Patent Application
20230171763
The present disclosure relates to uplink transmission to multiple Transmission and Reception Points (TRPs) in a cellular communications system.
The next generation mobile wireless communication system (5G), or new radio (NR), will support a diverse set of use cases and a diverse set of deployment scenarios. The later includes deployment at both low frequencies (i.e., frequencies below 6 Gigahertz (GHz)) and very high frequencies (i.e., frequencies up to 10's of GHz).
1 NR Frame Structure and Resource Grid
NR uses Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) in both downlink (DL) (i.e., from a network node, gNB, or base station, to a user equipment or UE) and uplink (UL) (i.e., from UE to gNB). Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) is also supported in the uplink. In the time domain, NR downlink and uplink are organized into equally sized subframes of 1 millisecond (ms) each. A subframe is further divided into multiple slots of equal duration. The slot length depends on subcarrier spacing. For subcarrier spacing of Δf=15 kilohertz (kHz), there is only one slot per subframe, and each slot consists of fourteen OFDM symbols.
Data scheduling in NR is typically in slot basis. An example is shown in
Different subcarrier spacing values are supported in NR. The supported subcarrier spacing values (also referred to as different numerologies) are given by Δf=(15×2μ) kHz where μ∈{0,1,2,3,4}. Δf=15 kHz is the basic subcarrier spacing. The slot durations at different subcarrier spacings is given by 1/2μ ms.
In the frequency domain, a system bandwidth is divided into resource blocks (RBs), each corresponds to twelve contiguous subcarriers. The RBs are numbered starting with 0 from one end of the system bandwidth. The basic NR physical time-frequency resource grid is illustrated in
In NR Release 15, UL data transmission can be dynamically scheduled by an UL grant contained in Downlink Control Information (DCI) carried by a Physical Downlink Control Channel (PDCCH). A UE first decodes the uplink grant and then transmits data over a Physical Uplink Share Channel (PUSCH) based the decoded control information in the UL grant such as modulation order, coding rate, uplink resource allocation, etc. Three DCI formats are supported in NR Release 16, i.e., DCI format 0_0, DCI format 0_1, and DCI format 0_2. Each DCI contains a number of bit fields each conveys certain information, including:
In addition to dynamic scheduling of PUSCH, there is also a possibility to configure semi-persistent transmission of PUSCH using configured grants (CGs). There are two types of CG based PUSCH defined in NR Release 15, which are referred to as CG type 1 and CG type 2. In CG type 1, a periodicity of PUSCH transmission as well as the start and stop of such transmission are configured by Radio Resource Control (RRC). In CG type 2, a periodicity of PUSCH transmission is configured by RRC and then the start and stop of such transmission is controlled by DCI, i.e., with a PDCCH.
In NR, it is possible to schedule a PUSCH with time repetition via a RRC parameter pusch-AggregationFactor for dynamically scheduled PUSCH and repK for PUSCH with UL configured grant. In this case, the PUSCH is scheduled but transmitted in multiple adjacent slots up until the number of repetitions as determined by the configured RRC parameter have been transmitted.
In the case of PUSCH with UL configured grant, the RV sequence to be used is configured by the repK-RV field when repetitions are used. If repetitions are not used for PUSCH with UL configured grant, then the repK-RV field is absent.
In NR Release 15, two mapping types applicable to PUSCH transmission are supported. These two mapping types are referred to as Type A and Type B. Type A PUSCH transmissions are usually referred to as slot-based transmissions, while Type B PUSCH transmissions may be referred to as non-slot-based transmissions or mini-slot-based transmissions. Mini-slot transmissions can be dynamically scheduled and for NR Release 15:
2 PUSCH Transmission Schemes
In NR, there are two transmission schemes specified for PUSCH.
2.1 Codebook Based PUSCH
Codebook based PUSCH is enabled if higher layer parameter txConfig=codebook. For dynamically scheduled PUSCH and configured grant PUSCH type 2, the codebook based PUSCH transmission scheme can be summarized as follows:
2.2 Non-Codebook Based PUSCH
Non-Codebook based UL transmission is also supported in NR, enabling reciprocity-based UL transmission in which SRS precoding is derived at a UE based on a configured DL Channel State Information Reference Signal (CSI-RS). By assigning a DL CSI-RS to the UE, it can measure and deduce suitable precoder weights for SRS transmission, resulting one or more (virtual) SRS ports, each corresponding to a spatial layer. A UE can be configured with up to four SRS resources, each with a single (virtual) SRS port, in an SRS resource set. A UE can transmit SRS in the up to four SRS resources, and the gNB measures the UL channel based on the received SRS and determines the preferred SRS resource(s) (or SRS port(s)). Subsequently, the gNB indicates the selected SRS resources via a SRS resource indicator (SRI), where the selected SRS resources are jointly encoded using
bits, where NSRS indicates the number of configured SRS resources, and Lmax is the maximum number of supported layers for PUSCH. Note that only a single SRS resource set can be configured with “non-codebook”.
3 Spatial Relation Definition
Spatial relation is used in NR to refer to a relationship between an UL signal or channel such as PUCCH, PUSCH, and SRS and another Reference Signal (RS), which can be either a DL RS (e.g., CSI-RS, SSB (synchronization signal block)) or an UL RS (e.g., SRS). This is also defined from a UE perspective.
If an UL signal or channel is spatially related to a DL RS, it means that the UE should transmit the UL signal or channel in the opposite (reciprocal) direction from which it received the DL RS previously. More precisely, the UE should apply the “same” Transmit (TX) spatial filtering configuration for the transmission of the UL signal or channel as the Receive (Rx) spatial filtering configuration it used to receive the spatially related DL RS previously. Here, the terminology ‘spatial filtering configuration’ may refer to the antenna weights that are applied at either the transmitter or the receiver for data/control transmission/reception. The DL RS is also referred as the spatial filter reference signal.
On the other hand, if a first UL signal or channel is spatially related to a second UL RS, then the UE should apply the same Tx spatial filtering configuration for the transmission for the first UL signal or channel as the Tx spatial filtering configuration it used to transmit the second UL RS previously.
For the SRS resource set for codebook based PUSCH scheme, it can contain up to two SRS resources. Each of the SRS resources can have 1, 2, or 4 SRS ports. Each SRS resource can be spatially related to another RS (e.g., a SSB, a Non-Zero Power (NZP) CSI-RS, or another SRS) through a spatial relation configuration. The spatial relation of a PUSCH is given by the spatial transmission properties associated with the associated SRS resource.
For the SRS resource set for non-codebook based PUSCH scheme, it can contain up to four SRS resources each with a single SRS port. Each SRS resource set is associated with a CSI-RS over which a UE derives SRS precoders for each SRS port. The spatial relation of a PUSCH is given by the CSI-RS configured for the SRS resource set.
