Antenna settings for uplink and downlink transmissions

Abstract

Embodiments of the invention relate to adaptation of uplink antenna settings for a client device (100). The client device (100) transmits uplink reference signals (510) in a set of uplink antenna settings (120) to a network access node (300) and receives an uplink antenna setting indication (512) from the network access node (300). The uplink antenna setting indication (512) indicates an uplink antenna setting in the set of uplink antenna settings (120) of the client device (100). Based on the received uplink antenna setting indication (512), the client device (100) determines an uplink antenna setting for an uplink transmission (514) to the network access node (300). Furthermore, embodiments of the invention also relate to the network access node (300) for adaptation of downlink antenna settings, corresponding methods and a computer program.

Description

[0001] ANTENNA SETTINGS FOR UPLINK AND DOWNLINK TRANSMISSIONS

[0002] TECHNICAL FIELD

[0003] Embodiments of the invention relate to a client device for determining an uplink antenna setting for an uplink transmission to a network access node and a network access node for determining a downlink antenna setting for downlink transmissions to client devices. Furthermore, embodiments of the invention also relate to corresponding methods and a computer program.

[0004] BACKGROUND

[0005] Multiple-input multiple-output (MIMO) is a primordial technology in 3GPP 5G new radio (NR). Depending on the utilized beamforming techniques and procedures, multi-antenna transmissions can be leveraged at the client device and / or network access node to increase coverage, improve capacity, throughput and reliability, among others. Multi-antenna communication is especially critical in higher frequency ranges to combat the detrimental effects of excessive pathloss and consequently to guarantee coverage.

[0006] Hence, during the specification work for 5G NR, several study items and work items focused on methods and procedures to leverage the great potential of multi-antenna and multi-panel based transmission techniques, in both uplink and downlink. This includes features such as, channel state information (CSI) reporting, beam management, beam failure recovery, machine learning-based beam management, and uplink precoder selection, among others.

[0007] 5G NR supports different layer 1 and layer 2 procedures to acquire and maintain precoders and beams, at the client device and / or the network access node. This includes receive (Rx) / transmit (Tx) beams, uplink precoders, downlink frequency selective and wideband precoders. For beam management, in higher frequency ranges, different procedures are defined for downlink beam, uplink beam and beam failure detection and recovery. For downlink beam management, the client device can measure downlink reference signals transmitted with different Tx beams at the network access nodes to support selection of downlink Tx / Rx beams, to change Tx beams of the network access nodes and to change the Rx beams of the client device. In case of downlink reference signal measurements for beam management, the client device can report, in a CSI report, a number of downlink reference signal resource indicators and corresponding beam quality quantities, such as e.g., reference signal received power (RSRP) and / or signal to interference noise ratio (SINR). Additionally, if configured accordingly, group-based beam management is supported, for multi-network access node scenarios.

[0008] SUMMARY

[0009] An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

[0010] Another objective of embodiments of the invention is to provide a solution for exploiting the advantages of dynamic antenna settings in transmissions between a client device and a network access node.

[0011] The above and further objectives are solved by the subject matter of the independent claims. Further embodiments of the invention can be found in the dependent claims.

[0012] According to a first aspect of the invention, the above mentioned and other objectives are achieved with a client device configured to: transmit uplink reference signals in a set of uplink antenna settings to a network access node, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings; receive an uplink antenna setting indication from the network access node, the uplink antenna setting indication indicating an uplink antenna setting in the set of uplink antenna settings of the client device; and determine an uplink antenna setting for an uplink transmission to the network access node based on the received uplink antenna setting indication.

[0013] An advantage of the client device according to the first aspect is that the client device can determine an uplink antenna setting for an uplink transmission so that the achievable performance for the uplink transmission is optimized. For a client device equipped with multiple antennas, having different possible antenna settings, selecting an antenna setting for an uplink transmission would define, among other parameters, the propagation conditions in which the uplink transmission is performed. For example, when the possible antenna settings are different slant angles for antenna polarization at the client device, selecting an antenna setting, i.e., a polarization slant angle, would impact, among others, fast fading coefficients and antenna field patterns. Subsequently, by basing the antenna setting selection on an uplink antenna setting indication, the client device can perform its uplink transmissions in optimized radio propagation conditions.

[0014] In an implementation form of a client device according to the first aspect, the client device is further configured to: transmit the uplink reference signals in the set of uplink antenna settings and in a set of uplink beams, wherein at least one uplink reference signal is transmitted in each uplink beam in the set of uplink beams of the client device.

[0015] An advantage with this implementation form is that the sounding and selection of uplink antenna settings can be performed based on a dedicated procedure or jointly with beam management and precoder selection procedures. Thus, adapting the polarization of the client device antennas could simplify subsequent precoding and render beamforming more suitable for power amplifiers by reducing amplitude tapping.

[0016] In an implementation form of a client device according to the first aspect, any two uplink antenna settings in the set of uplink antenna settings differs from each other in least: a polarization, a number of antenna elements, a position of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens.

[0017] An advantage with this implementation form is that the proposed solution supports client devices having reconfigurable antennas with one or multiple possible configurations impacting the radio channel and antenna radiation patterns. Different degrees of freedom can be supported depending on the antenna technology and client device radio frequency front end implementation.

[0018] In an implementation form of a client device according to the first aspect, the uplink antenna setting indication is indicated as a bitmap or as a combinatorial indicator.

[0019] An advantage with this implementation form is that different possible formats for the uplink antenna setting indication may be supported. The indication can be conveyed as part of dynamic downlink signaling, e.g., Downlink Control Information (DCI) or Medium Access Control (MAC) Control Element (CE). Additionally, the uplink antenna setting indication may be conveyed as part of Radio Resource Control (RRC) signaling.

[0020] In an implementation form of a client device according to the first aspect, the uplink antenna setting indication further indicates at least one channel quality associated with the set of uplink antenna settings of the client device. An advantage with this implementation form is that the client device may be supporting different links / carriers at the same time. Thus, by having channel quality associated with the set of uplink antenna settings, as part of uplink antenna setting indication, would enable the client device to select antenna settings that can support all active links / carriers, depending on the client device capabilities.

[0021] In an implementation form of a client device according to the first aspect, the channel quality is any of: a RSRP, a SINR, a difference or a gap in RSRP between different uplink antenna settings, and a difference or a gap in SINR between different uplink antenna settings.

[0022] An advantage with this implementation form is that the client device may be supporting different links / carriers at the same time. The client device can select antenna settings that can support all active links / carriers, depending on the client device capabilities. The RSRP, SINR, difference or gap in RSRP between different uplink antenna settings, and difference or gap in SINR between different uplink antenna settings, can be used by the client device as input for its algorithm or model that selects uplink antenna settings for its transmissions over all its active links / carriers. Alternatively, these channel qualities can be used as input for training, inference or monitoring of a beam and / or antenna setting prediction machine learning model.

[0023] In an implementation form of a client device according to the first aspect, the client device is further configured to: determine the uplink antenna setting for the uplink transmission further based on measurements of downlink reference signals received from the network access node.

[0024] An advantage with this implementation form is that the client device can select its uplink antenna setting based on downlink reference signal measurements, consequently avoiding costly uplink reference signals transmissions. In different Time Division Duplex (TDD) or Frequency Division Duplex (FDD) scenarios, at least partial channel reciprocity can be assumed. Consequently, selecting an optimal uplink antenna setting for an uplink transmission can be based on an optimal client device antenna setting for a downlink reception.

