Method, apparatus and computer program

Abstract

There is provided a method performed by a user equipment, UE. The method comprises receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource. The method further comprises demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource, and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource. The method further comprising determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

Description

METHOD, APPARATUS AND COMPUTER PROGRAMTECHNICAL FIELD

[0001] Various examples of this disclosure relate to methods, apparatuses, and computer programs. In particular, methods, apparatuses, and computer programs for a communication network.BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0003] Such communication networks operate in accordance with standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards are the so-called 5G (5th Generation) standards provided by 3GPP.SUMMARY

[0004] Some examples of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the embodiments of this disclosure, nor are they intended to be used to limit the scope thereof. Other features, aspects, and elements will be readily apparent to a person skilled in the art in view of this disclosure. For example, it should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described below.

[0005] According to a first aspect, there is provided a method performed by a user equipment, UE, the method comprising: receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI , for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0006] According to a second aspect, there is provided a user equipment comprising: means for receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antennaports associated with the first RS resource; means for demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and means for determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0007] According to a third aspect, there is a user equipment comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform: receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0008] According to a fourth aspect, there is provided a user equipment comprising: circuitry configured to perform: receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0009] According to a fifth aspect, there is provided a computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform: receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0010] The following are applicable to each (e.g., one or more, including all) of the above first to fifth aspects.

[0011] In some examples, the demodulating of the at least one first physical channel and the determining of the CSI both utilise the first RS resource.

[0012] In some examples, the user equipment is further caused to perform: receiving, from the network entity, the first RS resource, wherein the first RS resource is utilised for the demodulating of the at least one first physical channel and the determining of the CSI.

[0013] In some examples, the CSI comprises at least one of the following: a precoding matrix indicator, PMI, a rank indicator, Rl, a channel quality indicator, CQI, a signal to noise plus interference ratio, SINR, a power of interference plus noise, or information related to interference.

[0014] In some examples, the user equipment is further caused to perform: transmitting, to the network entity, a CSI report comprising information associated with the CSI.

[0015] In some examples, the information associated with the CSI comprises information related to a PMI, wherein the PMI comprises a rotation matrix.

[0016] In some examples, the rotation matrix comprises at least one of the following: information related to a quantised angle, or information related to a layer-pair index.

[0017] In some examples, at least one antenna port of the second group is comprised in the first group of antenna ports.

[0018] In some examples, antenna ports of the first group and the second group do not overlap with each other.

[0019] In some examples, antenna ports of the first group and the second group are all different, such that the first group and the second group do not overlap.

[0020] In some examples, the determining of the CSI for the radio channel comprises: determining, based on the configuration, information related to interference for the radio channel utilising the second group of antenna ports associated with the first RS resource.

[0021] In some examples, the second group of antenna ports corresponds to antenna ports of at least one further user equipment, the at least one further user equipment and the user equipment being in the same cell.

[0022] In some examples, at least one of: the first group of antenna ports, or the second group of antenna ports, comprises antenna ports associated with at least one code division multiplexing, CDM, group of the first RS resource.

[0023] In some examples, the user equipment is further caused to perform: transmitting, to the network entity, sounding reference signals.

[0024] According to a sixth aspect, there is provided a method performed by a network entity, the method comprising: transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group ofantenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0025] According to a seventh aspect, there is provided a network entity comprising: means for transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; means for transmitting, to the UE, the first RS resource; and means for transmitting, to the UE, at least one first physical channel.

[0026] According to an eight aspect, there is provided a network entity comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the network entity to perform: transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0027] According to an ninth aspect, there is provided a network entity comprising: circuitry configured to perform: transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0028] According to an tenth aspect, there is provided a computer program comprising instructions, which when executed by a network entity, cause the network entity to perform: transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group ofantenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0029] The following are applicable to each (e.g., one or more, including all) of the above sixth to tenth aspects.

[0030] In some examples, the network entity is further caused to perform: receiving, from the UE, sounding reference signals.

[0031] In some examples, the network entity is further caused to perform: determining, based on the sounding reference signals, a precoding for the at least one first physical channel.

[0032] In some examples, the network entity is further caused to perform: receiving, from the UE, a CSI report comprising information associated with CSI determined by the UE.

[0033] In some examples, the network entity is further caused to perform: performing, based on the CSI report, an adjustment of the precoding for the at least one first physical channel.

[0034] In some examples, the network entity is further caused to perform: transmitting, to the UE, the first physical channel with the adjusted precoding.

[0035] In some examples, the network entity is further caused to perform: performing, based on the CSI report, a link adaptation related to the radio channel.

[0036] In some examples, the configuration indicates for the UE to demodulate a physical channel and determine CSI utilising the first RS resource.

[0037] In some examples, the CSI comprises at least one of the following: a precoding matrix indicator, PMI, a rank indicator, Rl, a channel quality indicator, CQI, a signal to noise plus interference ratio, SINR, a power of interference plus noise, or information related to interference.

[0038] In some examples, the information associated with the CSI comprises information related to a PMI, wherein the PMI comprises a rotation matrix.

[0039] In some examples, the rotation matrix comprises at least one of the following: information related to a quantised angle, or information related to a layer-pair index.

[0040] In some examples, at least one antenna port of the second group is comprised in the first group of antenna ports.

[0041] In some examples, antenna ports of the first group and the second group do not overlap with each other.

[0042] In some examples, antenna ports of the first group and the second group are all different, such that the first group and the second group do not overlap.

[0043] In some examples, the second group of antenna ports corresponds to antenna ports of at least one further UE, the at least one further UE and the UE being in the same cell.

[0044] In some examples, at least one of: the first group of antenna ports, or the second group of antenna ports, comprises antenna ports associated with at least one code division multiplexing, CDM, group of the first RS resource.

[0045] According to an eleventh aspect, there is provided a method performed by a user equipment, UE, the method comprising: receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; and determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0046] According to a twelfth aspect, there is provided a user equipment comprising: means for receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; means for demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and means for determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; and means for determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0047] According to a thirteenth aspect, there is provided a user equipment comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform: receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between theUE and the network entity utilising the second group of antenna ports associated with the first RS resource; and determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0048] According to a fourteenth aspect, there is provided a user equipment comprising: circuitry configured to perform: receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; and determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0049] According to a fifteenth aspect, there is provided a computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform: receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource; and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; and determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0050] The following are applicable to each (e.g., one or more, including all) of the above eleventh to fifteenth aspects.

[0051] In some examples, the demodulating of the at least one first physical channel and the determining of the CSI both utilise the first RS resource.

