Method and apparatus for NR duplex operation

Abstract

Systems and methods are provided for dual operation enhancements, including providing user equipment (UE) preference gap indication, UE uplink (UL) to downlink (DL) interference mitigation, enhanced broadcast signal configuration, UE RF capability indication, or combinations thereof.

Description

[Technical field]

[0001] TECHNICAL FIELD This application relates generally to wireless communication systems, including duplex communication. [Background technology]

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G), 3GPP new radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs), commonly known to industry groups as Wi-Fi.

[0003] As contemplated by 3GPP, different wireless communication system standards and protocols may use various Radio Access Networks (RANs) for communication between base stations of the RAN (which may also be commonly referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices known as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN may perform communications between base stations and UEs using one or more radio access technologies (RATs). For example, a GERAN may implement a GSM and / or EDGE RAT, a UTRAN may implement a universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, an E-UTRAN may implement an LTE RAT (sometimes referred to simply as LTE), and an NG-RAN may implement an NR RAT (sometimes referred to herein as a 5G RAT, a 5G NR RAT, or simply NR). In certain deployments, an E-UTRAN may also implement an NR RAT. In certain deployments, an NG-RAN may also implement an LTE RAT.

[0005] A base station used by a RAN may correspond to that RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as an evolved Node B, enhanced Node B, eNode B, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes referred to as a Node B or gNB).

[0006] The RAN provides communication services with external entities via a connection to a Core Network (CN), for example, the E-UTRAN may utilize the Evolved Packet Core (EPC) and the NG-RAN may utilize the 5G Core Network (5GC).

[0007] To easily identify the discussion of any particular element or act, the most significant digit(s) of a reference number refers to the figure number in which that element is first introduced. [Brief description of the drawings]

[0008] [Figure 1A] 1 illustrates full-duplex operation in paired spectrum according to some embodiments.

[0009] [Figure 1B] 1 illustrates half-duplex operation in paired spectrum according to some embodiments.

[0010] [Figure 1C] 1 illustrates half-duplex operation in an unpaired spectrum according to some embodiments.

[0011] [Diagram 2] 1 is a timing diagram illustrating a transmission scheme including gaps according to some embodiments.

[0012] [Diagram 3] 1 illustrates interference in a cellular communication system, according to some embodiments.

[0013] [Figure 4] 4 illustrates a minimum frequency separation according to some embodiments.

[0014] [Diagram 5] FIG. 1 is a timing diagram illustrating overlapping and non-overlapping SSBs according to an embodiment.

[0015] [Figure 6] 4 is a flowchart of a method for a UE according to one embodiment.

[0016] [Figure 7] 4 is a flowchart of a method for a first UE for UL to DL interference mitigation according to one embodiment.

[0017] [Figure 8] 4 is a flowchart of a method for a UE according to one embodiment.

[0018] [Figure 9] 1 illustrates an example of a wireless communication system architecture according to embodiments disclosed herein.

[0019] [Figure 10]1 illustrates a system for performing signaling between a wireless device and a network device according to an embodiment disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Various embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The illustrative embodiments may be used with any electronic component that is capable of establishing a connection to a network and configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, a UE as described herein is used to represent any suitable electronic component.

[0021] The radio spectrum may be used in a paired spectrum configuration or an unpaired spectrum configuration. In paired spectrum, a block of spectrum in a lower frequency band is associated with a block of spectrum in a higher frequency band. Frequency division duplex (FDD) is an example of paired spectrum where one frequency band is used for the uplink (UL) and another frequency band is used for (DL). Unpaired spectrum, on the other hand, uses one frequency band for both UL and DL transmissions. Time division duplex (TDD) is an example of unpaired spectrum where the same frequency band is used for UL and DL at different times.

[0022] Duplex operation refers to two-way communication between two devices, while one-way communication may be referred to as simplex operation. When bidirectional, transmission over the link in each direction may occur simultaneously (referred to as full-duplex operation) or at mutually exclusive times (referred to as half-duplex operation). In some cellular communication systems, devices (e.g., base stations or UEs) are not expected to operate simultaneously in both DL and UL (i.e., transmit and receive operations) on the same frequency due to interference between transmit and receive radio resources (i.e., time and frequency resources).

[0023] In the case of paired spectrum (i.e., FDD), an NR communication system may support both full-duplex and half-duplex operation. Figure 1A illustrates full-duplex operation in paired spectrum, according to some embodiments. DL resources 102 are configured in a DL carrier frequency band (F1) that is different from the UL carrier frequency band (F2) used for UL resources 104. Because the frequency bands do not overlap, DL resources 102 and UL resources 104 may be used simultaneously.

[0024] 1B illustrates half-duplex operation in paired spectrum according to some embodiments, where DL resources 106 configured in the DL carrier frequency band are not used simultaneously with UL resources 108 configured in the UL carrier frequency band.

[0025] In the case of unpaired spectrum (i.e., TDD), some NR communication systems support only half-duplex operation. For example, FIG. 1C illustrates half-duplex operation in unpaired spectrum, according to some embodiments. In the illustrated example, a single carrier frequency band (F3) is used for DL ​​resources 110, 114 and UL resources 112, which are transmitted at different times. In some systems, there may be a gap 116 between switching from DL reception to UL transmission at the UE to account for propagation delay based on the path distance between the base station and the UE. Similarly, there may be a gap 118 between switching from UL transmission to DL reception at the UE.

[0026] Some cellular radio systems may enable advanced devices to cancel interference from transmitters to receivers in the same frequency band. Such advanced devices may be capable of simultaneously transmitting and receiving using the same spectrum. To provide duplex operation enhancements (e.g., duplex extensions at the base station side and / or half-duplex operation at the UE side), some embodiments disclosed herein provide UE preference gap indication, UE UL to DL interference mitigation, enhanced broadcast signal configuration, UE RF capability indication, or a combination of the foregoing.

