WO2020164095A1

WO2020164095A1 - Methods and apparatuses for low bandwidth wireless communications

Info

Publication number: WO2020164095A1
Application number: PCT/CN2019/075179
Authority: WO
Inventors: Qiaoyu Li; Chao Wei; Changlong Xu
Original assignee: Qualcomm Incorporated
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2020-08-20

Abstract

5G NR may need support low-bandwidth (BW) UEs, in addition to regular UEs and a physical downlink control channel (PDCCH) resource interleaving. Given the limited bandwidth and processing capabilities of the low-BW UE and the PDCCH resource interleaving, it may be very difficult for the low-BW UE to correctly receive and decode a PDCCH intended for a regular UE. The apparatus and methods are disclosed herein to enable the low-BW UE to correctly receive and decode a PDCCH intended for a regular UE via PDCCH repetitions. The method includes determining a PDCCH repetition pattern based at least in part on a main information block (MIB), receiving an initial PDCCH and at least one PDCCH repetition in next one or more messages based on the PDCCH repetition pattern, and decode the received initial PDCCH and at least one PDCCH repetition.

Description

METHODS AND APPARATUSES FOR LOW BANDWIDTH WIRELESS COMMUNICATIONS

BACKGROUND Field

The present disclosure relates generally to communication systems, and more particularly, to communications with user equipment with low bandwidths.

Background

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

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

5G NR may need to support interleaving of signaling resource such as (physical down link control channel) PDCCH resource for better performance. In addition, 5G NR may also need to accommodate UEs with different bandwidths and processing capabilities, including UEs with very limited or low bandwidth (low-BW) , and processing capability. For example, a low-BW UE may have a bandwidth equal to or less than 5 MHz, while a “regular” may have a bandwidth equal to or more than 20 MHz bandwidth processing capability. The examples of low-BW UEs include but are not limited to sensors, wearable devices, and logistic devices. Various issue may arise for low-BW UEs to correctly receive and decode signaling message such a cell-specific PDCCH designed for regular UEs, especially when PDCCH resource interleaving is supported.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

Initial signaling messages such as type-0 PDCCH is important for a UE to successfully initiate a random access channel (RACH) process to gain access to a cell. For a low-BW UE, it is difficult, if not impossible to correctly receive and decode a type-0 PDCCH message that is designed and intended for a regular UE. Because of the limited processing power and bandwidth, the low-BW may not be able to receive and decode the entire PDCCH that are carried on a PDCCH resource that is beyond the low-BW UE’s own bandwidth and processing capability. A proposed solution is to send an initial PDCCH and at least one PDCCH repetition. This allows the low-BW UE to correctly receive and decode a portion of the entire PDCCH each time the UE receives one of the initial PDCCH and the PDCCH repetitions. After a fixed number of PDCCH repetition, the UE is able to correctly receive and decode the whole PDCCH.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus is configured to enable a low-BW UE to correctly receive and decode a PDCCH intended for a regular UE via PDCCH repetitions. The method includes determining a PDCCH repetition pattern based at least in part on a main information block (MIB) received over a broadcast channel or a plurality of PDCCH repetition patterns stored in a local memory, and receiving and decoding an initial PDCCH and at least one PDCCH repetition in next one or more messages based on the PDCCH repetition pattern.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network, in accordance with aspects of the present disclosure.

FIG. 4 is a diagram illustrating a base station in communication with a UE, in accordance with aspects of the present disclosure.

FIG. 5 is a message diagram showing message flow between a gNB and a low-BW UE, in accordance with aspects of the present disclosure.

FIG. 6 includes a table and a diagram illustrating a PDCCH repetition pattern, in accordance with aspects of the present disclosure.

FIG. 7 includes a table and a diagram illustrating a PDCCH repetition pattern, in accordance with aspects of the present disclosure.

FIG. 8 is a diagram illustrating a PDCCH repetition pattern, in accordance with aspects of the present disclosure.

FIG. 9 is a diagram illustrating a PDCCH repetition pattern, in accordance with aspects of the present disclosure.

FIG. 10 is a flowchart of a method of wireless communication, in accordance with aspects of the present disclosure.

FIG. 11 is a conceptual data flow diagram illustrating the data flow between different means/components in an exemplary apparatus, in accordance with aspects of the present disclosure.

FIG. 12 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system, in accordance with aspects of the present disclosure.

FIG. 13 is a flowchart of a method of wireless communication, in accordance with aspects of the present disclosure.

FIG. 14 is a conceptual data flow diagram illustrating the data flow between different means/components in an exemplary apparatus, in accordance with aspects of the present disclosure.

FIG. 15 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system, in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

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

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes 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, systems on a chip (SoC) , 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 functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, 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 language, or otherwise.

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

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, and an Evolved Packet Core (EPC) 160. The base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station) . The macro cells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) , or New Radio (NR) generic NodeB (gNB) ) interface with the EPC 160 through backhaul links 132 (e.g., S1 interface) . In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160) with each other over backhaul links 134 (e.g., X2 interface) . The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 192. The D2D communication link 192 may use the DL/UL WWAN spectrum. The D2D communication link 192 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102′ , employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

The gNodeB (gNB) 180 may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW /near mmW radio frequency band has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 184 with the UE 104 to compensate for the extremely high path loss and short range.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a toaster, a low-power sensor, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, the UE 104 and base station 180 may be configured to have a PDCCH repetition module 198. The PDCCH repetition module 198 may be configured to allow a low-BW UE to correctly receive and decode a PDCCH sent from a gNB and designed for a regular UE via PDCCH repetitions.

FIG. 2A is a diagram 200 illustrating an example of a DL frame structure. FIG. 2B is a diagram 230 illustrating an example of channels within the DL frame structure. FIG. 2C is a diagram 250 illustrating an example of an UL frame structure. FIG. 2D is a diagram 280 illustrating an example of channels within the UL frame structure. Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent the two time slots, each time slot including one or more time concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs) ) . The resource grid is divided into multiple resource elements (REs) . For a normal cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols (for DL, OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. The DL-RS may include cell-specific reference signals (CRS) (also sometimes called common RS) , UE-specific reference signals (UE-RS) , and channel state information reference signals (CSI-RS) . FIG. 2A illustrates CRS for

antenna ports

0, 1, 2, and 3 (indicated as R ₀, R ₁, R ₂, and R ₃, respectively) , UE-RS for antenna port 5 (indicated as R ₅) , and CSI-RS for antenna port 15 (indicated as R) .

