SRS Enhancement For Multi-TRP Coherent Joint Transmit Operation

Abstract

In cellular wireless communications, a sounding reference signal (SRS) can be used to estimate uplink channel quality. A wireless communication device or a mobile device (i.e., a UE) can transmit an SRS to a base station (e.g., an eNB for LTE and a gNB for NR). The SRS gives information about a comprehensive impact of multipath fading, scattering, Doppler, and power loss of the transmitted signal. A number of enhancements can be introduced to the SRS for multi-TRP coherent joint transmission.

Description

Technical Field

[0001] The present application as a whole relates to wireless communication systems, including enhancements to non-periodic, semi-persistent and periodic sounding reference signals for multi-TRP coherent joint transmission operations. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to send data between base stations and wireless communication devices. Wireless communication system standards and protocols may include, for example, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as WLANs). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to communicate between base stations of the RAN (which may also sometimes be referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices referred to as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN may use one or more radio access technologies (RATs) for communication between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (sometimes referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to as 5G RAT, 5G NR RAT, or NR in this document). In some deployments, E-UTRAN may also implement NR RAT. In some deployments, NG-RAN may also implement LTE RAT.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (also sometimes referred to as a gNodeB or gNB).

[0006] The RAN provides its communication services together with external entities through its connection with the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC) while NG-RAN may utilize the 5G Core Network (5GC). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces the element.

[0008] Figure 1 A signal flow diagram of flexible cross-carrier AP-SRS triggering for multi-TRP coherent joint transmission operation according to one embodiment is illustrated.

[0009] Figure 2 A carrier indicator SRS request field divided into multiple parts according to one embodiment is illustrated.

[0010] Figure 3 A jointly encoded carrier indicator field according to one embodiment is illustrated.

[0011] Figure 4 An SRS request field is illustrated that is replicated multiple times according to one embodiment.

[0012] Figure 5 The jointly encoded SRS request field according to one embodiment is illustrated.

[0013] Figure 6 A method for a network node to trigger AP-SRS for multi-TRP coherent joint transmission operation according to one embodiment is illustrated.

[0014] Figure 7 A signal flow diagram of flexible periodic (P) SRS or semi-periodic (SP) SRS activation for multi-TRP coherent joint transmission operation according to one embodiment is illustrated.

[0015] Figure 8 A MAC CE for activating a SP-SRS resource set according to one embodiment is illustrated.

[0016] Fig. 9 It illustrates how the current NR standard handles transmission scheduling with conflicts between downlink transmissions and P / SP-SRS.

[0017] Fig.10 A transmission schedule for deferring periodic and semi-persistent SRS transmissions by a UE based on contention according to one embodiment is illustrated.

[0018] Fig.11A method for a UE to transmit P / SP-SRS for multi-TRP coherent joint transmission operation according to one embodiment is illustrated.

[0019] Fig.12 An example architecture of a wireless communication system according to embodiments disclosed herein is illustrated.

[0020] Fig.13 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is illustrated. DETAILED DESCRIPTION

[0021] Various embodiments are described with reference to UE. However, reference to UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software and / or firmware for exchanging information and data with the network. Therefore, UE as described herein is used to represent any suitable electronic component.

[0022] Many wireless communication standards provide for the use of known signals (e.g., pilot or reference signals) for various purposes, such as synchronization, measurement, equalization, control, etc. For example, in cellular wireless communications, a sounding reference signal (SRS) can be used to estimate uplink channel quality. A wireless communication device or mobile device (i.e., UE) is able to send SRS to a base station (e.g., eNB for LTE and gNB for NR). SRS gives information about the combined effects of multipath fading, scattering, Doppler, and power loss on the transmitted signal. Using SRS, the base station can estimate the channel quality and manage resources accordingly. For example, SRS can provide the base station with information about resources on the bandwidth. Using this information, the base station can determine which resources have better channel quality and allocate resources accordingly.

[0023] In NR Release 15 (Rel-15), the design for SRS is outlined. Some of the limitations of the SRS design in Rel-15 include that SRS can only be sent in the last six symbols of each slot. Additionally, SRS can only be repeated for a maximum of four symbols. Rel-15 is also limited to supporting SRS with comb 1 / 2 / 4.

[0024] NR Release 16 (Rel-16) provides an enhancement to the SRS of Rel-15. In Rel-16, SRS can be sent in any symbol in a time slot. In addition, SRS supports repetition using 8 and 12 symbols. Additionally, SRS with comb 8 is also supported in Rel-16.

[0025] NR Release 17 (Rel-17) provides further enhancements for SRS. For example, Rel-17 supports flexible aperiodic (AP) SRS triggering. Release 17 further supports RB-level partial frequency detection (RPFS). Additionally, SRS is configured to support repetition using 10 and 14 symbols. In Rel-17, SRS also supports comb 8 with four ports. The channel state information (CSI) feedback in Rel-17 is further enhanced for non-coherent joint transmission (NCJT) of multiple transmit and receive point (TRP) operations (referred to as multi-TRP or mTRP). In some wireless networks, NCJT can be used to provide multiple-input multiple-output (MIMO), multi-user (MU) MIMO and / or coordinated multi-point (CoMP) communications. In Rel-17, the CSI feedback for NCJT for multiple TRPs is based on a type-I MIMO codebook that only supports a single downlink control information (DCI) multi-TRP NCJT scheme 1a (i.e., spatial domain multiplexing).

[0026] In certain communication systems (e.g., Rel-18 NR), it may be desirable to provide SRS enhancement for multi-TRP coherent joint transmission (CJT) operation. In order to enhance SRS for multi-TRP CJT operation, some embodiments herein use flexible cross-carrier aperiodic SRS (AP-SRS) triggering. Some embodiments include flexible semi-persistent (SP-SRS) activation. Some embodiments include flexible periodic SRS or SP-SRS transmission. Some embodiments include flexible SRS resource configuration. Some embodiments include flexible SRS frequency hopping patterns.

