Random access response and contention resolution

Abstract

A base station and user equipment (UE) for random access and contention resolution are provided. A method for operating a UE includes receiving a configuration for: a first control resource set (CORESET), the first CORESET including a first number of resource blocks (RBs) in the frequency domain and a first number of symbols in the time domain; a second CORESET, the second CORESET including a second number of RBs in the frequency domain and a second number of symbols in the time domain; and a reference signal received power (RSRP) threshold. The method also includes determining a first RSRP value and receiving a first physical downlink control channel (PDCCH). When the first RSRP value is greater than the RSRP threshold, the first PDCCH reception is in the first CORESET, and when the first RSRP value is less than the RSRP threshold, the first PDCCH reception is in the second CORESET.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to random access responses and contention resolution. Background Art

[0002] Considering the development of wireless communication from generation to generation, technology mainly used for services for humans, such as voice calls, multimedia services and data services, has been developed. After the commercialization of 5G (5th generation) communication systems, it is expected that the number of networked devices will grow exponentially. These will be increasingly connected to communication networks. Examples of networked things can include vehicles, robots, drones, household appliances, displays, smart sensors connected to various infrastructures, construction machinery and factory equipment. It is expected that mobile devices will evolve in various form factors, such as augmented reality glasses, virtual reality headsets and hologram devices. In order to connect hundreds of billions of devices and things in the 6G (6th generation) era to provide various services, efforts have been made to develop improved 6G communication systems. For these reasons, 6G communication systems are called super 5G systems.

[0003] The 6G communication system, which is expected to be commercialized around 2030, will have a peak data rate of terabit (1,000 gigabits) bps and a radio latency of less than 100 μsec, and will therefore be 50 times faster than the 5G communication system and have 1 / 10 of its radio latency.

[0004] In order to achieve such high data rates and ultra-low latency, it has been considered to implement 6G communication systems in the terahertz band (e.g., 95GHz to 3THz band). It is expected that since the path loss and atmospheric absorption in the terahertz band are more serious than in the millimeter wave band introduced in 5G, the technology to ensure the signal transmission distance (that is, coverage) will become more critical. As the main technology to ensure coverage, it is necessary to develop radio frequency (RF) elements, antennas, new waveforms with better coverage than orthogonal frequency division multiplexing (OFDM) schemes, beamforming and large-scale multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and multi-antenna transmission technologies such as large-scale antennas. In addition, new technologies for improving the coverage of terahertz band signals have been discussed, such as lenses and antennas based on metamaterials, orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS).

[0005] In addition, in order to improve spectrum efficiency and overall network performance, the following technologies for 6G communication systems have been developed: full-duplex technology for achieving uplink transmission and downlink transmission using the same frequency resources at the same time; network technology for utilizing satellites, high altitude platform stations (HAPS), etc. in an integrated manner; improved network structure for supporting mobile base stations, etc. and achieving network operation optimization and automation, etc.; dynamic spectrum sharing technology via conflict avoidance based on prediction of spectrum use; use of artificial intelligence (AI) in wireless communication to improve overall network operation by utilizing AI from the design stage of developing 6G and internalizing end-to-end AI support functions; next-generation distributed computing technology to overcome the limits of UE computing power through achievable ultra-high performance communications and computing resources on the network (such as mobile edge computing (MEC), cloud, etc.). In addition, attempts are continuously made to strengthen connectivity between devices, optimize networks, promote softwareization of network entities, and improve the openness of wireless communications by designing new protocols to be used in 6G communication networks, developing mechanisms for achieving hardware-based security environments and secure use of data, and developing technologies for maintaining privacy.

[0006] It is expected that research and development of 6G communication systems for hyperconnectivity, including both human-to-machine (P2M) and machine-to-machine (M2M), will enable the next hyperconnectivity experience. In particular, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile holograms, and digital replicas can be provided through 6G communication systems. In addition, services such as remote surgery with enhanced safety and reliability, industrial automation, and emergency response will be provided through 6G communication systems, making it possible to apply technology in various fields such as industry, medical care, automobiles, and household appliances.

[0007] Initial commercialization of 5G mobile communications is expected around 2020, and its momentum has been increasing recently with all the technical activities around the world for various candidate technologies from industry and academia. Candidate enablers for 5G / NR mobile communications include massive antenna technology, from legacy cellular bands to high frequencies to provide beamforming gain and support increased capacity, new waveforms (e.g., new radio access technologies (RATs)) for flexible adaptation to various services / applications with different requirements, new multiple access schemes for supporting massive connectivity, and so on. Summary of the invention

[0008] Solution to the problem

[0009] The present disclosure relates to wireless communication systems, and more particularly, to random access response and contention resolution.

[0010] In one embodiment, a method for operating a user equipment (UE) is provided. The method includes receiving a configuration for: a first control resource set (CORESET), the first CORESET including a first number of resource blocks (RBs) in the frequency domain and a first number of symbols in the time domain; a second CORESET, the second CORESET including a second number of RBs in the frequency domain and a second number of symbols in the time domain; and a reference signal received power (RSRP) threshold. The second number of symbols is greater than the first number of symbols. The method also includes determining a first RSRP value and receiving a first physical downlink control channel (PDCCH). When the first RSRP value is greater than the RSRP threshold, the first PDCCH reception is in the first CORESET, and when the first RSRP value is less than the RSRP threshold, the first PDCCH reception is in the second CORESET.

[0011] In another embodiment, a UE is provided. The UE includes: a transceiver configured to receive a configuration for: a first CORESET including RBs of a first number of RBs in the frequency domain and symbols of a first number of symbols in the time domain, a second CORESET including RBs of a second number of RBs in the frequency domain and symbols of a second number of symbols in the time domain; and an RSRP threshold. The second number of symbols is greater than the first number of symbols. The UE also includes a processor configured to determine a first RSRP value. The transceiver is also configured to receive a first PDCCH. When the first RSRP value is greater than the RSRP threshold, the first PDCCH reception is in the first CORESET, and when the first RSRP value is less than the RSRP threshold, the first PDCCH reception is in the second CORESET.

[0012] In yet another embodiment, a base station is provided. The base station includes a processor and a transceiver operably connected to the processor. The transceiver is configured to transmit a configuration for: a first CORESET, the first CORESET including RBs of a first number of RBs in the frequency domain and symbols of a first number of symbols in the time domain, a second CORESET, the second CORESET including RBs of a second number of RBs in the frequency domain and symbols of a second number of symbols in the time domain; and an RSRP threshold. The second number of symbols is greater than the first number of symbols. The transceiver is also configured to transmit a first PDCCH. The first PDCCH transmission is in the first CORESET or in the second CORESET. The first PDCCH transmission schedules the transmission of a PDSCH including an RAR message. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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, in which like reference numerals represent like parts:

[0014] Figure 1 An example wireless network according to an embodiment of the present disclosure is presented;

[0015] Figure 2 An example gNB according to an embodiment of the present disclosure is shown;

[0016] Figure 3 An example UE according to an embodiment of the present disclosure is shown;

[0017] Figure 4 An example DL slot structure according to an embodiment of the present disclosure is shown;

[0018] Figure 5 An example UL slot structure for PUSCH transmission or PUCCH transmission according to an embodiment of the present disclosure is shown;

[0019] Fig. 6A An example E / R / R / BI MAC subheader is shown according to an embodiment of the present disclosure;

[0020] Figure 6B An example E / T / RAPID MAC subheader according to an embodiment of the present disclosure is shown;

[0021] Figure 6C An example MAC RAR according to an embodiment of the present disclosure is shown;

[0022] Figure 7 An example determination of the number of repetitions of a PDSCH transmission providing RAR based on RSRP range / CE level and UE power class according to an embodiment of the present disclosure is shown;

[0023] Figure 8 An example determination of a CORESET length for PDCCH monitoring associated with PDSCH reception scheduled to provide RAR by a UE based on RSRP range / CE level and UE power class according to an embodiment of the present disclosure is presented;

[0024] Fig. 9 An example determination of a starting symbol and length of a PDCCH monitoring window for scheduling PDSCH reception providing RAR with repeated PRACH preamble transmissions according to an embodiment of the present disclosure is presented;

[0025] Fig.10Another example determination of a starting symbol and length of a PDCCH monitoring window for scheduling PDSCH reception providing RAR with repeated PRACH preamble transmissions according to an embodiment of the present disclosure is presented; and

[0026] Fig.11 Example congestion control and UE distribution during initial access of NR-Light UEs according to embodiments of the present disclosure are presented. DETAILED DESCRIPTION

[0027] Other technical features may be apparent to those skilled in the art from the following drawings, descriptions and claims.

[0028] Before proceeding to the following inventive mode, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document. The term "connection" 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 "transmit", "receive" and "communication" and their derivatives cover both direct and indirect communication. The terms "include" and "includes" 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, included in, included in, connected to, or connected with, connected to, or connected with, can communicate with, collaborate with, interlace, juxtapose, be adjacent to, be combined with, or combine with, have, have characteristics, have a relationship with, or have a relationship with, etc. The term "controller" refers to 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. Whether local or remote, the functions associated with any particular controller can be centralized or distributed. 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 may be used, and only one item 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, B, and C.

[0029] In addition, the various functions described below can 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 part thereof suitable for implementation with 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 disc (DVD) or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical or other communication links that transmit instantaneous electrical signals or other instantaneous signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and then rewritten, such as rewritable optical disks or erasable memory devices.

[0030] 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.

[0031] The following discusses Figures 1 to 11 The various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be interpreted in any way as limiting 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.

[0032] The following documents are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS 38.211 v15.6.0, "NR; Physical channels and modulation"; 3GPP TS 38.212 v15.6.0, "NR; Multiplexing and Channel coding"; 3GPP TS 38.213 v15.6.0, "NR; Physical Layer Procedures for Control"; 3GPP TS 38.214 v15.6.0, "NR; Physical Layer Procedures for Data"; 3GPP TS 38.321 v15.6.0, "NR; Medium Access Control (MAC) protocol specification"; and 3GPP TS38.331v15.6.0, “NR; Radio Resource Control (RRC) Protocol Specification”.

[0033] 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. Figures 1 to 3 The description is not intended 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.

[0034] Figure 1 An example wireless network according to an embodiment of the present disclosure is presented. 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.

[0035] 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.

[0036] gNB 102 provides wireless broadband access to network 130 for a first plurality of user equipment (UE) located within coverage area 120 of gNB 102. The first plurality of UEs include: UE 111, which may be located in a small enterprise; UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi hotspot (HS); UE 114, which may be located in a first residence (R); UE 115, which may be located in a second residence (R); and UE 116, which may be a mobile device (M), 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 includes UE 115 and UE 116. In some embodiments, one or more of eNBs 101 to 103 may communicate with each other and with UEs 111-116 using 5G / NR, LTE, LTE-A, WiMAX, WiFi, or other wireless communication technologies.

[0037] Depending on the network type, the term "base station" or "BS" may refer to any component (or set of components) configured to provide wireless access to a network, such as a transmission point (TP), a transmission-receiving point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro base station, a femto base station, a WiFi access point (AP), or other devices with wireless functions. The base station may provide wireless access according to one or more wireless communication protocols, for example, 5G / NR 3GPP New Radio Interface / Access (NR), Long Term Evolution (LTE), LTE advanced (LTE-A), High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. 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", "receiving 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 smart phone) or is generally considered a fixed device (such as a desktop computer or a vending machine).

[0038] The dashed lines illustrate the approximate extents of coverage areas 120 and 125, which are shown as generally circular for purposes of illustration and explanation only. It should be clearly understood that coverage areas associated with a gNB, 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.

[0039] As described in more detail below, one or more of the UEs 111 to 116 include circuitry, programming, or a combination thereof, for efficient random access response and contention resolution for the UE. In certain embodiments, one or more of the gNBs 101 to 103 also include circuitry, programming, or a combination thereof, for efficient random access response and contention resolution for the UE.

[0040] Although Figure 1 shows an example of a wireless network, but can be 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, gNBs 102 to 103 may each communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. In addition, gNB 101, gNB 102, and / or gNB 103 may provide access to other or additional external networks, such as an external telephone network or other type of data network.

[0041] Figure 2 An example gNB 102 is shown according to an embodiment of the present disclosure. Figure 2 The embodiment of gNB 102 shown in FIG. 1 is for illustration purposes only, and Figure 1 gNBs 101 and 103 may have the same or similar configurations. However, gNBs have a wide variety of configurations, and Figure 2 The scope of this disclosure is not limited to any particular implementation of gNB.

[0042] like Figure 2 As shown, gNB 102 includes multiple antennas 205a to 205n, multiple RF transceivers 210a to 210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. gNB 102 also includes a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0043] RF transceivers 210a to 210n receive incoming RF signals from antennas 205a to 205n, such as signals transmitted by UEs in network 100. RF transceivers 210a to 210n downconvert incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 220, which generates processed baseband signals by filtering, decoding and / or digitizing the baseband or IF signals. RX processing circuitry 220 transmits the processed baseband signals to controller / processor 225 for further processing.

