WO2025193000A1 - Method for transmitting and receiving pusch and apparatus therefor - Google Patents

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving configuration information related to a PUSCH; and transmitting the PUSCH on the basis of one or more SRS resources. The PUSCH is transmitted on the basis of one or more antenna ports associated with the one or more SRS resources. A linear value of transmission power related to the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports over which the PUSCH is transmitted with non-zero power. On the basis of the number of SRS ports based on the one or more SRS resources being 3, the ratio is determined on the basis of one of a plurality of values.

Description

PUSCH transmission and reception method and device thereof

This specification relates to an SRS transmission and reception method and a device therefor.

Mobile communication systems were developed to provide voice services while ensuring user activity. However, they have expanded beyond voice to include data services. Currently, explosive growth in traffic is leading to resource shortages and users are demanding faster services, necessitating a more advanced mobile communication system.

Next-generation mobile communication systems must support explosive data traffic growth, dramatically increasing data rates per user, a vastly increased number of connected devices, ultra-low end-to-end latency, and high energy efficiency. To achieve these goals, various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.

In CB-based PUSCH transmission, the PUSCH transmit power (not in full-power mode) is distributed to the ports as follows: the linear value of the PUSCH transmit power is scaled by the ratio of the number of non-zero PUSCH ports to the maximum number of ports supported in one SRS resource (scaling factor s), and then is evenly distributed to the non-zero PUSCH ports.

When the above-described method is applied to a 3-port SRS resource of a 3 Tx UE, a problem occurs in which not all transmission power set for the PUSCH is fully distributed to the ports. For example, in the PUSCH of a 3 Tx UE, power equivalent to 1/4*P may be distributed to each of the three PUSCH ports.

The purpose of this specification is to propose a method to solve the above-mentioned problems.

The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

A method according to an embodiment of the present disclosure for solving the above-described technical problem includes the steps of receiving configuration information related to a Physical Uplink Shared Channel (PUSCH) and transmitting the PUSCH based on one or more Sounding Reference Signal (SRS) resources. The one or more SRS resources are related to codebook-based transmission. The PUSCH is transmitted based on one or more antenna ports associated with the one or more SRS resources. A linear value of transmission power associated with the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power. Based on the number of SRS ports based on the one or more SRS resources being 3, the ratio is characterized in that it is determined based on one of a plurality of values.

By scaling the linear value by a ratio determined based on one of the multiple values as described above, the problem described above (i.e., the problem that only a portion of the total transmission power that can be used/utilized by the terminal is utilized due to the power distribution method) can be solved.

Conventional methods can allocate lower transmit power per port for PUSCH transmission than the port-specific transmit power supported/usable by the corresponding terminal. In this case, only a portion of the total transmit power available to the terminal for PUSCH transmission is utilized, resulting in inefficient PUSCH transmission gain/coverage.

According to an embodiment of the present specification, when a PUSCH based on SRS resource(s) associated with three SRS ports is scheduled for a terminal supporting 3 Tx antennas or 3 port SRS resources, the PUSCH transmission power can be distributed to each port without loss in full by a ratio determined based on one of a plurality of values.

Therefore, compared to the existing method that only uses a defined ratio (e.g., the ratio of the number of ports with non-zero PUSCH transmission power and the maximum number of SRS ports supported in one SRS resource) for distribution of transmission power to ports, the power efficiency, gain and coverage of PUSCH transmission can be improved.

The effects that can be obtained from this specification are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the technical field to which this specification belongs from the description below.

Figure 1 is a flowchart showing an example of a UL BM procedure using SRS.

Figure 2 is a diagram illustrating flexible aperiodic SRS transmission timing control.

Figure 3 is a diagram illustrating partial band SRS transmission.

FIG. 4 is a flowchart illustrating a method according to one embodiment of the present specification.

FIG. 5 is a flowchart illustrating a method according to another embodiment of the present specification.

FIG. 6 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present invention.

In some cases, to avoid obscuring the concept of the present invention, well-known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

< SRS related actions >

A UE can be configured with one or more Sounding Reference Symbol (SRS) resource sets (via higher layer signaling, RRC signaling, etc.) configured by (higher layer parameter) SRS-ResourceSet. For each SRS resource set, the UE can be configured with K≥1 SRS resources (higher layer parameter SRS-resource). Here, K is a natural number, and the maximum value of K is indicated by SRS_capability.

Figure 1 is a flowchart showing an example of a UL BM procedure using SRS.

- The terminal receives RRC signaling (e.g., SRS-Config IE) containing usage parameters from the base station (S110). For example, the usage parameters may be set to 'beam management', 'codebook', 'nonCodebook', or 'antennaSwitching'.

Table 1 shows an example of an SRS-Config IE (Information Element), which is used to configure SRS transmission. The SRS-Config IE includes a list of SRS-Resources and a list of SRS-ResourceSets. Each SRS resource set represents a set of SRS-resources.

The network can trigger the transmission of an SRS resource set using the configured aperiodicSRS-ResourceTrigger (L1 DCI).

In Table 1, usage represents a higher layer parameter indicating whether the SRS resource set is used for beam management and for codebook-based or non-codebook-based transmission. 'spatialRelationInfo' is a parameter indicating the establishment of a spatial relation between a reference RS and a target SRS. Here, the reference RS can be an SSB, CSI-RS, or SRS corresponding to the L1 parameter 'SRS-SpatialRelationInfo'. The usage is set for each SRS resource set.

- The terminal determines the Tx beam for the SRS resource to be transmitted based on the SRS-SpatialRelation Info included in the SRS-Config IE (S120). Here, the SRS-SpatialRelation Info is set for each SRS resource and indicates whether to apply the same beam as the beam used in SSB, CSI-RS, or SRS for each SRS resource. In addition, the SRS-SpatialRelationInfo may or may not be set for each SRS resource.

- If SRS-SpatialRelationInfo is set in the SRS resource, the same beam used in SSB, CSI-RS, or SRS is applied for transmission. However, if SRS-SpatialRelationInfo is not set in the SRS resource, the terminal randomly determines a Tx beam and transmits SRS through the determined Tx beam (S130).

- Additionally, the terminal may or may not receive feedback on SRS from the base station (S140).

At least one of the terminal/base station operations based on S110 to S140 described above may be combined and applied with at least one of the embodiments described below (e.g., at least one of proposals 1 to 5).

< Sounding reference singal (SRS) >

In Rel-15 NR, spatialRelationInfo can be utilized to indicate the transmission beam to be used when the base station transmits the UL channel to the terminal. The base station can indicate which UL transmission beam to use when transmitting PUCCH and SRS by setting the DL reference signal (e.g., SSB-RI, CRI (P/SP/AP)) or SRS (i.e., SRS resource) as the reference RS for the target UL channel and/or target RS through RRC configuration. In addition, when the base station schedules the terminal for PUSCH, the transmission beam indicated by the base station and used for SRS transmission is indicated as the transmission beam for PUSCH through the SRI field and is used as the PUSCH transmission beam of the terminal.

< SRS for 'codebook' and 'non-codebook' >

First, in the case of CB UL, the base station first configures and/or instructs the terminal to transmit an SRS resource set for the purpose of ‘CB’, and the terminal can transmit any n port SRS resource within the SRS resource set. The base station acquires the UL channel based on the SRS transmission and can utilize this for PUSCH scheduling of the terminal. Thereafter, the base station performs PUSCH scheduling through UL DCI, and can indicate the PUSCH (transmission) beam of the terminal by indicating the SRS resource for the purpose of ‘CB’ previously transmitted by the terminal through the SRI field of the DCI. In addition, the base station can indicate the UL rank and UL precoder by indicating the uplink codebook through the TPMI field. Through this, the terminal can perform PUSCH transmission as instructed.

Next, in the case of NCB UL, the base station first configures and/or instructs the terminal to transmit an SRS resource set for a ‘non-CB’ purpose, and the terminal determines the precoder of the SRS resources (up to 4 resources, 1 port per resource) within the SRS resource set based on the reception of the NZP CSI-RS associated with the SRS resource set and can transmit the SRS resources simultaneously. Thereafter, the base station performs PUSCH scheduling via UL DCI, and can indicate some of the ‘non-CB’ purpose SRS resources previously transmitted by the terminal via the SRI field of the DCI, thereby indicating the PUSCH (transmission) beam of the terminal, and simultaneously indicating the UL rank and UL precoder. Through this, the terminal can perform PUSCH transmission as instructed.

< SRS for 'beam management' >

SRS can be utilized for beam management. Specifically, UL BM can be performed through beamformed UL SRS transmission, and whether an SRS resource set is applied to UL BM is configured by (higher layer parameter) usage. When usage is set to 'BeamManagement (BM)', only one SRS resource can be transmitted for each of multiple SRS resource sets at a given time instant. The UE can be configured with one or more Sounding Reference Symbol (SRS) resource sets configured by (higher layer parameter) SRS-ResourceSet (via higher layer signaling, RRC signaling, etc.). For each SRS resource set, the UE can be configured with K≥1 SRS resources (higher layer parameter SRS-resource). Here, K is a natural number, and the maximum value of K is indicated by SRS_capability.

< SRS for 'antennaSwitching' >

SRS can be used to acquire DL CSI (Channel State Information) information (i.e., DL CSI acquisition). For example, in a TDD-based single-cell or multi-cell (e.g., CA) scenario, a base station (BS) can schedule SRS transmission to a user equipment (UE) and then measure the SRS from the UE. In this case, the base station can schedule DL signals/channels to the UE based on measurements made by the SRS, assuming DL/UL reciprocity. In this case, with respect to SRS-based DL CSI acquisition, the SRS can be configured for antenna switching purposes.