[0027] Figure 1 A signal flow diagram 100 is illustrated for flexible cross-carrier AP-SRS triggering for multi-TRP coherent joint transmission operation according to one embodiment. The network node 104 may transmit one or more transmissions to the UE 102 to configure and trigger AP-SRS resources and trigger AP-SRS transmission 116. The network node 104 may measure AP-SRS 108 and coordinate with the UE to configure resources based on the AP-SRS measurement 106.

[0028] The transmissions from the network node 104 to the UE 102 that may be used to configure and trigger the AP-SRS include RRC, MAC CE, and DCI. As shown, the network node 104 may send a radio resource control (RRC) message 110 to the UE 102. The network node 104 may also send a medium access control control element (MAC CE) 112 to the UE 102. The network node 104 may also send one or more DCIs (e.g., a scheduling DCI 114) to the UE 102.

[0029] In previous standards, triggering of AP-SRS for multi-TRP coherent joint transmission operation was limited to one component carrier. If multiple component carriers are expected to be triggered, DCI for each component carrier is required. Triggering a single component carrier per DCI may introduce additional overhead and additional latency. The implementation scheme of this document provides flexible cross-carrier AP-SRS triggering for more than one component carrier for multi-TRP coherent joint transmission operation to support uplink carrier aggregation.

[0030] For example, the network node 104 may use the scheduling DCI 114 to trigger multiple component carriers for AP-SRS. In some embodiments, a new carrier indicator field may be introduced in addition to the current SRS indicator field. The new carrier indicator field may allow the network node 104 to schedule a second component carrier in addition to the component carrier scheduled by the previously existing indicator field. This will increase the DCI overhead, but provide flexible scheduling.

[0031] For example, an additional carrier indicator field may be included in the scheduling DCI 114. The scheduling DCI 114 may include the additional carrier indicator field and the original carrier indicator field, thereby providing multiple carrier indicator fields. In addition to the component carrier indicated by the original carrier indicator field, the additional carrier indicator field may also indicate the component carrier in which the UE 102 should send the AP-SRS. Although two component carrier indicator fields are discussed, the scheduling DCI 114 may include more component carrier indicator fields if additional component carriers are desired for the AP-SRS.

[0032] The additional carrier indicator field may be included in one or more DCIs. For example, the carrier indicator field for the AP-SRS component carrier may be one or more of DCI format 0_1, DCI format 0_2, DCI format 1_2, DCI format 1_2. The additional carrier indicator field for the AP-SRS component carrier may contain up to three bits. The mapping of each value of the carrier indicator field to the serving cell ID may be configured by RRC (e.g., RRC message 110).

[0033] In some implementations, the carrier indicator field may be enhanced to allow a single DCI (eg, scheduling DCI 114 ) to trigger AP-SRS in multiple component carriers simultaneously. Figure 2 and Figure 3 Two options for the enhanced carrier indicator field are illustrated.

[0034] Figure 2The carrier indicator field 200 is illustrated as being divided into multiple parts, namely, a first part 202 and a second part 204. Each part independently indicates a component carrier index. In other words, the first part 202 of the carrier indicator field 200 may indicate a first component carrier index, and the second part 204 of the carrier indicator field 200 may indicate a second component carrier index. Using multiple parts of the carrier indicator field 300 may allow a network node to trigger the transmission of AP-SRS on multiple component carriers simultaneously.

[0035] The mapping table 206 may be configured to indicate which component carrier should transmit the AP-SRS. In the illustrated embodiment, the mapping table 206 indicates that if the first portion 202 or the second portion 204 has a value of zero, the UE should use component carrier zero to transmit the AP-SRS. If the first portion 202 or the second portion 204 has a value of one, the UE should use component carrier one to transmit the AP-SRS. If the first portion 202 or the second portion 204 has a value of two, the UE should use component carrier two to transmit the AP-SRS. If the first portion 202 or the second portion 204 has a value of three, the UE should use component carrier three to transmit the AP-SRS.

[0036] For example, the network node may generate a DCI with the carrier indicator field 200 and set the first part 202 to one and the second part 204 to three. The network node may then send the DCI including the carrier indicator field 200 to the UE. The UE may decode the DCI and, based on the value of the first part 202 and the value of the second part 204 of the carrier indicator field 200, send the AP-SRS using component carrier one and component carrier three.

[0037] Figure 3 The carrier indicator field 300 is illustrated as being jointly coded. That is, each value of the carrier indicator field 300 may be mapped to one or more component carriers. The network node may configure a mapping table 302 using RRC. The mapping table 302 indicates a list of component carriers corresponding to possible values ​​of the carrier indicator field 300. The list of component carriers for each value may include one or more component carriers. Using a single value in the carrier indicator field 300 to indicate multiple component carriers may allow the network node to trigger the transmission of AP-SRS on multiple component carriers simultaneously.

[0038] In the illustrated embodiment, the carrier indicator field 300 includes two bits that produce four different possible values. More bits may be used to indicate additional component carrier configurations. In the illustrated embodiment, the mapping table 302 indicates that if the value is zero, the UE should use component carrier zero to send AP-SRS. If the value is one, the UE should use component carrier one to send AP-SRS. If the value is two, the UE should use component carrier two and component carrier three to send AP-SRS. If the value is three, the UE should use component carrier zero and component carrier one to send AP-SRS.

[0039] For example, the network node may generate a DCI with the carrier indicator field 300 and set the value to two. The network node may then send the DCI including the carrier indicator field 300 to the UE. The UE may decode the DCI and, based on the value of the carrier indicator field 300, send the AP-SRS using component carrier two and component carrier three.

[0040] Reference again Figure 1 , a single DCI (e.g., scheduling DCI 114) may be used to simultaneously trigger AP-SRS in multiple component carriers using multiple carrier indicator fields, multiple portions of the carrier indicator field, and / or carrier indicator field values ​​mapped to a component carrier list. When a single DCI is used to simultaneously trigger AP-SRS in multiple component carriers, the network node 104 should indicate whether a normal uplink (NUL) or a supplemental uplink (SUL) should be used for AP-SRS transmission in each component carrier. The network node 104 may associate the NUL / SUL indication with the corresponding component carrier to provide an indication of the uplink type to the UE 102.