FIG. 2B illustrates an example of various channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol 0 of slot 0, and carries a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustrates a PDCCH that occupies 3 symbols) . The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH may have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset including one RB pair) . The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0 and carries the HARQ indicator (HI) that indicates HARQ acknowledgement (ACK) /negative ACK (NACK) feedback based on the physical uplink shared channel (PUSCH) . The primary synchronization channel (PSCH) may be within symbol 6 of slot 0 within

subframes

0 and 5 of a frame. The PSCH carries a primary synchronization signal (PSS) that is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. The secondary synchronization channel (SSCH) may be within symbol 5 of slot 0 within

subframes

0 and 5 of a frame. The SSCH carries a secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSCH and SSCH to form a synchronization signal (SS) block. The MIB provides a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry demodulation reference signals (DM-RS) for channel estimation at the base station. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various channels within an UL subframe of a frame. A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

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

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

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

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

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression /decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

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

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

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

FIG. 4 is a diagram 400 illustrating a base station 402 in communication with a UE 404. Referring to FIG. 4, the base station 402 may transmit a beamformed signal to the UE 404 in one or more of the

directions

402a, 402b, 402c, 402d, 402e, 402f, 402g, 402h. The UE 404 may receive the beamformed signal from the base station 402 in one or more receive

directions

404a, 404b, 404c, 404d. The UE 404 may also transmit a beamformed signal to the base station 402 in one or more of the directions 404a-404d. The base station 402 may receive the beamformed signal from the UE 404 in one or more of the receive directions 402a-402h. The base station 402 /UE 404 may perform beam training to determine the best receive and transmit directions for each of the base station 402 /UE 404. The transmit and receive directions for the base station 402 may or may not be the same. The transmit and receive directions for the UE 404 may or may not be the same. Synchronization signals may be used for beam management.

FIG. 5 is a diagram illustrating example message flow 500 between a base station and a low-BW UE, in accordance with aspects of the present disclosure. In order to help understand the message flow 500 and PDCCH repetition patterns as illustrated in FIGs. 6-9 and described in the corresponding sections, various terms related to 5G NR, in addition to those as described above for FIGs. 1-4, are briefly introduced below.

A resource Element (RE) for NR is same as for LTE: it is the smallest unit of the resource grid made up of one subcarrier in frequency domain and one OFDM symbol in time domain. A resource Element Group (REG) is made up of one resource block (12 resource elements in frequency domain) and one OFDM symbol in time domain. A REG bundle is made up of multiple REGs. The bundle size is specified by the parameter ′L′ . A Control Channel Element (CCE) is made up of multiple REGs. The number of REG bundles within a CCE varies. An aggregation level in NR indicates how many CCEs are allocated for a PDCCH.

A control resource set (CORESET) in NR is a set of physical resources (i.e., a specific area on NR Downlink Resource Grid) and a set of parameters that is used to carry PDCCH/DCI. It is similar to LTE PDCCH area or region (the first 1, 2, 3, 4 OFDM symbols in a subframe) . But in LTE PDCCH region, the PDCCH generally spread across the whole channel bandwidth. An NR CORESET region is localized within each bandwidth part (BWP) to a specific region in frequency domain. A CORESET is made up of multiples resource blocks (i.e., multiples of 12 REs) in frequency domain and ′1 or 2 or 3′ OFDM symbols in time domain. In LTE, the frequency domain of the control region is same as the total system bandwidth, so no parameter is needed to define the frequency domain region for LTE control region. Time domain region can be {1, 2, 3} which is determined by PCFICH. In comparison, in NR both frequency region and time domain region can be defined by RRC signaling message.

A PDCCH may be a cell-specific PDCCH, broadcast to the entire cell. In contrast, there may be a dedicated PDCCH for a specific UE once a connection has been established between the UE and cell. The PDCCH, as described in the present disclosure refers to the cell-specific PDCCH unless indicated otherwise. A type-0 PDCCH is a special PDCCH that includes system information for the UE to initiate the RACH process to gain access to the cell. For example, a type-0 PDCCH may include a DCI. Included in the DCI may be information about a PDSCH which also include information for a UE to initiate a RACH process, the information such as RMSI. A PDCCH, as used in the present disclosure, refers to a type-0 PDCCH unless indicated otherwise. A CORESET 0 is a special CORESET that includes one or more type-0 PDCCH.

A CORESET search space refers to a frequency resource space where the UE may find a CORESET such as CORESET 0. The management information block (MIB) that is broadcast from the cell may include information about CORESET 0 search space, for example, starting symbol within a slot of the CORESET search space. CORESET 0 may be repeated a number of times. Type-0 PDCCH may also be repeated a number of times.

PDCCH resource interleaving refers to the fact that the REs for a PDCCH are spread over multiple places in the resource grid, rather than the REs being contiguous within the resource grid. With interleaving, the low-BW UE may not be able to correctly receive and decode the CORESET 0 at all, because the CORESET 0 may spread over a large bandwidth range and outstrip the UE’s bandwidth and processing capability. In one example aspect, CORESET 0 is used to carry a number of PDCCHs, including one or more of type-0 PDCCHs.

In both single beam and multi-beam scenarios, time division multiplexing of NR-PSS, NR-SSS, and NR-PBCH is supported. NR-PSS, NR-SSS and/or NR-PBCH can be transmitted within an SS block. For a given frequency band, an SS block corresponds to N OFDM symbols based on the default subcarrier spacing, and N is a constant. The signal multiplexing structure may be fixed. UE may be able to identify at least OFDM symbol index, slot index in a radio frame and radio frame number from an SS block. One or multiple SS block (s) compose an SS burst.

One or multiple SS burst (s) further compose an SS burst set where the number of SS bursts within a SS burst set is finite. From physical layer specification perspective, at least one periodicity of SS burst set is supported. From the UE perspective, SS burst set transmission is periodic and UE may assume that a given SS block is repeated with a SS burst set periodicity. Note that NR-PBCH contents in a given repeated SS block may change. A single set of possible SS block time locations is specified per frequency band. The maximum number of SS blocks within SS burst set may be carrier frequency dependent. The position (s) of actual transmitted SS-blocks can be signaled to a UE for helping CONNECTED/IDLE mode measurement, for helping CONNECTED mode UE to receive DL data/control in unused SS-blocks and potentially for helping IDLE mode UE to receive DL data/control in unused SS blocks. By default, the UE may neither assume the gNB transmits the same number of physical beam (s) , nor the same physical beam (s) across different SS-blocks within an SS burst set. For initial cell selection, UE may assume default SS burst set periodicity which may be frequency band-dependent. At least for multi-beams case, the time index of an SS block is indicated to the UE.

The SS burst set periodicity may be associated with a certain number of system frames. An SS burst set includes a number of SSB burst, which in turn includes a number of SSB. In one example, an SSB is used for beam management, for finding a suitable beam for communications between the UE and a gNB.

In conventional systems, a UE without a RRC configurations for CORESET may need to read MIB in PBCH to obtain the cell-specific CORESET and its search space. As indicated above, a CORESET carries a type-0 PDCCH and an associated DCI. The CORESET in conventional systems is also referred to as a CORESET-0. After successfully decoding the DCI carried by the type-0 PDCCH, the UE may decode the PDSCH scheduled by the DCI, where an RMSI is carried by the PDSCH. The bandwidth of the CORESET-0 may be too high for a low-BW UE with limited processing BW. As a result, the low-BW UE may not be able to decode the typep-0 PDCCH.

An alternative approach is disclosed in the present disclosure, that enable repetition of the type-0 PDCCH multiple times by the NW, such that the low-BW UE may receive partial frequency resource of the type-0 PDCCH during each of the initial PDCCH and subsequent PDCCH repetitions. The term “PDCCH repetitions, ” as used in the present disclosure, may refer to the total number of PDCCH transmissions needed for a low-BW UE to correctly receive and decode an entire PDCCH.

