GB2642254A - Methods, apparatus and computer programs - Google Patents

Abstract

In the proposed scheme the transmit signals have a spacing such that the intermodulation products resulting from the combination of the signals fall on a transmit occasion. An aggressor signal may have nulls in its transmission bandwidth placed on every Mth subcarrier and the signal of the victim may be placed on the null subcarriers. Therefore, a receiver which is in or near saturation can still receive the victim signal in the presence of strong interference. Hence the aggressor and victim signal may occupy the same bandwidth without any guard frequencies. The invention comprises receiving at a user equipment from a network, information indicative of a format for a time slot associated with a frequency allocation comprising a first and second set of second subcarriers to provide interleaved full duplex operation. The first and second subcarriers are interleaved. The information indicates one or more of the first set of first subcarriers of a resource block to be used for transmitting to the network by the user equipment, and a respective subcarrier of the second set of second subcarriers being unscheduled or scheduled to a user equipment.

Description

[0001] METHODS, APPARATUS AND COMPUTER PROGRAMS TECHNICAL FIELD Various example embodiments relate generally to methods, apparatus, system and computer programs and in particular, but not exclusively, methods, appa- ratus, system and computer programs relating to the transmitting and receiving of sig-nals.

[0002] BACKGROUND

[0003] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communica- tion devices access to a data network. A mobile or wireless communication net-work is one example of a communication network. Such communication networks operate in according with standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards are the so-called 5G (5th Generation) standards provided by 3GPP nand future standards such as 6G and beyond.

[0004] BRIEF DESCRIPTION

[0005] Some example embodiments of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the embodiments of this disclosure, nor are they intended to be used to limit the scope of thereof Other features, aspects, and elements will be readily apparent to a person

[0006] skilled in the art in view of this disclosure.

[0007] According a first aspect, there is provided a user equipment comprising: means for receiving from a network, information indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first resource block to be used for transmitting to the network by the user equipment a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and means for transmitting signals to the network on one or more of the first set of first subcarriers of the first frequency allocation.

[0008] Other optional features of the first aspect may be seen from the depend-ent claims.

[0009] According a second aspect, there is provided a method comprising: receiving from a network, information indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said in- formation indicating one or more of the first set of first subcarriers of the first resource block to be used for transmitting to the network by a user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and trans-mitting signals to the network on one or more of the first set of first subcarriers of the first frequency allocation.

[0010] The method may comprise receiving signals from the network on a respective subcarrier of the second set of second subcarriers of the first frequency allocation scheduled to the user equipment.

[0011] One or more different user equipment may be scheduled to one or more subcarriers of the second set of second subcarriers of the first frequency allocation. The method may comprise receiving information indicative of a format for a time slot associated with a second frequency allocation to provide interleaved full duplex operation, the second frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the second set of second subcarriers of the second frequency allocation is scheduled for the user equipment to transmit to the network.

[0012] The method may comprise transmitting information to the network, the information indicative of a capability of the user equipment to support interleaved full duplex operation.

[0013] A respective second subcarrier of the plurality of second subcarriers may be spaced from another subcarrier of the plurality of second subcarriers by M first subcarriers, where M is an integer equal to one or more.

[0014] The first frequency allocation may comprise n first subcarriers, and up to n of the first subcarriers may be allocated to the user equipment.

[0015] The method may comprise determining a quality of link between the user equipment and the network and transmitting to the network, information relating to the determined quality of the link.

[0016] The information indicative of the format for the time slot associated with the first frequency allocation may be provided by one or more of: a radio re-source control connection request; a radio resource control reconfiguration message; or a downlink control indicator message.

[0017] The frequency allocation may comprise a resource block.

[0018] According to a third aspect, there is provide an access node comprising: means for providing information to a first user equipment indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first frequency allocation to be used for transmitting to a net-work by the user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and means for receiving signals from the first user equipment on the one or more of the first set of first subcarriers of the frequency allocation.

[0019] Other optional features of the third aspect may be seen from the claims dependent on claim 10.

[0020] According to a fourth aspect, there is provide a method comprising: providing information to a first user equipment indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first frequency allocation to be used for transmitting to a network by the user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and receiving signals from the first user equipment on the one or more of the first set of first subcarriers of the frequency allocation.

[0021] The first frequency allocation may comprise m second subcarriers, and the m second subcarriers are allocated to the first user equipment The first frequency allocation may comprise m second subcarriers, and one or more second subcarriers are allocated to the first user equipment and one or more of the second subcarriers are allocated to one or more other user equipment.

[0022] The method may comprise receiving from the first user equipment, one or more of information indicating that the first user equipment has a capability to support transmitting and receiving in a same frequency allocation; or information relating to a quality of a link between the access node and the first user equipment The method may comprise determining the format for the time slot associated with the first frequency allocation.

