Phase tracking reference signal configuration for transmitting repetitive

Abstract

An apparatus receives a configuration of a phase tracking reference signal (PT-RS). The apparatus then determines at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of transmissions. The apparatus then receives or transmits components of the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions.

Description

Technical Field

[0001] The present disclosure relates generally to communication systems and, more particularly, to wireless communications related to phase tracking reference signals. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at municipal, national, regional and even global levels. An example of a telecommunication standard is 5G New Radio (NR). 5G NR is part of the continued mobile broadband evolution promulgated by the 3rd Generation Partnership Project (3GPP) to meet new requirements related to latency, reliability, security, scalability (e.g., Internet of Things (IoT)) and other requirements. 5G NR includes services related to enhanced mobile broadband (eMBB), massive machine type communications (mMTC) and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. Further improvements to 5G NR technology are needed. These improvements can also be applied to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the Invention

[0004] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects and is neither intended to identify key or critical elements of all aspects nor 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 is presented later.

[0005] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a user equipment (UE) are provided. The apparatus receives a configuration of a phase tracking reference signal (PT-RS). The apparatus determines at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of transmissions. The apparatus receives or transmits the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions.

[0006] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a base station are provided. The apparatus configures a UE for a PT-RS. The apparatus determines at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of transmissions. The apparatus receives or transmits the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions.

[0007] To accomplish the foregoing and related ends, one or more aspects described above comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and accompanying drawings set forth in detail certain illustrative features of one or more aspects described above. However, these features are indicative of but a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0009] Figure 2A 、 2B , 2C and 2D are diagrams showing 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, respectively.

[0010] Figure 3 is a diagram illustrating an example of a base station and a user equipment (UE) in an access network.

[0011] Figure 4A and 4B is an example diagram showing PT-RS with different time densities in a resource grid.

[0012] Figure 5 is a diagram illustrating example data transmission repetition in the frequency and time domains.

[0013] Figure 6 is a schematic diagram illustrating example frequency hopping.

[0014] Figure 7 is a schematic diagram illustrating example frequency hopping.

[0015] Figure 8 is a diagram illustrating example inter-slot repetition involving PT-RS.

[0016] Figure 9 is a diagram illustrating example time-domain PT-RS density with repetition.

[0017] Figure 10 is a diagram illustrating example time-domain PT-RS density with repetition.

[0018] Figure 11 is a diagram illustrating example time-domain PT-RS density with repetition.

[0019] Figure 12 is an example communication flow between a UE and a base station.

[0020] Figure 13 is an example communication flow between a UE and a base station.

[0021] Figure 14 is a flow chart of a wireless communication method.

[0022] Figure 15 is a flow chart of a wireless communication method. DETAILED DESCRIPTION

[0023] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details in order to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0024] Several aspects of telecommunications systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0025] For example, any part of an element or an element or any combination of elements can be implemented as a "processing system" comprising one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware that are configured to perform the various functions described throughout this disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted as instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc., whether or not referred to as software, firmware, middleware, microcode, hardware description languages, or other.

[0026] Therefore, in one or more example embodiments, the described functions can be implemented in hardware, software, or any combination thereof. If implemented in software, the function can be stored on a computer-readable medium or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media includes computer storage media. The storage medium can be any available medium that a computer can access. By way of example and not limitation, such computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of the above-mentioned types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0027] Figure 1 1 is a diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. Small cells include femto cells, pico cells, and micro cells.

[0028] A base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). A base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. The base station 102 can perform one or more of the following functions, among other things: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and transmission of warning messages. The base stations 102 can communicate with each other directly or indirectly (eg, through the EPC 160 or the core network 190) via a third backhaul link 134 (eg, an X2 interface). The third backhaul link 134 can be wired or wireless.

[0029] Base stations 102 can communicate wirelessly with UEs 104. Each base station 102 can provide communication coverage for its own geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network that includes both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved node base station (eNB) (HeNB), which can 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 can include uplink (UL) (also known as reverse link) transmissions from the UE 104 to the base station 102 and / or downlink (DL) (also known as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 can use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link can be over one or more carriers. Base station 102 / UE 104 can use spectrum bandwidth of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) per carrier, which is allocated in carrier aggregation for transmission in each direction totaling Yx MHz (x component carriers). The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). Component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0030] Some UEs 104 can communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 can use the DL / UL WWAN spectrum. The D2D communication links 158 can use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication can be achieved through various wireless D2D communication systems, such as WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0031] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) to determine whether the channel is available before communicating.

[0032] Small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, small cell 102' can use NR and use the same 5 GHz unlicensed spectrum used by Wi-Fi AP 150. Small cell 102' using NR in the unlicensed spectrum can improve the coverage of the access network and / or increase the capacity of the access network.

[0033] Whether a small cell 102' or a large cell (e.g., a macro base station), base station 102 may include and / or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations (e.g., gNB 180) may operate in the traditional sub-6 GHz spectrum, in millimeter wave (mmW) frequencies, and / or near-mmW frequencies to communicate with UE 104. When gNB 180 operates in mmW or near-mmW frequencies, gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is a portion of the RF spectrum in the electromagnetic spectrum. EHF has a frequency range between 30 GHz and 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near-mmW can extend down to frequencies of 3 GHz, with wavelengths of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using the mmW / near-mmW radio frequency (RF) band (e.g., 3 GHz–300 GHz) have extremely high path loss and very short range. The mmW base station 180 can use beamforming 182 with the UE 104 to compensate for the extremely high path loss and very short range. The base station 180 and the UE 140 can each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming.

[0034] Base station 180 may transmit beamformed signals in one or more transmit directions 182′ to UE 140. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182″. UE 104 may also transmit beamformed signals in one or more transmit directions to base station 180. Base station 180 may receive beamformed signals in one or more receive directions from UE 104. Base station 180 / UE 104 may perform beam training to determine optimal receive and transmit directions for each of base station 180 / UE 104. The transmit and receive directions of base station 180 may be the same or different. The transmit and receive directions of UE 104 may be the same or different.

[0035] 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. MME 162 may communicate with a Home Subscriber Server (HSS) 174. MME 162 is a control node that handles signaling between UE 104 and EPC 160. Generally, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides IP address allocation and other functions for UEs. PDN Gateway 172 and BM-SC 170 are connected to IP Services 176. IP Services 176 may include the Internet, Intranet, IP Multimedia Subsystem (IMS), PS streaming services, and / or other IP services. BM-SC 170 may provide service provisioning and delivery functions for MBMS users. The BM-SC 170 may serve as the entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area broadcasting a specific service, and may be responsible for session management (start / stop) and collecting eMBMS-related billing information.

[0036] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transported through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to the IP services 197. The IP services 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), packet switched (PS) stream (PSS) services, and / or other IP services.

