Slot aggregation in a single-frequency network

Abstract

A user equipment (UE) receives multiple repeated configurations for receiving transmissions in slot aggregation from a base station. The UE receives an indication of one or more beams for the multiple repetitions of the transmission. The UE receives the first repetition of the transmission in a first time slot operating based on a single-frequency network (SFN) using at least one configuration different from the configuration for receiving a second repetition in a second time slot operating based on the SFN. Optionally, the UE determines whether the base station transmits the repetitions of the multiple repetitions of the transmission based on the SFN operation or based on a non-SFN operation based on the indication.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 044,694, filed Jun. 26, 2020, entitled “SLOT AGGREGATION IN SINGLE - FREQUENCY NETWORK” and U.S. Patent Application No. 17 / 320,092, filed May 13, 2021, entitled “SLOT AGGREGATION IN SINGLE FREQUENCY NETWORK”. The entire contents of both applications are hereby incorporated by reference in their entirety. Technical Field

[0003] Broadly speaking, the present disclosure relates to communication systems. Specifically, the present disclosure pertains to wireless communication involving slot aggregation and single - frequency networks (SFNs). Background Art

[0004] Wireless communication systems have been widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may use multiple - access technologies that can support communication with multiple users by sharing available system resources. Examples of such multiple - access technologies include code - division multiple - access (CDMA) systems, time - division multiple - access (TDMA) systems, frequency - division multiple - access (FDMA) systems, orthogonal frequency - division multiple - access (OFDMA) systems, single - carrier frequency - division multiple - access (SC - FDMA) systems, and time - division synchronous code - division multiple - access (TD - SCDMA) systems.

[0005] Such multiple - access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate over urban, national, regional, or even global scales. One exemplary telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous evolution of mobile broadband released by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine - type communication (mMTC), and ultra - reliable low - latency communication (URLLC). Some aspects of 5G NR may be based on the 4G Long - Term Evolution (LTE) standard. There is a need to further improve 5G NR technology. In addition, these improvements may also be applicable to other multiple - access technologies and telecommunication standards that employ these technologies. Summary of the Invention

[0006] To provide a basic understanding of one or more aspects of the present invention, a brief summary of these aspects is given below. This summary section is not an exhaustive overview of all contemplated aspects, nor is it intended to identify key or critical elements of all aspects, or to 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 follows.

[0007] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus for wireless communication at a base station are provided. The apparatus configures a user equipment (UE) to receive multiple repetitions of a transmission using slot aggregation. The apparatus indicates to the UE one or more beams for each repetition of the transmission. The apparatus transmits the multiple repetitions of the transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is transmitted based on single-frequency network (SFN) operation using more than one beam.

[0008] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus for wireless communication at a UE are provided. The apparatus receives a configuration for receiving multiple repetitions of a transmission in slot aggregation from a base station. The apparatus receives an indication for indicating one or more beams for the multiple repetitions of the transmission. The apparatus receives the first repetition of the transmission in a first slot based on SFN operation using at least one configuration different from a configuration for receiving a second repetition in a second slot based on non-SFN operation.

[0009] To achieve the foregoing and related purposes, one or more aspects include the features specifically recited in the following detailed description and the claims. The following description and the drawings detail certain exemplary features of one or more aspects. However, these features merely illustrate some of the various ways in which the basic principles of these various aspects may be employed, and the description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network in accordance with some aspects.

[0011] Figure 2A , Figure 2B , Figure 2C and Figure 2D are diagrams respectively illustrating examples of a first 5G / NR frame, a DL channel within a 5G / NR subframe, a second 5G / NR frame, and a UL channel within a 5G / NR subframe in accordance with some aspects.

[0012] Figure 3 is a diagram illustrating an example of a base station and a user equipment (UE) in an access network in accordance with some aspects.

[0013] Figure 4A And Figure 4B are diagrams showing examples of SFN and non - SFN according to various aspects of the present disclosure.

[0014] Figure 5A 、 Figure 5B And Figure 5C are diagrams showing examples of beamforming under SFN and non - SFN according to various aspects of the present disclosure.

[0015] Figure 6 is a diagram showing an example communication flow between a UE and a base station according to various aspects of the present disclosure.

[0016] Figure 7A 、 Figure 7B And Figure 7C are diagrams showing examples of beamforming under non - transparent SFN according to various aspects of the present disclosure.

[0017] Figure 8 is a flowchart of a wireless communication method according to various aspects of the present disclosure.

[0018] Figure 9 is a diagram showing an example of a hardware implementation for an example device according to various aspects of the present disclosure.

[0019] Figure 10 is a flowchart of a wireless communication method according to various aspects of the present disclosure.

[0020] Figure 11 is a diagram showing an example of a hardware implementation for an example device. Detailed Description of the Invention

[0021] The detailed description below in conjunction with the accompanying drawings is only intended to describe various configurations and is not intended to imply that the concepts described herein can only be implemented in these configurations. To gain a thorough understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those of ordinary skill in the art that these concepts can be implemented without these specific details. In some instances, well - known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0022] Aspects of a telecommunications system are now presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and depicted in the drawings by various boxes, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). Such elements can be implemented using either 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.

[0023] By way of example, an element, or any portion of an element, or any combination of elements can be implemented as a "processing system" that includes one or more processors. Examples of processors include a microprocessor, a microcontroller, a graphics processing unit (GPU), a central processing unit (CPU), an application processor, a digital signal processor (DSP), a reduced instruction set computing (RISC) processor, a system on a chip (SoC), a baseband processor, a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in the processing system can execute software. Software should 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.

[0024] Thus, in one or more exemplary embodiments, the functions described herein can be implemented using hardware, software, or any combination thereof. When implemented in software, the functions can be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include random access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other media that can be used to store computer-executable code in the form of instructions or data structures and that can be accessed by a computer.

[0025] Figure 1FIG. is an example diagram showing a wireless communication system and an access network 100. In some aspects, the base station 102 / 180 may include a time slot aggregation and SFN configuration component 199, which is configured to configure time slot aggregation for transmission and transmit some time slots within the time slot aggregation under SFN. For example, the time slot aggregation and SFN configuration component 199 may configure time slots to be sent with multiple repetitions, where some repetitions may be sent using SFN time slots and some repetitions may be sent using non-SFN time slots. In one configuration, the time slot aggregation and SFN configuration component 199 may be configured to configure the UE to receive multiple repetitions of a transmission using time slot aggregation. In such a configuration, the time slot aggregation and SFN configuration component 199 may be configured to indicate to the UE one or more beams for each repetition of the transmission. In such a configuration, the time slot aggregation and SFN configuration component 199 may be configured to transmit multiple repetitions of the transmission based on the one or more beams indicated to the UE, where at least one of the multiple repetitions of the transmission is sent based on SFN operation using more than one beam.

[0026] In some aspects, the UE 104 may include a time slot aggregation and SFN determination component 198, which is configured to receive time slots sent in SFN mode and time slots sent in non-SFN mode. The time slot aggregation and SFN determination component 198 may further determine whether the time slot is sent in SFN mode and may configure one or more different beams to receive the SFN time slot. In one configuration, the time slot aggregation and SFN determination component 198 may be configured to receive from the base station a configuration for receiving multiple repetitions of a transmission in time slot aggregation. In such a configuration, the time slot aggregation and SFN determination component 198 may be configured to receive an indication for indicating one or more beams for multiple repetitions of the transmission. In such a configuration, the time slot aggregation and SFN determination component 198 may be configured to receive the first repetition of the transmission in a first time slot based on SFN operation using at least one configuration different from the configuration for receiving a second repetition in a second time slot based on non-SFN operation.

[0027] Base stations 102 configured for 4G LTE (collectively referred to as the evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interact with the EPC 160 via a first backhaul link 132 (e.g., the S1 interface). Base stations 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interact with the core network 190 via a second backhaul link 184. Among other functions, the base stations 102 can perform one or more of the following functions: transmission of user data, encryption and decryption of radio channels, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, radio access network information management (RIM), paging, positioning, and transmission of alert messages. The base stations 102 can communicate directly or indirectly with each other (e.g., via the EPC 160 or the core network 190) via a third backhaul link 134 (e.g., the X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 can be wired or wireless.

[0028] Base station 102 can communicate wirelessly with UE 104. Each of the base stations 102 can provide communication coverage for a corresponding geographical coverage area 110. There may be overlapping geographical coverage areas 110. For example, small cell 102’ may have a coverage area 110’ that overlaps with the coverage areas 110 of one or more macro base stations 102. A network including small cells and macro cells may be referred to as a heterogeneous network. In addition, a heterogeneous network may also include a home evolved Node B (HeNB), which may provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between the base station 102 and the UE 104 may include an uplink (UL) (which is also referred to as a reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (which is also referred to as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, which includes spatial multiplexing, beamforming, and / or transmit diversity. These communication links may be over one or more carriers. The base station 102 / UE 104 may use up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) of bandwidth for each carrier allocated in carrier aggregation with a total of up to Yx MHz (x component carriers) for transmission in each direction. These carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to the DL and UL (e.g., more or fewer carriers may be allocated for the DL compared to the UL). These component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell), and the secondary component carrier may be referred to as the secondary cell (SCell).