At least one repetition of the PDSCH scheduled by the DCI is also needed, which is scheduled after the last PDCCH repetition. After successfully decoding the DCI based on the PDCCH repetitions, the UE may obtain the resource information of the PDSCH repetition and decode the PDSCH.

For the message flow 500 which illustrates an example message flow for Type-0 PDCCH repetitions between a base station and a low-BW UE, base station 504 may be a 5G gNB such as base station 180 of FIG. 1. UE 502 may be a 5G-capable low-BW UE with limited bandwidth and processing power, such as a UE 104 of FIG. 1. A dotted line indicates the associated step may be optional.

At 505, the base station 504 may determine a repetition pattern. Upon knowing that there are some UEs in the cell with limited bandwidth and processing power, the base station may determine a repetition pattern to accommodate the low-BW UEs. Due to limited bandwidth and processing power, the UE may not be able to receive and decode PDCCH in a single transmission. Instead, based on the PDCCH repetition pattern, the UE may receive and decode a part of the PDCCH in an initial PDCCH transmission and receive and decode other parts of the PDCCH in a number of PDCCH repetitions. The PDCCH repetition pattern at least includes the information related to the initial PDCCH and PDCCH repetitions so that the UE know how and where to receive and decode the initial PDCCH and the PDCCH repetitions.

The base station may determine the repetition pattern based on a number of factors. The factors may include the processing bandwidth of the low-BW UEs within the cell, whether PDCCH resources are interleaved, a subcarrier spacing of the initial PDCCH, and the mapping of control channel element (CCE) to resource element groups, among other factors.

At 506, the base station 504 broadcast a physical broadcast channel (PBCH) carrying signaling information for the entire cell such as system information block (SIB) and/or main information block (MIB) . The MIB may include information for UE 504 to receive and decode a cell-specific PDCCH which may further include system information that the UE may use to initiate a random access channel (RACH) process to gain access to the cell and establish a connection with the base station. In one example aspect, UE 502 may receive a PDCCH repetition pattern included in the MIB. In an alternative aspect, both UE 502 and base station 504 may determine PDCCH repetition pattern from a plurality of PDCCH repetition patterns stored at a local memory of each side. Then the base station may simply indicate to the UE a specific PDCCH repetition pattern index in the MIB.

At 508, base station 504 transmits the initial PDCCH and PDCCH repetitions, according to the determined repetition pattern. The transmissions are carried on a broadcast channel to the entire cell.

At 509, the UE receives and decodes the initial PDCCH and the PDCCH repetitions, according to the successfully decoded PDCCH repetition pattern. The successfully decoded initial PDCCH and PDCCH repetitions may include one or more downlink control information (DCI) elements. The successfully decided DCI may include information related to a physical downlink shared channel (PDSCH) .

At 510, base station 504 may transmit an initial PDSCH and a number of PDSCH repetitions, based on the information in the DCI. At 511, UE 502 receives and decodes the initial PDSCH and PDSCH repetition, according to the information in the decoded DCI. The initial PDSCH and the PDSCH repetitions may include a remaining system information (RSMI) element. At this point, the UE may have the information sufficient to initiate a RACH process to gain access to and establish a connection with the cell.

As indicated above, FIG. 5 is provided merely as an example. Other examples are possible and may differ from what is described with regard to FIG. 5 but are still within the spirit of the current disclosure.

FIG. 6 illustrates an example PDCCH repetition pattern 600, in accordance with aspects of the present disclosure. Table 602 and a diagram 604 help illustrate the PDCCH repetition pattern 600 from various perspectives. At a high level, the PDCCH repetition pattern 600 is meant to show that the PDCCH repetitions take place across multiple synchronization signal (SS) burst sets.

Referring to Table 602 of FIG. 6, it shows relationships among system frame number (SFN) index, number of resource blocks (RBs) with different subcarrier spacings (SCSs) . For example, there may be three different CORESET configurations, with 24 RBs, 48 RBs, and 96 RBs respectively. Furthermore, for each CORESET configuration, there may be two SCSs, 15 KHz and 30 KHz respectively. An entry in table 602 may indicate the PDCCH repetition index number, if any. For example, for 24-RB CORESET configuration with a SCS of 15KHz, there may not be a need for any PDCCH repetition. For another example, for the 48-RB CORESET configuration with the 30 KHz SCS, there may be 4 PDCCH repetitions, represented by the table entries of #0, #1, #2, #3 across

SFN indices

0, 2, 4, through 30 respectively.

Diagram 604 illustrates an example of 4 PDCCH repetitions, including initial PDCCH transmission, according to the PDCCH repetition pattern 600. The vertical axis of diagram 604 represents resource block (RB) of an SSB burst set while the horizontal axis represents system frame numbers (SFN) , which represent burst sets. Diagram 602 shows four PDCCH repetitions including the initial PDCCH, taking place at SS burst sets 612, 614, 616, and 618 respectively.

For example, during SS burst set 612, the UE may capture and receive the first part of the PDCCH at SNF-#0. Subsequently, the UE may capture and receive remaining parts of the PDCCH during SS burst sets 614, 616, and 618 with SFN-#2, SFN-#4, SFN-#6 respectively.

For the PDCCH repetition pattern 600, the number of PDCCH repetitions is associated with the desired UE-processing bandwidth and the PDCCH bandwidth. The PDCCH bandwidth is directly associated with the subcarrier spacing of PDCCH resources. For example, if CORESET has 24 RBs, the SCS is 15 KHz, and the UE bandwidth is 10 MHz, then there may not be a need for PDCCH repetition. For another example, if the CORESET has 24 RBs, SCS is 30 KHz, and the UE bandwidth is 10 MHz, there may be two PDCCH repetitions (one initial PDCCH transmission and one retransmission) .

As shown above, the PDCCH repetition pattern 600 is associated with SFNs, for example, 20 ms SS burst set periodicity. Number of repetition is based on the bandwidth occupied by the CORESET and the processing capability of the low-BW UE. If PDCCH is repeated N times, 0 ＜ SFN ＜ SFN_max, the UE may make use of the following relationship: if mod (SFN/2, N) =0, a new PDCCH repetition starts; else PDCCH repetition is same as CORESET-0 with regard to the latest SFN index SFN_2, where mod (SFN_2/2, N) =0.

As indicated above, FIG. 6 is provided merely as an example. Other examples are possible and may differ from what is described with regard to FIG. 6 but are still within the spirit of the current disclosure.

FIG. 7 illustrates an example of PDCCH repetition pattern 700, in accordance with aspects of the present disclosure. Table 702 and diagram 704 together help illustrate the PDCCH repetition pattern 700. At a high level, the PDCCH repetition pattern 700 is meant to show that the PDCCH repetitions take place across multiple SSBs within a single SS burst set.

Table 702 of the PDCCH repetition pattern 700 shows relationships among SSB index, number of REGs or RBs with different SCSs. For example, there may be three different CORESET configurations, with 24 RBs, 48 RBs, and 96 RBs respectively. Furthermore, for each CORESET configuration, there may be two SCSs, 15KHz and 30 KHz respectively. The entries in table 602 indicate the PDCCH repetition number, if any. For example, for 24-PRB CORESET configuration with 15KHz, there may not be a need for any PDCCH repetition. For another example, for the 48-RB CORESET configuration with 30 KHz SCS, there may be 4 PDCCH repetitions, represented by #0, #1, #2, and #3, across

SSBs

0, 1, 2, to 7 of the same SS burst set.