[0027] I.UE Preference Gap Indication

[0028] FIG. 2 is a timing diagram illustrating a transmission scheme including gaps, according to some embodiments. A gNB (or other base station) transmits a DL signal 202 that includes one or more symbols. In this example, the DL signal 202 includes four symbols. The DL signal 202 arrives at the UE after a propagation delay 204. Those skilled in the art will recognize that the UE may use a timing advance (TA) scheme to control the transmission timing of the UL signal 206. For example, the gNB may measure the time difference between the UL transmission and the subframe time and send a TA command to the UE to change its uplink transmission by the indicated amount of time to better align it with the subframe timing at the gNB. For example, if the UL transmission arrives too early at the gNB, the gNB may send a TA command to the UE to indicate that the UE's transmission should start later. On the other hand, if the UL transmission arrives too late at the gNB, the gNB may send a TA command to the UE to indicate that the UE's transmission should start earlier.

[0029] 2 shows a TA adjustment 208 made by the UE in response to a TA command from the gNB to transmit the UL signal 206 earlier by the indicated TA value. That is, rather than starting transmission of the UL signal 206 at time T2 upon completing reception of the DL signal 202, the UE advances the transmission of the UL signal 206 to an earlier time T1 to account for the round trip propagation delay, such that the UL signal 206 is received by the gNB when the gNB completes transmission of the DL signal 202. However, to avoid interference between overlapping symbols of the DL and UL signals 202 and 206, the UE may use half-duplex operation and may be configured (e.g., based on a predetermined or fixed value) to use a minimum gap 210 between the end of reception of the DL signal 202 (i.e., DL reception (Rx) at time T2) and the start of transmission of the UL signal 206 (i.e., UL transmission (Tx) at time T3). Additionally, or in other configurations, the UE may be configured (e.g., based on a predetermined or fixed value) to use a minimum gap 212 between the end of transmission of an UL signal 206 (i.e., UL Tx at time T4) and the start of reception of another DL signal 214 (i.e., DL Rx at time T5).

[0030] However, using a predetermined or fixed value for the minimum gap 210 between DL Rx and UL Tx and / or for the minimum gap 212 between UL Tx and DL Rx may result in wasting radio resources. Of the three symbols shown for the UL signal 206, in the illustrated example, the UE may transmit only the last UL symbol beginning at time T3, which does not overlap in time with any of the symbols received at the UE for the DL signal 202. Thus, in this example, 66% of the UL symbols are unused.

[0031] Thus, in one embodiment, the UE indicates to the base station a preference gap between DL Rx and UL Tx for dual operation extension. The indication can be, for example, either part of radio resource (RRC) capability signaling or included in a specification. In some embodiments, the UE indicates its capability for a preference gap between DL Rx and UL Tx per frequency band.

[0032] In addition, or in other embodiments, the UE indicates to the base station a preference gap between UL Tx and DL Rx for dual operation extension. The indication may be part of the RRC capability signaling, for example, or may be included in the specification. In some embodiments, the UE indicates its capability for a preference gap between UL Tx and DL Rx per frequency band.

[0033] Scheduling of UL transmission or DL ​​reception may not meet the UE gap requirement. For example, the first UL Tx symbol(s) may not have a sufficient timing offset from the last DL Rx symbol received at the UE (i.e., when switching from DL Rx to UL Tx). As another example, the last UL Tx symbol(s) may not have a sufficient timing offset from the first DL Rx symbol (i.e., when switching from UL Tx to DL Rx). Thus, in some embodiments, when a scheduled UL transmission does not meet the UE gap requirement for half-duplex operation, the UE is allowed to drop the UL transmission. The UE may either drop the entire transmission or the UE may drop only the symbols that do not meet the UE gap requirement. In some embodiments, if a demodulation reference signal (DMRS) is dropped, the UE is allowed to shift the DMRS to the first valid symbol for UL transmission. To calculate the transport block (TB) size, the UE may calculate the number of resource elements (RE) based on the actual transmitted symbols.

[0034] In other embodiments, when the scheduled UL transmission or DL ​​reception does not meet the UE gap requirement for half-duplex operation, the UE is permitted to drop the DL reception. The UE may either drop the entire DL reception or the UE may drop only the symbols that do not meet the UE gap requirement. In some embodiments, if the DMRS is dropped, the UE expects the base station to shift the DMRS to the first valid symbol for DL ​​reception. To calculate the transport block (TB) size, the UE may calculate the number of resource elements (RE) based on the actual received symbols.

[0035] II. UE UL to DL Interference Mitigation

[0036] Even if a base station can cancel interference between transmission and reception in the same or adjacent frequency bands, the UE may not be able to achieve similar performance. As a result, the UE may still observe interference from the UL to the DL. For example, FIG. 3 illustrates interference in a cellular communication system according to some embodiments. In this example, a base station 302 may observe interference from transmitting a signal 304 to a first UE 310 (UE1) to a signal 308 received from a second UE 306 (UE2). Some advanced base stations may be able to reject or reduce such interference.

[0037] A first UE 306 may observe interference from a signal 312 transmitted by a second UE 310 on a signal 304 received from a base station 302. However, the first UE 306 may have a low ability to handle such interference (e.g., due to the complexity and / or cost of circuitry to reject or reduce the interference).

[0038] Thus, in one embodiment, the first UE 306 reports to the base station 302 a measurement of the signal 312 from the second UE 310. The reported measurement may be, for example, a reference signal received power (RSRP) of the signal 312 transmitted from the second UE 310 (i.e., measuring the received power of a sounding reference signal (SRS) or a channel state information reference signal (CSI-RS) transmitted by the second UE 310). Based on the measurement, the first UE 306 may estimate and report (to the base station 302) a path loss from the second UE 310. Additionally or in other embodiments, the first UE 306 may estimate and report (to the base station 302) a signal-to-interference-and-noise ratio (SINR) and / or a channel quality indicator (CQI) from the second UE 310.

