EP4338515A1

EP4338515A1 - Method and apparatus for determining guard period location for srs antenna switching

Info

Publication number: EP4338515A1
Application number: EP21941233.5A
Authority: EP
Inventors: Hiromasa Umeda; Lei Du; Juha Pekka Karjalainen; Kyoungmin Park
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2024-03-20
Also published as: CN117413590A; WO2022236657A1

Abstract

Disclosed are example embodiments of methods and apparatuses for determining guard period location for sound reference signal antenna switching. A method implemented at a terminal device may comprise receiving a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The method may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.

Description

METHOD AND APPARATUS FOR DETERMINING GUARD PERIOD LOCATION FOR SRS ANTENNA SWITCHING

TECHNICAL FIELD

Various example embodiments described herein generally relate to communication technologies, and more particularly, to methods and apparatuses for determining a location of a guard period for sounding reference signal (SRS) antenna port switching.

BACKGROUND

In 5G New Radio (NR) , a sounding reference signal (SRS) may be used to estimate uplink (UL) channel quality over a bandwidth or bandwidth part (BWP) . When channel reciprocity applies, for example in a time division duplexing (TDD) system, the SRS may also be used to estimate downlink (DL) channel quality.
SUMMARY
A brief summary of example embodiments is provided below to provide basic understanding of some aspects of various example embodiments. It should be noted that this summary is not intended to identify key features of essential elements or define scopes of the example embodiments, and its sole purpose is to introduce some concepts in a simplified form as a preamble for a more detailed description provided below.
In a first aspect, an example embodiment of a terminal device is provided. The terminal device may comprise at least one processor and at least one memory including computer program code stored thereon. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the terminal device to perform operations including receiving a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The operations may further include determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
In a second aspect, an example embodiment of a network device is provided. The network device may comprise at least one processor and at least one memory including computer program code stored thereon. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the network device to perform operations including configuring a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The operations may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
In a third aspect, an example embodiment of a method implemented at a terminal device is provided. The method may comprise receiving a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The method may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
In a fourth aspect, an example embodiment of a method implemented at a network device is provided. The method may comprise configuring a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The method may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
In a fifth aspect, an example embodiment of an apparatus is provided. The apparatus may comprise means for receiving a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The apparatus may further comprise means for determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
In a sixth aspect, an example embodiment of an apparatus is provided. The apparatus may comprise means for configuring a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The apparatus may further comprise means for determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
In a seventh aspect, an example embodiment of a computer program is provided. The computer program may comprise instructions stored on a computer readable medium. The instructions, when executed by at least one processor of a terminal device, may cause the terminal device to perform operations comprising receiving a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching between different antenna ports. The operations may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
In an eighth aspect, an example embodiment of a computer program is provided. The computer program may comprise instructions stored on a computer readable medium. The instructions, when executed by at least one processor of a network device, may cause the network device to perform operations comprising configuring a Sounding Reference Signal (SRS) resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching. The operations may further comprise determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
Other features and advantages of the example embodiments of the present disclosure will also be apparent from the following description of specific example embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of example embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.
Fig. 1 is a schematic diagram illustrating an example communication network.
Fig. 2 is a schematic diagram illustrating an example antenna port switching for sounding reference signal (SRS) transmissions.
Fig. 3 is a schematic diagram illustrating an example SRS resource set configuration.
Fig. 4 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 5A is a schematic diagram illustrating an example rule to determine a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 5B is a schematic diagram illustrating an example rule to determine a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 6 is a schematic diagram illustrating an example rule to determine a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 7A is a schematic diagram illustrating an example rule to determine a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 7B is a schematic diagram illustrating an example rule to determine a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 8 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 9 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 10 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment.
Fig. 11 is a functional block diagram illustrating an apparatus implemented at a user equipment device according to an example embodiment.
Fig. 12 is a functional block diagram illustrating an apparatus implemented at a network device according to an example embodiment.
Fig. 13 illustrates a structural block diagram of a communication system according to an example embodiment.
Throughout the drawings, same or similar reference numbers indicate same or similar elements. A repetitive description on the same elements would be omitted.