[0025] In an implementation form of a client device according to the first aspect, the client device is further configured to: transmit an uplink antenna setting switching indication to the network access node, the uplink antenna setting switching indication indicating that the client device supports dynamic switching of uplink antenna settings; and receive a downlink antenna setting switching indication from the network access node, the downlink antenna setting switching indication indicating that the network access node supports dynamic switching of downlink antenna settings.

[0026] An advantage with this implementation form is that client devices with different capabilities are supported. Indeed, depending on the client device capabilities none or multiple of different possible antenna settings may be supported. The transmitted uplink antenna setting switching indication would convey to the network access node, the different supported antenna settings that the client device supports, e.g., number of supported antenna polarization angles / types, number of different antenna elements activation patterns, orientations, number of possible settings for electromagnetic properties of a metamaterial antenna and / or a radio frequency lens.

[0027] In an implementation form of a client device according to the first aspect, the uplink antenna setting switching indication and / or the downlink antenna setting switching indication is a radio resource control message.

[0028] An advantage with this implementation form is that the uplink antenna setting switching indication and / or the downlink antenna setting switching indication can be transmitted during RRC configuration, reconfiguration or other messages during an initial access procedure. In an implementation form of a client device according to the first aspect, the client device is further configured to: receive an uplink antenna setting management resource configuration from the network access node, the uplink antenna setting management resource configuration indicating the uplink reference signals.

[0029] An advantage with this implementation form is that the behavior for reference signal transmission for uplink antenna setting management is configured by the network thereby avoiding any ambiguities. The resources used to convey the uplink antenna setting indication can be also configured by the network, in addition to the period in which uplink antenna setting is managed / switched.

[0030] In an implementation form of a client device according to the first aspect, the client device is further configured to: receive an uplink and / or a downlink antenna setting-aware transmission configuration indicator from the network access node; and determine the uplink antenna setting for the uplink transmission further based on the uplink and / or the downlink antenna setting-aware transmission configuration indicator.

[0031] An advantage with this implementation form is that antenna setting diversity can be utilized by dynamic indication of the uplink and / or a downlink antenna setting for each of the uplink and / or downlink channels transmissions.

[0032] In an implementation form of a client device according to the first aspect, the client device is further configured to: measure downlink reference signals received in a set of downlink antenna settings from the network access node, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings of the network access node; determine channel qualities for each downlink antenna setting in the set of downlink antenna settings of the network access node; select a subset of downlink antenna settings among the set of downlink antenna settings of the network access node based on the determined channel qualities; and transmit a downlink antenna setting indication to the network access node, the downlink antenna setting indication indicating the selected subset of downlink antenna settings and their associated channel qualities.

[0033] The associated channel qualities may e.g., relate to a RSRP, a SINR, a difference or a gap in RSRP between different downlink antenna settings, and a difference or a gap in SINR between different downlink antenna settings.

[0034] An advantage with this implementation form is that downlink reference signal measurements are used to a subset of downlink antenna settings, which are perceived by the client device as offering the best radio propagation conditions.

[0035] In an implementation form of a client device according to the first aspect, the client device is further configured to: perform the uplink transmission to the network access node in the determined uplink antenna setting; and / or perform a reception of a downlink transmission from the network access node in a downlink antenna setting associated with the determined uplink antenna setting.

[0036] An advantage with this implementation form is that antenna setting diversity can be utilized in order to improve achievable performance. By selecting an antenna setting that was determined as offering the best channel conditions for transmission of uplink channels and / or reception of downlink channels, the client device can improve the achievable uplink and downlink key performance indicators (KPIs). According to a second aspect of the invention, the above mentioned and other objectives are achieved with a network access node configured to: transmit downlink reference signals in a set of downlink antenna settings to client devices, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings of the network access node; receive a set of downlink antenna setting indications from the client devices, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings of the network access node; and determine a downlink antenna setting for downlink transmissions to the client devices based on the set of received downlink antenna indications.

[0037] An advantage of the network access node according to the second aspect is that the network access node can determine an antenna setting for transmitting downlink channels and receiving uplink transmissions from one or multiple client devices, based on downlink antenna setting indications from the client devices. Since the network access node is providing coverage for multiple client devices, its antenna settings may be set so that KPIs of all client devices are taken into consideration. It is up to implementation to define a proper procedure for the determination of the antenna setting at the network access node. The antenna setting that the network access node is using for transmission of a downlink channel and / or reception of an uplink channel may be conveyed to the client device in an uplink and / or a downlink antenna setting-aware transmission configuration indicator.

[0038] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: transmit the downlink reference signals in the set of downlink antenna settings and in a set of downlink beams, wherein at least one downlink reference signal is transmitted in each downlink beam in the set of downlink beams of the network access node.

[0039] An advantage with this implementation form is that the sounding and selection of downlink antenna settings can be performed based on a dedicated procedure or jointly with beam management and precoder selection procedures. Thus, adapting the polarization of the network access node antennas could simplify subsequent precoding and render beamforming more suitable for power amplifiers by reducing amplitude tapping.

[0040] In an implementation form of a network access node according to the second aspect, any two downlink antenna settings in the set of downlink antenna settings differs from each other in least: a polarization, a number of antenna elements, a position of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens.

[0041] An advantage with this implementation form is that the proposed solution supports network access nodes having reconfigurable antennas with one or multiple possible configurations impacting the radio channel and antenna radiation patterns. Different degrees of freedom can be supported, depending on the antenna technology and network access node radio frequency front end implementation.

[0042] In an implementation form of a network access node according to the second aspect, the downlink antenna setting indication is indicated as a bitmap or as a combinatorial indicator. An advantage with this implementation form is that different possible formats for the downlink antenna setting indication may be supported. The indication can be conveyed as part of dynamic downlink signaling, e.g., DCI or MAC CE. Additionally, the uplink antenna setting indication may be conveyed as part of RRC signaling.

[0043] In an implementation form of a network access node according to the second aspect, the downlink antenna setting indication further indicates at least one channel quality associated with the set of downlink antenna settings of the network access node.

[0044] An advantage with this implementation form is that the network access node may be supporting different links / carriers at the same time. Thus, by having channel quality associated with the set of downlink antenna settings, as part of downlink antenna setting indication, would enable the network access node to select antenna settings that can support all active links / carriers, depending on the capabilities of the network access node.

[0045] In an implementation form of a network access node according to the second aspect, the channel quality is any of: a RSRP, a SINR, a difference or a gap in RSRP between different uplink antenna settings, and a difference or a gap in SINR between different uplink antenna settings.

[0046] An advantage with this implementation form is that the network access node may be supporting different links / carriers at the same time. The network access node can select antenna settings that can support all active links / carriers, depending on the capabilities of the network access node. The RSRP, SINR, difference or gap in RSRP between different downlink antenna settings, and difference or gap in SINR between different downlink antenna settings, can be used by the network access node as input for its algorithm or model that selects downlink antenna settings for its transmissions over all its active links / carriers. Alternatively, these channel qualities can be used as input for training, inference or monitoring of a beam and / or antenna setting prediction machine learning model.

[0047] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: determine the downlink antenna setting for the downlink transmission further based on measurements of uplink reference signals received from the client devices.

