CN112369088A

CN112369088A - Sounding reference signal transmission in unlicensed spectrum

Info

Publication number: CN112369088A
Application number: CN201880093956.7A
Authority: CN
Inventors: 陶涛; 刘建国; 骆喆; 武卓; 沈钢; 孟艳
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Oyj
Priority date: 2018-05-29
Filing date: 2018-05-29
Publication date: 2021-02-12
Anticipated expiration: 2038-05-29
Also published as: CN112369088B; WO2019227316A1

Abstract

Embodiments of the present disclosure relate to methods, devices, and computer-readable storage media for Sounding Reference Signal (SRS) transmission in unlicensed spectrum. In an example embodiment, a method implemented at a terminal device is provided. According to the method, in response to determining that a transmission gap exists in the unlicensed spectrum, a configuration for transmitting the SRS to the network device in the transmission gap is determined. Based on the configuration, the SRS is transmitted to the network device in the transmission gap. Embodiments of the present disclosure enable SRS transmission in a transmission gap (e.g., within a self-contained COT) regardless of whether explicit triggering for SRS transmission is provided. By occupying transmission gaps for SRS transmission, transmission opportunities for uplink control information can also be increased.

Description

Sounding reference signal transmission in unlicensed spectrum

Technical Field

Embodiments of the present disclosure relate generally to the field of communications, and, in particular, to methods, devices, and computer-readable storage media for Sounding Reference Signal (SRS) transmission in unlicensed spectrum.

Background

It is proposed that in a fifth generation (5G) New Radio (NR), the concept of self-contained Channel Occupancy Time (COT) or self-contained transmission opportunity (TXOP) can be used in unlicensed spectrum in order to improve system performance. The TXOP or COT may include multiple slots or subframes. In a self-contained TXOP or COT, hybrid automatic repeat request (HARQ) feedback for data received via one or more slots of the TXOP or COT may be transmitted within the same TXOP or COT. For example, in a self-contained slot, hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback for the Physical Downlink Shared Channel (PDSCH) of the slot may be provided at the end of the same slot (e.g., the last symbol or last few symbols). Delay jitter and system complexity may be minimized if all HARQ feedback can be transmitted in the same COT as its associated PDSCH.

However, self-contained COT places severe requirements on the processing power of the terminal equipment. Although the processing capability of the terminal device has been greatly improved in 5G NR, within the self-contained COT, there may still be a transmission gap (e.g., at least two symbols) between the end of the PDSCH and the earliest start of HARQ feedback for the PDSCH. Such transmission gaps within the self-contained COT may pose a risk in the unlicensed spectrum because channel access may be lost if other devices are also contending for channel access. It is therefore desirable to minimize such transmission gaps within self-contained COTs.

Disclosure of Invention

In general, example embodiments of the present disclosure provide methods, devices, and computer-readable storage media for SRS transmission in unlicensed spectrum.

In a first aspect, a method implemented at a terminal device is provided. According to the method, in response to determining that a transmission gap exists in the unlicensed spectrum, a configuration for transmitting the SRS to the network device in the transmission gap is determined. Based on the configuration, the SRS is transmitted to the network device in the transmission gap.

In a second aspect, a method implemented at a network device is provided. According to the method, in response to determining that a transmission gap exists in the unlicensed spectrum, a configuration for receiving an SRS from a terminal device in the transmission gap is determined. Based on the configuration, an SRS is received from the terminal device in the transmission gap.

In a third aspect, an apparatus is provided. The apparatus includes a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the device to perform actions. These actions include: in response to determining that a transmission gap exists in the unlicensed spectrum, determining a configuration for transmitting the SRS to the network device in the transmission gap; and transmitting, based on the configuration, the SRS to the network device in the transmission gap.

In a fourth aspect, an apparatus is provided. The apparatus includes a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the device to perform actions. These actions include: in response to determining that a transmission gap exists in the unlicensed spectrum, determining a configuration for receiving an SRS from the terminal device in the transmission gap; and receiving an SRS from the terminal device in the transmission gap based on the configuration.

In a fifth aspect, a computer-readable medium having instructions stored thereon is provided. The instructions, when executed on at least one processor, cause the at least one processor to perform a method according to the first aspect of the present disclosure.

In a sixth aspect, a computer-readable medium having instructions stored thereon is provided. The instructions, when executed on at least one processor, cause the at least one processor to perform a method according to the second aspect of the present disclosure.

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

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent from the following more detailed description of some embodiments of the present disclosure in which:

FIG. 1 shows an example of a self-contained COT;

FIG. 2 is a block diagram of a communication environment in which embodiments of the present disclosure may be implemented;

fig. 3 illustrates a flow diagram of an example method for transmitting SRS, in accordance with some embodiments of the present disclosure;

fig. 4 illustrates an example of frequency domain resource allocation for SRS transmission, in accordance with some embodiments of the present disclosure;

fig. 5 illustrates a flow diagram of an example method for receiving SRS, in accordance with some embodiments of the present disclosure; and

fig. 6 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

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

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is understood that these examples are described for illustrative purposes only and to aid those skilled in the art in understanding and enabling the present disclosure, and do not imply any limitation on the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

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

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard or protocol, such as Long Term Evolution (LTE), LTE-advanced (LTE-a), and fifth generation (5G) New Radio (NR), and that employs any suitable communication technology, including, for example, multiple-input multiple-output (MIMO), OFDM, Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), bluetooth, ZigBee, Machine Type Communication (MTC), eMBB, MTC, and urrllc technologies. For purposes of discussion, in some embodiments, an LTE network, an LTE-a network, a 5G NR network, or any combination thereof are examples of communication networks.