[0029] Certain UEs 104 may communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 may use the DL / UL WWAN spectrum. The D2D communication links 158 may use one or more sidelink channels, such as the physical sidelink broadcast channel (PSBCH), the physical sidelink discovery channel (PSDCH), the physical sidelink shared channel (PSSCH), and the physical sidelink control channel (PSCCH). D2D communication may be performed through various wireless D2D communication systems (e.g., WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR).

[0030] The wireless communication system may further include a Wi-Fi access point (AP) 150, which communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a Clear Channel Assessment (CCA) before communicating to determine whether the channel is available.

[0031] The small cell 102’ may operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell 102’ may adopt NR and use the same 5 GHz unlicensed spectrum as that used by the Wi-Fi AP 150. The small cell 102’ adopting NR in the unlicensed spectrum may improve the coverage of the access network and / or increase the capacity of the access network.

[0032] The base station 102 (whether it is a small cell 102’ or a large cell (e.g., a macro base station)) may include and / or may be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations such as the gNB 180 may operate in the traditional sub-6 GHz spectrum at millimeter wave (mmW) frequencies and / or near mmW frequencies to communicate with the UE 104. When the gNB 180 operates at mmW or near mmW frequencies, the gNB 180 may be referred to as a mmW base station. The Extremely High Frequency (EHF) is a part of the RF in the electromagnetic spectrum. The EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. The radio waves in the band may be referred to as millimeter waves. 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, which is also referred to as centimeter waves. The frequency range band includes Frequency Range 1 (FR1) and Frequency Range 2 (FR2). FR1 includes the bands below 7.225 GHz, and FR2 includes the bands above 24.250 GHz. The frequencies between FR1 and FR2 are generally referred to as intermediate band frequencies. Although a part of FR1 is greater than 6 GHz, in various documents and articles, FR1 is generally (interchangeably) referred to as the “sub-6 GHz” band. Similar naming issues sometimes occur with FR2. Although it is different from the EHF band defined as the mmW band by the International Telecommunication Union (ITU), it is generally (interchangeably) referred to as the mmW band in various documents and articles.

[0033] Taking into account the above aspects, unless otherwise explicitly stated, it should be understood that the term "below 6 GHz" and the like (if used herein) can broadly represent frequencies less than 6 GHz, which can be within FR1 or can include mid-band frequencies. Additionally, unless otherwise explicitly stated, it should be understood that the term "millimeter wave" and the like (if used herein) can broadly represent frequencies that include mid-band frequencies, can be within FR2, or can be within the EHF band.

[0034] Communications using mmW / near mmW radio frequency (RF) bands (e.g., 3 GHz - 300 GHz) have extremely high path loss and short distances. The base station / UE can operate within one or more frequency range bands. The mmW base station 180 can utilize beamforming 182 with the UE 104 to compensate for this extremely high path loss and short communication distance. Both the base station 180 and the UE 104 can include multiple antennas (e.g., antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming.

[0035] The base station 180 can transmit beamformed signals to the UE 104 in one or more transmission directions 182’. The UE 104 can receive beamformed signals from the base station 180 in one or more reception directions 182”. The UE 104 can also transmit beamformed signals to the base station 180 in one or more transmission directions. The base station 180 can receive beamformed signals from the UE 104 in one or more reception directions. The base station 180 / UE 104 can perform beam training to determine the optimal reception and transmission directions for each of the base station 180 / UE 104. The transmission and reception directions of the base station 180 can be the same or different. The transmission and reception directions of the UE 104 can be the same or different.

[0036] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may communicate with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that processes signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the Serving Gateway 166, which is itself connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to an IP service 176. The IP service 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), and 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 transmissions, may be used to authorize and initiate MBMS bearer services in a Public Land Mobile Network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area for a particular broadcast service, and may be responsible for session management (start / stop) and collecting charging information related to eMBMS.

[0037] The core network 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may communicate with a Unified Data Management (UDM) 196. The AMF 192 is a control node that processes signaling between the UE 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) Streaming (PSS) service, and / or other IP services.

[0038] The base station may include and / or be referred to as a gNB, Node B, eNB, access point, base station transceiver, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmission reception point (TRP), or some other suitable term. The base station 102 provides an access point for the UE 104 to the EPC 160 or the core network 190. Examples of the UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptop computers, personal digital assistants (PDAs), satellite radio devices, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet devices, smart devices, wearable devices, vehicles, electricity meters, gas pumps, large or small kitchen appliances, medical devices, implants, sensors / actuators, displays, or any other similar functional devices. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). The UE 104 may also be referred to as a station, mobile station, user station, mobile unit, user unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, wireless terminal, remote terminal, handheld device, user agent, mobile client, client, or some other suitable term.

[0039] Figure 2A 200 is an example showing the first subframe in the 5G NR frame structure. Figure 2B 230 is an example showing the DL channel in the 5G NR subframe. Figure 2C 250 is an example showing the second subframe in the 5G NR frame structure. Figure 2D 280 is an example showing the UL channel in the 5G NR subframe. The 5G NR frame structure may be frequency division duplexing (FDD) or time division duplexing (TDD). In the case of FDD, for a specific set of subcarriers (carrier system bandwidth), the subframes within the set of subcarriers are dedicated to either DL or UL, while in the case of TDD, for a specific set of subcarriers (carrier system bandwidth), the subframes within the set of subcarriers are dedicated to both DL and UL. In Figure 2A 、 2CIn the provided example, it is assumed that the 5G NR frame structure is TDD, where subframe 4 is configured with slot format 28 (mainly DL), where D is DL, U is UL, and F is flexibly used between DL / UL, and subframe 3 is configured with slot format 34 (mainly UL). Although subframes 3 and 4 are shown with slot formats 34 and 28 respectively, any particular subframe can be configured with any one of the various available slot formats 0 - 61. Slot formats 0 and 1 are all-DL and UL respectively. The other slot formats 2 - 61 include a mixture of DL, UL, and flexible symbols. The slot format is configured for the UE via the received Slot Format Indicator (SFI) (configured dynamically via Downlink Control Information (DCI) or semi-statically / statically via Radio Resource Control (RRC) signaling). It should be noted that the following description also applies to the TDD 5G NR frame structure.

[0040] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10 ms) can be divided into 10 subframes of the same size (1 ms). Each subframe can include one or more slots. A subframe can also include mini-slots, which can include 7, 4, or 2 symbols. Depending on the slot configuration, each slot can include 7 or 14 symbols. For slot configuration 0, each slot can include 14 symbols, while for slot configuration 1, each slot can include 7 symbols. The symbols on the DL can be Cyclic Prefix (CP) OFDM (CP-OFDM) symbols. The symbols on the UL can be CP-OFDM symbols (for high throughput scenarios) or Discrete Fourier Transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single-stream transmission). The number of slots within a subframe is based on the slot configuration and the parameter set. For slot configuration 0, the different parameter sets μ0 to 4 respectively allow each subframe to have 1, 2, 4, 8, and 16 slots. For slot configuration 1, the different parameter sets 0 to 2 respectively allow each subframe to have 2, 4, and 8 slots. Thus, for slot configuration 0 and parameter set μ, there are 14 symbols / slot and 2 μ slots / subframe. The subcarrier spacing and symbol length / duration depend on the parameter set. The subcarrier spacing can be equal to 2 μ *15 kHz, where μ is the parameter set from 0 to 4. Thus, the subcarrier spacing for parameter set μ = 0 is 15 kHz, and the subcarrier spacing for parameter set μ = 4 is 240 kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figure 2A - 2DAn example of a time slot configuration with 14 symbols per time slot and a parameter set μ = 2 with 4 time slots per subframe is provided. The time slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) that are frequency division multiplexed (see Figure 2B ). Each BWP may have a specific parameter set.

[0041] A resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (which is also referred to as a physical RB (PRB)) that extends over 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0042] As Figure 2A shown, some of the REs carry reference (pilot) signals (RSs) for the UE. The RS may include a demodulation RS (DM-RS) (for a specific configuration, it is denoted as Rx, where 100x is the port number, but other DM-RS configurations are also possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement (BRRS), and a phase tracking RS (PT-RS).

