WO2024158253A1 - Method for transmitting and receiving sounding reference signal in wireless communication system, 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 sounding reference signal (SRS); and transmitting the SRS on the basis of an SRS resource. The configuration information comprises information regarding the SRS resource. A plurality of symbols are configured in the SRS resource. Eight ports are time-division mapped to the plurality of symbols. The plurality of symbols are characterized by being dropped on the basis that at least one of the plurality of symbols overlaps a symbol related to another uplink signal.

Description

Method and device for transmitting and receiving sounding reference signals in a wireless communication system

This specification relates to a method and device for transmitting and receiving a sounding reference signal in a wireless communication system.

Mobile communication systems were developed to provide voice services while ensuring user activity. However, mobile communication systems have expanded their scope to include not only voice but also data services. Currently, the explosive increase in traffic is causing a shortage of resources and users are demanding higher-speed services, so a more advanced mobile communication system is required. .

The requirements for the next-generation mobile communication system are to support explosive data traffic, a dramatic increase in transmission rate per user, a greatly increased number of connected devices, very low end-to-end latency, and high energy efficiency. Must be able to. For this purpose, dual connectivity, massive MIMO (Massive Multiple Input Multiple Output), full duplex (In-band Full Duplex), NOMA (Non-Orthogonal Multiple Access), and ultra-wideband (Super) Various technologies, such as wideband support and device networking, are being researched.

Uplink 8 Tx transmission is supported according to Rel-18 MIMO SRS enhancement. 8-port SRS is supported for the uplink 8 Tx transmission (e.g., PUSCH transmission based on up to 8 layers/8 antenna ports). As an example, an 8 port SRS resource may be set in the terminal. Eight ports can be divided into two symbols and mapped.

According to the previously defined collision handling operation, when among SRS symbols overlap with the symbol(s) of another uplink channel/signal, only the overlapped SRS symbol(s) are dropped.

As described above, according to the existing collision handling method, among the symbols to which 8 ports are mapped, only symbols for which some ports are set can be dropped. In this case, problems may occur in channel estimation for subsequent PUSCH scheduling.

The purpose of this specification is to propose a method for solving 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 will be clearly understood by those skilled in the art from the description below. You will be able to.

A method performed by a terminal in a wireless communication system according to an embodiment of the present specification includes receiving configuration information related to a sounding reference signal (SRS) and transmitting the SRS based on SRS resources. Includes.

The configuration information includes information about SRS resources. A plurality of symbols are set in the SRS resource. Eight ports are time division mapped to the plurality of symbols.

The plurality of symbols are characterized in that they are dropped based on at least one of the plurality of symbols overlapping with a symbol related to another uplink signal.

The eight ports can be divided into two subsets, and each subset with four ports can be mapped to a different symbol.

The plurality of symbols may be based on two symbols to which the two subsets are mapped.

Ports of the first subset of the eight ports may be mapped to a symbol based on an even symbol index among the two symbols.

Ports of the second subset of the eight ports may be mapped to a symbol based on an odd symbol index among the two symbols.

The ports of the first subset may be based on four port indices among port indices 1000 to 1007.

The ports of the second subset may be based on the remaining four port indices among the port indices 1000 to 1007.

The usage of the SRS resource set to which the SRS resource belongs can be set to antenna switching or codebook.

The number of symbols set in the SRS resource may be 2, 4, 8, 10, 12, or 14.

The plurality of symbols may be one of one or more symbol groups based on the number of symbols.

Each of the one or more symbol groups may include two symbols to which two subsets are mapped based on the partition of the eight ports.

The other uplink signal may include at least one of a physical uplink control channel (PUCCH) or a sounding reference signal (SRS).

The method further includes receiving downlink control information (DCI) for scheduling of a physical uplink shared channel (PUSCH) and transmitting the PUSCH based on the DCI. can do.

One or more ports associated with the PUSCH may be the same as one or more ports indicated based on the DCI.

Based on at least one of the plurality of symbols overlapping with the symbol related to the other uplink signal, the plurality of symbols or the at least one symbol may be dropped. Based on the at least one symbol being dropped, the indicated one or more ports may be based on ports excluding ports mapped to the at least one symbol among the eight ports.

A terminal operating in a wireless communication system according to another embodiment of the present specification includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

The instructions, based on execution by the one or more processors, configure the one or more processors to perform all steps of the method according to any one of the methods.

A device according to another embodiment of the present specification includes one or more memories and one or more processors connected to the one or more memories.

The one or more memories store instructions that, based on execution by the one or more processors, configure the one or more processors to perform all steps of the method according to any one of the methods. It is characterized by

One or more non-transitory computer readable media stores instructions according to another embodiment of the present disclosure. The instructions executable by one or more processors are characterized in that they configure the one or more processors to perform all steps of the method according to any one of the methods.

