WO2019232787A1

WO2019232787A1 - Bias control for dynamic time-division duplexing

Info

Publication number: WO2019232787A1
Application number: PCT/CN2018/090446
Authority: WO
Inventors: Haiyou Guo; Toni Aleksi Levanen
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2018-06-08
Filing date: 2018-06-08
Publication date: 2019-12-12
Anticipated expiration: 2020-12-08
Also published as: CN112292881A; CN112292881B

Abstract

An apparatus comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive one or more cross-link interference overload indications. The at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to transmit and/or receiving signals using the adjusted one or more link direction bias control parameters.

Description

BIAS CONTROL FOR DYNAMIC TIME-DIVISION DUPLEXING

BACKGROUND: Field:

Certain examples may relate to communication systems. For example, some examples may relate to dynamic time-division duplexing.

Description of the Related Art:

Dynamic time-division duplexing (TDD) , also referred to as enhanced interference mitigation and traffic adaptation (eIMTA) , allows a network to dynamically use resources for uplink (UL) or downlink (DL) transmissions in order to match instantaneous traffic situations. An UL/DL allocation may be signaled at the beginning of each frame, or at the beginning of a set of frames, to enable dynamically-varied UL/DL usage. The UL/DL configuration in eIMTA may not be static, but may instead vary on a frame-by-frame basis. Broadcasting allows a UL/DL configuration to adjust and satisfy various requirements of UL/DL traffic. Thus, eIMTA uses a frame structure with flexible subframes, where some subframes in one radio frame may be defined as flexible subframes where the UL/DL configuration is allowed to vary on a frame-by-frame basis.

However, the introduction of dynamic TDD has created a new type of inter-cell interference, sometimes referred to as cross-link interference (CLI) . Specifically, misalignment in link direction between neighboring cells generates user equipment (UE) -to-UE and Transmission Reception Point (TRP) -to-TRP interference, such as between network entities. CLI may also be responsible for the majority of transmission failures in a dynamic TDD system.

New radio (NR) systems use dynamic TDD to determine an appropriate sequence of UL/DL symbols/slots for associated cells, where each UL/DL OFDM symbol is scheduled for UE adapting to traffic variations and various CLI situations. The set of OFDM symbols to be assigned are distributed across multiple slots in consecutive or non-consecutive manners, without a loss of generality. In this way, coordination of symbol scheduling is the same for all of the cells. For example, the total number of symbols/slots may be denoted by N, with the set S _cell denoting all of the N _cell coordinated cells. Cell n ∈ S _cell is surrounded by a set of neighboring cells, denoted by

The sum number of UL/DL symbols/slots assigned for cell n would be N _n ^UL (N _n ^DL) . Each cell attempts to determine distinct N _n ^UL and N _n ^DL values which satisfy UL/DL traffic requirements, resulting in link direction conflict between neighboring cells, and as a result, undesirable CLI.

For example, FIG. 1 illustrates significant performance degradation due to link direction conflict based on signal-to-interference-plus-noise ratio (SINR) cumulative distribution functions (CDFs) . For two arbitrary neighboring cells m and n, the difference |N _m ^UL -N _n ^UL| (|N _m ^DL -N _n ^DL|) is link direction bias, where a greater difference indicates a greater potential for CLI since link direction bias and CLI are directly correlated. Thus, if one cell prevents its UL/DL ratio deviating from a predetermined UL/DL ratio, such as an average UL/DL ratio, over the neighboring cells, the conflicts of link direction would be controlled.

CLI may be reduced by reducing link direction bias, but at the same time, would degrade the flexibility gain of TDD. Each cell should need to balance traffic adaptation with CLI mitigation. As such, the link direction bias should be controlled within a predetermined range to balance duplexing flexibility with CLI hazard. In addition, link direction bias should be controlled between all neighboring cells. For example, one cell may cause UE-UE interference on some cells and TRP-TRP interference on other cells, further complicating link direction bias control. Link direction bias cannot be set to a static value with these temporal and spatial variations in traffic requirements and channel conditions. Thus, a need exists for cells to tune link bias parameters in response to CLI overload.

