Coverage enhancement for downlink broadcast channels

Abstract

This disclosure relates to coverage enhancement for downlink broadcast channels. This disclosure provides systems, methods, and apparatus for configuring and signaling the repetitive transmission of broadcast system information on downlink (DL) channels, including computer programs encoded on a computer storage medium. In some implementations, a user equipment (UE) may receive an indication for repetitive configuration of broadcast information carried on a physical downlink shared channel (PDSCH), may identify several time slots configured to carry broadcast information on the PDSCH based at least in part on the repetitive configuration, and may receive the broadcast information carried on the PDSCH in the identified time slots.

Description

[0001] This application is a divisional application of Chinese patent application No. 202080098094.4 (International Application No. PCT / CN2020 / 078741), filed on March 11, 2020, entitled “Coverage Enhancement for Downlink Broadcast Channel”. Technical Field

[0002] This disclosure generally relates to wireless communications, and more specifically to broadcast transmissions employing coverage enhancement techniques. Background Technology

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can support communication with multiple users by sharing available system resources, such as time, frequency, and power. Examples of such multiple access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems (such as Long Term Evolution (LTE) systems or 5G New Radio (NR) systems). A wireless multiple access communication system may include several base stations or access network nodes, each supporting communication from multiple communication devices simultaneously, which may also be referred to as User Equipment (UE).

[0004] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol enabling different wireless devices to communicate at the city, country, region, and even global levels. An example telecommunications standard is 5G NR, which is part of the Continuous Mobile Broadband Evolution program issued by the 3rd Generation Partnership Project (3GPP) to meet new requirements related to latency, reliability, security, scalability, and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low latency communications (URLLC). There is a need for further improvements to 5G NR technology. These improvements can also be applied to other multiple access technologies and telecommunications standards that employ them. Summary of the Invention

[0005] The systems, methods, and apparatus disclosed herein each have several innovative aspects, and no single aspect is solely responsible for the desired properties disclosed herein.

[0006] One innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communication. This method can be performed by a user equipment (UE) and may include: receiving downlink control information (DCI) indicating a repetition configuration for broadcast information carried on a physical downlink shared channel (PDSCH); identifying several time slots configured to carry broadcast information on the PDSCH based at least in part on the repetition configuration; and receiving the broadcast information carried on the PDSCH in the identified several time slots. The broadcast information may include a first system information block (SIB1), and the repetition configuration may include a bit mapping identifying time slots available for repetition within a transmission period of the SIB1. The bit mapping may include a number of... N One place, that N Each bit in the unit indicates that it can be used for repeated transmission. N The corresponding time slot within a time slot. In some instances, this bit mapping may be copied once or multiple times to identify one or more additional time slots available for repeated transmissions of SIB1. N A set of time slots. In other instances, only the first few available time slots... M One time slot was used for repeated transmission, of which M The value can be based on the number of available time slots. In some implementations, the method may also include receiving repetitions of SIB1 in one or more of several time slots identified by a bitmap.

[0007] Another innovative aspect of the subject matter described in this disclosure can be implemented in a user equipment (UE). The UE may include one or more processors coupled to a memory. The memory may store instructions that, when executed by the one or more processors, cause the UE to perform several operations. In some implementations, the several operations may include: receiving downlink control information (DCI) indicating a repetition configuration for broadcast information carried on a physical downlink shared channel (PDSCH); identifying several time slots configured to carry broadcast information on the PDSCH based at least in part on the repetition configuration; and receiving the broadcast information carried on the PDSCH in the identified time slots. The broadcast information may include a first system information block (SIB1), and the repetition configuration may include a bit mapping identifying time slots available for repetition within a transmission period of the SIB1. The bit mapping may include a number of... N One place, that N Each bit in the unit indicates that it can be used for repeated transmission. N The corresponding time slot within a time slot. In some instances, this bit mapping may be copied once or multiple times to identify one or more additional time slots available for repeated transmissions of SIB1. N A set of time slots. In other instances, only the first few available time slots... M One time slot was used for repeated transmission, of which MThe value can be based on the number of available time slots. In some implementations, the method may also include receiving repetitions of SIB1 in one or more of several time slots identified by a bitmap.

[0008] Another innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communication. This method can be performed by a user equipment (UE) and may include: receiving an indication of a frequency hopping mode for a physical downlink shared channel (PDSCH) carrying broadcast information; and receiving broadcast information on the PDSCH based on the frequency hopping mode. In some implementations, the broadcast information may include a first system information block (SIB1), and each of a plurality of frequency hopping offsets may be based on the size of a shared control resource set (CORESET#0) with index 0 allocated to the PDSCH. In some other implementations, the broadcast information may include one or more of a paging signal or a random access response (RAR), and each of the plurality of frequency hopping offsets may be configured by an SIB carried on the PDSCH. Additionally or alternatively, the indication may identify a plurality of frequency hopping offsets for the frequency hopping mode.

[0009] In some implementations, the method may further include: receiving an indication of several time slots of a PDSCH configured to carry broadcast information; determining a slot-specific frequency hopping offset based at least in part on the identified several time slots; and receiving the broadcast information carried in the identified several time slots based at least in part on the frequency hopping pattern and the slot-specific frequency hopping offset. In some instances, the slot-specific frequency hopping offset may include a first frequency hopping offset for even-numbered time slots among the identified several time slots, and may include a second frequency hopping offset for odd-numbered time slots among the identified several time slots. In some aspects, the indication may be received in a downlink control information (DCI) message.

[0010] In some other implementations, the method may further include: receiving a synchronization signal block (SSB) on a beam transmitted by a base station; determining a frequency hopping offset based at least in part on the received SSB; and receiving broadcast information carried on a PDSCH via the beam based at least in part on the frequency hopping pattern and the frequency hopping offset. The method may also include: receiving a downlink control information (DCI) message indicating whether a bandwidth portion (BWP) associated with the SSB has been shifted by the frequency hopping offset. In some instances, the frequency hopping offset may be semi-statically configured via radio resource control (RRC) signaling. RRC signaling may indicate a mapping between multiple beams associated with the base station and several frequency hopping offsets.

[0011] Another innovative aspect of the subject matter described in this disclosure can be implemented in a user equipment (UE). The UE may include one or more processors coupled to a memory. The memory may store instructions that, when executed by the one or more processors, cause the UE to perform several operations. In some implementations, the several operations may include: receiving an indication of a frequency hopping mode for a physical downlink shared channel (PDSCH) used to carry broadcast information; and receiving broadcast information on the PDSCH based on the frequency hopping mode. In some implementations, the broadcast information may include a first system information block (SIB1), and each of the several frequency hopping offsets may be based on the size of a shared control resource set (CORESET#0) with index 0 allocated to the PDSCH. In some other implementations, the broadcast information may include one or more of a paging signal or a random access response (RAR), and each of the several frequency hopping offsets may be configured by an SIB carried on the PDSCH. Additionally or alternatively, the indication may identify the several frequency hopping offsets used for the frequency hopping mode.

[0012] In some implementations, the operations may further include: receiving an indication of several time slots of a PDSCH configured to carry broadcast information; determining a time slot-specific frequency hopping offset based at least in part on the identified time slots; and receiving the broadcast information carried in the identified time slots based at least in part on the frequency hopping pattern and the time slot-specific frequency hopping offset. In some instances, the time slot-specific frequency hopping offset may include a first frequency hopping offset for even-numbered time slots among the identified time slots, and may include a second frequency hopping offset for odd-numbered time slots among the identified time slots. In some aspects, the indication may be received in a downlink control information (DCI) message.

[0013] In some other implementations, these operations may further include: receiving a synchronization signal block (SSB) on a beam transmitted by a base station; determining a frequency hopping offset based at least in part on the received SSB; and receiving broadcast information carried on a PDSCH via the beam based at least in part on the frequency hopping pattern and the determined frequency hopping offset. These operations may also include: receiving a downlink control information (DCI) message indicating whether a bandwidth portion (BWP) associated with the SSB has been shifted by the frequency hopping offset. In some instances, the frequency hopping offset may be semi-statically configured via radio resource control (RRC) signaling. RRC signaling may indicate a mapping between multiple beams associated with the base station and multiple frequency hopping offsets.

[0014] Another innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communication. This method can be performed by a user equipment (UE) and may include: transmitting a random access preamble sequence to a base station; receiving a physical downlink control channel (PDCCH) that schedules a physical downlink shared channel (PDSCH) within several consecutive time slots; receiving a random access response (RAR) from the base station in one or more of the consecutive time slots of the PDSCH, the RAR including a random access preamble identifier; and transmitting a radio resource control (RRC) connection establishment message to the base station based at least in part on the received RAR. In some instances, the PDSCH may be associated with a transport block size (TBS) scaling factor of one-eighth.

[0015] In some implementations, each of the several consecutive time slots of the PDSCH can be associated with a different transport block (TB), and the start of RRC connection establishment message transmission can be based on the last symbol period in the PDSCH time slot carrying RAR. In some other implementations, the several consecutive time slots of the PDSCH can be aggregated time slots associated with the same TB, and the start of RRC connection establishment message transmission can be based on the last symbol period of the aggregated time slot.

[0016] In some implementations, the method may further include: comparing the index of the random access preamble identifier with the index of the random access preamble sequence; and skipping decoding of the RAR in subsequent time slots based on the comparison. In some instances, skipping decoding may include: suppressing decoding of the RAR when the index of the random access preamble identifier is greater than the index of the random access preamble sequence; and continuing decoding of the RAR when the index of the random access preamble identifier is not greater than the index of the random access preamble sequence. In other instances, skipping decoding may include: suppressing decoding of the RAR when the index of the random access preamble identifier and the index of the random access preamble sequence are in different groups; and continuing decoding of the RAR when the index of the random access preamble identifier and the index of the random access preamble sequence are in the same group.