[0023] The information indicative of the format for the time slot associated with the first frequency allocation may be provided in one or more of: a radio re-source control connection request; a radio resource control reconfiguration message; or a downlink control indicator message.

[0024] The frequency allocation may comprise a resource block.

[0025] The method may be performed by an apparatus.

[0026] The apparatus may be an access node user equipment.

[0027] The apparatus may comprise at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to provide one or more of the methods of the fourth aspect.

[0028] According to another aspect, there is provided a computer readable medium comprising program instructions stored thereon for performing at least one of the above methods.

[0029] According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least one of the above methods.

[0030] According to an aspect, there is provided a non-volatile tangible memory medium comprising program instructions stored thereon for performing at least one of the above methods.

[0031] In the above, many different aspects have been described. It should be ap-preciated that further aspects may be provided by the combination of any two or more of the aspects described above.

[0032] Various other aspects are also described in the following detailed description and in the attached claims.

[0033] LIST OF THE DRAWINGS

[0034] In the following, the invention will be described in greater detail with reference to the embodiments and the accompanying drawings, in which Fig. 1 shows an example of a communication network to which examples disclosed herein may be applied; Figs. 2a to 2c which show three examples of duplexing schemes.

[0035] Fig. 3 shows an interleaved full duplex (IFD) mode of some embodiments and a SBFD scheme; Fig. 4 shows, an example of a scheme using uplink only, downlink only and IFD time slots; Fig. 5 shows an example of an apparatus; Fig. 6 which shows one example of UL/DL resource allocation and multiplexing of users in a IFD mode; Fig. 7 show an example of a signaling flow diagram of some embodiments; Fig. 8 shows a first method of some embodiments; Fig. 9 shows a second method of some embodiments; and Fig. 10 shows a third method of some embodiments. DESCRIPTION OF EMBODIMENTS The following embodiments are exemplary. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. Further, when a particular feature, structure, or characteristic is described in connection of an embodiment, it is within the knowledge of one skilled in the art to apply such feature, structure, or characteristic in connection with other embod-iments whether or not explicitly described. It shall be understood that although the terms "first" "second" and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0036] For the purposes of the present disclosure, the phrases "at least one of A or B", "at least one of A and B", and "A and/or B" means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase "A, B, and/or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0037] Embodiments described may be implemented in a communication net-work, such as any of the following radio access technologies (RATs): Worldwide lnteroperability for Micro-wave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GAPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and enhanced LTE (eLTE), SG (also called NR), or any future RAT such as 6G. Moreover, communication within the communication network may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIM0), Orthogonal Frequency Division Multiple (OFDM), and/or Discrete Fourier Transform spread OFDM (DFT-s-OFDM).

[0038] As used herein, the term "network device" or "network node" refers to a node in a communication network via which user equipment may access the net-work and/or which is capable of controlling radio communication and managing radio resources within a cell. The network node or network device may be referred to as a base station (BS), an access point (AP) or an access node. The network device may be, depending on the applied technology, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, or an aircraft network device.

[0039] Moreover, in connection of split radio access network (RAN), the net-work device may refer to a centralised unit (CU) of a base station and/or a distributed unit (DU) of a base station. An interface between CU and DU may be referred to as an Fl interface in NR. In the split RAN architecture, node operations may be carried out, at least partly, in the central/centralized unit, CU, (e.g. server, host or node) operationally coupled to the DU, (e.g. a radio head/node). One CU may con-trol one or more DUs, acting at least as transmit/receive (Tx/Rx) nodes. In some embodiments, the DUs may comprise e.g. a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the CU may comprise the layers above RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RAC) and an internet protocol (IP) layers. Other functional splits are possible too. In practice, any processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may depend on the applied implementation.

[0040] The term "terminal device" refers to any end device that may be capable 30 of wireless communication. By way of example, a terminal device may be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), or a Mobile Station (MS). The terminal device may include a mobile phone, a cellular phone, a smart phone, voice over IP (VolP) phones, wireless local loop phones a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, USB dongles, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device op-erating on commercial and/or industrial wireless networks, and the like.

[0041] A term "resource", as used herein, may refer to radio resources in time domain, in frequency domain, in space domain, and/or in code domain. Some examples of resources include e.g. a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a sub-carrier, a beam, etc. The term "transmission" and/or "reception" may refer to wirelessly transmitting and/or receiving via a wireless propagation channel on radio resources.

[0042] Fig. 1 illustrates an example of a communication network to which examples disclosed herein may be applied. The communication network or a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell may define a coverage area or a service area of the corresponding access node.

[0043] The network node 110 may provide a user equipment (HE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink (DL) communication from the network node to the HE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different network nodes 110, 112. UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-called sidelink (SL). Such D2D communications may be referred to as machine-to-machine, peer-to-peer (P2P) communications, or ve-hicle-to-vehicle (V2V), for example.