A method performed by a base station in a wireless communication system according to another embodiment of the present specification includes transmitting configuration information related to a sounding reference signal (SRS) and receiving the SRS based on SRS resources. Includes steps.

The configuration information includes information about SRS resources. A plurality of symbols are set in the SRS resource. Eight ports are time division mapped to the plurality of symbols.

The plurality of symbols are characterized in that they are dropped based on at least one of the plurality of symbols overlapping with a symbol related to another uplink signal.

A base station operating in a wireless communication system according to another embodiment of the present specification includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

The instructions, based on execution by the one or more processors, configure the one or more processors to perform all steps of the method.

According to an embodiment of the present specification, eight ports are mapped to a plurality of symbols, and based on some symbols among the plurality of symbols overlapping with symbols related to other uplink channels/signals, the plurality of symbols are It is dropped.

Therefore, it is possible to prevent a decrease in the accuracy of uplink channel estimation when transmitting SRS based on 8 ports. Specifically, it is possible to prevent a decrease in the accuracy of uplink channel estimation due to dropping of some symbols among the symbols to which 8 ports are mapped.

Additionally, the reliability of PUSCH transmission and reception operations performed after the corresponding SRS transmission can be improved. Specifically, in the transmission of the scheduled PUSCH after the corresponding SRS transmission, the antenna port(s)/beam (spatial domain filter) most suitable for the channel condition can be used. That is, the antenna port(s)/beam (spatial domain filter) most suitable for the channel condition can be determined/instructed based on the DCI scheduling the PUSCH.

The effects that can be obtained in this specification are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art 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.

Figure 4 is a flowchart to explain a method performed by a terminal according to an embodiment of the present specification.

Figure 5 is a flowchart to explain a method performed by a base station according to another embodiment of the present specification.

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

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. The detailed description set forth below in conjunction with the accompanying drawings is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details to provide a thorough understanding of the invention. However, one skilled in the art will appreciate that the present invention may be practiced without these specific details.

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

Hereinafter, downlink (DL: downlink) refers to communication from the base station to the terminal, and uplink (UL: uplink) refers to communication from the terminal to the base station. In the downlink, the transmitter may be part of the base station and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal and the receiver may be part of the base station. The base station may be represented as a first communication device, and the terminal may be represented as a second communication device. A base station (BS) is a fixed station, Node B, evolved-NodeB (eNB), Next Generation NodeB (gNB), base transceiver system (BTS), access point (AP), and 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. there is. Additionally, the terminal may be fixed or mobile, and may include UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), and 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 behavior

The terminal can receive one or more Sounding Reference Symbol (SRS) resource sets (via higher layer signaling, RRC signaling, etc.) set by (higher layer parameter) SRS-ResourceSet. For each SRS resource set, the UE may be configured with K≥1 SRS resources (higher later 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) including usage parameters from the base station (S110). As an example, the usage parameter may be set to ‘beam management’, ‘codebook’, ‘nonCodebook’, or ‘antennaSwitching’.

Table 1 shows an example of SRS-Config IE (Information Element), and SRS-Config IE is used for SRS transmission settings. SRS-Config IE includes a list of SRS-Resources and a list of SRS-ResourceSets. Each SRS resource set means a set of SRS-resources.

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

In Table 1, usage indicates a higher layer parameter indicating whether the SRS resource set is used for beam management, codebook-based or non-codebook-based transmission. 'spatialRelationInfo' is a parameter that indicates the setting of spatial relation between reference RS and target SRS. Here, the reference RS can be 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, 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. Additionally, SRS-SpatialRelationInfo may or may not be set in each SRS resource.

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

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

At least one of the operations of the terminal/base station based on S110 to S140 described above is combined with embodiments related to Rel-18 SRS enhancement (e.g., at least one of Proposal 1, Proposal 2, and/or Proposal 3) described later. It can be applied.

SRS enhancement in Rel-17 MIMO

In NR TDD systems, the importance of UE's SRS transmission to secure UL and DL channel estimation performance has increased. Accordingly, standardization was carried out in Rel-17 MIMO with the following three goals.

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

Second, an NR terminal that supports DL rank 8 transmission must be equipped with at least 8 receiving antennas, and the SRS antenna change transmission technique to estimate the DL channel based on channel reciprocity in the NR TDD system requires a terminal with up to 4 receiving antennas. Support was provided only up to. Therefore, Rel-17 carried out standardization with the goal of supporting the SRS antenna change transmission technique for terminals equipped with more than four receiving antennas.

Third, standardization was carried out for the purpose of increasing the transmission coverage of SRS and increasing the capacity of SRS considering simultaneous access of multiple terminals.

