WO2024028390A1

WO2024028390A1 - Methods, communications devices and infrastructure equipment

Info

Publication number: WO2024028390A1
Application number: PCT/EP2023/071417
Authority: WO
Inventors: Shin Horng Wong; Martin Warwick Beale; Naoki Kusashima
Original assignee: Sony Group Corporation; Sony Europe B.V.
Priority date: 2022-08-05
Filing date: 2023-08-02
Publication date: 2024-02-08

Abstract

A method of operating a communications device for transmitting uplink information is provided. The method comprises preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. The uplink information is prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information. The method comprises determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information. The determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met. The method comprises transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

Description

METHODS, COMMUNICATIONS DEVICES AND INFRASTRUCTURE EQUIPMENT

BACKGROUND

Field of Disclosure

The present disclosure relates to communications devices, infrastructure equipment and methods of operating communications devices and infrastructure equipment in a wireless communications network.

The present application claims the Paris Convention priority of European patent application number EP22189114.6, the contents of which are hereby incorporated by reference in their entirety.

Description of Related Art

The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

Previous generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support a wider range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to continue to increase rapidly.

Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles / characteristics depending on the application(s) it is running. For example, different consideration may apply for efficiently supporting data exchange with a smartphone when it is running a video streaming application (high downlink data) as compared to when it is running an Internet browsing application (sporadic uplink and downlink data) or being used for voice communications by an emergency responder in an emergency scenario (data subject to stringent reliability and latency requirements).

In view of this there is expected to be a desire for current wireless communications networks, for example those which may be referred to as 5G or new radio (NR) systems / new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements.

5G NR has continuously evolved and the current work plan includes 5G-NR-advanced in which some further enhancements are expected, especially to support new use-cases/scenarios with higher requirements. A desire to support these new use-cases and scenarios gives rise to new challenges for efficiently handling communications in wireless communications systems that need to be addressed.

SUMMARY OF THE DISCLOSURE

The present disclosure can help address or mitigate at least some of the issues discussed above.

Embodiments of the present technique can provide a method of operating a communications device for transmitting uplink information. The method comprises preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. The uplink information is prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information. The method comprises determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information. The determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met. The method comprises transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

Other example embodiments can provide a method of operating an infrastructure equipment forming part of a wireless communications network for transmitting downlink information. The method comprises preparing downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. The downlink information is prepared for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information. The method comprises determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information. The determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met. The method comprises transmitting the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements. As will be appreciated from an understanding of the following detailed description, example embodiments can provide methods in which a communications device or infrastructure equipment determines that a muting condition is met. By imposing a condition on the muting of resource elements, the number of instances of resource element muting can be reduced, thereby providing improved communications resource efficiency. The condition can take into account the interference expected to be caused at the infrastructure equipment by an uplink or a downlink transmission, for example. Therefore, the muting condition can be configured such that only resource elements of uplink or downlink transmissions which are expected to cause significant interference are muted.

Embodiments of the present technique, which, in addition to methods of operating communications devices, relate to methods of operating infrastructure equipment, communications devices and infrastructure equipment, circuitry for communications devices and infrastructure equipment, computer programs, and computer-readable storage mediums, can allow for the more efficient use of radio resources by a communications device operating in a wireless communications network.

Respective aspects and features of the present disclosure are defined in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the present technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

Figure 1 schematically represents some aspects of an LTE-type wireless telecommunication system which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 2 schematically represents some aspects of a new radio access technology (RAT) wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 3 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 4 schematically illustrates an example of inter-cell cross link interference;

Figure 5 illustrates an example approach for accounting for inter-cell cross link interference;

Figure 6 schematically illustrates an example of intra-cell cross link interference;

Figure 7 illustrates an example division of system bandwidth into dedicated uplink and downlink subbands;

Figure 8 illustrates an example of transmission power leakage; Figure 9 illustrates an example of receiver power selectivity;

Figure 10 illustrates an example of inter sub-band interference;

Figure 11 illustrates an example of intra sub-band interference;

Figure 12 illustrates a method of operating a communications device in accordance with example embodiments;

Figure 13 schematically illustrates an example of muting resource elements for an uplink transmission in accordance with example embodiments;

Figure 14 illustrates a method of operating infrastructure equipment in accordance with example embodiments;

Figure 15 schematically illustrates an example of muting resource elements for a downlink transmission in accordance with example embodiments;

Figure 16 schematically illustrates an example of muting guard resource elements for a downlink transmission in accordance with example embodiments;

Figure 17 schematically illustrates a plurality of resource element muting patterns with which a UE can be configured in accordance with example embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Long Term Evolution Advanced Radio Access Technology (4G)

Figure 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunications network / system 6 operating generally in accordance with LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [1], It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

The network 6 includes a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (i.e. a cell) within which data can be communicated to and from communications devices 4. Although each base station 1 is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the base station may be carried out by disparate, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

Data is transmitted from base stations 1 to communications devices 4 within their respective coverage areas 3 via a radio downlink. Data is transmitted from communications devices 4 to the base stations 1 via a radio uplink. The core network 2 routes data to and from the communications devices 4 via the respective base stations 1 and provides functions such as authentication, mobility management, charging and so on. Terminal devices may also be referred to as mobile stations, user equipment (UE), user terminal, mobile radio, communications device, and so forth. Services provided by the core network 2 may include connectivity to the internet or to external telephony services. The core network 2 may further track the location of the communications devices 4 so that it can efficiently contact (i.e. page) the communications devices 4 for transmitting downlink data towards the communications devices 4.

Base stations, which are an example of network infrastructure equipment, may also be referred to as transceiver stations, nodeBs, e-nodeBs, eNB, g-nodeBs, gNB and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

New Radio Access Technology (5G)

Systems incorporating NR technology are expected to support different services (or types of services), which may be characterised by different requirements for latency, data rate and/or reliability. For example, Enhanced Mobile Broadband (eMBB) services are characterised by high capacity with a requirement to support up to 20 Gb/s. The requirements for Ultra Reliable and Low Latency Communications (URLLC) services are for one transmission of a 32 byte packet to be transmitted from the radio protocol layer 2/3 SDU ingress point to the radio protocol layer 2/3 SDU egress point of the radio interface within 1 ms with a reliability of 1 - 10"⁵ (99.999 %) or higher (99.9999%) [2],

Massive Machine Type Communications (mMTC) is another example of a service which may be supported by NR-based communications networks. In addition, systems may be expected to support further enhancements related to Industrial Internet of Things (IIoT) in order to support services with new requirements of high availability, high reliability, low latency, and in some cases, high-accuracy positioning.

An example configuration of a wireless communications network which uses some of the terminology proposed for and used in NR and 5G is shown in Figure 2. In Figure 2 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a cell of the wireless communications network as represented by a circle 12. As such, wireless communications devices 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 20 may be connected to other networks 30.

The elements of the wireless access network shown in Figure 2 may operate in a similar way to corresponding elements of an LTE network as described with regard to the example of Figure 1. It will be appreciated that operational aspects of the telecommunications network represented in Figure 2, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

The TRPs 10 of Figure 2 may in part have a corresponding functionality to a base station or eNodeB of an LTE network. Similarly, the communications devices 14 may have a functionality corresponding to the UE devices 4 known for operation with an LTE network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

In terms of broad top-level functionality, the core network 20 connected to the new RAT telecommunications system represented in Figure 2 may be broadly considered to correspond with the core network 2 represented in Figure 1, and the respective central units 40 and their associated distributed units / TRPs 10 may be broadly considered to provide functionality corresponding to the base stations 1 of Figure 1. The term network infrastructure equipment / access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may lie with the controlling node / central unit and / or the distributed units / TRPs. A communications device 14 is represented in Figure 2 within the coverage area of the first communication cell 12. This communications device 14 may thus exchange signalling with the first central unit 40 in the first communication cell 12 via one of the distributed units / TRPs 10 associated with the first communication cell 12.

It will further be appreciated that Figure 2 represents merely one example of a proposed architecture for a new RAT based telecommunications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless telecommunications systems having different architectures.

Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment / access node and the communications device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE-type base station 1 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment may comprise a control unit / controlling node 40 and / or a TRP 10 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein.

A more detailed diagram of some of the components of the network shown in Figure 2 is provided by Figure 3. In Figure 3, a TRP 10 as shown in Figure 2 comprises, as a simplified representation, a wireless transmitter 30, a wireless receiver 32 and a controller or controlling processor 34 which may operate to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. As shown in Figure 3, an example UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44 which is configured to control the transmitter 49 and the receiver 48 to transmit signals representing uplink data to the wireless communications network via the wireless access interface formed by the TRP 10 and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with the conventional operation.

The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G/NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment / TRP / base station as well as the UE / communications device will in general comprise various other elements associated with its operating functionality.