[0037] A base station may include and / or be referred to as a gNB, Node B, eNB, access point, base transceiver station, radio base station, radio transceiver, transceiver functionality, basic service set (BSS), extended service set (ESS), transmit receive point (TRP), or some other suitable terminology. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smartphone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet computer, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, a toaster, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0038] Reference again Figure 1 In certain aspects, the UE 104 and / or the base station 102 or 180 may include a PT-RS configuration component 198 configured to determine a density of PT-RSs in the time and / or frequency domains based at least in part on an inter-slot repetition level of a corresponding physical uplink shared channel (PUSCH) or physical downlink shared channel (PDSCH). Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0039] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B FIG230 is a diagram showing an example of DL channels within a 5G / NR subframe. Figure 2C Figure 250 shows an example of a second subframe within a 5G / NR frame structure. Figure 2D280 is a diagram illustrating an example of UL channels within a 5G / NR subframe. The 5G / NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within a subcarrier set are dedicated to either DL or UL, or time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within a subcarrier set are dedicated to both DL and UL. Figure 2A 、 2C In the example provided, it is assumed that the 5G / NR frame structure is TDD, where subframe 4 is configured with slot format 28 (mostly DL), where D is DL, U is UL, and X is flexible between DL / UL, and subframe 3 is configured with slot format 34 (mostly UL). Although subframes 3 and 4 are shown with slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are both DL and UL, respectively. The other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with the slot format (dynamically via DL control information (DCI), or semi-statically / statically via radio resource control signaling) via the received slot format indicator (SFI). Note that the following description also applies to the 5G / NR frame structure as TDD.

[0040] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) can be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include mini-time slots, which may include 7, 4, or 2 symbols. Depending on the time slot configuration, each time slot may contain 7 or 14 symbols. For time slot configuration 0, each time slot may include 14 symbols; for time slot configuration 1, each time slot may include 7 symbols. The symbols on the DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe is based on the time slot configuration and parameter set. For slot configuration 0, different parameter sets μ0 to 5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different parameter sets 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and parameter set μ, there are 14 symbols / slot and 2 μ timeslots / subframes. The subcarrier spacing and symbol length / duration are functions of the parameter set. The subcarrier spacing can be equal to 2 μ*15kHz, where μ is a parameter set 0 to 5. Thus, parameter set μ=0 has a subcarrier spacing of 15kHz, and subcarrier μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2D An example of slot configuration 0 is provided, with 14 symbols per slot, parameter set μ = 2, and 4 slots per subframe. The slot duration is 0.25ms, the subcarrier spacing is 60kHz, and the symbol duration is approximately 16.67μs.

[0041] The resource grid can be used to represent the frame structure. Each time slot consists of a resource block (RB) (also called 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] like Figure 2A As shown in FIG, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration). x , 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. RS can also include beam measurement RS (BRS), beam refinement RS (BRRS) and phase tracking RS (PT-RS).

[0043] Figure 2B Examples of various DL channels within 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 includes nine RE groups (REGs), and each REG includes four consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) can be within symbol 2 of a specific subframe of the frame. The PSS is used by the UE 104 to determine the subframe / symbol timing and the physical layer identification. The secondary synchronization signal (SSS) can be within symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the physical layer cell identification group number and the radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the position of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information such as System Information Blocks (SIBs) that are not transmitted through the PBCH, and paging messages.

[0044] like Figure 2CAs shown, some of these REs carry DM-RSs for channel estimation at the base station (indicated as R for one specific configuration, but other DM-RS configurations are also possible). The UE can send DM-RSs for the physical uplink control channel (PUCCH) and DM-RSs for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first or first two symbols in the PUSCH. Depending on whether a short or long PUCCH is sent and on the specific PUCCH format used, the PUCCH DM-RS can be sent in different configurations. The UE can send 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 send the SRS on one of the comb structures. The base station can use the SRS for channel quality estimation to achieve frequency-dependent scheduling on the UL.

[0045] Figure 2D An example of each UL channel within a subframe of a frame is shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), power headroom report (PHR), and / or UCI.

[0046] Figure 33 is a block diagram of a base station 310 in an access network communicating with a UE 350. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes the radio resource control (RRC) layer, while 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 medium access control (MAC) layer. The controller / processor 375 provides RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with upper layer packet data unit (PDU) transmission, error correction through ARQ, concatenation, segmentation and assembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs into transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

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

[0048] At the UE 350, each receiver 354RX receives a signal via its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, the RX processor 356 can combine them into a single OFDM symbol stream. The RX processor 356 then uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most likely signal constellation point transmitted by the base station 310. These soft decisions can be based on the channel estimate calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by base station 310. The data and control signals are then provided to controller / processor 359, which performs layer 3 and layer 2 functions.

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

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

[0051] Channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier using a respective spatial stream for transmission.

[0052] At the base station 310, the UL transmission is processed in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to the RX processor 370.

[0053] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and 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 an ACK and / or NACK protocol to support HARQ operations.

[0054] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 of the UE 350 may be configured to combine Figure 1 198 to perform various aspects. At least one of the TX processor 316, RX processor 370, and controller / processor 375 of the base station 310 may be configured to combine Figure 1 The 198 came to perform all aspects.

[0055] Wireless communications such as those based on NR can include communications in frequency bands above 6 GHz to enable greater flexibility and scalability of wireless communication networks and devices. However, in high frequency bands such as frequency range 2 (FR2) covering 24.25 to 52.60 GHz, radio propagation may become more difficult compared to low frequency bands. For example, as the frequency increases, the wavelength decreases and shorter wavelengths are more susceptible to interference from the atmosphere and the environment, such as absorption by physical barriers such as walls and ceilings. Therefore, in higher frequency spectrums, coverage enhancement helps wireless communications and devices improve the coverage and latency of wireless communications.

[0056] Coverage enhancement can improve communications in frequency range 1 (FR1) covering 410 MHz-7125 MHz. In an urban environment, coverage enhancement can improve communications between outdoor base stations serving indoor UEs. For example, in a rural environment, coverage enhancement can improve communications for base stations serving UEs at long distances (such as 30 kilometers from the base station). Coverage enhancement can be used to improve communications between UEs and base stations, and can include various services including voice over internet protocol (VOIP), eMBB, etc., and can include downlink and / or uplink communications. In some examples, coverage enhancement for communications in FR1 spectrum can be constructed to improve uplink communications including PUSCH and / or PUCCH. For example, in an urban environment, the target downlink throughput can be approximately 10 Mbps, while the target uplink throughput can be approximately 1 Mbps. In a rural environment, the target downlink throughput can be approximately 1 Mbps, while the target uplink throughput can be approximately 100 kbps.

[0057] For FR2, indoor base stations can serve indoor UEs. In urban and / or rural environments, outdoor base stations can serve outdoor UEs and / or indoor UEs. Coverage enhancement can be used to improve communications (including services such as eMBB, VOIP, etc.). Coverage enhancement can address downlink and / or uplink communications. For example, in an indoor environment, the target downlink throughput can be approximately 25Mbps, while the target uplink throughput can be approximately 5Mbps. In an urban environment, the target downlink throughput can be approximately 25Mbps, while the target uplink throughput can be approximately 5Mbps. In a suburban environment, the target downlink throughput can be approximately 1Mbps, while the target uplink throughput can be approximately 50kbps.

[0058] For example, since high-frequency communication devices and network access points are more likely to encounter phase noise due to mismatches in transmitter and receiver frequency oscillators, PT-RS can be used to compensate for phase noise by enabling phase tracking of the oscillator at the transmitter and / or receiver. PT-RS can help suppress phase noise and common phase errors, especially at mmW frequencies, and PT-RS can appear in uplink channels (such as PUCCH and / or PUSCH) and / or downlink channels (e.g., PDCCH and / or PDSCH).