[0044] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications call such an interface as X2 interface. An interface between an LTE node and 15 a SG node, or between two SG nodes may be called Xn interface.

[0045] The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise e.g. a mobility management entity (MME) and a gateway node.

[0046] The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signalling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to/from the terminal devices. The SG specifications specify the core network as a SG core (5GC). The SG core may comprise e.g. an access and mobility management function (AMF) and a user plane function/gateway (UPF) and other functions. The AMF may handle termination of non-access stratum (NAS) signalling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management The UPF node may support packet routing and for-warding, packet inspection and quality of service (QoS) handling, for example.

[0047] Reference is made to Figure 2a to 2c which show three examples of duplexing schemes. Figure 2a shows a frequency division duplexing (FDD) example. In this example, the uplink (UL) communications are located a first frequency and the downlink (DL) communications are allocated a second different frequency. The uplink and downlink frequencies may be separated by a guard band.

[0048] Figure 2b shows a time division duplexing (TDD) example. In this exam-ple, the same frequency is used for the downlink communications and the uplink communications. However, the downlink communications are allocated different time slots to those allocated to the uplink communications.

[0049] Figure 2c shows sub-band non-overlapping Full Duplex (SBFD) exam-ple. SBFD may allow simultaneous DL transmission and UL reception on different physical resource blocks (PRBs) within an unpaired wideband NR carrier. Some slots are configured to be split between uplink and downlink sub bands, others are pure uplink and downlink like in TDD mode.

[0050] If the DL and UL resources are placed on non-overlapping resources as illustrated in Figure 2c, there may be a challenge of cross-link interference (CU) at both the UE and gNB side. This maybe due to non-ideal UE and gNB radio frequency (RF) frontends and transmit/receive filters where the UE or the gNB may emit power leaks outside the intended bandwidth towards non-allocated resource blocks.

[0051] CL1 interference may result in one or more of the following scenarios due to SBFD operation.

[0052] gNB self-interference (SI): Interference caused by DL transmission on a set of DL RBs in a carrier to UL reception on a set of UL RBs in the same carrier at the gNB side, where the two RB sets are non-overlapping in frequency.

[0053] intra-cell and inter-cell UE-UE co-channel inter-sub-band CL1: Cross Link interference caused by UL transmission of a first UE on a first set of RBs in a carrier to DL reception of a second UE on a second set of RBs in the same cell or neighbouring cell in the same carrier, where the two RB sets are non-overlapping in frequency.

[0054] Inter-sector and inter-site gNB-to gNB interference: Cross Link interfer-ence caused by DL transmission of a first gNB on a first set of RBs in a carrier to UL reception of a second gNB on a second set of RBs in the same cell or neighbouring cell in the same carrier, where the two RB sets are non-overlapping in frequency. A receiver may have relatively strong interference arising from inter-modulation products as a result of adjacent channel leakage from a transmitter which is placed relatively close to the receiver. The transmitter and receiver may be within the same device as is the case of gNB operating in SBFD mode or they can be in two different devices as is the case of sidelink or two UEs in SBFD mode. gNB self-interference in SBFD may be a challenge. Separate transmitter (Tx) and receiver (Rx) panels may be employed in the gNB to provide a certain level of analog isolation between the transmitter and the receiver of the gNB. For wide-area base stations, the RF output power may be as high as 53 dBm and the front end third order intercept point is believed to be from -5 dBm to +10 dBm. The RF coupling between a transmitter and receiver may change dynamically if objects like vehicles, persons or animals are moving near such antenna systems. The moving objects may result in reflected signals with similar amplitude as the directly cou-pled or compensated RF signals at the input of an ADC (analogue to digital convertor) or any other baseband circuitry of the given implementation.

[0055] The signal to interference noise ratio (S1NR) expected for a 20 MHz uplink signal received by a gNB with power of -92 dBm, when there is simultaneous transmission in downlink with power of 43 dBm and adjacent channel leakage ration (ACLR) of -45 dBc. A desired 0 dB SINR for the uplink signal may require an RF isolation of 104 dB or higher, when a RF Front end noise figure of 9 dB is assumed. This may be a challenge to achieve in practice.

[0056] It has also been noted that when a gNB is to handle the self-interference arising from the SBFD mode of operation, at least 80 to 90 dB isolation from a so-called aggressor transmitter(s) to a so-called victim receiver may be required with an aggressor output power of 25 dBm and 100 to 110 dB is required if an aggressor transmitter output power is 52 dBm.

[0057] Linearity performance of the RX front-end might also be an issue in the 30 SBFD mode of operation.