[0044] The TX processing circuit 215 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from the controller / processor 225. The TX processing circuit 215 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceivers 210a to 210n receive the outgoing processed baseband or IF signals from the TX processing circuit 215 and up-convert the baseband or IF signals into RF signals that are transmitted via the antennas 205a to 205n.

[0045] 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 forward channel signals and the transmission of reverse channel signals by the RF transceivers 210a to 210n, the RX processing circuitry 220, and the TX processing circuitry 215 in accordance with 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 to 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 functions in the gNB 102.

[0046] Controller / processor 225 is also capable of executing programs and other processes, such as an OS, that reside in memory 230. Controller / processor 225 may move data into or out of memory 230 as required by the executing process.

[0047] The controller / processor 225 is also connected to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or network. The interface 235 can support communication over any appropriate 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 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 can allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 235 includes any suitable structure that supports communication over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0048] 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.

[0049] Although Figure 2 An example of a gNB 102 is shown, but Figure 2 For example, gNB 102 may include any number of Figure 2 As a specific example, the access point may include multiple interfaces 235, and the controller / processor 225 may support routing functions to route data between different network addresses. As another specific example, although shown as including a single instance of TX processing circuitry 215 and a single instance of RX processing circuitry 220, the gNB 102 may include multiple instances of each (such as one instance per RF transceiver). 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.

[0050] 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 in FIG. 1 is for illustration only, and Figure 1 UEs 111 to 115 may have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3 The scope of the present disclosure is not limited to any particular implementation of a UE.

[0051] like Figure 3As shown, UE 116 includes antenna 305, radio frequency (RF) transceiver 310, TX processing circuit 315, microphone 320 and receive (RX) processing circuit 325. UE 116 also includes speaker 330, processor 340, input / output (I / O) interface (IF) 345, touch screen 350, display 355 and memory 360. Memory 360 includes operating system (OS) 361 and one or more application programs 362.

[0052] RF transceiver 310 receives incoming RF signals transmitted by gNBs of network 100 from antenna 305. RF transceiver 310 downconverts the incoming RF signals to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (such as for voice data) or processor 340 for further processing (such as for web browsing data).

[0053] The TX processing circuit 315 receives analog or digital voice data from the microphone 320, or receives other outgoing baseband data (such as network data, email, or interactive video game data) from the processor 340. The TX processing circuit 315 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal that is transmitted via the antenna 305.

[0054] The processor 340 may include one or more processors or other processing devices and execute 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 forward channel signals and the transmission of reverse channel signals by the RF transceiver 310, the RX processing circuit 325, and the TX processing circuit 315 according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0055] The processor 340 is also capable of executing other processes and programs resident in the memory 360, such as processes for beam management. The processor 340 can move data into or out of the memory 360 as needed for the executed 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 an 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.

[0056] Processor 340 is also coupled to touch screen 350 and display 355. An operator of UE 116 may use touch screen 350 to input data into UE 116. Display 355 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics (such as from a website).

[0057] 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).

[0058] Although Figure 3 An example of UE 116 is shown, but the Figure 3 Make various changes. For example, Figure 3 The various components in the embodiment may be combined, further subdivided, or omitted, and additional components may be added as required. 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 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.

[0059] In order to meet the increased demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop an improved 5G / NR or quasi-5G / NR communication system. Therefore, 5G / NR or quasi-5G / NR communication systems are also referred to as "super 4G networks" or "post-LTE systems". 5G / NR communication systems are considered to be implemented in higher frequency (millimeter wave) bands (e.g., 60GHz bands) to achieve higher data rates, or in lower frequency bands (such as 6GHz) to allow for robust coverage. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), omnidirectional MIMO (FD-MIMO), array antennas, analog beamforming, and large antenna technology are discussed in 5G / NR communication systems.

[0060] In addition, in the 5G / NR communication system, development of system network improvements based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, collaborative communications, coordinated multi-point (CoMP), receiving-end interference cancellation, etc. is underway.

[0061] The communication system includes downlink (DL) and uplink (UL), where downlink (DL) refers to transmission from a base station or one or more transmission points to a UE, and uplink (UL) refers to transmission from a UE to a base station or one or more reception points.

[0062] The time unit for DL ​​signaling or for UL signaling on a cell is called a time slot and may include one or more symbols. A symbol may also be used as an additional time unit. A frequency (or bandwidth (BW)) unit is called a resource block (RB). An RB includes multiple subcarriers (SCs). For example, a time slot may have a duration of 0.5 milliseconds or 1 millisecond, include 14 symbols, and an RB may include 12 SCs with an inter-SC spacing of 15 KHz or 30 KHz, and so on.

[0063] DL signals include data signals conveying information content, control signals conveying DL control information (DCI), and reference signals (RS) also known as pilot signals. The gNB transmits data information or DCI through the corresponding physical DL shared channel (PDSCH) or physical DL control channel (PDCCH). PDSCH or PDCCH can be transmitted through a variable number of time slot symbols including one time slot symbol. For simplicity, the DCI format used for scheduling PDSCH reception by the UE is called DL DCI format, and the DCI format used for scheduling PUSCH transmission from the UE is called UL DCI format.

[0064] The gNB transmits one or more of multiple types of RS including Channel State Information RS (CSI-RS) and Demodulation RS (DMRS). CSI-RS is primarily intended for UEs to perform measurements and provide Channel State Information (CSI) to the gNB. For channel measurements, non-zero power CSI-RS (NZP CSI-RS) resources are used. For Interference Measurement Reports (IMRs), CSI Interference Measurement (CSI-IM) resources associated with a Zero Power CSI-RS (ZP CSI-RS) configuration are used. The CSI process consists of NZP CSI-RS and CSI-IM resources.

[0065] The UE can determine the CSI-RS transmission parameters through DL control signaling from the gNB or higher layer signaling such as radio resource control (RRC) signaling. The transmission instance of CSI-RS can be indicated by DL control signaling or configured by higher layer signaling. DMRS is transmitted only in the BW of the corresponding PDCCH or PDSCH, and the UE can use DMRS to demodulate data or control information.

[0066] 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 codebook design and structure for a system with a 2D antenna array, as described in embodiments of the present disclosure.

[0067] like Figure 4 The transmit path 400 shown in FIG. 4 includes a channel coding and modulation block 405, a serial to parallel (S to P) block 410, a size N inverse fast Fourier transform (IFFT) block 415, a parallel to serial (P to S) block 420, an add cyclic prefix block 425, and an up-converter (UC) 430. Figure 5 The receive path 500 shown in FIG. 5 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.

[0068] like Figure 4As shown in , the 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 orthogonal phase shift keying (QPSK) or orthogonal amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols.

[0069] Serial to parallel block 410 converts (e.g., demultiplexes) the serial modulated symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UE 116. Size N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate a time domain output signal. Parallel to serial block 420 converts (e.g., multiplexes) the parallel time domain output symbols from size N IFFT block 415 to generate a serial time domain signal. Add cyclic prefix block 425 inserts a cyclic prefix into the time domain signal. Up converter 430 modulates (e.g., upconverts) the output of add cyclic prefix block 425 to RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

[0070] The RF signal transmitted from gNB 102 reaches UE 116 after passing through the wireless channel, and operations opposite to those at gNB 102 are performed at UE 116.

[0071] like Figure 5 , downconverter 555 downconverts the received signal to baseband frequency, and remove cyclic prefix block 560 removes the cyclic prefix to generate a serial time domain baseband signal. Serial to parallel block 565 converts the time domain baseband signal into parallel time domain signals. Size N FFT block 570 performs an FFT algorithm to generate N parallel frequency domain signals. Parallel to serial block 575 converts the parallel frequency domain signals into a sequence of modulated data symbols. Channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0072] Each of gNBs 101 to 103 may implement a similar method as that transmitted in the downlink to UEs 111 to 116. Figure 4 The transmission path 400 shown in FIG. 4 and may be implemented similarly to the transmission path 400 received from UEs 111 to 116 in the uplink. Figure 5 Similarly, each of UEs 111 to 116 may implement transmit path 400 for transmitting to gNBs 101 to 103 in the uplink, and may implement receive path 500 for receiving from gNBs 101 to 103 in the downlink.

[0073] Can be implemented using hardware only or a combination of hardware and software / firmware Figure 4 and Figure 5 As a specific example, Figure 4 and Figure 5 At least some of the components in can be implemented with 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 515 can be implemented as configurable software algorithms, wherein the value of size N can be modified according to the implementation.

[0074] In addition, although described as using FFT and IFFT, this is only by way of illustration and should 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 the value of the variable N may be any integer (such as 1, 2, 3, 4, etc.) for the DFT and IDFT functions, and the value of the variable N may be any integer (such as 1, 2, 4, 8, 16, etc.) as a power of two for the FFT and IFFT functions.

[0075] although Figure 4 and Figure 5 Examples of wireless transmit and receive paths are shown, but Figure 4 and Figure 5 Make various changes. For example, Figure 4 and Figure 5 The various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs. 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.

[0076] A hybrid slot includes a DL transmission region, a guard period region, and a UL transmission region, similar to a special subframe in the NR specification. For example, the DL transmission region may include PDCCH and PDSCH transmissions, and the UL transmission region may include PUCCH transmissions. For example, the DL transmission region may include PDCCH transmissions, and the UL transmission region may include PUSCH and PUCCH transmissions.

[0077] The UL signal also includes a data signal conveying information content, a control signal conveying a UL control signal (UCI), a DMRS associated with data or UCI demodulation, a sounding RS (SRS) enabling the gNB to perform UL channel measurements, and a random access (RA) preamble enabling the UE to perform random access (see also NR specifications). The UE transmits data information or UCI through the corresponding physical UL shared channel (PUSCH) or physical UL control channel (PUCCH). The PUSCH or PUCCH may be transmitted over a variable number of slot symbols including one slot symbol. The gNB may configure the UE to transmit signals on a cell within the UL BWP of the cell UL BW.

[0078] UCI includes Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) information indicating correct or incorrect detection of a transport block (TB) in the PDSCH, a Scheduling Request (SR) indicating whether the UE has data in its buffer, and a CSI report that enables the gNB to select appropriate parameters for PDSCH or PDCCH transmissions to the UE. The HARQ-ACK information can be configured with a smaller granularity than per TB and can be per data code block (CB) or per data CB group, where a TB includes multiple data CBs.

[0079] The CSI report from the UE may include a Channel Quality Indicator (CQI) that informs the gNB of the maximum modulation and coding scheme (MCS) that enables the UE to detect the data TB at a predetermined block error rate (BLER), such as 10% BLER (see NR specifications), a Precoding Matrix Indicator (PMI) that instructs the gNB how to combine signals from multiple transmitter antennas according to the Multiple Input Multiple Output (MIMO) transmission principle, and a Rank Indicator (RI) that indicates the transmission rank of the PDSCH.

[0080] UL RS includes DMRS and SRS. DMRS is transmitted only in the BW of the corresponding PUSCH or PUCCH transmission. The gNB can use DMRS to demodulate the information in the corresponding PUSCH or PUCCH. SRS is transmitted by the UE to provide UL CSI to the gNB, and for TDD systems, SRS transmission can also provide PMI for DL ​​transmission. In addition, in order to establish synchronization or initial higher layer connection with the gNB, the UE can transmit the Physical Random Access Channel (PRACH, as shown in the NR specification).

[0081] Many frequency bands are flexible duplex bands, where reception by the UE (or transmission from the gNB) and transmission from the UE (or reception by the gNB) are based on time division duplex (TDD). For example, most of the frequency bands used for 5G / NR are TDD bands. TDD operation provides some important advantages, such as using the same frequency band for DL ​​and UL transmissions, resulting in simpler UE implementation, for example because no duplexer is required, and being able to exploit channel reciprocity between DL and UL to provide accurate link adaptation. However, TDD operation also has some important disadvantages, such as increased latency (because transmission / reception in the link direction (UL or DL) is not possible at all times), reduced data rate, and reduced coverage at a given latency compared to frequency division duplex (FDD).

[0082] To address some of the shortcomings of TDD operation, dynamic adaptation of the link direction has been considered, where in addition to some symbols in some time slots supporting scheduled transmissions (such as for SS / PBCH blocks), the symbols of the time slots can have a flexible direction (UL or DL), which the UE can determine based on the scheduling information for reception or transmission. A control channel can also be used to provide a DCI format that can indicate the link direction of some flexible symbols in one or more time slots, such as DCI format 2_0 in the NR specification. However, in actual deployments, it is difficult for the gNB scheduler to adapt the transmission direction of the symbols without coordinating with other gNB schedulers in the network. This is because of cross-link interference (CLI), where, for example, UL transmissions on a cell can experience greater interference from DL transmissions on neighboring cells of the gNB.

[0083] Antenna ports are defined such that the channel that conveys one symbol on the same antenna port can be inferred from the channel that conveys another symbol on the same antenna port.