[0043] Figure 2BExamples of various DL channels in a subframe of a frame are shown. The Physical Downlink Control Channel (PDCCH) carries DCI in one or more Control Channel Elements (CCEs), each CCE including nine Resource Element Groups (REGs), and each REG including four consecutive Resource Elements (REs) in one OFDM symbol. The PDCCH within a Bandwidth Part (BWP) can be referred to as a Control Resource Set (CORESET). Additional BWPs can be located at higher and / or lower frequencies on the channel bandwidth. The Primary Synchronization Signal (PSS) can be within symbol 2 of a specific subframe of the frame. UE 104 uses the PSS to determine subframe / symbol timing and the physical layer identity. The Secondary Synchronization Signal (SSS) can be within symbol 4 of a specific subframe of the frame. The UE uses the SSS to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The Physical Broadcast Channel (PBCH) carrying the Master Information Block (MIB) can be logically combined with the PSS and SSS to form a Synchronization Signal (SS) / PBCH Block (also referred to as an SS Block (SSB)). The MIB provides the number of Resource Blocks (RBs) in the system bandwidth and the System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not sent via the PBCH (e.g., System Information Block (SIB)), and paging messages.

[0044] As Figure 2C shown, some of the REs carry DM-RS (indicated as R for a specific configuration, but other DMRS configurations are also possible) for channel estimation at the base station. The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the one or two symbols preceding the PUSCH. Depending on whether a short or long PUCCH is transmitted and according to the specific PUCCH format used, the PUCCH DM-RS can be transmitted in different configurations. The UE can transmit a Sounding Reference Signal (SRS). The SRS can be transmitted in the last symbol of the subframe. The SRS can have a comb structure, and the UE can transmit the SRS on one of these comb structures. The base station can use the SRS for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0045] Figure 2DExamples of various UL channels in a subframe of a frame are shown. The PUCCH can be located at the position indicated in one configuration. The PUCCH carries, for example, a scheduling request, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a hybrid automatic repeat request (HARQ) ACK / NACK feedback. The PUSCH carries data and can also be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0046] Figure 3 is a block diagram of the communication between the base station 310 and the UE 350 in an access network. In the DL, IP packets from the EPC 160 are provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes the radio resource control (RRC) layer, and layer 2 includes the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the media access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with the broadcast of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), mobility between radio access technologies (RATs), and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with the transfer of upper layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; MAC layer functions associated with the 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 via HARQ, priority handling, and logical channel prioritization.

[0047] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1, which includes the physical (PHY) layer, may include error detection for the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). Subsequently, the coded and modulated symbols may be segmented into parallel streams. Subsequently, each stream may be mapped to OFDM subcarriers, multiplexed with reference signals (e.g., pilots) in the time domain and / or frequency domain, and then combined together using an inverse Fourier transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM stream is space precoded to generate multiple spatial streams. Channel estimates from the channel estimator 374 may be used to determine the coding and modulation schemes and for implementing spatial processing. The channel estimates may be derived from reference signals transmitted by the UE 350 and / or channel status feedback. Subsequently, each spatial stream is provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier using each spatial stream for transmission.

[0048] At the UE 350, each receiver 354RX receives signals via its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 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, the RX processor 356 may combine them into a single OFDM symbol stream. Subsequently, the RX processor 356 uses a fast Fourier transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency-domain signal includes a separate OFDMA symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier 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 the channel estimates calculated by the channel estimator 358. Subsequently, these soft decisions are decoded and deinterleaved to recover the data and control signals initially transmitted by the base station 310 on the physical channel. Subsequently, these data and control signals are provided to the controller / processor 359, which implements layer 3 and layer 2 functions.

[0049] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between the transport channel and the logical channel, packet reassembly, decryption, header decompression, and control signal processing to recover the IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using the ACK and / or NACK protocols to support HARQ operations.

[0050] Similar to the functions described in connection with the DL transmission of the base station 310, the controller / processor 359 provides: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with the transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; MAC layer functions associated with the mapping between the logical channel and the transport channel, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

[0051] Channel estimators 358 derive channel estimates from reference signals or feedback sent by the base station 310, which can be used by the TX processor 368 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via their respective transmitters 354TX. Each transmitter 354TX may modulate an RF carrier using its respective spatial stream for transmission.

[0052] In a manner similar to that described in connection with the receiver function at the UE 350, the base station 310 processes UL transmissions. Each receiver 318RX receives signals via its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides the information to the RX processor 370.

[0053] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reconstitution, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using the ACK and / or NACK protocols to support HARQ operations.

[0054] At least one of the TX processor 368, RX processor 356, and controller / processor 359 may be configured to perform aspects related to Figure 1 the slot aggregation and SFN determination component 198.

[0055] At least one of the TX processor 316, RX processor 370, and controller / processor 375 may be configured to perform aspects related to Figure 1 the slot aggregation and SFN configuration component 199.

[0056] A communication network may support single-frequency network (SFN) operation. Under SFN operation, base stations (e.g., cells, TRPs, etc.) may use the same frequency to transmit (e.g., multicast, broadcast, etc.) the same information. This may enable the network to expand the coverage area without using other frequencies. For example, Figure 4A 400A is an example showing an SFN, where cell A, cell B, and cell C may operate at the same frequency to communicate with the UE 402, e.g., transmit the same data to the UE 402 on the same frequency and time resources. Figure 4B 400B is an example showing a non-SFN or multi-frequency network (MFN), where each cell (e.g., cell A, cell B, and cell C) may operate at a different frequency and may communicate with the UE 402 using different frequencies and / or time resources. The network may support the SFN mode and the non-SFN mode and may switch between the SFN and non-SFN modes when communicating with the UE. In the SFN mode, since multiple base stations may serve the UE at the same frequency, interference between the base station and the UE may be reduced. In some examples, the SFN mode may improve communication from the base station (e.g., transmit power) because more base stations may be used for data transmission. The SFN may also support information broadcasting, where multiple base stations may broadcast information to multiple UEs simultaneously.

[0057] As described above, the base station can communicate with the UE based on beamforming. When the network operates in the non-SFN mode and the UE is communicating with the base station, the beam from the UE (e.g., the Tx and / or Rx beam of the UE) and the beam from the base station (e.g., the Tx beam and / or Rx beam of the base station) can point to each other or be aligned in the relevant direction. For example, Figure 5A 500A is an example showing beamforming in the non-SFN mode. The base station 504 can communicate with the UE 502 using the beam 508 (e.g., send data to the UE 504), while the UE 502 can communicate with the base station 504 using the beam 510 (e.g., receive data from the base station 504). On the other hand, when the network operates in the SFN mode, the UE can communicate with multiple base stations, as Figure 4A shown. In some examples, the SFN can be a transparent SFN or a non-transparent SFN. Under the transparent SFN, the UE may not know whether the transmission / communication from one base station is from multiple base stations / TRPs and / or from other base stations / TRPs, while in the non-transparent SFN, the UE can know whether the transmission / communication from one base station is from multiple base stations / TRPs and / or from other base stations / TRPs.

[0058] Figure 5B 500B is an example showing the transparent SFN. The UE 502 can be served by the base station 504 and the base station 506, where the base stations 504 and 506 can use the beams 508 and 512 respectively to simultaneously send the same data to the UE 504 using the same frequency resource. However, the UE 502 may not know the transmission from the base station 506 or the beam 512, and the UE 502 may not have a configured beam to communicate with the base station 506. For example, the UE 502 can communicate with the base station 504 using the beam 510, but the beam 510 may not be fully or partially aligned with the beam 512. In other words, the UE 502 may not know that transmissions are being sent or broadcast from multiple base stations or other base stations under the transparent SFN operation. It should be noted that although this example illustrates the concept of two base stations 504 and 506, this concept can be applied to more than two base stations (e.g., four, six, etc.), which can be deployed to communicate with the UE 502 using the same frequency resource under the SFN.

[0059] Under the non-transparent SFN, as Figure 5CAs shown by 500C in [document], the UE 502 can receive from the serving base station 504 an indication that one or more transmission beams (e.g., beams 508 and 512) can be used to communicate with the UE 502 from different base stations or using multiple base stations (e.g., base stations 504 and 506). In other words, the base station 504 can indicate to the UE 502 to send a transmission in SFN mode. In response, the UE 502 can configure beam 510 for communicating with the base station 504 (e.g., receiving data from the base station 504), and can configure another beam 514 for communicating with the base station 516. Optionally, instead of using a separate or additional beam (e.g., beam 514) to communicate with the base station 506, the UE 502 can also configure a beam that can communicate with both the base station 504 and 506 (e.g., by using a wider beam). Thus, if the UE 502 realizes that one or more transmissions are sent from multiple base stations (e.g., sent in SFN mode), the UE 504 can optimize communication (e.g., data reception).

