CN109728882B

CN109728882B - Method and device for solving uplink channel resource conflict

Info

Publication number: CN109728882B
Application number: CN201711046002.4A
Authority: CN
Inventors: 李琳; 杨茜
Original assignee: Potevio Information Technology Co Ltd
Current assignee: Potevio Information Technology Co Ltd
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2021-08-03
Anticipated expiration: 2037-10-31
Also published as: CN109728882A

Abstract

The invention provides a method for solving uplink channel resource conflict, which comprises the steps of determining the format of a Physical Uplink Control Channel (PUCCH) according to downlink authorization information, calculating the ratio P of PUCCH resources and Physical Uplink Shared Channel (PUSCH) resources according to the format of the PUCCH, and issuing Downlink Control Information (DCI) to terminal UE if the ratio P and the number of available radio frames in the PDCCH period of the physical downlink control channel meet the following first preset condition, wherein the DCI comprises F2, MCS1 index and NF 1. According to the method for solving the uplink channel resource conflict, when the ratio P of the PUCCH resource to the PUSCH resource exceeds a certain threshold, the uplink data is ensured to have higher accuracy and efficiency when being transmitted by increasing the repeated transmission times of the uplink data.

Description

Method and device for solving uplink channel resource conflict

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for resolving an uplink channel resource conflict.

Background

In wireless communication technology, frequency spectrum resources are particularly precious, and how to improve the utilization rate of the frequency spectrum resources is a technical problem which needs to be solved in the field for a long time.

In a new scheme of a Long Term Evolution 230 (LTE 230) system, the uplink and downlink data transmission process is as follows: during Uplink data transmission, a base station sends Downlink Control Information (DCI) through a Physical Downlink Control Channel (PDCCH), an authorization terminal (User Equipment, UE) uploads data, and after the DCI is repeatedly issued and a certain time (radio frame is taken as a unit) elapses, the UE uploads data through a Physical Uplink Shared Channel (PUSCH). The uplink data Transport Blocks (TBSs) may be mapped to one or more radio frames, where the number of the radio frames is denoted by NF, and each radio frame includes three uplink subframes, where a part of Single-carrier frequency-Division Multiple Access (SC-FDMA) symbols in the three uplink subframes are used to carry Acknowledgement/No-Acknowledgement (ACK/NACK), and when there is No uplink pilot symbol in the SC-FDMA symbols in the uplink subframes of a radio frame, the radio frame does not upload data. And when the SC-FDMA symbol in the uplink subframe of the wireless frame contains an uplink pilot frequency symbol, the wireless frame uploads data, the data uploading adopts repeated transmission, and the repeated transmission times are represented by F. The DCI transmitted by the base station to the UE includes a Modulation and Coding Scheme (MCS) index, the number NF of radio frames mapped by the TBS, and the number F of uplink data retransmission times. The PUSCH is used to carry Uplink data Information, and a Physical Uplink Control Channel (PUCCH) is used to carry Uplink Control Information (UCI), where the UCI includes ACK/NACK.

In the prior art, the format of the PUCCH is determined by the number F of downlink data repeat transmissions when no uplink data is transmitted, and when the number F of downlink data repeat transmissions is less than or equal to 4, the PUCCH occupies 4 SC-FDM symbols, and the format of the PUCCH is format 0; when the number of times F of the downlink data repeat transmission is larger than 4 and smaller than or equal to 16, the PUCCH occupies 1 radio frame, and the format of the PUCCH is 1; when the downlink data repeat transmission frequency F is more than 16, the PUCCH occupies 2 radio frames, and the format of the PUCCH is format 2.

When uplink data are transmitted, the format of the PUCCH is determined by the number of times F of uplink data repeated transmission, and when the number of times F of uplink data repeated transmission is less than or equal to 4, the PUCCH occupies 4 SC-FDM symbols, and the format of the PUCCH is 0; when the number of times F of repeated transmission of the uplink data is larger than 4 and is less than or equal to 32, the PUCCH occupies 1 wireless frame, and the format of the PUCCH is 1; and when the number of times F of repeated transmission of the uplink data is greater than 32, the PUCCH occupies 2 radio frames, and the format of the PUCCH is format 2.

However, in the process of uplink and downlink data simultaneous transmission, there may be a case where the PUSCH and the PUCCH are simultaneously occupied in one uplink data transmission period, and a case where synchronization information is transmitted may also be considered. In this case, the UCI fed back by the terminal to the base station occupies PUCCH resources, which reduces available PUSCH resources for carrying uplink data, thereby reducing accuracy and efficiency of uplink data transmission.

