CN111865500B

CN111865500B - Method and device for determining PDCCH transmission in URLLC

Info

Publication number: CN111865500B
Application number: CN201910361407.XA
Authority: CN
Inventors: 徐夏刚
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2023-04-18
Anticipated expiration: 2039-04-30
Also published as: CN111865500A

Abstract

The invention aims to provide a method and equipment for determining PDCCH transmission in URLLC. Compared with the prior art, the single modified DCI is sent at the base station end to schedule a plurality of PDSCHs for data transmission; triggering to execute a PDCCH-ACK report when the number of the ACKs received from the corresponding UE for PDSCH data transmission in a first preset time period is counted to be less than a first threshold value, otherwise not executing; and when the PDCCH-ACK report is executed, determining a PDCCH transmission mode based on the counted ACK number for PDCCH data transmission received from the UE in a second preset time period according to the PDCCH-ACK report, and introducing a PDCCH-ACK which represents PDCCH performance for URLLC service to help a base station to determine a PDCCH transmission scheme to be implemented.

Description

Method and device for determining PDCCH transmission in URLLC

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a technology for determining PDCCH (Physical Downlink Control Channel) transmission in URLLC (Ultra Reliable and Low Latency Communication). .

Background

At TR38.802, the following protocol is reached regarding the NR (New Radio) coordinated transmission scheme: NR supports Downlink Transmission of the same NR-PDSCH (New Radio-Physical Downlink Shared Channel) data stream from multiple TRPs (Transmission points) at least in the case of ideal backhaul, and Downlink Transmission of different NR-PDSCH data streams from multiple TRPs in the case of ideal backhaul and non-ideal backhaul. Note that the case of supporting the same NR-PDSCH data stream may or may not have a specification impact.

In the latest RAN1#95 conference, REL-16 supports multiple PDCCHs and a single PDCCH, which is applicable only to EMBB (enhanced Mobile Broadband) service. For URLLC services, whether or how to design a new DCI (Downlink Control Information) applicable to multiple TRPs has not been determined. To improve the reliability of the PDCCH, coordinated TRPs may jointly transmit the same DCI to achieve diversity gain, or transmit separate DCIs with the same DCI content to achieve combining gain. However, PDCCH enhancement of URLLC by a single TRP, such as PDCCH repetition and compression (DCI), has been widely discussed. Thus, this enhancement may already be sufficient for certain scenarios where multiple TRPs are used, which means that the PDCCH transmission does not have to be repeated in every TRP. Therefore, how to effectively improve the performance of the PDCCH by using the two methods needs further research.

It is well known that discussions about URLLC enhancements in REL-16 are in progress at RAN1 conferences. Especially for PDCCH enhancement of URLLC, a lot of discussions are made on schemes such as PDCCH repetition and DCI compression for new application scenarios such as factory automation, transportation industry and power distribution in REL-16. However, before RAN1#95 conference, no such clear consensus has been reached for PDCCH enhancement of URLLC with multiple TRPs.

To improve the reliability of PDCCH, coordinated TRPs may jointly transmit the same DCI or transmit independent DCI with the same DCI content, especially for UEs (User Equipment) located at the cell edge. This will result in a loss of scheduling flexibility and multiplexing gain, new DCI formats must be designed to reduce certain fields (fields) containing different content in different TRPs, and cooperation between TRPs is required under the assumption of ideal backhaul or very short delay. For non-ideal backhaul, this approach does not work. Furthermore, the primary PDCCH enhancement of URLLC by a single TRP may be sufficient to meet the PDCCH detection BLER (Block Error rate) requirements of a UE located in the center of the cell. Therefore, for URLLC services, no matter where the UE is located, it is not mandatory to use a repetition scheme to enhance PDCCH. Therefore, when and how to balance between throughput enhancement and reliability enhancement will be the first issue we have to solve. This means that the UE should be informed whether or not to do a repetition combining.

As mentioned above, during the R15 to RAN1#90 conference, NR PDCCH enhancements for multiple TRPs have been discussed, and it has been agreed that the maximum supported number of unicast and dynamically scheduled NR-PDSCHs that can be received simultaneously on each component bearer is expected to be 2. In the recent RAN1#95 conference, a new protocol is reached, from which we can see that only the repeatability and diversity of DCI/UCI (Uplink Control Information) are solved. Most companies recommend using PDCCH repetition for multiple TRPs. This means that the PDCCH in the URLLC traffic is enhanced with repeated transmissions on multiple TRPs, regardless of where the UE is located in the cell. This will limit PDCCH transmission only over multiple seemingly less efficient and robust PDCCHs.