[0059] Figure 4A and 4B is an example diagram (400, 402) showing PT-RS with different time densities in a resource grid. Figure 4A The resource grid in has a PT-RS with a time density of one, which means there is one PT-RS in every symbol. Figure 4B The resource grid in has a PT-RS with a time density of two, which means there are two PT-RS in each symbol. Figure 4A The resource grid in Figure 4B Higher PT-RS density in the resource grid. Due to phase noise characteristics, PT-RS usually has low density in the frequency domain and high density in the time domain. PT-RS can be associated with one DMRS port during transmission and used for both PDSCH and PUSCH. Figure 4A and 4B As shown, PT-RS information can be mapped to several subcarriers per symbol because phase rotation affects all subcarriers within an OFDM symbol equally. Figure 4A and 4B The example in illustrates PT-RS in a single subcarrier, but this is only to illustrate the concept of different time densities of PT-RS, and different time densities can be applied to PT-RS with various frequency densities.

[0060] The Block Error Rate (BLER) is the ratio of the number of erroneous blocks received to the total number of blocks sent in a transmission. The BLER can be determined to demonstrate the quality of the transmission, where a lower BLER indicates better transmission quality. Generally speaking, a higher PT-RS density can achieve better BLER performance. When the density of PT-RS is high, the phase tracking accuracy is high and the common phase error can be better compensated to achieve better transmission performance. However, as the density of PT-RS increases, there is a trade-off between phase tracking accuracy and signaling overhead. The increased overhead may have a negative impact on the actual throughput of the transmission (e.g., P-RS). put ) (for example, the rate of data transmitted per unit time). Figure 4A and 4B As shown in Figure 1, a higher PT-RS density may result in greater signal overhead because more resources are used by PT-RS. Similarly, a higher PT-RS density in the spectrum increases the PT-RS overhead. This may result in lower spectral efficiency (SE) because the amount of information (i.e., bits) transmitted per second per Hz decreases with greater signal overhead.

[0061] In transmissions with smaller (e.g., narrow) bandwidths, increasing the density of PT-RSs may only provide a relatively small BLER gain for the transmission, but may not help improve the throughput performance of the transmission. For transmissions with smaller bandwidths, the number of code blocks within a scheduled TB may be smaller, allowing the code blocks to achieve more time-domain diversity. This in itself can improve transmission quality (i.e., reduce BLER). Therefore, the small BLER gain contributed by increasing the density of PT-RSs may not be worth the large overhead for transmissions with smaller bandwidths.

[0062] On the other hand, for transmissions with larger (e.g., wide) bandwidths, increasing the density of PT-RSs can help improve throughput performance. In larger bandwidth transmissions, the time-domain diversity of code blocks may be lower compared to smaller bandwidth transmissions because the number of code blocks within a scheduled TB may be larger. Due to the lower time-domain diversity, introducing more PT-RSs can help achieve greater BLER gains for the transmission. Therefore, the BLER improvements contributed by increasing the density of PT-RSs are worthwhile for larger bandwidth transmissions.

[0063] The temporal density of the PT-RS can be based on the scheduled MCS of the transmission. For example, the temporal density can be determined using a table that compares the transmitted MCS to the configured MCS. Table 1 below shows an example temporal density of the PT-RS as a function of the scheduled MCS, and Table 2 below shows an example frequency density of the PT-RS as a function of the scheduled bandwidth.

[0064] In Table 1, L PT-RSIndicates the time density of PT-RS and can refer to the time interval between the last DM-RS symbol and the first PT-RS symbol, and can refer to the time interval between PT-RS symbols. Figure 4A In the case of a time density of "1", the first PT-RS symbol can be in the first symbol after the DM-RS and in every symbol of the transmission. Figure 4B In the case where the time density is "2", the first symbol can be the second symbol after the DM-RS, and the PT-RS can be transmitted in the second symbol after the previous PT-RS. Similarly, if the time density is "4", the first PT-RS symbol can be the fourth symbol after the DM-RS and the fourth symbol after the previous PT-RS transmission. In Table 1, I MCS Refers to the MCS used for scheduled transmissions (e.g., PUCCH, PUSCH, PDCCH, PDSCH); ptrs-MCS1 corresponds to the first configured threshold; ptrs-MCS2 corresponds to the second configured threshold; ptrs-MCS3 corresponds to the third configured threshold; and ptrs-MCS4 corresponds to the fourth configured threshold.

[0065]

[0066] Table 1 - Temporal density of PT-RS as a function of scheduled MCS

[0067] In Table 2, K PT-RS Corresponding to the frequency density of PT-RS, it is shown as the scheduled bandwidth (e.g., N RB ). N RB0 and N RB1 Corresponds to the configured threshold.

[0068] Scheduled bandwidth <![CDATA[Frequency (FD) density (K PT-RS )]]> <![CDATA[N RB <N RB0 ]]> PT-RS does not exist <![CDATA[N RB0 ≤N RB <N RB1 ]]> 2 <![CDATA[N RB1 ≤N RB ]]> 4

[0069] Table 2 - Frequency density of PT-RS as a function of scheduled bandwidth

[0070] For example, when transform precoding is not enabled, and if the UE is configured with a higher layer function such as phaseTrackingRS (such as in a DMRS configuration), the higher layer functions of time density (e.g., timeDensity) and frequency density (e.g., frequencyDensity) in the PT-RS configuration may indicate the threshold ptrs-MCS, respectively. i , i=1,2,3 and N RB,I, i=0, 1, as shown in Table 1 and Table 2. The threshold may be RRC-configured and may be configured separately for uplink and downlink communications (eg, separately for PDSCH configuration and PUSCH configuration).

[0071] The UE may assume that the presence and pattern of PT-RS antenna ports is a function of the corresponding scheduled MCS and scheduled bandwidth in the corresponding bandwidth part as shown in Table 1 and Table 2, respectively. If the higher layer function timeDensity is not configured, the UE may assume that L PT-RS = 1. If no higher layer function timeDensity is configured, the UE may assume that K PT-RS = 2. If the higher layer functions timeDensity and timeDensity in PTRS-UplinkConfig are not configured, the UE may assume that L PT-RS =1 and K PT-RS =2.

[0072] If the parameters PT-RS time domain density (L PT-RS ) and PT-RS frequency domain density (K PT-RS ) indicates "PT-RS does not exist" or "np", the UE may assume that PT-RS does not exist, for example, it is not transmitted. If the base station configures the same adjacent MCS boundary value (i.e., ptrs-MCS i =ptrs-MCS i+1 , or N RBi =N RBi+1 ), the identified frequency / time domain PR-TS density value associated with the relevant MCS / BW can be considered as forbidden.

[0073] To improve data transmission and have a higher rate of successful data transmission, especially over noisy channels, the same data transmission (e.g., PDSCH, PUSCH, etc.) can be configured and scheduled to be repeatedly transmitted as PDSCH repetitions or PUSCH repetitions. Since noisy channels may corrupt transmissions in several places, transmitting repetitions of the same data transmission can increase the success rate of the transmission. Figure 5 is a diagram 500 illustrating example data transmission repetitions. Figure 5 In the example, code blocks 504 (e.g., #3) in TB 502 are repeatedly transmitted in different time slots using the same frequency bandwidth. The repeated transmission of code blocks 504 may be referred to as inter-slot repetition.

[0074] However, sometimes the noise level in a particular frequency region is particularly high, which disrupts the data transmission and all its repetitions. In this case, frequency hopping can be utilized. The frequency hopping used for transmission can be similar to the data transmission repetitions above, except that some repetitions can be sent on different frequency resources. Figure 6 6 is a diagram illustrating an example frequency hopping, where data transmission 602 is retransmitted using different frequency resources at different times. This may be referred to as inter-slot frequency hopping. By sending the same data packet on different frequencies, transmission failures caused by strong noise in a particular frequency region may be reduced or even avoided. Figure 6 Frequency hopping is shown for different time slots, but may also occur for different time ranges (eg within one subframe). Figure 7 7 is a diagram illustrating another example of frequency hopping, where a data packet 702 is retransmitted at different frequencies within a time slot, such as sub-band 0 and sub-band 3. This type of frequency hopping may be referred to as intra-slot frequency hopping. Figure 7 The examples in FIG. 1 only show two examples of frequency hopping patterns, and aspects presented herein can be applied to various frequency hopping patterns.

