Operation in uplink mtrp tdm

Abstract

Method comprising: providing, from a terminal to a network, a time information informing on a relevant time, wherein the relevant time is based on a switching time required by the terminal to switch between an earlier transmission and a later transmission subsequent to the earlier transmission, wherein the earlier transmission is one of a first transmission of a first slot comprising a predefined number of symbols to a first transmission reception point using a first beamformer and a second transmission of a second slot comprising the predefined number of symbols to a second transmission reception point using a second beamformer different from the first beamformer; and the later transmission is the other one of the first transmission and the second transmission.

Description

[0001] Operation in uplink MTRP TDM

[0002] Technical Field

[0003] The present disclosure relates to operation in uplink MTRP TDM, in particular for UEs not supporting STxMP.

[0004] Abbreviations

[0005] 3GPP 3rdGeneration Partnership Project

[0006] 5G / 6G / 7G 5th / 6th / 7thGeneration

[0007] CP Cyclic prefix

[0008] DCI Downlink control information

[0009] DL Downlink

[0010] FDM Frequency division multiplex

[0011] FR Frequency range

[0012] HARQ Hybrid Automatic Repeat Request

[0013] ICI Inter-carrier interference

[0014] ISI Inter-symbol interference

[0015] MAC-CE Medium access control - control element

[0016] MIMO Multiple-input multiple-output

[0017] MRTD Maximum receive timing difference

[0018] MTTD Maximum transmit timing difference

[0019] NCJT Non coherent joint transmission

[0020] NR New radio

[0021] NW Network

[0022] OFDM Orthogonal frequency division multiplexing

[0023] PDCCH Physical downlink control channel

[0024] PDSCH Physical downlink shared channel

[0025] PRB Physical resource block

[0026] PLICCH Physical uplink control channel

[0027] PLISCH Physical uplink shared channel

[0028] RF Radio frequency

[0029] RRC Radio resource control RTD Receive timing difference

[0030] SCS Subcarrier spacing

[0031] SDM Spatial division multiplex

[0032] STxMP Simultaneous multi-panel transmission

[0033] TA Timing advance

[0034] TAG Timing advance command

[0035] TCI Transmission configuration indicator

[0036] TDM Time division multiplex

[0037] TRP Transmission and reception point

[0038] UCI Uplink control information

[0039] UE User equipment

[0040] UL Uplink

[0041] Background

[0042] Downlink Multi-TRP schemes transmit information from spatially separated TRPs (spatial diversity). For downlink, several multi-TRP schemes (single DCI and multi-DCI (i.e. , an own DCI for each TRP and coordination between the TRPs via the (non-ideal) backhaul) are standardized by 3GPP, such as spatial division multiplex (SDM), non-coherent joint transmission (NCJT), time division multiplex (TDM), and frequency division multiplex (FDM). Fig. 1 shows an example of Multi-DCI multi-TRP NCJT scheme for PDSCH. DCI may comprise scheduling information for the UE. For uplink (i.e. transmission from the UE to multiple spatially separated TRPs), up to release 17, only TDM schemes have been defined.

[0043] The timing advance values to the different TRPs may be different from each other if there are different propagation delays between the UE and the TRPs. Timing advance (TA) is used to control the uplink transmission timing of individual UEs. It helps to ensure that uplink transmissions from all UEs are synchronized when received by the base station.

[0044] 3GPP agreed that for both intra-cell and inter-cell multi-TRP, the MRTD between multiple TRPs can be assumed within a CP length as baseline. With OFDM modulation, the transmitter (UE or gNB) copies a portion (some samples) of each OFDM symbol’s end to the beginning of the same symbol and transmits the obtained signal. The additional portion, which is copied to the beginning of the symbol, is called the cyclic prefix. I.e., the information contained in the cyclic prefix preceding the symbol is redundant to the information contained at the end of the symbol. A slot comprises plural symbols. For example, according to several 3GPP specifications, a slot may comprise 14 symbols. Each symbol comprises several samples.

[0045] Summary

[0046] It is an object to improve the prior art.

[0047] According to a first aspect, there is provided an apparatus comprising: one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: providing, from a terminal to a network, a time information informing on a relevant time, wherein the relevant time is based on a switching time required by the terminal to switch between an earlier transmission and a later transmission subsequent to the earlier transmission, wherein the earlier transmission is one of a first transmission of a first slot comprising a predefined number of symbols to a first transmission reception point using a first beamformer and a second transmission of a second slot comprising the predefined number of symbols to a second transmission reception point using a second beamformer different from the first beamformer; and the later transmission is the other one of the first transmission and the second transmission.

[0048] The instructions, when executed by the one or more processors, may further cause the apparatus to perform measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; providing the receive time difference to the network, wherein the relevant time is the switching time.

[0049] The instructions, when executed by the one or more processors, may further cause the apparatus to perform measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; calculating the relevant time based on the switching time and the receive time difference.

[0050] The instructions, when executed by the one or more processors, may further cause the apparatus to perform checking whether the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption: providing, to the network, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption; providing, to the network, an indication indicating at least one of:

[0051] - which one of the first transmission and the second transmission is the earlier transmission under the assumption; or

[0052] - which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a sum of the switching time and the receive time difference.

[0053] The instructions, when executed by the one or more processors, may further cause the apparatus to perform checking whether there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption: providing, to the network, an indication that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption; providing, to the network, an indication indicating at least one of: - which one of the first transmission and the second transmission is the earlier transmission under the assumption; or

[0054] - which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a difference between the switching time and the receive time difference.

[0055] The instructions, when executed by the one or more processors, may further cause the apparatus to perform determining a gap-causing transmission among the first transmission and the second transmission such that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that the gap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the gap-causing transmission; the calculating the relevant time such that the relevant time is a difference between the switching time and the receive time difference.

[0056] The instructions, when executed by the one or more processors, may further cause the apparatus to perform determining an overlap-causing transmission among the first transmission and the second transmission such that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that the overlap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the overlap-causing transmission; the calculating the relevant time such that the relevant time is a sum of the switching time and the receive time difference.

[0057] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving a scheduling information from the network in response to providing the time information; performing the first transmission and the second transmission according to the scheduling information; wherein the scheduling information determines which one of the first transmission and the second transmission is the earlier transmission.

[0058] The instructions, when executed by the one or more processors, may further cause the apparatus to perform calculating a number of samples the earlier transmission overlaps the later transmission; dropping the number of samples at the beginning of the first symbol at the beginning of the later transmission.

[0059] The instructions, when executed by the one or more processors, may further cause the apparatus to perform monitoring whether a dropping indication is received from the network along with the scheduling information; inhibiting the dropping the number of samples in response to monitoring that the dropping indication is not received.

