Enhancement for simultaneous multi-panel transmission

Abstract

An apparatus is configured to receive an indication related to simultaneous multi-panel transmission (STxMP) using a first transmission (Tx) panel and a second Tx panel for a physical uplink shared channel (PUSCH), wherein the indication comprises an association between a phase tracking reference signal (PTRS) to be transmitted using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be transmitted using the first Tx panel and the second Tx panel; and transmitting the PUSCH to a first transmit and receive point (TRP) and a second TRP of a base station using the first Tx panel and the second Tx panel based on the indication.

Description

Background Art

[0001] User equipment (UE) can support simultaneous multi-panel transmission (STxMP). The UE can support either or both of the spatial domain multiplexing (SDM) scheme or the single frequency network (SFN) scheme in STxMP. However, many aspects of STxMP remain undefined, such as the phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association for SDM and SFN, and the dynamic switching between SFN and single transmit and receive point (sTRP) operation. Summary of the Invention

[0002] Some example embodiments relate to an apparatus having processing circuitry configured to: receive an indication related to simultaneous multi-panel transmission (STxMP) using a first transmit (Tx) panel and a second Tx panel for a physical uplink shared channel (PUSCH), wherein the indication includes an association between a phase tracking reference signal (PTRS) to be transmitted using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be transmitted using the first Tx panel and the second Tx panel; and configure a transceiver circuit to transmit the PUSCH to a first transmit and receive point (TRP) and a second TRP of a base station using the first Tx panel and the second Tx panel based on the indication.

[0003] Other example embodiments relate to an apparatus having processing circuitry configured to: configure an indication related to simultaneous multi-panel transmission (STxMP) using a first transmit (Tx) panel and a second Tx panel for a physical uplink shared channel (PUSCH), wherein the indication includes an association between a phase tracking reference signal (PTRS) to be transmitted using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be transmitted using the first Tx panel and the second Tx panel; and configure a transceiver circuit to transmit the indication to a user equipment (UE) via a first transmit and receive point (TRP) or a second TRP. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 Example network arrangements are shown according to various example embodiments.

[0005] Figure 2 An example UE is shown according to various example embodiments.

[0006] Figure 3 An example base station is shown according to various example embodiments.

[0007] Figure 4 An example network arrangement with two transceiver points is shown according to various example embodiments.

[0008] Figure 5 Table 7.3.1.1.2-2, Table 7.3.1.1.2-3, and Table 7.3.1.1.2-5 of TS 38.212 are shown. DETAILED DESCRIPTION

[0009] Example embodiments may be further understood with reference to the following description and associated drawings, in which similar elements bear the same reference numerals. Example embodiments relate to a UE that performs simultaneous multi-panel transmission (STxMP) using a spatial domain multiplexing (SDM) scheme or a single frequency network (SFN) scheme. Specifically, example embodiments relate to defining an association between a phase tracking reference signal (PTRS) and a demodulation reference signal (DMRS) for SDM and SFN. Example embodiments also relate to dynamic switching by a UE between SFN and single transmit and receive point (sTRP) operation.

[0010] The example embodiments are described with reference to a UE. However, reference to a UE is provided for illustrative purposes only. The example embodiments may be utilized with any electronic component that can establish a connection with an accessory device and is configured with hardware, software, and / or firmware for exchanging information and data with the accessory device. Therefore, the term UE as described herein is intended to represent any electronic component.

[0011] Example embodiments are also described with reference to fifth generation (5G) New Radio (NR) networks and next generation Node Bs (gNBs). However, reference to 5G NR networks and gNBs is provided for illustrative purposes only. Example embodiments may also be implemented in other types of networks, including future evolutions of cellular protocols or any other type of network.

[0012] Throughout this specification, the terms "configured" and "indicated" are used to describe information that a UE is transmitted with that the UE may use to perform an operation (e.g., sent on a physical uplink shared channel (PUSCH)). Typically, the term "configured" is used when the information is signaled to the UE using radio resource control (RRC) signaling or included in a medium access control element (MAC CE). The term "indicated" is typically used when the information is signaled to the UE using downlink control information (DCI). However, configured information may also be indicated, and indicated information may also be configured. Thus, while there are typical ways to signal information, example embodiments are not limited to these ways.

[0013] A gNB may be configured with multiple transmit and receive points (TRPs). Throughout this specification, a TRP generally refers to a collection of components configured to transmit and / or receive beams. In some embodiments, multiple TRPs may be deployed locally at the gNB. For example, the gNB may include multiple antenna arrays / panels, each of which is configured to generate a different beam. In other embodiments, multiple TRPs may be deployed at various locations and connected to the gNB via a backhaul connection. For example, multiple small cells may be deployed at different locations and connected to the gNB. However, these examples are provided for illustrative purposes only. TRPs are configured to adapt to a variety of different conditions and deployment scenarios. Therefore, any reference to a TRP as a specific network component or to multiple TRPs deployed in a specific arrangement is provided for illustrative purposes only. The TRPs described herein may represent any type of network component configured to transmit and / or receive beams.

[0014] A UE supporting simultaneous multi-panel transmission (STxMP) may have multiple transmit (Tx) panels that can be used to simultaneously transmit uplink (UL) signals to a TRP. For example, UL transmissions to one TRP may be generated from two Tx panels of the UE. In the example embodiment, the UE may be considered to have two Tx panels. However, the principles described herein for the example embodiment may be extended to UEs having more than two TX panels.

[0015] An example implementation is also described with reference to a single downlink control information (sDCI) scenario in which the sDCI directs the UE to send information in the uplink (UL) via a physical uplink shared channel (PUSCH).

[0016] The UE may also support one or both of a spatial domain multiplexing (SDM) scheme or a single frequency network (SFN) scheme. In SDM, different Tx panels are used to transmit different layers of PUSCH transmission. For example, if the PUSCH has two layers, a different Tx panel will be used to transmit each layer. In another example, the PUSCH has three layers, where the first layer is transmitted using the first Tx panel, and the remaining two layers are transmitted using the second Tx panel (expressed as {1+2}). In yet another example, the PUSCH has three layers, where two layers are transmitted using the first Tx panel, and the remaining layers are transmitted using the second Tx panel (expressed as {2+1}).

