WO2023217680A1

WO2023217680A1 - Co-located back-lobe cross link interference (cli) digital canceler interface

Info

Publication number: WO2023217680A1
Application number: PCT/EP2023/062062
Authority: WO
Inventors: Christian Elgaard; Henrik Sjöland; Magnus ÅSTRÖM
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-05-09
Filing date: 2023-05-05
Publication date: 2023-11-16

Abstract

A method and network node for a collocated back lobe cross link interference digital canceler interface are disclosed. According to one aspect, a method in a network node includes obtaining a shared data sequence shared with a second network node in proximity to the network node. The method also includes canceling cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared data sequence.

Description

CO-LOCATED BACK-LOBE CROSS LINK INTERFERENCE (CLI) DIGITAL

C ANCELER INTERFACE

TECHNICAL FIELD

The present disclosure relates to wireless communications, and in particular, to a collocated back lobe cross link interference digital canceler interface.

BACKGROUND

The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes and between WDs. Sixth Generation (6G) wireless communication systems are also under development.

In-band full duplex (IBFD) solutions where transmission and reception occur simultaneously and on the same frequency channel, as well as sub-band full duplex (SB- FD) solutions, suffer from self-interference (SI) due to the strong transmit signal being present at the antenna while receiving the weak receive signal. Successful IBFD relies on Sl-cancelation in multiple steps. These are: air interface isolation, RF & analog frontend (AFE) cancellation, and cancellation in the digital back end (DBE).

Another obstacle during full duplex transmissions is cross link interference (CLI). As full duplex transmissions occur continuously, transmitted output power from other communication links may interfere with the reception. CLI may occur from network node (gNB) to network node, wireless device (WD) to WD, or network node to WD. In addition to full duplex (FD) and sub-band full duplex (SB-FD), CLI is a challenging problem when allowing dynamic time division duplex (TDD) patterns since the transmissions from different aggressors are not synchronized in time and may therefore interfere with the receiver at any time. FIG. 1 illustrates example requirements on SI as well as CLI for FD.

Network nodes (base stations) use antenna array systems (AAS) and beam steering to direct the transmit power in a wanted direction, and during reception the network node uses beam steering to direct the received power from a wanted direction. Methods to mitigate CLI from network node to network node primarily rely on beamforming strategies. The network node transmitter, i.e., the aggressor, performs null shaping in the direction of the victim receiver, and vice-versa, the network node receiver, i.e., the victim, may shape a null in the direction of the aggressor.

AAS are constructed from multiple individual antenna elements. Each antenna element has a radiation pattern, were the wanted bore-sight direction has the strongest transmission. As antenna elements are combined into arrays and sub-arrays, with a gradually-phase shifted signal across the array, beam steering patterns occur on top of the antenna element pattern. The AAS will have a main lobe, where the majority of the transmitted or received power is directed. However, in addition to the main lobe, several side lobes and even a back lobe will occur.

Any attempt to perform null shaping to mitigate network node to network node CLI will be limited if power is transmitted through a back lobe in the direction to the victim. The same reasoning may be used for null shaping in receive mode to limit the received power from the aggressor. Null shaping only functions to suppress side lobes. However, suppressing the back lobe is not possible without also nulling the main lobe.

A common deployment scenario is that network nodes are mounted in tri sectors, each network node covering 360/3=120 degrees in the horizontal plane. In such a deployment, the back lobe will be directed towards the other network nodes in the same trisector, effectively resulting in a CLI between the network nodes in the same trisector.

SI cancelation in the analog domain may be carried out since the analog transmitted signal is present at the receiver, and may therefore be used to cancel the leaked signal. SI cancelation in the digital domain may be carried out since the transmitted signal is known at the receiver.

For CLI between different network nodes, the interfering signal is not known to the victim and may therefore not be cancelled.

SUMMARY

Some embodiments advantageously provide methods and network nodes for a collocated back lobe cross link interference digital canceler interface.