[0041] In a first implementation, the network node 104 may include one separate bit for each component carrier in the DCI in the carrier indicator field. These bits may indicate to the UE whether NUL or SUL should be used for AP-SRS transmission in each component carrier.

[0042] In a second embodiment, the network node 104 may provide one common indication for the component carriers indicated by the DCI in the carrier indicator field. For example, the network node 104 may use a single bit in the DCI to indicate whether NUL or SUL should be used for AP-SRS transmission in all component carriers. In addition, in some embodiments, for each component carrier, if the common indication is SUL, but the corresponding component carrier does not have SUL, the UE 102 may send AP-SRS in NUL in the corresponding component carrier. For example, if two component carriers are triggered for AP-SRS and the first component carrier has SUL and the second component carrier does not have SUL, the UE 102 may send the first component carrier in SUL and the second component carrier in NUL. Otherwise, if the common indication is NUL or the corresponding component carrier includes SUL when the common indication is SUL, the UE 102 may send AP-SRS in the corresponding component carrier according to the common indication.

[0043] In some embodiments, the network node 104 may configure one or more component carrier lists via an RRC message 110 or a MAC CE 112. Each component carrier list may contain one or more component carriers. In some embodiments, optional restrictions may be imposed to prevent each component carrier from belonging to more than one component carrier list. The UE 102 may use the component carrier list to determine which component carriers to use to send the AP-SRS. For example, in some embodiments, when the network node 104 triggers the transmission of an AP-SRS in one component carrier, the UE 102 sends the AP-SRS in the scheduled component carrier and also sends the corresponding AP-SRS in other component carriers belonging to the same component carrier list as the scheduled component carrier.

[0044] For example, in an implementation with four component carriers, the network node 104 may provide two component carrier lists to the UE 102 via an RRC message 110 or a MAC CE 112. The first component carrier list may include component carrier zero and component carrier one, and the second component carrier list may include component carrier two and component carrier three. The network node 104 may send a scheduling DCI 114 to the UE 102. The scheduling DCI 114 may include a component carrier field indicating component carrier zero for AP-SRS. The UE 102 may check the component carrier lists and identify that component carrier zero is in the first list with component carrier one. The UE 102 may then transmit an AP-SRS transmission 116 in component carrier zero and component carrier one.

[0045] Each component carrier may correspond to multiple AP-SRS states. The network node 104 may indicate which AP-SRS state the UE 102 should use when sending the AP-SRS transmission 116. The network node 104 may use a DCI to indicate the AP-SRS state. In addition to being able to use a single DCI (e.g., scheduling DCI 114) to trigger multiple component carriers using any of the above embodiments, a single DCI may also be configured to trigger multiple AP-SRS triggering states simultaneously.

[0046] In some embodiments, the SRS request field may be enhanced to allow a single DCI to trigger multiple AP-SRS states simultaneously. Figure 4 and Figure 5 Two options for the Enhanced SRS Request field are illustrated.

[0047] Figure 4 An SRS request field 400 is illustrated that is replicated multiple times (e.g., a first SRS request field 402 and a second SRS request field 404). Each replicated SRS request field 400 independently indicates an AP-SRS triggering state. In other words, the first SRS request field 402 may indicate a first AP-SRS triggering state, and the second SRS request field 404 may indicate a second AP-SRS triggering state. In some embodiments, the AP-SRS triggering state may be used for multiple component carriers scheduled by the DCI. In some embodiments, the network node 104 may indicate which AP-SRS triggering state(s) should be used for each component carrier scheduled by the DCI.

[0048] The mapping table 406 may be configured to indicate which AP-SRS triggering state should be used. In the illustrated embodiment, the mapping table 406 indicates that if the first SRS request field 402 or the second SRS request field 404 has a value of zero, there is no AP-SRS corresponding to the field. If the first SRS request field 402 or the second SRS request field 404 has a value of one, the UE should use AP-SRS triggering state one. If the first SRS request field 402 or the second SRS request field 404 has a value of two, the UE should use AP-SRS triggering state two. If the first SRS request field 402 or the second SRS request field 404 has a value of three, the UE should use AP-SRS triggering state three.

[0049] Figure 5An SRS request field 500 that is jointly encoded is illustrated. That is, the value of the SRS request field 500 may be mapped to one or more AP-SRS triggering states. The network node may configure a mapping table 502 using RRC. The mapping table 502 indicates a list of AP-SRS triggering states corresponding to possible values ​​of the SRS request field 500. The list for each value may include one or more AP-SRS triggering states. Using a single value in the SRS request field 500 to indicate multiple AP-SRS triggering states may allow the network node to simultaneously trigger transmissions using multiple AP-SRS triggering states.

[0050] In the illustrated embodiment, the SRS request field 500 includes two bits that produce four different possible values. More bits may be used to indicate additional AP-SRS trigger state configurations. In the illustrated embodiment, the mapping table 502 indicates that if the value is zero, there is no AP-SRS. If the value is one, the UE should use AP-SRS trigger state one. If the value is two, the UE should use AP-SRS trigger state one and AP-SRS trigger state two. If the value is three, the UE should use AP-SRS trigger state three.

[0051] Reference again Figure 1 , the configuration of AP-SRS transmission 116 can also be enhanced by using flexible SRS resource configuration. In some embodiments, for an AP-SRS resource set, the network node 104 can configure different SRS resources in the same AP-SRS resource set in different time slots. For example, the SRS-Resource configuration can include a slotOffset integer as shown below to indicate different time slots.

[0052]

[0053] Using slotOffset will allow AP-SRS to span multiple time slots. This will allow UE 102 and network node 104 to have greater scheduling flexibility than when AP-SRS is restricted to a single time slot. Similarly, for SRS resource configuration (i.e., SRS-Resource), when the SRS resource contains more than one symbol repetition, the SRS resource may be allowed to cross the time slot boundary. Scheduling flexibility can help schedule multiple AP-SRS transmissions to support AP-SRS for multi-TRP coherent joint transmission operation.

