Procedure for concurrent MSG2 PDCCH monitoring

Abstract

A configuration for a random access procedure including concurrent Message 2 PDCCH monitoring utilizing different procedures. A device sends a first random access message 1. The device sends a second random access message 1 in response to determining that the first random access message 2 control portion was not received during a first portion of a first RAR window. The device concurrently monitors the first random access message 2 control portion and the second random access message 2 control portion during a second portion of the first RAR window. The monitoring procedure for coverage enhancement for the second message 2 control portion is different from the monitoring procedure for the first message 2 control portion. The device receives and decodes the random access message 2 control portion. The device monitors the random access message 2 data portion in response to decoding the random access message 2 control portion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of the following applications: U.S. Provisional Application entitled “ConcurrentMSG2 PDCCH Monitoring with Different Procedures” and Serial Number No. 63 / 012,016, filed on April 17, 2020; and U.S. Patent Application No. 17 / 214,472, entitled “Procedures for Concurrent MSG2PDCCH Monitoring”, filed on March 26, 2021, all of which are expressly incorporated herein by reference. Technical Field

[0003] Generally, the present disclosure relates to communication systems, and more particularly, to configuration for a random access procedure including concurrent message 2 Physical Downlink Control Channel (PDCCH) monitoring utilizing different procedures. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution released by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)), and other requirements. 5GNR includes services related to enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There is a need to further improve 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that use these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an exhaustive review of all contemplated aspects, and is neither intended to identify the key or important elements of all aspects nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be presented later.

[0007] Wireless communications may include a random access procedure that allows a user equipment (UE) to initiate or resume communications with a base station. Under certain channel conditions, various messages of the random access procedure may not be received correctly, which may delay or prevent the UE from connecting to the base station. For example, the coverage of the random access procedure may be enhanced by repeating messages. Such enhancements may consume additional resources and may not be suitable for UEs with good coverage.

[0008] In a random access procedure, a user equipment (UE) may send a first random access message 1. The UE may send a second random access message 1 in response to determining that a first random access message 2 physical downlink control channel (PDCCH) was not received during a first portion of a first random access response (RAR) window. The second random access message 1 may be considered as a request for an enhanced coverage random access message 2 PDCCH. The UE may monitor the first message 2 PDCCH and the second message 2 PDCCH simultaneously during a second portion of the first RAR window. The monitoring process for coverage enhancement of the second message 2 PDCCH is different from the monitoring process for the first message 2 PDCCH. For example, the monitoring process for coverage enhancement may monitor different PDCCH candidates, soft combine the PDCCH candidates, have different RAR windows, have different downlink control information (DCI) sizes, or have different DCI interpretations. The UE may receive and decode a random access message 2 PDCCH, which is one of the first random access message 2 PDCCH or the second random access message 2 PDCCH. The UE may monitor the random access message 2PDSCH in response to decoding the random access message 2PDCCH.By simultaneously monitoring the first message 2PDCCH and the second message 2PDCCH, the UE may improve the probability of successfully receiving the message 2PDCCH and the speed of completing the random access procedure.

[0009] In one aspect of the present disclosure, methods, computer-readable media, and apparatus are provided. The apparatus may be a device at a UE. The apparatus may be a processor and / or modem at the UE, or the UE itself. The apparatus sends a first random access message 1. The apparatus sends a second random access message 1 in response to determining that a first random access message 2 physical downlink control channel (PDCCH) is not received during a first portion of a first random access response (RAR) window. The apparatus simultaneously monitors a first random access message 2 PDCCH and a second random access message 2 PDCCH during a second portion of the first RAR window. The monitoring process for coverage enhancement of the second random access message 2 PDCCH is different from the monitoring process for the first random access message 2 PDCCH. The apparatus receives and decodes a random access message 2 PDCCH. The random access message 2 PDCCH is one of a first random access message 2 PDCCH or a second random access message 2 PDCCH. The apparatus monitors a random access message 2 PDSCH in response to decoding the random access message 2 PDCCH.

[0010] In one aspect of the present disclosure, methods, computer-readable media, and apparatus are provided. The apparatus may be a device at a base station. The apparatus may be a processor and / or modem at a base station, or the base station itself. The apparatus receives a first random access message 1 from a UE. The apparatus sends a first random access message 2PDCCH during a first RAR window in response to the first random access message 1. The apparatus receives a second random access message 1 during the RAR window. The apparatus sends a second random access message 2PDCCH during a second part of the first RAR window in response to the second random access message 1 for a coverage enhanced monitoring process different from the monitoring process for the first random access message 2PDCCH. The apparatus sends a first random access message 2PDSCH based on the first random access message 2PDCCH, and sends a second random access message 2PDSCH based on the second random access message 2PDCCH.

[0011] To achieve the foregoing and related ends, one or more aspects include features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0013] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0014] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0015] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0016] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0017] Figure 3 is a diagram showing an example of a base station and a user equipment (UE) in an access network.

[0018] Figure 4 is a diagram illustrating an example message exchange for a random access procedure between a base station and a UE in an access network.

[0019] Figure 5 is a resource diagram showing resources used to receive the PDCCH portion of Msg 2 using a coverage enhanced reception process.

[0020] Figure 6 is a flow chart of a method of wireless communication.

[0021] Figure 7 is a diagram illustrating an example of a hardware implementation for an example apparatus.

[0022] Figure 8 is a flow chart of a method of wireless communication.

[0023] Fig. 9 is a diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0024] The specific embodiments given below in conjunction with the accompanying drawings are intended to be descriptions of various configurations, and are not intended to represent the only configurations with which the concepts described herein can be implemented. For the purpose of providing a comprehensive understanding of various concepts, the specific embodiments include specific details. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in the form of block diagrams to avoid causing such concept ambiguity.

[0025] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements") and illustrated in the accompanying drawings. These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0026] For example, an element or any part of an element or any combination of elements can be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set operations (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware that are configured to perform various functions described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0027] Accordingly, in one or more example embodiments, the described functions may be implemented with hardware, software, or any combination thereof. If implemented with software, the functions may be stored on a computer-readable medium or encoded on a computer-readable medium as one or more instructions or codes. Computer-readable media include computer storage media. Storage media may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the above types, or any other medium that may be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0028] Figure 11 is a diagram showing an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0029] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G / NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via the third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0030] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 can include: an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link can be through one or more carriers. The base station 102 / UE 104 may use up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in carrier aggregation for up to a total of Yx MHz (x component carriers) for transmission in each direction. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

[0031] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through various wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0032] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, a 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating to determine whether the channel is available.

[0033] The small cell 102' may operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may utilize NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as used by the Wi-Fi AP 150. The small cell 102' utilizing NR in the unlicensed spectrum may improve coverage and / or increase capacity of the access network.

[0034] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating frequency bands have been identified with the frequency range names FR1 (410 MHz–7.125 GHz) and FR2 (24.25 GHz–52.6 GHz). Frequencies between FR1 and FR2 are typically referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the “sub-6 GHz” band in various documents and articles. Similar naming issues sometimes arise regarding FR2, which is often (interchangeably) referred to as the “millimeter wave” band in documents and articles, although FR2 is different from the extremely high frequency (EHF) band (30 GHz–300 GHz) which is identified as the “millimeter wave” band by the International Telecommunication Union (ITU).

[0035] In view of the above, unless otherwise explicitly stated, it should be understood that if used herein, the term "below 6 GHz" and the like can broadly refer to frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. In addition, unless otherwise explicitly stated, it should be understood that if used herein, the term "millimeter wave" and the like can broadly refer to frequencies that can include mid-band frequencies, can be within FR2, or can be within the EHF band.

[0036] Whether a small cell 102' or a large cell (e.g., a macro base station), the base station 102 may include and / or be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations (e.g., gNB 180) may operate in traditional sub-6 GHz spectrum, in millimeter wave frequencies, and / or near millimeter wave frequencies to communicate with UE 104. When the gNB 180 operates at or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for path loss and short distance. The base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays to facilitate beamforming.

[0037] The base station 180 may transmit beamformed signals in one or more transmit directions 182' to the UE 104. The UE 104 may receive beamformed signals from the base station 180 in one or more receive directions 182". The UE 104 may also transmit beamformed signals to the base station 180 in one or more transmit directions. The base station 180 may receive beamformed signals from the UE 104 in one or more receive directions. The base station 180 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 180 / UE 104. The transmit direction and receive direction for the base station 180 may be the same or may be different. The transmit direction and receive direction for the UE 104 may be the same or may be different.