In a trisector network node deployment scenario, where at least one of the network nodes is communicating with full duplex, or dynamic TDD, the network nodes should share the signal to be transmitted, or the signal that was transmitted, with the other network nodes in the same trisector. Sharing of the transmitted signal should occur via an alternative communication link, for instance a dedicated cable. In the victim network node, the wanted received signal and the relatively strong CLI signal from the back lobe radiation of the collocated network node are passed through the analog receiver chain and converted to the digital domain via the analog to digital converter (ADC). At this point, the strong interfering signal will make the signal to noise plus interference ratio (SNIR) very poor and will heavily degrade the reception. However, since the interfering signal is known to the victim from the aggressor sharing it, it is possible to use a digital SI canceler to remove the interfering signal and improve SNIR.

Some advantages may include one or more of the following:

• Sharing the transmit bit signal with other network nodes in the same trisector to enable CLI digital cancellation of the transmit signal from the collocated network nodes;

• Reduces effect of CLI from one network node to another network node in a collocated deployment during FD, SB-FD or dynamic TDD transmissions;

• Enables FD, SB-FD or dynamic TDD for collocated network node deployment;

• Digital CLI cancelation with low impact on latency due to short distance between the aggressor and victim; and/or

• Reduces the need for back lobe isolation measures that add cost and size and reduce flexibility of installation.

According to one aspect, a network node configured to communicate with a second network node in proximity to the network node via a communication link is provided. The network node includes processing circuitry configured to: obtain a shared data sequence shared with a second network node in proximity to the network node. The processing circuitry is also configured to cancel cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared data sequence

According to this aspect, in some embodiments, cancelling cross link interference includes applying at least one of a time shift, a phase shift and an amplitude adjustment. In some embodiments, the correlation is implemented sequentially on multiple shared data sequences. In some embodiments, each shared data sequence of the multiple shared data sequences is associated with different cross link interference signal. In some embodiments, cancelling cross link interference includes suppressing nonlinear components of an interfering signal. In some embodiments, the network node includes a radio interface in communication with the processing circuitry and suppressing the nonlinear components is based at least in part on nonlinear transmitter distortion in the radio interface. In some embodiments, suppressing the nonlinear components includes suppressing in-band interfering signals. In some embodiments, suppressing the nonlinear components includes suppressing out-of-band interfering signals. In some embodiments, cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning. In some embodiments, the modeling is performed at specified times during which the network node and the second network node are in a training mode. In some embodiments, the network node is one of three network nodes, each of the three network nodes covering a different sector of tri-sector coverage. In some embodiments, the cross link interference cancellation is performed in the analog domain. In some embodiments, the cross link interference cancellation is performed in the digital domain. In some embodiments, the cross link interference cancellation is performed for a common frequency band shared by the network node and the second network node. In some embodiments, the network node is shared by a plurality of providers.

According to another aspect, a method implemented in a network node configured to communicate with a second network node in proximity to the network node via a communication link, is provided. The method includes obtaining a shared data sequence shared with the second network node in proximity to the network node. The method includes canceling cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared data sequence.

According to this aspect, in some embodiments, cancelling cross link interference includes applying at least one of a time shift, a phase shift and an amplitude adjustment. In some embodiments, the correlation is implemented sequentially on multiple shared data sequences. In some embodiments, each shared data sequence of the multiple shared data sequences is associated with different cross link interference signal. In some embodiments, cancelling cross link interference includes suppressing nonlinear components of an interfering signal. In some embodiments, suppressing the nonlinear components is based at least in part on nonlinear transmitter distortion in a radio interface of the network node. In some embodiments, suppressing the nonlinear components includes suppressing in- band interfering signals. In some embodiments, suppressing the nonlinear components includes suppressing out-of-band interfering signals. In some embodiments, cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning. In some embodiments, the modeling is performed at specified times during which the network node and the second network node are in a training mode. In some embodiments, the network node is one of three network nodes, each of the three network nodes covering a different sector of tri-sector coverage. In some embodiments, the cross link interference cancellation is performed in the analog domain. In some embodiments, the cross link interference cancellation is performed in the digital domain. In some embodiments, the cross link interference cancellation is performed for a common frequency band shared by the network node and the second network node. In some embodiments, the network node is shared by a plurality of providers.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 illustrates requirements on SI as well as CLI for FD;

FIG. 2 is a schematic diagram of an example network architecture illustrating a communication system connected via an intermediate network to a host computer according to the principles in the present disclosure;