As shown in Figure 3, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides a communication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

The interface 46 between the DU 42 and the CU 40 is known as the Fl interface which can be a physical or a logical interface. The Fl interface 46 between CU and DU may operate in accordance with specifications 3GPP TS 38.470 and 3GPP TS 38.473, and may be formed from a fibre optic or other wired or wireless high bandwidth connection. In one example the connection 16 from the TRP 10 to the DU 42 is via fibre optic. The connection between a TRP 10 and the core network 20 can be generally referred to as a backhaul, which comprises the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the Fl interface 46 from the DU 42 to the CU 40. Full Duplex Time Division Duplex (FD-TDD)

NR/5G networks can operate using Time Division Duplex (TDD), where an entire frequency band or carrier is switched to either downlink or uplink transmissions for a time period and can be switched to the other of downlink or uplink transmissions at a later time period. Currently, TDD operates in Half Duplex mode (HD-TDD) where the gNB or UE can, at a given time, either transmit or receive packets, but not both at the same time. As wireless networks transition from NR to 5G- Advanced networks, a proposed new feature of such networks is to enhance duplexing operation for TDD by enabling Full Duplex operation in TDD (FD-TDD) [3], [4],

In FD-TDD, a gNB can transmit and receive data to and from the UEs at the same time on the same frequency band. In addition, a UE can operate either in HD-TDD or FD-TDD mode, depending on its capability. For example, when UEs are only capable of supporting HD-TDD, FD-TDD is achieved at the gNB by scheduling a DL transmission to a first UE and scheduling an UL transmission from a second UE within the same orthogonal frequency division multiplexing (OFDM) symbol (i.e. at the same time). Conversely, when UEs are capable of supporting FD-TDD, FD-TDD is achieved both at the gNB and the UE, where the gNB can simultaneously schedule this UE with DL and UL transmissions within the same OFDM symbol by scheduling the DL and UL transmissions at different frequencies (e.g. physical resource blocks (PRBs)) of the system bandwidth. A UE supporting FD- TDD requires more complex hardware than a UE that only supports HD-TDD. Development of current 5G networks is focused primarily on enabling FD-TDD at the gNB with UEs operating in HD-TDD mode.

Motivations for enhancing duplexing operation for TDD include an improvement in system capacity, reduced latency, and improved uplink coverage. For example, in current HD-TDD systems, OFDM symbols are allocated only for either an DL or UL direction in a semi-static manner. Hence, if one direction experiences less or no data, the spare resources cannot be used in the other direction, or are, at best, under-utilized. However, if resources can be used for DL data and UL data (as in FD-TDD) at the same time, the resource utilization in the system can be improved. Furthermore, in current HD- TDD systems, a UE can receive DL data, but cannot transmit UL data at the same time, which causes delays. If a gNB or UE is allowed to transmit and receive data at the same time (as with FD-TDD), the traffic latency will be improved. In addition, UEs are usually limited in the UL transmissions when located close to the edge of a cell. While the UE coverage at the cell-edge can be improved if more time domain resources are assigned to UL transmissions (e.g. repetitions), if the UL direction is assigned more time resources, fewer time resources can be assigned to the DL direction, which can lead to system imbalance. Enabling FD-TDD would help allow a UE to be assigned more UL time resources when required, without sacrificing DL time resources.

Inter-Cell Cross Link Interference (CLI)

In NR systems, a slot format (i.e. the allocation of DL and UL OFDM symbols in a slot) can be semi- statically or dynamically configured, where each OFDM symbol (OS) in a slot can be configured as Downlink (DL), Uplink (UL) or Flexible (F). An OFDM symbol that is semi-statically configured to be Flexible can be indicated dynamically as DL, UL or remain as Flexible by a Dynamic Slot Format Indicator (SFI), which is transmitted in a Group Common (GC) DCI using DCI Format 2 0, where the CRC of the GC-DCI is masked with SFI-RNTI. Flexible OFDM Symbols that remain Flexible after instruction from the SFI can be changed to a DL symbol or an UL symbol by a DL Grant or a UL Grant respectively. That is, a DL Grant scheduling a PDSCH that overlaps Flexible OFDM Symbols would convert these Flexible OFDM Symbols to DL and similarly an UL Grant scheduling a PUSCH that overlaps Flexible OFDM Symbols would convert these Flexible OFDM Symbols to UL.

Since each gNB in a network can independently change the configuration of each OFDM symbol, either semi-statically or dynamically, it is possible that in a particular OFDM symbol, one gNB is configured for UL and a neighbour gNB is configured for DL. This causes inter-cell Cross Link Interference (CLI) among the conflicting gNBs (due to the UL/DL symbol clash for one or more symbols). Inter-cell CLI occurs when a UE’s UL transmission interferes with a DL reception by another UE in another cell, or when a gNB’s DL transmission interferes with an UL reception by another gNB. That is, inter-cell CLI is caused by non-aligned (conflicting) slot formats among neighbouring cells. An example is shown in Figure 4, where gNBl 411 and gNB2 412 have synchronised slots. At a given slot, gNBl’s 411 slot format = {D, D, D, D, D, D, D, D, D, D, U, U, U, U} whilst gNB2’s 412 slot format = {D, D, D, D, D, D, D, D, D, D, D, U, U, U}, where ‘D’ indicates DL and ‘U’ indicates UL. Inter-cell CLI occurs during the 11^th OFDM symbol of the slot, where gNBl 411 is performing UL whilst gNB2 412 is performing DL. Specifically, inter-cell CLI 441 occurs between gNBl 411 and gNB2 412, where gNB2’s 412 DL transmission 431 interferes with gNBl’s 411 UL reception 432. CLI 442 also occurs between UE1 421 and UE2 422, where UEl’s 421 UL transmission 432 interferes with UE2’s 422 DL reception 431.

Some legacy implementations attempt to reduce inter-cell CLI in TDD networks caused by flexible and dynamic slot format configurations. Two CLI measurement reports to manage and coordinate the scheduling among neighbouring gNBs include: sounding reference signal (SRS) reference signal received power (RSRP) and CLI received signal strength indicator (RSSI). In SRS-RSRP, a linear average of the power contribution of an SRS transmitted by a UE is measured by a UE in a neighbour cell. This is measured over the configured resource elements within the considered measurement frequency bandwidth, in the time resources in the configured measurement occasions. In CLI-RSSI, a linear average of the total received power observed is measured only at certain OFDM symbols of the measurement time resource(s), in the measurement bandwidth, over the configured resource elements for measurement by a UE.

Both SRS-RSRP and CLI-RSSI are RRC measurements and are performed by a UE, for use in mitigating against UE to UE inter-cell CLI. For SRS-RSRP, an aggressor UE (i.e. a UE whose UL transmissions cause interference at another UE in a neighbouring cell) would transmit an SRS in the uplink and a victim UE (i.e. a UE that experiences interference due to an UL transmission from the UE in the neighbouring cell) in a neighbour cell would be configured with a measurement configuration including the aggressor UE’s SRS parameters, in order to allow the interference from the aggressor UE to be measured. An example is shown in Figure 5 where, at a particular slot, the 11^th OS (OFDM symbol) of gNBl 511 and gNB2 512 causes inter-cell CLI. Here, gNBl 511 has configured UE1 521, the aggressor UE, to transmit an SRS 540 and gNB2 512 has configured UE2 522, the victim UE, to measure that SRS 540. UE2 522 is provided with UEl’s 521 SRS configured parameters, e.g. RS sequence used, frequency resource, frequency transmission comb structure and time resources, so that UE2 522 can measure the SRS 540. In general, a UE can be configured to monitor 32 different SRSs, at a maximum rate of 8 SRSs per slot.

For CLI-RSSI measurements, the UE measures the total received power, i.e. signal and interference, following a configured periodicity, start and end OFDM symbols of a slot, and a set of frequency Resource Blocks (RBs). Since SRS-RSRP measures a transmission by a specific UE, the network can target a specific aggressor UE to reduce its transmission power and in some cases not schedule the aggressor UE at the same time as a victim UE that reports a high SRS-RSRP measurement. In contrast, CLI-RSSI cannot be used to identify a specific aggressor UE’s transmission, but CLI-RSSI does provide an overall estimate of the inter-cell CLI experienced by the victim UE.

Intra-Cell Cross Link Interference (CLI) and Sub-band Full Duplex (SBFD)

In addition to inter-cell CLI, FD-TDD also suffers from intra-cell CLI at the gNB and at the UE. An example is shown in Figure 6, where a gNB 610 is capable of FD-TDD and is simultaneously receiving UL transmission 631 from UE1 621 and transmitting a DL transmission 642 to UE2 622. At the gNB 610, intra-cell CLI is caused by the DL transmission 642 at the gNB’s transmitter self-interfering 641 with its own receiver that is trying to decode UL signals 631. At UE2 622, intra-cell CLI 632 is caused by an aggressor UE, e.g. UE1 621, transmitting in the UL 631, whilst a victim UE, e.g. UE2 622, is receiving a DL signal 642.

