System and method for uplink and downlink in multi-point communication

Abstract

Example wireless communication methods and apparatuses are described. One example includes receiving, by a user equipment (UE), first configuration information for a bandwidth part (BWP) in a carrier of a serving cell. The first configuration information includes a first set of parameters and a first resource group (RG) for the BWP in the carrier of the serving cell. The UE receives second configuration information for the BWP in the carrier, where the second configuration information includes a second set of parameters and a second RG for the BWP in the carrier. A transmission or reception associated with the first RG is performed based on the first set of parameters. A transmission or reception associated with the second RG is performed based on the second set of parameters.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 062,335, filed August 6, 2020. The entire disclosure of the aforementioned application is incorporated herein by reference. Technical Field

[0003] The present invention generally relates to wireless communication, and in specific embodiments, to systems and methods for uplink and downlink in multipoint communication. Background Technology

[0004] Wireless communication systems include Long Term Evolution (LTE), LTE-A, LTE-A Supersystem, 5G LTE, and 5G New Radio (NR). Modern wireless communication systems can include multiple NodeBs (NBs), which can also be referred to as base stations, network nodes, communication controllers, cells, or enhanced NBs (eNBs). A NodeB can include one or more network points or network nodes using different Radio Access Technologies (RATs), such as High-Speed ​​Packet Access (HSPA) NBs or WiFi access points. A NodeB can be associated with a single network point or multiple network points. A cell can include a single network point or multiple network points, and each network point can have a single antenna or multiple antennas. A network point can correspond to multiple cells operating on multiple component carriers. Typically, each component carrier in carrier aggregation is a serving cell, which can be a primary cell (PCell) or a secondary cell (SCell).

[0005] A cell or NodeB can serve multiple users (also commonly referred to as User Equipment (UE), mobile station, terminal, device, etc.) over a period of time. The communication channel from the base station to the UE is typically called the downlink (DL) channel, and transmissions from the base station to the UE are downlink transmissions. The communication channel from the UE to the base station is typically called the uplink (UL) channel, and transmissions from the UE to the base station are uplink transmissions. The UE receives a timing advance (TA) command associated with a configured TA group (TAG) to adjust its uplink transmission timing, thereby synchronizing with the network for uplink transmissions so that uplink transmissions from multiple UEs arrive at the base station approximately simultaneously within the Transmission Time Interval (TTI). Similarly, the UE needs to receive DL reference signal (RS) or synchronization signal (SS) blocks, also known as SS blocks (SSB) / Physical Broadcast Channel (PBCH) blocks, to acquire and maintain DL synchronization, for example, by maintaining a DL timing tracking loop. The UE places its FFT window within a cyclic prefix (CP) based on this DL timing tracking loop for its DL reception. In addition, both UL and DL signals / channels need to be correlated with other signals to derive signal / channel properties, such as delay spread, Doppler shift, etc. Summary of the Invention

[0006] This invention relates to methods and systems for wireless communication, and in specific embodiments, to systems and methods for uplink and downlink in multipoint communication. The methods and systems described herein can be applicable solutions for multi-transmitter-receiver point (M-TRP) scenarios in LTE and 5G (New Radio) systems.

[0007] In a first implementation, a wireless communication method includes: receiving first configuration information of a bandwidth portion (BWP) in a carrier for a serving cell by a user equipment (UE), the first configuration information including a first set of parameters and a first resource group (RG) on the BWP in the carrier for the serving cell; receiving second configuration information of the BWP in the carrier by the UE, the second configuration information including a second set of parameters and a second RG on the BWP in the carrier; and performing a transmission or reception associated with the first RG based on the first set of parameters, and performing a transmission or reception associated with the second RG based on the second set of parameters.

[0008] In a second implementation, an electronic device includes: a non-transient memory including instructions; and one or more hardware processors communicating with the memory, wherein the one or more hardware processors execute instructions to perform operations including: receiving first configuration information of a bandwidth portion (BWP) in a carrier for a serving cell, the first configuration information including a first set of parameters and a first resource group (RG) on the BWP in the carrier for the serving cell; receiving second configuration information of the BWP in the carrier, the second configuration information including a second set of parameters and a second RG on the BWP in the carrier; and performing a transmission or reception associated with the first RG based on the first set of parameters, and performing a transmission or reception associated with the second RG based on the second set of parameters.

[0009] In a third implementation, a non-transient computer-readable medium storing computer instructions for wireless communication, which, when executed by one or more hardware processors, cause the one or more hardware processors to perform operations including: receiving first configuration information for a bandwidth portion (BWP) of a carrier for a serving cell by a user equipment (UE), the first configuration information including a first set of parameters and a first resource group (RG) on the BWP of the carrier for the serving cell; receiving second configuration information for the BWP of the carrier by the UE, the second configuration information including a second set of parameters and a second RG on the BWP of the carrier; and performing a transmission or reception associated with the first RG based on the first set of parameters, and performing a transmission or reception associated with the second RG based on the second set of parameters.

[0010] In a fourth implementation, a method for wireless communication includes: receiving by a user equipment (UE) first configuration information of a bandwidth portion (BWP) in a carrier for a serving cell, the first configuration information including a first set of parameters on the BWP in the carrier for the serving cell, the first set of parameters including a first physical cell identifier (PCI) of the serving cell; receiving by the UE second configuration information of the BWP in the carrier, the second configuration information including a second set of parameters on the BWP in the carrier, the second set of parameters including a second PCI; and performing transmission or reception based on the first set of parameters, and performing transmission or reception based on the second set of parameters.

[0011] The above implementation can be achieved using the following: a computer-implemented method; a non-transient computer-readable medium storing computer-readable instructions to execute the computer-implemented method; or a computer-implemented system including a computer memory interoperably coupled to a hardware processor configured to execute the computer-implemented method and the instructions stored on the non-transient computer-readable medium.

[0012] Details of one or more implementations of the subject matter of this specification are set forth in the accompanying drawings and description. Other features, aspects, and advantages of the subject matter will become apparent from the detailed description, the drawings, and the claims. Attached Figure Description

[0013] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings.

[0014] Figure 1 An example wireless communication system is shown;

[0015] Figure 2 An example wireless network is shown;

[0016] Figure 3 An example of RG is shown;

[0017] Figure 4 A table showing example ID groups for different TRP configurations is provided;

[0018] Figure 5 An example method for exchanging and processing messages in M-DCI M-TRP communication is shown;

[0019] Figure 6 A table is shown, including an example M-TRP scenario;

[0020] Figure 7 The illustration is shown. Figure 6 A diagram of an example scenario in the image;

[0021] Figure 8 The illustration is shown. Figure 6 A diagram of another example scenario;

[0022] Figure 9 The illustration is shown. Figure 6 A diagram of another example scenario;

[0023] Figure 10 The illustration is shown. Figure 6 A diagram illustrating the three example scenarios;

[0024] Figure 11 An example processing system is shown; and

[0025] Figure 12 An example transceiver is shown.

[0026] In the diagram, items in square brackets are optional, and dashed lines represent optional relationships / transfers. Detailed Implementation

[0027] In multiple transmit-receive-receive (M-TRP) communication, transmission or reception in the serving cell of the UE, carrier, or bandwidth portion (BWP, which can be considered as part of the carrier the UE is currently operating on) needs to be adjusted based on the TRP used for transmission / reception to adjust transmission / reception timing and attributes. For example, if the uplink transmission timing of multiple TRPs on a carrier or BWP uses the same TA of the TAG associated with the serving cell, then, for example, when the TRP is out of sync with the serving cell, when the TRP has a non-ideal backhaul with the serving cell, and / or when the TRP is far from the serving cell, it may cause inaccurate uplink timing for the UE communicating with a TRP that is not co-located (NCLed) with the UE's serving cell, and when adjusting the UE's uplink timing, the difference in propagation delay between the UE, the TRP, and the serving cell cannot be ignored. Inaccurate uplink timing can negatively impact the reliability, spectral efficiency, and detection accuracy of uplink / downlink multiple-input multiple-output (MIMO) channel state information (CSI) acquisition for the UE's Physical Uplink Control Channel (PUCCH) / Physical Uplink Shared Channel (PUSCH). Therefore, the UE needs to configure separate TAGs for the serving cell and non-co-located TRPs, and apply different TAGs when transmitting to different TRPs. Similarly, the DL timing maintained by the tracking loop should also be adjusted according to which TRP is being transmitted to the UE. M-TRPs allow the UE to receive from multiple TRPs on potentially overlapping time-frequency resources. Therefore, the UE may need to maintain multiple DL tracking loops (one DL tracking loop for each non-co-located TRP) and apply associated FFT windows to receive DL transmissions from each TRP separately. Consequently, depending on the non-co-located TRP, UL / DL signals / channels, or generally, radio resources, may need to be grouped into groups called resource groups (RGs).

[0028] Embodiments of the present invention provide example methods for a UE to perform M-TRP communication via a carrier / BWP of the serving cell in a serving cell, wherein separate RGs are configured for different TRPs. The example methods described in some embodiments improve the UL / DL transmission / reception quality of the UE in M-TRP communication. Some embodiments of the present invention also provide example methods for configuring separate RGs for TRPs, and for the timing and association relationships of separate TAGs acquired / obtained / maintained by the UE. Details are provided below.

[0029] Figure 1 An example wireless communication system 100 is illustrated. As shown, the example wireless communication system 100 includes a base station 110 having a coverage area 101. Base station 110 serves multiple user equipments (UEs), including UE 120. Transmissions from base station 110 to UE 120 are referred to as downlink (DL) transmissions and occur on the downlink channel ( Figure 1 (Seen as a solid arrow line in the image), and the transmission from UE120 to base station 110 is called uplink (UL) transmission, which occurs on the uplink channel (…). Figure 1 (Dash lines are shown in the image). Data transmitted via the uplink / downlink connection may include data sent between UEs 120 and data sent to and from a remote end (not shown) via the backhaul network 130. Example uplink channels and signals include the Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Uplink Probe Reference Signal (SRS), or Physical Random Access Channel (PRACH). Service may be provided to multiple UEs 120 by a service provider (not shown) connected to base station 110 via backhaul network 130 (e.g., the Internet).

[0030] In the example communication system, there are several operating modes. In cellular operating mode, communication to and from multiple UEs 120 is conducted through base station 110. In device-to-device communication modes, such as proximity service (ProSe) operating mode, direct communication between UEs 120 is possible. As used herein, the term "base station" refers to any component (or set of components) used to provide radio access to a network. A base station may also be commonly referred to as Node B, Evolved Node B (eNB), Next Generation (NG) Node B (gNB), Master eNB (MeNB), Secondary eNB (SeNB), Master gNB (MgNB), Secondary gNB (SgNB), Network Controller, Control Node, Access Node, Access Point, Transmitting Point (TP), Transmitting and Receiving Point (TRP), Cell, Carrier, Macro Cell, Femtocell, Picocell, Relay, Customer Premises Equipment (CPE), Network Side, Network, etc. In this invention, unless otherwise stated, the terms "base station" and "TRP" are used interchangeably. As used herein, the term "UE" refers to any component (or set of components) capable of establishing a radio connection with a base station. UE can also be commonly referred to as mobile station, mobile device, mobile phone, terminal, user terminal, user, subscriber, site, communication equipment, CPE, repeater, access backhaul integrated (IAB) repeater, etc. It should be noted that when using trunks (based on trunks, pico, CPE, etc.), especially in multi-hop trunking, the boundary between the controller and the node controlled by the controller may become blurred, and a dual-node deployment (e.g., the controller or the node controlled by the controller) where the first node provides configuration or control information to the second node is considered the controller. Similarly, the concepts of UL and DL transmission can also be extended.