4 TCI States for Uplink
Several signals can be transmitted from different antenna ports of a same base station antenna. These signals can have the same large-scale properties, for instance in terms of Doppler shift/spread, average delay spread, or average delay, when measured at the receiver. These antenna ports are then said to be quasi co-located (QCL).
The network can then signal to the UE that two antenna ports are QCL. If the UE knows that two antenna ports are QCL with respect to a certain parameter (e.g., Doppler spread), the UE can estimate that parameter based on a reference signal transmitted one of the antenna ports and use that estimate when receiving another reference signal or physical channel the other antenna port. Typically, the first antenna port is represented by a measurement reference signal such as CSI-RS (known as source RS) and the second antenna port is a demodulation reference signal (DMRS) (known as target RS) for PDSCH or PDCCH reception.
In NR, four types of QCL relations between a transmitted source RS and transmitted target RS were defined:
Information about what assumptions can be made regarding QCL is signaled to the UE from the network through Transmission Configuration Indicator (TCI) states. Each TCI state contains QCL information, i.e., one or two source DL RSs, each source RS associated with a QCL type. For example, a TCI state contains a pair of reference signals, each associated with a QCL type, e.g. two different CSI-RSs {CSI-RS1, CSI-RS2} is configured in the TCI state as {qcl-Type1,qcl-Type2}={Type A, Type D}. It means the UE can derive Doppler shift, Doppler spread, average delay, delay spread from CSI-RS1 and Spatial Rx parameter (i.e., the RX beam to use) from CSI-RS2. TCI states are used in NR for downlink channels and signals.
In NR Release 15, the handling of spatial transmission properties is different for PUSCH, PUCCH, and SRS. For PUCCH, the spatial relation information is configured in information element PUCCH-SpatialRelationInfo, and the spatial relation information for SRS is configured as part of SRS resource configuration. The spatial transmission properties for PUSCH are given by the spatial transmission properties of the associated SRS resource(s) in the SRS resource set configured with ‘Codebook’ or ‘non-Codebook’. Such a handling of the spatial transmission properties is cumbersome and inflexible when it comes to uplink multi-panel transmission in NR.
There were proposals to also use a TCI states framework to indicate the spatial properties for all the UL channels or signals (i.e., PUSCH, PUCCH, and SRS) in uplink. The idea was to use uplink TCI state to indicate one out of multiple uplink panels and the corresponding transmission beams (i.e., transmission properties) at the UE to transmit UL PUSCH/PUCCH/SRS when the UE is equipped with multiple panels. Each TCI state can contain one reference signal for spatial relation indication, one RS for pathloss estimation, and possibly a set of power control parameters.
In general, a list of uplink TCI states can be configured by higher layers (i.e., RRC) for a UE. A subset may be activated by a Medium Access Control (MAC) Control Element (CE). One of the activated TCI states can be indicated in DCI for PUSCH.
5 PUSCH Power Control
For each SRI, a pathloss RS and a set of power control parameters (e.g., fractional power control coefficient, P0, closed-loop index) are preconfigured and signaled to a UE. PUSCH open loop transmit power is then derived based the SRI indicated in the DCI and the associated pre-configured pathloss RS and the set of power control parameters.
Closed-loop power control is done by sending a transmit power control command (TPC) in a 2-bit “TPC command for scheduled PUSCH” field in a DCI scheduling the PUSCH. The mapping between a TPC value and power correction is shown in Table 1, where the “Accumulated [dB]” column is used if the UE is configured with accumulation mode and the “Absolute” column is used otherwise.
Systems and methods are disclosed herein that relate to multi-Transmission/Reception Point (TRP) uplink transmission in a cellular communications system. In one embodiment, a method performed by a wireless communication device comprises receiving, from a network node, a configuration of two Sounding Reference Signal (SRS) resource sets, a first and second SRS resource sets, each comprising one or more SRS resources. The method further comprises receiving, from the network node, downlink control information (DCI) that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI. The method further comprises transmitting the physical uplink channel transmission in accordance with the DCI. In this manner, robust uplink transmission over multiple TRPs can be provided.
In one embodiment, the first and second SRS resources are indicated in a first and a second SRS Resource Indicator (SRI) fields in the DCI, respectively. In one embodiment, the first and second SRI fields are associated with the first and second SRS resource sets, respectively. In one embodiment, a set of possible codepoints for each of the first and second SRI fields in the DCI comprises a codepoint to indicate that a corresponding SRS resource is not selected.
In one embodiment, the method further comprises receiving a configuration of first and second sets of power control parameters associated with the first and second SRS resources, respectively, wherein each of the first and second sets of power control parameters comprise a pathloss reference signal, a fractional power control factor, a target receive power, a closed-loop power control index, or any combination thereof. In one embodiment, the first and second parts of the physical uplink channel transmission are transmitted with a first and second transmit powers, respectively, wherein the first and second transmit powers are calculated based on the first and second sets of power control parameters, respectively.
In one embodiment, the physical uplink channel transmission is a physical uplink shared channel (PUSCH) transmission.
In one embodiment, the DCI further indicates a first and second Transmit Power Control (TPC) commands for the first and second parts of the physical uplink channel transmission, respectively.
In one embodiment, the first and second parts of the physical uplink channel transmission are different parts of a single PUSCH transmitted in different frequency domain resources.
In one embodiment, the first and second parts of the physical uplink channel transmission are a first and second PUSCHs carrying different redundancy versions of a same Transport Block (TB) and transmitted in different frequency domain resources.
In one embodiment, the first and second parts of the physical uplink channel transmission are a first and second layers of a single PUSCH and are transmitted in a same time and frequency domain resource.
In one embodiment, the first and second SRS resources indicated in the DCI may be replaced with a first and second uplink Transmission Configuration Indicator (TCI) states, wherein each of the first and second TCI states comprises a reference signal index for spatial relation indication, a pathloss reference signal index, a set of power control parameters, or any combination thereof.
Corresponding embodiments of a wireless communication device are also disclosed. In one embodiment, a wireless communication device is adapted to receive, from a network node, a configuration of two SRS resource sets each comprising one or more SRS resources. The wireless communication device is further adapted to receive, from the network node, DCI that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI. The wireless communication device is further configured to transmit the physical uplink channel transmission in accordance with the DCI.
In one embodiment, a wireless communication device comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless communication device to receive, from a network node, a configuration of two SRS resource sets each comprising one or more SRS resources. The processing circuitry is further configured to cause the wireless communication device to receive, from the network node, DCI that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI. The processing circuitry is further configured to cause the wireless communication device to transmit the physical uplink channel transmission in accordance with the DCI.
Embodiments of a method performed by a network node are also disclosed herein. In one embodiment, a method performed by a network node comprises sending, to a wireless communication device, a configuration of two SRS resource sets, a first and second SRS resource sets, each comprising one or more SRS resources. The method further comprises sending, to the wireless communication device, DCI that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI.
Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node is adapted to send, to a wireless communication device, a configuration of two SRS resource sets, a first and second SRS resource sets, each comprising one or more SRS resources. The network node is further adapted to send, to the wireless communication device, DCI that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI.
In one embodiment, a network node comprises processing circuitry configured to cause the network node to send, to a wireless communication device, a configuration of two SRS resource sets, a first and second SRS resource sets, each comprising one or more SRS resources. The processing circuitry is further configured to cause the network node to send, to the wireless communication device, DCI that schedules a physical uplink channel transmission comprising a first part associated to a first SRS resource in the first SRS resource set and a second part associated to a second SRS resource in the second SRS resource set, wherein the first and second SRS resources are indicated in the DCI.
In one embodiment, a method performed by a wireless communication device for uplink transmission to a cellular communications network comprises transmitting one or more PUSCHs using two or more Transmission Configuration Indicator (TCI) states on either: (a) a same time and frequency domain resource or (b) a same time domain resource but different frequency domain resources. The two or more TCI states are associated with two or more different reference signals, respectively.
In one embodiment, the method further comprises receiving, from a network node, downlink control information that schedules transmission of the one or more PUSCHs, wherein the downlink control information indicates the two or more TCI states.
In one embodiment, the two or more reference signals are two or more downlink reference signals each associated with a respective one of the two or more TCI states. In one embodiment, each of the two or more downlink reference signals is a Synchronization Signal Block (SSB) or a Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS).
In one embodiment, the two or more reference signals are two or more SRS resources, each configured with a respective spatial relation. In one embodiment, the downlink control information comprises one or more SRIs that indicate the two or more SRS resources. In one embodiment, each of the two or more SRS resources is associated with a respective reference signal through a spatial relation configuration. In one embodiment, the respective reference signal is a SSB, a NZP CSI-RS, or another SRS.
In one embodiment, the two or more SRS resources are associated with two or more respective reference signals, and the two or more respective reference signals are associated with two or more respective cell identities. In one embodiment, the two or more respective reference signals are two or more respective SSBs or two or more respective NZP CSI-RSs. In one embodiment, the two or more respective reference signals are associated with the two or more respective cell identities via a field in a TCI state configuration.
In one embodiment, the two or more respective reference signals are two or more respective SSBs, and the two or more reference signals are associated with the two or more respective cell identities via SSB configuration.
In one embodiment, transmitting the one or more PUSCHs comprises transmitting a first part of the one or more PUSCHs using a first TCI state from among the two or more TCI states and transmitting a second part of the one or more PUSCHs using a second TCI state from among the two or more TCI states. The method further comprises receiving an indication of a pathloss reference signal and a set of power control parameters associated to each of the two or more TCI states via either: one or more SRIs comprised in downlink control information that schedules the one or more PUSCHs, wherein an association between each of the one or more SRIs and one or more pathloss reference signals and one or more sets of power control parameters is signaled to the wireless communication device, or the two or more TCI states, wherein an association between each of the TCI states and one or more pathloss reference signals and one or more sets of power control parameters is signaled to the wireless communication device. In one embodiment, transmitting the first part of the one or more PUSCHs comprises transmitting the first part of the one or more PUSCHs in accordance the set of power control parameters associated to the first TCI state, and transmitting the second part of the one or more PUSCHs comprises transmitting the second part of the one or more PUSCHs in accordance the set of power control parameters associated to the second TCI state.
In one embodiment, the method further comprises receiving, from a network node, an indication to use either a spatial division multiplexing scheme for PUSCH transmission or a frequency division multiplexing scheme for PUSCH transmission. In one embodiment, transmitting the one or more PUSCHs comprises transmitting the one or more PUSCHs on the same time and frequency domain resource if the received indication is an indication to use the spatial division multiplexing scheme for PUSCH transmission or on the same time domain resource but different frequency domain resources if the received indication is an indication to use the frequency division multiplexing scheme for PUSCH transmission.
In one embodiment, the one or more PUSCHs comprise two or more PUSCHs, and each PUSCH of the two or more PUSCHs is scheduled via a separate downlink control information.
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.
Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.
Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.
Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device.
Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gNB Central Unit (gNB-CU) or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node.
Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.
Communication Device: As used herein, a “communication device” is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection.
Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (IoT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless connection.
Network Node: As used herein, a “network node” is any node that is either part of the RAN or the core network of a cellular communications network/system.
Transmission/Reception Point (TRP): In some embodiments, a TRP may be either a network node, a radio head, a spatial relation, or a Transmission Configuration Indicator (TCI) state. A TRP may be represented by a spatial relation or a TCI state in some embodiments. In some embodiments, a TRP may be using multiple TCI states. In some embodiments, a TRP may a part of the gNB transmitting and receiving radio signals to/from UE according to physical layer properties and parameters inherent to that element. In some embodiments, in Multiple TRP (multi-TRP) operation, a serving cell can schedule UE from two TRPs, providing better Physical Downlink Shared Channel (PDSCH) coverage, reliability and/or data rates. There are two different operation modes for multi-TRP: single Downlink Control Information (DCI) and multi-DCI. For both modes, control of uplink and downlink operation is done by both physical layer and Medium Access Control (MAC). In single-DCI mode, UE is scheduled by the same DCI for both TRPs and in multi-DCI mode, UE is scheduled by independent DCIs from each TRP.
In some embodiments, a set Transmission Points (TPs) is a set of geographically co-located transmit antennas (e.g., an antenna array (with one or more antenna elements)) for one cell, part of one cell or one Positioning Reference Signal (PRS)-only TP. TPs can include base station (eNB) antennas, Remote Radio Heads (RRHs), a remote antenna of a base station, an antenna of a PRS-only TP, etc. One cell can be formed by one or multiple TPs. For a homogeneous deployment, each TP may correspond to one cell.
In some embodiments, a set of TRPs is a set of geographically co-located antennas (e.g., an antenna array (with one or more antenna elements)) supporting TP and/or Reception Point (RP) functionality.
Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.
Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.
There currently exist certain challenge(s). For dynamically scheduled Physical Uplink Shared Channel (PUSCH) and configured grant PUSCH type 2 (i.e., PUSCH transmission), existing NR Release 15/16 codebook based PUSCH only allows a single Sounding Reference Signal (SRS) resource to be indicated by the gNB in Downlink Control Information (DCI), where this single indicated SRS resource is then used to define the spatial relation for PUSCH. For non-codebook based PUSCH scheme, a single Channel State Information (CSI) Reference Signal (CSI-RS) is associated with the SRS resource set, and a PUSCH's spatial relation is defined by the CSI-RS configured for the corresponding SRS resource set. Therefore, the existing NR Release 15/16 PUSCH is only suitable for single Transmission and Reception Point (TRP) based transmission where the PUSCH transmission is targeted towards a single TRP. It is unsuitable for transmitting a PUSCH towards multiple TRPs. Thus, how to configure a UE for PUSCH transmissions towards multiple TRPs, particularly how to indicate the spatial relations associated to the TRPs, is a problem.
Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. Systems and methods are disclosed to support simultaneous uplink (UL) PUSCH transmission towards two or more TRPs by indicating two or more SRS resources in either a single SRS resource set or in different SRS resource sets, including:
Systems and methods for PUSCH power control per TRP and signaling enhancement in DCI are also disclosed herein.
In one embodiment, a method performed by a UE comprises transmitting one or more PUSCHs to two or more TRPs, each associated with a reference signal (RS), simultaneously in either a same time and frequency domain resource (e.g., using a Spatial Division Multiplexing (SDM) scheme) or a same time domain resource but different frequency domain resources (e.g., using Frequency Division Multiplexing (FDM) scheme).
In one embodiment, the one or more PUSCHs are scheduled by a single DCI.
In one embodiment, two or more RSs are indicated in the DCI. In one embodiment, the two or more RSs are two or more SRS resources each configured with a spatial relation, or two or more downlink (DL) RSs each associated with a Transmission Configuration Indicator (TCI) state. In one embodiment, the indication of two or more SRS resources is via one or more SRS resource indicators (SRIs).
In one embodiment, the two or more RSs indicated in the DCI are two or more SRS resources, and each of the two or more SRS resources is associated with a reference signal such as, e.g., a Synchronization Signal Block (SSB), a Non-Zero Power (NZP) CSI-RS, or another SRS through a spatial relation configuration. In one embodiment, each SSB or NZP CSI-RS is associated with a different physical cell identity (ID), e.g., by SSB configuration or by a field in the TCI state configuration.
In one embodiment, the indication of the two or more SRS resources is via one or more SRIs, and the UE also receives (e.g., is signaled with) a pathloss RS and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI, wherein association between an SRI and one or more pathloss RS and one or more set of power control parameters is signaled.
In one embodiment, the two or more SRS resources belong to either a same SRS set or different SRS resource sets.
In one embodiment, an indication(s) of whether the UE is to use the SDM scheme or the FDM scheme is signaled either semi-statically (e.g., via Radio Resource Control (RRC)) and/or dynamically (e.g., through DCI).
In one embodiment, each PUSCH is scheduled by a separate DCI.
In one embodiment, the two or more TRPs are indicated in the DCI through indication of two or more TCI states, wherein each TRP is associated with one TCI state.
Certain embodiments may provide one or more of the following technical advantage(s). The proposed solutions enable more robust UL data transmission over multiple TRPs with very low latency, where better reliability can be achieved via spatial diversity over the multiple TRPs simultaneously.
The base stations 302 and the low power nodes 306 provide service to wireless communication devices 312-1 through 312-5 in the corresponding cells 304 and 308. The wireless communication devices 312-1 through 312-5 are generally referred to herein collectively as wireless communication devices 312 and individually as wireless communication device 312. In the following description, the wireless communication devices 312 are oftentimes UEs and as such sometimes referred to herein as UEs 312, but the present disclosure is not limited thereto.
Now, a description of some embodiments of the present disclosure will be provided.
In this embodiment, one or multiple PUSCH(s) for a same Transport Block (TB) is transmitted to multiple TRPs simultaneously, either on the same time and frequency resource or on different frequency resources to different TRPs. Examples of the different TRPs are different base stations 302, different low power nodes 306, a mixture of one or more base stations 302 and one or more lower power nodes 306, or the like. Note that these are non-limiting examples of TRPs. Other examples include remote radio heads, multi-panels, etc.
In particular, the two SSBs may be possible to configure with different physical cell IDs even if they both are used to the same UE for PUSCH transmissions. That is, the two TRPs transmit SSBs that belong to two different cells and, since the SSB is a source for the QCL relation for the DL RS (target), then the DL RSs are also transmitted from the different cells, respectively. Alternatively, the DL RS belong to a TCI state and the TCI state includes a cell ID indicator so that the different DL RSs can be configured to belong to different cells (i.e., transmitted from TRPs served by different cells, with different cell IDs).
An example of the DL RS is the CSI-RS for tracking, i.e., Tracking Reference Signal (TRS).
A first SRS resource (SRS #1) is spatially related to the first DL RS, and a second SRS resource (SRS #2) is spatially related to the second DL RS. Then, a DCI scheduling the PUSCH is indicated to the UE via a Physical Downlink Control Channel (PDCCH). The two SRS resources are indicated in one or two “SRS resource indicator (SRI)” fields of the DCI. Two DMRS ports (i.e., DMRS ports x and y), each associated to one of the two layers, in two Code Division Multiplexing (CDM) groups (i.e., CDM groups 1 and 2) are also indicated in the DCI. The first SRS resource is linked to the first DMRS port indicated in the DCI field “Antenna Port(s)”, and the second SRS resource is linked to the second DMRS port indicated in the DCI field “Antenna Port(s)”. For codebook-based SRS and if there are more than one SRS port per SRS resource, a transmit precoding matrix indicator (TPMI) is also indicated for each SRS resource. In this example, joint decoding by combining the PUSCH signals received from the two TRPs is needed.
For the embodiment where the UE transmits different layers of a single PUSCH to two TRPs (as shown in the example of
Although two layers of a single PUSCH is covered in the above example embodiment, this embodiment can be extended to up to more than two layers. For example, the above example embodiment can be extended to up to four layers of a single PUSCH transmitted to up to three TRPs. Some examples are as follows:
Alternatively, for a same TB or different TBs, separate PUSCHs can be transmitted to each TRP. An example is shown in
In the examples above, the same time-frequency resource is allocated to both TRPs. In this embodiment, different frequency domain resources are allocated to different TRPs. An example is shown in
Alternatively, for a same TB or different TBs, a separate PUSCH is sent to each TRP on different frequency domain resources. An example is shown in
A single frequency resource allocation may be signaled, and the frequency resource is then divided between the two TRPs. In one embodiment, if N RBs are allocated, the first N/2 RBs are allocated to the first TRP and the remaining RBs are allocated to the second TRP. Alternatively, the even numbered RBs (or subcarriers) are allocated to the first TRP and the odd number of RBs (or subcarriers) are allocated to the second TRPs, or the other way around.
In one embodiment, in case of two PUSCHs (e.g., PUSCH1 and PUSCH2) are used, the TB size is determined based on the number of RBs (or subcarriers) allocated to the first TRP.
