Method, terminal device, network device and computer readable medium for communication

Abstract

Embodiments of the present disclosure provide a solution for the following. In a method for communication, a terminal device receives, from a network device, control information indicating a resource group and transmission configuration indicator (TCI) states for communication between the terminal device and the network device. The terminal device determines resource subgroups associated with respective TCI states, each resource subgroup being a portion of the resource group in the frequency domain. The terminal device determines a mapping of phase tracking reference signals (PT-RSs) to the resource subgroups. Embodiments of the present disclosure provide practical details on how to decide the PT-RS presence / density / pattern / offset if the scheduled resource group is shared by multiple TCI states, especially in the case of solution 2a / 2b.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to the field of communications, and more particularly to schemes for configuring phase tracking reference signals (PT-RS). Background Technology

[0002] At 3GPP meeting RAN#81, a new work item (WI) for NR eMIMO was approved, which includes the following aspects: First, enhancements to support multi-user (MU) - multiple-input multiple-output (MIMO) will be provided. Specifically, considering the trade-off between performance and overhead, overhead reduction based on Type II Channel State Information (CSI) feedback will be specified. Studies will be conducted, and if necessary, the specification will extend Type II CSI feedback to rank > 2. Second, enhancements to multi-TRP / plane transmission will be provided, including improved reliability and robustness with both ideal and non-ideal backhaul. In particular, enhancements to downlink control signaling(s) will be specified to effectively support incoherent joint transmission. Studies will be conducted, and if necessary, enhancements to uplink control signaling and / or(s) reference signals for incoherent joint transmission will be specified. Multi-TRP techniques for Ultra-Reliable Low-Latency Communication (URLLC) requirements are included in this WI.

[0003] Third, enhancements to multi-beam operation will be provided, primarily for FR2 operation. Specifically, studies will be conducted, and if necessary, enhancements will be made to the uplink (UL) and / or downlink (DL) transmit beam selection(s) specified in Rel-15 to reduce latency and overhead. UL transmit beam selection for multi-plane operation will be specified to facilitate plane-specific beam selection. Beam fault recovery for secondary cells (SCells) will be based on the beam fault recovery specifications specified in Rel-15. Measurement and reporting of L1-Reference Signal Received Quality (RSRQ) or L1-Signal-to-Interference-plus-Noise Ratio (SINR) will be specified. Fourth, studies and summaries will be conducted at the first RAN1 meeting after the start of WI, and if necessary, enhancements will be made to CSI-RS and demodulation reference signal, DMRS (both downlink and uplink) to reduce peak-to-average power ratio (PAPR) of one or more layers (the resource element (RE) mapping specified in Rel-15 remains unchanged). Summary of the Invention

[0004] In general, the exemplary embodiments of this disclosure provide a scheme for configuring a phase tracking reference signal (PT-RS).

[0005] In a first aspect, a method for communication is provided. The method includes receiving, at a terminal device, control information from a network device indicating resource group and Transmission Configuration Indicator (TCI) states for communication between the terminal device and the network device. The method further includes determining resource subgroups associated with corresponding TCI states, each resource subgroup being a portion of a resource group in the frequency domain. The method also includes determining a PT-RS mapping to the resource subgroups.

[0006] In a second aspect, a method for communication is provided. The method includes sending control information from a network device to a terminal device, indicating resource groups and TCI states for communication between the terminal device and the network device. The method also includes determining resource subgroups associated with corresponding TCI states, each resource subgroup being a portion of a resource group in the frequency domain. The method further includes determining a PT-RS mapping to the resource subgroups.

[0007] In a third aspect, a terminal device is provided. The terminal device includes a processor and a memory storing instructions. The memory and instructions are configured together with the processor to cause the terminal device to perform the method according to the first aspect.

[0008] In a fourth aspect, a network device is provided. The network device includes a processor and a memory storing instructions. The memory and instructions are configured together with the processor to cause the network device to perform the method according to the second aspect.

[0009] In a fifth aspect, a computer-readable medium having instructions stored thereon is provided. When executed on at least one processor of a device, the instructions cause the device to perform the method according to the first or second aspect.

[0010] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0011] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of some embodiments of the present disclosure in the accompanying drawings, wherein:

[0012] Figure 1 This is a schematic diagram of a communication environment that can be implemented in some embodiments of this disclosure;

[0013] Figure 2 An example communication process between a network device and a terminal device according to some embodiments of the present disclosure is shown;

[0014] Figure 3An example resource group is shown, which is divided into two resource subgroups associated with two TCI states in the frequency domain according to some embodiments of the present disclosure;

[0015] Figure 4 A flowchart of an example method according to some embodiments of this disclosure is shown;

[0016] Figure 5 A flowchart of another example method according to some embodiments of this disclosure is shown; and

[0017] Figure 6 This is a simplified block diagram of an apparatus suitable for implementing some embodiments of the present disclosure.

[0018] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0019] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art to understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. The disclosure described herein can be implemented in various ways other than those described below.

[0020] In the following description and claims, unless otherwise defined, 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 pertains.

[0021] As used herein, the terms “network equipment” or “base station” (BS) refer to equipment capable of providing or hosting a cell or coverage area that terminal equipment can communicate with. Examples of network equipment include, but are not limited to, NodeB (or NB), evolved NodeB (eNodeB or eNB), next-generation NodeB (gNB), infrastructure equipment for V2X (vehicle-to-everything) communication, transmit / receive points (TRPs), remote radio units (RRUs), radio headers (RHs), remote radio headers (RRHs), low-power nodes (such as femtonodes, piconodes), etc.

[0022] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), in-vehicle terminal equipment, pedestrian equipment, roadside units, personal computers, desktop computers, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback devices, or Internet devices capable of enabling wireless or wired Internet access and browsing. For purposes of discussion, some embodiments will be described below with reference to the UE as an example of a terminal device, and the terms "terminal device" and "user equipment" (UE) may be used interchangeably in the context of this disclosure.

[0023] In one embodiment, the terminal device may be connected to a first network device and a second network device. One of the first and second network devices may be a master node, and the other may be a slave node. The first and second network devices may use different Radio Access Technologies (RATs). In one embodiment, the first network device may be a first RAT device and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB and the second RAT device is a gNB. Information related to different RATs may be sent from at least one of the first and second network devices to the terminal device. In one embodiment, first information may be sent from the first network device to the terminal device, and second information may be sent from the second network device directly or via the first network device to the terminal device. In one embodiment, information related to the configuration of the terminal device configured by the second network device may be sent from the second network device via the first network device. Information related to the reconfiguration of the terminal device configured by the second network device may be sent from the second network device directly or via the first network device to the terminal device.

[0024] As used herein, the terms “transmit / receive point,” “transmit / receive point,” or “transmit and receive point” generally refer to a station communicating with user equipment. However, transmit and receive points can be referred to by different terms such as base station (BS), cell, Node B, evolved Node B (eNB), next-generation Node B (gNB), transmit / receive point (TRP), sector, site, base transceiver system (BTS), access point (AP), relay node (RN), remote radio header (RRH), radio unit (RU), antenna, etc.

[0025] That is, in the context of this disclosure, a transmission and reception point, a base station (BS), or a cell can be interpreted as an inclusive concept indicating a portion of an area or function covered by the Base Station Controller (BSC) in Code Division Multiple Access (CDMA), a Node B in WCDMA, an eNB or sector (site) in LTE, or a gNB or TRP in NR. Therefore, the concepts of transmission and reception point, base station (BS), and / or cell can include various coverage areas, such as megacells, macrocells, microcells, picocells, femtocells, etc. Furthermore, such concepts can include the communication range of a relay node (RN), a remote radio header (RRH), or a radio unit (RU).

[0026] In the context of this disclosure, "user equipment" and "transmit / receive point" can refer to two transmission / receive entities, and are used in an inclusive sense to embody the technologies and technical concepts disclosed herein, and are not limited to specific terms or words. Furthermore, "user equipment" and "transmit / receive point" can refer to uplink or downlink transmission / receive entities, and are used in an inclusive sense to embody the technologies and technical concepts disclosed in connection with this embodiment, and are not limited to specific terms or words. In this document, uplink (UL) transmission / receive refers to a scheme in which data is transmitted from a user equipment to a base station. Alternatively, downlink (DL) transmission / receive refers to a scheme in which data is transmitted from a base station to a user equipment.

[0027] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block,” or “sidelink resource” can refer to any resource used to perform communication (e.g., communication between a terminal device and a network device), such as resources in the time domain, resources in the frequency domain, resources in the spatial domain, resources in the code domain, or any other resource capable of enabling communication. In the following description, resources in both the frequency and time domains will be used as examples of transmission resources to illustrate some embodiments of this disclosure. Note that embodiments of this disclosure are equally applicable to other resources in other domains.