[0048] An advantage with this implementation form is that the network access node can select its downlink antenna setting based on uplink reference signal measurements, consequently avoiding costly uplink reference signals transmissions. In different Time Division Duplex (TDD) or Frequency Division Duplex (FDD) scenarios, at least partial channel reciprocity can be assumed. Consequently, selecting an optimal downlink antenna setting for a downlink transmission can be based on an optimal network access node antenna setting for an uplink reception.

[0049] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: receive a set of uplink antenna setting switching indications from the client devices, each uplink antenna setting switching indication indicating that a client device supports dynamic switching of uplink antenna settings; and transmit a set of downlink antenna setting switching indications to the client devices, each downlink antenna setting switching indication indicating that the network access node supports dynamic switching of downlink antenna settings.

[0050] An advantage with this implementation form is that client devices with different capabilities are supported. Indeed, depending on the client device capabilities none or multiple of different possible antenna settings may be supported. The transmitted uplink antenna setting switching indication would convey to the network access node, the different supported antenna settings that the client device supports, e.g., number of supported antenna polarization angles / types, number of different antenna elements activation patterns, orientations, number of possible settings for electromagnetic properties of a metamaterial antenna and / or a radio frequency lens.

[0051] In an implementation form of a network access node according to the second aspect, the uplink antenna setting switching indication and / or the downlink antenna setting switching indication is a RRC message.

[0052] An advantage with this implementation form is that the uplink antenna setting switching indication and / or the downlink antenna setting switching indication can be transmitted during RRC configuration, reconfiguration or other messages during an initial access procedure.

[0053] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: transmit a set of uplink antenna setting management resource configurations to the client devices, each uplink antenna setting management resource configuration indicating uplink reference signals to be transmitted by a client device.

[0054] An advantage with this implementation form is that the behavior for reference signal transmission for uplink antenna setting management is configured by the network thereby avoiding any ambiguities. The resources used to convey the uplink antenna setting indication can be also configured by the network, in addition to the period in which uplink antenna setting is managed / switched.

[0055] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: transmit uplink and / or downlink antenna setting-aware transmission configuration indicators to the client devices.

[0056] An advantage with this implementation form is that antenna setting diversity can be utilized by dynamic indication of the uplink and / or a downlink antenna setting for each of the uplink and / or downlink channels transmissions.

[0057] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: determine the downlink antenna setting for the downlink transmission to the client devices further based on the transmitted uplink and / or the downlink antenna setting-aware transmission configuration indicators.

[0058] An advantage with this implementation form is that antenna setting diversity can be utilized by dynamic indication of the uplink and / or a downlink antenna setting for each of the uplink and / or downlink channels transmissions.

[0059] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: measure uplink reference signals received in a set of uplink antenna settings from a client device, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings of the client device; determine channel qualities for each uplink antenna setting in the set of uplink antenna settings of the client device; select an uplink antenna setting among the set of uplink antenna settings of the client device based on the determined channel qualities; and transmit an uplink antenna setting indication to the client device, the uplink antenna setting indication indicating the selected uplink antenna setting. An advantage with this implementation form is that uplink reference signal measurements are used to a subset of uplink antenna settings, which are perceived by the network access node as offering the best radio propagation conditions.

[0060] In an implementation form of a network access node according to the second aspect, the network access node is further configured to: perform the downlink transmission to the client devices in the determined downlink antenna setting; and / or perform a reception of an uplink transmission from a client device in an uplink antenna setting associated with the determined downlink antenna setting.

[0061] An advantage with this implementation form is that antenna setting diversity can be utilized in order to improve achievable performance. By selecting an antenna setting that was determined as offering the best channel conditions for transmission of uplink channels and / or reception of downlink channels, the network access node can improve the achievable uplink and downlink KPIs.

[0062] According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a client device, the method comprises: transmitting uplink reference signals in a set of uplink antenna settings to a network access node, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings; receiving an uplink antenna setting indication from the network access node, the uplink antenna setting indication indicating an uplink antenna setting in the set of uplink antenna settings of the client device; and determining an uplink antenna setting for an uplink transmission to the network access node based on the received uplink antenna setting indication.

[0063] The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the client device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the client device.

[0064] The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the client device according to the first aspect.

[0065] According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a network access node, the method comprises: transmitting downlink reference signals in a set of downlink antenna settings to client devices, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings of the network access node; receiving a set of downlink antenna setting indications from the client devices, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings of the network access node; and determining a downlink antenna setting for downlink transmissions to the client devices based on the set of received downlink antenna indications.

[0066] The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the network access node according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the network access node. The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the network access node according to the second aspect.

[0067] Embodiments of the invention also relate to a computer program, characterized in program code, which when run by at least one processor causes the at least one processor to execute any method according to embodiments of the invention. Further, embodiments of the invention also relate to a computer program product comprising a computer readable medium and the mentioned computer program, wherein the computer program is included in the computer readable medium, and may comprises one or more from the group of: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.

[0068] Further applications and advantages of embodiments of the invention will be apparent from the following detailed description.

[0069] BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

[0071] - Fig. 1 shows a client device according to an embodiment of the invention;

[0072] - Fig. 2 shows a flow chart of a method for a client device according to an embodiment of the invention;

[0073] - Fig. 3 shows a network access node according to an embodiment of the invention;

[0074] - Fig. 4 shows a flow chart of a method for a network access node according to an embodiment of the invention;

[0075] - Fig. 5 shows a communication system according to an embodiment of the invention;

[0076] - Fig. 6 shows a signaling diagram for determining uplink antenna settings according to an embodiment of the invention;

[0077] - Fig. 7 shows joint uplink antenna setting and beam sweeping according to an embodiment of the invention;

[0078] - Fig. 8 shows a signaling diagram for determining downlink antenna settings according to an embodiment of the invention;

[0079] - Fig. 9 shows joint downlink antenna setting and beam sweeping according to an embodiment of the invention;

[0080] - Fig. 10 shows joint downlink antenna setting and beam sweeping according to another embodiment of the invention; and

[0081] - Fig. 11 shows a signaling diagram for antenna setting switching indication and antenna setting configuration according to an embodiment of the invention.

[0082] DETAILED DESCRIPTION

[0083] Beamforming is a critical part of modem wireless communication systems. The exact beamforming weights and their design, digital, analog or hybrid, are up to implementation. In most cases, co-phasing and amplitude tapping are utilized to form the beamforming weights, assuming a given antenna array structure, e.g., number of antenna elements, position, polarization, antenna layout, etc.

[0084] A change in the antenna' s tilt, polarization, activity, position, and transmit power amplifier level can have a considerable impact on the performance of the chosen beamforming weights. Additionally, with the advent of metamaterial-based antennas it is expected that antenna properties can be changed dynamically. Consequently, adequate methods are needed to adapt to situations wherein the antennas at the client device and / or network access node, are reconfigurable, in terms of position, polarization, orientation, sub-array activity, material properties, among others.

[0085] According to embodiments of the invention a solution for exploiting the advantages of dynamic adaptation of antenna settings at the client device and / or network access node is therefore provided. Fig. 1 shows a client device 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1, the client device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The client device 100 further comprises an antenna or antenna array 110 coupled to the transceiver 104, which means that the client device 100 is configured for wireless communications in a communication system. The antenna or antenna array 110 is configured to provide multiple antenna settings for transmission and reception in embodiments of the invention.

[0086] The processor 102 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, or one or more chipsets. The memory 106 may be a read-only memory, a random access memory (RAM), or a non-volatile RAM (NVRAM). The transceiver 104 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices. The transceiver 104, memory 106 and / or processor 102 may be implemented in separate chipsets or may be implemented in a common chipset.