[0031] A cell may include one or more bandwidth portions (BWPs) of a UL or DL ​​allocated to the UE. Each BWP can have its own BWP-specific system parameters (numerology) and configuration, such as the BWP bandwidth. It should be noted that not all BWPs need to be active for the UE simultaneously. A cell may correspond to one carrier, and in some cases, multiple carriers. In some cases, a cell (e.g., a primary cell (PCell) or secondary cell (SCell)) is a component carrier (e.g., a primary component carrier (PCC) or secondary CC (SCC)). For some cells, each cell may include multiple carriers in the UL; one carrier is referred to as a UL carrier with an associated DL or a non-supplementary UL (non-SUL, or simply UL) carrier, and the other carriers are referred to as supplementary UL (SUL) carriers without an associated DL. A cell or carrier may be configured with a time slot or subframe format consisting of DL and UL symbols, and the cell or carrier is considered to operate in Time Division Duplex (TDD) mode. Typically, for unpaired spectrum, the cell or carrier is in TDD mode, and for paired spectrum, the cell or carrier is in Frequency Division Duplex (FDD) mode. Transmission Time Interval (TTI) typically corresponds to a subframe (e.g., in LTE) or a time slot (e.g., in NR). Access nodes can provide radio access according to one or more wireless communication protocols, such as Long Term Evolution (LTE), LTE Advanced (LTE-A), 5G, 5G LTE, 5G NR, future 5G NR versions, 6G, High-Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. While it is understood that a communication system could employ multiple access nodes (or base stations) capable of communicating with multiple UEs, for simplicity... Figure 1 Only one access node and two UEs are shown in the image.

[0032] Uplink timing can be controlled by timing advance (TA). TA is typically used to compensate for propagation delays in signal transmission between the UE and its serving network node (e.g., TRP). The UE's uplink timing can be measured by the TRP using uplink signals or channels (e.g., PUSCH, PUCCH, PRACH, or SRS) transmitted by the UE. The TA value can be determined based on the measurement and assigned to the UE. Timing advance commands can be sent periodically by the TRP, typically within the Media Access Control (MAC) Command Entity (CE). Timing advance commands can include the TA value, which the UE uses to adjust its uplink transmission timing to align with the network-side timing. When appropriate TA values ​​are applied to UL transmissions from UEs within the cell, the UE's UL transmissions arrive at the base station at approximately the same time, facilitating the detection and / or decoding of UL transmissions from multiple UEs.

[0033] Cells are grouped into different Timing Advance Groups (TAGs). Cells with the same TA application on the uplink and using the same timing reference cell (e.g., cells hosted by the same transceiver) can be grouped into one TAG. Therefore, cells grouped in the same TAG have the same TA. Cells can be assigned to TAGs via Radio Resource Control (RRC) signaling. Thus, a cell is associated with a TAG. Each TAG can periodically update its corresponding TA. When a UE receives a TA command for a cell associated with a TAG, it adjusts its uplink transmission timing, for example, for transmitting the cell's PUCCH, PUSCH, and / or SRS, based on the received TA command for the associated TAG.

[0034] In 3GPP 5G NR Releases 15 and 16 (R15 / 16), TAGs are cell-based. On a carrier, there is only one serving cell, and that serving cell is assigned one TAG. In 3GPP R16, for M-TRP communication, a TRP not configured as a serving cell (e.g., TRP1 314) is configured with the same TAG as its co-channel cell (e.g., TRP0 312). The serving cell (PCell and / or SCell) configures a tag-Id field in its IE ServingCellConfig, which uniquely identifies the TAG. All serving cells configured with the same tag-Id belong to the same TAG. The current TA / TAG framework only supports serving cell configuration of TA / TAGs. On a carrier, there can only be one serving cell, and that serving cell is assigned one TAG. In the Rel-16 M-TRP design, for TRPs not co-located with the serving cell, Rel-16 does not assign a separate TA; the UE applies the TA of the co-channel serving cell to that TRP. Even in M-TRP scenarios, this can work fine if multiple TRPs are close to each other, connected via fast backhaul, and closely synchronized. However, this has limited application / deployment scenarios and requires enhancement.

[0035] When a UE is served by multiple TRPs in a serving cell associated with a TAG in the BWP on a carrier, the UE uplink transmission timing for all multiple TRPs in the BWP on the carrier is adjusted using the same TA (Transmission Timing) of the TAG associated with the serving cell. It should be noted that multiple TRPs on the same carrier operate on the same BWP as specified in Rel-16. In some cases, using the same TA of the serving cell to communicate with different TRPs may lead to inaccurate uplink timing (uplink TA). This can negatively impact the UE's PUCCH / PUSCH reliability, spectral efficiency, and the detection accuracy of uplink / downlink full multiple-input multiple-output (MIMO) channel state information (CSI) acquisition. The cyclic prefix (CP) may be insufficient to cover propagation delay differences, delay spread, and inaccurate M-TRP synchronization.

[0036] Similarly, the timing difference in DL between M-TRPs (especially between-cell TRPs) can also lead to insufficient CP or an FFT. The degree of time / frequency synchronization between M-TRPs can depend on the backhaul assumptions. If an ideal backhaul can be assumed, the timing / frequency differences between TRPs are likely negligible. Otherwise, non-negligible synchronization errors should be considered in the design. Regarding backhaul delay and coordination, ideal / fast backhaul cannot generally be assumed, at least for between-cell TRPs. Backhaul delays of several milliseconds to tens of milliseconds and semi-static coordination should be considered in the design. The signal delay spread between TRPs relative to the CP length should also be considered. Depending on the synchronicity between-cell TRPs and the relative distance between the TRP and the UE, possible assumptions include: the inter-cell signal delay spread is within the CP length, but close to the CP length. Even if the inter-TRP signal delay spread is within the CP length, the arrival time difference with the TRP can still be large.

[0037] Figure 2An example wireless network 200 is shown. In some cases, inaccurate uplink TA and downlink timing may occur within network 200. As shown, wireless network 200 includes a serving cell 210 (or base station) serving UE 202 on a carrier. A TRP0 212 operating on a BWP on the carrier is quasi-co-located with the base station or cell 210 and broadcasts the PCID / SSB of cell 210. TRP0 212 sends an SSB generated based on the PCID of cell 210, thus transmitting / broadcasting the PCID via the transmission of the SSB. For ease of explanation, in the following description of the invention, this is simplified to TRP sending (or broadcasting) PCID / SSB. An SSB generated based on the PCID of cell 210 is considered to be associated with or belong to cell 210 (or PCID). A signal not associated with cell 210 indicates that the signal is not associated with the PCID of the cell, or is not directly or indirectly associated with the signal of cell 210 (see the more detailed description below based on quasi-co-location). TRP0 212 can be used to operate on one or more carriers / BWPs. TRP0 212 can be referred to as the quasi-co-located TRP for cell 210.

[0038] TRP1 214 is located within the coverage area of ​​serving cell 210 (at a certain distance from TRP0 212) and is configured to cooperate with TRP0 212 to serve the UE in serving cell 210 on a carrier, i.e., to provide multi-TRP (m-TRP or M-TRP) communication on the carrier. Since TRP1 214 is within the coverage area of ​​serving cell 210, it assists serving cell 210 and does not broadcast the PCID / SSB of cell 210. It can also rely on serving cell 210 to perform certain functions (e.g., control plane functions), and is therefore considered an intra-cell TRP of cell 210. TRP1 214 can be referred to as an intra-cell TRP of cell 210 and co-channels with TRP0 212 (i.e., serving on the same carrier). TRP1 214 may not co-locate with cell 210 and does not broadcast any PCID or SSB. However, in some deployments, such as in frequency range 2 (FR2), TRP1 214 may also broadcast the same PCID as TRP0 212 and send an SSB as a timing / beam reference (e.g., the SSB may be used by the UE for timing synchronization and initial beam acquisition to communicate with TRP1 214), but on a different SSB resource than the SSB sent by TRP0 212.

[0039] Wireless network 200 also includes a TRPn 222 associated with cell 220, which may be a neighboring cell of serving cell 210. As a neighboring cell rather than a serving cell, TRPn 222 typically does not serve the UE serving cell 210, but may interfere with the UE serving cell 210, and is not used as the serving cell for the UE serving cell 210. This differs from the serving cell sending RRC / MAC / PHY layer signals to the UE and maintaining a connection with the UE. TRPs 224 and 226 are located within the coverage area of ​​cell 220 and are used to cooperate with TRPn 222 to serve the UE of cell 220 on one or more carriers supported by TRPn 222. UE 202 may be served by TRP0 212 and TRP1 214 on the same carrier or on different carriers. Each of cells 210 and 220 has an associated Physical Cell Identifier (PCID or PCI) and a Synchronization Signal Block (SSB), based on which the UE synchronizes with the corresponding cell.

[0040] As used herein, quasi-co-location of a TRP with another TRP (or base station, or cell) means that the two TRPs are located in the same location and share the same antenna set, and in some cases, even share the same antenna configuration (e.g., the same analog antenna beamforming). The co-location relationship between the two TRPs can be known to the network side but not revealed to the UE, i.e., transparent to the UE. In some cases, it may be useful for the UE to know whether two received signals come from the same transmitter (or TRP, or antenna) and to introduce a QCL assumption between the transmitter's RS ports and indicate this to the UE. Co-channeling of a TRP with another TRP (or base station, or cell) means that they operate on the same carrier frequency. An independent TRP transmits the cell's SSB / PCID (signals on the SSB are generated based on the PCID), so the UE can find it during cell search / initial access. The UE then connects to the independent TRP / cell. A non-independent TRP does not transmit the SSB / PCID, so the UE cannot find the SSB / PCID during cell search / initial access. The UE cannot directly connect to a non-independent TRP. Instead, the UE first connects to the standalone TRP / cell, and then the standalone TRP / cell instructs the UE on information about the non-standalone TRP so that the UE can communicate with the non-standalone TRP.

[0041] In this example, cell 210 is assigned TAG0 associated with the carrier. UE 202 can establish a connection with cell 210 via a random access procedure and receive the TA command for TAG0 from TRP0 212. The TA value in the TA command is typically related to the distance between TRP0 212 and UE 202. Then, if TRP0 212 and TRP1 214 have the same TAG in Rel-16, i.e., if TRP0 212 and TRP1 214 are configured with the same TAG according to Rel-16, then UE 202 transmits uplink signals / channels to both TRP0 212 and TRP1 214 via the carrier according to the TA command (i.e., the same TA value). However, when TRP0 212 and TRP1214 are far apart, for example, more than 300m, there is a non-ideal backhaul between TRP 212 and 214 (e.g., a backhaul delay of 10ms to 20ms or even longer, which may cause them to be out of sync). Furthermore, UE 202 is closer to TRP1214 (e.g., almost no propagation delay) than TRP0 212 (e.g., a propagation delay greater than 1µs). When UE 202 communicates with TRP1 214 using the TA value of TAG0 (which is assigned based on TRP0 212), uplink timing errors may occur. This is because, considering the distances between TRP1 214 and TRP0 212, between TRP1 214 and UE 202, and between TRP0 212 and UE 202, the TA of TAG0 is not well-suited for TRP1 214. In this scenario, a significant propagation delay difference exists between TRP1 214 and UE 202, as well as between TRP0 212 and UE 202. A cyclic prefix (CP) might help mitigate this propagation delay difference to some extent; however, for higher subcarrier spacing (SCS), such as greater than 15 kHz, the CP is short. Figure 2As shown in Table 230, the propagation delay difference may not be sufficient to absorb such a large difference, resulting in poor uplink timing alignment of UE 202 relative to TRP1 214. Therefore, it is desirable to configure a separate TA value for UE 202, thereby configuring a separate TAG for communication with TRP1 214, even though TRP0 212 and TRP1 214 co-channel in the same carrier as UE 202 in serving cell 210. That is, TRP0 212 and TRP1 214 can be associated with different TAGs, allowing UE 202 to adjust its uplink transmission timing separately for communication with TRP0 212 and TRP1 214. UE 202 may need to perform a random access procedure to obtain the TA of the TAG associated with TRP1 214 and synchronize with TRP1 214, which does not have a separate PCID, especially for SCS greater than 15 kHz. In this way, more TRPs (especially those that are far apart from each other) can be added to the UE 202's serving TRP pool and effectively utilized by UE 202. Similarly, in the DL, the first transmission from TRP0 212 and the second transmission from TRP1 214 can typically arrive at the UE at different timings. When TRP0 212 and TRP1 214 are far apart from each other, there is a non-ideal backhaul between TRPs 212 and 214 (e.g., a backhaul delay of 10ms to 20ms or even longer, which may cause them to be out of sync). The lack of close synchronization between TRPs 212 and 214, the long delay spread, and the timing difference relative to the CP length due to the large SCS, short OFDM symbol duration, etc., can make the timing difference more significant. One DL tracking loop / FFT window may not be sufficient. The UE may need to maintain multiple FFT windows on the same carrier for non-co-located TRPs. Furthermore, since the TRPs are not close to each other, the channel attributes (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter) between UE 202 and TRP0 212 may be significantly different from those between UE 202 and TRP1 214. Therefore, to improve transmission / reception quality, the UE needs to apply different parameters accordingly. Thus, it is necessary to signal the TRP used for transmission / reception to the UE, and then perform adaptation.

