DMRS-PTRS association

Abstract

Embodiments of the present disclosure relate to a method and apparatus for demodulation reference signal (DMRS) ports and phase tracking reference signal (PTRS) ports in a single frequency network (SFN)-based physical uplink shared channel (PUSCH). A terminal device receives a PTRS-DMRS association indication from a network device. The indication includes a PTRS-DMRS association field having a first portion indicating a scheduled DMRS port and a second portion indicating a PTRS port associated with the DMRS port. Based on the indication, the terminal device can simultaneously transmit uplink signals to the network device in an SFN manner via multiple antenna panels. This enables stable and highly accurate SFN uplink transmission using the DMRS port and the corresponding PTRS port.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from and the benefit of Finnish Application No. 20235188, filed February 17, 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] Various example embodiments relate to the field of telecommunications, and in particular to methods, devices, apparatus, and computer-readable storage media for demodulation reference signal (DMRS)-phase tracking reference signal (PTRS) association, especially for single frequency network (SFN) based uplink transmissions. [Background technology]

[0003] The communications sector is undergoing a constant evolution to provide efficient and reliable solutions for utilizing wireless communications networks. Each new generation presents its own technical challenges in handling different situations and processes required to connect and serve devices connected to a wireless network. 5G NR has been proposed to support simultaneous multi-panel UL transmission using at least two panels. Compared to the single downlink control information (S-DCI)-based Rel-17 time division multiplexing (TDM) repetition scheme, both S-DCI and multi-(M)-DCI-based simultaneous uplink multi-panel physical uplink channel (PUSCH) schemes will be investigated in Rel-18, targeting enhanced throughput and reliability with reduced latency.

[0004] Traditionally, uplink demodulation reference signals (DMRS) and phase tracking reference signals (PTRS) are reference signals associated with the PUSCH. DMRS is a special type of physical layer signal that serves as a reference signal for decoding the PUSCH and is used for channel estimation as part of coherent demodulation of the PUSCH. To compensate for common phase error (CPE), 3GPP 5G NR introduced the PTRS. PTRS is primarily used to estimate and minimize the effect of CPE on system performance. DCI has a PTRS-DMRS association field that is used to link a PTRS port to a DMRS port. However, the existing PTRS-DMRS association cannot be applied in S-DCI or multi-(M)-DCI-based simultaneous uplink multi-panel PUSCH schemes. Therefore, the association between PTRS and DMRS ports needs further research. Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, example embodiments of the present disclosure provide solutions for DMRS and PTRS ports for SFN-based PUSHC. [Means for solving the problem]

[0006] In a first aspect, a terminal device is provided, the terminal device comprising: at least one processor; and at least one memory having stored therein instructions, when executed by the at least one processor, that cause the terminal device to at least receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port, and to transmit uplink signals to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication.

[0007] In a second aspect, a network device is provided, the terminal device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device to at least: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to the terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0008] In a third aspect, a method performed in a terminal device is provided, the method including receiving, by the terminal device, a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port, and transmitting, by the terminal device, an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication.

[0009] In a fourth aspect, a method performed in a network device is provided, the method including: transmitting, by the network device, a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receiving, by the network device, an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0010] In a fifth aspect, an apparatus is provided that includes means for receiving a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and means for transmitting an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus based on the PTRS-DMRS association indication.

[0011] In a sixth aspect, an apparatus is provided, comprising: means for transmitting a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to a terminal device, wherein the PTRS-DMRS association indication comprises a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and means for receiving an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0012] In a seventh aspect, provided is a non-transitory computer-readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to at least receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and, based on the PTRS-DMRS association indication, transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus.

[0013] In an eighth aspect, a non-transitory computer-readable medium is provided comprising program instructions that, when executed by an apparatus, cause the apparatus to at least: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0014] In a ninth aspect, a computer program is provided comprising instructions that, when executed by an apparatus, cause the apparatus to at least receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and, based on the PTRS-DMRS association indication, transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus.

[0015] In a tenth aspect, a computer program is provided comprising instructions that, when executed by an apparatus, cause the apparatus to at least: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0016] In an eleventh aspect, a terminal device is provided, the terminal device comprising: one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, the one or more processors configured to cause the terminal device to receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and, based on the PTRS-DMRS association indication, transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device.

[0017] In a twelfth aspect, a network device is provided, the network device comprising: one or more transceivers; and one or more processors communicatively coupled to the one or more transceivers, the one or more processors configured to cause the network device to transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port, and to receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0018] In a thirteenth aspect, a terminal device is provided, the terminal device comprising: a receiving circuit apparatus configured to receive a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and a transmitting circuit apparatus configured to transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication.

[0019] In a fourteenth aspect, a network device is provided, the network device comprising: a transmitter circuit apparatus configured to transmit a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and a receiver circuit apparatus configured to receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0020] It should be understood that this summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent through the following description.

[0021] Some example embodiments will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram of an example communication network in which embodiments of the present disclosure may be implemented; [Figure 2] 10 is an example signaling flow diagram illustrating a process for DMRS-PTRS port association for SFN-based PUSCH in accordance with some embodiments of the present disclosure. [Figure 3] 1 is a schematic diagram of an example uplink sounding reference signal (SRS) resource set configuration for SFN-based simultaneous multi-panel PUSCH transmission with two layers in accordance with some embodiments of the present disclosure. FIG. [Figure 4] FIG. 10 is a schematic diagram of another example uplink sounding reference signal (SRS) resource set configuration for SFN-based simultaneous multi-panel PUSCH transmission with four layers in accordance with some embodiments of the present disclosure. [Figure 5] FIG. 10 is a schematic diagram of an example of PTRS-DMRS association for UL PTRS port 0 or for an actual UL PTRS port according to some embodiments of the present disclosure. [Figure 6] 10 is a flowchart of an example method performed on a terminal device according to some embodiments of the present disclosure. [Figure 7] 10 is a flowchart of an example method performed in a network device according to some other embodiments of the present disclosure. [Figure 8] FIG. 1 is a simplified block diagram of an example of an apparatus suitable for practicing embodiments of the present disclosure. [Figure 9] FIG. 1 is a block diagram of an example computer-readable medium according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

[0024] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only to help those skilled in the art understand and practice the present disclosure, but do not imply any limitation on the scope of the present disclosure. The present disclosure described herein can be implemented in various ways other than those described below.

[0025] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0026] References in this disclosure to "one embodiment," "embodiment," "example embodiment," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment is required to include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is suggested that one of ordinary skill in the art will recognize that such feature, structure, or characteristic also affects such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0027] While the terms "first," "second," etc. may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes," and / or "including," as used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. As used herein, "at least one of: " and "at least one of " and similar language, when a list of two or more elements is joined by "and" or "or", means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0029] As used in this application, the term "circuit equipment" means (a) purely hardware circuit implementations (e.g., implementations using only analog and / or digital circuitry); (b) (where applicable) (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) Any portion of a hardware processor, software, and memory along with software (including a digital signal processor) that functions together to cause a device such as a mobile phone or server to perform various functions. A combination of hardware circuits and software, such as and, (c) Hardware circuitry and / or processors, such as microprocessors or portions of microprocessors, that require software (e.g., firmware) for operation, but the software may be absent when not needed for operation. It may refer to one or more or all of the following:

[0030] This definition of circuit equipment applies to all uses of the term in this application, including any claims. As a further example, as used in this application, the term circuit equipment covers solely a hardware circuit or processor (or multiple processors), or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware implementations. The term circuit equipment also covers, for example, baseband or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices, if applicable to a particular claim element.