DETAILED DESCRIPTION

Herein below, some example embodiments are described in detail with reference to the accompanying drawings. The following description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known circuits, techniques and components are shown in block diagram form to avoid obscuring the described concepts and features.
As used herein, the term "network device" refers to any suitable entities or devices that can provide cells or coverage, through which the terminal device can access the network or receive services. The network device may be commonly referred to as a base station. The term "base station" used herein can represent a node B (NodeB or NB) , an evolved node B (eNodeB or eNB) , or a gNB. The base station may be embodied as a macro base station, a relay node, or a low power node such as a pico base station or a femto base station. The base station may consist of several distributed network units, such as a central unit (CU) , one or more distributed units (DUs) , one or more remote radio heads (RRHs) or remote radio units (RRUs) . The number and functions of these distributed units depend on the selected split RAN architecture.
As used herein, the term "terminal device" or "user equipment" (UE) refers to any entities or devices that can wirelessly communicate with the network devices or with each other. Examples of the terminal device can include a mobile phone, a mobile terminal (MT) , a mobile station (MS) , a subscriber station (SS) , a portable subscriber station (PSS) , an access terminal (AT) , a computer, a wearable device, an on-vehicle communication device, a machine type communication (MTC) device, a D2D communication device, a V2X communication device, a sensor and the like. The term "terminal device" can be used interchangeably with a UE, a user terminal, a mobile terminal, a mobile station, or a wireless device.
Fig. 1 illustrates a schematic diagram of an example communication network 100, such as a 5G NR network, in which aspects of the present disclosure may be performed. Referring to Fig. 1, the communication network 100, which may be a part of a larger network, may include a base station 120 shown as gNB and a user equipment (UE) device 110 which communicates with the gNB 120 on uplink (UL) and downlink (DL) channels. The gNB 120 may include a number of antenna elements and support multiple-input multiple-output (MIMO) technologies including for example spatial multiplexing, beam-forming and/or transmit diversity. The UE 110 may have multiple antenna ports which correspond to different communication channels, and channel quality for one antenna port may be different from channel quality for another antenna port. The UE 110 may be configured to transmit sounding reference signals (SRSs) on SRS resources to the gNB 120, and the number of the SRSs and/or the SRS resources may be determined based on the number of antenna ports. The gNB 120 may measure the channel quality based on the received SRSs.
Fig. 2 is a schematic diagram illustrating example uplink SRS transmissions on multiple antenna ports. In the example shown in Fig. 2, the UE 110 may have four antenna ports 232, 234, 236, 238, which are connected to Tx/Rx switches 222, 224, 226, 228, respectively. It is assumed that the UE 110 supports antenna switching capability "t2r4" for a TDD carrier component (CC) or band, where "t2" means that the UE 110 can use up to two transmit (Tx) chains, and "r4" means that the UE 110 can use up to four receive (Rx) chains. The antenna ports 232, 234 may be configured to transmit and receive signals, while the antenna ports 236, 238 may be configured to receive signals only except for SRS transmissions. In the example, since the number of Tx chains is less than the number of Rx antennas, the UE 110 needs to switch the Tx chains from the antenna ports 232, 234 to the antenna ports 236, 238 so as to sound spatial channels from all the Rx antennas, as shown in Fig. 2.
According to 3GPP technical specification, a guard period of Y symbols may be needed for the SRS antenna switching, in which the UE 110 does not transmit any other signals. The below Table 1 shows the minimum guard period requirements. Referring to Table 1, when a subcarrier spacing (SCS) Δf is less than 120 kHz, the minimum guard period is one OFDM symbol, and when the subcarrier spacing Δf is 120 kHz, the minimum guard period is two OFDM symbols. It means that the UE 110 should have an ability to complete the SRS antenna switching within one or two OFDM symbols.
Table 1: The minimum guard period Y