[0058] A dynamic range and linearity of the Rx front-end may need to be taken into account in addition to direct Tx ACLR contribution when in the SBFD mode of operation.

[0059] More than 100 dB of isolation from Tx antenna(s) to individual Rx antennas may be required to avoid desensitization of the receiver in a typical fre-quency range 1 (FR1) macro scenario in the SBFD mode of operation.

[0060] A required antenna-to-antenna isolation may scale dB-to-dB with transmit output power and sensitivity in the SBFD mode of operation.

[0061] UE to UE CLI in SBFD may also be an issue.

[0062] For cross link interference studies, 40 dB isolation between UEs has been used as a starting point, implying about 1 m separation between the UE's. This in turn imply that the aggressor transmitter may only be attenuated to about -17 dBm at the victim receiver input if the aggressor transmitter is transmitting at maximum power of -23 dBm. This may be problem for a victim UE which wants to receive in downlink when a SBFD scheme is being used. This means that reception at the victim UE may be difficult.

[0063] Direct ACLR from the aggressor transmitter as well as mixing products generated inside the LNA of the victim receiver are both present at the output of the LNA. This may cause in band or co-channel interference at the input of the base-band receive input (ADC) of the victim receiver.

[0064] In case no degradation of UE performance is desired for SBFD use cases, the physical separation (> 200 m) or coupling loss (>90 dB) between aggressor UE and victim UE may need to be very large.

[0065] If worst case UE ACLR performance is considered, ACLR contribution to the in-band noise at the receive input may be the strongest contribution compared with third-order intermodulation distortion (1MD3) contributions in SBFD use cases.

[0066] UE to UE CL1 may arise also in modes other than SBFD such as flexible duplexing and sidelink. In flexible duplexing an aggressor UE transmitting in uplink to one gNB can be in proximity of another victim UE trying to receive a downlink signal from another gNB. In this case CL1 can dynamically change if the physical separation and/or coupling loss between the two UEs is not large.

[0067] For non-overlapping SBFD systems, sufficiently high analog RE isolation may not be ensured for all use cases, as the isolation requirement could be 60 to 90dB to ensure linear RF front end behaviour. The powerful transmitted signal will drive the victim receiver into saturation creating mixing products between sub- carriers of aggressor transmissions which "land" directly on each receive sub car-rier frequency due to the nature of these mixing products. These mixing products from the aggressor transmissions along with the ACLR can be much stronger than the victim receivers desired signal.

[0068] 1n-band Adjacent channel leakage from the aggressor transmissions can be much stronger than desired signal of the victim receiver.

[0069] Strong mixing products of from the aggressor transmissions due to nonlinear receiver chain operation will land directly on top of each receive sub-carrier frequency.

[0070] This may lead to the following requirements when operating in SBFD mode: gNB requirement of 100 dB or more of isolation between TX and RX when transmitting at 43 dBm or more output power to avoid desensitization due to self-interference.

[0071] Aggressor UE to victim UE physical separation of > 200m (LOS case) or a coupling loss >90 dB to avoid HE to HE intra cell CL1.

[0072] These may be difficult to achieve.

[0073] Some embodiments may address the issues arising due to self or cross-link interference in a duplexing scenario. Some embodiments may allocate sub-carriers to receiver (victim) signals and transmitter (aggressor) signals such that their intermodulation products do not fall on top of each other. Some embodiments may use a so-called interleaved full duplexing 1FD mode.

[0074] In this regard, reference is made to Figure 3. The 1FD mode has the transmitted signals 300 interleaved with the received signals 304. It can be seen that the third order intermodulation products 304 of the aggressor sub-carrier (that is the transmitted signals) do not collide with the victim sub-carriers (that is the received signal. The third order intermodulation products instead coincide with the transmitted signals.

[0075] Figure 3 shows for comparison a SBFD scheme. The same UL:DL ratio (or higher UL-to-DL ratio) may be required to achieve the same benefits as the IFD mode.

[0076] Consider multiplying two tones with frequency fl and f2 and f2 = Third order intermodulation (or in other terms multiplication of two tones) result in mixing products with the following frequency content: 2*f2 -f1 = 2*(f1 at) -f1 = f1 2*f1 -f2 = 2*f1 -(f1 + = fl -And OFDM contains a comb of tones, any combination of two tones produce such intermodulation products, which result in a new comb of signals adjacent to the original spectrum, but with lower amplitude. Such intermodulation products are also produced inside the original spectrum resulting in reduced S1NR. These may not disturb the transmission too much if at all if they are about 30 dB below the desired transmit signal (and are not shown in the SBFD example for the transmit signals). However, in order to avoid receive desensitization during simultaneous transmission and reception (full duplex), the intermodulation products that fall on top of receive signals need to be attenuated by more than 100 dB in some cases.