[0054] Figure 6A method 600 for a network node to trigger an AP-SRS for a multi-TRP coherent joint transmission operation according to one embodiment is illustrated. In the illustrated embodiment, the network node determines 602 that the UE is configured to receive a signal using a multi-TRP CJT operation. The network node may generate 604 a DCI for the UE that is configured to trigger an aperiodic sounding reference signal (AP-SRS) for the multi-TRP CJT operation. The DCI may include an indication identifying a plurality of component carriers on which the UE should transmit the AP-SRS. The network node may transmit 606 the DCI to the UE to trigger the AP-SRS in the plurality of component carriers, and receive 608 the AP-SRS in the plurality of component carriers from the UE.

[0055] In some embodiments, the indication identifying the plurality of component carriers comprises a plurality of carrier indicator fields in the DCI. In some embodiments, the indication identifying the plurality of component carriers comprises a carrier indicator field divided into a plurality of parts, wherein each part of the carrier indicator field independently identifies one of the plurality of component carriers. In some embodiments, the indication identifying the plurality of component carriers comprises a carrier indicator field, wherein the value of the carrier indicator field is mapped to a component carrier list. In some embodiments, the DCI further comprises an independent one-bit indication for each component carrier, the independent one-bit indication indicating whether a normal UL or a supplementary UL should be used for AP-SRS transmission in each component carrier. In some embodiments, the network node may further configure one or more component carrier lists, wherein each list comprises one or more component carriers, wherein the indication identifying the plurality of component carriers comprises a value corresponding to one component carrier to indicate to the UE that all component carriers on the list comprising one component carrier are used for AP-SRS transmission. In some embodiments, the DCI further comprises a plurality of SRS request fields for triggering a plurality of AP-SRS triggering states. In some embodiments, the network node may further configure different SRS resources in the same AP-SRS resource set in different time slots. In some embodiments, the DCI also includes an SRS request field, wherein a value of the SRS request field is mapped to an AP-SRS triggering state list. In some embodiments, SRS resources are allowed to cross slot boundaries.

[0056] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 600. The apparatus may be, for example, an apparatus of a base station (such as network device 1318 being a base station, as described herein).

[0057] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 600. The non-transitory computer-readable medium may be, for example, a memory of a base station (such as memory 1322 of network device 1318 that is a base station, as described herein).

[0058] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuits operable to perform one or more elements of method 600. The apparatus may be, for example, an apparatus of a base station (such as network device 1318 being a base station, as described herein).

[0059] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 600. The apparatus may be, for example, an apparatus that is a base station (such as network device 1318 that is a base station, as described herein).

[0060] Embodiments contemplated herein include a signal as described in or in connection with one or more elements of method 600 .

[0061] Embodiments contemplated herein include a computer program or computer program product including instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of method 600. The processor may be a processor of a base station (such as processor 1320 of network device 1318 being a base station, as described herein). These instructions may be located, for example, in a processor of a base station and / or in a memory (such as memory 1322 of network device 1318 being a base station, as described herein).

[0062] Figure 7 A signal flow diagram 700 of flexible periodic (P) SRS or semi-periodic (SP) SRS activation for multi-TRP coherent joint transmission operation according to one embodiment is illustrated. P-SRS is a reference signal that is configured by RRC and occurs periodically (e.g., every 20 milliseconds). SP-SRS is a reference signal that is configured by RRC and is transmitted periodically when activated by MAC-CE.

[0063] For example, for P-SRS, network node 704 may send RRC message 710 to UE 702. RRC message 710 may include configuration details that may be used by receiving UE 702 to determine resources to use for P-SRS (eg, P / SP-SRS transmission 714).

[0064] Similarly, for SP-SRS, the network node 704 may send an RRC message 710 to the UE 702. The RRC message 710 may include configuration details for the SP-SRS. The UE 702 may then wait for the network node 704 to transmit a MAC CE 712 to activate the SP-SRS. When activated, the UE 702 may send the SP-SRS (e.g., P / SP-SRS transmission 714).

[0065] The network node 704 may measure the SRS 708 to determine channel state information. The network node 704 and the UE 702 may then configure resources 706 based on the SP-SRS measurements. SP-SRS and P-SRS configuration and activation may be enhanced to reduce overhead and latency for multi-TRP coherent joint transmission operations.

[0066] For example, Figure 8 A MAC CE 800 for activating an SP-SRS resource set according to one embodiment is illustrated. In current standards, a single MAC CE 800 may be used to activate only one SRS resource set in one component carrier. The SRS resource set to be activated may be indicated by an SRS resource set ID field 802. In addition, the component carrier may be indicated by a cell ID field 804 of the SRS resource set.

[0067] According to current standards, if a network node wishes to activate SRS in multiple component carriers or trigger multiple SRS resource sets, the network will have to transmit multiple MAC CEs, which will result in higher overhead and greater processing latency than a single MAC CE.

[0068] The embodiments herein provide an enhanced MAC CE for flexible SP-SRS activation. The enhanced MAC CE can activate SRS in multiple component carriers simultaneously. In addition, some embodiments can be configured to use a single MAC CE to activate multiple SRS resource sets within each component carrier.

[0069] For example, a single enhanced MAC CE may be used to perform one or both of activating multiple SP-SRS component carriers and activating multiple SP-SRS resource sets. For example, the MAC CE may simultaneously activate SP-SRS resource sets in different component carriers. In some implementations, the network node may generate a MAC CE with a cell ID field for multiple SRS resource sets. In other words, the cell ID fields for multiple SRS resource sets may be configured in the same MAC CE. In addition, the MAC CE may simultaneously activate multiple SP-SRS resource sets in the same component carrier. In some implementations, the network node may configure multiple SRS resource set ID fields in a single MAC CE. When the UE receives the MAC CE, the UE may determine the component carrier based on the cell ID field of the SRS resource set, and determine the resource set to be used for the SP-SRS based on the SRS resource set ID field.