As used herein, the term "network device" refers to any suitable device on the network side of a communication network. The network device may comprise any suitable device in an access network of a communication network, including, for example, a Base Station (BS), a relay, an Access Point (AP), a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a gigabit NodeB (gnb), a remote radio module (RRU), a Radio Header (RH), a Remote Radio Head (RRH), a low power node (such as a femto node, pico node, etc.). For discussion purposes, in some embodiments, an eNB is taken as an example of a network device.

The network equipment may also include any suitable equipment in the core network, including, for example, multi-standard radio (MSR) radios such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or Base Station Controllers (BSCs), multi-cell/Multicast Coordination Entities (MCEs), Mobile Switching Centers (MSCs) and MMEs, operations and management (O & M) nodes, Operations Support Systems (OSS) nodes, self-organizing network (SON) nodes, location nodes such as enhanced serving mobile location centers (E-SMLCs), and/or Mobile Data Terminals (MDTs).

As used herein, the term "terminal device" refers to a device that is capable, configured, arranged and/or operable to communicate with a network device or another terminal device in a communication network. Communication may involve the transmission and/or reception of wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for the transmission of information over the air. In some embodiments, the terminal device may be configured to transmit and/or receive information without direct human interaction. For example, when triggered by an internal or external event, or in response to a request from the network side, the terminal device may transmit information to the network device on a predetermined schedule.

Examples of end devices include, but are not limited to, User Equipment (UE), such as a smart phone, a wireless-enabled tablet, a laptop embedded device (LEE), a laptop installation device (LME), and/or a wireless Customer Premises Equipment (CPE). For discussion purposes, some embodiments will be described below with reference to a UE as an example of a terminal device, and the terms "terminal device" and "user equipment" (UE) may be used interchangeably in the context of this disclosure.

As used herein, the term "cell" refers to an area covered by radio signals transmitted by a network device. Terminal devices within a cell may be served by a network device and may access a communication network via the network device.

As used herein, the term "circuitry" may refer to one or more or all of the following:

(a) a purely hardware circuit implementation (such as an implementation in analog and/or digital circuitry only), and

(b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuitry and software/firmware, and (ii) a hardware processor with software (including a digital signal processor), any portion of software and memory that work together to cause a device such as a mobile phone or server to perform various functions, and

(c) hardware circuitry and/or a processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) for operation but may not be present when software is not required for operation.

This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" also encompasses an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers (e.g., and where applicable to the particular claim element (s)) a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "comprising" and its variants should be understood as open-ended terms, meaning "including but not limited to". The term "based on" should be understood as "based at least in part on". The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". Other definitions (explicit and implicit) may be included below.

As described above, one of the main motivations for using self-contained COT in unlicensed spectrum is to transmit HARQ-ACK feedback in the same COT as the associated PDSCH. However, self-contained COT places severe requirements on the processing power of the terminal equipment. Although the processing capability of the terminal device has been greatly improved in 5G NR, there may still be a gap of at least two symbols between the end of the PDSCH and the earliest start of HARQ feedback for the PDSCH within the self-contained COT.

Fig. 1 shows an example of a self-contained COT. FIG. 1 shows a self-contained COT 100 that includes four slots 110-1, 110-2, 110-3, and 110-4 (collectively referred to as slots 110), each slot including 14 symbols. Slots 110-1, 110-2, and 110-3 are downlink-only slots, while slot 110-4 is a bi-directional slot. Symbols 0 through 2 in slot 110-4 are used for Physical Downlink Control Channel (PDCCH) transmission. Symbols 3 to 8 in slot 110-4 are used for PDSCH transmission. However, the 12 th and 13 th symbols in slot 110-4 are used to transmit uplink control information (such as HARQ feedback for PDSCH transmitted in slot 110).

As shown in fig. 1, there is a transmission gap 120 (i.e., the 9 th to 11 th symbols in slot 110-4) between the end of the PDSCH (i.e., the 8 th symbol in slot 110-4) and the earliest start of HARQ feedback (i.e., the 12 th symbol in slot 110-4). Transmission gaps 120 within self-contained COT 100 as shown in fig. 1 may be very dangerous in unlicensed spectrum because channel access may be lost if other devices are also contending for channel access. It is therefore desirable to minimize such transmission gaps within self-contained COTs.

Embodiments of the present disclosure provide a scheme for filling the above transmission gaps within a self-contained COT. The basic idea is to transmit Sounding Reference Signals (SRS) in the transmission gaps. When the gap within the self-contained COT is not too large (e.g., no more than 4 Orthogonal Frequency Division Multiplexing (OFDM) symbols), SRS may be a good candidate for transmission because NR already supports SRS durations of 1, 2, and 4 symbols.

Such additional SRS transmission opportunities may provide additional benefits. For example, a network device (such as a gNB) may trigger aperiodic SRS transmissions in a less frequent manner. SRS may have a higher probability of transmission in a shared COT initiated by a network device. Furthermore, more frequent and reliable SRS transmissions may result in better uplink channel quality assessment, finer timing advance estimation, and more reliable beam management.

The inventors have realized that supporting SRS transmission in self-contained COT gaps may face some bottlenecks. For example, a gap between the end of the PDSCH and the start of the Physical Uplink Control Channel (PUCCH) may vary according to the processing time of the terminal device. Without dynamic resource configuration for such SRS transmission, SRS transmissions from different terminal devices may collide. Therefore, the main challenge is how to trigger SRS transmission and dynamically configure SRS resources.

It is known that the SRS resource can be configured via Radio Resource Control (RRC) signaling in NR. The configuration for SRS resources may include antenna ports, consecutive OFDM symbols, a starting position in time and frequency domains, a bandwidth, a cyclic shift for SRS transmission, and the like. Three types of resource configurations are supported in NR for SRS transmission.