[0017] In SFN, the same PUSCH information is sent on different Tx panels. For example, if the sDCI indicates that two layers are to be used for PUSCH transmission, two Tx panels are used to transmit these two layers. Therefore, the names {1+1} and {2+2} can be used for SFN, but they are different from the names described above for SDM. For example, {1+1} SFN transmission indicates that the same information from one layer is sent on two Tx panels. {2+2} SFN transmission indicates that the same information from two layers is sent on two Tx panels.

[0018] Figure 1 An example network arrangement 100 according to various example embodiments is shown. Example network arrangement 100 includes a UE 110. UE 110 can be any type of electronic component configured to communicate via a network, such as a mobile phone, tablet computer, desktop computer, smartphone, phablet, embedded device, wearable device, Internet of Things (IoT) device, etc. A practical network arrangement can include any number of UEs used by any number of users. Therefore, the example of one UE 110 is provided for illustrative purposes only.

[0019] UE 110 can be configured to communicate with one or more networks. In the example of network arrangement 100, the network with which UE 110 can wirelessly communicate is a 5G NR radio access network (RAN) 120. However, UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, next generation RAN (NG-RAN), traditional cellular networks, etc.), and UE 110 can also communicate with networks via wired connections. Referring to an example embodiment, UE 110 can establish a connection with 5G NR RAN 120. Therefore, UE 110 can have a 5G NR chipset to communicate with NR RAN 120.

[0020] The 5G NR RAN 120 may be part of a cellular network that may be deployed by a network operator (e.g., Verizon, AT&T, T-Mobile, etc.). The RAN 120 may include cells or base stations configured to transmit and receive traffic from UEs equipped with appropriate cellular chipsets. In this example, the 5G NR RAN 120 includes a gNB 120A. However, reference to a gNB is provided for illustrative purposes only, and any suitable base station or cell (e.g., a Node B, eNodeB, HeNB, eNB, gNB, gNodeB, macrocell, microcell, small cell, femtocell, etc.) may be deployed.

[0021] Any association procedure may be performed to connect the UE 110 to the 5G NR RAN 120. For example, as discussed above, the 5G NR RAN 120 may be associated with a specific network operator, where the UE 110 and / or its user has protocol and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR RAN 120, the UE 110 may send corresponding credential information in order to associate with the 5G NR RAN 120. More specifically, the UE 110 may be associated with a specific cell (e.g., gNB 120A).

[0022] The network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 manages traffic flowing between the cellular network and the Internet 140. The IMS 150 can generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 can generally be described as a collection of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 to communicate with various networks.

[0023] Figure 2 An example UE 110 is shown according to various example embodiments. The UE 110 will refer to Figure 1 100. UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. Other components 230 may include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting UE 110 to other electronic devices, sensors for detecting conditions of UE 110, and the like.

[0024] The processor 205 may be configured to execute multiple engines of the UE 110. For example, these engines may include an sDCI STxMP engine 235 for performing operations such as receiving configuration and instructions for STxMP operation, associating PTRS and DMRS, performing STxMP transmission based on the configuration and instructions, and switching from the STxMP SFN scheme to the sTRP mode. These operations and other operations are described in more detail below.

[0025] The engines referenced above as applications (e.g., programs) executed by the processor 205 are merely examples. The functionality associated with these engines may also be represented as separate incorporated components of the UE 110, or may be modular components coupled to the UE 110, such as integrated circuits with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. These engines may also be embodied as one application or multiple separate applications. Furthermore, in some UEs, the functionality described for the processor 205 is split between two or more processors, such as a baseband processor and an application processor. The example embodiments may be implemented in any of these or other configurations of the UE.

[0026] Memory arrangement 210 may be a hardware component configured to store data related to operations performed by UE 110. Display device 215 may be a hardware component configured to display data to a user, and I / O device 220 may be a hardware component that enables the user to enter input. Display device 215 and I / O device 220 may be separate components or may be integrated together (such as a touch screen).

[0027] The transceiver 225 may be a hardware component configured to establish a connection with the 5G-NR RAN 120. Thus, the transceiver 225 may operate on a variety of different frequencies or channels (e.g., a set of contiguous frequencies). The transceiver 225 includes circuitry configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information for implementing any of the methods described herein. The processor 205 may be operably coupled to the transceiver 225 and configured to receive signals from and / or send signals to the transceiver 225. The processor 205 may be configured to encode and / or decode signals (e.g., signaling from a base station of the network) for implementing any of the methods described herein.

[0028] Figure 3 An example base station 300 is shown according to various example embodiments. Base station 300 may represent a gNB 120A or any other access node that a UE 110 may use to establish a connection and manage network operations.

[0029] The base station 300 may include a processor 305, a memory arrangement 310, input / output (I / O) devices 315, a transceiver 320, and other components 325. These other components 325 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports for electrically connecting the base station 300 to other electronic devices and / or a power source, and the like.

[0030] The processor 305 may be configured to execute multiple engines of the UE 110. For example, these engines may include an sDCI STxMP configuration engine 335 for performing operations such as sending a configuration and indication for STxMP operation to the UE, receiving an STxMP transmission from the UE based on the configuration and indication, and indicating that the UE should switch from the STxMP SFN scheme to the sTRP mode. These operations and other operations are described in more detail below.

[0031] The memory arrangement 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I / O device 315 may be a hardware component or port that enables a user to interact with the base station 300.

[0032] The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UEs in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., a set of contiguous frequencies). Thus, the transceiver 320 may include one or more components (e.g., radio components) to enable data exchange with various networks and UEs. The transceiver 320 includes circuits configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information for implementing any of the methods described herein. The processor 305 may be operably coupled to the transceiver 320 and configured to receive signals from and / or send signals to the transceiver 320. The processor 305 may be configured to encode and / or decode signals (e.g., signaling from the UE) for implementing any of the methods described herein.