SUMMARY:

In accordance with an example, a method may include receiving, by a network entity, one or more cross-link interference overload indications. The method may further include updating, by the network entity, one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The method may further include transmitting and/or receiving, by the network entity, signals using the adjusted one or more link direction bias control parameters.

In accordance with an example, an apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code can be configured to, with the at least one processor, cause the apparatus to at least receive one or more cross-link interference overload indications. The at least one memory and the computer program code can be configured to, with the at least one processor, cause the apparatus to at least update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The at least one memory and the computer program code can be configured to, with the at least one processor, cause the apparatus to transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

In accordance with an example, an apparatus may include means for receiving one or more cross-link interference overload indications. The apparatus may further include means for updating one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The apparatus may further include means for transmitting and/or receiving signals using the adjusted one or more link direction bias control parameters.

In accordance with an example, a non-transitory computer readable medium can, in certain examples, be encoded with instructions that may, when executed in hardware, perform a process. The process may include a method that may receive one or more cross-link interference overload indications. The process may include a method that may update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The process may include a method that may transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

In accordance with an example, a computer program product may, according to certain examples, have instructions encoded for performing a process. The process may include a method that may receive one or more cross-link interference overload indications. The process may include a method that may further update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The process may include a method that may further transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

In accordance with an example, an apparatus may include circuitry configured to receive one or more cross-link interference overload indications. The apparatus may further include circuitry configured to update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. The apparatus may further include circuitry configured to transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

BRIEF DESCRIPTION OF THE DRAWINGS:

For proper understanding of this disclosure, reference should be made to the accompanying drawings, wherein:

FIG. 1 illustrates an example of uplink signal-to-interference-plus-noise ratio loss due to link direction bias in the prior art.

FIG. 2 illustrates an example of a signaling diagram according to certain examples.

FIG. 3 illustrates an example of cross-link indication overload indications according to certain examples.

FIG. 4 illustrates an example of a method performed by a network entity according to certain examples.

FIG. 5 illustrates another example of a method performed by a network entity according to certain examples.

FIG. 6 illustrates an example system composed of macro cells in a regular hexagonal grid according to certain examples.

FIG. 7 illustrates another example of a method performed by a network entity according to certain examples.

FIG. 8 illustrates another example of a method performed by user equipment according to certain examples.

FIG. 9 illustrates an example of a system according to certain examples.

DETAILED DESCRIPTION:

The features, structures, or characteristics of certain examples described throughout this specification may be combined in any suitable manner in one or more examples. For example, the usage of the phrases “certain examples, ” “some examples, ” “other examples, ” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the example may be included in at least one example of the present invention. Thus, appearance of the phrases “in certain examples, ” “in some examples, ” “in other examples, ” or other similar language, throughout this specification does not necessarily refer to the same group of examples, and the described features, structures, or characteristics may be combined in any suitable manner in one or more examples.

In response to the challenges in the prior art discussed above, certain examples described herein may help to reduce interference in a dynamic TDD system by balancing TDD flexibility gain with CLI hazard in a dynamic TDD system. The examples described herein may have various benefits and/or advantages. For example, some examples may balance the flexibility gain for traffic adaptation and performance loss caused by CLI through controlling the link direction conflict in an adaptive manner. Certain examples are, therefore, directed to improvements in computer-related technology, specifically, by conserving network resources and reducing power consumption of the UE and/or a network entity located within the network.

FIG. 2 illustrates an example of a signaling diagram showing communications between network entity (NE) 220, NE 230, and NE 240. NE 220, NE 230, and/or NE 240 may be similar to NE 910, as illustrated in FIG. 9.

In step 201, NE 220, NE 230, and/or NE 240 may assign an initial or updated value to an uplink direction bias control parameter and/or an initial or updated value to a downlink direction bias control parameter. The uplink direction bias control parameter may be denoted by Δ _n ^UL, and/or the downlink direction bias control parameter may be denoted by Δ _n ^DL. In some examples, 0 ≤ Δ _n ^UL and/or 0 ≤ Δ _n ^DL. In some examples, the uplink and/or downlink direction bias control parameters may be updated and/or tuned in time, denoted by Δ _n ^UL (t) and Δ _n ^UL (t) , respectively, in response to CLI.

