When the value 1 is the only value provided in the configuration, or all values ​​in the value set are one, the PRACH is sent without repetitions. The maximum number of repetitions may be greater than 8, such as 12 or 16.

[0098] The configuration of the number of PRACH repetitions may be cell specific and may provide a number of repetitions or a set of repetition numbers applicable to all SS / PBCH block indices in the cell. The layer 1 parameter indicating the number of repetitions provided in the PRACH configuration (e.g., provided via ssb-PositionsInBurst in SIB1 or ServingCellConfigCommon or via NonCellDefiningSSB) is defined per cell and is the same for all SS / PBCH block indices used in that cell. If more than one repetition value is configured, one of which may be 1, the UE may select different numbers of repetitions associated with the reception of different SS / PBCH block indices for the PRACH transmission. Thus, the configuration of the number of PRACH repetitions is cell specific and the content of the configuration is the same for all SS / PBCH block indices, or is equivalent for all beams.

[0099] The configuration of the number of PRACH repetitions may be cell specific and may provide a number of repetitions or a set of repetition numbers for each SS / PBCH block index in the cell. The number of repetitions or the set of repetition numbers is associated with the SS / PBCH block index or the set of SS / PBCH block indices. For each SS / PBCH block reception, the UE may use the configured repetition value or one of the configured values ​​in the set of repetition numbers associated with the SS / PBCH block index. Thus, the configuration of the number of PRACH repetitions is cell specific and the content of the configuration is per SS / PBCH block index or equivalently per beam.

[0100] The PRACH configuration may also not provide the number of repetitions. If not provided, a predefined fixed value or a set of predefined fixed values ​​is used. For example, the predefined value may be 1 or 2 or 4 or 8. A value of 1 indicates that the PRACH is sent without repetitions.

[0101] Figure 7 700 according to an embodiment of the present disclosure. The UE operation 700 may be performed by a UE (e.g., Figure 1 111-116) as shown. Figure 7 The embodiment of UE operations 700 shown in FIG. 7 is for illustration only. Figure 7 One or more of the components shown in the may be implemented in dedicated circuits configured to perform the functions described, or one or more components may be implemented by one or more processors executing instructions to perform the functions described.

[0102] Figure 7 An example is shown in which a UE according to the present disclosure determines the number of repetitions of a PRACH transmission based on configuration and RSRP measurement.

[0103] The UE is provided with a configuration of PRACH transmission parameters 710, including information on the number of PRACH repetitions. The UE selects one or more SS / PBCH block indices (e.g., 720). The UE determines the number of repetitions of the PRACH transmission corresponding to the selected SS / PBCH block indices based on the configuration (e.g., 730). The UE determines the time and frequency resources from the mapping of the SS / PBCH block indices and the RO, and determines (multiple) PRACH preamble indexes from the configured PRACH parameters for multiple PRACH transmissions 740. The UE sends multiple PRACH transmissions in the determined RO with the determined (multiple) PRACH preamble indexes 750.

[0104] In one example, at step 720, the selection may be based on the RSRP measurement of the SS / PBCH block being above a first threshold selected for the SS / PBCH block index. Over a time interval (e.g., a slot or cycle), the UE performs RSRP measurements on received SS / PBCH blocks with indices indicated in, for example, ssb-PositionsInBurst or NonCellDefiningSSB, and selects the SS / PBCH block index and the associated RO for PRACH transmission. The first threshold may be provided by configuration, or may be a predefined value, and may be cell-specific.

[0105] In another example, at step 720, at any given time, the UE selects the SS / PBCH block index corresponding to the transmitted SS / PBCH block, as indicated in ssb-PositionsInBurst or NonCellDefiningSSB (the index corresponding to the value 1 in the bitmap), and sends the PRACH in the RO associated with the transmitted SS / PBCH block.

[0106] In step 730, additionally or alternatively, the number of repetitions may be based on the RSRP measurement of the SS / PBCH block being above a second threshold for the number of PRACH repetitions, wherein the second threshold may be provided by configuration, or may be a predefined value, and may be cell-specific or associated with an SS / PBCH block index. The first threshold for SS / PBCH block index selection and the second threshold for the number of PRACH repetitions may be the same and provided by a single higher layer parameter. For example, the first threshold for SS / PBCH block index selection is also used to determine the number of repetitions.