[0084] For DM-RS associated with PDSCH, the channel conveying the PDSCH symbol on one antenna port can be inferred from the channel conveying the DM-RS symbol on the same antenna port only if the two symbols are within the same resources as the scheduled PDSCH, in the same time slot, and in the same PRG.

[0085] For DM-RS associated with PDCCH, the channel conveying the PDCCH symbol on one antenna port can be inferred from the channel conveying the DM-RS symbol on the same antenna port only if the two symbols are within resources for which the UE can assume the same precoding is used.

[0086] For DM-RS associated with PBCH, the channel conveying the PBCH symbol on one antenna port can be inferred from the channel conveying the DM-RS symbol on the same antenna port only if both symbols are within an SS / PBCH block transmitted in the same time slot and have the same block index.

[0087] If the large-scale properties of the channel that conveys the symbols on one antenna port can be inferred from the channel that conveys the symbols on the other antenna port, then the two antenna ports are considered to be quasi-co-located. Large-scale properties include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters.

[0088] The UE may assume that SS / PBCH blocks transmitted with the same block index at the same center frequency position are quasi-co-located in terms of Doppler spread, Doppler shift, average gain, average delay, delay spread, and spatial Rx parameters (when applicable). For any other SS / PBCH block transmissions, the UE may not assume quasi-co-location.

[0089] In the absence of CSI-RS configuration, and unless otherwise configured, the UE may assume that the PDSCH DM-RS and SS / PBCH blocks are quasi-co-located in terms of Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameters (when applicable). The UE may assume that the PDSCH DM-RS within the same CDM group are quasi-co-located in terms of Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx. The UE may also assume that the DMRS ports associated with the PDSCH are QCL type A, type D (when applicable), and average gain QCL. The UE may further assume that the DM-RS does not conflict with the SS / PBCH blocks.

[0090] The UE may be configured with a list of up to M TCI-State configurations within the higher layer parameter PDSCH-Config to decode the PDSCH based on a detected PDCCH with DCI intended for the UE and a given serving cell, where M depends on the UE capability maxNumberConfiguredTCIstatesPerCC. Each TCI-State contains parameters for configuring the quasi-co-location (QCL) relationship between one or two downlink reference signals and the DMRS ports of the PDSCH, the DMRS ports of the PDCCH, or the CSI-RS ports of the CSI-RS resources.

[0091] The quasi-co-location relationship is configured by the higher layer parameters qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS (if configured). For the case of two DL RSs, the QCL type may be different, regardless of whether the same DL RS or different DL RSs are referenced. The quasi-co-location type corresponding to each DL RS is given by the higher layer parameter qcl-Type in QCL-Info and can take one of the following values: QCL-TypeA: {Doppler shift, Doppler spread, average delay, delay spread}; QCL-TypeB: {Doppler shift, Doppler spread}; QCL-TypeC: {Doppler shift, average delay}; and QCL-TypeD: {spatial Rx parameters}.

[0092] The UE receives a MAC-CE activation command for mapping up to [N] (e.g., N=8) TCI states to a codepoint of the DCI field "Transmission Configuration Indication". When a HARQ-ACK corresponding to the PDSCH carrying the activation command is transmitted in time slot n, it may be after the MAC-CE application time, e.g., from time slot n. The mapping between the TCI state and the code point of the DCI field "Transmission Configuration Indication" is applied starting from the first time slot thereafter.

[0093] The Random Access (RA) procedure is started by: RRC (for SI request) - if SIB1 includes scheduling information for (on-demand) SI request; MAC; and PDCCH - order.

[0094] The random access procedure may be initiated due to at least one of the following triggers / purposes: (1) initial access for establishing an RRC connection (entering RRC_CONNECTED from RRC_IDLE); (2) reestablishing an RRC connection after a radio link failure (RLF); (3) on-demand system information (SI) request; (4) handover; (5) UL synchronization; (6) scheduling request (SR); (7) positioning; and (8) link recovery - also known as beam failure recovery (BFR).

[0095] Random access (RA) can operate in two modes: (i) contention-based random access (CBRA), where UEs within a serving cell can share the same RA resources and thus there may be conflicts between RA attempts from different UEs; and (ii) contention-free random access (CFRA), where a UE has dedicated RA resources indicated by the serving gNB and may not be shared with other UEs, so that RA conflicts can be avoided. For example, CBRA can be used for all triggers / purposes described above, while CFRA can be used only for triggers / purposes (4) to (8) as shown above.

[0096] The 4-step random access procedure, also known as the Type-1 (L1) random access procedure, consists of the following steps / operations of the UE: transmitting a PRACH preamble (Msg1); attempting to receive a random access preamble (RAR or Msg2); transmitting a contention resolution message (Msg3); and attempting to receive a contention resolution message (Msg4).

[0097] An alternative random access procedure may also be considered, which is a so-called 2-step RACH or type-2 L1 random access procedure, in which Msg1 and Msg3 are combined into "MsgA" for transmission, and Msg2 and Msg4 are combined into "MsgB" for reception.

[0098] Various embodiments of the present disclosure relate to 4-step RACH, but the embodiments may also be generally applicable to 2-step RACH, and explicit individual descriptions are generally omitted for the sake of brevity.

[0099] The PRACH preamble transmission (for both CBRA and CFRA modes) is associated with the DL RS. This association can help the serving gNB identify the uplink spatial receive filter / beam for receiving PRACH, and can also help the UE identify the uplink spatial transmit filter / beam for transmitting PRACH. For example, the UE can use the same or related uplink filter / beam (such as having the same quasi-co-site (QCL) properties and / or the same direction but narrower width) as the DL reception of the indicated DL RS for Msg1 transmission. This association can also be used in the NR specification to provide DLRS resources for path loss estimation, which is used to determine the PRACH preamble transmit power.

[0100] The DL RS for Msg1 transmission can be one of the following options based on the PRACH scenario: SSB: for BFR, CFRA, PDCCH-commanded PRACH, SI request, CBRA; or CSI-RS: for BFR, CFRA, CBRA.

[0101] Throughout this disclosure, SSB is used as a short form of SS / PBCH block. The terms SSB and SS / PBCH block are used interchangeably in this disclosure.

[0102] Furthermore, the serving cell may be configured with both SSB and CSI-RS for PRACH transmissions. For example, some PRACH preambles may be associated with SSB for QCL determination and some PRACH preambles may be associated with CSI-RS for QCL determination. It is also possible that a secondary serving cell (SCell) does not have any SSB configuration / transmission but only supports PRACH transmissions from a UE using CSI-RS for QCL determination. However, as described in the previous paragraph, certain random access triggers / modes (such as for PDDCH-command PRACH or for SI requests) are not applicable.

[0103] The PRACH configuration includes RACH opportunities (RO) that repeat with a certain periodicity in certain RACH time slots and certain frequency resource blocks.

[0104] Once the UE has transmitted the PRACH preamble (Msg1), there are three more PRACH steps to complete (step 4): the UE attempts to receive a random access response (RAR or Msg2) from the gNB; the UE transmits a contention resolution message to the gNB (Msg3); and the UE attempts to receive a contention resolution response message (Msg4) from the gNB.

[0105] The random access response (RAR or Msg2) is a PDCCH / PDSCH transmission received by the UE on the DL BWP of the SpCell, as follows: on the initial DL BWP of the PCell / SpCell (for the case of initial access, i.e., establishing (reestablishing) an RRC connection); or on the active DL BWP of the SpCell (with the same BWP index as the active UL BWP) (for random access triggers other than initial access). If the active DL BWP index (of the SpCell) is not equal to the active UL BWP index (of the serving cell), the active DL BWP is switched to the one with the same BWP index.

[0106] The SCS for the PDCCH in the RAR message is the SCS for the Type 1-PDCCH CSS set. The SCS for any future PDSCH is also the same SCS as the PDSCH in the RAR, unless the UE is configured with SCS.

[0107] The PDCCH for RAR is DCI format 1_0 that the UE monitors during a certain configured time window in the Type1-PDCCH common search space (CSS) set of the SpCell identified by RA-RNTI (or in the search space indicated by recoverySearchSpaceId of the SpCell identified by C-RNTI for the case of BFR with CF-RA).

[0108] The PDSCH part of the RAR contains the gNB response (note: PDSCH can carry RAR messages for multiple UEs), which can be one of the following three types.

[0109] In one example, the gNB sends a 4-bit backoff indicator (BI) indicating the maximum backoff time required before the UE's next PRACH transmission attempt [the actual backoff time is uniformly randomly selected by the UE between zero and the value indicated by the BI field], such a response identifies an overload condition of the serving cell.

[0110] In another example, the gNB sends only a 6-bit Random Access Preamble ID (RAPID) which indicates the ID of the preamble detected by the gNB. This response is only applicable for confirmation of SI request.

[0111] In one example, the gNB sends a RAPID along with a MAC payload (also known as MAC RAR) that includes a 12-bit Timing Advance (TA) command, a 27-bit Uplink Grant field of Msg3, and a 16-bit Temporary C-RNTI (TC-RNTI).

[0112] Fig. 6A An example E / R / R / BI MAC sub-header 600 is shown in accordance with an embodiment of the present disclosure. Fig. 6A The illustrated embodiment of the E / R / R / BI MAC subheader 600 is for illustration only. Fig. 6A One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0113] Figure 6B An example E / T / RAPID MAC sub-header 650 is shown in accordance with an embodiment of the present disclosure. Figure 6B The embodiment of the E / T / RAPID MAC sub-header 650 shown is for illustration only. Figure 6B One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0114] Figure 6C An example MAC RAR 670 is shown in accordance with an embodiment of the present disclosure. Figure 6C The embodiment of MAC RAR 670 shown is for illustration only. Figure 6COne or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0115] <Table 1, Random Access Response Grant Content Field Size>

[0116]

[0117]

[0118] Table 1 includes the Random Access Response Grant Content field sizes, which includes similar tables for LTE and NR specifications.

[0119] For the case of CFRA-based BFR, it is sufficient for the RAR to be considered successful simply by receiving the PDCCH during the time window and in the indicated search space of the SpCell and correctly addressed to the C-RNTI.

[0120] For other cases (such as CBRA and SI request), RAR is successful if: (i) a PDCCH in the Type1-PDCCH common search space (CSS) set of the SpCell is received during the configured time window and is addressed to the RA-RNTI; and (ii) the corresponding PDSCH is decoded correctly [note that RAR does not support HARQ]; and (iii) the MAC RAR contained in the PDSCH portion of the RAR contains the random access preamble ID (RAPID); and (iv) the RAPID in the MAC RAR matches the preamble selected by the UE and transmitted in Msg1. Then, for the serving cell that transmits the PRACH preamble / Msg1, the UE applies TA to adjust / correct the timing between the UE and the gNB, stores the TC-RNTI for future transmissions, and processes the RAR UL grant to transmit Msg3.

[0121] If RAR is unsuccessful, the UE attempts (possibly with fallback and / or up to N as specified in the NR specification) T，1 +0.75 msec UE processing time) with a new PRACH preamble transmission with PRACH resource selection (possibly including a different SSB and / or a different preamble) and a PRACH preamble power ramp may be applied, unless the UE has reached the configured maximum number of PRACH attempts, in which case the random access problem is reported to higher layers and the process stops.

[0122] The following is only about frequency domain resource allocation, because LTE only supports subframe-based PUSCH transmission, so time domain resource allocation information is not required.

[0123] The (frequency) resource allocation for Msg3 in LTE (as identified in the RAR UL grant) comprises: a 1-bit frequency hopping flag; and a 10-bit resource block assignment.

[0124] Based on the 10-bit resource assignment field, the b-bit field is generated as follows, where in is the system bandwidth in terms of the number of RBs (based on a 15kHz subcarrier spacing). Note that b is the bandwidth equal to The total number of contiguous resource allocations of any length in a system of PRBs.

[0125] if (such that b<10), then 10 bits of resource block assignment are truncated and the least significant b bits are used next.

[0126] if (so that b ≥ 10), then after the most significant bit of N_{UL, frequency hopping} = 0, 1, 2 of the 10-bit resource assignment field, add zero-padded bits, where The entire field is b bits.

[0127] If the frequency hopping flag is 0, then N_{UL, frequency hopping}=0 (ie, disabled).

[0128] If the frequency hopping flag is 1 and the system bandwidth is PRBs, then N_{UL, frequency hopping}=1.

[0129] If the frequency hopping flag is 1 and the system bandwidth is PRBs, then N_{UL, frequency hopping}=2.

[0130] Finally, as in LTE DCI format 0, the obtained b-bit field is interpreted as follows.

[0131] In one example, since the resource allocation type bit is not present in the RAR UL grant, only resource allocation type 0 is supported. In this example, uplink resource allocation type 0 indicates starting from resource blocks (RB START ) and has a length (L CRBs ≥1). The indication is via the parameter "Resource Indication Value" (RIV), which sets the RB START and L CRBs Combined to generate START and L CRBsThe values ​​can be described with a smaller number of bits than the number of bits required to separate and individually indicate the values.

