Methods, apparatus, and non-transitory computer-readable media for wireless communications

Abstract

Methods, systems, and apparatus for wireless communications are described. A relay node may determine a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on a downlink beamforming direction between the relay node and a child node. The relay node may send a report to the parent node indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of channel states. The relay node may receive a grant from the parent node indicating a first downlink beamforming direction. The relay node may monitor downlink transmissions from the parent node based at least in part on the grant and the first downlink beamforming direction.

Description

Technical Field

[0001] The following relates generally to wireless communications and, more particularly, to beamforming determinations for an integrated access and backhaul (IAB) system with full-duplex. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems can support communication for multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of these multiple access systems include fourth generation (4G) systems, such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems, which may be referred to as new radio (NR) systems. These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread spectrum orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include multiple base stations or network access nodes, each of which simultaneously supports communication for multiple communication devices, which may be otherwise referred to as user equipment (UE).

[0003] Wireless communication systems may operate in the mmW frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors such as temperature, atmospheric pressure, diffraction, etc. As a result, signal processing techniques such as beamforming may be used to coherently combine energy and overcome path loss at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from base stations and / or UEs may be beamformed. Additionally, a receiving device may use beamforming techniques to configure an antenna and / or antenna array so that the transmission is received in a directional manner.

[0004] Some wireless communication systems may support both access and backhaul wireless communications. For example, such a wireless communication system may include a node, which may also be referred to as an anchor node, parent node, relay node, or child node (depending on the node's location within the network), which facilitates wireless communication between a UE and the network. In some cases, a donor node (or anchor node) may have a high-capacity wired backhaul connection (e.g., optical fiber) to the network while simultaneously communicating with one or more downstream relay nodes (e.g., downstream parent nodes, relay nodes, and / or child nodes) or UEs. A network that supports communication between a relay node and a UE may be referred to as an access network or link, while a network that supports communication between one or more relay nodes may be referred to as a backhaul network or link. In a deployment that supports both access and backhaul, the network may be or implement an IAB network. Traditional beamforming techniques in IAB systems are flawed. Summary of the Invention

[0005] The described technology relates to improved methods, systems, devices, and apparatuses for supporting beamforming determination for an integrated access and backhaul (IAB) system with full-duplex. Generally, the described technology provides various techniques to support beamforming direction selection for downlink and uplink in an IAB network that is configured or otherwise supports non-full-duplex and full-duplex communications. In the downlink, this can include a relay node identifying or otherwise determining a channel state for each downlink beamforming direction between a parent node and the relay node. The relay node can determine the channel state based on the downlink beamforming direction between the relay node and one or more child nodes, at least in some aspects. The relay node can send or otherwise provide a report to the parent node that indicates at least a portion or subset of the channel state and, in some aspects, indicates a corresponding downlink beamforming direction from a plurality of downlink beamforming directions corresponding to each corresponding channel state.

[0006] The parent node may receive a report from the relay node and, based on the report, respond to the relay node with a grant indicating at least one (e.g., a first) downlink beamforming direction. The grant may also carry or convey an indication of resources corresponding to the first downlink beamforming direction for non-full-duplex mode and full-duplex mode (e.g., radio resource allocation in time and / or frequency). The relay node may monitor and receive downlink transmissions from the parent node based on the grant and the first downlink beamforming direction. The relay node may simultaneously use at least a portion of the allocated resources and, at least in some aspects, send downstream transmissions to its child nodes based on the first downlink beamforming direction.

[0007] In the uplink, the relay node may, at least in some aspects, identify or otherwise determine the channel state for each of a plurality of uplink beamforming directions between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node. The relay node may then send or otherwise communicate one or more uplink reference signals to the parent node using at least a portion of the plurality of uplink beamforming directions (e.g., based on the channel state). The relay node may indicate to the parent node whether the uplink reference signals are for full-duplex mode or non-full-duplex mode in reports and / or in separate transmissions.

[0008] The parent node may use the uplink reference signal and the indication to identify or otherwise determine a first uplink beamforming direction from a plurality of uplink beamforming directions. Thus, the parent node may send or otherwise communicate a grant to the relay node, the grant indicating the first uplink beamforming direction and resources (e.g., radio resource allocation in time and / or frequency) for uplink communications using the first uplink beamforming direction. The parent node may then monitor and receive uplink transmissions from the relay node based on the grant and the first uplink beamforming direction. The relay node may simultaneously monitor and receive uplink transmissions from the child node and / or UE using the granted resources and based on the first uplink beamforming direction, at least in some aspects.

[0009] A method of wireless communication at a relay node is described. The method may include determining a channel state for each of a set of downlink beamforming directions between a parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; sending a report to the parent node, the report indicating at least a subset of the channel states and an indication that a corresponding downlink beamforming direction of the set of downlink beamforming directions corresponds to a corresponding channel state in the subset of channel states; receiving a grant from the parent node indicating a first downlink beamforming direction from the set of downlink beamforming directions; and monitoring downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0010] An apparatus for wireless communication at a relay node is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to determine a channel state for each of a set of downlink beamforming directions between a parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node indicating at least a subset of the channel states and an indication that a corresponding downlink beamforming direction of the set of downlink beamforming directions corresponds to a corresponding channel state in the subset of channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the set of downlink beamforming directions; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0011] An apparatus for wireless communication at a relay node is described. The apparatus may include means for determining a channel state for each of a set of downlink beamforming directions between a parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; sending a report to the parent node indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the set of downlink beamforming directions corresponds to a respective channel state in the subset of channel states; receiving a grant from the parent node indicating a first downlink beamforming direction from the set of downlink beamforming directions; and monitoring downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0012] A non-transitory computer-readable medium storing code for wireless communication at a relay node is described. The code may include instructions executable by a processor to determine a channel state for each of a set of downlink beamforming directions between a parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node indicating at least a subset of the channel states and an indication that a corresponding downlink beamforming direction of the set of downlink beamforming directions corresponds to a corresponding channel state in the subset of channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the set of downlink beamforming directions; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a grant may also include operations, features, components, or instructions for receiving a grant indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a downlink transmission from a parent node within a resource allocation and sending a second downlink transmission to the child node within the resource allocation via downlink beamforming directions between the relay node and the child node.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for communicating a reference signal or a synchronization signal with a child node, wherein a downlink beamforming direction between the relay node and the child node may be identified based on the communication.

[0016] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for identifying a self-interference level between each downlink beamforming direction in a set of downlink beamforming directions between a parent node and a relay node and a downlink beamforming direction between the relay node and a child node, and determining, for full-duplex mode, a channel state for each of the set of downlink beamforming directions between the parent node and the relay node based on the identified self-interference level.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the channel state for each of the set of downlink beamforming directions may also include operations, features, components, or instructions for determining a first channel state for each of the set of downlink beamforming directions between the parent node and the relay node for non-full-duplex mode, and determining a second channel state for each of the set of downlink beamforming directions between the parent node and the relay node for full-duplex mode, wherein a report indicating a subset of the channel states may be based on the first and second channel states.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the channel state for each in the set of downlink beamforming directions may include operations, features, components, or instructions for determining a beamforming channel gain for each in the set of downlink beamforming directions between a parent node and a relay node, wherein a first channel state for each in the set of downlink beamforming directions between the parent node and the relay node may be determined based on the beamforming channel gain for each in the set of downlink beamforming directions between the parent node and the relay node, and determining a ratio of the beamforming channel gain to the self-interference level of each in the set of downlink beamforming directions between the parent node and the relay node based on an identified self-interference level and the determined beamforming channel gain, wherein a second channel state for each in the set of downlink beamforming directions between the parent node and the relay node may be determined based on the ratio.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining a non-full-duplex mode uplink beamforming direction for a non-full-duplex transmission from a parent node based on a grant, and determining a full-duplex uplink beamforming direction for a full-duplex mode of full-duplex communication between a parent node and a relay node and full-duplex communication between a relay node and a child node, or a combination thereof, based on a grant.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the child node may be a UE or a second relay node.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the relay node comprises a relay node within an IAB network.

[0022] A method of wireless communication at a relay node is described. The method may include determining a channel state for each of a set of uplink beamforming directions between a parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; sending an uplink reference signal to the parent node using at least a subset of the set of uplink beamforming directions based on the channel state; receiving a grant from the parent node indicating a first uplink beamforming direction from the set of uplink beamforming directions; and sending an uplink transmission to the parent node via the first uplink beamforming direction based on the grant.

[0023] An apparatus for wireless communication at a relay node is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to determine a channel state for each of a set of uplink beamforming directions between a parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; based on the channel state, send an uplink reference signal to the parent node using at least a subset of the set of uplink beamforming directions; receive a grant from the parent node indicating a first uplink beamforming direction from the set of uplink beamforming directions; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0024] An apparatus for wireless communication at a relay node is described. The apparatus may include means for determining a channel state for each of a set of uplink beamforming directions between a parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; sending an uplink reference signal to the parent node using at least a subset of the set of uplink beamforming directions based on the channel state; receiving a grant from the parent node indicating a first uplink beamforming direction from the set of uplink beamforming directions; and sending an uplink transmission to the parent node via the first uplink beamforming direction based on the grant.

[0025] A non-transitory computer-readable medium storing code for wireless communication at a relay node is described. The code may include instructions executable by a processor to determine a channel state for each of a set of uplink beamforming directions between a parent node and the relay node based on an uplink beamforming direction between the relay node and the child node; based on the channel state, send an uplink reference signal to the parent node using at least a subset of the set of uplink beamforming directions; receive a grant from the parent node indicating a first uplink beamforming direction from the set of uplink beamforming directions; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a grant may include operations, features, components, or instructions for receiving a grant indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0027] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an uplink transmission may also include operations, features, components, or instructions for sending an uplink transmission to a parent node within a resource allocation. The method also includes.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for communicating a reference signal or a synchronization signal with a child node, wherein an uplink beamforming direction between the relay node and the child node may be identified based on the communication.

[0029] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for identifying a self-interference level between each beamforming direction in a set of uplink beamforming directions between a parent node and a relay node and an uplink beamforming direction between the relay node and a child node, and determining, for full-duplex mode, a channel state for each of the set of uplink beamforming directions between the parent node and the relay node based on the identified self-interference level.

[0030] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an uplink reference signal may also include operations, features, components, or instructions for sending a first uplink reference signal to a parent node for non-full-duplex mode and sending a second uplink reference signal to the parent node for full-duplex mode, wherein the grant indicating the first uplink beamforming direction may be based on the first uplink reference signal and the second uplink reference signal.

[0031] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a signal to a parent node that identifies a first uplink reference signal for non-full-duplex mode and a second uplink reference signal for full-duplex mode.

[0032] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an uplink reference signal may also include operations, features, components, or instructions for sending a first uplink reference signal within a first resource associated with a non-full-duplex mode and sending a second uplink reference signal within a second resource associated with a full-duplex mode.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining a non-full-duplex mode uplink beamforming direction for non-full-duplex transmission to a parent node based on a grant, and determining a full-duplex uplink beamforming direction for full-duplex mode for full-duplex communication between a parent node and a relay node and full-duplex communication between a relay node and a child node, or a combination thereof, based on a grant.

[0034] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the relay node comprises a relay node within an IAB network.

[0035] A method of wireless communication at a parent node is described. The method may include receiving a report from a relay node indicating a set of channel states and corresponding downlink beamforming directions of a set of downlink beamforming directions between the parent node and the relay node, the corresponding downlink beamforming directions corresponding to corresponding channel states of the set of channel states, the channel state set being determined for the set of downlink beamforming directions between the parent node and the relay node based on the downlink beamforming directions between the relay node and the child node; sending a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the set of downlink beamforming directions; and sending a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0036] An apparatus for wireless communication at a parent node is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to receive a report from a relay node indicating a set of channel states and corresponding downlink beamforming directions of a set of downlink beamforming directions between the parent node and the relay node, the corresponding downlink beamforming directions corresponding to corresponding channel states of the set of channel states, the channel state set being determined for the set of downlink beamforming directions between the parent node and the relay node based on the downlink beamforming directions between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the set of downlink beamforming directions; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0037] Another apparatus for wireless communication at a parent node is described. The apparatus may include means for receiving a report from a relay node indicating a set of channel states and corresponding downlink beamforming directions of a set of downlink beamforming directions between the parent node and the relay node, the corresponding downlink beamforming directions corresponding to corresponding channel states of the set of channel states, the channel state set being determined for the set of downlink beamforming directions between the parent node and the relay node based on the downlink beamforming directions between the relay node and the child node; sending a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the set of downlink beamforming directions; and sending a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0038] A non-transitory computer-readable medium storing code for wireless communication at a parent node is described. The code may include instructions executable by a processor to receive a report from a relay node indicating a set of channel states and corresponding downlink beamforming directions of a set of downlink beamforming directions between the parent node and the relay node, the corresponding downlink beamforming directions corresponding to corresponding channel states of the set of channel states, the channel state set being determined for the set of downlink beamforming directions between the parent node and the relay node based on the downlink beamforming directions between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the set of downlink beamforming directions; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a grant may also include operations, features, components, or instructions for sending a grant indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0040] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a downlink transmission from a parent node within a resource allocation.

[0041] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a first downlink beamforming direction from a set of downlink beamforming directions for a resource allocation based on the report.

[0042] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, a send grant may include operations, features, components, or instructions for, for a non-full-duplex mode, sending a grant to identify a second downlink beamforming direction for a non-full-duplex transmission from a parent node, and sending a grant to identify, for a full-duplex mode, a first downlink beamforming direction for a full-duplex mode of full-duplex communication between a parent node and a relay node and full-duplex communication between a relay node and a child node, or a combination thereof.

[0043] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the child node includes a UE or a second relay node.

[0044] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the parent node comprises a parent relay node within the IAB network.

[0045] A method of wireless communication at a parent node is described. The method may include receiving an uplink reference signal from a relay node that is transmitted using a subset of a set of uplink beamforming directions; transmitting a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the set of uplink beamforming directions; and monitoring uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0046] An apparatus for wireless communication at a parent node is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to receive an uplink reference signal from a relay node that is transmitted using a subset of a set of uplink beamforming directions; transmit a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the set of uplink beamforming directions; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0047] Another apparatus for wireless communication at a parent node is described. The apparatus may include means for receiving an uplink reference signal from a relay node that is sent using a subset of a set of uplink beamforming directions; sending a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the set of uplink beamforming directions; and monitoring uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0048] A non-transitory computer-readable medium storing code for wireless communication at a parent node is described. The code may include instructions executable by a processor to receive an uplink reference signal from a relay node transmitted using a subset of a set of uplink beamforming directions; send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the set of uplink beamforming directions; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0049] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a grant may include operations, features, components, or instructions for sending a grant indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0050] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an uplink transmission from a relay node within a resource allocation.