Disclosure of Invention

Technical problem to be solved

The invention aims to provide a method for solving uplink channel resource conflict, which solves the technical problems that in the prior art, when uplink and downlink data are transmitted simultaneously, PUCCH resources are occupied, available PUSCH resources are reduced, and the accuracy and efficiency of uplink data transmission are reduced.

(II) technical scheme

In order to solve the above technical problem, in one aspect, the present invention provides a method for solving an uplink channel resource conflict, including:

determining a format of a Physical Uplink Control Channel (PUCCH) according to downlink authorization information, and calculating a ratio P of PUCCH resources and Physical Uplink Shared Channel (PUSCH) resources according to the format of the PUCCH, wherein the downlink authorization information comprises a first uplink data repeat transmission frequency F1, a first modulation and coding strategy MCS1 index and a first radio frame number NF1 mapped by an uplink data Transmission Block (TBS);

if the ratio P and the number of available radio frames in the PDCCH period are judged and known to meet the following first preset condition, sending DCI to terminal UE, wherein the DCI comprises the F2, the MCS1 index and the NF 1;

wherein the first preset condition comprises: the ratio P is greater than or equal to a preset threshold value, and the number of available wireless frames in the PDCCH period is greater than or equal to the product of the preset second uplink data repeated transmission times F2 and the NF 1;

f2 is greater than F1.

Further, the method also comprises

If the number of the available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH are judged and obtained to meet the following second preset condition, determining that the number of the available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH meet the following second preset condition

Acquiring the bit number B2 of a virtual uplink data transmission block TBS1 according to the ratio P and the bit number B1 of the TBS;

determining a second modulation and coding strategy MCS2 index and the number NF2 of second wireless frames mapped by the TBS1 by searching a preset lookup table according to the bit number B2, wherein the preset lookup table comprises a plurality of groups of lookup data, and each group of lookup data comprises a one-to-one correspondence relationship among the bit number, the MCS index and the number of the wireless frames mapped by the data transmission block;

issuing DCI to terminal UE, wherein the DCI comprises the F1, the MCS2 index and the NF 2;

wherein the second preset condition comprises: the ratio P is greater than or equal to a preset threshold value, the number of available radio frames in the PDCCH period is less than the product of the preset second uplink data repeat transmission times F2 and the NF1, and the uplink retransmission mode is a non-hybrid automatic repeat request HARQ mode.

Further, the obtaining of the bit number B2 of the virtual uplink data transport block TBS1 according to the ratio P and the bit number B1 of the TBS specifically includes:

B2＝(1-P)*B1

wherein, B2 is the bit number of the virtual uplink data transport block TBS1, B1 is the bit number of the uplink data transport block TBS, and P is the ratio of the PUCCH resource to the PUSCH resource.

Further, the MCS2 index is equal to the MCS1 index, the NF2 is less than the NF 1;

alternatively, the MCS2 index is less than the MCS1 index, and the NF2 is equal to the NF 1.

In another aspect, the present invention provides an apparatus for resolving uplink channel resource conflicts, including:

the system comprises a calculation module and a processing module, wherein the calculation module is used for determining the format of a Physical Uplink Control Channel (PUCCH) according to downlink authorization information, and calculating the ratio P of PUCCH resources and Physical Uplink Shared Channel (PUSCH) resources according to the format of the PUCCH, and the downlink authorization information comprises a first uplink data repeat transmission frequency F1, a first modulation and coding strategy MCS1 index and a first radio frame number NF1 mapped by an uplink data transmission block TBS;

a sending module, configured to send DCI to a terminal UE if it is determined that the ratio P and the number of available radio frames in a PDCCH period of a physical downlink control channel satisfy a first preset condition, where the DCI includes the F2, the MCS1 index, and the NF 1;

f2 is greater than F1.

Further, if it is determined that the number of available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH satisfy the following second preset condition, the sending module is further configured to:

B2＝(1-P)*B1

In another aspect, the present invention provides an electronic device for resolving an uplink channel resource conflict, including:

the processor and the memory are communicated with each other through a bus; the memory stores program instructions executable by the processor, which when called by the processor are capable of performing the methods described above.

In yet another aspect, the invention provides a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, cause the computer to perform the method described above.

In a further aspect, the invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method described above.