[0087] That the client device 100 is configured to perform certain actions can in this disclosure be understood to mean that the client device 100 comprises suitable means, such as e.g., the processor 102 and the transceiver 104, configured to perform the actions.

[0088] According to embodiments of the invention the client device 100 is configured to transmit uplink reference signals 510 in a set of uplink antenna settings 120 to a network access node 300, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120. The client device 100 is further configured to receive an uplink antenna setting indication 512 from the network access node 300, the uplink antenna setting indication 512 indicating an uplink antenna setting in the set of uplink antenna settings 120 of the client device 100 and determine an uplink antenna setting for an uplink transmission 514 to the network access node 300 based on the received uplink antenna setting indication 512.

[0089] Furthermore, in an embodiment of the invention, the client device 100 comprises a transceiver configured to transmit uplink reference signals 510 in a set of uplink antenna settings 120 to a network access node 300, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120; receive an uplink antenna setting indication 512 from the network access node 300, the uplink antenna setting indication 512 indicating an uplink antenna setting in the set of uplink antenna settings 120 of the client device 100. The client device 100 comprises a processor configured to determine an uplink antenna setting for an uplink transmission 514 to the network access node 300 based on the received uplink antenna setting indication 512.

[0090] Moreover, in yet another embodiment of the invention, the client device 100 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to: transmit uplink reference signals 510 in a set of uplink antenna settings 120 to a network access node 300, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120; receive an uplink antenna setting indication 512 from the network access node 300, the uplink antenna setting indication 512 indicating an uplink antenna setting in the set of uplink antenna settings 120 of the client device 100; and determine an uplink antenna setting for an uplink transmission 514 to the network access node 300 based on the received uplink antenna setting indication 512.

[0091] Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a client device 100, such as the one shown in Fig. 1. The method 200 comprises transmitting 202 uplink reference signals 510 in a set of uplink antenna settings 120 to a network access node 300, wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120. The method 200 further comprises receiving 204 an uplink antenna setting indication 512 from the network access node 300, the uplink antenna setting indication 512 indicating an uplink antenna setting in the set of uplink antenna settings 120 of the client device 100. The method 200 further comprises determining 206 an uplink antenna setting for an uplink transmission 514 to the network access node 300 based on the received uplink antenna setting indication 512.

[0092] Fig. 3 shows a network access node 300 according to an embodiment of the invention. In the embodiment shown in Fig. 3, the network access node 300 comprises a processor 302, a transceiver 304 and a memory 306. The processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 known in the art. The network access node 300 may be configured for wireless and / or wired communications in a communication system. The wireless communication capability may be provided with an antenna or antenna array 310 coupled to the transceiver 304, while the wired communication capability may be provided with a wired communication interface 312 e.g., coupled to the transceiver 304. The antenna or antenna array 310 is configured to provide multiple antenna settings for transmission and reception in embodiments of the invention.

[0093] The processor 302 may be referred to as one or more general-purpose CPU, one or more DSPs, one or more ASICs, one or more FPGAs, one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, one or more chipsets. The memory 306 may be a read-only memory, a RAM, or a NVRAM. The transceiver 304 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices, such as network nodes and network servers. The transceiver 304, the memory 306 and / or the processor 302 may be implemented in separate chipsets or may be implemented in a common chipset.

[0094] That the network access node 300 is configured to perform certain actions can in this disclosure be understood to mean that the network access node 300 comprises suitable means, such as e.g., the processor 302 and the transceiver 304, configured to perform the actions.

[0095] According to embodiments of the invention the network access node 300 is configured to transmit downlink reference signals 530 in a set of downlink antenna settings 320 to client devices 100, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300. The network access node 300 is further configured receive a set of downlink antenna setting indications 532 from the client devices 100, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings 320 of the network access node 300; and determine a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532.

[0096] Furthermore, in an embodiment of the invention, the network access node 300 comprises a transceiver configured to: transmit downlink reference signals 530 in a set of downlink antenna settings 320 to client devices 100, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300; receive a set of downlink antenna setting indications 532 from the client devices 100, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings 320 of the network access node 300. The network access node 300 comprises a processor configured to determine a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532.

[0097] Moreover, in yet another embodiment of the invention, the network access node 300 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to: transmit downlink reference signals 530 in a set of downlink antenna settings 320 to client devices 100, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300; receive a set of downlink antenna setting indications 532 from the client devices 100, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings 320 of the network access node 300; and determine a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532.

[0098] Fig. 4 shows a flow chart of a corresponding method 400 which may be executed in a network access node 300, such as the one shown in Fig. 3. The method 400 comprises transmitting 402 downlink reference signals 530 in a set of downlink antenna settings 320 to client devices 100, wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300. The method 400 further comprises receiving 404 a set of downlink antenna setting indications 532 from the client devices 100, each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings 320 of the network access node 300; and determining 406 a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532.

[0099] Fig. 5 shows a communication system 500 according to an embodiment of the invention. The communication system 500 in the disclosed embodiment comprises a client device 100 and a network access node 300. The network access node 300 may be connected to a network NW such as e.g., a core network over a communication interface. The communication system 500 may be a communication system according to the 3GPP standard such as e.g., a 5G system in which case the client device 100 may be a user equipment (UE) and the network access node 300 may be a transmission reception point (TRP), a next generation node B (gNB) or similar, but the invention is not limited thereto.

[0100] According to embodiments of the invention the client device 100 and / or the network access node 300 are configured to determine antenna settings for transmissions. The antenna settings may be related to one or more of polarization, number of antenna elements, position of antenna, orientation of antenna, antenna layout, switching pattern of antenna, and electromagnetic property of a metamaterial antenna and / or a radio frequency lens. The client device 100 and / or the network access node 300 may therefore comprise reconfigurable antennas, i.e., antennas which can be configured / adapted in terms of the mentioned properties. The antennas of the client device 100 and / or the network access node 300 may e.g., be adaptive polarization antennas, multiple antenna arrays where each antenna array has different polarization setting, mobile antennas capable of changing their position (e.g. foldable device in the client device), antenna arrays where antenna elements / panels can be switched-off / on dynamically, and / or metamaterial antennas with different settings where the metamaterial e.g., change property due to applied voltage.

[0101] According to embodiments of the invention antenna settings for the antennas of the client device 100 and / or the network access node 300 can be determined such that the antenna settings for transmissions between the client device 100 and the network access node 300 can be optimized to the current propagation conditions. To determine uplink antenna settings for uplink transmissions, the client device 100 transmits uplink reference signals 510 to the network access node 300, as shown in Fig. 5. The uplink reference signals 510 are transmitted in a set of uplink antenna settings 120 and at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120, as will be further described with reference to Figs. 6 and 7. The client device 100 receives an uplink antenna setting indication 512 from the network access node 300. The uplink antenna setting indication 512 indicates an uplink antenna setting in the set of uplink antenna settings 120 of the client device 100. Based on the received uplink antenna setting indication 512, the client device 100 may determine an uplink antenna setting for an uplink transmission 514 to the network access node 300. With reference to Fig. 5, the client device 100 may further perform the uplink transmission 514 to the network access node 300. The uplink transmission 514 is performed in the determined uplink antenna setting. To determine downlink antenna settings for downlink transmissions, the network access node 300 may transmit downlink reference signals 530 in a set of downlink antenna settings 320 to one or more client devices 100, receive a set of downlink antenna setting indications 532 from the client devices 100, and determine a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532, as will be further described below with reference to Figs. 8 and 9.