[0052] In some examples, the user equipment is further caused to perform: receiving, from the network entity, the first RS resource, wherein the first RS resource is utilised for the demodulating of the at least one first physical channel, the determining of the CSI, and the determining of the information related to interference.

[0053] In some examples, the CSI comprises at least one of the following: a precoding matrix indicator, PMI, a rank indicator, Rl, a channel quality indicator, CQI, a signal to noise plusinterference ratio, SINR, a power of interference plus noise, or information related to interference.

[0054] In some examples, the user equipment is further caused to perform: transmitting, to the network entity, a CSI report comprising information associated with at least one of: the CSI, and the information related to interference.

[0055] In some examples, the information associated with the CSI comprises information related to a PMI, wherein the PMI comprises a rotation matrix.

[0056] In some examples, the rotation matrix comprises at least one of the following: information related to a quantised angle, or information related to a layer-pair index.

[0057] In some examples, at least one antenna port of the second group is comprised in the first group of antenna ports.

[0058] In some examples, antenna ports of the first group and the third group do not overlap with each other.

[0059] In some examples, antenna ports of the first group and the third group are all different, such that the first group and the second group do not overlap.

[0060] In some examples, the determining of the CSI for the radio channel comprises: determining, based on the configuration, further information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0061] In some examples, the third group of antenna ports corresponds to antenna ports of at least one further user equipment, the at least one further user equipment and the user equipment being in the same cell.

[0062] In some examples, at least one of: the first group of antenna ports, the second group of antenna ports, or the third group of antenna ports, comprises antenna ports associated with at least one code division multiplexing, CDM, group of the first RS resource.

[0063] According to a sixteenth aspect, there is provided a method performed by a network entity, the method comprising: transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0064] According to a seventeenth aspect, there is provided a network entity comprising: means for transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource; means for transmitting, to the UE, the first RS resource; and means for transmitting, to the UE, at least one first physical channel.

[0065] According to an eighteenth aspect, there is provided a network entity comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the network entity to perform: transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0066] According to a nineteenth aspect, there is provided a network entity comprising: circuitry configured to perform: transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0067] According to a twentieth aspect, there is provided a computer program comprising instructions, which when executed by a network entity, cause the network entity to perform:

[0068] transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource; transmitting, to the UE, the first RS resource; and transmitting, to the UE, at least one first physical channel.

[0069] The following are applicable to each (e.g., one or more, including all) of the above sixteenth to twentieth aspects.

[0070] In some examples, the network entity is further caused to perform: receiving, from the UE, sounding reference signals.

[0071] In some examples, the network entity is further caused to perform: determining, based on the sounding reference signals, a precoding for the at least one first physical channel.

[0072] In some examples, the network entity is further caused to perform: receiving, from the UE, a CSI report comprising information associated with CSI determined by the UE.

[0073] In some examples, the network entity is further caused to perform: performing, based on the CSI report, an adjustment of the precoding for the at least one first physical channel.

[0074] In some examples, the network entity is further caused to perform: transmitting, to the UE, the first physical channel with the adjusted precoding.

[0075] In some examples, the network entity is further caused to perform: performing, based on the CSI report, a link adaptation related to the radio channel.

[0076] In some examples, the configuration indicates for the UE to demodulate a physical channel, determine CSI, and determine information related to interference utilising the first RS resource.

[0077] In some examples, the CSI comprises at least one of the following: a precoding matrix indicator, PMI, a rank indicator, Rl, a channel quality indicator, CQI, a signal to noise plus interference ratio, SINR, a power of interference plus noise, or information related to interference.

[0078] In some examples, the information associated with the CSI comprises information related to a PMI, wherein the PMI comprises a rotation matrix.

[0079] In some examples, the rotation matrix comprises at least one of the following: information related to a quantised angle, or information related to a layer-pair index.

[0080] In some examples, at least one antenna port of the second group is comprised in the first group of antenna ports.

[0081] In some examples, antenna ports of the first group and the third group do not overlap with each other.

[0082] In some examples, antenna ports of the first group and the third group are all different, such that the first group and the third group do not overlap.

[0083] In some examples, the third group of antenna ports corresponds to antenna ports of at least one further UE, the at least one further UE and the UE being in the same cell.

[0084] In some examples, at least one of: the first group of antenna ports, or the second group of antenna ports, comprises antenna ports associated with at least one code division multiplexing, CDM, group of the first RS resource.

[0085] A computer product stored on a medium may cause an apparatus to perform the methods as described herein.

[0086] A non-transitory computer readable medium comprising program instructions, that, when executed by an apparatus, cause the apparatus to perform the methods as described herein.

[0087] An electronic device may comprise apparatus as described herein.

[0088] Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.

[0089] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

[0090] List of Abbreviations:AN: Access NetworkBS: Base StationCSI: Channel state informationCSI-RS: CSI reference signalCN: Core NetworkCRI: CSI-RS resource indicatorDL: DownlinkDMRS: Demodulation reference signaleNB: eNodeBEPRE: Energy per resource elementFL: Front loadedgNB: gNodeBLI: Layer indicatorLTE: Long Term EvolutionNG-RAN: Next Generation Radio Access NetworkNF: Network FunctionNR: New RadioNW: NetworkNZP-CSI-RS: Non-zero power CSI-RSOFDM: Orthogonal frequency division multiplexPLMN: Public Land Mobile NetworkPMI: Precoding matrix indicatorPTRS: Phase tracking reference signalPUSCH: Physical uplink shared channelRAN: Radio Access NetworkRE: Resource elementRl: Rank indicatorRF: Radio FrequencyRS: Reference signalSRS: Sounding RSSSBRI: Synchronisation signal block resource indicatorUE: User EquipmentUL: Uplink3GPP: 3rdGeneration Partnership Project5G: 5thGeneration5GC: 5G Core network5G-AN: 5G Radio Access Network5GS: 5G SystemBRIEF DESCRIPTION OF DRAWINGS

[0091] Some examples will now be described, by way of illustrative and non-limiting example only, with reference to the accompanying drawings in which:

[0092] FIG. 1 shows a schematic representation of a 5G communication system;

[0093] FIG. 2 shows a schematic representation of an apparatus for the 5G communication system of FIG. 1 ;

[0094] FIG. 3 shows a schematic representation of a communication device;

[0095] FIG. 4 shows a schematic representation of a communication system for channel state information acquisition and reporting;

[0096] FIG. 5 shows an example signalling and operations diagram between a user equipment and network entity for physical channel demodulation and channel state information acquisition and reporting;

[0097] FIG. 6 shows an example method flow diagram performed by an apparatus;