Disclosure of Invention

The invention aims to provide a method and equipment for determining PDCCH transmission in URLLC.

According to an aspect of the present invention, a method for determining PDCCH transmission in URLLC at a base station is provided, wherein the method includes:

transmitting a single modified DCI to schedule the plurality of PDSCHs for data transmission;

when the number of the ACKs received from the corresponding UE in the first preset time period and aiming at the PDSCH data transmission is smaller than a first threshold value, triggering to execute a PDCCH-ACK report, otherwise, not executing the PDCCH-ACK report;

when the PDCCH-ACK report is executed, determining a PDCCH transmission mode based on the counted number of ACKs for PDCCH data transmission received from the UE in a second preset time period according to the PDCCH-ACK report.

In a preferred embodiment, determining the PDCCH transmission mode includes:

when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value, triggering repeated data transmission of the PDCCH from multiple TRPs;

otherwise, the PDCCH repeated data transmission from the multiple TRPs is closed.

In a preferred embodiment, the turning off PDCCH repetition data transmission from multiple TRPs further comprises:

and when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be larger than or equal to the sum of a second threshold value and an error tolerance value, the PDCCH repeated data transmission from the multiple TRPs is closed.

In a preferred embodiment, triggering the execution of PDCCH-ACK reporting comprises:

and sending an indication to the UE to inform the UE to report ACK information for PDCCH data transmission.

According to another aspect of the present invention, there is also provided a method implemented at a UE side for determining PDCCH transmission in URLLC, wherein the method includes:

and reporting ACK information aiming at PDCCH data transmission to the base station according to the indication received from the corresponding base station, so that the base station judges whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted ACK number aiming at PDCCH data transmission received from the UE in a second preset time period.

In a preferred embodiment, the method comprises:

and reporting ACK information aiming at PDSCH data transmission to the base station according to the indication received from the base station, so that the base station judges whether to trigger execution of a PDCCH-ACK report based on the counted ACK number aiming at PDSCH data transmission received from the UE in a first preset time period.

According to another aspect of the present invention, there is also provided a base station for determining PDCCH transmission in URLLC, wherein the base station includes:

a scheduling device, configured to send a single modified DCI to schedule multiple PDSCHs for data transmission;

triggering means for triggering execution of a PDCCH-ACK report when it is counted that the number of ACKs received from a corresponding UE for PDSCH data transmission within a first predetermined period is smaller than a first threshold, otherwise not executing;

and determining means for determining a PDCCH transmission mode based on the counted number of ACKs for PDCCH data transmission received from the UE within a second predetermined period of time when the PDCCH-ACK report is performed.

In a preferred embodiment, the determining means is further configured to: triggering repeated data transmission of the PDCCH from multiple TRPs when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value;

In a preferred embodiment, the determining means is further configured to:

In a preferred embodiment, the triggering device is further configured to: and sending an indication to the UE to inform the UE to report ACK information aiming at PDCCH data transmission.

According to another aspect of the present invention, there is also provided a UE for determining PDCCH transmission in URLLC, the UE comprising:

and the first reporting device is used for reporting ACK information aiming at PDCCH data transmission to the base station according to the indication received from the corresponding base station, so that the base station judges whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted ACK number aiming at PDCCH data transmission received from the UE in a second preset time period.

In a preferred embodiment, the UE further comprises:

and a second reporting device, configured to report, to the base station, ACK information for PDSCH data transmission according to an instruction received from the base station, so that the base station determines whether to trigger execution of a PDCCH-ACK report based on a counted number of ACKs for PDSCH data transmission received from the UE within a first predetermined time period.

According to still another aspect of the present invention, there is further provided a system for determining PDCCH transmission in URLLC, including the base station according to any preceding item and the UE according to any preceding item.

Compared with the prior art, the single modified DCI is sent at the base station end to schedule a plurality of PDSCHs for data transmission; triggering to execute a PDCCH-ACK report when the number of the ACKs received from the corresponding UE for PDSCH data transmission in a first preset time period is counted to be less than a first threshold value, otherwise not executing; and when the PDCCH-ACK report is executed, determining a PDCCH transmission mode based on the counted ACK number for PDCCH data transmission received from the UE in a second preset time period according to the PDCCH-ACK report, and introducing a PDCCH-ACK which represents PDCCH performance for URLLC service to help a base station to determine a PDCCH transmission scheme to be implemented.