[0017] Another innovative aspect of the subject matter described in this disclosure can be implemented in a User Equipment (UE). The UE may include one or more processors coupled to a memory. The memory may store instructions that, when executed by the one or more processors, cause the UE to perform several operations. In some implementations, these operations may include: transmitting a random access preamble sequence to a base station; receiving a Physical Downlink Control Channel (PDCCH) that schedules a Physical Downlink Shared Channel (PDSCH) within several consecutive time slots; receiving a Random Access Response (RAR) from the base station in one or more of the consecutive time slots of the PDSCH, the RAR including a random access preamble identifier; and transmitting a Radio Resource Control (RRC) connection establishment message to the base station, at least in part based on the received RAR. In some instances, the PDSCH may be associated with a transport block size (TBS) scaling factor of one-eighth.

[0018] In some implementations, each of the several consecutive time slots of the PDSCH can be associated with a different transport block (TB), and the start of RRC connection establishment message transmission can be based on the last symbol period in the PDSCH time slot carrying RAR. In some other implementations, the several consecutive time slots of the PDSCH can be aggregated time slots associated with the same TB, and the start of RRC connection establishment message transmission can be based on the last symbol period of the aggregated time slot.

[0019] In some implementations, these operations may further include: comparing the index of the random access preamble identifier with the index of the random access preamble sequence; and skipping the decoding of the RAR in subsequent time slots based on the comparison. In some instances, skipping decoding may include: suppressing RAR decoding when the index of the random access preamble identifier is greater than the index of the random access preamble sequence; and continuing RAR decoding when the index of the random access preamble identifier is not greater than the index of the random access preamble sequence. In other instances, skipping decoding may include: suppressing RAR decoding when the index of the random access preamble identifier and the index of the random access preamble sequence are in different groups; and continuing RAR decoding when the index of the random access preamble identifier and the index of the random access preamble sequence are in the same group.

[0020] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from this description and the accompanying drawings. It should be noted that the relative dimensions in the following drawings may not be drawn to scale. Attached Figure Description

[0021] Figure 1 A diagram illustrating an example wireless communication system is shown.

[0022] Figure 2A-2D Example 5G NR frame, example downlink (DL) channel within 5G NR time slot, another example 5G NR frame, and example uplink (UL) channel within 5G NR time slot are shown respectively.

[0023] Figure 3 The diagram illustrates an example base station and user equipment (UE) in an access network.

[0024] Figure 4A The diagram illustrates a sequence of example message exchanges between a base station and a UE, based on some implementations.

[0025] Figure 4B Example repeating configurations that can be used for broadcast DL transmissions are shown according to some implementations.

[0026] Figures 5A-5B The diagram illustrates a sequence of example message exchanges between a base station and a UE, based on some implementations.

[0027] Figure 5C Example SSB frequency hopping modes that can be used for broadcast DL transmissions are shown according to some implementations.

[0028] Figure 5D An example inter-slot frequency hopping mode, based on some implementations, is shown that can be used for broadcast DL transmission.

[0029] Figure 6A The diagram illustrates a sequence of example message exchanges between a base station and a UE, based on some implementations.

[0030] Figure 6B An explanation of an example scheduling of multiple transport blocks that can be used for broadcast DL transports is shown, based on some implementations.

[0031] Figure 6C An explanation of an example scheduling of repeating time slots that can be used for broadcast DL transmissions is shown, based on some implementations.

[0032] Figure 7 A flowchart depicting a repetitive wireless communication example operation that supports broadcast information is shown.

[0033] Figure 8 A flowchart depicting a repetitive wireless communication example operation that supports broadcast information is shown.

[0034] Figure 9 A flowchart depicting an example operation of wireless communication that supports frequency hopping on a downlink channel carrying broadcast information is shown.

[0035] Figures 10A-10CA flowchart depicting an example operation of wireless communication that supports frequency hopping on a downlink channel carrying broadcast information is shown.

[0036] Figure 11 A flowchart depicting an example operation of wireless communication supporting repeated transmissions with random access protocol is shown.

[0037] Figures 12A-12C A flowchart depicting an example operation of wireless communication supporting repeated transmissions with random access protocol is shown.

[0038] Similar reference numerals and naming conventions in the various figures indicate similar elements. Detailed Implementation

[0039] The following description is directed to certain specific implementations in order to describe the innovative aspects of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to one or more of the following: Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards published by the 3rd Generation Partnership Project (3GPP), the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, the IEEE 802.15 standard, or the Bluetooth® standard as defined by the Bluetooth Special Interest Group (SIG), etc. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Single User (SU) Multiple Input Multiple Output (MIMO), and Multi User (MU) MIMO. The described implementation can also be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless wide area network (WWAN), wireless personal area network (WPAN), wireless local area network (WLAN), or Internet of Things (IoT) network.

[0040] Some UEs may have limited capabilities for receiving DL transmissions. For example, a limited-capability or low-capability (LC) UE may have only one antenna and may not be able to receive more than one broadcast TB in a given time slot. Additionally, the BWP size of an LC UE is relatively small compared to high-performance UEs such as eMBB and URLLC devices. To compensate for the reduced service coverage of LC UEs, coverage enhancement techniques have been introduced, enabling LC UEs to transmit and receive data over longer distances and at lower power levels in the radio access network. Coverage enhancement techniques may include intra-subframe repetition, repetition across different subframes, power boosting, beamforming, and spatial multiplexing. Different coverage enhancement techniques may result in different coverage trade-offs. For example, data repetition across multiple subframes may improve range and / or reception reliability, but may also reduce the data rate. Boosting transmit power may also increase range and / or reception reliability, but may increase energy consumption and cause interference to other transmissions.

[0041] While repetition and slot aggregation can effectively provide coverage enhancement for unicast DL transmissions, they can present problems when applied to DL transmissions that include broadcast information. For example, while unicast DL transmissions can be clustered or repeated in coherent slots of one or more subframes, using slot aggregation or transmission repetition techniques for DL ​​channels carrying specific broadcast information may not be resource-efficient, for instance, because high-performance UEs or LC UEs located close to the base station may not require repetition or slot aggregation to receive broadcast information. Furthermore, when the PDSCH carries SIB1, which contains initial frame synchronization information (as well as cell access and scheduling information for SIB2) required for the UE's location service cell's UL and DL channels, repeating SIB1 in coherent slots of the radio frame may be infeasible. More specifically, since some slots in a TDD frame may be configured for UL transmissions (rather than DL transmissions), one or more coherent slots selected for repetition in a radio frame may be configured for UL transmissions and therefore may not be available for repetition of SIB1 transmissions. However, since reconfigurations are typically indicated to the UE via RRC signaling, they are not well-suited for use with broadcast information transmitted on DL channels such as PDSCH.

[0042] According to some aspects of this disclosure, the repetition configuration for broadcast information transmitted on the PDSCH can be indicated in the DCI message (rather than via RRC signaling), which allows the base station to dynamically signal and / or modify the repetition configuration for DL ​​broadcast information. In some instances, the number of time slots available for repetition can be at least partially based on the modulation and coding scheme (MCS) used by the UE or UE group. For example, a relatively small number of time slots can be used for repetition when the MCS used by the UE (or UE group) is relatively low, while a relatively large number of time slots can be used for repetition when the MCS used by the UE (or UE group) is relatively high. In some implementations, the DCI message may include a bit map that identifies several time slots available for repetition. In some instances, the bit map may identify several consecutive time slots available for repetition within a radio frame. In some other instances, the bit map may identify several time slots available for repetition within a transmission period of SIB1.

[0043] Repetition can also be used to provide coverage enhancement for LC UEs during random access procedures. In some implementations, the base station may transmit a PDCCH, which is scheduled within several consecutive time slots of the PDSCH in a radio frame. When the UE transmits a random access preamble sequence to the base station on the RACH, the base station can respond by transmitting a random access response (RAR) in one or more time slots of the consecutive time slots of the PDSCH. By repeatedly transmitting the RAR in one or more consecutive time slots of the PDSCH, the LC UE can use portions of the RAR received in subsequent time slots of the PDSCH to supplement or reconstruct portions of the RAR that were not received or correctly decoded in previous time slots of the PDSCH, thereby increasing the likelihood that the LC UE completes the RACH procedure and subsequently establishes an RRC connection with the base station.

[0044] In some implementations, frequency hopping can be used for DL ​​transmission of broadcast information from a base station to reduce interference from other devices, for example, by utilizing frequency diversity of the radio medium. Frequency hopping can also increase channel access because contention on relatively small frequency bands (such as hop channels associated with frequency hopping patterns) may be less than on relatively large frequency bands (such as the main channel used in broadband communications). In some implementations, the base station can provide an indication of the frequency hopping pattern for the PDSCH used to carry broadcast information. This indication can be transmitted from the base station to one or more UEs in a DCI message, and can allow each of the one or more UEs to receive broadcast information on the PDSCH based on the frequency hopping pattern. In some instances, the indication can identify several frequency hopping offsets. For example, the broadcast information may include a first System Information Block (SIB1), and each frequency hopping offset may be based on the size of a Common Control Resource Set (CORESET#0) with index 0 allocated to the PDSCH. As another example, the broadcast information may include one or more of a paging signal or a RAR, and each frequency hopping offset may be configured by a System Information Block (SIB) carried on the PDSCH.

[0045] Several aspects of a telecommunications system will now be described with reference to various apparatuses and methods. These apparatuses and methods will be described in detail below and explained in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, “elements”). These elements can 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.

[0046] As an example, an element, or any part of an element, or any combination of elements, may 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 computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms.

[0047] Accordingly, in one or more example implementations, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functionality may be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media can be any available medium accessible to 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 disc storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the types described above, or any other medium capable of being used to store computer-executable code in the form of instructions or data structures accessible to a computer.

[0048] Figure 1 A diagram illustrating an example wireless communication system 100 and an access network is shown. The wireless communication system 100 includes a base station 102, a user interface device (UE) 104, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some implementations, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low latency communication, or communication with low-cost and low-complexity devices.