[0051] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a first uplink beamforming direction from a set of uplink beamforming directions for a resource assignment based on an uplink reference signal.

[0052] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving an uplink reference signal may include operations, features, components, or instructions for receiving a first uplink reference signal from a relay node for non-full-duplex mode and receiving a second uplink reference signal from a relay node for full-duplex mode, wherein a grant indicating a first uplink beamforming direction may be based on the first uplink reference signal and the second uplink reference signal.

[0053] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a signal from a relay node that identifies a first uplink reference signal for non-full-duplex mode and a second uplink reference signal for full-duplex mode.

[0054] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a first uplink reference signal via a first resource associated with a non-full-duplex mode and receiving a second uplink reference signal via a second resource associated with a full-duplex mode.

[0055] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the parent node comprises a parent node within an IAB network. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 An example of a wireless communication system supporting beamforming determination for an integrated access and backhaul (IAB) system with full duplex according to aspects of the present disclosure is presented.

[0057] Figure 2 An example of a wireless communication system according to aspects of the present disclosure is shown.

[0058] Figure 3 An example of a process according to aspects of the present disclosure is shown.

[0059] Figure 4 An example of a process according to aspects of the present disclosure is shown.

[0060] Figure 5 An example of a wireless communication system according to aspects of the present disclosure is shown.

[0061] Figure 6 An example of a wireless communication system according to aspects of the present disclosure is provided.

[0062] Figure 7 and Figure 8 A block diagram of a device according to aspects of the present disclosure is shown.

[0063] Figure 9 A block diagram of a communications manager according to aspects of the present disclosure is shown.

[0064] Figure 10 A diagram illustrating a system including a user equipment (UE) according to aspects of the present disclosure is shown.

[0065] Figure 11 A diagram of a system including a base station according to aspects of the present disclosure is shown.

[0066] Figures 12 to 16 A flow chart illustrating a method according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0067] Wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors such as temperature, atmospheric pressure, diffraction, etc. As a result, signal processing techniques such as beamforming may be used to coherently combine energy and overcome path loss at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from base stations and / or user equipment (UE) may be beamformed, e.g., using transmit beams. Additionally, a receiving device may use beamforming techniques to configure an antenna and / or antenna array such that transmissions are received in a directional manner (e.g., using receive beams).

[0068] Some wireless communication systems may support an integrated access backhaul (IAB) network that includes an IAB donor (or anchor) node and one or more relay nodes downstream of the donor node. In some aspects, the IAB network shares resources between access and backhaul links. Typically, an IAB donor node (which may also be referred to as an anchor node) is an access node with a wired connection to a core network. The donor node may have a central unit (CU) function, which is a central entity that controls or otherwise configures resources within the IAB network. The donor node may also have a distributed unit (DU) function that serves as a scheduling node to schedule child nodes (e.g., UEs) of the IAB donor node. Downstream of the IAB donor node may include one or more IAB nodes (also referred to as parent nodes, relay nodes, and / or child nodes) within the IAB network, depending on the node's location within the IAB network, where each relay node constitutes a hop within the IAB network.

[0069] Each IAB node can relay traffic from a donor node through one or more hops (e.g., a relay node). In one example, each IAB node can have a DU function (e.g., a first communication link interface) and a mobile terminal (MT) function (e.g., a second communication link interface). The DU function of the relay node can act as a scheduling node for scheduling the child nodes of the particular relay node, which can be a UE and / or a downstream child node (e.g., a UE and / or a base station within the IAB network). The MT function can act as a scheduling node similar to a UE scheduled by its parent node. In this context, the parent node can be a donor node (e.g., an anchor node) or a parent node within the IAB network (e.g., an upstream wireless node from the perspective of the relay node). Similarly, from the perspective of the upstream donor node or parent node, the child node can include a downstream relay node within the IAB network.

[0070] Aspects of the present disclosure are initially described in the context of wireless communication systems. The described techniques relate to improved methods, systems, devices, and apparatuses that support beamforming determination for an IAB system with full-duplex. Generally, the described techniques provide various techniques to support beamforming direction selection for downlink and uplink in an IAB network that is configured or otherwise supports non-full-duplex and full-duplex communications. In the downlink, this may include a relay node identifying or otherwise determining a channel state for each downlink beamforming direction between its parent node and the relay node. The relay node may determine the channel state based on (multiple) downlink beamforming directions between the relay node and one or more child nodes, at least in some aspects. The relay node may send or otherwise provide a report to the parent node that indicates at least a portion or subset of the channel state and, in some aspects, indicates a corresponding downlink beamforming direction from a plurality of downlink beamforming directions that corresponds to the corresponding channel state.

[0071] The parent node may receive a report from the relay node and, based on the report, respond to the relay node with a grant indicating at least one (e.g., a first) downlink beamforming direction. The grant may also carry or convey an indication of resources corresponding to the first downlink beamforming direction for non-full-duplex mode and full-duplex mode. The relay node may monitor and receive downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0072] In the uplink, a relay node may, at least in some aspects, identify or otherwise determine the channel state of each of a plurality of uplink beamforming directions between its parent node and the relay node based on the uplink beamforming direction between the relay node and its child node. The relay node may then send or otherwise transmit one or more uplink reference signals to the parent node using at least a portion of the plurality of uplink beamforming directions (e.g., based on the channel state). The parent node may use the uplink reference signals to identify or otherwise determine a first uplink beamforming direction from the plurality of uplink beamforming directions. Accordingly, the parent node may send or otherwise transmit a grant to the relay node indicating the first uplink beamforming direction and resources for uplink communication using the first uplink beamforming direction. The parent node may then monitor and receive uplink transmissions from the relay node based on the grant and the first uplink beamforming direction. The relay node may simultaneously receive uplink transmissions from its child node using at least a portion of the resources indicated in the grant.

[0073] Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to beamforming determinations for an IAB system with full duplex.

[0074] Figure 1 1 shows an example of a wireless communication system 100 that supports beamforming determination for an IAB system with full duplex according to aspects of the present disclosure. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 can be a long term evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some cases, the wireless communication system 100 can support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices.

[0075] The base station 105 can communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (any of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0076] Each base station 105 may be associated with a particular geographic coverage area 110 in which it supports communications with various UEs 115. Each base station 105 may provide communication coverage for the respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0077] The geographic coverage area 110 of a base station 105 can be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for a macrocell, a small cell, a hotspot, or other types of cells, or various combinations thereof. In some examples, the base stations 105 can be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 can, for example, include a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0078] The term "cell" refers to a logical communication entity used for communication with base station 105 (e.g., via a carrier), and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish between adjacent cells operating via the same carrier or different carriers. In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types that can provide access to different types of devices (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), etc.). In some cases, the term "cell" can refer to a portion of the geographic coverage area 110 (e.g., a sector) on which the logical entity operates.

[0079] UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be fixed or mobile. UE 115 can also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can also be a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which can be implemented in various items such as appliances, vehicles, meters, etc.

[0080] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that incorporate sensors or meters to measure or capture information and relay that information to a central server or application, which may utilize the information or present it to a human interacting with the program or application. Some UEs 115 may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based billing for services.

[0081] Some UEs 115 may be configured to employ an operating mode that reduces power consumption, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception, but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power conservation techniques for the UE 115 include entering a power-saving "deep sleep" mode when not engaged in active communications or when operating over a limited bandwidth (e.g., in accordance with narrowband communications). In some cases, the UE 115 may be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0082] In some cases, a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more of the group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in the group may be outside the geographic coverage area 110 of the base station 105 or otherwise unable to receive transmissions from the base station 105. In some cases, the group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for the D2D communication. In other cases, the D2D communication is performed between the UEs 115 without the involvement of the base station 105.

[0083] The base stations 105 can communicate with the core network 130 and with each other. For example, the base stations 105 can interface with the core network 130 via backhaul links 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 can communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) via backhaul links 134 (e.g., via X2, Xn, or other interfaces).

[0084] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transferred via the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. Operator IP services may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet switched (PS) streaming services.

[0085] At least some of the network devices, such as the base station 105, may include a subcomponent, such as an access network entity, which may be an example of an access node controller (ANC). Each access network entity may communicate with the UE 115 through a plurality of other access network transport entities, which may be referred to as radio heads, smart radio heads, or transmission points / reception points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., the base station 105).

[0086] The wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Typically, the region of 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band, as wavelengths range from approximately one decimeter to one meter long. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves can penetrate structures sufficiently to allow a macrocell to provide service to a UE 115 located indoors. Transmission using UHF waves can be associated with smaller antennas and shorter distances (e.g., less than 100 km) compared to transmission using the lower frequencies and longer wavelengths of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0087] The wireless communication system 100 may also operate in the very high frequency (SHF) region using a frequency band of 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes frequency bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) band, which may be used opportunistically by devices that can tolerate interference from other users.

[0088] The wireless communication system 100 can also operate in the extremely high frequency (EHF) region of the spectrum (e.g., 30 GHz to 300 GHz), which is also referred to as the millimeter band. In some examples, the wireless communication system 100 can support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antennas of each device can be even smaller and more closely spaced than the UHF antennas. In some cases, this can facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The technology disclosed herein can be employed across transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions may vary from country to country or regulatory agency.

[0089] In some cases, the wireless communication system 100 can utilize licensed radio spectrum bands and unlicensed radio spectrum bands. For example, the wireless communication system 100 can use licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in an unlicensed radio spectrum band, wireless devices such as base stations 105 and UEs 115 can employ a listen-before-talk (LBT) process to ensure that the channel is idle before sending data. In some cases, operations in the unlicensed band can be based on a carrier aggregation configuration in combination with component carriers operating in a licensed band (e.g., LAA). Operations in the unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in the unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0090] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may employ a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may increase spectral efficiency by utilizing multipath signal propagation by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. Multiple signals may, for example, be transmitted by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO) in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO) in which multiple spatial layers are transmitted to multiple devices.

[0091] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape and steer an antenna beam (e.g., a transmit or receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array so that signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements can include the transmitting device or the receiving device applying an amplitude and phase offset to the signal carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0092] In one example, the base station 105 can use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) can be transmitted multiple times in different directions by the base station 105, which can include signals sent according to different sets of beamforming weights associated with different transmission directions. The transmissions in different beam directions can be used to identify (e.g., by the base station 105 or a receiving device such as the UE 115) the beam direction for subsequent transmission and / or reception by the base station 105.

[0093] Some signals, such as data signals associated with a particular receiving device, may be transmitted by base station 105 in a single beam direction (e.g., a direction associated with a receiving device such as UE 115). In some examples, the beam direction associated with transmissions along the single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, UE 115 may receive one or more of the signals transmitted by base station 105 in different directions, and UE 115 may report an indication of the signals it received to base station 105 at a highest signal quality or otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by UE 115) or for transmitting signals in a single direction (e.g., for transmitting data to a receiving device).

[0094] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, a receiving device (e.g., UE 115, which may be an example of a mmW receiving device) may try multiple receive beams. For example, the receiving device may try multiple receive directions by: receiving via different antenna subarrays; processing the received signal according to different antenna subarrays; receiving according to different receive beamforming weight sets applied to the signal received at multiple antenna elements of the antenna array; or processing the received signal according to different receive beamforming weight sets applied to the signal received at multiple antenna elements of the antenna array, any of which may be referred to as "listening" according to different receive beams or receive directions. In some examples, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). A single receive beam can be aligned in a beam direction determined at least in part based on monitoring according to different receive beam directions (e.g., a beam direction determined at least in part to have the highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on monitoring according to multiple beam directions).

[0095] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array with multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Similarly, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0096] In some cases, the wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or packet data convergence protocol (PDCP) layer can be IP-based. The radio link control (RLC) layer can perform data packet segmentation and reassembly to communicate via logical channels. The medium access control (MAC) layer can perform priority processing and multiplex logical channels into transport channels. The MAC layer can also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of RRC connections between the UE 115 and the base station 105 or the core network 130 that supports radio bearers for user plane data. At the physical layer, transport channels can be mapped to physical channels.

[0097] In some cases, UE 115 and base station 105 can support retransmission of data to increase the possibility of successfully receiving the data. HARQ feedback is a technology that increases the possibility of correctly receiving data via communication link 125. HARQ can include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC) and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput at the MAC layer under poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device can support HARQ feedback for the same time slot, wherein the device can provide HARQ feedback for data received in the previous symbol in a specific time slot. In other cases, the device can provide HARQ feedback in a subsequent time slot or according to some other time intervals.

[0098] Time intervals in LTE or NR can be expressed in multiples of a basic time unit, which can refer to, for example, a sampling period T s = 1 / 30,720,000 seconds. The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be denoted as T f =307,200T s . A radio frame can be identified by a system frame number (SFN) in the range of 0 to 1023. Each frame can include 10 subframes numbered from 0 to 9, and each subframe has a duration of 1 ms. The subframe can also be divided into 2 time slots, each time slot has a duration of 0.5 ms, and each time slot can contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix that precedes each symbol period). In addition to the cyclic prefix, each symbol period can contain 2048 sampling periods. In some cases, a subframe can be the smallest scheduling unit of the wireless communication system 100 and can be referred to as a transmission time interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 can be shorter than a subframe or can be dynamically selected (e.g., in a burst of a shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0099] In some wireless communication systems, a time slot may also be divided into multiple mini-slots containing one or more symbols. In some cases, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. For example, the duration of each symbol may vary depending on, for example, the subcarrier spacing or frequency band of operation. In addition, some wireless communication systems may implement time slot aggregation, in which multiple time slots or mini-slots are aggregated and used for communication between UE 115 and base station 105.

[0100] The term "carrier" refers to a set of radio spectrum resources that has a defined physical layer structure for supporting communications on the communication link 125. For example, a carrier of the communication link 125 may include a portion of a radio spectrum band that operates according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may be downlink or uplink (e.g., in FDD mode), or configured to carry both downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on the carrier may be composed of multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0101] The organization structure of the carrier can be different for different radio access technologies (e.g., LTE, LTE-A, LTE-APro, NR). For example, communications on the carrier can be organized according to TTIs or time slots, each of which can include user data and control information or signaling to support decoding of the user data. The carrier can also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate the operation of the carrier. In some examples (e.g., in carrier aggregation configurations), the carrier can also have acquisition signaling or control signaling to coordinate the operation of other carriers.