[0033] In the case of two simultaneous DL receptions (e.g., two AoA receptions), a process is required so that both the network and the UE ensure that the UE simultaneously receives both the new beam corresponding to AoA2 and the existing beam corresponding to AoA1. A UE operating in such a scenario may alternatively fall back to a single DL (e.g., with AoA1) reception, or the UE may restore two AoA receptions through the following process defined herein.

[0034] Figure 4 An example network arrangement 400 with two TRPs is shown according to various example embodiments. Network arrangement 400 includes a first TRP 410 and a second TRP 420. TRPs 410 and 420 communicate with UE 110. UE 110 may include multiple receive (Rx) panels and transmit (Tx) panels. The Rx panels are used to receive signals from TRPs 410 and 420. Example embodiments generally relate to UE 110 transmitting signals to TRPs 410 and 420, and therefore the Rx panels will not be described in further detail.

[0035] like Figure 4 As shown, UE 110 will send uplink (UL) physical uplink shared channel (PUSCH) transmissions to TRPs 410 and 420. Each UL PUSCH transmission can be considered to be sent via a separate Tx panel of UE 110, for example, the UL PUSCH transmission to TRP 410 is sent via a first Tx panel, and the UL PUSCH transmission to TRP 420 is sent via a second Tx panel. As described above, these UL PUSCH transmissions to TRPs 410 and 420 can be performed simultaneously by the UE, for example, both Tx panels are activated to perform transmissions at the same time. This is called simultaneous multi-panel transmission (STxMP). The example embodiments described below describe various aspects of STxMP operation.

[0036] As described above, UE 110 can operate in sDCI-based STxMP mode using the SDM scheme. In such PUSCH transmission, 2 PTRS ports can be defined. This may cause problems in associating these PTRS ports with DMRS ports because, in the SDM scheme, each layer of PUSCH will be transmitted using a different Tx panel. This means that there will be at least one DMRS port for each Tx panel. Recall the examples above, where the PUSCH has three layers, for example, represented as {1+2} or {2+1}. In these examples, there will be 3 DMRS ports, for example, in the {1+2} example, 1 DMRS port is used for the first Tx panel and 2 DMRS ports are used for the second Tx panel; and in the {2+1} example, 2 DMRS ports are used for the first Tx panel and 1 DMRS port is used for the second Tx panel.

[0037] Therefore, in sDCI-based STxMP SDM mode, a PTRS-DMRS association should be defined. Example implementations are described with reference to information (e.g., fields) in DCI formats 0_1 and 0_2 to signal this PTRS-DMRS association to UE 110. Although example implementations are described with reference to DCI formats 0_1 and 0_2, the principles described herein are applicable to any sDCI indication when UE 110 is operating in STxMP SDM mode.

[0038] In some example embodiments, the maximum number of layers per panel is indicated as 1 (e.g., {1+1}; 2 layers, 1 layer per panel). In these example embodiments, no bit is needed to signal the PTRS-DMRS association because it is implicit in the indication of the maximum number of layers per panel, e.g., a single PTRS port is mapped to a single DMRS port for each Tx panel.

[0039] In other example embodiments, the maximum number of layers per panel is indicated as {1+2} or {2+1}, as described above. In these examples, a 1-bit field may be used to signal the PTRS-DMRS association to UE 110. Similarly, for a Tx panel used to transmit a single layer, the PTRS-DMRS association is also implicit, for example, a single PTRS port is mapped to a single DMRS port. On the other hand, for a Tx panel used to transmit 2 layers, a 1-bit field may be used to signal the PTRS-DMRS association. For example, when the 1-bit field is set to a first value (e.g., "0"), the first scheduled DMRS port corresponds to a sounding reference signal (SRS) resource set having a maximum of 2 layers configured. When the 1-bit field is set to a second value (e.g., "1"), the second scheduled DMRS port corresponds to an SRS resource set having a maximum of 2 layers configured.

[0040] In another example embodiment, the maximum number of layers per panel is indicated as {2+2}, for example, each Tx panel is used to transmit 2 layers of PUSCH. In these examples, a 2-bit field can be used to signal the PTRS-DMRS association to UE 110. In the 2-bit field, a most significant bit (MSB) and a least significant bit (LSB) can be defined. The MSB can be used to signal the SRS resource indicator field and / or precoding information and the number of layers field. For example, when the MSB bit is set to a first value (e.g., "0"), the first scheduled DMRS port corresponds to the SRS resource indicator field and / or precoding information and the number of layers field. When the MSB bit is set to a second value (e.g., "1"), the second scheduled DMRS port corresponds to the SRS resource indicator field and / or precoding information and the number of layers field. The LSB can be used to signal the second SRS resource indicator field and / or precoding information. For example, when the LSB bit is set to a first value (e.g., "0"), the first scheduled DMRS port corresponds to the second SRS resource indicator field and / or precoding information. When the LSB bit is set to a second value (eg, '1'), the second scheduled DMRS port corresponds to a second SRS resource indicator field and / or precoding information.

[0041] In the example implementation above, the maximum number of layers per panel may be configured by the network and signaled to the UE 110 using, for example, radio resource control (RRC) signaling. Therefore, based on this information, the UE 110 will expect a corresponding number of bits in the sDCI related to PTRS-DMRS association. However, the configured maximum number of layers may not be the number of layers indicated. To provide an example, the UE 110 may be configured using RRC signaling with a maximum number of layers of {2+1}. This configured number of layers should be understood as a maximum. Therefore, the sDCI may still indicate 2 layers, 1 layer per Tx panel, as this does not violate the maximum value of {2+1}. Therefore, even if the UE 110 expects the sDCI to include a 1-bit field for PTRS-DMRS association in a {2+1} scenario, the UE 110 may also understand that when only 2 layers are indicated, the 1-bit field is not required, as the PTRS-DMRS association is similar to the {1+1} scenario. In these examples (e.g., where the number of layers indicated is less than the configured maximum number of layers), the 1-bit field in the sDCI may be ignored or reused for some other purpose.