μ	Δf = 2 ^μ ·15 [kHz]	Y [symbol]
0	15	1
1	30	1
2	60	1
3	120	2

When the gNB 120 schedules SRS resources for the UE 110, however, it is possible that two SRS resources in an SRS resource set are separated more than Y symbols. For example, referring to Fig. 3, an SRS resource set configured for the UE 110 may include SRS resource 1 provided in symbol 8 of a slot and SRS resource 2 provided in symbol 13 of the slot. The SRS resources 1, 2 may be mapped to different antenna ports and they can be called SRS resource pair. Thus, a guard period is needed between the SRS resources 1 and 2 to perform antenna switching. In the example shown in Fig. 3, there are four symbols in-between the SRS resource 1 and the SRS resource 2, and the UE 110 may perform antenna switching in any one or two consecutive symbols among the four symbols. Since the gNB 120 does not know in which symbols the antenna switching occurs, it would not schedule UL transmission or DL reception for the UE 110 in any one of the four symbols. Thus, at least two of the four symbols are wasted because they are not used for antenna switching or signal transmission/reception. This problem would become more severe in scenarios of carrier aggregation (CA) or multi-RAT dual connectivity (MR-DC) . Assuming a CA scenario where one TDD band and four FDD bands are aggregated on the UE 110 and the five bands share the antennas, at least additional (2 UL symbols + 2 DL symbols) *4 bands = 16 symbols would be wasted in the case shown in Fig. 3, which results in a performance loss of these bands.
Hereinafter, example embodiments of methods, apparatuses and systems for determining a position of the guard period for SRS antenna switching will be discussed. It would be appreciated that the term “SRS resource” refers to a time period such as an OFDM symbol (s) where the SRS is transmitted, and the term "guard period" refers to a time period such as an OFDM symbol (s) where the SRS antenna switching occurs, and during the guard period the UE does not transmit any other signals. When the location of the guard period is determined, the gNB can schedule UL transmission or DL reception for the UE in symbols positioned in-between SRS resources but not occupied by the guard period. Therefore, the waste of symbol resources would be avoided or minimized and the resource utilization efficiency of the serving bands would be improved.
Fig. 4 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment. In some implementations, the operations shown in Fig. 4 may be performed by the UE 110 and the gNB 120 shown in Fig. 1.
Referring to Fig. 4, at 310, the UE 110 may receive an SRS resource set configuration from the gNB 120. The SRS resource set configuration may include one or more SRS resource sets as configured by for example a higher layer parameter SRS-ResourceSet, and one of the one or more SRS resource set may include one or more SRS resources as configured by for example a higher layer parameter SRS-Resource. A SRS resource may occupy one or more (e.g. 1, 2, or 4) consecutive OFDM symbols e.g. within the last 6 symbols of a slot. In some embodiments, the SRS resource may also occupy any other symbols within a slot. Among the one or more SRS resource sets, at least one SRS resource set may be configured for SRS antenna switching as discussed above with reference to Fig. 2. For example, when the UE 110 is configured with a higher layer parameter usage in SRS-ResourceSet set as "antennaSwitching" , the SRS resource set is configured for the antenna switching. The SRS resource set for antenna switching may include two or more SRS resources for SRS transmissions on different antenna ports, and antenna switching is needed between two SRS resources that are associated with different antenna ports.
At 320, the UE 110 may determine a time-domain position of a guard period for the SRS antenna switching based on a predetermined rule. It would be appreciated that the predetermined rule refers to a rule or standard to determine the time-domain position of the guard period relative to the position of the SRS resources in the SRS resource set. Some examples of the predetermined rule will be discussed in detail later. The rule may be pre-configured at the UE 110 for example by UE vendors considering UE capability. By the operation 320, the UE 110 can determine an exact timing such as one or two consecutive OFDM symbols to perform the SRS antenna switching.
At 330, the UE 110 may send the predetermined rule to the gNB 120 so that the gNB 120 can also be aware of the guard period position. In some embodiments, the predetermined rule may be sent before the operation 310 of receiving the SRS resource set configuration from the gNB 120. For example, the UE 110 may send the predetermine rule while reporting UE capability to the gNB 120. The UE 110 may actively send the capability report including the predetermined rule to the gNB 120 e.g. during initial attachment to the network or in a tracking area updating procedure, or send the capability report including the predetermined rule in response to a capability enquiry received from the gNB 120. In some embodiments, the UE 110 may send the predetermined rule to the gNB 120 after the operation 310 of receiving the SRS resource set configuration.
Then at 340, the gNB 120 may determine the time-domain position of the guard period for the SRS antenna switching based on the received predetermined rule. When the gNB 120 knows the exact position of the guard period where the SRS antenna switching occurs, the gNB 120 can schedule UL and/or DL signal transmissions on symbols other than the guard period, for example on symbols in-between the SRS resources in a SRS resource set for antenna switching but not occupied or overlapped by the guard period. Therefore, the resource utilization efficiency of the serving bands would be improved.
For better understanding of the above operations, some examples of the predetermined rule to determine the guard period position will be discussed below with reference to Figs. 5A, 5B, 6, 7A and 7B. Referring Figs. 5A and 5B first, in some examples, the SRS resource set configured for the UE 110 may include SRS resources 1 and 2 for SRS transmissions on different antenna ports, and the SRS resources 1 and 2 may be configured in the same slot or in different slots. For example, in Fig. 5A, the SRS resource 1 is positioned in a slot n and the SRS resource 2 is positioned in a slot n+1. In Fig. 5B, both the SRS resources 1, 2 are positioned in a slot n.
When the UE 110 receives the SRS resource set configuration as shown in Figs. 5A or 5B at the operation 310, the UE 110 may determine a position of the guard period for SRS antenna switching according to the predetermined rule in the operation 320. For example, the UE 110 may position the guard period, which may be one or two OFDM symbols depending on the subcarrier spacing (SCS) Δf as shown in the above Table 1, right before or right after the respective SRS resources 1 and 2. The UE 110 may use one bit to indicate the position of the guard period. For example, as shown in Figs. 5A and 5B, Bit "0" indicates that the guard period is positioned right before the SRS resource, and Bit "1" indicates that the guard period is positioned right after the SRS resource. In some embodiments, considering radio resource management requirements such as power change, the UE 110 may position the guard period before and after the SRS resource. Then two bits may be used to indicate the guard period position. For example, Bits "10" indicate that the guard period is positioned before the SRS resource, Bits "01" indicate that the guard period is positioned after the SRS resource, and Bits "11" indicate that the guard period is positioned before and after the SRS resource. For example, when the subcarrier spacing Δf of the serving band is less than 120 kHz, Bits "11" indicate that one symbol before the SRS resource and one symbol after the SRS resource are used as the guard period, and when the subcarrier spacing Δf is 120 kHz, Bits "11" indicate that two symbols before the SRS resource and two symbols after the SRS resource are used as the guard period. In the operation 330 of Fig. 4, the UE 110 may inform the gNB 120 of the predetermined rule by sending the bit (s) . Then the gNB 120 may determine the guard period position based on the received bit (s) in the operation 340.