Further, when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value, triggering the PDCCH repeated data transmission from the multiple TRPs; otherwise, the PDCCH repeated data transmission from the multiple TRPs is closed, the base station is helped to distinguish that the PDSCH or the PDCCH causes the PDSCH failure, the PDCCH repeated data transmission from the multiple TRPs is triggered after the PDSCH failure caused by the PDCCH is confirmed, so that the multiple TRPs in the spatial domain are further enhanced, the performance loss caused by poor channels is solved, and if the PDSCH failure not caused by the PDCCH is found, the PDCCH is switched to be transmitted independently.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments thereof, made with reference to the following drawings:

fig. 1 shows a flow chart of a method for determining PDCCH transmission in URLLC implemented at a base station in accordance with an aspect of the invention;

fig. 2 illustrates a diagram for PDCCH data transmission using multiple TRPs according to a preferred embodiment of the present invention.

The same or similar reference numbers in the drawings identify the same or similar elements.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

The term "base station" as used herein may be considered synonymous with, and sometimes referred to hereinafter as: a node B, an evolved node B, a next generation node B, a gNB, an eNodeB, an eNB, a Base Transceiver Station (BTS), an RNC, etc., and may describe a transceiver that communicates with and provides radio resources for a mobile in a wireless communication network that may span multiple technology generations. The base stations discussed herein may have all of the functionality associated with conventional well-known base stations, except for the ability to implement the methods discussed herein.

The methods discussed below may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine or computer readable medium such as a storage medium. The processor(s) may perform the necessary tasks.

Specific structural and functional details disclosed herein are merely representative and are provided for purposes of describing example embodiments of the present invention. The present invention may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be termed a second element, and, similarly, a second element may be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Other words used to describe the relationship between elements (e.g., "between" versus "directly between", "adjacent" versus "directly adjacent to", etc.) should be interpreted in a similar manner.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be noted that, in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed substantially concurrently, or the figures may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It is known that in Rel-16SI of eURLLC, repeated transmission of PDCCH is being investigated. Therefore, when URLLC traffic arrives (traffic areas), this will first trigger the PDCCH enhancement, i.e. the repeated transmission of PDCCH. Since the gNB (next generation node B) cannot distinguish a link error, it cannot distinguish whether the PDSCH or the PDCCH caused the PDSCH failure, and it can only perform retransmission. If the error is due to PDCCH decoding failure, PDCCH enhancement via multiple TRPs may be triggered, if not, the performance of the PDCCH may warrant its need, and multiple different PDCCHs may be transmitted from multiple TRPs to increase its performance. To help the gNB recognize this point, an indicator is proposed to indicate PDCCH errors, e.g., ACK or NACK transmitted via PUCCH (Physical Downlink Control Channel) or other channels with respect to the PDCCH.

In view of the above problems, a new handover mechanism for URLLC is proposed for PDCCH transmission from separate TRPs through repeated PDCCH or separate PDCCH. To implement this mechanism, a PDCCH-ACK report is proposed, informing the gNB of the PDCCH decoding result when URLLC traffic arrives, and another indicator is proposed, such as adding another indicator in DCI or RRC signaling, to trigger the handover.

Furthermore, URLLC enhancements with multiple TRPs are always suitable for ideal backhaul with delays less than 2 milliseconds. In this case, the TRP can exchange information without delay or with very little delay, which has little effect on the synchronization of the TRP, and then only a single PDCCH can be triggered.

Fig. 1 shows a flow chart of a method for determining PDCCH transmission in URLLC according to an aspect of the invention.

In step S101, the base station transmits a single modified DCI to schedule multiple PDSCHs for data transmission.

Specifically, in step S101, when the URLLC service arrives, the base station, e.g., the gNB, transmits a single modified DCI to the corresponding UE by using a conventional method, e.g., PDCCH repetition in the time domain, so as to schedule multiple PDSCHs for data transmission, or schedule different layers (layers) from the same PDSCH for data transmission.

The base station may also send an indication to the corresponding UE, for example, by adding an indication to the DCI, or adding an indication to the upper layer RRC signaling, or sending the indication to the corresponding UE through an independent transmission channel, so that the UE reports ACK information for PDSCH data transmission to the base station accordingly.

Here, since RRC signaling is an upper layer signaling, the degree of freedom is larger, but the time required for indicating the UE is larger than that of DCI. Those skilled in the art should understand which way to select to indicate the UE can be adjusted according to the actual situation, and is not limited herein.