FIG. 3 is a block diagram of a host computer communicating via a network node with a wireless device over an at least partially wireless connection according to some embodiments of the present disclosure;

FIG. 4 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for executing a client application at a wireless device according to some embodiments of the present disclosure;

FIG. 5 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a wireless device according to some embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data from the wireless device at a host computer according to some embodiments of the present disclosure; FIG. 7 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a host computer according to some embodiments of the present disclosure;

FIG. 8 is a flowchart of an example process in a network node for a collocated back lobe cross link interference digital canceler interface;

FIG. 9 is a digital CLI canceler according to principles set forth herein;

FIG. 10 is a multi-digital CLI canceller according to principles set forth herein; and FIG. 11 is a canceller and a non-linear model according to principles set forth herein.

DETAILED DESCRIPTION

Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to a collocated back lobe cross link interference digital canceler interface. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description.

As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.

The term “network node” used herein may be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multistandard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3^rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.

In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein may be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device, etc.

Also, in some embodiments the generic term “radio network node” is used. It may be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, may be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Some embodiments provide a collocated back lobe cross link interference digital canceler interface.

Returning now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 2 a schematic diagram of a communication system 10, according to an embodiment, such as a 3 GPP -type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16.

Also, it is contemplated that a WD 22 may be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 may have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, WD 22 may be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN.

The communication system 10 may itself be connected to a host computer 24, which may be embodied in the hardware and/or software of a standalone server, a cloud- implemented server, a distributed server or as processing resources in a server farm. The host computer 24 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 26, 28 between the communication system 10 and the host computer 24 may extend directly from the core network 14 to the host computer 24 or may extend via an optional intermediate network 30. The intermediate network 30 may be one of, or a combination of more than one of, a public, private or hosted network. The intermediate network 30, if any, may be a backbone network or the Internet. In some embodiments, the intermediate network 30 may comprise two or more sub-networks (not shown).

The communication system of FIG. 2 as a whole enables connectivity between one of the connected WDs 22a, 22b and the host computer 24. The connectivity may be described as an over-the-top (OTT) connection. The host computer 24 and the connected WDs 22a, 22b are configured to communicate data and/or signaling via the OTT connection, using the access network 12, the core network 14, any intermediate network 30 and possible further infrastructure (not shown) as intermediaries. The OTT connection may be transparent in the sense that at least some of the participating communication devices through which the OTT connection passes are unaware of routing of uplink and downlink communications. For example, a network node 16 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 24 to be forwarded (e.g., handed over) to a connected WD 22a. Similarly, the network node 16 need not be aware of the future routing of an outgoing uplink communication originating from the WD 22a towards the host computer 24.

A network node 16a, 16b is configured to include a cancellation unit 32 which is configured to cancel cross link interference between the network node 16a and the second network node 16b based at least in part on correlation of a received signal with the shared data sequence. As used herein, a data sequence may be a sequence of bits.

Example implementations, in accordance with an embodiment, of the WD 22, network nodes 16a and 16b and host computer 24 discussed in the preceding paragraphs will now be described with reference to FIG. 3. In a communication system 10, a host computer 24 comprises hardware (HW) 38 including a communication interface 40 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 10. The host computer 24 further comprises processing circuitry 42, which may have storage and/or processing capabilities. The processing circuitry 42 may include a processor 44 and memory 46. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 42 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 44 may be configured to access (e.g., write to and/or read from) memory 46, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Processing circuitry 42 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by host computer 24. Processor 44 corresponds to one or more processors 44 for performing host computer 24 functions described herein. The host computer 24 includes memory 46 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 48 and/or the host application 50 may include instructions that, when executed by the processor 44 and/or processing circuitry 42, causes the processor 44 and/or processing circuitry 42 to perform the processes described herein with respect to host computer 24. The instructions may be software associated with the host computer 24. The software 48 may be executable by the processing circuitry 42. The software 48 includes a host application 50. The host application 50 may be operable to provide a service to a remote user, such as a WD 22 connecting via an OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the remote user, the host application 50 may provide user data which is transmitted using the OTT connection 52. The “user data” may be data and information described herein as implementing the described functionality. In one embodiment, the host computer 24 may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry 42 of the host computer 24 may enable the host computer 24 to observe, monitor, control, transmit to and/or receive from the network node 16 and or the wireless device 22.