[0038] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services in a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to allocate MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area that broadcasts a specific service, and may be responsible for session management (start / end) and for collecting eMBMS-related billing information.

[0039] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a packet switched (PS) streaming (PSS) service, and / or other IP services.

[0040] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other appropriate term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a medical device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, a toaster, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handheld device, a user agent, a mobile client, a client, or some other suitable terminology.

[0041] Refer again Figure 1 , in certain aspects, the UE 104 may be configured to perform a random access procedure including simultaneously monitoring a first message 2PDCCH and a second message 2PDCCH using an enhanced coverage monitoring procedure. For example, the UE 104 may include a random access component 198, and the random access component 198 is configured to perform a random access procedure including simultaneously monitoring a first message 2PDCCH and a second message 2PDCCH using an enhanced coverage monitoring procedure. The UE 104 may send a first random access message 1 from the UE. The UE 104 may send a second random access message 1 from the UE in response to determining that the first random access message 2PDCCH was not received during a first portion of the first RAR window. The UE 104 may simultaneously monitor the first random access message 2PDCCH and the second random access message 2PDCCH during a second portion of the first RAR window, wherein the monitoring procedure for coverage enhancement for the second random access message 2PDCCH is different from the monitoring procedure for the first random access message 2PDCCH. The UE 104 may receive and decode a random access message 2 PDCCH, which is one of the first random access message 2 PDCCH or the second random access message 2 PDCCH. The UE 104 may monitor the random access message 2 PDSCH in response to decoding the random access message 2 PDCCH.

[0042] In certain aspects, the base station 180 may be configured to perform a random access procedure including sending a first message 2PDCCH and a second message 2PDCCH using an enhanced coverage procedure. For example, the base station 180 may include a random access component 199, which is configured to perform a random access procedure including sending a first message 2PDCCH and a second message 2PDCCH using an enhanced coverage procedure. The base station 180 may receive a first random access message 1 from the UE 104. The base station 180 may send the first random access message 2PDCCH during the first RAR window in response to the first random access message 1. The base station 180 may receive the second random access message 1 during the first RAR window. The base station 180 may send the second random access message 2PDCCH during the second part of the first RAR window in response to the second random access message 1 for a coverage enhanced monitoring procedure different from the monitoring procedure for the first random access message 2PDCCH. The base station 180 may transmit a first random access message 2PDSCH based on the first random access message 2PDCCH, and transmit a second random access message 2PDSCH based on the second random access message 2PDCCH.

[0043] Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0044] Figure 2A is an example diagram 200 showing the first subframe within a 5G NR frame structure. Figure 2B is an example diagram 230 showing DL channels within a 5G NR subframe. Figure 2C is an example diagram 250 showing the second subframe within the 5G NR frame structure. Figure 2D is an example diagram 280 showing UL channels within a 5G NR subframe. The 5G / NR frame structure can be frequency division duplex (FDD) (in FDD, for a specific set of subcarriers (carrier system bandwidth) a subframe within a subcarrier set is dedicated to either DL or UL) or can be time division duplex (TDD) (in TDD, for a specific set of subcarriers (carrier system bandwidth) a subframe within a subcarrier set is dedicated to both DL and UL). Figure 2A , Figure 2CIn the example provided, it is assumed that the 5G NR frame structure is TDD, where subframe 4 is configured with slot format 28 (primarily DL), where D is DL, U is UL, and F is flexibly used between DL / UL, and subframe 3 is configured with slot format 1 (for all UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with a slot format (dynamically through DL control information (DCI) or semi-statically / statically through radio resource control (RRC) signaling) through the received slot format indicator (SFI). Note that the description below also applies to a 5G NR frame structure that is TDD.

[0045] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbols on the DL may be cyclic prefix (CP) orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single stream transmission). The number of time slots within a subframe is based on the time slot configuration and numerology. For slot configuration 0, different digital schemes μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and digital scheme μ, there are 14 symbols per slot and 2 per subframe. μ time slots. The subcarrier spacing and symbol length / duration are functions of the digital scheme. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is digital scheme 0 to 4. Thus, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figure 2A-2DAn example is provided for slot configuration 0 (with 14 symbols per slot) and digital scheme μ=2 (with 4 slots per subframe). The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP can have a specific numbering scheme.

[0046] The resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)), which includes 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0047] like Figure 2A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0048] Figure 2BAn example of each DL channel within a subframe of a frame is shown. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. The PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies across the channel bandwidth. The primary synchronization signal (PSS) may be within symbol 2 of a specific subframe in a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a specific subframe in a frame. SSS is used by UE to determine the physical layer cell identification group number and radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the position of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information (such as system information blocks (SIBs)) not sent via the PBCH, and paging messages.

[0049] like Figure 2C As shown in , some of the REs carry DM-RS for channel estimation at the base station (indicated as R for one specific configuration, but other DM-RS configurations are possible). The UE may send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first one or two symbols in the PUSCH. The PUCCH DM-RS may be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of the subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the combs. The SRS may be used by the base station for channel quality estimation to implement frequency-dependent scheduling on the UL.

[0050] Figure 2D An example of various UL channels within a subframe of a frame is shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) information (ACK / negative ACK (NACK)) feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR and / or UCI).

[0051] Figure 3 3 is a block diagram of a base station 310 in an access network communicating with a UE 350. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with upper layer packet data unit (PDU) transmission, error correction through ARQ, concatenation, segmentation and assembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0052] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include: error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation diagram based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from the channel estimator 374 can be used to determine the coding and modulation schemes and for spatial processing. The channel estimate can be derived based on a reference signal and / or channel condition feedback sent by the UE 350. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX can modulate an RF carrier with a corresponding spatial stream for transmission.

[0053] At the UE 350, each receiver 354RX receives a signal through its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be combined into a single OFDM symbol stream by the RX processor 356. Then, the RX processor 356 uses a fast Fourier transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on the channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359 which implements layer 3 and layer 2 functions.

[0054] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the UE 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0055] Similar to the functions described in conjunction with DL transmission performed by the base station 310, the controller / processor 359 provides: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression, and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and assembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0056] Channel estimates derived by the channel estimator 358 from a reference signal or feedback sent by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0057] At the base station 310, the UL transmission is processed in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0058] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0059] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 198 related aspects.

[0060] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 199 related aspects.

[0061] The UE and the base station can perform a four-step random access channel (RACH) procedure for the UE to obtain initial access to the base station. The UE can acquire the cell by reading the synchronization signal block (SSB) and the first system information block (SIB1). SIB1 provides parameters related to initial access. The UE can send msg1 on the physical random access channel (PRACH) with power ramping. If the msg2 random access response (RAR) is not received within the RAR window based on msg1, the UE can send msg1 again with increased power. If the base station detects msg1, the base station sends msg2, which can include two parts: a control part sent on the PDCCH and a data part sent on the PDSCH. The PDCCH is scrambled with a random access radio network temporary identifier (RA-RNTI), which is a function of the RACH opportunity (RO) used by the UE to send msg1. Within the PDSCH, there is a Medium Access Control (MAC) Element (CE) (MAC-CE) which acknowledges the reception of msg1 and grants the UE an uplink (UL) grant to send msg3.

[0062] The UE may monitor the PDCCH to detect downlink control information (DCI) with format 1_0 that is scrambled using the RA-RNTI corresponding to the RO that the UE uses to send msg1. If DCI is detected, the UE may proceed with PDSCH decoding. If a MAC-CE added to the preamble that the UE uses to send msg1 is found in the PDSCH, the UE may regard the MAC-CE as being for the UE. Therefore, the UE may follow the UL grant of the MAC-CE to send the UE-ID in msg3. If multiple UEs use the same preamble sequence to send msg1 in the same RO, there may be conflicts from multiple UEs. The UE may send msg3 on the same resources. The base station may receive one or more msg3s and perform contention resolution. The base station may send msg4.

[0063] PRACH and msg2 PDCCH are two of the bottlenecks in terms of coverage of mmWave 5G systems. For example, PRACH and msg2 PDCCH may be sent before beam training is completed. Therefore, PRACH and msg2 PDCCH may not be received correctly when they are sent. PRACH repetition and / or using different PRACH formats can help increase PRACH coverage. Msg2 PDCCH repetition can help increase msg2 coverage. However, these repetition techniques may increase the use of PRACH and control (e.g., PDCCH) resources.