[0075] Figure 8 800 is a diagram illustrating an example inter-slot repetition involving PT-RS. As can be seen, when a code block 802 with PT-RS is transmitted, all PT-RS may be repeated in all retransmissions. In some cases, since more PT-RS are transmitted compared to a single transmission (e.g., a single-slot PDSCH / PUSCH transmission), the density of PT-RS may be reduced for repetition. For example, if repetition and / or slot-specific virtual resource block (VRB) to physical resource block (PRB) interleaving is applied to the transmission, additional frequency diversity may be achieved. In other examples, the phase of the oscillator at the transmitter and receiver may have been tracked using the first number of retransmissions, and the PT-RS may not be used for subsequent retransmissions. Therefore, if the density configuration of PT-RS in the time domain and / or frequency domain further takes into account data transmission repetition, better throughput performance may be achieved.

[0076] In some examples, the PT-RS density for an uplink or downlink transmission can be determined based at least in part on the number of repetitions of the transmission. For example, in addition to the scheduled MCS or transmission bandwidth, the number of repetitions (e.g., inter-slot PDSCH / PUSCH repetitions, etc.) can also be considered, as discussed in conjunction with Tables 1 and 2.

[0077] Table 3 below shows an example table of PT-RS time density similar to Table 2, where the time density (e.g., L PT-RS) is a function of both the scheduled MCS for the transmission (e.g., PUSCH, PUCCH, PDSCH, or PDCCH) and the number of data transmission repetitions for the transmission. As shown, different combinations of scheduled MCS and scheduled repetitions (e.g., {MCS, #Rep}) have different temporal densities. In Table 3, N is the scheduled repetition number for the transmission. N1 and N2 correspond to repetition thresholds that can be configured for the UE.

[0078]

[0079]

[0080] Table 3 - TD density (L) as a function of scheduled MCS PT-RS )

[0081] Table 4 below is an example table of PT-RS density based on the scheduled repetition number of a transmission (e.g., PDSCH, PUSCH, etc.). As shown in Table 4, the scheduled repetition number can be used in conjunction with the scheduled bandwidth of the transmission to determine the frequency density of the transmission (e.g., K PT-RS ). For example, different PT-RS frequency domain density levels can be associated with different combinations of scheduled bandwidth and scheduled repetition number, such as {BW, #Rep}. In Table 4, N is the scheduled repetition number of the transmission. N1 and N2 correspond to the repetition thresholds that can be configured for the UE. N RB corresponds to the scheduled bandwidth, and N RB0 and N RB1 corresponds to the threshold bandwidth.

[0082]

[0083] Table 4 - FD density (K) as a function of scheduled bandwidth PT-RS )

[0084] For each MCS level (e.g., ptrs-MCS i ), the temporal density of PT-RS can be associated with different repetition levels (denoted as N). Similarly, for each BW level (e.g., N RBi ), the frequency density of PT-RS can be associated with different repetition levels (denoted as N). Each repetition level can be identified by multiple repetition regions, such as N <N1,…N i ≤N <N i+1 ,…,N k ≤N, etc.

[0085] There are multiple ways to associate the PT-RS density configuration with the number of repetitions per MCS or BW level. In some examples, the number of repetitions can be categorized into different regions or ranges, where each region or range is associated with a PT-RS density. For example, at a particular MCS level, when the scheduled number of repetitions is below a first threshold (e.g., N1), the PT-RS density can be 1 (e.g., 1 PT-RS per symbol), when the scheduled number of repetitions is between the first threshold and a second threshold (e.g., N2), the PT-RS density can be 2 (e.g., 1 PT-RS per 2 symbols), and when the repetitions are above the second threshold, the PT-RS density can be 4 (e.g., 1 PT-RS per 4 symbols). Different regions or ranges of repetitions can be associated with the same PT-RS density. For example, repetitions below the first threshold and repetitions between the first and second thresholds can all have the same PT-RS density (e.g., 1, 2, 4, etc.). There can also be more than two thresholds (e.g., N1, N2, N3...N k ), and define multiple repetition ranges, for example, N <N1,N1≤N<N2,N2≤N<N3,N3≤N<N4…N k ≤ N, etc. Using the number of repetitions to determine the temporal density of the PT-RS can be applied to uplink and / or downlink transmissions (e.g., PDSCH and / or PUSCH). PDSCH can use different thresholds than PUSCH. Alternatively, at least some thresholds can be the same for PDSCH and PUSCH.

[0086] The regions and / or boundaries may be RRC configured for the UE or may be defined and known at the UE and the base station. In some examples, if the base station sets the adjacent repetition threshold (i.e., N i =N i+1 ) is configured with the same value, then the relevant repetition level (N i ≤N <N i+1 ) can be considered as disabled. Therefore, the base station can indicate that the PT-RS density in time and / or frequency is disabled or absent by configuring adjacent thresholds to the same value.

[0087] Figures 9 to 11 This is an example showing time domain PT-RS density for different MCS levels and repetitions based on Table 3. In this example, N1 is "2" and N2 is "4". Figure 9 As shown in Figure 900, assuming ptrs-MCS3<=I MCSIf the uplink or downlink transmission 902 is configured to be repeated twice (e.g., N=2), the time-domain PT-RS density of the transmission is set to 1 based on Table 3, because N≤N1 (e.g., 1 PT-RS per 1 symbol). On the other hand, if the uplink or downlink transmission 1002 is instead configured to be repeated three times (e.g., N=3), the time-domain PT-RS density of the transmission is set to 2 (e.g., 1 PT-RS per 2 symbols), as shown in Table 3. Figure 10 As shown in Figure 1000, since N1≤N <N2。

[0088] exist Figure 11 FIG. 1100 is a diagram illustrating an example density of PT-RS in the frequency domain with a K-based PT-RS The spacing between PT-RSs in the frequency range of , for example from Table 3, because N2≤N.

[0089] In some examples, the density of PT-RS for uplink or downlink transmissions can be configured to depend on the number of transmission repetitions (e.g., PDSCH, PUSCH, etc.) without regard to or consideration of MCS or BW levels as shown in Tables 5 and 6 below. In some examples, the use of these tables can be based on whether repetitions are scheduled, or the number of transmission repetitions.

[0090]

[0091] Table 5 - TD density based on repeat (L PT-RS )

[0092]

[0093] Table 6 - FD density based on replicates (K PT-RS )

[0094] When repetition is enabled for uplink or downlink transmission, the modulation order can be limited to a lower level (such as QPSK), and the time density of PT-RS can be determined separately from MCS. For example, the time domain density of PT-RS can be a function of the frequency domain density of PT-RS, such as L PT-RS =f(K PT-RS ).

[0095] In some other examples, the PT-RS density configuration in the time domain and / or frequency domain can be based on a defined threshold such that when the number of repetitions is above the threshold, the PT-RS can be disabled or not present (e.g., as indicated by “np”) for transmission.