[0098] FIG. 7 shows another example method flow diagram performed by an apparatus;

[0099] FIG. 8 shows another example method flow diagram performed by an apparatus;

[0100] FIG. 9 shows another example method flow diagram performed by an apparatus; and

[0101] FIG. 10 shows a schematic representation of an apparatus.DETAILED DESCRIPTION

[0102] Reference signals (RSs) play an important role in many communication systems, such as in 4G and 5G (also called New Radio (NR)) systems, and are expected to be equally important in 6G systems. RSs are predefined signals that may occupy specific resource elements (REs) within a time-frequency grid. RSs may be used for a number of different reasons, such as for channel estimation, or for tracking time / frequency. In 5G systems, in order to increase protocol efficiency, and to keep transmissions contained within a slot / beam there are defined a plurality of different types of RSs, including a demodulation reference signal (DMRS), a phase tracking reference signal (PTRS), a sounding reference signal (SRS), and a non-zero power channel state information reference signal (NZP-CSI-RS, or simply ‘CSI-RS’).

[0103] DMRS is used by a receiver for radio channel estimation and for demodulation of an associated physical channel. DMRS design and mapping is specific to each downlink and uplink channel in 5G, such as physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH), and physical uplink control channel (PUCCH). DMRS is UE-specific and is transmitted on demand. DMRS may be beamformed / precoded and kept within a scheduled resource. Multiple orthogonal DMRS antenna ports can be allocated in frequency and time domains to support multiple input multiple output (MIMO) transmission. In 5G systems, front loaded (FL) DRMS is used for faster and efficient demodulation, which is achieved by including the DMRS in the first symbol of a physical channel slot. Orthogonality is achieved by CDM (Code Division Multiplexing) by cyclic shifting of the base sequence. In current systems, for a physical layer channel that carries data, there is an associated DMRS for demodulating the data.

[0104] An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. In this manner, an antenna port is an abstract concept that is a logical entity rather than a physical antenna. Stated differently, a receiver can assume that two transmissions correspond to the same radio channel if they use the same antenna port. In practice, each antenna port (e.g., for a downlink transmission) corresponds to a specific reference signal. The UE receiver assumes that this reference signal can be used to estimate the channel corresponding to specific antenna port. The reference signals can also be used by the UE to derive channel state information related to the antenna port.

[0105] As depicted in FIG. 4, in 5G systems, in order to determine channel state information, a gNodeB (gNB) transmits downlink (DL) RSs such as CSI-RS / NZP-CSI-RS to a UE, for the UE to measure the radio channel and signal to interference plus noise ratio (SINR) / signal to noise ratio (SNR). In some instances, noise variance in a channel is determined for channel estimation, based on received CSI-RS, which is termed SNR. In other instances, CSI-IM is also used. CSI-IM resources are a set of specific resource elements that are reserved for interference measurement. When CSI-IM resources are utilised, then interference is also measured, such that SINR is determined. The UE uses the measurements for CSI acquisition of parameters such as rank index (Rl), a precoding matrix indicator (PMI), and channel quality indicator (CQI). These parameters may be reported back to the gNB as the UE’s recommendation on the number of layers to transmit, precoder, and modulation and coding scheme (MCS) to maximize link capacity. The gNB may use this information to adapt the PDSCH transmission configuration, ensuring that the connection is maintained despite changes in the instantaneous link conditions.

[0106] At S401 of FIG.4, the gNB transmits CSI-RS to the UE. At S402, based on the received CSI-RS, the UE determines values for CSI parameters (i.e., CSI acquisition). At S403, the UE transmits a CSI report to the gNB, wherein the CSI report comprises one or more CSI parameters. At S404, based on the CSI report, the gNB performs link adaptation according to the CSI parameters. At S405, the gNB performs a physical downlink shared channel (PDSCH) transmission to the UE.

[0107] The gNB may request reporting on different combinations of CSI parameters (which are often referred to as ‘CSI reporting quantities’) to the UE. A request is communicated to the UE through higher layer radio resource control (RRC) signalling (CSI-ReportConfig), where one of the most common reporting quantities is “cri-RI-LI-PMI-CQI”. With this reporting quantity the UE is expected to report on CRI (CSI Resource Indicator), Rl, LI (Layer Indicator), PMI and CQI. While there are dependencies between these parameters, the exact implementation to select them may vary for each UE vendor.

[0108] If there are multiple CSI-RS resources, the UE will select, as CRI, the best resource, which is typically based on the received signal strength of all the CSI-RS resources. The UE obtains the channel estimation and SINR levels in that (NZP) CSI-RS resource to select the best number of layers v that maximize link capacity, given by Rl. Based on v , the UE will select the best precoder matrix, indicated by PMI, Pe cWpxv, where y is the total number of CSI-RS antenna ports and v is the number of layers indicated by Rl. For that combination of CRI, Rl and PMI, the UE calculates the SINR level per MIMO layer and chooses one CQI value to maximize capacity throughout the layers for a target block error rate (BLER), such as 0.1 (10%). This information is used to select the column (or layer) in the precoding matrix belonging to the strongest layer of the codeword, indicated by LI (Layer Indicator).

[0109] For CQI calculation, the SINR levels may be, as an example, mapped to tabled CQI index values, associated with a modulation scheme, code rate and efficiency. For example, there are 16 different CQI indexes per CQI table, and there are 4 distinct CQI tables defined in 3GPP TS 38.214 to support different scenarios of channel conditions and system configurations. Each CQI table has a corresponding MCS table and the gNodeB may use the CQI index to choose the appropriate MCS value for a codeword. MCS selection by the gNB is also based on MCS tables, like the CQI selection procedure.

[0110] If the channel conditions are favourable, a higher CQI index will be selected by the UE and fed back by the UE to the gNB. This will likely lead to a higher MCS index being selected for the codeword by the gNB for the PDSCH transmission. Conversely, if the channel conditions deteriorate and the SINR levels drop, the reported CQI index will be lower, and the gNB will opt for a lower MCS index for that codeword. However, the gNB is free to choose an MCS index that differs from the recommended by the UE due to other factors such as traffic load, service requirements or any other aspect that requires optimization in the network.

[0111] In the 5G NR CSI framework, there is a separation between reference signals for CSI acquisition and reference signals for demodulation of physical channels, such that measurements of CSI quantities are performed on single or multiple CSI-RS resource set(s), or synchronisation signal blocks (SSB) resource set(s). This distinction was inherited from later releases of LTE. In the first release of LTE, which was primarily a frequency divisional duplex (FDD) system, where cell-specific downlink (DL) reference signals where initially intended for both channel acquisition and data demodulation by a UE and were transmitted periodically. This assumption restricted the network to use spatial precoding or beamforming from a finite codebook of precoding options known to the UEs. When this restricted precoding was removed in subsequent LTE releases, UE-specific reference signals were introduced to enable demodulation of data signals whose precoding, in both spatial and frequency domain is unknown to the UE.