[0064] In one aspect, the present disclosure may provide improved coverage during a random access procedure by applying coverage enhancement of PRACH and msg2 PDCCH for UEs that may benefit from coverage enhancement. For example, a UE may selectively perform two or more concurrent PDCCH monitorings for msg2 PDCCH using different monitoring procedures on the same time slot and / or time slot set. For example, one of the monitoring procedures may be a coverage enhanced random access procedure.

[0065] The coverage enhanced random access procedure may involve different groupings of monitoring opportunities for blind detection. Multiple concurrent PDCCH monitorings may be associated with the same RA-RNTI or different RA-RNTIs for blind detection. Two concurrent msg2 PDCCH monitorings may include the following two concurrent procedures: 1) conventional msg2 PDCCH monitoring associated with a conventional random access channel (RACH) procedure, and 2) msg2 PDCCH monitoring associated with a second attempted coverage enhanced RACH procedure, wherein if no msg2 PDCCH is received (in response to PRACH) during the corresponding RAR window (or part of the RAR window), the UE initiates a second attempt for the four-step RACH procedure. The second attempted coverage enhanced RACH procedure follows an alternative four-step RACH procedure that includes one or more of the following: an alternative (e.g., coverage enhanced) transmission method for PRACH; an alternative (e.g., coverage enhanced) method for monitoring and receiving msg2 PDCCH; an alternative RAR window; an alternative size of the DCI carried by the msg2 PDCCH; or another interpretation of the DCI content carried by the msg2 PDCCH. In one aspect, use of the second attempted coverage enhanced RACH procedure may depend on previous measurements made by the UE (e.g., if the RSRP on an SSB basis is less than a certain threshold). In some cases, the second attempted coverage enhanced RACH procedure may exceed the PDCCH blind detection limit. The UE may discard a subset of concurrent msg2 monitoring procedures (e.g., the UE may only follow msg2 PDCCH monitoring using the coverage enhancement procedure).

[0066] In one aspect, alternative PDCCH monitoring and reception by a UE may include soft combining of multiple PDCCH candidates on multiple monitoring occasions prior to decoding and blind detection. For example, a base station (e.g., a gNB) repeats a msg2 PDCCH on multiple monitoring occasions (e.g., PDCCH candidates with the same index on multiple time slots). In aggregated monitoring occasions for PDCCH repetition, corresponding PDCCH candidates with the same aggregation level and position (and / or index) are paired together, and the receiver performs soft combining on them prior to decoding and checking a cyclic redundancy check (CRC). The monitoring occasions may be grouped into groups of k consecutive monitoring occasions, and a virtual monitoring occasion for an alternative msg2 PDCCH is formed at a control resource set (CORESET) position in each group of aggregated time slots.

[0067] Figure 44 is an example message exchange diagram 400 illustrating a RACH procedure between a base station 102 and a UE 104 in an access network. The UE 104 may include a UE random access component 198. The base station 102 may include a BS random access component 199.

[0068] With additional reference to Table 1 (below), during operation, due to the occurrence of one or more RACH triggering events 402, the UE 104 may perform an implementation of an NR RACH procedure 404 according to a 4-step NR RACH message flow. Suitable examples of RACH triggering events 402 may include, but are not limited to: (i) the UE 104 performs initial access to transition from the RRC_IDLE state to the RRC_CONNECTED ACTIVE state; (ii) the UE 104 detects downlink (DL) data arrival while in the RRC_IDLE state or the RRC_CONNECTED INACTIVE state; (iii) the UE 104 determines UL data arrival from a higher layer during the RRC_IDLE state or the RRC_CONNECTED INACTIVE state; (iv) the UE 104 performs a handover from another station to the base station 102 during a connected mode of operation; and (v) the UE performs a connection reestablishment procedure, such as a beam failure recovery procedure.

[0069] The NR RACH procedure 404 may be associated with a contention-based random access procedure or with a contention-free random access procedure. In one embodiment, the contention-based NR RACH procedure corresponds to the following RACH triggering events 402: initial access from RRC_IDLE to RRC_CONNECTED ACTIVE; UL data arrival during RRC_IDLE or RRC_CONNECTED INACTIVE; and connection re-establishment. In one embodiment, the contention-free NR RACH procedure corresponds to the following RACH triggering events 402: downlink (DL) data arrival during RRC_IDLE or RRC_CONNECTED INACTIVE; and switching during connected mode of operation.

[0070] When any of the above RACH triggering events 402 occurs, the execution of the NR RACH process 404 may include a 4-step NRRACH message flow (see Figure 4 and Table 1), where UE 104 exchanges messages with one or more base stations 102 to gain access to a wireless network and establish a communication connection. The messages may be referred to as random access messages 1 to 4, RACH messages 1 to 4, or alternatively may be referred to as a PHY channel carrying a message (e.g., message 3 PUSCH).

[0071]

[0072] Table 1 : NR RACH process, including the message and message content sent through the corresponding physical (PHY) channel.

[0073] For example, in a first step of a first RACH procedure, the UE 104 may send a first message (Msg 1) 410, which may be referred to as a random access request message, to one or more base stations 102 via a physical channel (e.g., a physical random access channel (PRACH)). For example, Msg 1 may include one or more of a RACH preamble and a resource request. The UE 104 may send Msg 1 on a RACH opportunity (RO). In one aspect, the RACH preamble may be a relatively long preamble sequence that may be easier for the base station 102 to receive than an OFDM symbol. In one aspect, the UE 104 may select a beam for transmitting Msg 1 based on a received synchronization signal block (SSB) sent by the base station 102.

[0074] In a second step, the base station 102 may respond to the Msg 1 by sending a second message (Msg2) that may be referred to as a random access response (RAR) message. The RAR message may include a control portion 420 (e.g., a PDCCH portion) and a data portion 430 (e.g., a PDSCH portion). In one aspect, the UE 104 may monitor the PDCCH during the first RAR window 460 based on the first Msg 1 410 to monitor the PDCCH portion 420 of the first RAR message as a DCI format 1_0 having a CRC scrambled by the RA-RNTI corresponding to the first Msg 1 410, and receive the PDSCH portion 430 of the RAR message as a transport block in the corresponding PDSCH within the RAR window 460.

[0075] In one aspect, to improve coverage of the PRACH and / or Msg 2 PDCCH, a coverage-enhanced RACH process may be used concurrently with the first RACH process. For example, in response to determining that the PDCCH portion 420 of the first RAR message was not received during the first portion 462 of the first RAR window 460, the UE 104 may send a second Msg 1 412 on the PRACH. That is, the UE 104 may be configured to initiate a second concurrent coverage-enhanced RACH process when such a process may be helpful. For example, the UE 104 may send the second Msg 1 412 in response to a measurement made by the UE 104 (e.g., if the RSRP based on the SSB is less than a certain threshold). The UE 104 may use a coverage-enhanced transmission method for the second Msg 1 412. For example, the UE 104 may repeat the transmission of the second Msg 1 412 on different ROs.

[0076] The base station 102 may respond to the second Msg1 412 by sending a second control portion 422 (e.g., a PDCCH portion) of the second Msg 2. The base station 102 may send the second PDCCH portion 422 of the second message 2 using a coverage enhancement transmission technique. For example, the base station 102 may repeat the transmission of the second PDCCH portion 422 into one or more repetitions 424. In an embodiment, the base station 102 may repeat the Msg 2 on corresponding PDCCH candidates within the random access search space on consecutive time slots. In an aspect, the BS 102 may determine whether to repeat the PDCCH portion of the Msg 2 based on the second Msg 1 412. For example, the UE 104 may indicate a request for coverage enhancement based on one or a combination of the following: the time resource of the Msg 1, the format of the Msg 1, or the sequence of the Msg 1. For example, a subset of available PRACH sequences may be associated with coverage enhancement.

[0077] For example, BS 102 may determine that the preamble of the second message 1 412 follows a pattern for requesting coverage enhancement. In one embodiment, the base station 102 may repeat the PDCCH portion of Msg 2 using different refined beams. In one aspect, each different refined beam may be a sub-beam of the beam corresponding to Msg 1. A sub-beam may refer to a beam at a lower level in a hierarchical set of beams. For example, a layer 1 (L1) beam may cover multiple L2 beams, and each L2 beam may cover multiple L3 beams. In one embodiment, the beam corresponding to Msg 1 is an L2 beam, and each different refined beam is an L3 beam.