[0042] Another issue related to PTRS-DMRS association in sDCI STxMP SDM mode is that the configured maximum number of PTRS ports (e.g., the UE is configured with the higher-layer parameter maxNrofPorts set to "n2" in PTRS-UplinkConfig) may be different from the actual number of UL PTRS ports used for the associated transmission layer. For example, for non-codebook-based UL transmission, if the UE is configured with the higher-layer parameter phaseTrackingRS in DMRSUplinkConfig, the UE can be configured with a PTRS port index for each configured SRS resource through the higher-layer parameter ptrs-PortIndex configured by SRS-Config. Therefore, if the PTRS port index associated with different SRS resource indicators (SRIs) is the same, the corresponding UL DMRS port is associated with one UL PT-RS port, which means that the configured maximum number of PTRS ports is 2, but the actual number of PTRS ports is 1. For codebook-based UL transmission, the actual number of PTRS ports is indicated by the transmit precoding matrix index (TPMI). PUSCH antenna ports 1000 and 1002 indicated in the TPMI share PT-RS port 0, and PUSCH antenna ports 1001 and 1003 indicated in the TPMI share PT-RS port 1. Similarly, there may be scenarios where the maximum configured number of PTRS ports is 2, but the actual number of PTRS ports is 1. In STxMP mode, because there are two Tx panels transmitting simultaneously, some of these scenarios may result in a single PTRS port being mapped to two Tx panels. In these scenarios, the UE will not be able to maintain phase tracking across the two Tx panels.

[0043] To address this issue, a UE operating in sDCI STxMP SDM mode may have maxNrofPorts set to 1 for each SRS resource set, and the port index (if configured) is different between the two SRS resource sets. This ensures that for non-codebook-based SDM STxMP, all SRS resources within an SRS resource set are associated with a single PTRS port that is different from the PTRS port of the other SRS resource set. For example, all SRS resources within the first SRS resource set are associated with ptrs-PortIndex 0, and all SRS resources within the second SRS resource set are associated with ptrs-PortIndex 1.

[0044] Now turning to PTRS-DMRS association in sDCI STxMP SFN mode, the DMRS port is treated similarly to PUSCH data, for example, two Tx panels are used to send the exact same DMRS. Since PTRS is associated with DMRS, the SFN used for DMRS means that PTRS is also sent in the same manner, for example, two Tx panels are used to send the exact same PTRS.

[0045] Before discussing PTRS-DMRS association, let's discuss the issue of the maximum configured number of PTRS ports and the actual number of ports in SFN-based STxMP. In some example embodiments, when a UE is configured with SFN-based STxMP, the configured number of UL PTRS ports and the actual number of UL PTRS ports are the same. As described above with reference to SDM, the actual number of UL PTRS ports can be different from the configured number of UL PTRS ports. However, in these example embodiments, when a UE is configured with SFN, the configured number of UL PTRS ports and the actual number of UL PTRS ports are considered to be the same.

[0046] Turning to PTRS-DMRS association, when a UE is configured with SFN-based STxMP, in some example implementations, a field may be used in the sDCI to signal the PTRS-DMRS association to the UE.

[0047] In the first example, when the transmission is a {1+1}SFN transmission (e.g., a single-layer SFN transmission), no additional field is required because, similar to the {1+1}SDM transmission, the information indicating a single-layer SFN transmission implicitly indicates a PTRS-DMRS association, e.g., there is a single PTRS port and a single DMRS port for each Tx panel.

[0048] In the second example, a 1-bit field can be used for the layer combination {2+2}, for example, two-layer SFN transmission. In the first option of the second example, it can be considered that the number of configured PTRS ports is 1. In this option, when the 1-bit field is set to a first value (e.g., "0"), one PTRS port can be mapped to the first scheduled DMRS port. When the 1-bit field is set to a second value (e.g., "1"), one PTRS port can be mapped to the second scheduled DMRS port.

[0049] In the second option of the second example, the number of configured PTRS ports can be considered to be 2. In this option, when the 1-bit field is set to a first value (e.g., "0"), one PTRS port can be mapped to the first scheduled DMRS port, the first PTRS port (e.g., PTRS port 0) is mapped to the first scheduled DMRS port, and the second PTRS port (e.g., PTRS port 1) is mapped to the second scheduled DMRS. When the 1-bit field is set to a second value (e.g., "1"), the second PTRS port (e.g., PTRS port 1) is mapped to the first scheduled DMRS port, and the first PTRS port (PTRS port 0) is mapped to the second scheduled DMRS.

[0050] As described above, another aspect of the example embodiments is to support DCI-based dynamic switching between the SFN scheme and sTRP transmission of the STxMP PUSCH based on a single DCI. In some example embodiments, the DCI field "SRS resource set indicator" can be used to indicate the switch between the SFN scheme and sTRP transmission. However, the example embodiments are not limited to this manner of signaling the UE to switch between the SFN scheme and sTRP transmission.

[0051] A problem that arises based on dynamic switching between SFN and sTRP is that the maximum number of layers sent by sTRP and SFN may be different. This may affect the DCI size. For example, when the UE is configured with two SRS resource sets in SFN mode, the UE will assume that it is operating in SFN mode when decoding the DCI. However, if dynamic switching based on DCI is supported, the DCI should support both SFN and sTRP, for example, the DCI should include information for both SFN and sTRP. This may lead to an unsatisfactory increase in the DCI size. Several example implementations for supporting dynamic switching between SFN and sTRP are provided below.

[0052] In the first example implementation, for a UE configured with SFN STxMP, the only allowed combinations of the maximum number of layers across the panel are {1+1} or {2+2}. This constraint limits the number of layers used for SFN and simplifies the configuration in the DCI, as only up to four layers are supported for simultaneous transmission, e.g., a maximum of 2x layers (L).

[0053] In a second exemplary embodiment, for a UE configured with SFN STxMP, the DMRS antenna port indications may be one or two ports in the same or separate code division multiplexing (CDM) groups. The second exemplary embodiment is related to the first exemplary embodiment, for example, because the maximum number of layers across a panel is {1+1} or {2+2}, the number of DMRS ports may also be limited to one or two ports.

