WO2021105553A1

WO2021105553A1 - Wireless communication device

Info

Publication number: WO2021105553A1
Application number: PCT/FI2020/050774
Authority: WO
Inventors: Benny Vejlgaard; Johannes Harrebek
Original assignee: Nokia Technologies Oy
Priority date: 2019-11-28
Filing date: 2020-11-18
Publication date: 2021-06-03

Abstract

There is provided an apparatus with means for performing, when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus. The means is also configured for determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

Description

Title

WIRELESS COMMUNICATION DEVICE

Field The present application relates to a method, apparatus, and computer program.

Background

A communication system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations/access points and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided, for example, by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

Summary According to an aspect, there is provided an apparatus comprising means for performing: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

The means may be further configured to perform determining a first key performance indicator, a second key performance indicator and a third key performance indicator.

The means may be further configured to perform detecting an effect of a user on the apparatus, wherein the first key performance indicator is based on a detected effect of the user on the apparatus.

The means may be further configured to perform the detecting an effect of a user on the apparatus by detecting the user covering an antenna element of the apparatus. The means may be further configured to perform the detecting the user covering an antenna element of the apparatus by using a determined reverse power on a feedback receiver of the apparatus.

The means may be further configured to perform determining a change in a transmission performance at the apparatus, wherein the second key performance indicator may be based on a determined change in the transmission performance at the apparatus.

The means may be further configured to perform calculating an adjacent channel leakage ratio in the apparatus, wherein the second key performance indicator is based on a calculated adjacent channel leakage ratio in the apparatus.

The means may be further configured to perform determining an increase in a residual error at a first self-interference cancellation point in the apparatus, wherein the third key performance indicator is based on a determined increase in the residual error at the first self-interference cancellation point in the apparatus. The means may be further configured to perform, calculating a sum of: interference in the apparatus, and transmission leakage at the first self-interference cancellation point, wherein the third key performance indicator may be based on a calculated sum of interference in the apparatus with transmission leakage at the first self-interference cancellation point. The means may be further configured to perform determining an availability of time periods for uplink activity with no downlink activity, wherein the third key performance indicator may be determined when there is availability of time periods for uplink activity with no downlink activity.

The means may be further configured to perform storing an initial calibration for self-interference cancellation in the apparatus.

The means may be further configured to perform determining at least one of a receive quality and a reference signal receive power at the apparatus, wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus may also be based on the determined receive quality and reference signal receive power.

The means may be further configured to perform a self-interference cancellation re-configuration.

The means may be further configured to perform determining whether a measured transmit power level is above a threshold value, and wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus may also be based on the determination of whether the measured transmit power level is above the threshold value.

The means may be further configured to perform receiving a scheduling from the network for communications using full duplex operation.

The apparatus may be comprised within a user equipment.

The means may comprise: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

According to an aspect, there is provided a method performed by an apparatus, comprising: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

The method may comprise determining a first key performance indicator, a second key performance indicator and a third key performance indicator.

The method may comprise detecting an effect of a user on the apparatus, wherein the first key performance indicator is based on a detected effect of the user on the apparatus.

The method may comprise detecting an effect of a user on the apparatus by detecting the user covering an antenna element of the apparatus.

The method may comprise detecting the user covering an antenna element of the apparatus using a determined reverse power on a feedback receiver of the apparatus.

The method may comprise determining a change in a transmission performance at the apparatus, wherein the second key performance indicator may be based on a determined change in the transmission performance at the apparatus.

The method may comprise calculating an adjacent channel leakage ratio in the apparatus, wherein the second key performance indicator is based on a calculated adjacent channel leakage ratio in the apparatus.

The method may comprise determining an increase in a residual error at a first self-interference cancellation point in the apparatus, wherein the third key performance indicator is based on a determined increase in the residual error at the first self-interference cancellation point in the apparatus.

The method may comprise calculating a sum of: interference in the apparatus, and transmission leakage at the first self-interference cancellation point, wherein the third key performance indicator may be based on a calculated sum of interference in the apparatus with transmission leakage at the first self-interference cancellation point.

The method may comprise determining an availability of time periods for uplink activity with no downlink activity, wherein the third key performance indicator may be determined when there is availability of time periods for uplink activity with no downlink activity.

The method may comprise storing an initial calibration for self-interference cancellation in the apparatus.

The method may comprise determining at least one of a receive quality and a reference signal receive power at the apparatus, wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus may also be based on the determined receive quality and reference signal receive power.

The method may comprise performing a self-interference cancellation re configuration.

The method may comprise determining whether a measured transmit power level is above a threshold value, and wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus may also be based on the determination of whether the measured transmit power level is above the threshold value.