[0031] As used herein, the term "communication network" refers to a network conforming to any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), or Narrowband Internet of Things (NB-IoT). Furthermore, communications between terminal devices and network devices in a communication network may be performed according to any suitable generation of communication protocols, including, but not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, future fifth-generation (5G) communication protocols, and / or any other protocols currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development of communications, there will naturally be future types of communication technologies and systems in which the present disclosure may be embodied. This should not be construed as limiting the scope of the present disclosure to only the aforementioned systems.

[0032] As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses and receives services from the network. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), such as a Node B (Node B or NB), evolved Node B (eNode B or eNB), NR NB (also referred to as gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, femto, pico, or other low-power node.

[0033] The term "terminal device" refers to any end device that may be capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMD), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “terminal device,” “communications device,” “terminal,” “user equipment,” and “UE” may be used interchangeably.

[0034] The Rel-15 specification allows a user equipment (UE) to be configured with codebook- or non-codebook-based physical uplink shared channel (PUSCH) transmission using two uplink (UL) sounding reference signal (SRS) resource sets. In other words, based on this configuration, the UE must transmit a PUSCH up to rank 4 on a single TRP using a single transmit (TX) antenna panel. This mode is called the Rel-15 UL TX mode.

[0035] For wireless communication systems (e.g., LTE and NR), a local oscillator (LO) is an essential component in transceivers to shift the carrier frequency up or down. The quality of the LO is defined by its phase noise. Depending on the combination of the scheduled / configured modulation order and bandwidth for data and / or control information transmission, the impact of phase noise can be detrimental to system performance, especially if there is no specification support for phase noise compensation at high carrier frequencies, e.g., above 52.6 GHz.

[0036] For Rel-15, the physical layer provides support for phase noise compensation by specifying a phase tracking reference signal (PTRS) for UL and DL with orthogonal frequency division multiplexing (OFDM) and UL single-carrier discrete-fourier-transform-spread orthogonal frequency division multiplexing (DFT-s-OFDM) waveforms. The PTRS is used to track the phase of local oscillators at the receiver and transmitter. This can enable suppression of phase noise and common phase errors, which is particularly important at higher carrier frequencies such as millimeter wave.

[0037] For the UL, depending on the reported capability, a UE may be scheduled with one or two PTRS ports. When the UE is capable of non- / partially coherent codebook-based PUSCH transmission, two PT-RS ports may be used for a UE with two local oscillators. Typically, this corresponds to the case where the UE is equipped with two or more UL TX antenna panels. When the UE reports the capability to support fully coherent UL transmission, only a single PT-RS port is used.

[0038] For non-codebook-based PUSCH transmission, the actual number of transmitted UL PTRS ports is determined based on the SRS resource indicator (SRI). The UE may be configured with a PTRS port index per configured SRS resource by the higher layer parameter ptrs-PortIndex configured by SRS-Config. If the PTRS port indexes associated with different SRIs are the same, the corresponding UL DM-RS ports are associated with one UL PT-RS port.

[0039] The downlink control information DCI Format 0_1 ​​or Format 0_2 defines a PTRS-DMRS Association field that is used to link a PTRS to an UL DMRS. This allows a pair of reference signals to be used in combination, i.e., channel estimates are derived from both and interpolated between them. If transform precoding is enabled or the configured maximum uplink rank is 1 (based on the maxRank information element), the PTRS-DMRS Association field is not required and is omitted from the DCI.

[0040] When only a single DMRS is configured, the PTRS is linked to this specific DMRS by default. Otherwise, the PTRS-DMRS association field in the DCI occupies two bits, which are used to identify the first or second DMRS. Table 1 shows an example of the PTRS-DMRS association field.

[0041] [Table 1]

[0042] When the UE transmits a single PTRS, the DCI indicates one of four different DMRSs, and the indicated DMRS antenna port is associated with the single PTRS antenna port. When the UE transmits two PTRS antenna ports, the MSB and LSB of the DCI field indicate one of the DMRS antenna ports for PTRS antenna port 0 or 1.

[0043] For codebook or non-codebook based UL transmission, the association between the UL PTRS port and the DMRS port is signaled by the PTRS-DMRS Association field in DCI Format 0_1 ​​and DCI Format 0_2, as shown in Table 1.

[0044] In Rel-17, there is a single downlink control information indicator (S-DCI) for time division multiplexing (TDM) multi-transmission-reception point (M-TRP) physical uplink shared channel (PUSCH) repetition and antenna panel selection. Rel-17 is specified to enhance the reliability of uplink transmissions in the context of multi-TRP scenarios. The UE is configured with two different UL SRS resource sets with the followUnifiedTCIstateSRS information element to follow two different DL / or joint DL and UL / UL transmission configuration indication (TCI) states associated as spatial sources.

[0045] Based on the Rel-17 Capability Set Index reporting, the network can know the UE antenna panel-specific transmission capabilities (including information about the number of UL SRS antenna ports) for UL SRS codebook-based transmissions in a particular spatial UL direction. Based on this information, the network can trigger transmission of two different UL SRS resource sets using the codebook to specifically obtain TRP-specific transmit precoding matrix identity (TPMI) hypothesized antenna panels (i.e., determine the precoder index and rank selection) for PUSCH transmissions.

[0046] Based on the obtained TRP-specific TPMI and SRI information, the network can trigger non-simultaneous TRP-specific Rel-17 PUSCH transmissions by indicating a code point for a single SRS resource set index via DCI. When two SRS resource sets are configured using a codebook or non-codebook, two bits and four values ​​are reserved; otherwise, a zero bit is reserved. The first value out of the four possible values ​​of the DCI code point can be used to indicate which of the two SRS resource indexes (SRIs), the first or second, is used to enable dynamic switching between single-TRP (either TRP1 or TRP2) PUSCH transmissions in a time-division multiplexed (TDM) manner. The other two remaining bits can be used to enable multi-TRP PUSCH transmissions between TRP1 and TRP2 in a TDM manner with repetition, where a cyclic or sequential mapping is configured via radio resource control (RRC) to map the two SRIs to PUSCH repetitions. Furthermore, in the case of codebook-based transmission, the DCI includes two separate codepoint fields for SRI and two fields for precoding information and the number of transmission layers. The first field indicates the number of transmission layers, while the second field does not. In the case of non-codebook-based transmission, the DCI may have two SRI codepoint fields, where the first SRI codepoint field indicates the transmission layer and the second SRI codepoint field does not. Based on the received S-DCI, the terminal device may then transmit a PUSCH transmission using multiple antenna panels (only one panel at a time). This mode is referred to as the Rel-17 UL TX mode.