[0102] Fig. 6 shows signaling for determining an uplink antenna setting according to an embodiment of the invention. The procedure to determine uplink antenna setting may be triggered by the client device 100 itself or by the network access node 300 using suitable control signaling such as dynamic downlink signaling or RRC signaling. The procedure to determine uplink antenna setting may further be configured to be performed periodically.

[0103] In step I in Fig. 6, the client device 100 transmits uplink reference signals 510 in a set of uplink antenna settings 120 to the network access node 300. The set of uplink antenna settings 120 thus comprises two or more antenna settings. At least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120. Each uplink antenna setting in the set of uplink antenna settings 120 may be associated with a specific polarization, number of antenna elements, position of antenna, orientation of an antenna, antenna layout, switching pattern of an antenna, and / or an electromagnetic property of a metamaterial antenna and / or a radio frequency lens. Furthermore, any two uplink antenna settings in the set of uplink antenna settings 120 differs from each other in least: a polarization, a number of antenna elements, a position of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens. Thus, the uplink antenna settings of the client device 100 are switched / changed during the transmission of the uplink reference signals 510. The uplink reference signals 510 may be transmitted at different time instances in a periodic, aperiodic or semi-persistent manner.

[0104] In step II in Fig. 6, the network access node 300 measures the uplink reference signals 510 received in the set of uplink antenna settings 120 from the client device 100. As described, at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings 120 of the client device 100. The network access node 300 further determines channel qualities for each uplink antenna setting in the set of uplink antenna settings 120 of the client device 100, i.e., determines a channel quality for each received uplink reference signal 510 and hence the uplink antenna setting the reference signal 510 was transmitted with. The network access node 300 further selects an uplink antenna setting among the set of uplink antenna settings 120 of the client device 300 based on the determined channel qualities, e.g., selects the uplink antenna setting giving the best channel quality at the network access node 300.

[0105] The network access node 300 then transmits an uplink antenna setting indication 512 to the client device 100, as shown in step III in Fig. 6. The uplink antenna setting indication 512 indicates the selected uplink antenna setting. The uplink antenna setting indication 512 may be indicated as a standalone quantity or as part of another quantity, e.g., in a beam report. The uplink antenna setting indication 512 may further be indicated as a bitmap or as a combinatorial indicator. The bitmap or combinatorial indicator may be determined based on the number of different antenna settings of the client device 100. For a client device 100 supporting NumSetnumber of antenna settings, the combinatorial indicator may be a combinatorial indicator of size log2(NumSet') and the bitmap indicator may be a bitmap with all zero entries, except for one entry in the index of the selected uplink antenna setting. The indication can be conveyed as part of dynamic downlink signaling, e.g., DCI or MAC CE. Additionally, the uplink antenna setting indication may be conveyed as part of RRC signaling.

[0106] The client device 100 receives the uplink antenna setting indication 512 from the network access node 300 and hence obtains the uplink antenna setting in the set of uplink antenna settings 120 indicated in the uplink antenna setting indication 512. In this way, the client device 100 is informed about the uplink antenna setting selected by the network access node 300, e.g., which of the uplink antenna setting in the set of uplink antenna settings 120 that the network access node 300 received with the highest channel quality.

[0107] In embodiments, the uplink antenna setting indication 512 further indicates at least one channel quality associated with the set of uplink antenna settings 120 of the client device 100. Thus, the network access node 300 may indicate one or more of the channel qualities determined in step II in the uplink antenna setting indication 512, i.e., one or more of the determined channel qualities for the set of uplink antenna settings 120 of the client device 100. The channel quality may be any of: a RSRP, a SINR, a difference or a gap in RSRP between different uplink antenna settings, and a difference or a gap in SINR between different uplink antenna settings. Thus, the uplink antenna setting indication 512 may further indicate the difference in quality between different antenna settings. These channel qualities can be used by the network access node 300 when selecting its own antenna setting or indicating antenna settings for the client device 100. For example, the channel quantities can be used by the network access node 300 in order to select a fallback antenna setting when an achievable performance has dropped below a threshold value. Alternately, these channel qualities can be used as input for training, inference or monitoring of a beam and / or antenna setting prediction machine learning model.

[0108] In step IV in Fig. 6, the client device 100 determines an uplink antenna setting for an uplink transmission 514 to the network access node 300 based on the received uplink antenna setting indication 512. The client device 100 may e.g., determine the uplink antenna setting for the uplink transmission 514 to be the uplink antenna setting indicated in the uplink antenna setting indication 512. The client device 100 may further determine the uplink antenna setting for the uplink transmission 514 based on the uplink antenna setting and at least one channel quality associated with the set of uplink antenna settings 120 indicated in the uplink antenna setting indication 512. Indeed, the client device 100 may be supporting multiple active links / carriers. Consequently, the determination of an uplink antennas setting needs to take into consideration the different active links / carriers of the client device 100.

[0109] In embodiments, the client device 100 determines the uplink antenna setting for the uplink transmission 514 further based on measurements of downlink reference signals received from the network access node 300. Thereby, the client device 100 can select its uplink antenna setting based on downlink reference signal measurements and consequently avoiding costly uplink reference signals transmissions. The measured downlink reference signals may be downlink reference signals transmitted by the network access node 300 e.g., for channel state information (CSI) measurements and / or other measurements. The client device 100 may perform different measurements of the same downlink reference signal resource, or a repetition of a downlink reference signal resource, transmitted with the same downlink antenna setting / beam combination, as shown in Fig. 10. At each measurement, the client device 100 may switch the active antenna setting of its receive antennas, e.g., polarization, position, etc. The client device 100 may then determine its uplink antenna setting based on the uplink antenna setting indication 512 and further based on the best downlink setting of its receive antennas. This approach can be used in TDD and some FDD scenarios, when at least a partial channel reciprocity is valid. Thus, selecting an optimal uplink antenna setting for an uplink transmission can be based on an optimal client device antenna setting for a downlink reception.

[0110] Based on the determined uplink antenna setting, the client device 100 may perform a transmission as indicated in optional steps V and VI in Fig. 6. The client device 100 may e.g., perform the uplink transmission 514 to the network access node 300 in the determined uplink antenna setting, as shown in step V in Fig. 6. The client device 100 may further perform a reception of a downlink transmission 524 from the network access node 300 in a downlink antenna setting associated with the determined uplink antenna setting, as shown in step VI in Fig. 6. In embodiments, the client device 100 may transmit the uplink reference signals 510 in the set of uplink antenna settings 120 and in a set of uplink beams 130, where at least one uplink reference signal is transmitted in each uplink beam in the set of uplink beams 130 of the client device 100. The uplink antenna settings may be switched at the same time as the beams, or the uplink antenna settings and the beams may be switched at different times. The uplink reference signals 510 may hence be transmitted in repetition with different uplink antenna settings / beam combinations each time or in repetition with a fixed beam and different uplink antenna setting each time. Thereby, also the different beam settings of the client device 100 are considered when determining the uplink antenna setting.