The method may comprise receiving a scheduling from the network for communications using full duplex operation.

The apparatus may be comprised within a user equipment.

According to an aspect, there is provided an apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self- interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining a first key performance indicator, a second key performance indicator and a third key performance indicator.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: detecting an effect of a user on the apparatus, wherein the first key performance indicator is based on a detected effect of the user on the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: detecting an effect of a user on the apparatus by detecting the user covering an antenna element of the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: detecting the user covering an antenna element of the apparatus using a determined reverse power on a feedback receiver of the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining a change in a transmission performance at the apparatus, wherein the second key performance indicator may be based on a determined change in the transmission performance at the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: calculating an adjacent channel leakage ratio in the apparatus, wherein the second key performance indicator is based on a calculated adjacent channel leakage ratio in the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining an increase in a residual error at a first self-interference cancellation point in the apparatus, wherein the third key performance indicator is based on a determined increase in the residual error at the first self-interference cancellation point in the apparatus. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: calculating a sum of: interference in the apparatus, and transmission leakage at the first self-interference cancellation point, wherein the third key performance indicator may be based on a calculated sum of interference in the apparatus with transmission leakage at the first self-interference cancellation point.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining an availability of time periods for uplink activity with no downlink activity, wherein the third key performance indicator may be determined when there is availability of time periods for uplink activity with no downlink activity.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: storing an initial calibration for self-interference cancellation in the apparatus.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining at least one of a receive quality and a reference signal receive power at the apparatus, wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus may also be based on the determined receive quality and reference signal receive power.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: performing a self-interference cancellation re-configuration.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: determining whether a measured transmit power level is above a threshold value, and wherein the determining whether to trigger a self-interference cancellation re configuration of the apparatus may also be based on the determination of whether the measured transmit power level is above the threshold value.

The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: receiving a scheduling from the network for communications using full duplex operation.

According to an aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

A computer product stored on a medium may cause an apparatus to perform the methods as described herein.

An electronic device may comprise apparatus as described herein.

In the above, various aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described above.

Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.

According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

Description of Figures

Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 shows a schematic diagram of an example communication system comprising a plurality of base stations and a plurality of communication devices; Figure 2 shows a schematic diagram of an example communication device; Figure 3 shows a schematic diagram of an example network function;

Figure 4 schematically shows an example of duplexing options;

Figure 5 schematically shows an example of a full duplex user equipment; Figure 6a schematically shows an example transmission part of an antenna array;

Figure 6b schematically shows an example of user equipment implementation of adjacent channel leakage ratio measurement;

Figure 7 shows an example flow diagram for a user equipment;

Figure 8 shows another example flow diagram for a user equipment; and Figure 9 shows an example method flow diagram. Detailed description

Before explaining in detail some examples of the present disclosure, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 3 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in Figure 1, mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices 102, 104 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices. The communication device may access a carrier provided by a station or access point, and transmit and/or receive communications on the carrier.

The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. A base station may be referred to more generally as simply a network apparatus or a network access point. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller. In Figure 1 control apparatus 108 and 109 are shown to control the respective macro level base stations 106 and 107. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller.

In Figure 1, base stations 106 and 107 are shown as connected to a wider communications network 113 via a gateway 112. A further gateway function may be provided to connect to another network. There may be smaller base stations or cells (not shown) in some networks. These may be pico or femto level base stations or the like.

A possible communication device will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a communication device 200. Such a communication device may be a user equipment (UE) or terminal. An appropriate communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a smart phone, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine type device or any combinations of these or the like.

The device 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2 transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the communication device. A device is typically provided with at least one data processing entity 201 , at least one memory 202 and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204.

The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. This may be optional in some embodiments.

A display 208, a speaker and a microphone can be also provided. One or more of these may be optional in some embodiments.

A communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto. One or more of these may be optional. The communication devices may access the communication system based on various access techniques.

An example of wireless communication systems are architectures standardized by the 3rd Generation Partnership Project (3GPP). A latest 3GPP based development is often referred to as 5G or New Radio (NR). The previous 3GPP based developments are often referred to as different generations for example 2G, 3G, 4G. Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as wireless local area network (WLAN) and/or WiMAX (Worldwide Interoperability for Microwave Access). It should be appreciated that although some embodiments are described in the context of a 4G and/or 5G system, other embodiments may be provided in any other suitable system including but not limited to subsequent systems or similar protocols defined outside the 3GPP forum.