[0077] With the IFD scheme, the transmit signals have a spacing of AS such that the intermodulation products resulting from the combination of the transmit signals fall on a transmit occasion.

[0078] However, greater flexibility in terms of UL:DL resource split can be achieved in some embodiments by using a combination (in time-domain) of IFD slots and UL-or DL-only slots as illustrated in Figure 4. For example, time slot 0 may be a downlink DL slot, time slots 1, 2 and 3 may be IFD slots, and time slot 4 may be an uplink UL slot.

[0079] With the interleaved full duplexing (IFD) mode a receiver which is in or near saturation can still receive the victim signal in the presence of strong interfer30 ence.

[0080] In some embodiments, IFD may be used when an aggressor transmitter needs to transmit in the vicinity of a victim receiver which is trying to receive a relatively weak signal.

[0081] With IFD, the aggressor signal (transmitted signal) and victim signal (received signal) may occupy the same bandwidth without any guard frequencies.

[0082] The aggressor signal has nulls in its transmission bandwidth which are placed on every Mth sub-carrier where M>=2. In some embodiments, M=2 but in other embodiments M may be greater than two.

[0083] The signal of the victim receiver signal may be placed on the null sub-carriers in the aggressor signal bandwidth. In other words, the transmitted aggres-sor signals and the received victim signals are interleaved.

[0084] Optionally, either the aggressor signal or the victim signal is frequency shifted to reduce the frequency offset between the two signals at the victim receiver.

[0085] The baseband signal generation with spectral nulls for IFD mode will now be described: Consider, x(t), an equivalent complex baseband signal for OFDM: N-1 X(t) =Z X kel2Hafkr, 0 < t <T k=o Where XI, is the number of data subcarrier symbols, N is the number of subcarriers, k is the subcarrier index, Af is the subcarrier spacing T is the OFDM symbol time, where APT=1 The equivalent complex baseband signal for IFD for a particular trans-mission on a set of sub-carrier,5"c(t) with N/M active subcarriers and frequency spacing M.Af can be written as: N-1 k(t) = X" 2 Afkt 0 < t < T k=0,M,2M,.

[0086] Here, 540 only utilizes active subcarriers spaced by M (i.e., k=0, M, 2M, ..., N-1) as opposed to duplexing based on OFDM where every subcarrier is active (i.e., k=0, 1,2, 3, ..., Ng). The non-active sub-carriers are spectrally nulled by the transmitter and used instead for reception in the opposite link direction.

[0087] In this example, k starts with index zero. However, k may start any other positive integer e.g. corresponding to the set of subcarriers/resource blocks that are scheduled by the gNB for transmission or reception.

[0088] In some embodiments, to provide orthogonality between subcarriers over each symbol period, the subcarrier spacing Af is equal to 1/T, i.e., Af:T=1.

[0089] Hence spectral nulling must be applied to x(t) for the non-active sub-carriers k#0,M,2M,... to obtain orthogonality by ensuring a resulting subcarrier spacing of M. Directly applying spectral nulling to the OFDM signal in the frequency 15 domain may lead to an increase in the peak to average power ratio PAPR in the IFD mode.

[0090] In some embodiments, a UE transmitting in uplink in an IFD slot can be configured with a pseudorandom sequence and a scaling factor to be used for transmitting on the unused interleaved sub-carriers meant for downlink.

[0091] The scaling factor may be used to let the UE transmit with a reduced power on unused sub-carriers. This may be used to reduce the PAPR.

[0092] The same sequence and scaling factor may be configured to the UE, which is receiving in the downlink direction on those sub-carriers in IFD mode. The receiving UE can then use this information to suppress the unwanted interference from a UE transmitting in the uplink direction.

[0093] In some embodiments, different UEs may be multiplexed in the time-frequency resource grid. The UL and DL data may be mapped to a corresponding set of subcarriers.

[0094] Reference is made to Figure 6 which shows one example of UL/DL re- source allocation and multiplexing of users in a IFD mode. Figure 6 shows an ex-ample allocation of radio resources in the OFDM time-frequency grid for two UEs: User #1 and User #2.

[0095] In this example, the gNB may signal the resources for each UE to each UE. In some embodiments, this may be done in the same or similar manner as in SG NR. For example, downlink control information (DC1) indicates to each UE which resources to be used for either UL transmission or DL reception (PUSCH or PDSCH, respectively, according to NR terminology). This may be with a resolution of resource block (RS) in the frequency domain. This may be with a resolution of slot or symbols in time domain.

[0096] In the example of Figure 6, for the indicated resources, the signal to be transmitted is mapped to every second subcarrier for one link direction (e.g. even subcarriers), while the other set of subcarriers (e.g. odd subcarriers) are used for the other link direction. This mapping rule may be configured by the gNB. In other embodiments, the mapping may be effectively hard-coded in the specifications so both the transmitter and receiver are aligned on which specific subcarriers of the scheduled RBs are to be considered for the signal generation and decoding proce-dures. In the example in Figure 6, the uplink carriers are shown as shaded while the downlink carriers are shown as unshaded.