[0107] In the present disclosure, determining time and frequency resources for multiple PRACH transmissions and a PRACH preamble index is provided.

[0108] The gNB may partition the PRACH resources in the cell and configure one partition for use by UEs transmitting PRACH without repetitions and another partition for use by UEs transmitting PRACH with repetitions, or generally configure different partitions for different numbers of repetitions. The resources in one partition may be used for PRACH transmissions with or without repetitions, while the resources in another partition may be used only for PRACH transmissions with repetitions.

[0109] For example, the ROs in the first partition may be used for PRACH transmissions without repetitions, and the ROs in the second partition may be used for PRACH transmissions with repetitions. In another example, the ROs in the first partition may be used for PRACH transmissions without repetitions or for transmissions of the first PRACH repetition, and the ROs in the second partition may be used for PRACH repetitions other than the first PRACH repetition. In yet another example, as an alternative or in addition to the partitioning of the ROs in the cell, the PRACH preamble index may be partitioned for use with or without PRACH repetitions.

[0110] The partitions of PRACH resources used for use with PRACH repetition (e.g., partitions for RO) may also correspond to the partitions used by UEs supporting sending Msg3 PUSCH with repetitions. Whether the UE sends Msg3 PUSCH with repetitions is subject to the gNB's indication of the number of repetitions in the RAR UL grant. Whether the UE sends PRACH with repetitions is subject to the UE's estimated RSRP value and one or more thresholds provided by the gNB.

[0111] It is possible that the partition of the RO is used by both UEs that transmit multiple PRACHs and UEs that request to transmit Msg3 PUSCH with repetitions, while the PRACH preamble is shared between UEs that transmit or do not transmit multiple PRACHs and / or request or do not request to transmit Msg3 PUSCH with repetitions. Based on a first threshold, the UE may select a PRACH resource from a RACH resource partition that is shared for multiple PRACH transmissions and Msg3 PUSCH transmissions with repetitions. Then, based on one or more additional thresholds, if more than one number of PRACH transmissions are possible, the UE determines the number of multiple PRACH transmissions. If no additional threshold is provided for determining the number of PRACH transmissions, in one example, the UE uses the first threshold to determine the number of multiple PRACH transmissions between two values ​​provided by a higher layer, where one value may be 1, or both values ​​may be 1, or both values ​​may be greater than 1. In another example, the UE uses a predetermined number for multiple PRACH transmissions.

[0112] It is possible that the first threshold is provided by a higher layer parameter rsrp-ThresholdMsg3 and that the UE uses this threshold to select PRACH resources from a PRACH resource partition common to multiple PRACH transmissions and PUSCH transmissions with repeated Msg3. The UE then determines the number of multiple PRACH transmissions based on the same threshold, or equivalently, the UE uses the number of multiple PRACH transmissions associated with the selected RACH resource partition. When the UE is configured with multiple values ​​for the number of multiple PRACH transmissions, if no other threshold UE is provided for selecting the number of multiple PRACH transmissions, the first value may be selected based on rsrp-ThresholdMsg3, or if one or more thresholds are provided, one of the configured values ​​for the number of multiple PRACH transmissions may be selected based on the one or more thresholds.

[0113] The gNB may provide two separate thresholds, e.g., rsrp-ThresholdPRACH and rsrp-ThresholdMsg3, one for multiple PRACH transmissions and one for Msg3 PUSCH repetitions, and depending on whether separate or common RACH resources can be used for multiple PRACH transmissions and for Msg3 PUSCH with repetitions, the gNB may set the values ​​of the two thresholds to the same or different values, and accordingly partition the RACH resources in a common partition (Partition A) for multiple PRACH transmissions and Msg3 repetition requests, or in two separate partitions, Partition B for multiple PRACH transmissions and Partition C for Msg3 repetition requests. It is also possible that, although two thresholds are provided, Partitions B and C include some resources as shared resources. For example, the RO in partition B is also in partition C, and vice versa; or the PRACH preamble in partition B is also in partition A, and vice versa; or partition B and partition C have a shared RO but separate PRACH preambles, or have separate ROs and shared PRACH preambles.