In some embodiments, the choice among which of the PUSCH transmission schemes among the SDM or FDM schemes and the variants covered above is configured to the UE with higher layer (e.g., RRC) signaling. That is, when the network configures the UE with ‘FDM’ scheme, then the UE assumes PUSCH multi-TRP transmission scheme according to the embodiment described above in the section “Simultaneous PUSCH Transmission to Multiple TRPs with Frequency Domain Multiplexing (FDM)”. In another embodiment, whether the UE is to use ‘SDM’ or ‘FDM’ multi-TRP PUSCH transmission is indicated jointly by the Antenna Ports field and the SRI field in UL DCI as follows:
For codebook based PUSCH transmission, in one embodiment, a single SRS resource set with two or more SRS resources is configured for a UE. Each of the two or more SRS resources is associated to a TRP via a spatial relation configuration, which includes a DL RS (or pathloss RS) for pathloss measurement and estimation. A set of PUSCH power control related parameters is also associated to an SRS resource. When one or more PUSCHs transmitted to two TRPs are scheduled by a DCI, two SRS resources are also indicated in the DCI. The transmit power of the PUSCH to each TRP can be calculated based on the pathloss estimation and the set of power control parameters associated to the corresponding SRS resource.
In another embodiment, two SRS resource sets each with one or more SRS resource are configured for a UE. Each of the SRS resource sets is associated with a DL RS for pathloss measurement and with a set of PUSCH power control related parameters. When one or more PUSCHs transmitted to two TRPs are scheduled by a DCI, two SRS resources, one in each SRS resource set, are indicated in the DCI. The transmit power of the one or more PUSCHs to each TRP can be calculated based on the estimated pathloss and the power control parameters associated to the corresponding SRS resource set.
For non-codebook based PUSCH transmission, two SRS resource sets can be configured for a UE. Each of the SRS resource sets is associated with a DL RS for pathloss calculation and also a set of power control related parameters. When one or more PUSCHs transmitted to two TRPs are scheduled by a DCI, SRS resource(s) in each SRS resource set are indicated in the DCI. The transmit power of the one or more PUSCHs to each TRP can be calculated based on the estimated pathloss and the power control parameters associated to the corresponding SRS resource set.
In case of codebook based PUSCH transmission, one or two SRS resources may be indicated in DCI for PUSCH transmission to one or two TRPs, respectively. For non-codebook based transmission, one or two SRS resource sets may be indicated in DCI for PUSCH transmission to one or two TRPs, respectively. If one SRS resource is indicated, a PUSCH towards a single TRP is scheduled. On the other hand, if two SRS resources are indicated, one or more PUSCH is scheduled towards two TRPs.
Two SRI fields, one for each TRP, may be used in a DCI for scheduling a PUSCH. To support dynamic switching between a single TRP and two TRPs, each SRI field may also include a codepoint to indicate the corresponding SRS resource is not selected.
To support independent power control of PUSCH to each TRP, separate TPC commands may be included in a DCI for each TRP. The “TPC command for scheduled PUSCH” field in DCI 0_1 and DCI 0_2 may be extended from 2 bits to 4 bits, with 2 bits each for each TRP.
Uplink Control Information (UCI) such as Hybrid Automatic Repeat Request Acknowledgement (HARQ-Ack), CSI feedback, or scheduling request (SR) on a PUCCH resource may be present is a same slot as a PUSCH. In this case, the UCI is carried on the PUSCH (instead of the PUCCH). How to multiplex the UCI and the PUSCH is a problem.
In one embodiment, if two PUSCHs, each toward a different TRP, overlaps with the PUCCH in one or more symbols in a slot and that the PUCCH has a same spatial relation as one of the two PUSCHs, the UCI is transmitted on both of the PUSCHs to both TRPs. Alternatively, the UCI is only transmitted on the PUSCH that has a same spatial relation as the overlapped PUCCH.
If UE is provided ACKNACKFeedbackMode=JointFeedback, the UCI is transmitted on both PUSCHs if the PUCCH overlaps with the PUSCHs with at least one symbol.
In another embodiment, a higher layer configuration may be provided to UE that UE always multiplex the UCI on PUSCH regardless of the spatial relations.
Besides the “TPC command for scheduled PUSCH” mentioned above in the section “PUSCH Power Control”, one or several of the DCI bit fields in DCI format 0_1 and 0_2 may be extended to have more bits in an existing field (i.e., joint encoding for 2 TRPs) or to add a new field (for the second TRP) to support 2 PUSCH transmission to two TRPs:
Though the UE may switch between single TRP mode and multi-TRP mode based on indication in received DCI, the DCI fields for each format 0_1 and 0_2, as well as the size of each field shall be aligned. Either truncation or padding can be applied to align each DCI field size. For example, a number of most significant bits with value set to ‘0’ are inserted to smaller bit width (i.e., single TRP) until the bit width for single TRP and Multi-TRP are the same.
If the enabling of PUSCH multi-TRP is configured per CORESET or per SearchSpace, each DCI field size shall be aligned per CORESET or per SearchSpace, and the total DCI payload size for the same format shall be aligned across all the CORESETs and SearchSpaces.
Although the discussion above focused on simultaneous PUSCH transmissions (e.g., PUSCH1 and PUSCH2) to two TRPs for a same TB, the embodiments can be easily extended to different TBs (e.g., PUSCH1 carries TB1 while PUSCH2 carries TB2). In addition, single DCI based scheduling is discussed above for PUSCH transmission; however, the embodiments can be extended to multi-DCI based scheduling in which the PUSCH to each TRP is scheduled by a separate DCI.
Furthermore, one or more SRIs are used to indicate the PUSCH transmission directions in the embodiments described above. However, in another embodiment, UL TCI states may be used instead for indicating PUSCH transmission directions. For example, two UL TCI states may be signaled in a DCI to indicate a PUSCH transmission to two TRPs.
The wireless communication device 312 transmits one or more PUSCHs (e.g., the PUSCH(s) scheduled by the DCI of step 806) to TRP1 and TRP2 on a same time and frequency domain resource or on a same time domain resource but different frequency domain resources (step 808). As discussed above, each TRP is associated with a different reference signal. The transmission includes a first part that is transmitted to TRP1 (step 808-1) and a second part that is simultaneously transmitted to TRP2 (step 808-2). For example, the first part and the second part are different layers of the same PUSCH transmitted on the same time and frequency domain resources (see, e.g.,
The details described above regarding the DCI received by the wireless communication device 312 (e.g., the UE) to schedule a multi-TRP PUSCH transmission are applicable to the process of
In another embodiment, the two or more reference signals are two or more SRS resources, each configured with a respective spatial relation. In one embodiment, the DCI comprises one or more SRIs that indicate the two or more SRS resources. In one embodiment, each of the two or more SRS resources is associated with a respective reference signal through a spatial relation configuration. In one embodiment, the respective reference signal is an SSB, a NZP CSI-RS, or another SRS. In one embodiment, the two or more SRS resources are associated with two or more respective reference signals, and the two or more respective reference signals are associated with two or more respective cell IDs (i.e., each respective reference signal is associated with a different cell ID). In one embodiment, the two or more respective reference signals are two or more respective SSBs or two or more respective NZP CSI-RSs. In one embodiment, the two or more respective reference signals are associated with the two or more respective cell IDs via a field in a TCI state configuration. In one embodiment, the two or more respective reference signals are two or more respective SSBs, and the two or more reference signals are associated with the two or more respective cell IDs via SSB configuration.