For example, according to the standard (e.g., 3gpp TS38.214), the purpose of SRS can be set to the base station and/or terminal using a higher layer parameter (e.g., the usage of the RRC parameter SRS-ResourceSet). In this case, the purpose of SRS can be set to beam management purpose, codebook transmission purpose, non-codebook transmission purpose, antenna switching purpose, etc.

Below, we will specifically examine the case where SRS transmission (i.e., transmission of SRS resources or a set of SRS resources) is set for antenna switching purposes among the above purposes.

For example, for a terminal with partial reciprocity, SRS transmission based on antenna switching (i.e., transmit antenna switching) may be supported to acquire downlink (DL) CSI (Channel State Information) through SRS transmission in situations such as TDD (Time Division Duplex). When antenna switching is applied, a typical time of about 15 μs may be required between SRS resources (and/or between SRS resources and PUSCH/PUCCH resources) for antenna switching of the terminal. Taking this into account, a (minimum) guard period may be defined as shown in Table 2 below.

In Table 2, μ represents numerology, represents the subcarrier spacing, and Y represents the number of symbols in the guard interval, i.e., the length of the guard interval. Referring to Table 2, the guard interval can be set based on the parameter μ that determines the numerology. In the guard interval, the terminal is set not to transmit any other signal, and the guard interval can be set to be used entirely for antenna switching. For example, the guard interval can be set considering SRS resources transmitted in the same slot. In particular, when the terminal is set and/or instructed to transmit an aperiodic SRS set with intra-slot antenna switching, the terminal transmits the SRS using a different transmission antenna for each designated SRS resource, and the above-described guard interval can be set between each resource.

In addition, as described above, when a terminal is configured with SRS resources and/or an SRS resource set for antenna switching purposes through upper layer signaling, the terminal may be configured to perform SRS transmission based on a terminal capability (UE capability) related to antenna switching. Here, the capability of the terminal related to antenna switching may be '1T2R', '2T4R', '1T4R', '1T4R/2T4R', '1T1R', '2T2R', '4T4R', etc. Here, 'mTnR' may mean a terminal capability that supports m transmissions and n receptions.

(Example S1) For example, for a terminal supporting 1T2R, up to two SRS resource sets can be configured with different values for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each SRS resource set can have two SRS resources transmitted in different symbols, and each SRS resource in a given SRS resource set can configure a single SRS port. In addition, the SRS port for the second SRS resource in an SRS resource set can be configured to be associated with a different UE antenna port than the SRS port for the first SRS resource in the same SRS resource set.

(Example S2) For another example, for a terminal supporting 2T4R, up to two SRS resource sets can be configured with different values for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each SRS resource set can have two SRS resources transmitted in different symbols, and each SRS resource in a given SRS resource set can configure two SRS ports. In addition, the SRS port pair for the second SRS resource in an SRS resource set can be configured to be associated with a different UE antenna port than the SRS port pair for the first SRS resource in the same SRS resource set.

(Example S3) For another example, for a terminal supporting 1T4R, SRS resource sets may be configured in different ways depending on whether SRS transmission is configured to be periodic, semi-persistent, and/or aperiodic. First, when SRS transmission is configured to be periodic or semi-persistent, 0 SRS resource sets or 1 SRS resource set consisting of 4 SRS resources may be configured to be transmitted in different symbols based on the resourceType of the upper layer parameter SRS-ResourceSet. In this case, each SRS resource in the given SRS resource set may configure a single SRS port, and the SRS port for each SRS resource may be configured to be associated with different UE antenna ports. In contrast, when SRS transmission is configured to be aperiodic, either 0 SRS resource sets or two SRS resource sets consisting of a total of 4 SRS resources, configured based on the resourceType of the upper layer parameter SRS-ResourceSet, may be configured to be transmitted in different symbols of two different slots. In this case, the SRS port for each SRS resource in the given two SRS resource sets may be configured to be associated with different UE antenna ports.

(Example S4) For another example, for a terminal supporting 1T1R, 2T2R, or 4T4R, up to two SRS resource sets, each consisting of one SRS resource, can be configured for SRS transmission, and the number of SRS ports of each SRS resource can be set to 1, 2, or 4.

If the indicated terminal capability is 1T4R/2T4R, the terminal may expect that the same number of SRS ports (e.g., 1 or 2) will be configured for all SRS resources in the SRS resource set(s). In addition, if the indicated terminal capability is 1T2R, 2T4R, 1T4R, or 1T4R/2T4R, the terminal may not expect that one or more SRS resource sets configured for antenna switching purposes in the same slot will be configured or triggered. In addition, even if the indicated terminal capability is 1T1R, 2T2R, or 4T4R, the terminal may not expect that one or more SRS resource sets configured for antenna switching purposes in the same slot will be configured or triggered.

< SRS enhancement in Rel-17 MIMO >

In NR TDD systems, the importance of SRS transmission at terminals to ensure UL and DL channel estimation performance has increased. Accordingly, Rel-17 MIMO standardization was conducted with the following three goals in mind.

First, standardization was carried out with the goal of more flexibly controlling aperiodic SRS transmission according to the DL and UL slot ratios and traffic conditions of various TDD systems.

Second, NR terminals supporting DL Rank 8 transmission must be equipped with at least 8 receive antennas, but the SRS antenna switching transmission technique for estimating DL channels based on channel reciprocity in NR TDD systems only supports terminals with up to 4 receive antennas. Therefore, Rel-17 standardized the technique with the goal of supporting the SRS antenna switching transmission technique for terminals equipped with more than 4 receive antennas.

Third, standardization was carried out to increase the transmission coverage of SRS and increase the capacity of SRS considering simultaneous access of multiple terminals.

A more flexible aperiodic SRS transmission triggering technique

Figure 2 is a diagram illustrating flexible aperiodic SRS transmission timing control.

In order to more flexibly control aperiodic SRS transmission according to the DL and UL slot ratios and traffic conditions of various TDD systems in Rel-17 MIMO, the following two techniques were standardized.

First, a technique was introduced to dynamically control slot offset values for aperiodic SRS transmission triggers via DCI. This was intended to address the issue of SRS transmissions being significantly delayed depending on DL and UL slot settings, as previously the slot offset values were semi-statically fixed.

To this end, a new DCI field was defined that specifies one of multiple slot offset values set by an RRC message. Furthermore, the slot offset value indicated by the DCI field was standardized to be calculated based on available slots, which are defined as uplink slots and slots composed of flexible symbols, thereby enabling flexible SRS transmission triggering with a small number of slot offset candidate values.

Second, we introduce a technique for triggering aperiodic SRS transmissions without accompanying UL data transmissions and CSI reporting. Conventionally, SRS transmissions could be triggered via UL DCI only when PUSCH allocation triggered UL data and/or CSI reporting. This made it difficult for base stations to estimate UL/DL channels by triggering SRS for UEs that had no UL data to transmit and no need for aperiodic CSI reporting. This technique aims to address the aforementioned issues.

SRS antenna change transmission for terminals equipped with more than four receiving antennas

As mentioned above, the SRS antenna switching transmission technique supported in the Rel-15/16 NR system only considered terminals equipped with 4 receive antennas. In Rel-17 MIMO, the SRS antenna switching transmission method was standardized for terminals equipped with 6 and 8 receive antennas. The extended antenna switching transmission method supports the following combinations of the number of transmit antennas Nt and the number of receive antennas Nr.

Terminal with Nr=6: Nt=1, Nt=2, Terminal with Nr=8: Nt=1, Nt=2, Nt=4

The above SRS transmission can be transmitted within one slot, or across two or four slots.

SRS Coverage and Capacity Enhancement Techniques

Figure 3 is a diagram illustrating partial band SRS transmission.

In Rel-17 MIMO, three major techniques were introduced to increase the coverage and capacity of SRS.

First, the maximum number of repetitions of SRS was increased to enable utilization in systems requiring wider coverage. In Rel-15 and Rel-16, SRS could be repeated in up to 4 symbols within a slot, except for cases for positioning. In Rel-17 MIMO, SRS can be repeated in up to 14 symbols within a slot to secure wider SRS coverage. Specifically, SRS can be transmitted in 8, 10, 12, or 14 consecutive symbols within a slot.

Another approach is to enable SRS transmission only in partial bands. To achieve this, the base station can configure the resource block location where SRS transmission begins and the SRS transmission band for the terminal. For SRS transmission, the corresponding frequency location can also be hopped or fixed according to established rules, depending on the SRS frequency hopping cycle. The introduction of this technique allows different terminals to simultaneously transmit SRS to the same base station in different partial bands, thereby increasing SRS capacity.

Finally, we support SRS with lower frequency densities. In Rel-15/16, except for positioning, the supported SRS frequency density was 1 RE per 2 REs or 1 RE per 4 REs. This ensured stable channel estimation performance in frequency-selective channel environments, but there were limitations in securing SRS capacity. Therefore, in Rel-17 MIMO, we additionally introduced a transmission technique that transmits SRS on 1 RE per 8 REs, thereby further increasing SRS capacity in frequency-nonselective channel environments.

In NR Rel-15 MIMO, SRS can be used for UL link adaptation (codebook/non-codebook), beam management, and DL CSI acquisition (antenna switching). In Rel-17 FeMIMO, standardization has been carried out to increase the repetition rate, introduce RPFS (RB-level Partial Frequency Sounding), and support comb value 8 to enhance SRS coverage and capacity.

In Rel-18, SRS was standardized to support 8-port transmission, taking into account terminals capable of 8 Tx transmission. Comb offset hopping and cyclic shift hopping were introduced to improve SRS capacity and interference randomization performance.

As shown below, Rel-19 will perform SRS enhancement for terminals with 3 Tx antennas.