[0042] In some cases, the network can also configure TRPn 222 to serve UE 202 on the same carrier, instead of configuring it as a secondary cell (SCell) for UE 202, to provide increased network capacity, etc. TRPn 222 is an inter-cell TRP, as opposed to an intra-cell TRP. However, TRPn 222 can be transparent to UE 202. In this case, using Rel-16 design, UE 202 can still use the TA of TAG0 for uplink transmission to TRPn 222, and the FFT window obtained from the RS / SSB of TRP0 212 for DL ​​reception with TRPn 222. However, if TRPn 222 is far from TRP0 212, for example, greater than 500 meters, and / or if the timing of TRPn 222 is not closely synchronized with TRP0 212, timing based on TRP0212 is unsuitable for TRPn 222 due to the distance / timing difference between TRPn 222 and TRP0212, and between TRPn 222 and UE 202. It is also desirable to configure separate TAG, DL timing, and RG for UE 202 to communicate with TRPn 222 via carrier. Therefore, more TRPs, including inter-cell TRPs, can be added to the serving TRP pool of UE 202 and utilized effectively by UE 202.

[0043] Some embodiments of the present invention provide example methods for a UE to perform M-TRP communication in a serving cell via the same carrier / BWP of the serving cell, wherein separate RGs are configured for multiple TRPs in the M-TRP communication. The example methods provide the above-mentioned... Figure 2The solutions to the problems discussed improve the timing accuracy of the UE in M-TRP communication. These example methods can be applied to intra-cell M-TRP communication, inter-cell M-TRP communication, or a combination of intra-cell and inter-cell M-TRP communication. In intra-cell M-TRP communication, multiple TRPs are located within the coverage area of ​​the UE's current serving cell. For ease of explanation, such TRPs among the multiple TRPs can be referred to in this invention as co-cell (or intra-cell) TRPs of the serving cell, for example, TRP1214, and if it also serves the UE by sending / receiving data to / from the UE, it can be referred to as an intra-cell serving TRP of the UE, or simply an intra-cell TRP of the UE. In inter-cell M-TRP communication, one or more TRPs may come from another cell different from the UE's serving cell, and for ease of explanation, they are referred to in this invention as inter-cell serving TRPs (or simply inter-cell TRPs). In this invention, for ease of explanation, the TRP of the PCID / SSB broadcasting the serving cell of the UE can be referred to as the UE's serving cell. For example, the TRP0212 of SSB0 of broadcasting cell 210 can be referred to as a "cell," "serving cell," or the "base station" of UE 202. Therefore, the TRP is associated with the UE's serving cell. Figure 2 For example, the TRP serving UE 202 can be called the serving TRP of UE 202, and the TRP can be an intra-cell TRP (e.g., TRP1214) and / or an inter-cell TRP (e.g., TRPn 222), co-located with a cell (e.g., TRP0 212), or non-co-located with a cell (e.g., TRP1 214 and TRPn 222). Intra-cell TRP1 214 may or may not broadcast the PCID / SSB of the UE's serving cell. In some deployments, such as FR2, TRP1 214 may also broadcast the same PCID as TRP0 212 and send the SSB as a timing / beam reference on a different SSB resource than TRP0 212. Inter-cell TRPn 222 may or may not broadcast the cell's PCID / SSB, and inter-cell TRPn 222 is located within the cell's coverage area. Each TRP can have one or more carriers. In M-TRP scenarios, the UE can also use carrier aggregation, that is, communicate with TRP0 212 via multiple carriers, and on each of these carriers, the UE can also be served by one or more intra-cell TRPs (e.g., TRP1 214 and / or inter-cell TRPs, e.g., TRPn 222). In other words, the UE can also communicate with these TRPs on multiple carriers.

[0044] In some embodiments, there is one serving cell in a carrier, but multiple TAGs, RGs, SSBs, and / or PCIDs are configured for the UE. For example, if conventionally configured RRC signaling is associated with the UE's serving cell 210, the UE's serving TRP (e.g., TRP0 212) can be associated with TAGs (or co-channel TAGs, e.g., TAG0) and RGs (or co-channel RGs, e.g., RG0) using conventionally configured RRC signaling, as discussed above. In the following, TAs can be considered as (optional) parameters associated with RGs, and therefore only RGs that also apply to TAGs are described (unless otherwise stated). In one embodiment, a set of UL signals / channels forms a UL RG, and a set of DL signals / channels forms a DL RG, i.e., RGs are separate for UL and DL. In one embodiment, a set of UL / DL signals / channels forms a RG, i.e., there are no separate RGs for UL and DL. In one embodiment, a UL RG is associated with a DL RG, and vice versa. In one embodiment, a UL RG is associated with multiple DL RGs. In one embodiment, a DL RG is associated with multiple UL RGs. In one embodiment, instead of configuring a separate TAG, a separate RG is configured, with each RG associated with a TA; this is an alternative to configuring a separate TAG. In one embodiment, instead of configuring a separate TAG, a separate ULRG is configured, with each UL RG associated with a TA. In one embodiment, separate TAGs and separate RGs are configured in parallel, with each TAG associated with an RG. Intra-cell or inter-cell serving TRPs (e.g., TRP1 214 or TRPn 222) that are not configured as serving cells or are not co-located with the UE's serving cell can be associated with separate RGs. For serving TRPs that do not transmit SSBs, such as TRP1 214, the tracking reference signal (TRS) of such serving TRPs, also known as the channel state information reference signal for tracking (CSI-RS), can be used to form a separate RG, even if a co-channel RG already exists associated with the serving cell (e.g., cell 210). The uplink / DL signals of a UE quasi-co-located (QCLed) with a TRS are associated with separate RGs. Therefore, a TRS can be used to form separate RGs. TRP0212 can operate on more than one carrier, and carriers that are not far apart in the frequency domain can belong to the same RG, i.e., RG0. TRP1 214 can also operate on more than one carrier, each carrier co-channeling with one carrier on TRP0 212, and each carrier transmits a TRS. All uplink / DL signals of UEs with these TRS quasi-co-located (QCLed) with TRP1 214 are associated with a separate RG. Typically, TRS transmitted from the same / quasi-co-located TRP on the same frequency band can be used to define an RG, while TRS transmitted from non-co-located TRPs can be associated with different RGs.The PUSCH and the demodulation reference signal (DMRS) of the PUSCH transmitted during random access may require (multiple) TRP / TRS-specific scrambling code IDs, as well as (multiple) TRP / TRS-specific scrambling code IDs for the DMRS of the PDSCH, (multiple) TRP / TRS-specific scrambling code IDs for the Physical Downlink Shared Channel (PDSCH), (multiple) TRP / TRS-specific scrambling code IDs for the DMRS of the Physical Downlink Control Channel (PDCCH), and (multiple) TRP / TRS-specific scrambling code IDs for the PDCCH.

[0045] The quasi-co-location (QCL) type corresponding to each DL RS (more specifically, the (multiple) ports or (multiple) antenna ports of the DL RS) is given by the higher-level parameter qcl-Type in QCL-Info and can take one of the following values: (1) "QCL-TypeA": {Doppler shift, Doppler spread, average delay, delay spread}; (2) "QCL-TypeB": {Doppler shift, Doppler spread}; (3) "QCL-TypeC": {Doppler shift, average delay}; (4) "QCL-TypeD": {spatial Rx parameter}. The QCL type can be configured / indicated in the Transmission Configuration Indication (TCI) status of the RS. The QCL assumption is primarily used for DL ​​RS, but can be extended to UL RS if the correlation between path loss RS and spatial relationship is specified. The QCL assumption can be specified as: {RS1: QCL type C to RS2}, {RS1: QCL type C to RS2 and QCL type D to RS3}. Then, RS1 (destination RS) derives the attributes specified according to the QCL type from the associated (i.e., source) RS (e.g., RS2). It should be noted that the source RS can be an SSB. It should also be noted that the source RS and destination RS can be on the same carrier or on different carriers (i.e., cross-carrier QCL).

[0046] For inter-cell serving TRPs, such as TRPn 222, the SSB of the inter-cell serving TRP can be configured for the UE, but not for the UE's SCell (i.e., the cell associated with the SSB of the inter-cell serving TRP is not one of the UE's serving cells). The TRS of the inter-cell serving TRP can be used to form a separate RG, even if a co-channel RG already exists associated with a serving cell (e.g., cell 210). The DMRS of the PUSCH and PUSCH transmitted during random access may require multiple TRP-specific scrambling code IDs, as well as multiple TRP / TRS-specific scrambling code IDs for the DMRS of the PDSCH, multiple TRP / TRS-specific scrambling code IDs for the DMRS of the PDSCH, and multiple TRP / TRS-specific scrambling code IDs for the DMRS of the PDCCH and the PDCCH.

[0047] PDCCH can be used to indicate, via ID or quasi-co-location (QCL) relationship and / or default relationship, which service TRP (e.g., TRP1 214 or TRPn 222) the UE needs to receive PDSCH from or to, or to which service TRP it needs to send PUSCH. Each TRP can be associated with an ID, such as a control resource set (CORESET) pool ID, such that, for example, a PDCCH received on a CORESET with CORESET pool ID 0 indicates a PUSCH transmission to the TRP associated with ID 0. In another example, a received PDCCH with a QCL relationship / TCI state linked to an SSB or TRS indicates a PUSCH transmission to the TRP associated with that SSB or TRS.

[0048] by Figure 2For example, UE 202 can synchronize with TRP0 212, the serving cell 210 of UE 202, on a carrier and receive TA commands including the first TAG or first RG of the serving cell 210, i.e., TAG0 or RG0. Therefore, UE 202 is configured with TAG0 or RG0 for communication with TRP0 212. When the base station of the serving cell 210 decides to connect the UE to TRP1 214, or when the base station of the serving cell 210 detects that the TA to TRP1 214 is lost or inaccurate, TRP0 212 or TRP1 214 can send a PDCCH command to UE 202, including information about random access parameters, and trigger / instruct UE 202 to perform a random access procedure with TRP1 214. Then, UE 202 can send a RACH preamble to TRP1 214 and receive a TA command in the Random Access Response (RAR) that is associated with the carrier and includes a second TAG or RG (e.g., TAG1 or RG1) of TRP1 214. Therefore, UE 202 is configured with TAG1 or RG1 for communicating with TRP1 214. TRP0 212 or TRPn 222 can also send a PDCCH command to UE 202, triggering UE 202 to perform a random access procedure with TRPn 222. UE 202 can send a RACH preamble to TRPn 222 and receive a TA command that is associated with the carrier and includes a third TAG or RG (e.g., TAG2 or RG2) of TRPn 222. Therefore, UE 202 is configured with TAG2 or RG2 for communicating with TRPn 222. In one embodiment, each of the TAGs or RGs can be associated with a TAG ID or RG ID that uniquely identifies the corresponding TAG or RG. In one embodiment, each TAG can be associated with a TAG ID that uniquely identifies the corresponding TAG, and RGs do not have RG IDs but are associated one-to-one with TAGs. Upon receiving TAs for different TAGs or RGs (i.e., TAG0, TAG1, and TAG2, or RG0, RG1, and RG2), UE 202 can perform uplink transmissions on the carrier with TRP0 212, TRP1214, and TRPn 222 according to the uplink transmission timing adjusted based on its corresponding TA. The TA associated with a TAG or RG can be updated periodically for each TAG or RG, for example, approximately every 20ms to 50ms, and the updated TA can be sent to UE 202 in a TA command. The TA command can be carried in the MAC CE. The network can update the TA by measuring uplink transmissions (e.g., SRS) from UE 202. UE 202 can adjust the uplink transmission timing of its TAGs or RGs based on the updated TAs.Therefore, UE 202 can be served on a carrier by two or more of TRP0 212, TRP1 214, and TRPn 222, each of which is associated with a separate TAG or RG. The separate TAG or RG allows UE 202 to more accurately adjust its uplink transmission timing using the TRP of the separate TAG or RG.