The communication system 10 further includes network node 16a and 16b provided in a communication system 10 and including hardware 58 enabling it to communicate with the host computer 24 and with the WD 22. The hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62a, 62b for setting up and maintaining at least a wireless connection 65 with a WD 22 located in a coverage area 18 served by the network node 16a and/or 16b. The radio interface 62a, 62b may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The communication interface 60 may be configured to facilitate a connection 66 to the host computer 24. The connection 66 may be direct or it may pass through a core network 14 of the communication system 10 and/or through one or more intermediate networks 30 outside the communication system 10. The radio interfaces 62a, 62b include antennas 64a, 64b, respectively, which may have different boresight directions. For example, there may be three network nodes 16a, 16b, 16c in close proximity, where each network node has an antenna array 64, each of the antenna arrays 64 having boresight directions separated by 120 degrees. Each network node 16a, 16b, and 16c may serve one or more of the same WDs 22 and/or different WDs 22.

In the embodiment shown, the hardware 58 of the network node 16a, 16b further includes processing circuitry 68. The processing circuitry 68 may include a processor 70 and a memory 72. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Note that the processing circuitry 68, processor 70 and memory 72 shown in network node 16a may also be present in network node 16b.

Thus, the network node 16a, 16b further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 74 may be executable by the processing circuitry 68. The processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16. Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein. The memory 72 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16. For example, processing circuitry 68 of the network node 16a or 16b may include a cancellation unit 32 which is configured to cancel cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared data sequence. Note that although only two network nodes are shown in FIG. 3, more than two network nodes can be in communication via a communication link to share the shared data sequence.

The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 65 with a network node 16a and/or 16b serving a coverage area 18 in which the WD 22 is currently located. The radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.

The hardware 80 of the WD 22 further includes processing circuitry 84. The processing circuitry 84 may include a processor 86 and memory 88. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 90 may be executable by the processing circuitry 84. The software 90 may include a client application 92. The client application 92 may be operable to provide a service to a human or non-human user via the WD 22, with the support of the host computer 24. In the host computer 24, an executing host application 50 may communicate with the executing client application 92 via the OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the user, the client application 92 may receive request data from the host application 50 and provide user data in response to the request data. The OTT connection 52 may transfer both the request data and the user data. The client application 92 may interact with the user to generate the user data that it provides.

The processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22. The processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein. The WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22.

In some embodiments, the inner workings of the network node 16, WD 22, and host computer 24 may be as shown in FIG. 3 and independently, the surrounding network topology may be that of FIG. 2. In FIG. 3, the OTT connection 52 has been drawn abstractly to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from the service provider operating the host computer 24, or both. While the OTT connection 52 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 65 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the WD 22 using the OTT connection 52, in which the wireless connection 65 may form the last segment. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc.

In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 52 between the host computer 24 and WD 22, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 52 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 48, 90 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 52 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary WD signaling facilitating the host computer’s 24 measurements of throughput, propagation times, latency and the like. In some embodiments, the measurements may be implemented in that the software 48, 90 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 52 while it monitors propagation times, errors, etc.

Thus, in some embodiments, the host computer 24 includes processing circuitry 42 configured to provide user data and a communication interface 40 that is configured to forward the user data to a cellular network for transmission to the WD 22. In some embodiments, the cellular network also includes the network node 16 with a radio interface 62. In some embodiments, the network node 16 is configured to, and/or the network node’s 16 processing circuitry 68 is configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the WD 22, and/or preparing/terminating/ maintaining/supporting/ending in receipt of a transmission from the WD 22.

In some embodiments, the host computer 24 includes processing circuitry 42 and a communication interface 40 that is configured to a communication interface 40 configured to receive user data originating from a transmission from a WD 22 to a network node 16. In some embodiments, the WD 22 is configured to, and/or comprises a radio interface 82 and/or processing circuitry 84 configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the network node 16, and/or preparing/ terminating/maintaining/supporting/ending in receipt of a transmission from the network node 16.