The intra-cell CLI at the gNB due to self-interference can be significant, as the DL transmission can in some cases be over 100 dB more powerful than the UL reception. Accordingly, complex RF hardware and interference cancellation are required to isolate this self-interference. In order to reduce selfinterference at the gNB, one possibility being considered in [3], [4] is Sub-band Full Duplex (SBFD). In SBFD, the frequency resource of a TDD system bandwidth or Bandwidth Part (BWP) (i.e. at the UE/gNB) is divided into two or more non-overlapping sub-bands, where each sub-band can be DL or UL [5], An example is shown in Figure 7, where simultaneous DL and UL transmissions occur in different non-overlapping sub-bands 701 to 704, i.e. in different sets of frequency Resource Blocks (RB): Sub-band# 1 701, Sub-band#2 702, Sub-band#3 703 and Sub-band#4 704 such that Sub-band# 1 701 and Sub-band#3 703 are used for DL transmissions whilst Sub-band#2 702 and Sub-band#4 704 are used for UL transmissions.

While Figure 7 shows the system bandwidth as being divided into four sub-bands, substantially any number of sub-bands could be used. For example, the system bandwidth may be divided into three subbands, which may include two downlink sub-bands 701, 703 and one uplink sub-band 702, though other sub-band arrangements are envisioned. To reduce leakage from one sub-band 701 to 704 to another, a guard sub-band 710 may be configured between UL and DL sub-bands 701 to 704. Guard sub-bands 710 are configured between UL Sub-band#4 704 and DL Sub-band#3 703, between DL Sub-band#3 703 and UL Sub-band#2 702 and between UL Sub-band#2 702 and DL Sub-band# 1 701. The arrangement of sub-bands 701 to 704 shown in Figure 7 is just one possible arrangement of the subbands and other arrangements are possible, and guard bands may be used in substantially any sub-band arrangement.

Inter Sub-Band Interference

In addition to inter-cell Cross Link Interference, SBFD also suffers from inter (and intra) sub-band interferences, which are caused by transmission leakage and receiver’s selectivity. Although a transmission is typically scheduled within a specific frequency channel (or sub-band), i.e. a specific set of RBs, transmission power can leak out to other channels. This occurs because channel filters are not perfect, and as such the roll-off of the filter will cause power to leak into channels adjacent to the intended specific frequency channel. While the following discussion uses the term “channel”, the term “sub-band”, such as the sub-bands shown in Figure 7, may be used instead.

An example of transmission generating adjacent channel leakage is shown in Figure 8. Here, the wanted transmission (Tx) power is the transmission power in the selected frequency band (i.e. the assigned channel 810). Due to roll-off of the transmission filter and nonlinearities in components of the transmitter, some transmission power is leaked into adjacent channels (including an adjacent channel 820), as shown in Figure 8. The ratio of the power within the assigned frequency channel 810 to the power in the adjacent channel 820 is the Adjacent Channel Leakage Ratio (ACLR). The leakage power 850 will cause interference at a receiver that is receiving the signal in the adjacent channels 820.

Similarly, a receiver’s filter is also not perfect and will receive unwanted power from adjacent channels due to its own filter roll-off. An example of filter roll-off at a receiver is shown in Figure 9. Here, a receiver is configured to receive transmissions in an assigned channel 910. However, the imperfect nature of the receiver filter means that some transmission power 950 can be received in adjacent channels 920. Therefore, if a signal 930 is transmitted on an adjacent channel 920, the receiver will inadvertently receive the adjacent signal 930 in the adjacent channel 920, to an extent. The ratio of the received power in the assigned frequency channel 910 to the received power 950 in the adjacent channel 920 is the Adjacent Channel Selectivity (ACS).

The combination of the ACL from the transmitter and the ACS of a receiver will lead to adjacent channel interference (ACI), otherwise known as inter-sub-band interference, at the receiver. An example is shown in Figure 10, where an aggressor transmits a signal 1010 in an adjacent channel at a lower frequency than the victim’s receiving 1020 channel. The interference 1050 caused by the aggressor’s transmission includes the ACL 1051 of the aggressor’s transmitting fdter and the ACS 1052 of the victim’s receiving fdter. In other words, the receiver will experience interference 1050 in the ACI frequency range shown in Figure 10.

As such, due to adjacent channel interference (ACI), cross link interference (CLI) will still occur despite the use of different sub-bands 701 to 704 for DL and UL transmissions in a FD-TDD cell as shown in the example of Figure 7. The proposed SRS-RSRP and CLI-RSSI measurements specified for intercell CLI assume that an aggressor and a victim transmit and receive in the same frequency channel. That is, the measurements for SRS-RSRP and CLI-RSSI at a victim UE are performed in the same frequency channel as the aggressor’s frequency channel. These approaches therefore do not take into account ACI and the use of sub-bands 701 to 704 to provide information for the scheduler to mitigate against intra-cell CLI.

Intra Sub-band Interference

Intra sub-band interference can occur when the sub-band configurations among gNBs are not aligned in the frequency domain. Here, CLI may occur in the overlapping frequencies of inter-cell sub-bands. An example is shown in Figure 11, where gNBl’s 1111 system bandwidth is divided into UL sub-band UL-SB#1 1152 occupying Jo to fi and DL sub-band DL-SB#1 1151 occupying/) to fi,, whilst gNB2’s 1112 system bandwidth is divided into UL sub-band UL-SB#2 1154 occupying Jo to fi and DL subband DL-SB#2 1153 occupying/i to J). The non-aligned sub-band configurations 1150 cause UL-SB#1 1152 to overlap with DL-SB#2 1153, thereby causing intra sub-band CLI within the overlapping frequencies fi to fi. In this example, intra sub-band CLI 1141 occurs at gNBl 1111 due to gNB2’s 1112 DL transmission 1132 within/i to/j in DL-SB#2 1153 interfering with gNBl’s 1111 UL reception 1131 from UE1 1121 within fi to/) in UL-SB#1 1152. In addition, intra sub-band CLI 1142 occurs at UE2 1122 due to UEl’s 1121 UL transmission 1131 within fi to/) in UL-SB#1 1152 interfering with UE2’s 1122 DL reception 1132 within fi to/) in DL-SB#2 1153.

One of the methods considered to manage CLI is to introduce gNB-gNB Reference Signals (RS), where a gNB transmits RS and another gNB measures the power level of this RS to determine the potential CLI that may be caused by the gNB that transmits the RS. The RS may be used by advanced receivers at the gNB for CLI cancellation. A gNB-gNB RS may also be used for inter-gNB signalling Over The Air (OTA). For example, it has been proposed that a gNB-gNB RS is used to signal the slot and subband format of the gNB [6] .

Recognising the importance of gNB-gNB RS, it has been proposed that the resource elements (REs) occupied by the gNB-gNB RS are muted at the receiving gNB so that the RS is received at high SNR [7], [8], However, muting REs means that less resources are available for traffic and/or that REs in scheduled PDSCH/PUSCH transmissions are frequently punctured. Furthermore, it is expected that a gNB can receive RSs from multiple gNBs which would lead to more RE mutings. Furthermore, cases arise in which resource elements of uplink/downlink transmissions are muted even though that uplink/downlink transmission would have caused negligible CLI at the gNB. Therefore, according to conventional methods, resource elements of uplink/downlink transmissions may be unnecessarily muted. In some cases, the uplink/downlink transmissions with the muted resource elements may have to be re-transmitted because they were unsuccessfully decoded by a receiver due to the muting.

There is therefore a need for methods, communications devices, and infrastructure equipment for improving communications efficiency.

Muting Resource Elements for an Uplink Transmission

In view of the above-described technical challenges, there is provided a method of operating a communications device for transmitting uplink information. The method comprises preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. The uplink information is prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information. The method comprises determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information. The determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met. The method comprises transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

A method of operating a communications device for transmitting uplink information in accordance with example embodiments is described with reference to Figure 12.

The method starts in step S 1.

In step S2, the method comprises preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. For example, the structure may be a time division duplex structure or sub-band full duplex structure. In some examples, the wireless access interface may be divided into uplink and downlink subbands. The uplink information is prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information. The uplink transmission may be scheduled by the infrastructure equipment in an uplink grant for example.

In step S3, the method comprises determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information. The one or more communications resource elements to be muted may coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment of the wireless communications network. The one or more reference signals to be received may be from another infrastructure equipment of the wireless communications network. In some examples, the infrastructure equipment may transmit an indication of communications resource elements which are designated for muting to the communications device, and the communications device may determine that the communications resource elements to be muted are those which coincide in time and frequency with the communications resource elements designated for muting. The communications resource elements designated for muting may include the communications resource elements allocated for the reception of the one or more reference signals. In some examples, the resource elements to be muted include one or more communications resource elements adjacent to or neighbouring the communications resource elements allocated for reception of the one or more reference signals.

The determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met. The communications parameters may comprise, for example, one or more of a modulation and coding scheme, MCS, for the transmission of the uplink information, an estimated pathloss of the transmission of the uplink information to the infrastructure equipment, an estimated received power of the transmission of the uplink information at the infrastructure equipment, a maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted, whether or not the transmission of the uplink information is a retransmission, a hybrid automatic repeat request, HARQ, process identification, PID, for the transmission of the uplink information, a priority of the transmission of the uplink information, or a waveform applied to the transmission of the uplink information.

In step S4, the method comprises transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements. For example, the transmitting may comprise rate matching the transmission of the uplink information around the one or more muted communications resource elements or puncturing the one or more muted communications resource elements.

In step S5, the method ends.

Those skilled in the art would appreciate that the method shown by Figure 12 may be adapted in accordance with embodiments of the present technique. For example, other intermediate steps may be included in this method, or the steps may be performed in any logical order.

As explained above, example embodiments provide a method in which a communications device determines that a muting condition based on one or more communications parameters is met. By imposing a condition on the muting of resource elements, the number of instances of resource element muting can be reduced, thereby providing improved communications resource efficiency. Since the condition is based on communications parameters of the uplink transmission, it can take into account the interference expected to be caused at the gNB by the uplink transmission, for example. Therefore, the muting condition can be configured such that only resource elements of uplink transmissions which are expected to cause significant interference are muted.

As will be appreciated by one skilled in the art, the muting of resource elements of a transmission includes puncturing the resource elements of the transmission or rate matching around the resource elements of the transmission.

In rate matching, transport channel processing is adapted to the number of resource elements in a transmission after the muted resource elements are taken out. The resource element mapping maps encoded symbols to avoid the muted resource elements of the transmission.

In puncturing, physical channel processing is adapted to avoid the muted resource elements by puncturing modulated symbols that are mapped to the muted resource elements. For example, 100 information bits are scheduled to occupy 150 resource elements. Here the MCS used is QPSK and 1/3 code is applied rate. If there is no muting (i.e. all 150 resource elements are used), then transport channel processing would produce 300 encoded bits, which is then modulated to 150 QPSK symbols and maps to the 150 resource elements. If 50 resource elements are muted (i.e. 100 resource elements out of 150 resource elements are available), then:

• In rate matching, the transport channel processing will produce 200 encoded bits which are then QPSK modulated to 100 symbols. These are then mapped to the 100 available resource elements.

• In puncturing, transport channel processing still produces 300 encoded bits, which are modulated to 150 QPSK symbols and maps to the 150 resource elements. The muted resource elements are then punctured, i.e. removed, thereby resulting in 100 resource elements being transmitted.

A method of performing resource element muting for an uplink transmission (such as a PUSCH or PUCCH) is described with reference to Figure 13. In the example shown in Figure 13, an uplink transmission overlaps with one or more resource elements that are designated for muting to reduce CLI for reference signal reception at a gNB.

Figure 13 schematically illustrates an uplink slot n 1451 for gNBl 1411, a downlink slot n 1461 for gNB2 1412 and an uplink slot n 1471 for UE1 1421. As shown in the slot n 1461 for gNB2 1412, a reference signal configuration comprising a set of resource elements 1453 is allocated for transmission 1441 of one or more reference signals from gNB2 1412 to gNBl 1411. As shown in the slot n 1451 for gNBl 1411, a PUSCH 1455 is allocated for reception 1432 by gNBl 1411 from UEl 1421. The PUSCH 1455 overlaps with the set of resource elements 1453 allocated for the transmission 1441 of the one or more reference signals. Although not shown in Figure 13, UE1 1421 is aware of the location of resource elements that are designated for muting. For example, gNBl 1411 may transmit an indication of resource elements which are designated for muting. In other examples, UE1 1421 is pre-configured to know the location of the resource elements that are designated for muting. In the example shown in Figure 13, the resource elements designated for muting are the set of resource elements 1453 allocated for the transmission 1441 of the one or more reference signals . However, in other examples, the resource elements designated for muting include other resource elements instead of, or in addition to, the set of resource elements 1453 allocated for the transmission 1441 of the one or more reference signals. Therefore, UE1 1421 determines a plurality of resource elements 1473 of the PUSCH 1455 which coincide with the resource elements 1453 designated for muting. UE1 1421 mutes the coinciding resource elements 1473 of the PUSCH 1455. The muted resource elements 1473 are not transmitted to gNB 1 1411. Physical channel processing may be adapted to puncture the muted resource elements 1473 or transport channel processing may be adapted to rate match to the other resource elements of the PUSCH 1455 which were not muted, and physical channel processing is adapted by not mapping to the muted resource elements 1473.

By muting resource elements 1473 of the PUSCH 1473 as explained above, gNB 1 1411 can receive the one or more reference signals from gNB2 1412 with a higher signal quality than if resource elements 1473 of the PUSCH 1455 were not muted. This is because the PUSCH 1455 with the muted resource elements 1473 causes less or no interference to the one or more reference signals. However, as mentioned above, if muting is performed every time a reference signal configuration overlaps with an uplink transmission, then communications resource efficiency is reduced because less resources are available for uplink traffic or uplink traffic will be frequently received with muted resource elements. However, it is recognised herein that, communications efficiency can be improved by imposing a condition on the muting of resource elements allocated for an uplink transmission based on one or more communications parameters for the uplink transmission.

Therefore, in accordance with example embodiments, a UE determines to mute resource elements of an uplink transmission based on a muting condition. The muting condition is based on one or more communications parameters for the uplink transmission. If the muting condition is met, the UE performs resource element muting on the uplink transmission. In other words, the UE mutes the resource elements of the uplink transmission which coincide in time and frequency with the resource elements designated for muting.

In some embodiments, the muting condition is based on a Modulation and Coding Scheme, MCS, of the uplink transmission. For example, if the MCS of the uplink transmission is above an MCS threshold, TMCS, then the UE performs resource element muting on the uplink transmission. Otherwise, the UE does not perform resource element muting on the uplink transmission. Such embodiments recognise that a lower MCS is more robust than a higher MCS and, typically, a lower MCS requires less transmission power, or is received at a lower power at the gNB. Therefore, the interference caused by the uplink transmission would be tolerable. In such embodiments, the gNB receiving the uplink transmission is aware that the UE has applied resource element muting or not because the gNB schedules the MCS of the uplink transmission.

In some embodiments, the muting condition is based on an estimated pathloss between the UE and gNB. If the estimated pathloss is below a pathloss threshold (for example, because the UE is located close to the gNB), the UE performs resource element muting on the uplink transmission. Such embodiments recognise that, if the UE-gNB pathloss is high, it is unlikely that the uplink transmission would cause significant interference to the reception of the one or more reference signals at the gNB. The UE may estimate the pathloss based on one or more downlink signals received from the gNB. Alternatively, the gNB may estimate the pathloss and transmit an indication of the pathloss to the UE. In embodiments where the gNB transmits an indication of the estimated pathloss to the UE, the gNB can be made aware of whether or not the UE will apply resource element muting on the uplink transmission or not. For example, the gNB can determine whether or not the estimated pathloss is above the pathloss threshold or not. This simplifies the processing load at the gNB because the gNB does not have to blind decode the received uplink transmission. In some embodiments, the muting condition is based on an estimated receive power of the uplink transmission at the gNB. The UE can estimate the gNB receive power by estimating the pathloss between the gNB and UE and a transmit power of the UE. If the estimated receive power is less than a threshold T_Kx ,,_r. then the UE does not perform resource element muting on the uplink transmission. Otherwise, the UE does perform resource element muting on the uplink transmission. Such embodiments recognise that if the receive power at the gNB is low, then it is less likely to cause significant interference to the one or more reference signals received by the gNB compared to if the receive power of the uplink transmission is high at the gNB. In such embodiments, the gNB may not be aware of whether or not the UE has performed resource element muting on the uplink transmission. This is because the gNB may not be aware of the transmit power of the uplink transmission applied by the UE or the gNB may not be aware of the most recent pathloss measurements performed by the UE. Therefore, the gNB may perform blind decoding on the uplink transmission.

In some embodiments, a maximum number of allowed resource element mutings MuL-Mute-Max is defined for an uplink transmission. For example, if the UE determines to perform resource element muting on the uplink transmission, it will mute a maximum of MuL-Mute-Max resource elements. MuL-Mute-Max may be a percentage of the resource elements of the uplink transmission. Therefore, MuL-Mute-Max can be selected to ensure that the uplink transmission can be decoded by the gNB despite the muting. In some embodiments, MuL-Mute-Max is based on a coding rate of the uplink transmission.