[0054] In a third example embodiment, the UE may be configured with simultaneous multi-TRP (mTRP) based SFN PUSCH transmission. In these example embodiments, the UE may be configured with a pair of parameters (L Smax ,L Mmax ). L Smax It can indicate the maximum number of layers when the UE is instructed to switch back to sTRP. Mmax Indicates the maximum number of layers when the UE is instructed to perform SFN-based mTRP transmission.

[0055] In the fourth example embodiment, when the UE is instructed to perform simultaneous mTRP-based SDM PUSCH transmission, L Mmax The maximum number of layers L corresponding to the first SRS resource set and the second SRS resource set may be based on 1,Mmax and L 2,Mmax For example, in some example embodiments, L Mmax =1 / 2(L 1,Mmax +L 2,Mmax ). In other exemplary embodiments, L Mmax =min(L 1,Mmax ,L 2,Mmax ). In yet another exemplary embodiment, L Mmax =max(L 1,Mmax ,L 2,Mmax ).

[0056] The fourth exemplary embodiment is related to the third exemplary embodiment in that L Mmax is the same as, for example, the maximum number of layers when the UE is instructed to perform SFN-based mTRP transmission. However, in the fourth example embodiment, L may not be directly signaled to the UE. MmaxInstead of using the value of L, the UE can derive the value based on the relationship between the SDM parameter and the SFN parameter. This allows saving RRC parameter signaling because L Mmax The value of does not need to be signaled to the UE, as the UE can derive the value.

[0057] In a fifth example embodiment, for a UE configured with SFN STxMP with two SRS resource sets (e.g., N1 and N2) using the codebook set to "nonCodebook", each SRS resource set may have more than one SRS resource. In addition, each SRS resource set may support a different number of SRS resources per set, e.g., when L Mmax =2, for all (L Smax ,L Mmax ) combination of N 1,SRS and N 2,SRS This allows for greater flexibility at the scheduler and enhances SFN transmission. In this example embodiment, L Smax The value of (e.g., the maximum number of layers for sTRP) is irrelevant, e.g., L Smax The value of can be 1, 2, 3 or 4. The DCI size for SRI supports switching between mTRP SFN and sTRP, for example, all combinations of resource sets can be supported.

[0058] In the sixth exemplary embodiment, in addition to L Mmax = 1, the UE is configured in the same manner as in the fifth example embodiment. Similar to the fifth example, with some exceptions, all combinations of resource sets can be supported. For example, when L Smax =2,3,4 and (N 1,SRS =2 and N 2,SRS =4) or (N 1,SRS =4 and N 2,SRS =2), where N j,SRS is the number of SRS resources within the jth SRS resource set. The problem with these exceptions is that the size of the DCI for the sTRP can be larger than the DCI for the mTRP SFN. These exceptions are implemented because the UE assumes that the DCI is for the mTRP SFN; for example, when the UE decodes the DCI, the UE is unaware that it is dynamically switching to the sTRP. By excluding these specific combinations, it is ensured that switching to the sTRP will result in an SRI bit field no larger than SRI1 + SRI2.

[0059] In the seventh example implementation, for a UE configured with a SFN STxMP with two SRS-ResourceSets using set to "codebook", it is not expected that the UE is configured with different numbers of SRS resources in the two SRS resource sets.

[0060] In an eighth example embodiment, for a UE configured with an SFN STxMP with two SRS-ResourceSets set to "codebook", the UE may be configured with different higher layer parameters nrofSRS-Port in the SRS-Resource in different SRS-ResourceSets and indicated using them. Allowing different numbers of ports allows for improvements in system performance, for example, allowing different precoders for different Tx panels. However, in order to keep the DCI size the same for SFN and sTRP, there are antenna port combinations that are excluded, for example, because the sTRP combination requires more DCI bits than SFN. This exclusion will be described in more detail below.

[0061] Similar to non-codebook based transmission, the UE will assume that the DCI is for SFN, and when decoding the DCI, the UE determines the two TPMI bit fields (TPMI1 and TPMI2) associated with each SRS resource set based on the existing Rel-16 table in TS 38.212, where the size of TPMI2 is a function of TPMI1. Similarly, except for the exclusions described below, this design ensures that for sTRP operation, the size of the TPMI bit field associated with the indicated SRS resource set is no larger than the size of (TPMI1 + TPMI2).

[0062] Reference will be made to Tables 7.3.1.1.2-2, 7.3.1.1.2-3 and 7.3.1.1.2-5 of TS 38.212. Figure 5 To describe the exclusion. It can be considered that (L Smax ,L Mmax )=(L Smax ,1),(N ap,SRS1 =4 / 2 and N ap,SRS2 =4 / 2), where N ap is the number of antenna ports in each SRS resource set. It can also be considered that L Mmax =1, and L Smax Can be 1, 2, 3, or 4. The exclusion applies when codebookSubset is non-coherent, the first resource set (e.g., SRS1) has 4 antenna ports and the second resource set (e.g., SRS2) has 2 antenna ports, and sTRP uses the first resource set. The exclusion also applies when codebookSubset is non-coherent, the first resource set (e.g., SRS1) has 2 antenna ports and the second resource set (e.g., SRS2) has 4 antenna ports, and sTRP uses the second resource set. As described above, these scenarios are excluded because the number of DCI bits for sTRP for this scenario is greater than the number of DCI bits for SFN.

[0063] To provide an example of exclusion, refer to Figure 5 . This example is the exclusion when the codebookSubset is non-coherent, the first resource set (e.g., SRS1) has 4 antenna ports and the second resource set (e.g., SRS2) has 2 antenna ports, and the sTRP uses the first resource set. Initially, referring to Table 7.3.1.1.2-3, it can be seen that the last two columns refer to the scenario where the codebookSubset is non-coherent for SFN. From the table, it can be seen that for SFN, for a resource set with 4 antenna ports (e.g., SRS1), there are 4 TPMI indices (0-3), which means that a 2-bit field is required in the DCI to provide this information to the UE. Now referring to Table 7.3.1.1.2-3, it can be seen that the last two columns refer to the scenario where the codebookSubset is non-coherent for SFN. From the table, it can be seen that for SFN, for a resource set with 2 antenna ports (e.g., SRS2), there are 2 TPMI indices (0-1), which means that a 1-bit field is required in the DCI to provide this information to the UE. Therefore, for SFN, DCI requires 3 bits (eg, 2+1) for the scenario described above.