Correspondingly, the UE corresponding to the base station reports ACK information for PDSCH data transmission to the base station according to the indication received from the base station, so that the base station judges whether to trigger execution of a PDCCH-ACK report based on the counted number of ACKs for PDSCH data transmission received from the UE in a first preset time period.

Specifically, after receiving the instruction, the UE reports ACK information for PDSCH data transmission to the base station by using a predefined resource on a PUSCH or PUCCH, for example, the ACK information may be combined with existing bit information on the PUSCH or PUCCH, and the combined information is reported to the base station, and the base station parses the ACK information from the combined information after receiving the ACK information, or after receiving the instruction, the UE reports ACK information for PDSCH data transmission to the base station by using a separate transmission channel. Therefore, after receiving the ACK information, the base station judges whether to trigger the execution of the PDCCH-ACK report based on the counted number of ACKs for PDSCH data transmission received from the UE in the first preset time period.

Those skilled in the art should understand which way the UE selects to report the ACK information for PDSCH data transmission may be adjusted according to the actual situation, and is not limited herein.

In step S102, when it is counted that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is less than the first threshold, the base station triggers performing PDCCH-ACK reporting, otherwise not performing the PDCCH-ACK reporting.

Specifically, in step S102, the base station counts the number of ACKs received within a period of time according to the number of ACKs received from the UE for PDSCH data transmission, for example, counts the number of ACKs received from the corresponding UE for PDSCH data transmission within a first predetermined period of time, and when the number is smaller than a first threshold, the base station triggers to execute a PDCCH-ACK report, for example, sends an indication to the corresponding UE to notify the UE to report ACK information for PDCCH data transmission, otherwise, the base station does not execute the PDCCH-ACK report.

Here, the base station may use a status parameter ON to indicate that the PDCCH-ACK report is in an ON state, and use a status parameter OFF to indicate that the PDCCH-ACK report is in an OFF state, for example. In step S102, if the base station determines that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is smaller than the first threshold, the status parameter of the PDCCH-ACK report is set to ON, the base station is in a PDCCH-ACK report ON state, and the base station triggers to execute a PDCCH-ACK report according to the status, for example, sends an indication to the corresponding UE to notify the UE of reporting ACK information for PDCCH data transmission. Or, in step S102, the base station determines that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is greater than or equal to the first threshold, and the current status parameter of the PDCCH-ACK report is ON, sets the status parameter to OFF, or if the current status parameter of the PDCCH-ACK report is OFF, does not perform any processing.

In one embodiment, the base station calculates the number of ACKs reported by the UE for PDSCH data transmission, denoted herein as N, for a pre-configured duration, i.e., a first predetermined period, e.g., N1 slots (slots) of PUCCH channel transmission _ACK A PDSCH, recording the first threshold as Thr1, and judging whether N is present _ACK _PDSCH<Thr1, if N _ACK _PDSCH<Thr1, the base station triggers and executes PDCCH-ACK report, otherwise, if N is not the case _ACK If the PDSCH is more than or equal to Thr1, the PDCCH-ACK report is not executed.

It is understood by those skilled in the art that the first threshold is determined according to the number of ACKs received in a time duration, and the first threshold can be defined as the number of ACKs received in a unit time period, for example, whether (N) is determined _ACK _PDSCH)/N1<Thr1, if (N) _ACK _PDSCH)/N1<Thr1, the base station triggers the execution of PDCCH-ACK report, otherwise, if (N) _ACK If the value of _ PDSCH)/N1 is larger than or equal to Thr1, the PDCCH-ACK report is not executed. Both of the two ways can be used to determine the number of ACKs reported by the UE for PDSCH data transmission, i.e., to determine the transmission success rate of the PDSCH, and to determine whether to trigger the execution of PDCCH-ACK reporting. And, the specific value of the first threshold value can be set according to the actual situation.

Wherein triggering the execution of the PDCCH-ACK report comprises: and sending an indication to the UE to inform the UE to report ACK information for PDCCH data transmission.

Specifically, when the base station determines in step S102 that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is smaller than the first threshold, the base station may further send an indication to the corresponding UE, for example, by adding an indication in the DCI, or adding an indication in the upper RRC signaling, or sending the indication to the corresponding UE through a separate transmission channel, so as to notify the UE to report ACK information for PDCCH data transmission to the base station accordingly.