[0049] Base station 102 can wirelessly communicate with UE 104 via one or more base station antennas. Base station 102 described herein may include, or may be referred to by those skilled in the art as, a base transceiver station, radio base station, access point, radio transceiver, B-node, evolved B-node (eNB), next-generation B-node, or gigabit B-node (any of which may be referred to as gNB), home B-node, home evolved B-node, or some other suitable term. Wireless communication system 100 may include different types of base station 102 (e.g., macrocell base station or small cell base station, etc.). UE 104 described herein may be able to communicate with various types of base station 102 and network equipment (including macro eNB, small cell eNB, gNB, relay base station, etc.).

[0050] Each base station 102 may be associated with a specific coverage area 110, within which communication with various UEs 104 is supported. Each base station 102 may provide communication coverage to the corresponding coverage area 110 via a communication link 125, and the communication link 125 between the base station 102 and the UE 104 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include uplink transmission from the UE 104 to the base station 102, or downlink transmission from the base station 102 to the UE 104. Downlink transmission may also be referred to as forward link transmission, and uplink transmission may also be referred to as reverse link transmission.

[0051] The geographic coverage area 110 of base station 102 can be divided into sectors that constitute only a part of the geographic coverage area 110, and in some implementations, each sector may be associated with a cell. For example, each base station 102 may provide communication coverage to macrocells, small cells, hotspots, or other types of cells, or various combinations thereof. In some examples, base station 102 may be mobile and thus provide communication coverage to mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 102 or different base stations 102. The wireless communication system 100 may include, for example, heterogeneous LTE / LTE-A / LTE-A Pro or NR networks, wherein different types of base stations 102 provide coverage to various geographic coverage areas 110.

[0052] The term "cell" refers to a logical communication entity used to communicate with base station 102 (e.g., on a carrier) and may be associated with identifiers to distinguish adjacent cells operating via the same or different carriers (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)). In some examples, a carrier may support multiple cells, and different cells may be configured based on different protocol types that can provide access for different types of devices (e.g., Machine-Type Communication (MTC), Narrowband Internet of Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or others). In some implementations, the term "cell" may refer to a portion (e.g., a sector) of the geographical coverage area 110 on which the logical entity operates.

[0053] Each UE 104 may be distributed throughout the wireless communication system 100, and each UE 104 may be stationary or mobile. UE 104 may also be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client. UE 104 may also be a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 104 may also refer to a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or MTC device, etc., which may be implemented in various items such as appliances, vehicles, instruments, etc.

[0054] Some UE 104 devices (such as MTC or IoT devices) may be low-cost or low-complexity (LC) devices and may provide automated machine-to-machine (M2M) communication. M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with base station 102 without human intervention. In some examples, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application that can utilize the information or present it to people interacting with the program or application. Some UE 104 devices may be designed to collect information or enable automated machine behavior. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wilderness survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0055] Some UEs 104 can be configured to operate in reduced-power modes, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UE 104 include entering a power-saving “deep sleep” mode when not engaged in active communication, or operating on limited bandwidth (e.g., according to narrowband communication). In some implementations, UE 104 can be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 can be configured to provide ultra-reliable communication for these functions.

[0056] In some implementations, UE 104 may also be able to communicate directly with other UE 104 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs in a group of UEs 104 utilizing D2D communication may be within the geographic coverage area 110 of base station 102. Other UEs 104 in the group may be outside the geographic coverage area 110 of base station 102, or may be unable to receive transmissions from base station 102 for other reasons. In some implementations, groups of UEs 104 communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 104 transmits to every other UE 104 in the group. In some implementations, base station 102 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between the individual UEs 104 without involving base station 102.

[0057] Base station 102 can communicate with core network 130 and with each other. For example, base station 102 can interface with core network 130 via backhaul link 132 (e.g., via S1, N2, N3 or another interface). Base stations 102 can communicate with each other directly (e.g., directly between base stations 102) or indirectly (e.g., via core network 130) on backhaul link 134 (e.g., via X2, Xn or other interfaces).

[0058] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME manages non-access stratum (e.g., control plane) functions, such as mobility, authentication, and bearer management of UE 104 served by base station 102 associated with the EPC. User IP packets can be delivered via the S-GW, which itself may connect to the P-GW. The P-GW provides IP address allocation and other functions. The P-GW may connect to network operator IP services. Operator IP services may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched (PS) streaming services.

[0059] At least some network devices (such as base station 102) may include sub-components, such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with each UE 104 through several other access network transport entities, which may be referred to as a radio headend, a smart radio headend, or a transmit / receive point (TRP). In some configurations, the various functions of each access network entity or base station 102 may be distributed across various network devices (e.g., radio headends and access network controllers) or combined into a single network device (e.g., base station 102).

[0060] Wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Generally, the 300 MHz to 3 GHz band is referred to as a UHF band or decimeter band because the wavelengths range from approximately 1 decimeter to 1 meter. UHF waves can be blocked or redirected by buildings and environmental features. However, these waves can penetrate various structures sufficiently for macrocells to provide service to UE 104 located indoors. Compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0061] The wireless communication system 100 can also operate in the ultra-high frequency (SHF) zone using a frequency band from 3 GHz to 30 GHz (also known as the centimeter band). The SHF zone includes frequency bands that can be used opportunistically by devices that can tolerate interference from other users (such as the 5 GHz Industrial, Scientific and Medical (ISM) band).

[0062] The wireless communication system 100 can also operate in extremely high frequency (EHF) zoning (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 104 and the base station 102, and the EHF antennas of the corresponding devices can be even smaller and more closely spaced than UHF antennas. In some implementations, this can facilitate the use of an antenna array within the UE 104. However, the propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein can be employed across transmissions using one or more different frequency zonings, and the frequency band usage specified across these frequency zonings may vary by country or regulatory authority.

[0063] In some implementations, the wireless communication system 100 may utilize both licensed and unlicensed radio spectrum bands. For example, the wireless communication system 100 may employ License-Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology in unlicensed frequency bands (such as the 5 GHz ISM band). When operating in unlicensed radio spectrum bands, wireless devices (such as base station 102 and UE 104) may employ a Listen-Before-Talk (LBT) protocol to ensure that the frequency channel is open before transmitting data. In some implementations, operation in unlicensed frequency bands may be coordinated with CC operation in licensed frequency bands based on CA configuration (e.g., LAA). Operation in unlicensed spectrum may include downlink transmission, uplink transmission, peer-to-peer transmission, or a combination thereof. Duplexing in unlicensed spectrum may be based on Frequency Division Duplex (FDD), Time Division Duplex (TDD), or a combination thereof.

[0064] In some examples, base station 102 or UE 104 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 102) and a receiving device (e.g., UE 104), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different combinations of antennas. Similarly, the receiving device may receive multiple signals via different antennas or different combinations of antennas. Each of these multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0065] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique used at a transmitting or receiving device (e.g., base station 102 or UE 104) to shape or guide an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array, such that signals propagating relative to a particular orientation of the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include the transmitting or receiving device applying specific amplitude and phase shifts to the signals carried via each antenna element associated with that device. The adjustments associated with each antenna element may be defined by a beamforming weight set associated with a particular orientation (e.g., relative to the antenna array of the transmitting or receiving device, or relative to some other orientation).

[0066] In one example, base station 102 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with UE 104. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 102 in different directions. This may include a signal being transmitted according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions can be used (e.g., by base station 102 or receiving device, such as UE 104) to identify the beam direction used by base station 102 for subsequent transmission and / or reception. Some signals (such as data signals associated with a particular receiving device) may be transmitted by base station 102 in a single beam direction (e.g., the direction associated with the receiving device, such as UE 104). In some examples, the beam direction associated with transmission along a single beam direction may be determined at least in part based on the signals transmitted in different beam directions. For example, UE 104 may receive one or more signals transmitted by base station 102 in different directions, and UE 104 may report to base station 102 an indication of the signals it received with the highest signal quality or other acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 102 in one or more directions, UE 104 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify the beam direction used by UE 104 for subsequent transmission or reception) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0067] A receiver device (e.g., UE 104, which may be an example of an mmW receiver device) may attempt multiple receive beams when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 102. For example, the receiver device may attempt multiple receive directions by: receiving via different antenna subarrays; processing received signals according to different antenna subarrays; receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array; or processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples, the receiver device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned on a beam direction determined at least in part based on listening according to different receive beam directions (e.g., a beam direction determined at least in part based on listening according to multiple beam directions to have the highest signal strength, highest signal-to-noise ratio, or other acceptable signal quality).

[0068] In some implementations, the antennas of base station 102 or UE 104 may be located within one or more antenna arrays that support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may coexist at an antenna assembly (such as an antenna tower). In some implementations, the antennas or antenna arrays associated with base station 102 may be located in different geographical locations. Base station 102 may have an antenna array with several rows and columns of antenna ports that base station 102 can use to support beamforming for communication with UE 104. Similarly, UE 104 may have one or more antenna arrays that support various MIMO or beamforming operations.

[0069] In some implementations, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. In some implementations, the Radio Link Control (RLC) layer may perform packet segmentation and reassembly for communication on logical channels. The Media Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use Hybrid Automatic Repeat Request (HARQ) to provide MAC layer retransmissions, thereby improving link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide the establishment, configuration, and maintenance of RRC connections between UE 104 and base station 102 or core network 130 supporting user plane data radio bearers. At the physical (PHY) layer, transport channels may be mapped to physical channels.

[0070] In some implementations, UE 104 and base station 102 may support data retransmission to increase the likelihood of successful data reception. HARQ feedback is a technique to increase the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve MAC layer throughput in poor radio conditions (e.g., signal-to-noise ratio conditions). In some implementations, the wireless device may support simultaneous time-slot HARQ feedback, where the device can provide HARQ feedback in a specific time slot for data received in previous symbols within that time slot. In other cases, the device may provide HARQ feedback in subsequent time slots or according to some other time interval.