[0060] In some examples, the base station can notify the UE of the beam used by the base station / TRP to communicate with the UE by sending a Transmission Configuration Indicator (TCI) state to the UE (e.g., via DCI). For example, the base station can indicate to the UE that the base station is communicating with the UE using a first TCI state (e.g., TCI state #1), where the first TCI state can correspond to the Tx / Rx beam or a set of Tx / Rx beams of the base station. In response, the UE can adjust its beam to communicate with the base station. If the TCI state includes a set of beams (e.g., multiple beams), in SFN mode, each beam in the set of beams can come from a different base station. For example, the TCI state can indicate that the base station is using three beams to communicate with the UE (e.g., sending to the UE), where one beam can come from the first base station (e.g., base station A), one beam can come from the second base station (e.g., base station B), and one beam can come from the third base station (e.g., base station C), etc. In the transparent SFN mode, the UE may not know that the transmission is sent from three base stations. Thus, the UE can treat the transmission as if there is no SFN, e.g., by using one beam aligned with one base station to receive the transmission. On the other hand, in non-transparent SFN, the UE can be made aware of the transmission from multiple base stations and the beam used by each base station.

[0061] The network can improve the transmission reliability based on slot aggregation. Under slot aggregation, after the initial transmission of a packet, there can be repetitions of the same packet (e.g., in consecutive time slots). The aggregation factor (e.g., the number of repetitions) K can be configured by a higher layer of the network, where K = 1 can indicate no aggregation (e.g., repetition) after the initial transmission, and K = 8 can indicate seven aggregations after the initial transmission. Since the transmitting device (e.g., a base station or a UE) can send the same packet (e.g., data) multiple times, the receiving device can have a higher chance of accurately / successfully receiving the packet, thus improving the transmission reliability. In addition, each repetition of slot aggregation can be transmitted from different beams of a base station and / or from different base stations (e.g., TRPs). For example, the first repetition (e.g., repetition #1) can be sent from the first TRP (e.g., TRP#1) based on the first beam of the first TRP (e.g., beam 1), the second repetition (e.g., repetition #2) can be sent from the second TRP (e.g., TRP#2) or the second beam of the first TRP (e.g., beam 2), and so on.

[0062] Aspects proposed in this document can enable the network to optimize communication between a base station and a UE by applying slot aggregation and SFN mode to communication. In one aspect, slot aggregation can be combined with SFN transmission, where data packets can be sent from one or more base stations using the same frequency resources in SFN mode, and data packets can also be sent using repetitions over time slots (e.g., based on slot aggregation).

[0063] In some examples, the UE may experience that, compared to transmissions from a single base station (e.g., in non-SFN mode), such as non-combined single-channel transmissions, combined transmissions from multiple channels / beams or base stations in SFN mode may have worse performance. For example, feeds from different beams and base stations may cancel each other out rather than combine. In other examples, the UE may experience that combined transmissions under SFN result in better performance than single-channel transmissions. Thus, by enabling the network to apply / configure time slot aggregation and SFN mode for transmissions, the network (e.g., base station and / or UE) can have greater flexibility in scheduling and configuring transmissions. For example, a wireless device (e.g., base station or UE) can send different data repetitions from different base stations / beams, or send one or more repetitions in SFN mode and one or more repetitions in non-SFN mode, etc. For example, the UE can be configured to receive a first repetition (e.g., repetition #1) from a first base station / TRP (e.g., base station 1 or TRP1), a second repetition (repetition #2) from a second base station / TRP (e.g., base station 2 or TRP2), and a third repetition (e.g., repetition #3) from both the first base station and the second base station (e.g., in SFN mode), etc. In some examples, if the base station is in broadcast mode (e.g., the base station is sending a broadcast message to one or more UEs), the base station may not know the location of the receiving UE. Thus, by repeatedly sending transmissions from different base stations and / or beams, the receiving UE is more likely to successfully receive the transmission.

[0064] To enable time slot aggregation when the base station transmits in SFN mode, a combined SFN TCI state and a non-SFN TCI state (e.g., a conventional TCI state) can be configured in one time slot aggregation, where one or more aggregated (e.g., repeated) time slots can be configured for SFN transmission and one or more aggregated time slots can be configured for non-SFN transmission. In one aspect of the present disclosure, if the transmission is associated with a non-transparent SFN, where the UE can know the beams used by one or more base stations to communicate with the UE, as described in connection with Figure 5C then the UE can determine its beam in advance to optimize the reception of the transmission. In another aspect of the present disclosure, one or more SFN transmissions / repetitions can be configured or arranged to be located after non-SFN transmissions or repetitions, to provide the UE with more time to adjust the FFT window and / or frequency error correction, and / or adjust its beam to receive one or more transmissions / repetitions from other directions. For example, during a single (e.g., non-SFN) transmission, the UE can refine its receive (e.g., Rx) beam based on the DM-RS, and then the UE can determine one or more optimal receive beams and / or channel equalizers (e.g., combined channels from previous non-SFN beams) for the SFN.

[0065] In one example, the base station can implement slot aggregation in the SFN mode by configuring slot aggregation at the base station and sending an indication to the receiving UE about the beams for each slot aggregation (e.g., repetition), where one or more beams associated with the SFN mode can be used to send some slots / repetitions, and one or more beams associated with the non-SFN mode can be used to send some slots / repetitions.

[0066] Figure 6 Communication flow 600 is an example showing communication between UE 602 and base station 604 based on slot aggregation and SFN / non-SFN modes, in accordance with various aspects of the present disclosure. At 606, the base station 604 can configure slot aggregation and apply it to transmission, e.g., by configuring and allocating an aggregation factor K for transmission. The base station 604 can also, at 606, configure one or more beams for each slot (or repetition) of the slot aggregation to be sent, where one or more beams can be configured to send SFN slots (e.g., slots sent in the SFN mode), and one or more beams can be configured to send non-SFN slots (e.g., slots sent in the non-SFN mode).

[0067] At 607, the base station 604 can send an indication or configuration to the UE 602 that indicates that the transmission from the base station 604 is configured with slot aggregation and an aggregation level (e.g., number of repetitions). This indication or configuration can also configure the UE 602 to receive multiple repetitions of the transmission based on slot aggregation.

[0068] At 608, the base station 604 can send an indication to the UE 602 that indicates one or more beams for each slot within the slot aggregation (e.g., for each repetition of the transmission). This indication can include one or more TCI states and can be sent in DCI for this transmission. For example, the base station 604 can indicate that the first slot in the transmission (e.g., the slot aggregation) is transmitted based on a first TCI state (e.g., TCI state #1), the second slot is transmitted based on a second TCI state (e.g., TCI state #2), and the third slot is transmitted based on a third TCI state (e.g., TCI state #3), where the beam associated with the third TCI state can include the beams for the first TCI state and / or the second TCI state, etc. The indication for slot aggregation at 607 and the indication for the transmit beam at 608 can be sent within one indication (e.g., a message) (e.g., sent via DCI), or they can be sent as two separate indications via different messages.

[0069] At 609, the base station 604 may transmit multiple repetitions of a transmission based on the beams indicated to the UE 602 (e.g., may transmit at least one repetition based on SFN operation using more than one beam). In other words, the base station 604 may use time slot aggregation including SFN time slots and non-SFN time slots to transmit the transmission.

[0070] As previously described, the SFN may operate in a transparent mode or a non-transparent mode. When the SFN operates in the transparent mode, the UE 602 may not know that the transmission comes from more than one base station (e.g., TRP). In some examples, if the base station 604 transmits an SFN time slot in the transparent SFN mode, at 610, the UE 602 may be configured to receive the transmission (e.g., SFN and non-SFN time slots) assuming that the transmission is not sent in the SFN mode. In other words, the UE 602 may receive the transmission based on the non-SFN setting as if there is no SFN. For example, the UE 602 may determine the beam for receiving the transmission assuming that the transmission comes from the base station 604 rather than from other base stations / TRPs.

[0071] On the other hand, if the base station 604 transmits an SFN time slot in the non-transparent SFN mode, at 612, the UE 602 may further determine which time slots in the transmission are sent based on the SFN mode and which time slots are sent based on the non-SFN mode, at least partially based on the indications sent at 607 and / or 608. In some examples, by determining which time slots are SFN time slots (e.g., time slots sent in the SFN mode) and which time slots are non-SFN time slots (e.g., time slots sent in the non-SFN mode), the UE 602 may further determine one or more configurations for receiving the SFN time slots and non-SFN time slots, such as determining its receiving beam and / or optimizing the reception of the transmission at 610. In other examples, the power delay profile (PDP) of the channel for transmitting SFN time slots may be different from the PDP of the channel for transmitting non-SFN time slots. Thus, by determining which time slots are SFN time slots and which time slots are not SFN time slots, as shown at 614, the UE 602 may determine a first configuration for receiving SFN time slots and a second configuration for receiving non-SFN time slots (e.g., a configuration different from the first configuration). For example, the UE 602 may use the same beam and / or receiver spatial filter to receive SFN time slots and non-SFN time slots, but the UE 604 may use different tracking reference signals (TRS) for SFN time slots and non-SFN time slots to derive different power delay profiles of the SFN and non-SFN channels. The UE 602 may also perform channel estimation and decoding using different PDP assumptions.