[0070] In some embodiments, the network node may configure multiple component carriers for activation using a single non-enhanced MAC-CE (e.g., MAC CE 800) at the RRC level. For example, the network node may generate an RRC message including one or more component carrier lists to be transmitted to the UE. Each component carrier list may include one or more component carriers. The component carriers in each list are considered to correspond to each other, so that activation of one component carrier on the list causes activation of all component carriers on the same list. In some embodiments, optional restrictions may be imposed to prevent each component carrier from belonging to more than one component carrier list.

[0071] For example, the network node may transmit an RRC message with one or more component carrier lists to the UE. The network node may also transmit a MAC CE 800 to the UE. The UE may determine that the cell ID field 804 of the SRS resource set activates SP-SRS transmission in one component carrier. The UE may identify a component carrier on the same list as one component carrier identified in the cell ID field 804 of the SRS resource set. The UE may activate SP-SRS transmission in the component carrier identified in the cell ID field 804 of the SRS resource set, and also activate corresponding SP-SRS transmission in other component carriers belonging to the same component carrier list as the component carrier indicated by the MAC CE.

[0072] Fig. 9 900 is illustrated how the current NR standard handles a transmission schedule 900 with a conflict between a downlink transmission 904 and a P / SP-SRS 902. As shown, the UE may transmit a periodic or semi-periodic (P / SP) SRS 902 transmission without conflict during a first time period. The P / SP-SRS 902 may have four symbol repetitions. During a second time period, the UE may transmit the P / SP-SRS 902 again.

[0073] However, during the second time period, the downlink transmission 904 conflicts with the second symbol of the SRS. As shown, when periodic and semi-persistent SRS (e.g., P / SP-SRS 902) transmissions (e.g., due to duplex direction conflicts) experience conflicts, the P / SP-SRS is cancelled and discarded. In the illustrated embodiment, because the second symbol conflicts with the downlink transmission 904, all remaining symbol repetitions in the second symbol and the P / SP-SRS 902 are cancelled, resulting in partial cancellation of the P / SP-SRS 902. This partial cancellation may cause coverage loss, resulting in less reliable SRS. For periodic and semi-persistent SRS, conflicts may be difficult to avoid due to their periodic nature.

[0074] In some embodiments, flexible P-SRS and SP-SRS transmission (e.g., P / SP-SRS transmission 714) can be used to support multi-TRP coherent joint transmission operation. Fig.10 A transmission schedule 1000 is illustrated in which a UE defers periodic and semi-persistent SRS (eg, P / SP-SRS 1002) transmissions based on contention.

[0075] In this implementation, when the P / SP-SRS 1002 transmission is expected to be dropped, the P / SP SRS transmission can be postponed to the earliest next available time slot (e.g., time slot 1004). If there is no available time slot before the next P / SP SRS resource set transmission time slot, the P / SP-SRS 1002 is dropped completely.

[0076] The UE may send the P / SP SRS again according to the SRS periodicity. During each cycle of the SRS periodicity, the UE may attempt to transmit the entire P / SP-SRS 1002 transmission, as discussed above. That is, if a discarded transmission is expected (e.g., conflicting with a downlink transmission), the UE postpones the P / SP-SRS 1002 to the earliest time slot that does not include a conflict, and if there is no available time slot before the next P / SP SRS resource set transmission time slot, the UE discards the P / SP-SRS 902 during the period.

[0077] Deferring the SRS will allow the UE to send the entire SRS, making the SRS more reliable. In addition, the ability to defer SRS transmission increases the flexibility of the periodic nature of the P / SP-SRS 1002.

[0078] The collision detection performed by the UE may be based on the RRC configuration. For example, in some embodiments, the determination by the UE whether a time slot is available may be based only on the RRC configuration, rather than on a semi-static MAC CE or a dynamic DCI indication. For example, the time slot format configured by the RRC may be based on which symbol is used for downlink operation and which symbol is used for uplink operation. The UE may check the RRC configuration to determine where the downlink symbols are to ensure that there is enough time for P / SP-SRS 1002 transmission.

[0079] Additionally, in some embodiments, the UE may determine whether a time slot is available based on the severity of the conflict. For example, in a first option, if any SRS resource in the SRS resource set has a conflict, the UE postpones P / SP-SRS 1002. In a second option, if all SRS resources in the SRS resource set have a conflict, the UE postpones P / SP-SRS 1002. The wireless communication system may support one or both of these two options. For example, in a wireless communication system that supports both options, the UE may indicate the capabilities of the UE, and the network node may indicate which option the network prefers.

[0080] In some embodiments, a flexible SRS frequency hopping pattern may be used to minimize interference using interference randomization. For periodic and semi-persistent SRS (e.g., P / SP-SRS transmission 714), interference may become persistent when nearby UEs transmit with the same periodicity. Interference randomization may reduce the likelihood that interference may become persistent. Through randomization, even if the first SRS transmission causes interference between UEs, interference is less likely to occur during the next SRS transmission.

[0081] Interference randomization can be implemented in a variety of ways. In some embodiments, randomization of the SRS sequence ID (i.e., the sequenceId field in the SRS-Resource configuration) may occur. Randomization of the SRS sequence ID may enable the UE to transmit using a different sequence at each interval of the SRS periodicity. Sequence randomization may be configured between the UE and the network node. For example, the network node transmits a predetermined randomization for the sequence ID to the UE.

[0082] In some embodiments, the comb configuration (i.e., transmissionComb in the SRS-Resource configuration) may be randomized. The comb size may remain the same, but the comb offset and cyclic shift may change for each interval of the SRS periodicity. The network node may configure the comb size and the comb offset. For example, the network node may segment the resources into combs 4. For each interval of the SRS periodicity, there may be different offsets and / or cyclic shifts. The offset and / or cyclic shift randomization may be configured between the UE and the network node. For example, the network node transmits a predetermined randomization for the offset and / or cyclic shift to the UE.

