WO2024074074A1

WO2024074074A1 - Methods and apparatus of two ptrs ports design for dft-s-ofdm pusch transmission

Info

Publication number: WO2024074074A1
Application number: PCT/CN2023/109186
Authority: WO
Inventors: Lingling Xiao; Bingchao LIU; Chenxi Zhu; Wei Ling
Original assignee: Lenovo (Beijing) Ltd.
Priority date: 2023-07-25
Filing date: 2023-07-25
Publication date: 2024-04-11

Abstract

Various aspects of the present disclosure relate to methods and apparatus of two PTRS ports design for DFT-s-OFDM PUSCH transmission. The apparatus includes a user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM); and map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

Description

METHODS AND APPARATUS OF TWO PTRS PORTS DESIGN FOR DFT-S-OFDM PUSCH TRANSMISSION

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to two Phase-Tracking Reference Signal (PTRS) ports design for Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) Physical Uplink Shared Channel (PUSCH) transmission.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

The following abbreviations and acronyms are herewith defined, at least some of which are referred to within the specification:

Third Generation Partnership Project (3GPP) , New Radio (NR) , Long Term Evolution (LTE) , LTE Advanced (LTE-A) , Orthogonal Frequency Division Multiplexing (OFDM) , Downlink (DL) , Uplink (UL) , User Equipment (UE) , Network Equipment (NE) , Receive or Receiver (RX, or Rx) , Transmit or Transmitter (TX, or Tx) , Physical Uplink Shared Channel (PUSCH) , Spatial Division Multiplexing (SDM) , Frequency Modulation (FM) , Binary Phase Shift Keying (BPSK) , Cyclic Prefix (CP) , Device to Device (D2D) , Downlink Control Information (DCI) , Demodulation Reference Signal (DMRS, or DM-RS) , Frequency Division Multiple Access (FDMA) , Index/Identifier (ID) , Information Element (IE) , Internet of Things (IoT) , Machine Type Communication (MTC) , Non-Access Stratum (NAS) , Protocol Data Unit (PDU) , Phase-shift keying (PSK) , Quadrature amplitude modulation (QAM) , Radio Access Network (RAN) , Radio Resource Control (RRC) , Reference Signal (RS) , Sounding Reference Signal (SRS) , Transmission Reception Point (TRP) , Vehicle-to-Everything (V2X) , Amplitude Modulation (AM) , Access and Mobility Management Function (AMF) , Band Category (BC) , Code-Division Multiple Access (CDMA) , Core Network (CN) , Discrete Fourier Transform (DFT) , Evolved Packet Core (EPC) , Frequency Range 1 (FR1) , Frequency Range 2 (FR2) , Institute of Electrical and Electronics Engineers (IEEE) , Low-Noise Amplifier (LNA) , Transmission Configuration Indication (TCI) , Time-Division Multiple Access (TDMA) , Technical Specification (TS) , User Plane Function (UPF) , Vehicle-to-Vehicle (V2V) , 5G Core Network (5GC) , Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) , Phase Tracking Reference Signal (PTRS, or PT-RS) , Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) , Simultaneous Transmission Across Multiple Panels (STxMP) .

SUMMARY

An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

Some implementations of the method and apparatuses described herein may include a user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

In some implementations of the method and apparatuses described herein, the two PTRS sequences for the two PTRS ports may be different from one another, or may be the same.

Some implementations of the method and apparatuses described herein may include a processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

Some implementations of the method and apparatuses described herein may include a method performed by a user equipment (UE) , the method comprising: generating two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

Some implementations of the method and apparatuses described herein may include a base station for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the base station to: determine physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and receive the two PTRS sequences for the two PTRS ports for the PUSCH transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

Figure 2 illustrates an example of a user equipment (UE) 200 in accordance with aspects of the present disclosure.

Figure 3 illustrates an example of a processor 300 in accordance with aspects of the present disclosure.

Figure 4 illustrates an example of a network equipment (NE) 400 in accordance with aspects of the present disclosure.

Figure 5 illustrates an example of sequences of two PTRS ports occupying different samples within each PTRS group in a symbol in accordance with aspects of the present disclosure.

Figure 6 illustrates an example of sequences of two PTRS ports occupying different PTRS groups in a symbol in accordance with aspects of the present disclosure.

Figure 7 illustrates a flowchart of method performed by a UE in accordance with aspects of the present disclosure.