"Specify non-coherent UL codebook to facilitate 3-antenna-port codebook-based transmissions, without enhancement on UL full power transmission and without enhancement on SRS resource

Note: UL full power transmission mode 1 and 2 are not supported."

Since the LTE standard, the uplink reference signal (SRS) has been used for DL CSI acquisition utilizing channel reciprocity in TDD environments in addition to its original purpose of UL link adaptation. In NR, "antenna switching," one of the four SRS "usages," is used for DL CSI acquisition. In many real-world UEs, the number of Tx chains and Rx chains is asymmetrical to reduce costs (e.g., the number of Rx chains including Rx antennas > the number of Tx chains). To enable sounding across a large number of Rx antennas using a small number of Tx chains, SRS antenna switching via RF switching has been standardized (see SRS for 'antennaSwitching' above). This SRS antenna switching operation has been enhanced in Rel-17 to include xT6R/xT8R configurations for terminals with more than four Rx antennas, and in Rel-18 to include 8T8R configurations for 8Tx terminals. Rel-18 plans to implement SRS enhancements for 3Tx terminals. 3 Discussion is needed on how SRS antenna switching of Tx terminals will be performed.

Below, we propose a method to introduce a new 3 Tx SRS antenna switching by extending/enhancing the existing SRS antenna switching configuration, and a method to introduce a 3 Tx SRS antenna switching by combining the existing SRS antenna switching configuration (with only minimal enhancement).

Based on this background, this paper proposes a method for setting up SRS antenna switching considering 3 Tx terminals of a base station and a subsequent terminal antenna switching SRS transmission operation.

In this document, '/' means 'and', 'or', or 'and/or' depending on the context.

In order to support 3-port SRS resources in this specification, the following methods may be considered.

Alt 1. A method of setting/indicating three CS values among the four CS (cyclic shift) values set for the legacy 4-port SRS resource for the 3-port resource.

Alt 2. A method of setting/indicating three comb values among the four comb values set for the legacy 4-port SRS resource for the 3-port resource.

Alt 3. A method of setting/indicating three comb/CS values out of the two comb values and two CS values (a total of four comb/CS values) set for a legacy 4-port SRS resource for a 3-port resource.

Alt 4. Redefine the 3-port SRS resource so that 3 CS values are assigned to the 3 ports of the 3-port SRS resource.

Alt 5. Redefine the 3-port SRS resource so that 3 comb values are assigned to the 3 ports of the 3-port SRS resource.

Alt 6. A method of configuring a 3-port SRS resource by combining a legacy 2-port SRS resource and a 1-port SRS resource, or a method of configuring a 3-port SRS resource by combining three legacy 1-port SRS resources.

Hereinafter, SRS resource transmission may refer to SRS transmission on an SRS resource. Hereinafter, it is assumed that the upper layer parameter usage of the SRS resource set is set to 'antennaSwitching'. Hereinafter, port may be interpreted/replaced with SRS port or antenna port.

Proposal 1

A method of introducing a new 3 Tx SRS antenna switching by extending/enhancing the existing SRS antenna switching setting can be considered.

1) Terminals that support 3T3R

i. A base station can configure one SRS resource set including one 3-port SRS resource for a 3T3R-supporting terminal. The terminal can perform sounding for three Rx antennas by transmitting the 3-port SRS resource without switching.

2) Terminals that support 3T4R

i. The base station may configure one SRS resource set including one 3-port SRS resource and one 1-port SRS resource for a 3T4R-supporting terminal. The 3-port SRS resource and the 1-port SRS resource may correspond to mutually exclusive SRS ports. The meaning of mutually exclusive SRS ports in this specification is described in more detail as follows. The fact that two SRS resources correspond to mutually exclusive SRS ports may mean that the SRS ports based on the first SRS resource (e.g., three SRS ports, ports 1000-1002) are different from the SRS port based on the second SRS resource (e.g., one SRS port, port 1003). For example, the base station may configure a Y gap symbol as shown in Table 2 between transmission of the 3-port SRS resource and the 1-port SRS resource in consideration of the antenna switching time of the terminal. For example, the base station may need to schedule the resources considering the Y gap symbol.

ii. The base station can configure one SRS resource set including two 2-port SRS resources for a 3T4R-supporting terminal. The two 2-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol as shown in Table 2 between the transmission of the two 2-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

iii. The base station can configure one SRS resource set including two 3-port SRS resources for a 3T4R-supporting terminal. The two 3-port SRS resources have two SRS port(s) in common, and the remaining one port of each resource can correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol as shown in Table 2 between transmissions of the two 3-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

3) Terminals that support 3T6R

i. The base station can configure one SRS resource set including two 3-port SRS resources for a 3T6R-supporting terminal. The two 3-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol as shown in Table 2 between transmissions of the two 3-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

4) Terminals that support 3T8R

i. The base station can configure one SRS resource set including two 3-port SRS resources and one 2-port SRS resource for a 3T8R-supporting terminal. Among the three resources, the first 3-port SRS resource, the second 3-port SRS resource, and the 2-port SRS resource can correspond to mutually exclusive SRS ports. The base station can configure a Y gap symbol as shown in Table 2 between transmissions of the three resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

ii. The base station can configure one SRS resource set including four 2-port SRS resources for a 3T8R-supporting terminal. The four 2-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol as shown in Table 2 between transmissions of the four 2-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

In the above proposal 1, the 3-port SRS resource can be composed of one or more SRS resources.

In Proposal 1, assuming that 3 Tx SRS resources are defined, we propose a method for configuring SRS antenna switching for a 3 Tx terminal utilizing 3 Tx SRS resources. By newly defining the SRS antenna switching configuration for a 3 Tx terminal, the terminal receives only the minimum resources from the base station. The terminal can perform the 3 Tx SRS antenna switching operation simply (with reduced delay) by utilizing the configured resources. In addition, as in iii) of 2) above, when there is an SRS port commonly included in different SRS resource transmissions, it can be helpful in correcting phase errors, etc. when the different SRS resources are transmitted with a time difference in the time domain.

Proposal 2

A method of introducing 3 Tx SRS antenna switching by combining existing SRS antenna switching settings (with minimal enhancement) can be considered.

1) Terminals that support 3T3R

i. A base station can configure a 2-port SRS resource and one 1-port SRS resource for a 3T3R supporting terminal. The two resources can be included in one SRS resource set or can be included in two SRS resource sets, respectively. The 2-port SRS resource and the 1-port SRS resource can correspond to mutually exclusive SRS ports. In the case of a terminal supporting 3T3R, since it is a terminal capable of transmitting simultaneously through three Tx antennas, operations i) or ii) can be performed by the terminal. i) The 2-port SRS resource and the 1-port SRS resource can be transmitted simultaneously (using the same time/frequency resource). ii) Transmission can be performed by concatenating (at a symbol level) the 2-port SRS resource and the 1-port SRS resource without setting a Y gap symbol between transmissions.

ii. Similar to paragraph i above, the base station can configure three 1-port SRS resources for a 3T3R-supporting terminal. The three resources can be included in one SRS resource set or can be included in three SRS resource sets, respectively. The terminal can perform either i) or ii) operations. i) The three 1-port SRS resources can be transmitted simultaneously (using the same time/frequency resources). ii) Transmission can be performed concatenatedly (at the symbol level) without setting a Y gap symbol between transmissions of each resource.

iii. The base station can configure one SRS resource set including two 2-port SRS resources for a 3T3R-supporting terminal. The two resources can be included in one SRS resource set or can be included in two SRS resource sets, respectively. The two 2-port SRS resources have one SRS port(s) in common, and the remaining one port of each resource can correspond to a mutually exclusive SRS port. The terminal can perform operations i) or ii). i) The two 2-port SRS resources can be transmitted simultaneously (using the same time/frequency resource). ii) Transmission can be performed concatenatedly (at a symbol level) without setting a Y gap symbol between transmissions of each resource.

2) Terminals that support 3T4R

i. The base station can configure two 2-port SRS resources for a 3T4R-supporting terminal. The two resources can be included in one SRS resource set or in two SRS resource sets, respectively. The two 2-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol, as shown in Table 2, between transmissions of the two 2-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

ii. Similar to paragraph i above, the base station can configure four 1-port SRS resources for a 3T4R supporting terminal. The four resources can be included in one SRS resource set or divided into two SRS resource sets, with three resources and one resource being included. The terminal can perform operations i) or ii). i) Three resources among the four 1-port SRS resources (belonging to the same SRS resource set) can be transmitted simultaneously (using the same time/frequency resources). ii) Transmission can be performed by concatenating (at the symbol level) the three resources without setting a Y gap symbol between transmissions.

iii. Similar to paragraph i above, the base station can configure one 2-port SRS resource and two 1-port SRS resources for a 3T4R supporting terminal. The three resources can be included in one SRS resource set, or two resources and one resource can be divided and included in two SRS resource sets. The terminal can perform operations i) or ii). i) Two resources among the three resources (belonging to the same SRS resource set) can be transmitted simultaneously (using the same time/frequency resources). ii) Transmission can be performed by concatenating (at the symbol level) the two resources without setting a Y gap symbol between transmissions.

3) Terminals that support 3T6R

i. The base station can configure three 2-port SRS resources for a 3T6R-supporting terminal. The three resources can be included in one SRS resource set or in three SRS resource sets, respectively. The three 2-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol, as shown in Table 2, between transmissions of the three 2-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

ii. The base station can configure six 1-port SRS resources for a 3T6R-supporting terminal. The six resources can be included in one SRS resource set or three resources can be included in two SRS resource sets each. The terminal can perform operations i) or ii). i) Three resources among the six 1-port SRS resources (belonging to the same SRS resource set) can be transmitted simultaneously (using the same time/frequency resources). ii) Transmission can be performed by concatenating (at the symbol level) the three resources without setting a Y gap symbol between transmissions.