[0071] Time intervals in LTE or NR can be expressed as multiples of a basic time unit (which may be, for example, a sampling period Ts = 1 / 30,720,000 seconds). Time intervals of communication resources can be organized according to radio frames, each with a duration of 10 milliseconds (ms), where the frame period can be expressed as Tf = 307,200 Ts. Radio frames can be identified by System Frame Numbers (SFNs) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. Subframes can be further divided into two time slots, each with a duration of 0.5 ms, and each time slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some implementations, a subframe may be the smallest scheduling unit of a wireless communication system 100 and may be referred to as a Transmission Time Interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0072] In some wireless communication systems, time slots can be further divided into multiple mini-slots containing one or more symbols. In some respects, a symbol or mini-slot can be the smallest unit of scheduling. For example, the duration of each symbol can vary depending on the subcarrier spacing or the operating frequency band.

[0073] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications on communication link 125. For example, a carrier of communication link 125 may include a portion of a radio spectrum band operating according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN)) and may be located according to a channel grid for discovery by UE 104. A carrier may be downlink or uplink (e.g., in FDD mode), or may be configured to carry both downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or DFT-s-OFDM).

[0074] The organization of a carrier can vary depending on the radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR, etc.). For example, communication on a carrier can be organized according to a TTI or time slot, each of which may include user data and control information or signaling that supports decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information) and control signaling that coordinates carrier operation. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers.

[0075] Physical channels can be multiplexed on a carrier using various techniques. Physical control channels and physical data channels can be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM), frequency division multiplexing (FDM), or a hybrid TDM-FDM technique. In some examples, control information transmitted in the physical control channel can be distributed in a cascaded manner between different control regions (e.g., between a shared control region or shared search space and one or more UE-specific control regions or UE-specific search spaces).

[0076] A carrier may be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 104 may be configured to operate on a portion or all of the carrier bandwidth. In other examples, some UEs 104 may be configured to operate using a narrowband protocol type associated with a predefined portion or range within the carrier (e.g., a set of subcarriers or RBs) (e.g., “in-band” deployment of a narrowband protocol type).

[0077] In some implementations, the carrier can be subdivided into portions, each with a bandwidth smaller than the carrier bandwidth (e.g., 100 MHz), and such portions may be referred to as bandwidth portions or BWPs. For example, some devices (e.g., some UEs 104) may not support the full bandwidth of the carrier, and thus may be able to communicate using one or more BWPs. In some implementations, UE 104 may establish communication with base station 102 using a first BWP (which may be referred to as the initial BWP), and UE 104 may subsequently switch to a different BWP. In some implementations, BWPs may be paired or otherwise grouped. For example, UE 104 may communicate using paired or grouped uplink and downlink BWPs (e.g., in an FDD implementation). Furthermore, in some implementations, UE 104 switching to a different BWP may switch from a first pair of BWPs or another group of BWPs to a second pair of BWPs or another group of BWPs (e.g., concurrently or simultaneously, or as part of a single BWP handover operation).

[0078] In a system employing MCM technology, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Therefore, the more resource elements UE 104 receives and the higher the order of the modulation scheme, the higher the data rate UE 104 can achieve. In a MIMO system, wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers), and using multiple spatial layers can further improve the data rate of communication with UE 104.

[0079] The devices of the wireless communication system 100 (e.g., base station 102 or UE 104) may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configurable to support communication on a single carrier bandwidth within a set of carrier bandwidths. In some examples, the wireless communication system 100 may include base station 102 and / or UE 104 that can support simultaneous communication via carriers associated with more than one different carrier bandwidth.

[0080] The wireless communication system 100 can support communication with the UE 104 on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. The UE 104 may be configured with multiple downlink CCs and one or more uplink CCs depending on the carrier aggregation configuration. Carrier aggregation can be used in conjunction with both FDD and TDD component carriers.

[0081] In some implementations, the wireless communication system 100 may utilize enhanced component carrier (eCC). eCC may be characterized by one or more features, including a wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or a modified control channel configuration. In some implementations, eCC may be associated with carrier aggregation configurations or dual connectivity configurations (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). eCC may also be configured for use in unlicensed or shared spectrum (e.g., where more than one operator is permitted to use the spectrum). eCC characterized by a wide carrier bandwidth may include one or more segments that may be utilized by a UE 104 that is unable to monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0082] In some implementations, eCC may utilize a symbol duration different from other CCs, which may include using a reduced symbol duration compared to other CCs. The shorter symbol duration may be associated with increased spacing between adjacent subcarriers. Devices utilizing eCC (such as UE 104 or base station 102) can transmit wideband signals (e.g., based on frequency channels or carrier bandwidths of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). The TTI in eCC may include one or more symbol periods. In some implementations, the TTI duration (i.e., the number of symbol periods in the TTI) may be variable.

[0083] Wireless communication systems (such as NR systems) can utilize any combination of licensed, shared, and unlicensed spectrum bands. The flexibility of eCC symbol duration and subcarrier spacing allows eCC to be used across multiple spectrums. In some examples, NR spectrum sharing can improve spectrum utilization and efficiency, particularly through dynamic vertical (e.g., across frequency domains) and horizontal (e.g., across time domains) sharing of resources.

[0084] Figure 2A An example of the first time slot 200 within the 5G NR frame structure is shown. Figure 2B An example of DL channel 230 within a 5G NR timeslot is shown. Figure 2C An example of the second time slot 250 within the 5G NR frame structure is shown. Figure 2D An example of UL channel 280 within a 5G NR timeslot is shown. In some instances, the 5G NR frame structure can be FDD, where timeslots within a specific set of subcarriers (carrier system bandwidth) are dedicated to either DL or UL transmission. In some other instances, the 5G NR frame structure can be TDD, where timeslots within a specific set of subcarriers (carrier system bandwidth) are dedicated to both DL and UL transmission. Figure 2A and 2C In the example shown, the 5G NR frame structure is based on TDD, where slot 4 is configured with slot format 28 (mostly DL) and slot 3 is configured with slot format 34 (mostly UL), where D indicates DL, U indicates UL, and X indicates that the slot can be flexibly used between DL and UL. Although slots 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular slot 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 mixture of DL, UL, and flexible symbols. The UE can be configured to have a slot format via a Slot Format Indicator (SFI) (dynamically configured via Downlink Control Information (DCI) or semi-statically configured via Radio Resource Control (RRC) signaling). The configured slot format can also be applied to FDD-based 5G NR frame structures.

[0085] Other wireless communication technologies may have different frame structures or different channels. A frame can be divided into several subframes of equal size. For example, a frame with a duration of 10 milliseconds (ms) can be divided into 10 subframes of equal size, each with a duration of 1 ms. Each subframe may include one or more time slots. Subframes may also include mini-time slots, 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, while for time slot configuration 1, each time slot may include 7 symbols. Symbols on the DL can be cyclic prefix (CP) OFDM (CP-OFDM) symbols. Symbols on the UL can be CP-OFDM symbols (such as for high-throughput scenarios) or Discrete Fourier Transform (DFT) Extended OFDM (DFT-s-OFDM) symbols (also known as single-carrier frequency division multiple access (SC-FDMA) symbols) (such as for power-constrained scenarios).

[0086] The number of time slots per subframe is based on the time slot configuration and parameter design. For time slot configuration 0, different parameter designs (µ) 0 to 5 allow 1, 2, 4, 8, 16, and 32 time slots per subframe, respectively. For time slot configuration 1, different parameter designs 0 to 2 allow 2, 4, and 8 time slots per subframe, respectively. Accordingly, for time slot configuration 0 and parameter design µ, there are 14 symbols per time slot and 2µ time slots per subframe. The subcarrier spacing and symbol length / duration vary depending on the parameter design. The subcarrier spacing can be equal to 2^μ. 15 kHz, where μ is the parameter design from 0 to 5. Thus, parameter design µ=0 has a subcarrier spacing of 15 kHz, while parameter design µ=5 has a subcarrier spacing of 480 kHz. Symbol length / duration is inversely correlated with subcarrier spacing. Figure 2A-2D Examples are provided for slot configuration 0 with 14 symbols per slot and parameter design µ=0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 microseconds (μs).

[0087] A resource grid can be used to represent the frame structure. Each time slot consists of a resource block (RB) spanning 12 coherent subcarriers and extending across several symbols (also known as a physical RB (PRB)). The intersection of the subcarriers spans 14 symbols. The intersection of the subcarriers and the RBs defines multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0088] like Figure 2A As explained, some REs carry reference signals (RS) for the UE. In some configurations, one or more REs may carry demodulation reference signals (DM-RS) (indicated as Rx for a particular configuration, where 100x is the port number, but other DM-RS configurations are possible). In some configurations, one or more REs may carry channel state information reference signals (CSI-RS) for channel measurements at the UE. REs may also include beam measurement reference signals (BRS), beam refinement reference signals (BRRS), and phase tracking reference signals (PT-RS).

[0089] Figure 2BExamples of various DL channels within a subframe of a frame are explained. The Physical Downlink Control Channel (PDCCH) carries the DCI within one or more Control Channel Elements (CCEs), each CCE comprising 9 RE Groups (REGs), each REG comprising 4 consecutive REs in OFDM symbols. The Primary Synchronization Signal (PSS) is located within symbol 2 of a specific subframe of the frame. The PSS is used by the UE 104 to determine subframe or symbol timing and physical layer identity. The Secondary Synchronization Signal (SSS) is located within symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing. Based on the physical layer identity and physical layer cell identity group number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DM-RS. The Physical Broadcast Channel (PBCH) carrying the Primary Information Block (MIB) can logically be grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block. 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)) that are not transmitted through the PBCH, and paging messages.

[0090] like Figure 2C As explained, some REs carry DM-RS for channel estimation at the base station (indicated as R for a specific configuration, but other DM-RS configurations are possible). The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the first or first two symbols of the PUSCH. The PUCCH DM-RS can be transmitted in different configurations depending on whether a short or long PUCCH is transmitted and depending on the specific PUCCH format used. Although not shown, the UE can transmit a Probe Reference Signal (SRS). The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0091] Figure 2D Examples of various UL channels within a subframe of a frame are explained. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and can additionally be used to carry buffer status reports (BSR), power clearance reports (PHR), or UCI.