More flexible aperiodic SRS transmission triggering technique

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

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

First, a technique was introduced to dynamically control the slot offset value for aperiodic SRS transmission trigger through DCI. This is to solve a problem in which SRS transmission may be significantly delayed depending on the DL and UL slot settings due to the existing slot offset value being semi-statically fixed.

For this purpose, a new DCI field was defined that specifies one of a plurality of slot offset values set in the RRC message. In addition, the slot offset value indicated through the DCI field is standardized to be calculated based on available slots, which are defined as uplink slots and slots composed of flexible symbols, thereby reducing the number of slots. Flexible SRS transmission triggering is possible with offset candidate values.

Second, a technique was introduced to trigger aperiodic SRS transmission without accompanying UL data transmission and CSI reporting. According to the conventional method, SRS transmission could be triggered together through UL DCI only when PUSCH is allocated to trigger UL data and/or CSI reporting. It was difficult for the base station to estimate the UL/DL channel by triggering SRS for a terminal in a situation where there was no UL data to transmit and aperiodic CSI reporting was not required. This technique is intended to solve the above-mentioned problems.

SRS antenna change transmission for terminals equipped with more than 4 receiving antennas

As described above, the SRS antenna change transmission technique supported by the Rel-15/16 NR system only considered terminals equipped with four receiving antennas. Rel-17 MIMO standardized the SRS antenna change transmission method for terminals equipped with 6 and 8 receiving antennas. The extended antenna change transmission method supports the following combinations of the number of Nt transmit antennas and the number of Nr receive antennas.

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 over two to four slots.

SRS coverage and capacity augmentation techniques

Figure 3 is a diagram illustrating partial band SRS transmission.

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

First, the maximum number of repeated transmissions of SRS was increased so that it could be used in systems that require wider coverage. In Rel-15 and Rel-16, SRS could be transmitted repeatedly for up to four symbols within one slot, except for location determination. In Rel-17 MIMO, SRS can be repeatedly transmitted 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.

The other is to allow SRS to be transmitted only in partial bands. To this end, the base station can set the resource block location and SRS transmission band where SRS transmission starts to the terminal. For SRS transmission, depending on the SRS frequency hopping period, the corresponding frequency position may also be hopping or fixed according to a set rule. Due to the introduction of this technique, different terminals can simultaneously transmit SRS in different partial bands to the same base station, increasing the capacity of SRS.

Lastly, SRS with lower frequency density was supported. Excluding the case for location determination in Rel-15/16, the frequency density of SRS supported was 1 RE per 2 RE or 1 RE per 4 RE. Accordingly, stable channel estimation performance could be secured in a frequency-selective channel environment, but there were limitations in securing SRS capacity. Therefore, in Rel-17 MIMO, a transmission technique that transmits SRS at 1 RE per 8 RE was additionally introduced, thereby enabling the SRS capacity to be further increased in a frequency non-selective channel environment.

The contents examined above can be applied in combination with the methods proposed in this specification, which will be described later, or can be supplemented to clarify the technical characteristics of the methods proposed in this specification. The methods described below are divided for convenience of explanation, and it goes without saying that some components of one method may be replaced with some components of another method or may be applied in combination with each other.

The definitions of abbreviations used in this specification are as follows.

MIMO (Multiple Input Multiple Output)

UL/DL (UpLink/DownLink)

CSI (Channel State Information)

RS (Reference Signal), SRS (Sounding Reference Signal)

PUSCH (Physical Uplink Shared Channel)

AS (Antenna Switching), CB (Codebook Based)

DCI (Downlink Control Information)

SRI (SRS Resource Indicator)

TDM (Time Division Multiplexing)

In NR Rel-15 MIMO, SRS can be used for UL link adaptation (codebook/non-codebook), beam management, and DL CSI acquisition (antenna switching). If there is a collision/partial collision between the SRS and another UL channel/RS (from time domain to symbol-level), the following operations can be performed.

Standardization has been carried out so that the following operations are performed on SRS resources. i) If the priority of the SRS is high, the SRS is transmitted as is. ii) If the priority of the other UL channel/RS is high, instead of dropping all of the SRS resources, only the SRS symbols in the overlapping area are dropped, and the other UL channel/RS is transmitted.

In Rel-18, multi ports (e.g. 8 ports) of SRS for AS (antenna switching)/CB (codebook-based) use to improve channel estimation performance in SRS enhancement to support up to 8 layer PUSCH transmission in relation to SRS The operation of TDM for multi symbols (e.g. 2 symbols) was agreed upon (see Table 2 below).

In this specification, we look at problems and solutions when mapping an SRS multi port to another multi symbol through TDM (different SRS port(s) are mapped to different symbols) in an 8Tx terminal. Specifically, the vulnerabilities/problems of the existing legacy SRS configuration are described in Problem 1, and then the proposed technology for them is described in Proposals 1 to 3.