Correspondingly, the UE reports the ACK information aiming at the PDCCH data transmission to the base station according to the indication received from the corresponding base station, so that the base station judges whether to trigger the PDCCH repeated data transmission from the multiple TRPs based on the counted ACK number aiming at the PDCCH data transmission received from the UE in a second preset time period.

Specifically, after receiving the indication, the UE reports ACK information for PDCCH data transmission to the base station by using a predefined resource on a PUSCH or PUCCH, for example, the ACK information may be combined with existing bit information on the PUSCH or PUCCH, and the combined information is reported to the base station, and the base station parses the ACK information from the combined information after receiving the ACK information, or after receiving the indication, the UE reports ACK information for PDCCH data transmission to the base station by using a separate transmission channel. Therefore, after receiving the ACK information, the base station judges whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted ACK number for PDCCH data transmission received from the UE in a second preset time period.

Those skilled in the art should understand which way the UE selects to report the ACK information for PDCCH data transmission may be adjusted according to the actual situation, and is not limited herein.

In step S103, when performing the PDCCH-ACK report, the base station determines a PDCCH transmission mode based on the counted number of ACKs received from the UE for PDCCH data transmission in a second predetermined period according to the PDCCH-ACK report.

Specifically, in step S103, after performing PDCCH-ACK reporting, that is, after instructing the corresponding UE to report the number of ACKs for PDCCH data transmission, the base station receives ACK information for PDCCH data transmission reported by the corresponding UE, and counts the ACK information received within a certain time period, for example, counts the number of ACKs for PDCCH data transmission received from the corresponding UE within a second predetermined time period, and determines a PDCCH transmission mode according to the number, for example, determines whether to perform PDCCH repeated data transmission from multiple TRPs or PDCCH single data transmission.

Preferably, the determining the PDCCH transmission mode includes: triggering repeated data transmission of the PDCCH from multiple TRPs when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value; otherwise, the PDCCH repeated data transmission from the multiple TRPs is closed.

Specifically, in step S103, the base station receives ACK information for PDCCH data transmission reported by the corresponding UE, and counts the ACK information received within a certain time period, and when the base station counts that the number of ACKs received from the UE for PDCCH data transmission within a second predetermined time period is smaller than a second threshold, the base station knows that the radio quality of the PDCCH is sufficiently poor, and triggers PDCCH repeated data transmission from multiple TRPs, so as to further enhance the spatial domain through multiple TRPs, thereby solving the performance loss caused by the channel problem. The PDCCH repetition data transmission from the multi-channel TRP can be seen in the lower graph of FIG. 2, wherein TRP-01 and TRP-02 perform PDCCH-1 repetition data transmission. The upper diagram of fig. 2 shows that TRP-01 and TRP-02 perform independent PDCCH data transmission, TRP-01 performs PDCCH-1 data transmission, and TRP-02 performs PDCCH-2 data transmission.

The base station may adopt a state parameter ON to indicate that the PDCCH repeated data transmission is in an ON state, adopt a state parameter OFF to indicate that the PDCCH repeated data transmission is in an OFF state, when the base station counts that the number of ACKs received from the UE in a second predetermined period for the PDCCH data transmission is smaller than a second threshold, set the state parameter of the PDCCH repeated data transmission to ON, and then the base station is in the PDCCH repeated data transmission ON state, and trigger PDCCH repeated data transmission from multiple TRPs according to the state. Or, in step S103, if the base station determines that the number of ACKs received from the UE for PDCCH data transmission in a second predetermined period is greater than or equal to a second threshold and the status parameter of the current PDCCH repeated data transmission is ON, the base station sets the status parameter to OFF, and turns OFF PDCCH repeated data transmission from multiple TRPs and switches to independent PDCCH data transmission, or if the status parameter of the current PDCCH repeated data transmission is OFF, no processing is performed.

In one embodiment, the base station calculates the number of ACKs, here denoted N, reported by the UE for PDCCH data transmission for a preconfigured duration, i.e. a second predetermined time period, e.g. N2 slots (slots) _ACK A PDCCH, a second threshold Thr2, and whether N is determined _ACK _PDCCH<Thr2, if N _ACK _PDCCH<Thr2, the base station triggers and executes PDCCH repeated data transmission from multiple TRPs, or else, if N is not the same _ACK And if the PDCCH is more than or equal to Thr2, the repeated data transmission of the PDCCH from the multiple TRPs is closed.