In step 203, any of the NEs may apply a feasible TDD pattern configuration for traffic adaptation that guarantees the link direction bias satisfies predefined criteria, for example, one or more quality metric parameters. In some examples, based upon a link direction control parameter, such as /Delta_n, any of the NEs may choose N_n which fulfills one or more currently used bias control constraints. In some examples, both numbers of UL and DL slots/symbols assigned for one cell may fall within a tolerable range centered by the average numbers over the neighboring cells. For example, N _m ^UL and N _m ^DL | m ∈ S _nei, n may be available for cell n according to existing signaling procedures such that the network entity may independently determine N _n ^UL and N _n ^DL for cell n, subject to bi-direction bias control constraints N _n ^UL-1/|S _nei, n| ∑ _m _{∈ Snei, n} N _m ^UL ≤Δ _n ^UL (t) , n ∈ S _cell, and N _n ^DL-1/|S _nei, n| ∑ _{m∈ Snei, n} N _m ^DL ≤Δ _n ^DL (t) , n ∈ S _cell, where |S _nei, n| denotes the cardinality of set S _nei, n, according to various optimization criteria, such as a maximum-minimum traffic matching method, as discussed below. In other examples, the bi-direction bias control constraints may be based on a mean of a number of UL and/or DL symbols used by neighboring cells, such as a simple mean, geometric mean, and/or weighted mean.

In some examples, the cells may determine the UL/DL transmission ratio for the next number of slots to maximize the minimum traffic matching factor, according to the current link direction bias control parameters. For slot t, such desired TDD pattern configurations may be determined by solving the integer optimization problem max (N _n ^UL, N _n ^DL) min _n min (N _n ^UL/N _demand,, n ^UL, N _n ^DL/N _demand, n ^DL) , such that N _n ^UL-1/|S _nei, n| ∑ _{m ∈ Snei, n} N _m ^UL ≤ Δ _n ^UL (t) , n ∈ S _cell, N _n ^DL-1/|S _nei, n| ∑ _{m ∈ Snei, n} N _m ^DL ≤ Δ _n ^DL (t) , n ∈ S _cell, N _n ^UL + N _n ^DL = N, n ∈ S _cell, and N _n ^UL, N _n ^DL ∈ {0, 1, L, ... N} , n ∈ S _cell, where Δ _n ^UL (t) and Δ _n ^DL (t) represent the current link direction bias control parameters, respectively. In some examples, the current link direction bias control parameters are updated for every predetermined number of slots, such as N = 10 slots. In addition, one or more time resources are used for transmission, where one slot may be either a UL or DL slot.

In step 205, any of the NEs may receive one or more CLI measurements, including NE-to-NE measurements and/or UE-to-UE measurements for one or more slot/symbol combinations. In some examples, at least one of one or more NE-to-NE interference measurements and UE-to-UE interference measurements may be received. In some examples, satisfactory CLI measurements may indicate which one or more network entities are causing NE-to-NE and/or UE-to-UE interference.

In step 207, any of the NEs may exchange one or more CLI measurement indication information elements (IEs) with one or more of the other network entities. In some examples, the one or more CLI measurement indication information elements may include one or more CLI overload indication information elements through an X _n interface between two or more NEs. CLI overload indication IEs may contain UE-to-UE interference overload indication IEs and/or NE-to-NE interference overload indication IEs. Any of these interference overload indication IEs may be included in one or more LOAD INFORMATION messages and/or other dedicated messages defined by an X _n application protocol.