4) Terminals that support 3T8R

i. The base station can configure four 2-port SRS resources for a 3T8R-supporting terminal. The four resources can be included in one SRS resource set or can be individually included in four SRS resource sets. The four 2-port SRS resources can each correspond to a mutually exclusive SRS port. The base station can configure a Y gap symbol as shown in Table 2 between transmissions of the four 2-port SRS resources, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

ii. The base station can configure eight 1-port SRS resources for a 3T8R-supporting terminal. The eight resources can be included in one SRS resource set, or three or two SRS resources can be included in each of three SRS resource sets. For example, the first and second SRS resource sets can include three SRS resources, and the third SRS resource set can include two SRS resources. Operations i) or ii) can be performed by the terminal. i) Two or three resources (belonging to the same SRS resource set) among the eight 1-port SRS resources can be transmitted simultaneously (using the same time/frequency resources). ii) Transmission can be performed by concatenating (at the symbol level) two or three resources without setting a Y gap symbol between transmissions.

In the above proposal 2, a method of configuring one or more 4-port SRS resources as SRS resource configurations to support 3TyR terminals is proposed. As a specific embodiment, for a terminal supporting 3T6R, a base station can configure two 4-port SRS resources and schedule the two resources in TDM format. A method of transmitting only resources corresponding to three ports when each 4-port SRS resource is transmitted by the terminal may be considered. For example, since the two SRS resources correspond to different SRS ports, it may be necessary to configure a Y gap symbol between the two resources considering the antenna switching time. For example, since transmission is performed on three ports each from two 4-port SRS resources, sounding can be performed for six Rx antennas in a 3T6R configuration. Examples related to SRS transmission based on three of the four ports are described in detail below.

In one embodiment, the terminal may transmit SRS by selecting three ports (e.g., ports 1000-1002) in ascending/descending order from the lowest/highest port index of a 4-port SRS resource. As an example of ascending port index, the terminal may transmit SRS based on three ports (e.g., ports 1000-1002) among four ports (e.g., ports 1000-1003). As an example of descending port index, the terminal may transmit SRS based on three ports (e.g., ports 1003, 1002, 1001) among four ports (e.g., ports 1000-1003). To put the above example differently, any port other than the three ports determined by ascending/descending port index (e.g. port 1003 or port 1000) can be muted or disabled.

In one embodiment, the terminal can transmit SRS by selecting three ports in ascending/descending order from the lowest/highest value among the CS values of a 4-port SRS resource.

In one embodiment, the terminal can transmit SRS by selecting three ports in ascending/descending order from the lowest/highest value (in the frequency domain) among the comb values of a 4-port SRS resource.

In one embodiment, a terminal can transmit an SRS by selecting three ports among two comb values and two CS values of a 4-port SRS resource.

In one embodiment, a base station can configure a single 4-port SRS resource for a terminal supporting 3T3R. The terminal can transmit only resources (e.g., symbols) corresponding to three ports according to the above-described rules. More specifically, the terminal can transmit SRS based on symbol(s) associated with three ports among the symbols based on the 4-port SRS resource.

In one embodiment, for a terminal supporting 3T8R, a base station can configure three 4-port SRS resources. For two specific 4-port SRS resources, the terminal can transmit only the resources corresponding to the three ports according to the above-described rule (e.g., ascending/descending order of port index). For the remaining one 4-port SRS resource, the terminal can transmit only the resources corresponding to the two ports by applying the above-described rule.

The above embodiments are methods for enabling SRS antenna switching of a 3 Tx terminal by using/utilizing only some ports of a 4-port SRS resource. According to the embodiments, there is an advantage in that 3 Tx SRS antenna switching is enabled without the need to separately define a 3-port resource. In addition, there is an advantage in that resources corresponding to ports not used/utilized by the terminal in the 4-port SRS resource can be utilized for SRS scheduling of other terminals.

According to Proposal 2, the SRS resource configuration for the existing 1TyR/2TyR is utilized/extended without utilizing the 3Tx SRS resource (3 port SRS resource). Specifically, Proposal 2 proposes an SRS antenna switching configuration method for a 3 Tx terminal by combining legacy configuration methods. It has the advantage of supporting the 3 Tx SRS antenna switching operation of the terminal by utilizing the existing RRC parameters without the need to newly define the SRS antenna switching configuration for the 3 Tx terminal. However, multiple SRS resource configurations, more than one, may be required for a specific 3TyR operation. In addition, when there is an SRS port commonly included in different SRS resource transmissions, as in iii) of 1) above, it can be helpful in correcting phase errors, etc. when the different SRS resources are transmitted with a time difference in the time domain.

Proposal 3

A method may be considered to perform SRS antenna switching configuration corresponding to a subset of a specific SRS UE capability report (e.g., xTyR) of the terminal.

First, we describe the existing operation based on the UE capability (e.g., xTyR) related to antenna switching. The UE capability xTyR indicates that the terminal is capable of transmitting SRS on x ports based on y antennas. The y antennas are based on all or a subset of the UE receive antennas.

After the Rel-15 SRS antenna switching standardization, a new antenna switching capability was added in the Rel-16 standardization (i.e., supportedSRS-TxPortSwitch-v1610) to enable the base station to configure xTyR less than the number of Tx antennas of the terminal, even if the terminal supports 2T2R, 2T4R, and 4T4R for terminals with 2 or more Tx. This is to take into account flexibility in base station configuration and terminal power saving. The operation based on the UE capability (UE sounding procedure) and the upper layer parameters related to the UE capability (see Table 3) are examined in turn below.

The UE sounding procedure for acquiring DL CSI is as follows.

If the upper layer parameter usage in the SRS-ResourceSet of the UE is set to 'antennaSwitching', the UE shall support the indicated UE capability supportedSRS-TxPortSwitch ('t1r2' for 1T2R, 't1r1-t1r2' for 1T=1R/1T2R, 't2r4' for 2T4R, 't1r4' for 1T4R, 't8r8' for 8T8R, 't1r1-t1r2-t1r4' for 1T=1R/1T2R/1T4R, 't1r4-t2r4' for 1T4R/2T4R, 't1r1-t1r2-t2r2-t2r4' for 1T=1R/1T2R/2T=2R/2T4R, Only one of the configurations can be set depending on the configuration ('t1r1-t1r2-t2r2-t1r4-t2r4' for 1T=1R/1T2R/2T=2R/1T4R/2T4R, 't1r1' for 1T=1R, 't2r2' for 2T=2R, 't1r1-t2r2' for 1T=1R/2T=2R, 't4r4' for 4T=4R, or 't1r1-t2r2-t4r4' for 1T=1R/2T=2R/4T=4R). Alternatively, the UE may configure only one of the configurations according to the indicated UE capability supportedSRS-TxPortSwitchBeyond4Rx ('t1r1' for 1T=1R, 't2r2' for 2T=2R, 't1r2' for 1T2R, 't4r4' for 4T=4R, 't2r4' for 2T4R, 't1r4' for 1T4R, 't2r6' for 2T6R, 't1r6' for 1T6R, 't4r8' for 4T8R, 't2r8' for 2T8R, 't1r8' for 1T8R). Here, the configurations refer to configurations of SRS resource sets/SRS resources defined for each UE capability, such as the examples S0 to S4 described above. As an example of 4T8R, 0, 1, or 2 SRS resource sets may be configured in the UE. Each SRS resource set contains two SRS resources transmitted in different symbols. Each SRS resource in a given set consists of four SRS ports. The SRS ports of a resource in a given set are associated with different UE antenna ports.

In a 3TyR configuration that a 3Tx terminal can support (e.g., SRS resource/SRS resource set configuration for 3T6R), a UE capability reporting method for a subset configuration corresponding to/associated with lower capability than the corresponding configuration is described in detail below.

1) A terminal supporting 3T3R can report the following capability combinations (at least one of the candidates) for subset configuration in the SRS antenna switching capability related to a 3 Tx terminal.

i. {1T1R, 1T2R, 1T3R, 2T2R, [2T3R], 3T3R}

2) A terminal supporting 3T4R can report a capability combination as follows (at least one of the candidates) for a subset configuration in the SRS antenna switching capability related to a 3 Tx terminal.

i. {1T1R, 1T2R, [1T3R], 1T4R, 2T2R, [2T3R], 2T4R, 3T3R, 3T4R}

3) A terminal supporting 3T6R can report a capability combination (at least one of the candidates) below for a subset configuration in the SRS antenna switching capability related to a 3 Tx terminal.

i. {1T1R, 1T2R, [1T3R], 1T4R, 1T6R, 2T2R, [2T3R], 2T4R, 2T6R, 3T3R, 3T4R, 3T6R}

4) A terminal supporting 3T8R can report a capability combination (at least one of the candidates) below for a subset configuration in the SRS antenna switching capability related to a 3 Tx terminal.

i. {1T1R, 1T2R, [1T3R], 1T4R, 1T6R, 1T8R, 2T2R, [2T3R], 2T4R, 2T6R, 2T8R, 3T3R, 3T4R, 3T6R, 3T8R}

Problem 1

The decision to standardize the transmit/receive method to support 3-Tx terminals in the current Rel-18 MIMO stems from market usage considerations. Specifically, the maximum number of Tx antennas currently supported by terminals in the market is two, and there is insufficient space for handheld terminals to infinitely increase the number of Tx antennas. As mentioned above, while developing terminals equipped with three Tx antennas is realistic, the standard only supports 1/2/4/8 Tx antennas for terminals. For these reasons, standardization for supporting 3-Tx antenna terminals was undertaken. Here, the Tx antenna and Tx chain structure for handheld terminals may be limited. For example, some of the three antennas may share an RF chain, including a power amplifier. For example, RF switching for antenna switching may not be possible between certain antennas among the three antennas (due to different transmit panels or physical separation). In Proposal 4, we propose a technique to enable 3 Tx SRS antenna switching to operate under these structural limitations.