[0097] In the example of Figure 6, it is assumed that a RB consists of 12 consecutive subcarriers. However, while a different numerology may be used in other em-bodiments. For example, a RB may consist of 24 consecutive subcarriers such that there are 12 UL and 12 DL subcarriers in each RB. This may be as in SG NR. Other examples of numerology may be used in different embodiments.

[0098] In the example shown in Figure 6, a first time slot and a second time slot are shown. The times slots are referenced 600. The first time slot and the second time slot each are shown with six resource blocks 602. In the example of Figure 6, the first UE, user #1, is associated with resource blocks 0 and 1 of the first time slot and with resource blocks 2 and 3 of the second time slot. The second UE, user #2, is associated with resource blocks 1, 2 and 3 of the first time slot and with resource blocks 3 and 4 of the second time slot The second and third resource blocks 602 and 606 of the second time slot are expanded out For each of the second and third resource block the DL subcarriers are interleaved with the UL subcarriers such that the DL subcarriers are provided alternately to the UL subcarriers. In this example, the UL subcarriers for the second UE, user #2, alternate with the DL subcarriers for the first UE, user #1 in resource block #3 606.1n resource block #2, the DL subcarriers may be used for first UE, user#1 and the UL subcarriers may not be schedule to any UE.

[0099] In some embodiments, RRC signaling may be used to provide the IFD mode. For example, a UE may be reconfigured to use IFD resources provided by the network.

[0100] The IFD mode may be setup during connection establishment or during a connection reconfiguration. Reference is made to Figure 7 which shows an exam-ple where the IFD mode is set up during a connection reconfiguration. By way of example only, the gNB may change between one duplexing mode (e.g. SBFD or TDD) to the IFD mode. This may be dependent on self-interference or CL1 measurements. For example, use may be made of UE CLI reports where some UEs transmit CL1-SRS (sounding reference signals) which are used by other UEs to measure SRS-RSRP (reference signal received power) or RSSI (received signal strength indicator) and report the corresponding measurements to the gNB.

[0101] In some embodiments, the IFD mode can also be used even when the receiver is not under compression. In some embodiments, the IFD may provide a similar EVM (error vector magnitude) performance as the traditional SBFD over a wide range of interference and desired signal power levels, when the receiver is not under compression.

[0102] To use IFD, the network and device should both support IFD. In some embodiments, the network and UE should have knowledge of each other's capabil-ities.

[0103] As referenced 1, the UE reports to the network, the capabilities of the UE. This may comprise information about the capability of the UE to support the IFD mode. The information may indicate if the UE is able to support SBFD as a base for IFD. The information may indicate if the UE is able to support IFD on a standalone basis.

[0104] To support the use of IFD, the network node configures the UE for a connection using the IFD.

[0105] As referenced 2, a RRC setup or RRC reconfiguration is started by the network node. This configuration or reconfiguration is to configure the UE for usage of IFD. This configuration or reconfiguration may provide one or more param-eters needed by the UE to configure the UE for the IFD. For example, one or more parameters may comprise one or more of: the ratio between uplink and downlink; which one or more interleaved resources are to be used for downlink; which one or more interleaved resources are to be used for uplink; which part of the configuration (e.g. which time slots and/or resource blocks) is used for IFD.

[0106] As referenced 3, the UE confirms that the configuration or reconfigu-ration is complete.

[0107] As referenced 4, the network node can start scheduling UL and DL grants in the IFD range of time and frequency.

[0108] In some embodiments, the victim receiver which receives the inter-leaved aggressor signal, and the desired victim signal can be under compression.

[0109] In some embodiments, the victim receiver may take one or more of the steps of Figure 8. This may be to help the victim receiver when the victim receiver is getting close to or is in saturation.

[0110] As referenced Si, in some embodiments, the victim receiver may com-pensate for the relative frequency offset that receiver has with respect to the strong interference signal.

[0111] This may need to be done before the signal is transformed to frequency domain. As referenced S2, the signal may be transformed to the frequency domain. As referenced 53, in some embodiments, the desired signals sub-carri-ers may be normalized by taking into the account the average power of only the desired sub-carriers.

[0112] As referenced S4, in some embodiments, any frequency offset and/or time offset the victim receiver might have with respect to the desired signal may be corrected in the frequency domain rather than in the time domain.

[0113] In some embodiments, a victim gNB receiver may normalize only the victim sub-carriers and then apply a frequency offset correction and/or time offset correction with respect to the desired signal in the frequency domain. Frequency offset correction with respect to interfering signal may not be required because the offset may be 0. This may be because the aggressor transmitter and the victim receiver may be in the same gNB.