An example apparatus is shown in Figure 3. Figure 3 shows an apparatus that could be comprised within a network function. As an example, the network function could be a base station (gNB, eNB, etc.), a management function, a serving gateway, a packet data network gateway, an access and mobility management function or a session management function. The apparatus 300 comprises at least one memory 301 , at least one data processing unit 302, 303 and an input/output interface 304. For example the apparatus 300 can be configured to execute an appropriate software code to provide functions. The apparatus 300 may be included in a chipset apparatus.

Some of the example embodiments as shown below may be applicable to 3GPP 5G standards. However, some example embodiments may also be applicable to 4G, 3G and other 3GPP standards.

In wireless communications, a duplex communication system is a point-to-point system with two or more devices that can communicate with the other devices in both directions. Simultaneous communication can be achieved in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex systems namely full-duplex (FD) and half-duplex (HD). In a full-duplex system, both devices can communicate with the other device simultaneously. In a half-duplex system, both devices can communicate with the other device, but not simultaneously.

In systems wherein channel access methods are used in point-to-multipoint networks for dividing forwards and backwards communication channels on the same physical communications medium, these may be known as duplexing methods. Two common duplexing methods are time division duplexing (TDD) and frequency division duplexing (FDD). These different duplexing options can be seen in Figure 4.

TDD uses a single frequency band for both transmitting and receiving. TDD shares the frequency band by assigning alternating time slots to transmit and receive. TDD alternates the transmission and reception of data over time.

FDD may have two separate wireless communications channels with different frequencies. One frequency may be for transmit and the other frequency may be used for received data. FDD may use twice the amount of frequency spectrum when compared to TDD.

As seen in Figure 4, during the first time-section 401 there is FDD in operation. There are two separate frequency bands. One frequency band for uplink, and another frequency band for downlink. Both the uplink and downlink frequency bands are operating at the same time.

In the second time-section 403 there is TDD in operation. In this example of TDD, one frequency band is used. There are alternating time slots for downlink and then uplink, in a periodic manner. In this example, the time slots for uplink and downlink are the same. In other examples, the time slots for uplink and downlink may be different.

In the third time-section 405 there is FD communication in operation. In this FD operation there is simultaneous uplink and downlink communication using the same frequency band.

The 3GPP NR Rel-15 specifications supports frequency division duplexing (FDD) and time division duplexing (TDD) modes. For FDD, non-overlapping carriers may be configured for the downlink (DL) and uplink (UL) transmissions, respectively. Flowever, network densification in ultra-reliable applications may pose stringent requirements which FDD may not be able to meet. TDD may imply that a cell either has exclusive UL, DL, or no transmission for a time-instant. Flence, there is no option for simultaneous UL and DL which is supported in NR Rel-15. For ultra-reliable low- latency communication (URLLC) devices and time-sensitive network (TSN) devices, where multiple simultaneously active UEs need to be served immediately, it is often required to have simultaneous UL and DL to accommodate the strict latency and ultra reliability requirements for all users. URLLC and TSN devices are used as an example only, and many other types of devices may also be suitable. The inventors have identified that FD operation may address these stringent requirements. FD operation has the potential to double the throughput. FD enables a device to receive and transmit simultaneously in the same frequency band.

An FD device may use dedicated transmit (TX) and receive (RX) chains for transmission and reception in the same physical resource blocks (PRBs). Flowever, FD may introduce self-interference (SI) and residual SI, in which the TX chain may leak a non-negligible amount of energy onto the RX chain. This leakage may contaminate the received signal.