Figure 8 illustrates a flowchart of method performed by a NE in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In Release 18, PUSCH with DFT-s-OFDM (i.e., PUSCH transmission with transform precoding enabled) only supports one layer transmission, and the number of DMRS ports and the number of PTRS ports are both 1. In RAN1 #113 meeting, it was discussed to support PUSCH with SDM transmission by DFT-s-OFDM for multi-panel simultaneous UL transmission. With this feature, each panel still transmits a single layer DFT-s-OFDM PUSCH. If this feature is to be supported, multiple orthogonal PTRS ports are needed for DFT-s-OFDM in FR2 since the phase noise is different for different panels. Besides, in Release 19, multi-layer (i.e., multiple layers) PUSCH transmission with DFT-s-OFDM waveform for lower cost UEs may be supported. To support this feature, multiple orthogonal PTRS ports are also needed to facilitate the PUSCH transmission in FR2 for the UE with multiple non-coherent antenna groups.

Two PTRS ports were specified for CP-OFDM in Release 15, but the method cannot be used for DFT-s-OFDM directly, since the PTRS sequence of the PTRS port for DFT-s-OFDM is mapped to physical resources in time domain while the PTRS sequence of the PTRS port for CP-OFDM is mapped to physical resources in frequency domain directly.

In the disclosure, two PTRS ports design for multi-layer PUSCH transmission with DFT-s-OFDM is proposed.

Aspects of the present disclosure are described in the context of a wireless communications system.

Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more NE 102, one or more UE 104, and a core network (CN) 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a New Radio (NR) network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi- Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN) , a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) . In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

The one or more UE 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N2, or network interface) . In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106. In some implementations, one or more NE 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N2, or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106) .

In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

Figure 2 illustrates an example of a UE 200 in accordance with aspects of the present disclosure. The UE 200 may include a processor 202, a memory 204, a controller 206, and a transceiver 208. The processor 202, the memory 204, the controller 206, or the transceiver 208, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 202, the memory 204, the controller 206, or the transceiver 208, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 202 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 202 may be configured to operate the memory 204. In some other implementations, the memory 204 may be integrated into the processor 202. The processor 202 may be configured to execute computer-readable instructions stored in the memory 204 to cause the UE 200 to perform various functions of the present disclosure.

The memory 204 may include volatile or non-volatile memory. The memory 204 may store computer-readable, computer-executable code including instructions when executed by the processor 202 cause the UE 200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 204 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 202 and the memory 204 coupled with the processor 202 may be configured to cause the UE 200 to perform one or more of the functions described herein (e.g., executing, by the processor 202, instructions stored in the memory 204) . For example, the processor 202 may support wireless communication at the UE 200 in accordance with examples as disclosed herein. The UE 200 may be configured to support a means for generating two PTRS sequences for two PTRS ports, respectively, for a multiple-layer PUSCH transmission with DFT-s-OFDM; and mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

The controller 206 may manage input and output signals for the UE 200. The controller 206 may also manage peripherals not integrated into the UE 200. In some implementations, the controller 206 may utilize an operating system such as or other operating systems. In some implementations, the controller 206 may be implemented as part of the processor 202.

In some implementations, the UE 200 may include at least one transceiver 208. In some other implementations, the UE 200 may have more than one transceiver 208. The transceiver 208 may represent a wireless transceiver. The transceiver 208 may include one or more receiver chains 210, one or more transmitter chains 212, or a combination thereof.

A receiver chain 210 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 210 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 210 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 210 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 210 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 212 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 212 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 212 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 212 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

Figure 3 illustrates an example of a processor 300 in accordance with aspects of the present disclosure. The processor 300 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 300 may include a controller 302 configured to perform various operations in accordance with examples as described herein. The processor 300 may optionally include at least one memory 304, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 300 may optionally include one or more arithmetic-logic units (ALUs) 306. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 300 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 300) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 302 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 300 to cause the processor 300 to support various operations in accordance with examples as described herein. For example, the controller 302 may operate as a control unit of the processor 300, generating control signals that manage the operation of various components of the processor 300. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 302 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 304 and determine subsequent instruction (s) to be executed to cause the processor 300 to support various operations in accordance with examples as described herein. The controller 302 may be configured to track memory address of instructions associated with the memory 304. The controller 302 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 302 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 300 to cause the processor 300 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 302 may be configured to manage flow of data within the processor 300. The controller 302 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 300.

The memory 304 may include one or more caches (e.g., memory local to or included in the processor 300 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 304 may reside within or on a processor chipset (e.g., local to the processor 300) . In some other implementations, the memory 304 may reside external to the processor chipset (e.g., remote to the processor 300) .

The memory 304 may store computer-readable, computer-executable code including instructions that, when executed by the processor 300, cause the processor 300 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 302 and/or the processor 300 may be configured to execute computer-readable instructions stored in the memory 304 to cause the processor 300 to perform various functions. For example, the processor 300 and/or the controller 302 may be coupled with or to the memory 304, the processor 300, the controller 302, and the memory 304 may be configured to perform various functions described herein. In some examples, the processor 300 may include multiple processors and the memory 304 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 306 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 306 may reside within or on a processor chipset (e.g., the processor 300) . In some other implementations, the one or more ALUs 306 may reside external to the processor chipset (e.g., the processor 300) . One or more ALUs 306 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 306 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 306 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 306 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 306 to handle conditional operations, comparisons, and bitwise operations.