[0112] In 5G NR, which operates at higher frequencies with time division duplexing (TDD) with larger transmit arrays, use cases have emerged that justify the need for UE-specific CSI-RS for measurement and reporting of CSI quantities. An example is for the network to obtain Rl and CQI measurements from a UE, based on precoding determined by the network from sounding reference signal (SRS) estimation which exploits full channel reciprocity. FDD requires two separate wireless communications channels on separate frequencies, one for transmit and the other for received data. TDD uses a single frequency band for both transmit and receive. Then it shares that band by assigning alternating time slots to transmit and receive operations.

[0113] A CSI report without PMI (e.g., with report quantities 'cri-RI-CQI') may be configured such that the precoding of the CSI-RS ports in spatial and frequency domains is a network implementation. In such an instance, the NW configures the link / correspondence between CSI-RS ports and physical channel layers. The precoder assumed by a UE in such a CQI measurement is a port-selection precoder following the network configuration for the mapping of CSI-RS antenna ports to layers of an assumed transmission rank. Another example is when only partial UL-DL reciprocity can be assumed and the network estimates the dominant angles and delays from SRS, but the fast-fading components of the channel are not reciprocal. In this case, a UE is configured to report PMI as well as Rl and CQI, where the PMI for each layer is formed by a linear combination of ports.

[0114] In current 5G NR specifications, cell-specific and UE-specific or UE-group-specific CSI-RS, are not distinct from each other because they are configured in the same way for a UE. However, a problem associated with UE-specific CSI-RS is that new CSI-RS resources need to be allocated for every new UE, which means that the resource utilization for reference signalling increases with the number of UEs. Typically, the use of UE-specific RS signals is limited to a small number of users in a cell, whereas all the remaining users are configured with cell-specific RS. Hence, for a gNB adopting UE-specific CSI-RS, typically periodic CSI-RS are transmitted alongside aperiodic / semi-persistent CSI-RS as well as DMRS, which leads to significant physical resource occupation. One way to mitigate this problem is to use aperiodic or semi-persistent CSI-RS resources, which are triggered / activated when CSI reporting is needed from a UE. On the other hand, using periodic cell-specific CSI-RS for CSI reporting (e.g., of Rl and CQI) in TDD operation is suboptimal because of the mismatch between the UE-calculated PMI and the precoder calculated by the gNB based on SRS measurements.

[0115] In TDD systems, a base station (e.g., gNB) that is able to calculate DL precoding from sounding reference signal (SRS) estimation, benefits from CSI reporting by the UE for better link adaptation. Link adaptation, e.g., in 5G networks, refers to the process of adjustingtransmission parameters, such as a modulation and coding scheme (MCS), or transmit power, in order to optimize a communication link / radio channel between the gNodeB and a UE. A goal of link adaptation is to maximize spectral efficiency, throughput, and reliability while adapting to changing channel conditions and user requirements. CSI measurements may be considered to be more accurate or most useful when the CSI measurements are based on UE-specific CSI-RS. With UE-specific RS, a UE measures the reference signals precoded by weights calculated by the gNB (e.g., based on SRS transmitted by the UE). A limit of this closed-loop-based link adaptation based on UE-specific reference signalling is the large resource utilization required to accommodate different reference signals for each UE in a cell.

[0116] In FDD systems, a base station (e.g., gNB) obtains DL precoding based on CSI reporting from UEs from CSI-RS based DL channel acquisition. However, CSI such as Rl and CQI are determined based on transmission hypothesis rather than based on an actual PDSCH signal. These hypothesis includes assumptions that the PDSCH signals are precoded by the reported PMI (i.e., the PMI reported by the UE to the gNB) and the transmit power on the PDSCH layers is as configured in the CSI-RS resource power control offset. In practice, the PDSCH precoder may be different than the one reported by the UE. For example, the PDSCH precoder may be different if zero-forcing (ZF) was applied by the gNB, and / or in case of MU-MIMO transmission. The transmit power may also be different because of the power back-off applied by the gNB and other transmit power balancing / optimisation techniques.

[0117] One or more of the following examples aim to address one or more of the problems identified above.

[0118] In examples, there is a method performed by a UE. The method comprises receiving, from a network entity (e.g., a gNB), a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource. The method further comprises demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource, and determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0119] In examples, there is a method performed by a UE. The method comprises receiving, from a network entity (e.g., a gNB), a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource. The method further comprises demodulating, based on the configuration, atleast one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource. The method further comprises determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource and determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource

[0120] In this manner, the measuring and reporting of CSI updates, such as a CSI report including at least one of PMI, Rl, CQI quantities, based on an RS measurement improves link adaptation, reduces the complexity of the CSI calculation (as the measurement is based on fewer antenna ports than those configured for full DL channel acquisition), and reduces feedback overhead.

[0121] These examples will be described in more detail below, alongside FIGS. 5 to 10.

[0122] Before explaining the examples above in greater detail, an example communication device, such as a UE (as shown in FIG. 3) that is capable of receiving and processing reference signals (e.g., for CSI acquisition and / or demodulation) will be described. The communication device is part of a communication system (as shown in FIG. 1). The communication device is able to communicate with one or more of the entities of the communication system (as shown in FIG. 1 ) via an apparatus (as shown in FIG. 2), which may be part of / comprised in a base station. As described above, a base station and communication device may communicate with each other, such that the base station is able to transmit reference signals to the UE, which the UE may utilise for CSI acquisition and / or channel demodulation.

[0123] Certain general aspects of the communication system and the communication device are briefly explained with reference to FIGS. 1 to 3 to assist in understanding the technology underlying the described examples.

[0124] FIG. 1 shows a schematic representation of a 5G communication system 100. In this manner, FIG. 1 illustrates an example of a communication network to which examples disclosed herein may be applied. The communication network or a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell may define a coverage area or a service area of the corresponding access node.

[0125] The network node 110 may provide a user equipment (UE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink(DL) communication from the network node to the UE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment.

[0126] There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different network nodes 110, 112. UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-called sidelink (SL). Such D2D communications may be referred to as machine-to-machine, peer-to-peer (P2P) communications, or vehicle-to-vehicle (V2V), for example.

[0127] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications call such an interface as X2 interface. An interface between an LTE node and a 5G node, or between two 5G nodes may be called Xn interface.