[0060] According to a second aspect, there is provided an apparatus comprising: one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: receiving, from a terminal, a time information informing on a relevant time; calculating an omission number based on the relevant time, a first timing advance value, and a second timing advance value; scheduling a first transmission of a first number of symbols in a first slot from the terminal to a first transmission reception point and a second transmission of a second number of symbols in a second slot from the terminal to a second transmission reception point; wherein, a later transmission among the first transmission and the second transmission is subsequent to an earlier transmission among the first transmission and the second transmission, each of a duration of the first slot and a duration of the second slot is equal to a duration of a predefined number of subsequent symbols; the number of symbols scheduled for transmission in the slot of the earlier transmission is a first symbol count number being equal to the predefined number minus a first omission portion number; the number of symbols scheduled for transmission in the slot of the later transmission is a second symbol count number being equal to the predefined number reduced by a second omission portion number; the first omission portion number is 0 or larger than 0; the second omission portion number is 0 or larger than 0; a sum of the first omission portion number and the second omission portion number is equal to the omission number; in the slot of the earlier transmission the first symbol count number of symbols are scheduled continuously at the beginning of the slot of the earlier transmission; in the slot of the later transmission the second symbol count number of symbols are scheduled continuously at the end of the slot of the later transmission; the first timing advance value indicates a timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the earlier transmission is directed to; and the second timing advance value indicates the timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the later transmission is directed to.

[0061] The instructions, when executed by the one or more processors, may further cause the apparatus to perform the calculating the omission number additionally based on a receive time difference, and the receive time difference is predefined.

[0062] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving a receive time difference from the terminal, the calculating the omission number additionally based on the receive time difference, wherein, according to the time information, the relevant time is a switching time required by the terminal to switch between a first beamformer to be used for the earlier transmission and a second beamformer to be used for the later transmission.

[0063] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving, from the terminal, an assumption indication indicating at least one of: that one of the first transmission and the second transmission is assumed to be the earlier transmission; or

[0064] - that the other one of the first transmission and the second transmission is assumed to be the later transmission; the scheduling of the first transmission and the second transmission in line with the assumption indication; calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as ceil(Trel+TA1- TA2), Trel indicates the relevant time, TA1 indicates the first timing advance value, and TA2 indicates the second timing advance value.

[0065] The instructions, when executed by the one or more processors, may further cause the apparatus to perform configuring the terminal such that the assumption indication indicates the at least one of: that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or

[0066] - that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is an overlap of the assumed earlier transmission and the assumed later transmission.

[0067] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving, from the terminal, an indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission; in response to receiving, from the terminal, the indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission: inhibiting the calculating the conservative estimation as ceil(Trel+TA1-TA2); and calculating the conservative estimation as max (0, ceil(Trel-TA1+TA2).

[0068] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving, from the terminal, an assumption indication indicating at least one of - that one of the first transmission and the second transmission is assumed to be the earlier transmission, or

[0069] - that the other one of the first transmission and the second transmission is assumed to be the later transmission; the scheduling of the first transmission and the second transmission in line with the assumption indication; calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as max (0, ceil(Trel- TA1+TA2), Trel indicates the relevant time, TA1 indicate the first timing advance value, and TA2 indicates the second timing advance value.

[0070] The instructions, when executed by the one or more processors, may further cause the apparatus to perform configuring the terminal such that the assumption indication indicates the at least one of:

[0071] - that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or

[0072] - that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is a gap between the assumed earlier transmission and the assumed later transmission.

[0073] The instructions, when executed by the one or more processors, may further cause the apparatus to perform receiving, from the terminal, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission; in response to receiving, from the terminal, the indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission: inhibiting the calculating the conservative estimation as max (0, ceil (Trel- TA1+TA2); and calculating the conservative estimation as ceil(Trel+TA1-TA2).

[0074] The instructions, when executed by the one or more processors, may further cause the apparatus to perform checking if the earlier transmission and the later transmission will overlap by less than a threshold if the omission number is equal to the conservative estimation minus 1 ; calculating the omission number as the conservative estimation minus 1 in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1 ; wherein the threshold is a duration of a cyclic prefix of a symbol of the later transmission multiplied by a predefined factor.

[0075] The instructions, when executed by the one or more processors, may further cause the apparatus to perform providing a dropping indication to the terminal in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

[0076] The instructions, when executed by the one or more processors, may further cause the apparatus to perform calculating the omission number as being equal to the conservative estimation in response to checking that the earlier transmission and the later transmission will not overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

[0077] According to a third aspect, there is provided a method comprising: providing, from a terminal to a network, a time information informing on a relevant time, wherein the relevant time is based on a switching time required by the terminal to switch between an earlier transmission and a later transmission subsequent to the earlier transmission, wherein the earlier transmission is one of a first transmission of a first slot comprising a predefined number of symbols to a first transmission reception point using a first beamformer and a second transmission of a second slot comprising the predefined number of symbols to a second transmission reception point using a second beamformer different from the first beamformer; and the later transmission is the other one of the first transmission and the second transmission.

[0078] The method may further comprise measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; providing the receive time difference to the network, wherein the relevant time is the switching time.

[0079] The method may further comprise measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; calculating the relevant time based on the switching time and the receive time difference.

[0080] The method may further comprise checking whether the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption: providing, to the network, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption; providing, to the network, an indication indicating at least one of:

[0081] - which one of the first transmission and the second transmission is the earlier transmission under the assumption; or

[0082] - which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a sum of the switching time and the receive time difference.

[0083] The method may further comprise checking whether there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption: providing, to the network, an indication that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption; providing, to the network, an indication indicating at least one of:

[0084] - which one of the first transmission and the second transmission is the earlier transmission under the assumption; or

[0085] - which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a difference between the switching time and the receive time difference.

[0086] The method may further comprise determining a gap-causing transmission among the first transmission and the second transmission such that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that the gap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the gap-causing transmission; wherein the relevant time is calculated such that the relevant time is a difference between the switching time and the receive time difference.

[0087] The method may further comprise determining an overlap-causing transmission among the first transmission and the second transmission such that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that the overlap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the overlap-causing transmission; the relevant time is calculated such that the relevant time is a sum of the switching time and the receive time difference.

[0088] The method may further comprise receiving a scheduling information from the network in response to providing the time information; performing the first transmission and the second transmission according to the scheduling information; wherein the scheduling information determines which one of the first transmission and the second transmission is the earlier transmission.

[0089] The method may further comprise calculating a number of samples the earlier transmission overlaps the later transmission; dropping the number of samples at the beginning of the first symbol at the beginning of the later transmission.

[0090] The method may further comprise monitoring whether a dropping indication is received from the network along with the scheduling information; inhibiting the dropping the number of samples in response to monitoring that the dropping indication is not received.

[0091] According to a fourth aspect, there is provided a method comprising: receiving, from a terminal, a time information informing on a relevant time; calculating an omission number based on the relevant time, a first timing advance value, and a second timing advance value; scheduling a first transmission of a first number of symbols in a first slot from the terminal to a first transmission reception point and a second transmission of a second number of symbols in a second slot from the terminal to a second transmission reception point; wherein, a later transmission among the first transmission and the second transmission is subsequent to an earlier transmission among the first transmission and the second transmission, each of a duration of the first slot and a duration of the second slot is equal to a duration of a predefined number of subsequent symbols; the number of symbols scheduled for transmission in the slot of the earlier transmission is a first symbol count number being equal to the predefined number minus a first omission portion number; the number of symbols scheduled for transmission in the slot of the later transmission is a second symbol count number being equal to the predefined number reduced by a second omission portion number; the first omission portion number is 0 or larger than 0; the second omission portion number is 0 or larger than 0; a sum of the first omission portion number and the second omission portion number is equal to the omission number; in the slot of the earlier transmission the first symbol count number of symbols are scheduled continuously at the beginning of the slot of the earlier transmission; in the slot of the later transmission the second symbol count number of symbols are scheduled continuously at the end of the slot of the later transmission; the first timing advance value indicates a timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the earlier transmission is directed to; and the second timing advance value indicates the timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the later transmission is directed to.