In one embodiment, the wireless communication device 312 further receives, from a network node (e.g., TRP1 in this example), an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI, wherein association between an SRI and one or more pathloss reference signals and one or more sets of power control parameters is signaled to the wireless communication device. In this example, the indication of the pathloss reference signal and the set of power control parameters for each of the one or more PUSCHs is included in the DCI and, more specifically, is provided by the SRI(s). In other words, in one embodiment, the wireless communication device 312 receives information that defines, for each SRI of a set of SRIs, an association between the SRI and one or more pathloss reference signals and one or more sets of power control parameters (step 802). In other words, as described in the section entitled “PUSCH Power Control” above, the wireless communication device 312 may receive a configuration of a pathloss reference signal and a set of power control related parameters for each SRS resource (e.g., in the case of a single SRS resource set) or for each SRS resource set (e.g., in the case of two (or more) SRS resource sets). The wireless communication device 312 then receives an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRIs included in the DCI of step 806. In one embodiment, in step 808, the wireless communication device 312 transmits the one or more PUSCHs to the two or more TRPs in accordance the indicated set of power control parameters for each of the one or more PUSCHs.
In one embodiment, the two or more SRS resources belong to either a same SRS resource set or different SRS resource sets.
In one embodiment, the wireless communication device 312 receives, from a network node (e.g., TRP1 in this example), an indication to use either the SDM for multi-TRP PUSCH transmission or the FDM scheme for multi-TRP PUSCH transmission (step 804). In this case, in step 808, the wireless communication device 312 transmits the one or more PUSCHs to the TRPs on the same time and frequency domain resource if the received indication is an indication to use the SDM scheme for multi-TRP PUSCH transmission or on the same time domain resource but different frequency domain resources if the received indication is an indication to use the FDM scheme for multi-TRP PUSCH transmission.
In one example alternative embodiment, the one or more PUSCHs comprise two or more PUSCHs, and each PUSCH of the two or more PUSCHs is scheduled via a separate downlink control information.
In one embodiment, the TRPs to which the PUSCH(s) are simultaneously transmitted are indicated in the DCI through indication of two or more TCI states, wherein each TRP is associated with one TCI state.
The wireless communication device 312 receives DCI that schedules transmission of one or more PUSCHs to TRP1 900-1 and TRP2 900-2 (step 904A). In other words, the received DCI schedules a PUSCH transmission that includes a first part that is to be transmitted to TRP1 900-1 (e.g., and is therefore associated to a first SRS resource indicted in the DCI or a first TCI state) and a second part that is to be transmitted to TRP2 900-2 (e.g., and is therefore associated to a second SRS resource indicated in the DCI or a second TCI state). The DCI indicates two SRS resources (i.e., a first SRS resource and second SRS resource) from the single SRS resource set configured in step 902A. Indication of the first SRS resource in the DCI is also an indication of the corresponding pathloss RS and set of PUSCH power control related parameters that are associated to the first SRS resource. Likewise, the indication of the second SRS resource in the DCI is also an indication of the corresponding pathloss RS and set of PUSCH power control related parameters that are associated to the second SRS resource. Also, the first SRS resource is associated to TRP1 900-1 (or the first TCI state), and the second SRS resource is associated to TRP2 900-2 (or the second TCI state).
The wireless communication device 312 transmits the one or more PUSCHs in accordance with the DCI (step 906A). More specifically, the PUSCH transmission of step 906A includes the first part that is transmitted to TRP1 900-1 (e.g., transmitted using the first TCI state) using a transmit power that is calculated based on a pathloss estimated that is based on the pathloss reference signal associated to the first SRS resource indicated by the DCI (step 906A-1). The PUSCH transmission of step 906A also includes transmission of the second part to TRP2 900-2 (e.g., transmitted using the second TCI state) using a transmit power that is calculated based on a pathloss estimate that is based on the pathloss reference signal associated to the second SRS resource indicated by the DCI (step 906A-2). For example, the first part and the second part are different layers of the same PUSCH transmitted. As another example, the first part and the second part are different PUSCH transmissions of different RVs of the same TB.
As illustrated in
The wireless communication device 312 transmits the one or more PUSCHs in accordance with the DCI (step 906A). More specifically, the PUSCH transmission of step 906A includes the first part that is transmitted to TRP1 900-1 (e.g., transmitted using the first TCI state) using a transmit power that is calculated based on a pathloss estimated that is based on the pathloss reference signal associated to the first SRS resource indicated by the DCI (step 906A-1). The PUSCH transmission of step 906A also includes transmission of the second part to TRP2 900-2 (e.g., transmitted using the second TCI state) using a transmit power that is calculated based on a pathloss estimate that is based on the pathloss reference signal associated to the second SRS resource indicated by the DCI (step 906A-2). For example, the first part and the second part are different layers of the same PUSCH transmitted. As another example, the first part and the second part are different PUSCH transmissions of different RVs of the same TB.
As discussed above, the DCI of step 904A or 904B includes, in one embodiment, two SRI fields, one to indicate the SRS resource for each of the TRPs 900-1 and 900-2. In one embodiment, to support dynamic switching between a single TRP and two TRPs, each SRI field may also include a codepoint to indicate the corresponding SRS resource is not selected, as described above.
In one embodiment, to support independent power control of PUSCH to each TRP, separate TPC commands may be included in the DCI of step 904A or 904B for each of the TRPs 900-1 and 900-2, as described above. In one embodiment, the “TPC command for scheduled PUSCH” field in DCI 0_1 and DCI 0_2 may be extended from 2 bits to 4 bits, with 2 bits each for each TRP, as described above.
As used herein, a “virtualized” radio access node is an implementation of the radio access node 1000 in which at least a portion of the functionality of the radio access node 1000 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 1000 may include the control system 1002 and/or the one or more radio units 1010, as described above. The control system 1002 may be connected to the radio unit(s) 1010 via, for example, an optical cable or the like. The radio access node 1000 includes one or more processing nodes 1100 coupled to or included as part of a network(s) 1102. If present, the control system 1002 or the radio unit(s) are connected to the processing node(s) 1100 via the network 1102. Each processing node 1100 includes one or more processors 1104 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1106, and a network interface 1108.
In this example, functions 1110 of the radio access node 1000 described herein (e.g., one or more functions of a TRP) are implemented at the one or more processing nodes 1100 or distributed across the one or more processing nodes 1100 and the control system 1002 and/or the radio unit(s) 1010 in any desired manner. In some particular embodiments, some or all of the functions 1110 of the radio access node 1000 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1100. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1100 and the control system 1002 is used in order to carry out at least some of the desired functions 1110. Notably, in some embodiments, the control system 1002 may not be included, in which case the radio unit(s) 1010 communicate directly with the processing node(s) 1100 via an appropriate network interface(s).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 1000 or a node (e.g., a processing node 1100) implementing one or more of the functions 1110 of the radio access node 1000 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device 1300 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
With reference to
The telecommunication network 1500 is itself connected to a host computer 1516, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer 1516 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 1518 and 1520 between the telecommunication network 1500 and the host computer 1516 may extend directly from the core network 1504 to the host computer 1516 or may go via an optional intermediate network 1522. The intermediate network 1522 may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network 1522, if any, may be a backbone network or the Internet; in particular, the intermediate network 1522 may comprise two or more sub-networks (not shown).