[0049] UE 202 can receive scheduling information that schedules uplink transmissions between the UE and TRP on a carrier, based on the RG associated with the TRP. In some embodiments, UE 202 can receive first configuration information of the carrier of serving cell 210 via RRC configuration signaling. The first configuration information may include / indicate the association between a first set of uplink signals and channels to be transmitted by the UE on the carrier in serving cell 210 and RG0, where RG0 is associated with a first TA value. That is, the first configuration information of the carrier instructs the UE to transmit the first set of uplink signals and channels according to the first TA value of RG0. The first configuration information can be sent to UE 202 by TRP0 212. UE 202 can also receive second configuration information of the carrier, which includes / indicates the association between a second set of uplink signals and channels to be transmitted by the UE on the carrier and uplink RG1, where RG1 is associated with a second TA value. That is, the second configuration information of the carrier instructs the UE to transmit the second set of uplink signals and channels according to the second TA value of RG1. The second configuration information can be sent to UE 202 by TRP0 212 or TRP1 214. Similarly, UE 202 can also receive third configuration information for the carrier. This third configuration information includes / indicates the association of a third set of uplink signals and channels on the carrier with uplink RG2, which is associated with a third TA value. That is, the third configuration information for the carrier instructs the UE to send the third set of uplink signals and channels according to the third TA value of RG2. This third configuration information can be sent to UE 202 by TRP0 212 or TRPn 222. The first, second, and third configuration information for the carrier can be sent by TRP0 212 in one message or in separate messages. Then, UE 202 can send either the first set of UL signals and channels (UL signals or UL channels) to TRP0 212 according to the first TA value. UE 202 can send the second set of UL signals and channels (UL signals or UL channels) to TRP1 214 according to the second TA value. UE 202 can send the third set of UL signals and channels (UL signals or UL channels) to TRPn 222 according to the third TA value. The first, second, and third groups of UL signals and channels can be configured with the same subcarrier spacing (SCS) within the same BWP. Both the second and third groups can be configured, or only one of the groups can be configured.

[0050] Serving cell 210 is associated with the first PCID and the first SSB. UL signals or channels in the first group of UL signals and channels may be quasi-co-located (QCLed) with the first SSB, or quasi-co-located with a downlink / uplink reference signal to the first SSB, or configured with a path loss RS as the first SSB or quasi-co-located with the first SSB, or configured with a spatial relationship RS as the first SSB or quasi-co-located with the first SSB. In one embodiment, all UL signals or channels in the first group of UL signals and channels are associated with the first RG.

[0051] The UL signals or channels in the second set of UL signals and channels may be quasi-co-located with the TRS of TRP1 214, or quasi-co-located with the downlink / uplink reference signal quasi-co-located with the TRS of TRP1 214, or configured with a path loss RS as the TRS or quasi-co-located with the TRS of TRP1 214. In one embodiment, all UL signals or channels in the second set of UL signals and channels are associated with a second TAG. In one embodiment of network deployment, the TRS of TRP1 214 may be "proximately" quasi-co-located with the first SSB of the serving cell or the TRS of the first SSB, even if TRP1 214 is not co-located with TRP0 212 broadcasting the first SSB / PCID. This typically requires TRPs to be close to each other, operating in frequency range 1 (FR1), and serving UEs with low mobility. A TAG different from the TAG of the first SSB / PCID may still be beneficial. In one embodiment of the network deployment, even if TRP1 214 is not co-located with the TRP broadcasting the first SSB / PCID, TRP1 214 can still broadcast the first PCID on an SSB resource different from the first SSB sent by TRP0 212. A different RG can be configured for TRP1 214 than for the first SSB / PCID. In FR2, SSBs associated with the same PCID but occupying different SSB resources within an SSB burst are distinguished by SSB indices; therefore, if SSBs with different SSB indices are sent from non-co-located TRPs, each SSB index can be used to define a separate RG.

[0052] The UL signals or channels in the third group of UL signals and channels may be quasi-co-located with the TRS of TRPn 222, quasi-co-located with the second SSB associated with a neighboring cell (e.g., cell 220) having a second PCID different from the first PCID, or quasi-co-located with the PCID of a cell other than the serving cell of UE202, or quasi-co-located with a downlink / uplink reference signal quasi-co-located to the TRS of TRPn 222 or the second SSB, or configured with a TRS as the TRS of TRPn 222 or the second SSB, or a path loss RS quasi-co-located with the TRS of TRPn 222 or the second SSB. In one embodiment, all UL signals or channels in the third group of UL signals and channels are associated with the third RG.

[0053] As discussed above, the example method associates a serving TRP, which may be directly / indirectly quasi-co-located with the SSB of a non-serving cell, or not quasi-co-located with the SSB of the serving cell, or not co-located with the TRP of the serving cell that transmits the SSB of the serving cell. The RG differs from the TAG of the serving cell. The UE also needs to perform random access with the serving TRP to obtain a separate TA. As used herein, the first RS can be directly quasi-co-located with the second RS / SSB, for example, by indicating to the UE with the QCL assumption of the first RS, which refers to the second RS / SSB of QCL type. For example, the UE receives a QCL assumption indicating {first RS: QCL type C to second RS}. The first RS can be indirectly co-located with the second RS / SSB. For example, through one or more QCL assumptions in a cascaded manner, the QCL assumption of the first RS is indicated to the UE, which refers to one or more RS / SSBs. These one or more RS / SSBs further refer to the second RS / SSB used for QCL. For example, the UE receives QCL assumptions indicating {first RS: QCL type C to third RS}, {third RS: QCL type A to fourth RS}, and {fourth RS: QCL type C to second RS}. In other words, a QCL assumption defines the relationship / link between the source RS and the destination RS, and multiple QCL assumptions can define the relationship / link chain that associates an RS directly using one link or indirectly using multiple links to another RS / SSB.

[0054] For example, the PDCCH DMRS can be configured / indicated as quasi-co-located with the first SSB of the serving cell or the TRS of the non-serving cell, and an ID can be configured for the PDCCH DMRS. The UE can then receive the PDCCH DMRS with the configured ID, and the DMRS and ID are associated with the TRP of the non-serving cell. QCL assumes / relations that all involved RSs, channels associated with RSs, and IDs associated with RSs / channels are associated or linked to the quasi-co-located SSB (directly or indirectly through other UL / DL RSs), and implicitly groups the signals / channels / IDs into RGs according to the TRP.

[0055] Figure 3 An example of an RG is shown. Within each RG, there is a set of signals including RS and possibly SSB. RGs are used for each non-co-located TRP, which is transparent to the UE. The UE is configured with RGs, within each RG, signals are directly or indirectly quasi-co-located with each other. The UE should not assume QCL relationships across RGs. Typically, each RG should include at least one of SSB and TRS. QCL relationships can be generalized to also include path loss RS relationships and spatial relationships. Any and all QCL types can be used to define RGs.

[0056] Figure 4 Table 400 shows example ID groups for different TRP configurations. Table 400 shows three sets of IDs: a first set of IDs for the first group of signals (and possibly the first beam) of the first TRP0 associated with RG0, a second set of IDs for the second group of signals (and possibly the second beam) of the second TRP1 associated with RG1, and a third set of IDs for the third group of signals (and possibly the third beam) of the third TRP2 associated with RG2. Each set of IDs includes ID1 through ID7. For PL CSI-RS, ID1 of these sets is supported in R15 / 16. R15 / 16 typically uses PCIDs ID2 through ID7 and requires fast backhaul. Each set of IDs can be pre-configured and reconfigured for the associated RG. The UE can use a set of IDs associated with the RG of a TRP to transmit or receive data from the TRP.

[0057] The UE can receive the Physical Downlink Control Channel (PDCCH). The PDCCH can be associated with a CORESET having a first control resource set (CORESET) pool index, or with a DMRS configured to be quasi-co-located with an SSB or a TRS quasi-co-located with an SSB. The DL RS can be quasi-co-located with an SSB, or it can be an SSB, or it can be a CSI-RS quasi-co-located with an SSB or a TRS, or it can be a TRS quasi-co-located with an SSB. If the SSB or TRS is associated with the UE's serving cell (e.g., ... Figure 2If the UE is associated with cell 210, then the UE can transmit / receive with the serving cell, and the signal / channel / ID of the serving cell's RG on the carrier can be used. In this case, the PDCCH can be transmitted by the UE's serving cell through the TRP associated with the serving cell (e.g., TRP0 212).

[0058] In some embodiments, the UE receives DL transmissions in an M-TRP deployment scenario. As mentioned above, many UL-related operations rely on DL operations. Consider the following deployment scenario-related assumptions. DL timing differences between M-TRPs (especially between inter-cell TRPs) may also lead to insufficient CP or an FFT. The degree of time / frequency synchronization between M-TRPs can depend on backhaul assumptions. If ideal backhaul can be assumed, timing / frequency differences between TRPs are likely to be negligible. Otherwise, non-negligible synchronization errors should be considered in the design. Regarding backhaul delay and coordination, ideal / fast backhaul generally cannot be assumed, at least for inter-cell TRPs. Backhaul delays of several milliseconds to tens of milliseconds and semi-static coordination should be considered in the design. The signal delay spread between TRPs relative to the CP length should also be considered. Based on the synchronicity between inter-cell TRPs and the relative distance between the TRP and the UE, possible assumptions include: (1) The inter-cell signal delay spread is within the CP length, but close to the CP length, that is, even if the signal delay spread between TRPs is within the CP length, the arrival time difference with the TRP may still be large. The UE may still need the ability to support multiple tracking loops and FFT windows in the DL to improve its signal reception performance. (2) If the inter-cell signal delay spread is greater than the CP length, then multiple tracking loops and FFT windows are required. In some embodiments, multiple tracking loops and FFT windows are used on the same carrier on the same OFDM symbol so that the UE can receive PDSCH / PDCCH from multiple TRPs. The standard can specify the assumptions / behaviors of the UE in multiple QCL / TCI states so that the UE can correctly use the tracking loops and FFT windows to receive PDCCH / PDSCH. The UE can maintain multiple FFT windows (i.e., DL fine timing synchronization) and apply FFT windows on the same carrier on the same OFDM symbol based on multiple TCI states received from multiple TRPs, where the first fine timing / first FFT window is associated with the first TCI state, the first PDCCH / PDSCH and the first TRP, and the second fine timing / first FFT window is associated with the second TCI state, the second PDCCH / PDSCH and the second TRP. On the other hand, only minimal UE assumptions can be specified, such as "the UE assumes multiple QCL assumptions based on multiple TCI states received by the DL, respectively linked to multiple SSBs (directly or indirectly through one or more RSs) on the same carrier on the same OFDM symbol" or "the UE should have the ability to simultaneously receive transmissions associated with more than one RG, where each RG can be associated with the DL time and frequency synchronization." It should be noted that in the prior art, on the same time-frequency resources, the QCL assumption directly / indirectly links to at most one SSB, but here, the QCL assumption directly / indirectly links to multiple SSBs to support more general M-TRP operation.The UE can link PDSCH / PDCCH and other transmit / receive functions to inter-cell TRPs via QCL relationships linked to non-serving SSBs. Therefore, in this case, explicit configuration of the CORESET pool index may not be necessary. A CORESET configured with TCI states (including QCLs directly or indirectly to the serving SSB) is used for a TRP associated with the serving SSB; that is, CORESETPoolIndex 0 is effectively allocated. A CORESET configured with TCI states (including QCLs directly or indirectly to non-serving SSBs) is used for a TRP associated with non-serving SSBs; that is, CORESETPoolIndex 1 is effectively allocated. In one embodiment, CORESETPoolIndex is used to identify each RG. The UE does not expect to configure CORESETs with TCI states (including QCLs directly or indirectly to both serving and non-serving SSBs). To support multi-tracking loop and FFT window reception, the UE needs the ability to extend the receive delay to inter-cell multi-TRPs with a length comparable to or longer than the CP length, which may require some redundant hardware. This parallels UL transmission, enabling new UE behaviors and the ability to acquire, maintain, and apply multiple TAs. These capabilities are typically similar to UE CA capabilities, but with the aggregation of additional radio resources on the same carrier and can be used in conjunction with CA capabilities. For example, if a UE can support 5 component carriers (CCs) and 2 TRPs on each CC, then the UE needs the ability to simultaneously aggregate 10 PDSCH transmissions. All DL signals / channels (PDSCH / PDCCH / DMRS / CSI-RS / CSI-IM / PTRS / etc.) should be directly or indirectly quasi-co-located with TRS / SSB. Similarly, all UL signals / channels (PUCCH / PUSCH / SRS / DMRS / PTRS / PRACH) should also be quasi-co-located with TRS / SSB (or through spatial relationships, path loss RS relationships, etc.) and belong to the TAG associated with that TRS / SSB.