Proposal 4

In a 3 Tx terminal, a method to support 3 Tx SRS antenna switching may be considered when an RF chain is shared between a specific antenna and some antennas.

1) In a 3 Rx antenna terminal, two Tx/Rx antennas share an RF chain and an independent RF chain is implemented in the remaining one Tx/Rx antenna.

i. 3T3R setup

- The base station can configure 2-port SRS resource and 1-port SRS resource for 3T3R supporting terminal (when receiving a terminal report that RF chain is shared between specific antennas in the terminal implementation) similar to 1)-i of the above proposal 2. In the case of a terminal supporting 3T3R, it is a terminal that can perform transmission based on 3 Tx antennas simultaneously. Operation of i) or ii) can be performed by the terminal. i) The 2-port SRS resource and the 1-port SRS resource can be transmitted simultaneously (using the same time/frequency resource). ii) Transmission can be performed by concatenating (at symbol level) the 2-port SRS resource and the 1-port SRS resource transmission without setting a Y gap symbol between them.

ii. 2T3R setup

- The base station may configure a 2-port SRS resource and a 1-port SRS resource for a 2T3R supporting terminal (when a terminal report is received that RF chains are shared between specific antennas in the terminal implementation). The 2-port SRS resource and the 1-port SRS resource correspond to mutually exclusive SRS ports. 2-ports associated/corresponding to two Tx/Rx antennas sharing an RF chain may be mapped to the 2-port SRS resource. The base station may configure a Y gap symbol as shown in Table 2 between transmissions of the 2-port SRS resource and the 1-port SRS resource, taking into account the antenna switching time of the terminal. For example, the base station may schedule the resources considering the Y gap symbol.

Or/and, the 2-port SRS resource and the 1-port SRS resource correspond to mutually exclusive SRS ports. The 2-port SRS resource may have 2 ports associated/corresponding to one of the two Tx/Rx antennas sharing an RF chain and one Tx/Rx antenna configured with the remaining independent RF chain. In this case, since antenna switching is not required between the 2-port SRS resource and the 1-port SR resource (since 1 port of the 2-port resource and 1 port of the 1-port resource share an RF chain), the two 2-port SRS resources can be configured to be transmitted concatenatedly (at a symbol level) without setting a Y gap symbol between transmissions.

- (Alternatively,) the base station may configure three 1-port SRS resources for a 2T3R supporting terminal (if the base station receives a terminal report that an RF chain is shared between specific antennas in the terminal implementation). The three 1-port SRS resources correspond to mutually exclusive SRS ports. A gap symbol configuration may not be required between transmissions of 1-port SRS resources associated with two Tx/Rx antennas that share an RF chain (since the terminal can transmit on two antennas simultaneously). In addition/or, the 1-port SRS resources associated with two Tx/Rx antennas that share the RF chain may be transmitted simultaneously (using the same time/frequency resources). On the other hand, the base station may configure a Y gap symbol as shown in Table 2 above, considering the antenna switching time of the terminal, between transmission of the 1-port SRS resources associated with the two Rx antennas and transmission of the 1-port SRS resource associated with the remaining one Tx/Rx antenna. For example, the base station may need to schedule the resources considering the Y gap symbol.

iii. 1T3R setting

The base station can configure three 1-port SRS resources for a 1T3R supporting terminal (when the base station receives a terminal report that an RF chain is shared between specific antennas in the terminal implementation). The three 1-port SRS resources correspond to mutually exclusive SRS ports, and no gap symbol configuration may be required between transmissions of 1-port SRS resources associated with two Tx/Rx antennas that share the RF chain (since the terminal can perform simultaneous transmission based on two antennas). In addition/or, the 1-port SRS resources associated with two Tx/Rx antennas that share the RF chain can be transmitted simultaneously (using the same time/frequency resources). On the other hand, the base station can configure a Y gap symbol as shown in Table 2 above, considering the antenna switching time of the terminal, between transmission of the 1-port SRS resources associated with the two Rx antennas and transmission of the 1-port SRS resource associated with the remaining one Tx/Rx antenna. For example, the base station may need to schedule the resources considering the Y gap symbol.

2) In a 4 Rx antenna terminal, two Tx/Rx antennas share an RF chain and the remaining two Tx/Rx antennas share an RF chain.

i. 3T4R setup

- The base station can configure two 2-port SRS resources for a 3T4R supporting terminal (when a terminal report is received that RF chains are shared between specific antennas in the terminal implementation). The two 2-port SRS resources correspond to mutually exclusive SRS ports, respectively. Each 2-port SRS resource can have a 2-port associated/corresponding to one of the first two Tx/Rx antennas sharing the RF chain and one of the second two Tx/Rx antennas sharing the RF chain mapped. In this case, since antenna switching is not required between the two 2-port SRSs (since each of the two ports of the 2-port resource and each of the two ports of the other 2-port resource share the RF chain), the two 2-port SRSs can be configured to be transmitted concatenatedly (at a symbol level) without configuring a Y gap symbol between transmissions.

ii. 2T4R setup

- The same base station/terminal operation as above i can be performed.

iii. 1T4R setting

- The base station can configure four 1-port SRS resources for a 1T4R supporting terminal (when the base station receives a terminal report that an RF chain is shared between specific antennas in the terminal implementation). The four 1-port SRS resources correspond to mutually exclusive SRS ports. A gap symbol configuration may not be required between transmissions of 1-port SRS resources associated with two Tx/Rx antennas that share an RF chain (since the terminal can transmit on two antennas simultaneously). In addition/or, the 1-port SRS resources associated with two Tx/Rx antennas that share the RF chain can be transmitted simultaneously (using the same time/frequency resources). On the other hand, the base station can configure a Y gap symbol as shown in Table 2 above, considering the antenna switching time of the terminal, between transmission of 1-port SRS resources associated with two Rx antennas that share the RF chain and transmission of 1-port SRS resources associated with two Tx/Rx antennas that share the remaining RF chain. For example, the base station may need to schedule the resources considering the Y gap symbol.

3) Similar to the above operations 1 and 2, 3 Tx SRS antenna switching of a 6 Rx/8 Rx antenna terminal can be performed. For example, transmission of multiple SRS resources related to Tx/Rx antennas sharing a Tx chain can be transmitted concatenatedly (at a symbol level) without setting a Y gap symbol, or the multiple SRS resources can be transmitted simultaneously (using the same time/frequency resources).

In the above proposal 4, multiple SRS resources related to ports sharing the same RF chain can be included in a specific SRS resource set. Or/and a connection relationship can be established/defined between multiple SRS resources related to ports sharing the same RF chain through signaling (such as RRC/MAC-CE). In more detail, if SRS resources are included in different SRS resource sets or the connection relationship is not established between SRS resources, it may mean that ports related to the corresponding SRS resources are related to different RF chains (do not share an RF chain) and a Y gap symbol needs to be established between transmissions of the corresponding SRS resources.

Proposal 4 exploits the fact that, in certain terminal implementations, there is no need for a Y gap symbol between multiple SRS resources for antenna switching, and that these multiple SRS resources can be transmitted simultaneously. Proposal 4 has the advantage of reducing the delay required for a terminal to complete transmission of a specific antenna switching configuration.

Problem 2

In the above proposals, it may be assumed that SRS resources with different numbers of ports are transmitted in TDM. For example, a 1-port SRS resource and a 2-port SRS resource may be transmitted in TDM. For example, a 2-port SRS resource and a 3-port SRS resource may be transmitted in TDM.

According to the SRS power control operation below, the SRS transmission power is determined according to the SRS transmission occasion, and (the linear power value) is equally split for each port in the corresponding transmission occasion. Accordingly, a power imbalance problem may occur in which the power for each Rx antenna that performed sounding for antenna switching is not constant. For example, it can be assumed that a 1-port SRS resource and a 2-port SRS resource are transmitted in TDM for antenna switching transmission for 3 Rx antennas. For the 1-port SRS resource, P_SRS,b,f,c is determined by the power control parameters set for the SRS resource set to which the corresponding resource is set, and the terminal transmits the SRS using the determined values (without splitting since it is a 1-port resource). On the other hand, for the 2-port SRS resource, P_SRS,b,f,c (same as the set) is determined by the power control parameters set for the SRS resource set (same as the set) to which the corresponding resource is set. A value corresponding to half the linear value of the determined value is allocated to each port. This leads to a power imbalance problem. Proposal 5 proposes a method to solve Problem 2 above.

First, we describe the existing operation related to the transmission power of SRS.

For SRS,

- If tdm is provided for an SRS resource with 8 ports in an SRS resource set with usage of 'codebook' or 'antennaSwitching' to the UE, the UE transmits power in the active UL BWP b of carrier f of serving cell c. Linear value of is evenly divided across the configured antenna ports for each symbol for SRS transmission (if a UE is provided tdm for an SRS resource with 8 ports in an SRS resource set with usage 'codebook' or 'antennaSwitching', the UE splits a linear value of the transmit power on active UL BWP of carrier of serving cell equally across the configured antenna ports on each symbol for SRS transmission).

- Otherwise, the UE transmits power at the active UL BWP b of carrier f of serving cell c. Linear value of is evenly split across the antenna ports configured for SRS (else, a UE splits a linear value of the transmit power on active UL BWP of carrier of serving cell equally across the configured antenna ports for SRS).