[0128] The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise e.g. a mobility management entity (MME) and a gateway node. The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signalling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to / from the terminal devices. The 5G specifications specify the core network as a 5G core (5GC). The 5G core may comprise e.g. an access and mobility management function (AMF) and a user plane function / gateway (UPF) and other functions. The AMF may handle termination of non-access stratum (NAS) signalling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node may support packet routing and forwarding, packet inspection and quality of service (QoS) handling, for example.

[0129] FIG. 2 illustrates an example of an apparatus 200. The apparatus 200 may be for the 5G communication system of FIG. 1. The apparatus 200 may be for controlling a function of one or more network entities and / or network functions, such as the entities of the 5G-RAN or the 5GC as illustrated on FIG. 1. The apparatus 200 comprises at least one random accessmemory (RAM) 211a, at least one read only memory (ROM) 211b, at least one processor 212, 213 and an input / output interface 214. The at least one processor 212, 213 is coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects or examples. The software code 215 may be stored in the ROM 211b. The apparatus 200 may be interconnected with another apparatus 200 controlling another entity / function of the 5G-AN or the 5GC. . In some examples, apparatus 200 may be configured to provide one or more functions of the 5G-AN or the 5GC. For example, apparatus 200 may be configured to perform at least some functionality of a particular function of the 5G-AN or the 5GC. For example, apparatus 200 may be configured to operate as a particular function of the 5G-AN or the 5GC. In alternative examples, apparatus 200 may be configured to perform at least some functionality of two or more functions of the 5G-AN and / or the 5GC. For example, apparatus 200 may be configured to operate as two or more functions of the 5G-AN and / or the 5GC. The apparatus 200 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

[0130] FIG. 3 illustrates an example of a communication device 300. The communication device 300 may be similar to the communication device 102 illustrated in FIG. 1. The communication device 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples of a communication device 300 are a user equipment, a terminal, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device, or a terrestrial / maritime / aerial vehicle such as a car, a truck, a boat, an air plane, or a drone, or any combinations of these or the like. The communication device 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

[0131] The communication device 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In FIG. 3, a transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0132] The communication device 300 may be provided with at least one processor 301 , at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a. The communication device 300 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

[0133] The processor, storage and other relevant control apparatus may be provided on an appropriate circuit board and / or in chipsets. This feature is denoted by reference 304. The communication device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device.

[0134] In examples, a reference signal (resource) that is transmitted by a base station to a user equipment is used by the user equipment for both physical channel reception (e.g., a PDSCH) and for CSI acquisition / reporting. In this manner, it may be considered that there is a unified design for reference signalling to be used for demodulation and CSI acquisition, rather than having two separate types of RS resources.

[0135] FIG. 5 shows an example signalling and operations diagram between a user equipment and network entity for physical channel demodulation and channel state information acquisition and reporting. In the example of FIG. 5, the network entity is a base station (e.g., a gNB).

[0136] At S501 , the UE transmits, to the gNB, sounding reference signals (SRS). The SRS Tx may be for antenna switching.

[0137] At S502, the gNB receives the SRS. Based on the SRS, the gNB determines precoding information for a physical channel. In this example, the physical channel is a physical downlink shared channel (PDSCH). In other examples, the physical channel may be any other DL physical channel, e.g., a physical downlink control channel.

[0138] At S503, the gNB transmits, to the UE, a configuration that indicates a first group of antenna ports associated with a first RS resource, and indicates a second group of antenna ports associated with the first RS resource. In this manner, the same RS resource is associated with both the first group and second group of antenna ports.

[0139] In some examples, the configuration further indicates a third group of antenna ports associated with the first RS resource.

[0140] Each of the first, second and third groups have at least one antenna port comprised within / associated with the respective group. In some examples, one or more of the groups have a single antenna port. In some examples, one or more of the groups have a plurality of antenna ports. In other examples, other suitable language is used to describe the ‘group’, such as, for example, ‘set’, or ‘cluster’. These terms may be used interchangeably.

[0141] The first group of antenna ports may be indicated for DL physical channel reception / demodulation. The second group of antenna ports (from the same RS resource) may be indicated for the measuring and reporting of CSI measurements, e.g., at least one of: CQI, Rl, PMI, SINR, interference measurements, or “nulling matrix indicator”. A nulling matrix indicator is a quantity that provides at least one spatial domain vector. The spatial domain vectors of a nulling matrix indicator may be similar to a PMI, but rather than being used to precode a UE’s own DL data signals (i.e. , the PMI), a nulling matrix indicator may be intended to precode signals for interfering UEs (e.g., in MU-MIMO transmission). When configured, the third group of antenna ports (from the same RS resource) may be indicated for the measuring and reporting of CSI measurements (e.g., CQI, Rl, PMI, SINR, interference measurements, nulling matrix indicator).

[0142] The first RS resource may be a DMRS resource, in some examples. In other examples, the first RS resource is another type of RS resource. It should be understood that any suitable type of RS may be utilized as the first RS resource.

[0143] At S504, the gNB transmits, to the UE, a DL physical channel (e.g., PDSCH). The gNB transmits, to the UE, the first RS resource. Stated differently, the gNB transmits the PDSCH and the first RS to the UE.

[0144] At S505, the UE receives the first RS (resource) and the PDSCH. Based on the configuration, the UE demodulates the PDSCH utilising (or based on) the first group of antenna ports. Based on the configuration, the UE determines CSI utilising (or based on) the second group of antenna ports. The UE performs the demodulation of the PDSCH and the determination of the CSI utilising the first RS (i.e., the same RS resource is used for demodulation and determination of CSI).

[0145] For example, the CSI may comprise at least one of the following: a precoding matrix indicator, PMI, a rank index, Rl, a channel quality indicator, CQI, a signal to noise plus interference ratio, SINR, or information related to interference.

[0146] In some examples, when configured, the UE also determines, based on the configuration, information related to interference for the radio channel between the UE and network entity utilising (or based on) the third group of antenna ports associated with the first RS resource. For example, the UE may demodulate a PDSCH based on the first group of antenna ports, determine CSI (e.g., PMI) based on the second group of antenna ports, and determine interference information based on the third group of antenna ports.

[0147] In some examples, the first group of antenna ports and the second group of antenna ports are the same. Stated differently, the antenna port(s) comprised in the first group is the same as the antenna port(s) comprised in the second group. For example, first group = AP1 , AP3, and second group = AP1 , AP3. It may be said that the first group of antenna ports and the second group of antenna ports overlap each other. When the second group of antenna ports is the same as the first group, the UE may measure CSI (e.g., Rl, CQI, PMI, etc.) on the antenna ports of the second group by assuming that the PDSCH transmission for v layers (i.e., Rl=v) corresponds to signals transmitted on the first v ports of the second group of antenna ports.