[0114] It is also possible that the partitioning of PRACH resources for multiple PRACH transmissions (e.g. partitioning of RO) may also correspond to a partitioning according to UE capabilities for repetition of PUCCH transmissions with HARQ-ACK information (when no dedicated PUCCH resource configuration is provided) (or repetition of PUCCH transmissions with HARQ-ACK information or repetition of PUCCH transmissions with HARQ-ACK information for reception of Msg4 PDSCH).

[0115] Additionally, the same PRACH resource may correspond to the capability or request to send a Msg3 PUSCH with repetitions. When the UE does not have dedicated PUCCH resources, based on a first threshold, where the first threshold may be rsrp-ThresholdMsg3 or a separately configured threshold, the UE may select a PRACH resource from a PRACH resource partition that is common for the capability of multiple PRACH transmissions and repetitions of PUCCH transmissions with HARQ-ACK information. It is also possible that the thresholds for selecting PRACH resource partitions for multiple PRACH transmissions and for PUCCH with repetitions are different, and whether some or all of the PRACH resources, ROs, and / or PRACH preambles are common depends on the gNB configuration of the RACH resources.

[0116] Similarly, the thresholds for selection of PRACH resource partitions for multiple PRACH transmissions, Msg3 PUSCH with repetitions, and PUCCH with repetitions may be separate thresholds, and the corresponding PRACH resources may be partially or completely shared or separated for the three features or capabilities. Additionally or alternatively, PRACH resources for multiple PRACH transmissions and / or Msg3 PUSCH with repetitions and / or PUCCH with repetitions when no dedicated PUCCH resource configuration is provided may also be associated with one or more features including RedCap and / or specific network slices as a group NSAG and / or small data transmission (SDT) and / or Msg3 repetition.

[0117] PRACH resource partitions for use with or without PRACH repetitions may also depend on the mapping between SS / PBCH block indices and ROs. For example, when a first partition of an RO is used for transmissions with repetitions and a second partition is used for transmissions without repetitions, the ROs that are part of the first partition are configured with a 1 to N mapping of SS / PBCH blocks and ROs such that a PRACH transmission with M ≤ N repetitions uses some or all of the N ROs mapped to the same SS / PBCH block. In another example, the ROs that are part of the first partition are configured with a 1 to 1 mapping of SS / PBCH blocks and ROs such that a PRACH transmission with M repetitions uses M ROs mapped to different SS / PBCH blocks.

[0118] The PRACH resource partitioning for with or without PRACH repetition may also depend on whether the gNB transmits SS / PBCH blocks with relatively wide beams to cover a corresponding wide area on the cell, or transmits SS / PBCH blocks with relatively narrow beams to associate different SS / PBCH block transmissions with different downlink beams. When the gNB transmits SS / PBCH blocks using relatively wide beams, the mapping of SS / PBCH block index and RO may be a 1 to N mapping so that the gNB can successfully detect PRACH transmissions from one or more receptions associated with the same SS / PBCH block index.

[0119] When the gNB sends SS / PBCH blocks with relatively narrow beams, the mapping of SS / PBCH block index and RO can be a 1-to-1 mapping, so that the gNB can determine the downlink beam in which the UE is located from one or more receptions associated with different SS / PBCH block indices. The mapping of each SS / PBCH block can also be a 1-to-N mapping, and the UE sends N PRACH repetitions in the corresponding N ROs associated with one SS / PBCH block. The number of ROs mapped to one SS / PBCH block can be the same or different for different SS / PBCH blocks. Therefore, the time and frequency resources used for multiple PRACH transmissions depend on the mapping between SS / PBCH block indices and ROs and the division of PRACH resources.

[0120] In one example, a first RO is associated with a first SS / PBCH block index, a second RO is associated with a second SS / PBCH block index, and the first and second ROs may be used for PRACH transmissions without repetition or for PRACH transmissions of a first PRACH repetition. Transmissions of PRACH repetitions other than the first repetition may occur in a RO configured for PRACH repetition and be associated with the same SS / PBCH block index as the RO of the first PRACH repetition.