[0039] In some embodiments, the base station 302 configures the second UE 310 to transmit an SRS for the first UE 306 to measure and report. For example, the configuration by the base station 302 of the SRS transmission by the second UE 310 may include one or more of a TA value, an SRS port, a sequence, a frequency domain resource configuration, a time domain resource configuration, and a power control configuration (as appropriate). The base station 302 may also configure the first UE 306 to measure and report SRS measurements. For example, the base station 302 may configure the first UE 306 with a time offset and measurement window for SRS timing acquisition, an SRS configuration (including, for example, a port, a sequence, a time domain resource allocation (TDRA), and a frequency domain resource allocation (FDRA)), and / or an SRS transmit power (e.g., if a path loss estimate is to be estimated). The first UE 306 reports the RSRP or path loss estimate to the base station 302. Reporting may be periodic, semi-persistent, or aperiodic. Different UEs may have SRS multiplexed on different ports, and the UE may report the RSRP or path loss corresponding to each port.

[0040] In some embodiments, when cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) is used for UL transmission, the base station 302 may configure the second UE 310 to transmit CSI-RS for measurement and reporting by the first UE 306. For example, the configuration by the base station 302 of the CSI-RS transmission by the second UE 310 may include one or more of a TA value, a CSI-RS port, a frequency domain resource configuration, a time domain resource configuration, and a power control configuration (as appropriate).

[0041] The base station 302 may also configure the first UE 306 to measure and report CSI-RS measurements. For example, the base station 302 may configure the first UE 306 with a time offset and measurement window for CSI-RS timing acquisition, a CSI-RS configuration (including, for example, port, sequence, TDRA, and FDRA), and / or a CSI-RS transmit power (e.g., if a path loss estimate is to be estimated). The first UE 306 reports the RSRP or path loss estimate to the base station 302. The reporting may be periodic, semi-persistent, or aperiodic. Different UEs may have CSI-RS multiplexed on different ports, and the UE may report the RSRP or path loss corresponding to each port.

[0042] In some embodiments, when the base station 302 schedules both the first UE 306 and the second UE 310 (e.g., simultaneously) and the first UE 306 receives a DL (i.e., a physical downlink shared channel (PDSCH)) from the base station 302 and the second UE 310 transmits a UL (i.e., a physical uplink shared channel (PUSCH)) to the base station 302, the base station 302 may also configure the first UE 306 to measure a PUSCH DMRS of the second UE 310. The DMRS of the PUSCH configuration of the second UE 310 may include at least one of a time offset and a measurement window. The DMRS configuration may include one or more of a port, a time domain resource allocation power, and a frequency domain resource allocation power. The first UE 306 reports further measurements to the base station 310 including the RSRP of the DMRS received from the second UE 310, the relative signal strength of the received signal from the base station 302 and the received interference from the second UE 310, and / or an estimated degradation of the CQI based on the received interference from the base station 302.

[0043] In some embodiments, the first UE 306 may report to the base station 302 a required minimum frequency separation between the intended DL reception and interference caused by a concurrent UL transmission of the second UE 310. For example, FIG. 4 illustrates a minimum frequency separation 402 according to some embodiments. In this example, the minimum frequency separation 402 is shown from the perspective of UE1 (e.g., the first UE 306 shown in FIG. 3). UE1 may determine the minimum frequency separation 402 based on avoiding or reducing interference between a base station DL transmission 404 to UE1 and a UE2 UL transmission 406 to the base station.

[0044] UE1 may report the minimum frequency separation 402 as the number of physical resource blocks (PRBs) between the base station DL transmission 404 to UE1 and the UE2 UL transmission 406 to the base station. In some embodiments, the minimum frequency separation may be a function of the bandwidth of the scheduled DL reception. For example, the bandwidth may be coarsely quantized (e.g., 40 PRBs, 80 PRBs, 120 PRBs, 160 PRBs, 200 PRBs, or 240 PRBs). In an embodiment, the minimum frequency separation 402 may be different for different bandwidths (e.g., typically smaller for wider bandwidths). In some embodiments, the minimum frequency separation 402 depends on the subcarrier spacing (SCS) used for DL ​​and UL scheduling. For example, UE1 may take into account the different SCS used for DL ​​and UL when determining the minimum frequency separation 402. In some embodiments, UE1 may report the minimum frequency separation 402 differently for different interfering UEs (i.e., from UE2 and from another UE (not shown)).

[0045] III. Broadcast Signal Configuration

[0046] Some embodiments provide duplex operation enhancements using broadcast signal configurations. Cellular networks typically broadcast system information (e.g., synchronization signal blocks (SSBs)) in a time-non-overlapping manner with random access channel (RACH) occasions, so that valid RACH occasions are available to UEs for initial access (e.g., in TDD half-duplex operation). For example, FIG. 5 is a timing diagram illustrating overlapping and non-overlapping SSBs, according to an embodiment. Specifically, FIG. 5 illustrates non-overlapping examples of SSBs 502 (depicted as SSB0, SSB1, SSB2, and SSB3) and overlapping examples in which RACH occasions 504 (depicted as RACH0, RACH1, RACH2, and RACH3) are configured at the same time that SSBs 502 are broadcast by the base station. In other words, the base station can be configured to both SSB transmissions and corresponding RACH occasions occur simultaneously. The base station can be configured to cancel or reduce interference from transmitting SSBs and receiving UL signals from the UEs at the same time during the RACH occasions.