[0092] Figure 3A block diagram of an example base station 310 and UE 350 in the access network is shown. In the DL, IP packets from the EPC can be provided to the controller / processor 375. The controller / processor 375 implements Layer 3 and Layer 2 functionality. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Serving Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Media Access Control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting system information (such as MIB and SIB), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-Radio Access Technology (RAT) mobility, and measurement configuration of UE measurement reports; PDCP layer functionality associated with header compression / decompression, security (cryptography, cryptographic decoding, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with upper-layer packet data unit (PDU) delivery, error correction via ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel priority differentiation.

[0093] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functionality associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) decoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping to the signal constellation based on various modulation schemes such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), and M-quadrature amplitude modulation (M-QAM). The decoded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (such as a pilot signal) in the time or frequency domain, and subsequently combined using 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. A channel estimate from channel estimator 374 can be used to determine the coding and modulation scheme and for spatial processing. This channel estimate can be derived from a reference signal or channel condition feedback transmitted by UE 350. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX can use the corresponding spatial stream to modulate an RF carrier for transmission.

[0094] At UE 350, each receiver 354RX receives signals via its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides this information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on this information to recover any spatial stream destined for UE 350. If multiple spatial streams are destined for UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal consists of a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, along with the reference signal, are recovered and demodulated by determining the signal constellation points most likely to be transmitted by base station 310. These soft decisions can be based on a channel estimate calculated by channel estimator 358. These soft decisions are then decoded and deinterleaved to recover the original data and control signals transmitted by base station 310 over the physical channel. This data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functionality.

[0095] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between the transport and logical channels, packet reassembly, cipher decoding, header decompression, and control signal processing to recover IP packets from the EPC. The controller / processor 359 is also responsible for error detection using ACK or NACK protocols to support HARQ operation.

[0096] Similar to the functionality described in conjunction with DL transmissions performed by base station 310, controller / processor 359 provides RRC layer functionality associated with system information (such as MIB and SIB) capture, RRC connectivity, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (cryptography, cryptographic decoding, integrity protection, integrity verification); RLC layer functionality associated with upper-layer PDU delivery, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto TBs, demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel priority differentiation.

[0097] The channel estimate derived by the channel estimator 358 from the reference signal or feedback transmitted by the base station 310 can be used by the TX processor 368 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial stream generated by the TX processor 368 can be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX can use the corresponding spatial stream to modulate an RF carrier for transmission.

[0098] UL transmissions are processed at base station 310 in a manner similar to that described in conjunction with the receiver function at UE 350. Each receiver 318RX receives signals via its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides that information to the RX processor 370.

[0099] The controller / processor 375 may be associated with a memory 376 that stores program code 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, cipher decoding, header decompression, and control signal processing to recover IP packets from the UE 350. IP packets from the controller / processor 375 may be provided to the EPC. The controller / processor 375 is also responsible for error detection using ACK or NACK protocols to support HARQ operation. Information to be wirelessly transmitted (such as LTE- or NR-based communications) is encoded at the PHY layer and mapped to one or more radio channels for transmission.

[0100] exist Figure 3 In the example, each antenna 352 of the UE 350 is coupled to a corresponding transmitter 354TX. However, in some other implementations, the UE 350 may include fewer transmitters (or transmit chains) than the receive (RX) antennas. Although not shown for simplicity, each transmitter may be coupled to a corresponding power amplifier (PA) that amplifies the signal to be transmitted. The combination of transmitters and PAs may be referred to herein as a “transmit chain” or “TX chain”. To save cost or die area, the same PA may be reused to transmit signals through multiple RX antennas. In other words, one or more TX chains of the UE may be selectively coupled to multiple RX antenna ports.

[0101] Some UEs may have limited capabilities for receiving DL transmissions. For example, a limited-capability or low-capability (LC) UE may have only one antenna and may not be able to receive more than one broadcast TB in a given time slot. Additionally, the BWP size of an LC UE is relatively small compared to high-performance UEs such as eMBB and URLLC devices. To compensate for the reduced service coverage of LC UEs, coverage enhancement techniques have been introduced, enabling LC UEs to transmit and receive data over longer distances and at lower power levels in the radio access network. Coverage enhancement techniques may include intra-subframe repetition, repetition across different subframes, power boosting, beamforming, and spatial multiplexing. Different coverage enhancement techniques may result in different coverage trade-offs. For example, data repetition across multiple subframes may improve range and / or reception reliability, but may also reduce the data rate. Boosting transmit power may also increase range and / or reception reliability, but may increase energy consumption and cause interference to other transmissions.

[0102] While repetition and slot aggregation can effectively provide coverage enhancement for unicast DL transmissions, they can present problems when applied to DL transmissions that include broadcast information. For example, while unicast DL transmissions can be clustered or repeated in coherent slots of one or more subframes, using slot aggregation or transmission repetition techniques for DL ​​channels carrying specific broadcast information may not be resource-efficient, for instance, because high-performance UEs or LC UEs located close to the base station may not require repetition or slot aggregation to receive broadcast information. Furthermore, when the PDSCH carries SIB1, which contains initial frame synchronization information (as well as cell access and scheduling information for SIB2) required for the UE's location service cell's UL and DL channels, repeating SIB1 in coherent slots of the radio frame may be infeasible. More specifically, since some slots in a TDD frame may be configured for UL transmissions (rather than DL transmissions), one or more coherent slots selected for repetition in a radio frame may be configured for UL transmissions and therefore may not be available for repetition of SIB1 transmissions. However, since reconfigurations are typically indicated to the UE via RRC signaling, they are not well-suited for use with broadcast information transmitted on DL channels such as PDSCH.

[0103] According to some aspects of this disclosure, the repetition configuration for broadcast information transmitted on the PDSCH can be indicated in the DCI message (rather than via RRC signaling), which allows the base station to dynamically signal and / or modify the repetition configuration for DL ​​broadcast information. In some instances, the number of time slots available for repetition can be at least partially based on the modulation and coding scheme (MCS) used by the UE or UE group. For example, a relatively small number of time slots can be used for repetition when the MCS used by the UE (or UE group) is relatively low, while a relatively large number of time slots can be used for repetition when the MCS used by the UE (or UE group) is relatively high. In some implementations, the DCI message may include a bit map that identifies several time slots available for repetition. In some instances, the bit map may identify several consecutive time slots available for repetition within a radio frame. In some other instances, the bit map may identify several time slots available for repetition within a transmission period of SIB1.

[0104] Figure 4A This diagram illustrates a sequence of example message exchanges 400 between base station 402 and UE 404 in an Explanatory Radio Access Network (RAN). Base station 402 may be... Figure 1 Base station 102 or Figure 3 An example of base station 310, and UE 404 can be Figure 1 UE 104 or Figure 3An example of UE 350. Base station 402 can be any suitable base station or node, including, for example, a gNB or eNB. RAN can be any suitable radio access network and can utilize any suitable radio access technology. In some implementations, the access network can be a 5G NR communication system.

[0105] Base station 402 transmits downlink control information (DCI) indicating a repeat configuration for broadcast information carried on the Physical Downlink Shared Channel (PDSCH). The repeat configuration may indicate or identify several time slots configured for repeated transmission of broadcast information. In some aspects, repeat configuration can provide coverage enhancement for UEs with limited capabilities, such as those provided by one or more NR-Light (NR Lightweight) technical specifications. UE 404 receives the DCI and decodes the repeat configuration to identify the time slots used for repeated transmission of broadcast information.

[0106] Base station 402 transmits broadcast information on the PDSCH in multiple time slots according to a repetition configuration. In some instances, UE 404 may receive all the broadcast information carried in the initial transmission and may not require retransmission of the broadcast information. In other instances, UE 404 may receive only a portion (or none) of the broadcast information carried in the initial transmission and may receive the remainder of the broadcast information in one or more repetition transmission time slots of the PDSCH. In this way, UEs with limited capabilities (such as eMTC or LCUE) that cannot receive and correctly decode all the broadcast information carried in the initial PDSCH transmission can receive the additional portion of the broadcast information carried in the repetition time slots.

[0107] In some implementations, the broadcast information may include SIB1, which contains access information (such as cell identity information, cell selection and reselection information) and scheduling information for other SIBs. The repetition configuration carried in the DCI transmission may include a bitmap that identifies time slots available for repetitive transmission of broadcast information from base station 402 within the transmission period of SIB1. The bitmap may include a number of... N One place, that N Each bit in the unit indicates that it can be used for repeated transmission. N The corresponding time slot within each time slot. In some instances, this bit mapping may be copied once or multiple times to identify one or more additional time slots that can be used for repeated transmissions of SIB1 on the PDSCH. N Time slot set. In other instances, base station 402 will select only the first few of the identified available time slots. M Each time slot is used for repeated transmission. M The value can be based on the number of time slots configured for repeated transmission of broadcast information.

[0108] Figure 4B An example repeat configuration 420 for broadcast DL transmission is shown according to some implementations. In some implementations, the repeat configuration 420 may be indicated in a DCI message 422 containing a bitmap 424. For Figure 4B For example, the DCI bitmap 424 includes five bits b0–b4, where b0 = 1, b1 = 0, b2 = 1, b3 = 1, and b4 = 1. See also... Figure 4A The DCI message 422 can be transmitted to the UE on a DL channel (such as the PDCCH), and the DCI bit mapping 424 can identify several time slots configured to repeat broadcast information on the PDSCH within a SIB1 transmission period (such as 20 ms), where a bit value of "0" indicates that the corresponding time slot of the SIB1 transmission period is not configured for repeating broadcast information on the PDSCH, while a bit value of "1" indicates that the corresponding time slot of the SIB1 transmission period is configured for repeating broadcast information on the PDSCH. In some instances, the first bit b0 can be set to "1", for example, because the corresponding time slot of the SIB1 transmission period (time slot 0) is used for the initial or original transmission of broadcast information on the PDSCH.

[0109] Therefore, for Figure 4B In the example, the first bit b0 = 1 indicates that the first time slot of the SIB1 transmission period is configured for the initial broadcast message transmission, the second bit b1 = 0 indicates that the second time slot of the SIB1 transmission period is not configured for broadcast message repetition, the third bit b2 = 1 indicates that the third time slot of the SIB1 transmission period is configured for broadcast message repetition, the fourth bit b3 = 1 indicates that the fourth time slot of the SIB1 transmission period is configured for broadcast message repetition, and the fifth bit b4 = 1 indicates that the fifth time slot of the SIB1 transmission period is configured for broadcast message repetition.