[0064] In contrast, referring to Table 7.3.1.1.2-2, it can be seen that the last two columns refer to scenarios in which the codebookSubset is non-coherent for sTRP. As can be seen from the table, for sTRP, for a resource set with 4 antenna ports (e.g., SRS1), there are 12 TPMI indices (0-11), which means that a 4-bit field is required in the DCI to provide this information to the UE. Therefore, the number of bits for sTRP (4 bits) is greater than the number of bits for SFN (3 bits). This will result in the DCI for sTRP being greater than the DCI for SFN, which is not allowed in this example embodiment. Therefore, this particular scenario is excluded. Other exclusions can be determined in the same way.

[0065] However, as described above, all other combinations of antenna ports support SFN and sTRP switching.

[0066] Example

[0067] In a first embodiment, a method performed by a user equipment (UE) including a first transmit (Tx) panel and a second Tx panel, the method including: receiving an indication related to simultaneous multi-panel transmission (STxMP) using the first Tx panel and the second Tx panel for a physical uplink shared channel (PUSCH), wherein the indication includes an association between a phase tracking reference signal (PTRS) to be sent using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be sent using the first Tx panel and the second Tx panel; and sending the PUSCH to a first transmit and receive point (TRP) and a second TRP of a base station using the first Tx panel and the second Tx panel based on the indication.

[0068] In a second embodiment, the method according to the first embodiment, wherein the indication is received from one of the first TRP or the second TRP via downlink control information (DCI).

[0069] In a third embodiment, the method according to the first embodiment is configured with STxMP using a spatial domain multiplexing (SDM) scheme, wherein different layers of the PUSCH are transmitted using different Tx panels.

[0070] In a fourth embodiment, the method according to the third embodiment, wherein the indication includes a maximum number of one layer for the first Tx panel and the second Tx panel, and wherein the association between the PTRS and the DMRS is based on the maximum number of one layer for the first Tx panel and the second Tx panel.

[0071] In a fifth embodiment, the method according to the third embodiment, wherein the indication includes a maximum number of two layers for the first Tx panel and the second Tx panel and a maximum number of 1 layer for the second Tx panel, and the indication also includes a 1-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel.

[0072] In a sixth embodiment, a method is provided according to the fifth embodiment, wherein the first value of the 1-bit field indicates an association between a first PTRS and a first scheduled DMRS port of a sounding reference signal (SRS) resource set corresponding to the first Tx panel, and the second value of the 1-bit field indicates an association between the first PTRS and a second scheduled DMRS port of the SRS resource set corresponding to the first Tx panel.

[0073] In a seventh embodiment, a method according to the third embodiment is provided, wherein the indication includes a maximum number of two layers for the first Tx panel and the second Tx panel, and the indication further includes a 2-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel and the second Tx panel, wherein the most significant bit (MSB) of the 2-bit field indicates (i) a first SRS resource indicator field or (ii) first precoding information and (iii) a layer number field, and wherein the least significant bit (LSB) of the 2-bit field indicates a second SRS resource indicator field or second precoding information.

[0074] In an eighth embodiment, a method according to the seventh embodiment is provided, wherein the first value of the MSB indicates that the first scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information, and the second value of the MSB indicates that the second scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information.

[0075] In a ninth embodiment, a method according to the seventh embodiment is provided, wherein the first value of the LSB indicates that the first scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information, and the second value of the LSB indicates that the second scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information.

[0076] In a tenth embodiment, the method according to the third embodiment is described, wherein, when operating using the SDM scheme, a first sounding reference signal (SRS) resource set corresponds to the first Tx panel, and a second SRS resource set corresponds to the second Tx panel, wherein the maximum number of ports of each SRS resource set is one.

[0077] In an eleventh embodiment, the method according to the tenth embodiment, wherein a port index is different between the first SRS resource set and the second SRS resource set.

[0078] In a twelfth embodiment, the method according to the first embodiment, wherein the UE is configured with STxMP using a single frequency network (SFN) scheme, wherein each layer of the PUSCH is transmitted using both the first Tx panel and the second Tx panel.

[0079] In a thirteenth embodiment, the method according to the twelfth embodiment, wherein the configured number of PTRS ports and the actual number of PTRS ports are the same.

[0080] In a fourteenth embodiment, according to the method of the twelfth embodiment, the indication indicates that the PUSCH includes a layer, and the association between the PTRS and the DMRS is based on the indication of a layer of PUSCH.

[0081] In a fifteenth embodiment, the method according to the twelfth embodiment, wherein the indication indicates that the PUSCH includes two layers, and wherein there is a configured PTRS port for each Tx panel, the indication also includes a 1-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel and the second Tx panel.

[0082] In a sixteenth embodiment, a method according to the fifteenth embodiment is provided, wherein the first value of the 1-bit field indicates, for each Tx panel, an association between the configured PTRS port and a first scheduled DMRS port, and the second value of the 1-bit field indicates, for each Tx panel, an association between the configured PTRS port and a second scheduled DMRS port.

[0083] In a seventeenth embodiment, a method according to the twelfth embodiment, wherein the indication indicates that the PUSCH includes two layers, and wherein there are two configured PTRS ports for each Tx panel, and the indication also includes a 1-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel and the second Tx panel.

[0084] In an eighteenth embodiment, a method according to the seventeenth embodiment is provided, wherein the first value of the 1-bit field indicates, for each Tx panel, an association between a first PTRS port among the configured PTRS ports and a first scheduled DMRS port, and an association between a second PTRS port among the configured PTRS ports and a second scheduled DMRS port, and the second value of the 1-bit field indicates, for each Tx panel, an association between the second PTRS port among the configured PTRS ports and the first scheduled DMRS port, and an association between the first PTRS port among the configured PTRS ports and the second scheduled DMRS port.