[0059] Figure 5An example method 500 for exchanging and processing messages is illustrated. In some cases, example method 500 may be performed by a device participating in M-DCI M-TRP communication on a carrier. As shown, example method 500 is performed by TRP0 502, UE 504, and TRP1 506. TRP0 502 is configured as the serving cell of UE 504 on the carrier (broadcasting the serving cell's SSB0 / PCID0). TRP1 506 is the co-channel serving TRP of UE 504. Typically, the serving cell broadcasts the serving cell's SSB0 / PCID0. In some embodiments, for in-band carrier aggregation (CA), the SCell may not transmit an SSB, and the SCell's signal / channel may be quasi-co-located with the SSB of another serving cell on another carrier within the same frequency band of the same TRP. For example, UE 504 may configure two (2) carriers (e.g., carriers A and B) within the frequency band of carrier A. UE 504 can be configured with cell A having a first SSB, and on carrier B, UE is configured with cell B without an SSB (e.g., specified by the higher-layer parameter scellWithoutSSB). The cell's signal / channel is transmitted / received by TRP0 502. UE 504 receives the first SSB on cell A, not on cell B, and the signal / channel of cell B is directly / indirectly quasi-co-located with the first SSB on cell A. Similarly, on TRP1 506, TRS may not be transmitted on a carrier (e.g., the first carrier), but may be transmitted on a second (different) carrier on which TRP1 506 also operates and is configured for UE 504, and the signal / channel to and from TRP1 506 on the first carrier may be directly / indirectly quasi-co-located with the TRS transmitted on the second carrier. SSB0 may be transmitted on this carrier or on a different carrier, TRS0 may be transmitted on this carrier or on a different carrier, and other signals / channels may be quasi-co-located with SSB0 and / or TRS0.

[0060] UE 504 can receive TRS1 or SSB1 from TRP1 506, and can also receive configuration information for a separate RG from TRP1 506 (step 518). SSB1 can be transmitted on this carrier or on a different carrier (similar to the description of scellWithoutSSB in TRP0502 above), and TRS1 can be transmitted on this carrier or on a different carrier (similar to the description of TRP1 506 above, TRS is not transmitted on a carrier). Other signals / channels can be quasi-co-located with SSB1 and / or TRS1.

[0061] UE 504 can monitor a CSI-RS (CSI-RS1) with CSI-RS ID (CSI-RS ID1) from TRP1 506. CSI-RS1 can be scrambled using CSI-RS ID1. UE 504 receives a PDCCH command (DCI1 PDCCH command) associated with the CORESET pool (CORESET pool 1) (step 520). The PDCCH may have an associated DMRS and indicates a PDSCH with an associated DMRS, which is sent based on Coreset pool 1 and using scrambling ID1 (scrambling ID1) from TRP1 506. The PUSCH may have an associated DMRS. In step 522, the PUSCH is scrambled using the PUSCH scrambling ID (PUSCH scrambling ID1), and the DMRS is scrambled using the PUSCH DMRS scrambling ID (PUSCH DMRS scrambling ID1). In step 524, UE 504 may send one or more PUCCHs (scrambled using PUCCH scrambling ID1), PUSCHs (scrambled using PUSCH scrambling ID1) with associated DMRS (scrambled using PUSCH DMRS scrambling ID1), and / or SRSs (scrambled using SRS ID1) to TRP1506. Typically, RG0 parameters (e.g., ID, timing) and RSs (e.g., TRS, CSI-RS, DMRS) and channels (e.g., PDSCH, PUSCH, etc.) are used for communication with TRP0 502, while RG1 parameters (e.g., ID, timing) and RSs (e.g., TRS, CSI-RS, DMRS) and channels (e.g., PDSCH, PUSCH, etc.) are used for communication with TRP1 506.

[0062] The PUSCH scramblingID can be called dataScramblingIdentityPUSCH. For M-TRP, they can be called dataScramblingIdentityPUSCH and dataScramblingIdentityPUSCH2 (or AdditionaldataScramblingIdentityPUSCH). Furthermore, if a higher-level signaling index is configured for each CORESET, such as CORESETPoolIndex, then dataScramblingIdentityPUSCH is associated with the higher-level signaling index for each CORESET and applied to PUSCHs scheduled using DCI detected on CORESETs with the same higher-level index. For example, dataScramblingIdentityPUSCH is associated with CORESETPoolIndex 0 (or no explicit index), and AdditionaldataScramblingIdentityPUSCH is associated with CORESETPoolIndex 1. Similarly, DMRS for PUSCH can also be performed, typically with another set of scrambling identifiers; now, M-TRP PUSCH DMRS needs to be added.

[0063] Table 1 below shows the number of PCIDs per carrier in existing 3GPP standards (versions) and newer embodiments. For all existing configurations, a carrier supports a maximum of one PCID / RG / TAG configuration, even if there may be multiple TRPs on that carrier. In embodiment designs, a carrier may allow more than one PCID / RG / TAG configuration.

[0064] Table 1

[0065] #PCID / Carrier #RG / Carrier R15 1 1 M-TRP in R16 community 1 1 CA 1 1 DC 1 1 Example: Intracellular M-TRP 1 2 Example of inter-cell M-TRP 2 2

[0066] Figure 6Table 600 shows an example M-TRP scenario including RG and observations as analysis results of the scenario. In this example, "cell with SSB" refers to an independent cell with an independent SSB / PCID. The cell's TRP broadcasts the SSB / PCID. "TRP without SSB" refers to a non-independent TRP without an independent SSB / PCID, or a non-independent TRP that can share an SSB / PCID with an independent cell. The TRP itself does not send the SSB / PCID. "Tightly synchronized" means that two TRPs are synchronized with a timing error of at most a few percent of the CP length, which is generally negligible. Table 600 shows eight example scenarios (e.g., scenarios 1 to 8), including tightly synchronized cells and TRPs (cell / TRP), loosely synchronized cells / TRPs, cells / TRPs with fast backhaul, cells / TRPs without fast backhaul, and cells / TRPs with single downlink control information (S-DCI) or multiple DCI (M-DCI). Analysis shows that, at least for large and small cells or loosely synchronized cells / TRPs, a separate RG is required. In all scenarios, a separate RG can be configured for each TRP to achieve better UL / DL transmission quality. The RG does not have to be cell-based, but rather TRP-based; for example, a cell with an associated SSB can be used as the TRP instead of the serving cell.

[0067] Figure 7 The illustration is shown. Figure 6Figure 700 illustrates Example Scenario 1 in Table 600. Figure 700 shows TRP0 702 configured as the serving cell for UE 704 on a carrier. TRP1 706, not configured as the serving cell for UE 704, is not co-located with TRP0 702 on the same carrier. TRP0 702 and TRP1 706 provide M-TRP communication services for the UE in the serving cell. In this example, TRP0 702 and TRP1 706 are synchronized with each other and have fast backhaul between them. Separate RGs (i.e., RG0 and RG1) can be configured for TRP0 702 and TRP1 706. The resulting benefits include improved UL / DL spectral efficiency (SE). Take TA acquisition as an example, as it involves almost all signals / channels in the UL / DL. TRP0 702 sends a PDCCH command to UE 704 to instruct UE 704 to initiate a random access procedure. The PDCCH command can indicate to UE 704 which of TRP0 702 and TRP1 706 to use for the random access procedure. For example, the PDCCH command can request UE 704 to send a RACH preamble to either TRP1 706 or TRP0 702. TRP0 702 also sends a DCI (e.g., DCI0 712) to UE 704 to schedule a PDSCH (e.g., PDSCH0 714) from TRP0 702 or a PDSCH (e.g., PDSCH1 716) from TRP1 706. The DCI / PDSCH can be a RAR as part of the random access procedure or for other DL data transmissions. In this example, only TRP0 702 sends a DCI to UE 704 (i.e., S-DCI). DMRS (DMRS 718) is used for modulation / demodulation of DCI0 712 and PDSCH0 714. DMRS 718 can be quasi-co-located with TRS 720 of TRP0 702. TRS 720 of TRP0 702 can be quasi-co-located with SSB 722 associated with the serving cell (TRP0 702). TRP0 702 can also send CSI-RS 724 to UE 704 for channel measurements. CSI-RS 724 can be quasi-co-located with SSB 722 or quasi-co-located with TRS 720. DMRS (e.g., DMRS 726) is used for modulation / demodulation of PDSCH1 716 of TRP1 706. DMRS 726 can be quasi-co-located with TRS 728 of TRP1 706. TRP1 706, which is not configured to be used as a serving cell, has no associated SSB.TRP1706 transmits TRS 728, and TRS 728 can be quasi-co-located with SSB 722 or TRS 720 with weak QCL assumptions (e.g., QCL type C, or even QCL used only for averaging delay). Typically, for non-co-located TRPs, they can only share coarse / coarse time / frequency synchronization, such as slot / OFDM symbol boundaries and subcarrier / PRB alignment, but cannot share Doppler shift, Doppler spread, average gain, delay spread, spatial reception parameters, etc. However, if the TRPs are not too far apart and are closely synchronized, QCL type C can be assumed for either SSB 722 or TRS 720. TRP1 706 can send CSI-RS 730 to UE 704. UE 704 can estimate the PL between UE 704 and TRP1 706 based on this CSI-RS 730, and send a RACH preamble to TRP1 706 (e.g., based on non-contention) during the random access procedure based on the estimated PL. CSI-RS 730 can be quasi-co-located with TRS 728. In this example, the PL is based on the CSI-RS of TRP1 706, while the RACH to TRP1 706 is based on the PL. However, other steps of the random access procedure are performed between UE 704 and TRP0 702 based on TRP0 702 and the PCID associated with SSB 722 (similar to that specified in R16). In one embodiment, TRS 728 is not quasi-co-located with SSB 722 or TRS 720, but the UE needs to search for a TRS 728 similar to a discovery signal (DS) within the search time window.

[0068] Figure 8 The illustration is shown. Figure 6 Figure 800 illustrates Example Scenario 2 in Table 600. Figure 800 shows TRP0 802 configured as the serving cell for UE 804 on a carrier. TRP1 806, not configured as the serving cell for UE 804, co-channels with TRP0 802. TRP0 802 and TRP1 806 provide M-TRP communication services for the UE in the serving cell. In this example, TRP0 802 and TRP1 806 are synchronized with each other and have fast backhaul between them. Separate RGs (i.e., RG0 and RG1) are configured for TRP0 802 and TRP1 806.