[0028] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context explicitly indicates otherwise. The term “comprising” and its variations should be interpreted as open-ended terms, meaning “including but not limited to.” The term “based on” should be interpreted as “at least partially based on.” The terms “one embodiment” and “embodiment” should be interpreted as “at least one embodiment.” The term “another embodiment” should be interpreted as “at least one other embodiment.” The terms “first,” “second,” etc., can refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0029] In some examples, values, processes, or appliances are referred to as “best,” “lowest,” “highest,” “minimum,” “maximum,” etc. It should be understood that such descriptions are intended to indicate that a choice can be made among many functional alternatives used, and that such a choice does not need to be better, smaller, higher, or otherwise preferred than other choices.

[0030] Figure 1 This is a schematic diagram of a communication environment 100 in which some embodiments of this disclosure may be implemented. The communication environment 100 includes a network device 110 and terminal devices 120 served by the network device 110. The service area of ​​the network device 110 may be referred to as cell 102. In the communication environment 100, the network device 110 can send data and control information to the terminal device 120, and the terminal device 120 can also send data and control information to the network device 110. The communication link from the network device 110 to the terminal device 120 is referred to as a downlink (DL) or forward link, while the communication link from the terminal device 120 to the network device 110 is referred to as an uplink (UL) or reverse link.

[0031] like Figure 1 As shown, network device 110 is coupled to two TRPs 131 and 132 and can communicate with terminal device 120 via these two TRPs 131 and 132. For example, in repeated transmissions between network 110 and terminal device 120, such as in multi-TRP URLLC transmissions, network device 110 can send or receive the same data 140 via TRPs 131 and 132. As used herein, data 140 can include any data that can be transmitted between network device 110 and terminal device 120, including user plane data, control plane data, etc. For example, data 140 can be a transport block (TB) or a packet. Hereinafter, TRP 131 may also be referred to as the first TRP, and TRP 132 may also be referred to as the second TRP. The first and second TRPs 131 and 132 can be included in the same serving cell (e.g., as shown in the image). Figure 1 The cell shown is 102) or a different service cell provided by network device 110.

[0032] In some embodiments, the first and second TRPs 131 and 132 may be explicitly associated with different higher-level configurations. For example, the index of the higher-level configuration may be associated with a predefined control resource set (CORESET), a predefined reference signal (RS), or a predefined transmission configuration indication (TCI) state used to distinguish between transmissions between different TRPs and terminal device 120. When terminal device 120 receives two DCIs from two CORESETs associated with different higher-level configurations, these two DCIs are indicated from different TRPs. Furthermore, the first and second TRPs 131 and 132 may be implicitly identified by dedicated configurations of physical channels or signals. For example, dedicated CORESETs, RSs, and TCI states associated with a TRP are used to identify transmissions from different TRPs to terminal device 120. For example, when terminal device 120 receives a DCI from a dedicated CORESET, that DCI is indicated from an associated TRP dedicated to the CORESET.

[0033] In the repeated transmission or reception via these two TRPs 131 and 132, network device 110 may use a repeating scheme from among multiple available repeating schemes. The repeating scheme may specify the transmission method in which network device 110 cooperates in using these two TRPs 131 and 132, such as the multiplexing scheme between these two TRPs 131 and 132, the corresponding resource allocation for these two TRPs 131 and 132, etc.

[0034] For example, to facilitate further downward selection of one or more schemes in 3GPP meeting RAN1#96bis, some schemes for multi-TRP-based URLLC scheduled by a single DCI are at least clarified as follows.

[0035] Option 1 (SDM): within a single time slot n (n≤N) s There are 10 TCI states with overlapping time and frequency resource allocations.

[0036] Option 1a: Each transmission timing is a layer or group of layers of the same TB, and each layer or group of layers is associated with one TCI and a set (or more) of DMRS ports. A single codeword with one RV is used across all spatial layers or groups of layers. From the UE's perspective, different coded bits are mapped to different layers or groups of layers according to the same mapping rules as in Rel-15.

[0037] Option 1b: Each transmission timing is a layer or group of layers of the same TB, and each layer or group of layers is associated with a TCI and a set (or more) of DMRS ports. A single codeword with one RV is used for each spatial layer or group of layers. The RV corresponding to each spatial layer or group of layers can be the same or different. The codeword-to-layer mapping when the total number of layers is ≤4 is for future research.

[0038] Option 1c: One transmission timing is a layer of the same TB where a DMRS port is associated with multiple TCI status indices, or a layer of the same TB where multiple DMRS ports are associated one-to-one with multiple TCI status indices.

[0039] Furthermore, it is indicated that different MCS / modulation orders can be discussed for different layers or layer groups.

[0040] Option 2 (FDM): n (n≤N) f Each TCI state has non-overlapping frequency resource allocations within a single time slot. Each non-overlapping frequency resource allocation is associated with one TCI state. The same single / multiple DMRS ports are associated with all non-overlapping frequency resource allocations.

[0041] Option 2a: A single codeword with one RV is used across the entire resource allocation. From the UE's perspective, a generic RB mapping (such as codeword-to-layer mapping in Rel-15) is applied across the entire resource allocation.

[0042] Option 2b: A single codeword with one RV is used for each non-overlapping frequency resource allocation. The RV corresponding to each non-overlapping frequency resource allocation can be the same or different.

[0043] Furthermore, it is indicated that different MCS / modulation orders can be applied to different non-overlapping frequency resource allocations. It is also indicated that details regarding the frequency resource allocation mechanism of FDM 2a / 2b, including allocation granularity and time-domain allocation, can be discussed.

[0044] Option 3 (TDM): within a single time slot n (n≤N) t1 There are 10 TCI states with non-overlapping time resource allocations. Each transmission opportunity in a TB has one TCI and one RV, with a time granularity of micro-slots. All transmission opportunities within a slot use a common MCS with the same single or multiple DMRS ports. The RV / TCI states can be the same or different within a transmission opportunity. Channel estimation interpolation across micro-slots with the same TCI index is used for future research.

[0045] Option 4 (TDM): n (n≤N) t2There are K TCI states, each with K (n≤K) distinct time slots. Each transmission opportunity in a TB has one TCI and one RV. All transmission opportunities spanning K time slots use a common MCS with the same single or multiple DMRS ports. The RV / TCI states can be the same or different within a transmission opportunity. Channel estimation interpolation across time slots with the same TCI index is used for future research. Note that URLLC schemes based on M-TRP / plane should be compared in terms of improved reliability, efficiency, and canonical impact. Note that the layer support for each TRP can be discussed.

[0046] Furthermore, before transmitting data 140 to terminal device 120, network device 110 may send control information 135 associated with the transmission of data 140. For example, control information 135 may be a transmission scheduling resource group for data 140 and indicate various transmission parameters associated with the transmission of data 140 as defined in the 3GPP specification, such as one or more TCI states, frequency domain resource allocation (FDRA), time domain resource allocation (TDRA) which may include slot offsets and start / length indicator values, demodulation reference signal (DMRS) groups, and redundancy version (RV). It should be understood that the transmission parameters indicated in control information 135 are not limited to those listed above. Embodiments of this disclosure are equally applicable to control information including any transmission parameters.

[0047] In some embodiments, control information 135 may be a DCI defined in the 3GPP specification, which can dynamically (i.e., over a relatively short time scale) indicate various transmission parameters. In some other embodiments, control information 135 may be a Radio Resource Control (RRC) message or a Media Access Control (MAC) Control Element (CE) message, which can semi-statically (i.e., over a relatively long time scale) indicate various transmission parameters.

[0048] Although some embodiments of this disclosure are described with reference to first and second TRPs 131 and 132 within the same serving cell provided by network device 110, these embodiments are for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not imply any limitation on the scope of this disclosure. It should be understood that the embodiments of this disclosure described herein can be implemented in various ways other than those described below.

[0049] It should be understood that Figure 1The number of network devices, terminal devices, and TRPs shown are for illustrative purposes only and do not imply any limitation. In practice, the communication environment 100 may include any suitable number of network devices, any suitable number of terminal devices, and any suitable number of TRPs suitable for implementing the embodiments of this disclosure. In other words, the embodiments of this disclosure can also be applied to scenarios where terminal devices communicate with more than one network device or with network devices coupled to two or more TRPs.

[0050] The communications in Communication Environment 100 can conform to any suitable standard, including but not limited to Global System for Mobile Communications (GSM), Extended Coverage Global Mobile Internet of Things System (EC GSM IoT), Long Term Evolution (LTE), LTE Evolution, LTE-A, Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM Edge Radio Access Network (GERAN), etc. Furthermore, communications can be performed according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, and fifth-generation (5G) communication protocols.