[0132] In another example, for PUSCH frequency hopping (resource allocation type 0 only): N UL_hop The MSB bit is used to obtain The value of , as indicated in the LTE specification; and (bN UL_hop ) bits provide resource allocation for the first time slot in the UL subframe.

[0133] In yet another example, for non-frequency hopping PUSCH with resource allocation type 0: b bits provide the resource allocation in the UL subframe, as defined in the LTE specification.

[0134] The following is only about frequency domain resource allocation, because LTE MTC only supports subframe-based PUSCH transmission, so time domain resource allocation information is not required.

[0135] Resource allocation for Msg3 in LTE MTC CEmodeA (as identified in the RAR UL grant) includes: Narrowband index for Msg3 PUSCH bits (assuming 100 PRBs = 20 MHz maximum system bandwidth) together with zero padding bits (to keep the size of the RAR UL grant fixed), and 4 bits for resource allocation within the narrowband, where and and is the total UL system bandwidth.

[0136] The Resource Allocation field (for LTE MTC CEmodeA) is interpreted as follows: one most significant bit with the value set to "0" is inserted and the extended resource allocation is interpreted using the UL resource allocation type 0 within the indicated narrowband. It should be noted that in general, the indication of all possible contiguous resource allocations within a 6-PRB narrowband requires 5 bits (e.g., this is the case with DCI format 6-0A), however, using only four bits and by concatenating the "0" MSBs, contiguous resource allocations of length 1, 2, 3 and 6 PRBs within the narrowband can be indicated (i.e., RAR UL cannot indicate a PUSCHMsg3 of length 4 or 5 PRBs). It should be noted that the 1-bit frequency hopping flag for PUSCH Msg3 is not present in the RAR UL grant.

[0137] The RAR UL grant also includes a 2-bit field for the number of Msg3 PUSCH repetitions, so that the repetition level (N) of the initial transmission of Msg3 PUSCH is Msg3 ) is based on Table 2 (as shown in the LTE specification), where if Y is signaledA , then Y A Determined by the higher layer parameter pusch-maxNumRepetitionCEmodeA-r13, otherwise Y A =8.

[0138] <Table 2. Msg3 PUSCH repetition level values ​​for CEmodeA>

[0139] The value of "Number of Repetitions" Msg3 PUSCH repetition level "00” <![CDATA[Y A / 8]]> "01” <![CDATA[Y A / 4]]> "10” <![CDATA[Y A / 2]]> "11” <![CDATA[Y A ]]>

[0140] The resource allocation for Msg3 in the NR specification (as identified in the RAR UL grant) includes: 1-bit frequency hopping flag; 4-bit PUSCH time resource allocation; and 14-bit PUSCH frequency resource allocation.

[0141] A 4-bit field for time resource allocation may be used as per the NR specification to identify the starting symbol and time domain length of the Msg3 PUSCH transmission.

[0142] This 14-bit field used for frequency domain resource allocation is carried out by uplink resource allocation type 1 as per the NR specification, which identifies the allocation of contiguous (virtual) resource blocks, similar to the LTE resource allocation type 0 described above.

[0143] Based on the 14-bit resource assignment field, the b-bit field is generated as follows, where in is the bandwidth of the initial UL BWP in terms of the number of RBs (in terms of the subcarrier spacing of the initial UL BWP), regardless of whether the active UL BWP of PUSCHMsg3 is the initial UL BWP or another UL BWP with the same / different subcarrier spacing. It should be noted that b is equal to The total number of contiguous resource allocations of any length in a BWP of PRBs.

[0144] if (so that b<14), then 14 bits of frequency resource allocation are truncated and the least significant b bits are used next.

[0145] if (so that b ≥ 14), then after the most significant bit of N_{UL, frequency hopping} = 0, 1, 2 of the 10-bit resource assignment field, add zero-padded bits, where The entire field is b bits.

[0146] If the frequency hopping flag is 0, then N_{UL, frequency hopping}=0 (ie, disabled).

[0147] If the frequency hopping flag is 1 and the system bandwidth is PRBs, then N_{UL, frequency hopping}=1 (also consistent with the 2 offset values ​​configured in the higher layer parameter frequencyHoppingOffsetLists).

[0148] If the frequency hopping flag is 1 and the system bandwidth is PRBs, then N_{UL, frequency hopping}=2 (also consistent with the 4 offset values ​​configured in the higher layer parameter frequencyHoppingOffsetLists).

[0149] Finally, as in NR DCI format 0_0, the obtained b-bit field is interpreted as follows.

[0150] In one example, for DCI format 0_0 (and therefore for PUSCH Msg3 in the NR specification), only resource UL allocation type 1 is supported.

[0151] In this example, uplink resource allocation type 1 indicates that starting from resource blocks (RB START ) and has a length (L RBs ) is a set of consecutively allocated virtual resource blocks. The indication is via the parameter "Resource Indication Value" (RIV), which sets the RB START and L RBs Combined to generate START and L RBs The values ​​can be described with a smaller number of bits than the number of bits required to separate and individually indicate the values.

[0152] In this example, it should be noted that in DCI format 0_0, the size of the bit field of frequency resource allocation type 1 conforms to the size of UL BWP, however, RAR UL grant is considered to have a fixed size field of 14 bits.

[0153] In another example, for PUSCH frequency hopping with resource allocation type 1: N UL_hop The MSB bits are used to obtain the frequency hopping parameters, as indicated in the NR specification; and (bX UL_hop ) bits provide resource allocation for the first time slot in the UL subframe.

[0154] In yet another example, for non-frequency hopping PUSCH utilizing resource allocation type 1: the b bit provides the resource allocation in the UL subframe as defined in the NR specification.

[0155] In the present disclosure, the terms "4-step RACH" and "Type-1 random access procedure" and "Type-1 L1 random access procedure" are used interchangeably. Throughout the present disclosure, the terms "2-step RACH" and "Type-2 random access procedure" and "Type-2 L1 random access procedure" are used interchangeably.

[0156] Before starting the physical random access procedure, Layer 1 receives an indication from higher layers to perform a type-1 random access procedure (4-step RACH) or a type-2 random access procedure (2-step RACH).

[0157] From the perspective of the physical layer, the type-2 L1 random access procedure includes transmitting a random access preamble and transmitting a PUSCH (MsgA) in the PRACH and receiving a RAR message (MsgB) with a PDCCH / PDSCH. When the random access response of the 2-step RACH indicates a fallback to the 4-step RACH (i.e., fallbackRAR), the 2-step RACH procedure continues similar to the 4-step RACH procedure, i.e., transmitting a PUSCH scheduled by a RAR UL grant and transmitting a PDSCH for contention resolution.

[0158] The PRACH preambles for 2-step RACH are separated from those for 4-step RACH, e.g., the contention-based preamble R per SS / PBCH block per valid PRACH opportunity for type-2 random access procedure starts after the preamble for type-1 random access procedure.

[0159] The RACH occasions (RO) for 2-step RACH may be common / shared with those for 4-step RACH or may be separated.

[0160] In response to transmissions of PRACH and PUSCH, the UE attempts to detect DCI format 1_0 with CRC scrambled by RA-RNTI / MsgB-RNTI during a window controlled by higher layers, as indicated in the NR specification.

[0161] As defined in the NR specification, the window starts at the first symbol of the earliest CORESET where the UE is configured to receive PDCCH for the Type1-PDCCH CSS set, and the window is at least one symbol after the last symbol of the PUSCH opportunity corresponding to a PUSCH transmission (associated with a 2-step RACH), where the symbol duration corresponds to the SCS of the type1-PDCCH CSS set. Based on the SCS of the type1-PDCCH CSS set, the length of the window in number of slots is provided by the ra-ResponseWindow (such as for 4-step RACH) or the separately configured time window length for 2-step RACH.

[0162] If the UE detects a transport block in DCI format 1_0 and the corresponding PDSCH with a CRC scrambled by RA-RNTI / MsgB-RNTI within the window, the UE delivers the transport block to higher layers.

[0163] The higher layers indicate to the physical layer: if the RAR message is for fallbackRAR and the random access preamble identifier (RAPID) associated with the PRACH transmission is identified, then an uplink grant is indicated, and the UE process continues as in the 4-step RACH process when the UE detects the RAR UL grant; or if the RAR message is for successRAR, then the transmission of PUCCH is indicated, the PUCCH has HARQ-ACK information, and the HARQ-ACK information has an ACK value.

[0164] In this case, the PUCCH resource used for the transmission of the PUCCH is indicated by a 4-bit PUCCH resource indicator field in the successRAR from the PUCCH resource set provided by pucch-ResourceCommon; the time slot used for the PUCCH transmission is indicated by a 3-bit PDSCH-to-HARQ feedback timing indicator field in the successRAR with a value k from {1, 2, 3, 4, 5, 6, 7, 8} and refers to a PDSCH-to-HARQ feedback timing indicator field with a duration T slot The time slot for PUCCH transmission is determined as ceil(n+k+Δ+t Δ / T slot ), where n is the timeslot of PDSCH reception, Δ is, for example, as defined for PUSCH transmission (as shown in the NR specification) or as per a different table provided in the system specification, and t Δ ≥ 0; the UE does not expect the first symbol of the PUCCH transmission to be less than N after the last symbol of the PDSCH reception T，1 +0.5+t Δ msec, where N T，1 is the PDSCH processing time for UE processing capability 1 as defined in the NR specification; and / or the PUCCH transmission has the same spatial domain transmit filter as the last PUSCH transmission and is in the same active UL BWP.

[0165] If the UE detects a transport block in DCI format 10 with a CRC scrambled by the C-RNTI and the corresponding PDSCH within the window, the UE transmits a PUCCH with the HARQ-ACK information having an ACK value if the UE correctly detects the transport block or a NACK value if the UE incorrectly detects the transport block and the time alignment timer is running.

[0166] The UE does not wish to be instructed to transmit a PUCCH with HARQ-ACK information at a time prior to the time at which the UE applies the TA command provided by the transport block.

[0167] If the UE does not detect DCI format 10 with a CRC scrambled by the corresponding RA-RNTI / MsgB-RNTI within the window, or if the UE does not correctly receive the corresponding transport block in the PDSCH within the window, or if the higher layer does not recognize the RAPID associated with the PRACH transmission from the UE, the higher layer may instruct the physical layer to transmit only PRACH according to a type-1 random access procedure or to transmit both PRACH and PUSCH according to a type-2 random access procedure.

[0168] If requested by higher layers, the UE is expected to receive the signal no later than N after the last symbol of the window or the last symbol of PDSCH reception. T，1 +0.75msec to transmit PRACH, where N T，1 N is the PDSCH processing time corresponding to UE processing capability 1 1 For μ = 0, the UE assumes N 1，0 =14 (as shown in the NR specification).

[0169] Unless the UE is configured with SCS, the UE receives subsequent PDSCH using the same SCS as the PDSCH reception providing the RAR message.

[0170] For the case of Contention-Free Random Access (CF-RA) (and SI Request), the correct reception of Msg2 / RAR is the last step of the Random Access procedure. However, for the case of Contention-Based Random Access (CB-RA), multiple UEs may have used the same preamble and more steps are needed to resolve the contention. For the case of Random Access before RRC_CONNECTED state (i.e., for initial access), the UE and gNB need to exchange more information to set up the connection.

[0171] Thus, the contention resolution request and possibly the connection setup request require an uplink PUSCH transmission (Msg3), and the contention resolution response and possibly the connection setup response require a downlink transmission (Msg4). Contention resolution (and connection setup, if applicable) is considered successful if the UE receives Msg4 within a certain time window after the transmission of Msg3, and for the case where the UE does not yet have a C-RNTI, it is also successful if the contention resolution ID in Msg4 matches the ID transmitted by the UE in Msg3.

[0172] Otherwise, the contention resolution Msg3 / 4 and hence the RACH attempt is considered unsuccessful and the UE needs to make another RACH attempt unless the configured maximum number of RACH attempts has been exhausted, in which case the entire random access procedure is declared unsuccessful.

[0173] After a RACH attempt fails (due to no RAR reception, RAP-ID in RAR does not match that in Msg1, or failure of contention resolution of Msg3 / 4), the UE may reselect RACH resources, including selecting DLRS for PRACH, selecting PRACH preamble, and selecting RACH timing. Therefore, a different SSB / CSI-RS and / or a different PRACH preamble and / or a different RACH timing may be used for the next PRACH attempt compared to the previous PRACH attempt. However, power ramping is only applied if the same DL RS is used in the next PRACH attempt compared to the previous PRACH attempt.

[0174] Hereinafter and throughout the present disclosure, the terms "NR-Light UE", "Reduced Capability UE" or "RedCap UE" and "BL / CE UE" may be used interchangeably to refer to a UE or a group of UEs having reduced cost and / or complexity and / or capabilities (such as reduced bandwidth, reduced number of Rx and / or Tx RF chains, reduced power amplifier class (or simply, reduced power class)) compared to UEs or UE groups / categories such as those defined by the NR specifications. In addition, although certain embodiments may refer to NR-Light UEs or RedCap UEs having reduced capabilities, costs and / or complexity compared to traditional UEs, any embodiments of the present disclosure may also be implemented in any type of UE, including, for example, UEs having the same, similar, or more capabilities compared to traditional UEs.