Diagram 704 of the PDCCH repetition pattern 700 illustrates an example of 4 PDCCH repetitions, including the initial PDCCH transmission. The vertical axis of diagram 704 represents resource block (RB) of an SSB burst set while the horizontal axis represents SSB index number within the same SS burst set. Diagram 704 shows four PDCCH repetitions that take place at

SSBs

712, 714, 716, and 718 respectively.

For example, during SSB-#0 712, the UE may capture and receive the first part of the PDCCH. Subsequently, the UE may capture and receive remaining parts of type0 PDCCH during

SSBs

714, 716, and 718 with the SSB index numbers SSB-#1, SSB-#2, and SSB-#3 respectively.

The PDCCH repetition pattern 700 is associated with the desired UE-processing bandwidth and the PDCCH bandwidth. The PDCCH bandwidth is directly associated with the subcarrier spacing of PDCCH resources. For example, if CORESET has 24 RBs, the SCS is 15 KHz, and the UE bandwidth is 10 MHz, then there may not be a need for PDCCH repetition. For another example, if the CORESET has 24 RBs, SCS is 30 KHz, and the UE bandwidth is 10 MHz, there may need to be two PDCCH repetitions (one initial PDCCH transmission and one retransmission) .

As shown above, the PDCCH repetition pattern 700 is associated with SSBs within a single SS burst set. Multiple SSBs are generally used for beam management, and some SSB may not contain CORESET #0. To enable CORESET #0 repetition, in one example aspect, each SSB should have at least one CORESET #0 and should be repeated in certain pattern. In another example aspect, one bit in the MIB may be used to indicate to a UE whether the SSBs are used for CORESET 0 repetitions or beam management.

As shown above, the PDCCH repetition pattern 700 is associated with SSBs, for example, 20 ms SSB periodicity. Number of repetition is based on the bandwidth occupied by the CORESET and the processing capability of the low-BW UE. If PDCCH is repeated N times, and 0 ＜ SSB-index ＜ SSB_max, the UE may make use of the following relationship: if mod (SSB-index/N) =0, it is the start of a new PDCCH repetition; else, PDCCH repetition is same as CORESET-0 with regard to the latest SSB index SSB-index_2, where mod (SSB-index_2, N) =0.

As indicated above, FIG. 7 is provided merely as an example. Other examples are possible and may differ from what is described with regard to FIG. 7 but are still within the spirit of the current disclosure.

FIG. 8 illustrates an example of PDCCH repetition pattern 800, in accordance with aspects of the present disclosure. At a high level, the PDCCH repetition pattern 800 is meant to show that the PDCCH repetitions take place across multiple slots within a single SS burst set.

In one example aspect, FIG. 8 shows 4 SSBs and 2 type-0 PDCCH repetitions. For example, the initial PDCCH transmission 802 takes place at slot 0 of SSB 0 and a repetition of the PDCCH happens on slot 4. Similarly, an initial transmission of a second PDCCH 804 takes place at slot 1 and its repetition happens at slot 5. Similarly, an initial transmission of a third PDCCH 806 takes place at slot 2 and its repetition happens at slot 6. Similarly, an initial transmission of a fourth PDCCH 808 takes place at slot 3 and its repetition happens at slot 7. Slots 0 through 7 are all within one SS burst set.

In one example aspect, one slot contains one SSB. There may be at least one CORESET 0 search space associated with the corresponding SSB, also within the same slot. Slots not transmitting SSB may be used for type-0 PDCCH repetitions. The DMRS of a repetition slot such as slot 4, slot, 5, slot 6, or slot 7 may be quasi co-located with the corresponding SSB, meaning that the repeated type-0 PDCCH is transmitted using the same beam as the corresponding SSB. The search space of a specific PDCCH repetition may be obtained implicitly, via its associated original CORESET 0’s search space.

As indicated above, FIG. 8 is provided merely as an example. Other examples are possible and may differ from what is described with regard to FIG. 8 but are still within the spirit of the current disclosure.

FIG. 9 illustrates an example of PDCCH repetition pattern 900, in accordance with aspects of the present disclosure. At a high level, the PDCCH repetition pattern 900 is meant to show that the PDCCH repetitions take place across different symbols within a single SSB.

In one example aspect, FIG. 9 shows 4 SSBs and 4 PDCCHs, each with 2 repetitions (initial type-0 PDCCH and a PDCCH repetition) . For example, the initial PDCCH transmission 902 takes place at one symbol of SSB 0 and slot 0 and a repetition of the PDCCH happens at another symbol within the same slot and SSB. Similarly, an initial transmission of a second PDCCH 904 takes place at one symbol and its repetition happens at a later symbol of the same SSB 1 and slot 1. Similarly, an initial transmission of a third PDCCH 906 takes place at one symbol and its repetition happens at a later symbol of the slot 2 and SSB 2. Similarly, an initial transmission of a fourth PDCCH 908 takes place at a symbol and its repetition happens at a later symbol within the same slot and SSB (slot 3 and SSB 3) . In this example, one slot contains 1 SSB.

In one example aspect, within a slot, some of its symbols may be transmitting an SSB, and those symbols within the slot not transmitting a legacy PDCCH may be used for PDCCH repetitions for low-BW UE. The DMRS of the repeated PDCCH may be quasi co-located with the corresponding legacy type-0 PDCCH and the associated SSB, meaning that the repeated PDCCH is transmitted using the same beam as the corresponding SSB.

As indicated above, FIG. 9 is provided merely as an example. Other examples are possible and may differ from what is described with regard to FIG. 9 but are still within the spirit of the current disclosure.

FIG. 10 is a flowchart of a method of wireless communication, illustrating method 1000 of wireless communication in accordance with various aspects of the present disclosure. The method 1000 implements a method for a UE with a limited bandwidth and processing power to receive and decode a PDCCH intended for a UE with regular bandwidth and processing power. The method 1000 may be performed by a UE such as the UE 504 of FIG. 5 or any of the UE 120s of FIG. 1. The optional steps are indicated in dotted lines.

At 1002, the method 1000 includes receiving a PBCH. All UEs in the cell such as UE 504 of FIG. 5 may receive a PBCH from the base station over a broadcast channel. The PBCH may include system wide information for the cell such as main information block (MIB) . The MIB may include information for the UE to receive and decode a PDCCH.

At 1004, the method 1000 includes determining a PDCCH repetition pattern. The repetition pattern may indicate, among other items, whether a PDCCH is repeated; a number of times the PDCCH is repeated, and a time domain repetition pattern.

In one example aspect, the UE may determine the PDCCH repetition pattern locally based on information from a received MIB and a number of factors. The factors may include, but are not limited to the processing bandwidth of the low-BW UE, whether PDCCH resources are interleaved, a subcarrier spacing of the initial PDCCH and the at least one PDCCH repetition, and the mapping of control channel element (CCE) to resource element groups. In one example aspect, if the PDCCH resources are interleaved, the search space for the low-BW UE will be larger than when the PDCCH resource are not interleaved. The UE may determine the PDCCH repetition pattern, using a set of agreed rules and based on the factors described above, if the UE is to determine the PDCCH repetition pattern locally based on the set of agreed rules.