[0047] However, as explained above, the UE may not have the same interference cancellation or capability reduction as the base station. Thus, in some embodiments, when system information (e.g., master information block (MIB), remaining system information (RMSI), and / or other system information (SI)) monitoring at the UE side conflicts with a configured UE RACH transmission occasion, the UE may take different actions depending on whether the UE is in an idle RRC state, an inactive RRC state, or a connected RRC state. When the UE is in an idle RRC state or an inactive RRC state, when system information monitoring conflicts with a RACH occasion, the UE may be configured to decide by itself (i.e., without further instructions from the base station) whether to monitor the system information or perform a RACH transmission. When the UE is in a connected RRC state, when system information monitoring conflicts with a RACH occasion, the base station may configure the UE to monitor the system information or perform a RACH transmission.

[0048] IV.UE RF Capability Instructions

[0049] In some embodiments, for each frequency band, the UE may indicate to the base station whether it can operate in extended duplex operation. In other words, the UE may indicate whether it can be scheduled with DL and / or UL operation simultaneously with another UE or its own UL and / or DL ​​operation. In the case of unpaired spectrum (i.e., TDD bands), the UE may report capabilities per frequency band. In the case of paired spectrum (i.e., FDD bands), the UE may report capabilities separately for DL ​​and UL frequency bands.

[0050] In some embodiments, for each frequency band in intra-band carrier aggregation (CA) or dual connectivity (DC), the UE is configured to signal whether it supports mixed duplexing directions. If the UE does not support mixed duplexing directions, for intra-band CA and DC, the base station can only configure the UE with the same duplexing direction for all component carriers (CCs) in the same band (i.e., either all DL or all UL).

[0051] In some embodiments, for each frequency band in intra-band CA or DC, the UE is configured to signal a minimum duplexing distance D (i.e., frequency separation) for mixed duplexing directions. For example, for a first CC frequency F1 having a UL center frequency of F_ul with bandwidth (BW) BW_ul, and a second CC frequency F2 having a DL center frequency of F_dl with BW BW_dl, the UE can be scheduled for both DL on F2 and UL on F1 only if min(|F_ul±(BW_ul / 2)-F_dl±(BW_dl / 2)|)≧D.

[0052] 6 is a flow chart of a method 600 for a UE according to one embodiment. At block 602, the method 600 includes determining a preference gap between at least one of switching from DL Rx at the UE to UL Tx from the UE and switching from UL Tx from the UE to DL Rx at the UE based on a propagation delay between the base station and the UE. At block 604, the method 600 includes transmitting an indication of the preference gap to the base station for dual operation extension.

[0053] In some embodiments of the method 600, transmitting the indication comprises including the indication in radio resource control (RRC) capability signaling from the UE to the base station. The RRC capability signaling may communicate the indication of the preference gap per frequency band.

[0054] In some embodiments of the method 600, the preference gap is further based on a timing advance (TA).

[0055] Some embodiments of the method 600 further include dropping at least a portion of the UL Tx or DL ​​Rx in response to determining that the configured grant for the UL Tx does not meet the UE gap requirement.

[0056] In some embodiments, the dropping includes the UE skipping transmission of all UL symbols of the configured UL grant. In another embodiment, the dropping includes the UE skipping transmission of only one or more symbols of the configured UL grant that do not meet the UE gap requirement. When the one or more symbols include a demodulation reference signal (DMRS), the UE shifts the DMRS to the first valid symbol of the configured UL grant. The method 600 may include calculating a number of resource elements (REs) based on the actual transmitted symbols to calculate a transport block (TB) size.

[0057] In another embodiment, the dropping includes the UE skipping reception of all DL symbols in DL Rx.

[0058] In another embodiment, the dropping includes the UE skipping reception of only one or more symbols of DL Rx that do not meet the UE gap requirement. When the one or more symbols include a demodulation reference signal (DMRS), the UE expects the base station to shift the DMRS to the first valid symbol of DL Rx. The method 600 may further include calculating a number of resource elements (RE) based on the actual received symbols to calculate a transport block (TB) size.

[0059] 7 is a flow chart of a method 700 for a first UE for UL to DL interference mitigation according to one embodiment. At block 702, the method 700 includes measuring, at the first UE, a signal from a second UE. At block 704, the method 700 includes determining, at the first UE, one or more characteristics of the signal from the second UE. At block 706, the method 700 includes transmitting, from the first UE to a base station, an indication of the one or more characteristics of the signal from the second UE.

[0060] In some embodiments of the method 700, the one or more characteristics are selected from the group consisting of an estimated path loss from the second UE, an estimated signal-to-interference-and-noise ratio (SINR), and an estimated channel quality indicator (CQI).

[0061] In some embodiments of the method 700, the signal from the second UE includes a sounding reference signal (SRS) or a channel state information reference signal (CSI-RS), and the one or more characteristics include a reference signal received power (RSRP) or an estimated path loss from the second UE.

[0062] When the signal includes the SRS, the first UE is configured by the base station to measure and report SRS measurements including one or more of: a time offset and measurement window for SRS timing acquisition; an SRS configuration including a port, a sequence, a time domain resource allocation (TDRA), and a frequency domain resource allocation (FDRA); and, if necessary, an SRS transmit power for determining an estimated path loss. In some embodiments, the method 700 further includes reporting the RSRP or the estimated path loss from the first UE to the base station, the reporting being periodic, semi-persistent, or aperiodic. In some embodiments, the SRS is multiplexed on different ports, and the method 700 further includes reporting the RSRP or the estimated path loss corresponding to each port from the first UE to the base station.