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

Problem 1

In Rel-18, as shown in the above standardization agreement result (Table 2), TDM operation in which multi ports of CB-use SRS are mapped to multi symbols can be supported. As a specific example, 8 ports can be time-division mapped to 2 symbols. Among the two symbols, four of the eight ports may be mapped to the first symbol, and the remaining four ports may be mapped to the second symbol.

At this time, a collision may occur between other UL channel/RS and SRS for CB use in some symbol(s). According to the existing method (e.g. legacy SRS setting), the following operations are performed. If the priority of the other UL channel/RS is high, the symbol(s) in which collision occurred among the symbols for the corresponding SRS is dropped.

As shown above, if only the symsol(s) where the collision occurred is dropped, some ports out of the maximum 8 ports set in the SRS for CB use are not transmitted. In other words, due to the drop of some symbols in paired symbols (where time division mapping has been performed for up to 8 port SRS transmission), it becomes impossible to transmit all ports (e.g. 8 ports) set in the corresponding SRS resource. To solve this problem, we propose a method for handling collisions between SRS and other UL channels/RS.

Hereinafter, 'specific SRS resource set' may be an SRS resource set whose usage is set to codebook or antenna switching.

In addition, 'TDMed SRS resource' may mean an SRS resource in which a plurality of symbols (eg, 2 symbols) to which a plurality of ports (eg, 8 ports) are time division mapped are set.

Additionally, 'paired symbols' may mean symbols in which a plurality of ports (e.g., 8 ports) are time division mapped.

As an example, 8 antenna ports which are partitioned into 2 subsets may be set in the SRS resource (e.g., in Table 1, the nrofSRS-Ports-n8 parameter is set to ports8tdm ). Each subset can have 4 different ports. Subsets are mapped to different symbols.

Specifically, when 4 symbols are set in the SRS resource (e.g. nrofSymbols = n4, symbol indexes 0~3), 2 subsets are created for each 2 symbols (e.g. symbol indexes 0 & 1, symbol indexes 2 & 3). is mapped. 'Paired symbols' may mean symbols to which the two subsets are mapped (e.g., two symbols based on symbol indexes 0 & 1, symbol indexes 2 & 3).

In this specification, 'port' may mean an antenna port or SRS port. In this specification, the port index may be indicated as 0 to 7 or 1000 to 1007. That is, port #0 to #7 may mean port index #1000 to #1007, and vice versa.

suggestion 1

The base station can perform scheduling/resource allocation to prevent collisions (for some symbols corresponding to some antenna ports) with other UL channels/RSs for TDMed SRS resources within a specific SRS resource set.

According to Proposal 1, the UE does not expect collisions with other channels (some symbols to which some antenna ports are mapped) for TDM multi-port SRS resources.

According to Proposal 1, scheduling/resource allocation is performed to prevent situations like Problem 1 described above from occurring. Accordingly, the problem of deterioration of channel estimation accuracy when transmitting an SRS based on symbols to which a plurality of ports are time-division mapped can be prevented.

suggestion 2

If a collision occurs in a partial symbol among paired symbols in the SRS resource within a specific SRS resource set, the terminal may be set/instructed/defined to drop all corresponding paired symbols. The following will explain with a specific example.

For example, it can be assumed that 8 ports are set to the SRS resource in the SRS resource set for CB use, and the 8 ports are TDM mapped to symbols #0, 1, 2, and 3 (repetition factor, R= 2). Four ports (e.g. port #0, 2, 4, 6 or port # 0, 1, 4, 5) are mapped/set to symbol #0, 2, and the remaining 4 ports are mapped to symbol #1, 3. (e.g. port #1,3,5,7 or port #2, 3, 6, 7) can be mapped/configured. At this time, a collision may occur in symbol #1 with another UL channel/RS that has a higher priority than the corresponding SRS.

According to the existing legacy SRS settings, only symbol #1 is dropped and symbols #0, 2, and 3 are transmitted. That is, the corresponding SRS is transmitted based on symbols #0, 2, and 3. Sounding based on 8 ports in paired symbols #0, #1 cannot be achieved, and 4 ports (e.g. port #0, 2, 4, 6 or port # 0, 1, 4, 5) based on symbol #0 are not possible. ) only sounding based on is performed.

For 4 ports (e.g. port #0,2,4,6 or port #0, 1, 4, 5), 2 symbols are transmitted and for the remaining 4 ports (e.g. port #1,3,5, 7 or port # 2, 3, 6, 7), 1 symbol is transmitted. Therefore, differences in channel estimation performance may occur between port groups consisting of 8 ports (e.g., each subset consisting of 4 ports).