[0083] In some embodiments, the time domain position of the SRS within the time slot (i.e., resourceMapping in the SRS-Resource configuration) may be randomized in each period. For example, the starting symbol of the SRS may change each interval of the periodicity. Time domain randomization may be configured between the UE and the network node. For example, the network node transmits a predetermined randomization for the time domain to the UE.

[0084] In some embodiments, quasi co-location (QCL) (ie, spatialRelationInfo in SRS-Resource configuration) may be randomized. QCL randomization may be configured between the UE and the network node. For example, the network node transmits a predetermined randomization for the QCL to the UE.

[0085] Fig.11 A method for a UE to transmit a P / SP-SRS for a multi-TRP coherent joint transmission operation according to one embodiment is illustrated. The UE may be configured 1102 to receive a signal using a multi-TRP CJT operation. The UE may receive 1104 an RRC transmission from a network node, the RRC transmission including configuration details for the P-SRS or SP-SRS. The UE may determine 1106 whether a scheduled P-SRS or SP-SRS transmission will conflict with a downlink transmission from the network node. When a conflict is expected in the current time slot, the UE may postpone 1108 the scheduled P-SRS or SP-SRS transmission to the next available time slot. When a conflict is not expected in the current time slot, the UE may transmit 1110 a P-SRS or SP-SRS transmission to the network node in one or more CCs.

[0086] In some embodiments, if there is no available time slot before the next scheduled P-SRS or SP-SRS transmission, the scheduled P-SRS or SP-SRS transmission is discarded. In some embodiments, the method also includes receiving a MAC CE from the network node, wherein the MAC CE performs one or both of the following operations: activating SP-SRS resource sets in different CCs at the same time, and activating multiple SP-SRS resource sets in the same CC at the same time. In some embodiments, the MAC CE includes one or both of the following: a cell ID field of multiple SRS resource sets, and multiple SRS resource set ID fields. In some embodiments, the RRC transmission also includes one or more CC lists, each of which includes one or more CCs, wherein the MAC CE includes one CC, wherein the UE includes all CCs on the list of the one CC from the MAC CE for the SP-SRS transmission. In some embodiments, determining the conflict is based on the RRC configuration. In some embodiments, if any SRS resource in the SRS resource set is affected by the conflict, the current time slot is not available for the P-SRS or SP-SRS transmission. In some embodiments, the current time slot is unavailable for the P-SRS or SP-SRS transmission only when all SRS resources in the SRS resource set are affected by the conflict. In some embodiments, the method further includes randomizing an SRS sequence used to transmit the P-SRS or SP-SRS transmission to the network node. In some embodiments, the method further includes randomizing a comb offset or cyclic shift used to transmit the P-SRS or SP-SRS transmission to the network node.

[0087] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the method 1100. The apparatus may be, for example, an apparatus that is a UE (such as the wireless device 1302 as a UE, as described herein).

[0088] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 1100. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1306 of wireless device 1302 as a UE, as described herein).

[0089] Embodiments contemplated herein include an apparatus including logical components, modules, or circuits for performing one or more elements of the method 1100. The apparatus may be, for example, an apparatus of a UE (such as the wireless device 1302 as a UE, as described herein).

[0090] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 1100. The apparatus may be, for example, an apparatus of a UE (such as wireless device 1302 as a UE, as described herein).

[0091] Implementations contemplated herein include signals as described in or related to one or more elements of method 1100 .

[0092] Embodiments contemplated herein include a computer program or computer program product that includes instructions, where execution of the program by a processor causes the processor to perform one or more elements of the method 1100. The processor may be a processor of a UE (such as the processor 1304 of the wireless device 1302 as a UE, as described herein). These instructions may be located, for example, in a processor and / or on a memory of a UE (such as the memory 1306 of the wireless device 1302 as a UE, as described herein).

[0093] Fig.12 An example architecture of a wireless communication system 1200 according to embodiments disclosed herein is illustrated. The description provided below is for an example wireless communication system 1200 operating in conjunction with LTE system standards and / or 5G or NR system standards provided in 3GPP technical specifications.

[0094] like Fig.12 As shown, wireless communication system 1200 includes UE 1202 and UE 1204 (although any number of UEs may be used). In this example, UE 1202 and UE 1204 are illustrated as smartphones (e.g., handheld touch screen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0095] UE 1202 and UE 1204 may be configured to be communicatively coupled to RAN 1206. In an embodiment, RAN 1206 may be NG-RAN, E-UTRAN, etc. UE 1202 and UE 1204 utilize connections (or channels) (shown as connection 1208 and connection 1210, respectively) with RAN 1206, where each connection (or channel) includes a physical communication interface. RAN 1206 may include one or more base stations, such as base station 1212 and base station 1214, to implement connection 1208 and connection 1210.

[0096] In this example, connection 1208 and connection 1210 are air interfaces that enable such communicative coupling and may conform to the RAT used by RAN 1206, such as LTE and / or NR.

[0097] In some embodiments, UE 1202 and UE 1204 may also directly exchange communication data via sidelink interface 1216. UE 1204 is shown configured to access an access point (shown as AP 1218) via connection 1220. For example, connection 1220 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, wherein AP 1218 may include In this example, AP 1218 may not be connected to another network (eg, the Internet) through CN 1224.

[0098] In an embodiment, UE 1202 and UE 1204 may be configured to communicate with each other or with base station 1212 and / or base station 1214 over a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. OFDM signals may include multiple orthogonal subcarriers.

[0099] In some embodiments, all or part of base station 1212 or base station 1214 may be implemented as one or more software entities running on a server computer as part of a virtual network. In addition, or in other embodiments, base station 1212 or base station 1214 may be configured to communicate with each other via interface 1222. In an embodiment where wireless communication system 1200 is an LTE system (e.g., when CN 1224 is an EPC), interface 1222 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. In an embodiment where wireless communication system 1200 is an NR system (e.g., when CN 1224 is a 5GC), interface 1222 may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to a 5GC, between a base station 1212 (e.g., a gNB) and an eNB connected to a 5GC, and / or between two eNBs connected to a 5GC (e.g., CN 1224).