The processor 300 may support wireless communication in accordance with examples as disclosed herein. The processor 300 may be configured to or operable to support a means for generating two PTRS sequences for two PTRS ports, respectively, for a multiple-layer PUSCH transmission with DFT-s-OFDM; and mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

Figure 4 illustrates an example of a NE 400 in accordance with aspects of the present disclosure. The NE 400 may include a processor 402, a memory 404, a controller 406, and a transceiver 408. The processor 402, the memory 404, the controller 406, or the transceiver 408, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 402, the memory 404, the controller 406, or the transceiver 408, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 402 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 402 may be configured to operate the memory 404. In some other implementations, the memory 404 may be integrated into the processor 402. The processor 402 may be configured to execute computer-readable instructions stored in the memory 404 to cause the NE 400 to perform various functions of the present disclosure.

The memory 404 may include volatile or non-volatile memory. The memory 404 may store computer-readable, computer-executable code including instructions when executed by the processor 402 cause the NE 400 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 404 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 402 and the memory 404 coupled with the processor 402 may be configured to cause the NE 400 to perform one or more of the functions described herein (e.g., executing, by the processor 402, instructions stored in the memory 404) . For example, the processor 402 may support wireless communication at the NE 400 in accordance with examples as disclosed herein. The NE 400 may be configured to support a means for determining physical resources that are mapped with two PTRS sequences for two PTRS ports, respectively, for a multiple-layer PUSCH transmission with DFT-s-OFDM; and receiving the two PTRS sequences for the two PTRS ports for the PUSCH transmission.

The controller 406 may manage input and output signals for the NE 400. The controller 406 may also manage peripherals not integrated into the NE 400. In some implementations, the controller 406 may utilize an operating system such as or other operating systems. In some implementations, the controller 406 may be implemented as part of the processor 402.

In some implementations, the NE 400 may include at least one transceiver 408. In some other implementations, the NE 400 may have more than one transceiver 408. The transceiver 408 may represent a wireless transceiver. The transceiver 408 may include one or more receiver chains 410, one or more transmitter chains 412, or a combination thereof.

A receiver chain 410 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 410 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 410 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 410 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 410 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 412 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 412 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 412 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 412 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

In the present Technical Specifications (TS) of the 3GPP, the following are provided in relation to PTRS.

6.3.1.4 Transform precoding in TS 38.211

If transform precoding is not enabled according to 6.1.3 of [6, TS38.214] , y ^(λ) (i) =x ^(λ) (i) for each layer λ=0, 1, ..., υ-1.

If transform precoding is enabled according to 6.1.3 of [6, TS38.214] , υ=1 anddepends on the configuration of phase-tracking reference signals.

6.4.1.2.1.2 Sequence generation if transform precoding is enabled in TS 38.211

If transform precoding is enabled, the phase-tracking reference signal r_m (m′) to be mapped in position m before transform precoding, where m depends on the number of PT-RS groupsthe number of samples per PT-RS groupandaccording to Table 6.4.1.2.2.2-1, shall be generated according to

where the pseudo-random sequence c (i) is defined in clause 5.2.1 and w (i) is given by Table 6.4.1.2.1.2-1. The pseudo-random sequence generator shall be initialized with

where l is the lowest OFDM symbol number in the PUSCH allocation in slotthat contains PT-RS according to clause 6.4.1.2.2.2 and N_ID is given by the higher-layer parameter nPUSCH-Identity.

Table 6.4.1.2.1.2-1: The orthogonal sequence w (i) .

6.4.1.2.2.2 Mapping to physical resources if transform precoding is enabled in TS 38.211

The UE shall transmit phase-tracking reference signals only in the resource blocks and OFDM symbols used for the PUSCH, and only if the procedure in [6, TS 38.214] indicates that phase-tracking reference signals are being used.

The sequence r_m (m′) shall be multiplied by β′ and mapped tocomplex valued symbols inwhere

- are the complex-valued symbols in OFDM symbol l before transform precoding according to clause 6.3.1.4

- m depends on the number of PT-RS groupsthe number of samples per PT-RS group andaccording to Table 6.4.1.2.2.2-1

- β′ is the ratio between amplitude of one of the outermost constellation points for the modulation scheme used for PUSCH and one of the outermost constellation points for π/2-BPSK as defined in clause 6.2.3 of [TS 38.214]

The set of time indices l for which PT-RS shall be transmitted is defined relative to the start of the PUSCH allocation and is defined by

1. set i=0 and l_ref=0

2. if any symbol in the interval max (l_ref+ (i-1) L_PT-RS+1, l_ref) , …, l_ref+iL_PT-RS overlaps with a symbol used for DM-RS according to clause 6.4.1.1.3

- set i=1

- set l_ref to the symbol index of the DM-RS symbol in case of a single-symbol DM-RS and to the symbol index of the second DM-RS symbol in case of a double-symbol DM-RS

- repeat from step 2 as long as l_ref+iL_PT-RS is inside the PUSCH allocation

3. add l_ref+iL_PT-RS to the set of time indices for PT-RS

4. increment i by one

5. repeat from step 2 above as long as l_ref+iL_PT-RS is inside the PUSCH allocation where L_PT-RS∈ {1, 2} is given by the higher-layer parameter timeDensityTransformPrecoding in the PTRS-UplinkConfig IE.