One of the three types is used for periodic SRS transmission. When the higher layer parameter "SRS-ResourceConfigType" is set to "periodicity", the terminal device will transmit SRS on the SRS resource configured via higher layer signaling. Another of the three types is used for semi-persistent SRS transmission. When the higher layer parameter "SRS-ResourceConfigType" is set to "semi-persistent", SRS transmission will be activated by a higher layer command and deactivated by another higher layer command. If the terminal device receives a command to activate SRS transmission, the terminal device will transmit SRS on SRS resources configured via higher layer signaling. The remaining one of the three types is used for aperiodic SRS transmission. When the higher layer parameter "SRS-ResourceConfigType" is set to "aperiodic", SRS transmission will be triggered by downlink or uplink control information. The control information may include a field that may be used to select at least one SRS resource from the set of configured SRS resources.

It can be seen that in NR, SRS resources can only be configured via higher layer signaling. Currently, dynamic configuration of SRS resources is not supported in NR. This means that current mechanisms for SRS transmission in NR cannot support SRS transmission in gaps within self-contained COT.

Embodiments of the present disclosure provide a solution for SRS transmission in unlicensed spectrum. With this solution, a terminal device can autonomously determine an SRS resource configuration and then perform SRS transmission accordingly, regardless of whether the terminal device receives an explicit trigger for SRS transmission.

The principles and several embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Fig. 2 illustrates an example communication network 200 in which embodiments of the present disclosure may be implemented. Network 200 includes a network device 210 and three terminal devices 220-1 and 220-3 (collectively referred to as terminal devices 220 or individually as terminal devices 220) served by network device 210. The coverage area of network device 210 is also referred to as cell 202. It should be understood that the number of base stations and terminal devices is for illustration purposes only and does not imply any limitations. Network 200 may include any suitable number of base stations and terminal devices suitable for implementing embodiments of the present disclosure. Although not shown, it should be understood that there may be one or more neighboring cells adjacent to cell 202, where one or more corresponding network devices serve several terminal devices located therein.

In the communication network 200, the network device 210 may transmit data and control information to the terminal device 220, and the terminal device 220 may also transmit data and control information to the network device 210. The link from the network device 210 to the terminal device 220 is referred to as the Downlink (DL), and the link from the terminal device 220 to the network device 210 is referred to as the Uplink (UL).

Communications in network 200 may conform to any suitable standard including, but not limited to, global system for mobile communications (GSM), Long Term Evolution (LTE), LTE evolution, LTE advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), and so forth. Further, the communication may be performed according to any generational communication protocol currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communication protocols.

In addition to normal data communication, the network device 210 can transmit an RS to the terminal device 220 in downlink. Similarly, terminal device 220 may transmit an RS in the uplink to network device 210. In general, the RS is a signal sequence (also referred to as "RS sequence") known to both the network device 210 and the terminal device 220. For example, the uplink RS may be generated and transmitted by the terminal device 220 based on a certain rule, and the network device 210 may derive the RS based on the same rule. Examples of RSs may include, but are not limited to, downlink or uplink demodulation reference signals (DMRSs), channel state information reference signals (CSI-RSs), Sounding Reference Signals (SRS), Phase Tracking Reference Signals (PTRS), Tracking Reference Signals (TRSs), fine time-frequency Tracking Reference Signals (TRSs), and so forth.

To transmit a downlink or uplink RS, corresponding resources (also referred to as "RS resources") may be allocated for transmission. In some scenarios, both network device 210 and terminal device 220 are equipped with multiple antenna ports (or antenna elements) and may utilize the antenna ports (antenna elements) to transmit a specified RS sequence. As used herein, an RS resource may be referred to as one or more resource elements allocated for RS transmission in the time, frequency, and/or code domain.

In the communication network 200, the terminal device 220 may autonomously transmit the SRS to the network device 210, irrespective of whether the terminal device 220 receives an explicit trigger for the transmission of the SRS. For example, when terminal device 220 finds a transmission gap in the unlicensed spectrum, it may perform SRS transmission. Specifically, the terminal device 220 may autonomously determine the SRS resource configuration and then perform SRS transmission accordingly.

Fig. 3 illustrates a flow diagram of an example method 300 for transmitting SRS, in accordance with some embodiments of the present disclosure. The method 300 may be implemented at the terminal device 220 as shown in fig. 1. For discussion purposes, the method 300 will be described with reference to fig. 1 from the perspective of the terminal device 220. It should be understood that method 300 may include additional blocks not shown, and/or may omit some blocks shown, and the scope of the present disclosure is not so limited.

At block 310, the terminal device 220 determines whether a transmission gap exists in the unlicensed spectrum.

In some embodiments, the transmission gap may exist before the start of the uplink channel. For example, the uplink channel may be any one of PUCCH, Physical Uplink Shared Channel (PUSCH), and the like. In this case, for example, terminal device 220 may determine the existence of a transmission gap based at least on the configuration for the uplink channel from network device 210.

Alternatively or additionally, in some embodiments, a transmission gap may exist in the COT between the end of the downlink channel and the start of the uplink channel. For example, the transmission gap may be located between the end of the PDSCH and the start of the PUCCH in the same self-contained COT as the PDSCH. The terminal device 220 may determine the existence of a transmission gap based on the configuration of the downlink channel and the uplink channel from the network device 210.

For illustration purposes only, in some of the following examples, transmission gaps may be shown to be within a self-contained COT in unlicensed spectrum. It should be understood that this is done for illustrative purposes only and does not imply any limitation on the scope of the disclosure. Indeed, embodiments of the present disclosure are also applicable to any transmission gap in the unlicensed spectrum, whether or not the transmission gap is within a self-contained COT.

If terminal device 220 determines that a transmission gap (e.g., transmission gap 120 shown in fig. 1) exists in the unlicensed spectrum, method 300 proceeds to block 320, at block 320, terminal device 220 determines a configuration for transmitting an SRS to network device 210 in the transmission gap.