[0063] When the signal includes CSI-RS, the first UE is configured by the base station to measure and report CSI-RS measurements including one or more of: a time offset and measurement window for CSI-RS timing acquisition; a CSI-RS configuration including a port, a sequence, a time domain resource allocation (TDRA), and a frequency domain resource allocation (FDRA); and, if necessary, a CSI-RS transmit power for determining an estimated path loss. In some embodiments, the method 700 further includes reporting the RSRP or the estimated path loss from the first UE to the base station, the reporting being periodic, semi-persistent, or aperiodic. In some embodiments, the CSI-RS is multiplexed on different ports, and the method 700 further includes reporting the RSRP or the estimated path loss corresponding to each port from the first UE to the base station.

[0064] In some embodiments, the first UE is configured by the base station to measure a Physical Uplink Shared Channel (PUSCH) Demodulation Reference Signal (DMRS) from the second UE, and the method 700 further includes reporting from the first UE to the base station one or more measurements selected from a group including: a Reference Signal Received Power (RSRP) of the DMRS received from the second UE, a relative signal strength of the received signal from the base station and the interference received from the second UE, and an estimated degradation of a Channel Quality Indicator (CQI) based on the interference received from the second UE.

[0065] In some embodiments, the method 700 further includes reporting from the first UE to the base station a required minimum frequency separation between the scheduled DL reception at the first UE and interference due to the UL transmission from the second UE. The required minimum frequency separation may be reported as a number of physical resource blocks. The required minimum frequency separation may include a function of the bandwidth of the scheduled DL reception, and the required minimum frequency separation may be different for different bandwidths. The required minimum frequency separation may be based on a subcarrier spacing (SCS) used for at least one of the DL scheduling and the UL scheduling.

[0066] 8 is a flow chart of a method 800 for a UE according to one embodiment. In block 802, the method 800 includes determining, at the UE, that system information broadcast from a base station overlaps with a configured UE RACH transmission occasion. In block 804, when the UE is in an idle RRC state or an inactive RRC state, the method 800 includes selecting, at the UE, whether to monitor the system information or perform a RACH transmission without further input from the base station. In block 806, when the UE is in a connected RRC state, the method 800 includes selecting, based on the input from the base station, whether to monitor the system information or perform a RACH transmission.

[0067] In some embodiments, the method 800 further includes reporting from the UE to the base station whether the UE can be configured to operate in extended duplex operation, where in the case of unpaired spectrum the reporting is per frequency band and in the case of paired spectrum the reporting is separate for downlink (DL) and uplink (UL) frequency bands.

[0068] In some embodiments, the method 800 further includes reporting whether the UE supports mixed duplexing directions for each frequency band in intra-band carrier aggregation (CA) or dual connectivity (DC). When the UE does not support mixed duplexing directions, for intra-band CA and DC, the UE is configured with only the same duplexing directions for component carriers (CCs) in the same frequency band.

[0069] In some embodiments, the method 800 further includes signaling a minimum duplexing distance for mixed duplexing directions for each frequency band in intra-band carrier aggregation (CA) or dual connectivity (DC) from the UE to the base station.

[0070] 9 illustrates an example architecture of a wireless communication system 900 according to an embodiment disclosed herein. The following description is provided for the example wireless communication system 900 operating in conjunction with an LTE system standard and / or a 5G or NR system standard, as provided by the 3GPP technical specifications.

[0071] 9, the wireless communication system 900 includes a UE 902 and a UE 904 (although any number of UEs may be used). In this example, the UEs 902 and 904 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may comprise any mobile or non-mobile computing devices configured for wireless communication.

[0072] UE 902 and UE 904 may be configured to be communicatively coupled to RAN 906. In an embodiment, RAN 906 may be an NG-RAN, an E-UTRAN, etc. UE 902 and UE 904 utilize connections (or channels) with RAN 906 (shown as connection 908 and connection 910, respectively), each of which comprises a physical communication interface. RAN 906 may include one or more base stations, such as base station 912 and base station 914, that facilitate connection 908 and connection 910.

[0073] In this example, connection 908 and connection 910 are air interfaces for enabling such communication coupling and may correspond to the RAT(s) used by RAN 906, such as, for example, LTE and / or NR.

[0074] In some embodiments, the UE 902 and UE 904 may also directly exchange communication data via the sidelink interface 916. The UE 904 is configured to access an access point (shown as AP 918) via a connection 920 as shown. As an example, the connection 920 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, and the AP 918 may include a Wi-Fi router. In this example, the AP 918 may be connected to other networks (e.g., the Internet) without passing through the CN 924.

[0075] In an embodiment, UE 902 and UE 904 may be configured to communicate with each other or base station 912 and / or base station 914 using Orthogonal Frequency Division Multiplexing (OFDM) communication signals over multi-carrier communication channels according to various communication technologies, such as, but not limited to, an Orthogonal Frequency Division Multiple Access (OFDMA) communication technology (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink communications), and the scope of the embodiments is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0076] In some embodiments, all or a portion of the base station 912 or the base station 914 may be implemented as one or more software entities executing on a server computer as part of a virtual network. In addition, or in other embodiments, the base station 912 or the base station 914 may be configured to communicate with each other via the interface 922. In an embodiment where the wireless communication system 900 is an LTE system (e.g., where the CN 924 is an EPC), the interface 922 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) that connect to the EPC and / or between two eNBs that connect to the EPC. In an embodiment where the wireless communication system 900 is an NR system (e.g., where the CN 924 is a 5GC), the interface 922 may be an Xn interface. The Xn interface may be defined between two or more base stations (e.g., two or more gNBs, etc.) that connect to 5GC, between the base station 912 (e.g., a gNB) and an eNB that connect to 5GC, and / or between two eNBs (e.g., the CN 924) that connect to 5GC.