[0051] As specified in the 3GPP specification, if the UE is configured with the higher-layer parameter tci-PresentInDCI set to "Enabled" for CORESET to schedule the Physical Downlink Shared Channel (PDSCH), the UE assumes that the TCI field exists in the DCI format 1_1 of the PDCCH transmitted on the CORESET. If tci-PresentInDCI is not configured for CORESET to schedule the PDSCH or is scheduled via DCI format 1_0, then in order to determine the quasi-co-addressable PDSCH antenna port, the UE assumes that the TCI state for the PDSCH is the same as the TCI state of the CORESET applied for PDCCH transmission.

[0052] If tci-PresentInDCI is set to "Enabled", when scheduling PDSCH via DCI format 1_1, the UE should use TCI-State to determine the quasi-co-address of the PDSCH antenna port based on the value of the "Transmission Configuration Indication" field in the PDCCH detected using DCI. If the time offset between the reception of DL DCI and the corresponding PDSCH is equal to or greater than the threshold Threshold-Sched-Offset (where the threshold is based on the reported UE capability), the UE can assume that the DM-RS port of the serving cell's PDSCH is quasi-co-addressed with respect to (multiple) RSs in the TCI state with respect to (multiple) quasi-co-address (QCL) type parameters given by the indicated TCI state.

[0053] In the current specification, the downlink control information (DCI) may contain a TCI field, and the terminal device may be configured with a TCI state. The TCI state may include parameters for configuring the QCL relationship between one or two downlink reference signals and the DMRS ports of the PDSCH. The terminal device may be configured with a DMRS type and / or a maximum number / length and / or number of codewords for DMRS. If the terminal device is configured with a given DMRS type, a given maximum number / length of DMRS, and a given number of codewords, a corresponding table exists indicating at least one of the following: antenna port, number of DMRS CDM groups without data, number of DMRS symbols loaded at the front end, number of DMRS ports, and at least one of the indices of the DMRS ports.

[0054] In some embodiments, if more than one (e.g., two) DMRS groups are configured for a terminal device, one or two TCI states may exist in one DCI of that terminal device. In some embodiments, the number of TCI states in a DCI depends on the QCL relationship between the DMRS ports from the two DMRS groups. For example, if the DMRS ports from the two DMRS groups are not mutually QCLed with respect to at least one of QCL-Type A, QCL-Type B, QCL-Type C, and QCL-Type D, the number of TCI states in a DCI may be 2. As another example, if the DMRS ports from the two DMRS groups are mutually QCLed with respect to {Doppler shift, Doppler spread, average delay, average spread, spatial Rx parameter} and / or average gain, the number of TCI states in a DCI may be 1.

[0055] In some embodiments, the number of TCI states in a DCI depends on the number of DMRS ports. For example, if the number of DMRS ports is 2, the number of TCI states in a DCI can be 2. For example, two TCI states in a DCI can be the same or different from each other. As another example, if the number of DMRS ports is 1, the number of TCI states in a DCI can be 1.

[0056] Typically, network devices (e.g., eNBs or gNBs) can transmit downlink reference signals (RS), such as demodulation reference signals (DMRS), channel state information reference signals (CSI-RS), sounding reference signals (SRS), phase tracking reference signals (PT-RS), fine time-frequency tracking reference signals (TRS), etc. Terminal devices in the system (e.g., user equipment) can receive downlink RSs on allocated resources. Terminal devices can also transmit uplink RSs to the network devices on corresponding allocated resources. To indicate the allocated resources for the RSs and / or other necessary information, the network devices can send RS configuration to the terminal devices before the RSs are transmitted.

[0057] In other words, in addition to normal data communication, network device 110 can transmit downlink reference signals (RS) to one or more terminal devices 120 in the downlink (DL) via broadcast, multicast, and / or unicast. Similarly, one or more terminal devices 120 can transmit RS to network device 110 in the uplink (UL). Examples of RS may include, but are not limited to, downlink or uplink demodulation reference signals (DMRS), channel state information reference signals (CSI-RS), sounding reference signals (SRS), phase tracking reference signals (PT-RS), fine time-frequency tracking reference signals (TRS), etc.

[0058] As used herein, RS is a signal sequence (also referred to as an "RS sequence") known to both network device 110 and terminal device 120. For example, network device 110 can generate and transmit RS sequences based on specific rules, and terminal device 120 can derive RS sequences based on the same rules. In the transmission of downlink and uplink RS, network device 110 can allocate corresponding resources (also referred to as "RS resources") and / or specify which RS sequence will be transmitted.

[0059] In some scenarios, both network device 110 and terminal device 120 are equipped with multiple antenna ports (or antenna elements) and can transmit a specified RS sequence using these antenna ports (antenna elements). A set of RS resources associated with the multiple RS ports is also specified. An RS port can be referred to as part or all of the RS sequence as a specific mapping to one or more resource elements (REs) of a resource region allocated for RS transmission in the time domain, frequency domain, and / or code domain. Such resource allocation information can be indicated to terminal device 120 before RS transmission.

[0060] In NR, PT-RS can be introduced to compensate for phase noise. Phase noise typically increases with carrier frequency, so PT-RS can be used to eliminate phase noise in wireless networks operating at high frequencies. Currently, PT-RS mapping patterns in the time and frequency domains have been studied, but detailed patterns have not yet been fully designed. For example, it has been agreed that the density of PT-RS in the time domain (also known as the "time density" of PT-RS) is associated with the modulation and coding scheme (MCS) being scheduled, while the density of PT-RS in the frequency domain (also known as the "frequency density" of PT-RS) and the group pattern of PT-RS ports (such as the number of PT-RS groups and the number of samples per PT-RS group) are associated with the scheduled BWs (such as the number of scheduled RBs).

[0061] For OFDM-based systems, the PT-RS time density can be one of the following: zero (i.e., PT-RS does not exist), every 4 symbols (i.e., 1 / 4), every 2 symbols (i.e., 1 / 2), or every symbol (i.e., 1). The PT-RS time density is associated with the scheduling MCS. For example, Table 5.1.6.3-1 of 3GPP TS 38.214 shows the relationship between the scheduling MCS and the PT-RS time density. In Table 5.1.6.3-1, ptrs-MCS1 to ptrs-MCS4 each represent the MCS threshold that needs to be configured by the network device.

[0062] Table 5.1.6.3-1: PT-RS time density of functions based on scheduling MCS

[0063] Scheduling MCS <![CDATA[Time density (L PT-RS )]]> <![CDATA[I MCS <ptrs-MCS1]]> PT-RS does not exist <![CDATA[ptrs-MCS1≤I MCS <ptrs-MCS2]]> 4 <![CDATA[ptrs-MCS2≤I MCS <ptrs-MCS3]]> 2 <![CDATA[ptrs-MCS3≤I MCS <ptrs-MCS4]]> 1

[0064] Similarly, the frequency density of PT-RS can be one of the following: zero (i.e., no PT-RS), per RB (i.e., 1), per 2 RBs (i.e., 1 / 2), or per 4 RBs (i.e., 1 / 4). The frequency density of PT-RS is associated with the scheduling bandwidth (i.e., the number of scheduling RBs). For example, Table 5.1.6.3-2 of 3GPP TS 38.214 shows the scheduling bandwidth (denoted as N) as follows. RBThe correlation between N and the frequency density of PT-RS. In Table 5.1.6.3-2, N... RB0 and N RB1 Each represents the bandwidth threshold that needs to be configured by the network device.

[0065] Table 5.1.6.3-2: Frequency density of PT-RS based on scheduling PRB function

[0066] Schedule PRB <![CDATA[Frequency density (K PT-RS )]]> <![CDATA[N RB <N RB0 ]]> PT-RS does not exist <![CDATA[N RB0 ≤N RB <N RB1 ]]> 2 <![CDATA[N RB1 ≤N RB ]]> 4

[0067] The M-TRP URLLC schemes 2a and 2b based on a single DCI have been agreed to support the following design: Comb-like frequency resource allocation between / within TRPs. For Wideband Precoding Resource Block Groups (PRGs), the first [N_RB / 2] RBs are allocated to TCI state 1 (also known as TCI state A), and the remaining [N_RB / 2] RBs are allocated to TCI state 2 (also known as TCI state B). For PRG sizes of 2 or 4, even-numbered PRGs within the allocated FDRAs are allocated to TCI state 1, and odd-numbered PRGs within the allocated FDRAs are allocated to TCI state 2.

[0068] Regarding PRG, as defined in the 3GPP specification, the UE can assume a precoding granularity P′. BWPi It is a contiguous resource block in the frequency domain. P′ BWPi It can be equal to one of the values ​​in {2, 4, broadband}. If P′ BWPi If identified as "broadband," then non-continuous PRB scheduling of the UE is not expected, and the UE can assume that the same precoding is applied to the allocated resources. If P′ BWPi If determined to be one of the values ​​in {2,4}, then the precoded resource block group (PRG) is represented by P′. BWPi Each consecutive PRB divides the bandwidth into i portions. The actual number of consecutive PRBs in each PRG can be one or more.