[0047] Rel-17 defines a scheme for associating PTRS and DMRS antenna ports with different TRPs according to the configured maxRank. The first PTRS-DMRS Association field in the DCI shown in Table 2 is applied as follows: The first PTRS-DMRS Association field may be set as two bits, and Tables 2 and 3 are used to indicate the association between a PTRS port and a DMRS port when one PT-RS port and two PT-RS ports are configured, respectively, by maxNrofPorts in PTRS-UplinkConfig, and the DMRS port is indicated by the antenna port field. When the SRS Resource Set Index field is present and maxRank > 2, this field indicates the association between a PTRS port and a DMRS port corresponding to the SRS Resource Index field and / or the Number of Precoding Information and Layers field according to Tables 2 and 3. When the SRS Resource Set Index field is present and equal to "10" and "11", and maxRank=2, the MSB of this field indicates the association between the PTRS port and the DMRS port corresponding to the SRS Resource Index and / or Precoding Information and Number of Layers fields, and the LSB of this field indicates the association between the PTRS port and the DMRS port corresponding to the Second SRS Resource Index field and / or the Second Precoding Information field according to Table 2.

[0048] [Table 2]

[0049] When the maxRank of the scheduled PUSCH is > 2, the second PTRS-DMRS Association field in the DCI shown in Table 3 is applied together with the first PTRS-DMRS Association field, such that if the PTRS-DMRS Association field and the SRS Resource Set Index field are present and maxRank > 2, then the second PTRS-DMRS Association-2 bit, otherwise the 0 bit.

[0050] Tables 2 and 3 are used to indicate the association between the PTRS port and the DMRS port corresponding to the second SRS resource index field and / or the second precoding information field when one PT-RS port and two PT-RS ports are configured by maxNrofPorts in PTRS-UplinkConfig, respectively, and the DMRS port is indicated by the antenna port field.

[0051] [Table 3]

[0052] As shown in Table 2, the two MSB and LSB bits of the PTRS-DMRS Association field indicate the scheduled DMRS ports corresponding to different SRS Resource Index fields and / or Precoding Information and Number of Layers fields when there is one PTRS port. Furthermore, when the PTRS-DMRS Association field and the SRS Resource Set Index field are present and maxRank>2, the second PTRS-DMRS Association field is used.

[0053] Compared to the single (S)-DCI based Rel-17 TDM repetition scheme, Rel-18 will specify support for both S-DCI and multiple (M)-DCI based simultaneous uplink multi-panel PUSCH schemes with SDM and SFN, aiming to enhance throughput and reliability with reduced latency.

[0054] For S-DCI, the network is assumed to have a centralized scheduler with ideal backhaul among multiple TRPs, while for M-DCI, a distributed scheduler with non-ideal backhaul is assumed. In an SDM-based scheme, different layers / DMRS ports of a PUSCH are separately precoded and transmitted simultaneously from different UE panels. In an SFN-based transmission scheme, all of the same layers / DMRS ports in a PUSCH transmission are transmitted simultaneously from two different UE panels.

[0055] Additionally, it was agreed that Rel-18 UEs can be configured to use single frequency network (SFN) or spatial division multiplexing (SDM) transmission modes. In an SDM scheme, different PUSCH layers and DMRS antenna ports of one codeword are separately precoded and transmitted simultaneously from different UE antenna panels, while in an SFN-based transmission scheme, the same PUSCH layer and DMRS antenna port are transmitted simultaneously with two different precoders via two different UE antenna panels associated with different TCI states.

[0056] Thus, for a single DCI-based ST×MP PUSCH SDM scheme, this may support layer combinations of {1+1, 1+2, 2+1, and 2+2} for the single codeword (CW) case. DMRS port indication for SDM scheme single DCI-based ST×MP transmission is also supported, and the DMRS antenna ports associated with the two TPMI / SRI fields can be in the same CDM group or in different CDM groups.

[0057] Therefore, the Rel-18 specification provides support for a different simultaneous multi-panel PUSCH transmission mode, namely SDM. Additionally, Rel-18 also provides support for legacy PUSCH transmission modes, e.g., Rel-15 single antenna panel to single TRP, and Rel-17 TDM-based single antenna panel to multi-TRP, as discussed in the previous section.

[0058] Nevertheless, due to the above differences, the existing DMRS-PTRS association cannot be applied in Rel-18, and ambiguity remains as to how a Rel-18 UE should correctly interpret the PTRS-DMRS association for SFN-based simultaneous multi-panel PUSCH transmission (i.e., how to distinguish between SFN-based operation and SDM-based operation with respect to legacy operation). In other words, the PTRS-DMRS association for SFN-based simultaneous multi-panel PUSCH transmission is not resolved.

[0059] According to an embodiment of the present disclosure, a solution for DMRS-PTRS port association for SFN-based PUSCH is provided. In this solution, a terminal device receives a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device. Based on the PTRS-DMRS association indication, the terminal device transmits an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device. The PTRS-DMRS association indication comprises a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port. The terminal device reports the indication to the network device based on measurements, and the indication indicates at least one uplink transmission scheme that may be used.

[0060] Therefore, with the embodiments, the PTRS-DMRS association may be indicated to the terminal device in a flexible and efficient manner, and the terminal can then determine the DMRS port and the corresponding PTRS port for SFN-based simultaneous multi-panel PUSCH transmission. Thus, the solution proposed herein may enable SFN-based simultaneous multi-panel PUSCH transmission.

[0061] The principles and embodiments of the present disclosure are explained in detail below with reference to the accompanying drawings. Nevertheless, it should be noted that these embodiments are illustrated by way of example and are not intended to limit the scope of the present application in any way.

[0062] Reference is first made to FIG. 1, which illustrates an example communication system 100 in which embodiments of the present disclosure may be implemented. As illustrated in FIG. 1, system 100 includes two transmit and receive points (TRPs), such as TRPs 120 and 130. TRPs 120 and 130 may each have one respective group of antenna ports. In other words, TRPs 120 and 130 may be associated with or function as two respective network devices and thus may sometimes be referred to as network device 120 and network device 130 in this disclosure. For clarity, TRP 120 may also be referred to as a first TRP, and TRP 130 may also be referred to as a second TRP.

[0063] Each TRP 120, 130 may operate using different frequency bands in both the DL and UL. In a communication system, "UL" refers to the communication link in the direction from the terminal device to the network device, and "DL" refers to the communication link in the direction from the network device to the terminal device.

[0064] The system 100 also includes one or more terminal devices, such as a terminal device 110. The terminal device 110 is capable of, for example, wirelessly connecting and communicating on the UL and DL with either or both of the TRPs 120, 130 depending on the location of the terminal device within the cell of the TRPs 120, 130. The terminal device 110 may be configured to communicate with the network via one or more TRPs, for example, two TRPs. The two TRPs may be located in the same cell (intra-cell TRP) or in different cells (inter-cell TRP).

[0065] The terminal device 110 may be an MP-UE with multiple panels. From a wireless communication perspective, the MP-UE may comprise any device with multiple antenna groups configured as panels. The MP-UE may provide flexibility in selecting antennas for wireless communication. In one aspect, multiple panels of the MP-UE may be active, but one panel may be selected for uplink transmission using a single beam. In other aspects, multiple beams may be transmitted simultaneously from multiple panels.