Alternatively, the UE may determine the PDCCH repetition pattern from a plurality of PDCCH repetition patterns that are predetermined and stored in the UE local memory. The base station may indicate a PDCCH repetition index number in the MIB for the UE to select a PDCCH repetitions from the plurality of the predetermined PDCCH repetition patterns.

In another example aspect, when subcarrier spacing is larger for the PDCCH resources, the UE would need larger bandwidth to receive and process the PDCCH. Accordingly, there is a greater need for PDCCH repetitions than otherwise.

The PDCCH repetition pattern includes at least a control resource set (CORESET) repetition pattern and a corresponding search space repetition pattern.

The PDCCH repetition pattern may also indicate how a PDCCH repetition is carried and transmitted over wireless resources. In one example aspect, the PDCCH repetitions may takes place across multiple SS burst sets. In this case, the repetition pattern may be associated with the UE processing bandwidth which is further associated with a subcarrier spacing and a number of resource blocks in the COREDSET. Furthermore, in this case, the PDCCH repetition is associated with an SS burst set periodicity.

In another example aspect, the PDCCH repetition pattern may indicate that PDCCH repetitions may take place across multiple SSBs within a single SS burst set. the PDCCH repetitions may be associated with an SSB index. Each of the multiple SSBs includes at least one CORESET, and the MIB includes an indicator indicating whether the SSBs are used for beam management or for the at least one PDCCH repetition. In general case, the SSBs may be used for tuning and synchronizing the beams between the UE and the gNB. If the SSB is not used for a purpose other than beam management, the information may be indicated in the MIB so that the UE know the SSB may be used for PDCCH repetition.

In another example aspect, the PDCCH repetitions may take place across one or more slots within a SS burst set. A slot that does not transmit an SSB may be used to carry a PDCCH repetition. The CORESET and its corresponding search space of the PDCCH repetitions may be associated with the initial PDCCH within the SS burst set corresponding to the PDCCH repetition. In this case, the demodulation reference signal (DMRS) for a PDCCH repetition may be quasi co-located with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition.

In yet another example aspect, the repetition pattern may indicate that the PDCCH repetitions may take place across different symbols within an SSB. In this case, the DMRS for each of the PDCCH repetitions may be quasi co-located with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition. A symbol within the SSB that is not transmitting the initial PDCCH may be used to carry the PDCCH repetition.

At 1006, the method 1000 includes receiving an initial PDCCH and one or more PDCCH repetitions in next one or more messages. Upon determining the PDCCH repetition pattern, the UE knows how and where to receive the initial PDCCH and each of the at least one PDCCH repetition. In one example aspect, the initial PDCCH is a PDCCH intended for the low-BW UE and information not related to low-BW UE may not be included in the PDCCH repetition. In one example aspect, the UE may use a local buffer to store the received initial PDCCH and one or more PDCCH repetitions to facilitate decoding of the received PDCCH repetitions.

At 1008, the method 1000 includes decoding the received initial PDCCH and one or more PDCCH repetitions. In one example aspect, upon receiving the initial PDCCH and one or more PDCCH repetitions, the UE may extract part of the original PDCCH from each of the received initial PDCCH and PDCCH repetitions and combine them into a complete, original PDCCH. Then the UE may decode the combined PDCCH. This process may allow the UE to decode only the parts that are related to low-BW UEs and avoid decoding the parts the PDCCHs that are not intended for the low-BW UEs.

In another example aspect, a message from the gNB may include information for both regular UEs and a low-BW UEs. Based on the determined PDCCH repetition pattern, the low-BW UE may decode portions of the next one or more message that is related to the initial PDCCH and the PDCCH repetitions, and avoid decoding the part of the next one or more messages that are not related to the low-BW UE and the PDCCH repetition. After decoding the low-BW related portions of PDCCHs, then the UE may combine them into the complete, original PDCCH that a regular UE may receive.

At 1010, the method 1000 includes receiving an initial PDSCH and PDSCH repetition based on the decoded PDCCH as described above. The UE may receive and decode an initial PDSCH and at least one PDSCH repetition for the low-BW UE in the next one or more messages based at least in part on a successful decoding of one of the at least one DCI included the received and decoded initial PDCCH and PDCCH repetitions. In one example aspect, the initial PDSCH includes, among other information, a remaining system information (RMSI) element that the UE may use to initiate a RACH procedure.

In one example aspect, there is a predefined relationship between resources for the at least one PDSCH repetition for the low-BW UE and a DCI for the initial PDSCH. In one example aspect, each of the PDSCH repetitions may be carried in a same slot as a PDCCH repetition which includes a corresponding successfully decoded DCI.

As indicated above, the method 1000 is for illustration purpose and shows one possible method for a low-BW UE to correctly receive and decode a PDCCH with PDCCH repetition. In practice, one or more steps shown in illustrative flowchart for the method 1000 may be combined with other steps, performed in any suitable order, performed in parallel (e.g., simultaneously or substantially simultaneously) , or removed.

FIG. 11 is a conceptual data flow diagram 1100 illustrating the data flow between different means/components in an exemplary apparatus 1102. The apparatus may be a low-BW UE that has limited bandwidth and processing capability such as 5MHz or less. The apparatus includes a reception component 1104 that receive broadcast SIB, MIB and PBCH, initial PDCCH, PDCCH repetitions, initial PDSCH and PDSCH repetition, among other items, a PDCCH repetition component 1106 that may determine a PDCCH repetition pattern, and process received initial PDCCH and one or more subsequent PDCCH repetitions, a PDSCH repetition component 1108 that may process received initial PDSCH and PDSCH repetitions, and a transmission component 1110 that may transmit information related to random access channel (RACH) procedure after PDCCH repetitions and PDSCH repetitions are correctly received and decoded.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIGs. 5 and 10. As such, each block in the aforementioned flowcharts of FIGs 5 and 10 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 12 is a diagram 1200 illustrating an example of a hardware implementation for an apparatus 1102′ employing a processing system 1214. The processing system 1214 may be implemented with a bus architecture, represented generally by the bus 1224. The bus 1224 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1214 and the overall design constraints. The bus 1224 links together various circuits including one or more processors and/or hardware components, represented by the processor 1204, the

components

1104, 1106, 1108, and 1110 and the computer-readable medium /memory 1206. The bus 1224 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system 1214 may be coupled to a transceiver 1210. The transceiver 1210 is coupled to one or more antennas 1220. The transceiver 1210 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1210 receives a signal from the one or more antennas 1220, extracts information from the received signal, and provides the extracted information to the processing system 1214, specifically the reception component 1104. In addition, the transceiver 1210 receives information from the processing system 1214, specifically the transmission component 1110, and based on the received information, generates a signal to be applied to the one or more antennas 1220. The processing system 1214 includes a processor 1204 coupled to a computer-readable medium /memory 1206. The processor 1204 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory 1206. The software, when executed by the processor 1204, causes the processing system 1214 to perform the various functions described supra for any particular apparatus. The computer-readable medium /memory 1206 may also be used for storing data that is manipulated by the processor 1204 when executing software. The processing system 1214 further includes at least one of the

components

1104, 1106, 1108, and 1110. The components may be software components running in the processor 1204, resident/stored in the computer readable medium /memory 1206, one or more hardware components coupled to the processor 1204, or some combination thereof. The processing system 1214 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359.