[0092] The method may further comprise the omission number is calculated additionally based on a receive time difference, and the receive time difference is predefined.

[0093] The method may further comprise receiving a receive time difference from the terminal, wherein the omission number is calculated additionally based on the receive time difference, wherein, according to the time information, the relevant time is a switching time required by the terminal to switch between a first beamformer to be used for the earlier transmission and a second beamformer to be used for the later transmission.

[0094] The method may further comprise receiving, from the terminal, an assumption indication indicating at least one of:

[0095] - that one of the first transmission and the second transmission is assumed to be the earlier transmission; or - that the other one of the first transmission and the second transmission is assumed to be the later transmission; the scheduling of the first transmission and the second transmission in line with the assumption indication; calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as ceil(Trel+TA1- TA2), Trel indicates the relevant time, TA1 indicates the first timing advance value, and TA2 indicates the second timing advance value.

[0096] The method may further comprise configuring the terminal such that the assumption indication indicates the at least one of: that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or

[0097] - that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is an overlap of the assumed earlier transmission and the assumed later transmission.

[0098] The method may further comprise receiving, from the terminal, an indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission; in response to receiving, from the terminal, the indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission: inhibiting the calculating the conservative estimation as ceil(Trel+TA1-TA2); and calculating the conservative estimation as max (0, ceil(Trel-TA1+TA2).

[0099] The method may further comprise receiving, from the terminal, an assumption indication indicating at least one of

[0100] - that one of the first transmission and the second transmission is assumed to be the earlier transmission, or

[0101] - that the other one of the first transmission and the second transmission is assumed to be the later transmission; calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as max (0, ceil(Trel- TA1+TA2), Trel indicates the relevant time, TA1 indicate the first timing advance value, and TA2 indicates the second timing advance value; wherein the first transmission and the second transmission are scheduled in line with the assumption indication.

[0102] The method may further comprise configuring the terminal such that the assumption indication indicates the at least one of:

[0103] - that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or

[0104] - that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is a gap between the assumed earlier transmission and the assumed later transmission.

[0105] The method may further comprise receiving, from the terminal, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission; in response to receiving, from the terminal, the indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission: inhibiting the calculating the conservative estimation as max (0, ceil (Trel-

[0106] TA1+TA2); and calculating the conservative estimation as ceil(Trel+TA1-TA2).

[0107] The method may further comprise checking if the earlier transmission and the later transmission will overlap by less than a threshold if the omission number is equal to the conservative estimation minus 1 ; calculating the omission number as the conservative estimation minus 1 in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1 ; wherein the threshold is a duration of a cyclic prefix of a symbol of the later transmission multiplied by a predefined factor.

[0108] The method may further comprise providing a dropping indication to the terminal in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

[0109] The method may further comprise calculating the omission number as being equal to the conservative estimation in response to checking that the earlier transmission and the later transmission will not overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

[0110] Each of the methods of the third and fourth aspects may be a method of uplink MTRP TDM.

[0111] According to a fifth aspect, there is provided a computer program product comprising a set of instructions which, when executed on an apparatus, is configured to cause the apparatus to carry out the method according to any of the third and fourth aspects. The computer program product may be embodied as a computer-readable medium or directly loadable into a computer.

[0112] According to some example embodiments, at least one of the following advantages may be achieved:

[0113] • overlaps of symbols may be avoided with no (or a small) loss of throughput;

[0114] • compared to a conservative baseline scenario, the throughput may be (considerably) enhanced;

[0115] • small signalling effort only.

[0116] It is to be understood that any of the above modifications can be applied singly or in combination to the respective aspects to which they refer, unless they are explicitly stated as excluding alternatives.

[0117] Brief description of the drawings

[0118] Further details, features, objects, and advantages are apparent from the following detailed description of the preferred embodiments which is to be taken in conjunction with the appended drawings, wherein: Fig. 1 shows a multi-DCI multi-TRP NCJT scheme for PDSCH;

[0119] Fig. 2 illustrates overlaps and gaps between slots in inter-slot TDM;

[0120] Fig. 3 illustrates a message sequence according to some example embodiments;

[0121] Fig. 4 illustrates a message sequence according to some example embodiments;

[0122] Fig. 5 illustrates a message sequence according to some example embodiments;

[0123] Fig. 6 shows an apparatus according to an example embodiment;

[0124] Fig. 7 shows a method according to an example embodiment;

[0125] Fig. 8 shows an apparatus according to an example embodiment;

[0126] Fig. 9 shows a method according to an example embodiment; and

[0127] Fig. 10 shows an apparatus according to an example embodiment.

[0128] Detailed description of certain example embodiments

[0129] Herein below, certain example embodiments are described in detail with reference to the accompanying drawings, wherein the features of the embodiments can be freely combined with each other unless otherwise described. However, it is to be expressly understood that the description of certain embodiments is given by way of example only, and that it is by no way intended to be understood as limiting the disclosure to the disclosed details.

[0130] Moreover, it is to be understood that the apparatus is configured to perform the corresponding method, although in some cases only the apparatus or only the method are described.

[0131] When a UE (e.g. in FR2) is equipped (and can use) multiple Tx RF chains, it can configure (if there is no obstacle / blockage), its panels / sub-panels such that each chain is transmitting with a specific TA toward each TRP. Therefore, in such a situation, even a large difference in the two propagation delays (and a corresponding large difference in the TA values) can be handled.

[0132] On the other hand, when a UE is equipped with just one active Tx RF chain (for example because it is equipped with a single panel only, or because it is multi-panel but has only one single shared UL digital baseband), in the time domain the UL signals with different TA values may overlap because of the different propagation delays of the two links TRP1-UE and TRP2- UE. An example is shown in Fig. 2. As shown in Fig. 2, the UE is transmitting in UL toward two TRPs with inter-slot TDM, i.e., the UE transmits alternately one slot to TRP1 and one slot to TRP2. The upper row shows the transmissions of slots n, n+2, n+4 etc. to TRP1 , and the lower row shows the transmission of slots n+1 , n+3, etc. to TRP2. In this example, the slot toward TRP2 (e.g. slot n+1) is supposed to start “before” the end of the preceding slot (e.g. slot n) toward TRP1. In this example, this situation may happen because the TA value for UL1 (towards TRP1) is smaller than the TA value for UL2 (towards TRP2), and therefore there is an overlap on the transmit time for UL1 and UL2. Another reason for the overlap may be that the reference signal used by the UE for determining the reference timing for UL1 and UL2 differs, e.g. RS for UL1 is received with smaller delay than RS for UL2.