[0175] Such UE or UE group may be considered as a UE category (or multiple UE categories) that meets certain radio / service requirements similar to 3GPP LTE UE Cat-M1. In addition, such UE or UE group / category may support features for coverage enhancement.

[0176] Examples of such NR-light UEs may include wearable devices, smart watches, surveillance cameras, and other mid-range wireless sensors used in industry, residences, health, or public safety, etc. In some scenarios and deployments, there may be hundreds or thousands of NR-Light UEs in the RRC_CONNECTED state within a serving cell. Unless explicitly mentioned otherwise, in the remainder of this disclosure, the term "UE" is also used to refer to NR-Light UEs as exemplary implementations, or in general, to any UE intended for / requiring coverage restoration or coverage enhancement of PRACH and / or other UL / DL transmissions, such as any (class of) low-capability UEs, such as feature phones, etc.

[0177] Although various embodiments of the present disclosure discuss 3GPP 5G NR communication systems, the embodiments may generally be applicable to UEs operating with other RATs and / or standards such as next release / next generation 3GPP, IEEE WiFi, etc.

[0178] Hereinafter, unless explicitly stated otherwise, providing a parameter value by a higher layer includes providing the parameter value by a system information block (SIB) such as SIB1, or by common RRC signaling, or by UE-specific RRC signaling.

[0179] In the following, the association between a DL RS (such as an SS / PBCH block (SSB) or CSI-RS) and a PRACH preamble is with respect to the quasi co-location (QCL) property or the transmission configuration indicator (TCI) state (as shown in the NR specification).

[0180] The key element for improving the detection / miss detection probability of PRACH transmissions from UEs at the serving gNB is to increase the SINR of PRACH reception at the gNB. One way to increase the SINR is to repeat the PRACH transmissions in multiple occasions to increase the probability of correct detection of the PRACH preamble by the gNB and / or reduce the probability of collisions between a large number of UEs.

[0181] Accordingly, operations / messages after PRACH preamble transmission, such as random access response (RAR) and possibly Msg3 / 4 for contention resolution, can be repeated if necessary to increase reliability / robustness and improve coverage. Improved coverage leads to faster (initial) access, connection setup, UL synchronization, etc.

[0182] When considering a random access procedure with repetitions, several issues need to be addressed, including the following: timing of these messages when repetitions are configured for random access Msg2 / 3 / 4; time / frequency resource allocation for Msg3 PUSCH as indicated in the RAR UL grant; and congestion control for a large number of UEs via their distribution over the spectrum.

[0183] The present disclosure addresses the above issues and provides additional design aspects for supporting a random access procedure in which associated messages are repeatedly transmitted, and provides a solution as outlined in the next section and fully detailed further below.

[0184] The present disclosure considers a method for repetition of RAR and Msg3 / 4, in which the following concepts are introduced: repetition of random access response (RAR) and Msg3 / 4 based on RSRP range / CE level / UE power level; new DCI format / new length of RNTI and CORESET of RAR PDCCH depending on RSRP range / CE level / UE power level; timing of RAR reception with repetition - including the starting point of RAR PDCCH monitoring and the length of the monitoring window; timing of PRACH transmission after RAR failure when repeating RAR; timing of Msg3PUSCH transmission / Msg4 PDSCH reception when repeating RAR and / or Msg3 / 4; modification of RAR UL grant - new fields, such as number of repetitions of Msg3 PUSCH, UL BWP index of Msg3 PUSCH, DL BWP index of Msg3 / 4PDCCH, modified fields, such as fewer bits / no bits for Msg3 frequency hopping, time / frequency allocation, MCS or TPC command; using RAR Use the UL BWP index of Msg3PUSCH in the UL grant to distribute UEs in different parts of the spectrum and achieve congestion control; use the DL BWP index of Msg3 / 4PDCCH in the RAR UL grant to distribute UEs in different parts of the spectrum and achieve congestion control; use UL resource allocation type 2 (i.e., RBG level indication) for Msg3 PUSCH; and / or avoid the minimum K2 value for Msg3 PUSCH; and / or use the "cellBarred" and "intraFreqReselection" fields in the MIB during initial access to distribute UEs (such as NR-Light or low-capability UEs) on the spectrum.

[0185] In one embodiment, each of the PDCCH and PDSCH transmissions associated with the scheduling and transmission of a random access response (RAR) may have respective N repetitions, where the value of N (same or different for PDCCH and PDSCH) may be fixed in the specification or provided by a higher layer (from a list of specified values ​​for the number of repetitions). The motivation is to improve / restore / enhance the DL coverage of the UE for the random access procedure. The embodiments may be applied before and / or after the UE operates in RRC connected mode and / or is provided with a UE-specific configuration.

[0186] In one example, the number of repetitions of the PDSCH transmission providing the RAR may be the same for all RSRP ranges, CE levels, and / or all UE power levels. In another example, the number of repetitions may be different for different RSRP ranges, CE levels, and / or different UE power levels. For example, the power amplifier level (or simply, the power level) of a UE (such as RedCap / NR-Light UE) may be a reduced power amplifier level, such as one of 10 dBm, 14 dBm, 17 dBm, and 20 dBm, compared to a reference power amplifier level (or simply, a reference power level) such as 23 dBm.

[0187] In a related example, for all different CE levels and / or different UE power classes, the number of repetitions of the PDSCH transmission providing the RAR is provided by higher layers, such as a value N for RSRP range 0 / CE level 0. 0 , value N for RSRSP scope / CE level 1 1 wait.

[0188] In another example, the number of repetitions of the PDSCH transmission providing the RAR is configured only for a reference RSRP range / CE level and / or UE power class, and the number for another RSRP range / CE level and / or UE power class is determined based on some predefined rule, such as N for RSRP range / CE level 1. 1 Than N for RSRP range / CE level 0 0 Twice as big.

[0189] In one example, the number of repetitions of the PDSCH transmission providing the RAR may be different from the number of repetitions of the PDCCH scheduling the PDSCH transmission, and each number may be provided separately by a higher layer per RSRP range / UE power level, or one number (such as the number of repetitions of the PDSCH transmission) may be derived from another number (such as the number of repetitions of the PDCCH transmission) provided by a higher layer.

[0190] Figure 7 An example determination 700 of a number of repetitions of a PDSCH transmission providing a RAR based on RSRP range / CE level and UE power class according to an embodiment of the present disclosure is shown. Figure 7 The illustrated embodiment of determining the number of repetitions 700 is for illustration only. Figure 7 One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0191] In step 710, the UE selects a DL RS resource associated with the PRACH transmission, such as an SSB or a CSI-RS. In step 720, the UE then measures the RSRP of the selected DL RS resource, and in step 730, adjusts the measured RSRP value based on the UE power level, for example, based on the difference between the UE amplifier power level (or simply, the UE power level) (such as 10, 14, 17, 20 dBm) and the reference UE power amplifier level (or simply, the reference UE power level) (such as 23 dBm). In step 740, the UE compares the adjusted RSRP with a first threshold provided by a higher layer.

[0192] When the adjusted RSRP is less than the first threshold, the UE determines a first repetition number of PDSCH reception providing the RAR in step 750. When the adjusted RSRP is not less than the first threshold, the UE compares the adjusted RSRP with a second threshold provided by a higher layer in step 760. When the adjusted RSRP is less than the second threshold, the UE determines a second repetition number of PDSCH reception providing the RAR in step 770; otherwise, the UE continues the same process until, in step 780, the UE compares the adjusted RSRP with a final threshold provided by a higher layer.

[0193] When the adjusted RSRP is less than the last threshold, the UE determines the second last repetition number of PDSCH reception providing RAR in step 790. When the adjusted RSRP is not less than the last threshold, the UE determines the last repetition number of PDSCH reception providing RAR in step 795.

[0194] In one embodiment, when the determined RSRP value is greater than the RSRP threshold, the UE may receive the RAR with a first repetition number, and when the determined RSRP value is less than the RSRP threshold, receive it with a second repetition number. Here, the first repetition number is less than the second repetition number.

[0195] In one embodiment, the UE may receive the RAR via a PDCCH / PDSCH transmission, where the PDCCH provides a DCI format different from DCI format 1_0 used in the NR specification and may be similar to DCI format 1_2 introduced in the NR specification.

[0196] In one example, the CRC for the DCI format may be scrambled by a new RNTI (such as L-RNTI or RC-RNTI) different from the RA-RNTI.

[0197] In one embodiment, the number of symbols of the CORESET in which the UE monitors the PDCCH for scheduling PDSCH reception providing RAR depends on the RSRP range / CE level and / or the number of PRACH preamble repetitions and / or the number of repetitions of PDSCH transmission providing RAR.

[0198] In one example, the UE may monitor the PDCCH in a search space set associated with a CORESET having a number of symbols determined for a corresponding CE level or UE power class. For example, when the UE operates with a smaller CE level (such as CE level 0) and a larger RSRP range, the UE may monitor the PDCCH in a search space set associated with a CORESET having a length of {1, 2, 3} symbols, and when the UE operates with a larger CE level (such as CE level 1) and a lower RSRP range, the UE may monitor the PDCCH in a search space set associated with a CORESET having a length of {1, 2, 3, 6} symbols.

[0199] In one example, the search space set associated with a CORESET for monitoring PDCCH (including a PDCCH that schedules a PDSCH transmission that provides RAR) can be based on a single / same reference baseline CORESET#0 configured with a fixed maximum symbol length (such as 6 symbols) as specified in system operation or provided by higher layers, wherein UEs of each CE level or UE power class monitor PDCCH in the search space set associated with the reference baseline CORESET#0 only within a certain number of symbols associated with the CE level or UE power class according to a mapping specified in system operation or provided by higher layers, for example, UEs at smaller CE levels monitor the reference baseline CORESET#0 in only 2 symbols out of 6 symbols. In these examples, all associated configurations can be provided by higher layers (such as SIB1 and / or RRC).

[0200] In one example, a UE may be provided with multiple search space sets for monitoring the PDCCH.

[0201] In one example, the aforementioned examples and / or embodiments may be applied to any PDCCH, regardless of whether it corresponds to a PDSCH providing a RAR.

[0202] In the foregoing examples and / or embodiments, the symbol duration corresponds to the SCS of the type1-PDCCH CSS set as defined in the NR specification.

[0203] Figure 8An example determination of a CORESET length 800 for PDCCH monitoring associated with scheduling of PDSCH reception providing RAR by a UE based on RSRP range / CE level and UE power class according to an embodiment of the present disclosure is shown. Figure 8 The illustrated embodiment of the UE's determination of the CORESET length 800 is for illustration only. Figure 8 One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0204] In step 810, the UE selects a DL RS resource associated with the PRACH transmission, such as an SSB or a CSI-RS, and in step 820, measures the RSRP of the selected DL RS resource. Next, in step 830, the measured RSRP value is adjusted based on the UE power level, such as based on the difference between the UE power amplifier level and the reference UE power amplifier level. In step 850, the UE compares the adjusted RSRP with a threshold that may be indicated by a higher layer. When the adjusted RSRP is less than the threshold, in step 850, the UE determines to monitor the PDCCH in a CORESET having a length of {1, 2, 3, 6} symbols for scheduling PDSCH reception providing RAR. When the adjusted RSRP is not less than the threshold, in step 860, the UE determines to monitor the PDCCH in a CORESET having a length of {1, 2, 3} symbols for scheduling PDSCH reception providing RAR.

[0205] In one embodiment, the start of the window for monitoring the PDCCH for scheduling a PDSCH providing a RAR corresponding to a PRACH preamble transmission with more than one repetition may be determined according to the following options.

[0206] In one example of option (A), the window starts after the last PRACH preamble repetition and at the first symbol of the earliest CORESET, where the UE is configured to monitor the PDCCH for a Type 1-PDCCH CSS set, where the Type 1-PDCCH CSS set is located at least one symbol after the last symbol of the PRACH opportunity corresponding to the last repetition of the PRACH transmission.

[0207] In another example of option (B), the window starts after the first PRACH preamble repetition transmission and at the first symbol of the earliest CORESET, where the UE is configured to monitor the PDCCH for a Type1-PDCCH CSS set, where the Type1-PDCCH CSS set is located at least one symbol after the last symbol of the PRACH opportunity corresponding to the first repetition of the PRACH transmission.