In some embodiments, instead of obtaining the configuration via RRC signaling, the terminal device 220 may determine the configuration for transmission of the SRS in an implicit manner. For example, terminal device 220 may determine at least one resource to use for transmission of SRS and then determine a configuration for transmission of SRS based on the at least one resource.

In some embodiments, terminal device 220 may determine at least one resource to use for transmission of SRS based on at least one of: its processing capabilities, Downlink Control Information (DCI) received from network device 210, an indication of PUCCH resources received from network device 210 (e.g., an acknowledgement/negative acknowledgement (ACK/NACK) resource indicator (ARI)), etc. The at least one resource for transmission of the SRS may include at least one of a time domain resource, a frequency domain resource, and a code domain resource.

In some embodiments, the at least one resource for transmission of SRS may comprise a time domain resource. The terminal device 220 may determine the time domain resource by determining at least one of: a starting position in the time domain at which the SRS is transmitted and a duration of transmission of the SRS (e.g., a number of consecutive OFDM symbols).

In some embodiments, terminal device 220 may determine the starting location and/or duration of SRS transmission based on its own processing capabilities. For example, if the processing time from the end of the PDSCH to the earliest start of HARQ feedback is 4 OFDM symbols, the terminal device may determine the duration of SRS transmission as 4 OFDM symbols. Additionally, terminal device 220 may determine that the starting position of SRS transmission is 4 OFDM symbols before the start of PUCCH for transmitting HARQ feedback.

Alternatively or additionally, in some embodiments, when the transmission gap is between the end of the downlink channel and the start of the uplink channel in the COT, the terminal device 220 may determine the time domain resource based on the position of the transmission gap in the COT. That is, terminal device 220 may determine the starting position and/or duration of SRS transmission based on the OFDM symbols occupied by the transmission gaps.

Alternatively or additionally, in some embodiments, terminal device 220 may determine the starting location and/or duration of SRS transmission based on DCI received from network device 210. For example, the DCI may include a Slot Format Indication (SFI) indicating whether the OFDM symbol is uplink, downlink, or flexible. Terminal device 220 may determine a starting location for SRS transmission based at least on the SFI. In some embodiments, network device 210 may transmit an explicit SRS trigger to terminal device 220 via layer 1 signaling. For example, network device 210 may use an SRS request field in DCI (e.g., with format 1_1) to trigger SRS transmission in self-contained COT gaps. In some embodiments, terminal device 220 may determine the duration of SRS transmission based on the SRS request field in the DCI.

In NR, the submitted SRS request typically contains two or three bits indicating the selected set of SRS resources configured via higher layer signaling. In some embodiments, the SRS request field in the DCI may be used to support dynamic SRS transmission in a self-contained COT. For example, the 2-bit information may be used to indicate a duration of SRS transmission (e.g., a number of consecutive OFDM symbols). Table 1 shows an example of an SRS request field according to some embodiments of the present disclosure.

Table 1: examples of SRS request fields

Value of SRS request field	Description of the invention
		“00”	SRS is not triggered.
“01”	The number of consecutive OFDM symbols used for SRS transmission is 1.
		“10”	The number of consecutive OFDM symbols used for SRS transmission is 2.
“11”	The number of consecutive OFDM symbols used for SRS transmission is 4.

When terminal device 220 receives DCI including an SRS request field from network device 210 and the value of the SRS request field is not "00", terminal device 220 may determine the duration of SRS transmission based on the value of the SRS request field. Furthermore, terminal device 220 may also determine that the starting position of SRS transmission is at X OFDM symbols before the start of the PUCCH for transmitting HARQ feedback, where X may be 1, 2, or 4.

In some embodiments, the at least one resource for transmission of SRS may comprise a frequency domain resource. The terminal device 220 may determine the frequency domain resources by determining at least one of a location of the frequency domain resources in the frequency domain and a bandwidth used for transmission of the SRS.

In some embodiments, terminal device 220 may receive an indication of PUCCH resources from network device 210. For example, terminal device 220 may receive an ACK/NACK resource indicator (ARI) from network device 210. Terminal device 220 may determine PUCCH resources based on the ARI and may also determine frequency domain resources for SRS transmission based on the PUCCH resources.

Fig. 4 illustrates an example of frequency domain resource allocation for SRS transmission, in accordance with some embodiments of the present disclosure. In the example shown in fig. 4, the bandwidth of the unlicensed spectrum may be divided into a plurality of consecutive Physical Resource Blocks (PRBs). These PRBs may be further divided into a plurality of interleaved units, each of which includes several full or partial PRBs separated at the same interval. It is assumed herein that the frequency domain resources for SRS transmission may be allocated in units of PRB or interleaved units. It should be understood that this is for illustrative purposes only and does not imply any limitations on the present disclosure. In some other embodiments, the frequency domain resources may be allocated in different units.

As shown in FIG. 4, the self-contained COT 400 includes two slots 410-1 and 410-2, each of which includes 14 symbols. Time slot 410-1 is a downlink-only time slot and time slot 410-2 is a bi-directional time slot. Symbols 0 to 1 in slot 410-2 are used for PDCCH transmission. Symbols 2 to 7 in slot 410-2 are used for PDSCH transmission. Symbol 8 in slot 410-2 is used for DL-UL handover and Timing Advance (TA) adjustment. The 9 th through 12 th symbols in slot 410-2 are used for SRS transmission, and the 13 th symbol in slot 410-2 is used for PUCCH transmission (e.g., transmission of HARQ feedback for PDSCH transmitted in slots 410-1 and 410-2).

In some embodiments, if one or more full interleaving units are configured as PUCCH resources for transmitting HARQ feedback, the frequency domain resources for SRS transmission may be located in the same interleaving unit as the PUCCH resources. For example, as shown in fig. 4, interleaving unit 420 is allocated to terminal device 220-1 for PUCCH transmission. In this case, terminal device 220-1 may determine interleaving unit 420 as a frequency domain resource for SRS transmission. Additionally, terminal device 220-1 may also determine a bandwidth for SRS transmission based on the bandwidth of interleaving unit 420.