[0066] The terminal device 110 of FIG. 1 may include multiple panels, such as a first panel 111, a second panel 112, and additional optional panels (not shown), if needed. In general, a panel may be a component of a UE that includes one or more antenna groups. An antenna group may include one or more antennas, antenna elements, and / or antenna arrays. Each panel may operate somewhat independently. For example, each panel may be individually activated or deactivated. An activated panel may be used for transmission and / or reception, while a disabled panel may not be used for transmission and / or reception. Panels may be elements of antenna groups that independently control beams. For example, within a panel, one beam may be selected and used for UL transmission. Furthermore, multiple panels may be used for UL transmission, and multiple beams (each beam selected for a panel) may be used for UL transmission across different panels.

[0067] 1, the number of network devices and terminal devices is for illustrative purposes only and does not imply any limitation. Moreover, the number of panels of the terminal devices is also given for illustrative purposes only. System 100 can include any suitable number of network devices and terminal devices, and the terminal devices can include any suitable number of panels, as long as the number can be adapted to implement embodiments of the present disclosure.

[0068] Communications in communication system 100 may be performed according to any suitable communication protocol, including, but not limited to, third-generation (3G), fourth-generation (4G), fifth-generation (5G) and later cellular communication protocols, wireless local network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocol now known or to be developed in the future. Moreover, communications may utilize any suitable wireless communication technology, including, but not limited to, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology now known or to be developed in the future.

[0069] As illustrated in FIG. 1 , the terminal device 110 may receive a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device such as one of the TRPs 120, 130. Based on the PTRS-DMRS association indication, the terminal device 110 transmits an uplink signal to the network device such as one of the TRPs 120, 130 simultaneously in a single frequency network (SFN) manner via two or more antenna panels of the terminal device. The PTRS-DMRS association indication comprises a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port. The terminal device 100 reports an indication to the network device such as one of the TRPs 120, 130 based on measurements, the indication indicating at least one uplink transmission scheme that may be used.

[0070] Reference is now made to Figure 2, which illustrates an example process 200 for DMRS-PTRS port association for SFN-based PUSCH in accordance with some embodiments of the present disclosure. For discussion purposes, process 200 will be described with reference to Figure 1. Network device 120 and terminal device 110 may be involved in process 200 for illustrative purposes.

[0071] In process 200, terminal device 110 receives a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device 202. The PTRS-DMRS association indication comprises a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port. To facilitate the terminal device transmitting uplink signals, network device 120 needs to send information about the PTRS port and the DMRS port to terminal device 110.

[0072] After obtaining the PTRS-DMRS association indication, the terminal device can transmit uplink signals to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication 204. Thus, the network device can receive uplink signals in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port. The PTRS-DMRS association indication can dynamically indicate uplink PTRS-DMRS antenna port association for SFN-based simultaneous multi-panel PUSCH transmission.

[0073] In some embodiments, the first portion of the PTRS-DMRS association field is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field. The second portion of the PTRS-DMRS association field is configured to indicate scheduled DMRS ports that share the PTRS port. For example, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0074] To dynamically indicate uplink PTRS-DMRS antenna port association for SFN-based simultaneous multi-panel PUSCH transmission, the PTRS-DMRS association indication can be configured, for example, using a signal DMRS-PTRS association field, which is also referred to as Solution A below.

[0075] Solution A In this solution, when a UE is scheduled for SFN-based simultaneous multi-panel PUSCH with DCI, the PTRS-DMRS association field in the scheduling DCI indicates only the association between PTRS antenna port 0 / 1 (or 0 / 1 / .... / port N) and the scheduled DMRS antenna port corresponding to both the first and second SRS resource index and / or both the first and second precoding information and number of layers (irrespective of the number of layers).

[0076] For example, the PTRS-DMRS association field indicates information where the most significant bit (MSB) indicates the kth scheduled UL DMRS antenna port and the least significant bit (LSB) indicates the nth indicated PTRS antenna port out of N different ones configured by RRC or activated PTRS antenna ports, and MAC level signaling, e.g., medium access control (MAC) control element (CE), is used to activate and overwrite the PTRS-DMRS association table with the activated PTRS antenna ports.

[0077] When the PTRS-DMRS association field indicates the above information, i.e., when a combination of MSB and LSB and SFN transmission is scheduled, the UE shall apply the association between the kth scheduled DMRS antenna port and the nth indicated PTRS antenna port when transmitting UL DMRS and PTRS resources in SFN-based simultaneous multi-panel transmission by using both the first SRI and the second SRI and / or both the first and second precoding information and the number of layers.

[0078] In some examples, the PTRS-DMRS association indication may comprise two PTRS-DMRS association fields, i.e., another PTRS-DMRS association field. In such a case, the UE must ignore information associated with the another PTRS-DMRS association field (regardless of the indicated number of layers), which means that the terminal device will still interpret only one of the two PTRS-DMRS association fields, for example, the first PTRS-DMRS association field.

[0079] In some embodiments, the PTRS-DMRS association indication may comprise a separate PTRS-DMRS association field, which may have the same structure as the PTRS-DMRS association field. For example, the separate PTRS-DMRS association field has a most significant bit (MSB) and a least significant bit (LSB), where the MSB indicates the kth scheduled UL DMRS antenna port and the LSB indicates the nth indicated PTRS antenna port out of N different ones configured by RRC or activated PTRS antenna ports.

[0080] The two PTRS-DMRS association fields may be used for different scenarios, for example, a first PTRS-DMRS association field is used for a smaller number of layers associated with the PUSCH and a second PTRS-DMRS association field is used for a larger number of layers associated with the PUSCH.

[0081] In some embodiments, network device 120 may notify the terminal device of the layer number, for example, in the precoding information and number of layers field. Thus, network device 120 determines 206 the number of layers for terminal device 110 to transmit uplink signals in the SFN manner and transmits 208 a layer number indication capable of indicating the number of layers to terminal device 110. Terminal device 110 may then obtain from network device 120 the layer number indication capable of indicating the number of layers configured for transmitting uplink signals in the SFN manner. Furthermore, network device 120 selects 210 one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port. The PTRS-DMRS association indication may then be placed in the selected PTRS-DMRS association field and sent to the terminal device.

[0082] After receiving the PTRS-DMRS association indication, the terminal device 110 may select 212 one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and the predetermined layer number threshold in 206 to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0083] The terminal device 110 and the network device 120 may determine the total number of layers used by them. For example, the total number of layers may be included in the DCI. Additionally or alternatively, the predetermined layer number threshold may be based on the total number of layers.

[0084] In some embodiments, when the number of layers is not greater than a predetermined layer number threshold, a first PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port. When the number of layers is greater than a predetermined layer number threshold, a second PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port. Additionally, in both the first and second PTRS-DMRS association fields, the first portion comprises one or more most significant bits (MSBs) and the second portion comprises one or more least significant bits (LSBs), which may be used in a similar manner. In the present disclosure, such a solution may also be referred to as Solution B and will be further described below.