It is understood by those skilled in the art that the aforementioned second threshold is determined according to the number of received ACKs in a time duration, and the second threshold can be defined as the number of received ACKs in a unit time period, for example, whether (N) is determined _ACK _PDCCH)/N2<Thr2, if (N) _ACK _PDCCH)/N2<Thr2, the base station knows that the radio quality of the PDCCH is poor enough, and triggers the execution of repeated PDCCH data transmission from multiple TRPs, otherwise, if (N) _ACK And if the PDCCH)/N2 is more than or equal to Thr2, the PDCCH repeated data transmission from the multiple TRPs is closed. Both the two manners can be used for judging the number of ACK (acknowledgement character) reported by the UE and aiming at the PDCCH data transmission, namely judging the channel quality of the PDCCH, and determining whether to trigger execution of PDCCH repeated data transmission from multiple TRPs (physical downlink control channels). And, the specific value of the second threshold can be set according to actual conditions.

Preferably, the turning off PDCCH repetition data transmission from multiple TRPs further comprises: and when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be larger than or equal to the sum of a second threshold value and an error tolerance value, the PDCCH repeated data transmission from the multiple TRPs is closed.

Specifically, when it is determined whether the counted number of ACKs received from the UE for PDCCH data transmission in the second predetermined period is greater than or equal to the second threshold, there may be an error tolerance value used for buffering, that is, the base station does not immediately shut down PDCCH repeated data transmission from multiple TRPs once it is counted that the number of ACKs received from the UE for PDCCH data transmission in the second predetermined period is greater than or equal to the second threshold, but only shuts down PDCCH repeated data transmission from multiple TRPs when it is counted that the number of ACKs received from the UE for PDCCH data transmission in the second predetermined period is greater than or equal to the sum of the second threshold and the error tolerance value.

The specific value of the error tolerance value can be set according to actual conditions. Here, the fault tolerance value is represented by Δ, when (N) _ACK When the period of _ PDCCH)/N2 is more than or equal to Thr2+ delta, the base station knows that the radio quality of the PDCCH is good enough, namely, the PDCCH single data transmission can be carried out, and the PDCCH repeated data transmission from the multiple TRPs is closed.

In a specific embodiment, the base station sends a single modified DCI to schedule multiple PDSCHs or to schedule different layers from the same PDSCH for data transmission. The base station sends an indication to the corresponding UE, informs the UE to report ACK information aiming at PDSCH data transmission to the base station, after the base station receives the ACK information, counts the ACK number aiming at PDSCH data transmission received from the corresponding UE in a first preset time period, when the ACK number is smaller than a first threshold value, the fact that the PDSCH channel quality is poor probably or a wrong PDSCH is scheduled by DCI issued by a PDCCH possibly is shown, and because the base station cannot distinguish a link error, whether the PDSCH or the PDCCH causes PDSCH failure cannot be distinguished, therefore, in order to solve the problem, when the counted ACK number aiming at PDSCH data transmission received from the corresponding UE in the first preset time period is smaller than the first threshold value, a PDCCH-ACK report is triggered, namely, the base station sends the indication to the corresponding UE, and informs the UE to report the ACK information aiming at the PDCCH data transmission. And the corresponding UE reports the ACK information aiming at the PDCCH data transmission to the base station according to the indication. The base station then counts the number of ACKs for the PDCCH data transmission received from the UE within a second preset time period according to the ACK information for the PDCCH data transmission received from the UE, if the number of the ACKs is smaller than a second threshold value, the radio quality of the PDCCH is indicated to be poor enough, the PDCCH repeated data transmission from multiple TRPs needs to be triggered, and the performance loss caused by the channel problem is solved through a plurality of TRPs for enhancing the spatial domain. And if the base station counts that the number of the ACKs received from the UE in the second preset time period and aiming at the PDCCH data transmission is larger than or equal to the second threshold value, the radio quality of the PDCCH is good enough, the PDCCH repeated data transmission from the multiple TRPs is not needed, only the PDCCH single data transmission is needed, and therefore, the execution of the PDCCH repeated data transmission from the multiple TRPs is closed. Moreover, the radio quality of the PDCCH is good enough to indicate that the PDSCH data transmission failure is not caused by the PDCCH, and other PDSCH enhancement schemes may be triggered, which is not described herein again. In addition, if the base station counts that the number of ACKs received from the corresponding UE in the first predetermined time period for PDSCH data transmission is greater than or equal to the first threshold, it indicates that PDSCH data transmission is good, and therefore, it is not necessary to determine the channel problem of the PDCCH, and it is not necessary to start a PDCCH-ACK report.