According to Proposal 2, the terminal also drops symbol #0, which did not collide among paired symbols #0 and #1. Specifically, the terminal drops paired symbols #0 and #1 that have collided, and transmits symbols #2 and #3. SRS is transmitted with the same number of symbols for each subset consisting of 4 ports. Sounding for all 8 ports can be performed under equal conditions (e.g. number of symbols).

According to Proposal 2, the following effects are derived.

If channel estimation is performed based on some of the subsets that make up the 8 ports, there may be differences with information in the existing SRS and the channel estimation quality may deteriorate. Instead of dropping only the symbol(s) in which a collision occurred, all paired symbols can be dropped to prevent deterioration in channel estimation quality and improve resource utilization.

Proposal 3

Partial symbol collisions may be allowed in paired symbols for SRS resources within a specific SRS resource set. That is, as before, the terminal can drop only the symbol in which a collision occurred among the paired symbols and transmit the SRS based on the remaining symbol(s).

In this case, the base station does not perform scheduling for PUSCH of up to 8 ports when scheduling PUSCH through UL grant DCI after transmitting the relevant SRS resource (until transmitting SRS for additional codebook purposes) or sets a rule that prevents the scheduling from being performed. Constraints can be defined.

The existing legacy PUSCH scheduling operation can be performed as follows. The base station receives the SRS for codebook use from the terminal. Afterwards, the base station can use the SRI field in the UL grant DCI (i.e., DCI for scheduling of PUSCH) to indicate some SRS resources among the SRS resources for the received codebook. Based on the instruction, the transmission beam (i.e. spatial domain filter) and port(s) to be used for PUSCH can be determined/instructed. The terminal interprets the SRI indication based on SRS resources for codebook purposes recently transmitted before receiving the corresponding UL grant DCI. Specifically, the terminal utilizes the transmission beam and port(s) of the latest SRS resource for PUSCH transmission.

If partial drop (drop of a partial symbol among paired symbols) occurs in the recent SRS resource transmission as in problem 1, sounding of up to 8 ports may not be performed fairly or some ports may be dropped. Considering this, constraints that allow the base station to perform scheduling based on up to The X port(s) may be set/indicated/defined in advance.

Alternatively, X port may be defined/defined as the number of ports on which remaining transmissions were performed after some port transmissions were dropped due to partial drop. For example, it can be assumed that SRS transmission for codebook purposes was transmitted by distributing 4 ports to symbols #0 and #1, of which symbol #1 was dropped. The base station can perform PUSCH scheduling based on up to 4 ports after transmitting the corresponding SRS (until before transmitting SRS for additional codebook purposes).

According to Proposal 3, the following effects are derived.

The operation of dropping some symbols in which collisions occurred among paired symbols is problematic in that channel sounding is performed unbalanced for each of the two subsets that make up eight ports, affecting subsequent PUSCH scheduling.

According to Proposal 3, the number of ports in subsequent PUSCH scheduling is limited until additional SRS transmission is performed. Unbalanced sounding is performed for each subset to minimize negative effects on subsequent PUSCH scheduling.

Additionally, according to Proposal 3, the existing behavior defined for collision handling is maintained. In other words, this embodiment has an advantage in terms of implementation complexity compared to defining additional operations for collision handling.

Proposals 1 to 3 may be implemented using specific combinations.

Proposals 1 to 3 above are also applicable to 8 port SRS for antenna switching/non-codebook purposes.

Below, we look at signaling procedures based on the above-described embodiments.

An example of a terminal (or base station) operation based on at least one of the above-described embodiments (e.g., at least one of the embodiments of Proposals 1 to 3) is as follows.

1) The terminal (base station) receives (transmits) settings related to SRS (e.g. SRS-config in Table 1). The setting information may include information/settings based on at least one of Proposals 1 to 3.

2) The terminal (base station) receives (transmits) a message that sets/instructs/triggers transmission of the SRS. The message may be based on RRC, MAC CE or DCI.

3) The terminal (base station) transmits (receives) SRS based on the message. At this time, settings based on at least one of Proposals 1 to 3 may be applied.

As an example, the SRS can be set/scheduled/instructed/triggered so that some of the paired symbols do not collide with other UL channels/signals (Proposal 1).

For example, based on some of the paired symbols colliding with other UL channels/signals, the terminal may drop the paired symbols (Proposal 2).

For example, based on the fact that some of the paired symbols collide with other UL channels/signals, the terminal can drop only the symbols in which the collision occurred (Proposal 3).

4) The terminal (base station) receives (transmits) a message (e.g. DCI) that sets/instructs PUSCH transmission. The message may be based on the embodiment of Proposal 3. The UE can expect the PUSCH to be scheduled based on ports mapped to symbols that were not dropped. The base station can schedule PUSCH based on ports mapped to symbols that were not dropped.

5) The terminal (base station) transmits (receives) PUSCH based on the above message.