[0208] In another example (C) of the option, the window starts after the transmission of the number of repetitions provided by the higher layer according to the total number of PRACH preamble repetitions. For example, the window starts after half of the total number of repetitions is completed. The window starts at the first symbol of the earliest CORESET, where the UE is configured to monitor the PDCCH for a Type1-PDCCH CSS set, where the Type1-PDCCH CSS set is located at least one symbol after the last symbol of the PRACH opportunity corresponding to the Nth repetition of the PRACH transmission, where N is fixed in the specification or provided by the higher layer. The value N can be the same for all CE levels and / or UE power levels and / or UE bandwidth values / complexity levels / capabilities, or can be different for different CE levels and / or different UE power levels and / or different UE bandwidth values. In the latter case, the higher layer can provide the value N for each CE level and / or UE power level and / or bandwidth value / complexity level / capability separately, or the higher layer can provide the value N only for the reference setting, and the UE can determine the value N for other settings based on the reference value and a predetermined rule. For example, the value of N for RSRP range / CE level 1 is twice the value of N for RSRP range / CE level 0.

[0209] In the example, the symbol duration corresponds to the SCS of the type1-PDCCH CSS set as defined in the NR specification.

[0210] The motivation for options (B) and (C) as shown above is that the gNB can detect the PRACH preamble before all PRACH preamble / Msg1 repetitions are completed. Then, the gNB can transmit PDSCH with RAR earlier.

[0211] In one example, the UE may transmit a PRACH preamble and monitor the PDCCH on a different serving cell for scheduling reception of a PDSCH providing a RAR.

[0212] In another example, a timing relationship / PDCCH monitoring gap between each repetition of a PRACH preamble transmission and a PDCCH monitoring opportunity for scheduling a PDSCH providing a RAR may be defined.

[0213] In yet another example, the PRACH preamble transmission and PDCCH monitoring opportunities may overlap. In other examples, different options may be used for different UE capabilities and / or operating bands. For example, option (A) may be applied to a half-duplex UE, while option (A) or (B) or (C) may be applied to a full-duplex UE or for a UE operating in a TDD band or in an FDD band with a reference TDD UL / DL configuration.

[0214] In one example, for option (B) or (C), when the UE detects a DCI format that schedules reception of a PDSCH providing a RAR, the UE may instruct the gNB to stop transmitting the remaining repetitions of the PDCCH / PDSCH providing the RAR.

[0215] In another example, the indication may be implicit, e.g., by transmitting HARQ ACK in the PUCCH, such that when the gNB receives a PUCCH with HARQ-ACK in response to a repetition of a PDCCH / PDSCH providing a RAR, the gNB stops transmitting the remaining repetitions of the PDCCH / PDSCH providing the RAR.

[0216] In one embodiment, for a UE configured with PRACH repetition transmission, the window size in terms of number of time slots for monitoring PDCCH scheduling PDSCH reception with RAR (as configured by higher layer parameter ra-ResponseWindow) depends on the RSRSP range / CE level and / or the starting symbol of the CORESET used for PDCCH monitoring and / or the number of repetitions of PRACH preamble transmission and / or the number of repetitions of PDSCH reception providing RAR. In one example, different window lengths are configured for different RSRP ranges / CE levels, or the same window length is configured for different repetition numbers of PRACH transmissions.

[0217] For example, a larger window size can be configured for a higher RSRP range / CE level and / or a larger number of repetitions of PRACH transmissions and / or a larger number of repetitions of PDSCH receptions providing RAR. In another example, the window size can be extended to include all repetitions of PDSCH receptions providing RAR, for example, as described in the aforementioned embodiments.

[0218] In another example, the window length may be different depending on the start symbol of the PDCCH monitoring opportunity, as described in the aforementioned embodiment. For example, the window size indicates the number of time slots after the last repetition of the PRACH preamble transmission, so that if the PDCCH monitoring starts after the first repetition of the PRACH preamble transmission (option (B) in the aforementioned embodiment) or after a later repetition of the PRACH preamble transmission as defined in the specification of the system operation or indicated by a higher layer (option (C) in the aforementioned embodiment), the actual length of the PDCCH monitoring window is the indicated window size value plus the number of time slots between the start symbol of the PDCCH monitoring opportunity and the last repetition of the PRACH preamble transmission.

[0219] In one example, the window size provided by higher layers indicates the actual window size and captures the impact of the start symbol of PDCCH monitoring (as described in the previous embodiments).

[0220] In yet another example, the value provided by a higher layer for the window size is the actual window size, but the indication and / or actual length of the window for monitoring the PDCCH for scheduling reception of the PDSCH providing RAR is independent of the start symbol of the corresponding PDCCH monitoring opportunity (i.e., independent of all options in the aforementioned embodiments), so that a sliding window for monitoring the PDCCH for scheduling reception of the PDSCH providing RAR can be applied.

[0221] In an example, the size of the window is with respect to the number of slots as determined by the SCS of the Type 1-PDCCH CSS set as defined in the NR specification.

[0222] Fig. 9 An example determination 900 of a start symbol and length of a PDCCH monitoring window for scheduling PDSCH reception providing RAR with repeated PRACH preamble transmissions according to an embodiment of the present disclosure is shown. Fig. 9 The illustrated embodiment of the determination of the starting symbol and length 900 is for illustration only. Fig. 9 One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0223] Fig. 9 The determination of the starting symbol and length of the PDCCH monitoring window for scheduling PDSCH reception providing RAR in the case of repeated PRACH preamble transmission is shown. Fig. 9 4 replicates are shown).

[0224] The upper figure shows an example where the PDCCH monitoring window starts after the last repetition of the PRACH preamble transmission. The middle figure shows an example where the PDCCH monitoring window starts after the first repetition of the PRACH preamble transmission. Therefore, the window length is extended based on the remaining number of repetitions of the PRACH preamble transmission (3 repetitions). The lower figure shows an example where the PDCCH monitoring window starts after half of the repetitions of the PRACH preamble transmission have been completed (2 repetitions in the example figure). Therefore, the window length is extended based on the remaining number of repetitions of the PRACH preamble transmission (2 repetitions in the example figure).

[0225] Fig.10 Another example determination 1000 of a start symbol and length of a PDCCH monitoring window for scheduling PDSCH reception providing RAR with repeated PRACH preamble transmissions according to an embodiment of the present disclosure is shown. Fig.10 The illustrated embodiment of the determination 1000 of the starting symbol and length is for illustration only. Fig.10 One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0226] Fig.10 Another example of determining the starting symbol and length of the PDCCH monitoring window for scheduling PDSCH reception providing RAR in the case of PRACH preamble repetitions (4 repetitions in this example figure) is shown. In this example, the UE operates a sliding PDCCH monitoring window, where the UE considers a fixed size window of the same length after each PRACH preamble transmission.

[0227] In one embodiment, after a RAR failure (due to failure to detect a DCI format with RA-RNTI within the RAR window or due to incorrect decoding of a RAR message in a PDSCH reception, or due to the absence of any RAR message containing the preamble ID used by the UE for PRACH transmission), the UE is expected to receive the RA-RNTI signal no later than N after the last symbol of the window or the last symbol of the last PDSCH reception (the last repetition of a PDSCH reception). T，1 +0.75msec transmit PRACH, where N T，1 is the N of the PDSCH reception times corresponding to UE processing capability 1 when additional PDSCH DM-RS is configured 1 For μ = 0, the UE assumes N 1，0 =14, as shown in the NR specification.

[0228] In one example, a (NR-light) UE needs to prepare to transmit PRACH based on the above timeline, but may actually transmit PRACH later in the first available cell-specific / UE-specific NR-Light valid timeslot for uplink transmission.

[0229] In one embodiment, for the RAR UL grant included in Msg2 / RAR, the content of the field and / or the field and / or the bit width may be different for NR UEs and / or may depend on the RSRP range / CE level / UE power class of operation. An example is provided in Table 3.

[0230] In such an embodiment, the total size (in bits) of the RAR UL grant may be the same as in the NR specification, which may be of reduced size. For example, 19 bits may be used for a RAR UL grant of reduced size, while 27 bits may be used for an NR specification grant. The UL grant size (such as 19 bits or 27 bits) may depend on the RSRP range / CE level of operation and / or UE power class. Zero padding may be used to ensure a fixed size RAR UL grant when needed.

[0231] In one example, at least some of the methods for relaxed scheduling of Msg3 described below may be applied to PUSCH / PDSCH transmissions after Msg3.

[0232] <Table 3. RAR UL Grant Content field size for NR-Light UE>

[0233]

[0234] In one example, if frequency hopping is performed, the frequency hopping flag is not present in the RAR UL grant.

[0235] In one example of UL BWP for Msg3, a new field is introduced in the RAR UL grant, which indicates the UL BWP index for Msg3 PUSCH, for example, as shown in Table 4. This operation can distribute UEs across the serving cell bandwidth, thereby alleviating congestion in the initial UL BWP when there are a large number of UEs in the serving cell. In a related example, multiple (e.g., up to four) UL BWPs are indicated by higher layers (including by SIB), and a 2-bit field of the UL BWP index in the RAR UL grant for the UE indicates the UL BWP that the UE from the four UL BWPs can use for Msg3 transmission.

[0236] In another example, higher layers may indicate two UL BWPs, and 1 bit in the RAR UL grant indicates the UL BWP for Msg3 transmission from the two UL BWPs. A value of 0 may indicate the initial UL BWP.

[0237] In yet another example, at least before the UE receives the dedicated RRC configuration, multiple (e.g., maximum 2 or 4) initial UL BWP configurations (shared with other UEs) are provided to the UE by higher layers (including by the SIB), and the UE transmits PUSCH Msg3 in one of the multiple initial ULBWPs whose index is provided in the RAR UL grant.

[0238] In one example, SIB or RRC common signaling may provide a complete configuration of a first initial UL BWP (such as a legacy / NR initial UL BWP), and a relative configuration of a second initial UL BWP in the same carrier / cell, such as one or more of a relative frequency position, a relative bandwidth size, etc.

[0239] In another example, one or more of the relative configuration parameters may be fixed in the system specifications.

[0240] In yet another example, the UE may be instructed through UE-specific higher layer configuration to reuse one or more of the multiple initial UL BWPs as a UE-dedicated / specific UL BWP.

[0241] According to the second example, the subcarrier spacing of the Msg3 PUSCH may be different in different UL BWPs because each of a plurality of UL BWPs indicated by a higher layer for the Msg3 PUSCH may have a separate subcarrier spacing configuration.

[0242] For legacy NR UEs, the active UL BWP for Msg3 PUSCH transmission is indicated by higher layers and the corresponding subcarrier spacing is provided by the higher layer parameter subcarrierSpacing in BWP-UplinkCommon.

[0243] <Table 4. UL BWP for Msg3 PUSCH transmission>

[0244]

[0245] In one example of frequency resource allocation, the Msg3PUSCH Frequency Domain Resource Allocation (FDRA) field in the RAR UL grant for a UE indicates the RB allocation within the active UL BWP for Msg3 PUSCH transmission. The bit width of the FDRA field may be reduced, e.g., from 14 bits to 11 bits, compared to NR UEs (as shown in the NR specification).

[0246] The motivation is that the UL grant for Msg3 PUSCH transmission can target UEs that support reduced bandwidth compared to NR UEs.

[0247] In one example, in addition to the UL BWP for PUSCH Msg3 transmission Except for the "cut-off" value of the size of RBs changing from 180 RBs (as shown in the NR specification) to a smaller value (such as 63 RBs), the FDRA for Msg3 PUSCH can follow the UL resource allocation type 1 in the NR specification and use consecutive / contiguous (virtual) resource blocks, so that the FDRA field in the RAR UL grant requires 11 bits.

[0248] In another example, the FDRA for Msg3 PUSCH may follow UL resource allocation type 2 as per NR specification and use a (virtual) resource block group (RBG) level allocation different from that of NR UEs. According to this example, the FDRA field in the RAR UL grant indicates the RBG allocated for Msg3 PUSCH transmission.

[0249] In yet another example, the RBG size can be determined based on the value of "Configuration 2" of RBG-Size (as shown below), regardless of the actual configuration of the layer parameter rbg-Size. Therefore, no more than 9 RBGs need to be addressed, and the bit width of the FDRA field for Msg3PUSCH transmission is reduced to 9 bits.

[0250] <Table 5. Nominal RBG size P>

[0251] Carrier bandwidth portion size Configuration 1 Configuration 2 1 to 36 2 4 37 to 72 4 8 73 to 144 8 16 145 to 275 16 16

[0252] In yet another example, the RBG size for Msg3 PUSCH may be determined based on a new configuration different from both “Configuration 1” and “Configuration 2” in Table 5 (as shown in the NR specification).

[0253] In one example, a (reduced capability) UE may follow this restriction / simplification in FDRA for frequency resource allocation for one or both of Msg3 PUSCH and other PDSCH / PUSCH transmissions after Msg3.

[0254] In one example of time resource allocation, a limited set of time domain resource allocations (TDRA) may be used to schedule Msg3 PUSCH transmissions from a UE, and the size / bits of the TDRA field for Msg3 PUSCH transmissions are reduced compared to the NR specification.

[0255] In one example, Type B TDRA that allows PUSCH transmissions not to start from the beginning of a slot may not be supported in Tables 6A and 7A (as shown in the NR specification).