[0102] Physical channels can be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels can be multiplexed on a downlink carrier using, for example, time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. In some examples, control information transmitted in the physical control channel can be distributed in a concatenated manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0103] A carrier can be associated with a particular bandwidth of radio spectrum, and in some examples, the carrier bandwidth can be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth can be one of a plurality of predetermined bandwidths of the carrier for a particular radio access technology (e.g., 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). In some examples, each served UE 115 can be configured to operate on part or all of the carrier bandwidth. In other examples, some UEs 115 can be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0104] In a system employing MCM technology, a resource element may consist of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Therefore, the more resource elements a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate for the UE 115 may be. In a MIMO system, wireless communication resources may refer to a combination of radio spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communicating with the UE 115.

[0105] A device of the wireless communication system 100 (e.g., a base station 105 or a UE 115) may have a hardware configuration that supports communication on a particular carrier bandwidth, or may be configured to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 and / or a UE 115 that supports simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0106] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers, a feature that may be referred to as carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used for both FDD and TDD component carriers.

[0107] In some cases, the wireless communication system 100 can utilize an enhanced component carrier (eCC). An eCC can be characterized by one or more characteristics, including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC can be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC can also be configured for use in unlicensed spectrum or shared spectrum (e.g., allowing more than one operator to use the spectrum). An eCC characterized by a wide carrier bandwidth can include one or more segments that can be utilized by UEs 115 that are unable to monitor the entire carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0108] In some cases, an eCC may utilize a different symbol duration than other component carriers, which may include using a reduced symbol duration compared to the symbol duration of other component carriers. The shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device utilizing an eCC (such as a UE 115 or a base station 105) may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20 MHz, 40 MHz, 60 MHz, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0109] The wireless communication system 100 may be an NR system that may utilize any combination of licensed spectrum bands, shared spectrum bands, and unlicensed spectrum bands. The flexibility of eCC symbol duration and subcarrier spacing may allow eCCs to be used across multiple spectrums. In some examples, NR shared spectrum may improve spectrum utilization and spectrum efficiency, particularly through dynamic vertical resource sharing (e.g., in the frequency domain) and horizontal resource sharing (e.g., in the time domain).

[0110] A relay node (e.g., a base station 105 and / or a UE 115 acting as or otherwise configured as a relay node within an IAB network) may determine a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on the downlink beamforming direction between the relay node and the child node. The relay node may send a report indicating at least a subset of the channel states to the parent node, along with an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of channel states. The relay node may receive a grant from the parent node indicating a first downlink beamforming direction from the plurality of downlink beamforming directions. The relay node may monitor downlink transmissions from the parent node based at least in part on the grant and the first downlink beamforming direction.

[0111] A relay node (e.g., a base station 105 and / or a UE 115 acting as or otherwise configured as a relay node within an IAB network) may determine a channel state for each of a plurality of uplink beamforming directions between a parent node and the relay node based at least in part on the uplink beamforming direction between the relay node and the child node. The relay node may transmit an uplink reference signal to the parent node using at least a subset of the plurality of uplink beamforming directions based at least in part on the channel state. The relay node may receive a grant from the parent node indicating a first uplink beamforming direction from the plurality of uplink beamforming directions. The relay node may transmit an uplink transmission to the parent node via the first uplink beamforming direction based at least in part on the grant.

[0112] A parent node (e.g., a base station 105 and / or a UE 115 acting as or otherwise configured as a parent node within an IAB network) may receive from a relay node a report indicating a channel state set and corresponding downlink beamforming directions of a plurality of downlink beamforming directions between the parent node and the relay node, the corresponding downlink beamforming directions corresponding to corresponding channel states of the channel state set, the channel state set being determined for the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the downlink beamforming directions between the relay node and the child node. The parent node may send a grant to the relay node based at least in part on the report, the grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions. The parent node may send a downlink transmission to the relay node based at least in part on the grant and the first downlink beamforming direction.

[0113] A parent node (e.g., a base station 105 and / or a UE 115 acting as or otherwise configured as a parent node within an IAB network) may receive an uplink reference signal from a relay node that is transmitted using a subset of a plurality of uplink beamforming directions. The parent node may send a grant to the relay node based at least in part on the uplink reference signal, the grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions. The parent node may monitor uplink transmissions from the relay node based at least in part on the grant and the first uplink beamforming direction.

[0114] Figure 2 An example of a wireless communication system 200 that supports beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include a parent node 205, a relay node 210, a child node 215, and a UE 220, which can be examples of corresponding devices described herein. More specifically, the parent node 205, the relay node 210, and / or the child node 215 can be examples of a UE (such as UE 220) or a base station, such as described herein. The wireless communication system 200 can be configured (at least in some aspects) as an IAB network. Therefore, the parent node 205, the relay node 210, and / or the child node 215 can be considered as a node within the IAB network.

[0115] Next-generation (e.g., 5G) wireless networks are expected to provide ultra-high data rates and support a wide range of application scenarios. Wireless full-duplex (FD) communication can double the link capacity and support radio network nodes to transmit and receive simultaneously on the same frequency band and in the same time slot. This contrasts with half-duplex operation, in which transmission and reception are separated in time or frequency.

[0116] In some cases, an IAB system (such as wireless communication system 200) may include an IAB donor (e.g., in some examples, parent node 205), an IAB node (e.g., relay node 210 and / or child node 215), and a UE (e.g., UE 220). Multiple IAB nodes may be connected in series to improve coverage, where, for a particular IAB node, a node closer to the IAB donor (e.g., an upstream node) is referred to as its parent node, and a node on the other side (e.g., a downstream node) is referred to as its child node. Thus, parent node 205 may be closer to a donor node or anchor node than relay node 210 and / or child node 215. Parent node 205 may be a parent node relative to relay node 210 and a grandparent node relative to child node 215. In some aspects, from the perspective of relay node 210 and / or child node 215, parent node 205 may be a donor node or may simply be an upstream relay node within the IAB network. From the perspective of parent node 205 , relay node 210 may be considered a child node, and from the perspective of child node 215 , may be considered a parent node.

[0117] For a certain IAB node (e.g., relay node 210), there may be six types or categories of links: a downlink (DL) parent backhaul (BH) link and an uplink (UL) parent BH link with its parent node, a DL child BH link and an UL child BH link with its child nodes, and a DL access link and an UL access link with its served UE. Thus, relay node 210 may have DL and UL parent BH links with parent node 205, DL and UL child BH links with child node 215, and DL and UL access links with UE 220. In some examples, relay node 210 may also have DL and UL access links with child node 215 for access communications, e.g., similar to the DL and UL access links with UE 220.

[0118] In a traditional IAB system without full-duplex, for an IAB node, its transmission and reception cannot be carried out simultaneously. Among its six links (for example, from the perspective of relay node 210), the DL father BH, UL child BH and UL access link are reception links, while the UL father BH, DL child BH and DL access link are transmission links. In a non-full-duplex operation mode, any reception link and any transmission link cannot simultaneously transmit data. When the transmission and reception traffic is static, the pattern of the non-simultaneous transmission and reception time slot can be based on the ratio of the transmission traffic and the reception traffic. However, when the transmission and reception traffic is dynamic, or when a certain emergency traffic occurs in the reverse time slot, this non-simultaneous transmission-reception mode cannot meet the requirements. In addition, the half-duplex mode limits the radio resource spectrum efficiency and thus reduces the system throughput. Therefore, the aspects of the described technology can support the use of full-duplex technology to realize simultaneous transmission and reception at an IAB node (such as relay node 210), so as to support dynamic traffic allocation, improved system capacity and the ability to quickly deliver any directional packet.

[0119] According to aspects of the described technology, a full-duplex network node (e.g., a parent node 205, a relay node 210, and / or a child node 215) (such as a base station and / or a UE in a cellular network) can communicate with two half-duplex terminals simultaneously in the uplink and downlink using the same radio resources. Another example wireless full-duplex application scenario is that a relay node can communicate with an anchor node and a mobile terminal simultaneously in a single-hop scenario, or communicate with two other relay nodes in a multi-hop scenario. By doubling the capacity of each single link, full-duplex significantly increases the system throughput of different applications in the wireless communication network 200 and also reduces the transmission latency of time-critical services.

[0120] Aspects of the described techniques support determining enhanced (e.g., optimal) beamforming directions (e.g., precoding weights) in a chain of IAB nodes, where full-duplex mode is activated at each IAB node (e.g., each parent node 205, relay node 210, and / or child node 215 of the IAB network) because the DL / UL beamforming parameters and channel conditions along the chain can be tightly coupled.

[0121] Aspects of the described technology provide an efficient solution for enabling the parent node 205 to determine the beamforming direction (e.g., precoding weight) of a parent BH link based on feedback information from an IAB node (e.g., relay node 210) regarding its full-duplex beamforming direction (e.g., precoding weight).

[0122] Aspects of the described technology can support in-band full-duplex transmission. One aspect of enabling full-duplex transmission is the ability to cancel self-interference from downlink to uplink and vice versa. The nodes of the wireless communication system 200 can support full-duplex radio designs that can suppress up to 110 dBm or more of this self-interference by combining beamforming, analog cancellation, digital cancellation, antenna cancellation, and other techniques. Aspects of the described technology support beamforming direction determination in downlink (or downstream) and uplink (or upstream) transmissions within an IAB network.

[0123] In a downlink scenario, this may include an IAB system (e.g., wireless communication system 200) with full duplex, where, for a particular IAB node (e.g., relay node 210), transmission and reception are occurring simultaneously. A transmitted signal with a particular beamforming direction (e.g., precoding matrix, antenna port, etc.) may cause self-interference to the received signal, and different beamforming directions will result in different self-interference strengths. To reduce or eliminate such self-interference, aspects of the described technology may include transmitting signals in appropriate beamforming directions (e.g., in at least the first downlink or uplink beamforming direction). Thus, aspects of the described technology may support a beamforming direction determination scheme for an IAB node (such as relay node 210) with full duplex.

[0124] In some aspects, downlink data transmission of information (e.g., downlink transmission) may include the relay node 210 determining a channel state for each of a plurality of downlink beamforming directions between the parent node 205 and the relay node 210 based at least in part on the downlink beamforming direction between the relay node 210 and the child node 215. For example, the relay node 210 may determine a plurality of beamforming directions (e.g., precoding matrices, antenna ports, etc.) in a DL child node BH link between the relay node 210 and the child node 215 and / or a DL access link between the relay node 210 and the UE 220. These beamforming directions may be selected to enhance the channel state of the DL child BH link and / or the DL access link. That is, the best of these beamforming directions may constitute the downlink beamforming direction between the relay node 210 and the child node 215.

[0125] Based on the self-interference caused by the determined beamforming direction between the relay node 210 and the child node 215, the relay node 210 can determine the downlink beamforming direction in the DL parent BH link, which has at least a defined channel state (e.g., maximum SINR), with the highest channel state, for example, under self-interference. Such a beamforming direction can be represented by a channel state information reference signal (CSI-RS) resource indicator (CRI), a precoding matrix indicator (PMI), etc. For full-duplex mode, the relay node 210 can determine the CSI (e.g., CRI, rank indicator (RI), PMI, channel quality indicator (CQI), etc.) of the DL parent BH link between the relay node 210 and the parent node 205.

[0126] The relay node 210 may send a report indicating at least a subset of the channel states, and an indication that a corresponding downlink beamforming direction of a plurality of downlink beamforming directions corresponds to a corresponding channel state in the subset of the channel states, to the parent node 205. For example, for each of one or more downlink beamforming directions between the relay node 210 and the child node 215, the relay node 210 may report the CSI of the DL parent BH link to the parent node 205 in non-full duplex mode and full duplex mode, respectively.

[0127] The parent node 205 may receive the report and, based at least in part on the report, send a grant to the relay node 210 indicating a first downlink beamforming direction from a plurality of downlink beamforming directions. For example, the parent node 205 may determine the beamforming direction and radio resource allocation for a DL parent BH link in non-full-duplex mode and / or full-duplex mode, and then indicate the beamforming direction and radio resource allocation to the relay node 210 in a grant (e.g., or in multiple grants).

[0128] The relay node 210 may monitor and receive downlink transmissions from the parent node 205 based at least in part on the grant and the first downlink beamforming direction. For example, the relay node 210 may schedule transmissions using full-duplex mode radio resources and the determined beamforming direction on a DL sub-BH link between the relay node 210 and the child node 215 and / or a DL access link between the relay node 210 and the UE 220.

[0129] In an uplink scenario, the relay node 210 can determine, at least in some aspects, the channel state of each of the multiple uplink beamforming directions between the parent node 205 and the relay node 210 based on one or more uplink beamforming directions between the relay node 210 and the child node 215. For example, the relay node 210 can determine multiple beamforming directions (e.g., precoding matrices, antenna ports, etc.) in the UL child node BH link between the relay node 210 and the child node 215 and / or the UL access link between the relay node 210 and the UE 220. These beamforming directions can be selected to enhance the channel state of the UL child BH link and / or the UL access link. Based on these determined beamforming directions, the relay node 210 can determine a beamforming direction in the UL parent BH link that meets certain SINR-related criteria (e.g., meets a threshold), for example, at the UL parent BH link, the UL child BH link, and / or the UL access link. Such beamforming directions can be represented by SRI, transmitted PMI (TPMI), etc.

[0130] The relay node 210 may, at least in some aspects, transmit an uplink reference signal to the parent node 205 using at least a subset of a plurality of uplink beamforming directions between the relay node 210 and the parent node 205 based on the channel state. For example, the relay node 210 may transmit or otherwise send a sounding reference signal (SRS) transmission to the parent node 205 in the determined beamforming direction on the UL parent BH link. The relay node 210 may also indicate to the parent node 205 whether each transmitted SRS is for full-duplex mode or non-full-duplex mode. For example, the relay node 210 may transmit a first uplink reference signal (or synchronization signal) to the parent node 205 for non-full-duplex mode and a second uplink reference signal (or synchronization signal) to the parent node 205 for full-duplex mode. The relay node 210 may also indicate to the parent node 205 which reference signal is used for which mode, e.g., full-duplex or non-full-duplex.