The MCS threshold TMCS, Received Power threshold TRXPWX, and the maximum number of resource elements mutings MuL-Mute-Max, can be semi-statically configured by the network, dynamically indicated e.g. in the DCI or fixed in the specifications.

In embodiments where the UE autonomously performs resource element muting on the uplink transmission (for example, when the muting condition is based on estimated receive power at the gNB or estimated path loss), the gNB may not be aware of whether resource element muting has been performed on the uplink transmission or not. In such embodiments, the gNB may blind decode the uplink transmission according to the two hypotheses that (1) resource muting had not been applied by the UE and (2) resource element muting had been applied by the UE.

In some embodiments, the muting condition is based on whether or not the uplink transmission from the UE is an initial transmission or a re-transmission (for example, a Hybrid Automatic Repeat Request, HARQ, retransmission). If the uplink transmission is a retransmission, then the UE may not perform resource element muting on the uplink transmission because retransmissions are typically only transmitted when the received signal level of the initial transmission at the gNB is low, thereby causing decoding of the initial transmission to fail. If the received signal level is low, the retransmission is unlikely to cause interference with one or more reference signals received by the gNB.

In some embodiments, the muting condition is based on a HARQ process ID (PID) that is applied to the uplink transmission. The gNB can configure a set of HARQ PID where resource element mutings are not applied. For example, the gNB can configure UE to perform resource element muting for PUSCH with HARQ PID = {0, 1, 2, 3, 4} and so, if a UE is scheduled with a PUSCH with HARQ PID = 0 for the uplink transmission, then resource element muting is performed on the uplink transmission. For other HARQ PIDs not in the HARQ PID set, resource element muting is not performed on the uplink transmission. It should be appreciated other sets of HARQ Process ID can be configured for resource element muting, e.g. the UE only performs resource element muting when the HARQ PID is even. Furthermore, by basing the muting condition on a HARQ PID, the gNB can implicitly control whether or not resource element muting is performed on the uplink transmission. In the same example, if the gNB desires for resource element muting to be performed on an uplink transmission, the gNB may schedule the uplink transmission with a HARQ PID within the HARQ PID set {0, 1, 2, 3, 4}.

In some embodiments, the muting condition is based on a priority of the uplink transmission. For example, an uplink transmission may be regarded as high priority if it carries URLLC traffic. For a high priority uplink transmission (e.g. an uplink transmission which carries URLLC traffic), resource element muting is not applied to the uplink transmission because the uplink transmission requires high reliability which means more resource elements are required for the uplink transmission. For a low priority uplink transmission (e.g. an uplink transmission which carries traffic other than URLLC), resource element muting is applied to the uplink transmission. In some embodiments, a priority index is used to indicate whether or not an uplink transmission is a high or low priority transmission. The priority index may be indicated to the UE in downlink control information (DCI) for dynamic grant UL or in RRC configuration for configured grant UL.

In some embodiments, the muting condition is based on a waveform applied to the uplink transmission. For example, if Orthogonal Frequency Division Multiplexing (OFDM) is applied to the uplink transmission, then resource element muting is performed on the uplink transmission. On the other hand, if Discrete Fourier Transform spread OFDM (DFT-s-OFDM), which is a waveform with single carrier characteristics, is applied to the uplink transmission, then resource element muting is not performed on the uplink transmission because it is difficult to mute at the resource element level for a single carrier type waveform.

It will be appreciated that the muting condition may be based on one or more of the above communications parameters of the uplink transmission.

Muting Resource Elements for a Downlink Transmission

In view of the above-described technical challenges, there is also provided a method of operating an infrastructure equipment forming part of a wireless communications network for transmitting downlink information. The method comprises preparing downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for downlink transmission and some communications resource elements are designated for uplink transmission. The downlink information is prepared for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information. The method comprises determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information. The determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met. The method comprises transmitting the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements. A method of operating an infrastructure equipment forming part of a wireless communications network for transmitting downlink information in accordance with example embodiments is described with reference to Figure 14.

In step S10, the method starts.

In step S20, the method comprises preparing downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information. The wireless access interface comprises a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission. For example, the structure may be a time division duplex structure or a sub-band full-duplex structure. In some examples, the wireless access interface may be divided into uplink and downlink subbands. The downlink information is prepared for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information.

In step S30, the method comprises determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information. The one or more communications resource elements to be muted may coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment. In some examples, the one or more reference signals are received from another infrastructure equipment of the wireless communications network. In some examples, the resource elements to be muted include one or more communications resource elements adjacent to or neighbouring the communications resource elements allocated for reception of the one or more reference signals.

The determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met. The communications parameters may include, for example, one or more of a number of the communications elements to be muted, and/or a maximum allowed number of communications resource elements allocated for the transmission of the downlink information which can be muted.

In step S40, the method comprises transmitting the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements. For example, the transmitting may comprise rate matching the transmission of the downlink information around the one or more muted communications resource elements or puncturing the one or more muted communications resource elements.

In step S50, the method ends.

Those skilled in the art would appreciate that the method shown by Figure 14 may be adapted in accordance with embodiments of the present technique. For example, other intermediate steps may be included in this method, or the steps may be performed in any logical order. As explained above, example embodiments provide a method in which an infrastructure equipment determines that a muting condition is met. By imposing a condition on the muting of resource elements, the number of instances of resource element muting can be reduced, thereby providing improved communications resource efficiency. The condition can take into account the interference expected to be caused at the gNB by a downlink transmission, for example. Therefore, the muting condition can be configured such that only resource elements of downlink transmissions which are expected to cause significant interference are muted.

A method of performing resource element muting for a downlink transmission (such as a PDSCH) is described with reference to Figure 15. In the example shown in Figure 15, the PDSCH overlaps with one or more resource elements that are designated for muting to reduce CLI for reference signal reception at a gNB.

Figure 15 schematically illustrates a downlink slot n 1551 for gNBl 1511, a downlink slot n 1561 for gNB2 1512 and a downlink slot n 1571 for UE1 1521. As shown in the slot n 1561 for gNB2 1512, a reference signal configuration comprising a set of resource elements 1553 is allocated for transmission 1541 of one or more reference signals from gNB2 1512 to gNBl 1511. As shown in the slot n 1551 for gNBl 1511, aPDSCH 1555 is allocated for transmission 1532 by gNBl 1511 to UEl 1521. The PDSCH 1555 overlaps with the set of resource elements 1553 allocated for the transmission 1541 of the one or more reference signals. gNBl 1511 determines a plurality of resource elements 1573 of the PDSCH 1555 which coincide with the set of resource elements 1553 allocated for the transmission 1541 of the one or more reference signals. gNBl 1511 mutes the coinciding resource elements 1573 of the PDSCH 1555. In some examples, as will be explained in more detail below, gNBl may determine to mute other resource elements in addition to the coinciding resource elements 1573. The muted resource elements 1573 are not transmitted to UE1 1521. Physical channel processing may be adapted to puncture the muted resource elements 1573 or transport channel processing may be adapted to rate match to the other resource elements of the PDSCH 1555 which were not muted, and physical channel processing is adapted by not mapping to the muted resource elements 1573. If puncturing is used, UE1 1521 may or may not need to be aware of the punctured resource elements 1573.

Therefore, in accordance with example embodiments, gNBl 1511 determines whether or not to mute the resource elements 1573 of the PDSCH 1555 which coincide with the set of resource elements 1553 for the one or more reference signals based on a muting condition.

In some embodiments, the gNB mutes one or more additional resource elements to the resource elements occupied by the one or more reference signals from the other gNB. Such embodiments recognise that the resource elements occupied by the one or more reference signals may close enough in time/frequency to a downlink transmission for the power leakage from the downlink transmission to cause interference to the one or more reference signals. In other words, the additional muted resource elements are used as guard resource elements around the one or more reference signals. An example is shown in Figure 16.

Figure 16 illustrates a downlink slot 1671 for a gNB. As shown in the slot 1671, a reference signal configuration comprising a set of resource elements 1653 is allocated for transmission of one or more reference signals from another gNB to the gNB. As shown in slot 1671, a PDCSH 1655 is allocated for transmission by the gNB to a UE. The PDSCH 1655 overlaps with the set of resource elements 1653 allocated for the transmission of the one or more reference signals. The gNB determines a plurality of resource elements 1673 of the PDSCH 1655 which coincide with the set of resource elements 1653 allocated for the transmission of the one or more reference signals. The gNB mutes the coinciding resource elements of the PDSCH 1665. In accordance with example embodiments, the gNB also mutes one or more additional resource elements 1681 of the PDSCH 1655. As shown in Figure 16, the one or more additional muted resource elements 1681 are adjacent (or neighbouring) in frequency to the muted resource elements 1673. In the example shown in Figure 16, one resource element on either side of one of the muted resource elements 1673 is muted. The one or more additional muted resource elements 1681 act as guard resource elements to reduce power leakage from the other resource elements of the PDSCH 1655 transmission which were not muted.