Table 6.4.1.2.2.2-1: PT-RS symbol mapping.

In the disclosure, two PTRS ports design for multi-layer PUSCH transmission with DFT-s-OFDM is proposed. That is, a new PTRS port is included compared to the only one PTRS port for PUSCH with DFT-s-OFDM in Release 18. Following methods are provided to generate sequences of two PTRS ports for multi-layer PUSCH transmission with DFT-s-OFDM waveform and for STxMP SDM PUSCH transmission with DFT-s-OFDM. In some examples, methods on PTRS sequence generation for two PTRS ports are proposed to ensure the sequences of different PTRS ports are orthogonal or pseudo-orthogonal; in some examples, methods on PTRS mapping to physical resources are proposed so that the sequences of different PTRS ports are mapped to different samples in time domain. In some examples, the above two kinds of methods may be combined such that the sequence and the time location of the new PTRS port are both orthogonal to the legacy PTRS port.

Different PTRS ports using different orthogonal PTRS sequences

In the current standards, the sequence of a PTRS port is a pseudo-random sequence modulated by Pi/2 BPSK and is generated according to

where the pseudo-random sequence c (i) is defined in clause 5.2.1 and w (i) is given by Table 6.4.1.2.1.2-1 in TS 38.211. The pseudo-random sequence generator shall be initialized with

Table 6.4.1.2.1.2-1: The orthogonal sequence w (i) .

To ensure the sequences of different PTRS ports are orthogonal or pseudo-orthogonal, there are two kinds of schemes: 1. the sequences of different PTRS ports are generated with a pseudo-random sequence generator initialized with different values of an initialization parameter; 2. the sequences of different PTRS ports are generated with a pseudo-random sequence multiplying different orthogonal sequences.

In the first kind of schemes, the sequences of different PTRS ports are generated with different C_init, i.e., with a pseudo-random sequence generator initialized with different values of an initialization parameter.

For different PTRS ports, the C_init for the pseudo-random sequence generator are different. Specifically, the formula of C_init may be enhanced as follows:

where the value of PTRS port index can be 0 to the number of PTRS ports –1. Thus, the pseudo-random sequence generator shall be initialized with different PTRS port indices for different PTRS ports. For example, the PTRS port indices can be 0 and 1 for two PTRS ports, respectively. Other parameters in formula (3) are the same as those in formula (2) .

Alternatively, the formula of C_init may be enhanced as formula (4) below, which is based on C_init calculation for DMRS sequence for CP-OFDM:

where the value of n_SCID can be 0 or 1 and different states of n_SCID are associated with different PTRS ports. One ofmay be the same as N_ID, which is given by the higher-layer parameter nPUSCH-Identity, and another new nPUSCH-Identity may need to be configured for the otherFor example, n_SCID=0 may be used to calculate C_init for PTRS port 0, and n_SCID=1 may be used to calculate C_init for PTRS port 1, andand are given by the higher-layer parameters nPUSCH-Identity and nPUSCH-Identity1 (i.e., newly added parameter) , respectively. Alternatively, theandmay be given by pi2BPSK-ScramblingID0 and pi2BPSKScramblingID1, respectively. Other parameters in formula (4) are the same as those in formula (2) . Alternatively, two different virtual cell IDs, i.e., andmay be configured for PTRS port 0 and port 1, respectively.

In the second kind of schemes, the sequences of different PTRS ports are generated with different orthogonal sequence w (i) , i.e., with a pseudo-random sequence multiplying different orthogonal sequences.

From formula (1) , it can be seen that different samples in a PTRS group multiply an orthogonal sequence. Therefore, for different PTRS ports, different orthogonal sequences w(i) may be multiplied to ensure the orthogonality between the sequences of different PTRS ports. Specifically, Table 6.4.1.2.1.2-1 from TS 38.211 may be enhanced as Table 1 below, where PTRS port indices can be 0 and 1 for two orthogonal PTRS ports, respectively.