[0111] Fig . 7 shows an embodiment where the client device 100 transmits the uplink reference signals 510 in the set of uplink antenna settings 120 and in the set of uplink beams 130 using a joint uplink antenna setting and beam sweeping. The set of uplink antenna settings 120 comprises a first uplink antenna setting indicated with a checkered pattern in Fig. 7 and a second uplink antenna setting indicated with a striped pattern in Fig. 7. The set of uplink beams 130 comprises four uplink beams in this example. The client device 100 sweeps through all the combinations of uplink antenna settings and uplink beams. Thus, the uplink reference signal 510 is transmitted twice in each uplink beam, one time with the first uplink antenna setting and one time with the second uplink antenna setting, as indicated in Fig. 7 for the first and last beams.

[0112] In the embodiment shown in Fig. 7, the network access node 300 receives the uplink reference signals 510 using a fixed beam. The network access node 300 further transmits the uplink antenna setting indication 512 indicating the uplink antenna setting in the set of uplink antenna settings 120 using this fixed beam. However, the network access node 300 may in embodiments instead use different beams and / or antenna settings when receiving the uplink reference signals 510 from the client device 100 and / or transmitting the uplink antenna setting indication 512 to the client device 100. This may be the case when data collection measurements for training, inference or monitoring of a beam and / or antenna setting prediction model is performed.

[0113] Fig. 8 shows signaling for determining downlink antenna settings according to an embodiment of the invention. The procedure to determine downlink antenna settings may be triggered by the client device 100 or the network access node 300 which is describe with reference to Fig. 11 in the following disclosure. The procedure to determine downlink antenna settings may further be configured to be performed periodically.

[0114] In step I in Fig. 8, the network access node 300 transmits downlink reference signals 530 in a set of downlink antenna settings 320 to client devices 100. At least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300. Any two downlink antenna settings in the set of downlink antenna settings 320 differs from each other in least: a polarization, a number of antenna elements, a position of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens. Thus, the downlink antenna settings of the network access node 300 are changed / switched during the transmission of the downlink reference signals 530. The downlink reference signals 530 may be transmitted at different time instances in a periodic, a periodic or semi-persistent manner.

[0115] In step II in Fig. 8, each client device 100 measures the downlink reference signals 530 received in the set of downlink antenna settings 320 from the network access node 300, where at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300. The client device 100 further determines channel qualities for each downlink antenna setting in the set of downlink antenna settings 320 of the network access node 300, i.e., determines a channel quality for each received downlink reference signal 530 and hence the downlink antenna setting it was transmitted with. The client device 100 further selects a subset of downlink antenna settings among the set of downlink antenna settings 320 of the network access node 300 based on the determined channel qualities, e.g., selects the uplink antenna settings with the best channel qualities. Each client device 100 then transmits a downlink antenna setting indication 532 to the network access node 300, as shown in step III in Fig. 8. The downlink antenna setting indication 532 indicates the selected subset of downlink antenna settings and may further indicate their associated channel qualities. In a similar way as for the uplink antenna setting indication 512, the downlink antenna setting indication 532 may be indicated as a standalone quantity or as part of another quantity, e.g., in a beam report. The downlink antenna setting indication 532 may further be indicated as a bitmap or as a combinatorial indicator as explained previously.

[0116] The network access node 300 receives the set of downlink antenna setting indications 532 from the client devices 100. Each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings 320 of the network access node 300. The use of a subset of downlink antenna settings is due to the fact that the network access node 300 may need to accommodate multiple client devices when employing a single antenna panel. Since a single downlink antenna setting may not be optimal for all client devices, a subset of downlink antenna settings is needed so that the network access node 300 can make an informed selection later on. The downlink antenna setting indication and associated channel quality values may be used by the network access node 300 to select an appropriate antenna setting for downlink transmission, uplink reception and for constructing valid antenna setting-aware TCI states.

[0117] In step IV in Fig. 8, the network access node 300 determines a downlink antenna setting for downlink transmissions 524 to the client devices 100 based on the set of received downlink antenna indications 532. Thus, the network access node 300 may determine a downlink antenna setting for downlink transmission 524 to the client devices 100 based on the indicated subsets of downlink antenna settings and based on any indicated channel qualities associated with the set of downlink antenna settings 320. The network access node 300 may determine a downlink antenna setting for each of its antenna panels. The determined antenna setting may depend on the connected client devices channel conditions and scheduled downlink channels on each of the network access node transmission panels. For example, the network access node 300 may determine a downlink antenna setting that achieves highest average effective channel gain for all scheduled downlink channels.

[0118] In embodiments, the network access node 300 may determine the downlink antenna setting for the downlink transmission 524 further based on measurements of uplink reference signals received from the client devices 100. The uplink reference signals may be uplink reference signals transmitted by the client devices 100 e.g., for channel state information (CSI) measurements, beam management and / or uplink reference signals 510 transmitted by the client devices 100 as part of a determination of uplink antenna settings according to the invention.

[0119] Based on the determined downlink antenna settings, the network access node 300 may perform at least one transmission as indicated in optional steps V and VI in Fig. 8. The network access node 300 may e.g., perform the downlink transmission 524 to the client devices 100 in the determined downlink antenna setting, as shown in step V in Fig. 8. The network access node 300 may further perform a reception of an uplink transmission 514 from a client device 100 in an uplink antenna setting associated with the determined downlink antenna setting, as shown in step VI in Fig. 8.

[0120] In embodiments, the network access node 300 transmits the downlink reference signals 530 in the set of downlink antenna settings 320 and in a set of downlink beams 330, wherein at least one downlink reference signal is transmitted in each downlink beam in the set of downlink beams 330 of the network access node 300. The downlink antenna settings may be switched at the same time as the beams, or the downlink antenna settings and the beams may be switched at different times. The downlink reference signals 530 may hence be transmitted in repetition with different downlink antenna settings / beam combinations each time or in repetition with a fixed beam and different downlink antenna setting each time.

[0121] Fig. 9 shows an embodiment where the network access node 300 transmits the downlink reference signals 530 in the set of downlink antenna settings 320 and in the set of downlink beams 330. The set of downlink antenna settings 320 comprises a first downlink antenna setting indicated with a checkered pattern in Fig. 9 and a second downlink antenna setting indicated with a horizontal striped pattern in Fig. 9. The set of downlink beams 330 comprises four downlink beams in this example. The network access node 300 sweeps through all or a subset of the combinations of downlink antenna settings and downlink beams. Thus, the downlink reference signal 530 is transmitted twice in each downlink beam, one time with the first downlink antenna setting and one time with the second downlink antenna setting, as indicated in Fig. 9 for the first and last beams.

[0122] In the embodiment shown in Fig . 9, the client device 100 receives the downlink reference signals 510 using a fixed beam and / or a fixed antenna setting. The client device 100 further transmits the downlink antenna setting indication 532 indicating the downlink antenna setting in the set of downlink antenna settings 320 using the fixed beam and / or the fixed antenna setting.

[0123] Fig. 10 shows an embodiment where the network access node 300 transmits downlink reference signals RSs in the same downlink antenna setting / beam combination. The client device 100 may perform measurements on the downlink reference signals RSs and use the measurements when determining its uplink antenna settings, as described with reference to step IV in Fig. 6. With reference to Fig. 10, at each measurement, the client device 100 may switch its downlink antenna setting / beam combination. The uplink antenna setting is then determined based on the antenna setting that provided the highest channel quality when receiving downlink reference signals.

[0124] Fig. 11 shows signaling for capability exchange and configuration related to antenna settings according to an embodiment of the invention.