[0133] If the UE, in a scenario such as that shown in Fig. 2, was equipped with multiple Tx RF chains, then it could use different Tx RF chains for each TRP and some overlap in transmissions for UL1 and UL2 would be supported.

[0134] However, if the UE is equipped with a single Tx RF chain (or equipped with multiple Tx RF chains but uses only one of them for any reason, e.g., UE power saving, blockage in front of some panels, etc...), this overlap in the time domain may force the UE to choose to transmit either UL1 or UL2. If it transmits both UL1 and UL2, the UE may lose one or more symbols of the two slots.

[0135] Some example embodiments provide a time gap between two UL transmissions in order to allow a UE not using STxMP to switch among the two UL transmissions toward two different TRPs. The time gap depends on four parameters:

[0136] • RTD: Receive timing difference;

[0137] • TA1 : Timing advance value from TRP1 ;

[0138] • TA2: Timing advance value from TRP2;

[0139] • Ts: Switching time, i.e., the time it takes for a UE to switch from the beamformer used toward a first TRP to the beamformer used toward a second TRP.

[0140] In some example embodiments, in the time gap, symbols are not transmitted at the beginning of the later scheduled slot. In some example embodiments, in the time gap, symbols are not transmitted at the end of the earlier scheduled slot. In some example embodiments, in the time gap, some symbols are not transmitted at the end of the earlier scheduled slot and some symbols are not transmitted at the beginning of the later scheduled slot. The number of symbols that could be transmitted in the time gap (but are not transmitted) is called omission number X. The omission number X may be split into a first omission portion number indicating the number of symbols omitted at the end of the earlier scheduled slot and a second omission portion number indicating the number of symbols omitted at the beginning of the later scheduled slot. The first omission portion number may be 0 or larger. The second omission portion number may be 0 or larger. The sum of the first omission portion number and second omission portion number is equal to the omission number X.

[0141] As shown in Fig. 2, there are two different situations that may occur due to the different TA values:

[0142] • There is an overlap between the two slots (such as between Slot n to TRP1 and Slot n+1 to TRP2);

[0143] • There is a gap between the two slots (such as between slot n+1 to TRP2 and slot n+2 to TRP1). Even if there is a gap, the UE may not be able to switch sufficiently fast between the two beamformers because of the switching time Ts needed by the UE.

[0144] Thus, X indicates the number of symbols which cannot be used for information transmission because of the overlap of the slots towards different TRPs or because of the gap between the slots towards different TRPs being too small compared to the UE#s switching time. During the duration of the X * (symbol duration), symbols are not transmitted in at least one of the (immediately) subsequently numbered slots.

[0145] The network may know TA1 and TA2. There are different ways for the network to get TA1 and TA2, for example:

[0146] • Keeping track at the gNB of all the TACs that has been sent to that UE, or

[0147] • Exploiting some TA reporting procedure, such as for NTN, see 3GPP TS 38.321 , sec. 5.4.8, and 3GPP TS 38.331 , sec. 6.3.2.

[0148] Conventionally, the network knows neither RTD nor the UE’s switching time Ts.

[0149] Accordingly, conventionally, the TRPs (or the network (represented e.g. by gNB)) may not have knowledge on the overlap or the gap. For such a knowledge, the network should know the four parameters RTD, TA1 , TA2, and Ts. Accordingly, conventionally, the TRPs (or the network (gNB)) can mitigate the overlap only if they assume the worst conditions allowed by the respective standard. Such a baseline scheme is as follows: The network may apply scheduling restrictions by computing the worst case with maximum switching time as allowed by requirements (for example, assuming the transient period requirement Ts = 10 us [3GPP TS 38.101-1]) and the maximum RTD (for example, MRTD = 8 us [3GPP R4-2217278]), which may result in omitting X=3 OFDM symbols (for SCS = 120 kHz). The drawback of this baseline scheme is that the performance loss in terms of throughput is the largest possible.

[0150] The omission number X of OFDM symbols X in which a transmission of symbols must not be scheduled towards one of the TRPs (although a slot towards this TRP is scheduled) is different depending on whether there is an overlap or a gap between the two slots. By denoting with Dt=RTD+TA1-TA2, there are the following cases:

[0151] • If there is a gap: o If Ts<Dt, then the beamformer switching can happen before the start of the next slot transmission, i.e., no scheduling restriction is needed, i.e., X=0. o Otherwise, the time occupied by the first “X=ceil(Ts-Dt)" OFDM symbols in the next slot transmission are needed to complete the beamformer switching. I.e., during this time at the beginning of the next slot or at the end of the previous slot, OFDM symbols must not be transmitted, ceil denotes the ceiling operation.

[0152] • If there is an overlap: o Then, there is an overlap with the next slot transmission of “X=ceil(Ts+Dt)" OFDM symbols.

[0153] Some example embodiments make the network aware of RTD and Ts (or of a time derived at least from Ts) so that the network can apply the scheduling restriction such that scheduling restrictions are mostly avoided or reduced compared to the baseline scheme. Namely, compared to the baseline scheme (i.e., a conservative X=3 OFDM symbols according to current standards), it allows in certain situations to reduce the value of X to 2, 1 , or even 0 (for example, when there is a gap and the switching time is small enough). Thus, the throughput may be (considerably) enhanced. For example, considering a slot comprising 14 OFDM symbols, reducing X from 3 to 0 (i.e. transmitting 14 OFDM symbols per slot instead of 11 OFDM symbols per slot) can be interpreted as about 27% throughput gain.

[0154] According to some example embodiments, the UE sends a report including some information about Ts and optionally about RTD. The information indicates a relevant time Trel which is based at least on Ts. Example Embodiment 1 : UE provides both RTD and Ts as separate values to network.

[0155] • For example, UE may send RTD via MAC-CE or as a CSI report, whereas UE may send Ts as a UE capability via RRC signalling. o The UE may be configured to determine (measure) RTD based on reference signals of 2 TCI states, 2 TAGs, or 2 coresetPool Index from the different TRPs. o The CSI reporting may be configured as periodic, semi persistent, or aperiodic. The advantage of having periodic reports is that the gNB may keep the updated information considering timing advance commands received by TRP1 and TRP2, changes in synchronization between TRPs, and autonomous adjustments performed by the UE. o Ts may be a UE capability or a fixed value for the requirement of UEs supporting that feature.

[0156] In terms of throughput gain, example embodiment 1 is preferred, as it allows the gNB to have all the information to optimize the omission number X. However, there may be UE implementations that always report the maximum allowed Ts, leading to suboptimal performance. In addition, the signaling effort may be larger than in other example embodiments.

[0157] Fig. 3 shows a signalling chart of the Example Embodiment 1 :

[0158] - In the initialization phase (1), the UE performs initial access (2) and is configured to transmit in UL with mTRP TDM (3).

[0159] - Then, the UE indicates Ts to the NW in a UE capability field (4).

[0160] - During operations, the network (TRPs) estimates the TAs to be used by the UE (5) for the respective UL transmission and informs the UE about the TA values (6, 7).