Alternatively, the orthogonal sequence table may be the same as legacy (i.e., Table 6.4.1.2.1.2-1 from TS 38.211) and two continuous sequences are applied to the two PTRS ports, where the first sequence w (i) for PTRS port 0 is determined based on the and the next sequence is used for PTRS port 1. For example, if w (i) for a PTRS port, e.g., PTRS port 0, is entry 3 in Table 6.4.1.2.1.2-1 in TS 38.211, then the w (i) for the other PTRS port, e.g., PTRS port 1, is entry 0 in Table 6.4.1.2.1.2-1.

Table 1: Orthogonal sequences w (i) for two PTRS ports

Combination of the above two kinds of schemes is also applicable, which means that the C_init and orthogonal sequence w (i) are both different for different PTRS ports.

In an example, it is assumed that a DCI #1 schedules a codebook based PUSCH transmission with DFT-s-OFDM waveform, and the number of PTRS ports determined based on the precoder is two andIf the above second kind of schemes is adopted, then the sequence of PTRS port 0 is generated by formula (1) where w (i) is [+1 +1], and C_init is determined based on formula (2) ; the sequence of PTRS port 1 is generated by formula (1) where w (i) is [+1 -1] , and C_init is determined based on formula (2) . If the combination of the above two kinds of schemes is adopted, then the sequence of PTRS port 0 is generated by formula (1) where w (i) is [+1 +1] , and C_init is determined based on formula (3) with PTRS port index being 0 or based on formula (4) with n_SCID=0; the sequence of PTRS port 1 is generated by formula (1) where w (i) is [+1 -1] , and C_init is determined based on formula (3) with PTRS port index being 1 or based on formula (4) with n_SCID=1.

Sequences of different PTRS ports being mapped to different samples in time domain

The orthogonality between different PTRS ports may also be ensured by mapping to different samples in the time domain regardless of whether the sequences of different PTRS ports are the same or different. In the current standards, a PTRS port is mapped in several PTRS groupswhere each group includessamples, and the values of andare determined by the number of scheduled RBs (i.e., resource block) in Table 6.2.3.2-1 in TS 38.214. groups are uniformly placed in the symbol containing the PTRS, and thesamples in each group are consecutive. The specific samples of a PTRS port in an OFDM symbol is specified by Table 6.4.1.2.2.2-1 in TS 38.211.

Table 6.4.1.2.2.2-1: PT-RS symbol mapping.

To ensure the sequences of different PTRS ports are mapped to different samples in time domain, there are two kinds of schemes: 1. the sequences of different PTRS ports are mapped to different samples within a PTRS group; 2. the sequences of different PTRS ports are mapped in different PTRS groups.

In the first kind of schemes where the PTRS sequences of different PTRS ports are mapped to different samples within a PTRS group, if two PTRS ports are determined, the total number of PTRS groups is the same as legacy (i.e., by Release 18) , but the number of samples within a PTRS group is doubled.

In the scheme, different sets of samples may be dedicated for different PTRS ports. That means the sequence of a first PTRS port (i.e., which may be referred to as a first PTRS sequence) is mapped to a first set of samples that are distributed among one or more PTRS groups and the sequence of a second PTRS port (i.e., which may be referred to as a second PTRS sequence) is mapped to a second set of samples that are distributed among the same one or more PTRS groups. Each PTRS group of the one or more PTRS groups includes a first subgroup of the first set of samples and a second subgroup of the second set of samples. The first set of samples, including the first half of samples of each group, and the second set of samples, including the send half of samples of each group, are of the same size.

The specific locations of the first set of samples within an OFDM symbols are determined based on Table 6.4.1.2.2.2-1 in TS 38.211. That is, a sample index of each sample in the first set of samples within an OFDM symbol is determined based on a legacy PTRS symbol mapping table. In some examples, the second set of samples are mapped adjacent to the first set of samples in each PTRS group. In some other examples, there may besamples between the two sets of samples for PTRS transmission. That is, the second set of samples and the first set of samples are separated by a gap in each PTRS group. The gap, i.e., may be configured by RRC parameter; and if not configured,

Table 2 illustrates one example of symbol mapping of samples for two PTRS ports within a symbol, where the first set of samples are the same as legacy, for a first PTRS port, e.g., PTRS port 0, and the second set of samples in bold are for a second PTRS port, e.g., PTRS port 1. The sequences of different PTRS ports are mapped to different sets of samples. The number of samples per PT-RS groupin Table 2 is the total number of samples of the two PTRS ports and the value is doubled as legacy defined in in Table 6.2.3.2-1 in TS 38.214.

Table 2: PT-RS symbol mapping for two PTRS ports

Table 3 illustrates another example of symbol mapping of the samples for two PTRS ports, where the first set of samples are determined by p=0 for a PTRS port, e.g., PTRS port 0, and the second set of samples are determined by p=1 or p= -1 for different cases as in Table 3 for another PTRS port, e.g., PTRS port 1. Specifically, forp= -1 when determining the second set of samples in the last PTRS group, and otherwise, p=1. The sequences of different PTRS ports are mapped to different sets of samples. The number of samples per PT-RS groupin Table 3 is the number of samples of a PTRS port and the value is same as legacy defined in in Table 6.2.3.2-1 in TS 38.214.