In various examples, one or more generated CLI overload indicator IEs may indicate one or more levels of CLI associated with various frequency and/or time resources of a neighboring NE. The one or more CLI overload indicator IEs may be generated according to the method illustrated in FIG. 5. The one or more CLI overload indicator IEs may define CLI as low, medium, and high. In addition, for each resource block, the one or more CLI overload indicator IEs may provide a report on CLI interference overload, similar to the table shown in FIG. 3. In particular, if one or more UE-to-UE interference overload indication IEs are received in a particular message, this may indicate the time-averaging UE-to-UE interference level caused by the receiving network entity and/or experienced by an indicated network entity on some or all resource blocks. Furthermore, the receiving network entity may utilize one or more UE-to-UE interference overload indication IEs in creating one or more scheduling policies, and may consider one or more UE-to-UE interference overload indication IE values valid until reception of one or more new messages that include an updated version of the one or more UE-to-UE interference overload indication IEs.

Similarly, if one or more NE-to-NE interference overload indication IEs are received in one or more messages, this may indicate one or more time-averaging NE-to-NE interference levels caused by the receiving network entity and/or experienced by the indicated network entity on some or all resource blocks. Furthermore, the receiving network entity may utilize one or more NE-to-NE interference overload indication IEs in creating one or more scheduling policies, and may consider one or more NE-to-NE interference overload indication IE values valid until reception of one or more new messages that include an updated version of the one or more UE-to-UE interference overload indication IEs.

In step 209, any of the NEs may update link direction bias control parameters. In step 211, any of the NEs may transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

FIG. 4 illustrates an example event triggering mechanism for generating one or more CLI overload indications, with one CLI overload indication for each Nslot. For example, the event triggering mechanism may be applicable for multiple UEs, where one cell serves only one UE within one slot, and different UEs are allowed to be served at different slots. At each slot, a NE and/or UE may measure the power of current UL/DL SINR, NE-to-NE interference, and/or UE-to-UE interference. The UE should transmit the related measurement results to its serving network entity so that the network entity may compute the mean UL/DL SINRs over the previous N slots.

NE-to-NE and/or UE-to-UE interference overload indications may be triggered once one or more mean UL/DL SINRs are less than one or more corresponding thresholds. In response, the network entity may send one or more UE-to-UE interference overload indication IEs and/or NE-to-NE interference overload indication IEs indicating high, medium, and/or low interference values. The interference values may be transmitted to one or more identified interfering cells that cause the smallest corresponding number of UL/DL SINRs at the different slots. For example, the smallest corresponding number of UL/DL SINRs at different slots t ₁, t ₂, and t ₃, and the largest NE-to-NE interferences received at slots t ₁, t ₂, and t ₃, may be from neighboring cells m ₁, m ₂, and m ₃, respectively. Thus, the network cell may send NE-to-NE interference overload indication IEs with “high interference, ” “medium interference, ” and “low interference” values to neighboring cells m ₁, m ₂, and m ₃, respectively. Accordingly, one or more link direction bias control parameters may be updated for each N slots/symbols.

In step 401, a parameter n may be set to a value, such as 0. In step 403, a determination may be made of whether slot n is a UL or DL slot. Ifslot n is a DL slot, the UE measures DL SINR and/or UE-to-UE interference power from all neighboring cells, and then identifies an aggressor cell with the maximum UE-to-UE interference in step 405. Then, in step 407, the UE transmits the measurement SINR value and/or an identification of the aggressor cell to its serving network entity. If the slot n is determined to be a UL in step 403, then in step 409, a network entity measures UL SINR and NE-to-NE interference power from all neighboring cells, and then identifies the aggressor cell with the maximum NE-to-NE interference.

In step 411, in some examples, n is determined to be equal to mod (n + 1, N) , and the method returns to step 403. In step 413, in some examples, a determination is made if whether n = N -1, and if so, in step 415, the network entity computes the mean UL and DL SINRs over the previous N slots. In some embodiments, a step size may be adapted based on one or more of CLI measurements, information exchanged by one or more network entities, and/or other higher-level signaling. In step 417, a determination is made whether the mean UL SINR is less than a threshold, and ifso, in step 419, the network entity sends one or more NE-or-NE interference overload indication IEs with “high interference, ” “medium interference, ” and “low interference” values to a number of aggressor cells which cause a corresponding smallest number UL SINR at the corresponding slots. In parallel, in step 421, a determination is made whether the mean DL SINR is less than threshold, and if so, in step 423, the network entity sends one or more NE-or-NE interference overload indication IEs with “high interference, ” “medium interference, ” and “low interference” values to a number of aggressor cells which cause a corresponding smallest number UL SINR at the corresponding slots.