[0077] The RAN 906 is shown communicatively coupled to the CN 924. The CN 924 may comprise one or more network elements 926 configured to provide various data and telecommunication services to customers / subscribers (e.g., users of UEs 902 and 904) connected to the CN 924 via the RAN 906. The components of the CN 924 may be implemented in one physical device or separate physical devices, including components for reading and executing instructions from a machine-readable medium or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0078] In an embodiment, the CN 924 may be an EPC, and the RAN 906 may be connected to the CN 924 via an S1 interface 928. In an embodiment, the S1 interface 928 may be divided into two parts: an S1 user plane (S1-U) interface that carries traffic data between the base station 912 or the base station 914 and a serving gateway (S-GW), and an S1-MME interface that is a signaling interface between the base station 912 or the base station 914 and a mobility management entity (MME).

[0079] In an embodiment, the CN 924 may be a 5GC, and the RAN 906 may be connected to the CN 924 via an NG interface 928. In an embodiment, the NG interface 928 may be divided into two parts: an NG-User Plane (NG-U) interface, which carries traffic data between the base station 912 or 914 and a User Plane Function (UPF), and an S1-Control Plane (NG-C) interface, which is a signaling interface between the base station 912 or 914 and an Access and Mobility Management Function (AMF).

[0080] In general, the application server 930 may be an element that provides applications that use Internet Protocol (IP) bearer resources (e.g., packet-switched data services) with the CN 924. The application server 930 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UEs 902 and 904 via the CN 924. The application server 930 may communicate with the CN 924 via an IP communication interface 932.

[0081] 10 illustrates a system 1000 for performing signaling 1034 between a wireless device 1002 and a network device 1018 according to embodiments disclosed herein. The system 1000 may be part of a wireless communication system as described herein. The wireless device 1002 may be, for example, a UE of the wireless communication system. The network device 1018 may be, for example, a base station (e.g., eNB or gNB) of the wireless communication system.

[0082] The wireless device 1002 may include one or more processor(s) 1004. The processor(s) 1004 may execute instructions such that various operations of the wireless device 1002 are performed, as described herein. The processor(s) 1004 may include, for example, one or more baseband processors implemented using a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0083] The wireless device 1002 may include a memory 1006. The memory 1006 may be a non-transitory computer-readable storage medium that stores instructions 1008 (which may include, for example, instructions being executed by the processor(s) 1004). The instructions 1008 may also be referred to as program code or computer programs. The memory 1006 may also store data used by the processor(s) 1004 and results calculated by the processor 1004.

[0084] The wireless device 1002 may include one or more transceiver(s) 1010, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses antenna(s) 1012 of the wireless device 1002 to facilitate signaling (e.g., signaling 1034) to and / or from the wireless device 1002 with other devices (e.g., network device 1018) according to a corresponding RAT.

[0085] The wireless device 1002 may include one or more antenna(s) 1012 (e.g., one, two, four, or more). In an embodiment with multiple antenna(s) 1012, the wireless device 1002 may exploit the spatial diversity of such multiple antenna(s) 1012 to transmit and / or receive multiple different data streams over the same time and frequency resources. This behavior may be referred to, for example, as multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting and receiving devices that enable this aspect). MIMO transmission by the wireless device 1002 may be achieved in accordance with precoding (or digital beamforming) applied at the wireless device 1002 that multiplexes data streams across the antenna(s) 1012 in accordance with known or assumed channel characteristics such that each data stream is received at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream) with an appropriate signal strength relative to the other streams. Some embodiments may use Single-User MIMO (SU-MIMO) methods (wherein all data streams are directed to a single receiver) and / or Multi-User MIMO (MU-MIMO) methods (wherein individual data streams may be directed to individual (different) receivers in different locations in the spatial domain).

[0086] In some embodiments having multiple antennas, the wireless device 1002 may implement analog beamforming techniques whereby the phases of the signals sent by the antenna(s) 1012 are adjusted relatively to one another so that the (joint) transmission of the antenna(s) 1012 may be directed (this may be referred to as beam steering).

[0087] The wireless device 1002 may include one or more interface(s) 1014. The interface(s) 1014 may be used to provide input to or output from the wireless device 1002. For example, a wireless device 1002 that is a UE may include interface(s) 1014 such as a microphone, speaker, touch screen, buttons, etc. to enable a user of the UE to provide input and / or output to the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 1010 / antenna(s) 1012 already described) to enable communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi, Bluetooth, etc.).

[0088] The wireless device 1002 may include a dual operation module 1016. The dual operation module 1016 may be implemented via hardware, software, or a combination thereof. For example, the dual operation module 1016 may be implemented as a processor, circuitry, and / or instructions 1008 stored in memory 1006 and executed by the processor(s) 1004. In some examples, the dual operation module 1016 may be integrated within the processor(s) 1004 and / or transceiver(s) 1010. For example, the dual operation module 1016 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor(s) 1004 or transceiver(s) 1010.

[0089] Dual operation module 1016 may be used in various embodiments of the present disclosure, such as the embodiments of FIGS.

[0090] The network device 1018 may include one or more processor(s) 1020. The processor(s) 1020 may execute instructions such that various operations of the network device 1018 are performed, as described herein. The processor(s) 1020 may include, for example, one or more baseband processors implemented using a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0091] The network device 1018 may include a memory 1022. The memory 1022 may be a non-transitory computer-readable storage medium that stores instructions 1024 (which may include, for example, instructions being executed by the processor(s) 1020). The instructions 1024 may also be referred to as program code or computer programs. The memory 1022 may also store data used by the processor(s) 1020 and results calculated by the processor 1020.

[0092] The network device 1018 may include one or more transceiver(s) 1026, which may include RF transmitter and / or receiver circuitry that uses antenna(s) 1028 of the network device 1018 to facilitate signaling (e.g., signaling 1034) to and / or from the network device 1018 with other devices (e.g., the wireless device 1002) in accordance with a corresponding RAT.

[0093] The network device 1018 may include one or more antenna(s) 1028 (e.g., one, two, four, or more). In embodiments having multiple antenna(s) 1028, the network device 1018 may perform MIMO, digital beamforming, analog beamforming, beamsteering, etc., as described.