Table 3: PT-RS symbol mapping for two PTRS ports

Figure 5 illustrates an example of sequences of two PTRS ports occupying different samples within each PTRS group in a symbol in accordance with aspects of the present disclosure. In the example, it is assumed that a DCI #1 schedules a PUSCH transmission with DFT-s-OFDM waveform and the number of PTRS ports determined is two. It is further assumed that the scheduled number of RBs is 50 RBs, and are determined based on Table 6.2.3.2-1 in TS 38.214. Then, for two PTRS ports, the total number of PTRS groups is 4 and each PTRS group includes 4 samples. In Figure 5, in the symbol 500, the first set of samples 512 for PTRS port 0 are shown in solid black lines and the second set of samples 514 for PTRS port 1 are adjacent to the first set of samples 512 and are shown in dashed grey lines. Each one of the four PTRS groups includes a first subgroup of the first set of samples 512 and a second subgroup of the second set of samples 514. For example, PTRS group 502 includes a subgroup 522 containing samples 74 and 75 (which is determined by the third entry in Table 2 or Table 3) and a subgroup 524 containing samples 76 and 77. The two black samples in each PTRS group (e.g., samples 74 and 75 in PTRS group 502) are dedicated for PTRS port 0, and the two grey samples appended after the black samples in each group (e.g., samples 76 and 77 in PTRS group 502) are dedicated for PTRS port 1. The UE will map the sequence of PTRS port 0 to the black samples in the symbol 500 and map the sequence of PTRS port 1 to the grey samples in the symbol 500.

In the second kind of schemes where the PTRS sequences of different PTRS ports are mapped in different PTRS groups, if two PTRS ports are determined, the number of samples within a PTRS group is the same as legacy (i.e., by Release 18) , but the total number of PTRS groups is doubled.

Different sets of PTRS groups are dedicated for different PTRS ports. That means the sequence of a first PTRS port (i.e., a first PTRS sequence) is mapped to samples in a first set of PTRS groups and the sequence of a second PTRS port (i.e., a second PTRS sequence) is mapped to samples in a second set of PTRS groups. For simplicity, in some examples, the first set of PTRS groups include the first half of PTRS groups and the second set of PTRS groups include the second half of PTRS groups. In some other examples, the first set of PTRS groups include the first and every other PTRS groups and the second set of PTRS groups include the second and every other PTRS groups, which may have a better performance since the sequence of a PTRS port is mapped uniformly in a symbol. That is, the first set of PTRS groups and the second set of PTRS groups may form all PTRS groups in a sequential manner; or the first set of PTRS groups and the second set of PTRS groups may form all PTRS groups in an interlaced manner.

Specifically, ifandare determined based on the legacy rule (i.e., by the number of scheduled RBs) , then for two PTRS ports, (i.e., the total number of PTRS groups is doubled) , and two PTRS groups are dedicated for one PTRS port and the other two PTRS groups are dedicated for the other PTRS port. Then, the specific samples of the two PTRS ports can be determined using the third entry in Table 6.4.1.2.2.2-1 in TS 38.211 (or the entry with combinations of (number of PTRS groups, number of samples per PTRS group) being (4, 2) in Table 4) .

Similarly, foranddetermined based on the legacy rule, the specific samples of the two PTRS ports can be determined by the fourth entry in Table 6.4.1.2.2.2-1 (or the entry with combinations of (number of PTRS groups, number of samples per PTRS group) being (4, 4) in Table 4) ; forandthe specific samples of the two PTRS ports can be determined by the fifth entry in table 6.4.1.2.2.2-1 (or the entry with combinations of (number of PTRS groups, number of samples per PTRS group) being (8, 4) in Table 4) .

However, forandand forandif two PTRS ports are determined, the samples shall be determined byand andandrespectively; however, they are not included in the legacy Table 6.4.1.2.2.2-1 . Therefore, in the scheme, entry forandand entry forandshall be added to determine the PTRS samples for the two PTRS ports. Table 4 illustrates one example of a PTRS symbol mapping table for determining the PTRS samples including entries forand (entry with combinations of (number of PTRS groups, number of samples per PTRS group) being (8, 2) ) , andand (entry with combinations of (number of PTRS groups, number of samples per PTRS group) being (16, 4) ) .