[0161] - In 8 the UE measures the RTD using RSs from the two TRPs and sends the measured RTD to the NW (9). In some example embodiments, 8 and 9 may be performed prior to, in parallel, or after 6 and 7.

[0162] - In 10 the NW uses RTD, Ts, TA1 , and TA2 to determine the value of X both in case of gap and overlap, X(gap) and X(overlap), respectively. Details are described further below. They may depend on gNB implementation.

[0163] - In 11 the NW schedules the UL transmission from that UE using the determined value of X. The values of X may be different for the case of a gap (X(gap)) and the case of an overlap (X(overlap)). 12: In some example embodiments, the gNB, in an aggressive approach, may determine the omission number X such that the time gap between the two UL transmissions is not large enough to allow the UE to switch among the two beamformers. The UE may then implement a “sample dropping scheme”, for example dropping some samples at the beginning of the CP of the later scheduled slot. For further details, see below.

[0164] 13: The UE then starts transmitting toward the two TRPs on the scheduled resources using, if necessary, sample dropping.

[0165] As another option to acquire the TA values (6 and 7 in Fig. 3), the UE may receive the TA value from one TRP (via TAC), e.g., TA1 for TRPI , and calculates TA for the other TRP, e.g., TA2 for TRP2, based on the estimation of the RTD with the other TRP. In this case, as one option, the UE may report the calculated TA (e.g., TA2) to the network.

[0166] Example Embodiment 2: In case there is only a single transition between different UL transmissions (transmissions to different TRPs) (e.g. the transmission from the UE lasts only two slots being alternately transmitted to TRP1 and TRP2), then there may be either an overlap or a gap. In such a scenario, the UE sends to the network: o Ts-RTD (as the relevant time), if there is a gap. o Ts+RTD (as the relevant time), if there is an overlap. o However, sending either Ts-RTD or Ts+RTD to the network is not enough, as the gNB does not know if such value refers to the TRP1->TRP2 transition or to the TRP2->TRP1 transition, and therefore the UE sends in addition:

[0167] ■ An indication about which of the TRPs is scheduled earlier (first): A single bit may used for the indication, for example bit-0 for TRP1 and bit-1 for TRP2.

[0168] ■ An indication whether there is a gap or an overlap: again, a single bit may be used for this indication, for example bit-0 for the gap and bit-1 for the overlap. o The relevant time and the indications can be sent to the network via MAC-CE or a CSI report.

[0169] Thus, the gNB has all the information to optimize X if there is only a single transition between the different UL transmissions. In case there are plural transitions between different UL transmissions (transmissions to different TRPs) (e.g. the UL transmission lasts many slots being alternately transmitted to TRP1 and TRP2), the gNB may proceed as follows: If, for instance, the UE sends Ts-RTD for the gap case to the network, the gNB can: o Optimize X for the gap case; o Apply the conservative baseline, i.e., X=3, for the overlap case.

[0170] The same applies correspondingly for the case that the UE sends the relevant time for the overlap case. Apparently, the throughput may be reduced in case of plural transitions between UL transmissions to different TRPs compared to that of the Example Embodiment 1 , but signaling effort may be reduced, too.

[0171] Fig. 4 shows a signalling chart for the Example Embodiment 2:

[0172] In the initialization phase (1), the UE performs initial access (2) and is configured to transmit in UL with mTRP TDM (3).

[0173] During operations, the network (TRPs) estimates the TAs to be used by the UE (4) for the respective UL transmission and informs the UE about the TA values (5, 6).

[0174] 7: the UE measures the RTD using RSs from the two TRPs. 7 and 5, 6 may be performed in an arbitrary sequence. They may be performed fully or partly in parallel. 8: the UE sends that back to the NW:

[0175] • the relevant time Trel: Either Ts-RTD for the gap or Ts+RTD for the overlap.

[0176] • FirstTRPIndex: first TRP to be scheduled to get either that gap or that overlap (bit- O for TRPI and bit-1 for TRP2).

[0177] • Overlapindex: bit-0 for the gap and bit-1 for the overlap. In some example embodiments, either gap or overlap may be a default case, and need not be indicated. In such embodiments, only the other case (overlap or gap) is indicated.

[0178] 9: the NW uses Trel, TA1 , TA2, and Overlapindex to determine either X(gap) (if Overlaplndex=0) or X(overlap) (if Overlaplndex=1).

[0179] Then, in case there is a single transition between transmissions to different TRPs (e.g. the UE transmission lasts only two slots being alternately transmitted to TRP1 and TRP2) (10):

[0180] • The NW schedules the UL transmission from that UE using the determined X and FirstTRPIndex.

[0181] • In some example embodiments, the UE assesses if “sample dropping scheme” is needed (12). For details see below.

[0182] • UE starts transmitting toward the two TRPs on the scheduled resources (13). In case there is more than one transition between transmissions to different TRPs (e.g the UE transmission lasts more than two slots being transmitted alternately to TRP1 and TRP2) (not shown in Fig. 4):

[0183] • The NW applies the conservative baseline, i.e., X=3 for the case not covered by Overlapindex, schedules the UL transmission and then the UE starts transmitting.

[0184] Example Embodiment 3: In case there is only one transition between 2 ULs (e.g. the transmission from the UE lasts only two slots being alternately transmitted to TRP1 and TRP2), the UE may be configured to indicate to the network which transmission (the transmission to TRP1 or the transmission to TRP2) should be performed first to have a gap between the transmissions. In Example Embodiment 3, the UE sends to the network: o Ts-RTD (as the relevant time); o Which TRP should be scheduled first (earlier) to get the gap. The corresponding transmission may be called “gap-causing transmission”. A single bit may be used to indicate the TRP, for example bit-0 for TRP1 and bit-1 for TRP2. The indication may be sent back via MAC-CE or a CSI report.

[0185] Thus, the gNB has all the information to optimize X if there is a single transition between different UL transmissions with a reduced signaling effort. The extension (as in Example Embodiment 2) in case there is more than one transition between transmissions to different TRPs is also applicable correspondingly.

[0186] Fig. 5 shows a signalling chart of the Example Embodiment 3:

[0187] In the initialization phase (1), the UE performs initial access (2) and is configured to transmit in UL with mTRP TDM (3). In addition, in some example embodiments, the network configures the UE to report “Relevant Time” and “firstTRPindex” always for the gap case. In other example embodiments, the UE may be preconfigured to report “Relevant Time” and “firstTRPindex” always for the gap case (e.g. according to an upcoming 3GPP standard).

[0188] During operations, the network (TRPs) estimates the TAs to be used by the UE (4) for the respective UL transmission and informs the UE about the TA values (5, 6).

[0189] 7: the UE measures the RTD using RSs from the two TRPs. 7 and 5, 6 may be performed in an arbitrary sequence. They may be performed fully or partly in parallel.

[0190] 8: the UE sends to the network:

[0191] • Ts-RTD. • FirstTRPIndex: first TRP to be scheduled (bit-0 for TRP1 and bit-1 for TRP2) to have a gap between first and second slots.

[0192] 9: the NW uses Ts-RTD, TA1 , and TA2, to determine X(gap).