[0096]

[0097] Table 7 - TD density (L) as a function of the scheduled MCS PT-RS )

[0098]

[0099]

[0100] Table 8 - FD density (K) as a function of the scheduled bandwidth PT-RS )

[0101] For example, as shown in Table 7 and Table 8, the PT-RS density can be configured in such a way that when the repetition number N exceeds a certain threshold (such as the threshold defined by N2), the PT-RS density configuration for transmission can be disabled. For repetitions below the threshold, they can still be assigned to multiple regions (e.g., Region 1: N < N1; Region 2: N1 ≤ N < N2), where different or the same PT-RS density values are assigned to each region as shown in the table. In other examples, the PT-RS density below the threshold can simply be assigned the same PT-RS density, such that when the repetition number is higher than the threshold, the PT-RS configuration is disabled, and when the repetition number is lower than the threshold, a fixed PT-RS density value is assigned to the transmission (e.g., N < threshold: PT-RS density = 2; threshold < N: PT-RS disabled).

[0102] When the repetition number N is higher than a certain threshold, since the transmission power (e.g., UL-Tx-power) may be limited, the number of scheduled resource blocks for transmission may be limited, and at the same time, the modulation order may also be limited to QPSK (similar to the above example). Therefore, when the repetition is higher than the thresholds in the time domain and frequency domain, the PT-RS can be completely disabled.

[0103] Figure 12 An example communication flow 1200 between the UE 1202 and the base station 1204 is shown, including the UE 1202 receiving the configuration 1206 of the PT-RS. The configuration 1206 of the PT-RS can be received in the RRC signaling, and the configuration 1206 includes one or more parameters, such as a first parameter (e.g., N1) for the first threshold repetition number or a second parameter (e.g., N2) for the second threshold repetition number.

[0104] At 1208, based on the configuration 1206, the UE 1202 can determine at least one of the time density or frequency density of the PT-RS based on the inter-slot repetition of the transmission. For example, when the transmission includes the PDSCH, the UE 1202 can use at least one of the time density or frequency density to receive the PT-RS. When the transmission includes the PUSCH, the UE can use the same or different time density or different frequency density to send the PT-RS.

[0105] For example, UE 1202 may determine the time density of the PT-RS based on the number of inter-slot repetitions of the transmission, e.g., as described in conjunction with Tables 3, 5, or 7. UE 1202 may further determine the time density of the PT-RS based on the MCS of the transmission, where different time densities are associated with different repetition levels for each MCS level. Similarly, UE 1202 may determine the frequency density of the PT-RS based on the number of inter-slot repetitions of the transmission, e.g., as described in conjunction with Tables 4, 6, or 8. UE 1202 may further determine the frequency density of the PT-RS based on the bandwidth of the transmission, where different frequency densities are associated with different repetition levels for each bandwidth level, as described in conjunction with Table 4.

[0106] In some examples, UE 1202 may determine at least one of a time density or a frequency density of the PT-RS based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of a first repetition number (e.g., N1) or a second repetition number (e.g., N2). If N1=N2, UE 1202 may determine that the time density or the frequency density of the PT-RS does not exist. N1 and / or N2 may be configured for the UE, for example, in RRC signaling, or may be defined and known to UE 1202.

[0107] In other examples, if inter-slot repetition is not enabled for a transmission, the temporal density of the PT-RS may be determined based on the MCS of the transmission, and if inter-slot repetition is enabled for a transmission, the temporal density of the PT-RS may not be determined based on the MCS of the transmission. If inter-slot repetition is enabled, the temporal density of the PT-RS may be based on the frequency density of the PT-RS. In some other examples, the PT-RS may be disabled when the number of repetitions is above a threshold. This may apply when the transmission includes a PUSCH.

[0108] At 1212, after UE 1202 determines at least one of a time density or a frequency density of a PT-RS based on the inter-slot repetition of transmissions, UE 1202 may receive a PDSCH or PDCCH with the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions. At 1214, after UE 1202 determines at least one of a time density or a frequency density of a PT-RS based on the inter-slot repetition of transmissions, UE 1202 may transmit a PUSCH or PUCCH with the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions.

[0109] Figure 13Another example communication flow 1300 between a base station 1304 and a UE 1302 is shown, including the base station 1304 determining a PT-RS density over time and / or frequency for the UE. At 1306, the base station 1304 configures the UE 1302 for the PT-RS. The PT-RS configuration 1306 may be sent in RRC signaling and may include one or more of the first parameters for a first threshold repetition number (e.g., N1) or a second repetition number (e.g., N2).

[0110] At 1308, based on the configuration 1306, the base station 1304 may determine at least one of a time density or a frequency density of the PT-RS based on the inter-slot repetition of the transmission. For example, when the transmission includes the PDSCH 1312, the base station may use at least one of the time density or the frequency density to transmit the PT-RS. When the transmission includes the PUSCH 1314, the base station may use at least one of the time density or the frequency density to receive the PT-RS.

[0111] For example, the base station 1304 may determine the temporal density of the PT-RS based on the inter-slot repetition of the transmission, e.g., as described in conjunction with Tables 3, 5, or 7. The base station 1304 may further determine the temporal density of the PT-RS based on the MCS of the transmission, where different temporal densities are associated with different repetition levels for each MCS level. Similarly, the base station 1304 may determine the frequency density of the PT-RS based on the inter-slot repetition of the transmission, e.g., as described in conjunction with Tables 4, 6, or 8. The base station 1304 may further determine the frequency density of the PT-RS based on the bandwidth of the transmission, where different frequency densities are associated with different repetition levels for each bandwidth level.

[0112] In some examples, base station 1304 may determine at least one of time density or frequency density based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of a first threshold repetition number (e.g., N1) or a second threshold repetition number (e.g., N2). Base station 1304 may indicate that time density and / or frequency density of the PT-RS is absent by configuring the first threshold repetition number to be equal to the second threshold repetition number (e.g., N1=N2). N1 and / or N2 may be defined rather than configured.

[0113] In other examples, if inter-slot repetition is not enabled for a transmission, the temporal density of the PT-RS may be determined based on the MCS of the transmission, and if inter-slot repetition is enabled for a transmission, the temporal density of the PT-RS may not be determined based on the MCS of the transmission. If inter-slot repetition is enabled, the temporal density of the PT-RS may be based on the frequency density of the PT-RS. In some other examples, the PT-RS may be disabled when the number of repetitions is above a threshold. This may apply when the transmission includes a PUSCH.

[0114] At 1312, after the base station 1304 determines at least one of the time density or frequency density of the PT-RS based on the inter-time slot repetition of the transmission, the base station 1304 may send the PT-RS, for example in the PDSCH or PDCCH, based on at least one of the time density or frequency density determined based on the inter-time slot repetition of the transmission.

[0115] At 1314, after the base station 1304 determines at least one of the time density or frequency density of the PT-RS based on the inter-time slot repetition of the transmission, the base station 1304 may receive the PT-RS, for example, in the PUSCH or PUCCH, based on at least one of the time density or frequency density determined based on the inter-time slot repetition of the transmission.

[0116] Figure 14 1400 is a flow chart of a wireless communication method. The method may be performed by a UE or a component thereof (e.g., UE 104, 350, 1202, 1302; a processing system, which may include memory 360 and may be the entire UE 350 or a component thereof, such as TX processor 368, RX processor 356, and / or controller / processor 359). Optional aspects are shown with dashed lines. The method may enable the UE to determine a PT-RS density for transmission based, at least in part, on the number of inter-slot repetitions.

[0117] At 1402, the UE may receive a PT-RS configuration. The PT-RS configuration may be received in RRC signaling. The configuration may include one or more of a first parameter for a first repetition number or a second parameter for a second repetition number. These parameters may correspond to N1 and / or N2, as described in conjunction with any of Tables 3-8.