In one configuration, the apparatus 1102/1102′ for wireless communication includes means for determining PDCCH repetition pattern, means for receiving and decoding an initial PDCCH and at least one PDCCH repetition, and means for receiving and decoding an initial PDSCH and at least one PDSCH repetition. The aforementioned means may be one or more of the aforementioned components of the apparatus 1102 and/or the processing system 1214 of the apparatus 1102′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system 1214 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

FIG. 13 is a flowchart of a method of wireless communication, illustrating method 1300 of wireless communication in accordance with various aspects of the present disclosure. The method 1300 implements a way for a gNB to transmit a PDCCH in such a way to enable a UE with a limited bandwidth and processing capability to correctly receive and decode a PDCCH intended for a UE with regular bandwidth and processing capability. The method 1300 may be performed by a gNB such as the gNB 502 of FIG. 5 or any of the base stations 102s of FIG. 1. The optional steps are indicated in dotted lines.

At 1302, the method 1300 includes broadcasting a PBCH intended for all UEs in the cell over a broadcast channel. The PBCH may include system wide information for the cell such as system information block (SIB) and/or main information block (MIB) . The MIB may include information for the UEs in the cell to receive and decode a cell-specific PDCCH.

At 1304, the method 1300 includes determining a PDCCH repetition pattern. The repetition pattern may indicate, among other items, whether a type-0 PDCCH is repeated; a number of times the type-0 PDCCH is repeated in at least one of an initial PDCCH, and PDCCH repetitions; and a time domain repetition pattern.

In one example aspect, the gNB may determine the PDCCH repetition patterns either in part based on a variety of factors or a plurality of PDCCH repetition patterns that are predetermined and stored in a memory of the gNB.

The PDCCH repetition pattern may be determined based on a number of factors. The factors may include, but are not limited to the processing bandwidth of the low-BW UEs in the cell, whether PDCCH resources are interleaved, a subcarrier spacing of the initial PDCCH and the at least one PDCCH repetition, and the mapping of control channel element (CCE) to resource element groups. In one example aspect, if the PDCCH resources are interleaved, the search space for the low-BW UEs will be larger than when the PDCCH resources are not interleaved. Accordingly, it becomes more challenging for the low-BW UE to receive and process the regular PDCCH. PDCCH repetitions is more needed than otherwise, in order for the low-BW UEs in the cell to correctly receive and process the PDCCH.

In another example aspect, when subcarrier spacing is larger for the PDCCH resources, a UE would need larger bandwidth to receive and process the PDCCH. Accordingly, there is a stronger need for PDCCH repetitions than otherwise for a low-BW UE.

Each of the initial PDCCH and the at least one PDCCH repetition may be carried within one or more synchronization blocks (SSBs) . The PDCCH repetition pattern may include at least a CORESET repetition pattern and a corresponding search space repetition pattern. The PDCCH repetition pattern may also indicate how a PDCCH repetition is carried and transmitted over wireless resources. In one example aspect, the PDCCH repetition pattern indicates that the PDCCH repetitions may takes place across multiple SS burst sets.

In an alternative example aspect, the PDCCH repetition pattern may also indicate that PDCCH repetitions may take place across multiple SSBs within a single SS burst set. The PDCCH repetitions may be associated with an SSB index. Each of the multiple SSBs includes at least one CORESET, and the MIB includes an indicator indicating whether the SSBs are used for beam management or for the PDCCH repetitions. In general case, the SSBs may be used for tuning and synchronizing the beams between the UE and the gNB. If the SSB is not used for beam management, the information may be indicated in the MIB so that the UE may know the SSB is used for the PDCCH repetitions.

In another example aspect, the PDCCH repetition may take place across one or more slots within a SS burst set. A slot that does not transmit an SSB may be used to carry the PDCCH repetition. The CORESET and its corresponding search space of the PDCCH repetition is associated with the initial PDCCH within the SS burst set corresponding to the PDCCH repetition. In this case, the DMRS for the PDCCH repetition may be quasi co-located with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition.

In yet another example aspect, the repetition pattern may indicate that the PDCCH repetition may take place across different symbols within an SSB. In this case, the DMRS for each of the at least one PDCCH repetition is quasi co-located with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition. A symbol within the SSB that is not transmitting the initial PDCCH may be used to carry the PDCCH repetition.

At 1306, the method 1300 includes transmitting an initial PDCCH and one or more PDCCH repetitions in next one or more messages. Upon determining the PDCCH repetition pattern, the gNB knows how and where to transmit the initial PDCCH and each of the PDCCH repetitions.

In one example aspect, the gNB may transmit initial PDCCH is a type-0 PDCCH related to low-BW UE and information not related to low-BW UE is not included in the PDCCH repetition.

In an example aspect, the gNB may include information for both regular UE and a low-BW UE in an initial PDCCH or subsequent PDCCH repetitions. Based on the determined PDCCH repetition pattern, the UE may decode portions of the next one or more message that is related the initial PDCCH and the PDCCH repetitions, and avoid decoding the part of the next one or more messages that are not related to low-BW UE and the PDCCH repetition.

At 1308, the method 1300 includes transmitting an initial PDSCH and PDSCH repetition based on determined PDCCH repetition pattern. In one example aspect, the initial PDSCH includes, among other information, a RMSI element that enable a UE to initiate a random access channel (RACH) process to gain access to the cell.

In one example aspect, there is a predefined relationship between resources for the at least one PDSCH repetition for the low-BW UE and a DCI for the initial PDSCH. In one example aspect, each of the PDSCH repetitions may be carried in a same slot as a PDCCH repetition which includes a corresponding DCI.

As indicated above, the method 1300 is for illustration purpose and shows one possible process for a gNB to perform PDCCH repetitions to enable a low-BW UE to receive and encode a PDCCH correctly. In practice, one or more steps shown in illustrative flowchart for the method 700 may be combined with other steps, performed in any suitable order, performed in parallel (e.g., simultaneously or substantially simultaneously) , or removed.