[0193] Then, in case there is only a single transition between the transmissions to different TRPs (e.g. the UE transmission lasts only two slots, one slot to TRP1 and one slot to TRP2) (10):

[0194] • 11 : the NW schedules the UL transmission from that UE using the determined X(gap) and FirstTRPIndex.

[0195] • In some example embodiments, the UE assesses if “sample dropping scheme” is needed (12). For details see below.

[0196] • The UE starts transmitting toward the two TRPs on the scheduled resources (13). In case there are more transitions between the transmissions to different UEs (e.g. the UE transmission lasts more than two slots transmitted alternately to the TRPs) (14):

[0197] • The network applies the conservative baseline for the overlap, i.e. , X(overlap)=3 (15).

[0198] • 16: the network schedules the UL transmission from that UE using the determined X(gap), X(overlap) and FirstTRPIndex.

[0199] • In some example embodiments, the UE assesses if “sample dropping scheme” is needed (17).

[0200] • UE starts transmitting toward the two TRPs on the scheduled resources (18).

[0201] Example Embodiment 4: This example embodiment corresponds to the Example embodiment 3, except that the UE is configured to indicate to the network which transmission (the transmission to TRP1 or the transmission to TRP2) should be performed first to have an overlap of the transmissions. This earlier transmission may be called “overlap-causing transmission”. In this case, the relevant time is Ts+RTD, and the UE indicates which TRP should be scheduled first to get the overlap.

[0202] Depending on implementation, in example embodiments 3 and 4, the UE may indicate which transmission should be performed later to have the gap and the overlap, respectively.

[0203] In some example embodiments, the values of RTD and / or TS may be quantized in classes. Thus, UE may indicate to the network, instead of the exact values of RTD and / or TS, an indication of the respective class. For example, 3GPP defined already (in FR2) two different classes for MRTD (which is a UE requirement): o MRTD = CP as baseline; o MRTD = 8 ps.

[0204] Since RTD has to be equal to or smaller than MRTD, the MRTD classes may be used to indicate an upper value for RTD, too.

[0205] For Ts, the following classes may be defined, for example: o Ts = 10 ps as baseline (from 3GPP TS 38.101); o Ts = 1 ps for fast switching; o Ts = 100 ns for super-fast switching.

[0206] If 1 ps < Ts < 10 ps, UE indicates the class Ts = 10 ps, if 100 ns < Ts < 1 ps, UE indicates the class Ts = 1 ps, and if Ts < 100 ns, UE indicates the class Ts = 100 ns. For calculating the value of X, gNB uses the value of RTD and / or Ts denoting the respective class. Since the number of classes may be limited such that a few bits are sufficient to indicate the class (e.g. 2 bits for up to 4 classes), the signaling effort may be reduced compared to the Example embodiment 1 where the UE sends the actual values to the network. A corresponding classification may be used for the values of Ts+RTD and / or Ts-RTD. gNB implementation for determination of the omission number X

[0207] In all the example embodiments, the NW (represented by gNB, for example) is provided with sufficient information to compute the number of OFDM symbols X at the beginning of a slot in which a UE cannot be properly scheduled because of the overlap with the transmission of the previous slot to the other TRP and / or the switching time necessary to change the beamformer. More specifically, the NW may compute:

[0208] For the overlap case, X = ceil(Ts+ RTD + TA1 - TA2);

[0209] For the gap case, X = max( 0, ceil(Ts - RTD - TA1 + TA2)).

[0210] In reality, such approach may be considered as conservative, because when applying it, it may happen that a UE is not scheduled in an OFDM symbol, although, for instance, in the gap case, the switching time can be completed within the CP of such OFDM symbol. In such situation, the NW may decide to anyhow schedule the UE in that OFDM symbol, and the UE can for instance drop the few samples at the beginning of the symbol, with minimum performance degradation. More generally, for example with the overlap case, the NW may calculate X in a more aggressive approach as follows (for instance in 10 of Fig. 3):

[0211] The NW computes Xt = Ts+ RTD + TA1 - TA2;

[0212] - If “ceil(Xt)-Xt > TH”

[0213] • X = ceil(Xt) Otherwise:

[0214] • X = ceil(Xt) - 1

[0215] The threshold TH can be implementation specific. One or more of the following criteria may be used to determine the threshold TH, for instance:

[0216] The switching needs to be completed within the CP. However, in this case ISI may be caused in the first scheduled OFDM symbol.

[0217] The switching needs to be completed within a fraction of the CP. That would limit the amount of ISI.

[0218] - The switching time may be larger than the CP if it is completed within a fraction of the whole OFDM symbol duration (for example 10%). However, that approach may cause ICI besides ISI.

[0219] Sample dropping at the UE

[0220] As outlined in the previous section “gNB implementation for determination of the omission number X”, if the NW does not adopt the conservative approach but the more aggressive approach with the reduced omission number, UE should drop some samples of the first symbol (OFDM symbol) transmitted in the later scheduled slot. However, gNB cannot schedule the transmission of each sample but only of a symbol comprising plural samples. To make the UE dropping a few samples of the first symbol transmitted in the later scheduled slot, for example a small portion of the CP, at the beginning of the first OFDM symbol transmitted in the later scheduled slot (as reported in Fig. 3 (12), Fig. 4 (12), and Fig. 5 (12,17)), there are two options: The sample dropping is indicated by the NW to the UE (by a “dropping indication”), e.g. on the DCI scheduling the UL transmission (in Fig. 3 (11), Fig. 4 (11), and Fig. 5 (11 , 16)), so that the UE is aware that it must implement some sample dropping. There are different implementation options. For example, a single bit may be used as follows: bit-0 need of sample dropping at the UE, bit-1 no need of sample dropping at the UE. In some example embodiments, gNB may calculate the number of samples to be dropped and indicate this number to the UE, e.g. as the dropping indication or as a part thereof. In such example embodiments, UE may not calculate the number of samples to be dropped.

[0221] The sample dropping is not indicated by the NW to the UE, and the UE decides autonomously, based on the UL resources scheduled by the NW, whether or not it will drop some samples at the beginning of the first OFDM symbol transmitted in the later scheduled slot.

[0222] Fig. 6 shows an apparatus according to an example embodiment. The apparatus may be a terminal (such as a UE or a MTC device) or an element thereof. Fig. 7 shows a method according to an example embodiment. The apparatus according to Fig. 6 may perform the method of Fig. 7 but is not limited to this method. The method of Fig. 7 may be performed by the apparatus of Fig. 6 but is not limited to being performed by this apparatus.

[0223] The apparatus comprises means for providing 110. The means for providing 110 may be a providing means. The means for providing 110 may be a provider. The means for providing 110 may be a providing processor.

[0224] The means for providing 110 provides, from a terminal to a network, a time information (S110). The time information informs on a relevant time. The relevant time is based on a switching time required by the terminal to switch between an earlier transmission and a later transmission subsequent to the earlier transmission. That is, the relevant time may be equal to the switching time or may be calculated based on the switching time.

[0225] The earlier transmission is one of a first transmission of a first slot comprising a predefined number of symbols to a first transmission reception point using a first beamformer and a second transmission of a second slot comprising the predefined number of symbols to a second transmission reception point using a second beamformer different from the first beamformer. The later transmission is the other one of the first transmission and the second transmission.