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

In terms of implementation, the operations of the base station/terminal according to the above-described embodiments (e.g., operations based on at least one of the embodiments of Proposals 1 to 3) are similar to the device of FIG. 6 (e.g., the processor of FIG. 6 (e.g., the processor of FIG. 6) to be described later. It can be processed by 110, 210)).

Additionally, the operations of the base station/terminal according to the above-described embodiments (e.g., operations based on at least one of the embodiments of Proposals 1 to 3) include at least one processor (e.g., the processors 110 and 210 in FIG. 6). It may be stored in memory (e.g., 140 and 240 in FIG. 6) in the form of instructions/programs (e.g., instructions, executable code) for operation.

Hereinafter, the above-described embodiments will be described in detail with reference to FIGS. 4 and 5 in terms of operations of the terminal and the base station. The methods described below are divided for convenience of explanation, and it goes without saying that some components of one method may be replaced with some components of another method or may be applied in combination with each other.

Figure 4 is a flowchart to explain a method performed by a terminal according to an embodiment of the present specification.

Referring to FIG. 4, the method performed by the terminal in the wireless communication system according to an embodiment of the present specification includes a step of receiving configuration information related to SRS (S410) and a step of transmitting SRS based on SRS resources (S420). Includes.

In S410, the terminal receives configuration information related to a sounding reference signal (SRS) from the base station. The configuration information includes information about SRS resource(s). As an example, the configuration information may be based on SRS-Config in Table 1.

The usage of the SRS resource set to which the SRS resource belongs can be set to codebook, non-codebook, beam management, or antenna switching.

The setting information may include information related to operations/settings based on at least one of proposals 1 to 3 described above.

Multiple symbols may be set in the SRS resource. Eight ports may be time division mapped to the plurality of symbols.

The eight ports can be divided into two subsets. Each subset with four (different) ports can be mapped to a different symbol. As an example, two subsets may be mapped to two symbols.

The number of symbols (eg, nrofSymbols) set in the SRS resource may be 2, 4, 8, 10, 12, or 14. The plurality of symbols may mean all or part of the symbols based on the number of symbols set in the SRS resource.

As an example, the plurality of symbols may be based on two symbols to which the two subsets are mapped. That is, the number of symbols set in the SRS resource is 2 and the plurality of symbols may be total symbols (2 symbols) based on the number of symbols.

As an example, the plurality of symbols may be one of one or more symbol groups based on the number of symbols. Each of the one or more groups of symbols may include two symbols to which two subsets are mapped based on the partition of the eight ports.

Referring to the example of Proposal 2 above, the one or more symbol groups are group 1 (symbols #0, #1), group 2 (symbols #2, #) based on the number of symbols 4 (symbols #0 to #3). 3) may be included.

Among the eight ports (ports #0~#7), the first subset containing four ports (e.g. port #0,2,4,6 or port #0,1,4,5) is symbols #0. , can be mapped to #2. The second subset containing the remaining four ports (e.g. port #1, 3, 5, 7 or port #2, 3, 6, 7) may be mapped to symbols #1 and #3.

As above, the two subsets can be mapped based on the symbol index. According to one embodiment, the ports of the first subset of the eight ports are mapped to symbols based on an even symbol index (e.g., symbol index 0, 2..) among the two symbols. It can be.

Ports of the second subset of the eight ports may be mapped to symbols based on odd symbol indices (e.g., symbol index 1, 3, etc.) among the two symbols.

The ports of the first subset may be based on four port indices (eg, 1000, 1002, 1004, 1006 or 1000, 1001, 1004, 1005) among port indices 1000 to 1007. The ports of the second subset may be based on the remaining four port indices (eg, 1001, 1003, 1005, 1007 or 1002, 1003, 1006, 1007) among the port indices 1000 to 1007.

In S420, the terminal transmits the SRS to the base station based on the SRS resource.

For example, the SRS may be transmitted in symbols based on the SRS resource. For example, the SRS may be transmitted based on the eight ports. For example, in each of the symbols based on the SRS resource, the SRS may be transmitted based on the port(s) mapped to the corresponding symbol.

As an example, the SRS may be periodic SRS (periodic SRS), aperiodic SRS (aperiodic SRS), or semi-persistent SRS (semi-persistent SRS).

According to one embodiment, the plurality of symbols or the at least one symbol may be dropped based on the fact that at least one of the plurality of symbols overlaps a symbol related to another uplink signal. Here, being dropped may mean that the corresponding SRS is not transmitted in the dropped symbol(s).

This embodiment may be based on Proposal 2 and/or Proposal 3. As an example, the plurality of symbols may be dropped. As an example, the at least one symbol may be dropped.

The other uplink signal may include at least one of a physical uplink control channel (PUCCH) or a sounding reference signal (SRS).