[0069] and Figure 7Unlike Scenario 1, in this example, each of TRP0 802 and TRP1 806 can send a PDCCH command to instruct UE 804 to initiate a random access procedure with a TRP (i.e., TRP0 802 or TRP1 806). For example, TRP0 802 can send a PDCCH command to request UE 804 to send a RACH preamble to either TRP0 802 or TRP1 806. Similarly, TRP1 806 can send a PDCCH command to request UE 804 to send a RACH preamble to either TRP0 802 or TRP1 806. In one example, the PDCCH command may include an indication of which of TRP0 802 or TRP1 806 UE 804 will send the RACH preamble to. In another example, the PDCCH command does not include such an indication that UE 804 determines that the TRP sending the PDCCH command is the TRP to which UE 804 intends to send the RACH preamble. TRP0 802 and TRP1 806 send their respective DCIs to schedule their respective PDSCHs. For example, as shown, TRP0 802 sends a DCI (e.g., DCI0 812) to UE 804 that schedules a PDSCH (e.g., PDSCH0814) from TRP0 802. TRP1 806 sends a DCI (e.g., DCI1 816) to UE 804 that schedules a PDSCH (e.g., PDSCH1 818) from TRP1 806. In this example, TRP0 802 sends DCIs to UE 804 (i.e., M-DCI). The DCI / PDSCH can be a RAR as part of the random access procedure or for other DL data transmissions.

[0070] DMRS (e.g., DMRS 820) is used for modulation / demodulation of DCI0 812 and PDSCH0 814. DMRS 820 can be quasi-co-located with TRS 822 of TRP0 802. TRS 822 of TRP0 802 can be quasi-co-located with SSB 824 associated with the serving cell (TRP0 802). CSI-RS 826 of TRP0 802 can be quasi-co-located with SSB 824. DMRS (e.g., DMRS 828) is used for modulation / demodulation of DCI1 816 and PDSCH1 818 of TRP1806. DMRS 828 can be quasi-co-located with TRS 830 of TRP1 806. TRP1 806, which is not configured as the serving cell for UE 804, has no associated SSB. TRP1 806 can send CSI-RS 832 to UE 804. UE 804 can estimate the PL between UE 804 and TRP1 806 based on this CSI-RS 832, and send a RACH preamble to TRP1 806 during the random access procedure based on the estimated PL (e.g., based on non-contention). CSI-RS 832 can be quasi-co-located with TRS 830. In this example, the PL is based on the CSI-RS of TRP1 806, while the RACH to TRP1 806 is based on the PL. However, other steps of the random access procedure are performed between UE 804 and TRP0 802 based on TRP0 802 and the PCID associated with SSB 824 (similar to that specified in R16). In one embodiment, TRS 830 is not quasi-co-located with SSB 824 or TRS 822, but UE 804 needs to search for TRS 830 similar to a discovery signal (DS) within the search time window.

[0071] Figure 9 The illustration is shown. Figure 6Figure 900 illustrates Example Scenario 5 as shown in Table 600. Figure 900 shows TRP0 902 configured on a carrier to serve as the serving cell for UE 904. The serving cell is associated with SSB 922. TRP1 906 is associated with SSB 930 but is not configured as a secondary cell for UE 904. TRP0 902 and TRP1 906 provide M-TRP communication services to the UE via the carrier. In this example, TRP0 902 and TRP1 906 are synchronized with each other for communication between TRP0 902 and TRP1 906. Separate RGs (i.e., RG0 and RG1) are configured for TRP0 902 and TRP1 906. TRP0 902 can send a PDCCH command to UE 904 to instruct UE 904 to initiate a random access procedure, and can indicate to UE 904 which of TRP0 902 and TRP1 906 to send the RACH preamble. For example, the PDCCH command can request UE 904 to send the RACH preamble to either TRP1 906 or TRP0 902. TRP0 902 sends a DCI (e.g., DCI0 912) to UE 904 for scheduling PDSCH from TRP0 902 (e.g., PDSCH0 914) or from TRP1 906 (e.g., PDSCH1 916) as part of the random access procedure, or can be used for other DL data transmissions. In this example, only TRP0 902 sends a DCI to UE 904 (i.e., S-DCI). DMRS (e.g., DMRS 918) is used for modulation / demodulation of DCI0 912 and PDSCH0 914. DMRS 918 can be quasi-co-located with TRS 920 of TRP0 902. TRS 920 of TRP0 902 can be quasi-co-located with SSB 922 associated with the serving cell (TRP0 902). TRP0 902 can also send CSI-RS 924 to UE 904 for channel measurements. CSI-RS 924 can be quasi-co-located with SSB 922. DMRS (e.g., DMRS 926) is used for modulation / demodulation of PDSCH1 916 of TRP1 906. DMRS 926 can be quasi-co-located with TRS 928 of TRP1 906. Figure 7Unlike Scenario 1, in this example, TRP1 906 is associated with SSB 930. SSB 930 can be configured to be associated with TAG1, but not as a secondary cell (SCell) for UE 904. TRS 928 can be quasi-co-located with SSB 930. TRP1 906 can send CSI-RS 932 to UE 904. UE 904 can estimate the PL between UE 904 and TRP1 906 based on this CSI-RS 932, and send a RACH preamble to TRP1 906 during random access based on the estimated PL (e.g., based on non-contention). CSI-RS 932 can be quasi-co-located with TRS 928. In this example, the PL is based on the CSI-RS of TRP1 906, while the RACH to TRP1 906 is based on the PL. However, additional steps of the random access procedure are performed between UE 904 and TRP0 902 based on TRP0 902 and the PCID associated with SSB 922 (similar to that specified in R16). The scrambling ID used with TRP1 906 can be based on the associated non-serving SSB, or can be configured for one or more of the signals / channels transmitted with TRP1 906.

[0072] Figure 10 The illustration is shown. Figure 6Figure 1000 illustrates example scenarios 6, 7, and 8 in Table 600. Figure 1000 shows TRP0 1002 configured on a carrier to serve as the serving cell for UE 1004. The serving cell is associated with SSB 1024. TRP1 1006 is associated with SSB 1032, and TRP1 1006 may or may not serve as a secondary cell for UE 1004 on the carrier. TRP0 1002 and TRP1 1006 provide M-TRP communication services to the UE via the carrier. In this example, TRP0 1002 and TRP1 1006 may or may not be synchronized with each other. Separate RGs (i.e., RG0 and RG1) are configured for TRP0 1002 and TRP1 1006. TRP01002 transmits TRS / CSI-RS / DMRS directly or indirectly through other RSs, which can be quasi-co-located with the associated SSB 1024. TRP1 1006 transmits TRS / CSI-RS / DMRS directly or indirectly through other RSs, which can be quasi-co-located with the associated SSB 1032. For example, in the case of spatial division multiplexing (SDM) with overlapping time / frequency resources, multiple PDSCH DMRS ports are quasi-co-located with the TRS / CSI-RS of the corresponding TRP (e.g., QCL type A), and the TRS / CSI-RS are further quasi-co-located with the SSB of the corresponding TRP (e.g., QCL type A). As another example, in the case of SDM with overlapping time / frequency resources, multiple PDSCH DMRS ports are directly quasi-co-located with the SSB of the corresponding TRP (e.g., QCL type A). It should be noted that PDSCH DMRS ports may not be in the same CDM group because they are intended for different TRPs with non-negligible timing differences or that are geographically dispersed. Similarly, PDCCH DMRS ports may also need to be configured with such QCL / TCI states, but a PDCCH DMRS port always originates from a single TRP. FDM / TDM can also be considered in a similar, but generally simpler, manner.

[0073] Each of TRP0 1002 and TRP1 1006 can send a PDCCH command to instruct UE 1004 to initiate a random access procedure. In this example, the PDCCH command is linked to a TRP. That is, the PDCCH command itself means that UE 1004 initiates a random access procedure to the TRP linked to the PDCCH command. TRP0 1002 and TRP1 1006 send corresponding DCIs that schedule their respective PDSCHs. For example, as shown, TRP0 1002 sends a DCI (e.g., DCI0 1012) to UE 1004 that schedules a PDSCH (e.g., PDSCH01014) from TRP0 1002. TRP1 1006 sends a DCI (e.g., DCI11016) to UE 1004 that schedules a PDSCH (e.g., PDSCH1 1018) from TRP1 1006. In this example, TRP0 1002 transmits DCI to UE1004 (i.e., M-DCI). DMRS (e.g., DMRS1020) is used for modulation / demodulation of DCI0 1012 and PDSCH0 1014. DMRS1020 can be quasi-co-located with TRS1022 of TRP0 1002. TRS1022 of TRP0 1002 can be quasi-co-located with SSB 1024 associated with the serving cell (TRP0 1002). CSI-RS1026 can be quasi-co-located with SSB 1024. DMRS (e.g., DMRS1028) is used for modulation / demodulation of DCI1 1016 and PDSCH1 1018 of TRP1 1006. DMRS1028 can be quasi-co-located with TRS1030 of TRP1 1006. The TRS1030 of TRP1 1006 can be quasi-co-located with the SSB 1032 associated with TRP1 1006.

[0074] SSB 1032 can be configured to be associated with TAG1, but not as a SCell for UE 1004. TRS 1030 can be quasi-co-located with SSB 1032. TRP1 1006 can send CSI-RS 1034 to UE 1004. UE 1004 can estimate the PL between UE 1004 and TRP1 1006 based on this CSI-RS 1034, and send a RACH preamble to TRP1 1006 during random access based on the estimated PL (e.g., contention-free). CSI-RS 1034 can be quasi-co-located with either TRS 1030 or SSB 1032. In this example, the PL is based on the CSI-RS of TRP1 1006, while the RACH to TRP1 1006 is based on the PL. However, based on TRP01002 and the PCID associated with SSB 1024 (similar to that specified in R16), additional steps of the random access procedure (e.g., RAR) are performed between UE 1004 and TRP0 1002. The scrambling ID used with TRP1 1006 can be based on the associated non-serving SSB 1032, or can be configured for use with one or more of the signals / channels transmitted with TRP1 1006.

[0075] In some embodiments, examples of M-TRP PUCCH enhancements are described. In URLLC, to meet the 1E-5BLER requirement for data transmission, the reliability of the PUCCH needs to be at least equal to or better than 1E-5BLER (i.e., lower), preferably an order of magnitude better. In Rel-16, individual and / or combined A / N feedback in the PUCCH is supported. For individual A / N, TDMed long and / or short PUCCHs are supported, and each PUCCH resource can be associated with a higher-level index for each CORESET. For combined A / N, a combined semi-static HARQ-ACK codebook can be used, with A / N bits concatenated in a specific order. Switching between individual and combined A / N feedback is supported via RRC configuration. In one embodiment, the enhancements from PUCCH with ACK / NACK to PUCCH with CSI described above are extended to include: (1) support for individual and / or combined CSI feedback in PUCCH; (2) differentiation between URLLC-oriented and non-URLLC-oriented CSI reports in terms of content, format, repetition, and conflict handling, with explicit bits used to indicate to the UE that the CSI is associated with a higher priority so that other transmissions are dropped when they conflict with a PUCCH carrying a higher priority CSI; (3) TDM of M-TRP PUCCH, and repetition of PUCCH in the time domain (UE sends the same PUCCH to the same TRP multiple times) and the spatial domain (UE sends the same PUCCH to multiple TRPs multiple times respectively). In one embodiment, a PDCCH / PDSCH transmission followed by multiple (i.e., repeated) PUCCH A / N feedbacks may be supported. The UE may perform repeated A / N transmissions to one or two TRPs. This may be useful if the reliability of the ACK / NACK feedback cannot meet the target BLER. In one embodiment, soft merging / joint reception on the network side may be supported. Whether soft merging / joint reception is feasible for multiple TRPs depends on the backhaul assumptions between TRPs. However, soft merging with repeated PUCCH transmissions is always feasible for the same TRP.

[0076] In some embodiments, examples of M-TRP PUSCH enhancements are described. In one embodiment, TDM supports M-TRP PUSCH. PUSCH temporal repetition (repetition of the same TRP) and spatial repetition (repetition of multiple TRPs) can be supported. Repetition should target the same TB, but multiple PUSCHs can use the same or different RVs. In one embodiment, single-DCI and multi-DCI scheduling of PUSCHs is supported, similar to single-DCI and multi-DCI scheduling of PDSCHs. In one embodiment, the network and UE distinguish between URLLC-oriented PUSCHs and non-URLLC-oriented PUSCHs in terms of content, format, repetition, and conflict handling. Explicit bits can be used to indicate to the UE that a PUSCH is associated with a higher priority so that other transmissions are dropped in the event of a conflict with a PUSCH with a higher priority. The PUSCH may carry URLLC UL data, URLLC-related A / N feedback, and / or URLLC-related CSI reports.