Fig. 6 shows another example of the rule to determine the guard period position where the guard period is positioned in-between two SRS resources in a set. Referring to Fig. 6, an SRS resource set configured for the UE 110 may include SRS resources 1 and 2 (i.e., SRS 1 and SRS 2) for SRS transmissions on different antenna ports, and the SRS resources 1 and 2 are configured within the same slot n. In some embodiments, the SRS resources may be configured in the last 6 symbols in a slot, and the maximum interval between the SRS resources 1 and 2 in the set may include 4 symbols. Any one or two consecutive symbols of the 4 interval symbols, depending on the subcarrier spacing Δf as shown in the above Table 1, may be used as the guard period. It would be appreciated that the interval between the SRS resources 1 and 2 in the set may also include 3 symbols, 2 symbols or 1 symbol dependent on the SRS resource configuration. A bitmask or bitmap may be used to identify one or two symbols in the interval that are used as the guard period, and the bitmask may have a length (in unit of bit) equal to the interval (in unit of symbol) . For example, when the interval between the SRS resources 1, 2 includes 4 symbols, a bitmask "1100" indicates that the first two symbols are used as the guard period, or a bitmask "0010" indicates that the third symbol is used as the guard period. When the interval between the SRS resources 1, 2 includes 2 symbols and the subcarrier spacing Δf is less than 120 kHz, a bitmask "10" indicates that the first symbol is used as the guard period, and a bitmask "01" indicates that the second symbol is used as the guard period. It would be appreciated that when the interval includes 2 symbols and the subcarrier spacing Δf is 120 kHz, or when the interval includes 1 symbol, no bitmask is needed because all the interval symbols would be used as the guard period.
Table 2 shows an example of bitmasks representing the rule to determine the guard period position. In Table 2, the bitmasks are provided per interval length and subcarrier spacing Δf. It would be appreciated that the Table 2 is given as an example, and the bitmask may be provided in another manner. For example, the bitmask may be provided per interval per subcarrier spacing Δf<120 kHz or Δf=120 kHz. That is to say, for Δf=15, 30, 60 kHz the bitmask is identical. In some embodiments, the SRS resource may be applied at any position in a slot, and the maximum interval between the SRS resources 1, 2 in a SRS resource set would be up to 12 symbols. Therefore, the bitmask may have a maximum length of 12 bits. In some embodiments, the bitmask may have an extended length to further cover e.g. one or two symbols before the SRS resource 1 and/or one or two symbols after the SRS resource 2.
Table 2: bitmask per interval and subcarrier spacing
In the operation 330 of Fig. 4, the UE 110 may inform the gNB 120 of the predetermined rule by sending the bitmasks shown in Table 2 to the gNB 120. As discussed above, the bitmasks may be sent before or after the operation 310 of receiving the SRS resource set configuration from the gNB 120. Then the gNB 120 may determine the position of the guard period by selecting a proper bitmask in the operation 340. For example, if the scheduled SRS resources 1, 2 in a set have an interval of 3 symbols and the subcarrier spacing Δf is 60 kHz, the gNB 120 would use the bitmask g ₁g ₂g ₃ to determine the position of the guard period.
Figs. 7A and 7B show another example of the rule to determine the guard period position. Referring to Figs. 7A and 7B, the SRS resource set configured for the UE 110 may include SRS resources 1 and 2 (e.g., SRS 1 and SRS 2) for SRS transmissions on different antenna ports, and the SRS resources 1 and 2 may be configured in different slots (Fig. 7A) or in the same slot (Fig. 7B) . In the example, an offset parameter GP_offset may be used to indicate an offset of the guard period relative to a corresponding SRS resource.
Referring to Fig. 7A, when the SRS resources 1, 2 are configured in different slots, the offset parameter GP_offset may indicate that the guard period starts from the (GP_offset+1) symbol after the corresponding SRS resource. For example, if GP_offset is 0, the one or two consecutive symbols right after the SRS resource are used as the guard period. If GP_offset is 2, the guard period starts at the third symbol after the corresponding SRS resource. In some embodiments, the offset parameter may be used together with the position bit (s) to indicate if the guard period is positioned before and/or after the corresponding SRS resource as shown in Figs. 5A and 5B. For example, if the offset parameter is 1 and the position bit is 0, the guard period is positioned before the SRS resource and there is one symbol between the guard period and the SRS resource. If the offset parameter is 1 and the position bit is 1, the guard period is positioned after each of the SRS resource 1 and 2 and there is one symbol between the guard period and each of the SRS resources 1 and 2.
Fig. 7B shows an example where the SRS resources 1, 2 in the SRS resource set are configured in the same slot. The guard period may be positioned between the SRS resources 1 and 2, and the offset parameter GP_offset may indicate an offset of the guard period from the first SRS resource (i.e., SRS resource 1) . For example, if the offset parameter GP_offset is 2, the guard period starts from the third symbol after the SRS resource 1. If the offset parameter GP_offset is 0, the guard period is positioned right after the SRS resource 1. Table 3 shows an example of the offset parameter to indicate the positon of the guard period. In Table 3, the parameters are provided per interval and subcarrier spacing, and it would be appreciated that in some embodiments, the offset parameter may be identical for the subcarrier spacing less than 120 kHz.
Table 3: The offset parameter per interval and subcarrier spacing
In the operation 330 of Fig. 4, the UE 110 may inform the gNB 120 of the predetermined rule by sending the offset parameter (s) . As discussed above, the offset parameter (s) may be sent before or after the operation 310 of receiving the SRS resource set configuration from the gNB 120. Then the gNB 120 may determine the position of the guard period based on the received offset parameter (s) in the operation 340.
Some examples of the rule to determine the position of the guard period have been discussed above with reference to Figs. 5A-7B. It would be appreciated that the present disclosure is not limited in any way to the examples, and the rule may also be represented in other forms as long as it can indicate the time-domain position of the guard period.