[0078] As another example, the second PDCCH portion 422 may utilize an alternative size of the DCI or an alternative interpretation of the contents of the DCI. In one aspect, the base station 102 may transmit the second PDCCH portion 422 and any repetitions 424 during the second portion 464 of the first RAR window 460. In some implementations, a second RAR window 470 and any repetitions 424 for the second PDCCH portion 422 may be defined based on the second Msg 1 412. The second RAR window 470 may overlap with the second portion 464 of the RAR window 460.

[0079] UE 104 can monitor the PDCCH part 420 of the first Msg 2 and the second PDCCH part 422 of the second Msg 2 simultaneously during the second part 464 of the RAR window 460. UE 104 can use the monitoring process of coverage enhancement to monitor the second PDCCH part 422. For example, UE 104 can perform soft combination on the PDCCH candidates repeated twice or more for the second PDCCH part 422. UE 104 can perform blind detection after the soft combination of the PDCCH candidates. That is, UE 104 can receive a signal corresponding to each PDCCH candidate, soft combine the signal received for each PDCCH candidate, and perform blind detection for DCI on the combined signal. Accordingly, UE 104 may be more likely to successfully detect Msg 2PDCCH. As another example, UE can monitor the alternative size of DCI. As another example, UE can apply alternative interpretation to the content of DCI received according to the monitoring process of coverage enhancement.

[0080] The base station 102 may transmit a first data portion 430 (e.g., a PDSCH portion) of Msg 2 and a second data portion 432 (e.g., a PDSCH portion) of Msg 2. Because the UE 104 may successfully decode either the first PDCCH portion 420 or the second PDCCH portion 422, transmitting both PDSCH portions 430, 432 may allow the UE 104 to receive the complete Msg 2 based on the PDCCH portions 420, 422.

[0081] The UE 104 may receive a transport block in a corresponding PDSCH indicated by one of the first PDCCH part 420 or the second PDCCH part 422 being successfully decoded. The UE 104 may decode the transport block and parse the transport block to obtain a random access preamble identifier (RAPID) associated with Msg 1. For example, Msg 2 may include one or more of the following: a detected preamble identifier (ID), a timing advance (TA) value, a temporary cell radio network temporary identifier (TC-RNTI), a fallback indicator, an UL grant, and a DL grant. If the UE 104 identifies a RAPID corresponding to the first Msg 1 410 or the second Msg 1 412 in the transport block, the UE 104 may identify a corresponding UL grant for Msg 3. This is referred to as a RAR UL grant in the physical layer.

[0082] In response to receiving Msg 2 , UE 104 sends a third message (Msg 3 ) 440 to base station 102 via a physical uplink channel (eg, PUSCH) based on the RARUL grant provided in Msg 2 of the selected serving base station 102 .

[0083] In response to receiving Msg 3 440, base station 102 may send a fourth message (Msg4) 450, which may be referred to as a contention resolution message, to UE 104 via PDCCH and PDSCH. For example, message 4 may include a cell radio network temporary identifier (C-RNTI) for use by UE 104 in subsequent communications.

[0084] In some example scenarios, a collision may occur between two or more UEs 104 requesting access. For example, two or more UEs 104 may send Msg 1 with the same RACH preamble, because the number of RACH preambles may be limited and may be randomly selected by each UE 104 in a contention-based NR RACH process. Therefore, each colliding UE 104 that selects the same RACH preamble will receive the same temporary C-RNTI and the same UL grant, and therefore each UE 104 may send a similar Msg 3. In this case, the base station 102 may resolve the collision in one or more ways. In the first scenario, the corresponding Msg 3 from each colliding UE 104 may interfere with another Msg 3, so the base station 102 may not send Msg 4. Each UE 104 will then resend Msg 1 using a different RACH preamble. In the second scenario, the base station 102 may successfully decode one of the conflicting Msg3s and send an ACK message to the UE 104 corresponding to the successfully decoded Msg3. In the third scenario, the base station 102 may successfully decode Msg3 from each conflicting UE 104 and then send Msg4 with a contention resolution identifier (e.g., an identifier associated with one of the UEs) to each conflicting UE. Each conflicting UE 104 receives Msg4, decodes Msg4, and determines whether the UE 104 is the correct UE by successfully matching or identifying the contention resolution identifier. Such a problem may not occur in a contention-free NR RACH process because in that case, the base station 102 can inform the UE 104 which RACH preamble to use.

[0085] Figure 55 is a resource diagram 500 showing resources for receiving the PDCCH portion of Msg 2 using a coverage enhanced reception process (e.g., for the second PDCCH portion 422 and the repetition 424). Resources 510 may be located within consecutive time slots 520, 522, 524, and 526, which may be during a RAR window. The base station 102 may repeat the msg2 PDCCH on multiple monitoring occasions (e.g., PDCCH candidates with the same index on multiple time slots). For example, the base station 102 may send repetitions of Msg 2 on PDCCH candidates 530, 532, 534, and 536 in each time slot 520, 522, 524, and 526, for example using different refined beams. The PDCCH candidates 530, 532, 534, and 536 may be located within a random access search space portion of a control resource set (CORESET) 540. That is, each PDCCH candidate 530, 532, 534, and 536 may include the same data, but sent with different beamforming parameters. For example, the base station 102 may send each repetition of Msg 2 on the PDCCH candidates 530, 532, 534, and 536 in the corresponding time slots 520, 522, 524, and 526 using a different L3 refined beam. The L3 refined beam may be based on the L2 beam used for Msg 1. That is, the base station 102 may generate different sub-beams of the L2 beam to try to improve the reception of Msg 2.

[0086] In one aspect, UE 104 may perform an enhanced monitoring process on PDCCH candidates 530, 532, 534, and 536. For example, UE 104 may perform soft combining on signals corresponding to multiple repeated PDCCH candidates. In the aggregated monitoring occasion for PDCCH repetition, corresponding PDCCH candidates with the same aggregation level and position (and / or index) may be grouped together. For example, the monitoring occasions may be grouped into groups of k consecutive monitoring occasions, and the CORESET positions in each group of aggregated time slots may form a virtual monitoring occasion for an alternative Msg 2PDCCH. The receiver may perform soft combining on all monitoring occasions within the virtual monitoring occasion before decoding and checking the CRC. UE 104 may perform blind detection of DCI format 1_0 on the soft-combined combined signal. Therefore, the possibility of successful detection may be increased by soft combining.

[0087] Figure 6600 is a flow chart of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., UE 104; apparatus 702; cellular baseband processor 704, which may include memory 360, and which may be the entire UE 350 or a component of UE 350, such as TX processor 368, RX processor 356 and / or controller / processor 359). One or more of the illustrated operations may be omitted, swapped, or performed simultaneously. Optional aspects are shown with dashed lines. The method may allow a UE to simultaneously perform two monitoring processes for a random access message 2 PDCCH, thereby allowing the UE to improve coverage of the message 2 PDCCH.

[0088] At 610, the UE may send a first random access message 1. For example, 610 may be performed by a random access component 740 of the apparatus 702. The UE may send a first random access message 1 to a base station. For example, the random access component 740 may select a first random access preamble for transmission on the PRACH. The random access component 740 may provide the first random access preamble to the transmission component 734 for transmission.

[0089] At 620, the UE may send a second random access message 1 from the UE. For example, 620 may be performed by a random access component 740 of the apparatus 702. The UE may send the second random access message 1 in response to determining that the first random access message 2 PDCCH was not received during the first portion of the first RAR window. In some aspects, the UE may determine whether the first random access message 2 PDCCH (e.g., the PDCCH portion 420) has been received during the first portion of the RAR window. When the PDCCH portion is not received during the first portion of the RAR window, the UE may indicate to the random access component 740. The UE may select a second random access preamble for the second message 1 to be transmitted on the PRACH. The second random access preamble may be the same as or different from the first random access preamble.

[0090] In some aspects, for example, at 622, the UE may utilize a coverage enhancement transmission method to transmit a second random access message 1. For example, 622 may be performed by a random access component 740 of the apparatus 702. In some aspects, the coverage enhancement transmission method may include using different beams and / or multiple repetitions. In some aspects, the UE may transmit the second random access message 1 on different beams. For example, at 624, the random access component 740 may repeat the transmission of the second message 1. Each transmission may be on a different beam.