[0077] In some embodiments, an example of M-TRP PDCCH enhancement is described. In one embodiment, PDCCH repetition is supported in both the time domain (repeated by the same TRP) and the spatial domain (repeated by multiple TRPs). For example, DCI1 can be sent from TRP1. DCI1 can be an S-DCI for jointly scheduling PUSCH / PDSCH of TRP1 and TRP2, or it can be one of the M-DCIs used only for scheduling PUSCH / PDSCH of TRP1. DCI1 can be repeated in later OFDM symbols, sent by TRP1, TRP2, or even both. PDCCH repetition can be used to achieve higher reliability. However, there is a problem that needs to be addressed. When the UE receives multiple PDCCH transmissions, each PDCCH transmission schedules one PDSCH (or PUSCH). The UE may not understand that these PDCCH transmissions are actually repetitions, and that they should only result in one PDSCH (or only one PUSCH). The UE may mistakenly assume that it is simultaneously scheduled for two PDSCH transmissions (or two PUSCH transmissions) and decide to discard one or both transmissions. This is an example demonstrating that PDCCH duplication must be explicitly indicated to the UE. Otherwise, the UE assumption should be standardized so that the UE assumes PDCCH duplication based on the same resource allocation across multiple DCIs. Explicit indication can be a field in the DCI used as a flag, assuming that DCIs with the same flag schedule the same PDSCH or PUSCH. Implementations also include cross-TRP scheduling (TRP1 DCI for scheduling TRP2PDSCH / PUSCH or vice versa), joint DCIs sent from either TRP (S-DCI for scheduling two TRPs), or joint transmissions of the same DCI (for one or two TRPs, or a single PDSCH / PUSCH transmission). To support these enhancements, the QCL / TCI state and CORESET pool index should be enhanced to ensure that transmissions are correctly associated with the intended TRP.

[0078] In HST-SFN deployment scenarios, DL operations rely on Rel-16eMIMO's multi-TRP-based URLLC scheme 1c, which utilizes a single DCI. The protocol for scheme 1c is as follows:

[0079] To facilitate further downward selection of one or more schemes in RAN1#96bis, the URLLC schemes based on multiple TRPs, which are scheduled by at least a single DCI, are described below:

[0080] Option 1 (SDM): within a single time slot n (n<=N) s ( ) TCI states, with overlapping time and frequency resource allocation

[0081] Option 1c: A layer with the same TB has one DMRS port associated with multiple TCI status indices, or a layer with the same TB has multiple DMRS ports associated with multiple TCI status indices one by one.

[0082] Based on scheme 1c, the Rel-17 HST-SFN can be operated as follows:

[0083] Network configuration

[0084] Multiple TRPs connect to the ideal backhaul with the same cell ID, thereby providing services to UEs on the HST.

[0085] SSB Configuration

[0086] In principle, some TRPs may not need to send an SSB, and sending a TRP-specific TRS may be sufficient for data transmission. However, since the distance between TRPs is typically several hundred meters, it may be desirable for all TRPs to send an SSB to cover the entire range. Therefore, typically, each TRP can send an SSB associated with a common cell ID. For some or all TRPs (i.e., the SFN of the SSB) or TRP-specific SSBs, the SSB may be the same; however, since the SSB is directionally transmitted along the HST direction, i.e., with different beams, the SSB should generally be a TRP-specific SSB.

[0087] TRS Configuration

[0088] TRS precompensation for Doppler frequency shift can be achieved using two options:

[0089] Option 1 TRS Design: Doppler shift with little or no pre-compensation, utilizing TRP-specific TRS

[0090] For this option, the TRPs are synchronized; they are transmitted synchronously without pre-compensation for Doppler shift. The UE then sees different Doppler shifts for different TRSs, meaning the TRS is TRP-specific. Based on the TRS, the UE can estimate the TRP-specific Doppler shift. It should be noted that different TRPs result in significantly different Doppler shifts for the HST.

[0091] Each TRP-specific TRS can be quasi-co-located with the corresponding TRP-specific SSB (type A, and for FR2, type D).

[0092] Option 2 TRS Design: Pre-compensation for Doppler frequency shift, SFN for TRS from different TRPs.

[0093] For this option, the TRPs are synchronized; they are transmitted synchronously and adequately pre-compensated for the Doppler shift. The UE then sees that the Doppler shifts of different TRSs are nearly identical, thus the TRSs can form an SFN. Based on the TRSs, the UE can estimate the residual Doppler shift as needed.

[0094] TRS can be quasi-co-located with one or more SSBs.

[0095] PDSCH DMRS Configuration

[0096] Multiple TRPs transmit the same PDSCH (and possibly PDCCH) on the same time-frequency resources, forming an SFN that is essentially based on scheme 1c.

[0097] It should be noted that each TRP can send all layers (e.g., L layers), meaning all TRPs (e.g., n TRPs) send the same TB / codeword across all L layers. This is a simplified summary of one layer in Rel-16 scheme 1c. It should also be noted that SFN is possible due to ideal backhaul between TRPs.

[0098] PDSCH's DMRS has two options:

[0099] Option A: All TRP (multiple) SFN DMRS ports

[0100] For this option, the UE receives L DMRS ports, each corresponding to a layer 1 of all TRPs. In other words, each DMRS port consists of the SFN of all TRPs. The DMRS port needs to be quasi-co-located with the TRS:

[0101] Option A-1: ​​Multiple SFN DMRS ports co-located with a TRP-specific TRS quasi-addressable port

[0102] SFN DMRS requires association with multiple TCI state indices, each specifying the QCL relationship with a TRP-specific TRS of the TRP. QCL type A (Doppler shift, Doppler spread, average delay, delay spread) should be specified in the TCI state.

[0103] The following is an example of QCL configuration for (multiple) DMRS ports:

[0104] TCI State 1: QCL A, TRS1 (for TRP 1)

[0105] TCI State 2: QCL A, TRS2 (for TRP 2)

[0106] ...

[0107] TCI state n: QCL A, TRSn (for TRP n)

[0108] Option A-2: Multiple SFN DMRS ports quasi-co-located with SFN TRS

[0109] SFN DMRS can be associated with a TCI state index, which specifies the QCL relationship with the SFN TRS of the TRP. QCL type A (Doppler shift, Doppler spread, average delay, delay spread) should be specified in the TCI state.

[0110] The following is an example of QCL configuration for (multiple) DMRS ports:

[0111] TCI Status: QCL A, TRS (for all TRPs)

[0112] Option B: TRP specific DMRS port

[0113] For this option, the UE receives n x L DMRS ports. These n x L ports can form L sets, each set including n ports associated with the same layer in n TRPs. Alternatively, the n x L ports can form n groups, each group including L ports associated with the same TRP in L layers (the groups can be CDM groups). The L ports of the same TRP are likely to be CDM groups, but the ports of different TRPs should be orthogonalized in the time / frequency / sequence domains. This option is only applicable to Option 1 TRS designs with TRP-specific TRSs.

[0114] It should be noted that although WID does not list option B as an example, it does not exclude it.

[0115] The following is an example of QCL configuration for the DMRS port:

[0116] Group 1 L DMRS ports: TCI state 1: QCL A, TRS1 (for TRP 1)

[0117] Second group of L DMRS ports: TCI state 2: QCL A, TRS2 (for TRP 2)

[0118] ...

[0119] Group n L DMRS ports: TCI state n: QCL A, TRSn (for TRP n)

[0120] Based on the above description, the following issues may need to be addressed in Rel-17:

[0121] Decisions regarding support for TRS / DMRS options, such as option A (option A-1 and option A-2) and / or option B.

[0122] Option A has lower DMRS overhead, but channel estimation on DMRS with composite channels from all TRPs may be more complex and less accurate than Option B. In particular, channel estimation for Option A-1 may be challenging. The trade-offs should be studied in Rel-17, and an agreement needs to be reached where one or both should be supported.

[0123] Specify UE behavior / assumptions

[0124] For each option, UE assumptions and minimum UE behavior (if any) must be specified. For example, for option A, the UE needs to assume that the channel on the DMRS port is a composite channel, which is a superposition of individual channels associated with the TRS. For option B, the UE needs to assume that the PDSCH channel is a composite channel, which is a superposition of individual channels associated with the corresponding n DMRS ports.

[0125] To enable the network to apply Doppler shift pre-compensation values ​​to each TRP before sending the SFN PDSCH, the UE may need to send an SRS to each TRP, and the SRS can be based on the Doppler shift experienced by the UE in the DL for that TRP. This may require the UL signal and DL signal to be correlated, for example, with respect to the Doppler shift. This can be suitable for a general QCL framework, i.e., the UL / DL signals can be defined as quasi-co-located. Furthermore, defining the UL / DL signal relationship as QCL has significant advantages because QCL / TCI information can be dynamically signaled to the UE via DCI, providing greater flexibility in dynamic network deployment scenarios (e.g., HST) than using an RRC / MAC-based signaling framework.

[0126] Embodiments of the present invention can be implemented as computer-based methods. These embodiments can be executed by a processing system. Figure 11 An example processing system 1100 for performing the methods described herein is shown, and the system may be installed in a host device. As shown, the processing system 1100 includes at least one processor 1104, at least one memory 1106, and interfaces 1110, 1112, and 1114, which may or may not be as described herein. Figure 11The arrangement is shown. Processor 1104 can be any component or set of components for performing computational and / or other processing-related tasks, and memory 1106 can be any component or set of components for storing programs and / or instructions executed by processor 1104. In one embodiment, memory 1106 includes a non-transitory computer-readable medium. Interfaces 1110, 1112, and 1114 can be any component or set of components that enable the processing system 1100 to communicate with other devices / components and / or users. For example, one or more of interfaces 1110, 1112, and 1114 can be used to send data, control, or management messages from processor 1104 to applications installed on host devices and / or remote devices. As another example, one or more of interfaces 1110, 1112, and 1114 can be used to enable interaction / communication between a user or user device (e.g., a personal computer (PC)) and the processing system 1100. The processing system 1100 may include Figure 11 Additional components not shown, such as long-term memory (e.g., non-volatile memory, etc.).

[0127] In some embodiments, the processing system 1100 is included in a network device that accesses or otherwise becomes part of a telecommunications network. In one example, the processing system 1100 is located in a network-side device within a wireless or wired telecommunications network, such as a base station, relay station, scheduler, controller, gateway, router, application server, or any other device within the telecommunications network. In other embodiments, the processing system 1100 is located in a user-side device accessing a wireless or wired telecommunications network, such as a mobile station, user equipment (UE), personal computer (PC), tablet computer, wearable communication device (e.g., smartwatch), or any other device used for accessing the telecommunications network.

[0128] In some embodiments, one or more of interfaces 1110, 1112, and 1114 connect the processing system 1100 to a transceiver for sending and receiving signaling over a telecommunications network. Figure 12An example transceiver 1200 for sending and receiving signaling over a telecommunications network is shown. The transceiver 1200 can be installed in a host device. As shown, the transceiver 1200 includes a network-side interface 1202, a coupler 1204, a transmitter 1206, a receiver 1208, a signal processor 1210, and a device-side interface 1212. The network-side interface 1202 may include any component or set of components for sending or receiving signaling over a wireless or wired telecommunications network. The coupler 1204 may include any component or set of components for facilitating bidirectional communication over the network-side interface 1202. The transmitter 1206 may include any component or set of components (e.g., an up-converter, a power amplifier, etc.) for converting a baseband signal into a modulated carrier signal suitable for transmission over the network-side interface 1202. The receiver 1208 may include any component or set of components (e.g., a down-converter, a low-noise amplifier, etc.) for converting a carrier signal received over the network-side interface 1202 into a baseband signal. Signal processor 1210 may include any component or set of components for converting baseband signals into data signals suitable for communication via one or more device-side interfaces 1212, or for performing the reverse conversion. The one or more device-side interfaces 1212 may include interfaces for communication between signal processor 1210 and a host device (e.g., ...). Figure 11 Any component or set of components that communicates data signals between components within the processing system 1100, local area network (LAN) ports, etc.