[0131] The parent node 205 may receive an uplink reference signal from the relay node 210 and, at least in some aspects based on the uplink reference signal, send a grant indicating a first uplink beamforming direction from a plurality of beamforming directions to the relay node 210. For example, the parent node 205 may determine the beamforming direction and radio resource allocation for the UL parent BH link for non-full-duplex mode and full-duplex mode, respectively, and then indicate this information to the relay node 210.

[0132] The relay node 210 may receive a grant from the parent node 205 and send an uplink transmission to the parent node 205 using a first uplink beamforming direction and based at least in part on the grant. For example, the relay node 210 may schedule UL sub-BH link and / or UL access link transmissions using radio resources in full-duplex mode and the determined beamforming direction at the UL sub-BH link and / or UL access link.

[0133] Thus, the wireless communication system 200 provides or is otherwise configured to support a method for a full-duplex-based IAB network to perform beamforming determinations for downlink and uplink data transmissions. During the determination process, the beamforming channel conditions in the parent backhaul link, child backhaul links, and / or access link are jointly considered, and the scheduling results are designed to produce enhanced and balanced throughput across all of these links. The wireless communication system 200 leverages aspects of conventional techniques, but adds a few additional information elements between the relay node 210 and its parent node 205.

[0134] Figure 3 An example of a process 300 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. In some examples, process 300 can implement aspects of wireless communication systems 100 and / or 200. Aspects of process 300 can be implemented by a parent node 305, a relay node 310, a child node 315, and / or a UE 320, which can be examples of corresponding devices described herein. That is, parent node 305, relay node 310, and / or child node 315 can be examples of nodes within an IAB network, which can be implemented in a base station and / or a UE as described herein. Broadly speaking, process 300 illustrates one example of downlink beamforming determination in an IAB network.

[0135] At 325, the relay node 310 may determine a plurality of beamforming directions for a downlink sub-backhaul link between the relay node 310 and the child node 315 and / or a downlink access link between the relay node 310 and the UE 320. In some aspects, the relay node 310 may use a variety of methods to determine the beamforming directions for the downlink sub-backhaul link and / or the downlink access link. One method may include the relay node 310 transmitting SSBs, CSI-RS, etc., whereby the child node 315 and / or the UE 320 select a preferred (e.g., optimal) beamforming direction in the downlink sub-backhaul or downlink access link, respectively, and then reporting the information back to the relay node 310, for example, in a channel state feedback report. Another method may be for the relay node 310 to receive SRSs from the child node 315 and / or the UE 320 and then determine the beamforming directions in the uplink sub-backhaul and / or uplink access link, respectively, based on the quality of the received signals. The relay node 310 may use these beamforming directions in the downlink sub-backhaul and / or the downlink access link according to channel reciprocity.

[0136] At 330 , the parent node 305 may transmit (and the relay node 310 may receive) one or more reference signals, such as a CSI-RS.

[0137] At 335, the relay node 310 may determine, at least in some aspects, a plurality of beamforming directions at the downlink parent backhaul link for full-duplex mode based on the determined beamforming directions at the downlink sub-backhaul link and / or the downlink access link (e.g., based on the beamforming directions determined at 325). For example, the plurality of beamforming directions may be determined based on the beamforming directions determined at 325 and the reference signal received at 330.

[0138] At 340 , the relay node 310 may determine a plurality of beamforming directions at the downlink parent backhaul link for the non-full-duplex mode. For example, the plurality of beamforming directions may be determined based on the reference signal received at 330 .

[0139] At 345 , the relay node 310 may identify or otherwise determine the channel status (eg, CSI) for the non-full-duplex mode and the full-duplex mode, respectively.

[0140] Thus, the relay node 310 can determine the channel state (e.g., CSI) of the beamforming direction in the downlink parent backhaul link in full-duplex mode. This can include the relay node 310 determining the beamforming direction in the downlink parent backhaul link based on the channel gain of the beamforming channel in the downlink parent backhaul link (denoted as S_p) and the self-interference (denoted as I_c2p) caused by the beamforming channel in the downlink sub-backhaul link and / or downlink access link to the beamforming channel in the downlink parent backhaul link. The beamforming channel and the downlink sub-backhaul and / or downlink access link can be generated by a previously determined beamforming direction (e.g., the beamforming direction determined at 325). An example of a criterion that can be used for selecting the beamforming direction in the downlink parent backhaul link can include, but is not limited to, the relay node 310 identifying the beamforming direction associated with a defined (e.g., maximum) value of S_p / I_c2p. The relay node 310 may then determine the channel state or CSI (e.g., CRI, RI, PMI, CQI, etc.) of the downlink parent backhaul link in full-duplex mode. In some aspects, the downlink beamforming direction may be indicated by CRI (e.g., if a beamformed CSI-RSS is transmitted at 330) or PMI (e.g., if a non-beamformed CSI RS is transmitted at 330).

[0141] At 350, the relay node 310 may send (and the parent node 305 may receive) reports (e.g., CSI reports) for both non-full-duplex mode and full-duplex mode, wherein the reports include a flag that indicates or otherwise identifies the CSI reports having the corresponding modes. That is, the report may include a flag that identifies the first CSI as corresponding to the non-full-duplex mode and another flag that identifies the second CSI as corresponding to the full-duplex mode. Thus, the relay node 310 may send or otherwise transmit CSI reports for both full-duplex mode and non-full-duplex mode to the parent node 305, wherein the flag indicates or identifies the non-full-duplex mode and the full-duplex mode (e.g., a subset of the channel states) for each CSI included in the report. The CSI report may indicate a set of channel state information and indicate which beamforming direction each instance of the channel state information corresponds to between the parent node 305 and the relay node 310.

[0142] At 355, the parent node 305 may determine one or more beamforming directions and one or more radio resource allocations (e.g., time, frequency, space, code, etc.) for the non-full-duplex mode and the full-duplex mode, respectively. In some aspects, the radio resource allocation partitioning between the full-duplex mode and the non-full-duplex mode may be in the time domain, the frequency domain, or a mixture of the time and frequency domains.

[0143] In some aspects, this may include the parent node 305 determining the radio resource allocation for the downlink parent backhaul link in full-duplex mode and non-full-duplex mode, respectively. This may depend on, for example, the throughput, traffic conditions, etc. in the downlink parent backhaul link and the downlink sub-backhaul link and / or downlink access link. For example, assuming that the throughput of the downlink parent backhaul link is T1 for non-full-duplex mode and T2 for full-duplex mode, the throughput of the downlink sub-backhaul / downlink access link may be T3 in full-duplex mode. The target throughput ratio of the downlink parent backhaul link to the downlink sub-backhaul / downlink access link may be denoted as β, and the radio resource ratio of the non-full-duplex mode to the full-duplex mode may be γ. In this context, the parent node 305 may implement the formula: Therefore, the parent node 305 can calculate the The percentage of radio resources that is determined to be in non-full-duplex mode, and The percentage of radio resources in full-duplex mode is determined, which can be calculated based on the values T1, T2, T3, and β. Next, the non-full-duplex mode beamforming direction and the full-duplex beamforming direction as reported by the relay node 310 at 350 can be adopted at the allocated radio resources in the downlink parent backhaul link in full-duplex mode and non-full-duplex mode, respectively. In some examples, the parent node 305 can select one or more of the reported beam directions based on the throughput and the corresponding channel state.

[0144] At 360, the parent node 305 may send (and the relay node 310 may monitor and receive) a grant (e.g., a downlink grant) that identifies at least a first downlink beamforming direction and a radio resource allocation for a non-full-duplex mode and a full-duplex mode. For example, the grant may include a first flag that identifies the downlink beamforming direction and radio resource allocation for the non-full-duplex mode and a second flag that identifies the downlink beamforming direction and radio resource allocation for the full-duplex mode. Thus, the parent node 305 may send downlink grants for the full-duplex mode and the non-full-duplex mode to the relay node 310, wherein the grant includes one or more flags that indicate or otherwise identify the non-full-duplex mode and full-duplex mode configuration / configuration for each downlink grant.

[0145] At 365 , the parent node 305 may send (and the relay node 310 may monitor and receive) transmissions on the downlink parent backhaul link using beamforming directions and corresponding radio resource allocations for a non-full-duplex mode.

[0146] At 370 , the parent node 305 may send (and the relay node 310 may monitor and receive) transmissions on the downlink parent backhaul link using beamforming directions and corresponding radio resource allocations in full-duplex mode.

[0147] Concurrently with the transmission at 370 , at 375 , the relay node 310 may send (and the sub-node 315 may monitor and receive) a downlink transmission on the downlink sub-backhaul link using beamforming directions and corresponding radio resource allocations in full-duplex mode.

[0148] Simultaneously with the transmissions at 370 and / or 375, at 380, the relay node 310 may transmit (and the UE 320 may monitor and receive) a downlink transmission on the downlink access link using the beamforming directions and corresponding radio resource allocations in full-duplex mode. That is, according to full-duplex operation, the transmissions at 370, 375, and / or 380 may occur simultaneously. Thus, the relay node 310 may receive a downlink transmission from the parent node 305 at 370 while simultaneously performing a downlink transmission at 375 to the child node 315 and / or to the UEs 320 and 380.

[0149] Figure 4 An example of a process 400 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. In some examples, process 400 can implement aspects of wireless communication systems 100 and / or 200 or process 300. Aspects of process 400 can be implemented by a parent node 405, a relay node 410, a child node 415, and / or a UE 420, which can be examples of corresponding devices described herein. That is, parent node 405, relay node 410, and / or child node 415 can be examples of nodes within an IAB network, which can be implemented in a base station and / or a UE as described herein. Broadly speaking, process 400 illustrates one example of uplink beamforming determination in an IAB network.

[0150] At 425, the relay node 410 may determine a plurality of beamforming directions at the uplink sub-backhaul link between the relay node 410 and the child node 415 and / or at the uplink access link between the relay node 410 and the UE 420. For example, in one option, the relay node 410 may transmit SSBs, CSI-RSs, etc., in such a manner that the child node 415 and / or the UE 420 may be used to select the optimal beamforming direction for the downlink sub-backhaul link / downlink access link, respectively. The child node 415 and / or the UE 420 may then provide a report to the relay node 410 indicating feedback information for each link. The relay node 410 may use the feedback information (e.g., the identified optimal beamforming direction) as the determined beamforming direction based on channel reciprocity. In another option, the relay node 410 may receive one or more SRSs, CSI-RSs, etc. from the sub-node 415 and / or the UE 420, and use these reference signals to determine the beamforming direction in the uplink sub-backhaul link and / or the uplink access link, respectively, based on the quality of the received uplink signal.

[0151] At 430 , the relay node 410 may determine multiple beamforming directions at the uplink parent backhaul link in full duplex mode based on the determined beamforming directions at the uplink child backhaul link and / or uplink access link (eg, as determined at 425 ).

[0152] At 435, the relay node 410 may transmit (and the parent node 405 may monitor and receive) an uplink reference signal (e.g., SRS) in full-duplex mode. At 440, the relay node 410 may transmit (and the parent node 405 may monitor and receive) an uplink reference signal (e.g., SRS) in non-full-duplex mode. In some examples, the SRS in FD mode may be transmitted along with one or more determined beamforming directions.

[0153] At 445, the relay node 410 may transmit (and the parent node 405 may receive) a signal identifying or otherwise indicating the purpose of the uplink reference signal. For example, the signal may indicate that the uplink reference signal transmitted at 435 corresponds to full-duplex mode, and that the uplink reference signal transmitted at 440 corresponds to non-full-duplex mode. In some examples, the relay node 410 may implicitly indicate whether the uplink reference signal is for full-duplex mode or non-full-duplex mode based on the resource location of the uplink reference signal. For example, a first resource may be used to transmit an SRS for non-full-duplex mode, and a different second resource may be used to transmit an SRS for full-duplex mode.

[0154] Therefore, the relay node 410 can send SRS to the parent node 405 in the uplink parent backhaul link in full-duplex mode and non-full-duplex mode. The SRS in full-duplex mode can be sent together with the determined beamforming direction. The relay node 410 can send a message to the parent node 405 to indicate whether each SRS is for non-full-duplex mode or full-duplex mode.

[0155] The relay node 410 may determine, at least in some aspects, a beamforming direction for an uplink parent backhaul link in full-duplex mode based on the functions performed at 430, 435, 440, and / or 445. This may include the relay node 410 determining the beamforming direction in the uplink parent backhaul link based on a channel gain (denoted as S_p) of a beamformed channel in the uplink parent backhaul link and a self-interference (denoted as I_p2c) caused by the beamformed channel in the uplink parent backhaul link relative to a beamformed channel in an uplink sub-backhaul link and / or an uplink access link, wherein the beamformed channels in the uplink sub-backhaul link and / or the uplink access link are generated by or based on previously determined beamforming directions, such as those determined at 430. One example of a criterion that may be used to select a beamforming direction in the uplink parent backhaul link is that the uplink beamforming direction may have a maximum value of S_p / I_p2c. If the relay node 410 does not know S_p, the criterion may be the beamforming direction with the minimum value I_p2c.

[0156] Thus, the relay node 410 can determine the channel state for each of the multiple uplink beamforming directions between the parent node 405 and the relay node 410 based on the uplink beamforming directions between the relay node 410 and the child node 415 and the relay node 410 and the UE 420, at least in some aspects.

[0157] At 450, the parent node 405 may determine one or more beamforming directions and / or one or more radio resource allocations for the non-full-duplex mode and the full-duplex mode, respectively. In some aspects, the parent node 405 may determine the beamforming directions and radio resource allocations for the full-duplex mode and the non-full-duplex mode according to the techniques discussed above with respect to process 300 (e.g., at 355 of process 300). In some aspects, the radio resource allocation partitioning between the full-duplex mode and the non-full-duplex mode may be in the time domain, the frequency domain, or a mixture of the time-frequency domain.

[0158] At 455, the parent node 405 may transmit (and the relay node 410 may monitor and receive) an uplink grant (or uplink grants) that identify the determined beamforming direction and / or radio resource allocation and, in at least some aspects, include a flag indicating whether the beamforming direction / radio resource allocation is for full-duplex mode or for non-full-duplex mode. Thus, the parent node 405 may transmit uplink grants for full-duplex mode and non-full-duplex mode to the relay node 410, wherein a flag in each grant indicates whether the grant is for non-full-duplex mode or full-duplex mode. In some aspects, the beamforming direction (e.g., the first uplink beamforming direction) may be represented by an SRI (e.g., if a beamformed SRS is transmitted at 435 / 440) or a TPMI (e.g., if a non-beamformed SRS is transmitted at 435 / 440).