Fig. 8 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment. The operations shown in Fig. 8 may be performed for example by the UE 110 and the gNB 120 shown in Fig. 1. It would be appreciated that some operations in Fig. 8 may be similar to those shown in Fig. 4, and the below description will focus on operations different from those in Fig. 4.
Referring to Fig. 8, at 410, the UE 110 may receive a rule for determining a position of a guard period for SRS antenna switching from the gNB 120. In some embodiments, the gNB 120 may be pre-configured with the rule to determine the guard period position and it sends the rule to the UE 110 when the UE 110 initially connects to the gNB 120. For example, the gNB 120 may send the rule in a radio resource control (RRC) configuration or re-configuration message. In some embodiments, the gNB 120 may send the rule to the UE 110 when it receives a UE capability report indicating that the UE supports SRS antenna switching. In some embodiments, the gNB 120 may send the rule to the UE 110 when the gNB 120 configures the SRS resources for the UE 110. For example, the rule may be included in the SRS resource set configuration sent from the gNB 120 to the UE 110.
At 420, the UE 110 may receive an SRS resource set configuration from the gNB 120. The operation 420 may substantially similar to the operation 310 in Fig. 4, except that in some embodiments, the SRS resource set configuration sent in the operation 420 may further include the rule for determining the guard period position as mentioned above with reference to the operation 410.
At 430, the gNB 120 may determine the position such as one or two OFDM symbols of the guard period for SRS antenna switching based on the rule. The gNB 120 would not schedule UL and/or DL signal transmissions for the UE 110 during the guard period. Instead, the gNB 120 may schedule UL and/or DL signal transmissions on symbols other than the guard period.
At 440, the UE 110 may also determine the position of the guard period based on the rule. Then the UE 110 would perform the SRS antenna switching during the determined guard period and perform signal transmission/reception on other symbols. Therefore, the resource utilization efficiency of the serving bands would be improved.
In the embodiment shown in Fig. 4, the rule for determining the guard period position may be pre-configured at the UE 110 and it is sent from the UE 110 to the gNB 120. In the embodiment shown in Fig. 8, the rule for determining the guard period position may be pre-configured at the gNB 120 and it is sent from the gNB 120 to the UE 110. It would be appreciated that in some embodiments, the rule for determining the guard period position may be pre-configured at both the UE 110 and the gNB 120, and the UE 110 does not need to send/receive the rule to/from the gNB 120. It may further reduce the signaling overhead of the network. It is appreciated that the rule used in Fig. 8 can be referred to in the previous embodiments.
Fig. 9 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment. The operations shown in Fig. 9 may be performed for example by the UE 110 and the gNB 120 shown in Fig. 1. It would be appreciated that some operations in Fig. 9 may be similar to those shown in Figs. 4 and 8, and the below description will focus on operations different from those in Figs. 4 and 8.
Referring to Fig. 9, at 510, the UE 110 may receive an SRS resource set configuration from the gNB 120. In the embodiment, the SRS resource set configuration includes at least one SRS resource set configured for SRS antenna switching.
At 520, the UE 110 and the gNB 120 may determine a position of a guard period for the SRS antenna switching according to a predetermined rule, respectively. In some embodiments, the rule may be pre-configured at the UE 110 and have been sent from the UE 110 to the gNB 120. In some embodiments, the rule may be pre-configured at the gNB 120 and have been sent from the gNB 120 to the UE 110. In some embodiments, the rule may be pre-configured at both the UE 110 and the gNB 120 and rule transmission is not needed therebetween.
At 530, the UE 110 may determine if the guard period position determined at the operation 520 is available. For example, referring to Fig. 3, the symbol 9 may be determined as the guard period according to the rule at the operation 520, but the symbol 9 may be unavailable for the guard period due to some reasons such as implementation constraints.
If the UE 110 determines at the operation 530 that the guard period position determined at the operation 520 is available, the UE 110 may use the guard period to perform antenna switching for the SRS transmissions. On the other hand, if the UE 110 determines at the operation 530 that the guard period position determined at the operation 520 is unavailable, then at 540, the UE 110 may determine a new actual time-domain position for the guard period. For example, referring to Fig. 3, if the symbol 9 determined according to the predetermined rule at the operation 520 is unavailable, the UE 110 may instead select any one of the symbols 10-12 as the guard period for antenna switching if the symbols 10-12 are available. At this point of time, the actual guard period determined at the UE 110 is different from the guard period determined at the gNB 120.
Then at 550, the UE 110 may inform the gNB 120 of the actual guard period determined at the UE 110 so that the gNB 120 and the UE 110 can reach an agreement on the position of the guard period. The UE 110 would perform the SRS antenna switching during the actual guard period, and the gNB 120 would not schedule DL and/or UL signal transmissions for the UE 110 during the actual guard period.
Fig. 10 is a signaling diagram illustrating example operations for determining a position of a guard period for SRS antenna switching according to an example embodiment. The operations shown in Fig. 10 may be performed for example by the UE 110 and the gNB 120 shown in Fig. 1. It would be appreciated that some operations in Fig. 10 may be the same or similar to those shown in Fig. 9, and the below description will focus on differences between the embodiment shown in Fig. 10 and the embodiment shown in Fig. 9.
Referring to Fig. 10, at 510, the UE 110 may receive from the gNB 120 an SRS resource set configuration including at least one SRS resource set for SRS antenna switching, and at 520, the UE 110 and the gNB 120 may determine a position of a guard period for the SRS antenna switching according to a predetermined rule, respectively. As discussed above, the rule may be pre-configured at the UE 110 and have been sent from the UE 110 to the gNB 120, be pre-configured at the gNB 120 and have been sent from the gNB 120 to the UE 110, or be pre-configured at both the UE 110 and the gNB 120.
At 560, the gNB 120 may determine if the guard period position determined at the operation 520 is available. For example, referring to Fig. 3, the symbol 9 may be determined as the guard period according to the rule at the operation 520, but the symbol 9 may be unavailable for the guard period because the gNB 120 has allocated the symbol 9 for other bands for the UE 110 and/or for other UEs with higher priority.