[0129] Transceiver 1200 can send and receive signaling via any type of communication medium. In some embodiments, transceiver 1200 sends and receives signaling via a wireless medium. For example, transceiver 1200 may be a wireless transceiver for communicating according to a wireless telecommunications protocol, such as a cellular protocol (e.g., Long Term Evolution (LTE), etc.), a wireless local area network (WLAN) protocol (e.g., Wi-Fi), or any other type of wireless protocol (e.g., Bluetooth, Near Field Communication (NFC), etc.). In these embodiments, network-side interface 1202 includes one or more antenna / radiating elements. For example, network-side interface 1202 may include a single antenna, multiple independent antennas, or a multi-antenna array for multi-layer communication, such as single-input multiple-output (SIMO), multiple-input single-output (MISO), multiple-input multiple-output (MIMO), etc. In other embodiments, transceiver 1200 sends and receives signaling via a wired medium such as twisted-pair cable, coaxial cable, or optical fiber. A particular processing system and / or transceiver may utilize all of the components shown, or only a subset of these components, and the level of integration may vary from device to device.

[0130] Although the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to those skilled in the art upon reference to this specification. Therefore, the appended claims cover any such modifications or embodiments.

Claims

1. A method for wireless communication, the method comprising: The user equipment (UE) receives first configuration information for a bandwidth portion (BWP) in a carrier of a serving cell. The first configuration information includes a first set of parameters and a first resource group (RG) on the BWP in the carrier of the serving cell. The first RG is associated with the first set of parameters. The first RG includes at least one of a first synchronization signal block (SSB) and a first CSI-RS for tracking. The first set of parameters includes a first timing advance (TA) value, or includes at least one of a first set of quasi-co-location (QCL) relationships or a first set of TCI states. The UE receives second configuration information of the BWP in the carrier. The second configuration information includes a second set of parameters and a second RG on the BWP in the carrier. The second RG is associated with the second set of parameters. The second RG includes at least one of a second SSB and a second CSI-RS for tracking. The second set of parameters includes a second TA value or at least one of a second set of QCL relationships or a second set of TCI states. The transmission or reception associated with the first RG is performed based on the first set of parameters, and the transmission or reception associated with the second RG is performed based on the second set of parameters.

2. The method of claim 1, wherein performing a transmission or reception associated with the first RG based on the first set of parameters and performing a transmission or reception associated with the second RG based on the second set of parameters comprises at least one of the following: The UE transmits a first uplink (UL) signal or channel associated with the first RG based on the first set of parameters; The UE receives a first downlink (DL) signal or channel associated with the first RG based on the first set of parameters; The UE transmits a second UL signal or channel associated with the second RG based on the second set of parameters; or The UE receives the second DL signal or channel associated with the second RG based on the second set of parameters.

3. The method according to claim 2, wherein: The first SSB is associated with the serving cell and the first physical cell identifier (PCI) of the serving cell; The second SSB is associated with the second PCI.

4. The method according to claim 2, wherein: The first SSB is associated with the serving cell and the first physical cell identifier (PCI) of the serving cell, and wherein the first CSI-RS for tracking is quasi-co-located with the first SSB.

5. The method of claim 4, wherein the first set of QCL relationships comprises at least one of the following: The first DL signal or channel associated with the first RG is quasi-co-located (QCLed) with the first SSB or the first CSI-RS used for tracking; The first DL signal or channel associated with the first RG is quasi-co-located with the DL reference signal (RS) in the first RG, and the DL RS is quasi-co-located with the first SSB or the first CSI-RS used for tracking; or The first UL signal or channel associated with the first RG is configured with a path loss RS or spatial relationship RS that is quasi-co-located with the first SSB or the first CSI-RS used for tracking.

6. The method of claim 4, wherein the second set of QCL relationships comprises at least one of the following: The second DL signal or channel associated with the second RG is quasi-co-located (QCLed) with the second SSB or the second CSI-RS used for tracking; The second DL signal or channel associated with the second RG is quasi-co-located with the DL reference signal (RS) in the second RG, and the DL RS is quasi-co-located with the second SSB or the second CSI-RS used for tracking; or The second UL signal or channel associated with the second RG is configured with a path loss RS or spatial relationship RS that is quasi-co-located with the second SSB or the second CSI-RS used for tracking.

7. The method according to claim 2, wherein: The first configuration information indicates the association between the first RG and a first group of UL / DL signals and channels, wherein the first group of UL / DL signals and channels includes the first UL signal or channel and the first DL signal or channel; and The second configuration information indicates the association between the second RG and the second set of UL / DL signals and channels, wherein the second set of UL / DL signals and channels includes the second UL signal or channel and the second DL signal or channel.

8. The method of claim 2, wherein the first RG is associated with the first TA value, the second RG is associated with the second TA value, and wherein: The transmission of a first UL signal or channel associated with the first RG by the UE based on the first set of parameters includes: The UE transmits the first UL signal or channel associated with the first RG based on the first set of parameters and using the first TA value; The UE transmitting a second UL signal or channel associated with the second RG based on the second set of parameters includes: The UE transmits the second UL signal or channel associated with the second RG using the second TA value based on the second set of parameters.

9. The method of claim 2, wherein the first set of parameters includes the first set of TCI states, the second set of parameters includes the second set of TCI states, and wherein: The UE receiving the first DL signal or channel associated with the first RG based on the first set of parameters includes: The UE uses the first TCI state in the first group of TCI states to receive the first DL signal or channel associated with the first RG; The UE receiving the second DL signal or channel associated with the second RG based on the second set of parameters includes: The UE uses the second TCI state in the second group of TCI states to receive the second DL signal or channel associated with the second RG.

10. A user equipment (UE), comprising: Non-transient memory, including instructions; One or more hardware processors communicate with the memory, wherein the one or more hardware processors execute the instructions to perform operations including: The system receives first configuration information for a bandwidth portion (BWP) in a carrier for a serving cell, the first configuration information including a first set of parameters and a first resource group (RG) on the BWP in the carrier for the serving cell, wherein the first RG is associated with the first set of parameters, the first RG including at least one of a first synchronization signal block (SSB) and a first CSI-RS for tracking, and the first set of parameters including a first timing advance (TA) value, or including at least one of a first set of quasi-co-location (QCL) relationships or a first set of TCI states; Receive second configuration information of the BWP in the carrier, the second configuration information including a second set of parameters and a second RG on the BWP in the carrier, wherein the second RG is associated with the second set of parameters, the second RG including at least one of a second SSB and a second CSI-RS for tracking, the second set of parameters including a second TA value, or including at least one of a second set of QCL relationships or a second set of TCI states; The transmission or reception associated with the first RG is performed based on the first set of parameters, and the transmission or reception associated with the second RG is performed based on the second set of parameters.

11. The user equipment of claim 10, wherein performing transmission or reception associated with the first RG based on the first set of parameters and performing transmission or reception associated with the second RG based on the second set of parameters comprises at least one of the following: Based on the first set of parameters, a first uplink (UL) signal or channel associated with the first RG is transmitted; Receive a first downlink (DL) signal or channel associated with the first RG based on the first set of parameters; Based on the second set of parameters, a second UL signal or channel associated with the second RG is transmitted; or The second DL signal or channel associated with the second RG is received based on the second set of parameters.

12. The user equipment according to claim 11, wherein: The first SSB is associated with the serving cell and the first physical cell identifier (PCI) of the serving cell; and The second SSB is associated with the second PCI.

13. The user equipment according to claim 11, wherein: The first SSB is associated with the serving cell and the first physical cell identifier (PCI) of the serving cell, and wherein the first CSI-RS for tracking is quasi-co-located with the first SSB.

14. The user equipment of claim 13, wherein the first set of QCL relationships includes at least one of the following: The first DL signal or channel associated with the first RG is quasi-co-located (QCLed) with the first SSB or the first CSI-RS used for tracking; The first DL signal or channel associated with the first RG is quasi-co-located with the DL reference signal (RS) in the first RG, and the DL RS is quasi-co-located with the first SSB or the first CSI-RS used for tracking; or The first UL signal or channel associated with the first RG is configured with a path loss RS or spatial relationship RS that is quasi-co-located with the first SSB or the first CSI-RS used for tracking.

15. The user equipment of claim 13, wherein the second set of QCL relationships comprises at least one of the following: The second DL signal or channel associated with the second RG is quasi-co-located (QCLed) with the second SSB or the second CSI-RS used for tracking; The second DL signal or channel associated with the second RG is quasi-co-located with the DL reference signal (RS) in the second RG, and the DL RS is quasi-co-located with the second SSB or the second CSI-RS used for tracking; or The second UL signal or channel associated with the second RG is configured with a path loss RS or spatial relationship RS that is quasi-co-located with the second SSB or the second CSI-RS used for tracking.

16. The user equipment according to claim 11, wherein: The first configuration information indicates the association between the first RG and a first group of UL / DL signals and channels, wherein the first group of UL / DL signals and channels includes the first UL signal or channel and the first DL signal or channel; and The second configuration information indicates the association between the second RG and the second set of UL / DL signals and channels, wherein the second set of UL / DL signals and channels includes the second UL signal or channel and the second DL signal or channel.

17. The user equipment of claim 11, wherein the first RG is associated with the first TA value, the second RG is associated with the second TA value, and wherein: The transmission of a first UL signal or channel associated with the first RG by the UE based on the first set of parameters includes: The UE transmits the first UL signal or channel associated with the first RG based on the first set of parameters and using the first TA value; The UE transmitting a second UL signal or channel associated with the second RG based on the second set of parameters includes: The UE transmits the second UL signal or channel associated with the second RG using the second TA value based on the second set of parameters.

18. The user equipment of claim 11, wherein the first set of parameters includes the first set of TCI states, the second set of parameters includes the second set of TCI states, and wherein: The UE receiving the first DL signal or channel associated with the first RG based on the first set of parameters includes: The UE uses the first TCI state in the first group of TCI states to receive the first DL signal or channel associated with the first RG; The UE receiving the second DL signal or channel associated with the second RG based on the second set of parameters includes: The UE uses the second TCI state in the second group of TCI states to receive the second DL signal or channel associated with the second RG.

19. A non-transient computer-readable medium storing computer instructions for wireless communication, said computer instructions, when executed by one or more hardware processors, causing said one or more hardware processors to perform operations including: The user equipment (UE) receives first configuration information for a bandwidth portion (BWP) in a carrier of a serving cell. The first configuration information includes a first set of parameters and a first resource group (RG) on the BWP in the carrier of the serving cell. The first RG is associated with the first set of parameters. The first RG includes at least one of a first synchronization signal block (SSB) and a first CSI-RS for tracking. The first set of parameters includes a first timing advance (TA) value, or includes at least one of a first set of quasi-co-location (QCL) relationships or a first set of TCI states. The UE receives second configuration information of the BWP in the carrier. The second configuration information includes a second set of parameters and a second RG on the BWP in the carrier. The second RG is associated with the second set of parameters. The second RG includes at least one of a second SSB and a second CSI-RS for tracking. The second set of parameters includes a second TA value or at least one of a second set of QCL relationships or a second set of TCI states. as well as The transmission or reception associated with the first RG is performed based on the first set of parameters, and the transmission or reception associated with the second RG is performed based on the second set of parameters.

20. The non-transient computer-readable medium of claim 19, wherein performing transmission or reception associated with the first RG based on the first set of parameters and performing transmission or reception associated with the second RG based on the second set of parameters comprises at least one of the following: The UE transmits a first uplink (UL) signal or channel associated with the first RG based on the first set of parameters; The UE receives a first downlink (DL) signal or channel associated with the first RG based on the first set of parameters; The UE transmits a second UL signal or channel associated with the second RG based on the second set of parameters; or The UE receives the second DL signal or channel associated with the second RG based on the second set of parameters.

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