[0159] At 460, the relay node 410 may send (and the parent node 405 may monitor and receive) an uplink transmission on the uplink parent backhaul link using non-full-duplex mode resources.

[0160] At 465, the relay node 410 may send (and the parent node 405 may monitor and receive) an uplink transmission on the uplink parent backhaul link using full-duplex mode resources. In some examples, the radio resource partitioning between full-duplex mode and non-full-duplex mode may be in the time domain, frequency domain, or a mixed time-frequency domain, among others.

[0161] Concurrently with the transmission at 465 , at 470 , the child node 415 may send (and the parent node 410 may monitor and receive) an uplink transmission on the uplink sub-backhaul link using full-duplex mode resources.

[0162] Simultaneously with the transmissions at 465 and 470, the UE 420 may send (and the relay node 410 may monitor and receive) uplink transmissions on the uplink access link using full-duplex mode resources. That is, the uplink transmissions at 465, 470, and / or 475 may be full-duplex transmissions because the relay node 410 may receive uplink transmissions from the child node 415 and / or the UE 420 on their respective links while simultaneously performing uplink transmissions to the parent node 405 on the uplink parent backhaul link.

[0163] Figure 5An example of a wireless communication system 500 that supports beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. In some examples, the wireless communication system 500 can implement aspects of the wireless communication systems 100 and / or 200 or the processes 300 and / or 400. Aspects of the wireless communication system 500 can be implemented by a parent node 505, a relay node 510, and / or a child node 515, which can be examples of corresponding devices described herein. That is, the parent node 505, the relay node 510, and / or the child node 515 can be examples of nodes within an IAB network, which can be implemented in a base station and / or a UE as described herein. In some examples, the child node 515 can be a child node that communicates with the relay node 510 via an access link (e.g., acting as a UE, e.g., implementing MT functionality from the perspective of the relay node 510), or can be an actual UE that communicates with the relay node 510 via an access link. Broadly speaking, the wireless communication system 500 illustrates an example of downlink beamforming determination in an IAB network. Broadly speaking, the relay node 510 may be configured for or otherwise support full-duplex mode operation.

[0164] In some aspects, a parent node 505 (which may be an example of a donor / anchor node or an upstream relay node from the perspective of a relay node 510) may use transmit (Tx) beam 1 or transmit beam 2 in a downlink parent backhaul link for communication with the relay node 510. Correspondingly, the relay node 510 may use receive (Rx) beam 1 or receive beam 2 for downstream communication with the parent node 505. For example, the parent node 505 may use transmit beam 1 and the relay node 510 may use receive beam 1 for direct or line-of-sight communication, or may use transmit beam 2 and receive beam 2 for indirect communication (e.g., transmit beam 2 may be reflected from a reflective object to the relay node 510). Typically, in the absence of other interference, transmit beam 1 / receive beam 1 may have or otherwise achieve a higher beamforming channel gain than transmit beam 2 / receive beam 2.

[0165] Relay node 510 can use the same radio resource allocation for its downlink access link as child node 515 using transmit beam 3. That is, relay node 510 can select transmit beam 3 because it has the highest channel gain in the downlink access link. However, transmit beam 3 may typically introduce self-interference with receive beam 1 / receive beam 2, with transmit beam 3 introducing higher self-interference with receive beam 1 than with receive beam 2.

[0166] Therefore, when the relay node 510 determines the beamforming direction for the downlink parent backhaul link in full-duplex mode, it can consider the self-interference from the downlink access link (beamformed by transmit beam 3) to the downlink parent backhaul link (beamformed by receive beam 1 or 2). In this case, the relay node 510 can assume that this self-interference is strong for receive beam 1 and weak for receive beam 2. Therefore, the relay node 510 can determine the downlink beamforming direction (e.g., receive beam 2) that can result in the maximum value of the beamforming channel gain in the downlink parent backhaul link divided by the self-interference strength. The relay node 510 can assume that the determined beam is receive beam 2 because the high beamforming channel gain of receive beam 1 is mitigated by its strong self-interference.

[0167] Thus, the relay node 510 may determine, at least in some aspects, a channel state (e.g., CSI, CRI, etc.) for each of a plurality of downlink beamforming directions (e.g., receive beam 1 and receive beam 2) between the parent node 505 and the relay node 510 based on a downlink beamforming direction (e.g., transmit beam 3) between the relay node 510 and the child node 515. The relay node 510 may send a report to the parent node 505 indicating at least a subset of the channel states (e.g., receive beam 1 and / or receive beam 2), along with an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of channel states. The parent node 505 may send a grant to the relay node 510 indicating a first downlink beamforming direction (e.g., transmit beam 2 and / or receive beam 2) from the plurality of beamforming directions. The grant may also carry or convey an indication of resources for the corresponding first downlink beamforming direction for full-duplex mode and non-full-duplex mode (e.g., radio resource allocation in the time and / or frequency domain). The relay node 510 may use this information to monitor (and receive) downlink transmissions from the parent node 505 based on the grant and the first downlink beamforming direction (e.g., using receive beam 2).

[0168] Figure 6An example of a wireless communication system 600 supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. In some examples, the wireless communication system 600 can implement aspects of the wireless communication systems 100, 200, and / or 500 and / or processes 300 and / or 400. Aspects of the wireless communication system 600 can be implemented by a parent node 605, a relay node 610, and / or a child node 615, which can be examples of corresponding devices described herein. That is, the parent node 605, the relay node 610, and / or the child node 615 can be examples of nodes within an IAB network, which can be implemented in a base station and / or a UE as described herein. In some examples, the child node 615 can be a child node communicating with the relay node 610 via an access link (e.g., acting as a UE, such as implementing MT functionality from the perspective of the relay node 610), or can be an actual UE communicating with the relay node 610 via an access link. Broadly speaking, the wireless communication system 600 illustrates an example of uplink beamforming determination in an IAB network. Broadly speaking, the relay node 610 may be configured for or otherwise support full-duplex mode operation.

[0169] In some aspects, the parent node 605 (which may be an example of a donor / anchor node or an upstream relay node from the perspective of the relay node 610) may use receive beam 1 or receive beam 2 in the uplink parent backhaul link for communication with the relay node 610. Correspondingly, the relay node 610 may use transmit beam 1 or transmit beam 2 for such communication with the parent node 605. For example, the relay node 610 may use transmit beam 1 and the parent node 605 may use receive beam 1 for direct or line-of-sight communication, or may use transmit beam 2 and receive beam 2, respectively, for indirect communication (e.g., transmit beam 2 may be reflected from a reflective object to the parent node 605). In general, in the absence of other interference, transmit beam 1 / receive beam 1 may have or otherwise achieve a higher beamforming channel gain than transmit beam 2 / receive beam 2.

[0170] Relay node 610 can use the same radio resource allocation for its uplink access link as child node 615 using receive beam 3. That is, relay node 610 can select receive beam 3 because it has the highest channel gain in the uplink access link. However, transmit beams 1 and 2 can generally introduce self-interference into receive beam 3. In some aspects, the self-interference from receive beam 3 can be higher than that from transmit beam 2.

[0171] The relay node 610 can determine the beamforming direction of the uplink parent backhaul link in full-duplex mode by considering the self-interference from the uplink parent backhaul link (beamformed by transmit beam 1 or transmit beam 2) to the uplink access link (beamformed by receive beam 3). In this case, the relay node 610 can assume that this self-interference is strong for transmit beam 1 and weak for transmit beam 2. Therefore, if the relay node 610 does not have information about the beamforming channel gain in the uplink parent backhaul link, it can identify or determine the first uplink beamforming direction (e.g., transmit beam 2) that may result in the minimum value of the self-interference strength in full-duplex mode.

[0172] Thus, the relay node 610 may, at least in some aspects, determine a channel state for each of a plurality of uplink beamforming directions (e.g., transmit beam 1 and transmit beam 2) between the parent node 605 and the relay node 610 based on an uplink beamforming direction (e.g., receive beam 3) between the relay node 610 and the child node 615. The relay node 610 may, at least in some aspects, transmit an uplink reference signal to the parent node 605 using at least a subset of the plurality of uplink beamforming directions (e.g., transmit beam 1 and / or transmit beam 2) based on the channel state.

[0173] The parent node 605 may receive the uplink reference signal and send a grant to the relay node 610, indicating a first uplink beamforming direction (e.g., receive beam 2 and / or transmit beam 2) from a plurality of uplink beamforming directions. The relay node 610 may receive the grant from the parent node 605 and, based on the grant, send an uplink transmission to the parent node 605 via the first uplink beamforming direction (e.g., transmit beam 2). Simultaneously, the relay node 610 may also receive an uplink transmission from the child node 615 using receive beam 3 (e.g., for full-duplex mode operation).

[0174] Figure 7 A block diagram 700 of a device 705 supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The device 705 can be an example of aspects of a parent node, a relay node, a child node, a UE 115, or a base station 105 as described herein. The device 705 can include a receiver 710, a communication manager 715, and a transmitter 720. The device 705 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0175] The receiver 710 may receive information associated with various information channels (e.g., control channels, data channels, and information related to beamforming determination for an IAB system with full duplex, etc.), such as packets, user data, or control information. The information may be passed to other components of the device 705. The receiver 710 may be as described in reference to Figure 10 and Figure 11 Examples of aspects of the depicted transceiver 1020 or 1120. The receiver 710 may utilize a single antenna or a set of antennas.

[0176] In some examples, the communication manager 715 can be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 710 and transmitter 720 can be implemented as analog components (e.g., amplifiers, filters, antennas, etc.) coupled to the mobile device modem to enable wireless transmission and reception.

[0177] The communication manager 715 as described herein can be implemented to achieve one or more potential advantages. Various implementations can achieve self-interference mitigation for full-duplex transmissions of a device 705 that includes the communication manager 715 in a shared resource. At least one implementation can enable the communication manager 715 to efficiently select beamforming directions. At least one implementation can enable the communication manager 715 to increase throughput to the device 705 by enabling reporting of one or more channel states and one or more corresponding beamforming directions between the device 705 and a child node to enhance selection of one or more beamforming directions between a parent node and the device 705.

[0178] When the device 705 is configured as a relay node, the communication manager 715 can determine the channel state of each of the downlink beamforming directions in the set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node, the report indicating at least a subset of the channel states and an indication that the corresponding downlink beamforming directions of the set of downlink beamforming directions correspond to the corresponding channel states in the subset of channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the set of downlink beamforming directions; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0179] When the device 705 is configured as a relay node, the communication manager 715 can also determine the channel state of each of the uplink beamforming direction set between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; based on the channel state, use at least a subset of the uplink beamforming direction set to send an uplink reference signal to the parent node; receive a grant from the parent node indicating a first uplink beamforming direction from the uplink beamforming direction set; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0180] When the device 705 is configured as a parent node, the communication manager 715 may also receive a report from the relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between the parent node and the relay node, the corresponding downlink beamforming direction corresponding to the corresponding channel state of the channel state set, which is determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the downlink beamforming direction set; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0181] When the device 705 is configured as a parent node, the communication manager 715 may also receive an uplink reference signal from the relay node that is sent using a subset of the set of uplink beamforming directions; send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the set of uplink beamforming directions; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction. The communication manager 715 may be an example of aspects of the communication manager 1010 or 1110 as described herein.

[0182] The communication manager 715 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 715 or its subcomponents may be performed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

[0183] The communication manager 715 or its subcomponents can be physically located in various locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, the communication manager 715 or its subcomponents can be separate and distinct components according to various aspects of the present disclosure. In some examples, the communication manager 715 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof according to various aspects of the present disclosure.

[0184] The transmitter 720 can transmit signals generated by other components of the device 705. In some examples, the transmitter 720 can be co-located with the receiver 710 in the transceiver module. For example, the transmitter 720 can be as described in reference Figure 10 and Figure 11 Examples of aspects of the depicted transceiver 1020 or 1120. The transmitter 720 may utilize a single antenna or a set of antennas.

[0185] Figure 8 A block diagram 800 of a device 805 supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The device 805 can be an example of aspects of a parent node, a relay node, a child node, a device 705, a UE 115, or a base station 105 as described herein. The device 805 can include a receiver 810, a communication manager 815, and a transmitter 830. The device 805 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0186] The receiver 810 may receive information associated with various information channels (e.g., control channels, data channels, and information related to beamforming determination for an IAB system with full duplex, etc.), such as packets, user data, or control information. The information may be passed to other components of the device 805. The receiver 810 may be as described in reference to Figure 10 and Figure 11 Examples of aspects of the depicted transceiver 1020 or 1120. The receiver 810 may utilize a single antenna or a set of antennas.

[0187] The communication manager 815 may be an example of aspects of the communication manager 815 as described herein. The communication manager 815 may include a DL beam direction selection manager 820 and a UL beam direction selection manager 825. The communication manager 815 may be an example of aspects of the communication manager 1010 or 1110 as described herein.

[0188] The DL beam direction selection manager 820 can determine the channel state of each of the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node, the report indicating at least a subset of the channel states and an indication that the corresponding downlink beamforming directions of the downlink beamforming direction set correspond to the corresponding channel states in the subset of the channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the downlink beamforming direction set; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0189] The UL beam direction selection manager 825 can determine the channel state of each of the uplink beamforming direction set between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; based on the channel state, use at least a subset of the uplink beamforming direction set to send an uplink reference signal to the parent node; receive a grant from the parent node indicating a first uplink beamforming direction from the uplink beamforming direction set; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0190] The DL beam direction selection manager 820 can receive a report from a relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between a parent node and the relay node, wherein the corresponding downlink beamforming direction corresponds to a corresponding channel state of the channel state set, and the channel state set is determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the downlink beamforming direction set; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0191] The UL beam direction selection manager 825 can receive an uplink reference signal from a relay node sent using a subset of the uplink beamforming direction set; send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the uplink beamforming direction set; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0192] The transmitter 830 can transmit signals generated by other components of the device 805. In some examples, the transmitter 830 can be co-located with the receiver 810 in the transceiver module. For example, the transmitter 830 can be as described in reference Figure 10 and Figure 11Examples of aspects of the depicted transceiver 1020 or 1120. The transmitter 830 may utilize a single antenna or a set of antennas.