If the gNB 120 determines at the operation 560 that the guard period position determined at the operation 520 is available, the gNB 120 may consider that the UE 110 would perform antenna switching during the guard period and thus the gNB 120 would not schedule signal transmission for the UE 110 during the guard period. On the other hand, if the gNB 120 determines at the operation 560 that the guard period position determined at the operation 520 is unavailable, then at 570, the gNB 120 may determine a new actual time-domain position for the guard period. For example, the gNB 120 may consider resource allocations for other bands for the UE 110 and/or for other UEs and select one or two appropriate symbols as the guard period for antenna switching. At this point of time, the actual guard period determined at the gNB 120 is different from the guard period determined at the UE 110.
Then at 580, the gNB 120 may send the actual guard period determined at the operation 570 to the UE 110 so that the gNB 120 and the UE 110 can reach an agreement on the position of the guard period. The UE 110 would perform the SRS antenna switching during the actual guard period, and the gNB 120 would not schedule DL and/or UL signal transmissions for the UE 110 during the actual guard period.
Fig. 11 is a functional block diagram illustrating an apparatus 600 according to an example embodiment. The apparatus 600 may be implemented at or as a part of a terminal device such as the UE 110 discussed above. Referring to Fig. 11, the apparatus 600 may comprise a first means 610 for receiving an SRS resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching. The at least one SRS resource set may include two or more SRS resources for SRS transmissions on different antenna ports.
The apparatus 600 may further comprise a second means 620 for determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule. The predetermined rule may indicate a time-domain positon of the guard period relative to the SRS resources in the at least one SRS resource set for antenna switching. For example, the SRS resource set may include at least two SRS resources for SRS transmissions on different antenna ports, and the guard period may be positioned before and/or after the respective SRS resources. In some embodiments, when the at least two SRS resources for SRS transmissions on different antenna ports include two SRS resources configured within the same slot, the guard period may be positioned in-between the two SRS resources.
In some embodiments, optionally, the apparatus 600 may further comprise a third means 630 for sending the predetermined rule to a network device such as the gNB 120 discussed above. The predetermined rule may be pre-configured at the UE 110 and it is sent to the gNB 120 before or after the UE 110 receives the SRS resource set for SRS antenna switching. For example, the UE 110 may send the predetermined rule in a capability report to the gNB 120.
In some embodiments, optionally, the apparatus 600 may further comprise a fourth means 640 for receiving the predetermined rule from a network device such as the gNB 120 discussed above. The predetermined rule may be pre-configured at the gNB 120 and it is sent from the gNB 120 to the UE 110 together with the SRS resource set configuration or before the gNB 120 sends the SRS resource set configuration to the UE 110.
In some embodiments, optionally, the apparatus 600 may further comprise a fifth means 650 for determining an actual time-domain position for the guard period when the guard period position determined according to the predetermined rule is unavailable, and a sixth means 660 for reporting the actual time-domain position of the guard period to the network device. For example, if the guard period position determined according to the predetermined rule is unavailable due to some reasons such as implementation constraints, the UE 110 may determine a new available position for the guard period and report the new position to the gNB 120.
In some embodiments, optionally, the apparatus 600 may further comprise a seventh means 670 for receiving indication of an actual time-domain position of the guard period from a network device. For example, if the gNB 120 recognizes that the guard period position determined according to the predetermined rule is unavailable because it has been allocated to other bands for the UE 110 or for other UEs with higher priority, the gNB 120 will determine a new actual time-domain position for the guard period and notify the UE 110 of the new actual position.
Fig. 12 is a functional block diagram illustrating an apparatus 700 according to an example embodiment. The apparatus 700 may be implemented at or as a part of a network device such as the gNB 120 discussed above. Referring to Fig. 12, the apparatus 700 may comprise a first means 710 for configuring a terminal device such as the UE 110 discussed above with an SRS resource set configuration. The SRS resource set configuration may include at least one SRS resource set configured for SRS antenna switching. The at least one SRS resource set may include two or more SRS resources for SRS transmissions on different antenna ports.
The apparatus 700 may further comprise a second means 720 for determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule. The predetermined rule may indicate a time-domain positon of the guard period relative to the SRS resources in the at least one SRS resource set for antenna switching. For example, the SRS resource set may include at least two SRS resources for SRS transmissions on different antenna ports, and the guard period may be positioned before and/or after the respective SRS resources. In some embodiments, when the at least two SRS resources for SRS transmissions on different antenna ports include two SRS resources configured within the same slot, the guard period may be positioned in-between the two SRS resources.
In some embodiments, optionally, the apparatus 700 may further comprise a third means 730 for receiving the predetermined rule from the terminal device such as the UE 110 discussed above. The predetermined rule may be pre-configured at the UE 110 and it is sent to the gNB 120 before or after the gNB 120 configures the UE 110 with the SRS resource set configuration. For example, the gNB 120 may receive the predetermined rule in a capability report sent from the UE 110.
In some embodiments, optionally, the apparatus 700 may further comprise a fourth means 740 for transmitting the predetermined rule to the terminal device such as the UE 110. The predetermined rule may be pre-configured at the gNB 120 and it is sent from the gNB 120 to the UE 110 together with the SRS resource set configuration or before the gNB 120 sends the SRS resource set configuration to the UE 110.
In some embodiments, optionally, the apparatus 700 may further comprise a fifth means 750 for receiving indication of an actual time-domain position of the guard period from the terminal device. For example, when the guard period position determined according to the predetermined rule is unavailable, the UE 110 may determine a new available position for the guard period and report the new guard period position to the network device. Then the gNB 120 and the UE 110 can reach an agreement on the position of the guard period for SRS antenna switching.