[0114] In some embodiments, a victim UE receiver may first do a frequency off-set correction of the strong interference signal before applying a FFT (Fast Fourier Transform) to convert the signal to the frequency domain.

[0115] The UE victim receiver may normalize only the victim sub-carriers and then apply a frequency offset correction and/or time offset correction with respect 10 to the desired signal in the frequency domain. A frequency offset may be present if the aggressor transmitter is from a different UE.

[0116] Some embodiments may enable communication even when the victim receiver is in or near saturation.

[0117] Some embodiments may provide up to 25 dB improvement of desensi15 tization level with an interference power of -25 dBm to -10 dBm.

[0118] Some embodiments may provide up 13dB improvement in EVM.

[0119] Some embodiments may not be affected by the time offset and frequency offset of the strong interferer.

[0120] Some embodiments may provide a similar performance to SBFD mode when receiver is not in saturation.

[0121] Reference is made to FIG. 9 which show a method of some example embodiments.

[0122] This method may be performed by an apparatus. The apparatus may comprise or be a user equipment The apparatus may comprise suitable means, such as circuitry for providing the method.

[0123] Alternatively or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0124] Alternatively or additionally, the apparatus may be such as discussed in relation to FIG. S. The method may be provided by computer program code or computer executable instructions.

[0125] The method may comprise as referenced Al, receiving from a network, information indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency alloca-tion comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first resource block to be used for transmitting to the network by a user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of un-scheduled or scheduled to a user equipment.

[0126] The method may comprise as referenced A2, transmitting signals to the network on one or more of the first set of first subcarriers of the first frequency allocation.

[0127] This method may be modified to include any of the features of previ-ously described embodiments.

[0128] Reference is made to FIG. 10 which show a method of some example embodiments.

[0129] This method may be performed by an apparatus. The apparatus may comprise or be an access node, for example a base station.

[0130] The apparatus may comprise suitable means, such as circuitry for providing the method.

[0131] Alternatively, or additionally, the apparatus may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor cause the apparatus at least to provide the method below.

[0132] Alternatively, or additionally, the apparatus may be such as discussed in relation to FIG. S. The method may be provided by computer program code or computer executable instructions.

[0133] The method may comprise as referenced B1, providing information to a first user equipment indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first fre-quency allocation to be used for transmitting to a network by the user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment. The method may comprise as referenced B2, receiving signals from the first user equipment on the one or more of the first set of first subcarriers of the frequency allocation.

[0134] This method may be modified to include any of the features of previously described embodiments.

[0135] Fig. 5 shows, by way of example, a block diagram of an apparatus 10. The apparatus 10 comprises, for example, at least one processor 12 and at least one memory 14 storing instructions 15 that, when executed by the at least one proces-sor, cause the apparatus 10 at least to perform the method or methods as disclosed herein, and any of the embodiments thereof. In an example, the at least one memory and the instructions (e.g. a computer program code, software), are configured, with the at least one processor, to cause the apparatus 10 to perform the method or methods as disclosed herein, and any of the embodiments thereof.

[0136] A processor 12 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with example embodiments described herein. As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a user equipment, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or net-The memory 14 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 14 may be at least in part external to apparatus 10 but accessible to apparatus 10.

[0137] The instructions 15 may be comprised in a computer readable medium or a non-transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. random access memory, RAM, vs. read only memory, ROM).

[0138] For example, the apparatus 10 is a terminal device, such as the UE of Fig. 1. As another example, the apparatus is comprised in such a terminal device, e.g. as a chipset configured to control the terminal device. The apparatus 10 may be caused or configured to perform at least the method of Fig. 9 and/or any one or more of the embodiments described.

[0139] As another example, the apparatus 10 is a network node, e.g. the access node or base station of Fig. 1.1n another embodiment, the apparatus is comprised in such a network node, e.g. as a chipset configured to control the network node. The apparatus 10 may be caused or configured to perform at least the method of Fig. Wand/or any one or more of the embodiments described.

[0140] The apparatus may comprise one or more entities of any of protocol lay-ers, such as a MAC entity, an RRC entity, an RLC entity, a PDCP entity or a PHY entity.

[0141] In some embodiments, the entity is configured to perform at least the method of Fig. 9 or Fig. 10, and/or any one or more of the embodiments described.

[0142] The apparatus 10 comprises a radio interface 16. The radio interface 16 may provide the apparatus 10 with communication capabilities. The radio inter-face 16 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 16 may comprise a transmitter configured to transmit information in accordance with at least one cellular or non-cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio in-terface 16 may comprise a transceiver configured to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0143] The apparatus 10 may optionally comprise a user interface 18 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 18 may be used to control the apparatus by the user. The user interface 18 may be external to the apparatus 10. For example, the apparatus 10 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 10 is controlled by the user via the computer.