In some embodiments, if a portion of the complete interleaving unit is configured as a PUCCH resource for transmission of HARQ feedback, the frequency domain resource for SRS transmission may be located in the same portion of the interleaving unit as the PUCCH resource. For example, one interleaving unit may be shared by a plurality of terminal devices. In this case, code domain multiplexing may be utilized to avoid collisions from multiple terminal devices in the same interleaving unit. For example, as shown in fig. 4, interleaving unit 430 may be shared by terminal devices 220-2 and 220-3 for transmitting HARQ feedback, and terminal devices 220-2 and 220-3 may each occupy a respective portion of PRBs in interleaving unit 430. In this case, both terminal devices 220-2 and 220-3 may perform SRS transmission in interleaving unit 430, but with different cyclic shifts.

In some embodiments, the at least one resource for transmission of SRS may comprise a code domain resource. Terminal device 220 may determine the code domain resources by determining a cyclic shift to be used for transmission of the SRS. In some embodiments, terminal device 220 may receive an indication of PUCCH resources from network device 210. For example, terminal device 220 may receive an ACK/NACK resource indicator (ARI) from network device 210. Terminal device 220 can determine a PUCCH resource based on the ARI and further determine a cyclic shift to be used for transmission of the SRS based on the PUCCH resource.

In some embodiments, the mapping function may be predetermined based on a dependency between a cyclic shift to be used for transmission of the SRS and a starting position of the PUCCH resource or the ACK/NACK resource in the frequency domain. The terminal device 220 may determine a cyclic shift to be used for transmission of the SRS based on the predetermined mapping function. For example, an example of a mapping function may be represented as follows:

wherein

An index indicating a cyclic shift to be used for transmission of the SRS,

indicates an index of a starting cluster for PUCCH in an interleaving unit,

indicates the maximum number of clusters for PUCCH in the interleaving unit.

In this way, terminal device 220 may autonomously determine the resource configuration for transmission of SRS in a transmission gap, regardless of whether an explicit trigger for SRS transmission is received. Although the transmission gaps are shown within the self-contained COT in some examples as described above, it should be understood that this is for illustration purposes only and does not imply any limitation on the scope of the disclosure. Indeed, embodiments of the present disclosure are also applicable to any transmission gap in the unlicensed spectrum, whether or not the transmission gap is within a self-contained COT.

Referring again to fig. 3, method 300 proceeds to block 330, where terminal device 220 transmits SRS to network device 210 in transmission gaps based on the configuration.

In some embodiments, terminal device 220 may autonomously transmit SRS without explicit trigger from network device 210. For example, when terminal device 220 is triggered to transmit HARQ feedback in the short PUCCH at the end of the self-contained COT and terminal device 220 finds that there is a gap between the end of the PDSCH and the start of the short PUCCH, terminal device 220 may transmit SRS in the transmission gap.

Alternatively, in some embodiments, network device 210 may transmit an explicit SRS trigger to terminal device 220 via layer 1 signaling. For example, network device 210 may use an SRS request field in DCI (e.g., with format 1_1) to trigger SRS transmission in self-contained COT gaps. In some embodiments, terminal device 220 may transmit the SRS in response to receiving the explicit SRS trigger from network device 110.

In this way, the SRS may be transmitted in transmission gaps in the unlicensed spectrum, thereby reducing the risk of losing channel access.

In some embodiments, the mechanism for transmitting SRS in transmission gaps of the unlicensed spectrum may always be enabled. That is, if the terminal device 220 finds a transmission gap in the unlicensed spectrum, SRS transmission may be performed. Specifically, the terminal device 220 may autonomously determine the SRS resource configuration and then perform SRS transmission accordingly.

Alternatively, in some other embodiments, the mechanism for transmitting SRS in transmission gaps in the unlicensed spectrum may be enabled by network device 210 via RRC signaling. For example, method 300 may be performed in response to receiving RRC signaling from network device 210 to enable the mechanism. Similarly, the mechanism may also be disabled via RRC signaling from network device 210. For example, if terminal device 220 receives RRC signaling from network device 210 to disable the mechanism, terminal device 220 may stop transmitting SRS in the transmission gap.

In some embodiments, if the mechanism for transmitting SRS in transmission gaps in the unlicensed spectrum is enabled, network device 110 may receive SRS from terminal device 120 in transmission gaps in a manner corresponding to method 300 described above.

Fig. 5 illustrates a flow diagram of an example method 500 for receiving SRS, in accordance with some embodiments of the present disclosure. Method 500 may be implemented at network device 210 as shown in fig. 1. For discussion purposes, the method 500 will be described with reference to fig. 1 from the perspective of the network device 210. It should be understood that method 500 may include additional blocks not shown, and/or may omit some blocks shown, and the scope of the present disclosure is not limited in this respect.

At block 510, the network device 210 determines whether a transmission gap exists in the unlicensed spectrum. In some embodiments, the transmission gap is before the start of the uplink channel. In some embodiments, the transmission gap is located in the COT between the end of the downlink channel and the start of the uplink channel.

If network device 210 determines that a transmission gap (e.g., transmission gap 120 as shown in fig. 1) exists in the unlicensed spectrum, method 500 proceeds to block 520, at block 520, network device 210 determines a configuration for receiving an SRS from terminal device 220 in the transmission gap.

In some embodiments, network device 210 may determine at least one resource to use for reception of SRS. Network device 210 may also determine a configuration based on the at least one resource.

In some embodiments, network device 210 may determine the at least one resource based on at least one of: processing capability of the terminal device; downlink Control Information (DCI) transmitted to the terminal device 220; an indication of PUCCH resources (e.g., ARI) transmitted to terminal device 220.