A UE full duplex operation may cause the UEs own transmitter interference onto the UEs own receiver. Therefore, a self-interference cancellation (SIC) scheme may be needed for maintaining specification compliant receiver performance. Flowever, changes in the characteristics in the UE, caused by for example, a user holding the UE may cause some SIC schemes to work in a sub-optimal manner. A SIC scheme may need to be re-configured/re-characterised based on the conditions. Some previously presented solutions have significant UE radio front end RX/TX isolation because a digital SIC cancellation gain may not be adequate. A UE receiver has dynamic range limitation and so solutions may have a first TX cleaning stage prior to the receiver low-noise amplifier (LNA) stage. This may be done to prevent RX saturation. With reference to Figure 5, one of the problems with enabling FD operation on a UE/terminal is to identify the transfer function from the UE TX path to the UE RX path. Figure 5 schematically shows a simplified model of a FD UE. There is provided a first input 501 labelled TX1 which is provided into digital to analogue converter (DAC) block 503. The DAC 503 feeds into a summing block 505. The summing block feeds into a power amplifier (PA) 507. The PA 507 feeds into a TX antenna 509. The first input 501 also is provided to an analogue SIC model block 511. The analogue SIC model block 511 feeds into a DAC 513. The DAC 513 feeds into a summing block 515. The summing block 515 feeds into a driver (DRV) 517. The DRV 517 feeds into a subtraction block 519. An RX antenna 521 also feeds into the subtraction block 519. The subtraction block 519 marks a first TX leakage cleaning point, “Cleaning Point 1”. In some examples, the “Cleaning Point 1” may be referred to as a self-interference cancellation point. In other examples, the “Cleaning Point 1” may be referred to as an analogue self-interference cancellation point. A cleaning point is a cancellation of the TX signal in the RX path. The subtraction block 519 feeds into an LNA 523. The LNA 523 feeds into a summing block 525. A local oscillator (LO) 527 feeds into the summing block 505, 515 and 525. The LO 527 feeds into the summing block 505 performing UL signal and cleaning signal up-conversion to the RF frequency in the TX chain/”Cleaning point 1” chain. The LO 527 also feeds into the summing block 525 performing DL signal down-conversion in the RX chain. The summing block 525 feeds into an analogue-to-digital converter (ADC) 529. The ADC 529 feeds into a digital cancellation block 531. The digital cancellation block 531 also has an input from the first input 501 . The digital cancellation block 531 marks a second TX leakage cleaning point, “Cleaning Point 2”. In some examples, the “Cleaning Point 2” may be referred to as a self-interference cancellation point. In other examples, the “Cleaning Point 2” may be referred to as a digital self-interference cancellation point. The digital cancellation block 531 feeds into an RX output 533.

Figure 5 shows a first dotted path labelled P1 . The path of P1 follows the DAC 513, the summing block 515, DRV 517 and subtraction block 519. P1 represents a first transfer function. Figure 5 also shows a second dotted path labelled P2. The path of P2 follows the DAC 503, summing block 505, PA 507 and TX antenna 509 onto the RX antenna 521 . P2 represents a second transfer function.

The target may be to model the transfer function of path (P2) with path (P1 ) to obtain a low residual error at the output of cleaning point 1 that can be handled in the digital domain.

The transfer function of path (P2) can be characterized for base stations/network entities or devices without human or other proximity objects interaction.

For UEs/handheld devices, the path (P2) will be impacted by the human touch (for example, loading effect and/or mismatch) and consequently the SIC may have to be dynamically updated in order to maintain TX/RX isolation in the field. A problem in this context is how to characterize path (P2) under dynamic field conditions.

In the example shown in Figure 5, the ADC 529 should have its resolution kept to a minimum due to, for example, cost and power consumption. The dynamic range of the ADC 529 should be limited for the benefit of UE receiver performance. Thus, the residual error after “Cleaning point 1” should be kept at a minimum. The characterization of the analogue “Cleaning point 1” means that the interference from other transmit points (for example, other gNBs and/or other UEs) should be muted or minimized. A problem identified in this disclosure is how to know when a SIC update is needed.

Embodiments of the present disclosure will aim to address one or more of the problems as identified above.

In this disclosure, there are examples for an implementation in a user device detecting when a mismatch occurs in either the TX or RX chain. A mismatch in the TX or RX chain may invalidate the characterized leakage from TX to RX used by the self interference cancellation block which is used for full duplex operation in a user device.

Some examples as shown below propose to use a combination of parameters to detect a change in the transfer characteristic between TX and RX having a significant impact on the “Cleaning point 1” of Figure 5.

An example of a prerequisite for initiating a live operation re-configuration of the analog SIC 511 is a condition of high DL reference signal receive power (RSRP) while RX quality remains low. In this example, a cause for low RX quality may be suboptimum SIC performance. This may be combined with high UE TX power above a given threshold.

A full duplex user device as shown in Figure 5 may calculate, for example, three key performance indicators (KPI) in the device. The KPIs may be useful for determining when to perform a SIC re-characterisation/re-configuration. This will be described in more detail below.

A first KPI may be load mismatch. A UE may detect user or proximity reflector impact on the UE device using a reverse power of the feedback receiver in the UE. This will be discussed in more detail below.

A second KPI may be TX performance. A UE may measure TX performance by measuring an adjacent channel leakage ratio (ACLR). This will be discussed in more detail below.

A third KPI may be an increase/decrease of residual errors for “Cleaning point 1”. In a perfect system, the target for “Cleaning point 1” is to have a residual error of zero. Flowever, external interference may result in a non-zero error. This will be discussed in more detail below.