When a UE transmits an SRS according to the configuration of the SRS-ResourceSet on an active UL BWP b of carrier f of a serving cell c using an SRS power control adjustment state with index l, the UE may adjust the SRS transmission power at an SRS transmission opportunity i. is determined as follows (If a UE transmits SRS based on a configuration by SRS-ResourceSet on active UL BWP of carrier of serving cell using SRS power control adjustment state with index , the UE determines the SRS transmission power in SRS transmission occasion as).

[dbm]

Proposal 5

Below, we examine a method for solving the power imbalance problem, such as problem 2 above, when SRS resources containing different numbers of ports are transmitted in TDM (for 3 Tx SRS antenna switching).

1) Embodiment 1: SRS resources transmitted in TDM may be assumed as a single SRS transmission occasion. As a specific example, the terminal may assume a plurality of SRS resources (configured for 3-port transmission) for transmission based on a specific single antenna switching configuration (e.g., xTyR configuration) or for 3-port SRS transmission as a single SRS transmission occasion. Or/and the assumption for the single SRS transmission occasion may be agreed/specified between the base station/terminal. For example, if a 2-port SRS resource and a 1-port SRS resource are utilized for 3T3R antenna switching transmission, (the resources are included in the same SRS resource set) the P_SRS,b,f,c values for the two SRS resources may be defined/determined for a single SRS transmission occasion i. The (linear values of) the P_SRS,b,f,c values may be evenly divided for 2-port + 1-port = 3-port.

2) Embodiment 2: To solve problem 2, the existing power splitting method for each SRS port can be extended. Specifically, for transmission based on a specific single antenna switching configuration (e.g., xTyR configuration) or/and for multiple SRS resources (configured for 3-port transmission) for 3-port SRS transmission, the terminal can equally split the transmission power for each port. This SRS power control operation can be defined or configured by the base station. For example, the following base station/terminal assumptions can be promised/specified.

- If [3port] is provided for an SRS resource(s) with 3 ports in an SRS resource set with usage 'codebook' or 'antennaSwitching', the UE transmits power in the active UL BWP b of carrier f of serving cell c. Linear value of is evenly divided across the three antenna ports configured for SRS transmission (if a UE is provided [3port] for SRS resource(s) with 3 ports in an SRS resource set with usage 'codebook' or 'antennaSwitching', the UE splits a linear value of the transmit power on active UL BWP of carrier of serving cell equally across the configured three antenna ports for SRS transmission).

- In the above, [3port] may be an example of a configuration for at least one 3-port SRS resource(s). For example, provision of [3port] to the UE may mean that parameters/information related to SRS transmission based on three ports are configured/instructed to the UE.

3) Example 3: The terminal can perform power allocation for each SRS port by the following procedure.

Step 1: For each of the multiple SRS resources (configured for 3-port transmission) for transmission based on a specific single antenna switching configuration (e.g., xTyR configuration) or/and 3-port SRS transmission, the terminal determines the power for each SRS transmission occasion as before.

Step 2: The terminal calculates the minimum power P_min for each SRS port determined in Step 1. The terminal finally sets/applies the power per port of the plurality of SRS resources to P_min.

Through the above proposal 5, power is equally allocated to each SRS port related to antenna switching in SRS resources set for a specific SRS antenna switching configuration, thereby solving the power imbalance problem.

In the above proposals 1 to 4, the Y gap symbol may be a value that increases from the Y values in Table 2, depending on the sub-carrier spacing. For example, as the sub-carrier spacing increases to 240/480/960 KHz, a separate Y value (proportionally increased) may be set/defined.

In the above proposals 1 to 4, the fact that multiple SRS resources can be transmitted simultaneously (using the same time/frequency resources) may mean that the following operations i) or ii) are performed. i) The base station configures multiple SRS resources for the terminal in the same symbol. At this time, each SRS resource may be configured to have a different CS/Comb value (so as to correspond to/map to mutually exclusive port(s)). ii) The base station configures multiple SRS resources for the terminal in the same symbol. At this time, each SRS resource may be configured to have a non-overlapped SRS PRB location. In the case of i), even if the multiple SRS resources are configured with the same FDRA parameters such as C_SRS, B_SRS, etc., the multiple SRS resources are transmitted using (orthogonal/quasi-orthogonal) resources corresponding to different ports, so that transmission is possible without collision between the resources. Methods such as i) and ii) have the advantage that the base station can perform channel estimation for multiple SRS ports based on a specific single symbol.

<PUSCH power control in case that multiple SRS resources are aggregated for 3 Tx codebook based SRS transmission>

As in Proposal 5 above, when multiple 1-port or 2-port SRS resources are aggregated and transmitted in a TDM format for 3 Tx SRS transmission, an imbalance problem may arise in terms of power allocation per SRS port. To address this problem, Proposal 5 is described. Similarly, when transmitting a codebook-based SRS using multiple SRS resources as described above and subsequently transmitting a codebook-based PUSCH, a problem may arise in PUSCH power allocation. Discussions regarding this issue are ongoing in standardization, as shown in Table 4 below.

Specifically, the power split method for each PUSCH port when transmitting PUSCH of a terminal in 38.213 is as shown in Table 5 below.

In Table 5 above, if the full power mode is not set for the UE, the UE scales the P_PUSCH using a ratio and then equally splits the PUSCH across the PUSCH ports transmitting at non-zero power. The ratio may be (the number of antenna ports with a non-zero PUSCH transmission power)/(the maximum number of SRS ports supported by the UE in one SRS resource). The ratio may be referred to as 's', 'factor s', or 'scale factor s'. The P_PUSCH may be set by the base station for PUSCH transmission.

For example, if a terminal that reports the maximum number of SRS ports in one resource as 4 transmits a 2-port PUSCH, the PUSCH transmission power can be distributed to the two ports as follows. Since the ratio is 2/4=1/2, P_PUSCH is scaled as 1/2*P_PUSCH. If the PUSCH transmission power is split across the two PUSCH ports, 1/4*P_PUSCH power is allocated to each PUSCH port.

However, for 3 Tx terminals, the problem arises that the power split method for each PUSCH port is ambiguous. For example, the candidate value for terminal capability reporting for the current maximum number of SRS ports in one resource is one of {1, 2, 4, 8}. The ambiguous definition of the scale factor s for 3 Tx terminals makes PUSCH power splitting difficult. If a 3 Tx terminal reports 4 as the maximum number of SRS ports in one SRS resource, 1/4*P_PUSCH is allocated to each PUSCH port for the 3 Tx PUSCH, resulting in a loss in transmission power per port. In the following, methods for solving the above-described problem will be examined in detail.

Proposal 6

It can be assumed that a 3-port codebook-based SRS transmission is performed by a 3-Tx terminal utilizing SRS resource(s). Below, we will examine in detail the PUSCH power control method of the terminal when the base station performs PUSCH transmission configuration/instruction using the SRS resource(s).

Example 1) A method of adding 3 to the candidate value range {1, 2, 4, 8} for reporting the maximum number of SRS ports in one resource of a UE may be considered. Specifically, the UE may report one of the values {1, 2, 3, 4, 8} to the base station for reporting the maximum number of SRS ports in one resource. Through this operation, a 3 Tx UE may report 3 among the values, and based on this, a scale factor s(ratio) = (the number of antenna ports with a non-zero PUSCH transmission power)/(maximum number of SRS ports supported by the UE in one SRS resource) may be calculated. Specifically, the UE may calculate the scale factor s(ratio) as (the number of antenna ports with a non-zero PUSCH transmission power)/(3). The terminal can split the P_PUSCH by 3 (=maximum number of SRS ports in one resource) and allocate it to actual PUSCH ports (e.g., 3 PUSCH antenna ports with non-zero PUSCH transmission power).

Embodiment 2) The terminal reports one value from the candidate value range {1, 2, 4, 8} to the base station for reporting the maximum number of SRS ports in one resource, and the power scale factor s for PUSCH transmission of the 3 Tx terminal can be set/defined as s=(the number of antenna ports with a non-zero PUSCH transmission power)/3. Through this, power corresponding to 1/3*P_PUSCH can be allocated to each PUSCH port during PUSCH transmission. The above proposal can be defined as shown in Table 6 below. As an example, the present embodiment can be applied to a case where one or more SRS resources are utilized for 3-port codebook based SRS transmission.

In the above, [3port] may be an example of a configuration that configures a 3 Tx SRS resource. For example, the configuration of a 3 Tx SRS resource may be based on the configuration of two or more SRS resources (e.g., a 1-port SRS resource + a 2-port SRS resource). For example, the configuration of a 3 Tx SRS resource may be based on the configuration of one SRS resource with one of the four ports disabled (e.g., a 4-port SRS resource with one of the 4 ports disabled).

It can be assumed that a 3 Tx UE reports 4 out of the candidate value range {1, 2, 4, 8} for reporting the maximum number of SRS ports in one resource. The base station needs to distinguish whether the UE that performed the report is a 3 Tx UE that supports 4-port SRS resources or a 4 Tx UE that supports 4-port SRS resources. To this end, the UE can introduce an existing capability or a new UE capability related to SRS/PUSCH power scaling and report it. In other words, if the UE reports 4 out of the candidate value range {1, 2, 4, 8} for reporting the maximum number of SRS ports in one resource and reports the existing capability or new UE capability related to SRS/PUSCH power scaling, the base station can recognize that the UE is a 3 Tx UE. Subsequently, the base station can perform SRS configuration for the 3 Tx UE, etc. If an existing capability or new UE capability related to the above SRS/PUSCH power scaling is reported, it may be based on at least one of the following examples.