(III) advantageous effects

When the ratio P of PUCCH resources to PUSCH resources exceeds a certain threshold, according to the MCS index in the downlink authorization information, the number NF of wireless frames mapped by the TBS and the number F of uplink data repeated transmission times, when the PDCCH period has enough wireless frames, the method ensures higher accuracy and efficiency during uplink data transmission by increasing the number of uplink data repeated transmission times and adjusting the number of the MCS index or the number of the wireless frames mapped by the TBS when the PDCCH period has no enough wireless frames.

Drawings

Fig. 1 is a schematic diagram illustrating a method for resolving uplink channel resource conflicts according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for resolving uplink channel resource conflicts according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating an apparatus for resolving uplink channel resource conflicts according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an electronic device for resolving an uplink channel resource conflict according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

fig. 1 is a schematic diagram of a method for resolving an uplink channel resource conflict according to an embodiment of the present invention, and as shown in fig. 1, an embodiment of the present invention provides a method for resolving an uplink channel resource conflict, including:

step S10, determining the format of a Physical Uplink Control Channel (PUCCH) according to downlink authorization information, and calculating the ratio P of PUCCH resources to Physical Uplink Shared Channel (PUSCH) resources according to the format of the PUCCH, wherein the downlink authorization information comprises a first uplink data repeat transmission frequency F1, a first modulation and coding strategy MCS1 index and a first radio frame number NF1 mapped by an uplink data Transmission Block (TBS);

step S20, if judging that the ratio P and the number of available radio frames in the PDCCH period meet the following first preset condition, issuing Downlink Control Information (DCI) to a terminal UE, wherein the DCI comprises the F2, the MCS1 index and the NF 1;

f2 is greater than F1.

Specifically, in the process of simultaneously transmitting uplink and downlink data, one uplink data transmission period refers to that the uplink data starts to be transmitted until the data transmission is completed, before the uplink data starts to be transmitted, the UE needs to report the size of an uplink data transmission block TBS to the base station, that is, the bit number of the uplink data transmission block TBS is reported to the base station, the base station presets downlink authorization information for the UE according to the size of the uplink data transmission block TBS reported by the UE and the number of available radio frames in the PDCCH period, where the downlink authorization information includes multiple parameters that need to be configured when the UE uploads data, including a first uplink data repeat transmission frequency F1, a first modulation and coding strategy MCS1 index, and a first radio frame number NF1 mapped by the uplink data transmission block TBS. In the LTE 230 system, DCI is delivered to a UE through a PDCCH, and is repeatedly delivered multiple times to ensure that the UE can receive the DCI. And after receiving the DCI issued by the base station, the UE starts to upload data according to the corresponding parameters.

Due to the fact that uplink and downlink data are transmitted simultaneously, the UE needs to report ACK/NACK to the base station continuously through the PUCCH, the PUCCH resources are occupied, the PUSCH resources available for uploading data are correspondingly reduced, and if the condition of synchronous frame sending is considered, the PUSCH resources available for uploading data are correspondingly reduced. The selection of the PUCCH format is determined by the first number of uplink data retransmission times F1 in the downlink grant information. When the first uplink data repeat transmission frequency F1 is less than or equal to 4, the PUCCH occupies 4 SC-FDM symbols, and the format of the PUCCH is format 0; when the first uplink data repeat transmission frequency F1 is greater than 4 and less than or equal to 32, the PUCCH occupies 1 radio frame, and the format of the PUCCH is format 1; when the first uplink data repeat transmission frequency F1 is greater than 32, the PUCCH occupies 2 radio frames, and the format of the PUCCH is format 2.

And the base station determines the format of the PUCCH according to the first uplink data repeated transmission times F1 in the downlink authorization information, and calculates the ratio P of the PUCCH resources and the PUSCH resources according to the format and the occupied position of the PUCCH.

It should be noted that: and if the condition of sending the synchronous frame is considered, calculating the ratio of the PUCCH resource and the synchronous frame resource to the PUSCH resource according to the format and the occupied position of the PUCCH and the known occupied position of the synchronous frame. In this case, the method for solving the collision between the PUCCH resource and the synchronization frame resource and the PUSCH resource is the same as that in this embodiment, and is not described here again.

And then, judging the ratio P of the PUCCH resources to the PUSCH resources, and if the ratio P of the PUCCH resources to the PUSCH resources is smaller than a preset threshold value, considering that the occupation of the PUCCH resources has small influence on data uploading through the PUSCH resources, and normally uploading the data according to a punching mode or a rate matching mode.

And if the ratio P of the PUCCH resource to the PUSCH resource is greater than or equal to a preset threshold value, increasing the first uplink data repeated transmission times F1 to preset second uplink data repeated transmission times F2.