The first KPI, load mismatch and user interference detection, will be discussed in more detail with the help of Figure 6a which schematically shows a TX part of a front end for an antenna array 600 of a user equipment. An antenna element is an element which can provide an antenna beam for a UE. The antenna array 600 of a UE may comprise a plurality of antenna elements. Antenna elements can be blocked or covered by, for example, the hands of users holding the device.

As shown in Figure 6a, for the detection of the covered antenna elements to be possible, a transmission path comprises a Directional Coupler (DC) 601 , 603, 605, a Power Detector (PD) 607, 609, 611 and an Analog to Digital Convertor (ADC) 613, 615, 617, where both the forward and reverse power can be monitored. Figure 6a shows three sets of the DC 601 , 603, 605, the PD 607, 609, 611 and the ADC 613, 615, 617, wherein DC 601 , PD 607, and ADC 613 form a first set, DC 603, PD 609, and ADC 615 form a second set, and DC 605, PD 611 , and ADC 617 form a third set. In this example, the sets of DC, PD and ADC components are in circuit series with one another. In the example of Figure 6a the antenna array 600 are five beams 619, 621 , 623, 625, 627. In other examples, the antenna array 600 has less than five beams. In other examples, the antenna array 600 has more than five beams.

The detection of an antenna element being covered may be provided by the ratio between the coupler reverse and forward power (reflection constant |GI_|2). When the reflection constant |GI_|2 = 0, this will indicate that no power is reflected. No power being reflected means that the antenna is perfectly matched. When the reflection constant |GI_|2 = 1 , this means that all the power is reflected. All power being reflected means that the antenna is very badly matched. The reflection constant should be low in free space conditions, since the impedance match of the individual elements should typically be optimised for this condition. An increase in the reflection constant may indicate that something is close to that antenna element. As an example, an increase in reflection constant may be an indication that a user is close to or touching the UE. In this case, it might be beneficial to switch off that element in the UE and transition to an updated codebook. Switching off a badly matched antenna may also save current/power consumption.

A decision threshold for switching off an antenna element can be made static (for example, a system design parameter) or dynamic. An example of a static decision threshold is a system design parameter. An example of a dynamic decision threshold may be based on previously observed statistics regarding the user interference. Thus, the UE can adapt the sensitivity of the decision threshold.

As the movement of a user typically occurs in a much longer timescale than the changes in the radio environment, then the periodicity of this detection should occur on the timescale of, for example, a few seconds. In other examples the periodicity for detection may be lower than a few seconds. In other examples the periodicity for detection may be more than a few seconds.

The second KPI, TX performance using ACLR, will be discussed in more detail with the help of Figure 6b. Figure 6b shows schematically a UE implementation for measuring ACLR. As discussed above, the ACLR represents the ratio of in-band TX power vs. the out of band TX power. More specifically, the ACLR represents the ratio of in-band TX power for a channel vs. the out of band TX power for an adjacent channel. This may be in both the lower and upper bandwidth next to the desired TX bandwidth. The ACLR is may be measured during the design and the manufacturing of the UE. In other examples, the ACLR can be measured using the UE feedback receiver with bandwidth 3x of the transmitted signal. The UE can then measure power of both lower, desired, and upper bandwidth. Power amplifier temperature rise while maintaining the same output power may also indicate change on the TX operation and potential leakage. Figure 6b shows an upper bandwidth circuit 629. There is also provided a desired bandwidth circuit 631. There is also provided a lower bandwidth circuit 633. The upper bandwidth 629, desired bandwidth 631 and lower bandwidth circuit 633 are arranged in parallel. Bandwidth circuits 629, 631 , 633 comprise a power detector and a directional coupler. Bandwidth circuits 629, 631, 633 are able to measure the transmitted power via the directional coupler.

For the third KPI, the residual error detection, the target for “Cleaning point 1” is to have a residual error of zero. However, external interference may result in a non zero error. An increase in residual error combined with a change in the UE performance either due to, for example, human touch or environmental effects will indicate that a re-configuration may be needed. The residual error can be estimated by: during TX operation when no scheduled RX activities are present, the UE will open the RX receiver (even there is no scheduled RX) and disable the digital SIC block to get an undistorted version of the Point 1 residual, as shown below in equation 1. Eqn (1): RpX, - mean(X)

Since RX is not scheduled, then the resulting estimator will be: the sum of interference and TX leakage after “Cleaning point 1”. A combination of changes in these three KPIs may indicate that the leakage from TX to RX has changed and a new characterization may be needed in order to minimize the residual error at “Cleaning point 1”.