In some embodiments, the at least one resource comprises a time domain resource to be used for reception of the SRS. Network device 210 may determine the time domain resource by determining at least one of: a starting position of the received SRS in the time domain; and a duration of reception of the SRS.

In some embodiments, the network device 210 may determine the time domain resources based on the processing capabilities of the terminal device 220.

In some embodiments, if the transmission gap is between the end of the downlink channel and the start of the uplink channel in the COT, the network device 210 may determine the time domain resource based on the position of the transmission gap in the COT.

In some embodiments, network device 210 may transmit Downlink Control Information (DCI) to terminal device 220 that includes a trigger for transmission of the SRS. Network device 210 may determine the time domain resources based on the trigger for SRS.

In some embodiments, the at least one resource comprises a frequency domain resource to be used for reception of the SRS. The network device may determine the frequency domain resources by determining at least one of: the location of the frequency domain resources in the frequency domain; and a bandwidth for transmission of the SRS.

In some embodiments, network device 210 may transmit an indication of PUCCH resources (e.g., ARI) to terminal device 220. Network device 210 may determine the frequency domain resources based on PUCCH resources (e.g., ACK/NACK resources).

In some embodiments, the at least one resource comprises a code domain resource to be used for reception of SRS. Network device 210 can determine a cyclic shift associated with a code domain resource to be used for reception of an SRS.

In some embodiments, network device 210 may transmit an indication of PUCCH resources to terminal device 220. Network device 210 may determine the cyclic shift based on the PUCCH resources. In some embodiments, the mapping function may be predetermined based on a dependency between a cyclic shift to be used for transmission of the SRS and a starting position of the PUCCH resource or the ACK/NACK resource in the frequency domain. Network device 210 may determine a cyclic shift to be used for reception of SRS based on the predetermined mapping function.

At block 530, the network device 210 receives an SRS from the terminal device 210 in the transmission gap based on the configuration.

In some embodiments, network device 210 may not transmit an explicit trigger for SRS transmission to terminal device 220. In this case, the terminal device 220 may autonomously transmit the SRS to the network device 210. For example, when terminal device 220 is triggered to transmit HARQ feedback in the short PUCCH at the end of the self-contained COT and terminal device 220 finds that there is a gap between the end of the PDSCH and the start of the short PUCCH, terminal device 220 may transmit SRS in the transmission gap. Similarly, in this case, when network device 210 finds that there is a gap between the end of the PDSCH and the start of the short PUCCH, it may attempt to receive SRS from terminal device 220.

In some embodiments, network device 210 may transmit Downlink Control Information (DCI) to the terminal device that includes a trigger for transmission of the SRS. In response to the DCI being transmitted to the terminal device 220, the network device 210 may receive the SRS from the terminal device 220.

It can be seen that embodiments of the present disclosure provide a solution for transmitting SRS in unlicensed spectrum. Embodiments of the present disclosure enable SRS transmission in a transmission gap (e.g., within a self-contained COT) regardless of whether explicit triggering for SRS transmission is provided. By occupying transmission gaps for SRS transmission, transmission opportunities for uplink control information can also be increased.

Additionally, such additional SRS transmission opportunities may provide additional benefits. For example, a network device (such as a gNB) may trigger aperiodic SRS transmissions in a less frequent manner. SRS may have a higher probability of transmission in a shared COT initiated by a network device. Furthermore, more frequent and reliable SRS transmissions may result in better uplink channel quality assessment, finer timing advance estimation, and more reliable beam management.

In some embodiments, an apparatus (e.g., terminal device 220) capable of performing method 300 may include means for performing the respective steps of method 300. The components may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules.

In some embodiments, the apparatus comprises: means for determining a configuration for transmitting a Sounding Reference Signal (SRS) to a network device in a transmission gap in response to determining that the transmission gap exists in an unlicensed spectrum; and means for transmitting the SRS to a network device in the transmission gap based on the configuration.

In some embodiments, the transmission gap is before the start of the uplink channel.

In some embodiments, the transmission gap is between the end of the downlink channel and the start of the uplink channel in a Channel Occupancy Time (COT).

In some embodiments, the means for determining the configuration comprises: means for determining at least one resource to use for transmission of the SRS; and means for determining the configuration based on the at least one resource.

In some embodiments, the means for determining at least one resource comprises means for determining the at least one resource based on at least one of: processing capability of the terminal device; downlink Control Information (DCI) received from a network device; and an indication of PUCCH resources received from the network device.

In some embodiments, the at least one resource comprises a time domain resource to be used for transmission of the SRS. The means for determining at least one resource comprises means for determining a time domain resource by determining at least one of: a starting position of transmitting the SRS in the time domain; and a duration of transmission of the SRS.

In some embodiments, the means for determining the time domain resource comprises: means for determining time domain resources based on processing capabilities of a terminal device.

In some embodiments, the transmission gap is located in the COT between the end of the downlink channel and the start of the uplink channel. The means for determining time domain resources comprises: means for determining a time domain resource based on a location of the transmission gap in the COT.

In some embodiments, the means for determining the time domain resource comprises: means for determining time domain resources based on a trigger for the SRS in response to receiving Downlink Control Information (DCI) from a network device that includes the trigger for the transmission of the SRS.

In some embodiments, the at least one resource comprises a frequency domain resource to be used for transmission of the SRS. The means for determining at least one resource comprises means for determining frequency domain resources by determining at least one of: the location of the frequency domain resources in the frequency domain; and a bandwidth for transmission of the SRS.

In some embodiments, the means for determining frequency domain resources comprises: means for determining, in response to receiving an indication of a PUCCH resource from a network device, a PUCCH resource based on the indication; and means for determining frequency domain resources based on the PUCCH resources.

In some embodiments, the at least one resource comprises a code domain resource to be used for transmission of the SRS. The means for determining at least one resource comprises: means for determining a cyclic shift associated with a code domain resource to be used for transmission of the SRS.