[0193] Figure 9 A block diagram 900 of a communication manager 905 supporting beamforming determinations for an IAB system with full duplex according to aspects of the present disclosure is shown. The communication manager 905 may be an example of aspects of the communication manager 715, the communication manager 815, or the communication manager 1010 described herein. The communication manager 905 may include a DL beam direction selection manager 910, a grant resource manager 915, a reference signal manager 920, a self-interference manager 925, a channel state manager 930, and a UL beam direction selection manager 935. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0194] The DL beam direction selection manager 910 may determine a channel state of each of a downlink beamforming direction set between a parent node and the relay node based on the downlink beamforming direction between the relay node and the child node.

[0195] In some examples, the DL beam direction selection manager 910 can send a report to a parent node indicating at least a subset of channel states and an indication that corresponding downlink beamforming directions of the set of downlink beamforming directions correspond to corresponding channel states in the subset of channel states.

[0196] In some examples, DL beam direction selection manager 910 may receive a grant from a parent node indicating a first downlink beamforming direction from a set of downlink beamforming directions.

[0197] In some examples, DL beam direction selection manager 910 may monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0198] In some examples, the DL beam direction selection manager 910 can receive a report from a relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between the parent node and the relay node, wherein the corresponding downlink beamforming direction corresponds to a corresponding channel state of the channel state set, and the channel state set is determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node.

[0199] In some examples, the DL beam direction selection manager 910 may send a grant to the relay node indicating a first downlink beamforming direction from the set of downlink beamforming directions based on the report.

[0200] In some examples, the DL beam direction selection manager 910 can send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction. In some cases, the child node is a UE or a second relay node. In some cases, the relay node includes a relay node within an IAB network. In some cases, the child node includes a UE or a second relay node. In some cases, the parent node includes a parent relay node within the IAB network.

[0201] The UL beam direction selection manager 935 may determine a channel state of each of the uplink beamforming direction sets between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node.

[0202] In some examples, the UL beam direction selection manager 935 may send an uplink reference signal to the parent node using at least a subset of the set of uplink beamforming directions based on the channel state.

[0203] In some examples, the UL beam direction selection manager 935 may receive a grant from a parent node indicating a first uplink beamforming direction from a set of uplink beamforming directions.

[0204] In some examples, the UL beam direction selection manager 935 may send an uplink transmission to the parent node via the first uplink beamforming direction based on the grant.

[0205] In some examples, the UL beam direction selection manager 935 may receive an uplink reference signal from a relay node that is sent using a subset of the set of uplink beamforming directions.

[0206] In some examples, the UL beam direction selection manager 935 may send a grant to the relay node indicating a first uplink beamforming direction from a set of uplink beamforming directions based on an uplink reference signal.

[0207] In some examples, the UL beam direction selection manager 935 may monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0208] The grant resource manager 915 may receive grants indicating resource allocations for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0209] In some examples, the grant resource manager 915 may receive a downlink transmission from a parent node within a resource allocation.

[0210] In some examples, the grant resource manager 915 can send the second downlink transmission to the child node within the resource allocation via a downlink beamforming direction between the relay node and the child node.

[0211] In some examples, grant resource manager 915 may receive grants indicating resource allocations for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0212] In some examples, the grant resource manager 915 may send an uplink transmission to the parent node within the resource allocation, the method also including.

[0213] In some examples, grant resource manager 915 may send grants indicating resource allocations for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0214] In some examples, the grant resource manager 915 may send downlink transmissions from the parent node within the resource allocation.

[0215] In some examples, the grant resource manager 915 may select a first downlink beamforming direction from a set of downlink beamforming directions for resource allocation based on the report.

[0216] In some examples, the grant resource manager 915 may send a grant to identify a second downlink beamforming direction for non-full-duplex transmission from the parent node for non-full-duplex mode.

[0217] In some examples, the grant resource manager 915 may send a grant to identify a first downlink beamforming direction for full duplex mode for full duplex communication between a parent node and a relay node and full duplex communication between a relay node and a child node, or a combination thereof.

[0218] In some examples, grant resource manager 915 may send grants indicating resource allocations for simultaneous transmission and reception when the relay node operates in full-duplex mode.

[0219] In some examples, the grant resource manager 915 can receive an uplink transmission from a relay node within a resource allocation.

[0220] In some examples, the grant resource manager 915 may select a first uplink beamforming direction from a set of uplink beamforming directions for a resource allocation based on an uplink reference signal.

[0221] The reference signal manager 920 may transmit a reference signal or a synchronization signal together with the subnode, wherein a downlink beamforming direction between the relay node and the subnode is identified based on the transmission.

[0222] In some examples, the reference signal manager 920 may transmit a reference signal or a synchronization signal with the subnode, wherein the uplink beamforming direction between the relay node and the subnode is identified based on the transmission.

[0223] In some examples, the reference signal manager 920 may send a first uplink reference signal to the parent node for non-full-duplex mode.

[0224] In some examples, the reference signal manager 920 can send a second uplink reference signal to the parent node for full-duplex mode, where the grant indicating the first uplink beamforming direction is based on the first uplink reference signal and the second uplink reference signal.

[0225] In some examples, the reference signal manager 920 can send a signal to the parent node that identifies a first uplink reference signal for non-full-duplex mode and a second uplink reference signal for full-duplex mode.

[0226] In some examples, the reference signal manager 920 may send a first uplink reference signal within a first resource associated with a non-full-duplex mode.

[0227] In some examples, reference signal manager 920 may send a second uplink reference signal within second resources associated with full-duplex mode.

[0228] In some examples, reference signal manager 920 may determine a non-full-duplex mode uplink beamforming direction for non-full-duplex transmission to a parent node based on the grant.

[0229] In some examples, the reference signal manager 920 may determine full-duplex uplink beamforming directions for full-duplex modes of full-duplex communication between a parent node and a relay node and full-duplex communication between a relay node and a child node, or a combination thereof, based on the grant.

[0230] In some examples, the reference signal manager 920 may receive a first uplink reference signal from a relay node for non-full-duplex mode.

[0231] In some examples, the reference signal manager 920 may receive a second uplink reference signal from the relay node for full-duplex mode, wherein the grant indicating the first uplink beamforming direction is based on the first uplink reference signal and the second uplink reference signal.

[0232] In some examples, the reference signal manager 920 may receive a signal from a relay node that identifies a first uplink reference signal for a non-full-duplex mode and a second uplink reference signal for a full-duplex mode.

[0233] In some examples, the reference signal manager 920 may receive a first uplink reference signal via a first resource associated with a non-full-duplex mode.

[0234] In some examples, reference signal manager 920 may receive a second uplink reference signal via second resources associated with full-duplex mode.

[0235] The self-interference manager 925 may identify a self-interference level between each downlink beamforming direction in the set of downlink beamforming directions between the parent node and the relay node and the downlink beamforming direction between the relay node and the child node.

[0236] In some examples, the self-interference manager 925 may determine the channel state for each of the set of downlink beamforming directions between the parent node and the relay node based on the identified self-interference level for full-duplex mode.

[0237] In some examples, the self-interference manager 925 can identify a self-interference level between each beamforming direction in a set of uplink beamforming directions between the parent node and the relay node and the uplink beamforming direction between the relay node and the child node.

[0238] In some examples, the self-interference manager 925 may determine the channel state for each of the set of uplink beamforming directions between the parent node and the relay node based on the identified self-interference level for full-duplex mode.

[0239] The channel state manager 930 may determine a first channel state for each of a set of downlink beamforming directions between the parent node and the relay node for non-full-duplex mode.

[0240] In some examples, the channel state manager 930 can determine a second channel state for each of a set of downlink beamforming directions between a parent node and a relay node for full-duplex mode, wherein a report indicating a subset of channel states is determined based on the first and second channel states.

[0241] In some examples, the channel state manager 930 can determine a beamforming channel gain for each of the downlink beamforming direction sets between the parent node and the relay node, wherein a first channel state for each of the downlink beamforming direction sets between the parent node and the relay node is determined based on the beamforming channel gain for each of the downlink beamforming direction sets between the parent node and the relay node.

[0242] In some examples, the channel state manager 930 can determine a ratio of the beamforming channel gain to the self-interference level of each of the downlink beamforming directions in the set between the parent node and the relay node based on the identified self-interference level and the determined beamforming channel gain, wherein the second channel state of each of the downlink beamforming directions in the set between the parent node and the relay node is determined based on the ratio.

[0243] In some examples, channel state manager 930 may determine a non-full-duplex mode downlink beamforming direction for a non-full-duplex transmission from a parent node based on the grant.

[0244] In some examples, the channel state manager 930 may determine full-duplex downlink beamforming directions for full-duplex modes of full-duplex communication between a parent node and a relay node and full-duplex communication between a relay node and a child node, or a combination thereof, based on the grant.

[0245] Figure 10 A diagram of a system 1000 of a device 1005 supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The device 1005 may be an example of or include components of a parent node, relay node, child node, device 705, device 805, or UE 115 as described herein. The device 1005 may include components for two-way voice and data communication, including components for sending and receiving communications, including a communication manager 1010, a transceiver 1020, an antenna 1025, a memory 1030, a processor 1040, and an I / O controller 1050. These components may communicate electronically via one or more buses (e.g., bus 1055).

[0246] The communication manager 1010 can determine the channel state of each of the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node, the report indicating at least a subset of the channel states and an indication that the corresponding downlink beamforming directions of the downlink beamforming direction set correspond to the corresponding channel states in the subset of channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the downlink beamforming direction set; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0247] The communication manager 1010 can also determine the channel state of each of the uplink beamforming direction set between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; based on the channel state, use at least a subset of the uplink beamforming direction set to send an uplink reference signal to the parent node; receive a grant from the parent node indicating a first uplink beamforming direction from the uplink beamforming direction set; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0248] The communication manager 1010 may also receive a report from the relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between the parent node and the relay node, the corresponding downlink beamforming direction corresponding to the corresponding channel state of the channel state set, the channel state set being determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the downlink beamforming direction set; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0249] The communication manager 1010 may also receive an uplink reference signal from the relay node sent using a subset of the uplink beamforming direction set; send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the uplink beamforming direction set; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0250] The transceiver 1020 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 1020 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1020 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, as well as demodulate packets received from the antenna.

[0251] In some cases, a wireless device may include a single antenna 1025. However, in some cases, a device may have more than one antenna 1025, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

[0252] Memory 1030 may include RAM, ROM, or a combination thereof. Memory 1030 may store computer-readable code 1035 including instructions that, when executed by a processor (e.g., processor 1040), cause the device to perform the various functions described herein. In some cases, memory 1030 may contain, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0253] The processor 1040 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1040 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks that support beamforming determination for an IAB system with full duplex).

[0254] I / O controller 1050 can manage input and output signals for device 1005. I / O controller 1050 can also manage peripheral devices that are not integrated into device 1005. In some cases, I / O controller 1050 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1050 can utilize a computer such as 1005 .

[0255] The code 1035 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 1035 may not be directly executable by the processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0256] Figure 11A diagram of a system 1100 of a device 1105 supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The device 1105 may be an example of or include components of the device 705, device 805, parent node, relay node, child node, or base station 105 as described herein. The device 1105 may include components for two-way voice and data communication, including components for sending and receiving communications, including a communication manager 1110, a network communication manager 1115, a transceiver 1120, an antenna 1125, a memory 1130, a processor 1140, and an inter-station communication manager 1145. These components may communicate electronically via one or more buses (e.g., bus 1155).

[0257] The communication manager 1110 can determine the channel state of each of the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a report to the parent node, the report indicating at least a subset of the channel states and an indication that the corresponding downlink beamforming directions of the downlink beamforming direction set correspond to the corresponding channel states in the subset of channel states; receive a grant from the parent node indicating a first downlink beamforming direction from the downlink beamforming direction set; and monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction.

[0258] The communication manager 1110 can also determine the channel state of each of the uplink beamforming direction set between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node; based on the channel state, send an uplink reference signal to the parent node using at least a subset of the uplink beamforming direction set; receive a grant from the parent node indicating a first uplink beamforming direction from the uplink beamforming direction set; and based on the grant, send an uplink transmission to the parent node via the first uplink beamforming direction.

[0259] The communication manager 1110 may also receive a report from the relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between the parent node and the relay node, the corresponding downlink beamforming direction corresponding to a corresponding channel state of the channel state set, the channel state set being determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node; send a grant to the relay node based on the report, the grant indicating a first downlink beamforming direction from the downlink beamforming direction set; and send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction.

[0260] The communication manager 1110 may also receive an uplink reference signal from the relay node sent using a subset of the uplink beamforming direction set; send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from the uplink beamforming direction set; and monitor uplink transmissions from the relay node based on the grant and the first uplink beamforming direction.

[0261] The network communications manager 1115 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1115 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0262] The transceiver 1120 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 1120 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1120 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, as well as demodulate packets received from the antenna.

[0263] In some cases, a wireless device may include a single antenna 1125. However, in some cases, a device may have more than one antenna 1125, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

[0264] Memory 1130 may include RAM, ROM, or a combination thereof. Memory 1130 may store computer-readable code 1135 including instructions that, when executed by a processor (e.g., processor 1140), cause the device to perform the various functions described herein. In some cases, memory 1130 may contain, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0265] The processor 1140 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1140 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1140. The processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks that support beamforming determination for an IAB system with full duplex).

[0266] The inter-site communication manager 1145 can manage communications with other base stations 105 and can include a controller or scheduler for coordinating with other base stations 105 to control communications with the UE 115. For example, the inter-site communication manager 1145 can coordinate the scheduling of transmissions to the UE 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-site communication manager 1145 can provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between the base stations 105.

[0267] The code 1135 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. The code 1135 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 1135 may not be directly executable by the processor 1140, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0268] Figure 12 1 is a flow chart illustrating a method 1200 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure. The operations of the method 1200 may be implemented by a UE 115 or a base station 105 as described herein or components thereof. For example, the method 1200 may be implemented by a reference to Figures 7 to 11 The communication manager described herein performs the operations of method 1200. In some examples, the UE or base station may execute an instruction set to control functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

[0269] At 1205, the UE or base station may determine the channel state of each of the downlink beamforming direction sets between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node. The operation of 1205 may be performed according to the method described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1205 are described.