Although FIGS. 2 and 3 show various “units” such as cancellation unit 32 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

FIG. 4 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIGS. 2 and 3, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIG. 3. In a first step of the method, the host computer 24 provides user data (Block SI 00). In an optional substep of the first step, the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50 (Block SI 02). In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block SI 04). In an optional third step, the network node 16 transmits to the WD 22 the user data which was carried in the transmission that the host computer 24 initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block SI 06). In an optional fourth step, the WD 22 executes a client application, such as, for example, the client application 92, associated with the host application 50 executed by the host computer 24 (Block SI 08).

FIG. 5 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 2, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 2 and 3. In a first step of the method, the host computer 24 provides user data (Block SI 10). In an optional substep (not shown) the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50. In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block SI 12). The transmission may pass via the network node 16, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step, the WD 22 receives the user data carried in the transmission (Block SI 14).

FIG. 6 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 2, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 2 and 3. In an optional first step of the method, the WD 22 receives input data provided by the host computer 24 (Block SI 16). In an optional substep of the first step, the WD 22 executes the client application 92, which provides the user data in reaction to the received input data provided by the host computer 24 (Block SI 18). Additionally or alternatively, in an optional second step, the WD 22 provides user data (Block S120). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application 92 (Block S122). In providing the user data, the executed client application 92 may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD 22 may initiate, in an optional third substep, transmission of the user data to the host computer 24 (Block S124). In a fourth step of the method, the host computer 24 receives the user data transmitted from the WD 22, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126).

FIG. 7 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 2, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 2 and 3. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 16 receives user data from the WD 22 (Block S128). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (Block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (Block SI 32).

FIG. 8 is a flowchart of an example process in a network node 16 for a collocated back lobe cross link interference digital canceler interface. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including the cancellation unit 32), processor 70, radio interface 62 and/or communication interface 60. Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to obtain a shared data sequence shared with a second network node in proximity to the network node (Block SI 34). The method includes canceling cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared data sequence (Block S136).

In some embodiments, cancelling cross link interference includes applying at least one of a time shift, a phase shift and an amplitude adjustment. In some embodiments, the correlation is implemented sequentially on multiple shared data sequences. In some embodiments, each shared data sequence of the multiple shared data sequences is associated with different cross link interference signal. In some embodiments, cancelling cross link interference includes suppressing nonlinear components of an interfering signal. In some embodiments, suppressing the nonlinear components is based at least in part on nonlinear transmitter distortion in the radio interface. In some embodiments, suppressing the nonlinear components includes suppressing in-band interfering signals. In some embodiments, suppressing the nonlinear components includes suppressing out-of-band interfering signals. In some embodiments, cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning. In some embodiments, the modeling is performed at specified times during which the network node and the second network node are in a training mode. In some embodiments, the network node is one of three network nodes, each of the three network nodes covering a different sector of tri-sector coverage. In some embodiments, the cross link interference cancellation is performed in the analog domain. In some embodiments, the cross link interference cancellation is performed in the digital domain. In some embodiments, the cross link interference cancellation is performed for a common frequency band shared by the network node and the second network node. In some embodiments, the network node is shared by a plurality of providers.

Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for a collocated back lobe cross link interference digital canceler interface.

Referring to FIG. 9, in some embodiments, the network node 16 converts the received signal to a digital signal to produce a received digital signal. The received digital signal is input to the digital CLI canceller 32 which correlates the received digital signal with a shared transmitted digital data sequence from a collocated network node 16. After correlation, proper time and phase shift may be applied by, for example processing circuitry 68, including the digital CLI canceller 32, when applying the cancellation signal in the adder 36. Accuracy of time and phase shift is strongly dependent on the signal bandwidth to be cancelled. The higher the bandwidth, the more stringent the requirements for this accuracy. For canceling multiple CLI signals, for example when the network node 16 suffers from CLI from more than one collocated network node 16, the procedure may be carried out sequentially. This is in principle identical to the case when the aggressor network node 16 transmits multiple layers, resulting in multiple digital data sequences to correlate and cancel, as shown in the example embodiment of FIG. 10. Of note, the gNB, referenced in FIG. 9 and 10 is one example implementation of use of a network node 16 in those embodiments.

In cases of suppressing nonlinear components from the interfering signal, the digital canceler may be nonlinear. Such a nonlinear cancelation could be in-band nonlinear transmitter distortion or distortion due to receiver nonlinearity. For an IBFD signal, a nonlinear digital canceler may under favorable circumstances reach 48 dB suppression.