In some embodiments, the means for determining the cyclic shift comprises: means for determining, in response to receiving an indication of a PUCCH resource from a network device, a PUCCH resource based on the indication; and means for determining a cyclic shift based on the PUCCH resources.

In some embodiments, the means for transmitting the SRS comprises: means for transmitting, to a network device, an SRS in response to receiving Downlink Control Information (DCI) from the network device that includes a trigger for transmission of the SRS.

In some embodiments, an apparatus (e.g., network device 210) capable of performing method 500 may include means for performing the respective steps of method 500. The components may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules.

In some embodiments, the apparatus comprises: means for determining a configuration for receiving an SRS from a terminal device in a transmission gap in response to determining that the transmission gap exists in an unlicensed spectrum; and means for receiving an SRS from the terminal device in the transmission gap based on the configuration.

In some embodiments, the transmission gap is between the end of the downlink channel and the start of the uplink channel in the COT.

In some embodiments, the means for determining the configuration comprises: means for determining at least one resource to be used for reception of an SRS; and means for determining the configuration based on the at least one resource.

In some embodiments, the means for determining at least one resource comprises means for determining the at least one resource based on at least one of: processing capability of the terminal device; downlink Control Information (DCI) transmitted to a terminal device; and an indication of PUCCH resources transmitted to the terminal device.

In some embodiments, the at least one resource comprises a time domain resource to be used for reception of the SRS. The means for determining at least one resource comprises means for determining frequency domain resources by determining at least one of: the location of the frequency domain resources in the frequency domain; and a bandwidth for transmission of the SRS.

In some embodiments, the means for determining the time domain resource comprises: means for transmitting DCI comprising a trigger for transmission of an SRS to a terminal device; and means for determining time domain resources based on the trigger for the SRS.

In some embodiments, the at least one resource comprises a frequency domain resource to be used for reception of the SRS. The means for determining at least one resource comprises means for determining frequency domain resources by determining at least one of: the location of the frequency domain resources in the frequency domain; and a bandwidth for transmission of the SRS.

In some embodiments, the means for determining frequency domain resources comprises: means for transmitting an indication of PUCCH resources to a terminal device; and means for determining frequency domain resources based on the PUCCH resources.

In some embodiments, the at least one resource comprises a code domain resource to be used for reception of SRS. The means for determining at least one resource comprises: means for determining a cyclic shift associated with a code domain resource to be used for reception of the SRS.

In some embodiments, the means for determining the cyclic shift comprises: means for transmitting an indication of PUCCH resources to a terminal device; and means for determining a cyclic shift based on the PUCCH resource.

In some embodiments, the means for transmitting the SRS comprises: means for transmitting Downlink Control Information (DCI) including a trigger for transmission of the SRS to the terminal device; and means for receiving the SRS from the terminal device in response to the DCI being transmitted to the terminal device.

Fig. 6 is a simplified block diagram of a device 600 suitable for implementing embodiments of the present disclosure. Device 600 may be implemented at terminal device 220 as shown in fig. 1 or as at least a portion of terminal device 220.

As shown, the device 600 includes a processor 610, a memory 620 coupled to the processor 610, a suitable Transmitter (TX) and Receiver (RX)640 coupled to the processor 610, and a communication interface coupled to the TX/RX 640. Memory 620 stores at least a portion of program 630. TX/RX 640 is used for bi-directional communication. TX/RX 640 has at least one antenna to facilitate communication, although in practice an access node referred to in this application may have several antennas. The communication interface may represent any interface necessary for communication with other network elements, such as an X2 interface for bidirectional communication between enbs, an S1 interface for communication between a Mobility Management Entity (MME)/serving gateway (S-GW) and an eNB, a Un interface for communication between an eNB and a Relay Node (RN), or a Uu interface for communication between an eNB and a terminal device.

The programs 630 are assumed to include program instructions that, when executed by the associated processor 610, enable the device 600 to operate in accordance with implementations of the present disclosure, as discussed herein with reference to fig. 2-5. Implementations herein may be implemented by computer software executable by the processor 610 of the device 600, or by hardware, or by a combination of software and hardware. The processor 610 may be configured to implement various implementations of the present disclosure. Further, the combination of the processor 610 and the memory 620 may form a processing device 650 suitable for implementing various implementations of the present disclosure.

The memory 620 may be of any type suitable to the local technology network and may be implemented using any suitable data storage technology, such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. Although only one memory 620 is shown in device 600, there may be several physically distinct memory modules in device 600. The processor 610 may be of any type suitable to the local technology network and may include one or more of general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. Device 600 may have multiple processors, such as application specific integrated circuit chips that are time-dependent from a clock synchronized to the main processor.

The components included in the apparatus and/or devices of the present disclosure may be implemented in various ways, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more of the units may be implemented using software and/or firmware, e.g., machine executable instructions stored on a storage medium. Some or all of the elements of an apparatus and/or device may be implemented, at least in part, by one or more hardware logic components in addition to or in place of machine-executable instructions. By way of example, and not limitation, illustrative types of hardware logic components that may be used include Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs), system on a Chip Systems (SOCs), Complex Programmable Logic Devices (CPLDs), and the like.

In general, the various embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that execute in a device on a target real or virtual processor to perform the method 300 described above with reference to fig. 3 or the method 500 described above with reference to fig. 5. Generally, program modules include routines, programs, libraries, objects, classes, components, data types, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

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

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of a computer-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

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

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

Claims

1. A method implemented at a terminal device, comprising:

in response to determining that a transmission gap exists in an unlicensed spectrum, determining a configuration for transmission of a Sounding Reference Signal (SRS) to a network device in the transmission gap; and

transmitting the SRS to the network device in the transmission gap based on the configuration.