[0085] Solution B In this solution, when a UE is scheduled for SFN-based simultaneous multi-panel PUSCH with L layers via DCI, the first PTRS-DMRS or second PTRS-DMRS association field in the scheduling DCI indicates only the association (irrespective of the number of layers) between PTRS antenna port 0 / 1 (or 0 / 1 / .... / port N) and the scheduled DMRS antenna port corresponding to both the first and second SRS resource index and / or both the first and second precoding information and the number of layers.

[0086] When the indicated PUSCH layer ≦L / 2, the first PTRS-DMRS association field may be used to indicate the following information: The most significant bit (MSB) indicates the kth scheduled UL DMRS antenna port that shares the indicated nth PTRS antenna port, where k≦L / 2; The least significant bit (LSB) indicates the nth indicated PTRS antenna port out of N different ones configured by RRC or activated PTRS antenna ports, and MAC level signaling, e.g. MAC CE, is used to activate and overwrite the PTRS-DMRS association table at the activated PTRS antenna port.

[0087] When the first PTRS-DMRS Association field indicates the above information, i.e., when a combination of MSB and LSB and SFN transmission is scheduled, the UE shall apply the association between the kth scheduled DMRS antenna port and the nth indicated PTRS antenna port as indicated in the first PTRS-DMRS Association field when transmitting UL DMRS and PTRS resources in SFN-based simultaneous multi-panel transmission. During transmission, the terminal device may use both the first SRI and the second SRI and / or both the first and second precoding information and the number of layers. In this case, the UE shall ignore information associated with another PTRS-DMRS Association field (independent of the indicated number of layers) and interpret only the most significant bit (MSB) and least significant bit (LSB) of the PTRS-DMRS Association field.

[0088] On the other hand, when the indicated PUSCH layer > L / 2, the second PTRS-DMRS association field indicates the following information: The most significant bit (MSB) indicates the jth scheduled UL DMRS antenna port that shares the indicated nth PTRS antenna port, where j>L / 2. The least significant bit (LSB) indicates the nth indicated PTRS antenna port out of N different ones configured by RRC or activated PTRS antenna ports, and MAC level signaling, e.g. MAC CE, is used to activate and overwrite the PTRS-DMRS association table at the activated PTRS antenna port.

[0089] When the second PTRS-DMRS association field indicates the above information, i.e., when a combination of MSB and LSB and SFN transmission is scheduled, the UE shall apply the association between the jth scheduled DMRS antenna port and the nth indicated PTRS antenna port when transmitting UL DMRS and PTRS resources in SFN-based simultaneous multi-panel transmission. During transmission, the terminal device may use both the first SRI and the second SRI and / or both the first and second precoding information and the number of layers. In this case, the UE shall ignore the information associated with the PTRS-DMRS association field (independent of the indicated number of layers) and interpret only the most significant bit (MSB) and least significant bit (LSB) of another PTRS-DMRS association field.

[0090] In some embodiments, the PTRS-DMRS association indication may be configured in another solution, which may be referred to as solution C, that is different from solutions A and B.

[0091] Solution C In this solution, when a UE is scheduled for SFN-based simultaneous multi-panel PUSCH with DCI, an indication is made via a PTRS-DMRS association field and another PTRS-DMRS association field as follows: the PTRS-DMRS association field in the scheduling DCI indicates an association between the PTRS antenna port x and the scheduled DMRS antenna port corresponding to the first and second SRS resource indices and / or the first and second precoding information and the number of layers (irrespective of the number of layers).

[0092] In one example, the MSB and LSB bits are repurposed by defining a restricted set of allowable MSB and LSB combinations for the UE, e.g., PUSCH transmission with two layers (easy to extend to a larger number of layers): "00" MSB: The first scheduled DMRS port corresponding to the SRS resource index field and / or the precoding information and number of layers field; LSB: The first scheduled DMRS port corresponding to the second SRS resource index field and / or the second precoding information field. "11" MSB: The second scheduled DMRS port corresponding to the SRS resource indicator field and / or the precoding information and number of layers field; LSB: The second scheduled DMRS port corresponding to the second SRS resource index field and / or the second precoding information field.

[0093] When the Alternate PTRS-DMRS Association field is configured, the association field indicates the PTRS antenna port x associated with the scheduled DMRS antenna port. In some embodiments, the PTRS antenna port x may be associated with the LSB or the MSB. In some embodiments, the PTRS antenna port x may be associated with a combination of the LSB and the MSB. Otherwise (i.e., the Alternate PTRS-DMRS Association field is not configured when scheduling the DCI), the RRC-configured PTRS antenna port x is associated with the indicated DMRS-PTRS association via the PTRS-DMRS Association field.

[0094] When the PTRS-DMRS and another PTRS-DMRS association fields are configured for SFN-based simultaneous multi-panel PUSCH transmission, the UE shall apply the association between the k-th scheduled DMRS antenna port and the x-th indicated / configured PTRS antenna port when transmitting UL DMRS and PTRS resources in SFN-based simultaneous multi-panel transmission by using both the first SRI and the second SRI and / or both the first and second precoding information and number of layers.

[0095] In some embodiments, the PTRS-DMRS association indication may be configured in another solution, which may be referred to as solution D, that is different from solutions A, B, and C.

[0096] In particular, two PTRS-DMRS association fields may correspond to different SRS resource index fields and / or different precoding information and number of layers fields. For example, a first PTRS-DMRS association field may be configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field. A second PTRS-DMRS association field may be configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0097] Additionally, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field. This solution may be referred to as Solution D.

[0098] Solution D In this solution, when a UE is scheduled with SFN-based simultaneous multi-panel PUSCH triggered via DCI, the PTRS-DMRS association field indicates that the DMRS port associated with each SRI and precoder matrix index (PMI) is also associated with its own PTRS antenna port. In other words, there are two PTRS antenna ports, one for each SRI and / or precoding information and layer information pair.

[0099] For example, the PTRS-DMRS association field in the scheduling DCI indicates an association between a PTRS antenna port x corresponding to a first SRS resource index and / or a first precoding information and number of layers and a scheduled DMRS antenna port, and the second PTRS-DMRS association field in the scheduling DCI indicates an association between a PTRS antenna port y corresponding to a second SRS resource index and / or a second precoding information and number of layers and a scheduled DMRS antenna port.

[0100] In some embodiments, the PTRS-DMRS association indication may be included in downlink control information (DCI). In some embodiments, SFN-specific PTRS-DMRS associations may be defined.

[0101] For embodiments as proposed herein, this may dynamically indicate DMRS-PTRS association for scheduled SFN-based simultaneous multi-panel PUSCH transmissions with precoding. Furthermore, corresponding UE behavior (i.e., how the UE should interpret the indicated information) for the proposed indication method for SFN-based simultaneous multi-panel PUSCH transmissions is provided.

[0102] In some embodiments, the gNB may select one of the above solutions to be applied when the UE receives a scheduling DCI. For example, the gNB may configure / activate solution A or solution B when the UE is to transmit simultaneously from two panels to a single TRP, and may configure / activate solution C when the UE is to transmit simultaneously from two panels to two TRPs, each panel having its own target receiving TRP. The selection of the solution to be applied may be configured via RRC or MAC or L1 signaling.