[0072] For example, the UE 602 may know that the base station 604 transmits the first time slot (e.g., time slot #1) in non-SFN mode, and the base station 604 and the second base station transmit the second time slot (e.g., time slot #2) and the third time slot (e.g., time slot #3) in SFN mode from two different directions. Thus, in some examples, the UE 602 may determine to use a first receive beam pointing to the base station 604 to receive the first time slot, and the UE 604 may determine to use a second receive beam pointing to the base station 604 or the second base station to receive the second time slot and the third time slot. In other examples, the UE 602 may determine to use a first receive configuration (e.g., the first PDP) to receive the first time slot, and the UE 602 may determine to use a second receive configuration (e.g., the second PDP) to receive the second time slot and the third time slot, and so on.

[0073] In some examples, the UE 602 may determine which receive beam / configuration to use based on the channel conditions between the UE 602 and the base station / TRP (e.g., the base station 604 and the second base station), where the UE 602 may select a receive beam pointing to the base station or a receive configuration with better channel conditions. Alternatively or additionally, the UE 602 may use a receive beam (but with the same or different receive configurations) to receive from two base stations, e.g., by using a wider beam capable of receiving beams from two base stations. In another example, the UE 602 may also use one receive beam for each base station, such that there is a first beam for receiving SFN time slots from the base station 604 and a second beam for receiving SFN time slots from the second base station, and so on. It should be noted that although this example is illustrated using two base stations, more than two base stations (e.g., four, six, etc.) may be deployed to transmit SFN time slots from more than two directions.

[0074] Aspects proposed herein may enable the UE 602 to determine whether a time slot in transmission is transmitted by the base station 604 in SFN mode or in non-SFN mode. In one aspect, the base station 604 may send an explicit indication to the UE 602 indicating which time slots are transmitted in SFN mode and which base stations / TRPs are transmitting these SFN time slots (e.g., at steps 607 and / or 608, or at other steps). For example, the base station 604 may signal to the UE that the third time slot (e.g., time slot #3) will be transmitted from the base station 604 in SFN mode using the first beam (e.g., beam #1) and the second beam (e.g., beam #2), and so on.

[0075] In another aspect, the UE 602 can identify SFN time slots and non-SFN time slots at least partially based on the beam configurations used for each time slot aggregation. For example, the base station can configure one beam (e.g., one TCI state) for non-SFN time slots and multiple beams (e.g., multiple TCI states) for SFN time slots. Thus, when the UE 602 receives the beam configuration from the base station 604 (e.g., at 608), the UE 602 can identify the time slot type (e.g., SFN or non-SFN) of each time slot based on the number of beams configured for each time slot (e.g., the number of TCI states). In another example, the base station 604 can associate / map a tracking reference signal (TRS), such as CRI-RS, to the TCI state, where the UE 602 can use the TRS to derive the refined time and / or frequency tracking of the PDSCH / PDCH channel. The UE 602 can also derive one or more channel statistics of the corresponding TCI state associated with the TRS, where the one or more channel statistics can include the power delay distribution and / or Doppler distribution, etc., of the beamforming channel of the TCI state. In this way, the base station can configure / associate one TRS for non-SFN time slots and multiple TRSs for SFN time slots. Thus, when the UE 602 receives the beam configuration from the base station 604 (e.g., at 608), the UE 604 can identify the time slot type (e.g., SFN or non-SFN) of each time slot based on the number of TRSs configured for or associated with each time slot.

[0076] In another aspect, the UE 602 can identify SFN and non-SFN time slots based on predefined rules or configurations. For example, the base station 604 can configure an aggregation factor K for time slot aggregation and indicate (K-1) beams to the UE 602, where each of the (K-1) beams can come from (K-1) TRPs. Then, (K-1) single beams can be used to transmit the first (K-1) time slots, and an SFN beam (e.g., a combination of the (K-1) beams) can be used to transmit the last (the Kth) time slot. For example, if the base station 604 configures an aggregation factor of 5 (e.g., K = 5) for time slot aggregation, four single beams (e.g., (K-1) beams) can be used to transmit the first four time slots (e.g., (K-1) time slots) from four TRPs (e.g., (K-1) TRPs), and an SFN beam that can be a combination of these four beams (e.g., (K-1) beams) can be used to transmit the fifth time slot (e.g., the Kth time slot). In another example, the base station can also configure a more complex combination of SFN and non-SFN time slots, where some time slots can use a single beam for non-SFN, while some time slots can use a subset of beams (not all beams) for SFN. For example, SFN time slot #1 can use beam #1 and beam #2, SFN time slot #2 can use beam #2 and beam #3, SFN time slot #3 can use beam #1 and beam #3, and so on. Determining which beam to use for each time slot can be based on a preconfigured table or predefined rules, such that the base station 604 can allocate the beams used for each time slot based on the preconfigured table or predefined rules. In response, the UE 602 can also adjust its beams based on the preconfigured table or predefined rules.

[0077] When transmissions can be sent from multiple TRPs (e.g., TRP#1 706 and TRP#2 708), the base station can use a TCI code point composed of at least two TCI states (e.g., a pair of beams: TCI state #1 and TCI state #2) to configure the beams for transmission. For example, the first time slot can use TCI state #1 in the TCI code point, the second time slot can use TCI state #2 in the TCI code point, and the third time slot can use both TCI state #1 and TCI state #2 in the TCI code point, and so on. It should be noted that the use of "first" and "second" does not specify a particular time order, but only indicates different time slots or repetitions. Therefore, in slot aggregation, since PDSCH transmissions can be repeated over multiple time slots, the TCI code point can be used for PDSCH transmissions, such that one or more of the two TCI states defined by the TCI code point can be used to transmit multiple time slots in the transmission (e.g., by alternating between the two TCI states or using both of the two TCI states, etc.). In one aspect, in addition to the alternation of TCI states, SFN transmissions can also be configured for slot aggregation, e.g., in combination with Figure 5A , Figure 5B , Figure 5C and Figure 6 as described.

[0078] Figure 7A , Figure 7B and Figure 7C are 700A, 700B, and 700C showing examples of applying slot aggregation to non-transparent SFNs. In one example, in non-transparent SFN mode, if slot aggregation with an aggregation factor of 3 (e.g., K = 3) is configured by the base station associated with the first TRP 704 (e.g., TRP#2) and the second TRP 706 (e.g., TRP#2), a TCI code point including TCI state #1 and TCI state #2 can be further configured for slot aggregation, such that time slot #1 can use TCI state #1, time slot #2 can use TCI state #2, and time slot #3 can use one or more SFN beams including both TCI state #1 and TCI state #2, and so on. As Figure 7A shows, the UE 702 can configure beam 714 to receive time slot #1 from the second TRP 706, which is transmitted through beam 712 indicated by TCI state #1. As Figure 7B shows, the UE 702 can configure beam 710 to receive time slot #2 from the first TRP 704, which is transmitted through beam 708 indicated by TCI state #2. As Figure 7CAs shown, the UE 702 may configure beam 716 for receiving time slot #3 (e.g., SFN time slot), which is transmitted from the first TRP 704 and the second TRP 706 using beams 708 and 712 respectively, as indicated by TCI state #1 and TCI state #2. It should be noted that the use of "first", "second", and "third" (e.g., #1, #2, and #3) does not specify a particular time order, they only indicate different repetitions. For example, the second repetition and the third repetition etc. may be received before receiving the first time slot (e.g., repetition).

[0079] Figure 8 It is a flowchart 800 of a wireless communication method. This method may be performed by a base station or a component of the base station (e.g., base stations 102, 180, 310, 504, 604; TRPs 704, 706; device 902; which may include a memory 376 and may be the entire base station 310 or a component of the base station 310 (such as TX processor 316, RX processor 370, and / or controller / processor 375)). This method may enable the base station to aggregate transmission configuration time slots and transmit some of the time slots within the time slot aggregation in SFN mode and some of these time slots in non-SFN mode.