FIG. 5 illustrates a strategy for updating link direction bias control parameters. In step 501, one or more network entities may receive one or more NE-to-NE/UE-to-UE interference overload indication IEs from one or more neighboring cells. In step 503, if the one or more network entities received NE-to-NE interference overload indication IEs, a determination is made whether the aggressor cell is causing NE-to-NE interference. If the aggressor cell is causing NE-to-NE interference, in step 505, Δ _n ^DL= max {Δ _n ^DL -1, 0} . If the aggressor cell is not causing NE-to-NE interference, in step 507, Δ _n ^DL= min {Δ _n ^DL + 1, N} .

In step 509, if the one or more network entities received UE-to-UE interference overload indication IEs, a determination is made whether the aggressor cell is causing UE-to-UE interference. If the aggressor cell is causing UE-to-UE interference, in step 511, Δ _n ^UL = max {Δ _n ^UL -1, 0} . If the aggressor cell is not causing UE-to-UE interference, in step 513, Δ _n ^UL = min {Δ _n ^UL + 1, N} .

In some examples, a designed updating strategy may involve a negative feedback mechanism, which may lead to improved stability and performance of the parameter updating process. The negative feedback mechanism may accommodate various algorithms that are used to determine whether a cell is an aggressor cell of NE-to-NE/UE-to-UE interference. Each cell may employ different criteria and/or algorithms. For example, one or more simple majority and/or minority mechanisms may apply. For a majority mechanism, if more than half of the neighboring cells inform one or more cells that cause high interference in NE-to-NE/UE-to-UE via CLI overload IEs, the cell may be viewed as an aggressor cell of NE-to-NE/UE-to-UE interference. Alternatively, for a minority mechanism, one or more cells may be identified as an aggressor cell of NE-to-NE/UE-to-UE interference as long as one cell informs it of high interference in NE-to-NE/UE-to-UE interference via CLI overload IE.

In some examples, a maximum-minimum traffic matching scheme may be applied with closed-loop link direction bias controls. For example, a system may be composed of macro cells in a regular hexagonal grid, as illustrated in FIG. 6. For example, each cell may adjust the UL/DL transmission ratio every N = 10 slots, based upon UL/DL traffic demands and CLI overload indication IEs sent from the neighboring cells. For given demanded UL/DL traffic ratio of cell n Δ _demand, n ^UL: Δ _demand, n ^DL, such that N _demand, n ^UL + N _demand, n ^DL = N, the perfect traffic matching may be N _n ^UL/N _demand, n ^UL = N _n ^DL/N _demand, n ^DL = 1 for all cells. N _n ^UL/N _demand, n ^UL and N _n ^DL/N _demand, n ^DL may be traffic matching factors. Thus, traffic adaptation may be improved by the traffic matching factors of all cells being closer to one. In order to achieve the UL/DL traffic adaptation, the minimum traffic matching factor may be maximized over {N _n ^UL, N _n ^DL} . The minimum traffic matching factor may be equivalent to the minimum element in the set {N _n ^X/N _demand, n ^X|X ∈ {UL, DL} , n ∈ S _cell} . When this criterion is applied under the constraint N _n ^UL + N _n ^DL = N, the maximal traffic matching factor may be decreased.