[0069] Given the above, for URLLC schemes 2a / 2b, if the total number of PRBs is N, then based on convention, a portion of the PRBs is allocated to each TCI state. However, how to determine the specific configuration or mapping of PT-RS for each TCI state is unclear; for example, how to obtain the PT-RS density for PT-RS mapping and the PRBs are not designed.

[0070] To address the aforementioned technical problems and other potential technical issues in conventional solutions, embodiments of this disclosure provide a scheme for configuring PT-RS (especially PT-RS presence / density / mode / offset) based on multi-TRP transport. In some embodiments, for schemes 2a / 2b based on multi-TRP transport, PT-RS presence / density / mode / offset is determined independently / separately in each part of the scheduled resource. In some other embodiments, PT-RS presence / density is the same for two or more parts of the scheduled resource and is determined based on the largest of the two or more parts. In some further embodiments, PT-RS offset is the same for two or more parts and is determined based on the smallest of the two or more parts. Embodiments of this disclosure provide practical details on how to determine PT-RS presence / density / mode / offset if a group of scheduled resources is shared by multiple TCI states (especially in the case of schemes 2a / 2b). The principles and implementation of the invention will be described in detail below.

[0071] Figure 2 An example communication process 200 between a network device 110 and a terminal device 120 according to some embodiments of the present disclosure is illustrated. For discussion purposes, the communication process 200 will be referred to... Figure 1 This is used to describe the process. However, it should be understood that the communication process 200 can be equally applied to any other communication scenario in which network devices and terminal devices communicate with each other.

[0072] like Figure 2 As shown, network device 110 sends control information 205 135 to terminal device 120. Therefore, terminal device 120 receives control information 205 135 from network device 110. In some embodiments, control information 135 may be downlink control information (DCI) as defined in the 3GPP specification. In some other embodiments, control information 135 may include any existing or future signaling as defined in the 3GPP specification or other standard specifications. Control information 135 may indicate resource groups and more than one TCI state for communication (e.g., transmission of data 140) between terminal device 120 and network device 110.

[0073] In some embodiments, a resource group may include multiple physical resource blocks (PRBs) as defined in the 3GPP specification. However, in some other embodiments, a resource group may be any other form as defined in the 3GPP specification or other standard specifications. Furthermore, in some embodiments, a TCI state may include up to eight TCI states as defined in the 3GPP specification. However, in some other embodiments, a TCI state may include any existing or future transport configuration indication state having functionality similar to or the same as that defined in the 3GPP specification. Examples of resource groups and TCI states will be referenced below. Figure 3 To describe.

[0074] Figure 3 An example resource group 300 is shown, according to some embodiments of the present disclosure, which is divided in the frequency domain into two resource subgroups 310 and 320 associated with two TCI states (TCI state A and TCI state B). Figure 3 In the diagram, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. As shown, the control information 135 sent by network device 110 to terminal device 120 can indicate resource group 300, such as the time and frequency location of resource group 300, and the control information 135 can also indicate two of the eight TCI states defined in the 3GPP specification (e.g., TCI state A and TCI state B). Resource group 300, as well as TCI states A and B, will be used for communication between terminal device 120 and network device 110 (e.g., data 140 transmission).

[0075] Return to reference Figure 2 Network device 110 determines resource subgroups associated with corresponding TCI states, and each resource subgroup is a portion of a resource group in the frequency domain. Similarly, terminal device 120 also determines resource subgroups associated with corresponding TCI states. For example, refer to... Figure 3 Network device 110 or terminal device 120 can identify resource subgroup 310 associated with TCI state A and resource subgroup 320 associated with TCI state B. It is evident that resource subgroups 310 and 320 are two parts of resource group 300 in the frequency domain.

[0076] It should be understood that, such as Figure 3 The number of TCI states, the broadband PRG configuration of resource group 300, and the specific division method of resource group 300 shown are for illustrative purposes only and do not imply any limitation. In other embodiments, any suitable number of TCI states indicated in control information 135 may exist, resource group 300 may have any suitable PRG configuration, and resource group 300 may be divided into any number of subgroups associated with the corresponding TCI states in any suitable manner.

[0077] Return to reference Figure 2 Network device 110 determines the mapping of 220 PT-RS to resource subgroups, for example, to determine whether the PT-RS will be sent to or received from terminal device 120 for the corresponding resource subgroup, and if the PT-RS will be sent or received, which resources in the resource subgroup will be used. Similarly, terminal device 120 also determines the mapping of 225 PT-RS to resource subgroups. For example, refer to... Figure 3 Network device 110 or terminal device 120 can determine how the PT-RS will be mapped to resources in resource subgroups 310 and 320, respectively. Various possible options exist for mapping the PT-RS to resources in the resource subgroups, which will be described below.

[0078] In the first option, the PT-RS mapping in each resource subgroup can be determined independently. For example, the PT-RS mapping in each resource subgroup can be based on resources (such as PRBs) for each TCI state. Using this straightforward option, the most suitable mapping can be configured for each resource subgroup (i.e., for each TCI state). Specifically, for schemes 2a / 2b, the scheduled PRB for PDSCH is divided into two parts, and the PT-RS mapping for each part is independent. In other words, the PT-RS presence / mode / mapping is for each part of the scheduled PRB.

[0079] More specifically, if the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI, and if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point, then the PT-RS presence / density / mapping is based on the scheduling PRB assigned / associated to each TCI state. That is, network device 110 or terminal device 120 can determine the corresponding values ​​of mapping parameters (such as PT-RS frequency density, PT-RS resource offset, etc.) for the resource subgroup, respectively. For example, refer to Figure 3 The mapping from PT-RS to resources can be determined separately for resource subgroups 310 and 320. In particular, for schemes 2a / 2b, the PT-RS on the two parts of the scheduling PRB assigned / associated with the two TCI states are independent.

[0080] In some embodiments, a TCI code point may have two TCI states, such as TCI state A and TCI state B. As an example of a first option, the PT-RS frequency density can be configured independently for each resource subgroup. Thus, the most suitable PT-RS frequency density can be determined for each resource subgroup. For this purpose, network device 110 or terminal device 120 can determine the PT-RS frequency density for each resource subgroup based on the number of resources in that subgroup. For example, as... Figure 3 As shown, it is assumed that the number of resources (e.g., PRBs) (resource subgroup 310) assigned / associated with TCI state A is N. RB_a And the number of resources (e.g., PRBs) (resource subgroup 320) assigned / associated with TCI state B is N. RB_b For example, the total number of resource blocks or scheduling bandwidth of a PDSCH scheduled by a single DCI can be N. RB For example, N RB_a +N RB_b =N RB .

[0081] Therefore, the frequency density of PT-RS in resource subgroup 310 can be based on N RB_a It is determined that the frequency density of PT-RS in resource subgroup 320 can be based on N. RB_b Determined. For example, based on Table 5.1.6.3-2 as defined in 3GPP TS 38.214, the PT-RS frequency density in resource subgroup 310 can be determined by adjusting the parameter "N". RB Replace "N" RB_a The PT-RS frequency density in resource subgroup 320 can be determined by adjusting the parameter "N". RB Replace "N" RB_b "To decide."

[0082] As another example of the first option, the PT-RS resource offset can be configured independently for each resource subgroup. In this way, the most suitable PT-RS resource offset can be determined for each resource subgroup. For this purpose, network device 110 or terminal device 120 can determine the offset between the starting resource for mapping and the resource with the lowest frequency in the resource subgroup, based on the resource quantity, frequency density, and the terminal device's identifier, for each resource subgroup. For example, refer to... Figure 3 The PT-RS resource offset in resource subgroup 310 can be based on N RB_a It is determined that the PT-RS resource offset in resource subgroup 320 can be based on N. RB_b Sure.

[0083] More specifically, based on the following formula (1) defined in Section 7.4.1.2.2 of 3GPP TS 38.211, the PT-RS resource offset in resource subgroup 310 can be determined by adjusting the parameter "N". RB Replace "N" RB_a The PT-RS resource offset in resource subgroup 320 can be determined by adjusting the parameter "N". RB Replace "N" RB_b The other parameters in formula (1) are defined in the 3GPP specification.

[0084]

[0085] In some embodiments, using the first option discussed above, section 5.1.6.3 of the current technical specification 3GPP TS 38.214 can be updated as follows.

[0086] 5.1.6.3 PT-RS Reception Process

[0087] If the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI (and / or if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point), the UE should assume the presence and mode of the PT-RS antenna port according to each part of the scheduling PRB assigned / associated to each TCI state.

[0088] If the UE is configured with the higher-layer parameter phaseTrackingRS in DMRS-DownlinkConfig, then

[0089] The higher-layer parameters timeDensity and frequencyDensity in -PTRS-DownlinkConfig are shown in Tables 5.1.6.3-1 and 5.1.6.3-2, respectively, indicating the threshold ptrs-MCS. i (i = 1, 2, 3) and N RB,i (i = 0, 1).