[0091] At 630, the UE may simultaneously monitor the first random access message 2 PDCCH and the second random access message 2 PDCCH during the second portion of the first RAR window. For example, 630 may be performed by the monitoring component 742 of the device 702. In some aspects, the monitoring process for coverage enhancement of the second random access message 2 PDCCH may be different from the monitoring process for the first random access message 2 PDCCH. For example, the monitoring component 742 may monitor the first message 2 PDCCH using a standard monitoring process (e.g., blind decoding each PDCCH candidate within the RAR window). The monitoring component 742 may monitor the second message 2 PDCCH using a coverage enhancement monitoring process. For example, at 632, for the coverage enhancement monitoring process, the monitoring component 742 may include soft combining multiple PDCCH candidates on multiple monitoring occasions before decoding the second random access message 2. For example, the monitoring component 742 may add together the log-likelihood ratios (LLRs) of the received signals for the PDCCH candidates before performing a decoding process on the combined signal. As another example, at 634, the monitoring component 742 can monitor an alternative size of the DCI for the second random access message 2PDCCH. The alternative size can be based on different configurations of the DCI format for the second random access message 2PDCCH. Similarly, at 636, the monitoring component 742 can determine an alternative interpretation of the DCI for the second random access message 2PDCCH. The alternative interpretation can be based on different configurations of the DCI format for the second random access message 2PDCCH. In some cases, the first random access message 2PDCCH and the second random access message 2PDCCH can be monitored simultaneously and more PDCCH candidates and / or blind detection operations can be used than the defined restrictions. In such a case, the monitoring component 742 can discard a subset of concurrent PDCCH candidates for the monitoring process for the first random access message 2PDCCH at 638. That is, the monitoring component 742 can allocate processing resources to the monitoring process for coverage enhancement, which may be more likely to detect the random access message 2PDCCH.

[0092] At 640, the UE may receive and decode the random access message 2 PDCCH. For example, 640 may be performed by a decoding component 744 of the apparatus 702. In some aspects, the random access message 2 PDCCH may be one of a first random access message 2 PDCCH or a second random access message 2 PDCCH. For example, the decoding component 744 receives and decodes the random access message 2 first PDSCH portion or the PDSCH portion. For example, the decoding component 744 may successfully decode the PDCCH portion to obtain a DCI including time domain and frequency domain resources for the PDSCH portion. Therefore, the decoding component 744 may instruct the receiving component 730 to receive a signal for the PDSCH portion on the indicated resources.

[0093] At 650, the UE may monitor the random access message 2 PDSCH. For example, 650 may be performed by the PDSCH component 746 of the apparatus 702. The UE may monitor the random access message 2 PDSCH in response to decoding the random access message 2 PDCCH. For example, the PDSCH component 746 receives a signal for the PDSCH portion indicated by the successfully decoded message 2 PDCCH.

[0094] Figure 7 700 is an example diagram illustrating a hardware implementation of an apparatus 702. The apparatus 702 is a UE and includes a cellular baseband processor 704 (also referred to as a modem) coupled to a cellular RF transceiver 722 and one or more subscriber identity modules (SIM) cards 720, an application processor 706 coupled to a secure digital (SD) card 708 and a screen 710, a Bluetooth module 712, a wireless local area network (WLAN) module 714, a global positioning system (GPS) module 716, and a power supply 718. The cellular baseband processor 704 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 722. The cellular baseband processor 704 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-transitory. The cellular baseband processor 704 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the cellular baseband processor 704, causes the cellular baseband processor 704 to perform the various functions described above. The computer-readable medium / memory may also be used to store data operated on by the cellular baseband processor 704 when executing software. The cellular baseband processor 704 also includes a receiving component 730, a communication manager 732, and a transmitting component 734. The communication manager 732 includes one or more of the components shown. The components within the communication manager 732 may be stored in the computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 704. The cellular baseband processor 704 may be a component of the UE 350 and may include at least one of the TX processor 368, the RX processor 356, and the controller / processor 359, and / or the memory 360. In one configuration, the device 702 may be a modem chip and include only the cellular baseband processor 704, and in another configuration, the device 702 may be the entire UE (e.g., see Figure 3 350) and includes additional modules of the device 702 discussed above.

[0095] The communication manager 732 includes a random access component 740 configured to send a first random access message, for example, as described in conjunction with Figure 6 The random access component 740 may be configured to send a second random access message 1 from the UE, for example, as described in conjunction with Figure 6 The random access component 740 may be configured to send the second random access message 1 using a coverage enhancement transmission method, for example, as described in conjunction with Figure 6 The random access component 740 may be configured to repeat the transmission of the second message 1, for example, as described in conjunction with Figure 6 The communication manager 732 also includes a monitoring component 742 configured to simultaneously monitor the first random access message 2PDCCH and the second random access message 2PDCCH during the second portion of the first RAR window, for example, as described in conjunction with Figure 6 The monitoring component 742 may be configured to soft combine multiple PDCCH candidates on multiple monitoring occasions before decoding the second random access message 2, for example, as combined with Figure 6 The monitoring component 742 may be configured to monitor an alternative size of the DCI for the second random access message 2PDCCH, for example, as described in conjunction with Figure 6 The monitoring component 742 may be configured to determine an alternative interpretation of the DCI for the second random access message 2PDCCH, for example, as combined with Figure 6 The monitoring component 742 may be configured to discard a subset of concurrent PDCCH candidates for the monitoring process for the first random access message 2 PDCCH, for example, as described in conjunction with Figure 6 The communication manager 732 also includes a decoding component 744, which is configured to receive and decode the random access message 2PDCCH, for example, as described in conjunction with Figure 6 The communication manager 732 also includes a PDSCH component 746, which is configured to monitor the random access message 2PDSCH, for example, as described in conjunction with Figure 6 of 650 as described.

[0096] The apparatus may include performing the above Figure 6 The flowchart of the algorithm in each box has additional components. Figure 6 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of those components. The component may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0097] In one configuration, the device 702, and in particular the cellular baseband processor 704, includes a unit for sending a first random access message 1 from a UE. The device includes a unit for sending a second random access message 1 from the UE in response to determining that the first random access message 2PDCCH was not received during a first portion of a first RAR window. The device includes a unit for simultaneously monitoring the first random access message 2PDCCH and the second random access message 2PDCCH during a second portion of the first RAR window. The monitoring process for coverage enhancement of the second random access message 2PDCCH is different from the monitoring process for the first random access message 2PDCCH. The device includes a unit for receiving and decoding a random access message 2PDCCH, the random access message 2PDCCH being one of the first random access message 2PDCCH or the second random access message 2PDCCH. The device includes a unit for monitoring the random access message 2PDSCH in response to decoding the random access message 2PDCCH. The unit for sending the second random access message 1 is configured to utilize a coverage enhancement transmission method. The unit for sending the second random access message 1 is configured to repeat the transmission of the second random access message 1. The device also includes a unit for soft combining multiple PDCCH candidates on multiple monitoring occasions before decoding the second random access message 2PDCCH. The device also includes a unit for monitoring the alternative size of the DCI for the second random access message 2PDCCH. The device also includes a unit for determining an alternative interpretation of the DCI for the second random access message 2PDCCH. The device also includes a unit for discarding a subset of concurrent PDCCH candidates for the monitoring process for the first random access message 2PDCCH. The aforementioned unit may be one or more aforementioned components of the device 702 configured to perform the functions described by the aforementioned unit. As described above, the device 702 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Therefore, in one configuration, the aforementioned unit may be a TX processor 368, an RX processor 356, and a controller / processor 359 configured to perform the functions described by the aforementioned unit.

[0098] Figure 8 800 is a flow chart of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., base station 102 / 180; apparatus 902; baseband unit 904, which may include memory 376, and which may be the entire base station 310 or a component of base station 310, such as TX processor 316, RX processor 370 and / or controller / processor 375). One or more of the illustrated operations may be omitted, swapped, or performed simultaneously. Optional aspects are shown with dashed lines. The method may allow a base station to send a message 2 PDCCH for two concurrent monitoring processes, thereby enhancing coverage of the message 2 PDCCH.