Table 4: PT-RS symbol mapping for two PTRS ports

Figure 6 illustrates an example of sequences of two PTRS ports occupying different PTRS groups in a symbol in accordance with aspects of the present disclosure. In the example, it is assumed that a DCI #1 schedules a PUSCH transmission with DFT-s-OFDM waveform and the number of PTRS ports determined is two. It is further assumed that the scheduled number of RBs is 20 RBs, andandare determined. Then, for two PTRS ports, the total number of PTRS groups is 4 and each PTRS group includes 4 samples. In Figure 6, in the symbol 600, the first set of PTRS groups 632 (i.e., PTRS group 602 and PTRS group 606) for PTRS port 0 include samples in solid black lines and the second set of PTRS groups 634 (i.e., PTRS group 604 and PTRS group 608) for PTRS port 1 include samples in dashed grey lines. Each one of the four PTRS groups includes four samples, e.g., PTRS group 602 includes samples 0-3 and PTRS group 604 includes samples 88-91 which is determined by the forth entry in Table 4. As shown in Figure 6, the two PTRS groups including black samples are dedicated for PTRS port 0, and the two PTRS groups including grey samples are dedicated for PTRS port 1. The UE will map sequence of PTRS port 0 to the black samples in the symbol 600 and map sequence of PTRS port 1 to the grey samples in the symbol 600. In the example, the first set of PTRS groups 632 and the second set of PTRS groups 634 are in an interlaced manner.

After the sequences of two PTRS ports are generated, for SDM PUSCH transmission with DFT-s-OFDM, the number of actual PTRS ports is two if the maximum number of PTRS ports is two. One PTRS port is for PUSCH transmission to one TRP. Specifically, in the first kinds of methods, different C_init and/or orthogonal sequences w (i) are used for generating PTRS sequences for PTRS ports to different TRPs. That is, each PTRS port index or n_SCID is associated with a TRP. For example, PTRS port index 0 or n_SCID=0 is associated with TRP 0 and PTRS port index 1 or n_SCID=1 is associated with TRP 1. Then, for PUSCH transmission to TRP 0, the PTRS port index being 0 or n_SCID=0 is used for generating the sequence of PTRS of the PUSCH transmission to TRP 0, and for PUSCH transmission to TRP 1, the PTRS port index being 1 or n_SCID=1 is used for generating the sequence of PTRS of the PUSCH transmission to TRP 1. Similarly, in the second kinds of methods, each set of samples or each set of groups is associated with a TRP and the sequence of a PTRS port for a TRP is mapped to a set of samples or a set of groups which are associated with the TRP.

In the disclosure, PUSCH transmission with DFT-s-OFDM to different TRPs means that the PUSCH transmission is transmitted based on different SRS resource sets or with different beams (e.g., spatial relation or UL TCI states, or DLorJoint-TCIState specified in TS 38.331) .

In some aspects, examples of the disclosure concerning UE may be summarized as follows:

A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

A method performed by a user equipment (UE) , the method comprising: generating two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.

In some embodiments, the two PTRS sequences for the two PTRS ports are different from one another.

In some embodiments, the two PTRS sequences for the two PTRS ports are the same.

In some embodiments, the two PTRS sequences are generated with a pseudo-random sequence generator initialized with different values of an initialization parameter.

In some embodiments, the two PTRS sequences are generated with a pseudo-random sequence multiplying different orthogonal sequences.

In some embodiments, the two PTRS sequences comprise a first PTRS sequence and a second PTRS sequence, and are mapped to different samples in an Orthogonal Frequency Division Multiplexing (OFDM) symbol in time domain.

In some embodiments, the first PTRS sequence is mapped to a first set of samples that are distributed among one or more PTRS groups; and the second PTRS sequence is mapped to a second set of samples that are distributed among the same one or more PTRS groups.

In some embodiments, each PTRS group of the one or more PTRS groups comprises a first subgroup of the first set of samples and a second subgroup of the second set of samples.

In some embodiments, a sample index of each sample in the first set of samples within an OFDM symbol is determined based on a legacy PTRS symbol mapping table, and the second set of samples are mapped adjacent to the first set of samples in each PTRS group.

In some embodiments, a sample index of each sample in the first set of samples within an OFDM symbol is determined based on a legacy PTRS symbol mapping table, and the second set of samples and the first set of samples are separated by a gap in each PTRS group, and the gap is configured by RRC parameter in sample unit.

In some embodiments, the first PTRS sequence is mapped to samples in a first set of PTRS groups; and the second PTRS sequence is mapped to samples in a second set of PTRS groups.

In some embodiments, the first set of PTRS groups and the second set of PTRS groups form all PTRS groups in a sequential manner.

In some embodiments, the first set of PTRS groups and the second set of PTRS groups form all PTRS groups in an interlaced manner.

In some embodiments, the two PTRS sequences are mapped to samples in different sets of PTRS groups based on a PTRS symbol mapping table with mapping schemes including combinations of (number of PTRS groups, number of samples per PTRS group) being (8, 2) and (16, 4) .

In some embodiments, the PUSCH transmission is transmitted to multiple TRPs; and each one of the two PTRS sequences is for the PUSCH transmission to a corresponding TRP.