The method may further include a DCI receiving step and a PUSCH transmitting step.

In the DCI reception step, the terminal receives downlink control information (DCI) for scheduling of a physical uplink shared channel (PUSCH) from the base station.

In the PUSCH transmission step, the terminal transmits the PUSCH to the base station based on the DCI. One or more ports associated with the PUSCH may be the same as one or more ports indicated based on the DCI.

As an example, the DCI may include an SRS Resource Indicator (SRI) field. Based on the SRI field, one or more SRS resources among the SRS resources of the SRS resource set may be determined. The one or more ports associated with the PUSCH may be based on the port(s) associated with the one or more SRS resources (e.g., the eight ports).

According to one embodiment, based on at least one of the plurality of symbols overlapping with the symbol related to the other uplink signal, the at least one symbol may be dropped.

If some of the symbols mapped to the two subsets are dropped as described above, the number of ports related to PUSCH scheduling may be limited. Specifically, based on the at least one symbol being dropped, the indicated one or more ports may be based on ports excluding ports mapped to the at least one symbol among the eight ports. This embodiment may be based on Proposal 3. For example, referring to the above-mentioned example, it may be assumed that symbol #1 among symbols #0 and #1 is dropped. The one or more ports indicated above are ports (e.g. port #0) excluding the four ports mapped to symbol #1 (e.g. port #1,3,5,7 or port #2,3,6,7). ,2,4,6 or port #0,1,4,5).

Operations based on the above-described steps S410 to S420, the DCI reception step, and the PUSCH transmission step can be implemented by the device in FIG. 6. For example, the terminal 200 may control one or more transceivers 230 and/or one or more memories 240 to perform operations based on S410 to S420, the DCI reception step and the PUSCH transmission step.

Hereinafter, the above-described embodiments will be described in detail in terms of base station operation.

S510 to S520, the DCI transmission step and the PUSCH reception step, described later, correspond to S410 to S420, the DCI reception step and the PUSCH transmission step described in FIG. 4. Considering the above correspondence, redundant description will be omitted. That is, the detailed description of the base station operation described later can be replaced with the description/embodiment of FIG. 4 corresponding to the corresponding operation.

As an example, the description/embodiment of S410 to S420 of FIG. 4 may be additionally applied to the base station operation of S510 to S520, which will be described later. As an example, the description/embodiment of the DCI reception step and PUSCH transmission step described above may be additionally applied to the base station operation according to the DCI transmission step and PUSCH reception step described later.

Figure 5 is a flowchart to explain a method performed by a base station according to another embodiment of the present specification.

In S510, the base station transmits configuration information related to a sounding reference signal (SRS) to the terminal.

In S520, the base station receives the SRS from the terminal based on the SRS resource.

The method may further include a DCI transmission step and a PUSCH reception step.

In the DCI transmission step, the base station transmits downlink control information (DCI) for scheduling of a physical uplink shared channel (PUSCH) to the terminal.

In the PUSCH reception step, the base station receives the PUSCH from the terminal based on the DCI.

The operations based on the above-described steps S510 to S520, the DCI transmission step and the PUSCH reception step can be implemented by the device of FIG. 6. For example, the base station 100 may control one or more transceivers 130 and/or one or more memories 140 to perform operations based on S510 to S520, the DCI transmission step and the PUSCH reception step.

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) will be described with reference to FIG. 6.

Figure 6 is a diagram 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 an upper layer processing unit 111 and a physical layer processing unit 115. The upper layer processing unit 111 can process operations of the MAC layer, RRC layer, or higher layers. The physical layer processing unit 115 can process PHY layer operations. For example, when the first device 100 is a base station device in base station-to-device 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 the first terminal device in terminal-to-device communication, the physical layer processing unit 115 performs downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. can do. 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 may support MIMO transmission and reception when it includes a plurality of antennas. The transceiver 130 may include a radio frequency (RF) transmitter and an RF receiver. The memory 140 may store information processed by the processor 110 and software, operating system, and applications related to the operation of the first device 100, and may also include components such as buffers.

The processor 110 of the first device 100 is set to implement the operation of the base station in communication between base stations and terminals (or the operation of the first terminal device in communication between terminals) in the embodiments described in this disclosure. It can be.

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 an upper layer processing unit 211 and a physical layer processing unit 215. The upper layer processing unit 211 can process operations of the MAC layer, RRC layer, or higher layers. The physical layer processing unit 215 can process PHY layer operations. For example, when the second device 200 is a terminal device in communication between a base station and a terminal, 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-device communication, the physical layer processing unit 215 performs downlink received signal processing, uplink transmitted signal processing, sidelink received signal processing, etc. can do. 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 may support MIMO transmission and reception when it includes a plurality of antennas. Transceiver 230 may include an RF transmitter and an RF receiver. The memory 240 may store information processed by the processor 210 and software, operating system, and applications related to the operation of the second device 200, and may also include components such as buffers.