[0121] Figure 8 and Fig. 9 An example of a PRACH transmission with repetitions 800 and 900 is shown according to an embodiment of the present disclosure. Figure 8 and Fig. 9 The embodiment of PRACH transmission with repetitions 800 and 900 shown in FIG. 8 is for illustration only.

[0122] Figure 8An example of a PRACH transmission with repetitions is shown, the PRACH transmission being associated with an SS / PBCH block index and being sent in ROs with consecutive time resource indices and the same frequency resources, and different mappings of ROs and repetitions in a time period can be associated with the same or different SSBs. In 810, a first PRACH transmission associated with a first SS / PBCH block index has 4 repetitions, wherein the first repetition is sent in a first RO associated with the first SS / PBCH block index, the second, third, and fourth repetitions are sent in valid ROs with consecutive time resource indices and the same frequency resources, and a second PRACH transmission associated with a second SS / PBCH block index has no repetitions. In 820, the first PRACH transmission in the first RO has no repetitions, and the PRACH transmission in the second RO has 4 repetitions, and the repetitions are transmitted in valid ROs with consecutive time resource indices and the same frequency resources. In 830, both the first PRACH transmission and the second PRACH transmission have repetitions. Figure 8 The first PRACH transmission and the second PRACH transmission in may refer to a first PRACH attempt and a second PRACH attempt.

[0123] The PRACH repetition may be transmitted in an RO with subsequent non-contiguous time resource indexes and the same frequency resource, or in an RO with subsequent consecutive or non-contiguous frequency resource indexes and the same time resource, or in an RO with subsequent time and frequency resource indexes. Figure 8 The periodicity or association period shown as a mapping of RO resources and repetition numbers to SSB periods in FIG. 1 is equally applicable to any duration of the association period provided to the UE by higher layers.

[0124] Fig. 9 An example of PRACH transmissions with repetitions associated with SS / PBCH block indexes is shown. RO1, RO2, and RO3 are associated with corresponding SS / PBCH block indexes SS1, SS2, and SS3. RO1, RO2, and RO3 are used to send the first repetition of corresponding PRACH1, PRACH2, and PRACH3 transmissions with repetitions. The RO used to send the repetitions of each PRACH transmission is associated with the same SS / PBCH block index.

[0125] like Fig. 9 As shown, in 910, RO1, RO2 and RO3 or equivalently ROs in a RO group or set have consecutive time indexes and the same frequency index, and for each PRACH transmission, the ROs used to transmit the second, third and fourth repetitions have consecutive frequency resource indexes.

[0126] In 920, RO1, RO2, and RO3 have non-consecutive time indexes and the same frequency index, and for each PRACH transmission, the ROs for the second, third, and fourth repeated transmissions have subsequent time and frequency resource indexes.

[0127] In 930, RO1, RO2, and RO3 have consecutive time indexes and the same frequency index, and the RO for the second repetition for the corresponding 3 PRACH transmissions is obtained by shifting the pattern of the RO for the first repetition in time and frequency.

[0128] In 940, RO1, RO2, and RO3 have consecutive time indexes and the same frequency index, and the RO for subsequent repetition is obtained by shifting the pattern of three ROs in time and / or frequency.

[0129] In 950, RO1, RO2, and RO3 have consecutive time indexes and the same frequency index, and ROs for subsequent repetitions have subsequent time indexes. PRACH1 transmission has 4 repetitions, PRACH2 transmission has 2 repetitions, and PRACH3 transmission has 2 repetitions.

[0130] In 960, RO1, RO2, and RO3 have consecutive time indexes and the same frequency index. The PRACH1 transmission has 4 repetitions, the PRACH2 transmission has 2 repetitions, and the PRACH3 transmission has 2 repetitions. The ROs for the second repetitions of the corresponding 3 PRACH transmissions are obtained by shifting the pattern of the ROs for the first repetition in time and frequency. The additional repetitions of the PRACH1 transmission are shifted in time relative to the first repetition.

[0131] In the present disclosure, indications of time and frequency resource indexes are provided.

[0132] The RO for the first repetition of PRACH transmission with repetition may be one of the ROs reserved for transmission with repetition, or may be one of the ROs available for transmission with or without repetition.The RO for repetitions other than the first repetition may be a reserved RO for repetition.