[0080] At 802, the base station may configure the UE to receive multiple repetitions of a transmission using time slot aggregation, for example in combination with Figure 6 , 7A , 7B, and Figure 7C as described. For example, at 606 and 607, the base station 604 may configure time slot aggregation and beams for one or more repetitions of the transmission, and the base station 604 may send an indication / configuration for the time slot aggregation to the UE 602. For example, Figure 9 the time slot aggregation configuration component 940 and / or the transmission component 934 of the device 902 in

[0081] At 804, the base station may indicate to the UE one or more beams for each repetition of the transmission, for example in combination with Figure 6 , 7A , 7B, and Figure 7C as described. For example, at 608, the base station 604 may indicate to the UE 602 one or more beams for the time slot aggregation (e.g., for each repetition of the transmission). For example, Figure 9 the beam indication component 942 and / or the transmission component 934 of the device 902 in

[0082] In one example, the base station may indicate a set of one or more beams in a configuration for slot aggregation. In another example, one or more beams for each repetition of the transmission may be indicated to the UE via a TCI state, where the TCI state may be transmitted in DCI, e.g., in combination with Figure 6 as described.

[0083] At 806, the base station may send multiple repetitions of the transmission based on one or more beams indicated to the UE, where at least one of the multiple repetitions of the transmission is sent using more than one beam based on SFN operation, e.g., in combination with Figure 6 , 7A , 7B, and Figure 7C as described. For example, at 609, the base station 604 may send multiple repetitions of the transmission based on one or more beams indicated to the UE 602, where at least one repetition may be sent using more than one beam based on SFN operation. For example, Figure 9 the slot aggregation processing component 944 and / or the transmission component 934 of the apparatus 902 in

[0084] In one example, the multiple repetitions of the transmission may include an initial transmission. In another example, at least one of the multiple repetitions of the transmission may be sent based on non-SFN operation using a single beam, where the base station may indicate one or more beams for each time slot of the multiple repetitions to the UE, e.g., in combination with Figure 6 as described. In another example, the base station may indicate SFN operation based on multiple TCI states and non-SFN operation based on a single TCI state, e.g., in combination with Figure 6 as described. For example, at least one of the multiple repetitions may be transmitted using a beam different from another of the multiple repetitions.

[0085] Figure 9900 is an example showing a hardware implementation for apparatus 902. Apparatus 902 may be a base station and includes a baseband unit 904. The baseband unit 904 may communicate with the UE 104 via a cellular RF transceiver. The baseband unit 904 may include a computer-readable medium / memory. The baseband unit 904 is responsible for general processing, which includes executing software stored on the computer-readable medium / memory. When the software is executed by the baseband unit 904, it causes the baseband unit 904 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 904 when executing the software. The baseband unit 904 further includes a receiving component 930, a communication manager 932, and a transmitting component 934. The communication manager 932 includes one or more of the illustrated components. The components within the communication manager 932 may be stored in the computer-readable medium / memory and / or configured as hardware within the baseband unit 904. The baseband unit 904 may be a component of the BS 310 and may include at least one of the memory 376 and / or the TX processor 316, the RX processor 370, and the controller / processor 375.

[0086] The communication manager 932 includes a time slot aggregation configuration component 940 configured to configure the UE to receive multiple repetitions of a transmission using time slot aggregation, such as described in 802 in conjunction with Figure 8 The communication manager 932 further includes a beam indication component 942 configured to indicate to the UE one or more beams for each repetition of the transmission, such as described in 804 in conjunction with Figure 8 The communication manager 932 further includes a time slot aggregation processing component 944 configured to transmit multiple repetitions of a transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is transmitted based on an SFN operation using more than one beam, such as described in 806 in conjunction with Figure 8 The communication manager 932 further includes a time slot aggregation processing component 944 configured to transmit multiple repetitions of a transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is transmitted based on an SFN operation using more than one beam, such as described in 806 in conjunction with

[0087] The apparatus may include additional components for performing each block of the algorithms in the Figure 8 flowcharts. Thus, each block in the Figure 8 flowcharts may be performed by components, and the apparatus may include one or more of these components. These components may be one or more hardware components specifically configured to perform the stated processing / algorithms, these components may be implemented by a processor configured to perform the stated processing / algorithms, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0088] In one configuration, the apparatus 902, and specifically the baseband unit 904, includes means for configuring a UE to receive a plurality of repetitions of a transmission using time slot aggregation (e.g., a time slot aggregation configuration component 940 and / or a transmission component 934). The apparatus 902 includes means for indicating to the UE one or more beams for each repetition of a transmission (e.g., a beam indication component 942 and / or a transmission component 934). The apparatus 902 includes means for sending a plurality of repetitions of a transmission based on the one or more beams indicated to the UE, wherein at least one of the plurality of repetitions of a transmission is sent based on SFN operation using more than one beam (e.g., a time slot aggregation processing component 944 and / or a transmission component 934).

[0089] These means may be one or more of the components of the apparatus 902 configured to perform the functions recited by these aforementioned means. As described above, the apparatus 902 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, these means may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by these aforementioned means.

[0090] Figure 10 1 is a flow chart of a wireless communication method 1000. The method may be performed by a UE or a component of a first UE (e.g., UE 106, 350, 402, 502, 602, 702; apparatus 1102; a processing system, which may include a memory 360, and may be the entire UE 350 or a component of the UE 350 (e.g., a TX processor 368, an RX processor 356, and / or a controller / processor 359). The method may enable the UE to receive time slots under time slot aggregation and SFN networks. The method may also enable the UE to determine whether a base station is transmitting a time slot in SFN mode.

[0091] At 1002, the UE may receive from a base station a configuration for receiving a plurality of repetitions of a transmission in a timeslot aggregation, e.g., in conjunction with Figure 5A , 5B , 5C, 6, 7A, 7B and Figure 7C For example, at 607, UE 602 may receive from base station 604 a configuration for receiving multiple repetitions of a transmission based on time slot aggregation. Figure 11 The time slot aggregation processing component 1140 and / or the receiving component 1130 of the device 1102 can perform the reception of this configuration.

[0092] In one example, multiple repetitions of a transmission may include an initial transmission. In another example, each repetition may be a time slot or mini-time slot.

[0093] At 1004, the UE may receive an indication of one or more beams for multiple repetitions of a transmission, such as in conjunction with Figure 6 、 7A 、7B and Figure 7C as described. For example, at 608, the UE 602 may receive from the base station 604 an indication of one or more beams for multiple repetitions of a transmission. For example, Figure 11 the beam indication processing component 1142 and / or the receiving component 1130 of the apparatus 1102 in

[0094] In one example, the indication may indicate one or more beams for each repetition of the transmission. In such an example, one or more beams for each repetition of the transmission may be indicated based on the TCI, where the UE may receive the TCI in the DCI. In another example, the indication may include a TCI code point that includes a first TCI state and a second TCI state.

[0095] At 1006, the UE may, based on the above indication, determine whether the base station transmits the repetitions in the multiple repetitions of the transmission based on SFN operation or non-SFN operation, such as in conjunction with Figure 6 、 7A 、7B and Figure 7C as described. For example, at 612, the UE 602 may determine which time slots in the transmission are transmitted based on the SFN mode and which time slots are transmitted based on the non-SFN mode. For example, Figure 11 the SFN and non-SFN time slot determination component 1144 of the apparatus 1102 in

[0096] In one example, the UE determines whether the base station transmits the repetitions in the multiple repetitions based on SFN operation or non-SFN operation based on the number of beams used by the base station to transmit the repetition, where the first repetition may be received using more than one beam, the second repetition includes being received using a single beam, and so on. In another example, the indication may indicate a set of one or more beams for the configuration of time slot aggregation, and the UE may, based on pre-configured or predefined rules, determine whether the repetitions in the multiple repetitions are transmitted by the base station under SFN operation or under non-SFN operation, such as in conjunction with Figure 6 as described. In another example, the UE may receive from the base station an explicit indication regarding whether each repetition is transmitted based on SFN operation or based on non-SFN operation.

[0097] At 1008, the UE may receive a first repetition of the transmission in a first time slot operating in SFN mode using at least one configuration different from the configuration used to receive a second repetition in a second time slot operating in non - SFN mode, e.g., as described in conjunction with Figure 6 , 7A , 7B, and Figure 7C . For example, at 614, UE 602 may receive a first repetition of the transmission in a first time slot operating in SFN mode using at least one configuration different from the configuration used to receive a second repetition in a second time slot operating in non - SFN mode. For example, Figure 11 the SFN and non - SFN time slot processing components 1146 and / or the receiving component 1130 of the apparatus 1102 in

[0098] may perform reception of SFN time slots and non - SFN time slots. Figure 7A , 7B and Figure 7C . It should be noted that the use of "first", "second", and "third" does not specify a particular time order, but merely indicates different repetitions. For example, the second and third repetitions etc. may be received before receiving the first time slot (e.g., repetition). In another example, the UE may determine one or more beams for receiving each of the multiple repetitions based on pre - configured or pre - defined rules. Repetitions transmitted by the base station under SFN operation may use more than one beam, and each beam may come from a different base station or different TRP.