Physical channel processing may be adapted to puncture the muted resource elements 1673 and the additional resource elements 1681. Alternatively, transport channel processing may be adapted to rate match to the other resource elements of the PDSCH 1655 which were not muted, and physical channel processing is adapted by not mapping to the muted resource elements 1673 and the additional resource elements 1681. If puncturing is used, the UE may or may not need to be aware of the muted resource elements 1673 and additional muted resource elements 1681.

In accordance with example embodiments, a gNB determines whether or not to mute resource elements of a downlink transmission based on a muting condition.

In some embodiments, the muting condition is based on a number of resource elements in the downlink transmission to be muted. For example, if the number of resource elements in the downlink transmission which coincide with the resource elements of the one or more reference signals is above a threshold TDL-RE, then the gNB does not mute perform resource element muting on the coinciding resource elements. Otherwise, the gNB does perform resource element muting on the coinciding resource elements. Such embodiments recognise that, if the number of muted resource elements in a downlink transmission is too high, a UE receiving the downlink transmission may not be able to decode the downlink transmission because there are too few encoded bits.

In some embodiments, a maximum allowed number of muted resource elements, MoL-Mute-Max, is defined for a downlink transmission. In such embodiments, the gNB will not mute any further resource elements of the downlink transmission once MoL-Mute-Maxhas been reached. In some embodiments, MDL- Mute-Max IS a proportion (such as a percentage) of the total number of resource elements allocated for the downlink transmission. Such embodiments can improve the likelihood that the downlink transmission can be successfully decoded by the UE.

The resource elements muting threshold TDL-RE and maximum number of muted resource elements. MDL- Mute-Max- parameters are configurable or fixed in the specifications.

It will be appreciated that the muting condition may be based on one or more of the above communications parameters for the downlink transmission.

Configuration of Resource Element Muting Patterns

In some embodiments, the gNB receives a plurality of reference signal configurations from a respective plurality of other gNBs. For example, the gNB may receive the plurality of reference signal configurations via Operations, Administrations and Management, OAM. Each reference signal configuration indicates a set of one or more resource elements of a wireless access interface allocated for transmission of one or more reference signals to one of the other gNBs, or for reception from one of the other gNBs. For example, each reference signal configuration may indicate sequence, time and frequency resources used for the one or more reference signals in the reference signal configuration. In some embodiments, the gNB may select a sub-set of the received plurality of reference signal configurations to monitor. In some embodiments, the gNB may monitor the selected sub-set of reference signal configurations more frequently than the other reference signal configurations. For example, the sub-set of reference signal configurations may be reference signal configurations received from gNBs which are closer to the gNB and which are therefore more likely to cause CLI. In some embodiments, the gNB may only monitor the selected sub-set of reference signal configurations for overlap. Therefore, resource elements of transmissions which coincide with resource elements for the other received reference signal configurations will not be muted.

In some embodiments, the gNB configures a UE with one or more resource element muting patterns each including an indication of one or more resource elements of the wireless access interface designated for muting. Each pattern of the resource elements designated for muting may correspond to a different reference signal configuration. In response, the UE determines whether it has an uplink or a downlink transmission which overlaps with the resource elements designated for muting indicated in the muting pattern. The UE mutes the resource elements of the uplink or the downlink transmission which coincide with the resource elements designated for muting (for example by puncturing, or rate matching around, the coinciding resource elements of the uplink or the downlink transmission).

In some embodiments, a resource element muting pattern indicates a repeated pattern of resource elements designated for muting. The resource element muting pattern may indicate a pattern of the resource elements designated for muting in one of a plurality of resource sets into which the wireless access interface is divided. For example, the resource element muting pattern may indicate a position in time and frequency of the resource elements designated for muting in one of the plurality of resource sets. The resource element muting pattern may indicate a periodicity (PRS) of the pattern in the plurality of resource sets. For example, a periodicity of “1” may indicate that the pattern is repeated in each of the plurality of resource sets, a periodicity of “2” may indicate that the pattern is repeated in every second one of the plurality of resource sets and so on. The resource element muting pattern may indicate a time offset of the pattern. The time offset may be a time offset relative to the other patterns. For example, as shown in Figure 17 below, Pattern 4 is offset from the other patterns by one slot.

An example is shown in Figure 17. As shown in Figure 17, a gNB has configured a UE with four resource muting patterns.

Pattern 1 comprises two repeated sub-patterns. To indicate a first of the sub-patterns to the UE, the gNB indicates a position in time and frequency of the resource elements for the reference signals in slot n and indicates that the first sub-pattern has a periodicity of PRS=2 slots to indicate that the first subpattern is repeated in every second slot after slot n (i.e. slot n+2, slot n+4 etc). Furthermore, to indicate a second of the sub-patterns to the UE, the gNB indicates the position in time and frequency of the resource elements designated for muting in slot n+1 and indicates that the second sub-pattern has a periodicity of PRS=2 slots to indicate that the second sub-pattern is repeated in every second slot after slot n+1 (i.e. n+3, n+5, etc).

To indicate Pattern 2 to the UE, the gNB indicates the position in time and frequency of the resource elements designated for muting in slot n and indicates that Pattern 2 has a periodicity of PRS=\ slots to indicate that Pattern 2 is repeated in every subsequent slot after slot n (i.e. slot n+1, slot n+2, etc). To indicate Pattern 3 to the UE, the gNB indicates the position in time and frequency of the resource elements designated for muting in slot n and indicates that Pattern 3 has a periodicity of PRS=4 slots to indicate that Pattern 3 is repeated in every fourth slot after slot n (i.e. slot n+4, slot n+8, etc).

To indicate Pattern 4 to the UE, the gNB indicates the position in time and frequency of the resource elements designated for muting in slot n+1 and indicates that Pattern 4 has a periodicity of PRS=2 slots to indicate that Pattern 4 is repeated in every second slot after slot n+1 (i.e. slot n+3, slot n+5, etc).

It will be appreciated that the UE can be configured with other patterns, and the patterns can have different periodicities than the example shown in Figure 17.

In some embodiments, the gNB indicates to the UE whether or not to perform resource element muting for a downlink or an uplink transmission. For example, the gNB may transmit a 1 -bit indicator to the UE in an uplink grant which allocates the uplink transmission or in a downlink grant which allocates the downlink transmission, and the 1 -bit indicator indicates to the UE whether or not it should perform resource element muting.

In some embodiments, the gNB configures the one or more resource element muting patterns for the UE semi-statically. In such embodiments, the gNB may dynamically indicate (using downlink control information, DCI, for example) one of the semi-statically configured resource element muting patterns for the UE to apply. In other words, the UE will determine whether its uplink transmission or downlink reception overlaps with the indicated resource element pattern and, if so, it will mute the resource elements of the uplink or the downlink transmission which coincide with the resource elements designated for muting in the resource element pattern. As will be appreciated, such embodiments increase flexibility because the gNB can decide which resource element muting pattern it wants the UE to use. For the example in Figure 17, the gNB may include 2 bits in the uplink grant or downlink Grant to indicate which one of four RE Muting patterns the UE should apply on its uplink transmission or downlink reception.

In some embodiments, one of the resource element muting patterns does not indicate any resource elements designated for muting. In other words, the resource element muting pattern is empty. This indicates to the UE that resource element muting is not to be applied to its transmissions. For example, the gNB may configure 8 resource element muting patterns for the UE. The gNB may indicate Pattern 1 in a DCI which does not indicate any resource elements designated for muting. Therefore, the UE determines that it does not need to apply muting (such as rate matching or puncturing) to its uplink transmission or downlink reception.

The following numbered paragraphs provide further example aspects and features of the present technique:

Paragraph 1. A method of operating a communications device for transmitting uplink information, the method comprising preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the uplink information being prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

Paragraph 2. A method according to paragraph 1, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment of the wireless communications network.

Paragraph 3. A method according to paragraph 1 or paragraph 2, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises receiving, from the infrastructure equipment, an indication of one or more communications resource elements designated for muting, determining that the one or more communications resource elements allocated for the transmission of the uplink information to be muted coincide in time and frequency with one or more of the communications resource elements designated for muting.