[0133] The information of the RO that can be used for PRACH repetition can be provided to the UE. This information can be provided by an index i indicating a time resource and an index j indicating a frequency resource, where the index Is an absolute index or an index relative to the time and frequency resource of the first PRACH repetition The relative index of .

[0134] For example, the RO for PRACH repetition is identified by offsets δ and γ as , where δ and γ have different values ​​for different PRACH repetitions: For the second repetition, , for the third repetition, , and so on. A single offset δ may also be used, and the RO for the repetition is equally shifted in time and frequency relative to the RO of the first PRACH transmission. For example, for the second repetition, , for the third repetition, , and so on.

[0135] In one example, for 4 PRACH repetitions, the offset is referenced to the index of the previous repetition: Given the values ​​of δ and Y, and As the RO index of the first PRACH repetition, for the second repetition, , for the third repetition, , for the third repetition, .

[0136] In another example, for 4 PRACH repetitions, the offset refers to the index of the previous repetition: Given the values ​​of δ and Y, and as the index of the first PRACH repetition, and for the second repetition, , for the third repetition, , for the third repetition, Therefore, PRACH is repeated in subsequent time resources (or consecutive time resources if ) and the same frequency resource. Alternatively or additionally, If both offsets have a value of zero, the PRACH repetition is sent using the same RO index and a different PRACH preamble index.

[0137] In yet another example, for 4 PRACH repetitions, the offset is referenced to the first repetition: given as well as value, and As the RO index of the first PRACH repetition, for the second repetition, , for the third repetition, , for the third repetition, .

[0138] The offset value can be determined based on higher layer configuration or predefined fixed values. If both the configured value and the predefined value are provided, the configured value is used. If neither is provided, The default value can be ,or ,or .

[0139] In the present disclosure, determination of a PRACH preamble for PRACH repetition is provided.

[0140] When repeating a PRACH transmission sent in an RO mapped to the same SS / PBCH block index, the same PRACH preamble can be used for all repetitions. Alternatively, the UE can use different PRACH preambles for different repetitions, or use the same preamble for some repetitions and different preambles for some other repetitions.

[0141] The repetition of a PRACH transmission can be sent using a single RO associated with an SS / PBCH block index and different PRACH preambles for each repetition.

[0142] In the present disclosure, determination of a RA-RNTI for a PRACH transmission with repetition is provided.

[0143] The gNB can detect a number of PRACH preambles from a UE sending a PRACH with repetition using multiple ROs and send a RAR. The UE attempts to detect a DCI format with a CRC scrambled by the corresponding RA-RNTI during a window controlled by a higher layer, where the RA-RNTI is a function of parameters related to the PRACH transmission (such as the time and frequency of the RO for the PRACH transmission) and can be determined by the UE.

[0144] For a PRACH transmission in a single RO, the RA-RNTI associated with the RO corresponding to the RAR is calculated as: RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id, where s_id is the index of the first OFDM symbol of the PRACH occasion (0 < s_id < 14), t_id is the index of the first time slot of the PRACH occasion in the system frame (0 ≤ t_id < 80), where the subcarrier spacing (SCS) for determining t_id is based on the value of the SCS configuration μ, f_id is the index of the PRACH occasion in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the UL carrier used for PRACH preamble transmission.

[0145] For multiple PRACH transmissions, the calculation of the RA-RNTI needs to consider the time resources and frequency resources of the ROs for the multiple PRACH transmissions and whether the ROs occupy consecutive or non-consecutive time and / or frequency resources.

[0146] In one example, a PRACH transmission with N_t repetitions occupies N_t ROs in consecutive time resources and the same frequency resources. The RA-RNTI associated with the RO for multiple PRACH transmissions is calculated as RA-RNTI = 1 + s_id +14 × t_id + 14 × (N_t -1) + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id, where the term is 14 × (N_t -1), or alternatively j × (N_t -1), where j ≥ 1, considering multiple ROs in the time domain. For N_t repeated PRACH transmissions, or generally for a PRACH transmission of multiple (N_t) PRACHs in N_t ROs, for each repetition or transmission, i=1,…, N_t, a corresponding RA-RNTI may be calculated, and the PRACH transmission may be associated with one RA-RNTI corresponding to one index i, or with multiple RA-RNTIs associated with multiple indices, including the case of N_t RA-RNTIs. It is possible that the RA-RNTI is associated with one RA-RNTI corresponding to a first index i=1, or a second index i=2, or a last index i=N_t.