The communication system of
Example implementations, in accordance with an embodiment, of the UE, base station, and host computer discussed in the preceding paragraphs will now be described with reference to
The communication system 1600 further includes a base station 1618 provided in a telecommunication system and comprising hardware 1620 enabling it to communicate with the host computer 1602 and with the UE 1614. The hardware 1620 may include a communication interface 1622 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1600, as well as a radio interface 1624 for setting up and maintaining at least a wireless connection 1626 with the UE 1614 located in a coverage area (not shown in
The communication system 1600 further includes the UE 1614 already referred to. The UE's 1614 hardware 1634 may include a radio interface 1636 configured to set up and maintain a wireless connection 1626 with a base station serving a coverage area in which the UE 1614 is currently located. The hardware 1634 of the UE 1614 further includes processing circuitry 1638, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE 1614 further comprises software 1640, which is stored in or accessible by the UE 1614 and executable by the processing circuitry 1638. The software 1640 includes a client application 1642. The client application 1642 may be operable to provide a service to a human or non-human user via the UE 1614, with the support of the host computer 1602. In the host computer 1602, the executing host application 1612 may communicate with the executing client application 1642 via the OTT connection 1616 terminating at the UE 1614 and the host computer 1602. In providing the service to the user, the client application 1642 may receive request data from the host application 1612 and provide user data in response to the request data. The OTT connection 1616 may transfer both the request data and the user data. The client application 1642 may interact with the user to generate the user data that it provides.
It is noted that the host computer 1602, the base station 1618, and the UE 1614 illustrated in
In
The wireless connection 1626 between the UE 1614 and the base station 1618 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1614 using the OTT connection 1616, in which the wireless connection 1626 forms the last segment.
A measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1616 between the host computer 1602 and the UE 1614, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1616 may be implemented in the software 1610 and the hardware 1604 of the host computer 1602 or in the software 1640 and the hardware 1634 of the UE 1614, or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1616 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software 1610, 1640 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1616 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station 1618, and it may be unknown or imperceptible to the base station 1618. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 1602's measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software 1610 and 1640 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1616 while it monitors propagation times, errors, etc.
Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.
While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).
Some example embodiments of the present disclosure are as follows:
Embodiment 1: A method performed by a wireless communication device for uplink transmission to a cellular communications network, the method comprising: transmitting (808) one or more Physical Uplink Shared Channels, PUSCHs, to two or more Transmission and Reception Points, TRPs, of a cellular communications network on a same time and frequency domain resource or on a same time domain resource but different frequency domain resources; wherein the two or more TRPs are associated with two or more different reference signals, respectively.
Embodiment 2: The method of embodiment 1 further comprising receiving (806), from a network node (e.g., one of the two or more TRPs), downlink control information that schedules transmission of the one or more PUSCHs.
Embodiment 3: The method of embodiments 1 and 2 wherein the downlink control information indicates the two or more reference signals.
Embodiment 4: The method of embodiments 1 to 3 wherein the two or more reference signals are two or more downlink reference signals each associated with a respective TCI state.
Embodiment 4a: The method of embodiment 4 wherein each of the two or more downlink reference signal is an SSB or a NZP CSI-RS.
Embodiment 5: The method of embodiments 1 to 3 wherein the two or more reference signals are two or more Sounding Reference Signal, SRS, resources, each configured with a respective spatial relation.
Embodiment 6: The method of embodiment 5 wherein the downlink control information comprises one or more SRS resource indicators, SRIs, that indicate the two or more SRS resources.
Embodiment 7: The method of embodiment 6 wherein each of the two or more SRS resources is associated with a respective reference signal through a spatial relation configuration.
Embodiment 8: The method of embodiment 7 wherein the respective reference signal is an SSB, a NZP CSI-RS, or another SRS.
Embodiment 9: The method of embodiment 6 wherein: the two or more SRS resources are associated with two or more respective reference signals; and the two or more respective reference signals are associated with two or more respective cell IDs (i.e., each respective reference signal is associated with a different cell ID).
Embodiment 10: The method of embodiment 9 wherein the two or more respective reference signals are two or more respective SSBs or two or more respective NZP CSI-RSs.
Embodiment 11: The method of embodiment 9 or 10 wherein the two or more respective reference signals are associated with the two or more respective cell IDs via a field in a TCI state configuration.
Embodiment 12: The method of embodiment 9 wherein the two or more respective reference signals are two or more respective SSBs, and the two or more reference signals are associated with the two or more respective cell IDs via SSB configuration.
Embodiment 13: The method of any one of embodiments 1 to 12 further comprising receiving (806) an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI or the one or more TCI state, wherein association between an SRI or a TCI state and one or more pathloss reference signals and one or more sets of power control parameters is signaled to the wireless communication device.
Embodiment 14: The method of any one of embodiments 6 to 12 further comprising: receiving (802) information that defines, for each SRI of a set of SRIs comprising the one or more SRIs or each TCI state of a set of TCI states comprising the one or more TCI state, an association between the SRI or the TCI state and one or more pathloss reference signals and one or more sets of power control parameters; and receiving (806) an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI or the one or more TCI state.
Embodiment 15: The method of embodiment 13 or 14 wherein transmitting (808) the one or more PUSCHs to the two or more TRPs comprises transmitting (808) the one or more PUSCHs to the two or more TRPs in accordance the indicated set of power control parameters for each of the one or more PUSCHs.
Embodiment 16: The method of any one of embodiments 5 to 15 wherein the two or more SRS resources belong to either a same SRS resource set or different SRS resource sets.
Embodiment 17: The method of any one of embodiments 1 to 16 further comprising receiving (804), from a network node (e.g., one of the two or more TRPs), an indication to use either a spatial division multiplexing scheme for multi-TRP PUSCH transmission or a frequency division multiplexing scheme for multi-TRP PUSCH transmission.
Embodiment 18: The method of embodiment 17 wherein transmitting (808) the one or more PUSCHs to the two or more TRPs comprises transmitting (808) the one or more PUSCHs to the two or more TRPs on the same time and frequency domain resource if the received indication is an indication to use the spatial division multiplexing scheme for multi-TRP PUSCH transmission or on the same time domain resource but different frequency domain resources if the received indication is an indication to use the frequency division multiplexing scheme for multi-TRP PUSCH transmission.
Embodiment 19: The method of embodiment 1 wherein the one or more PUSCHs comprise two or more PUSCHs, and each PUSCH of the two or more PUSCHs is scheduled via a separate downlink control information.