Then, the number of available radio frames in the PDCCH period and the product of the preset second uplink data retransmission frequency F2 and the NF1 are determined. And if the number of available radio frames in the PDCCH period is more than or equal to the product of the preset second uplink data repeated transmission times F2 and the NF1, the base station issues DCI to the terminal UE, wherein the DCI comprises the F2, the MCS1 index and the NF 1. And the terminal uploads the data according to the parameters in the DCI issued by the base station.

When the ratio P of PUCCH resources to PUSCH resources exceeds a certain threshold, according to the MCS index in the downlink authorization information, the number NF of wireless frames mapped by the TBS and the number F of uplink data repeated transmission times, when the number of the wireless frames in the PDCCH period is enough, the method for solving the uplink channel resource conflict ensures higher accuracy and efficiency during uplink data transmission by increasing the number of the uplink data repeated transmission times.

Example 2:

this embodiment is substantially the same as embodiment 1, and for the sake of brevity of description, in the description process of this embodiment, the same technical features as embodiment 1 are not described again, and only differences between this embodiment and embodiment 1 are explained:

further, if it is determined that the number of available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH satisfy the following second preset condition, the method further includes determining that the number of available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH satisfy the following second preset condition

B2＝(1-P)*B1

Specifically, if the number of available radio frames in the PDCCH period is less than the product of the preset number F2 of second uplink data retransmission times and the NF1, the base station determines whether the uplink retransmission mode is a Hybrid Automatic Repeat reQuest (HARQ).

If the uplink retransmission mode is judged to be not the HARQ, the base station obtains the bit number B2 of the virtual uplink data transport block TBS1 according to the ratio P of the PUCCH resource to the PUSCH resource and the bit number B1 of the uplink data transport block TBS, and calculates the bit number B2 of the virtual uplink data transport block TBS1 according to the formula B2 ═ 1-P × B1, where B2 is the bit number of the virtual uplink data transport block TBS1, B1 is the bit number of the uplink data transport block TBS, and P is the ratio of the PUCCH resource to the PUSCH resource.

Then, the second modulation and coding strategy MCS2 index and the second number NF2 of radio frames mapped by the virtual uplink data transport block TBS1 are determined by looking up a preset look-up table according to the bit number B2 of the virtual uplink data transport block TBS1, where the preset look-up table includes a plurality of sets of look-up data, and each set of look-up data includes a one-to-one correspondence relationship among the bit number, the MCS index, and the number of radio frames mapped by the data transport block. During searching, according to the bit number B2 of the virtual uplink data transport block TBS1, a group of MCS indexes corresponding to the bit number value closest to the bit number B2 and the number of radio frames mapped by the data transport block are searched in the lookup table, that is, the MCS2 index and the number NF2 of second radio frames mapped by the virtual uplink data transport block TBS1 are searched.

In addition, when an MCS2 index and the number NF2 of the second radio frames mapped by the virtual uplink data transport block TBS1 are selected, the MCS2 index is preferentially selected to be equal to the MCS1 index, and a group of search data of which the NF2 is smaller than the NF1 is ensured; alternatively, the MCS2 index is less than the MCS1 index while ensuring that the NF2 is equal to the set of lookup data of the NF 1.

Then, the base station issues DCI to the terminal UE according to the determined MCS2 index and the number NF2 of the second radio frames mapped by the virtual uplink data transport block TBS1, wherein the DCI comprises the F1, the MCS2 index and the NF 2. And the terminal uploads the data according to the parameters in the DCI issued by the base station.

And if the uplink retransmission mode is judged to be HARQ, the operation is not carried out, and the terminal continues to upload data according to the parameters in the DCI primarily issued by the base station.

Fig. 2 is a flowchart illustrating a method for resolving uplink channel resource conflicts according to an embodiment of the present invention.

When the ratio P of PUCCH resources to PUSCH resources exceeds a certain threshold, according to the MCS index of the downlink authorization information, the number NF of wireless frames mapped by the TBS and the number F of repeated transmission of uplink data, when the number of the wireless frames in the PDCCH period is enough, the number of the repeated transmission of the uplink data is increased, and when the number of the wireless frames in the PDCCH period is not enough, the number of the wireless frames mapped by the MCS index or the TBS is adjusted, so that higher accuracy and efficiency are ensured during the transmission of the uplink data.