[0147] It is also possible that two RA-RNTIs are associated with the first and second index, or with the first and last, or more than two RA-RNTIs are associated with more than two indexes.The UE receives a RAR message in one or more RAR windows using one or more RA-RNTIs.

[0148] In another example, a PRACH transmission with N_f repetitions occupies N_f ROs in consecutive frequency resources and the same time resources. The RA-RNTI associated with the RO for multiple PRACH transmissions is calculated as RA-RNTI = 1 + s_id +14 × t_id + 14 × 80 × f_id + 14 × 80 × (N_f -1) + 14 × 80 × 8 × ul_carrier_id, where the term is 14 × 80 × (N_f -1), or alternatively j × (N_f -1), where j ≥ 1, considering multiple ROs in the frequency domain. For N_f repeated PRACH transmissions, or generally for a PRACH transmission of multiple (N_f) PRACHs in N_f ROs, for each repetition or transmission, i=1,…, N_f, a corresponding RA-RNTI can be calculated, and the PRACH transmission can be associated with one RA-RNTI corresponding to one index i, or with multiple RA-RNTIs associated with multiple indices, including the case of N_f RA-RNTIs. It is possible that the RA-RNTI is associated with a RA-RNTI corresponding to a first index i=1, or a second index i=2, or a last index i=N_f. It is also possible that two RA-RNTIs are associated with the first and second indices, or with the first and last indices, or more than two RA-RNTIs are associated with more than two indices. The UE receives the RAR message in one or more RAR windows using one or more RA-RNTIs.

[0149] For multiple PRACH transmissions in N ROs occupying nt consecutive ROs in the time domain and nf consecutive ROs in the frequency domain, the RA-RNTI associated with the ROs for the multiple PRACH transmissions is calculated as RA-RNTI = 1 + s_id + 14 × (t_id + nt) + 14 × 80 × (f_id + nf) + 14 × 80 × 8 × ul_carrier_id.

[0150] If the ROs for multiple PRACH transmissions are not contiguous in the time domain and / or frequency domain, nt indicates the number of contiguous ROs in the time domain starting from the RO for the first repetition and including the RO with the largest time index, and nf indicates the number of contiguous ROs in the frequency domain starting from the RO for the first repetition and including the RO with the largest frequency index. Thus, for a PRACH transmission with N repetitions or for N PRACH transmissions, where the N repetitions or multiple (N) PRACH transmissions may be transmitted in the N ROs using the same beam or more than one different beams and the same PRACH preamble or more than one different PRACH preamble or equivalently in a RO group, where the ROs may occupy the same or different time resources and the same or different frequency resources, the RA-RNTI may be associated with any RO in the RO group and may accordingly be calculated using the time and frequency resource indices associated with the RO.

[0151] The RA-RNTI may be associated with one RO in the RO group and may accordingly be calculated using the time and frequency resource indexes associated with the RO, or the RA-RNTI may be associated with more than one RO in the RO group and may accordingly be calculated using the time and frequency resource indexes associated with more than one RO, wherein the time or frequency indexes associated with one or more ROs may be the same or different. When one RA-RNTI is associated with the RO group, the UE attempts to detect a DCI format with a CRC scrambled by the one RA-RNTI during the RAR window, wherein the one RA-RNTI is calculated using the indexes of the time and frequency resources associated with the first RO or any RO in the group.

[0152] When more than one RA-RNTI is associated with a RO group, wherein the more than one RA-RNTI is calculated using indices of time and frequency resources associated with the corresponding multiple ROs, the UE attempts to detect a DCI format with a CRC scrambled by a first RA-RNTI during a first RAR window, a DCI format with a CRC scrambled by a second RA-RNTI during a second RAR window, and so on. It is possible that the UE attempts to detect more than one DCI format scrambled by the corresponding more than one RA-RNTI during the same RAR window.