[0118] At 1404, based on the received configuration, the UE may determine at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of the transmission, for example, as described in conjunction with Tables 3-8 or Figure 12 or Figure 13 Any of the ones described.

[0119] For example, the UE may determine the temporal density of the PT-RS based on the inter-slot repetition of the transmission, e.g., as combined with Figure 5-10 and any of Tables 3, 5, or 7. The UE may further determine the temporal density of the PT-RS based on the MCS of the transmission, where different temporal densities are associated with different repetition levels for the MCS level, as described in conjunction with Table 3. Similarly, the UE may determine the frequency density of the PT-RS based on the inter-slot repetition of the transmission, for example, as described in conjunction with Figure 11 and as described in any one of Tables 4, 6, or 8. The UE may further determine the frequency density of the PT-RS based on the bandwidth of the transmission, where different frequency densities are associated with different repetition levels for each bandwidth level, as described in conjunction with Table 4.

[0120] In some examples, the UE may determine at least one of the time density or the frequency density based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of the first repetition number or the second repetition number (e.g., N1 and / or N2). If the configuration configures the first repetition number to be equal to the second repetition number (e.g., N1=N2), the UE may determine that the time density or the frequency density of the PT-RS does not exist. Alternatively or additionally, one or more of the first repetition number or the second repetition number may be defined.

[0121] In other examples, if inter-slot repetition is not enabled for a transmission, the temporal density of the PT-RS may be determined based on the MCS of the transmission, and if inter-slot repetition is enabled for a transmission, the temporal density of the PT-RS may not be determined based on the MCS of the transmission. If inter-slot repetition is enabled, the temporal density of the PT-RS may be based on the frequency density of the PT-RS. In some other examples, the PT-RS may be disabled when the number of repetitions is above a threshold. This may apply when the transmission includes a PUSCH.

[0122] At 1406, after the UE determines at least one of a time density or a frequency density of the PT-RS based on the inter-slot repetition of the transmission, the UE may receive or transmit the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of the transmission. For example, when the transmission includes a PDSCH, the UE may receive the PT-RS using at least one of the time density or the frequency density. When the transmission includes a PUSCH, the UE may transmit the PT-RS using at least one of the time density or the frequency density.

[0123] The foregoing Figure 14 Each box in the flowchart and the Figure 12 and 13The aspects performed by UE 1202, 1302 in the embodiment may be performed by at least one component of the wireless device, each component being one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for processor implementation, or some combination thereof.

[0124] These components may be software components running in a processor, resident / stored in a computer-readable medium / memory, one or more hardware components coupled to a processor, or some combination thereof. The processing system may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. Alternatively, the processing system may be the entire UE (e.g., see Figure 3 of 350).

[0125] In one configuration, an apparatus for wireless communication at a UE may include: means for receiving a configuration of a PT-RS; means for determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of transmissions; and means for receiving or transmitting the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions, e.g., as in conjunction with Figure 14 The aforementioned components may be one or more of the aforementioned components of the device and / or the processing system of the device may be configured to perform the functions listed in the aforementioned components. The processing system may include a TX processor 368, an RX processor 356, and a controller / processor 359. Thus, in one configuration, the aforementioned components may be the TX processor 368, the RX processor 356, and the controller / processor 359, which are configured to perform the functions listed in the aforementioned components.

[0126] Figure 15 15 is a flow chart of a wireless communication method 1500. The method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, 1204, 1304; a processing system, which may include memory 376 and may be the entire base station 310 or a component of base station 310, such as TX processor 316, RX processor 370, and / or controller / processor 375). Optional aspects are shown with dashed lines. The method may enable the base station to determine PT-RS density in time and / or frequency of transmission based, at least in part, on the number of inter-slot repetitions.

[0127] At 1502, base station 1304 may configure a UE for a PT-RS. The PT-RS configuration may be sent in RRC signaling and may include one or more of a first parameter for a first repetition number or a second parameter for a second repetition number (e.g., N1 and / or N2).

[0128] At 1504, the base station may determine at least one of a time density or a frequency density of the PT-RS based on the inter-slot repetition of the transmission, for example, as described in conjunction with Tables 3-8 or Figure 12 or Figure 13 Any of the ones described.

[0129] For example, the base station may determine the time density of the PT-RS based on the inter-slot repetition of the transmission, for example, as shown in combination with Table 3, Table 5, Table 7 and / or Figure 5-10 The base station may further determine the time density of the PT-RS based on the transmitted MCS, where different time densities are associated with different repetition levels for the MCS level, as described in conjunction with Table 3. Similarly, the base station may determine the frequency density of the PT-RS based on the inter-slot repetition of the transmission, for example, as described in conjunction with Table 4, Table 6, Table 8, and / or Figure 11 The base station may further determine the frequency density of the PT-RS based on the bandwidth of the transmission, wherein for each bandwidth level, different frequency densities are associated with different repetition levels, as described in conjunction with Table 4.

[0130] In some examples, the base station may determine at least one of the time density or the frequency density based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of the first repetition number or the second repetition number. The base station may indicate that the time density or the frequency density of the PT-RS does not exist by configuring the first repetition number to be equal to the second repetition number. In addition, one or more of the first repetition number or the second repetition number may be defined.

[0131] In other examples, if inter-slot repetition is not enabled for a transmission, the temporal density of the PT-RS may be determined based on the MCS of the transmission, and if inter-slot repetition is enabled for a transmission, the temporal density of the PT-RS may not be determined based on the MCS of the transmission. If inter-slot repetition is enabled, the temporal density of the PT-RS may be based on the frequency density of the PT-RS. In some other examples, the PT-RS may be disabled when the number of repetitions is above a threshold. This may apply when the transmission includes a PUSCH.

[0132] At 1506, after the base station determines at least one of a time density or a frequency density of the PT-RS based on the inter-slot repetition of the transmission, the base station may receive or transmit the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of the transmission. For example, when the transmission includes a PDSCH, the base station may use at least one of the time density or the frequency density to transmit the PT-RS. When the transmission includes a PUSCH, the base station may use at least one of the time density or the frequency density to receive the PT-RS.

[0133] The foregoing Figure 15 Each box in the flowchart and the Figure 12 and 13 The aspects performed by base stations 1204, 1304 in the may be performed by at least one component of the wireless device, each component being one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for processor implementation, or some combination thereof.

[0134] These components may be software components running in the processor, resident / stored in a computer-readable medium / memory, one or more hardware components coupled to the processor, or some combination thereof. The system may be a component of the base station 310 and may include the memory 376 and / or at least one of the TX processor 316, the RX processor 370, and the controller / processor 375. Alternatively, the processing system may be the entire base station (e.g., see Figure 3 310).

[0135] In one configuration, an apparatus for wireless communication at a base station may include: means for configuring a user equipment (UE) for a phase tracking reference signal (PT-RS); means for determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of transmissions; and means for receiving or transmitting the PT-RS based on at least one of the time density or the frequency density determined based on the inter-slot repetition of transmissions, e.g., as in conjunction with Figure 15 As described above. The aforementioned means may be one or more of the aforementioned components of the device and / or the processing system of the device configured to perform the functions listed in the aforementioned means. As described above, the processing system may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370, and the controller / processor 375, which are configured to perform the functions listed in the aforementioned means.

[0136] The following examples are merely illustrative, and aspects thereof may be combined with aspects of other embodiments or teachings described herein without limitation.