[0125] In step I in Fig. 11, the client device 100 transmits an uplink antenna setting switching indication 516 to the network access node 300. The uplink antenna setting switching indication 516 indicates that the client device 100 supports dynamic switching of uplink antenna settings. The network access node 300 receives the uplink antenna setting switching indications 516 from the client devices 100 and hence obtains the indication that the client device 100 supports dynamic switching of uplink antenna settings. The network access node 300 may receive uplink antenna setting switching indications 516 from a plurality of client devices 100, i.e., the network access node 300 may receive a set of uplink antenna setting switching indications 516 from the client devices 100. Each uplink antenna setting switching indication 516 indicates that a client device 100 supports dynamic switching of uplink antenna settings.

[0126] In step II in Fig. 11, the network access node 300 transmits a set of downlink antenna setting switching indications 518 to the client devices 100 (of which only one is shown in Fig. 11), each downlink antenna setting switching indication 518 indicating that the network access node 300 supports dynamic switching of downlink antenna settings. The client device 100 receives the downlink antenna setting switching indication 518 from the network access node 300 and hence obtains the indication that the network access node 300 supports dynamic switching of downlink antenna settings.

[0127] The uplink antenna setting switching indication 516 and / or the downlink antenna setting switching indication 518 may be a RRC message. The uplink antenna setting switching indication 516 and / or the downlink antenna setting switching indication 518 may be a new RRC message or may be or be comprised in an existing RRC message. The uplink antenna setting switching indication 516 and / or the downlink antenna setting switching indication 518 may e.g., be indicated in a RRC message transmitted as part of a RRC configuration procedure such as e.g., the RRC capability message.

[0128] In embodiments, the network access node 300 may configure the client devices 100 with uplink reference signals 510 using an uplink antenna setting management resource configuration 520 message. Thus, the network access node 300 may transmit a set of uplink antenna setting management resource configurations 520 to the client devices 100, each uplink antenna setting management resource configuration 520 indicating uplink reference signals 510 to be transmitted by a client device 100. Step III in Fig. 11 shows the network access node 300 transmitting an uplink antenna setting management resource configuration 520 to the client device 100. The uplink antenna setting management resource configuration 520 indicates uplink reference signals 510 to be transmitted by the client device 100. The client device 100 receives the uplink antenna setting management resource configuration 520 from the network access node 300 and hence obtains the uplink reference signals 510 indicated in the uplink antenna setting management resource configuration 520. In embodiments, the transmission of the uplink reference signals 510 performed by the client device 100 in step I in Fig. 6 may be based on the received uplink antenna setting management resource configuration 520.

[0129] The network access node 300 may further configure the client device 100 with antenna setting-aware transmission configuration indicator (TCI) states. The antenna setting-aware TCI states may be indicated in DCI from the network access node 300 to the client device 100. With reference to step IV in Fig. 11, the network access node 300 may transmit uplink and / or downlink antenna setting-aware transmission configuration indicators 522 to the client devices 100. Each uplink and / or downlink antenna setting-aware transmission configuration indicator may configure a quasi co-location relationship between one or more reference signals and applicable uplink and / or downlink antenna settings. In embodiments, the network access node 300 may determine the downlink antenna setting for the downlink transmission 524 to the client devices 100 further based on the transmitted uplink and / or the downlink antenna setting-aware transmission configuration indicators 522. For example, the network access node 300 may use the uplink and / or downlink antenna setting-aware transmission configuration indicators 522 to determine the downlink antenna setting for the downlink transmission 524 to the client devices 100 in step V in Fig. 8. The downlink antenna setting determined based on the uplink and / or the downlink antenna setting-aware transmission configuration indicators 522 may further be used by the network access node 300 to determine an uplink antenna setting for reception of an uplink transmission 514 from a client device 100. For example, each downlink antenna setting-aware TCI state contains parameters to configure a quasi co-location relationship between one or two downlink reference signals and the reference signal ports of downlink channels, e.g., DMRS, CSI-RS. The downlink antenna setting-aware TCI state may further indicate, the antenna setting for the client device 100 and / or the network access node 300, to be used for reception and / or transmission of the downlink channels.

[0130] The client device 100 receives the uplink and / or a downlink antenna setting-aware transmission configuration indicator 522 from the network access node 300 and may determine the uplink antenna setting for an uplink transmission 514 to the network access node 300 further based on the uplink and / or the downlink antenna setting-aware transmission configuration indicator 522. For example, the client device 100 may use the uplink and / or downlink antenna setting-aware transmission configuration indicators 522 to determine the uplink antenna setting for the uplink transmission 514 to the network access node 300 in step V in Fig. 6. The client device 100 may use the uplink and / or downlink antenna setting-aware transmission configuration indicators 522 to adapt both its spatial filters, i.e., both antenna settings and beams.

[0131] The client device herein may be denoted as a user device, a user equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and / or a mobile terminal, and is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in this context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and / or data, via a radio access network (RAN), with another communication entity, such as another receiver or a server. The UE may further be a station, which is any device that contains an IEEE 802.11 -conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The UE may be configured for communication in 3GPP related long term evolution (LEE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR), and their evolutions, as well as in IEEE related Wi-Fi, worldwide interoperability for micro wave access (WiMAX) and their evolutions.

[0132] The network access node herein may also be denoted as a radio network access node, an access network access node, an access point (AP), or a base station (BS), e.g., a radio base station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the standard, technology and terminology used. The radio network access nodes may be of different classes or types such as e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby the cell size. The radio network access node may further be a station, which is any device that contains an IEEE 802.11 -conformant MAC and PHY interface to the WM. The radio network access node may be configured for communication in 3GPP related LTE, LTE-advanced, 5G wireless systems, such as NR and their evolutions, as well as in IEEE related Wi-Fi, WiMAX and their evolutions.

[0133] Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as previously mentioned a ROM, a PROM, an EPROM, a flash memory, an EEPROM, or a hard disk drive.

[0134] Moreover, it should be realized that the client device and the network access node comprise the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing or implementing embodiments of the invention. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

[0135] Therefore, the processor(s) of the client device and the network access node may comprise, e.g., one or more instances of a CPU, a processing unit, a processing circuit, a processor, an ASIC, a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like. Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

CLAIMS1. A client device (100) configured to: transmit uplink reference signals (510) in a set of uplink antenna settings (120) to a network access node (300), wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings (120); receive an uplink antenna setting indication (512) from the network access node (300), the uplink antenna setting indication (512) indicating an uplink antenna setting in the set of uplink antenna settings (120) of the client device (100); and determine an uplink antenna setting for an uplink transmission (514) to the network access node (300) based on the received uplink antenna setting indication (512).

2. The client device (100) according to claim 1, configured to: transmit the uplink reference signals (510) in the set of uplink antenna settings (120) and in a set of uplink beams (130), wherein at least one uplink reference signal is transmitted in each uplink beam in the set of uplink beams (130) of the client device (100).

3. The client device (100) according to claim 1 or 2, wherein any two uplink antenna settings in the set of uplink antenna settings (120) differs from each other in least: a polarization, a number of antenna elements, aposition of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens.

4. The client device (100) according to any one of the preceding claims, wherein the uplink antenna setting indication (512) is indicated as a bitmap or as a combinatorial indicator.

5. The client device (100) according to any one of the preceding claims, wherein the uplink antenna setting indication (512) further indicates at least one channel quality associated with the set of uplink antenna settings (120) of the client device (100).