[0103] In the following, some specific examples of the above solutions will be described in detail with reference to FIGS.

[0104] Figure 3 illustrates a schematic diagram of an uplink sounding reference signal (SRS) resource set configuration for SFN-based simultaneous multi-panel PUSCH transmission with two layers according to some embodiments of the present disclosure. Figure 3 shows an example of an UL SRS resource configuration for an SFN-based ST x MP PUSCH having two layers with two TRPs, namely, TRP1 302 and TRP2 304. A UE 306 is equipped with two transmit antenna panels 308 and 310, capable of two TX antenna ports per antenna panel, that is, panel 1 310 and panel 2 308, used to simultaneously transmit PUSCH in an SFN manner via these panels. The UE 306 also includes a precoder PREC1 328 and a precoder PREC2 330. Based on the UE capability report, PUSCH TXCoherency is configured as "fullyAndPartialNonCoherent" and DMRS-UplinkConfig is configured with phaseTrackingRS (i.e., PTRS-UplinkConfig) with maxNRofPorts=2.

[0105] Furthermore, the UE 306 is configured with two UL SRS resource sets, e.g., Set #1 312 and Set #2 314, with usage set to "Codebook" and with "followUnifiedTCIstateSRS-r17," where the resource sets are configured with the same or different number of resources with the same or different number of antenna ports. Here, each UL SRS resource set has one SRS resource with two antenna ports, e.g., Set 1 with 2-AP SRI #1 316 and Set 2 with 2-AP SRI #2 318. Furthermore, the UE 306 is configured with a UE-specific PUSCH-Config parameter, i.e., UL-TXMode-r18=SFN. The UE is dynamically indicated via DCI1_1 or 1_2 with two different TCI states, TCI-state1 (associated with TRP1) and TCI-state2 (associated with TRP2), that both UL SRS resource sets are configured to follow.

[0106] In Solution A, SFN-based simultaneous multi-panel PUSCH transmissions are scheduled via uplink DCI format 0_1, and a first DMRS-PTRS association field conveys information about the association between the scheduled DMRS antenna port and the associated PTRS antenna port. Upon detection of DCI 0_1, the first SRI and second SRI codepoint fields indicate SRI#1, SRI#4, and both the first precoding and layer number information and the second precoding and layer number information indicate 2 (using two layers but different TPMI). Moreover,

[0107] DMRS antenna ports indicate 0 (i.e., port 0 322 and port 1 320) and PTRS-DMRS associations set to 0 (00). For codebook or non-codebook based UL transmission, the association between the UL PTRS port and the DMRS port is indicated by the first PTRS-DMRS association field. For example, the PTRS ports include PTRS port 0 324 and PTRS port 1 326.

[0108] For illustrative purposes, Table 4 shows an example PTRS-DMRS Association field. As shown, the MSB of the PTRS-DMRS Association field indicates the scheduled kth, k=1·K (K=number of PUSCH layers), DMRS antenna port corresponding to both the SRS Resource Index and Second SRS Resource Index fields and / or both the Precoding Information and Number of Layers and Second Precoding Information and Number of Layers fields. Additionally, the LSB of the PTRS-DMRS Association field indicates the nth PTRS antenna port, where n=0·N-1 (=1), where N defines the number of supported PTRS antenna ports and is dependent on the UE capabilities.

[0109] Note that the reserved bits in the LSB can be used to indicate a larger number of PTRS ports, for example, 2 and 3. Moreover, the table can be easily extended to support a larger number of scheduled DMRS antenna ports, for example, 8, by adding four additional rows with two columns.

[0110] [Table 4]

[0111] 4 illustrates another schematic diagram of uplink sounding reference signal (SRS) resource set configuration for SFN-based simultaneous multi-panel PUSCH transmission with four layers according to some embodiments of the present disclosure. In FIG. 4, there are two TRPs, TRP1 402 and TRP2 404. A UE 406 is equipped with two antenna panels, namely, two transmit antenna panels 408 and 410, capable of four TX antenna ports per antenna panel, used to simultaneously transmit PUSCH in an SFN manner via panel #1 410 and panel #2 408. Based on the UE capability report, PUSCH TX Coherency is configured as "fullyAndPartialNonCoherent" and DMRS-UplinkConfig is configured with phaseTrackingRS (i.e., PTRS-UplinkConfig) with maxNRofPorts=2.

[0112] Furthermore, the UE 406 is configured with two UL SRS resource sets, e.g., Set #1 416 and Set #2 418, with usage set to "Codebook" and with "followUnifiedTCIstateSRS-r17," where the resource sets are configured with the same or different number of resources with the same or different number of antenna ports. Each UL SRS resource set has one SRS resource with four antenna ports, e.g., Set #1 with 4-AP SRI #1 420 and Set #2 with 4-AP SRI #1 422. Furthermore, the UE is configured with a UE-specific PUSCH-Configuration parameter, i.e., UL-TXMode-r18=SFN.

[0113] In this example, Solution A may be extended to operate with four layers, and the same principles as previously described with two PUSCH layers can be applied. In this example, four DMRS ports and two PTRS ports are used. For example, one DMRS port is selected from DMRS Port P0 424, DMRS Port P1 426, DMRS Port P2 428, and DMRS Port P3 430, and an associated PTRS port is selected from PTRS Port 0 432 and PTRS Port 1 434.

[0114] In some embodiments, solution B may be used, and the PTRS-DMRS association field may be the same as the PTRS-DMRS association field in solution A, with the difference being that two PTRS-DMRS association fields are used for lower and higher tiers, respectively, and the ray number indication may help determine which tier indicates the DMRS-PTRS association.

[0115] For Solution C, upon detection of DCI0_1, the first SRI and second SRI codepoint fields indicate SRI#1, SRI#4, and both the first precoding and layer number information and the second precoding and layer number information indicate 2 (using two layers but different TPMI). Additionally, the DMRS antenna ports indicate 0 (i.e., ports 0 and 1) and the PTRS-DMRS association set to 11. For codebook or non-codebook based UL transmission, the association between the UL PT-RS port and the DM-RS port is indicated by the PTRS-DMRS association field, and the indicated value is 11 as shown in Table 5.

[0116] When the PTRS-DMRS association is set to 11 and the number of configured PTRS antenna ports is 1, the UE shall associate the PTRS antenna port, i.e., port 0, with both indicated DMRS antenna ports, i.e., p0 and p1, associated with the indicated SRI (i.e., SRI#1) of the first UL SRS resource set (i.e., set #1) and the SRI (i.e., SRI#4) of the second UL SRS resource set (i.e., set #2).

[0117] In fact, when a UE is configured for SFN-based simultaneous PUSCH transmission, the UE shall assume that the indicated PTRS-DMRS association value is restricted to only the values ​​'11' or '00'. In other words, for SFN-based codebook PUSCH transmission with a single PTRS antenna port, the UE shall assume that a single PTRS antenna port is always indicated for the same scheduled DMRS antenna port, regardless of the number of SRS resource indicators (i.e., the first or second SRI).