[0270] At 1210, the UE or base station may send a report to the parent node, the report indicating at least a subset of channel states and an indication that a corresponding downlink beamforming direction of a set of downlink beamforming directions corresponds to a corresponding channel state in the subset of channel states. The operations of 1210 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1210 are described.

[0271] At 1215, the UE or base station may receive a grant from a parent node indicating a first downlink beamforming direction from a set of downlink beamforming directions. The operations of 1215 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1215 are described.

[0272] At 1220, the UE or base station may monitor downlink transmissions from the parent node based on the grant and the first downlink beamforming direction. The operations of 1220 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1220 are described.

[0273] Figure 13 13. A flowchart of a method 1300 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE 115 or a base station 105 as described herein or components thereof. For example, the method 1300 may be implemented by a reference to Figures 7 to 11 The communication manager described herein performs the operations of method 1300. In some examples, the UE or base station may execute an instruction set to control functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

[0274] At 1305, the UE or base station may determine the channel state of each of the downlink beamforming direction sets between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node. The operation of 1305 may be performed according to the method described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1305 are described.

[0275] At 1310, the UE or base station may send a report to a parent node indicating at least a subset of channel states and an indication that a corresponding downlink beamforming direction of a set of downlink beamforming directions corresponds to a corresponding channel state in the subset of channel states. The operations of 1310 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1310 are described.

[0276] At 1315, the UE or base station may receive a grant from a parent node indicating a first downlink beamforming direction from a set of downlink beamforming directions. The operations of 1315 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11Aspects of the operations of the DL beam direction selection manager 1315 are described.

[0277] At 1320, the UE or base station may receive a grant indicating resource allocation for simultaneous transmission and reception when the relay node operates in full-duplex mode. The operations of 1320 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operation of the licensing resource manager execution 1320 are described.

[0278] At 1325, the UE or base station may monitor the downlink transmission from the parent node based on the grant and the first downlink beamforming direction. The operations of 1325 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1325 are described.

[0279] Figure 14 14 is a flow chart illustrating a method 1400 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure. The operations of the method 1400 may be implemented by a UE 115 or a base station 105 as described herein or components thereof. For example, the method 1400 may be implemented by a reference to Figures 7 to 11 The communication manager described herein performs the operations of method 1400. In some examples, the UE or base station may execute an instruction set to control functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

[0280] At 1405, the UE or base station may determine the channel state of each of the uplink beamforming direction sets between the parent node and the relay node based on the uplink beamforming direction between the relay node and the child node. The operation of 1405 may be performed according to the method described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1405 are described.

[0281] At 1410, the UE or base station may send an uplink reference signal to the parent node using at least a subset of the uplink beamforming direction set based on the channel state. The operations of 1410 may be performed according to the methods described herein. In some examples, the reference signal may be transmitted by the parent node. Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1410 are described.

[0282] At 1415, the UE or base station may receive a grant from a parent node indicating a first uplink beamforming direction from a set of uplink beamforming directions. The operations of 1415 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1415 are described.

[0283] At 1420, the UE or base station may send an uplink transmission to the parent node via the first uplink beamforming direction based on the grant. The operations of 1420 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1420 are described.

[0284] Figure 15 1 is a flow chart illustrating a method 1500 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE 115 or a base station 105 as described herein or components thereof. For example, the method 1500 may be implemented by a reference to Figures 7 to 11 The communication manager described herein performs the operations of method 1500. In some examples, the UE or base station may execute an instruction set to control functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

[0285] At 1505, the UE or base station may receive a report from the relay node indicating a channel state set and a corresponding downlink beamforming direction of a downlink beamforming direction set between the parent node and the relay node, the corresponding downlink beamforming direction corresponding to a corresponding channel state of the channel state set, the channel state set being determined for the downlink beamforming direction set between the parent node and the relay node based on the downlink beamforming direction between the relay node and the child node. The operation of 1505 may be performed according to the methods described herein. In some examples, the operation may be performed by reference to Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1505 are described.

[0286] At 1510, the UE or base station may send a grant to the relay node indicating a first downlink beamforming direction from a set of downlink beamforming directions based on the report. The operations of 1510 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1510 are described.

[0287] At 1515, the UE or base station may send a downlink transmission to the relay node based on the grant and the first downlink beamforming direction. The operations of 1515 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the DL beam direction selection manager 1515 are described.

[0288] Figure 16 16. A flow chart of a method 1600 for supporting beamforming determination for an IAB system with full duplex according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a UE 115 or a base station 105 as described herein or components thereof. For example, the method 1600 may be implemented by a reference to Figures 7 to 11 The communication manager described herein performs the operations of method 1600. In some examples, the UE or base station may execute an instruction set to control functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

[0289] At 1605, the UE or base station may receive an uplink reference signal from a relay node that is sent using a subset of the uplink beamforming direction set. The operations of 1605 may be performed according to the methods described herein. In some examples, the reference signal may be transmitted by the relay node using a subset of the uplink beamforming direction set. Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1605 are described.

[0290] At 1610, the UE or base station may send a grant to the relay node based on the uplink reference signal, the grant indicating a first uplink beamforming direction from a set of uplink beamforming directions. The operations of 1610 may be performed according to the methods described herein. In some examples, the reference signal may be transmitted by the relay node. Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1610 are described.

[0291] At 1615, the UE or base station may monitor the uplink transmission from the relay node based on the grant and the first uplink beamforming direction. The operation of 1615 may be performed according to the methods described herein. In some examples, the reference Figures 7 to 11 Aspects of the operations of the UL beam direction selection manager 1615 are described.

[0292] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more of the methods may be combined.

[0293] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. A CDMA system can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and the like. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 versions can be commonly referred to as CDMA2000 1X, 1X, and the like. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system can implement radio technologies such as Global System for Mobile Communications (GSM).

[0294] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization called "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization called "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the systems and radio technologies mentioned herein as well as other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in many descriptions, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.

[0295] A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by a UE through a service subscription with a network provider. Compared to a macro cell, a small cell may be associated with a lower-power base station and may operate in the same or different frequency band (e.g., licensed, unlicensed, etc.) as the macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. For example, a pico cell may cover a smaller geographic area and may allow unrestricted access by a UE through a service subscription with a network provider. A femto cell may also cover a smaller geographic area (e.g., a home) and may provide restricted access by a UE associated with the femto cell (e.g., a UE in a closed subscriber group (CSG), a UE of a home user, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communications using one or more component carriers.

[0296] The wireless communication systems described herein can support synchronous operation or asynchronous operation. For synchronous operation, base stations can have similar frame timing, and transmissions from different base stations can be roughly aligned in time. For asynchronous operation, base stations can have different frame timing, and transmissions from different base stations can be misaligned in time. The techniques described herein can be used for either synchronous or asynchronous operation.

[0297] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0298] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0299] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using a processor, hardware, firmware, hardwiring, or a combination of any of these. Features that implement the functions may also be physically located in different locations, including distributed, such that portions of the functions are implemented at different physical locations.

[0300] Computer-readable media include non-transitory computer storage media and communication media, and the communication media include any medium that is convenient for transmitting a computer program from one place to another.Non-transitory storage media can be any available medium that can be accessed by a general-purpose computer or a special-purpose computer.As an example and not limitation, non-transitory computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or can be used to carry or store required program code components and any other non-transitory medium that can be accessed by a general-purpose computer or a special-purpose computer or a general-purpose processor or a special-purpose processor in the form of instructions or data structures. In addition, any connection is appropriately referred to as a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwaves are used to transmit software from a website, a server or other remote source, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are included in the definition of medium. Disk and disc, as used herein, include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0301] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0302] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes the similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, regardless of the second reference number or other subsequent reference numbers.

[0303] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that can be implemented or within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "superior to other examples." To provide an understanding of the described techniques, this detailed description includes specific details. However, these techniques can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0304] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the invention. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be construed in the widest sense consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a relay node, comprising: determining a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on the downlink beamforming direction between the relay node and the child node; sending a report to the parent node, the report indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of the channel states; receiving a grant from the parent node indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as Downlink transmissions from the parent node are monitored based at least in part on the grant and the first downlink beamforming direction.

2. The method according to claim 1, wherein Receiving the license also includes: The grant is received indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

3. The method according to claim 2, further comprising: receiving the downlink transmission from the parent node within the resource allocation; as well as A second downlink transmission is sent to the child node within the resource allocation via the downlink beamforming direction between the relay node and the child node.

4. The method according to claim 1, further comprising: A reference signal or a synchronization signal is communicated with the child node, wherein the downlink beamforming direction between the relay node and the child node is identified based at least in part on the communication.

5. The method according to claim 1, further comprising: identifying a self-interference level between each of the plurality of downlink beamforming directions between the parent node and the relay node and the downlink beamforming direction between the relay node and the child node; as well as For full-duplex mode, the channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined based at least in part on the identified self-interference level.

6. The method according to claim 1, wherein Determining the channel state for each of the plurality of downlink beamforming directions further comprises: determining a first channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node for a non-full-duplex mode; and For full-duplex mode, determining a second channel state for each of the multiple downlink beamforming directions between the parent node and the relay node, wherein the report indicating the subset of the channel states is based at least in part on the first channel state and the second channel state.

7. The method according to claim 5, wherein: Determining the channel state for each of the plurality of downlink beamforming directions comprises: determining a beamforming channel gain for each of the plurality of downlink beamforming directions between the parent node and the relay node, wherein, for a non-full-duplex mode, a first channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined at least in part based on the beamforming channel gain for each of the plurality of downlink beamforming directions between the parent node and the relay node; and determining a ratio of a beamforming channel gain to a self-interference level for each of the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the identified self-interference level and the determined beamforming channel gain, wherein, for full-duplex moderation, a second channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined based at least in part on the ratio.

8. The method according to claim 6, further comprising: determining a non-full-duplex mode downlink beamforming direction for a non-full-duplex transmission from the parent node based at least in part on the grant; as well as A full-duplex downlink beamforming direction for a full-duplex mode of full-duplex communication between the parent node and the relay node, full-duplex communication between the relay node and the child node, or a combination thereof is determined based at least in part on the grant.

9. The method according to claim 1, wherein The child node is a user equipment (UE) or a second relay node.

10. The method according to claim 1, wherein The relay node includes a relay node within an integrated access and backhaul (IAB) network.

11. A method for wireless communication at a relay node, comprising: determining a channel state for each of a plurality of uplink beamforming directions between a parent node and the relay node based at least in part on the uplink beamforming direction between the relay node and the child node; sending an uplink reference signal to the parent node using at least a subset of the plurality of uplink beamforming directions based at least in part on the channel state; receiving a grant from the parent node indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Based at least in part on the grant, an uplink transmission is sent to the parent node via the first uplink beamforming direction.

12. The method according to claim 11, wherein Receiving the permission includes: The grant is received indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

13. The method according to claim 12, wherein: Sending the uplink transmission further includes: sending the uplink transmission to the parent node within the resource allocation, the method further comprising; and A second uplink transmission is received from the child node within the resource allocation via the uplink beamforming direction between the relay node and the child node.

14. The method according to claim 11, further comprising: A reference signal or a synchronization signal is communicated with the child node, wherein the uplink beamforming direction between the relay node and the child node is identified based at least in part on the communication.

15. The method according to claim 11, further comprising: identifying a self-interference level between each of the plurality of uplink beamforming directions between the parent node and the relay node and the uplink beamforming direction between the relay node and the child node; as well as For full-duplex mode, the channel state for each of a plurality of uplink beamforming directions between the parent node and the relay node is determined based at least in part on the identified self-interference level.

16. The method according to claim 11, wherein Sending the uplink reference signal further includes: For non-full-duplex mode, sending a first uplink reference signal to the parent node; and For full-duplex mode, a second uplink reference signal is sent to the parent node, wherein the grant indicating the first uplink beamforming direction is based at least in part on the first uplink reference signal and the second uplink reference signal.

17. The method according to claim 16, further comprising: A signal is sent to the parent node, the signal identifying the first uplink reference signal for the non-full-duplex mode and the second uplink reference signal for the full-duplex mode.

18. The method according to claim 16, wherein Sending the uplink reference signal further includes: transmitting the first uplink reference signal within first resources associated with the non-full-duplex mode; and The second uplink reference signal is sent within second resources associated with the full-duplex mode.

19. The method according to claim 16, further comprising: determining a non-full-duplex mode uplink beamforming direction for non-full-duplex transmission to the parent node based at least in part on the grant; as well as A full-duplex uplink beamforming direction for a full-duplex mode of full-duplex communication between the parent node and the relay node, full-duplex communication between the relay node and the child node, or a combination thereof is determined based at least in part on the grant.

20. The method according to claim 11, wherein The relay node includes a relay node within an integrated access and backhaul (IAB) network.

21. A method for wireless communication at a parent node, comprising: receiving, from a relay node, a report indicating a set of channel states and respective downlink beamforming directions of a plurality of downlink beamforming directions between the parent node and the relay node, the respective downlink beamforming directions corresponding to respective channel states of the set of channel states, the set of channel states being determined for the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the downlink beamforming directions between the relay node and a child node; sending a grant to the relay node based at least in part on the report, the grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as A downlink transmission is sent to the relay node based at least in part on the grant and the first downlink beamforming direction.

22. The method according to claim 21, wherein Sending the permission also includes: The grant is sent indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

23. The method according to claim 22, further comprising: The downlink transmission from the parent node is sent within the resource allocation.

24. The method of claim 22, further comprising: Based at least in part on the report, the first downlink beamforming direction is selected from the plurality of downlink beamforming directions of the resource allocation.

25. The method according to claim 21, wherein Sending the permission includes: For non-full-duplex mode, sending the grant to identify a second downlink beamforming direction for non-full-duplex transmission from the parent node; and For full-duplex mode, the grant is sent to identify the first downlink beamforming direction of the full-duplex mode of full-duplex communication between the parent node and the relay node, full-duplex communication between the relay node and the child node, or a combination thereof.

26. The method according to claim 21, wherein The child node includes a user equipment (UE) or a second relay node.

27. The method according to claim 21, wherein The parent node comprises a parent relay node within an integrated access and backhaul (IAB) network.

28. A method for wireless communication at a parent node, comprising: receiving, from a relay node, an uplink reference signal transmitted using a subset of the plurality of uplink beamforming directions; sending a grant to the relay node based at least in part on the uplink reference signal, the grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Uplink transmissions from the relay node are monitored based at least in part on the grant and the first uplink beamforming direction.