[0153] The above flow charts illustrate example methods that can be implemented according to the principles of the present disclosure, and various changes can be made to the methods shown in the flow charts herein. For example, although shown as a series of steps, the various steps in each figure can overlap, occur in parallel, occur in different orders, or occur multiple times. In another example, a step can be omitted or replaced by another step.

[0154] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. The present disclosure is intended to cover these changes and modifications that fall within the scope of the appended claims. The description in this application should not be interpreted as implying that any particular element, step or function is an essential element that must be included in the scope of the claims. The scope of the patent subject matter is defined by the claims.

Claims

1. A user equipment (UE) in a communication system, the UE comprising: Transceiver; and a processor operably coupled to the transceiver, the processor being configured to: receiving a system information block (SIB) indicating a first number of multiple physical random access channel (PRACH) transmissions, a first PRACH opportunity (RO) partition associated with the multiple PRACH transmissions, a second RO partition associated with one PRACH transmission, and one or more first sets of multiple ROs associated with the first number of multiple PRACH transmissions, the one or more first sets including ROs from the first RO partition and excluding ROs from the second RO partition, determining a RO group from the one or more first sets of a plurality of ROs, determining a PRACH preamble for transmission in a first number of ROs of the RO group, and The PRACH preamble is sent in the first number of ROs.

2. The UE according to claim 1, wherein: The SIB also indicates an association period for mapping ROs in the one or more first sets of a plurality of ROs to the first number of the plurality of PRACH transmissions.

3. The UE according to claim 1, wherein: The processor is further configured to: A synchronization signal and physical broadcast channel (SS / PBCH) block is received, and ROs in the one or more first sets of a plurality of ROs associated with the first number of plurality of PRACH transmissions are mapped to an index of the SS / PBCH block.

4. The UE according to claim 1, in, The SIB also indicates: a second number of multiple PRACH transmissions, one or more second sets of a plurality of ROs associated with the second number of plurality of PRACH transmissions, wherein the one or more second sets include ROs from the first RO partition, and an association period for mapping ROs in the one or more first sets of multiple ROs to the first number of multiple PRACH transmissions, and mapping ROs in the one or more second sets of multiple ROs to the second number of multiple PRACH transmissions, and Wherein, the processor is further configured to: receiving a first reference signal received power (RSRP) value, Receive the Synchronization Signal and Physical Broadcast Channel (SS / PBCH) blocks, determining a second RSRP value based on the received SS / PBCH block, When the second RSRP value is not greater than the first RSRP value, determining that the RO group is a set in the one or more first sets of multiple ROs, and When the second RSRP value is greater than the first RSRP value, the RO group is determined to be a set in the one or more second sets of multiple ROs.

5. The UE according to claim 1, wherein: The ROs in the RO group associated with the first repetition number are mapped to one of the following: different time resource indexes and the same frequency resource index, and Different time resource indexes and different frequency resource indexes.

6. The UE according to claim 1, wherein: The processor is further configured to: receiving a downlink control information (DCI) format 1_0 with a cyclic redundancy check (CRC) scrambled by a random access radio network temporary identifier (RA-RNTI) during a window controlled by higher layers, and A RA-RNTI associated with a last RO in the RO group is received.

7. A base station (BS) in a communication system, the BS comprising: Transceiver; and a processor operably coupled to the transceiver, the processor being configured to: Sending a system information block (SIB), wherein the SIB indicates: receiving a first plurality of physical random access channels (PRACHs), a first PRACH opportunity (RO) partition associated with multiple PRACH receptions, a second RO partition associated with one PRACH reception, one or more first sets of a plurality of ROs associated with the first number of plurality of PRACH receptions, wherein the one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition, determining a RO group from the one or more first sets of a plurality of ROs, and determining a PRACH preamble for reception in a first number of ROs in the RO group, The transceiver is further configured to receive the PRACH preamble code in the first number of ROs.

8. The BS according to claim 7, wherein: The SIB also indicates an association period for mapping ROs in the one or more first sets of multiple ROs to the first number of multiple PRACH receptions.