Paragraph 4. A method according to paragraph 3 wherein the indication of the one or more communications resource elements designated for muting comprises an indication of a pattern of the communications resource elements designated for muting in a plurality of sets of communications resource elements into which the wireless access interface is divided, the indication of the pattern comprising an indication of the communications resource elements designated for muting in a first of the plurality of sets of communications resource elements into which the wireless access interface is divided, the indication of the pattern indicating a position in time and frequency of the communications resource elements designated for muting in the first set, and an indication of a periodicity of the pattern of the communications resource elements designated for muting in the plurality of sets of communications resource elements. Paragraph 5. A method according to paragraph 4, comprising receiving an indication of one or more other patterns of the communications resource elements designated for muting in the plurality of sets of communications resource elements into which the wireless access interface is divided, receiving an indication of a selected one of the patterns from the infrastructure equipment, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that the one or more communications resource elements allocated for the transmission of the uplink information to be muted coincide in time and frequency with one or more of the communications resource elements designated for muting in the selected pattern. Paragraph 6. A method according to paragraph 5, wherein the indication of the patterns includes an indication of a time offset of the patterns. Paragraph 7. A method according to any of paragraphs 1 to 6, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a modulation and coding scheme, MCS, for transmitting the uplink information, and determining that the MCS for transmitting the uplink information is above a pre-defined MCS threshold.

Paragraph 8. A method according to paragraph 7, wherein the determining that the MCS for transmitting the uplink information is above a pre-defined MCS threshold comprises receiving an indication of the pre-defined MCS threshold from the infrastructure equipment. Paragraph 9. A method according to any of paragraphs 1 to 8, wherein determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment.

Paragraph 10. A method according to paragraph 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises receiving one or more downlink signals from the infrastructure equipment, estimating a pathloss between the communications device and the infrastructure equipment based on the received one or more downlink transmissions.

Paragraph 11. A method according to paragraph 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises receiving an indication of the estimated pathloss from the infrastructure equipment.

Paragraph 12. A method according to any of paragraphs 9 to 11, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises determining that the estimated pathloss is below a pre-defined pathloss threshold.

Paragraph 13. A method according to paragraph 12, wherein the determining that the estimated pathloss is below a pre-defined pathloss threshold comprises receiving an indication of the pre-defined pathloss threshold from the infrastructure equipment.

Paragraph 14. A method according to any of paragraphs 9 to 11, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises estimating a received power of the transmission of the uplink information at the infrastructure equipment based on the estimated pathloss and a transmission power for transmitting the uplink information, and determining that the estimated received power of the transmission of the uplink information at the infrastructure equipment is above a pre-defined power threshold.

Paragraph 15. A method according to paragraph 14, wherein the determining that the estimated received power of the transmission of the uplink information at the infrastructure equipment is above a pre-defined power threshold comprises receiving an indication of the pre-defined power threshold from the infrastructure equipment. Paragraph 16. A method according to any of paragraphs 1 to 15, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information comprises determining a maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted, wherein the number of the one or more communications resource elements to be muted is less than or equal to the maximum allowed number.

Paragraph 17. A method according to paragraph 16, wherein the determining a maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises receiving an indication of the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted from the infrastructure equipment.

Paragraph 18. A method according to paragraph 16 or paragraph 17, wherein the determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises determining a coding rate for transmitting the uplink information, determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted based on the coding rate for transmitting the uplink information.

Paragraph 19. A method according to any of paragraphs 16 to 18, wherein the determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises determining an allowed proportion of the communications resource elements allocated for the transmission of the uplink information which can be muted, determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted based on the allowed proportion of the communications resource elements allocated for the transmission of the uplink information which can be muted.

Paragraph 20. A method according to any of paragraphs 1 to 19, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining that the transmission of the uplink information is not a retransmission.

Paragraph 21. A method according to any of paragraph 1 to 20, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a hybrid automatic repeat request, HARQ, process identification, PID, for the transmission of the uplink information, and determining that the muting condition is met based on the HARQ PID for the transmission of the uplink information.

Paragraph 22. A method according to any of paragraphs 1 to 21, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a priority for the transmission of the uplink information, and determining that the muting condition is met based on the priority for the transmission of the uplink information. Paragraph 23. A method according to any of paragraphs 1 to 22, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a waveform to be applied to the transmission of the uplink information, and determining that the muting condition is met based on the waveform to be applied to the transmission of the uplink information.

Paragraph 24. A method according to any of paragraphs 1 to 23, wherein the transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements comprises rate matching the transmission around the one or more muted communications resource elements.

Paragraph 25. A method according to any of paragraphs 1 to 24, wherein the transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements comprises puncturing the one or more muted communications resource elements.

Paragraph 26. A method of operating an infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the method comprising preparing downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the downlink information being prepared for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmitting the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

Paragraph 27. A method according to paragraph 26, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment.

Paragraph 28. A method according to paragraph 27, wherein the determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining the one or more communications resource elements to be muted from a pattern of the reference signals which identifies the communications resource elements of the wireless access interface which are to be used by the infrastructure equipment for receiving the reference signals. Paragraph 29. A method according to paragraph 28, wherein the one or more communications resource elements to be muted include one or more neighbouring/adjacent communications resource elements to one or more of the communications resource elements identified by the pattern of reference signals. Paragraph 30. A method according to any of paragraphs 27 to 29, wherein the determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met comprises identifying communications resource elements which should be muted based on the pattern of reference signals, to reduce interference with the reference signals, determining a total number of the identified communications resource elements which should be muted, and if the determined number of identified resource elements which should be muted exceeds a predetermined threshold, TDL-RE, not muting one or more of the identified communications resource elements which should be muted and using these communications resource elements to transmit the downlink information, or if the determined number of identified resource elements which should be muted is below the predetermined threshold, TDL-RE, muting those of the identified communications resource elements below the predetermined threshold.

Paragraph 31. A method according to any of paragraphs 26 to 29, wherein the determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met comprises identifying communications resource elements for transmitting the downlink information, based on a number of the communications resource elements for transmitting the downlink information, determining a maximum number of the identified communications resource elements which can be muted, determining a total number of the identified communications resource elements which should be muted, and if the determined number of identified communications resource elements which should be muted exceeds the maximum number of the communications identified resource elements which can be muted, muting those of the identified communications resource elements up to and including the maximum number which can be muted, and not muting one or more of the identified communications resource elements which should be muted after the maximum number.

Paragraph 32. A communications device for transmitting uplink information, the communications device comprising a transmitter configured to transmit signals, a receiver configured to receive signals, and a controller configured in combination with the transmitter and the receiver to prepare uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the controller being configured in combination with the transmitter and the receiver to prepare the uplink information for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the controller is configured in combination with the transmitter and the receiver to determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmit the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

Paragraph 33. A communications device according to paragraph 32, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment of the wireless communications network. Paragraph 34. An infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the infrastructure equipment comprising a transmitter configured to transmit signals, a receiver configured to receive signals, and a controller configured in combination with the transmitter and the receiver to prepare downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, wherein the controller is configured in combination with the transmitter and the receiver to prepare the downlink information for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the controller is configured in combination with the transmitter and the receiver to determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmit the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

Paragraph 35. An infrastructure equipment according to paragraph 34, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment.

Paragraph 36. Circuitry for a communications device for transmitting uplink information, the circuitry comprising transmitter circuitry configured to transmit signals, receiver circuitry configured to receive signals, and controller circuitry configured in combination with the transmitter and the receiver to prepare uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the controller circuitry being configured in combination with the transmitter circuitry and the receiver circuitry to prepare the uplink information for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmit the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

Paragraph 37. Circuitry for an infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the circuitry comprising transmitter circuitry configured to transmit signals, receiver circuitry configured to receive signals, and controller circuitry configured in combination with the transmitter and the receiver to prepare downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to prepare the downlink information for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmit the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

Paragraph 38. A wireless communications system comprising a communications device according to paragraph 32 and an infrastructure equipment according to paragraph 34.

Paragraph 39. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to any of paragraphs 1 to 31.

Paragraph 40. A non-transitory computer-readable storage medium storing a computer program according to paragraph 39.

It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and/or processors may be used without detracting from the embodiments. Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

REFERENCES

[1] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009. [2] TR 38.913, “Study on Scenarios and Requirements for Next Generation Access Technologies

(Release 14)”, 3rd Generation Partnership Project, vl4.3.0, August 2017.

[3] RP-213591, “New SI: Study on evolution of NR duplex operation,” CMCC, RAN#94e, December 2021.

[4] RP -220633, “Revised SID: Study on evolution of NR duplex operation,” CMCC, RAN#95e, March 2022.

[5] European Patent No. 3545716.

[6] European Patent Application No. EP22184813.8.

[7] Rl-2204305, “Discussion on potential enhancements on flexible/dynamic TDD,” CMCC, RANl#109e [8] Rl-2204503, “Potential enhancements on dynamic/flexible TDD,” Lenovo, RANl#109e

Claims

1. A method of operating a communications device for transmitting uplink information, the method comprising preparing uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the uplink information being prepared for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

2. A method according to claim 1, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment of the wireless communications network.

3. A method according to claim 1, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises receiving, from the infrastructure equipment, an indication of one or more communications resource elements designated for muting, determining that the one or more communications resource elements allocated for the transmission of the uplink information to be muted coincide in time and frequency with one or more of the communications resource elements designated for muting.