For sub-band FD, where the interfering signal is an out of band signal, the in- band components that require suppression from digital cancellation, may only be due to transmitter distortion and distorting due to receiver nonlinearities. Therefore, for sub- band FD, the digital canceler may be nonlinear to suppress in-band interference. Such non-linearities are well known and may be accurately modeled in the receiver, after which a linear canceller may still be applied.

Alternatively, an artificial intelligence/machine learning (AI/ML) network may be trained to model the non-linearities and then be used in the canceller. Such training could take place at specified times such that both the aggressor and victim network nodes 16 know about the training and may assume appropriate configurations, e.g., setting the network in a training mode. An example of one embodiment utilizing a canceller 94 in combination with a non-linear model 96 is shown in FIG. 11.

Since the network nodes 16 are collocated, a dedicated short connection enables digital cancellation with minimum impact on latency.

Some embodiments may include one or more of the following:

Embodiment Al . A network node configured to communicate with a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: obtain a shared bit sequence shared with a second network node in proximity to the network node; and cancel cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared bit sequence.

Embodiment A2. The network node of Embodiment Al, wherein cancelling cross link interference includes applying at least one of a time shift and a phase shift.

Embodiment A3. The network node of any of Embodiments Al and A2, wherein the correlation is implemented sequentially on multiple shared bit sequences.

Embodiment A4. The network node of any of Embodiments A1-A3, wherein each shared bit sequence of the multiple shared bit sequences is associated with different cross link interference signal.

Embodiment A5. The network node of any of Embodiments A1-A4, wherein cancelling cross link interference includes suppressing nonlinear components of an interfering signal.

Embodiment A6. The network node of Embodiment A5, wherein the nonlinear component suppression is based at least in part on nonlinear transmitter distortion in the radio interface.

Embodiment A7. The network node of any of Embodiments A5 and A6, wherein the nonlinear component suppression is configured to suppress in-band interfering signals. Embodiment A8. The network node of any of Embodiments A5 and A6, wherein the nonlinear component suppression is configured to suppress out-of-band interfering signals.

Embodiment A9. The network node of any of Embodiments A1-A8, wherein cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning.

Embodiment A10. The network node of Embodiment A9, wherein the modeling is performed at specified times during which the network node and the second network node are in a training mode.

Embodiment Bl. A method implemented in a network node, the method comprising: obtaining a shared bit sequence shared with a second network node in proximity to the network node; and canceling cross link interference between the network node and the second network node based at least in part on correlation of a received signal with the shared bit sequence.

Embodiment B2. The method of Embodiment Bl, wherein cancelling cross link interference includes applying at least one of a time shift and a phase shift.

Embodiment B3. The method of any of Embodiments Bl and B2, wherein the correlation is implemented sequentially on multiple shared bit sequences.

Embodiment B4. The method of any of Embodiments B1-B3, wherein each shared bit sequence of the multiple shared bit sequences is associated with different cross link interference signal.

Embodiment B5. The method of any of Embodiments B1-B4, wherein cancelling cross link interference includes suppressing nonlinear components of an interfering signal.

Embodiment B6. The method of Embodiment B5, wherein the nonlinear component suppression is based at least in part on nonlinear transmitter distortion in the radio interface.

Embodiment B7. The method of any of Embodiments B5 and B6, wherein the nonlinear component suppression is configured to suppress in-band interfering signals.

Embodiment B8. The method of any of Embodiments B5 and B6, wherein the nonlinear component suppression is configured to suppress out-of-band interfering signals. Embodiment B9. The method of any of Embodiments B1-B8, wherein cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning.

Embodiment BIO. The method of Embodiment B9, wherein the modeling is performed at specified times during which the network node and the second network node are in a training mode.

As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that may be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable memory or storage medium that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments may be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

Abbreviations that may be used in the preceding description include:

AAS Antenna Array System

AFE Analog Front End

CLI Cross Link Interference

DBE Digital Back End

EBD Electrical Balanced Duplexer gNB Mobile Base Station

IBFD In-band Full Duplex

LNA Low Noise Amplifier

PA Power Amplifier

RF Radio Frequency

RX Receiver

SI Self-Interference

TX Transmitter

It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

1. A network node (16) configured to communicate with a second network node (16) in proximity to the network node (16) via a communication link, the network node (16) comprising processing circuitry (68) configured to: obtain a shared data sequence shared with the second network node (16) in proximity to the network node (16); and cancel cross link interference between the network node (16) and the second network node (16) based at least in part on correlation of a received signal with the shared data sequence.