9. The BS according to claim 7, in, The processor is further configured to: A synchronization signal and physical broadcast channel (SS / PBCH) block is transmitted, and ROs in the one or more first sets of a plurality of ROs associated with the first number of plurality of PRACH receptions are mapped to an index of the SS / PBCH block, and The SIB further indicates: a second number of multiple PRACH receptions, one or more second sets of a plurality of ROs associated with the second number of plurality of PRACH receptions, wherein the one or more second sets include ROs from the first RO partition, and An association period is used to map the ROs in the one or more first sets of multiple ROs to the first number of multiple PRACH receptions, and to map the ROs in the one or more second sets of multiple ROs to the second number of multiple PRACH receptions.

10. The BS according to claim 7, in, The ROs in the RO group associated with the first repetition number are mapped to one of the following: different time resource indexes and the same frequency resource index, and Different time resource indexes and different frequency resource indexes, Wherein, the processor is further configured to: Sending Downlink Control Information (DCI) format 1_0 with a Cyclic Redundancy Check (CRC) scrambled by a Random Access Radio Network Temporary Identifier (RA-RNTI) during a window controlled by higher layers, and The RA-RNTI associated with the last RO in the RO group is sent.

11. A method performed by a user equipment UE in a communication system, the method comprising: Receiving a system information block (SIB), wherein the SIB indicates: a first number of multiple physical random access channel (PRACH) transmissions, a first PRACH opportunity (RO) partition associated with a plurality of PRACH transmissions, a second RO partition associated with a PRACH transmission, and one or more first sets of a plurality of ROs associated with the first number of plurality of PRACH transmissions, wherein the one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition; determining an RO group from the one or more first sets of a plurality of ROs; determining a PRACH preamble code for transmission in a first number of ROs in the RO group; and The PRACH preamble is transmitted in a first number of ROs in the RO group.

12. The method according to claim 11, in, The SIB further indicates an association period for mapping ROs in the one or more first sets of multiple ROs to the first number of multiple PRACH transmissions, The method further comprises: Receive the Synchronization Signal and Physical Broadcast Channel (SS / PBCH) blocks, The ROs in the one or more first sets of the plurality of ROs associated with the first number of PRACH transmissions are mapped to indexes of the SS / PBCH blocks.

13. The method according to claim 11, in, The SIB also indicates: a second number of multiple PRACH transmissions, one or more second sets of a plurality of ROs associated with the second number of plurality of PRACH transmissions, wherein the one or more second sets include ROs from the first RO partition, an association period for mapping the one or more first sets of ROs of the plurality of ROs to the first number of multiple PRACH transmissions, and mapping the ROs in the one or more second sets of the plurality of ROs to the second number of multiple PRACH transmissions, and Wherein, the method further comprises: receiving a first reference signal received power (RSRP) value, Receive synchronization signal and physical broadcast channel (SS / PBCH) blocks; determining a second RSRP value based on the received SS / PBCH block; When the second RSRP value is not greater than the first RSRP value, determining that the RO group is a set in the one or more first sets of multiple ROs; and When the second RSRP value is greater than the first RSRP value, the RO group is determined to be a set in the one or more second sets of multiple ROs.

14. The method according to claim 11, in, The ROs in the RO group associated with the first repetition number are mapped to one of the following: different time resource indexes and the same frequency resource index, and Different time resource indexes and different frequency resource indexes, Wherein, the method further comprises: receiving a downlink control information (DCI) format 1_0 with a cyclic redundancy check (CRC) scrambled by a random access radio network temporary identifier (RA-RNTI) during a window controlled by higher layers, The RA-RNTI is associated with the last RO in the RO group.

15. A method performed by a base station (BS) in a communication system, the method comprising: Sending a system information block (SIB), wherein the SIB indicates: receiving a first plurality of physical random access channels (PRACHs), a first PRACH opportunity (RO) partition associated with multiple PRACH receptions, a second RO partition associated with one PRACH reception, and one or more first sets of a plurality of ROs associated with the first number of plurality of PRACH receptions, wherein the one or more first sets include ROs from the first RO partition and do not include ROs from the second RO partition; determining an RO group from the one or more first sets of a plurality of ROs; determining a PRACH preamble for reception in a first number of ROs in the RO group; and The PRACH preamble is received in the first number of ROs.

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