29. The method according to claim 28, wherein Sending the permission includes: The grant is sent indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

30. The method of claim 29, further comprising: The uplink transmission is received from the relay node within the resource allocation.

31. The method of claim 29, further comprising: The first uplink beamforming direction is selected from the plurality of uplink beamforming directions of the resource assignment based at least in part on the uplink reference signal.

32. The method of claim 28, wherein: Receiving the uplink reference signal includes: For non-full-duplex mode, receiving a first uplink reference signal from the relay node; and For full-duplex mode, a second uplink reference signal is received from the relay node, wherein the grant indicating the first uplink beamforming direction is based at least in part on the first uplink reference signal and the second uplink reference signal.

33. The method of claim 32, further comprising: A signal is received from the relay node, the signal identifying the first uplink reference signal of the non-full-duplex mode and the second uplink reference signal of the full-duplex mode.

34. The method of claim 32, further comprising: receiving the first uplink reference signal via a first resource associated with the non-full-duplex mode; as well as The second uplink reference signal is received via second resources associated with the full-duplex mode.

35. The method of claim 28, wherein The parent node includes a parent node within an integrated access and backhaul (IAB) network.

36. An apparatus for wireless communication at a relay node, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: determining a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on the downlink beamforming direction between the relay node and the child node; sending a report to the parent node, the report indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of the channel states; receiving a grant from the parent node indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as Downlink transmissions from the parent node are monitored based at least in part on the grant and the first downlink beamforming direction.

37. The apparatus of claim 36, further comprising a receiver, wherein The instructions for receiving the permission are also executable by the processor to cause the device to: The grant is received via the receiver, indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

38. The apparatus according to claim 37, wherein The instructions are further executable by the processor to cause the apparatus to: receiving the downlink transmission from the parent node within the resource allocation; and A second downlink transmission is sent to the child node within the resource allocation via the downlink beamforming direction between the relay node and the child node.

39. The apparatus according to claim 36, wherein The instructions are further executable by the processor to cause the apparatus to: A reference signal or a synchronization signal is communicated with the child node, wherein the downlink beamforming direction between the relay node and the child node is identified based at least in part on the communication.

40. The apparatus of claim 36, wherein The instructions are further executable by the processor to cause the apparatus to: identifying a self-interference level between each of the plurality of downlink beamforming directions between the parent node and the relay node and the downlink beamforming direction between the relay node and the child node; as well as For full-duplex mode, the channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined based at least in part on the identified self-interference level.

41. The apparatus of claim 36, wherein: The instructions for determining the channel state for each of the plurality of downlink beamforming directions are further executable by the processor to cause the apparatus to: determining, for a non-full-duplex mode, a first channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node; as well as For full-duplex mode, determining a second channel state for each of the multiple downlink beamforming directions between the parent node and the relay node, wherein the report indicating the subset of the channel states is based at least in part on the first channel state and the second channel state.

42. The apparatus of claim 40, wherein: The instructions for determining the channel state for each of the plurality of downlink beamforming directions are executable by the processor to cause the apparatus to: determining a beamforming channel gain for each of the plurality of downlink beamforming directions between the parent node and the relay node, wherein, for a non-full-duplex mode, a first channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined at least in part based on the beamforming channel gain for each of the plurality of downlink beamforming directions between the parent node and the relay node; and determining a ratio of a beamforming channel gain to a self-interference level for each of the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the identified self-interference level and the determined beamforming channel gain, wherein, for full-duplex mode, a second channel state for each of the plurality of downlink beamforming directions between the parent node and the relay node is determined based at least in part on the ratio.

43. The apparatus according to claim 41, wherein The instructions are further executable by the processor to cause the apparatus to: determining a non-full-duplex mode downlink beamforming direction for a non-full-duplex transmission from the parent node based at least in part on the grant; as well as A full-duplex downlink beamforming direction for a full-duplex mode of full-duplex communication between the parent node and the relay node, full-duplex communication between the relay node and the child node, or a combination thereof is determined based at least in part on the grant.

44. The apparatus of claim 36, wherein: The child node is a user equipment (UE) or a second relay node.

45. The apparatus of claim 36, wherein The relay node includes a relay node within an integrated access and backhaul (IAB) network.

46. An apparatus for wireless communication at a relay node, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: determining a channel state for each of a plurality of uplink beamforming directions between a parent node and the relay node based at least in part on the uplink beamforming direction between the relay node and the child node; sending an uplink reference signal to the parent node using at least a subset of the plurality of uplink beamforming directions based at least in part on the channel state; receiving a grant from the parent node indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Based at least in part on the grant, an uplink transmission is sent to the parent node via the first uplink beamforming direction.

47. The apparatus of claim 46, wherein: The instructions for receiving the permission are executable by the processor to cause the device to: The grant is received indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

48. The apparatus of claim 47, wherein The instructions for sending the uplink transmission are further executable by the processor to cause the apparatus to: The uplink transmission is sent to the parent node within the resource allocation.

49. The apparatus of claim 46, wherein The instructions are further executable by the processor to cause the apparatus to: A reference signal or a synchronization signal is communicated with the child node, wherein the uplink beamforming direction between the relay node and the child node is identified based at least in part on the communication.

50. The apparatus of claim 46, wherein The instructions are further executable by the processor to cause the apparatus to: identifying a self-interference level between each of the plurality of uplink beamforming directions between the parent node and the relay node and the uplink beamforming direction between the relay node and the child node; as well as For full-duplex mode, the channel state for each of a plurality of uplink beamforming directions between the parent node and the relay node is determined based at least in part on the identified self-interference level.

51. The apparatus of claim 46, wherein The instructions for sending the uplink reference signal are further executable by the processor to cause the apparatus to: For non-full-duplex mode, sending a first uplink reference signal to the parent node; as well as For full-duplex mode, a second uplink reference signal is sent to the parent node, wherein the grant indicating the first uplink beamforming direction is based at least in part on the first uplink reference signal and the second uplink reference signal.

52. The apparatus of claim 51, wherein The instructions are further executable by the processor to cause the apparatus to: A signal is sent to the parent node, the signal identifying the first uplink reference signal for the non-full-duplex mode and the second uplink reference signal for the full-duplex mode.

53. The apparatus of claim 51, wherein The instructions for sending the uplink reference signal are further executable by the processor to cause the apparatus to: transmitting the first uplink reference signal within first resources associated with the non-full-duplex mode; as well as The second uplink reference signal is sent within second resources associated with the full-duplex mode.

54. The apparatus of claim 51, wherein The instructions are further executable by the processor to cause the apparatus to: determining a non-full-duplex mode uplink beamforming direction for non-full-duplex transmission to the parent node based at least in part on the grant; as well as A full-duplex uplink beamforming direction for a full-duplex mode of full-duplex communication between the parent node and the relay node, full-duplex communication between the relay node and the child node, or a combination thereof is determined based at least in part on the grant.

55. The apparatus of claim 46, wherein The relay node includes a relay node within an integrated access and backhaul (IAB) network.

56. An apparatus for wireless communication at a parent node, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: receiving, from a relay node, a report indicating a set of channel states and respective downlink beamforming directions of a plurality of downlink beamforming directions between the parent node and the relay node, the respective downlink beamforming directions corresponding to respective channel states of the set of channel states, the set of channel states being determined for the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the downlink beamforming directions between the relay node and a child node; sending a grant to the relay node based at least in part on the report, the grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as A downlink transmission is sent to the relay node based at least in part on the grant and the first downlink beamforming direction.

57. The apparatus of claim 56, wherein: The instructions for sending the permission are further executable by the processor to cause the device to: The grant is sent indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

58. The apparatus of claim 57, wherein The instructions are further executable by the processor to cause the apparatus to: The downlink transmission from the parent node is sent within the resource allocation.

59. The apparatus of claim 57, wherein The instructions are further executable by the processor to cause the apparatus to: Based at least in part on the report, the first downlink beamforming direction is selected from the plurality of downlink beamforming directions of the resource allocation.

60. The apparatus of claim 56, wherein The instructions for sending the permission are executable by the processor to cause the device to: For non-full-duplex mode, sending the grant to identify a second downlink beamforming direction for non-full-duplex transmission from the parent node; as well as For full-duplex mode, the grant is sent to identify the first downlink beamforming direction of the full-duplex mode of full-duplex communication between the parent node and the relay node and full-duplex communication between the relay node and the child node, or a combination thereof.

61. The apparatus of claim 56, wherein: The child node includes a user equipment (UE) or a second relay node.

62. The apparatus of claim 56, wherein: The parent node comprises a parent relay node within an integrated access and backhaul (IAB) network.

63. An apparatus for wireless communication at a parent node, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: receiving, from a relay node, an uplink reference signal transmitted using a subset of the plurality of uplink beamforming directions; sending a grant to the relay node based at least in part on the uplink reference signal, the grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Uplink transmissions from the relay node are monitored based at least in part on the grant and the first uplink beamforming direction.

64. The apparatus of claim 63, wherein: The instructions for sending the permission are executable by the processor to cause the device to: The grant is sent indicating an allocation of resources for simultaneous transmission and reception when the relay node operates in full-duplex mode.

65. The apparatus of claim 64, wherein The instructions are further executable by the processor to cause the apparatus to: The uplink transmission is received from the relay node within the resource allocation.

66. The apparatus of claim 64, wherein The instructions are further executable by the processor to cause the apparatus to: The first uplink beamforming direction is selected from the plurality of uplink beamforming directions of the resource assignment based at least in part on the uplink reference signal.

67. The apparatus of claim 63, wherein The instructions for receiving the uplink reference signal are executable by the processor to cause the apparatus to: For non-full-duplex mode, receiving a first uplink reference signal from the relay node; as well as For full-duplex mode, a second uplink reference signal is received from the relay node, wherein the grant indicating the first uplink beamforming direction is based at least in part on the first uplink reference signal and the second uplink reference signal.

68. The apparatus of claim 67, wherein The instructions are further executable by the processor to cause the apparatus to: A signal is received from the relay node, the signal identifying the first uplink reference signal of the non-full-duplex mode and the second uplink reference signal of the full-duplex mode.

69. The apparatus of claim 67, wherein The instructions are further executable by the processor to cause the apparatus to: receiving the first uplink reference signal via a first resource associated with the non-full-duplex mode; as well as The second uplink reference signal is received via second resources associated with the full-duplex mode.

70. The apparatus of claim 63, wherein The parent node includes a parent node within an integrated access and backhaul (IAB) network.

71. An apparatus for wireless communication at a relay node, comprising: means for determining a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on the downlink beamforming direction between the relay node and the child node; means for sending a report to the parent node, the report indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of the channel states; means for receiving, from the parent node, a grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as means for monitoring a downlink transmission from the parent node based at least in part on the grant and the first downlink beamforming direction.

72. An apparatus for wireless communication at a relay node, comprising: means for determining a channel state for each of a plurality of uplink beamforming directions between a parent node and the relay node based at least in part on the uplink beamforming direction between the relay node and the child node; means for sending an uplink reference signal to the parent node using at least a subset of the plurality of uplink beamforming directions based at least in part on the channel state; means for receiving, from the parent node, a grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Means for sending an uplink transmission to the parent node via the first uplink beamforming direction based at least in part on the grant.

73. An apparatus for wireless communication at a parent node, comprising: means for receiving, from a relay node, a report indicating a set of channel states and respective downlink beamforming directions of a plurality of downlink beamforming directions between the parent node and the relay node, the respective downlink beamforming directions corresponding to respective channel states of the set of channel states, the set of channel states being determined for the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the downlink beamforming directions between the relay node and a child node; means for sending a grant to the relay node based at least in part on the report, the grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as means for sending a downlink transmission to the relay node based at least in part on the grant and the first downlink beamforming direction.

74. An apparatus for wireless communication at a parent node, comprising: means for receiving, from a relay node, an uplink reference signal transmitted using a subset of a plurality of uplink beamforming directions; means for sending a grant to the relay node based at least in part on the uplink reference signal, the grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as means for monitoring an uplink transmission from the relay node based at least in part on the grant and the first uplink beamforming direction.

75. A non-transitory computer-readable medium storing code for wireless communication at a relay node, the code comprising instructions executable by a processor to: determining a channel state for each of a plurality of downlink beamforming directions between a parent node and the relay node based at least in part on the downlink beamforming direction between the relay node and the child node; sending a report to the parent node, the report indicating at least a subset of the channel states and an indication that a respective downlink beamforming direction of the plurality of downlink beamforming directions corresponds to a respective channel state in the subset of the channel states; receiving a grant from the parent node indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as Downlink transmissions from the parent node are monitored based at least in part on the grant and the first downlink beamforming direction.

76. A non-transitory computer-readable medium storing code for wireless communication at a relay node, the code comprising instructions executable by a processor to: determining a channel state for each of a plurality of uplink beamforming directions between a parent node and the relay node based at least in part on the uplink beamforming direction between the relay node and the child node; sending an uplink reference signal to the parent node using at least a subset of the plurality of uplink beamforming directions based at least in part on the channel state; receiving a grant from the parent node indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Based at least in part on the grant, an uplink transmission is sent to the parent node via the first uplink beamforming direction.

77. A non-transitory computer-readable medium storing code for wireless communication at a parent node, the code comprising instructions executable by a processor to: receiving, from a relay node, a report indicating a set of channel states and respective downlink beamforming directions of a plurality of downlink beamforming directions between the parent node and the relay node, the respective downlink beamforming directions corresponding to respective channel states of the set of channel states, the set of channel states being determined for the plurality of downlink beamforming directions between the parent node and the relay node based at least in part on the downlink beamforming directions between the relay node and a child node; sending a grant to the relay node based at least in part on the report, the grant indicating a first downlink beamforming direction from the plurality of downlink beamforming directions; as well as A downlink transmission is sent to the relay node based at least in part on the grant and the first downlink beamforming direction.

78. A non-transitory computer-readable medium storing code for wireless communication at a parent node, the code comprising instructions executable by a processor to: receiving, from a relay node, an uplink reference signal transmitted using a subset of the plurality of uplink beamforming directions; sending a grant to the relay node based at least in part on the uplink reference signal, the grant indicating a first uplink beamforming direction from the plurality of uplink beamforming directions; as well as Uplink transmissions from the relay node are monitored based at least in part on the grant and the first uplink beamforming direction.

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