[0256] In another example, some TDRA values ​​of Type-A, such as those with the smallest K2 values, are also not supported, for example due to lower UE processing capabilities, as highlighted in Table 6A and Table 7A. To explicitly illustrate the new result tables to be used (for NR-Light / reduced capability UEs), the exemplary supported entries are merged and captured in Table 6B (for Normal CP) and Table 7B (for Extended CP), respectively. According to this example, the size / bit width of the TDRA field in the RAR UL grant is 3 bits compared to 4 bits for NR UEs. Table 8 captures the table as shown in the NR specification.

[0257] In one example, a (reduced capability) UE may follow this restriction / simplification in TDRA for time resource allocation for one or both of Msg3 PUSCH and other PDSCH / PUSCH transmissions after Msg3.

[0258] In another example, the number of repetitions of PUSCH (including PUSCH for Msg3) is jointly encoded with TDRA.

[0259] <Table 6A. Default PUSCH time domain resource allocation for normal CP A>

[0260] Row Index PUSCH mapping type <![CDATA[K 2 ]]> S L 1 Type A j 0 14 2 Type A j 0 12 3 Type A j 0 10 4 Type B j 2 10 5 Type B j 4 10 6 Type B j 4 8 7 Type B j 4 6 8 Type A j+1 0 14 9 Type A j+1 0 12 10 Type A j+1 0 10 11 Type A j+2 0 14 12 Type A j+2 0 12 13 Type A j+2 0 10 14 Type B j 8 6 15 Type A j+3 0 14 16 Type A j+3 0 10

[0261] <Table 6B. New default PUSCH time domain resource allocation A for normal CP (for NR-Light UE)

[0262] (NR-Light UE does not support rows 1 to 7.)>

[0263]

[0264]

[0265] <Table 7A. Default PUSCH time domain resource allocation for extended CP A

[0266] (Lines 1 to 7 and 14 are not supported by NR-Light UE.)

[0267] Row Index PUSCH mapping type <![CDATA[K 2 ]]> S L 1 Type A j 0 8 2 Type A j 0 12 3 Type A j 0 10 4 Type B j 2 10 5 Type B j 4 4 6 Type B j 4 8 7 Type B j 4 6 8 Type A j+1 0 8 9 Type A j+1 0 12 10 Type A j+1 0 10 11 Type A j+2 0 6 12 Type A j+2 0 12 13 Type A j+2 0 10 14 Type B j 8 4 15 Type A j+3 0 8 16 Type A j+3 0 10

[0268] < Table 7B. New default PUSCH time domain resource allocation A for extended CP (for NR-Light UE)

[0269] (NR-Light UE does not support rows 1 to 7.)>

[0270]

[0271]

[0272] <Table 8. Definition of value j>

[0273] <![CDATA[μ PUSCH ]]> j 0 1 1 1 2 2 3 3

[0274] In one example of the reception of Msg3, a new field is introduced in the RAR UL grant to indicate the number of repetitions of the Msg3 PUSCH. The mapping of the field to the actual number of repetitions of the Msg3 PUSCH transmission may depend on the configured maximum Msg3 repetition value and a specific table depending on the RSRP range / CE level. For example, the repetition level (N) of the initial transmission of the Msg3 PUSCH may be Msg3 ) is based on Table 9, where Y A Determined by the higher layer parameter puschMsg3-maxNumRepetition (if provided); otherwise, Y A =8. Potential values ​​of puschMsg3-maxNumRepetition may include {8, 16, 32}. The motivation for supporting repetition of Msg3 PUSCH transmission is to enhance / restore the coverage of Msg3. In one example, a similar process for indicating the number of PUSCH / PDSCH repetitions may be used for other PDSCH / PUSCH transmissions after Msg3.

[0275] <Table 9. Msg3 PUSCH repetition level values ​​for NR-Light UE. >

[0276]

[0277]

[0278] In one example of TPC commands, the UE may use a limited set of TPC commands for Msg3 PUSCH transmissions, particularly in the case of repetitions where the Msg3 PUSCH may have maximum power and the TPC commands are not actually useful. A reduced number of bits (including 0 bits) may be used to indicate the TPC command for Msg3 PUSCH compared to the 3 bits used in the NR specification. Therefore, certain entries from Table 10 (as shown in the NR specification) are not used, and such exemplary entries are grayed out in the table below and are also explicitly indicated separately as new TPC values ​​and new TPC commands.

[0279] <Table 10. TPC command δ for Msg3 PUSCHmsg2，b，f，c

[0280] (Lines 0, 1, 6, and 7 are not supported)>

[0281]

[0282] In one example of MCS, a reduced set of MCS configurations may be used. For example, 3 bits are used to indicate the MCS index, such as the first 8 MCS indices from the legacy / NR configuration table, compared to 4 bits in NR. The motivation is that especially for Msg3 PUSCH transmissions with repetitions, the spectral efficiency corresponding to the operation may be in a lower range, and the modulation scheme (pi / 2BPSK or QPSK) may be sufficient.

[0283] In one example of DL BWP for Msg3 / 4 PDCCH, a new field (e.g., with 2 bits) is introduced to indicate the UE to monitor the DL BWP of PDCCH for possible Msg3 retransmission and / or Msg4 transmission and / or any other PDSCH / PUSCH transmission after the first / initial transmission of Msg3 (e.g., configured by a temporary C-RNTI, i.e., "TC-RNTI" and / or C-RNTI and / or MCS-C-RNTI in the random access procedure, or a different RNTI, such as L-RNTI), for example, as shown in Table 11.

[0284] The motivation is to distribute the UEs over the serving cell bandwidth and facilitate congestion control for a potentially large number of UEs on the serving cell.

[0285] In one example, up to four DL BWPs may be indicated by higher layers, and a 2-bit field of DL BWP index in the RAR UL grant for the UE may indicate the DL BWP for the UE to use for Msg3 / 4 PDCCH reception and / or for PDCCH reception corresponding to any other PDSCH / PUSCH transmissions after the initial transmission of Msg3.

[0286] In another example, higher layers may indicate two UL BWPs, and 1 bit in the RAR UL grant indicates the UL BWP for Msg3 transmission from the two UL BWPs. A value of 0 may indicate an initial DL BWP / default DL BWP or a DL BWP for PDCCH for Msg3 retransmission, which is the same as the DL BWP for RAR PDCCH reception.

[0287] In yet another example, at least for the UE before receiving the dedicated RRC configuration, multiple (e.g., maximum 2 or 4) initial DL BWP configurations (shared with other UEs) are provided to the UE by higher layers (including by SIB), and the UE performs PDCCH monitoring and / or Msg3 / 4 PDCCH monitoring corresponding to any other PDSCH / PUSCH transmissions after the initial transmission of Msg3 in one of the multiple initial DL BWPs whose index is provided in the RAR UL grant. For example, the SIB or RRC common signaling may provide a complete configuration of a first initial DL BWP (such as a legacy / NR initial DL BWP), and a relative configuration of a second initial DL BWP in the same carrier / cell, such as one or more of a relative frequency position, a relative bandwidth size, etc.

[0288] In yet another example, one or more of the relative configuration parameters may be fixed in the system specification.In yet another example, the UE may be instructed through UE-specific higher layer configuration to reuse one or more of the multiple initial DL BWPs as a UE-dedicated / specific DL BWP.

[0289] In one example, a UE may be provided with multiple search space sets for monitoring the PDCCH for scheduling Msg3 retransmissions and / or Msg4 receptions and / or any other PDSCH / PUSCH transmissions after the initial transmission of Msg3. Multiple search space sets may be mapped to corresponding multiple CORESETs, where the multiple CORESETs may have different numbers of symbols to facilitate different coverage (enhancement) levels of the PDCCH. For example, a first CORESET from a plurality of CORESETs may have a duration of 1 to 3 symbols, while a second CORESET may have a duration of 4 to 6 (or 1 to 6 or a subset thereof) OFDM symbols. For example, the group of multiple CORESETs may be the same as those used for RAR PDCCH reception in the previous embodiment. In another example, the group of multiple CORESETs may have the same time domain duration as those of the CORESETs used for RAR PDCCH reception, e.g., the same number of symbols, as described in the previous embodiment. In one example, the UE may determine the search space set (and corresponding CORESET) for monitoring the PDCCH based on the RSRP or CE level. For example, if the RSRSP for a DL RS (e.g., SSB or CSI-RS) is less than or equal to a threshold, the UE monitors the PDCCH for scheduling the aforementioned PDSCH / PUSCH according to a search space set associated with a CORESET having a first number of symbols (such as 1 to 3 symbols), and if the RSRSP for a DL RS (e.g., SSB or CSI-RS) is greater than the threshold, the UE monitors the PDCCH for scheduling the aforementioned PDSCH / PUSCH according to a search space set associated with a CORESET having a second number of symbols (such as 1 to 6 symbols (or 4 to 6 symbols or a subset thereof)). In this document: The threshold may be provided by a specification and / or SIB signaling (such as SIB1) and / or common RRC signaling, and / or determined by the UE based on predetermined or configured rules and / or formulas; (possibly) the configuration of multiple search space sets other than the default search space set determined according to the MIB and used for scheduling of the SIB may be provided by a specification and / or SIB signaling (such as SIB1) and / or common RRC signaling, and / or determined by the UE based on predetermined or configured rules and / or formulas. In one example, the frequency resource allocations of each CORESET from the group of multiple CORESETs may be the same as those of the CORESET used for RARPDCCH reception, as described in the previous embodiment. In another example, the frequency resource allocations of each CORESET from the group of multiple CORESETs may be an offset compared to those of a group of multiple CORESETs (corresponding CORESETs) used for RAR PDCCH reception as described in the previous embodiment.According to this example, compared to a group of multiple CORESETs (corresponding CORESETs) for RAR PDCCH reception as described in the previous embodiment, a common / same offset value or a different offset value can be configured for the frequency domain resource allocation of each CORESET from the group of multiple CORESETs. In addition, the configuration of the offset value can be provided by the specification and / or SIB signaling (such as SIB1) and / or common RRC signaling, and / or determined by the UE based on predetermined or configured rules and / or formulas. In another example, the group of multiple CORESETs for monitoring / receiving PDCCH corresponding to Msg3 retransmission and / or Msg4 reception and / or any other PDSCH / PUSCH transmission after the initial transmission of Msg3 can be configured in one or more of the multiple (initial) DL BWPs indicated by the RAR uplink grant field. For example, a first CORESET (or a first subset of CORESETs) from the set of multiple CORESETs may be configured on a first initial DL BWP, and a second CORESET (or a second subset of CORESETs) from the set of multiple CORESETs may be configured on a second initial DL BWP. A CORESET may be associated with PDCCH monitoring by configuration of a corresponding search space set.

[0290] According to this example, the subcarrier spacing for Msg3 / 4 PDCCH reception can be different in different DL BWPs because each of the multiple DL BWPs indicated by higher layers for Msg3 / 4 PDCCH reception and / or PDCCH reception corresponding to any other PDSCH transmission after the initial transmission of Msg3 can have a separate configuration of the subcarrier spacing.

[0291] In one example, a new field in the RAR UL grant corresponding to the DL BWP for Msg3 / 4 PDCCH monitoring indicates the DL BWP for the first slot / first repetition for receiving PDCCH transmission for Msg3 retransmission and / or Msg4 transmission and / or any other PDSCH transmission after the initial transmission of Msg3. The remaining slots / remaining repetitions for PDCCH monitoring of Msg3 retransmission and / or Msg4 transmission and / or any other PDSCH transmission after the initial transmission of Msg3 can be on other DL BWPs, following the frequency hopping pattern specified or indicated by higher layers and / or the BWP switching command in the DCI format scheduling the Msg3 retransmission and / or Msg4 transmission and / or any other PDSCH transmission after the initial transmission of Msg3.

[0292] <Table 11. DL BWP for Msg3 / 4 PDCCH reception>

[0293]

[0294] In one example of an SRS request, a new field is introduced for the SRS request, for example, with 1 to 3 bits. This can help with future beam management and scheduling. For example, such an SRS request field can replace or supplement the CSI request field.

[0295] In one embodiment, with reference to the time slots used for PUSCH transmissions scheduled by a RAR UL grant, if the UE receives the last repetition of PDSCH with a RAR message for a corresponding PRACH transmission from the UE, which ends in time slot n, then the UE transmits the first repetition of Msg3 PUSCH in the first valid time slot, which is n+k as determined by higher layer configuration. 2 +Δ or thereafter, where k 2 and Δ are provided in the NR specification.

[0296] In one example, if the subcarrier spacing (SCS) used for RAR PDSCH reception is different from the SCS used for Msg3 PUSCH transmission, the timing relationship is adjusted by the relative SCS between PDSCH and PUSCH to where μ PUSCH and μ PDSCH The subcarrier spacing configurations used for PUSCH and PDSCH respectively.