- In the case where the terminal reports 3 in the maximum number of SRS ports in one resource report of the above embodiment 1

- When the terminal reports the maximum number of supported layers as 3 during codebook-based (or non-codebook-based) PUSCH transmission.

- If the terminal reports the supported max number of SRS resources per set for non-codebook based SRS as 3

- When transmitting non-codebook based SRS, if the terminal reports the maximum number of simultaneous transmitted SRS resources at one symbol as 3.

- Full power transmission mode 3 is newly defined as a new capability, and when the terminal reports full power transmission mode 3.

- When the terminal reports that it supports the terminal capability for 3-port SRS resource support, etc.

In relation to the existing capability or new UE capability-based operation related to the above-described SRS/PUSCH power scaling, the same operation can be performed when the UE reports 2 out of the candidate value range {1, 2, 4, 8} for reporting the maximum number of SRS ports in one resource.

If a 3 Tx UE reports the maximum number of SRS ports supported in one SRS resource as 3 (according to Embodiment 1), the transmission power per port can be evenly distributed using the existing method. However, it can be assumed that a 4 Tx UE transmits a PUSCH based on 3 antenna ports. In this case, since the maximum number of SRS ports supported by the UE in one SRS resource will be reported as 4, the problem related to power distribution described above may occur in the same way. Even if 3 is added to the candidate values of the maximum number of SRS ports reported in the UE capability as described above, a problem related to power distribution may occur when transmitting a PUSCH based on 3 ports. An embodiment for solving this problem will be described in detail below.

Example 3) The base station can set/instruct the terminal to set/instruct the value of the power scale factor s for PUSCH power allocation. For example, the base station can set/instruct the terminal to set/instruct one of a plurality of values related to the power scale factor s (ratio). For example, one of the plurality of values can be set/instructed based on RRC signaling/MAC CE/DCI. For example, the plurality of values can be set based on RRC signaling, and one of the plurality of values can be instructed based on MAC CE/DCI.

In one embodiment, the base station may set multiple candidate values for the s value to the terminal. The base station may indicate one of the multiple candidate values to the terminal based on MAC CE/DCI.

In one embodiment, the base station may set a value corresponding to the denominator term of the s value (maximum number of SRS ports supported by the UE in one SRS resource) to the terminal (e.g., set via RRC signaling).

In one embodiment, the base station can set multiple candidate values for the value corresponding to the denominator term of the s value (maximum number of SRS ports supported by the UE in one SRS resource) to the UE. The base station can indicate one of the multiple candidate values to the UE through MAC CE/DCI. In this case, the base station can set the s value (indicate one of the multiple candidate values of the denominator term of the s value) so that 1/3*P_PUSCH power is allocated per PUSCH port when the UE transmits PUSCH.

According to the above Example 3, the following effects are obtained.

Embodiment 3 relates to a base station configuration/instruction method for more dynamically performing transmission power distribution for PUSCH ports. Through Embodiment 3, an effect similar to an operation of performing a TPC command through a downlink control channel can be achieved. In particular, in cases where the number of ports utilized for PUSCH transmission rapidly changes due to panel switching or multi-panel simultaneous transmission in PUSCH transmission, such as in an uplink multi-panel environment of a terminal, the operation of Embodiment 3 allows the base station to adaptively perform transmission power distribution for PUSCH ports.

A combination of two or more of the embodiments of the above proposal 6 may be applied to terminal/base station operation.

The embodiments of the above proposal 6 can also be applied when a base station configures a 4-port SRS resource to support a 3-port SRS resource and configures/instructs a terminal to utilize only the 3-port resource among the 4-port resources. For example, embodiments 1 to 3 can be applied.

In one embodiment, an operation of multiplying the above-described scale factor s by an additional scale factor X/3 may be applied. The X may mean a value reported by the terminal as the maximum number of SRS ports in one resource. For example, the X may be one of the candidate value ranges {1, 2, 4, 8}.

For example, if multiple SRS resources (e.g., 1 port SRS resource + 2 port SRS resource) are configured for a UE for 3 Tx SRS, the UE can report X=2. In this case, the UE can additionally multiply s by X/3=2/3 to scale the PUSCH transmission power. In other words, the UE can scale the linear value of the PUSCH transmission power by s*2/3.

For example, if a 4-port SRS resource is configured for a UE for 3 Tx SRS and only 3 of the 4 ports are enabled (1 of the 4 ports are disabled), the UE can report X=4. In this case, the UE can additionally multiply s by X/3=4/3 to scale the PUSCH transmission power. In other words, the UE can scale the linear value of the PUSCH transmission power by s*4/3.

For example, the additional embodiments described above may be applied when the UE reports an existing capability or a new UE capability related to the SRS/PUSCH power scaling (e.g., when the UE reports a capability based on at least one of the examples of Embodiment 2 or a new UE capability).

The above-described operation can have the effect of allocating transmission power corresponding to 1/3 of P_PUSCH to each PUSCH port.

In one embodiment, among the embodiments related to Proposal 6, setting/instruction/switching may be performed to determine which embodiment of the operation corresponding to the terminal is to perform. For example, based on RRC signaling, the base station may set/instruct the terminal to perform one of the embodiments related to Proposal 6.

The embodiments of the above proposals 1 to 6 can operate in certain combinations.

Below, we will examine signaling procedures based on the embodiments described above.

An example of a terminal (or base station) operation based on at least one of the embodiments described above (e.g., at least one of Proposals 1 to 6) is as follows.

1) The terminal (base station) receives (transmits) SRS-related setting information.

The above configuration information may include configurations for SRS resource(s) within a specific SRS resource set (of codebook or/and antennaSwitching usage) based on Proposals 1 to 6.

2) The terminal (base station) transmits (receives) SRS according to P/SP/AP-SRS transmission settings/activation/instructions.

The terminal transmits the SRS resource set (including one or more SRS resources) configured/activated/indicated by RRC/MAC CE/DCI based on the settings of Proposals 1 to 5. Transmitting the SRS resource (set) means transmitting the SRS based on the SRS resource (set).

The terminal allocates power per SRS port based on Proposal 5.

3) The terminal (base station) transmits (receives) PUSCH based on the SRS resource set of the previously transmitted codebook usage.

The terminal performs power split operation for each PUSCH port based on the settings of Proposal 6.

The above terminal/base station operations are only an example, and each operation (or step) is not necessarily essential, and operations related to SRS/PUSCH transmission of the terminal according to the above-described embodiments may be omitted or added depending on the terminal/base station implementation method.

In terms of implementation, the operations of the base station/terminal according to the embodiments described above (e.g., operations based on at least one of Proposals 1 to 6) can be processed by the device of FIG. 6 described below (e.g., processor (110, 210) of FIG. 6).

In addition, the operations of the base station/terminal according to the above-described embodiment (e.g., operations based on at least one of proposals 1 to 6) may be stored in a memory (e.g., 140, 240 of FIG. 6) in the form of commands/programs (e.g., instructions, executable codes) for driving at least one processor (e.g., 110, 210 of FIG. 6).

The embodiments described below are specifically described with reference to FIGS. 4 and 5 in terms of the operation of the terminal and base station. The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for or combined with some components of another method.

FIG. 4 is a flowchart illustrating a method according to one embodiment of the present specification.

Referring to FIG. 4, a method according to one embodiment of the present specification includes a step of receiving configuration information related to PUSCH (S410) and a step of transmitting PUSCH based on one or more SRS resources (S420).

In S410, the terminal receives configuration information related to a physical uplink shared channel (PUSCH) from the base station.

For example, the configuration information may be based on the upper layer parameter PUSCH-Config.

For example, the configuration information may include information related to a configuration/operation based on at least one of the above-described proposals 1 to 6. As a specific example, the configuration information may include information related to proposal 6.

In S420, the terminal transmits the PUSCH to the base station based on one or more Sounding Reference Signal (SRS) resources.

For example, one or more of the SRS resources may be associated with codebook based transmission.

For example, the PUSCH may be transmitted based on one or more antenna ports associated with the one or more SRS resources. As a specific example, the one or more antenna ports may be identical to the SRS port(s) within the one or more SRS resources.

Assuming that the number of the one or more antenna ports is 3 and the number of SRS ports in the one or more SRS resources is 3, the three antenna ports may be equivalent to the three SRS ports.

Assuming that the number of the one or more antenna ports is 2 and the number of SRS ports in the one or more SRS resources is 3, two antenna ports may be based on two SRS ports out of the three SRS ports. As described above, the three SRS ports may be based on one SRS resource (an SRS resource in which one SRS port out of four SRS ports is disabled) or multiple SRS resources (e.g., a 1-port SRS resource + a 2-port SRS resource).

For example, the PUSCH may be i) a PUSCH scheduled based on Downlink Control Information (DCI) (e.g., DCI format 0_1, 0_2 or 0_3) or ii) a PUSCH configured semi-statically based on a configured grant. As a specific example, the one or more SRS ports may be indicated based on the DCI (e.g., an SRS Resource Indicator field and/or a second SRS Resource Indicator field in the DCI). As a specific example, the one or more SRS ports may be indicated based on a configuration related to the configured grant (e.g., srs-ResourceIndicator and/or srs-ResourceIndicator2 in a higher layer parameter configuredGrantConfig).

For example, a linear value of the transmit power associated with the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power. In other words, the linear value of the transmit power is scaled by the ratio and the transmit power is equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power.

At this time, in the case of 3 Tx UL transmission (e.g., transmission of 3 TX UE or 3 port SRS resource-based UL transmission (of 4 Tx UE), according to the existing method, the transmission power per port for PUSCH transmission may be allocated lower than the transmission power per port that can be supported/used by the terminal. In this case, it is inefficient in terms of gain/coverage of PUSCH transmission. Embodiments for solving the above-described problem are described in detail with reference to Proposal 6.