[0110] In other implementations, the slots indicated by the DCI bit map for repetition can be identified relative to the PDCCH slots carrying the DCI message. For example, the first bit b0 could correspond to the PDCCH slot carrying the DCI message, the second bit b1 could correspond to the next slot in the SIB1 transmission period, the third bit b2 could correspond to the next slot in the SIB1 transmission period, and so on. In some other implementations, the DCI bit map 424 can include any suitable number of additional bits.

[0111] A base station (not shown for simplicity) may transmit a DCI message 422 to a UE (not shown for simplicity) to indicate a repeat configuration for DL ​​broadcast transmissions on the PDSCH. The UE may receive the DCI message 422, decode the bitmap 424, and identify time slots 0, 2, 3, and 4 of the radio frame as configured for repeating broadcast information on the PDSCH. Based on the bitmap 424, the UE may receive (if necessary) repeated transmissions of broadcast information in time slots 2, 3, and 4 of the radio frame. In this way, the repeat configuration for DL ​​broadcast transmissions on the PDSCH can be indicated to one or more UEs via the DCI message 424 (e.g., instead of RRC signaling), and therefore can be dynamically signaled and / or modified by the base station.

[0112] In some implementations, the DCI bitmap 424 includes a number of N One place, that N Each bit in the unit indicates that it can be used for repeated transmission. N The corresponding time slot in each time slot (where N (is an integer greater than 1), such as Figure 4B As depicted in [the document]. In some instances, only the first [number] of the identified available time slots is [selected]. M One time slot is used for repeated transmission, among which M It is less than N An integer. Additionally or alternatively, the DCI bit map 424 may be copied once or multiple times to identify one or more additional bits that can be used for repeated transmissions of SIB1. N Time slot set. In some other implementations, the DCI bit map 424 can identify the number of repeating time slots available within a SIB1 transmission period.

[0113] Frequency diversity of a radio medium or channel can be utilized by frequency hopping across a set of frequency resources or hopping channels according to a frequency hopping pattern. The frequency hopping pattern used for broadcast channels can be based on a set of hopping parameters configured by the network. Hopping parameters may include, for example, a hopping enable flag, one or more hopping offsets, the number and order of hopping channels to be hopped, and the hopping duration. In some aspects, the hopping parameters used for broadcast channel hopping can be configured independently by the network, and the base station can use RRC signaling to communicate the hopping parameter configuration information to the UE. In other aspects, the hopping parameters used for broadcast channel hopping can be the same as or based on hopping parameters defined in the SIB.

[0114] Figure 5A This diagram illustrates a sequence of example message exchanges 500 between base station 402 and UE 404 in an interpretive radio access network (RAN). Base station 402 may be... Figure 1 Base station 102 or Figure 3 An example of base station 310, and UE 404 can be Figure 1 UE 104 or Figure 3 An example of UE 350. Base station 402 can be any suitable base station or node, including, for example, a gNB or eNB. The RAN can be any suitable radio access network and can include any suitable radio access technology. The network includes a 5G NR communication system. In some implementations, base station 402 and UE 404 can use frequency hopping to utilize frequency diversity.

[0115] Base station 402 can select or determine a frequency hopping mode for transmitting broadcast information to one or more UEs, and transmit an indication of the frequency hopping mode for the PDSCH used to carry the broadcast information. In some implementations, the indication may also include or indicate several frequency hopping offsets associated with the frequency hopping mode. Base station 402 may transmit the indication of the frequency hopping mode and frequency hopping offsets in any suitable manner. In some instances, base station 402 may transmit these indications to UE 404 in the DCI.

[0116] UE 404 receives the PDSCH transmission and determines the frequency hopping mode and corresponding frequency hopping offset configured for the broadcast PDSCH. UE 404 can then receive the broadcast information carried on the PDSCH according to the indicated frequency hopping mode. In some instances, UE 404 may receive all the broadcast information carried in the initial transmission and may not need to repeat the broadcast information. In other instances, UE 404 may receive only a portion (or none) of the broadcast information carried by the initial broadcast PDSCH and may receive the remainder of the broadcast information on one or more hop channels in the frequency hopping mode.

[0117] In some implementations, the broadcast message may include a first system information block (SIB1), and the frequency hopping offset may be based on the size of the shared control resource set (CORESET#0) with index 0 allocated to the PDSCH. In other implementations, the broadcast message may include a paging signal or a random access response (RAR), and the frequency hopping offset may be configured by the SIB.

[0118] In some other implementations, base station 402 may indicate several time slots configured for carrying broadcast information in a PDSCH. The time slot indication may be transmitted in a broadcast PDSCH transmission or provided to UE 404 in one or more DCI messages. UE 404 receives one or more indications provided by base station 402 and may determine several time slot-specific frequency hopping offsets based on the indications received from base station 402. In some instances, the time slot-specific frequency hopping offsets may include a first frequency hopping offset for even-numbered time slots configured to carry broadcast information, and may include a second frequency hopping offset for odd-numbered time slots configured to carry broadcast information.

[0119] Figure 5BA sequence diagram illustrating another example message exchange 510 between base station 402 and UE 404 is shown. Base station 402 can select or determine a frequency hopping mode for transmitting broadcast information to one or more UEs and transmits an indication of the frequency hopping mode for a specific PDSCH on one of a plurality of beams available to base station 402. Base station 402 may also transmit one or more DCI messages indicating whether the bandwidth portion (BWP) associated with the SSB is shifted by the frequency hopping offset. If a BWP shift is indicated for an SSB, the UE can receive all subsequent broadcast PDSCH transmissions on the shifted BWP based on the indicated frequency hopping offset. If a BWP shift is not indicated, the frequency hopping mode is used only for the scheduled PDSCH carrying broadcast information. That is, the BWP shift is only used for the indicated SSB; for other unindicated SSBs, the BWP is not shifted. In some implementations, the BWP shift may also be applied to UL transmissions, such as, for example, the UL BWP for transmitting PRACH. UE 404 receives PDSCH transmissions and determines the frequency hopping mode for the PDSCH used to carry broadcast information. UE 404 can then receive broadcast PDSCH transmissions based on the indicated frequency hopping mode.

[0120] Base station 402 can also transmit synchronization signal blocks (SSBs) on specific beams. Except for other information not discussed herein for simplicity, the SSB can also indicate one or more frequency hopping offsets associated with the frequency hopping pattern. In some implementations, the frequency hopping offset can be based at least in part on the SSB associated with a specific beam. The frequency hopping offset can be semi-statically configured via Radio Resource Control (RRC) signaling. In some aspects, the RRC signaling can indicate a mapping between multiple beams associated with the base station and several frequency hopping offsets.

[0121] In some instances, UE 404 may receive all broadcast information carried in the initial transmission and may not require repeated transmission of the broadcast information. In other instances, UE 404 may receive only a portion (or none) of the broadcast information carried by the initial broadcast PDSCH and may receive the remainder of the broadcast information on one or more hop channels in frequency hopping mode.

[0122] Figure 5C Example inter-SSB frequency hopping mode 520 for broadcast DL transmissions is shown according to some implementations. Inter-SSB frequency hopping mode 520 can be used to assign broadcast PDSCH transmissions associated with different beams or SSBs of a base station to different frequency bands or hopping channels of one or more frequency hopping modes. In some implementations, an SSB-specific frequency hopping offset can be used to ensure that broadcast PDSCH transmissions on different beams or associated with different SSBs do not share the frequency hopping channel (sharing the frequency hopping channel would cause collisions). For Figure 5CFor example, SIB1 for each of SSB1-SSB4 can be transmitted on four distinct, non-overlapping frequency hopping channels by using SSB-specific frequency hopping offsets. That is, the frequency hopping offset associated with the first beam can be based on SSB1, the frequency hopping offset associated with the second beam can be based on SSB2, the frequency hopping offset associated with the third beam can be based on SSB3, and the frequency hopping offset associated with the fourth beam can be based on SSB4.

[0123] Specifically, the first DCI message DCI-1 can send a signaling notification or trigger the use of the first frequency resource 521 in time slot 0 for DL ​​transmission of SIB1 for SSB1, while the second DCI message DCI-2 can send a signaling notification or trigger the use of the second frequency resource 522 in time slot 0 for DL ​​transmission of SIB1 for SSB2. The third DCI message DCI-3 can send a signaling notification or trigger the use of the third frequency resource 523 in time slot 1 for DL ​​transmission of SIB1 for SSB3, and the fourth DCI message DCI-4 can send a signaling notification or trigger the use of the fourth frequency resource 524 in time slot 1 for DL ​​transmission of SIB1 for SSB4.

[0124] Figure 5D An example inter-slot frequency hopping pattern 530 for broadcast DL transmission is illustrated according to some implementations. Inter-slot frequency hopping pattern 530 can be used with repeating PDSCHs by using slot-specific frequency hopping offsets. As shown, a DCI message can signal to notify or trigger DL transmissions for SIB1 for SSB0 using four example different frequency hopping channels 531-534 that do not overlap in time or frequency. In some implementations, the broadcast information may include SIB1, and each frequency hopping offset may be based on the size of a shared control resource set (CORESET#0) with index 0 allocated to the PDSCH. In some other implementations, the broadcast information may include one or more of a paging signal or a random access response (RAR), and each frequency hopping offset may be configured by the SIB carried on the PDSCH. Additionally or alternatively, the slot-specific frequency hopping offset may include a first frequency hopping offset for even-numbered slots among the identified slots, and may include a second frequency hopping offset for odd-numbered slots among the identified slots.

[0125] Figure 6A This diagram illustrates a sequence of example message exchanges 600 between base station 402 and UE 404 in an Explanatory Radio Access Network (RAN). Base station 402 may be... Figure 1 Base station 102 or Figure 3 An example of base station 310, and UE 404 can be Figure 1 UE 104 or Figure 3An example of UE 350. Base station 402 can be any suitable base station or node, including, for example, a gNB or eNB. RAN can be any suitable radio access network and can employ any suitable radio access technology.