[0297] In one embodiment, the UE may assume that the minimum time between the last symbol of the PDSCH reception conveying the last repetition of the RAR message with the RAR UL grant and the first symbol of the first reception of the corresponding PUSCH transmission scheduled by the RAR UL grant is equal to N T，1 +N T，2 +0.5msec, where N T，1 is the N of the PDSCH reception times corresponding to UE processing capability 1 when additional PDSCH DM-RS is configured 1 The duration of a symbol, N T，2 N is the PUSCH preparation time corresponding to UE processing capability 1 2 The duration of N symbols (as indicated in the NR specification), and to determine the minimum time, the UE considers N 1 and N 2 Corresponds to the smaller of the SCS configurations for PDSCH and PUSCH. For μ = 0, the UE assumes N 1，0 =14 (as shown in the NR specification).

[0298] In another embodiment, in response to a Msg3 PUSCH transmission being scheduled by a RAR UL grant when the UE has not been provided with a C-RNTI, the UE attempts to detect a DCI format with a CRC scrambled by the corresponding TC-RNTI, such as DCI format 1_0 (as shown in the NR specification), that schedules a PDSCH including a UE contention resolution identifier.

[0299] In response to a PDSCH reception with a UE contention resolution indicator, the UE transmits HARQ-ACK information in the PUCCH. The PUCCH transmission is within the same active UL BWP as the PUSCH transmission. The minimum time between the last symbol of the last repetition of the PDSCH reception and the first symbol of the corresponding PUCCH transmission with HARQ-ACK information is equal to N T，1 +0.5msec. N T，1 is the N of the PDSCH reception times corresponding to UE processing capability 1 when additional PDSCH DM-RS is configured 1 For μ = 0, the UE assumes N 1，0 =14 (as shown in the NR specification).

[0300] In yet another embodiment, when a DCI format (such as DCI format 0_0) with a CRC scrambled by the TC-RNTI provided in the corresponding RAR message is detected in response to a PUSCH transmission scheduled by an RAR UL grant as described in the NR specification, or a corresponding PUSCH retransmission scheduled by a DCI format as described in the NR specification, the UE may assume that the PDCCH provided with the DCI format has the same DM-RS antenna port quasi-co-located property as in the NR specification with respect to the SS / PBCH blocks used by the UE for PRACH association, regardless of whether the UE is provided with the TCI-state of the CORESET in which the UE receives the PDCCH using that DCI format.

[0301] In one example, PDSCH reception with a UE contention resolution indicator has the same DM-RS antenna port quasi-co-location property as the SS / PBCH blocks (as described in the NR specification) used by the UE for PRACH association, as described in the NR specification.

[0302] In one example, UE distribution / congestion control during initial access of NR-Light UEs is provided in Table 12A and Table 12B.

[0303]

[0304]

[0305] <Table 12B. MIB field description>

[0306]

[0307] In one embodiment, after the UE is allowed to access the serving cell based on the master information block (MIB) parameter cellBarred with the value "notBarred", the UE checks and re-interprets the MIB parameter intraFreqReselection to determine the initial DL / UL BWP and / or CORESET#0 of the serving cell.

[0308] In one example, if the MIB parameter intraFreqReselection is set to "allowed", the UE may maintain / camp on the initial DL / UL BWP as indicated by pdcch-ConfigSIB1 in NR and use CORESET#0. However, if the MIB parameter intraFreqReselection is set to "notAllowed", the UE determines that the UE needs to camp on another part of the system bandwidth (another DL / UL BWP in addition to the initial DL / UL BWP) and / or use a different CORESET#0 (e.g., CORESET#0-light) by re-interpreting the configuration in pdcch-ConfigSIB1 based on an alternative specified table (e.g., size and position for CORESET#0, SSB and CORESET#0-light multiplexing, etc.).

[0309] In another example, the UE access behavior is opposite to that described in the previous example for the MIB parameter intraFreqReselection values ​​"allowed" and "notAllowed". It should be noted that the NR specification already specifies certain UE behaviors based on the MIB parameter intraFreqReselection when another MIB parameter cellBarred is set to the value "Barred".

[0310] However, there is no UE behavior specified in the NR specification based on the MIB parameter intraFreqReselection for the case where the MIB parameter cellBarred is set to the value "notBarred". This is why this MIB parameter might be used for further re-interpretation in case of NR-Light / non-legacy UEs. It should be noted that legacy NR UEs are not expected to perform any such re-interpretation.

[0311] This solution may move all NR-Light UEs / low capability / non-legacy UEs to different / separate DL / UL BWPs and / or CORESET#0. It may be possible to combine this solution with other UE IDs (such as global UE IDs, etc.) so that only certain groups of NR-Light UEs perform this re-interpretation, while other NR-Light UEs do not perform this behavior.

[0312] In one example, all NR-Light / non-legacy UEs perform the solution provided in this embodiment to move to different / separate DL / UL BWPs and / or CORESET#0, but each group of NR-Light UEs / low-capability / non-legacy UEs can camp / remain in different DL / UL BWPs and / or CORESET#0 based on other UE IDs. This solution can further help congestion control and UE distribution on the system bandwidth of NR-Light UEs during initial access.

[0313] Fig.11 An example congestion control and UE distribution 1100 during initial access of an NR-Light UE according to an embodiment of the present disclosure is shown. Fig.11 The illustrated embodiment of congestion control and UE distribution 1100 is for illustration only. Fig.11 One or more components shown in the can be implemented in a dedicated circuit configured to perform the functions, or one or more components can be implemented by one or more processors that execute instructions to perform the functions. Other embodiments are used without departing from the scope of the present disclosure.

[0314] like Fig.11 , in step 1110, the UE receives and reads the MIB from the PBCH. In step 1120, the UE determines whether the MIB parameter cellBarred has a value equal to "barred". If the UE determines that the MIB parameter cellBarred has a value equal to "barred", then in step 1130, the UE operates as in the NR specification based on another MIB parameter intraFreqReselection. However, if the UE determines that the MIB parameter cellBarred has a value equal to "notBarred", then in step 1140, the UE considers the value of the MIB parameter intraFreqReselection.

[0315] If the UE determines that the MIB parameter ntraFreqReselection has a value equal to "allowed", the UE camps on the initial DL / UL BW and uses CORESET#0 as indicated by pdcch-ConfigSIB1 in the NR specification in step 1150. However, if the UE determines that the MIB parameter ntraFreqReselection has a value equal to "notAllowed", the UE re-interprets pdcch-ConfigSIB1 in step 1160 to camp on a DL / UL BWP other than the initial DL / UL BWP and use a different CORESET#0 (e.g., CORESET#0-Light).

[0316] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be proposed to those skilled in the art. The present disclosure is intended to include such changes and modifications that fall within the scope of the appended claims. Any description in this application should not be construed as implying that any particular element, step or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is limited only by the claims.

Claims

1. A method for receiving a physical downlink control channel (PDCCH) by a user equipment (UE), include: receiving a master information block MIB comprising a first configuration for a first control resource set CORESET, the first CORESET comprising a first number of resource blocks (RBs) in the frequency domain and a first number of symbols in the time domain; receiving a system information block SIB including a second configuration for a second CORESET and a reference signal received power (RSRP) threshold, the second CORESET including a second number of RBs in the frequency domain and a second number of symbols in the time domain, wherein the second number of symbols is greater than the first number of symbols; Measuring a first RSRP value based on the selected downlink reference signal DL RS resource; determining a CORESET from the first CORESET or the second CORESET to monitor a first physical downlink control channel PDCCH based on the first RSRP value and the RSRP threshold, wherein the first PDCCH schedules transmission of a physical downlink shared channel PDSCH including a random access response RAR message; and The first PDCCH is received in the determined CORESET, wherein: When the first RSRP value is greater than the RSRP threshold, receiving the first PDCCH in the first CORESET, and When the first RSRP value is less than the RSRP threshold, the first PDCCH is received in the second CORESET.

2. The method according to claim 1, in, The second RB number is smaller than the first RB number.

3. The method according to claim 1, further comprising: include: Sure: the value of the difference between the reference power amplifier level and the power amplifier level of the power amplifier, and determining a second RSRP value by subtracting the value from the first RSRP value; and The power amplifier is used to transmit a physical random access channel PRACH with the following number of repetitions: When the second RSRP value is greater than the RSRP threshold, transmitting the PRACH with a first number of repetitions, and When the second RSRP value is less than the RSRP threshold, the PRACH is transmitted with a second number of repetitions, wherein the first number of repetitions is less than the second number of repetitions.

4. The method according to claim 1, further comprising: include: Receive the physical downlink shared channel PDSCH, where: The PDSCH reception is scheduled by the first PDCCH, The PDSCH includes the RAR message, The RAR message includes control information for scheduling transmission of a physical uplink shared channel PUSCH, and The control information includes a bandwidth part (BWP) indicator field having a value; and The PUSCH is transmitted in a UL BWP indicated by the value of the BWP indicator field from a set of uplink UL BWPs provided by the SIB.

5. The method according to claim 4, further comprising: include: A second PDCCH is received in a third CORESET, wherein: The third CORESET includes a third number of RBs in the frequency domain and a third number of symbols in the time domain, The third symbol quantity is the same as: If the UE receives the first PDCCH in the first CORESET, the third number of symbols is the same as the first number of symbols, or If the UE receives the first PDCCH in the second CORESET, the third number of symbols is the same as the second number of symbols, The third CORESET is included in a DLBWP from a set of downlink DL BWPs linked to the UL BWP, The set of DL BWPs is provided by the system information block, and The second PDCCH schedules reception of a second PDSCH; and The second PDSCH is received.

6. The method according to claim 5, in: The third number of RBs is determined based on an offset relative to: determining the third number of RBs based on an offset relative to the first number of RBs when receiving the first PDCCH in the first CORESET, or determining the third number of RBs based on an offset relative to the second number of RBs when receiving the first PDCCH in the second CORESET, and The offset is provided by the system information block.

7. A user equipment UE for receiving a physical downlink control channel PDCCH, include: Transceiver; A processor connected to the transceiver and configured to control: receiving a master information block MIB comprising a first configuration for a first control resource set CORESET, the first CORESET comprising a first number of resource blocks (RBs) in the frequency domain and a first number of symbols in the time domain, receiving a system information block SIB including a second configuration for a second CORESET and a reference signal received power (RSRP) threshold, the second CORESET including RBs of a second number of RBs in the frequency domain and symbols of a second number of symbols in the time domain, wherein the second number of symbols is greater than the first number of symbols, Based on the selected downlink reference signal DL RS resource, measuring a first RSRP value, determining a CORESET from the first CORESET or the second CORESET to monitor a first physical downlink control channel PDCCH based on the first RSRP value and the RSRP threshold, wherein the first PDCCH schedules transmission of a physical downlink shared channel PDSCH including a random access response RAR message, and receiving the first PDCCH in the determined CORESET, wherein, when the first RSRP value is greater than the RSRP threshold, receiving the first PDCCH in the first CORESET, and When the first RSRP value is less than the RSRP threshold, the first PDCCH is received in the second CORESET.

8. The UE according to claim 7, in, The second RB number is smaller than the first RB number.

9. The UE according to claim 7, in: The processor is further configured to determine: the value of the difference between the reference power amplifier level and the power amplifier level of the power amplifier, and determining a second RSRP value by subtracting the value from the first RSRP value; The transceiver is further configured to transmit a physical random access channel (PRACH) using the power amplifier with the following number of repetitions: When the second RSRP value is greater than the RSRP threshold, transmitting the PRACH with a first number of repetitions, and When the second RSRP value is less than the RSRP threshold, transmitting the PRACH with a second number of repetitions; and The first number of repetitions is smaller than the second number of repetitions.

10. The UE according to claim 7, wherein the transceiver is further configured to: Receive the physical downlink shared channel PDSCH, in: The PDSCH reception is scheduled by the first PDCCH, The PDSCH includes the RAR message, The RAR message includes control information for scheduling transmission of a physical uplink shared channel PUSCH, and The control information includes a bandwidth part BWP indicator field having a value; as well as The PUSCH is transmitted in a UL BWP indicated by the value of the BWP indicator field from a set of uplink UL BWPs provided by the SIB.

11. The UE according to claim 10, wherein the transceiver is further configured to receive a second PDCCH in a third CORESET, in: The third CORESET includes a third number of RBs in the frequency domain and a third number of symbols in the time domain, The third symbol quantity is the same as: If the UE receives the first PDCCH in the first CORESET, the third number of symbols is the same as the first number of symbols, or If the UE receives the first PDCCH in the second CORESET, the third number of symbols is the same as the second number of symbols, The third CORESET is included in a DLBWP linked to the UL BWP from a set of downlink DL BWPs provided by the system information block, and The second PDCCH schedules reception of a second PDSCH; and The second PDSCH is received.

12. The UE according to claim 11, in: The third number of RBs is determined based on an offset relative to: determining the third number of RBs based on an offset relative to the first number of RBs when receiving the first PDCCH in the first CORESET, or when receiving the first PDCCH in the second CORESET, determining the third number of RBs based on an offset relative to the second number of RBs, and The offset is provided by the system information block.

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