[0118] Figure 5 shows, in dashed lines, an example 500 of allowable PTRS-DMRS association values ​​for UL PTRS Port 0. In this example, only values ​​00 and 11 are used.

[0119] [Table 5]

[0120] In this way, the network is dynamically indicated for UE DMRS-PTRS antenna port association for SFN-based simultaneous multi-panel PUSCH transmission.

[0121] In some embodiments, for Solution D, the structure of the PTRS-DMRS association field may be similar or the same as that of Solution A.

[0122] 6 illustrates a flowchart of an example method 600 performed at a terminal device in accordance with some embodiments of the present disclosure. For purposes of discussion, the method 600 will be described from the perspective of the terminal device 110 with reference to FIG.

[0123] In block 602, the terminal device 110 receives a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from the network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port. In block 604, the terminal device 110 transmits an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication.

[0124] In some embodiments, the first portion is configured to indicate scheduled DMRS ports that correspond to both the first and second sounding reference signal (SRS) resource index fields and / or both the first and second precoding information and number of layers fields, and the second portion is configured to indicate scheduled DMRS ports that share the PTRS port.

[0125] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0126] In some embodiments, the terminal device 110 may obtain a layer number indication from a network device, the layer number indication being capable of indicating the number of layers configured for transmitting uplink signals in an SFN manner, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0127] In some embodiments, the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0128] In some embodiments, another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0129] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0130] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0131] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0132] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0133] 7 illustrates a flowchart of an example method 700 performed in a network device according to some embodiments of the present disclosure. For purposes of discussion, the method 700 will be described from the perspective of the network device.

[0134] In block 702, the network device transmits a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to the terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port. In block 704, the network device receives an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0135] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion indicates scheduled DMRS ports that share the PTRS port.

[0136] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0137] In some embodiments, the network device may determine a number of layers for the terminal device to transmit uplink signals in the SFN manner, send a layer number indication to the terminal device capable of indicating the number of layers, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0138] In some embodiments, the PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0139] In some embodiments, a separate PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0140] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0141] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0142] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0143] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0144] In some embodiments, a terminal device includes at least one processor and at least one memory having stored thereon instructions that, when executed by the at least one processor, cause the terminal device to at least receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port, and to transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication.

[0145] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion is configured to indicate scheduled DMRS ports that share the PTRS port.

[0146] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0147] In some embodiments, the terminal device is further configured to obtain, from the network device, a layer number indication capable of indicating the number of layers configured for transmitting uplink signals in an SFN manner, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0148] In some embodiments, the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0149] In some embodiments, another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0150] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0151] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0152] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0153] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0154] In some embodiments, the network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device to at least: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0155] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion indicates scheduled DMRS ports that share the PTRS port.

[0156] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0157] In some embodiments, the network device is further configured to determine a number of layers for the terminal device to transmit uplink signals in the SFN manner, send a layer number indication to the terminal device capable of indicating the number of layers, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0158] In some embodiments, the PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0159] In some embodiments, a separate PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0160] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0161] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0162] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0163] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0164] In some embodiments, an apparatus capable of performing any of the methods 600 (e.g., terminal device 110) may comprise means for performing each step of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in circuitry or a software module.

[0165] In some embodiments, an apparatus comprises: means for receiving a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and means for transmitting an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus based on the PTRS-DMRS association indication.

[0166] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion is configured to indicate scheduled DMRS ports that share the PTRS port.

[0167] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0168] In some embodiments, the apparatus comprises means for obtaining a layer number indication from a network device, the layer number indication being capable of indicating a number of layers configured to transmit uplink signals in an SFN manner; and means for selecting one of a PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0169] In some embodiments, the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0170] In some embodiments, another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0171] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0172] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0173] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0174] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0175] In some embodiments, an apparatus (e.g., a network device) capable of performing any of the methods 700 may comprise means for performing each step of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in circuitry or a software module.

[0176] In some embodiments, the apparatus comprises: means for transmitting a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and means for receiving an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0177] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion indicates scheduled DMRS ports that share the PTRS port.

[0178] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0179] In some embodiments, the apparatus further comprises means for determining a number of layers for the terminal device to transmit an uplink signal in the SFN manner; means for transmitting a layer number indication to the terminal device capable of indicating the number of layers; and means for selecting one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0180] In some embodiments, the PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0181] In some embodiments, a separate PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0182] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0183] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0184] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0185] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0186] In some embodiments, a non-transitory computer-readable medium comprises program instructions that, when executed by an apparatus, cause the apparatus to receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and, based on the PTRS-DMRS association indication, transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus.

[0187] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion is configured to indicate scheduled DMRS ports that share the PTRS port.

[0188] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0189] In some embodiments, the program instructions further cause the apparatus to obtain a layer number indication from the network device, the layer number indication being capable of indicating a number of layers configured to transmit uplink signals in an SFN manner, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0190] In some embodiments, the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0191] In some embodiments, another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0192] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0193] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0194] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0195] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0196] In some embodiments, a non-transitory computer-readable medium comprises program instructions that, when executed by an apparatus, cause the apparatus to: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive uplink signals from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0197] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion indicates scheduled DMRS ports that share the PTRS port.

[0198] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0199] In some embodiments, the program instructions further cause the apparatus to determine a number of layers for the terminal device to transmit uplink signals in the SFN manner, send a layer number indication to the terminal device capable of indicating the number of layers, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0200] In some embodiments, the PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0201] In some embodiments, a separate PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0202] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0203] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0204] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0205] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0206] In some embodiments, the computer program comprises instructions that, when executed by the apparatus, cause the apparatus to at least receive a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and, based on the PTRS-DMRS association indication, transmit an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the apparatus.

[0207] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion is configured to indicate scheduled DMRS ports that share the PTRS port.

[0208] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0209] In some embodiments, the apparatus is further configured to obtain a layer number indication from the network device, the layer number indication being capable of indicating the number of layers configured to transmit the uplink signal in the SFN manner, and to select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0210] In some embodiments, the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0211] In some embodiments, another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0212] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0213] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0214] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0215] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0216] In some embodiments, the computer program comprises instructions that, when executed by the apparatus, cause the apparatus to at least: transmit a Phase Tracking Reference Signal (PTRS)-Demodulation Reference Signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receive an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port.

[0217] In some embodiments, the first portion is configured to indicate scheduled DMRS ports corresponding to both the first sounding reference signal (SRS) resource index field and the second SRS resource index field and / or both the first precoding information and number of layers field and the second precoding information and number of layers field, and the second portion indicates scheduled DMRS ports that share the PTRS port.

[0218] In some embodiments, the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, where the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

[0219] In some embodiments, the apparatus is further configured to determine a number of layers for the terminal device to transmit uplink signals in the SFN manner, transmit a layer number indication to the terminal device capable of indicating the number of layers, and select one of the PTRS-DMRS association field or another PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port.

[0220] In some embodiments, the PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is not greater than a predetermined layer number threshold.