[0148] In some examples, additionally, the UE may calculate a PMI based on the second group of antenna ports. For example, the PMI may be selected from a codebook of rotation matrices, e.g., formed by orthogonal and unit-norm vectors, of size v x v for a rank-v assumption and applied to the first v ports of the second group of antenna ports. Reason for refining a precoder matrix by applying a rotation matrix is discussed in more detail below.

[0149] In some examples, the second group of antenna ports is used to measure information related to interference. For example, the information related to interference may comprise at least one of the following: power of interference plus noise, null matrix indicator, SINR, etc. The interference being measured may be from co-scheduled UEs, e.g., in multi-user MIMO (MU-MIMO) transmission. When being used to measure information related to interference, the second group of antenna ports may not overlap with the first group of antenna ports. The second group of antenna ports may correspond to (or be associated with) antenna ports (e.g., layers) of other UEs in the same cell (as of the cell of the UE). For example, first group = AP1 , AP3, and second group = AP2, AP4.

[0150] Power of interference plus noise refers to the combined power level of both interfering signals (e.g., from other sources) and the background noise present in a system. In this manner, the power of interference plus noise essentially represents the total unwanted signal power that competes with the desired signal in a channel. Power of interference plus noise may be denoted as "I + N" where "I" is the interference power and "N" is the noise power. Power of interference plus noise is used to determine a signal-to-interference-plus-noise ratio(SINR). SINR is calculated by dividing the power of the desired signal by the combined power of interference and noise.

[0151] In some examples, the third group of antenna ports may be indicated for measuring information about interference (which may be referred to as ‘interference measurement’). The second group of antenna ports may overlap (at least partially) with the first group of antenna ports, wherein the second group of antenna ports is used to measure the channel precoded by the PDSCH layers. For example, first group = AP1 , AP3, and second group = AP1 , AP4 (at least one antenna port in comprised in both the first and second groups). In some examples, the second group of antenna ports is used to measure CSI. The third group of antenna ports, corresponding to the layers of co-scheduled UEs, may be used to measure interference. For example, Rl and CQI may be determined, at the UE, by accounting for the interference generated by co-scheduled UEs. In this manner, the UE determines CSI based on: i) the measurements performed utilising the second group of antenna ports, and ii) the interference measurements performed utilising the third group of antenna ports.

[0152] In some examples, at least one of: the first group of antenna ports, the second group of antenna ports, or the third group of antenna ports, comprises antenna ports associated with at least one code division multiplexing, CDM, group of the first RS resource. A CDM group refers to a set of users / UEs or signals that share the same frequency band simultaneously using code division multiple access (CDMA) technology. CDM is a form of multiplexing that allows multiple users to share the same frequency band by assigning a unique code to each user. In this context, a CDM group would comprise multiple users or signals that are multiplexed together using this technique.

[0153] At S506, the UE generates a CSI report, wherein the CSI report comprises information related to the CSI (determined in S505). For example, the CSI report may indicate at least one of: PMI, CQI, SINR, interference measurements, etc.

[0154] The UE transmits, to the network entity, the CSI report (also termed a ‘report for CSI’).

[0155] At S507, the network entity receives the CSI report. Based on the CSI report, the network entity may perform an adjustment of the precoding for a physical channel transmission (e.g., adjusting the precoding determined in S502). Based on the CSI report, the network entity may perform a link adaptation. For example, the network entity may adapt, e.g., an MCS or transmit power, for the radio channel between the UE and the network entity. In some examples, the network entity adjusts the precoding and performs the link adaptation.

[0156] It should be understood that in other examples, one or more of the steps of FIG. 5 may not be performed or may be performed in a different order.

[0157] As discussed above, in some examples, PMI may be selected from a codebook of rotation matrices. A reason for refining a precoder matrix by applying a rotation matrix, also referred to (in algebraic terms) as a ‘unitary matrix’ or a ‘square orthonormal matrix’, is that interference is not reciprocal and the gNB cannot estimate DL interference from UL SRS. Due to this, a UE may want to steer the SRS-based precoding vectors away from beamforming directions where there is strong interference. The beamforming directions with the strongest gains may need to be adjusted due to the implementation of the UE-receiver and channel variations in time. These refinement PMI matrices may be defined differently than in current systems. In current systems, Type-I PMIs are formed by vectors that are orthogonal between layers. For example, a rank-2 PMI, where both layers are transmitted on a spatial-domain (SD) beam represented by a vector, v, is formed by applying co-phasing across polarizations:W = WtW2of size PCSI-RSXwith v = 2, where the wideband SD beam matrix is=-0 0 V0V °1l and the subband co-p Mhasing » matrix < << {1,7} and PCSI-RS is the number of ports per polarization of a CSI-RS resource.

[0158] Type-ll PMIs in current systems, on the other hand, are not orthogonal in general, because they are expressed in the form: W =are formed by orthogonal SD-basis and frequency-domain (FD)-basis vectors, respectively, but W2contains quantized non-zero coefficients.

[0159] Conversely, a DMRS-based PMI refinement matrix per sub-band may be defined as the combination of one or more rotations. For example, in case of a rank-3 refinement PMI with a single rotation between the first and second DM-RS ports, the PMI matrix is given by cos 012-sin 012WR=fii2. where R12= sin012cos 012. In general, for multiple rotations, the DMRS- . 0 0based refinement PMI may be given by:is a matrix introducing a rotation between the precoder of layer I and j. In some examples, a port-selection codebook is used by a UE to report a PMI refinement, whereby the UE updates the precoder for a layer by a linear combination of the DMRS ports.

[0160] In one or more of the examples described above, there is the advantage of a reduction in the amount / number of resources allocated for reference signals by avoiding transmission of UE-specific CSI-RS. Stated differently, there is a reduction in reference signal overhead. A further advantage is a reduced latency in providing CSI updates because some CSI quantities are measured from the same reference signal that is also used for receiving DL data. Thismeans that a UE does not need to wait for the next transmission occasion of a different reference signal dedicated to CSI measurement. Another advantage is the increased accuracy in calculating such CSI quantities as Rl, CQI, interference power etc., because they can be measured on the actual precoded layers going through the DL channel and in the presence of other interfering layers, rather than by assuming the UE-reported PMI and no interfering layers. The UE-specific CSI-RS may be precoded by the network based on weights calculated by the network from SRS estimation. The network (e.g., gNB) transmits (only) cell-specific CSI-RS / DMRS. As described above, these two types of RS signal (i.e., CSI-RS and DMRS) may be combined as a single RS resource, wherein the distinction between CSI-RS ports and DM-RS ports is indicated by the gNB in a configuration provided to the UE. Stated differently, as UE-specific CSI-RS for CSI acquisition may be a duplication of DMRS, measuring (at least some) CSI quantities on DMRS leads to a significant saving in reference signalling overhead which frees up resources for data transmission.