[0144] In an embodiment, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and/or hardware components of the apparatus 10. For example, the at least one processor 12, the memory 14, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the embodiments thereof As used herein the term "means" is to be construed in singular form, i.e. referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology "means for [performing A, B, C]", is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology "means for performing A, means for performing B, means for performing C" is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Even though the invention has been described above with reference to an example according to the accompanying drawings, it is clear that the invention is not restricted thereto but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that as technology advances, the inventive concept can be implemented in various ways. Further, it is clear to a person skilled in the art that the described embodiments may, but are not required to, be combined with other embodiments in various ways.

Claims (19)

1. CLAIMS1. A user equipment comprising: means for receiving from a network, information indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first resource block to be used for transmitting to the network by the user equipment, a respective subcarrier of the second set of second subcar-Hers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and means for transmitting signals to the network on one or more of the first set of first subcarriers of the first frequency allocation.

2. The user equipment as claimed in claim 1, comprising means for receiving signals from the network on a respective sub carrier of the second set of second subcarriers of the first frequency allocation scheduled to the user equipment.

3. The user equipment as claimed in any preceding claim, wherein one or more different user equipment are scheduled to one or more sub-carriers of the second set of second subcarriers of the first frequency allocation.

4. The user equipment as claimed in any preceding claim, comprising means for transmitting information to the network, the information in-dicative of a capability of the user equipment to support interleaved full duplex operation.

5. The user equipment as claimed in any preceding claim, wherein a respective second subcarrier of the plurality of second subcarriers is spaced from another subcarrier of the plurality of second subcarriers by M first subcarriers, where M is an integer equal to one or more.

6. The user equipment as claimed in any preceding claim, wherein the first frequency allocation comprises n first subcarriers, and up to n of the first subcarriers are allocated to the user equipment.

7. The user equipment as claimed in any preceding claim, comprising means for determining a quality of link between the user equipment and the network and means for transmitting to the network, information relating to the determined quality of the link.

8. The user equipment as claimed in any preceding claim, wherein the information indicative of the format for the time slot associated with the first frequency allocation is provided by one or more of: a radio resource con-trol connection request; a radio resource control reconfiguration message; or a downlink control indicator message.

9. The user equipment as claimed in any preceding claim, wherein the frequency allocation comprises a resource block. 20

10. An access node comprising: means for providing information to a first user equipment indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second sub-carriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first frequency allocation to be used for transmitting to a network by the user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and means for receiving signals from the first user equipment on the one or more of the first set of first subcarriers of the frequency allocation.

11. The access node as claimed in claim 10, wherein the first frequency allocation comprises m second subcarriers, and the m second subcarri-ers are allocated to the first user equipment.

12. The access node as claimed in claim 10, wherein the first frequency allocation comprises m second subcarriers, and one or more second sub-carriers are allocated to the first user equipment and one or more of the second subcarriers are allocated to one or more other user equipment

13. The access node as claimed in any of claims 10 to 12, wherein the means for receiving is further for receiving from the first user equipment one or more of information indicating that the first user equipment has a capability to support transmitting and receiving in a same frequency allocation; or information relating to a quality of a link between the access node and the first user equipment.

14. The access node as claimed in any of claims 10 to 13, comprising determining the format for the time slot associated with the first fre-quency allocation.

15. The access node as claimed in any of claims 10 to 14, wherein the information indicative of the format for the time slot associated with the first frequency allocation is provided in one or more of: a radio resource control connection request; a radio resource control reconfiguration message; or a downlink control indicator message.

16. The access node as claimed in any of claims 10 to 15, wherein the frequency allocation comprises a resource block.

17. A method comprising: receiving from a network, information indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being in- terleaved, said information indicating one or more of the first set of first subcarriers of the first resource block to be used for transmitting to the network by a user equipment a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equip-ment; and transmitting signals to the network on one or more of the first set of first subcarriers of the first frequency allocation.

18. A method comprising: providing information to a first user equipment indicative of a format for a time slot associated with a first frequency allocation to provide interleaved full duplex operation, the first frequency allocation comprising a first set of first subcarriers and a second set of second subcarriers, the first and second subcarriers being interleaved, said information indicating one or more of the first set of first subcarriers of the first frequency allocation to be used for transmitting to a net-work by the user equipment, a respective subcarrier of the second set of second subcarriers of the first frequency allocation being one of unscheduled or scheduled to a user equipment; and receiving signals from the first user equipment on the one or more of the first set of first subcarriers of the frequency allocation.

19. A computer program comprising computer executable instructions which when executed cause the method of claim 17 or 18 to be performed.