[0094] The network device 1018 may include one or more interface(s) 1030. The interface(s) 1030 may be used to provide input to or output from the network device 1018. For example, a network device 1018 that is a base station may include interface(s) 1030 consisting of a transmitter, receiver, and other circuitry (e.g., other than the transceiver(s) 1026 / antenna(s) 1028 already described) that allows the base station to communicate with other equipment in the core network and / or to communicate with external networks, computers, databases, etc., for purposes of operation, management, and maintenance of the base station or other equipment operatively connected thereto.

[0095] The network device 1018 may include a dual operation module 1032. The dual operation module 1032 may be implemented via hardware, software, or a combination thereof. For example, the dual operation module 1032 may be implemented as a processor, circuitry, and / or instructions 1024 stored in memory 1022 and executed by the processor(s) 1020. In some examples, the dual operation module 1032 may be integrated within the processor(s) 1020 and / or transceiver(s) 1026. For example, the dual operation module 1032 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor(s) 1020 or transceiver(s) 1026.

[0096] The dual operation module 1032 may be used for various aspects of the disclosure.

[0097]

[0023] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the methods for a UE described herein, which may be, for example, an apparatus of a UE (such as a wireless device 1002, which is a UE described herein).

[0098] Embodiments contemplated herein may include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the methods for a UE described herein. The non-transitory computer-readable media may be, for example, a memory of the UE (such as memory 1006 of a wireless device 1002 that is a UE, as described herein).

[0099] Embodiments contemplated herein include an apparatus having logic, modules, or circuitry for performing one or more elements of the methods for a UE described herein, which may be, for example, a UE apparatus (such as wireless device 1002, which is a UE described herein).

[0100] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of a method for a UE described herein. The apparatus may be, for example, an apparatus of a UE (such as a wireless device 1002 that is a UE described herein).

[0101] Embodiments contemplated herein include signals described in or associated with one or more elements of the methods for a UE described herein.

[0102] Embodiments contemplated herein include computer programs or computer program products that include instructions, where execution of the program by a processor causes the processor to perform one or more elements of a method for a UE as described herein. The processor may be a processor of a UE (such as processor(s) 1004 of a wireless device 1002 that is a UE, as described herein). These instructions may be located, for example, within the processor and / or on a memory of the UE (such as memory 1006 of a wireless device 1002 that is a UE, as described herein).

[0103]

[0023] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the methods for a base station described herein, which may be, for example, a base station apparatus (such as the base station network device 1018 described herein).

[0104] Embodiments contemplated herein may include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the methods for a base station described herein. The non-transitory computer-readable medium may be, for example, a memory of a base station (e.g., memory 1022 of a network device 1018 that is a base station as described herein).

[0105] Embodiments contemplated herein include an apparatus having logic, modules, or circuitry for performing one or more elements of the methods for a base station described herein, which may be, for example, a base station apparatus (such as the base station network device 1018 described herein).

[0106]

[0023] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of a method for a base station as described herein. The apparatus may be, for example, a base station apparatus (such as a network device 1018 that is a base station as described herein).

[0107] Embodiments contemplated herein include signals described in or associated with one or more elements of the method for a base station described herein.

[0108] Embodiments contemplated herein include a computer program or computer program product including instructions, where execution of the program by a processing element causes the processing element to perform one or more elements of a method for a base station as described herein. The processor may be a processor of the base station (e.g., processor(s) 1020 of a network device 1018 that is a base station, as described herein). These instructions may be located, for example, within the processor and / or on a memory of the base station (e.g., memory 1022 of a network device 1018 that is a base station, as described herein).

[0109] For one or more embodiments, at least one of the components depicted in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described above in connection with one or more of the figures herein may be configured to operate according to one or more of the examples described herein. As another example, circuitry associated with a UE, a base station, a network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein.

[0110] Any of the above embodiments can be combined with any other embodiment (or combination of embodiments) unless otherwise stated. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0111] The embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that contain specific logic for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0112] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, split into multiple systems, or otherwise split or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in another embodiment. It is appreciated that parameters, attributes, aspects, etc. are described in one or more embodiments for clarity only, and that parameters, attributes, aspects, etc. may be combined or substituted with parameters, attributes, etc. of another embodiment, unless specifically disclaimed herein.

[0113] It is understood that use of personally identifiable information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or governmental requirements for maintaining user privacy. In particular, personal information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized uses should be clearly indicated to users.

[0114] Although the foregoing has been described in some detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. Thus, the present embodiments should be considered as illustrative and not restrictive, and the description should not be limited to the details given herein, but may be modified within the scope of the appended claims and their equivalents.

Claims

1. 1. A method for a user equipment (UE), the method comprising: Based on a propagation delay between a base station and the UE, switching from downlink (DL) reception (Rx) at the UE to uplink (UL) transmission (Tx) from the UE; determining a preference gap between at least one of: switching from the UL Tx from the UE to the DL Rx at the UE; transmitting an indication of the preference gap to the base station for dual operation extension; A method comprising:

2. 2. The method of claim 1, wherein transmitting the indication of the preference gap comprises including the indication of the preference gap in radio resource control (RRC) capability signaling from the UE to the base station.

3. The method of claim 2 , wherein the RRC capability signaling communicates the indication of the preference gap per frequency band.

4. The method of claim 1 , wherein the preference gap is further based on a timing advance (TA).

5. 10. The method of claim 1, further comprising: dropping at least a portion of the UL Tx or the DL Rx in response to determining that a configured grant for the UL Tx does not meet a UE gap requirement.

6. The method of claim 5 , wherein the dropping comprises the UE skipping transmission of all UL symbols of the configured UL grant.