[0090] - If one or both of the additional higher-layer parameters timeDensity and frequencyDensity are configured, and RNTI equals MCS-C-RNTI, C-RNTI, or CS-RNTI, then the UE should assume the presence and mode of the PT-RS antenna port as a function of the scheduling PRB associated with a TCI state in the corresponding codeword, as shown in Tables 5.1.6.3-1 and 5.1.6.3-2.

[0091] - If the higher-layer parameter timeDensity given by PTRS-DownlinkConfig is not configured, the UE should assume L PT-RS =1.

[0092] - If the higher-layer parameter frequencyDensity given by PTRS-DownlinkConfig is not configured, the UE should assume K PT-RS =2.

[0093] Otherwise, if the additional higher-layer parameters timeDensity and frequencyDensity are not configured and RNTI equals MCS-C-RNTI, C-RNTI, or CS-RNTI, then the UE in L PT-RS =1, K PT-RS When the value is 2, the PT-RS should be assumed to exist, and the UE should assume that the PT-RS does not exist in the following cases:

[0094] - The scheduling MCS from Table 5.1.3.1-1 is less than 10, or

[0095] - The scheduling MCS from Table 5.1.3.1-2 is less than 5, or

[0096] - The scheduling MCS from Table 5.1.3.1-3 is less than 15, or

[0097] -N RB Less than 3, (and if the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI, then N) RB It is a scheduled PRB that is assigned / associated with a TCI state, otherwise N RB (is scheduling bandwidth), or

[0098] Otherwise, if RNTI equals RA-RNTI, SI-RNTI, or P-RNTI, the UE should assume that PT-RS does not exist. Table 5.1.6.3-1: PT-RS temporal density based on the function of scheduling MCS

[0099] Scheduling MCS <![CDATA[Time density (L PT-RS )]]> <![CDATA[I MCS <ptrs-MCS1]]> PT-RS does not exist <![CDATA[ptrs-MCS1≤I MCS <ptrs-MCS2]]> 4 <![CDATA[ptrs-MCS2≤I MCS <ptrs-MCS3]]> 2 <![CDATA[ptrs-MCS3≤I MCS <ptrs-MCS4]]> 1

[0100] Table 5.1.6.3-2: Frequency density of PT-RS based on scheduling PRB function

[0101] Schedule PRBs <![CDATA[Frequency density (K PT-RS )]]> <![CDATA[N RB <N RB0 ]]> PT-RS does not exist <![CDATA[N RB0 ≤N RB <N RB1 ]]> 2 <![CDATA[N RB1 ≤N RB ]]> 4

[0102] In some embodiments, using the first option discussed above, section 5.1.6.3 of the current technical specification 3GPP TS 38.214 can be updated as follows.

[0103] 5.1.6.3 PT-RS Reception Process

[0104] If the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI (and / or if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point), the UE should assume the presence and mode of the PT-RS antenna port according to each part of the scheduling PRB assigned / associated to each TCI state.

[0105] If the UE is configured with a higher-level parameter phaseTrackingRS in DMRS-DownlinkConfig

[0106] The higher-level parameters timeDensity and frequencyDensity in -PTRS-DownlinkConfig are shown in Tables 5.1.6.3-1 and 5.1.6.3-2, respectively, indicating the threshold ptrs-MCS. i (i = 1, 2, 3) and N RB,i (i = 0, 1).

[0107] - If one or both of the additional higher-layer parameters timeDensity and frequencyDensity are configured, and RNTI equals MCS-C-RNTI, C-RNTI, or CS-RNTI, then the UE should assume the presence and mode of the PT-RS antenna port as shown in Tables 5.1.6.3-1 and 5.1.6.3-2, corresponding to the scheduling MCS and N of the corresponding codewords. RB The function, and if the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI, (and / or if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point, otherwise N RB If N is the scheduling bandwidth, then RB It corresponds to the scheduled PRB that is allocated / associated with a TCI state in the bandwidth portion.

[0108] - If the higher-layer parameter timeDensity given by PTRS-DownlinkConfig is not configured, the UE should assume L PT-RS =1.

[0109] - If the higher-layer parameter frequencyDensity given by PTRS-DownlinkConfig is not configured, the UE should assume K PT-RS =2.

[0110] Otherwise, if the additional higher-layer parameters timeDensity and frequencyDensity are not configured and RNTI equals MCS-C-RNTI, C-RNTI, or CS-RNTI, then the UE in L PT-RS =1, K PT-RS When = 2, PT-RS should be assumed to exist, and PT-RS should be assumed to not exist for the UE in the following cases:

[0111] - The scheduling MCS from Table 5.1.3.1-1 is less than 10, or

[0112] - The scheduling MCS from Table 5.1.3.1-2 is less than 5, or

[0113] - The scheduling MCS from Table 5.1.3.1-3 is less than 15, or

[0114] - NRB is less than 3 (and if the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI, then the NRB is the scheduling PRB assigned / associated with a TCI state; otherwise, the NRB is the scheduling bandwidth), or

[0115] Otherwise, if RNTI equals RA-RNTI, SI-RNTI, or P-RNTI, the UE should assume that PT-RS does not exist.

[0116] Table 5.1.6.3-1: PT-RS time density of functions based on scheduling MCS

[0117] Scheduling MCS <![CDATA[Time density (L PT-RS )]]> <![CDATA[I MCS <ptrs-MCS1]]> PT-RS does not exist <![CDATA[ptrs-MCS1≤I MCS <ptrs-MCS2]]> 4 <![CDATA[ptrs-MCS2≤I MCS <ptrs-MCS3]]> 2 <![CDATA[ptrs-MCS3≤I MCS <ptrs-MCS4]]> 1

[0118] Table 5.1.6.3-2: Frequency density of PT-RS based on scheduling PRB function

[0119] Schedule PRBs <![CDATA[Frequency density (K PT-RS )]]> <![CDATA[N RB <N RB0 ]]> PT-RS does not exist <![CDATA[N RB0 ≤N RB <N RB1 ]]> 2 <![CDATA[N RB1 ≤N RB ]]> 4

[0120] In some embodiments, using the first option discussed above, section 7.4.1.2.2 of the current technical specification 3GPP TS 38.211 can be updated as follows.

[0121] 7.4.1.2.2 Mapping to physical resources

[0122] If the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI (and / or if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point), the UE shall assume that the phase tracking reference signal exists only in the resource block assigned / associated to each TCI state for the PDSCH; otherwise, the UE shall assume that the phase tracking reference signal exists only in the resource block used for the PDSCH, and only if the procedure in [6, TS38.214] indicates that the phase tracking reference signal is being used.

[0123] The UE should assume that the phase tracking reference signal exists only in the resource block that is assigned / associated with each TCI state for the PDSCH, and only if the procedure in [6,TS 38.214] indicates that the phase tracking reference signal is being used.

[0124] If present, then the UE should assume that PDSCH PT-RS passes through factor β. PT-RS，i Scaling to conform to the transmission power specified in Clause 4.1 of [6, TS 38.214], and mapping to resource elements (k, l) according to the following. p，μ

[0125]

[0126] When all of the following conditions are met

[0127] -l within OFDM symbols allocated for PDSCH transmission

[0128] -(k, l) p，μ Resource elements are not used for DM-RS, non-zero power CSI-RS (except those configured for mobility measurement or having a resourceType configured as "non-periodic" in the corresponding CSI ResourceConfig), zero power CSI-RS, SS / PBCH blocks, detected PDCCHs according to Clause 5.1.4.1 of [6, TS 38.214], or declared as "unavailable" according to Clause 5.1.4 of [6, TS 38.214].

[0129] The time index group l, relative to the initial definition of PDSCH allocation, is defined as follows:

[0130] 1. Set i = 0 and l ref =0

[0131] 2. According to clause 7.4.1.1.2, if the interval max(l) ref+(i-1)L PT-RS +1, l ref ), ..., l ref +i L PT-RS Any symbols that overlap with those used for DM-RS

[0132] - Set i = 1

[0133] - In the case of single-symbol DM-RS, l ref Set as the symbol index of the DM-RS symbol, and in the case of a dual-symbol DM-RS, set as the symbol index of the second DM-RS symbol.

[0134] -As long as l ref +iL PT-RS Within the PDSCH allocation, repeat from step 2.

[0135] 3. Place l ref +iL PT-RS Added to the time index group for PT-RS

[0136] 4. Increment i by one.

[0137] 5. As long as l ref +iL PT-RS Within the PDSCH allocation, repeat step 2 above.

[0138] Where L PT-RS ∈{1,2,4}.