[0100] RAN 1206 is shown as being communicatively coupled to CN 1224. CN 1224 may include one or more network elements 1226 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 1202 and users of UE 1204) connected to CN 1224 via RAN 1206. Components of CN 1224 may be implemented in one physical device or separate physical devices including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0101] In an embodiment, CN 1224 may be an EPC, and RAN 1206 may be connected to CN 1224 via an S1 interface 1228. In an embodiment, S1 interface 1228 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 1212 or base station 1214 and a serving gateway (S-GW), and an S1-MME interface, which is a signaling interface between base station 1212 or base station 1214 and a mobility management entity (MME).

[0102] In an embodiment, CN 1224 may be a 5GC, and RAN 1206 may be connected to CN 1224 via an NG interface 1228. In an embodiment, NG interface 1228 may be divided into two parts: an NG user plane (NG-U) interface that carries traffic data between base station 1212 or base station 1214 and a user plane function (UPF), and an S1 control plane (NG-C) interface that is a signaling interface between base station 1212 or base station 1214 and an access and mobility management function (AMF).

[0103] In general, the application server 1230 may be an element that provides applications that use Internet Protocol (IP) bearer resources with the CN 1224 (e.g., packet-switched data services). The application server 1230 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 1202 and UE 1204 via the CN 1224. The application server 1230 may communicate with the CN 1224 via the IP communication interface 1232.

[0104] Fig.13A system 1300 for performing signaling 1334 between a wireless device 1302 and a network device 1318 according to embodiments disclosed herein is illustrated. The system 1300 may be part of a wireless communication system as described herein. The wireless device 1302 may be, for example, a UE of a wireless communication system. The network device 1318 may be, for example, a base station (e.g., an eNB or a gNB) of a wireless communication system.

[0105] The wireless device 1302 may include one or more processors 1304. The processor 1304 may execute instructions to perform various operations of the wireless device 1302 as described herein. The processor 1304 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0106] The wireless device 1302 may include a memory 1306. The memory 1306 may be a non-transitory computer-readable storage medium that stores instructions 1308 (which may include, for example, instructions executed by the processor 1304). The instructions 1308 may also be referred to as program code or a computer program. The memory 1306 may also store data used by the processor 1304 and results calculated by the processor.

[0107] The wireless device 1302 may include one or more transceivers 1310, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 1312 of the wireless device 1302 to facilitate signaling (e.g., signaling 1334) sent or received by the wireless device 1302 with other devices (e.g., network device 1318) according to a corresponding RAT.

[0108] The wireless device 1302 may include one or more antennas 1312 (e.g., one, two, four, or more). For implementations with multiple antennas 1312, the wireless device 1302 may take full advantage of the spatial diversity of these multiple antennas 1312 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). MIMO transmission by the wireless device 1302 may be implemented based on precoding (or digital beamforming) applied to the wireless device 1302, which multiplexes the data streams between the antennas 1312 based on known or assumed channel characteristics, so that each data stream is received with appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain embodiments may use a single-user MIMO (SU-MIMO) approach (where data streams are all directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0109] In certain embodiments with multiple antennas, the wireless device 1302 may implement analog beamforming techniques whereby the phases of signals transmitted by the antennas 1312 are adjusted relative to each other so that the (joint) transmissions of the antennas 1312 are directional (this is sometimes referred to as beam steering).

[0110] The wireless device 1302 may include one or more interfaces 1314. The interfaces 1314 may be used to provide input to or output from the wireless device 1302. For example, a wireless device 1302 that is a UE may include an interface 1314, such as a microphone, a speaker, a touch screen, buttons, etc., to allow a user of the UE to provide input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuits that allow the UE to communicate with other devices (e.g., in addition to the transceiver 1310 / antenna 1312 described above), and may communicate according to known protocols (e.g., etc.) to perform the operation.

[0111] The wireless device 1302 may include an SRS module 1316. The SRS module 1316 may be implemented via hardware, software, or a combination thereof. For example, the SRS module 1316 may be implemented as a processor, circuit, and / or instructions 1308 stored in the memory 1306 and executed by the processor 1304. In some examples, the SRS module 1316 may be integrated within the processor 1304 and / or the transceiver 1310. For example, the SRS module 1316 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 1304 or the transceiver 1310.

[0112] The SRS module 1316 may be used in various aspects of the present disclosure, for example, Figures 1 to 12 The SRS module 1316 is configured to transmit the SRS based on the configuration from the network device 1318.

[0113] The network device 1318 may include one or more processors 1320. The processor 1320 may execute instructions to perform various operations of the network device 1318 as described herein. The processor 1320 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0114] The network device 1318 may include a memory 1322. The memory 1322 may be a non-transitory computer-readable storage medium that stores instructions 1324 (which may include, for example, instructions executed by the processor 1320). The instructions 1324 may also be referred to as program code or a computer program. The memory 1322 may also store data used by the processor 1320 and results calculated by the processor.

[0115] The network device 1318 may include one or more transceivers 1326, which may include RF transmitter and / or receiver circuits that use an antenna 1328 of the network device 1318 to facilitate signaling (e.g., signaling 1334) to and / or from the network device 1318 with other devices (e.g., wireless device 1302) according to a corresponding RAT.

[0116] The network device 1318 may include one or more antennas 1328 (e.g., one, two, four, or more). In embodiments with multiple antennas 1328, the network device 1318 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc. as described above.

[0117] The network device 1318 may include one or more interfaces 1330. The interface 1330 may be used to provide input to or output from the network device 1318. For example, a network device 1318 that is a base station may include an interface 1330 consisting of a transmitter, a receiver, and other circuits (e.g., in addition to the transceiver 1326 / antenna 1328 already described), which enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., for the purpose of operating, managing, and maintaining the base station or other equipment that is operably connected to the base station.