[0126] UE 404 can use random access procedures to establish Layer-1 (physical layer) and Layer-2 (MAC layer) connections with base station 402, and subsequently use RRC procedures to establish Layer-3 connections (such as RRC connections) with base station 402. Figure 6A As shown, UE 404 transmits a random access preamble as Msg1 to base station 402 on the random access channel (RACH). The random access preamble comprises a sequence of preambles selected randomly or pseudo-randomly. In some implementations, the selection of the preamble sequence may indicate to the UE a request for coverage enhancement (CE) associated with the transmission of the random access response (RAR) on the PDSCH. In some aspects, when the SSB-based reference signal received power (RSRP) level is less than a certain value (e.g., indicating that the UE may need RAR repetition to receive and correctly decode the RAR), the UE may transmit a random access preamble requesting RAR coverage enhancement. In some other implementations, the base station may determine that the UE is capable of receiving the RAR on a PDSCH with repetition based on the capabilities reported by the UE. In some instances, the RACH may be a contention-based UL channel, while in other instances, the RACH may be a contention-free UL channel.

[0127] In some implementations, base station 402 may transmit the Physical Downlink Control Channel (PDCCH) that schedules PDSCH over several consecutive time slots, and subsequently transmit a RAR containing a random access preamble identifier as Msg2 in one or more of the consecutive time slots of the PDSCH. In some instances, the PDSCH may be associated with a transport block size (TBS) scaling factor of one-eighth, for example, to effectively reduce the MCS used for PDSCH transmission for coverage enhancement. In some other instances, the PDSCH carrying the RAR may be associated with a TBS scaling factor of other values, such as greater than one-eighth, and coverage enhancement may be achieved through repetitive transmission of the RAR over several consecutive time slots of the PDSCH.

[0128] In some implementations, the base station can indicate whether the RAR is transmitted with or without duplication, for example, to enable the UE to determine whether coverage enhancement is provided for the RAR. In some instances, the base station can use a CRC mask of the PDCCH to distinguish between RAR transmissions with and without coverage enhancement (e.g., based on different RA-RNTIs used for PDCCHs with and without coverage enhancement). In other instances, the base station can use bits (such as MSB) of the MCS field in the DCI message to distinguish between RAR transmissions with and without coverage enhancement. In some still instances, the base station can use an additional CRC mask for several MSBs of the CRC parity bits to distinguish between RAR transmissions with and without coverage enhancement. For example, the base station can use an 8-bit mask to scramble 8 MSBs of the CRC parity bits based on the following expression:

[0129] ,for k = A , …, A +7

[0130] as well as ,for k = A +8, A +9, …, A +23,

[0131] in It is the sequence after CRC appending. It is the sequence after CRC scrambling, and It is the 8-bit mask defined in Table 1:

[0132]

[0133] Table 1

[0134] UE 404 receives RAR in one or more time slots of the PDSCH and determines whether the random access preamble identifier contained in Msg2 matches the preamble sequence transmitted to base station 402 in Msg1. When a match is found, UE 404 can initiate an RRC connection establishment procedure. When no match is found, UE 404 can continue to monitor the PDSCH (such as one or more subsequent time slots of the PDSCH identified by the PDCCH).

[0135] In some implementations, when the index of the random access preamble identifier contained in Msg2 matches the index of the random access preamble sequence contained in Msg1, UE 404 may skip decoding the RAR in one or more subsequent time slots of the PDSCH. In some instances, when the index of the random access preamble identifier is greater than the index of the random access preamble sequence, UE 404 may suppress decoding of the RAR in subsequent time slots. In other instances, when the index of the random access preamble identifier and the index of the random access preamble sequence are in different groups, UE 404 may suppress decoding of the RAR in subsequent time slots.

[0136] UE 404 may transmit an RRC connection request as Msg3 to base station 402. The RRC connection request may contain a UE identity (UEID) uniquely identifying UE 404. Base station 402 receives Msg3 and can use the UE identity to retrieve the UE's context and capabilities from associated core network entities. In some instances, base station 402 may use the UE's radio capability information to determine the initial signaling radio bearer (SRB1) configuration for UE 404. Base station 402 may transmit the SRB1 configuration to UE 404 as Msg4 in an RRC connection establishment message. UE 404 receives Msg4, determines its SRB1 configuration, and transmits an RRC connection establishment complete message as Msg5 to base station 402. Base station 402 can terminate the RRC connection establishment procedure upon receiving Msg5.

[0137] In some implementations, base station 402 may transmit the Physical Downlink Control Channel (PDCCH) of the PDSCH within several consecutive time slots, and subsequently transmit the RAR (Msg2) in one or more time slots of the consecutive time slots of the PDSCH. In some instances, each time slot of the consecutive time slots of the PDSCH may be associated with a different Transport Block (TB), and the transmission of the RRC Connection Establishment Message (Msg3) may be initiated based on the last symbol period of the time slot carrying the RAR in the PDSCH. In some other implementations, the consecutive time slots of the PDSCH may be aggregated time slots associated with the same TB, and the transmission of the RRC Connection Establishment Message (Msg3) may be initiated based on the last symbol period of the aggregated time slot.

[0138] Figure 6B Explanation 620 illustrates an example scheduling of multiple transport blocks that can be used for broadcast DL transport, based on some implementations. See also: Figure 6ADCI message 622 can be transmitted to the UE on a DL channel (such as PDCCH) to schedule multiple PDSCHs carrying a RAR (Msg2) in consecutive timeslots of the same PDCCH. In such implementations, the start of Msg3 transmission can be based on the last symbol of the corresponding PDSCH timeslot. In some instances, each of several consecutive timeslots of the PDSCH can be associated with a different transport block (TB) and a different RAR.

[0139] Figure 6C Explanation 630 illustrates an example scheduling of repeating time slots that can be used for broadcast DL transmission, based on some implementations. See also... Figure 6A DCI message 632 can be transmitted to the UE on a DL channel (such as PDCCH) to schedule PDSCH carrying RAR with slot aggregation or repetition. In such implementations, the start of Msg3 transmission can be based on the last symbol of the corresponding PDSCH repetition transmission slot. In some instances, several consecutive slots of the PDSCH are aggregated slots associated with the same transport block (TB) and the same RAR.

[0140] Figure 7 A flowchart depicting an example operation 700 of repeated wireless communication supporting broadcast information is shown. Operation 700 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 4A The UE (404) performs the following steps: In block 702, the UE receives downlink control information (DCI) indicating a repeat configuration for carrying broadcast information on the Physical Downlink Shared Channel (PDSCH). In block 704, the UE identifies several time slots configured to carry broadcast information on the PDSCH, based at least in part on this repeat configuration. In block 706, the UE receives the broadcast information carried on the PDSCH in the identified time slots.

[0141] A repetition configuration can indicate or identify several time slots configured for repeated transmission of broadcast information. In some implementations, the broadcast information may include a first system information block (SIB1), and the repetition configuration may include a bit map identifying the time slots available for repetition within the transmission period of SIB1. The bit map may include a number of... N One place, that N Each bit in the unit indicates that it can be used for repeated transmission. N The corresponding time slot within a time slot. In some implementations, UE 404 may receive SIB1 in one or more repeating time slots identified by a bitmap. In some instances, this bitmap may be copied once or multiple times to identify one or more additional time slots available for repeated transmission of SIB1. NA set of time slots. In other instances, only the first few available time slots... M One time slot was used for repeated transmission, of which M The value can be based on the number of available time slots.

[0142] Figure 8 A flowchart depicting an example operation 800 of a repeating wireless communication supporting broadcast information is shown. Operation 800 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 4A Executed via UE 404. In some implementations, example operation 800 can be performed with... Figure 7 In operation 700, block 706, the UE receives broadcast information on the PDSCH at least partially concurrently. In block 802, the UE receives repetitions of SIB1 in one or more of several time slots identified by a bitmap. In some implementations, the bitmap may be copied once or multiple times to identify one or more additional time slots available for repetition. N Time slot set.

[0143] Figure 9 A flowchart depicting an example operation of wireless communication supporting frequency hopping on a broadcast PDSCH is shown. Operation 800 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 5A The UE (404) performs the following: In block 902, the UE receives an indication of the frequency hopping mode for the Physical Downlink Shared Channel (PDSCH) used to carry broadcast information. In block 904, the UE receives broadcast information on the PDSCH based on the frequency hopping mode.

[0144] In some implementations, the broadcast information may include a first system information block (SIB1), and each of the several frequency hopping offsets may be based on the size of a shared control resource set (CORESET#0) with index 0 allocated to the PDSCH. In some other implementations, the broadcast information may include one or more of a paging signal or a random access response (RAR), and each of the several frequency hopping offsets may be configured by an SIB carried on the PDSCH. Additionally or alternatively, this indication may identify the several frequency hopping offsets used for the frequency hopping mode.

[0145] Figure 10A A flowchart depicting an example operation 1000 of wireless communication supporting frequency hopping on a broadcast PDSCH is shown. Operation 1000 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 5AUE 404) is executed. In some implementations, example operation 1000 can be performed. Figure 9 Operation 900 is executed before receiving broadcast information in box 904. In other implementations, example operation 1000 can be... Figure 9 The operations 900 are performed separately. In block 1002, the UE receives indications of several time slots configured to carry broadcast information using a PDSCH. In block 1004, the UE determines a time slot-specific frequency hopping offset based at least in part on the identified several time slots. In block 1006, the UE receives broadcast information carried in the identified several time slots based at least in part on the frequency hopping mode and the time slot-specific frequency hopping offset.

[0146] In some implementations, the slot-specific frequency hopping offset may include a first frequency hopping offset for an even number of identified time slots, and may include a second frequency hopping offset for an odd number of identified time slots. In some aspects, this indication may be received in a downlink control information (DCI) message.