[0221] In some embodiments, a separate PTRS-DMRS association field is selected to indicate a scheduled DMRS port and a PTRS port associated with the scheduled DMRS port when the number of layers is greater than a predetermined layer number threshold.

[0222] In some embodiments, the first portion comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second portion comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

[0223] In some embodiments, a PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field, and another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

[0224] In some embodiments, the PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from the PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

[0225] In some embodiments, the PTRS-DMRS association indication is included in downlink control information (DCI).

[0226] 8 is a simplified block diagram of a device 800 suitable for implementing embodiments of the present disclosure. Device 800 may be provided to implement a communications device, such as terminal device 110 or network devices 120 and 130 as shown in FIG. 1. As shown, device 800 includes one or more processors 810, one or more memories 820 coupled to processor 810, and one or more communications modules 840 coupled to processor 810.

[0227] The communication module 840 is for two-way communication. The communication module 840 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communication with other network elements.

[0228] The processor 810 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 800 may have multiple processors, such as application-specific integrated circuit chips, time-sent to a clock that synchronizes the main processor.

[0229] The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 824, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage. Examples of volatile memory include, but are not limited to, random access memory (RAM) 822 and other volatile memory that does not persist when power is off.

[0230] The computer program 830 includes computer-executable instructions that are executed by the associated processor 810. The program 830 may be stored in the ROM 824. The processor 810 may perform any suitable actions and processes by loading the program 830 into the RAM 822.

[0231] Embodiments of the present disclosure may be implemented by a program 830 such that the device 800 may perform any of the processes of the present disclosure, such as those discussed with reference to Figures 2 to 7. Embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0232] In some embodiments, the program 830 may be tangibly contained on a computer-readable medium that may be included in the device 800 (such as in the memory 820) or other storage device accessible by the device 800. The device 800 may load the program 830 from the computer-readable medium into RAM 822 for execution. The computer-readable medium may include any type of tangible non-volatile storage, such as ROM, EPROM, flash memory, hard disk, CD, DVD, and the like. Figure 8 shows an example of a computer-readable medium 900 in the form of a CD or DVD. The computer-readable medium stores the program 830.

[0233] In general, various embodiments of the present disclosure may be implemented in hardware or special-purpose circuits, software, logic, or any combination thereof. While some aspects may be implemented in hardware, other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams or flowcharts or using some other graphical representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting example, hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or controller, or other computing device, or some combination thereof.

[0234] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that execute on a target real or virtual processor or device to perform method 600 or 700 as described above with reference to FIGS. 2-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or divided among program modules as desired in various embodiments. The machine-executable instructions for the program modules may be executed in local or distributed devices. In distributed devices, the program modules may be located in both local and remote storage media.

[0235] Program codes for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be performed. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0236] In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations as described above. Examples of carriers include signals, computer-readable media, and the like.

[0237] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, not a signal), as opposed to a limitation on the permanence of data storage (e.g., RAM vs. ROM).

[0238] Furthermore, although operations are depicted in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while some specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0239] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure as defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. at least one processor; at least one memory that, when executed by the at least one processor, receiving a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and transmitting uplink signals to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication; at least one memory storing instructions for causing the terminal device to perform the A terminal device comprising:

2. The first portion is both a first sounding reference signal (SRS) resource index field and a second SRS resource index field; and / or Both the first precoding information and number of layers field and the second precoding information and number of layers field configured to indicate a scheduled DMRS port corresponding to The terminal device of claim 1 , wherein the second part is configured to indicate scheduled DMRS ports that share a PTRS port.

3. The terminal device of claim 1 , wherein the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, and the another PTRS-DMRS association field has the same structure as the PTRS-DMRS association field.

4. The terminal device obtaining a layer number indication from the network device, the layer number indication being capable of indicating a number of layers configured to transmit the uplink signal in the SFN format; selecting one of the PTRS-DMRS association field or the other PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port; The terminal device of claim 3 , further comprising:

5. 5. The terminal device of claim 4, wherein the PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than the predetermined layer number threshold.

6. 5. The terminal device of claim 4, wherein the another PTRS-DMRS association field is selected to determine the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than the predetermined layer number threshold.

7. 6. A terminal device according to claim 2, wherein the first part comprises one or more most significant bits (MSBs) of the PTRS-DMRS association field, and the second part comprises one or more least significant bits (LSBs) of the PTRS-DMRS association field.

8. the PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a first sounding reference signal (SRS) resource index field and / or a first precoding information and number of layers field; 4. The terminal device of claim 3, wherein the another PTRS-DMRS association field is configured to indicate a PTRS-DMRS association corresponding to a second SRS resource index field and / or a second precoding information and number of layers field.

9. 9. The terminal device of claim 8, wherein a PTRS port corresponding to the first SRS resource index and / or the first precoding information and number of layers field is at least partially different from a PTRS port corresponding to the second SRS resource index and / or the second precoding information and number of layers field.

10. The terminal device of claim 1 , wherein the PTRS-DMRS association indication is included in downlink control information (DCI).

11. at least one processor; at least one memory that, when executed by the at least one processor, Transmitting a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; and receiving an uplink signal from the terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port; at least one memory storing instructions for causing the network device to perform the A network device comprising:

12. The first portion is both a first sounding reference signal (SRS) resource index field and a second SRS resource index field; and / or Both the first precoding information and number of layers field and the second precoding information and number of layers field configured to indicate a scheduled DMRS port corresponding to The network device of claim 11 , wherein the second portion indicates scheduled DMRS ports that share a PTRS port.

13. The network device of claim 11 , wherein the PTRS-DMRS association indication further comprises another PTRS-DMRS association field, the another PTRS-DMRS association field having the same structure as the PTRS-DMRS association field.

14. The network device: determining a number of layers for the terminal device to transmit the uplink signal in the SFN format; transmitting a layer number indication to the terminal device capable of indicating the number of layers; selecting one of the PTRS-DMRS association field or the other PTRS-DMRS association field based on the number of layers and a predetermined layer number threshold to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port; The network device of claim 13 further configured to:

15. 15. The network device of claim 14, wherein the PTRS-DMRS association field is selected to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is not greater than the predetermined layer number threshold.

16. 15. The network device of claim 14, wherein the separate PTRS-DMRS association field is selected to indicate the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port when the number of layers is greater than the predetermined layer number threshold.

17. receiving, by a terminal device, a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication from a network device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; transmitting, by the terminal device, an uplink signal to the network device in a single frequency network (SFN) manner simultaneously via two or more antenna panels of the terminal device based on the PTRS-DMRS association indication; A method comprising:

18. transmitting, by a network device, a phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association indication to a terminal device, the PTRS-DMRS association indication comprising a PTRS-DMRS association field having a first portion capable of indicating a scheduled DMRS port and a second portion capable of indicating a PTRS port associated with the scheduled DMRS port; receiving, by the network device, an uplink signal from a terminal device in a single frequency network (SFN) manner on the scheduled DMRS port and the PTRS port associated with the scheduled DMRS port; A method comprising:

19. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method of claim 17 or 18.

20. An apparatus (800) comprising means (810, 820, 840) for performing at least the method according to claim 17 or 18.

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