With the help of Figure 7 there is presented an example procedure for estimating when to trigger a full duplex TX to RX SIC re-configuration. It should be understood that the terms, re-configuration, re-characterisation and re-calibration could be used interchangeably. The procedure shown below for Figure 7 may be performed by an apparatus. The apparatus may be a user device such as a user equipment or terminal. In other examples, the apparatus may be comprised within a user device.

A time-consuming live operation FD analog SIC re-configuration should be initiated upon clear identification of increased TX leakage onto the RX chain. Therefore, there is a need for a procedure for triggering such re-configuration based on TX leakage indicators. As shown in Figure 7 a UE will be configured with a factory/initial calibration for full duplex operation.

In UE field deployment, the UE is in radio resource control (RRC) connected mode in full duplex mode. This will be referred to as the start point. This may be configured/scheduled by a base station. For example, in the field, a serving gNB may schedule the UE for full duplex operation

At S701, it is determined whether the receive RSRP is high and the receive quality is low. In a case wherein the UE is experiencing low RX quality but at high RX RSRP that may be an indicator that conditions have changed. Thus, the TX residual leaking to RX may be too high and the analog SIC needs re-configuration. If the determination of S701 is no, then the flow will return to the start point. If the determination of S701 is yes, then the flow will continue to S703.

At S703, it is determined whether the UE TX power level is above a threshold. At a high TX power there may be an issue with overly high TX residual leakage to RX. Using UE characterization, a TX power threshold may be defined below which there will not be issues with the UE’s own TX interfering with RX. In other words, the UE characterisation meaning the transfer function from the TX path towards the RX path. By UE characterisation a TX power threshold can be established below which the TX leakage onto the UEs own RX path will be negligible. The may be in any network conditions. Below this TX power threshold it unlikely that the low RX quality is due to too high TX leakage. Therefore, in this case, a re-configuration may not be necessary. If the determination of S703 is no, then the flow will return to the start point. If the determination of S703 is yes, then the flow will continue to the S705.

At S705, it is determined whether a load mismatch is detected (i.e. the first KPI). Antenna load mismatch may occur dynamically in the field. The likelihood that such a load mismatch impacts the SIC performance may be high. Load mismatch may be detected in the radio front end by a directional coupler, a power detector and an ADC measuring both forward and reverse power, as described earlier. Load mismatch may also be detected by monitoring PA current vs TX power level. In other examples, a proximity sensor may be used to detect a load mismatch scenario. If the determination of S705 is no, then the flow will continue to S707. If the determination of S705 is yes, then the flow will continue to S709.

At S707, it is determined whether TX linearity is detected (i.e. the second KPI). TX linearity may change dynamically in the field due to, for example, battery voltage, temperature, power level and/or load conditions. A TX ACLR calculated for a UE is normally measured in the UE production. In other examples, the TX ACLR is measured by the UE in the field using the UE TX feedback receiver at 3x the TX BW. Increased TX ACLR compared to a pre-characterized threshold can be used as an indicator for possible increased TX leakage into the RX chain. If the determination of S707 is no, then the flow will return to the start point. If the determination of S707 is yes, then the flow will continue to S709.

At S709, it is determined whether there are periods with no RX activity available. When monitoring the third KPI it may be beneficial to determine the availability of periods of UL activity, with no scheduled DL. If such a scenario is confirmed as available, the UE may trigger a third KPI assessment. If such scenario is not available, a UE decision to trigger a re-configuration may be done based on the positive detection for first KPI, second KPI, or both. Therefore, if the determination of S709 is no, then the flow will proceed to triggering a re-configuration. If the determination of S709 is yes, then the flow will continue to S711 .

At S711 , it is determined whether there is an increased analogue self interference cancellation (SIC) residual error (i.e. the third KPI). The target for the analog SIC is to output a TX residual error of zero. Therefore, an increase in residual error may be an indicator of a need for re-configuration. As stated in S709 a scenario of TX with no scheduled RX activity may be beneficial for determining a SIC residual error in S711. The UE may enable the receiver (with no DL traffic). The UE may then disable the digital SIC. The UE may then measure directly the residual error of the analog SIC comparing with a pre-characterized threshold. If the residual error is higher than expected this may be due to increased TX leakage. In other examples, it may be due to external interference. In other examples, it may be a combination of external interference and increased TX leakage. A combination of positive determination for the first KPI and the second KPI, with a positive determination for the third KPI may give a strong indication that there is an increased TX leakage. If the determination of S711 is no, then the flow will return to the start point. If the determination of S711 is yes, then this will trigger a re-configuration.

At S713, a silent slot is obtained for performing the re-configuration. A silent slot may be a slot with no transmission from close neighbours. This may be for both base stations and UEs.