In some embodiments, optionally, the apparatus 700 may further comprise a sixth means 760 for determining an actual time-domain position for the guard period when the guard period position determined according to the predetermined rule is unavailable, and a seventh means 770 for sending the actual time-domain position of the guard period to the terminal device. For example, if the gNB 120 recognizes that the guard period position determined according to the predetermined rule is unavailable because it has been allocated to other bands for the UE 110 or for other UEs with higher priority, the gNB 120 will determine a new actual time-domain position for the guard period and notify the UE 110 of the new actual position. Then the gNB 120 and the UE 110 can reach an agreement on the position of the guard period for SRS antenna switching.
Fig. 13 is a block diagram illustrating an example communication system 800 in which example embodiments of the present disclosure can be implemented. As shown in Fig. 13, the communication system 800 may include a terminal device 810 which may be implemented as the UE 110 discussed above, and a network device 820 which may be implemented as the gNB 120 discussed above. Although Fig. 13 shows only one network device 120, it would be appreciated that the terminal device 810 may wirelessly communicate with two network devices for example in an MR-DC scenario.
Referring to Fig. 13, the terminal device 810 may comprise one or more processors 811, one or more memories 812 and one or more transceivers 813 interconnected through one or more buses 814. The one or more buses 814 may be address, data, or control buses, and may include any interconnection mechanism such as series of lines on a motherboard or integrated circuit, fiber, optics or other optical communication equipment, and the like. Each of the one or more transceivers 813 may comprise a receiver and a transmitter, which are connected to a plurality of antennas 816. The terminal device 810 may wirelessly communicate with the network device 820 through the plurality of antennas 816. The one or more memories 812 may include computer program code 815. The one or more memories 812 and the computer program code 815 may be configured to, when executed by the one or more processors 811, cause the terminal device 810 to perform operations and procedures relating to the UE 110 as described above.
The network device 820 may comprise one or more processors 821, one or more memories 822, one or more transceivers 823 and one or more network interfaces 827 interconnected through one or more buses 824. The one or more buses 824 may be address, data, or control buses, and may include any interconnection mechanism such as a series of lines on a motherboard or integrated circuit, fiber, optics or other optical communication equipment, and the like. Each of the one or more transceivers 823 may comprise a receiver and a transmitter, which are connected to a plurality of antennas 826. The network device 820 may operate as a base station for the terminal device 810 and wirelessly communicate with the terminal device 810 through the plurality of antennas 826. The one or more network interfaces 827 may provide wired or wireless communication links through which the network device 820 may communicate with other network devices, entities or functions. The one or more memories 822 may include computer program code 825. The one or more memories 822 and the computer program code 825 may be configured to, when executed by the one or more processors 821, cause the network device 820 to perform operations and procedures relating to the gNB 120 as described above.
The one or more processors 811, 821 discussed above may be of any appropriate type that is suitable for the local technical network, and may include one or more of general purpose processors, special purpose processor, microprocessors, a digital signal processor (DSP) , one or more processors in a processor based multi-core processor architecture, as well as dedicated processors such as those developed based on Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . The one or more processors 811, 821 may be configured to control other elements of the terminal/network device and operate in cooperation with them to implement the procedures discussed above.
The one or more memories 812, 822 may include at least one tangible storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include but not limited to for example a random access memory (RAM) or a cache. The non-volatile memory may include but not limited to for example a read only memory (ROM) , a hard disk, a flash memory, and the like. Further, the one or more memories 812, 822 may include but not limited to an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.
The network device 820 can be implemented as a single network node, or disaggregated/distributed over two or more network nodes, such as a central unit (CU) , a distributed unit (DU) , a remote radio head-end (RRH) , using different functional-split architectures and different interfaces.
It would be understood that blocks in the drawings may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In some example embodiments, one or more blocks may be implemented using software and/or firmware, for example, machine-executable instructions stored in the storage medium. In addition to or instead of machine-executable instructions, parts or all of the blocks in the drawings may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-Programmable Gate Arrays (FPGAs) , Application-Specific Integrated Circuits (ASICs) , Application-Specific Standard Products (ASSPs) , System-on-Chip systems (SOCs) , Complex Programmable Logic Devices (CPLDs) , etc.
Some example embodiments further provide computer program code or instructions which, when executed by one or more processors, may cause a device or apparatus to perform the procedures described above. The computer program code for carrying out procedures of the example embodiments may be written in any combination of one or more programming languages. The computer program code may be provided to one or more processors or controllers of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a 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.
Some example embodiments further provide a computer program product or a computer readable medium having the computer program code or instructions stored therein. The computer readable medium may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but is not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
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 certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular example embodiments. Certain features that are described in the context of separate example embodiments may also be implemented in combination in a single example embodiment. Conversely, various features that are described in the context of a single example embodiment may also be implemented in multiple example embodiments separately or in any suitable sub-combination.
Although the subject matter has been described in a language that is specific to structural features and/or method actions, it is to be understood the subject matter defined in the appended claims is not limited to the specific features or actions described above. On the contrary, the above-described specific features and actions are disclosed as an example of implementing the claims.
Abbreviations used in the description and/or in the figures are defined as follows:
BS Base Station
CA Carrier Aggregation
FDD Frequency Division Duplex
gNB nest Generation Base Station
MR-DC Multi-RAT Dual Connectivity
NR New Radio
OFDM Orthogonal Frequency Division Multiplexing
RRC Radio Resource Control
SCS Subcarrier Spacing
SRS Sounding Reference Signal
TDD Time Division Duplex
UE User Equipment