[0147] Figure 10B A flowchart depicting an example operation 1010 of wireless communication supporting frequency hopping on a downlink channel carrying broadcast information is shown. Operation 1010 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 5A (UE 404) is executed. In some implementations, example operation 1010 can be performed. Figure 9 Operation 900 is executed before receiving broadcast information in box 904. In other implementations, example operation 1010 can be... Figure 9 The operations 900 are performed separately. In block 1012, the UE receives a synchronization signal block (SSB) on the beam transmitted by the base station. In block 1014, the UE determines the frequency hopping offset based at least in part on the received SSB. In block 1016, the UE receives broadcast information carried on the PDSCH via the beam based at least in part on the frequency hopping mode and the determined frequency hopping offset.

[0148] In some implementations, frequency hopping offsets can be configured semi-statically via Radio Resource Control (RRC) signaling. RRC signaling can indicate the mapping between multiple beams associated with a base station and several frequency hopping offsets, and can indicate the mapping between each of the multiple beams and its corresponding SSB among multiple SSBs.

[0149] Figure 10C A flowchart depicting an example operation 1020 of wireless communication supporting frequency hopping on a downlink channel carrying broadcast information is shown. Operation 1020 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3UE 350, or Figure 5A (UE 404) is executed. In some implementations, example operation 1020 can be performed. Figure 9 Operation 900 is executed before receiving broadcast information in box 904. In other implementations, example operation 1020 can be... Figure 9 The operations 900 and 900 are performed separately. In box 1022, the UE receives a downlink control information (DCI) message indicating whether the bandwidth portion (BWP) associated with the SSB has been shifted by the frequency hopping offset.

[0150] Figure 11 A flowchart depicting an example operation 1100 of wireless communication supporting repeated transmissions with random access procedures is shown. Operation 1100 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 6A The UE (404) performs the following steps: In block 1102, the UE transmits a random access preamble sequence to the base station. In block 1104, the UE receives a Physical Downlink Control Channel (PDCCH), which schedules a Physical Downlink Shared Channel (PDSCH) in several consecutive time slots. In block 1106, the UE receives a Random Access Response (RAR) from the base station in one or more time slots of the PDSCH, the RAR including a random access preamble identifier. In block 1108, the UE transmits a Radio Resource Control (RRC) connection establishment message to the base station, at least in part, based on the received RAR.

[0151] In some implementations, each of the several consecutive time slots of the PDSCH can be associated with a different transport block (TB), and the start of RRC connection establishment message transmission can be based on the last symbol period in the PDSCH time slot carrying RAR. In some other implementations, the several consecutive time slots of the PDSCH can be aggregated time slots associated with the same TB, and the start of RRC connection establishment message transmission can be based on the last symbol period of the aggregated time slot.

[0152] Figure 12A A flowchart depicting an example operation 1200 of wireless communication supporting repeated transmissions with random access procedures is shown. Operation 1200 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 6A UE 404) is executed. In some implementations, example operation 1200 can be performed. Figure 11The operation 1100 is performed after receiving the RAR in box 1104. In box 1202, the UE compares the index of the random access preamble identifier with the index of the random access preamble sequence. In box 1204, the UE skips decoding the RAR in subsequent time slots based on this comparison.

[0153] Figure 12B A flowchart depicting an example operation 1210 of wireless communication supporting repeated transmissions with random access protocol is shown. Operation 1210 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 6A The UE 404) is executed. In some implementations, example operation 1210 can be Figure 12A An example of skipping RAR decoding is shown in box 1204 of operation 1200. In box 1212, the UE suppresses RAR decoding when the index of the random access preamble identifier is greater than the index of the random access preamble sequence. In box 1214, the UE continues RAR decoding when the index of the random access preamble identifier is not greater than the index of the random access preamble sequence.

[0154] Figure 12C A flowchart depicting an example operation 1220 of wireless communication supporting repeated transmissions with random access procedures is shown. Operation 1220 can be performed by a wireless communication device (such as...) Figure 1 UE 104 Figure 3 UE 350, or Figure 6A The UE 404) is executed. In some implementations, example operation 1220 can be Figure 12A An example of skipping RAR decoding is shown in box 1204 of operation 1200. In box 1222, the UE suppresses RAR decoding when the index of the random access preamble identifier and the index of the random access preamble sequence are in different groups. In box 1224, the UE continues RAR decoding when the index of the random access preamble identifier and the index of the random access preamble sequence are in the same group.

[0155] As used in this article, the phrase “at least one of” refers to any combination of these items, including a single member. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc.

[0156] The various descriptive logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the implementations disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. This interchangeability between hardware and software has been generally described in terms of its functionality, and is explained in the various descriptive components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0157] Hardware and data processing apparatuses for implementing the various descriptive logics, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed using general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (such as a combination of a DSP and a microprocessor), multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by a circuit system dedicated to a given function.

[0158] In one or more aspects, the described functionality may be implemented in hardware, digital electronic circuit systems, computer software, firmware (including the structures disclosed in this specification and their structural equivalents), or any combination thereof. Implementation of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus.

[0159] If implemented in software, the functions can be stored or transmitted as one or more instructions or codes on or through a computer-readable medium. The processes of the methods or algorithms disclosed herein can be implemented in a processor-executable software module that can reside on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium that can be implemented to transfer a computer program from one location to another. Storage media can be any available medium accessible to a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection can also be properly referred to as a computer-readable medium. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operation of a method or algorithm may reside as one of code and instructions, or any combination or set of code and instructions, on a machine-readable and computer-readable medium that may be incorporated into a computer program product.

[0160] Various modifications to the implementations described in this disclosure may be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the implementations shown herein, but are to be granted the broadest scope consistent with this disclosure, the principles disclosed herein, and the novel features.

Claims

1. A wireless communication method performed by a user equipment (UE), comprising: Receive instructions for frequency hopping mode; as well as Broadcast information is received via the Physical Downlink Shared Channel (PDSCH) based at least in part on the frequency hopping pattern and one or more frequency hopping offsets, wherein the one or more frequency hopping offsets are based at least in part on: The number of time slots associated with the PDSCH, or Synchronization signal block SSB, The method further includes at least one of the following: The SSB is received via a beam associated with the one or more frequency hopping offsets. Receive Radio Resource Control (RRC) signaling, the RRC signaling indicating a mapping between multiple beams and the number of one or more frequency hopping offsets, or Receive a downlink control information (DCI) message, the DCI message indicating whether the bandwidth portion (BWP) associated with the SSB has been shifted from the frequency hopping offset in one or more frequency hopping offsets.

2. The method of claim 1, wherein the indication identifies the number of the one or more frequency hopping offsets.

3. The method of claim 1, wherein the broadcast information includes a first system information block SIB1, and each of the one or more frequency hopping offsets is based at least in part on the size of a shared control resource set CORESET#0 with index 0 allocated to the PDSCH.

4. The method of claim 1, wherein the broadcast information includes one or more of a paging signal or a random access response (RAR), and each of the one or more frequency hopping offsets is configured by a System Information Block (SIB).

5. The method of claim 1, further comprising: Receive an indication of the number of time slots, wherein the one or more frequency hopping offsets are one or more time slot-specific frequency hopping offsets and are at least partially based on the number of time slots, and The broadcast information is received in the number of time slots based at least in part on the frequency hopping mode and the one or more time slot-specific frequency hopping offsets.

6. The method of claim 5, wherein the one or more time slot-dedicated frequency hopping offsets comprise: The first frequency hopping offset for the even number of time slots in the stated number of time slots, and The second frequency hopping offset is used for the odd number of time slots in the said number of time slots.

7. The method of claim 1, wherein one or more of the plurality of beams have different frequency hopping offsets among the one or more frequency hopping offsets.

8. A user equipment (UE), comprising: transceiver; One or more processors; as well as A memory coupled to the one or more processors and storing instructions that, when executed by the one or more processors, cause the UE to: The transceiver receives an instruction for frequency hopping mode. as well as Broadcast information is received via the Physical Downlink Shared Channel (PDSCH) and via the transceiver, based at least in part on the frequency hopping mode and one or more frequency hopping offsets, wherein the one or more frequency hopping offsets are based at least in part on: The number of time slots associated with the PDSCH, or Synchronization signal block SSB, The instructions, when executed by the one or more processors, cause the UE to perform at least one of the following: The SSB is received via the transceiver through a beam associated with the one or more frequency hopping offsets. Radio Resource Control (RRC) signaling is received via the transceiver, the RRC signaling indicating a mapping between multiple beams and the number of one or more frequency hopping offsets, or The transceiver receives a downlink control information (DCI) message, which indicates whether the bandwidth portion (BWP) associated with the SSB has been shifted from the frequency hopping offset in one or more frequency hopping offsets.

9. The UE of claim 8, wherein the indication identifies the number of the one or more frequency hopping offsets.

10. The UE of claim 8, wherein the broadcast information includes a first system information block SIB1, and each of the one or more frequency hopping offsets is based at least in part on the size of a shared control resource set CORESET#0 with index 0 allocated to the PDSCH.

11. The UE of claim 8, wherein the broadcast information includes one or more of a paging signal or a random access response (RAR), and each of the one or more frequency hopping offsets is configured by a System Information Block (SIB).

12. The UE of claim 8, wherein the instructions, when executed by the one or more processors, cause the UE to: The transceiver receives an indication of the number of time slots, wherein the one or more frequency hopping offsets are one or more time slot-specific frequency hopping offsets and are at least partially based on the number of time slots. The broadcast information is received in the number of time slots based at least in part on the frequency hopping mode and the one or more time slot-specific frequency hopping offsets.

13. The UE of claim 12, wherein the one or more time slot-dedicated frequency hopping offsets include: The first frequency hopping offset for the even number of time slots in the stated number of time slots, and The second frequency hopping offset is used for the odd number of time slots in the said number of time slots.

14. The UE of claim 8, wherein one or more of the plurality of beams have different frequency hopping offsets among the one or more frequency hopping offsets.

15. A computer-readable medium storing computer-executable code, wherein the code, when executed, causes a processor to implement the method of any one of claims 1 to 7.

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