[0099] Figure 111100 is an example showing a hardware implementation for apparatus 1102. Apparatus 1102 may be a UE and includes a cellular baseband processor 1104 (also referred to as a modem) coupled to a cellular RF transceiver 1122 and one or more subscriber identity module (SIM) cards 1120, an application processor 1106 coupled to a secure digital (SD) card 1108 and a screen 1110, a Bluetooth module 1112, a wireless local area network (WLAN) module 1114, a global positioning system (GPS) module 1116, and a power supply 1118. The cellular baseband processor 1104 communicates with the UE 104 and / or the BS 102 / 180 via the cellular RF transceiver 1122. The cellular baseband processor 1104 may include a computer-readable medium / memory. The cellular baseband processor 1104 is responsible for general processing, which includes executing software stored on the computer-readable medium / memory. When the software is executed by the cellular baseband processor 1104, it causes the cellular baseband processor 1104 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the cellular baseband processor 1104 when executing the software. The cellular baseband processor 1104 further includes a receiving component 1130, a communication manager 1132, and a transmitting component 1134. The communication manager 1132 includes one or more of the illustrated components. The components within the communication manager 1132 may be stored in the computer-readable medium / memory and / or be configured as hardware within the cellular baseband processor 1104. The cellular baseband processor 1104 may be a component of the UE 350 and may include at least one of a memory 360 and / or a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, apparatus 1102 may be a modem chip and include only the baseband processor 1104, and in another configuration, apparatus 1102 may be an entire UE (e.g., see Figure 3 of 350) and include other modules of apparatus 1102.

[0100] The communication manager 1132 includes a time slot aggregation processing component 1140 configured to receive multiple repeated configurations for receiving transmissions in time slot aggregation from a base station, e.g., as described in connection with Figure 10 of 1002. The communication manager 1132 further includes a beam indication processing component 1142 configured to receive an indication indicating one or more beams of multiple repeats for transmission, e.g., as described in connection with Figure 10 of 1004. The communication manager 1132 further includes an SFN and non-SFN time slot determination component 1144 configured to determine, based on the above indication, whether the base station is transmitting repeats of multiple repeats of a transmission based on SFN operation or non-SFN operation, e.g., as described in connection with Figure 10The communication manager 1132 also includes a SFN and non-SFN time slot processing component 1146, which is configured to receive a first repetition of a transmission in a first time slot based on SFN operation using at least one configuration different from a configuration used to receive a second repetition in a second time slot based on non-SFN operation, for example, as described in conjunction with Figure 10 As described in 1008.

[0101] The apparatus may include means for performing Figure 10 Each box in the algorithm in the flowchart is an additional component. Therefore, Figure 10 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of these components. These components may be one or more hardware components specifically configured to perform the stated processing / algorithm, these components may be implemented by a processor configured to perform the stated processing / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0102] In one configuration, the apparatus 1102 (specifically, the cellular baseband processor 1104) includes: a unit for receiving a configuration for receiving multiple repetitions of a transmission in a time slot aggregation from a UE (e.g., a time slot aggregation processing component 1140 and / or a receiving component 1130). The apparatus 1102 includes: a unit for receiving an indication of one or more beams for the multiple repetitions of the transmission (e.g., a beam indication processing component 1142 and / or a receiving component 1130). The apparatus 1102 includes: a unit for determining whether the base station sends the repetitions of the multiple repetitions of the transmission based on SFN operation or non-SFN operation based on the above indication (e.g., an SFN and non-SFN time slot determination component 1144). The apparatus 1102 includes: a unit for receiving a first repetition of the transmission in a first time slot based on SFN operation using at least one configuration different from a configuration for receiving a second repetition in a second time slot based on non-SFN operation (e.g., a non-SFN time slot processing component 1146 and / or a receiving component 1130).

[0103] These means may be one or more of the components of the apparatus 1102 configured to perform the functions recited by these aforementioned means. As described above, the apparatus 1102 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, these means may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by these aforementioned means.

[0104] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein, but are not limited thereto.

[0105] Aspect 1 is a method for wireless communication at a base station, which includes: configuring a UE to receive multiple repetitions of a transmission using slot aggregation; indicating to the UE one or more beams for each repetition of the transmission; and transmitting the multiple repetitions of the transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is transmitted using SFN operation based on more than one beam.

[0106] In aspect 2, the method according to aspect 1 further includes: transmitting at least one repetition of the multiple repetitions of the transmission using a single beam based on non-SFN operation.

[0107] In aspect 3, the method according to aspect 1 or aspect 2 further includes: the base station indicating the one or more beams for each time slot of the multiple repetitions.

[0108] In aspect 4, the method according to any one of aspects 1-3 further includes: the base station indicating a set of the one or more beams in a configuration for the slot aggregation.

[0109] In aspect 5, the method according to any one of aspects 1-4 further includes: the base station indicating the SFN operation based on multiple TCI states, and the base station indicating the non-SFN operation based on a single TCI state.

[0110] In aspect 6, the method according to any one of aspects 1-5 further includes: at least one repetition of the multiple repetitions being transmitted with a beam different from another repetition of the multiple repetitions.

[0111] In aspect 7, the method according to any one of aspects 1-6 further includes: indicating to the UE the one or more beams for each repetition of the transmission via a TCI state.

[0112] In aspect 8, the method according to any one of aspects 1-7 further includes: transmitting the TCI state in DCI.

[0113] In aspect 9, the method according to any one of aspects 1-8 further includes: the multiple repetitions of the transmission including an initial transmission.

[0114] Aspect 10 is a device for wireless communication at a base station, comprising: a plurality of repeating units for configuring a UE to receive transmissions using slot aggregation; a unit for indicating to the UE one or more beams for each repetition of the transmission; a plurality of repeating units for transmitting the transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the plurality of repetitions of the transmission is transmitted using more than one beam based on SFN operation.

[0115] In aspect 11, the method according to aspect 10 further comprises: a unit for performing the method according to any one of aspects 2-9.

[0116] Aspect 12 is a device for wireless communication at a base station, comprising: a memory; and at least one processor coupled to the memory, the memory and the at least one processor being configured to perform the method according to aspects 1-9.

[0117] Aspect 13 is a computer-readable medium storing computer-executable code for wireless communication at a base station, which when executed by a processor causes the processor to perform the method according to any one of aspects 1-9.

[0118] Aspect 14 is a method for wireless communication at a UE, comprising: receiving from a base station a configuration of a plurality of repetitions for receiving a transmission in slot aggregation; receiving an indication indicating one or more beams for the plurality of repetitions of the transmission; and receiving the first repetition of the transmission in a first time slot based on SFN operation using at least one configuration different from a configuration for receiving a second repetition in a second time slot based on non-SFN operation.

[0119] In aspect 15, the method according to aspect 14 further comprises: the indication indicating the one or more beams for each repetition of the transmission.

[0120] In aspect 16, the method according to aspect 14 or aspect 15 further comprises: based on the indication, determining whether the base station transmits the repetitions of the plurality of repetitions of the transmission based on the SFN operation or the non-SFN operation.

[0121] In aspect 17, the method according to any one of aspects 14-16 further comprises: the UE determining whether the base station transmits the repetitions of the plurality of repetitions based on the SFN operation or the non-SFN operation based on the number of beams used by the base station for transmitting the repetitions.

[0122] In aspect 18, the method according to any one of aspects 14 - 17 further comprises: receiving the first repetition using more than one beam, and the second repetition comprises receiving using a single beam.

[0123] In aspect 19, the method according to any one of aspects 14 - 18 further comprises: the indication indicates a set of one or more beams for the configuration for the slot aggregation, and wherein, the UE determines whether the base station transmits the repetition among the multiple repetitions based on the SFN operation or based on the non - SFN operation, based on a pre - configured rule or a predefined rule.

[0124] In aspect 20, the method according to any one of aspects 14 - 19 further comprises: receiving an explicit indication from the base station indicating whether each repetition is transmitted based on the SFN operation or based on the non - SFN operation.

[0125] In aspect 21, the method according to any one of aspects 14 - 20 further comprises: indicating, based on TCI, one or more beams for each repetition of the transmission.

[0126] In aspect 22, the method according to any one of aspects 14 - 21 further comprises: the TCI is received in a DCI.

[0127] In aspect 23, the method according to any one of aspects 14 - 22 further comprises: the multiple repetitions of the transmission include an initial transmission.

[0128] In aspect 24, the method according to any one of aspects 14 - 23 further comprises: the indication includes a TCI code point, and the TCI code point includes a first TCI state and a second TCI state.

[0129] In aspect 25, the method according to any one of aspects 14 - 24 further comprises: receiving the first repetition based on the SFN operation using at least one configuration different from the configuration for receiving the second repetition based on the non - SFN operation, including: receiving the first repetition using a first beam indicated in the first TCI state and a second beam indicated in the second TCI state, receiving the second repetition using the second beam indicated in the second TCI state, and receiving a third repetition using the first beam indicated in the first TCI.