[0139] For PT-RS mapping purposes, if the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI (and / or if the UE is configured with more than one (e.g., two, three, or four) TCI states in a TCI code point), then the resource blocks allocated for PDSCH transmissions are numbered from 0 to N, from the lowest scheduled resource block allocated / associated to each TCI state to the highest scheduled resource block. RB -1; otherwise, the resource blocks allocated for PDSCH transport are numbered from 0 to N, from the lowest scheduled resource block to the highest scheduled resource block. RB -1. The corresponding subcarriers in this resource block are numbered from 0 to 1 in ascending order, starting from the lowest frequency. The UE should assume that the PT-RS is mapped to a subcarrier by the following given conditions.

[0140]

[0141]

[0142] in

[0143] -i = 0, 1, 2, ...

[0144] -According to Clause 5.1.6.2 of [6, TS 38.214], As given in Table 7.4.1.2.2-1 for the DM-RS port associated with the PT-RS port. If the higher-level parameter resourceElementOffset in the PTRS-DownlinkConfig IE is not configured, the column corresponding to "00" should be used.

[0145] -n RNTI It is the RNTI associated with the DCI of the scheduled transmission.

[0146] - If the UE is configured with M-TRP URLLC schemes 2a and 2b based on a single DCI (and / or if the UE is configured with more than one (or two) TCI states in a TCI code point), then N RB It is the scheduled PRB that is assigned / associated with a TCI state; otherwise, it is the number of scheduled resource blocks.

[0147] -K PT-RS ∈{2, 4} is given by [6, TS 38.214].

[0148] Table 7.4.1.2.2-1: Parameters

[0149]

[0150] As an alternative to the first option, in the second option for mapping PT-RS to resource subgroups, common values ​​for the mapping parameters can be configured for all resource subgroups based on the number of resources in the respective resource subgroup. For example, the frequency density of PT-RS, PT-RS resource offset, etc., in all resource subgroups can be configured to be the same. In particular, for schemes 2a / 2b, the PT-RS on both parts of the scheduling PRB assigned / associated with the two TCI states can be made as identical as possible. By utilizing common values ​​for the mapping parameters across all resource subgroups, the communication performance between network device 110 and terminal device 120 can be improved because the resource subgroups can be associated with TCI states using the same codewords for transmitting data 140.

[0151] As an example of the second option, the common value of the PT-RS frequency density can be configured for all resource subgroups. In this way, the distribution of PT-RS across different resource subgroups can be made as uniform as possible. To determine this common value of the frequency density, network device 110 or terminal device 120 can determine the number of resources in the corresponding resource subgroup. For example, refer to... Figure 3Assume that the number of resources (e.g., PRBs) (resource subgroup 310) assigned / associated with TCI state A is N. RB_a And the number of resources (e.g., PRBs) (resource subgroup 320) assigned / associated with TCI state B is N. RB_b Then, network device 110 or terminal device 120 can determine the maximum number of resources in the corresponding resource subgroup. For example, in Figure 3 In the middle, use max(N) RB_a N RB_b N represents RB_a and N RB_b The maximum value can be determined.

[0152] Next, network device 110 or terminal device 120 can determine the common frequency density of PT-RS in all resource subgroups based on the maximum number. For example, refer to Figure 3 For example, the parameter "N" in Table 5.1.6.3-2 of the 3GPP specification TS 38.214. RB "Can be replaced with max(N)" RB_a N RB_b The common frequency density of the PT-RS is determined, which can be applied to both resource subgroups 310 and 320. Therefore, for schemes 2a / 2b, the PT-RS frequency density is based on the larger of the two parts associated with the two TCI states, and the presence / density of the PT-RS is the same for both parts. By using the maximum number of resources in the resource subgroup, individual calculations of the PT-RS frequency density based on individual resource quantities can be avoided.

[0153] As another example of the second option, the common value of the PT-RS frequency density can be configured for all resource subgroups. In this way, the distribution of PT-RS across different resource subgroups can be made as uniform as possible. To determine this common value of the frequency density, network device 110 or terminal device 120 can determine the number of resources in the corresponding resource subgroup. For example, refer to... Figure 3 Assume that the number of resources (e.g., PRBs) (resource subgroup 310) assigned / associated with TCI state A is N. RB_a And the number of resources (e.g., PRBs) (resource subgroup 320) assigned / associated with TCI state B is N. RB_b Then, network device 110 or terminal device 120 can determine the minimum number of resources in the corresponding resource subgroup. For example, in Figure 3 In the middle, use min(N) RB_a N RB_b N represents RB_a and N RB_b The minimum value can be determined.

[0154] Next, network device 110 or terminal device 120 can determine the common frequency density of PT-RS in all resource subgroups based on a minimum number. For example, refer to Figure 3 For example, the parameter "N" in Table 5.1.6.3-2 of the 3GPP specification TS 38.214. RB "Can be replaced with min(N)" RB_a N RB_b The common frequency density of PT-RS is determined, which can be applied to both resource subgroups 310 and 320. Therefore, for schemes 2a / 2b, the PT-RS frequency density is based on the smaller of the two parts associated with the two TCI states, and the presence / density of PT-RS is the same for both parts. Individual calculations of the PT-RS frequency density based on individual resource quantities can be avoided by using the minimum number of resources in the resource subgroups.

[0155] As an alternative to determining the common frequency density for subgroups 310 and 320, network device 110 or terminal device 120 can determine the PT-RS frequency density in the corresponding resource subgroup based on the number of resources in the corresponding resource subgroup. For example, refer to Figure 3 Based on Table 5.1.6.3-2 as defined in 3GPP TS 38.214, the PT-RS presence / density for subgroup 310 can be determined by adjusting the parameter "N". RB Replace "N" RB_a "and was identified as d1, and the presence / density of PT-RS for subgroup 320 can be determined by adjusting the parameter "N RB Replace "N" RB_b It was identified as d2.

[0156] Then, network device 110 or terminal device 120 can determine the mapping based on the maximum frequency density. In other words, for schemes 2a / 2b, the frequency density of PT-RS is the same throughout the entire scheduling PRB for PDSCH, and the density can be determined as max(d1, d2). In some embodiments, PT-RS exists throughout the entire scheduling PRB if it exists for at least a portion. For example, if PT-RS may exist for one portion but not for another, then PT-RS should exist for both portions. By comparing individually calculated frequency densities, comparisons of the number of individual resources in resource subgroups can be avoided.

[0157] As another example of the second option, a common value for the PT-RS resource offset can be configured for resource subgroups. In this way, the distribution of PT-RS across different resource subgroups can be made as uniform as possible. To determine this common value for the PT-RS resource offset, network device 110 or terminal device 120 can determine the offset between the starting resource for mapping and the resource with the lowest frequency in the corresponding resource subgroup, based on the number of resources in the corresponding resource subgroup, the frequency density in the corresponding resource subgroup, and the identifier of the terminal device.

[0158] For example, refer to Figure 3 Assume that the number of resources (e.g., PRBs) (resource subgroup 310) assigned / associated with TCI state A is N. RB_a And the number of resources (e.g., PRBs) (resource subgroup 320) assigned / associated with TCI state B is N. RB_b The frequency density in the corresponding resource subgroup can be determined as described above based on Table 5.1.6.3-2 as defined in 3GPP TS 38.214. The identifier of terminal device 120 is known to network device 110 and terminal device 120. Then, using the above formula (1) as defined in 3GPP TS 38.211, network device 110 and terminal device 120 can determine the corresponding offsets for resource subgroups 310 and 320 (e.g., and ).

[0159] Then, network device 110 or terminal device 120 can determine the PT-RS mapping for all resource subgroups based on the minimum offset. In other words, the minimum offset can be used as a common value for the PT-RS resource offsets for all resource subgroups. For example, refer to Figure 3 For the entire scheduling PRB of PDSCH, the PT-RS resource offset is the same, and the PT-RS resource offset can be determined as follows: Thus, the common value of PT-RS resource offsets can be determined by using the existing formula (1) and comparing the offsets calculated for the corresponding resource offsets.

[0160] As an alternative to determining a common PT-RS resource offset value for a subgroup, the common PT-RS resource offset value can be based on the smallest one in the resource subgroup, i.e., the one with the smallest number of resources. For example, refer to Figure 3 Assume that the number of resources (e.g., PRBs) (resource subgroup 310) assigned / associated with TCI state A is N. RB_a And the number of resources (e.g., PRBs) (resource subgroup 320) assigned / associated with TCI state B is N. RB_b .

[0161] Then, network device 110 or terminal device 120 can determine the common value of the PT-RS resource offset based on the following formula (2). That is, for schemes 2a / 2b, the resource offsets for the two parts associated with the two TCI states are the same, and the values ​​can be determined as follows:

[0162]

[0163] In Formula (2), the other parameters are defined in 3GPP specifications (e.g., TS 38.211 and TS 38.214). Through this Formula (2), the final common value... It can be determined directly without calculating and comparing individual PT-RS resource offsets for resource subgroups.