FIG. 14 is a conceptual data flow diagram 1400 illustrating the data flow between different means/components in an exemplary apparatus 1402. The apparatus may be a gNB that communicates with a UE of regular bandwidth and a low-BW UE that has limited bandwidth and processing capability such as 5MHz or less. The apparatus includes a reception component 1404 that may receive signals from both regular UEs and low-BW UEs. The apparatus may include a PDCCH repetition component 1406 that may determine a PDCCH repetition pattern, and build contents of an initial PDCCH and one or more subsequent PDCCH repetitions. The apparatus may also include a PDSCH repetition component 1408 that builds contents of an initial PDSCH and PDSCH repetitions, and a transmission component 1410 that may transmit a PBCH, an initial PDCCH, PDCCH repetitions, an initial PDSCH, and PDSCH repetitions, among other information to a low-BW UE.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIGs. 5 and 13. As such, each block in the aforementioned flowcharts of FIGs 5 and 13 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 15 is a diagram 1500 illustrating an example of a hardware implementation for an apparatus 1402′ employing a processing system 1514. The processing system 1514 may be implemented with a bus architecture, represented generally by the bus 1524. The bus 1524 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1514 and the overall design constraints. The bus 1524 links together various circuits including one or more processors and/or hardware components, represented by the processor 1504, the

components

1404, 1406, 1408, and 1410 and the computer-readable medium /memory 1506. The bus 1524 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system 1514 may be coupled to a transceiver 1510. The transceiver 1510 is coupled to one or more antennas 1520. The transceiver 1510 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1510 receives a signal from the one or more antennas 1520, extracts information from the received signal, and provides the extracted information to the processing system 1514, specifically the reception component 1104. In addition, the transceiver 1510 receives information from the processing system 1514, specifically the transmission component 1110, and based on the received information, generates a signal to be applied to the one or more antennas 1520. The processing system 1514 includes a processor 1504 coupled to a computer-readable medium /memory 1506. The processor 1504 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory 1506. The software, when executed by the processor 1504, causes the processing system 1514 to perform the various functions described supra for any particular apparatus. The computer-readable medium /memory 1506 may also be used for storing data that is manipulated by the processor 1504 when executing software. The processing system 1514 further includes at least one of the

components

1404, 1406, 1408, and 1410. The components may be software components running in the processor 1504, resident/stored in the computer readable medium /memory 1506, one or more hardware components coupled to the processor 1504, or some combination thereof. The processing system 1514 may be a component of the base station 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

In one configuration, the apparatus 1402/1402′ for wireless communication includes means for determining a PDCCH repetition pattern, means for transmitting an initial PDCCH and at least one PDCCH repetition, means for transmitting the PDCCH repetition pattern or a PDCCH repetition pattern index in a MIB, and means for transmitting an initial physical downlink shared channel (PDSCH) and at least one PDSCH repetition. The aforementioned means may be one or more of the aforementioned components of the apparatus 1402 and/or the processing system 1514 of the apparatus 1402′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system 1514 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes /flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

Claims

A method for wireless communications by a low-bandwidth (BW) UE, comprising:

determining a physical downlink control channel (PDCCH) repetition pattern based at least in part on a main information block (MIB) received over a broadcast channel or a plurality of PDCCH repetition patterns stored in a local memory;

receiving an initial PDCCH and at least one PDCCH repetition in next one or more messages based on the PDCCH repetition pattern; and

decoding the received initial PDCCH and the at least one PDCCH repetition.
The method of claim 1, wherein the initial PDCCH and the at least one PDCCH repetition comprise a type-0 PDCCH and the type-0 PDCCH comprises at least one downlink control information (DCI) ; and wherein each of the initial PDCCH and the at least one PDCCH repetition is carried within one or more synchronization blocks (SSBs) and wherein the PDCCH repetition pattern includes at least a control resource set (CORESET) repetition pattern and a corresponding search space repetition pattern.
The method of claim 1, further comprising receiving and decoding an initial PDSCH and at least one PDSCH repetition for the low-BW UE in the next one or more messages based at least in part on a successful decoding of one of the at least one DCI, wherein the initial PDSCH includes at least remaining system information (RMSI) .
The method of claim 2, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across multiple SS burst sets, wherein the PDCCH repetition pattern is associated with a UE processing bandwidth which is based on a subcarrier spacing and a number of resource blocks in a control resource set and wherein the at least one PDCCH repetition is associated with an SS burst set periodicity.
The method of claim 2, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across multiple SSBs within a single SS burst set; wherein the at least one PDCCH repetition is associated with at least an SSB index; wherein each of the multiple SSBs includes at least one CORESET, and the MIB includes an indicator indicating whether the SSBs are used for beam management or for the at least one PDCCH repetition.
The method of claim 2, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across one or more slots within a SS burst set, and a slot that does not transmit a SSB is used to carry one of the at least one PDCCH repetition, and wherein the CORESET and its corresponding search space of the at least one PDCCH repetition is associated with the initial PDCCH within the SS burst set corresponding to the at least one PDCCH repetition, and wherein a DMRS for the PDCCH repetition is quasi collocated with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition.
The method of claim 2, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place in different symbols within an SSB, and wherein a DMRS for each of the at least one PDCCH repetition is quasi collocated with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition; and wherein, a symbol within the SSB not transmitting the initial PDCCH is used to carry one of the at least one PDCCH repetition.
The method of claim 3, wherein a first DMRS of each of the at least one PDSCH repetition is quasi co-located with an associated SSB, with a second DMRS of the initial PDSCH, and/or with a third DMRS of the initial PDCCH or one of the at least PDCCH repetition.
The method of claim 3, wherein decoding the next one or more messages comprises decoding portion of the one or more message that is related to a low-bandwidth UE and each of the at least one PDCCH repetition includes information in type-0 PDCCH related to low-BW UE and information not related to low-BW UE is not included in the PDCCH repetition.
The method of claim 3, wherein each of the at least one PDSCH repetition is carried in a same slot as a PDCCH repetition which includes a corresponding successfully decoded DCI.
The method of claim 9, wherein the at least one PDSCH repetition for the low-BW UE is scheduled in the DCI carried in the initial PDCCH.
The method of claim 9, wherein there is a predefined relationship between resources for the at least one PDSCH repetition for the low-BW UE and the initial PDSCH associated with the at least one PDSCH repetition.
The method of claim 9, wherein decoding each of the at least one PDSCH repetition is after decoding of each of the at least one PDCCH repetition is completed if the PDCCH repetition and the PDSCH repetition are not in the same slot.
The method of claim 1, wherein the PDCCH repetition pattern is at least related to a processing bandwidth of the low-BW UE, whether PDCCH resources are interleaved, a subcarrier spacing of the initial PDCCH and the at least one PDCCH repetition, a mapping of control channel element (CCE) to resource element groups.
The method of claim 1, wherein the PDCCH repetition pattern indicates at least one of:

whether the PDCCH is repeated;

a number of times the PDCCH is repeated in the at least one PDCCH repetition;

and

a time domain repetition pattern.
An apparatus for wireless communications implemented at a low-bandwidth (BW) user equipment (UE) , comprising

a transceiver;

a memory; and

at least one processor coupled to the memory and configured to

determine a physical downlink control channel (PDCCH) repetition pattern based at least in part on a main information block (MIB) received over a broadcast channel or a plurality of PDCCH repetition patterns stored in a local memory;

receive an initial PDCCH and at least one PDCCH repetition in next one or more messages based on the PDCCH repetition pattern; and