[0099] In some aspects, for example, at 810, the base station may send a configuration indicating a monitoring procedure for coverage enhancement. For example, 810 may be performed by the configuration component 940 of the apparatus 902. The base station may send a configuration indicating a monitoring procedure for coverage enhancement to the UE. For example, the configuration may indicate a duration of a first portion of a RAR window before the UE may send a second random access message 1, a repetition pattern of a second random access message 2 PDCCH, a duration of a second RAR window, an alternative DCI size, or an alternative DCI interpretation. The base station may send the configuration indicating a monitoring procedure for coverage enhancement as system information or an RRC configuration message.

[0100] At 820, the base station may receive a first random access message 1 from the UE. For example, 820 may be performed by the random access component 942 of the apparatus 902. In some aspects, the base station may receive a signal for the PRACH during the RO. The base station may provide the PRACH to the random access component 942 for decoding. The random access component 942 may determine the PRACH preamble sent by the UE and determine the RAR window based on the RO.

[0101] At 830, the base station may send a first random access message 2 PDCCH during the first RAR window. For example, 830 may be performed by the random access component 942 of the apparatus 902. The base station may send the first random access message 2 PDCCH during the first RAR window in response to the first random access message 1. The base station may send the first random access message 2 PDCCH (e.g., the first PDCCH portion 420) during the first RAR window in response to the first Msg 1. The base station may schedule the first PDCCH portion during the monitoring opportunity of the first RAR window according to the first monitoring process.

[0102] At 840, the base station may receive a second random access message 1. For example, 840 may be performed by a random access component 942 of the apparatus 902. In some aspects, the base station may receive a second random access message 1 from the UE in response to the UE determining that the UE did not receive the first random access message 2 PDCCH during the first portion of the first RAR window. In some aspects, for example, at 842, the base station may utilize a coverage-enhanced capture method. For example, 842 may be performed by a random access component 942. The random access component 942 may be configured to utilize a coverage-enhanced capture method. For example, the second random access message 1 may be repeated, and the random access component 942 may combine multiple ROs to detect the second random access message 1.

[0103] At 850, the base station may send a second random access message 2 PDCCH. For example, 850 may be performed by the random access component 942 of the device 902. The base station may send a second random access message 2 PDCCH for a monitoring process for coverage enhancement in response to the second random access message 1 during the second part of the first RAR window. The monitoring process for coverage enhancement may be different from the monitoring process for the first random access message 2 PDCCH. In some aspects, for example, the base station may include a coverage enhancement component 946 that determines whether to send a second random access message 2 according to a monitoring process for coverage enhancement. For example, the coverage enhancement component 946 may receive a PRACH preamble for the second random access message 1 and determine whether the second random access message 1 is a request for enhanced coverage. For example, when the PRACH preamble is repeated in accordance with a pattern specified in an enhanced coverage configuration, the coverage enhancement component 946 may determine that enhanced coverage is requested. The coverage enhancement component 946 may provide a signal to the random access component 942 indicating that the second random access message 1 has requested enhanced coverage. The random access component 942 may then send a second random access message 2PDCCH according to the coverage enhancement monitoring procedure.

[0104] In some aspects, for example, at 852, the base station may send a second random access message 2 on a different monitoring opportunity group than the first random access message 2 PDCCH. For example, 852 may be performed by the random access component 942 of the device 902. In some aspects, for example, at 854, the base station may send the second random access message 2 PDCCH using a different RA-RNTI than the first random access message 2 PDCCH. For example, 854 may be performed by the random access component 942 of the device 902. In some aspects, for example, at 856, the base station may repeat the second random access message 2 PDCCH on multiple monitoring opportunities. For example, 856 may be performed by the random access component 942 of the device 902. In some aspects, for example, at 858, the base station may send a second random access message 2 PDCCH on corresponding PDCCH candidates with the same aggregation level and position within multiple monitoring opportunities. For example, 858 may be performed by the random access component 942 of the device 902. In some aspects, the base station may send an alternative size of DCI for the second random access message 2PDCCH, for example at 860. For example, 860 may be performed by the random access component 942 of the apparatus 902. The second random access message 2PDCCH may have an alternative interpretation compared to the first random access message 2PDCCH.

[0105] At 870, the base station may send a first random access message 2PDSCH based on the first random access message 2PDCCH and send a second random access message 2PDSCH based on the second random access message 2PDCCH. For example, 870 may be performed by a PDSCH component 944 of the apparatus 902. For example, the PDSCH component 902 may send a first random access message 2PDSCH (e.g., a first Msg 2PDSCH portion 430) based on the first random access message 2PDCCH (e.g., a first Msg 2PDCCH portion 420) and send a second random access message 2PDSCH (e.g., a second Msg 2PDSCH portion 432) based on the second random access message 2PDCCH (e.g., a second Msg 2PDCCH portion 422). The PDSCH component 944 may receive an indication of a PDSCH resource from the random access component 942, which sends the indication in the DCI. The PDSCH component 944 may generate a RAR message including a UL grant for Msg 3.

[0106] Fig. 9 900 is an example diagram showing a hardware implementation for an apparatus 902. The apparatus 902 is a BS and includes a baseband unit 904. The baseband unit 904 can communicate with the UE 104 via a cellular RF transceiver 922. The baseband unit 904 may include a computer-readable medium / memory. The baseband unit 904 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 904, enables the baseband unit 904 to perform the various functions described above. The computer-readable medium / memory may also be used to store data that is operated on by the baseband unit 904 when executing the software. The baseband unit 904 also includes a receiving component 930, a communication manager 932, and a sending component 934. The communication manager 932 includes one or more of the components shown. The components within the communication manager 932 may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 904. The baseband unit 904 may be a component of the BS 310 and may include the TX processor 316 , the RX processor 370 , and at least one of the controller / processor 375 , and / or the memory 376 .

[0107] The communication manager 932 includes a configuration component 940 that can send a configuration indicating a monitoring process for coverage enhancement, such as in conjunction with Figure 8 The communication manager 932 also includes a random access component 942, which receives a first random access message 1 from the UE, for example, as described in conjunction with Figure 8As described in 820. The random access component 942 can be configured to send a first random access message 2PDCCH during the first RAR window, for example, as combined with Figure 8 The random access component 942 may be configured to receive a second random access message 1, for example, as described in conjunction with Figure 8 The random access component 942 may be configured to utilize a coverage enhancement acquisition method, such as in conjunction with Figure 8 As described in 842. The random access component 942 can be configured to send a second random access message 2PDCCH, for example, as combined Figure 8 The random access component 942 may be configured to send the second random access message 2 on a different monitoring opportunity group than the first random access message 2 PDCCH, for example, as described in conjunction with Figure 8 The random access component 942 may be configured to send a second random access message 2PDCCH using a different RA-RNTI than the first random access message 2PDCCH, for example, as described in conjunction with Figure 8 As described in 854. The random access component 942 can be configured to repeat the second random access message 2PDCCH on multiple monitoring occasions, for example, as combined Figure 8 As described in 856. The random access component 942 can be configured to send a second random access message 2PDCCH on corresponding PDCCH candidates with the same aggregation level and position within multiple monitoring opportunities, for example, as combined Figure 8 As described in 858. The random access component 942 can be configured to send an alternative size of the DCI for the second random access message 2PDCCH, for example, as combined Figure 8 The communication manager 932 also includes a PDSCH component 944, which can send a first random access message 2PDSCH based on the first random access message 2PDCCH and send a second random access message 2PDSCH based on the second random access message 2PDCCH, for example, as combined with Figure 8 The communication manager 932 also includes a coverage enhancement component 946 that determines whether to send a second random access message 2 according to a monitoring process for coverage enhancement, for example, as described in conjunction with Figure 8 The coverage enhancement component 946 may be configured to receive a PRACH preamble for a second random access message 1 and determine whether the second random access message 1 is a request for enhanced coverage, for example, as described in conjunction with Figure 8The coverage enhancement component 946 may be configured to determine that enhanced coverage is requested when the PRACH preamble is repeated following a pattern specified in an enhanced coverage configuration, for example, as described in conjunction with Figure 8 The coverage enhancement component 946 may be configured to indicate that the second random access message 1 has requested enhanced coverage, for example, as described in conjunction with Figure 8 of 850 as described.