[0137] Example 1 is a method for wireless communication at a UE, comprising: receiving a configuration of a PT-RS; determining at least one of a time density or a frequency density of the PT-RS based on inter-time slot repetition of the transmission; and receiving or sending the PT-RS based on at least one of the time density or the frequency density determined based on the inter-time slot repetition of the transmission.

[0138] In Example 2, the method of Example 1 further includes: the transmission includes a PDSCH, and the UE receives the PT-RS using at least one of a time density or a frequency density.

[0139] In Example 3, the method of Example 1 or Example 2 further includes: the transmission includes a PUSCH, and the UE sends the PT-RS using at least one of a time density or a frequency density.

[0140] In Example 4, the method of any one of Examples 1-3 further includes: the UE determining a time density of the PT-RS based on an inter-slot repetition of the transmission.

[0141] In Example 5, the method of any one of Examples 1-4 further includes: the UE further determining a time density of the PT-RS based on the transmitted MCS, wherein for the MCS level, different time densities are associated with different repetition levels.

[0142] In Example 6, the method of any one of Examples 1-5 further includes: the frequency density of the PT-RS is based on an inter-slot repetition of the transmission.

[0143] In Example 7, the method of any one of Examples 1-6 further includes determining a frequency density of the PT-RS based further on a bandwidth of the transmission, wherein different frequency densities are associated with different repetition levels for bandwidth levels.

[0144] In Example 8, the method of any one of Examples 1-7 further includes: the UE determining a time density and a frequency density of the PT-RS based on an inter-slot repetition of the transmission.

[0145] In Example 9, the method of any one of Examples 1-8 further includes: the UE determining at least one of the time density or the frequency density based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of the first number of repetitions or the second number of repetitions.

[0146] In Example 10, the method of any one of Examples 1-9 further includes: the PT-RS is received in RRC signaling, and the PT-RS includes one or more of a first parameter for the first repetition number or a second parameter for the second repetition number.

[0147] In Example 11, the method of any one of Examples 1-10 further includes: if the configuration configures the first number of repetitions to be equal to the second number of repetitions, the UE determining that the time density or the frequency density of the PT-RS does not exist.

[0148] In Example 12, the method of any one of Examples 1-11 further includes one or more of the first number of repetitions or the second number of repetitions being defined.

[0149] In Example 13, the method of any one of Examples 1-12 further includes: if inter-slot repetition is not enabled for the transmission, determining the time density of the PT-RS based on the MCS of the transmission; and if inter-slot repetition is enabled for the transmission, not determining the time density of the PT-RS based on the MCS of the transmission.

[0150] In Example 14, the method of any one of Examples 1-13 further includes: if inter-slot repetition is enabled, the time density of the PT-RS is based on the frequency density of the PT-RS.

[0151] In Example 15, the method of any one of Examples 1-14 further includes disabling PT-RS when the number of repetitions is higher than a threshold.

[0152] In Example 16, the method of any one of Examples 1-15 further includes: the transmission including a PUSCH.

[0153] Example 17 is an apparatus for wireless communication at a UE, comprising: a component for receiving a configuration of a PT-RS; a component for determining at least one of a time density or a frequency density of the PT-RS based on inter-time slot repetition of the transmission; and a component for receiving or sending the PT-RS based on at least one of the time density or the frequency density determined based on the inter-time slot repetition of the transmission.

[0154] In Example 18, the apparatus of Example 17 further comprises means for performing the method of any one of Examples 2-16.

[0155] Example 19 is an apparatus for wireless communication at a UE, comprising: a memory; and at least one processor coupled to the memory and configured to perform the method of any one of Examples 1-16.

[0156] Example 20 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 of any one of Examples 1-16.

[0157] Example 21 is a method for wireless communication at a base station, comprising: configuring a UE for PT-RS; determining at least one of a time density or a frequency density of the PT-RS based on inter-time slot repetition of transmission; and receiving or sending the PT-RS based on at least one of the time density or the frequency density determined based on the inter-time slot repetition of transmission.

[0158] In Example 22, the method of Example 21 further includes: the transmission includes a PDSCH, and the base station sends the PT-RS using at least one of a time density or a frequency density.

[0159] In Example 23, the method of Example 21 or Example 22 further includes: the transmission includes a PUSCH, and the base station receives the PT-RS using at least one of a time density or a frequency density.

[0160] In Example 24, the method of any one of Examples 21-23 further includes the base station determining a temporal density of the PT-RS based on an inter-slot repetition of the transmission.

[0161] In Example 25, the method of any one of Examples 21-24 further includes: the base station further determining the time density of the PT-RS based on the MCS of the transmission, wherein for the MCS level, different time densities are associated with different repetition levels.

[0162] In Example 26, the method of any one of Examples 21-25 further includes: the base station determining a frequency density of the PT-RS based on an inter-slot repetition of the transmission.

[0163] In Example 27, the method of any one of Examples 21-26 further includes: the base station determining a frequency density of the PT-RS further based on a bandwidth of the transmission, wherein different frequency densities are associated with different repetition levels for bandwidth levels.

[0164] In Example 28, the method of any one of Examples 21-27 further includes the base station determining a time density and a frequency density of the PT-RS based on an inter-slot repetition of the transmission.

[0165] In Example 29, the method of any one of Examples 21-28 further includes: the base station determining at least one of the time density or the frequency density based on whether the transmission includes a first number of inter-slot repetitions that satisfies one or more of the first number of repetitions or the second number of repetitions.

[0166] In Example 30, the method of any one of Examples 21-29 further includes: the base station configuring the UE for the PT-RS in the RRC signaling, and configuring one or more of the first parameter for the first repetition number or the second parameter for the second repetition number.

[0167] In Example 31, the method of any one of Examples 21-32 further includes: the base station indicating that the time density or frequency density of the PT-RS does not exist by configuring the first repetition number to be equal to the second repetition number.

[0168] In Example 32, the method of any one of Examples 21-31 further includes one or more of the first number of repetitions or the second number of repetitions being defined.

[0169] In Example 33, the method of any one of Examples 21-32 further includes: if inter-slot repetition is not enabled for the transmission, determining the time density of the PT-RS based on the MCS of the transmission; and if inter-slot repetition is enabled for the transmission, not determining the time density of the PT-RS based on the MCS of the transmission.

[0170] In Example 34, the method of any one of Examples 21-33 further includes: if inter-slot repetition is enabled, the time density of the PT-RS is based on the frequency density of the PT-RS.

[0171] In Example 35, the method of any one of Examples 21-34 further includes disabling PT-RS when the number of repetitions is above a threshold.

[0172] In Example 36, the method of any one of Examples 21-35 further includes: the transmission comprising a PUSCH.

[0173] Example 37 is an apparatus for wireless communication at a base station, comprising: a component for configuring a UE for PT-RS; a component for determining at least one of a time density or a frequency density of the PT-RS based on inter-time slot repetition of transmission; and a component for receiving or sending the PT-RS based on at least one of the time density or the frequency density determined based on the inter-time slot repetition of transmission.

[0174] In Example 38, the apparatus of Example 37 further comprises means for performing the method of any one of Examples 22-36.

[0175] Example 39 is an apparatus for wireless communication at a base station, comprising: a memory; and at least one processor coupled to the memory and configured to perform the method of any one of Examples 21-36.

[0176] Example 40 is a computer-readable medium storing computer-executable code for wireless communication at a base station, which code, when executed by a processor, causes the processor to perform the method of any one of Examples 21 to 36.

[0177] It should be understood that the specific order or hierarchy of blocks in the disclosed processes / flowcharts is illustrative of exemplary methods. Based on design preferences, it should be understood that the specific order or hierarchy of blocks in the processes / flowcharts may be rearranged. In addition, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in an example order and are not meant to be limited to the specific order or hierarchy presented.