[0226] Fig. 8 shows an apparatus according to an example embodiment. The apparatus may be a network, for example represented by a base station (such as a gNB or a eNB), or an element thereof. Fig. 9 shows a method according to an example embodiment. The apparatus according to Fig. 8 may perform the method of Fig. 9 but is not limited to this method. The method of Fig. 9 may be performed by the apparatus of Fig. 8 but is not limited to being performed by this apparatus.

[0227] The apparatus comprises means for receiving 210, means for calculating 220, and means for scheduling 230. The means for receiving 210, means for calculating 220, and means for scheduling 230 may be a receiving means, calculating means, and scheduling means, respectively. The means for receiving 210, means for calculating 220, and means for scheduling 230 may be a receiver, calculator, and scheduler, respectively. The means for receiving 210, means for calculating 220, and means for scheduling 230 may be a receiving processor, calculating processor, and scheduling processor, respectively.

[0228] The means for receiving 210 receives, from a terminal, a time information informing on a relevant time (S210).

[0229] The means for calculating 220 calculates an omission number (e.g. X, as described hereinabove) based on the relevant time, a first timing advance value, and a second timing advance value (S220). The first timing advance value indicates a timing advance between the terminal and one transmission reception point among a first transmission reception point and a second transmission reception point an earlier transmission is directed to. The second timing advance value indicates the timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point a later transmission is directed to. The later transmission among a first transmission and a second transmission is subsequent to the earlier transmission among the first transmission and the second transmission.

[0230] The first transmission is a transmission of a first number of symbols in a first slot from the terminal to the first transmission reception point. The second transmission is a transmission of a second number of symbols in a second slot from the terminal to the second transmission reception point. The durations of the first slot and the second slot are equal to each other and equal to a duration of a predefined number of subsequent symbols.

[0231] The means for scheduling 230 schedules the first transmission and the second transmission (S230). The total number of symbols scheduled for transmission in the slot of the earlier transmission and the slot of the later transmission is twice the predefined number minus the omission number. The omitted symbols may be distributed arbitrarily among the slot of the earlier transmission and the slot of the later transmission. The distribution may be indicated by first and second omission portion numbers indicating the number of symbols omitted from the slot of the earlier transmission and omitted from the slot of the later transmission. Each of the first and second omission portion numbers may be 0 or larger than 0. The sum of the first and second omission portion numbers is equal to the omission number. That is, the first number of symbols transmitted in the slot of the earlier transmission is equal to the predefined number minus the first omission portion number; and the second number of symbols transmitted in the slot of the later transmission is equal to the predefined number minus the second omission portion number.

[0232] In the slot of the earlier transmission, the first number of symbols are scheduled continuously at the beginning of the slot of the earlier transmission. I.e., the first number of symbols is transmitted in the slot of the earlier transmission, and then symbols are not transmitted in the slot of the earlier transmission for the duration of the first omission portion number of symbols.

[0233] In the slot of the later transmission, the second number of symbols are scheduled continuously at the end of the slot of the later transmission. I.e., symbols are not transmitted in the slot of the later transmission for the duration of the second omission portion number of symbols, and then, the second number of symbols is transmitted in the slot of the later transmission.

[0234] Fig. 10 shows an apparatus according to an example embodiment. The apparatus comprises at least one processor 810, at least one memory 820 storing instructions that, when executed by the at least one processor 810, cause the apparatus at least to perform the method according to at least one of the following figures and related description: Fig. 7, or Fig. 9.

[0235] Some example embodiments are employed in UEs not supporting STxMP. However, some example embodiments may be employed in UEs supporting STxMP. For example, in UEs supporting STxMP, these example embodiments may support an energy saving mode.

[0236] The number of different TRPs to which the UE performs uplink transmissions is not limited to 2 and may be 2 or larger. The gNB may schedule the slots alternately one slot per TRP, as described in the above example embodiments. However, in some example embodiments, an arbitrary first number of slots may be transmitted to one TRP, and then an arbitrary second number of slots may be transmitted to another TRP. The first number may be different from the second number or the same as the second number. Some example embodiments are applicable if two directly subsequent slots are scheduled to different TRPs.

[0237] Example embodiments may be applied to an arbitrary generation of a 3GPP network, such as 4G, 5G, 6G, 7G etc.. They may be applied to non-3GPP networks providing uplink transmission to different TRPs.

[0238] One piece of information may be transmitted in one or plural messages from one entity to another entity. Each of these messages may comprise further (different) pieces of information.

[0239] Names of network elements, network functions, protocols, and methods are based on current standards. In other versions or other technologies, the names of these network elements and / or network functions and / or protocols and / or methods may be different, as long as they provide a corresponding functionality. The same applies correspondingly to the terminal.

[0240] If not otherwise stated or otherwise made clear from the context, the statement that two entities are different means that they perform different functions. It does not necessarily mean that they are based on different hardware. That is, each of the entities described in the present description may be based on a different hardware, or some or all of the entities may be based on the same hardware. It does not necessarily mean that they are based on different software. That is, each of the entities described in the present description may be based on different software, or some or all of the entities may be based on the same software. Each of the entities described in the present description may be deployed in the cloud.

[0241] According to the above description, it should thus be apparent that example embodiments provide, for example, a terminal (such as a UE or a MTC device) or a component thereof, an apparatus embodying the same, a method for controlling and / or operating the same, and computer program(s) controlling and / or operating the same as well as mediums carrying such computer program(s) and forming computer program product(s). According to the above description, it should thus be apparent that example embodiments provide, for example, a base station (such as a gNB or eNB) or a component thereof, an apparatus embodying the same, a method for controlling and / or operating the same, and computer program(s) controlling and / or operating the same as well as mediums carrying such computer program(s) and forming computer program product(s).

[0242] Implementations of any of the above described blocks, apparatuses, systems, techniques or methods include, as non-limiting examples, implementations as hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. Each of the entities described in the present description may be embodied in the cloud.

[0243] It is to be understood that what is described above is what is presently considered the preferred example embodiments. However, it should be noted that the description of the preferred example embodiments is given by way of example only and that various modifications may be made without departing from the scope of the disclosure as defined by the appended claims.

[0244] The terms “first X” and “second X” include the options that “first X” is the same as “second X” and that “first X” is different from “second X”, unless otherwise specified. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

Claims

Claims:

1. Apparatus comprising: one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: providing, from a terminal to a network, a time information informing on a relevant time, wherein the relevant time is based on a switching time required by the terminal to switch between an earlier transmission and a later transmission subsequent to the earlier transmission, wherein the earlier transmission is one of a first transmission of a first slot comprising a predefined number of symbols to a first transmission reception point using a first beamformer and a second transmission of a second slot comprising the predefined number of symbols to a second transmission reception point using a second beamformer different from the first beamformer; and the later transmission is the other one of the first transmission and the second transmission.

2. The apparatus according to claim 1 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; providing the receive time difference to the network, wherein the relevant time is the switching time.