The processor 210 of the second device 200 is set to implement the operation of the terminal in communication between base stations and terminals (or the operation of the second terminal device in communication between terminals) in the embodiments described in this disclosure. It can be.

Regarding the operation of the first device 100 and the second device 200, in the examples of the present disclosure, the base station and the terminal in base station-to-device communication (or the first terminal and the second terminal in terminal-to-device communication) The items described can be applied equally, and overlapping explanations will be omitted.

Here, the wireless communication technology implemented in the devices 100 and 200 of the present disclosure may include Narrowband Internet of Things (NB-IoT) for low-power communication as well as LTE, NR, and 6G. 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-mentioned names.

Additionally or alternatively, the wireless communication technology implemented in the devices 100 and 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 various names such as enhanced Machine Type Communication (eMTC). For example, LTE-M technologies include 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. It can be implemented in at least one of various standards such as Type Communication, and/or 7) LTE M, and is not limited to the above-mentioned names.

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

Claims (17)

In a method performed by a terminal in a wireless communication system, Receiving configuration information related to a sounding reference signal (SRS), the configuration information including information about SRS resources; and Transmitting the SRS based on the SRS resource; including, A plurality of symbols are set in the SRS resource, Eight ports are time division mapped to the plurality of symbols, A method wherein the plurality of symbols are dropped based on at least one of the plurality of symbols overlapping with a symbol related to another uplink signal. According to claim 1, A method characterized in that the eight ports are divided into two subsets, and each subset having four ports is mapped to a different symbol. According to clause 2, A method wherein the plurality of symbols are based on two symbols to which the two subsets are mapped. According to clause 3, Ports of the first subset of the eight ports are mapped to a symbol based on an even symbol index among the two symbols, A method characterized in that ports of a second subset of the eight ports are mapped to a symbol based on an odd symbol index among the two symbols. According to clause 4, The ports of the first subset are based on four port indices of port indices 1000 to 1007, The method characterized in that the ports of the second subset are based on the remaining four port indices of the port indices 1000 to 1007. According to claim 1, A method characterized in that the usage of the SRS resource set to which the SRS resource belongs is set to antenna switching or codebook. According to claim 1, A method characterized in that the number of symbols set in the SRS resource is 2, 4, 8, 10, 12, or 14. According to clause 7, The plurality of symbols are one of one or more symbol groups based on the number of symbols, Wherein each of the one or more symbol groups includes two symbols to which two subsets are mapped based on the partition of the eight ports. According to claim 1, Wherein the other uplink signal includes at least one of a Physical Uplink Control CHannel (PUCCH) or a Sounding Reference Signal (SRS). According to claim 1, Receiving downlink control information (DCI) for scheduling of a physical uplink shared channel (PUSCH); and The method further comprising transmitting the PUSCH based on the DCI. According to claim 10, wherein one or more ports associated with the PUSCH are the same as one or more ports indicated based on the DCI. According to claim 11, Based on at least one of the plurality of symbols overlapping with the symbol related to the other uplink signal, the plurality of symbols or the at least one symbol is dropped, Based on the at least one symbol being dropped, the indicated one or more ports are based on ports excluding ports mapped to the at least one symbol among the eight ports. In a terminal operating in a wireless communication system, One or more transceivers; one or more processors; and One or more memories coupled to the one or more processors and storing instructions, 13. A terminal, characterized in that, based on the instructions being executed by the one or more processors, the one or more processors are configured to perform all steps of the method according to any one of claims 1 to 12. A device comprising one or more memories and one or more processors coupled to the one or more memories, The one or more memories are provided with instructions for setting the one or more processors to perform all steps of the method according to any one of claims 1 to 12, based on execution by the one or more processors. ) A device characterized in that it stores. One or more non-transitory computer-readable media storing instructions, comprising: The instructions executable by one or more processors configure the one or more processors to perform all steps of the method according to any one of claims 1 to 12. ) computer-readable media. In a method performed by a base station in a wireless communication system, Transmitting configuration information related to a sounding reference signal (SRS), the configuration information including information about SRS resources; and Including; receiving the SRS based on the SRS resource, A plurality of symbols are set in the SRS resource, Eight ports are time division mapped to the plurality of symbols, A method wherein the plurality of symbols are dropped based on at least one of the plurality of symbols overlapping with a symbol related to another uplink signal. In a base station operating in a wireless communication system, One or more transceivers; one or more processors; and One or more memories coupled to the one or more processors and storing instructions, The base station, wherein the instructions configure the one or more processors to perform all steps of the method according to claim 16, based on which the instructions are executed by the one or more processors.

Images