In one embodiment, based on the number of SRS ports based on the one or more SRS resources being 3, the ratio may be determined based on one of a plurality of values.

In one embodiment, the plurality of values may be based on candidate values of the ratio (e.g., candidate values of scale factor s). Specifically, the ratio may be determined as one of the plurality of values.

In one embodiment, the plurality of values may be based on candidate values of the denominator of the ratio (e.g., candidate values of the denominator term of the scale factor s). Specifically, the ratio may be determined based on i) the number of the one or more antenna ports and ii) one of the plurality of values. For example, the ratio may be expressed as (the number of the one or more antenna ports)/(one of the plurality of values).

In one embodiment, the plurality of values may be set based on the configuration information or RRC signaling. For example, the configuration information may include information about the plurality of values. For example, the terminal may receive information about the plurality of values from the base station based on the RRC signaling.

In one embodiment, one of the plurality of values may be indicated based on Downlink Control Information (DCI) or a Medium Access Control Element (MAC CE). For example, the DCI may be DCI for scheduling the PUSCH. For example, the DCI may be DCI indicating activation of the PUSCH that is semi-statically configured. For example, the MAC CE may be a MAC CE associated with a configured grant.

In one embodiment, the one or more SRS resources may be based on one SRS resource or multiple SRS resources.

For example, the one or more SRS resources may be based on a single SRS resource in which one of the four SRS ports is disabled. As a specific example, among the four SRS ports (e.g., ports 1000-1003) configured in the single SRS resource, the last SRS port (e.g., port 1003) based on the ascending order of the antenna port index may be disabled.

For example, the one or more SRS resources may be based on i) an SRS resource with one SRS port configured (e.g., a 1 port SRS resource) and ii) an SRS resource with two SRS ports configured (e.g., a 2 port SRS resource).

In one embodiment, the method may further include a capability information transmitting step. Specifically, the terminal transmits capability information to the base station. The capability information transmitting step may be performed before S410. The capability information may include information indicating the maximum number of SRS ports supported for each SRS resource (e.g., the maximum number of SRS ports per each SRS resource). In this specification, an SRS port may be interpreted/replaced with an SRS antenna port. For example, the maximum number of supported SRS ports may be 1, 2, 3, 4, or 8.

In one embodiment, the linear value may be scaled by the ratio and X/3, where X may be the maximum number of the supported SRS ports.

In one embodiment, a ratio to be used for the PUSCH may be configured based on RRC signaling. Specifically, the linear value may be scaled by a first ratio or a second ratio. The first ratio may be the ratio (or a previously defined ratio/scale factor s). The second ratio may be based on the ratio (or a previously defined ratio/scale factor s) and X/3. The X may be the maximum number of the supported SRS ports. The configuration information may include information indicating the first ratio or the second ratio used for the PUSCH.

The operations based on the above-described S410 to S420 and performance information transmission steps can be implemented by the device of FIG. 6. For example, the terminal (200) can control one or more transceivers (230) and/or one or more memories (240) to perform the operations based on S410 to S420 and performance information transmission steps.

The embodiments described below are specifically described in terms of base station operation.

The S510 to S520 and performance information reception steps described below correspond to the S410 to S420 and performance information transmission steps described in FIG. 4. Considering the above correspondence, redundant descriptions are omitted. That is, the specific description of the base station operations described below may be replaced with the corresponding descriptions/exemplifications of FIG. 4.

FIG. 5 is a flowchart illustrating a method according to another embodiment of the present specification.

Referring to FIG. 5, a method according to another embodiment of the present specification includes a step of transmitting configuration information related to PUSCH (S510) and a step of receiving PUSCH based on one or more SRS resources (S520).

In S510, the base station transmits configuration information related to the physical uplink shared channel (PUSCH) to the terminal.

In S520, the base station receives the PUSCH from the terminal based on one or more Sounding Reference Signal (SRS) resources.

For example, one or more of the SRS resources may be associated with codebook based transmission.

For example, the PUSCH may be transmitted based on one or more antenna ports associated with the one or more SRS resources. In other words, the base station may receive the PUSCH transmitted from the terminal based on one or more antenna ports associated with the one or more SRS resources.

For example, a linear value of the transmission power associated with the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power.

In one embodiment, based on the number of SRS ports based on the one or more SRS resources being 3, the ratio may be determined based on one of a plurality of values.

In one embodiment, the method may further include a capability information receiving step. Specifically, the base station receives capability information from the terminal. The capability information receiving step may be performed before S510. The capability information may include information indicating the maximum number of SRS ports supported for each SRS resource (e.g., the maximum number of SRS ports per each SRS resource).

The operations based on the above-described S510 to S520 and performance information receiving steps can be implemented by the device of FIG. 6. For example, the base station (100) can control one or more transceivers (130) and/or one or more memories (140) to perform operations based on the S510 to S520 and performance information receiving steps.

Hereinafter, a device to which an embodiment of the present specification can be applied (a device that implements a method/operation according to an embodiment of the present specification) is described with reference to FIG. 6.

FIG. 6 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

The processor (110) performs baseband-related signal processing and may include a higher layer processing unit (111) and a physical layer processing unit (115). The higher layer processing unit (111) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (115) may process operations of a PHY layer. For example, when the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (100) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (115) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (110) may also control the overall operation of the first device (100).

The antenna unit (120) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110), and software, an operating system, applications, etc. related to the operation of the first device (100), and may also include components such as a buffer.

The processor (110) of the first device (100) may be configured to implement the operation of the base station in the base station-to-terminal communication (or the operation of the first terminal device in the terminal-to-terminal communication) in the embodiments described in the present disclosure.

The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

The processor (210) performs baseband-related signal processing and may include a higher layer processing unit (211) and a physical layer processing unit (215). The higher layer processing unit (211) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (215) may process operations of a PHY layer. For example, when the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (200) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (210) may also control the overall operation of the second device (210).

The antenna unit (220) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210), software, an operating system, applications, etc. related to the operation of the second device (200), and may also include components such as a buffer.

The processor (210) of the second device (200) may be configured to implement operations of the terminal in base station-to-terminal communication (or operations of the second terminal device in terminal-to-terminal communication) in the embodiments described in the present disclosure.

In the operation of the first device (100) and the second device (200), the same explanations given for the base station and the terminal (or the first terminal and the second terminal in the terminal-to-terminal communication) in the examples of the present disclosure may be applied, and redundant explanations are omitted.

Here, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described names.

Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the above-described names.

Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) that take low-power communication into account, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PANs) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

Claims (15)

In terms of method, A step of receiving configuration information related to a physical uplink shared channel (PUSCH); and A step of transmitting the PUSCH based on one or more Sounding Reference Signal (SRS) resources; comprising: The above one or more SRS resources are related to codebook based transmission, The PUSCH is transmitted based on one or more antenna ports associated with the one or more SRS resources, A linear value of the transmission power associated with the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power, A method characterized in that the ratio is determined based on one of a plurality of values, based on the number of SRS ports based on the one or more SRS resources being 3. In the first paragraph, A method characterized in that the above ratio is determined as one of the above plurality of values. In the first paragraph, A method characterized in that the above ratio is determined based on i) the number of said one or more antenna ports and ii) one of said plurality of values. In the first paragraph, A method characterized in that the above plurality of values are set based on the above setting information or RRC signaling. In the first paragraph, A method characterized in that one of the plurality of values is indicated based on downlink control information (DCI) or MAC CE (Medium Access Control Control Element). In the first paragraph, A method characterized in that the one or more SRS resources are based on one SRS resource in which one of the four SRS ports is disabled. In the first paragraph, further comprising a step of transmitting capability information; A method characterized in that the above performance information includes information indicating the maximum number of SRS ports supported for each SRS resource. In paragraph 7, A method characterized in that the linear value is scaled by the ratio and X/3, wherein X is the maximum number of the supported SRS ports. In paragraph 7, The above linear values are scaled by a first ratio or a second ratio, The above first ratio is the above ratio, The second ratio is based on the ratio and X/3, where X is the maximum number of supported SRS ports, A method characterized in that the above setting information includes information indicating the first ratio or the second ratio used for the PUSCH. In paragraph 7, A method characterized in that the maximum number of the supported SRS ports is 1, 2, 3, 4 or 8. In the terminal, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A terminal characterized in that the instructions, based on being executed by the one or more processors, cause the terminal to perform all steps of the method according to any one of claims 1 to 10. In a device comprising one or more memories and one or more processors functionally connected to the one or more memories, A device characterized in that said one or more memories store instructions that cause said device to perform all steps of a method according to any one of claims 1 to 10, based on being executed by said one or more processors. In one or more non-transitory computer-readable storage media storing instructions, One or more non-transitory computer-readable storage media, characterized in that the instructions executable by one or more processors cause a terminal to perform all steps of a method according to any one of claims 1 to 10. In terms of method, A step of transmitting configuration information related to a physical uplink shared channel (PUSCH); and A step of receiving the PUSCH based on one or more Sounding Reference Signal (SRS) resources; comprising: The above one or more SRS resources are related to codebook based transmission, The PUSCH is transmitted based on one or more antenna ports associated with the one or more SRS resources, A linear value of the transmission power associated with the PUSCH is scaled by a ratio and then equally split across the one or more antenna ports through which the PUSCH is transmitted with non-zero power, A method characterized in that the ratio is determined based on one of a plurality of values, based on the number of SRS ports based on the one or more SRS resources being 3. At the base station, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A base station characterized in that the instructions, based on being executed by the one or more processors, cause the base station to perform all steps of the method according to claim 14.