4. A method according to claim 3, wherein the indication of the one or more communications resource elements designated for muting comprises an indication of a pattern of the communications resource elements designated for muting in a plurality of sets of communications resource elements into which the wireless access interface is divided, the indication of the pattern comprising an indication of the communications resource elements designated for muting in a first of the plurality of sets of communications resource elements into which the wireless access interface is divided, the indication of the pattern indicating a position in time and frequency of the communications resource elements designated for muting in the first set, and an indication of a periodicity of the pattern of the communications resource elements designated for muting in the plurality of sets of communications resource elements.

5. A method according to claim 4, comprising receiving an indication of one or more other patterns of the communications resource elements designated for muting in the plurality of sets of communications resource elements into which the wireless access interface is divided, receiving an indication of a selected one of the patterns from the infrastructure equipment, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted comprises determining that the one or more communications resource elements allocated for the transmission of the uplink information to be muted coincide in time and frequency with one or more of the communications resource elements designated for muting in the selected pattern.

6. A method according to claim 5, wherein the indication of the patterns includes an indication of a time offset of the patterns.

7. A method according to claim 1, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a modulation and coding scheme, MCS, for transmitting the uplink information, and determining that the MCS for transmitting the uplink information is above a pre-defined MCS threshold.

8. A method according to claim 7, wherein the determining that the MCS for transmitting the uplink information is above a pre-defined MCS threshold comprises receiving an indication of the pre-defined MCS threshold from the infrastructure equipment.

9. A method according to claim 1, wherein determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment.

10. A method according to claim 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises receiving one or more downlink signals from the infrastructure equipment, estimating a pathloss between the communications device and the infrastructure equipment based on the received one or more downlink transmissions.

11. A method according to claim 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises receiving an indication of the estimated pathloss from the infrastructure equipment.

12. A method according to claim 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises determining that the estimated pathloss is below a pre-defined pathloss threshold.

13. A method according to claim 12, wherein the determining that the estimated pathloss is below a pre-defined pathloss threshold comprises receiving an indication of the pre-defined pathloss threshold from the infrastructure equipment.

14. A method according to claim 9, wherein the determining that the muting condition is met based on an estimated pathloss between the communications device and the infrastructure equipment comprises estimating a received power of the transmission of the uplink information at the infrastructure equipment based on the estimated pathloss and a transmission power for transmitting the uplink information, and determining that the estimated received power of the transmission of the uplink information at the infrastructure equipment is above a pre-defined power threshold.

15. A method according to claim 14, wherein the determining that the estimated received power of the transmission of the uplink information at the infrastructure equipment is above a pre-defined power threshold comprises receiving an indication of the pre-defined power threshold from the infrastructure equipment.

16. A method according to claim 1, wherein the determining that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information comprises determining a maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted, wherein the number of the one or more communications resource elements to be muted is less than or equal to the maximum allowed number.

17. A method according to claim 16, wherein the determining a maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises receiving an indication of the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted from the infrastructure equipment.

18. A method according to claim 16, wherein the determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises determining a coding rate for transmitting the uplink information, determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted based on the coding rate for transmitting the uplink information.

19. A method according to claim 16, wherein the determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted comprises determining an allowed proportion of the communications resource elements allocated for the transmission of the uplink information which can be muted, determining the maximum allowed number of communications resource elements allocated for the transmission of the uplink information which can be muted based on the allowed proportion of the communications resource elements allocated for the transmission of the uplink information which can be muted.

20. A method according to claim 1, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining that the transmission of the uplink information is not a retransmission.

21. A method according to any of claim 1 , wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a hybrid automatic repeat request, HARQ, process identification, PID, for the transmission of the uplink information, and determining that the muting condition is met based on the HARQ PID for the transmission of the uplink information.

22. A method according to claim 1, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a priority for the transmission of the uplink information, and determining that the muting condition is met based on the priority for the transmission of the uplink information.

23. A method according to claim 1, wherein the determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met comprises determining a waveform to be applied to the transmission of the uplink information, and determining that the muting condition is met based on the waveform to be applied to the transmission of the uplink information.

24. A method according to claim 1, wherein the transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements comprises rate matching the transmission around the one or more muted communications resource elements.

25. A method according to claim 1, wherein the transmitting the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements comprises puncturing the one or more muted communications resource elements.

26. A method of operating an infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the method comprising preparing downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the downlink information being prepared for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmitting the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

27. A method according to claim 26, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment.

28. A method according to claim 27, wherein the determining that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted comprises determining the one or more communications resource elements to be muted from a pattern of the reference signals which identifies the communications resource elements of the wireless access interface which are to be used by the infrastructure equipment for receiving the reference signals.

29. A method according to claim 28, wherein the one or more communications resource elements to be muted include one or more neighbouring/adjacent communications resource elements to one or more of the communications resource elements identified by the pattern of reference signals.

30. A method according to claim 27, wherein the determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met comprises identifying communications resource elements which should be muted based on the pattern of reference signals, to reduce interference with the reference signals, determining a total number of the identified communications resource elements which should be muted, and if the determined number of identified resource elements which should be muted exceeds a predetermined threshold, TDL-RE, not muting one or more of the identified communications resource elements which should be muted and using these communications resource elements to transmit the downlink information, or if the determined number of identified resource elements which should be muted is below the predetermined threshold, TDL-RE, muting those of the identified communications resource elements below the predetermined threshold.

31. A method according to claim 26, wherein the determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met comprises identifying communications resource elements for transmitting the downlink information, based on a number of the communications resource elements for transmitting the downlink information, determining a maximum number of the identified communications resource elements which can be muted, determining a total number of the identified communications resource elements which should be muted, and if the determined number of identified communications resource elements which should be muted exceeds the maximum number of the communications identified resource elements which can be muted, muting those of the identified communications resource elements up to and including the maximum number which can be muted, and not muting one or more of the identified communications resource elements which should be muted after the maximum number.

32. A communications device for transmitting uplink information, the communications device comprising a transmitter configured to transmit signals, a receiver configured to receive signals, and a controller configured in combination with the transmitter and the receiver to prepare uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the controller being configured in combination with the transmitter and the receiver to prepare the uplink information for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the controller is configured in combination with the transmitter and the receiver to determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmit the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

33. A communications device according to claim 32, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment of the wireless communications network.

34. An infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the infrastructure equipment comprising a transmitter configured to transmit signals, a receiver configured to receive signals, and a controller configured in combination with the transmitter and the receiver to prepare downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, wherein the controller is configured in combination with the transmitter and the receiver to prepare the downlink information for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the controller is configured in combination with the transmitter and the receiver to determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmit the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

35. An infrastructure equipment according to claim 34, wherein the one or more communications resource elements to be muted coincide in time and frequency with one or more communications resource elements of the wireless access interface allocated for reception of one or more reference signals by the infrastructure equipment.

36. Circuitry for a communications device for transmitting uplink information, the circuitry comprising transmitter circuitry configured to transmit signals, receiver circuitry configured to receive signals, and controller circuitry configured in combination with the transmitter and the receiver to prepare uplink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the uplink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, the controller circuitry being configured in combination with the transmitter circuitry and the receiver circuitry to prepare the uplink information for uplink transmission to infrastructure equipment of the wireless communications network via the plurality of communications resource elements allocated for the uplink information, determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted and not used for transmitting the uplink information, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to determine that one or more of the communications resource elements allocated for the transmission of the uplink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the uplink information is met, and transmit the uplink information using the plurality of communications resource elements allocated for transmission of the uplink information except the one or more muted communications resource elements.

37. Circuitry for an infrastructure equipment forming part of a wireless communications network for transmitting downlink information, the circuitry comprising transmitter circuitry configured to transmit signals, receiver circuitry configured to receive signals, and controller circuitry configured in combination with the transmitter and the receiver to prepare downlink information for transmission via a plurality of communications resource elements of a wireless access interface allocated for the transmission of the downlink information, the wireless access interface comprising a plurality of communications resource elements disposed in time and frequency according to a structure in which some communications resource elements are designated for uplink transmission and some communications resource elements are designated for downlink transmission, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to prepare the downlink information for downlink transmission to a communications device via the plurality of communications resource elements allocated for the downlink information, determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted and not used for transmitting the downlink information, wherein the controller circuitry is configured in combination with the transmitter circuitry and the receiver circuitry to determine that one or more of the communications resource elements allocated for the transmission of the downlink information are to be muted by determining that a muting condition based on one or more communications parameters for transmitting the downlink information is met, and transmit the downlink information using the plurality of communications resource elements allocated for transmission of the downlink information except the one or more muted communications resource elements.

38. A wireless communications system comprising a communications device according to claim 32 and an infrastructure equipment according to claim 34.

39. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to claim 1.

40. A non-transitory computer-readable storage medium storing a computer program according to claim 39.