FIG. 7 illustrates an example method performed by a network entity according to some examples. The network entity may be similar to network entity 910, as illustrated in FIG. 9. In step 701, the network entity may assign an initial or updated value to an uplink direction bias control parameter and an initial or updated value to a downlink direction bias control parameter. In step 703, the network entity may apply a time-division duplex pattern configuration that guarantees that the link direction bias satisfies predefined criteria, for example, one or more quality metric parameters. In some examples, based upon a link direction control parameter, such as/Delta_n, any of the NEs may choose N_n which fulfills one or more currently used bias control constraints. In step 705, the network entity may receive cross-link interference measurements. In step 707, the network entity may exchange one or more CLI measurement indication information elements with one or more network entities. In step 709, the network entity may update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications. In step 711, the network entity may transmit and/or receive signals using the adjusted one or more link direction bias control parameters.

FIG. 8 illustrates an example method performed by user equipment according to some examples. The user equipment may be similar to user equipment 920, as illustrated in FIG. 9. In step 801, if a slot n is a downlink slot, the user equipment may measure DL SINR and/or UE-to-UE interference power from one or more neighboring cells. In step 803, the user equipment may identify an aggressor cell with the maximum UE-to-UE interference. In step 805, the user equipment may transmit the measurement SINR value and/or an identification of the aggressor cell to a serving network entity. The network entity may be similar to network entity 910, as illustrated in FIG. 9. In some examples, the measurement SINR value and/or identification of the aggressor cell may be configured to compute mean UL and/or DL SINRs over previous N slots.

FIG. 9 illustrates an example of a system according to certain examples. In one example, a system may include multiple devices, such as, for example, network entity 910 and user equipment 920.

UE 920 may include one or more of a mobile device, such as a mobile phone, smart phone, personal digital assistant (PDA) , tablet, or portable media player, digital camera, pocket video camera, video game console, navigation unit, such as a global positioning system (GPS) device, desktop or laptop computer, single-location device, such as a sensor or smart meter, or any combination thereof. Network entity 910 may be one or more of a base station, such as an evolved node B (eNB) or 5G or New Radio node B (gNB) , a serving gateway, a server, and/or any other access node or combination thereof. Furthermore, user equipment 920 and/or network entity 910 may be one or more of a citizens broadband radio service device (CB SD) .

One or more of these devices may include at least one processor, respectively indicated as 911 and 921. At least one memory may be provided in one or more of devices indicated at 912 and 922. The memory may be fixed or removable. The memory may include computer program instructions or computer code contained therein.

Processors

911 and 921 and

memories

912 and 922 or a subset thereof, may be configured to provide means corresponding to the various blocks of FIGS. 1-8. Although not shown, the devices may also include positioning hardware, such as GPS or micro electrical mechanical system (MEMS) hardware, which may be used to determine a location of the device. Other sensors are also permitted and may be included to determine location, elevation, orientation, and so forth, such as barometers, compasses, and the like.

As shown in FIG. 9,

transceivers

913 and 923 may be provided, and one or more devices may also include at least one antenna, respectively illustrated as 914 and 924. The device may have many antennas, such as an array of antennas configured for multiple input multiple output (MIMO) communications, or multiple antennas for multiple radio access technologies. Other configurations of these devices, for example, may be provided.

Transceivers

913 and 923 may be a transmitter, a receiver, or both a transmitter and a receiver, or a unit or device that may be configured both for transmission and reception.

Processors

911 and 921 may be embodied by any computational or data processing device, such as a central processing unit (CPU) , application specific integrated circuit (ASIC) , or comparable device. The processors may be implemented as a single controller, or a plurality of controllers or processors.

Memories

912 and 922 may independently be any suitable storage device, such as a non-transitory computer-readable medium. A hard disk drive (HDD) , random access memory (RAM) , flash memory, or other suitable memory may be used. The memories may be combined on a single integrated circuit as the processor, or may be separate from the one or more processors. Furthermore, the computer program instructions stored in the memory and which may be processed by the processors may be any suitable form of computer program code, for example, a compiled or interpreted computer program written in any suitable programming language. Memory may be removable or non-removable.

The memory and the computer program instructions may be configured, with the processor for the particular device, to cause a hardware apparatus such as user equipment to perform any of the processes described below (see, for example, FIGS. 1-8) . Therefore, in certain examples, a non-transitory computer-readable medium may be encoded with computer instructions that, when executed in hardware, perform a process such as one of the processes described herein. Alternatively, certain examples may be performed entirely in hardware.