According to another aspect of the present invention, there is also provided a base station for determining PDCCH transmission in URLLC, wherein the base station includes scheduling means, triggering means and determining means. According to another aspect of the present invention, there is also provided a UE for determining PDCCH transmission in URLLC, where the UE includes the first reporting apparatus, or further includes the second reporting apparatus. In a preferred embodiment, a system for determining PDCCH transmission in URLLC is also provided, and the system includes the foregoing base station and the foregoing UE.

The scheduling device in the base station is configured to send a single modified DCI to schedule the multiple PDSCHs for data transmission.

Specifically, when the URLLC service arrives, the scheduling apparatus in the base station, e.g., the gNB, uses a conventional method, e.g., PDCCH repetition in the time domain, to send a single modified DCI to the corresponding UE, so as to schedule multiple PDSCHs for data transmission, or schedule different layers (layers) from the same PDSCH for data transmission.

The base station may further send an indication to the corresponding UE, for example, by adding an indication to the DCI, or adding an indication to the upper RRC signaling, or sending the indication to the corresponding UE through a separate transmission channel, so that the UE reports ACK information for PDSCH data transmission to the base station accordingly.

Correspondingly, the UE corresponding to the base station, and a second reporting device thereon report ACK information for PDSCH data transmission to the base station according to the indication received from the base station, so that the base station determines whether to trigger execution of a PDCCH-ACK report based on the counted number of ACKs for PDSCH data transmission received from the UE within a first predetermined time period.

Specifically, after receiving the instruction, the second reporting device on the UE reports ACK information for PDSCH data transmission to the base station by using predefined resources on the PUSCH or PUCCH, for example, the ACK information and the existing bit information may be combined on the PUSCH or PUCCH, and the combined information is reported to the base station, and the base station parses the ACK information from the combined information after receiving the ACK information, or after receiving the instruction, the second reporting device on the UE reports the ACK information for PDSCH data transmission to the base station by using a separate transmission channel. Therefore, after receiving the ACK information, the base station judges whether to trigger the execution of PDCCH-ACK report based on the counted number of ACKs for PDSCH data transmission received from the UE in the first preset time period.

And when counting that the number of the ACKs received from the corresponding UE in the first preset time period and aiming at the PDSCH data transmission is smaller than a first threshold value, triggering a triggering device in the base station to execute the PDCCH-ACK report, otherwise, not executing the PDCCH-ACK report.

Specifically, the triggering device in the base station counts the number of ACKs received within a period of time, for example, counts the number of ACKs received within a first predetermined period of time for PDSCH data transmission from the corresponding UE, and when the number is smaller than a first threshold, the triggering device in the base station triggers to perform a PDCCH-ACK report, for example, sends an indication to the corresponding UE to notify the UE to report ACK information for PDCCH data transmission, and otherwise, does not perform the report.

Here, the base station may use a status parameter ON to indicate that the PDCCH-ACK report is in an ON state, and use a status parameter OFF to indicate that the PDCCH-ACK report is in an OFF state, for example. When the base station judges that the number of ACKs for PDSCH data transmission received from the corresponding UE in the first preset time period is smaller than a first threshold value, the triggering device ON the base station sets the state parameter of the PDCCH-ACK report to be ON, the base station is in a PDCCH-ACK report opening state, and the base station triggers and executes the PDCCH-ACK report according to the state, for example, sends an instruction to the corresponding UE and informs the UE of reporting ACK information for PDCCH data transmission. Or, when the base station determines that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is greater than or equal to the first threshold and the current status parameter of the PDCCH-ACK report is ON, the triggering device thereon sets the status parameter to OFF, or if the current status parameter of the PDCCH-ACK report is OFF, no processing is performed.

In one embodiment, a triggering device in the base station calculates the number of ACKs reported by the UE for PDSCH data transmission, denoted as N herein, within a preconfigured duration, i.e., a first predetermined time period, e.g., N1 slots (slots) of PUCCH channel transmission _ACK A PDSCH, recording the first threshold as Thr1, and judging whether N is present _ACK _PDSCH<Thr1, if N _ACK _PDSCH<Thr1, triggering device in base station triggers and executes PDCCH-ACK report, otherwise, if N is _ACK If PDSCH is greater than or equal to Thr1, then PDCCH-ACK report is not executed。

It is understood by those skilled in the art that the first threshold is determined according to the number of ACKs received in a time duration, and the first threshold can be defined as the number of ACKs received in a unit time period, for example, whether (N) is determined _ACK _PDSCH)/N1<Thr1, if (N) _ACK _PDSCH)/N1<Thr1, a triggering device in the base station triggers the execution of PDCCH-ACK report, otherwise, if (N) _ACK If the value of _ PDSCH)/N1 is larger than or equal to Thr1, the PDCCH-ACK report is not executed. Both of the two ways can be used to determine the number of ACKs reported by the UE for PDSCH data transmission, i.e., to determine the transmission success rate of the PDSCH, and to determine whether to trigger the execution of PDCCH-ACK reporting. And, the specific value of the first threshold can be set according to actual conditions.