At S715, the UE will perform a SIC re-configuration. Another example flow diagram for triggering a full duplex TX to RX re configuration is shown in Figure 8. The procedure shown below for Figure 8 may be performed by an apparatus. The apparatus may be a user device such as a user equipment or terminal. In other examples, the apparatus may be comprised within a user device. Firstly, it will be identified whether there is an issue with RX quality. If there are no problems with the RX quality then there may not be a need to do anything at this stage regarding SIC re-configuration. If there is a high RX RSRP and a low RX quality, then the flow of Figure 8 will continue to the first determination S801.

At S801 , it is determined whether the UE TX power level is above a threshold. At a high TX power there may be an issue with overly high TX residual leakage to RX. Using UE characterization, a TX power threshold may be defined below which there will not be issues with own the UE’s own TX interfering with RX. If the determination of S801 is no, then the nothing needs to be done (i.e. no triggering of SIC re configuration). If the determination of S801 is yes, then the flow will continue to S803. At S803, it is determined whether a load mismatch is detected (i.e. the first KPI).

Antenna load mismatch may occur dynamically in the field. The likelihood that such a load mismatch impacts the SIC performance may be high. Load mismatch may be detected in the radio front end by a directional coupler, a power detector and an ADC measuring both forward and reverse power, as described earlier. Load mismatch may also be detected by monitoring PA current vs TX power level. In other examples, a proximity sensor may be used to detect a load mismatch scenario. If the determination of S803 is no, then the flow will continue to S805. If the determination of S803 is yes, then the flow will continue to S807.

At S805, it is determined whether TX linearity degradation is detected (i.e. the second KPI). TX linearity may change dynamically in the field due to, for example, battery voltage, temperature, power level and/or load conditions. A TX ACLR calculated for a UE is normally measured in the UE production. In other examples, the TX ACLR is measured by the UE in the field using the UE TX feedback receiver at 3x the TX BW. Increased TX ACLR compared to a pre-characterized threshold can be used as an indicator for possible increased TX leakage into the RX chain. If the determination of S805 is no, then nothing needs to be done (i.e. no triggering of SIC re-configuration). If the determination of S805 is yes, then the flow will continue to S807.

At S807, it is determined whether there is an increased analogue self interference cancellation (SIC) residual error (i.e. the third KPI). The target for the analog SIC is to output a TX residual error of zero. Therefore, an increase in residual error may be an indicator of a need for re-configuration. The UE may enable the receiver (with no DL traffic). The UE may then disable the digital SIC. The UE may then measure directly the residual error of the analog SIC comparing with a pre characterized threshold. If the residual error is higher than expected this may be due to increased TX leakage. In other examples, it may be due to external interference. In other examples, it may be a combination of external interference and increased TX leakage. If the determination of S807 is no, then nothing needs to be done (i.e. no triggering of SIC re-configuration). If the determination of S807 is yes, then this will trigger a SIC re-configuration.

As shown above, a UE can utilize measurements of one or more KPI in order to determine a suitable time to trigger a re-configuration.

A UE detecting that a user is touching the device can be done using the load mismatch seen from the feedback receiver in the reverse power. However, this may not change the TX to RX leakage. Combining this with the change in residual error may indicate a likelihood of changes in the TX to RX leakage. Thus, triggering a SIC re-configuration. A UE detecting a change in TX performance can be done by the in-line ACLR measurements from the feedback receiver. However, this may not change the TX to RX leakage. Combining this with the change in residual error may indicate a likelihood of changes in the TX to RX leakage and thus trigger a re-configuration. A detected change in three KPI parameters may be a strong indicator of changes to the TX to RX leakage which may therefore trigger a SIC re-configuration.

Some of the examples disclosed above may allow the dynamic range of the ADC in the UE to be kept at a minimum. By keeping the dynamic range of the ADC at a minimum this may save power. Keeping the dynamic range of the ADC at a minimum may save cost. One of the key power consumers in a device is the ADC. The more bits in an ADC the more power that is consumed. Furthermore, the cost of an ADC scales with the number of bits in said ADC. A lower dynamic range of the ADC correlates to less bits in the ADC.

Some of the examples also enables full duplex operation in a UE with human contact. Furthermore, one or more examples keeps live operation re-configuration overhead to a minimum by triggering updates in an efficient manner.

Figure 9 shows an example flow diagram showing a method flow. The method flow may be performed by an apparatus. The apparatus may be comprised within a terminal device. The apparatus may be comprised within a user equipment. At block 901 , the flow comprises when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus.

At block 903, the flow comprises determining whether to trigger a self interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

The method steps shown in Figures 7, 8 and 9 respectively may be performed in different orders. Some method steps may not need to be performed.