Embodiment 20: The method of any one of embodiments 1 to 19 wherein the two or more TRPs are indicated in the downlink control information through indication of two or more TCI states, or two or more SRS resources, wherein each TRP is associated with one TCI state or one SRS resource.
Embodiment 21: The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission of the one or more PUSCHs to the two or more TRPs.
Embodiment 22: A method performed by a Transmission and Reception Point, TRP, for a cellular communications network, the method comprising: Receiving (808-1) a first part of a multi-TRP Physical Uplink Shared Channel, PUSCH, from a wireless communication device, the multi-TRP PUSCH transmission comprising one or more PUSCHs to two or more TRPs of a cellular communications network on a same time and frequency domain resource or on a same time domain resource but different frequency domain resources; wherein the two or more TRPs are associated with two or more different reference signals, respectively.
Embodiment 23: The method of embodiment 22 further comprising transmitting (806), to the wireless communication device, downlink control information that schedules transmission of the one or more PUSCHs.
Embodiment 24: The method of embodiments 22 and 23 wherein the downlink control information indicates the two or more reference signals.
Embodiment 25: The method of embodiments 22 to 24 wherein the two or more reference signals are two or more downlink reference signals each associated with a respective TCI state.
Embodiment 26: The method of embodiments 22 to 24 wherein the two or more reference signals are two or more Sounding Reference Signal, SRS, resources, each configured with a respective spatial relation.
Embodiment 27: The method of embodiment 26 wherein the downlink control information comprises one or more SRS resource indicators, SRIs, that indicate the two or more SRS resources.
Embodiment 28: The method of embodiment 27 wherein each of the two or more SRS resources is associated with a respective reference signal through a spatial relation configuration.
Embodiment 29: The method of embodiment 28 wherein the respective reference signal is an SSB, a NZP CSI-RS, or another SRS.
Embodiment 30: The method of embodiment 27 wherein: the two or more SRS resources are associated with two or more respective reference signals; and the two or more respective reference signals are associated with two or more respective cell IDs (i.e., each respective reference signal is associated with a different cell ID).
Embodiment 31: The method of embodiment 30 wherein the two or more respective reference signals are two or more respective SSBs or two or more respective NZP CSI-RSs.
Embodiment 32: The method of embodiment 30 or 31 wherein the two or more respective reference signals are associated with the two or more respective cell IDs via a field in a TCI state configuration.
Embodiment 33: The method of embodiment 30 wherein the two or more respective reference signals are two or more respective SSBs, and the two or more reference signals are associated with the two or more respective cell IDs via SSB configuration.
Embodiment 34: The method of any one of embodiments 27 to 33 further comprising transmitting (806), to the wireless communication device, an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI, or one or more TCI state, wherein association between an SRI or a TCI state and one or more pathloss reference signals and one or more sets of power control parameters is signaled to the wireless communication device.
Embodiment 35: The method of any one of embodiments 27 to 33 further comprising: transmitting (802), to the wireless communication device, information that defines, for each SRI of a set of SRIs comprising the one or more SRIs or for each TCI state of a set of TCI states comprising the one or more TCI state, an association between the SRI or the TCI state and one or more pathloss reference signals and one or more sets of power control parameters; and transmitting (806), to the wireless communication device, an indication of a pathloss reference signal and a set of power control parameters for each of the one or more PUSCHs via the one or more SRI, or one or more TCI state.
Embodiment 36: The method of any one of embodiments 26 to 35 wherein the two or more SRS resources belong to either a same SRS resource set or different SRS resource sets.
Embodiment 37: The method of any one of embodiments 22 to 36 further comprising transmitting (804), to the wireless communication device, an indication to use either a spatial division multiplexing scheme for multi-TRP PUSCH transmission or a frequency division multiplexing scheme for multi-TRP PUSCH transmission.
Embodiment 38: The method of embodiment 22 wherein the one or more PUSCHs comprise two or more PUSCHs, and each PUSCH of the two or more PUSCHs is scheduled via a separate downlink control information.
Embodiment 39: The method of any one of embodiments 22 to 38 wherein the two or more TRPs are indicated in the downlink control information through indication of two or more TCI states, or two or more SRS resources, wherein each TRP is associated with one TCI state or one TCI state.
Embodiment 40: The method of any of the previous embodiments, further comprising: receiving user data from the wireless communication device via the first part of the multi-TRP PUSCH transmission; and forwarding the user data to a host computer.
Embodiment 41: A wireless communication device comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the wireless communication device.
Embodiment 42: A TRP comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; and power supply circuitry configured to supply power to the TRP.
Embodiment 43: A User Equipment, UE, comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.
Embodiment 44: A communication system including a host computer comprising: communication interface configured to receive user data originating from a multi-TRP PUSCH transmission from a User Equipment, UE, to two or more TRPs; wherein the UE comprises a radio interface and processing circuitry, the UE's processing circuitry configured to perform any of the steps of any of the Group A embodiments.
Embodiment 45: The communication system of the previous embodiment, further including the UE.
Embodiment 46: The communication system of the previous 2 embodiments, further including the two or more TRPs, wherein each of the two or more TRPs comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a respective part of the multi-TRP PUSCH transmission from the UE to the TRP.
Embodiment 47: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE's processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.
Embodiment 48: The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE's processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.
Embodiment 49: A method implemented in a communication system including a host computer, two or more TRPs, and a User Equipment, UE, the method comprising: at the host computer, receiving user data transmitted to the two or more TRPs from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.
Embodiment 50: The method of the previous embodiment, further comprising, at the UE, providing the user data to the two or more TRPs.
Embodiment 51: The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application.
Embodiment 52: The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application; wherein the user data to be transmitted is provided by the client application in response to the input data.
Embodiment 53: A communication system including a host computer comprising a communication interface configured to receive user data originating from a multi-TRP PUSCH transmission from a User Equipment, UE, to two or more TRPs, wherein each of the two or more TRPs comprises a radio interface and processing circuitry, the TRP's processing circuitry configured to perform any of the steps of any of the Group B embodiments.
Embodiment 54: The communication system of the previous embodiment further including the TRP.
Embodiment 55: The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the two or more TRPs.
Embodiment 56: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.
Embodiment 57: A method implemented in a communication system including a host computer, two or more TRPs, and a User Equipment, UE, the method comprising: at the host computer, receiving, from the two or more TRPs, user data originating from a multi-TRP PUSCH transmission which the two or more TRPs have received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.
Embodiment 58: The method of the previous embodiment, further comprising at the two or more TRPs, receiving the user data from the UE.
Embodiment 59: The method of the previous 2 embodiments, further comprising at the two or more TRPs, initiating a transmission of the received user data to the host computer.
Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.
This application claims the benefit of provisional patent application Ser. No. 63/011,707, filed Apr. 17, 2020, the disclosure of which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/053177 | 4/16/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63011707 | Apr 2020 | US |