[0164] In the third option of mapping PT-RS to resource subgroups, the mapping can be determined based on the entire resource group (i.e., scheduling bandwidth) indicated in control information 135. In other words, common values ​​for the mapping parameters can be configured for resource subgroups based on the entire resource group rather than the corresponding number of resources in the resource subgroups. For example, for repetition schemes 2a / 2b, the PT-RS configuration (i.e., PT-RS presence / density / mapping) on ​​both parts of the scheduling PRB assigned / associated with the two TCI states can be based on the entire scheduling bandwidth.

[0165] As an example of the third option, network device 110 or terminal device 120 can determine the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource group. For example, refer to Figure 3 Assume that resource group 300 has N resources. RB Then, the common value of the frequency density of PT-RS in resource subgroups 310 and 320 can be based on N. RB (For example, by using Table 5.1.6.3-2 as defined in 3GPP TS 38.214).

[0166] Then, based on the common frequency density, network device 110 or terminal device 120 can map PT-RS to resource subgroups in a sequence where one resource subgroup follows another. In other words, for schemes 2a / 2b, the PT-RS mapping order is that the PT-RS is mapped to a portion of a scheduling PRB assigned / associated with one TCI state, and then mapped to another portion of a scheduling PRB assigned / associated with other TCI states. For example, refer to... Figure 3 The PT-RS mapping is performed on resource subgroup 310, and then on resource subgroup 320. In this way, the distribution of PT-RS across different resource subgroups can be made as uniform as possible.

[0167] As another example of the third option, network device 110 or terminal device 120 can determine the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource group multiplied by the number of resource subgroups. Specifically, the PT-RS frequency density is based on Table 5.1.6.3-2 as defined in 3GPP TS 38.214, while for schemes 2a / 2b, N in the table... RB Replaced with 2 * the number of scheduled PRBs (i.e., twice the number of scheduled PRBs). For example, refer to Figure 3 Since resource group 300 is divided into two subgroups, the common value of the frequency density of PT-RS in resource subgroups 310 and 320 can be based on 2N. RB This simplifies the calculation of the common value of the frequency density of PT-RS without requiring the determination of the number of individual resources in the resource subgroup.

[0168] As another example of the third option, network device 110 or terminal device 120 can determine the initial frequency density of PT-RS based on the number of resources in the resource group. For example, refer to Figure 3 The initial frequency density of PT-RS can be determined using Table 5.1.6.3-2 as defined in 3GPP TS 38.214, based on N. RB Determine. Then, network device 110 or terminal device 120 can determine the mapping based on the initial frequency density multiplied by the number of resource subgroups and the minimum value of 1 / 2.

[0169] Specifically, for schemes 2a / 2b, the PT-RS frequency density is based on Table 5.1.6.3-2 as defined in 3GPP TS 38.214, and the final density is min(1 / 2, 2*density) or min(1, 2*density). For example, refer to Figure 3 If this value is less than 1 / 2 or 1, then the common value of the frequency density of PT-RS in resource subgroups 310 and 320 can be based on N. RB The frequency density of PT-RS is doubled to prevent it from becoming too high, thus avoiding potential interference caused by PT-RS transmission. Additionally, in this way, the calculation of the common value of the PT-RS frequency density can be simplified without determining the number of individual resources in the resource subgroup.

[0170] As another example of the third option, for schemes 2a / 2b, the PT-RS frequency density can be based on a newly designed table different from Table 5.1.6.3-2 as defined in 3GPP specification TS38.214. In this way, the PT-RS frequency density in the resource subgroup can be determined in any other suitable manner, without being limited to Table 5.1.6.3-2 as defined in the 3GPP specification. For example, the new table could be shown in Table 1 below.

[0171] Table 1. Frequency density of PT-RS based on the function of scheduling PRB

[0172] Schedule PRB <![CDATA[Frequency density (K PT-RS )]]> <![CDATA[N RB <N RB0 ]]> PT-RS does not exist <![CDATA[N RB0 ≤N RB <N RB1 ]]> 1 <![CDATA[N RB1 ≤N RB <N RB2 ]]> 2 <![CDATA[N RB3 ≤N RB ]]> 4

[0173] Return to reference Figure 2 After determining the mapping from PT-RS to resource subgroups, network device 110 and terminal device 120 can perform PT-RS transmissions between them. For example, if downlink PT-RS is transmitted between network device 110 and terminal device 120, then for each TCI state, network device 110 transmits PT-RS to terminal device 120 in the resource subgroup associated with the TCI state according to the determined mapping. On the receiving side, terminal device 120 receives the PT-RS from network device 110 in the resource subgroup associated with the TCI state according to the determined mapping.

[0174] Alternatively, if the uplink PT-RS is transmitted between network device 110 and terminal device 120, then for each TCI state, terminal device 120 transmits the PT-RS to network device 110 in the resource subgroup associated with the TCI state according to the determined mapping. On the receiving side, network device 110 receives the PT-RS from terminal device 120 in the resource subgroup associated with the TCI state according to the determined mapping.

[0175] Figure 4 A flowchart of another example method 400 according to some embodiments of the present disclosure is shown. In some embodiments, method 400 can be performed on a terminal device (such as...) Figure 1 This is implemented at the terminal device 120 shown. Alternatively or additionally, method 400 can also be implemented at... Figure 1 Implemented at other terminal devices not shown. For discussion purposes, method 400 will refer to Figure 1 It is described as being executed by terminal device 120 without loss of generality.

[0176] At box 410, the terminal device receives control information from the network device indicating resource groups and TCI states for communication between the terminal device and the network device. At box 420, the terminal device determines resource subgroups associated with the corresponding TCI states, each resource subgroup being a portion of a resource group in the frequency domain. At box 430, the terminal device determines the PT-RS mapping to the resource subgroups.

[0177] In some embodiments, determining a mapping includes: determining values ​​for mapping parameters for each resource subgroup; or determining a common value for mapping parameters for each resource subgroup.

[0178] In some embodiments, determining the mapping includes: for each of the resource subgroups, determining the frequency density of the PT-RS based on the number of resources in the resource subgroup.

[0179] In some embodiments, determining the mapping further includes: for each of the resource subgroups and based on the quantity, frequency density, and identifier of the terminal device, determining the offset between the starting resource for mapping and the resource with the lowest frequency in the resource subgroup.

[0180] In some embodiments, determining the mapping includes: determining the number of resources in the corresponding resource subgroup; determining the maximum number of resources; and determining the common frequency density of PT-RS in the resource subgroup based on the maximum number.

[0181] In some embodiments, determining the mapping includes: determining the frequency density of PT-RS in the corresponding resource subgroup based on the number of resources in the corresponding resource subgroup; and determining the mapping based on the maximum frequency density of the frequency density.

[0182] In some embodiments, determining the mapping further includes: determining an offset between the starting resource for mapping and the resource with the lowest frequency in the corresponding resource subgroup based on the quantity, frequency density, and identifier of the terminal device; and determining the mapping based on the minimum offset of the offset.

[0183] In some embodiments, determining the mapping includes: determining the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource group; and mapping PT-RS to resource subgroups in order of one resource subgroup following another, based on the common frequency density.

[0184] In some embodiments, determining the mapping includes: determining the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource subgroup multiplied by the number of resource subgroups.

[0185] In some embodiments, determining the mapping includes: determining an initial frequency density of the PT-RS based on the number of resources in the resource group; and determining the mapping based on the minimum value of the initial frequency density multiplied by the number of resource subgroups and 1 / 2.

[0186] Figure 5 A flowchart of another example method 500 according to some embodiments of the present disclosure is shown. In some embodiments, method 500 can be implemented in a network device (such as...) Figure 1 This is implemented at the network device 110 shown. Alternatively or additionally, method 500 can also be implemented at... Figure 1 Implemented at other network devices not shown. For discussion purposes, method 500 will refer to Figure 1 It is described as being performed by network device 110 without loss of generality.

[0187] At box 510, the network device sends control information to the terminal device indicating resource groups and TCI states for communication between the terminal device and the network device. At box 520, the network device determines resource subgroups associated with the corresponding TCI states, each resource subgroup being a portion of a resource group in the frequency domain. At box 530, the network device determines the PT-RS mapping to the resource subgroups.

[0188] In some embodiments, determining a mapping includes: determining values ​​for mapping parameters for each resource subgroup; or determining a common value for mapping parameters for each resource subgroup.

[0189] In some embodiments, determining the mapping includes: for each of the resource subgroups, determining the frequency density of the PT-RS based on the number of resources in the resource subgroup.

[0190] In some embodiments, determining the mapping further includes: for each of the resource subgroups and based on the quantity, frequency density, and identifier of the terminal device, determining the offset between the starting resource for mapping and the resource with the lowest frequency in the resource subgroup.

[0191] In some embodiments, determining the mapping includes: determining the number of resources in the corresponding resource subgroup; determining the maximum number of resources; and determining the common frequency density of PT-RS in the resource subgroup based on the maximum number.