[0178] The preceding description is provided to enable anyone skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the present claims are not intended to be limited to the aspects shown herein, but rather to the full scope consistent with the language claims, wherein, unless otherwise specified, reference to an element in the singular is not intended to mean "one and only one," but rather "one or more." The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as superior to or better than other aspects. Unless otherwise specified, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combination may contain one or more members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to one of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. The words “module,” “mechanism,” “element,” “device,” etc. are not intended to be substituted for the word “component.” Thus, any claim element shall not be construed as part-plus-function unless the element is expressly recited using the phrase “component for.”

Claims

1. A method for wireless communication at a user equipment (UE), comprising: Receive configuration of a phase tracking reference signal PT-RS; determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of data transmission; and The PT-RS is received or transmitted based on at least one of a time density or a frequency density determined based on the inter-slot repetition of the data transmission. 2 . The method according to claim 1 , wherein the data transmission comprises a physical downlink shared channel (PDSCH), and the UE receives the PT-RS using at least one of the time density or the frequency density. 3 . The method according to claim 1 , wherein the data transmission comprises a physical uplink shared channel (PUSCH), and the UE transmits the PT-RS using at least one of the time density or the frequency density.

4. The method of claim 1 , wherein the UE determines the temporal density of the PT-RS based on the inter-slot repetition of the data transmission.

5. The method of claim 1 , wherein the UE further determines the temporal density of the PT-RS based on a modulation and coding scheme (MCS) of the data transmission, wherein for each MCS level, different temporal densities are associated with different repetition levels.

6. The method of claim 1, wherein the UE determines the frequency density of the PT-RS based on the inter-slot repetition of the data transmission.

7. The method of claim 1 , wherein the UE further determines the frequency density of the PT-RS based on a bandwidth of the data transmission, wherein different frequency densities are associated with different repetition levels for each bandwidth level.

8. The method of claim 1, wherein the UE determines the time density and the frequency density of the PT-RS based on the inter-slot repetition of the data transmission.

9. The method of claim 1 , wherein the UE determines at least one of the time density or the frequency density based on whether the data transmission includes a first number of inter-slot repetitions that satisfies one or more of a first number of repetitions or a second number of repetitions.

10. The method of claim 9, wherein the configuration of the PT-RS is received in radio resource control (RRC) signaling and includes one or more of a first parameter for the first number of repetitions or a second parameter for the second number of repetitions. 11 . The method according to claim 10 , wherein if the configuration configures the first number of repetitions to be equal to the second number of repetitions, the UE determines that the time density or the frequency density of the PT-RS does not exist.

12. The method of claim 9, wherein one or more of the first number of repetitions or the second number of repetitions is defined.

13. The method of claim 1 , wherein if the inter-slot repetition is not enabled for the data transmission, the temporal density of the PT-RS is determined based on a modulation and coding scheme (MCS) of the data transmission; and If the inter-slot repetition is enabled for the data transmission, the temporal density of the PT-RS is not determined based on the MCS of the data transmission.

14. The method of claim 13, wherein if the inter-slot repetition is enabled, the temporal density of the PT-RS is based on the frequency density of the PT-RS. The method of claim 1 , wherein the PT-RS is disabled when the number of repetitions is higher than a threshold.

16. The method of claim 15, wherein the data transmission comprises a Physical Uplink Shared Channel (PUSCH).

17. An apparatus for performing wireless communication at a user equipment (UE), comprising: A component configured to receive a phase tracking reference signal PT-RS; means for determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of data transmission; as well as means for receiving or transmitting the PT-RS based on at least one of a time density or a frequency density determined based on the inter-slot repetition of the data transmission.

18. The apparatus of claim 17, further comprising means for performing the method of any one of claims 2-16.

19. An apparatus for performing wireless communication at a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory and configured to execute the method according to any one of claims 1-16.

20. A computer-readable medium storing computer-executable code for wireless communication at a user equipment (UE), the code, when executed by a processor, causing the processor to perform the method according to any one of claims 1-16.

21. A method for wireless communication at a base station, comprising: Configuring a user equipment UE for a phase tracking reference signal PT-RS; determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of data transmission; and The PT-RS is received or transmitted based on at least one of the time density or the frequency density determined based on the inter-slot repetition of the data transmission.

22. The method of claim 21, wherein the data transmission comprises a physical downlink shared channel (PDSCH), and the base station transmits the PT-RS using at least one of the time density or the frequency density.

23. The method of claim 21, wherein the data transmission comprises a physical uplink shared channel (PUSCH), and the base station receives the PT-RS using at least one of the time density or the frequency density.

24. The method of claim 21, wherein the base station determines the temporal density of the PT-RS based on the inter-slot repetition of the data transmission.

25. The method of claim 24, wherein the base station further determines the temporal density of the PT-RS based on a modulation and coding scheme (MCS) of the data transmission, wherein for each MCS level, different temporal densities are associated with different repetition levels.

26. The method of claim 21, wherein the base station determines the frequency density of the PT-RS based on the inter-slot repetition of the data transmission.

27. The method of claim 26, wherein the base station further determines the frequency density of the PT-RS based on a bandwidth of the data transmission, wherein different frequency densities are associated with different repetition levels for each bandwidth level.

28. The method of claim 21, wherein the base station determines the time density and the frequency density of the PT-RS based on the inter-slot repetition of the data transmission.

29. The method of claim 21, wherein the base station determines at least one of the time density or the frequency density based on whether the data transmission includes a first number of inter-slot repetitions that satisfies one or more of a first number of repetitions or a second number of repetitions.

30. The method of claim 29, wherein the base station configures the UE for the PT-RS in radio resource control (RRC) signaling and configures one or more of a first parameter for the first repetition number or a second parameter for the second repetition number. 31 . The method according to claim 30 , wherein the base station may indicate that the time density or the frequency density of the PT-RS does not exist by configuring the first repetition number to be equal to the second repetition number.

32. The method of claim 29, wherein one or more of the first number of repetitions or the second number of repetitions is defined.

33. The method of claim 21 , wherein if the inter-slot repetition is not enabled for the data transmission, the temporal density of the PT-RS is determined based on a modulation and coding scheme (MCS) of the data transmission; and If the inter-slot repetition is enabled for the data transmission, the temporal density of the PT-RS is not determined based on the MCS of the data transmission.

34. The method of claim 33, wherein if the inter-slot repetition is enabled, the temporal density of the PT-RS is based on the frequency density of the PT-RS.

35. The method of claim 21, wherein the PT-RS is disabled when the number of repetitions is above a threshold.

36. The method of claim 35, wherein the data transmission comprises a Physical Uplink Shared Channel (PUSCH).

37. An apparatus for wireless communication at a base station, comprising: means for configuring a user equipment UE for a phase tracking reference signal PT-RS; means for determining at least one of a time density or a frequency density of the PT-RS based on inter-slot repetition of data transmission; as well as means for receiving or transmitting the PT-RS based on at least one of a time density or a frequency density determined based on the inter-slot repetition of the data transmission.

38. The apparatus of claim 37, further comprising means for performing the method of any one of claims 22-36.

39. An apparatus for wireless communication at a base station, comprising: Memory; as well as At least one processor coupled to the memory and configured to execute the method of any one of claims 21-36.

40. A computer-readable medium storing computer-executable code for wireless communication at a base station, the code, when executed by a processor, causing the processor to perform the method according to any one of claims 21-36.

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