[0085] In a nineteenth embodiment, a method according to the twelfth embodiment is provided, wherein the UE supports switching from the STxMP using the SFN scheme to a single TRP (sTRP) mode based on information included in the indication, wherein the indication is received from one of the first TRP or the second TRP via downlink control information (DCI).

[0086] In a twentieth embodiment, the method according to the nineteenth embodiment, wherein a maximum number of layers for PUSCH for STxMP using the SFN scheme is two.

[0087] In a twenty-first embodiment, the method according to the nineteenth embodiment, wherein the maximum number of DMRS antenna ports per Tx panel is two.

[0088] In a twenty-second embodiment, the method according to the twenty-first embodiment, wherein the DMRS antenna ports are in the same code division multiplexing (CDM) group or different CDM groups.

[0089] In a twenty-third embodiment, according to the method of the nineteenth embodiment, the indication includes a maximum number of layers (L Smax ) and the maximum number of layers (L) when the UE is instructed to perform SFN-based multi-TRP (mTRP) transmission Mmax ).

[0090] In a twenty-fourth embodiment, according to the method of the nineteenth embodiment, when the UE is instructed to perform simultaneous mTRP-based spatial domain multiplexing (SDM) PUSCH transmission, a first maximum number of layers (L) corresponding to a first sounding reference signal (SRS) resource set is indicated to the UE. 1,Mmax ) and the second maximum number of layers corresponding to the second SRS resource set (L 2,Mmax ), the method further comprises: based at least on L 1,Mmax and L 2,Mmax The value of determines the maximum number of layers (L) when the UE is instructed to perform SFN-based mTRP transmission Mmax ).

[0091] In a twenty-fifth embodiment, according to the method of the twenty-fourth embodiment, the L Mmax Based on L Mmax =1 / 2(L 1,Mmax +L 2,Mmax ) to determine.

[0092] In a twenty-sixth embodiment, according to the method of the twenty-fourth embodiment, the L Mmax Based on L Mmax =min(L 1,Mmax ,L 2,Mmax ) to determine.

[0093] In a twenty-seventh embodiment, according to the method of the twenty-fourth embodiment, the L Mmax Based on L Mmax =max(L 1,Mmax ,L 2,Mmax) to determine.

[0094] In a twenty-eighth embodiment, the method according to the nineteenth embodiment, wherein the UE is configured with two sounding reference signal (SRS) resource sets with usage set to nonCodebook, wherein each SRS resource set includes more than one SRS resource, wherein a different number of SRS resources is configured for each SRS resource set, and wherein when L Mmax =2, the UE supports the maximum number of layers (L Smax ) and the maximum number of layers (L) when the UE is instructed to perform SFN-based multi-TRP (mTRP) Mmax ) all combinations, switching from the STxMP using the SFN scheme to sTRP mode.

[0095] In a twenty-ninth embodiment, the method according to the nineteenth embodiment, wherein the UE is configured with two sounding reference signal (SRS) resource sets with usage set to nonCodebook, wherein each SRS resource set includes more than one SRS resource, wherein a different number of SRS resources is configured for each SRS resource set, and wherein when L Mmax = 1, except when L Smax＝ 2, 3 or 4 and the first resource set or the second SRS resource set includes four SRS resources and the other of the first resource set or the second SRS resource set includes two SRS resources, the UE supports the maximum number of layers (L) for when the UE is instructed to switch to sTRP Smax ) and the maximum number of layers (L) when the UE is instructed to perform SFN-based multi-TRP (mTRP) Mmax ) all combinations, switching from the STxMP using the SFN scheme to sTRP mode.

[0096] In a thirtieth embodiment, the method according to the nineteenth embodiment is configured with two sounding reference signal (SRS) resource sets using a codebook set, wherein each SRS resource set includes more than one SRS resource, and wherein each SRS resource set includes the same number of SRS resources.

[0097] In a thirty-first embodiment, a method according to the thirtieth embodiment, wherein the UE is configured with or indicated by a first number of SRS ports for a first SRS resource set and a second number of SRS ports for a second SRS resource set, except that when the first SRS resource set includes four SRS ports, the second SRS resource set includes two SRS ports, the codebook subset is set to non-coherent and sTRP uses the first SRS resource set, or when the first SRS resource set includes two SRS ports, the second SRS resource set includes four SRS ports, the codebook subset is set to non-coherent and sTRP uses the second SRS resource set.

[0098] In a thirty-second embodiment, a processor is provided, wherein the processor is configured to perform any one of the methods described in accordance with the first to thirty-first embodiments.

[0099] In a thirty-third embodiment, a user equipment comprises: a transceiver configured to communicate with a base station; and a processor communicatively coupled to the transceiver and configured to perform any one of the methods described in embodiments 1 to 31.

[0100] In a thirty-fourth embodiment, a method performed by a base station including a first transmission and reception point (TRP) and a second TRP, the method including: receiving information from a user equipment (UE), the information indicating that the UE supports switching from simultaneous multi-panel transmission (STxMP) using a single frequency network (SFN) scheme to a single TRP (sTRP) mode based on downlink control information (DCI) received from one of the first TRP or the second TRP; sending configuration information related to STxMP using SFN to the UE, wherein the configuration information includes two sounding reference signal (SRS) resource sets using a codebook set, wherein each SRS resource set includes More than one SRS resource, wherein each SRS resource set includes the same number of SRS resources, wherein the configuration information also includes a first number of SRS ports for the first SRS resource set and a second number of SRS ports for the second SRS resource set, except that when the first SRS resource set includes four SRS ports, the second SRS resource set includes two SRS ports, the codebook subset is set to non-coherent and the sTRP uses the first SRS resource set, or when the first SRS resource set includes two SRS ports, the second SRS resource set includes four SRS ports, the codebook subset is set to non-coherent and the sTRP uses the second SRS resource set.

[0101] In a thirty-fifth embodiment, a processor of a base station is configured to execute the thirty-fourth embodiment.