In some embodiments, different subgroups of samples within each PTRS group, or different sets of PTRS groups, are associated with different TRPs.

In some other aspects, examples of the disclosure concerning base station may be summarized as follows:

A base station for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the base station to: determine physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and receive the two PTRS sequences for the two PTRS ports for the PUSCH transmission.

A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: determine physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and receive the two PTRS sequences for the two PTRS ports for the PUSCH transmission.

A method performed by a base station, the method comprising: determining physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and receiving the two PTRS sequences for the two PTRS ports for the PUSCH transmission.

In some embodiments, the PUSCH transmission is received by multiple TRPs; and each one of the two PTRS sequences is for PUSCH transmission to a corresponding TRP.

Figure 7 illustrates a flowchart of a method in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions.

At 702, the method may include generating two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) . The operations of 702 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 702 may be performed by a UE as described with reference to Figure 2.

At 704, the method may include mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission. The operations of 704 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 704 may be performed by a UE as described with reference to Figure 2.

It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

Figure 8 illustrates a flowchart of a method in accordance with aspects of the present disclosure. The operations of the method may be implemented by a NE as described herein. In some implementations, the NE may execute a set of instructions to control the function elements of the NE to perform the described functions.

At 802, the method may include determining physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) . The operations of 802 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 802 may be performed by a NE as described with reference to Figure 4.

At 804, the method may include receiving the two PTRS sequences for the two PTRS ports for the PUSCH transmission. The operations of 804 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 804 may be performed by a NE as described with reference to Figure 4.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and

map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.
The UE of claim 1, wherein the two PTRS sequences for the two PTRS ports are different from one another.
The UE of claim 1, wherein the two PTRS sequences for the two PTRS ports are the same.
The UE of claim 2, wherein the two PTRS sequences are generated with a pseudo-random sequence generator initialized with different values of an initialization parameter.
The UE of claim 2, wherein the two PTRS sequences are generated with a pseudo-random sequence multiplying different orthogonal sequences.
The UE of claim 2 or 3, wherein the two PTRS sequences comprise a first PTRS sequence and a second PTRS sequence, and are mapped to different samples in an Orthogonal Frequency Division Multiplexing (OFDM) symbol in time domain.
The UE of claim 6, wherein the first PTRS sequence is mapped to a first set of samples that are distributed among one or more PTRS groups; and the second PTRS sequence is mapped to a second set of samples that are distributed among the same one or more PTRS groups.
The UE of claim 7, wherein each PTRS group of the one or more PTRS groups comprises a first subgroup of the first set of samples and a second subgroup of the second set of samples.
The UE of claim 8, wherein a sample index of each sample in the first set of samples within an OFDM symbol is determined based on a legacy PTRS symbol mapping table, and the second set of samples are mapped adjacent to the first set of samples in each PTRS group.
The UE of claim 8, wherein a sample index of each sample in the first set of samples within an OFDM symbol is determined based on a legacy PTRS symbol mapping table, and the second set of samples and the first set of samples are separated by a gap in each PTRS group, and the gap is configured by RRC parameter in sample unit.
The UE of claim 6, wherein the first PTRS sequence is mapped to samples in a first set of PTRS groups; and the second PTRS sequence is mapped to samples in a second set of PTRS groups.
The UE of claim 11, wherein the first set of PTRS groups and the second set of PTRS groups form all PTRS groups in a sequential manner.
The UE of claim 11, wherein the first set of PTRS groups and the second set of PTRS groups form all PTRS groups in an interlaced manner.
The UE of claim 11, wherein the two PTRS sequences are mapped to samples in different sets of PTRS groups based on a PTRS symbol mapping table with mapping schemes including combinations of (number of PTRS groups, number of samples per PTRS group) being (8, 2) and (16, 4) .
The UE of claim 2, wherein the PUSCH transmission is transmitted to multiple TRPs; and each one of the two PTRS sequences is for the PUSCH transmission to a corresponding TRP.
The UE of claim 8 or 11, wherein different subgroups of samples within each PTRS group, or different sets of PTRS groups, are associated with different TRPs.
A processor for wireless communication, comprising:

at least one controller coupled with at least one memory and configured to cause the processor to:

generate two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and

map the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.
The processor of claim 17, wherein the two PTRS sequences for the two PTRS ports are different from one another.
A method performed by a user equipment (UE) , the method comprising:

generating two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and

mapping the two PTRS sequences for the two PTRS ports to physical resources for the PUSCH transmission.
A base station for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the base station to:

determine physical resources that are mapped with two Phase Tracking Reference Signal (PTRS) sequences for two PTRS ports, respectively, for a multiple-layer Physical Uplink Shared Channel (PUSCH) transmission with Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) ; and

receive the two PTRS sequences for the two PTRS ports for the PUSCH transmission.