In certain examples, an apparatus may include circuitry configured to perform any of the processes or functions illustrated in FIGS. 1-8. For example, circuitry may be hardware-only circuit implementations, such as analog and/or digital circuitry. In another example, circuitry may be a combination of hardware circuits and software, such as a combination of analog and/or digital hardware circuit (s) with software or firmware, and/or any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and at least one memory that work together to cause an apparatus to perform various processes or functions. In yet another example, circuitry may be hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that include software, such as firmware for operation. Software in circuitry may not be present when it is not needed for the operation of the hardware.

One having ordinary skill in the art will readily understand that certain examples discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims.

Partial Glossary

3GPP Third Generation Partnership Project

5G Fifth Generation Wireless System

CDF Cumulative Distribution Function

CLI Cross-link Interference

DL Downlink

eIMTA Enhanced Interference Mitigation and Traffic Adaption

gNB Next Generation Node

IE Information Element

LTE Long Term Evolution

NR New Radio

OFDM Orthogonal Frequency Division Multiplexing

OI Overload Indication

SINR Signal-to-Interference-Plus-Noise Ratio

TDD Time-Division Duplex

TRP Transmission Reception Point

UE User Equipment

UL Uplink

Claims

An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

receive one or more cross-link interference overload indications;

update one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications; and

transmit and/or receive signals using the adjusted one or more link direction bias control parameters.
The apparatus according to claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

assign an initial or updated value to an uplink direction bias control parameter and an initial or updated value to a downlink direction bias control parameter.
The apparatus according to any of claims 1 or 2, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

apply a time-division duplex pattern configuration that guarantees the link direction bias satisfies predefined criteria.
The apparatus according to any of claims 1-3, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

measure one or more of cross-link interference between the apparatus and a network entity and cross-link interference between a first user equipment and a second user equipment.
The apparatus according to any of claims 1-4, wherein the one or more link direction bias control parameters are updated based upon one or more cross-link interference overload indications transmitted by the apparatus.
A method, comprising:

receiving, by a network entity, one or more cross-link interference overload indications;

updating, by the network entity, one or more link direction bias control parameters based at least upon the one or more cross-link interference overload indications; and

transmitting and/or receiving, by the network entity, signals using the adjusted one or more link direction bias control parameters.
The method according to claim 6, further comprising:

assigning, by the network entity, an initial or updated value to an uplink direction bias control parameter and an initial or updated value to a downlink direction bias control parameter.
The method according to any of claims 6 or 7, further comprising:

applying, by the network entity, a time-division duplex pattern configuration that guarantees the link direction bias satisfies predefined criteria.
The method according to any of claims 6-8, further comprising:

measuring, by the network entity, one or more of cross-link interference between the apparatus and a network entity and cross-link interference between a first user equipment and a second user equipment.
The method according to claims 6-9, wherein the one or more link direction bias control parameters are updated based upon one or more cross-link interference overload indications transmitted by the apparatus.
An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

measure DL SINR and/or UE-to-UE interference power from one or more neighboring cells if a slot n is a downlink slot;

identify an aggressor cell with the maximum UE-to-UE interference; and

transmit one or more measurement SINR values and/or an identification of the aggressor cell to a serving network entity.
A method, comprising:

measuring, by user equipment, DL SINR and/or UE-to-UE interference power from one or more neighboring cells if a slot n is a downlink slot;

identifying, by the user equipment, an aggressor cell with the maximum UE-to-UE interference; and

transmitting, by the user equipment, one or more measurement SINR values and/or an identification of the aggressor cell to a serving network entity.
A non-transitory computer-readable medium encoding instructions that, when executed in hardware, perform a process according to any of claims 1-12.
An apparatus comprising means for performing a process according to any of claims 1-12.
An apparatus comprising circuitry configured to cause the apparatus to perform a process according to any of claims 1-12.
A computer program product encoded with instructions for performing a process according to any of claims 1-12.