[0102] In a thirty-sixth embodiment, a base station comprises: a transceiver configured to communicate with a user equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform the thirty-fourth embodiment.

[0103] Those skilled in the art will appreciate that the example embodiments described above may be implemented with any suitable software configuration or hardware configuration or combination thereof. Example hardware platforms for implementing the example embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. The example embodiments of the methods described above may be embodied as a program comprising lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0104] Although this application describes various embodiments, each having different features in various combinations, those skilled in the art will understand that any of the features of one embodiment may be combined with features of other embodiments in any manner that is not expressly negated or that is not functionally or logically inconsistent with the operation of the device or the specified function of the disclosed embodiment.

[0105] It is widely acknowledged 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 authorized use should be clearly stated to users.

[0106] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, it is intended that the present disclosure covers modifications and variations of the present disclosure as long as they come within the scope of the appended claims and their equivalents.

Claims

1. An apparatus comprising a processing circuit configured to: receiving an indication related to simultaneous multi-panel transmission (STxMP) for a physical uplink shared channel (PUSCH) using a first transmit (Tx) panel and a second Tx panel, wherein the indication includes an association between a phase tracking reference signal (PTRS) to be transmitted using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be transmitted using the first Tx panel and the second Tx panel; and The transceiver circuit is configured to transmit the PUSCH to a first transmit and receive point (TRP) and a second TRP of a base station using the first Tx panel and the second Tx panel based on the indication.

2. The apparatus of claim 1, wherein the indication is received from one of the first TRP or the second TRP via downlink control information (DCI). 3 . The apparatus of claim 1 , wherein the apparatus is configured with STxMP using a spatial domain multiplexing (SDM) scheme, wherein different layers of the PUSCH are transmitted using different Tx panels.

4. The apparatus of claim 3 , wherein the indication comprises a maximum number of one layer for the first Tx panel and the second Tx panel, and wherein the association between the PTRS and the DMRS is based on the maximum number of one layer for the first Tx panel and the second Tx panel.

5. The apparatus of claim 3 , wherein the indication includes a maximum number of two layers for the first Tx panel and the second Tx panel, the indication further comprising a 2-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel and the second Tx panel, wherein the most significant bit (MSB) of the 2-bit field indicates (i) the first SRS resource indicator field or (ii) the first precoding information and (iii) the layer number field, and The least significant bit (LSB) of the 2-bit field indicates a second SRS resource indicator field or second precoding information.

6. The apparatus of claim 5 , wherein a first value of the MSB indicates that a first scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information, and a second value of the MSB indicates that a second scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information.

7. The apparatus of claim 5, wherein a first value of the LSB indicates that a first scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information, and a second value of the LSB indicates that a second scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information. 8 . The apparatus of claim 1 , wherein the apparatus is configured with STxMP using a single frequency network (SFN) scheme, wherein each layer of the PUSCH is transmitted using both the first Tx panel and the second Tx panel.

9. An apparatus according to claim 8, wherein the apparatus supports switching from the STxMP using the SFN scheme to a single TRP (sTRP) mode based on information included in the indication, wherein the indication is received from one of the first TRP or the second TRP via downlink control information (DCI).

10. The apparatus of claim 9, wherein the indication comprises a maximum number of layers (L) when the apparatus is instructed to switch to sTRP Smax ) and the maximum number of layers (L) when the device is instructed to perform SFN-based multi-TRP (mTRP) transmission Mmax ).

11. The apparatus of claim 1, wherein the apparatus comprises a processor of a user equipment (UE) or the UE.

12. An apparatus comprising a processing circuit configured to: configuring an indication related to simultaneous multi-panel transmission (STxMP) for a physical uplink shared channel (PUSCH) using a first transmit (Tx) panel and a second Tx panel, wherein the indication includes an association between a phase tracking reference signal (PTRS) to be transmitted using the first Tx panel and the second Tx panel and a demodulation reference signal (DMRS) to be transmitted using the first Tx panel and the second Tx panel; and The transceiver circuit is configured to send the indication to a user equipment (UE) via a first transmit and receive point (TRP) or a second TRP.

13. The apparatus of claim 12, wherein the processing circuit is further configured to: The PUSCH is received based on the indication, wherein the PUSCH is received from the first TRP and the second TRP.

14. The apparatus of claim 12, wherein the indication is sent from one of the first TRP or the second TRP via downlink control information (DCI).

15. The apparatus of claim 12, wherein the indication comprises a maximum number of one layer for the first Tx panel and the second Tx panel, and wherein the association between the PTRS and the DMRS is based on the maximum number of one layer for the first Tx panel and the second Tx panel.

16. The apparatus of claim 12 , wherein the indication includes a maximum number of two layers for the first Tx panel and the second Tx panel, the indication further comprising a 2-bit field for indicating the association between the PTRS and the DMRS for the first Tx panel and the second Tx panel, wherein the most significant bit (MSB) of the 2-bit field indicates (i) the first SRS resource indicator field or (ii) the first precoding information and (iii) the layer number field, and The least significant bit (LSB) of the 2-bit field indicates a second SRS resource indicator field or second precoding information.

17. The apparatus of claim 16, wherein a first value of the MSB indicates that a first scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information, and a second value of the MSB indicates that a second scheduled DMRS port corresponds to the first SRS resource indicator field or the first precoding information.

18. The apparatus of claim 16, wherein a first value of the LSB indicates that a first scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information, and a second value of the LSB indicates that a second scheduled DMRS port corresponds to the second SRS resource indicator field or the second precoding information.

19. The apparatus of claim 12, wherein the processing circuit is further configured to: Information indicating that the UE supports switching from simultaneous multi-panel transmission (STxMP) using a single frequency network (SFN) scheme to a single TRP (sTRP) is received from the UE.

20. The apparatus of claim 19, wherein the indication comprises a maximum number of layers (L) when the UE is instructed to switch to sTRP Smax ) and the maximum number of layers (L) when the UE is instructed to perform SFN-based multi-TRP (mTRP) transmission Mmax ).

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