decode the received initial PDCCH and the at least one PDCCH repetition.
The apparatus of claim 16, wherein the initial PDCCH and the at least one PDCCH repetition comprise a type-0 PDCCH and the type-0 PDCCH comprises at least one downlink control information (DCI) ; and wherein each of the initial PDCCH and the at least one PDCCH repetition is carried within one or more synchronization blocks (SSBs) and wherein the PDCCH repetition pattern includes at least a control resource set (CORESET) repetition pattern and a corresponding search space repetition pattern.
The apparatus of claim 16, wherein the at least one processor is further configured to receive and decode an initial PDSCH and at least one PDSCH repetition for the low-BW UE in the next one or more messages based at least in part on a successful decoding of one of the at least one DCI, wherein the initial PDSCH includes at least remaining system information (RMSI) .
The apparatus of claim 17, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across multiple SS burst sets, wherein the PDCCH repetition pattern is associated with a UE processing bandwidth which is based on a subcarrier spacing and a number of resource blocks in a control resource set and wherein the at least one PDCCH repetition is associated with an SS burst set periodicity.
The apparatus of claim 17, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across multiple SSBs within a single SS burst set; wherein the at least one PDCCH repetition is associated with at least an SSB index; wherein each of the multiple SSBs includes at least one CORESET, and the MIB includes an indicator indicating whether the SSBs are used for beam management or for the at least one PDCCH repetition.
The apparatus of claim 17, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across one or more slots within a SS burst set, and a slot that does not transmit a SSB is used to carry one of the at least one PDCCH repetition, and wherein the CORESET and its corresponding search space of the at least one PDCCH repetition is associated with the initial PDCCH within the SS burst set corresponding to the at least one PDCCH repetition, and wherein a DMRS for the PDCCH repetition is quasi collocated with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition.
The apparatus of claim 17, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place in different symbols within an SSB, and wherein a DMRS for each of the at least one PDCCH repetition is quasi collocated with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition; and wherein, a symbol within the SSB not transmitting the initial PDCCH is used to carry one of the at least one PDCCH repetition.
The apparatus of claim 18, wherein a first DMRS of each of the at least one PDSCH repetition is quasi co-located with an associated SSB, with a second DMRS of the initial PDSCH, and/or with a third DMRS of the initial PDCCH or one of the at least PDCCH repetition.
The apparatus of claim 18, wherein decoding the next one or more messages comprises decoding portion of the one or more message that is related to a low-bandwidth UE and each of the at least one PDCCH repetition includes information in type-0 PDCCH related to low-BW UE and information not related to low-BW UE is not included in the PDCCH repetition.
The apparatus of claim 18, wherein each of the at least one PDSCH repetition is carried in a same slot as a PDCCH repetition which includes a corresponding successfully decoded DCI.
The apparatus of claim 25, wherein the at least one PDSCH repetition for the low-BW UE is scheduled in the DCI carried in the initial PDCCH.
The apparatus of claim 25, wherein there is a predefined relationship between resources for the at least one PDSCH repetition for the low-BW UE and the initial PDSCH associated with the at least one PDSCH repetition.
The apparatus of claim 25, wherein decoding each of the at least one PDSCH repetition is after decoding of each of the at least one PDCCH repetition is completed if the PDCCH repetition and the PDSCH repetition are not in the same slot.
The apparatus of claim 16, wherein the PDCCH repetition pattern is at least related to a processing bandwidth of the low-BW UE, whether PDCCH resources are interleaved, a subcarrier spacing of the initial PDCCH and the at least one PDCCH repetition, a mapping of control channel element (CCE) to resource element groups.
The apparatus of claim 16, wherein the PDCCH repetition pattern indicates at least one of:

whether the PDCCH is repeated;

a number of times the PDCCH is repeated in the at least one PDCCH repetition;

and

a time domain repetition pattern.
A method for wireless communications by a generic NodeB (gNB) in communication with a low-bandwidth (BW) UE, comprising:

determining a PDCCH repetition pattern based at least in part on a plurality of PDCCH repetition patterns stored in a local memory and/or at least one of characteristics of the low-BW UE; and

transmitting an initial physical downlink control channel (PDCCH) and at least one PDCCH repetition in next one or more messages based on the PDCCH repetition pattern.
The method of claim 31, wherein the initial PDCCH and the at least one PDCCH repetition comprises a type-0 PDCCH and the type-0 PDCCH comprises at least one downlink control information (DCI) , and wherein the PDCCH repetition pattern includes at least a control resource set (CORESET) repetition pattern and a corresponding search space repetition pattern.
The method of claim 31, further comprising at least one of:

transmitting the PDCCH repetition pattern in a main information block (MIB) over a broadcast channel; and

transmitting an initial physical downlink shared channel (PDSCH) and at least one PDSCH repetition for the low-BW UE in the next one or more messages and wherein the initial PDSCH includes at least remaining system information (RMSI) .
The method of claim 32, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across multiple SS burst sets, wherein the PDCCH repetition pattern is associated with a UE processing bandwidth which is based on a subcarrier spacing and a number of resource blocks in a control resource set and wherein the PDCCH repetitions are associated with an SS burst set periodicity.
The method of claim 33, wherein the PDCCH repetition pattern indicates the at least one PDCCH repetition takes place take place across multiple SSBs within a single SS burst set; wherein the PDCCH repetitions are associated with at least an SSB index; wherein each of the multiple SSBs includes at least one CORESET, and the MIB includes an indicator indicating whether the SSBs are used for beam management or for the PDCCH repetitions.
The method of claim 32, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place across one or more slots within a SS burst set, and a slot that does not transmit a SSB is used to carry a PDCCH repetition, and wherein the CORESET and its corresponding search space of a PDCCH repetition is associated with an initial PDCCH within the SS burst set corresponding to the PDCCH repetition, and wherein a DMRS for a PDCCH repetition is quasi collocated with the SSB associated with the initial PDCCH corresponding to the PDCCH repetition.
The method of claim 32, wherein the PDCCH repetition pattern indicates that the at least one PDCCH repetition takes place in different symbols within an SSB, and wherein a DMRS for the PDCCH repetition is quasi collocated with the SSB associated with an initial PDCCH corresponding to the PDCCH repetition; and wherein, a symbol within the SSB not transmitting the initial PDCCH is used to carry a PDCCH repetition.
The method of claim 32, wherein each of the at least one PDCCH repetition includes information in PDCCH related to low-BW UE and information not related to low-BW UE is not included in each of the PDCCH repetitions.
The method of claim 33, wherein a first DMRS of each of the at least one PDSCH repetition is quasi co-located with an associated SSB, with a second DMRS of the initial PDSCH, and/or with a third DMRS of the initial PDCCH or one of the at least PDCCH repetition.
The method of claim 33, wherein each of the at least one PDSCH repetition is carried in a same slot as the PDCCH repetition including a corresponding successfully decoded DCI.
The method of claim 40, wherein the PDSCH repetition for the low-BW UE are scheduled in the DCI carried in one of the at least PDCCH repetition.
The method of claim 40, wherein there is a predefined relationship between resources for the at least one PDSCH repetition for the low-BW UE and a DCI for an initial PDSCH.
The method of claim 40, wherein transmitting the next one or more message comprise transmitting the at least one PDSCH repetitions after transmitting the at least one PDCCH repetitions if one of the at least one PDCCH repetitions and one of the at least one PDSCH repetition are not in a same slot.
The method of claim 31, wherein the PDCCH repetition pattern is at least based on a processing bandwidth of the low-BW UE, whether PDCCH resources are interleaved, a subcarrier spacing of the PDCCH, a mapping of control channel element (CCE) to resource element groups.
The method of claim 31, wherein the PDCCH repetition pattern indicates at least one of:

whether type-0 PDCCH is repeated to support a low-BW UE;

a number of PDCCH repetitions; and

a time domain repetition pattern.