[0192] In some embodiments, determining the mapping includes: determining the frequency density of PT-RS in the corresponding resource subgroup based on the number of resources in the corresponding resource subgroup; and determining the mapping based on the maximum frequency density of the frequency density.

[0193] In some embodiments, determining the mapping further includes: determining an offset between the starting resource for mapping and the resource with the lowest frequency in the corresponding resource subgroup based on the quantity, frequency density, and identifier of the terminal device; and determining the mapping based on the minimum offset of the offset.

[0194] In some embodiments, determining the mapping includes: determining the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource group; and mapping PT-RS to resource subgroups in order of one resource subgroup following another, based on the common frequency density.

[0195] In some embodiments, determining the mapping includes: determining the common frequency density of PT-RS in a resource subgroup based on the number of resources in the resource subgroup multiplied by the number of resource subgroups.

[0196] In some embodiments, determining the mapping includes: determining an initial frequency density of the PT-RS based on the number of resources in the resource group; and determining the mapping based on the minimum value of the initial frequency density multiplied by the number of resource subgroups and 1 / 2.

[0197] Figure 6 This is a simplified block diagram of a device 600 suitable for implementing some embodiments of the present disclosure. Device 600 can be considered as... Figure 1 This is another example embodiment of the network device 110 and terminal device 120 shown. Therefore, device 600 can be implemented at or as a part of the network device 110 and terminal device 120.

[0198] As shown, device 600 includes processor 610, memory 620 coupled to processor 610, suitable transmitter (TX) and receiver (RX) 640 coupled to processor 610, and communication interface coupled to TX / RX 640. Memory 620 stores at least a portion of program 630. TX / RX 640 is used for bidirectional communication. TX / RX 640 has at least one antenna for communication, but in practice, there may be several access nodes mentioned in this application. The communication interface can represent any interface required for communication with other network elements, such as an X2 interface for bidirectional communication between gNBs or eNBs, an S1 interface for communication between a Mobility Management Entity (MME) / Serving Gateway (S-GW) and a gNB or eNB, an Un interface for communication between a gNB or eNB and a relay node (RN), or a Uu interface for communication between a gNB or eNB and a terminal device.

[0199] Program 630 is assumed to include program instructions that, when executed by the associated processor 610, enable device 600 to perform operations as described herein. Figure 4 and 5 The embodiments of this disclosure discussed herein operate. The embodiments herein can be implemented by computer software executable by the processor 610 of device 600, or by hardware, or by a combination of software and hardware. Processor 610 can be configured to implement various embodiments of this disclosure. Furthermore, a combination of processor 610 and memory 620 can form a processing apparatus 650 suitable for implementing various embodiments of this disclosure.

[0200] As a non-limiting example, memory 620 can be of any type suitable for a local technology network and can be implemented using any suitable data storage technology such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. While only one memory 620 is shown in device 600, there can be several physically different memory modules in device 600. As a non-limiting example, processor 610 can be of any type suitable for a local technology network and can include one or more general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Device 600 can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock synchronized with the main processor.

[0201] The components included in the apparatus and / or device disclosed herein can be implemented in various ways, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units may be implemented using software and / or firmware (e.g., machine-executable instructions stored on a storage medium). In addition to or in lieu of machine-executable instructions, some or all of the units in the apparatus and / or device may be implemented at least partially by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that may be used include field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-chips (SoCs), complex programmable logic devices (CPLDs), etc.

[0202] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0203] This 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 instructions included in a program module) that execute on a device targeting a real or virtual processor to perform the functions described above. Figure 4 and Figure 5Any of the described processes or methods. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. The functionality of a program module can be combined or split among program modules as needed in various embodiments. The machine-executable instructions of a program module can execute on a local or distributed device. In a distributed device, a program module can reside on both local and remote storage media.

[0204] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code enables the functions / operations specified in the flowcharts and / or block diagrams to be implemented. 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.

[0205] The aforementioned program code may be embodied on a machine-readable medium, which may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of machine-readable storage media will include electrical connections having one or more wires, portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0206] Furthermore, although the operations are described in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or sequentially, or that all shown operations be performed to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific embodiment details are included in the foregoing discussion, these should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0207] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

Claims

1. A method for communication, comprising: At the terminal device, control information is received from the network device indicating the status of resource groups and transport configuration indicator (TCI) for communication between the terminal device and the network device. Identify resource subgroups associated with the corresponding TCI states, each resource subgroup being a portion of the resource group in the frequency domain; as well as Determine the mapping of the phase tracking reference signal PT-RS to the resource subgroup. Determining the mapping includes: For each of the resource subgroups, the frequency density of the PT-RS is determined based on the number of resources in the resource subgroup; as well as For each of the resource subgroups and based on the quantity, the frequency density, and the identifier of the terminal device, an offset is determined between the starting resource for the mapping and the resource with the lowest frequency in the resource subgroup.

2. The method of claim 1, wherein determining the mapping further comprises: Determine the values ​​of the mapping parameters for each of the resource subgroups; or Determine common values ​​for the mapping parameters for the resource subgroups.

3. The method of claim 1, wherein determining the mapping further comprises: Determine the number of resources in the corresponding resource subgroup; Determine the maximum quantity among the stated quantities; as well as Based on the maximum number, the common frequency density of the PT-RS in the resource subgroup is determined.

4. The method of claim 1, wherein determining the mapping further comprises: The mapping is determined based on the maximum frequency density of the frequency density.

5. The method of claim 4, wherein determining the mapping further comprises: The mapping is determined based on the minimum offset of the offset.

6. The method of claim 1, wherein determining the mapping further comprises: Based on the number of resources in the resource group, determine the common frequency density of the PT-RS in the resource subgroup; as well as Based on the common frequency density, PT-RS are mapped to the resource subgroups in a sequence following one resource subgroup to another.

7. The method of claim 1, wherein determining the mapping further comprises: The common frequency density of the PT-RS in the resource subgroup is determined based on the number of resources in the resource group multiplied by the number of resource subgroups.

8. The method of claim 1, wherein determining the mapping further comprises: The initial frequency density of the PT-RS is determined based on the number of resources in the resource group. as well as The mapping is determined based on the initial frequency density multiplied by the number of resource subgroups and the minimum value of 1 / 2.

9. A method for communication, comprising: Control information is sent from the network device to the terminal device, indicating the status of the resource group and transport configuration indicator (TCI) for communication between the terminal device and the network device. Identify resource subgroups associated with the corresponding TCI states, each resource subgroup being a portion of the resource group in the frequency domain; as well as Determine the mapping of the phase tracking reference signal PT-RS to the resource subgroup. Determining the mapping includes: For each of the resource subgroups, the frequency density of the PT-RS is determined based on the number of resources in the resource subgroup; as well as For each of the resource subgroups and based on the quantity, the frequency density, and the identifier of the terminal device, an offset is determined between the starting resource for the mapping and the resource with the lowest frequency in the resource subgroup.

10. The method of claim 9, wherein determining the mapping further comprises: Determine the values ​​of the mapping parameters for each of the resource subgroups; or Determine common values ​​for the mapping parameters for the resource subgroups.

11. The method of claim 9, wherein determining the mapping further comprises: Determine the number of resources in the corresponding resource subgroup; Determine the maximum quantity among the stated quantities; as well as Based on the maximum number, the common frequency density of the PT-RS in the resource subgroup is determined.

12. The method of claim 9, wherein determining the mapping further comprises: The mapping is determined based on the maximum frequency density of the frequency density.

13. The method of claim 12, wherein determining the mapping further comprises: The mapping is determined based on the minimum offset of the offset.

14. The method of claim 9, wherein determining the mapping further comprises: Based on the number of resources in the resource group, determine the common frequency density of the PT-RS in the resource subgroup; as well as Based on the common frequency density, PT-RS are mapped to the resource subgroups in a sequence following one resource subgroup to another.

15. The method of claim 9, wherein determining the mapping further comprises: The common frequency density of the PT-RS in the resource subgroup is determined based on the number of resources in the resource group multiplied by the number of resource subgroups.

16. The method of claim 9, wherein determining the mapping further comprises: The initial frequency density of the PT-RS is determined based on the number of resources in the resource group. as well as The mapping is determined based on the initial frequency density multiplied by the number of resource subgroups and the minimum value of 1 / 2.

17. A terminal device, comprising: processor; as well as A memory that stores instructions. The memory and the instructions are configured together with the processor to cause the terminal device to perform the method according to any one of claims 1 to 8.

18. A network device, comprising: processor; as well as A memory that stores instructions. The memory and the instructions are configured together with the processor to cause the network device to perform the method according to any one of claims 9 to 16.

19. A computer-readable medium having instructions stored thereon, which, when executed on at least one processor of a device, cause the device to perform the method according to any one of claims 1 to 8 and 9 to 16.

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