[0161] For example, DMRS antenna ports (i.e., antenna ports for DMRS) are the antenna ports used for receiving PDSCH and are included in the first group of antenna ports. ‘Cellspecific’ CSI-RS antenna ports (i.e., antenna ports for CSI-RS that are specific to the cell) for channel measurement may be antenna ports configured in the second group of ports that are not comprised in the first group of ports. ‘UE-specific’ CSI-RS antenna ports (i.e., antenna ports for CSI-RS that are specific to the UE) for channel measurement may be antenna ports configured in the second group of antenna ports that are also comprised in the first group of antenna ports. NZP-CSI-RS antenna ports (i.e., antenna ports for NZP-CSI-RS) for interference measurement may be antenna ports configured in the second or third group of antenna ports that are not comprised in the first group of antenna ports.

[0162] In this manner, this allows the gNB to receive accurate CSI (e.g., CQI and Rl) indications based on measurements of the (radio) channel that has been precoded by SRS-based precoding determined by the gNB. When PMI is included in the CSI report, this allows the gNB to receive PMI that may be used as a refinement of the SRS-based precoding. An example of such a PMI (herein referred to as a ‘refinement PMI’) may a rotation matrix or a co-phasing matrix, WR, of size v x v, for a rank-v transmission hypothesis, calculated and reported by a UE. The gNB may use this refinement PMI to refine the precoding matrix W of size PCSI-RSX V> used to pre-code the DMRS ports indicated to receive the PDSCH. The updated PMI used by the gNB may be given by: W -> WWR. The precoding matrix W is calculated by the gNB and is not known to the UE. The precoding matrix W may be calculated from SRS estimation of DL channel and obtained by applying, for example, zero-forcing (ZF) or other precoding solutions. Reporting a precoder refinement by a UE is justified by the fact that SRS estimation may accurately estimate the vector space associated with the dominant angles (e.g., dominant channel eigenvectors), but the fast-fading components may be refinedby UE measurements. In this example, when the refinement rotation matrix for a rank-3COS 012- sin01201hypothesis (v = 3) is given by WR= R12= sin 012cos 012, the PMI may be reported0 0 1Jby indicating a pair of DMRS ports (e.g., layers where the rotation applies) and the quantised angle 012. The pair of DMRS ports may be indicated by an index associated to one of the possible pairs, whose number is ). This means that the index bitwidth is log2)] . For example, for a single rotation in a rank-3 hypotheses, by quantising the angle with 3 bits, a total of 5 bits would be sufficient to report a refinement rotation matrix WR. This rotation matrix may be reported per sub-band or per group of sub-bands, or as a wideband indication.

[0163] FIG. 6 shows an example method flow performed by an apparatus. The apparatus may be a user equipment, or other communication device. The apparatus may be comprised within a user equipment, or other communication device. The apparatus may comprise one or more means for performing the method of FIG. 6. For example, the one or more means may comprise: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform the method of FIG. 6. For example, the one or more means may comprise circuitry configured to perform the method of FIG. 6.

[0164] In S601 , the method comprises: receiving, from a network entity, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource.

[0165] In S602, the method comprises: demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource.

[0166] In S603, the method comprises: determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0167] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 6 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 6 detailed above may not be performed, or may be performed in a different order.

[0168] FIG. 7 shows an example method flow performed by an apparatus. The apparatus may be a network entity, such as a base station, gNB, etc. The apparatus may be comprised within a network entity. The apparatus may comprise one or more means for performing the method of FIG. 7. For example, the one or more means may comprise: at least one processor, and at least one memory storing instructions that, when executed by the at leastone processor, cause the apparatus to perform the method of FIG. 7. For example, the one or more means may comprise circuitry configured to perform the method of FIG. 7.

[0169] In S701 , the method comprises: transmitting, to a user equipment, UE, a configuration that indicates a first group of antenna ports associated with a first reference signal, RS, resource, and indicates a second group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, and indicates for the UE to determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0170] In S702, the method comprises: transmitting, to the UE, the first RS resource.

[0171] In S703, the method comprises: transmitting, to the UE, at least one first physical channel

[0172] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 7 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 7 detailed above may not be performed, or may be performed in a different order.

[0173] FIG. 8 shows an example method flow performed by an apparatus. The apparatus may be a user equipment, or other communication device. The apparatus may be comprised within a user equipment, or other communication device. The apparatus may comprise one or more means for performing the method of FIG. 8. For example, the one or more means may comprise: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform the method of FIG. 8. For example, the one or more means may comprise circuitry configured to perform the method of FIG. 8.

[0174] In S801 , the method comprises: receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource.

[0175] In S802, the method comprises: demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource.

[0176] In S803, the method comprises: determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource.

[0177] In S804, the method comprises: determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0178] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 8 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 8 detailed above may not be performed, or may be performed in a different order.

[0179] FIG. 9 shows an example method flow performed by an apparatus. The apparatus may be a network entity, such as a base station, gNB, etc. The apparatus may be comprised within a network entity. The apparatus may comprise one or more means for performing the method of FIG. 9. For example, the one or more means may comprise: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform the method of FIG. 9. For example, the one or more means may comprise circuitry configured to perform the method of FIG. 9.

[0180] In S901 , the method comprises: transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

[0181] In S902, the method comprises: transmitting, to the UE, the first RS resource.

[0182] In S903, the method comprises: transmitting, to the UE, at least one first physical channel.

[0183] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 9 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 9 detailed above may not be performed, or may be performed in a different order.

[0184] FIG. 10 shows a schematic representation of an apparatus. FIG. 10 shows, by way of example, a block diagram of an apparatus 10. The apparatus 10 comprises, for example, at least one processor 12 and at least one memory 14 storing instructions 15 that, when executed by the at least one processor, cause the apparatus 10 at least to perform the method or methods as disclosed herein, and any of the embodiments thereof. In an example, the at least one memory and the instructions (e.g. a computer program code, software), are configured, with the at least one processor, to cause the apparatus 10 to perform the method or methods as disclosed herein, and any of the embodiments thereof.

[0185] A processor 12 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with example embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (I) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a user equipment, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0186] The memory 14 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 14 may be at least in part external to apparatus 10 but accessible to apparatus 10.