3. The apparatus according to claim 1 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform measuring a receive time difference between a receipt of a reference signal from the first transmission reception point by the terminal and a receipt of the reference signal from the second transmission reception point by the terminal; calculating the relevant time based on the switching time and the receive time difference.

4. The apparatus according to claim 3, wherein the instructions, when executed by the one or more processors, further cause the apparatus to performchecking whether the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption: providing, to the network, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under the assumption; providing, to the network, an indication indicating at least one of:- which one of the first transmission and the second transmission is the earlier transmission under the assumption; or- which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a sum of the switching time and the receive time difference.

5. The apparatus according to any of claims 3 to 4, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform checking whether there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that one of the first transmission and the second transmission is the earlier transmission; in response to checking that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption: providing, to the network, an indication that there is the gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under the assumption; providing, to the network, an indication indicating at least one of:- which one of the first transmission and the second transmission is the earlier transmission under the assumption; or- which one of the first transmission and the second transmission is the later transmission under the assumption; the calculating the relevant time such that the relevant time is a difference between the switching time and the receive time difference.

6. The apparatus according to claim 3, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform determining a gap-causing transmission among the first transmission and the second transmission such that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission under an assumption that the gap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the gap-causing transmission; the calculating the relevant time such that the relevant time is a difference between the switching time and the receive time difference.

7. The apparatus according to any of claims 3 and 6, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform determining an overlap-causing transmission among the first transmission and the second transmission such that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission under an assumption that the overlap-causing transmission is the earlier transmission; providing, to the network, an indication indicating the one of the first transmission and the second transmission being the overlap-causing transmission; the calculating the relevant time such that the relevant time is a sum of the switching time and the receive time difference.

8. The apparatus according to any of claims 1 to 7, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving a scheduling information from the network in response to providing the time information; performing the first transmission and the second transmission according to the scheduling information; wherein the scheduling information determines which one of the first transmission and the second transmission is the earlier transmission.

9. The apparatus according to claim 8, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform calculating a number of samples the earlier transmission overlaps the later transmission;dropping the number of samples at the beginning of the first symbol at the beginning of the later transmission.

10. The apparatus according to claim 9, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform monitoring whether a dropping indication is received from the network along with the scheduling information; inhibiting the dropping the number of samples in response to monitoring that the dropping indication is not received.

11. Apparatus comprising: one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: receiving, from a terminal, a time information informing on a relevant time; calculating an omission number based on the relevant time, a first timing advance value, and a second timing advance value; scheduling a first transmission of a first number of symbols in a first slot from the terminal to a first transmission reception point and a second transmission of a second number of symbols in a second slot from the terminal to a second transmission reception point; wherein, a later transmission among the first transmission and the second transmission is subsequent to an earlier transmission among the first transmission and the second transmission, each of a duration of the first slot and a duration of the second slot is equal to a duration of a predefined number of subsequent symbols; the number of symbols scheduled for transmission in the slot of the earlier transmission is a first symbol count number being equal to the predefined number minus a first omission portion number; the number of symbols scheduled for transmission in the slot of the later transmission is a second symbol count number being equal to the predefined number reduced by a second omission portion number; the first omission portion number is 0 or larger than 0; the second omission portion number is 0 or larger than 0; a sum of the first omission portion number and the second omission portion number is equal to the omission number;in the slot of the earlier transmission the first symbol count number of symbols are scheduled continuously at the beginning of the slot of the earlier transmission; in the slot of the later transmission the second symbol count number of symbols are scheduled continuously at the end of the slot of the later transmission; the first timing advance value indicates a timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the earlier transmission is directed to; and the second timing advance value indicates the timing advance between the terminal and one transmission reception point among the first transmission reception point and the second transmission reception point the later transmission is directed to.

12. The apparatus according to claim 11 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform the calculating the omission number additionally based on a receive time difference, and the receive time difference is predefined.

13. The apparatus according to claim 11 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving a receive time difference from the terminal, the calculating the omission number additionally based on the receive time difference, wherein, according to the time information, the relevant time is a switching time required by the terminal to switch between a first beamformer to be used for the earlier transmission and a second beamformer to be used for the later transmission.

14. The apparatus according to claim 11 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving, from the terminal, an assumption indication indicating at least one of:- that one of the first transmission and the second transmission is assumed to be the earlier transmission; or- that the other one of the first transmission and the second transmission is assumed to be the later transmission; the scheduling of the first transmission and the second transmission in line with the assumption indication;calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as ceil(Trel+TA1- TA2), Trel indicates the relevant time, TA1 indicates the first timing advance value, and TA2 indicates the second timing advance value.

15. The apparatus according to claim 14, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform configuring the terminal such that the assumption indication indicates the at least one of: that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or- that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is an overlap of the assumed earlier transmission and the assumed later transmission.

16. The apparatus according to any of claims 14 and 15, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving, from the terminal, an indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission; in response to receiving, from the terminal, the indication that there is a gap between the slot transmitted in the earlier transmission and the slot transmitted in the later transmission: inhibiting the calculating the conservative estimation as ceil(Trel+TA1-TA2); and calculating the conservative estimation as max (0, ceil(Trel-TA1+TA2).

17. The apparatus according to claim 11 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving, from the terminal, an assumption indication indicating at least one of- that one of the first transmission and the second transmission is assumed to be the earlier transmission, or- that the other one of the first transmission and the second transmission is assumed to be the later transmission; the scheduling of the first transmission and the second transmission in line with the assumption indication;calculating a conservative estimation and the omission number based on the conservative estimation, wherein the conservative estimation is calculated as max (0, ceil(Trel- TA1+TA2), Trel indicates the relevant time, TA1 indicate the first timing advance value, and TA2 indicates the second timing advance value.

18. The apparatus according to claim 17, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform configuring the terminal such that the assumption indication indicates the at least one of:- that the one of the first transmission and the second transmission is assumed to be the earlier transmission; or- that the other one of the first transmission and the second transmission is assumed to be the later transmission in response to determining that there is a gap between the assumed earlier transmission and the assumed later transmission.

19. The apparatus according to any of claims 17 and 18, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform receiving, from the terminal, an indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission; in response to receiving, from the terminal, the indication that the slot transmitted in the later transmission overlaps the slot transmitted in the earlier transmission: inhibiting the calculating the conservative estimation as max (0, ceil (Trel- TA1+TA2); and calculating the conservative estimation as ceil(Trel+TA1-TA2).

20. The apparatus according to any of claims 14 to 19, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform checking if the earlier transmission and the later transmission will overlap by less than a threshold if the omission number is equal to the conservative estimation minus 1 ; calculating the omission number as the conservative estimation minus 1 in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1 ; wherein the threshold is a duration of a cyclic prefix of a symbol of the later transmission multiplied by a predefined factor.

21. The apparatus according to claim 20, wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform providing a dropping indication to the terminal in response to checking that the earlier transmission and the later transmission will overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

22. The apparatus according to any of claims 20 to 21 , wherein the instructions, when executed by the one or more processors, further cause the apparatus to perform calculating the omission number as being equal to the conservative estimation in response to checking that the earlier transmission and the later transmission will not overlap by less than the threshold if the omission number is equal to the conservative estimation minus 1.

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