[0108] The apparatus may include performing the above Figure 8 The flowchart of the algorithm in each box has additional components. Figure 8 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of those components. The component may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0109] In one configuration, the apparatus 902, and in particular the baseband unit 904, comprises a unit for receiving a first random access message 1 from a UE. The apparatus comprises a unit for sending a first random access message 2PDCCH during a first RAR window in response to the first random access message 1. The apparatus comprises a unit for receiving a second random access message 1 during the RAR window. The apparatus comprises a unit for sending a second random access message 2PDCCH during a second part of the first RAR window in response to the second random access message 1 for a monitoring process for coverage enhancement that is different from the monitoring process for the first random access message 2PDCCH. The apparatus comprises a unit for sending a first random access message 2PDSCH based on the first random access message 2PDCCH and sending a second random access message 2PDSCH based on the second random access message 2PDCCH. The unit for receiving the second random access message 1 is configured to utilize a coverage enhancement reception method. The unit for sending the second random access message 2PDCCH is configured to send on a monitoring opportunity group different from the first random access message 2PDCCH. The unit for sending the second random access message 2PDCCH is configured to send the second random access message 2PDCCH using a random access radio network temporary identifier (RA-RNTI) different from the first random access message 2PDCCH. The unit for sending the second random access message 2PDCCH is configured to repeat the second random access message 2PDCCH on multiple monitoring occasions. The device for sending the second random access message 2PDCCH is configured to send the second random access message 2PDCCH on the corresponding PDCCH candidates with the same aggregation level and position within multiple monitoring occasions. The unit for sending the second random access message 2PDCCH is configured to send an alternative size of the DCI for the second random access message 2PDCCH. The aforementioned unit may be one or more aforementioned components of the device 902 configured to perform the functions set forth by the aforementioned unit. As described above, the device 902 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Thus, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the aforementioned means.

[0110] It is to be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary method. It is to be understood that the specific order or hierarchy of the blocks in the process / flowchart may be rearranged according to design preferences. In addition, some blocks may be combined or omitted. The attached method claims present the elements of the various blocks in an exemplary order and are not intended to be limited to the specific order or hierarchy presented.

[0111] The following examples are merely illustrative and may be combined with other embodiments or aspects of the teachings described herein without limitation.

[0112] Aspect 1 is a wireless communication method at a UE, comprising: sending a first random access message 1 from the UE; in response to determining that the first random access message 2PDCCH is not received during the first part of the first RAR window, sending a second random access message 1 from the UE; simultaneously monitoring the first random access message 2PDCCH and the second random access message 2PDCCH during the second part of the first RAR window, wherein the monitoring process for coverage enhancement of the second random access message 2PDCCH is different from the monitoring process for the first random access message 2PDCCH; receiving and decoding the random access message 2PDCCH, the random access message 2PDCCH being one of the first random access message 2PDCCH or the second random access message 2PDCCH; and in response to decoding the random access message 2PDCCH, monitoring the random access message 2PDSCH.

[0113] In aspect 2, the method according to aspect 1 further includes: the monitoring process for the second random access message 2PDCCH includes a monitoring opportunity grouping different from the monitoring process for the first random access message 2PDCCH.

[0114] In aspect 3, the method according to any aspect of aspect 1 or 2 further includes: the monitoring process for the second random access message 2PDCCH includes a different RA-RNTI from the monitoring process for the first random access message 2PDCCH.

[0115] In aspect 4, the method according to any of aspects 1-3 further includes: sending the second random access message 1 includes utilizing a coverage enhancement transmission method.

[0116] In aspect 5, the method according to any of aspects 1-4 further includes: sending the second random access message 1 includes repeating the transmission of the second random access message 1.

[0117] In aspect 6, the method according to any aspect of aspects 1-5 further includes: the coverage enhanced monitoring process includes: before decoding the second random access message 2PDCCH, soft combining multiple PDCCH candidates at multiple monitoring occasions.

[0118] In aspect 7, the method according to any of aspects 1-6 further comprises: corresponding PDCCH candidates having the same aggregation level and position in different monitoring occasions are combined.

[0119] In aspect 8, the method according to any of aspects 1-7 further includes: the monitoring process of coverage enhancement includes a second RAR window overlapping the second part of the first RAR window.

[0120] In aspect 9, the method according to any aspect 1-8 further includes: the monitoring process of coverage enhancement includes: monitoring the alternative size of the DCI used for the second random access message 2PDCCH.

[0121] In aspect 10, the method according to any of aspects 1-9 further comprises: the monitoring process of coverage enhancement comprises: determining an alternative interpretation of the DCI for the second random access message 2PDCCH.

[0122] In aspect 11, the method described in any aspect of aspects 1-10 also includes: the number of PDCCH candidates included in the monitoring process for the first random access message 2 PDCCH and the monitoring process for the second random access message 2 is greater than the limit; and also includes: discarding a subset of concurrent PDCCH candidates for the monitoring process for the first random access message 2 PDCCH.

[0123] Aspect 12 is a device comprising one or more processors and one or more memories, the one or more memories being in electronic communication with the one or more processors and storing instructions executable by the one or more processors to cause the device to implement the method in any of aspects 1-11.

[0124] Aspect 13 is a system or an apparatus comprising means for implementing the method in any of aspects 1-11 or implementing the apparatus in any of aspects 1-11.

[0125] Aspect 14 is a non-transitory computer-readable storage medium storing instructions executable by one or more processors to cause the one or more processors to implement the method in any of aspects 1-11.

[0126] Aspect 15 is a wireless communication method at a base station, comprising: receiving a first random access message 1 from a UE; in response to the first random access message 1, sending a first random access message 2PDCCH during a first RAR window; receiving a second random access message 1 during the RAR window; in response to the second random access message 1, sending a second random access message 2PDCCH during a second part of the first RAR window for a coverage enhanced monitoring process different from the monitoring process used for the first random access message 2PDCCH; and sending a first random access message 2PDSCH based on the first random access message 2PDCCH, and sending a second random access message 2PDSCH based on the second random access message 2PDCCH.

[0127] In aspect 16, the method according to aspect 15 further comprises: sending the second random access message 2PDCCH comprises: sending on a monitoring occasion group different from the first random access message 2PDCCH.

[0128] In aspect 17, the method according to aspect 15 or 16 further comprises: sending the second random access message 2 PDCCH comprises: sending the second random access message 2 PDCCH using a different RA-RNTI from the first random access message 2 PDCCH.

[0129] In aspect 18, the method according to any of aspects 15-17 further comprises: receiving the second random access message 1 comprises utilizing a coverage enhancement reception method.

[0130] In aspect 19, the method according to any of aspects 15-18 further comprises: repeating the second random access message 1.

[0131] In aspect 20, the method according to any of aspects 15-19 further comprises: sending the second random access message 2 PDCCH comprises: repeating the second random access message 2 PDCCH at a plurality of monitoring occasions.

[0132] In aspect 21, the method according to any of aspects 15-20 further comprises: sending the second random access message 2 PDCCH comprises: sending the second random access message 2 PDCCH on corresponding control part candidates having the same aggregation level and position within a plurality of monitoring occasions.

[0133] In aspect 22, the method according to any of aspects 15-21 further comprises: the monitoring process of coverage enhancement includes a second RAR window overlapping the second part of the first RAR window.

[0134] In aspect 23, the method according to any of aspects 15-22 further comprises: sending the second random access message 2 PDCCH comprises: sending an alternative size of the DCI for the second random access message 2 PDCCH.

[0135] In aspect 24, the method according to any of aspects 15-23 further comprises: the second random access message 2PDCCH having an alternative interpretation of DCI.

[0136] In aspect 25, the method according to any of aspects 15-24 further comprises: sending a configuration indicating a monitoring process for coverage enhancement.

[0137] Aspect 26 is a device comprising one or more processors and one or more memories in electronic communication with the one or more processors and storing instructions executable by the one or more processors to cause the device to implement the method in any of aspects 15-25.

[0138] Aspect 27 is a system or an apparatus comprising means for implementing the method in any of aspects 15-25 or the apparatus in any of aspects 1-11.

[0139] Aspect 28 is a non-transitory computer-readable storage medium storing instructions executable by one or more processors to cause the one or more processors to implement the method of any of Aspects 15-25.