[0187] The instructions 15 may be comprised in a computer readable medium or a non-transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. random access memory, RAM, vs. read only memory, ROM).

[0188] For example, the apparatus 10 is a terminal device, such as the UE associated with FIG. 5. In another example, the apparatus 10 is comprised in such a UE, e.g. as a chipset configured to control the UE. The apparatus 10 may be caused or configured to perform at least the method of FIG. 6 or FIG. 8 and / or any one or more of the examples described herein.

[0189] As another example, the apparatus 10 is a network entity, e.g. the gNB associated with FIG. 5. In another example, the apparatus 10 is comprised in such a network entity, e.g. as a chipset configured to control the network entity. The apparatus 10 may be caused or configured to perform at least the method of FIG. 7 or FIG. 9 and / or any one or more of the examples described herein.

[0190] The apparatus 10 comprises a radio interface 16. The radio interface 16 may provide the apparatus 10 with communication capabilities. The radio interface 16 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 16 may comprise a transmitter configured to transmit information in accordance with at least one cellular or non-cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio interface 16 may comprise a transceiver configured to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0191] The apparatus 10 may comprise a user interface 18 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 18 may be used to control the apparatus by the user. The user interface 18 may be external to the apparatus 10. For example, the apparatus 10 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 10 is controlled by the user via the computer.

[0192] In an embodiment, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and / or hardware components of the apparatus 10. For example, the at least one processor 12, the memory 14, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the embodiments thereof. As used herein the term “means” is to be construed in singular form, i.e. referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology “means for [performing A, B, C]”, is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0193] The examples may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by acontroller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as nonlimiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0194] The examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

[0195] The term “non-transitory”, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. RAM vs ROM).

[0196] As used herein, “at least one of the following:” and “at least one of: ” and similar wording, where the list of two or more elements are joined by “and”, or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0197] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

[0198] As used herein, the terms “means for”, “means for performing operations including”, “means configured to perform operations including”, or “means configured to perform” (or similar) may be any means that are suitable for performing the feature(s). The “means” may be configured to perform one or more of the functions and / or method steps previously described. For example, the “means” may include one or more of: at least one processor, atleast one memory, transceiver circuitry, antenna circuitry, etc. It should be understood that these are provided as non-limiting examples.

[0199] Alternatively, or additionally some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and / or method steps previously described. That circuitry may be provided in the base station and / or in the communications device.

[0200] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analogue and / or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0201] This definition of circuitry applies to uses of the term “means” in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example integrated device. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

[0202] The foregoing description has provided byway of exemplary and non-limiting examples a full and informative description of some embodiments. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

CLAIMS1 . A user equipment, UE, comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to perform:receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource; demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource;determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; anddetermining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

2. The user equipment according to claim 1 , wherein the UE is further caused to perform:receiving, from the network entity, the first RS resource, wherein the first RS resource is utilised for the demodulating of the at least one first physical channel, the determining of the CSI, and the determining of the information related to interference.

3. The user equipment according to claim 1 or claim 2, wherein the CSI comprises at least one of the following: a precoding matrix indicator, PMI, a rank indicator, Rl, a channel quality indicator, CQI, a signal to noise plus interference ratio, SINR, a power of interference plus noise, or information related to interference.

4. The user equipment according to any one of claims 1 to 3, wherein the UE is further caused to perform:transmitting, to the network entity, a CSI report comprising information associated with at least one of: the CSI, and the information related to interference.

5. The user equipment according to claim 4, wherein the information associated with the CSI comprises information related to a PMI, wherein the PMI comprises a rotation matrix.

6. The user equipment according to claim 5, wherein the rotation matrix comprises at least one of the following: information related to a quantised angle, or information related to a layer-pair index.

7. The user equipment according to any one of claims 1 to 6, wherein at least one antenna port of the second group is comprised in the first group of antenna ports.

8. The user equipment according to any one of claims 1 to 6, wherein antenna ports of the first group and the third group do not overlap with each other.

9. The user equipment according to any one of claims 1 to 8, wherein the determining of the CSI for the radio channel comprises:determining, based on the configuration, further information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

10. The user equipment according to any one of claims 1 to 9, wherein the third group of antenna ports corresponds to antenna ports of at least one further UE, the at least one further UE and the UE being in the same cell.

11. A network entity comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the network entity to perform:transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource, wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource;transmitting, to the UE, the first RS resource; andtransmitting, to the UE, at least one first physical channel.

12. The network entity according to claim 11 , wherein the network entity is further caused to perform:receiving, from the UE, sounding reference signals.

13. The network entity according to claim 12, wherein the network entity is further caused to perform:determining, based on the sounding reference signals, a precoding for the at least one first physical channel.

14. The network entity according to any one of claims 11 to 13, wherein the network entity is further caused to perform:receiving, from the UE, a CSI report comprising information associated with CSI determined by the UE.

15. The network entity according to claim 14, wherein the network entity is further caused to perform:performing, based on the CSI report, an adjustment of the precoding for the at least one first physical channel.

16. The network entity according to claim 15, wherein the network entity is further caused to perform:transmitting, to the UE, the first physical channel with the adjusted precoding.

17. The network entity according to any one of claims 14 to 16, wherein the network entity is further caused to perform:performing, based on the CSI report, a link adaptation related to the radio channel.

18. The network entity according to any one of claims 11 to 17, wherein the configuration indicates for the UE to demodulate a physical channel and determine CSI utilising the first RS resource.

19. A method performed by a user equipment, UE, the method comprising:receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource;demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource;determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; anddetermining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

20. A user equipment comprising:means for receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource;means for demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource;means for determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; andmeans for determining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

21. A network entity comprising:means for transmitting, to a user equipment, UE, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource,wherein the configuration indicates for the UE to: demodulate a physical channel utilising the first group of antenna ports associated with the first RS resource, determine channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource, and determining information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource;means for transmitting, to the UE, the first RS resource; andmeans for transmitting, to the UE, at least one first physical channel.

22. A computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform:receiving, from a network entity, a configuration that indicates: a first group of antenna ports associated with a first reference signal, RS, resource, a second group of antenna ports associated with the first RS resource, and a third group of antenna ports associated with the first RS resource;demodulating, based on the configuration, at least one first physical channel received from the network entity utilising the first group of antenna ports associated with the first RS resource;determining, based on the configuration, channel state information, CSI, for a radio channel between the UE and the network entity utilising the second group of antenna ports associated with the first RS resource; anddetermining, based on the configuration, information related to interference for the radio channel utilising the third group of antenna ports associated with the first RS resource.

Images