Example 3:

fig. 3 is a schematic diagram of an apparatus for resolving uplink channel resource conflicts according to an embodiment of the present invention, and as shown in fig. 3, an embodiment of the present invention discloses an apparatus for resolving uplink channel resource conflicts, which includes a calculating module 10 and a sending module 20, wherein,

the calculation module 10 is configured to determine a format of a physical uplink control channel PUCCH according to downlink grant information, and calculate a ratio P between a PUCCH resource and a physical uplink shared channel PUSCH resource according to the format of the PUCCH, where the downlink grant information includes a first uplink data repeat transmission frequency F1, a first modulation and coding strategy MCS1 index, and a first radio frame number NF1 mapped by an uplink data transport block TBS;

if judging that the ratio P and the number of available radio frames in the PDCCH period of the PDCCH satisfy the following first preset condition, the sending module 10 is configured to issue DCI to the UE, where the DCI includes the F2, the MCS1 index, and the NF 1;

f2 is greater than F1.

Further, if it is determined that the number of available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH satisfy the following second preset condition, the sending module 20 is further configured to:

B2＝(1-P)*B1

Specifically, the apparatus for solving the uplink channel resource conflict provided in the embodiment of the present invention corresponds to the method embodiment 1 and embodiment 2, and is configured to complete the method in each embodiment. Specifically, the process of solving the uplink channel resource conflict through the apparatus is the same as that in the foregoing embodiments, and details are not described here.

According to the device for solving the uplink channel resource conflict, when the ratio P of PUCCH resources to PUSCH resources exceeds a certain threshold, according to the MCS index in the downlink authorization information, the number NF of wireless frames mapped by the TBS and the number F of uplink data repeated transmission times, when the number of the wireless frames in the PDCCH period is enough, the number of the uplink data repeated transmission times is increased, and when the number of the wireless frames in the PDCCH period is not enough, the number of the wireless frames mapped by the MCS index or the TBS is adjusted, so that higher accuracy and efficiency are ensured during uplink data transmission.

Example 4:

fig. 4 is a schematic structural diagram of an electronic device for resolving an uplink channel resource conflict according to an embodiment of the present invention, and as shown in fig. 4, the device includes: a processor (processor)801, a memory (memory)802, and a bus 803;

wherein, the processor 801 and the memory 802 complete the communication with each other through the bus 803;

the processor 801 is configured to call program instructions in the memory 802 to perform the methods provided by the above-described method embodiments, including, for example:

f2 is greater than F1.

Example 5:

an embodiment of the present invention discloses a computer program product, which includes a computer program stored on a non-transitory computer readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, the computer can execute the methods provided by the above method embodiments, for example, the method includes:

f2 is greater than F1.

Example 6:

embodiments of the present invention provide a non-transitory computer-readable storage medium, which stores computer instructions, where the computer instructions cause the computer to perform the methods provided by the above method embodiments, for example, the methods include:

f2 is greater than F1.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

The above-described embodiments of the apparatuses and devices are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A method for resolving uplink channel resource conflicts, comprising:

if the ratio P and the number of available radio frames in the PDCCH period meet the following first preset conditions, Downlink Control Information (DCI) is issued to terminal UE, wherein the DCI comprises preset second uplink data repeated transmission times F2, the MCS1 index and the NF 1;

f2 is greater than F1.

2. The method of claim 1, further comprising

3. The method of claim 2, wherein the obtaining of the bit number B2 of the virtual uplink data transport block TBS1 according to the ratio P and the bit number B1 of the TBS is specifically:

B2＝(1-P)*B1

4. The method of claim 2, wherein the MCS2 index is equal to the MCS1 index, and wherein the NF2 is less than the NF 1;

5. An apparatus for resolving uplink channel resource conflicts, comprising:

a sending module, configured to send DCI to a terminal UE if it is determined that the ratio P and the number of available radio frames in a PDCCH period of a physical downlink control channel satisfy a first preset condition, where the DCI includes a preset second uplink data retransmission frequency F2, an MCS1 index, and NF 1;

f2 is greater than F1.

6. The apparatus of claim 5,

if it is determined that the number of available radio frames and the uplink retransmission mode in the period of the ratio P, PDCCH satisfy the following second preset condition, the sending module is further configured to:

7. The apparatus of claim 5, wherein the obtaining of the bit number B2 of the virtual uplink data transport block TBS1 according to the ratio P and the bit number B1 of the TBS is specifically:

B2＝(1-P)*B1

8. An electronic device configured to resolve uplink channel resource conflicts, comprising:

the processor and the memory are communicated with each other through a bus; the memory stores program instructions executable by the processor, the processor invoking the program instructions to perform the method of any of claims 1 to 4.

9. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the method according to any one of claims 1 to 4.