The method steps may be performed by an apparatus. The apparatus may be comprised within a communication device, such as a terminal or UE configured to access a communication network via an access point. In other examples, the terminal may be within the apparatus. Each method step may be performed by a different part or component of the terminal. The method steps may be performed by an apparatus, such as chipset or IC, within the terminal. It is to be understood that one or more steps may be omitted or take place in an alternate order. It should be understood that each step in the signalling diagram of the Figures and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry. It is noted that whilst embodiments have been described in relation to one example of a standalone 5G networks, similar principles maybe applied in relation to other examples of standalone 3G or LTE networks. It should be noted that other embodiments may be based on other cellular technology other than 5G or on variants of 5G. Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

It should be understood that the apparatuses may comprise or be coupled to other units or modules. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities. In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The embodiments of this invention may be implemented by computer software executable by a data processor, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it. A non-transitory computer readable medium may comprise program instructions for causing an apparatus to perform embodiments of this invention.

Further in this regard it should be noted that any steps in the signalling diagrams as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. Flowever, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. Flowever, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

Claims

Claims:

1. An apparatus comprising means for performing: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

2. The apparatus as claimed in claim 1 , wherein the means are further configured to perform determining a first key performance indicator, a second key performance indicator and a third key performance indicator.

3. The apparatus as claimed in claim 2, wherein the means are further configured to perform detecting an effect of a user on the apparatus, wherein the first key performance indicator is based on a detected effect of the user on the apparatus.

4. The apparatus as claimed in claim 3, wherein the means are further configured to perform the detecting an effect of a user on the apparatus by detecting the user covering an antenna element of the apparatus.

5. The apparatus as claimed in claim 4, wherein the means are further configured to perform the detecting the user covering an antenna element of the apparatus by using a determined reverse power on a feedback receiver of the apparatus.

6. The apparatus as claimed in claim 2, wherein the means are further configured to perform determining a change in a transmission performance at the apparatus, wherein the second key performance indicator is based on a determined change in the transmission performance at the apparatus.

7. The apparatus as claimed in claim 6, wherein the means are further configured to perform calculating an adjacent channel leakage ratio in the apparatus, wherein the second key performance indicator is based on a calculated adjacent channel leakage ratio in the apparatus.

8. The apparatus as claimed in claim 2, wherein the means are further configured to perform determining an increase in a residual error at a first self interference cancellation point in the apparatus, wherein the third key performance indicator is based on a determined increase in the residual error at the first self interference cancellation point in the apparatus.

9. The apparatus as claimed in claim 8, wherein the means are further configured to perform, calculating a sum of: interference in the apparatus, and transmission leakage at the first self-interference cancellation point, wherein the third key performance indicator is based on a calculated sum of interference in the apparatus with transmission leakage at the first self-interference cancellation point.

10. The apparatus as claimed in claim 8 or claim 9, wherein the means are further configured to perform determining an availability of time periods for uplink activity with no downlink activity, wherein the third key performance indicator is determined when there is availability of time periods for uplink activity with no downlink activity.

11. The apparatus as claimed in any of claims 1 to 10, wherein the means are further configured to perform storing an initial calibration for self-interference cancellation in the apparatus.

12. The apparatus as claimed in any of claims 1 to 11 , wherein the means are further configured to perform determining at least one of a receive quality and a reference signal receive power at the apparatus, wherein the determining whether to trigger a self-interference cancellation re-configuration of the apparatus is also based on the determined receive quality and reference signal receive power.

13. The apparatus as claimed in any of claims 1 to 12, wherein the means are further configured to perform a self-interference cancellation re-configuration.

14. The apparatus as claimed in any of claims 1 to 13, wherein the means are further configured to perform determining whether a measured transmit power level is above a threshold value, and wherein the determining whether to trigger a self interference cancellation re-configuration of the apparatus is also based on the determination of whether the measured transmit power level is above the threshold value.

15. The apparatus as claimed in any of claims 1 to 14, wherein the means are further configured to perform receiving a scheduling from the network for communications using full duplex operation.

16. The apparatus as claimed in any of claims 1 to 15, wherein the apparatus is comprised within a user equipment.

17. The apparatus as claimed in any of claims 1 to 16 wherein the means comprises: at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

18. A method performed by an apparatus, comprising: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.

19. A computer readable medium comprising program instructions for causing an apparatus to perform at least the following: when connected to a network and operating in a full duplex mode, determining one or more key performance indicators of the apparatus; and determining whether to trigger a self-interference cancellation re-configuration of the apparatus based on one or more of the determined one or more key performance indicators.