7. The method of claim 5 , wherein the dropping comprises the UE skipping transmission of only one or more symbols of the configured UL grant that do not meet the UE gap requirement.

8. 8. The method of claim 7, wherein when the one or more symbols include a demodulation reference signal (DMRS), the UE shifts the DMRS to a first valid symbol of the configured UL grant.

9. 8. The method of claim 7, further comprising: calculating a number of resource elements (REs) based on actual transmitted symbols to calculate a transport block (TB) size.

10. The method of claim 5 , wherein the dropping includes the UE skipping reception of all DL symbols in the DL Rx.

11. The method of claim 5 , wherein the dropping comprises the UE skipping reception of only one or more symbols of the DL Rx that do not meet the UE gap requirement.

12. 12. The method of claim 11, wherein when the one or more symbols include a demodulation reference signal (DMRS), the UE expects the base station to shift the DMRS to a first valid symbol of DL Rx.

13. 12. The method of claim 11, further comprising: calculating a number of resource elements (REs) based on actual received symbols to calculate a transport block (TB) size.

14. 1. A method for a first user equipment (UE) for uplink (UL) to downlink (DL) interference mitigation, the method comprising: measuring, at the first UE, a signal from a second UE; determining, at the first UE, one or more characteristics of the signal from the second UE; transmitting, from the first UE to a base station, an indication of the one or more characteristics of the signal from the second UE; A method comprising:

15. 15. The method of claim 14, wherein the one or more characteristics are selected from the group consisting of an estimated path loss from the second UE, an estimated signal-to-interference-and-noise ratio (SINR), and an estimated channel quality indicator (CQI).

16. 15. The method of claim 14, wherein the signal from the second UE comprises a Sounding Reference Signal (SRS) or a Channel State Information Reference Signal (CSI-RS), and the one or more characteristics comprise a Reference Signal Received Power (RSRP) or an estimated path loss from the second UE.

17. When the signal includes the SRS, the first UE is notified by the base station of time offset and measurement window for SRS timing acquisition; an SRS configuration including a port, a sequence, a time domain resource allocation (TDRA), and a frequency domain resource allocation (FDRA); and, if necessary, an SRS transmit power for determining the estimated path loss.

18. 20. The method of claim 17, further comprising reporting the RSRP or the estimated path loss from the first UE to the base station, the reporting being periodic, semi-persistent, or aperiodic.

19. 18. The method of claim 17, wherein the SRS is multiplexed on different ports, the method further comprising: reporting the RSRP or the estimated path loss corresponding to each port from the first UE to the base station.

20. When the signal includes the CSI-RS, the first UE is time offsets and measurement windows for CSI-RS timing acquisition; a CSI-RS configuration including a port, a sequence, a time domain resource allocation (TDRA), and a frequency domain resource allocation (FDRA); and, if necessary, a CSI-RS transmit power for determining the estimated path loss.

21. 21. The method of claim 20, further comprising reporting the RSRP or the estimated path loss from the first UE to the base station, the reporting being periodic, semi-persistent, or aperiodic.

22. The method of claim 20, wherein the CSI-RS is multiplexed on different ports, the method further comprising: reporting the RSRP or the estimated path loss corresponding to each port from the first UE to the base station.

23. The first UE is configured by the base station to measure a Physical Uplink Shared Channel (PUSCH) Demodulation Reference Signal (DMRS) from the second UE, and the method includes transmitting, from the first UE to the base station: A reference signal received power (RSRP) of the DMRS received from the second UE; and the relative signal strength of the received signal from the base station and the interference received from the second UE; and an estimated degradation of a channel quality indicator (CQI) based on the interference received from the second UE.

24. 15. The method of claim 14, further comprising reporting from the first UE to the base station a required minimum frequency separation between a scheduled DL reception at the first UE and interference due to a UL transmission from the second UE.

25. 25. The method of claim 24, wherein the required minimum frequency separation is reported as a number of physical resource blocks.

26. 25. The method of claim 24, wherein the required minimum frequency separation comprises a function of a bandwidth of the scheduled DL reception, the required minimum frequency separation being different for different bandwidths.

27. 25. The method of claim 24, wherein the required minimum frequency separation is based on a subcarrier spacing (SCS) used for at least one of DL scheduling and UL scheduling.

28. 1. A method for a user equipment (UE), the method comprising: determining, at the UE, that system information broadcast from a base station overlaps with a configured UE Random Access Channel (RACH) transmission occasion; selecting, at the UE, whether to monitor the system information or to perform a RACH transmission without further input from the base station when the UE is in an idle radio resource configuration (RRC) state or an inactive RRC state; selecting, when the UE is in a connected RRC state, whether to monitor the system information or to perform the RACH transmission based on an input from the base station; A method comprising:

29. 30. The method of claim 28, further comprising reporting from the UE to the base station whether the UE can be configured to operate in enhanced duplex operation, wherein in case of unpaired spectrum, the reporting is per frequency band, and in case of paired spectrum, the reporting is separate for downlink (DL) and uplink (UL) frequency bands.

30. 30. The method of claim 28, further comprising reporting whether the UE supports mixed duplexing directions for each frequency band in intra-band carrier aggregation (CA) or dual connectivity (DC).

31. 31. The method of claim 30, wherein, for intra-band CA and DC, when the UE does not support mixed duplexing directions, the UE is configured with only the same duplexing direction for component carriers (CCs) in the same frequency band.

32. 30. The method of claim 28, further comprising signaling a minimum duplexing distance for mixed duplexing directions for each frequency band in intra-band carrier aggregation (CA) or dual connectivity (DC) from the UE to the base station.

33. A computer program product comprising instructions which, when executed by a processor, perform the steps of the method of any one of claims 1 to 32.

34. Apparatus comprising means for carrying out the steps of the method according to any one of claims 1 to 32.

Images