2. The method of claim 1, wherein the transmission gap is before a start of an uplink channel.

3. The method of claim 1, wherein the transmission gap is between an end of a downlink channel and a start of an uplink channel in a Channel Occupancy Time (COT).

4. The method of claim 1, wherein determining the configuration comprises:

determining at least one resource to be used for transmission of the SRS; and

determining the configuration based on the at least one resource.

5. The method of claim 4, wherein determining the at least one resource comprises:

determining the at least one resource based on at least one of:

processing capability of the terminal device;

downlink Control Information (DCI) received from the network device; and

an indication of Physical Uplink Control Channel (PUCCH) resources received from the network device.

6. The method of claim 4, wherein the at least one resource comprises a time domain resource to be used for transmission of the SRS, and wherein determining the at least one resource comprises:

determining the time domain resource by determining at least one of:

a starting position in a time domain at which the SRS is transmitted; and

a duration of transmission of the SRS.

7. The method of claim 6, wherein determining the time domain resource comprises:

determining the time domain resource based on processing capabilities of the terminal device.

8. The method of claim 6, wherein the transmission gap is located in the COT between an end of a downlink channel and a start of an uplink channel, and wherein determining the time domain resource comprises:

determining the time domain resource based on a location of the transmission gap in the COT.

9. The method of claim 6, wherein determining the time domain resource comprises:

in response to receiving Downlink Control Information (DCI) from the network device that includes a trigger for transmission of the SRS, determining the time domain resources based on the trigger for the SRS.

10. The method of claim 4, wherein the at least one resource comprises a frequency domain resource to be used for transmission of the SRS, and wherein determining the at least one resource comprises:

determining the frequency domain resources by determining at least one of:

a location of the frequency domain resource in a frequency domain; and

a bandwidth for transmission of the SRS.

11. The method of claim 10, wherein determining the frequency domain resources comprises:

in response to receiving an indication of a PUCCH resource from the network device, determining the PUCCH resource based on the indication; and

determining the frequency domain resource based on the PUCCH resource.

12. The method of claim 4, wherein the at least one resource comprises a code domain resource to be used for transmission of the SRS, and wherein determining the at least one resource comprises:

determining a cyclic shift associated with the code domain resources to be used for transmission of the SRS.

13. The method of claim 12, wherein determining the cyclic shift comprises:

determining the cyclic shift based on the PUCCH resources.

14. The method of any of claims 1-13, wherein transmitting the SRS comprises:

transmitting the SRS to the network device in response to receiving Downlink Control Information (DCI) from the network device that includes a trigger for transmission of the SRS.

15. A method implemented at a network device, comprising:

in response to determining that a transmission gap exists in an unlicensed spectrum, determining a configuration for receiving a Sounding Reference Signal (SRS) from a terminal device in the transmission gap; and

receiving the SRS from the terminal device in the transmission gap based on the configuration.

16. The method of claim 15, wherein the transmission gap is before a start of an uplink channel.

17. The method of claim 15, wherein the transmission gap is between an end of a downlink channel and a start of an uplink channel in a Channel Occupancy Time (COT).

18. The method of claim 15, wherein determining the configuration comprises:

determining at least one resource to be used for reception of the SRS; and

determining the configuration based on the at least one resource.

19. The method of claim 18, wherein determining the at least one resource comprises:

determining at least one resource based on at least one of:

processing capability of the terminal device;

downlink Control Information (DCI) transmitted to the terminal device; and

an indication of Physical Uplink Control Channel (PUCCH) resources transmitted to the terminal device.

20. The method of claim 18, wherein the at least one resource comprises a time domain resource to be used for reception of the SRS, and wherein determining the at least one resource comprises:

determining the time domain resource by determining at least one of:

a starting position in a time domain at which the SRS is received; and

a duration of reception of the SRS.

21. The method of claim 20, wherein determining the time domain resource comprises:

22. The method of claim 20, wherein the transmission gap is located in the COT between an end of a downlink channel and a start of an uplink channel, and wherein determining the time domain resource comprises:

23. The method of claim 20, wherein determining the time domain resource comprises:

transmitting Downlink Control Information (DCI) to the terminal device including a trigger for transmission of the SRS; and

determining the time domain resources based on the trigger for the SRS.

24. The method of claim 18, wherein the at least one resource comprises a frequency domain resource to be used for reception of the SRS, and wherein determining the at least one resource comprises:

determining the frequency domain resources by determining at least one of:

a location of the frequency domain resource in a frequency domain; and

a bandwidth for transmission of the SRS.

25. The method of claim 24, wherein determining the frequency domain resources comprises:

transmitting an indication of PUCCH resources to the terminal device; and

determining the frequency domain resource based on the PUCCH resource.

26. The method of claim 18, wherein the at least one resource comprises a code domain resource to be used for reception of the SRS, and wherein determining the at least one resource comprises:

determining a cyclic shift associated with the code domain resources to be used for reception of the SRS.

27. The method of claim 26, wherein determining the cyclic shift comprises:

transmitting an indication of PUCCH resources to the terminal device; and

determining the cyclic shift based on the PUCCH resources.

28. The method of any of claims 15-27, wherein transmitting the SRS comprises:

receiving the SRS from the terminal device in response to the DCI being transmitted to the terminal device.

29. An apparatus, comprising:

a processor; and

a memory coupled to the processor and having stored thereon instructions that, when executed by the processor, cause the apparatus to perform the method of any of claims 1-14.

30. An apparatus, comprising:

a processor; and

a memory coupled to the processor and having stored thereon instructions that, when executed by the processor, cause the apparatus to perform the method of any of claims 15-28.

31. A computer-readable storage medium having instructions stored thereon, which when executed on at least one processor causes the at least one processor to perform the method of any one of claims 1 to 14.

32. A computer-readable storage medium having instructions stored thereon, which when executed on at least one processor causes the at least one processor to perform the method of any one of claims 15 to 28.