Claims

A terminal device comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the terminal device to:

receive a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determine a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
The terminal device of Claim 1, wherein the predetermined rule indicates the time-domain position of the guard period relative to SRS resources in one of the at least one SRS resource set.
The terminal device of Claim 1, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned before and/or after the respective SRS resources.
The terminal device of Claim 1, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned in-between two SRS resources of the at least two SRS resources when the two SRS resources are configured within a slot.
The terminal device of Claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to:

send the predetermined rule to a network device before or after receiving the SRS resource set configuration for the SRS antenna switching.
The terminal device of Claim 5, wherein the predetermined rule is sent in a capability report from the terminal device to the network device.
The terminal device of Claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to:

receive the predetermined rule from a network device.
The terminal device of Claim 7, wherein the predetermined rule is received together with or before receiving the SRS resource set configuration.
The terminal device of Claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to:

determine an actual time-domain position for the guard period when the position determined based on the predetermined rule is unavailable; and

report the actual time-domain position of the guard period to a network device.
The terminal device of Claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to:

receive indication of an actual time-domain position of the guard period from a network device, where the actual time-domain position of the guard period is different from the time-domain position of the guard period determined based on the predetermined rule.
A network device comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the network device to:

configure a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determine a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
The network device of Claim 11, wherein the predetermined rule indicates the time-domain position of the guard period relative to SRS resources in one of the at least one SRS resource set.
The network device of Claim 11, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned before and/or after the respective SRS resources.
The network device of Claim 11, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned in-between two SRS resources of the at least two SRS resources when the two SRS resources are configured within a slot.
The network device of Claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to:

receive the predetermined rule from a terminal device before or after configuring the terminal device with the SRS resource set configuration.
The network device of Claim 15, wherein the predetermined rule is received in a capability report from the terminal device.
The network device of Claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to:

transmit the predetermined rule to a terminal device.
The network device of Claim 17, wherein the predetermined rule is transmitted together with or before transmitting the SRS resource set configuration to the terminal device.
The network device of Claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to:

determine an actual time-domain position for the guard period when the time-domain position determined based on the predetermined rule is unavailable; and

send the actual time-domain position of the guard period.
The network device of Claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to:

receive indication of an actual time-domain position of the guard period from a terminal device, where the actual time-domain position of the guard period is different from the time-domain position of the guard period determined based on the predetermined rule.
A method implemented at a terminal device comprising:

receiving a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
The method of Claim 21, wherein the predetermined rule indicates the time-domain position of the guard period relative to SRS resources in one of the at least one SRS resource set.
The method of Claim 21, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned before and/or after the respective SRS resources.
The method of Claim 21, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned in-between two SRS resources of the at least two SRS resources when the two SRS resources are configured within a slot.
The method of Claim 21, further comprising:

sending the predetermined rule to a network device before or after receiving the SRS resource set configuration for the SRS antenna switching.
The method of Claim 25, wherein the predetermined rule is sent in a capability report from the terminal device to the network device.
The method of Claim 21, further comprising:

receiving the predetermined rule from a network device.
The method of Claim 27, wherein the predetermined rule is received together with or before receiving the SRS resource set configuration.
The method of Claim 21, further comprising:

determining an actual time-domain position for the guard period when the position determined based on the predetermined rule is unavailable; and

reporting the actual time-domain position of the guard period to a network device.
The method of Claim 21, further comprising:

receiving indication of an actual time-domain position of the guard period from a network device, where the actual time-domain position of the guard period is different from the time-domain position of the guard period determined based on the predetermined rule.
A method implemented at a network device comprising:

configuring a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
The method of Claim 31, wherein the predetermined rule indicates the time-domain position of the guard period relative to SRS resources in one of the at least one SRS resource set.
The method of Claim 31, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned before and/or after the respective SRS resources.
The method of Claim 31, wherein the one of the at least one SRS resource set includes at least two SRS resources for SRS transmissions on one or more of the different antenna ports, and the guard period is positioned in-between two SRS resources of the at least two SRS resources when the two SRS resources are configured within a slot.
The method of Claim 31, further comprising:

receiving the predetermined rule from a terminal device before or after configuring the terminal device with the SRS resource set configuration.
The method of Claim 35, wherein the predetermined rule is received in a capability report from the terminal device.
The method of Claim 31, further comprising:

transmitting the predetermined rule to a terminal device.
The method of Claim 37, wherein the predetermined rule is transmitted together with or before transmitting the SRS resource set configuration to the terminal device.
The method of Claim 31, further comprising:

receiving indication of an actual time-domain position of the guard period from a terminal device, where the actual time-domain position of the guard period is different from the time-domain position of the guard period determined based on the predetermined rule.
The method of Claim 31, further comprising:

determining an actual time-domain position for the guard period when the time-domain position determined based on the predetermined rule is unavailable; and

sending the actual time-domain position of the guard period.
An apparatus comprising:

means for receiving a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

means for determining a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
An apparatus comprising:

means for configuring a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

means for determining a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.
A computer program comprising instructions stored on a computer readable medium, the instructions, when executed by at least one processor of a terminal device, causing the terminal device to:

receive a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determine a time-domain position of a guard period where the SRS antenna switching occurs based on indication of a predetermined rule.
A computer program comprising instructions stored on a computer readable medium, the instructions, when executed by at least one processor of a network device, causing the network device to:

configure a Sounding Reference Signal (SRS) resource set configuration, the SRS resource set configuration including at least one SRS resource set configured for SRS antenna switching between different antenna ports; and

determine a time-domain position of a guard period where the SRS antenna switching occurs based on a predetermined rule.