[0130] In aspect 26, the method according to any one of aspects 14 - 25 further comprises: each of the multiple repetitions is a slot or a mini - slot.

[0131] In aspect 27, the method according to any one of aspects 14 - 26 further comprises: determining one or more beams for receiving each repetition of the plurality of repetitions based on preconfigured rules or predefined rules.

[0132] In aspect 28, the method according to any one of aspects 14 - 27 further comprises: the repetitions transmitted by the base station under the SFN operation use more than one beam, and each beam comes from a different base station or a different TRP.

[0133] Aspect 29 is a device for wireless communication at a UE, comprising: a unit for receiving, from the UE, a configuration for receiving a plurality of repetitions of a transmission in slot aggregation; a unit for receiving an indication of one or more beams for the plurality of repetitions of the transmission; a unit for receiving, based on SFN operation, a first repetition of the transmission in a first slot using at least one configuration different from a configuration for receiving a second repetition in a second slot based on non - SFN operation.

[0134] In aspect 30, the method according to aspect 27 further comprises: a unit for performing the method according to any one of aspects 15 - 28.

[0135] Aspect 31 is a device for wireless communication at a UE, comprising: a memory; and at least one processor coupled to the memory, the memory and the at least one processor being configured to perform the method according to aspects 14 - 28.

[0136] Aspect 32 is a computer - readable medium storing computer - executable code for wireless communication at a UE, which, when executed by a processor, causes the processor to perform the method according to any one of aspects 14 - 28.

[0137] It should be understood that the specific order or block hierarchy in the process / flowcharts disclosed herein is merely an example of a method. It should be understood that based on design preferences, the specific order or block hierarchy in these process / flowcharts can be rearranged. Additionally, some blocks can be combined or omitted. The appended method claims present the elements of the various blocks in an example order, but are not meant to be limited by the specific order or hierarchy presented.

[0138] The various aspects described above are presented to enable any person of ordinary skill in the art to make and use the invention. For a person of ordinary skill in the art, various modifications to these aspects will be apparent, and the general principles defined herein can be applied to other aspects. Thus, the invention is not limited to the aspects shown herein, but is consistent with the full scope of the disclosure herein, where, unless otherwise specified, the singular form of an element does not mean "one and only one" but can be "one or more". Terms such as "if", "when", and "while" should be construed as "under the condition that" rather than implying a direct temporal relationship or reaction. That is, these phrases (e.g., "when") do not mean to take action immediately in response to an action or during the occurrence of an action, but simply mean that if a condition is met, a certain action will occur, without requiring a specific or immediate temporal constraint on the occurrence of the action. The term "exemplary" as used herein means "serving as an example, illustration, or instance". Any aspect described herein as "exemplary" should not be construed as more preferred or more advantageous than other aspects. Unless otherwise specifically stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof", including any combination of A, B, and / or C, may include multiple A's, multiple B's, or multiple C's. 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" can be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination can include one or more members or some members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure are expressly incorporated herein by reference and are intended to be covered by the claims, and such structural and functional equivalents are known or will be known to persons of ordinary skill in the art. Additionally, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims. Words such as "module", "apparatus", "element", "device", etc. are not substitutes for the word "unit". Thus, an element of a claim should not be construed as a functional module unless the element is expressly recited using the language "functional module".

Claims

1. An apparatus for wireless communication at a base station, comprising: a memory; and at least one processor coupled to the memory and configured to: configure a UE to receive multiple repetitions of a transmission using slot aggregation; indicate to the UE one or more beams for each repetition of the transmission; and send the multiple repetitions of the transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is sent using more than one beam based on single frequency network (SFN) operation, and at least one repetition of the multiple repetitions of the transmission is sent using a single beam based on non-SFN operation.

2. The apparatus according to claim 1, wherein the base station indicates the one or more beams for each time slot of the multiple repetitions.

3. The apparatus according to claim 1, wherein the base station indicates a set of the one or more beams in a configuration for the slot aggregation.

4. The apparatus according to claim 1, wherein the base station indicates the SFN operation based on multiple transmission configuration indicator (TCI) states or multiple tracking reference signals (TRS), and the base station may indicate the non-SFN operation based on a single TCI state or a single TRS.

5. The apparatus according to claim 1, wherein at least one repetition of the multiple repetitions is sent with a beam different from another repetition of the multiple repetitions.

6. The apparatus according to claim 1, wherein the one or more beams for each repetition of the transmission are indicated to the UE via a transmission configuration indicator (TCI) state.

7. The apparatus according to claim 6, wherein the TCI state is sent in a downlink control indicator (DCI).

8. The apparatus according to claim 1, wherein the multiple repetitions of the transmission include an initial transmission.

9. The apparatus according to claim 1, further comprising: a transceiver coupled to the at least one processor.

10. A method for wireless communication at a base station, comprising: configuring a UE to receive multiple repetitions of a transmission using slot aggregation; indicating to the UE one or more beams for each repetition of the transmission; and sending the multiple repetitions of the transmission based on the one or more beams indicated to the UE, wherein at least one repetition of the multiple repetitions of the transmission is sent using more than one beam based on single frequency network (SFN) operation, and at least one repetition of the multiple repetitions of the transmission is sent using a single beam based on non-SFN operation.

11. The method according to claim 10, wherein the base station indicates the one or more beams for each time slot of the multiple repetitions.

12. The method according to claim 10, wherein the base station indicates a set of the one or more beams in a configuration for the slot aggregation.

13. The method according to claim 10, wherein the base station indicates the SFN operation based on multiple transmission configuration indicator (TCI) states or multiple tracking reference signals (TRS), and the base station may indicate the non-SFN operation based on a single TCI state or a single TRS.

14. The method according to claim 10, wherein, at least one of the multiple repetitions is transmitted with a beam different from another one of the multiple repetitions.

15. The method according to claim 10, wherein, the one or more beams for each repetition of the transmission are indicated to the UE by a transmission configuration indicator (TCI) state.

16. The method according to claim 15, wherein, the TCI state is transmitted in a downlink control indicator (DCI).

17. The method according to claim 10, wherein, the multiple repetitions of the transmission include an initial transmission.

18. An apparatus for wireless communication at a user equipment (UE), comprising: a memory; and at least one processor coupled to the memory and configured to: receive, from a base station, a configuration for receiving multiple repetitions of a transmission in slot aggregation; receive an indication indicating one or more beams for the multiple repetitions of the transmission; and receive the first repetition of the transmission in a first slot based on an SFN operation, using at least one configuration different from a configuration for receiving a second repetition in a second slot based on a non-single frequency network (SFN) operation, wherein the first repetition is received using more than one beam and the second repetition is received using a single beam.

19. The apparatus according to claim 18, wherein, the indication is for indicating the one or more beams for each repetition of the transmission.

20. The apparatus according to claim 19, wherein, the UE determines whether the repetition among the multiple repetitions is transmitted by the base station based on the SFN operation or based on the non-SFN operation based on the number of beams used by the base station for transmitting the repetition.

21. The apparatus according to claim 18, wherein, the at least one processor is further configured to: determine whether the repetition among the multiple repetitions of the transmission is transmitted by the base station based on the SFN operation or the non-SFN operation based on the indication.

22. The apparatus according to claim 21, wherein, the indication indicates a set of the one or more beams of the configuration for the slot aggregation, and wherein the UE determines whether the repetition among the multiple repetitions is transmitted by the base station based on the SFN operation or based on the non-SFN operation based on a pre-configured rule or a predefined rule.

23. The apparatus according to claim 18, wherein, the at least one processor is further configured to: receive, from the base station, an explicit indication for indicating whether each repetition is transmitted based on the SFN operation or based on the non-SFN operation.

24. The apparatus according to claim 18, wherein, The indication includes a TCI code point, and the TCI code point includes a first TCI state and a second TCI state.

25. The apparatus according to claim 24, wherein, receiving the first repetition based on the SFN operation using at least one configuration different from the configuration used for receiving the second repetition based on the non-SFN operation, the at least one processor is further configured to: receive the first repetition using a first beam indicated in the first TCI state and a second beam indicated in the second TCI state, receive the second repetition using the second beam indicated in the second TCI state, and receive a third repetition using the first beam indicated in the first TCI.

26. The apparatus according to claim 18, further comprising: a transceiver coupled to the at least one processor.

27. A method for wireless communication at a user equipment (UE), comprising: receiving, from a base station, a configuration for receiving a plurality of repetitions of a transmission in slot aggregation; receiving an indication indicating one or more beams for the plurality of repetitions of the transmission; and receiving a first repetition of the transmission in a first slot based on a single frequency network (SFN) operation using at least one configuration different from a configuration used for receiving a second repetition in a second slot based on a non-SFN operation, wherein the first repetition is received using more than one beam and the second repetition is received using a single beam.

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