[0118] The network device 1318 may include an SRS configuration module 1332. The SRS configuration module 1332 may be implemented via hardware, software, or a combination thereof. For example, the SRS configuration module 1332 may be implemented as a processor, circuit, and / or instructions 1324 stored in the memory 1322 and executed by the processor 1320. In some examples, the SRS configuration module 1332 may be integrated within the processor 1320 and / or the transceiver 1326. For example, the SRS configuration module 1332 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 1320 or the transceiver 1326.

[0119] The SRS configuration module 1332 may be used in various aspects of the present disclosure, for example, Figures 1 to 12 The SRS configuration module 1332 is configured to configure SRS transmission from the UE.

[0120] For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein. For another example, circuits associated with a UE, a base station, a network element, etc., as described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein.

[0121] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the above teachings, modifications and variations are possible, or can be obtained from the practice of various embodiments.

[0122] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine executable instructions to be executed by a computer system. A computer system may include one or more general or special purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic components for performing operations; or may include a combination of hardware, software, and / or firmware.

[0123] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of another embodiment may be used in one embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated herein.

[0124] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0125] Although the foregoing has been described in considerable detail for the sake of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways to implement both the processes and the apparatus described herein. Therefore, the embodiments of the present invention should be regarded as illustrative rather than restrictive, and the specification is not limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a network node, the method include: determining that a user equipment (UE) is configured to receive a signal using a multiple transmit and receive point (multi-TRP) coherent joint transmit (CJT) operation; generating downlink control information (DCI) for the UE, the DCI being configured to trigger an aperiodic sounding reference signal (AP-SRS) for the multi-TRPCJT operation, wherein the DCI includes an indication identifying a plurality of component carriers (CCs) on which the UE should send the AP-SRS; transmitting the DCI to the UE to trigger the AP-SRS in the plurality of component carriers; as well as The AP-SRS in the plurality of component carriers is received from the UE.

2. The method of claim 1, wherein the indication identifying a plurality of CCs comprises a plurality of carrier indicator fields in the DCI.

3. The method of claim 1, wherein the indication identifying a plurality of CCs comprises a carrier indicator field divided into a plurality of portions, wherein each portion of the carrier indicator field independently identifies one CC of the plurality of CCs. 4 . The method of claim 1 , wherein the indication identifying a plurality of CCs comprises a carrier indicator field, wherein a value of the carrier indicator field is mapped to a CC list.

5. The method of claim 1, wherein the DCI further includes an independent one-bit indication for each CC, the independent one-bit indication indicating whether a normal UL or a supplemental UL should be used for AP-SRS transmission in each CC.

6. The method according to claim 1 further includes configuring one or more CC lists, each list including one or more CCs, wherein the indication identifying multiple CCs includes a value corresponding to one CC to indicate to the UE that all CCs on the list including the one CC are to be used for the AP-SRS transmission. 7 . The method according to claim 1 , wherein the DCI further comprises a plurality of SRS request fields for triggering a plurality of AP-SRS triggering states. 8 . The method according to claim 1 , wherein the DCI further includes an SRS request field, wherein a value of the SRS request field is mapped to an AP-SRS triggering state list.

9. The method according to claim 1, further comprising configuring different SRS resources in different time slots in the same AP-SRS resource set.

10. The method of claim 1, wherein SRS resources are allowed to cross time slot boundaries.

11. A method for a UE, the method comprising: include: configured to receive signals using a multiple transmit and receive point (multiple TRP) coherent joint transmit (CJT) operation; receiving a radio resource control (RRC) transmission from a network node, the RRC transmission including configuration details for a periodic sounding reference signal (P-SRS) or a semi-persistent sounding reference signal (SP-SRS), determining whether a scheduled P-SRS or SP-SRS transmission will collide with a downlink transmission from the network node; deferring the scheduled P-SRS or SP-SRS transmission to a next available time slot when a collision is expected in the current time slot; as well as The P-SRS or SP-SRS transmission is transmitted to the network node in one or more component carriers (CCs) when the collision is not expected in the current time slot.

12. The method of claim 11, wherein if there is no available time slot before the next scheduled P-SRS or SP-SRS transmission, the scheduled P-SRS or SP-SRS transmission is dropped.

13. The method of claim 11, further comprising receiving a medium access control element (MAC CE) from the network node, wherein the MAC CE performs one or both of the following operations: Activate SP-SRS resource sets in different CCs simultaneously, and Multiple SP-SRS resource sets in the same CC are activated simultaneously.

14. The method of claim 13, wherein the MAC CE comprises one or both of the following: The cell ID fields of multiple SRS resource sets, and Multiple SRS resource set ID fields.

15. The method of claim 13, wherein the RRC transmission further comprises one or more CC lists, wherein each list comprises one or more CCs, wherein the MAC CE comprises one CC, wherein the UE uses all CCs on the list including the one CC from the MAC CE for the SP-SRS transmission. The method of claim 11 , wherein the conflict is determined based on an RRC configuration. 17 . The method according to claim 11 , wherein in case any SRS resource in the SRS resource set is affected by the conflict, the current time slot cannot be used for the P-SRS or SP-SRS transmission.

18. The method according to claim 11, wherein the current time slot cannot be used for the P-SRS or SP-SRS transmission only when all SRS resources in the SRS resource set are affected by the conflict.

19. The method of claim 11, further comprising randomizing an SRS sequence used to transmit the P-SRS or SP-SRS transmission to the network node.

20. The method of claim 11, further comprising randomizing a comb offset or cyclic shift used to transmit the P-SRS or SP-SRS transmission to the network node.

21. An apparatus comprising means for performing the method according to any one of claims 1 to 20.

22. A computer-readable medium comprising instructions, wherein when one or more processors of an electronic device execute the instructions, the electronic device executes the method according to any one of claims 1 to 20.

23. An apparatus comprising logic components, modules or circuits for performing the method according to any one of claims 1 to 20.

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