2. The network node (16) of Claim 1, wherein cancelling cross link interference includes applying at least one of a time shift, a phase shift and an amplitude adjustment.

3. The network node (16) of any of Claims 1 and 2, wherein the correlation is implemented sequentially on multiple shared data sequences.

4. The network node (16) of Claim 3, wherein each shared data sequence of the multiple shared data sequences is associated with different cross link interference signal.

5. The network node (16) of any of Claims 1-4, wherein cancelling cross link interference includes suppressing nonlinear components of an interfering signal.

6. The network node (16) of Claim 5, further comprising a radio interface in communication with the processing circuitry (68) and suppressing the nonlinear component is based at least in part on nonlinear transmitter distortion in the radio interface.

7. The network node (16) of any of Claims 5 and 6, wherein suppressing the nonlinear components includes suppressing in-band interfering signals.

8. The network node (16) of any of Claims 5 and 6, wherein suppressing the nonlinear components includes suppressing out-of-band interfering signals.

9. The network node (16) of any of Claims 1-8, wherein cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning.

10. The network node (16) of Claim 9, wherein the modeling is performed at specified times during which the network node (16) and the second network node (16) are in a training mode.

11. The network node (16) of any of Claims 1-10, wherein the network node (16) is one of three network nodes (16), each of the three network nodes (16) covering a different sector of tri-sector coverage.

12. The network node (16) of any of Claims 1-11, wherein the cross link interference cancellation is performed in the analog domain.

13. The network node (16) of any of Claims 1-11, wherein the cross link interference cancellation is performed in the digital domain.

14. The network node (16) of any of Claims 1-13, wherein the cross link interference cancellation is performed for a common frequency band shared by the network node (16) and the second network node (16).

15. The network node (16) of any of Claims 1-14, wherein the network node (16) is shared by a plurality of providers.

16. A method implemented in a network node (16) configured to communicate with a second network node (16) in proximity to the network node (16) via a communication link, the method comprising: obtaining (S134) a shared data sequence shared with the second network node (16) in proximity to the network node (16); and canceling (SI 36) cross link interference between the network node (16) and the second network node (16) based at least in part on correlation of a received signal with the shared data sequence.

17. The method of Claim 16, wherein cancelling cross link interference includes applying at least one of a time shift, a phase shift and an amplitude adjustment.

18. The method of any of Claims 16 and 17, wherein the correlation is implemented sequentially on multiple shared data sequences.

19. The method of Claim 18, wherein each shared data sequence of the multiple shared data sequences is associated with different cross link interference signal.

20. The method of any of Claims 16-19, wherein cancelling cross link interference includes suppressing nonlinear components of an interfering signal.

21. The method of Claim 20, wherein suppressing the nonlinear components is based at least in part on nonlinear transmitter distortion in a radio interface of the network node (16).

22. The method of any of Claims 20 and 21, wherein suppressing the nonlinear components includes suppressing in-band interfering signals.

23. The method of any of Claims 20 and 21, wherein suppressing the nonlinear components includes suppressing out-of-band interfering signals.

24. The method of any of Claims 16-23, wherein cancelling cross link interference includes modeling nonlinearities of the received signal based at least in part on machine learning.

25. The method of Claim 24, wherein the modeling is performed at specified times during which the network node (16) and the second network node (16) are in a training mode.

26. The method of any of Claims 16-25, wherein the network node (16) is one of three network nodes (16), each of the three network nodes (16) covering a different sector of tri-sector coverage.

27. The method of any of Claims 16-26, wherein the cross link interference cancellation is performed in the analog domain.

28. The method of any of Claims 16-26, wherein the cross link interference cancellation is performed in the digital domain.

29. The method of any of Claims 16-28, wherein the cross link interference cancellation is performed for a common frequency band shared by the network node (16) and the second network node (16).

30. The method of any of Claims 16-29, wherein the network node (16) is shared by a plurality of providers.