6. The client device (100) according to claim 5, wherein the channel quality is any of: a RSRP, a SINR, a difference or a gap in RSRP between different uplink antenna settings, and a difference or a gap in SINR between different uplink antenna settings.

7. The client device (100) according to any one of the preceding claims, configured to: determine the uplink antenna setting for the uplink transmission (514) further based on measurements of downlink reference signals received from the network access node (300).

8. The client device (100) according to any one of the preceding claims, configured to: transmit an uplink antenna setting switching indication (516) to the network access node (300), the uplink antenna setting switching indication (516) indicating that the client device (100) supports dynamic switching of uplink antenna settings; and receive a downlink antenna setting switching indication (518) from the network access node (300), the downlink antenna setting switching indication (518) indicating that the network access node (300) supports dynamic switching of downlink antenna settings.

9. The client device (100) according to claim 8, wherein the uplink antenna setting switching indication (516) and / or the downlink antenna setting switching indication (518) is a RRC message.

10. The client device (100) according to any one of the preceding claims, configured to:receive an uplink antenna setting management resource configuration (520) from the network access node (300), the uplink antenna setting management resource configuration (520) indicating the uplink reference signals (510).

11. The client device (100) according to any one of the preceding claims, configured to: receive an uplink and / or a downlink antenna setting-aware transmission configuration indicator (522) from the network access node (300); and determine the uplink antenna setting for the uplink transmission (514) further based on the uplink and / or the downlink antenna setting-aware transmission configuration indicator (522).

12. The client device (100) according to any one of the preceding claims, configured to: measure downlink reference signals (530) received in a set of downlink antenna settings (320) from the network access node (300), wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings (320) of the network access node (300); determine channel qualities for each downlink antenna setting in the set of downlink antenna settings (320) of the network access node (300); select a subset of downlink antenna settings among the set of downlink antenna settings (320) of the network access node (300) based on the determined channel qualities; and transmit a downlink antenna setting indication (532) to the network access node (300), the downlink antenna setting indication (532) indicating the selected subset of downlink antenna settings and their associated channel qualities.

13. The client device (100) according to any one of the preceding claims, configured to: perform the uplink transmission (514) to the network access node (300) in the determined uplink antenna setting; and / or perform a reception of a downlink transmission from the network access node (300) in a downlink antenna setting associated with the determined uplink antenna setting.

14. A network access node (300) configured to: transmit downlink reference signals (530) in a set of downlink antenna settings (320) to client devices (100), wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings (320) of the network access node (300); receive a set of downlink antenna setting indications (532) from the client devices (100), each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings (320) of the network access node (300); and determine a downlink antenna setting for downlink transmissions (524) to the client devices (100) based on the set of received downlink antenna indications (532).

15. The network access node (300) according to claim 14, configured to: transmit the downlink reference signals (530) in the set of downlink antenna settings (320) and in a set of downlink beams (330), wherein at least one downlink reference signal is transmitted in each downlink beam in the set of downlink beams (330) of the network access node (300).

16. The network access node (300) according to claim 14 or 15, wherein any two downlink antenna settings in the set of downlink antenna settings (320) differs from each other in least: a polarization, a number of antenna elements, a position of antenna, an orientation of an antenna, an antenna layout, a switching pattern of an antenna, and an electromagnetic property of a metamaterial antenna and / or a radio frequency lens.

17. The network access node (300) according to any one of claims 14 to 16, wherein the downlink antenna setting indication (532) is indicated as a bitmap or as a combinatorial indicator.

18. The network access node (300) according to any one of claims 14 to 17, wherein the downlink antenna setting indication (532) further indicates at least one channel quality associated with the set of downlink antenna settings (320) of the network access node (300).

19. The network access node (300) according to claim 18, wherein the channel quality is any of: a RSRP, a SINR, a difference or a gap in RSRP between different uplink antenna settings, and a difference or a gap in SINR between different uplink antenna settings.

20. The network access node (300) according to any one of claims 14 to 19, configured to: determine the downlink antenna setting for the downlink transmission (524) further based on measurements of uplink reference signals received from the client devices (100).

21. The network access node (300) according to any one of claims 14 to 20, configured to: receive a set of uplink antenna setting switching indications (516) from the client devices (100), each uplink antenna setting switching indication (516) indicating that a client device (100) supports dynamic switching of uplink antenna settings; and transmit a set of downlink antenna setting switching indications (518) to the client devices (100), each downlink antenna setting switching indication (518) indicating that the network access node (300) supports dynamic switching of downlink antenna settings.

22. The network access node (300) according to claim 21, wherein the uplink antenna setting switching indication (516) and / or the downlink antenna setting switching indication (518) is a RRC message.

23. The network access node (300) according to any one of claims 14 to 22, configured to: transmit a set of uplink antenna setting management resource configurations (520) to the client devices (100), each uplink antenna setting management resource configuration (520) indicating uplink reference signals (510) to be transmitted by a client device (100).

24. The network access node (300) according to any one of claims 14 to 23, configured to: transmit uplink and / or downlink antenna setting-aware transmission configuration indicators (522) to the client devices (100).

25. The network access node (300) according to claim 24, configured to: determine the downlink antenna setting for the downlink transmission (524) to the client devices (100) further based on the transmitted uplink and / or the downlink antenna setting-aware transmission configuration indicators (522).

26. The network access node (300) according to any one of claims 14 to 25, configured to: measure uplink reference signals (510) received in a set of uplink antenna settings (120) from a client device (100), wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings (120) of the client device (100); determine channel qualities for each uplink antenna setting in the set of uplink antenna settings (120) of the client device (100);select an uplink antenna setting among the set of uplink antenna settings (120) of the client device (300) based on the determined channel qualities; and transmit an uplink antenna setting indication (512) to the client device (100), the uplink antenna setting indication (512) indicating the selected uplink antenna setting.

27. The network access node (300) according to any one of claims 14 to 26, configured to: perform the downlink transmission (524) to the client devices (100) in the determined downlink antenna setting; and / or perform a reception of an uplink transmission from a client device (100) in an uplink antenna setting associated with the determined downlink antenna setting.

28. A method (200) for a client device (100), the method (200) comprises: transmitting (202) uplink reference signals (510) in a set of uplink antenna settings (120) to a network access node (300), wherein at least one uplink reference signal is transmitted in each uplink antenna setting in the set of uplink antenna settings (120); receiving (204) an uplink antenna setting indication (512) from the network access node (300), the uplink antenna setting indication (512) indicating an uplink antenna setting in the set of uplink antenna settings (120) of the client device (100); and determining (206) an uplink antenna setting for an uplink transmission (514) to the network access node (300) based on the received uplink antenna setting indication (512).

29. A method (400) for a network access node (300), the method (200) comprises: transmitting (402) downlink reference signals (530) in a set of downlink antenna settings (320) to client devices (100), wherein at least one downlink reference signal is transmitted in each downlink antenna setting in the set of downlink antenna settings (320) of the network access node (300); receiving (404) a set of downlink antenna setting indications (532) from the client devices (100), each downlink antenna setting indication indicating a subset of downlink antenna settings in the set of downlink antenna settings (320) of the network access node (300); and determining (406) a downlink antenna setting for downlink transmissions (524) to the client devices (100) based on the set of received downlink antenna indications (532).

30. A computer program with a program code for performing amethod according to claim 28 or 29 when the computer program runs on a computer.

Images