[0140] The above description is provided so that any person skilled in the art can understand the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but to be given the full scope consistent with the language claims, wherein, unless explicitly stated, references to singular elements are not intended to mean "one and only one", but "one or more". Terms such as "if", "when ......" and "while" should be interpreted as meaning "under the conditions of ......", rather than meaning a direct temporal relationship or reaction. That is, these phrases, such as "when ......", do not mean immediate action in response to the occurrence of an action or during the occurrence of an action, but only mean that an action will occur if the condition is met, but no specific or immediate time constraints are required for the occurrence of the action. The word "exemplary" is used herein to mean "used as an example, instance or illustration". Any aspect described as "exemplary" in this article is not necessarily interpreted as preferred or advantageous over other aspects. Unless otherwise specifically stated, the term "some" refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be only A, only A, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout the present disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. The words “module,” “mechanism,” “element,” “device,” etc. may not be substitutes for the word “unit.” Thus, no claim element should be construed as a functional unit unless the element is explicitly recited using the phrase “a means for….”

Claims

1. A method of wireless communication at a user equipment (UE), comprising: Sending a first random access message 1 from the UE; in response to determining that a first random access message 2 control part is not received during a first part of a first random access response (RAR) window, sending a second random access message 1 from the UE; monitoring the first random access message 2 control part and the second random access message 2 control part simultaneously during the second part of the first RAR window, wherein the monitoring process for coverage enhancement of the second random access message 2 control part is different from the monitoring process for the first random access message 2 control part, wherein the monitoring process for coverage enhancement comprises at least one of the following: soft combining a plurality of control part candidates at a plurality of monitoring occasions, monitoring an alternative size of downlink control information (DCI) for the second random access message 2 control part, or determining an alternative interpretation of the DCI for the second random access message 2 control part; receiving and decoding a random access message 2 control part, the random access message 2 control part being one of the first random access message 2 control part or the second random access message 2 control part; and In response to decoding the random access message 2 control portion, the random access message 2 data portion is monitored.

2. The method according to claim 1, wherein: The monitoring procedure for coverage enhancement of the control part of the second random access message 2 includes a monitoring opportunity grouping different from the monitoring procedure for the control part of the first random access message 2.

3. The method according to claim 1, wherein: The monitoring procedure for coverage enhancement of the second random access message 2 control part includes a different random access radio network temporary identifier (RA-RNTI) than the monitoring procedure for the first random access message 2 control part.

4. The method according to claim 1, wherein: Sending the second random access message 1 includes utilizing a coverage enhancement transmission method.

5. The method according to claim 4, wherein: Sending the second random access message 1 includes repeating transmission of the second random access message 1.

6. The method according to claim 1, wherein: The coverage enhancement monitoring process includes: before decoding the control part of the second random access message 2, performing the soft combining on the multiple control part candidates at the multiple monitoring occasions.

7. The method according to claim 6, wherein: Corresponding control portion candidates with the same aggregation level and position within different monitoring occasions are combined.

8. The method according to claim 1, wherein: The coverage enhancement monitoring process includes a second RAR window overlapping the second portion of the first RAR window.

9. The method according to claim 1, wherein: The coverage enhancement monitoring process includes: monitoring the alternative size of the DCI used for the control part of the second random access message 2.

10. The method according to claim 1, wherein: The coverage enhancement monitoring process includes: determining the alternative interpretation of the DCI for the control part of the second random access message 2.

11. The method according to claim 1, wherein: Sending the second random access message 1 is in response to measurements performed by the UE.

12. The method according to claim 1, wherein: The number of control part candidates included in the monitoring process for the control part of the first random access message 2 and the monitoring process for the second random access message 2 is greater than a limit; and It also includes: discarding a subset of concurrent control part candidates used for the monitoring process of the control part of the first random access message 2.

13. An apparatus for wireless communication at a user equipment (UE), comprising: Memory; as well as at least one processor coupled to the memory and configured to: Sending a first random access message 1 from the UE; in response to determining that a first random access message 2 control part is not received during a first part of a first random access response (RAR) window, sending a second random access message 1 from the UE; monitoring the first random access message 2 control part and the second random access message 2 control part simultaneously during the second part of the first RAR window, wherein the monitoring process for coverage enhancement of the second random access message 2 control part is different from the monitoring process for the first random access message 2 control part, wherein the monitoring process for coverage enhancement comprises at least one of the following: soft combining a plurality of control part candidates at a plurality of monitoring occasions, monitoring an alternative size of downlink control information (DCI) for the second random access message 2 control part, or determining an alternative interpretation of the DCI for the second random access message 2 control part; receiving and decoding a random access message 2 control part, the random access message 2 control part being one of the first random access message 2 control part or the second random access message 2 control part; and In response to decoding the random access message 2 control portion, the random access message 2 data portion is monitored.

14. The device according to claim 13, wherein: The monitoring procedure for coverage enhancement of the control part of the second random access message 2 includes a monitoring opportunity grouping different from the monitoring procedure for the control part of the first random access message 2.

15. The device according to claim 13, wherein: The monitoring procedure for coverage enhancement of the second random access message 2 control part includes a different random access radio network temporary identifier (RA-RNTI) than the monitoring procedure for the first random access message 2 control part.

16. The device according to claim 13, wherein: The number of control part candidates included in the monitoring process for the control part of the first random access message 2 and the monitoring process for coverage enhancement of the control part of the second random access message 2 is greater than a limit, wherein the at least one processor is further configured to: A subset of concurrent control part candidates for the monitoring process of the control part of the first random access message 2 is discarded.

17. A method of wireless communication at a base station, comprising: Receiving a first random access message 1 from a user equipment (UE); In response to the first random access message 1, sending a first random access message 2 control part during a first random access response (RAR) window; Receiving a second random access message 1 during the first RAR window; In response to the second random access message 1, sending a second random access message 2 control part during a second part of the first RAR window for a coverage enhanced monitoring procedure different from the monitoring procedure for the first random access message 2 control part, wherein sending the second random access message 2 control part includes at least one of the following: repeating the second random access message 2 control part over a plurality of monitoring occasions, or sending an alternative size of downlink control information (DCI) for the second random access message 2 control part; as well as A first random access message 2 data part is sent based on the first random access message 2 control part, and a second random access message 2 data part is sent based on the second random access message 2 control part.

18. The method according to claim 17, wherein: Sending the second random access message 2 control part includes: sending it on a different monitoring opportunity group than the first random access message 2 control part.

19. The method according to claim 17, wherein: Sending the second random access message 2 Control part includes sending the second random access message 2 Control part using a different random access radio network temporary identifier (RA-RNTI) than the first random access message 2 Control part.

20. The method according to claim 17, wherein: Receiving the second random access message 1 includes utilizing a coverage enhancement reception method.

21. The method according to claim 20, wherein: The second random access message 1 is repeated.

22. The method according to claim 17, wherein: Sending the second random access message 2 control part includes: repeating the second random access message 2 control part at the plurality of monitoring occasions.

23. The method according to claim 22, sending the second random access message 2 control part comprises: The second random access message 2 control part is sent on corresponding control part candidates having the same aggregation level and position within the plurality of monitoring occasions.

24. The method of claim 17, wherein: The coverage enhancement monitoring process includes a second RAR window overlapping the second portion of the first RAR window.

25. The method of claim 17, wherein: Sending the second random access message 2 control part includes: sending the alternative size of the DCI for the second random access message 2 control part.

26. The method of claim 17, wherein: The second random access message 2 control part has an alternative interpretation of the DCI.

27. The method of claim 17, further comprising: A configuration indicating a monitoring process for the coverage enhancement is sent.

28. An apparatus for wireless communication at a base station, comprising: Memory; as well as at least one processor coupled to the memory and configured to: Receiving a first random access message 1 from a user equipment (UE); In response to the first random access message 1, sending a first random access message 2 control part during a first random access response (RAR) window; Receiving a second random access message 1 during the first RAR window; In response to the second random access message 1, sending a second random access message 2 control part during a second part of the first RAR window for a coverage enhanced monitoring procedure different from the monitoring procedure for the first random access message 2 control part, wherein sending the second random access message 2 control part comprises at least one of the following: repetition of the second random access message 2 control part at multiple monitoring occasions, or transmission of an alternative size of downlink control information (DCI) for the second random access message 2 control part; as well as A first random access message 2 data part is sent based on the first random access message 2 control part, and a second random access message 2 data part is sent based on the second random access message 2 control part.

29. The device according to claim 28, wherein Sending the second random access message 2 control part includes: sending it on a different monitoring opportunity group than the first random access message 2 control part.

30. The device according to claim 28, wherein Sending the second random access message 2 Control part includes sending the second random access message 2 Control part using a different random access radio network temporary identifier (RA-RNTI) than the first random access message 2 Control part.

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