Wherein, the triggering device in the base station is further configured to: and sending an indication to the UE to inform the UE to report ACK information aiming at PDCCH data transmission.

Specifically, when the triggering device in the base station determines that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined period is smaller than the first threshold, the triggering device in the base station may further send an indication to the corresponding UE, for example, by adding an indication in the DCI, or adding an indication in the upper RRC signaling, or by using a separate transmission channel, sending the indication to the corresponding UE, so as to notify the UE to report ACK information for PDCCH data transmission to the base station accordingly.

Correspondingly, a first reporting device in the UE reports ACK information for PDCCH data transmission to the base station according to an indication received from a corresponding base station, so that the base station determines whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted number of ACKs for PDCCH data transmission received from the UE in a second predetermined period.

Specifically, after receiving the indication, the first reporting device on the UE reports ACK information for PDCCH data transmission to the base station by using a predefined resource on a PUSCH or PUCCH, for example, the ACK information and existing bit information may be combined on the PUSCH or PUCCH, and the combined information is reported to the base station, and the base station parses the ACK information from the combined information after receiving the ACK information, or after receiving the indication, the first reporting device on the UE reports ACK information for PDCCH data transmission to the base station by using a separate transmission channel. Therefore, after receiving the ACK information, the base station judges whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted ACK number for PDCCH data transmission received from the UE in a second preset time period.

When the PDCCH-ACK report is executed, the determining device in the base station determines the PDCCH transmission mode based on the counted ACK number for PDCCH data transmission received from the UE in a second preset time period according to the PDCCH-ACK report.

Specifically, after the base station performs PDCCH-ACK reporting, that is, after instructing the corresponding UE to report the number of ACKs for PDCCH data transmission, the base station receives ACK information for PDCCH data transmission reported by the corresponding UE, and a determining device thereon counts the ACK information received within a certain time period, for example, counts the number of ACKs for PDCCH data transmission received within a second predetermined time period, and determines a PDCCH transmission mode according to the number, for example, determines whether to perform PDCCH repeated data transmission from multiple TRPs or perform PDCCH single data transmission.

Preferably, the determining means is further configured to: triggering repeated data transmission of the PDCCH from multiple TRPs when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value; otherwise, the PDCCH repeated data transmission from the multiple TRPs is closed.

Specifically, the base station receives ACK information for PDCCH data transmission reported by the corresponding UE, and the determining device in the base station counts the ACK information received within a certain time period, and when the determining device in the base station counts that the number of ACKs for PDCCH data transmission received from the UE within a second predetermined time period is smaller than a second threshold, the base station knows that the radio quality of the PDCCH is sufficiently poor, and triggers PDCCH repeated data transmission from multiple TRPs, so as to further enhance the spatial domain through multiple TRPs, thereby solving the performance loss caused by the channel problem. The PDCCH repeated data transmission from the multi-channel TRP can be seen in the lower graph of FIG. 2, wherein TRP-01 and TRP-02 perform PDCCH-1 repeated data transmission. The upper diagram of FIG. 2 shows that TRP-01 and TRP-02 perform independent PDCCH data transmission, TRP-01 performs PDCCH-1 data transmission, and TRP-02 performs PDCCH-2 data transmission.

The base station may adopt a state parameter ON to indicate that the PDCCH repeated data transmission is in an ON state, adopt a state parameter OFF to indicate that the PDCCH repeated data transmission is in an OFF state, and when a determination device in the base station counts that the number of ACKs received from the UE for PDCCH data transmission in a second predetermined period is smaller than a second threshold, set the state parameter of PDCCH repeated data transmission to ON, so that the base station is in a PDCCH repeated data transmission ON state, and trigger PDCCH repeated data transmission from multiple TRPs according to the state. Or, the determining device of the base station determines that the number of ACKs received from the UE for PDCCH data transmission in a second predetermined period is greater than or equal to a second threshold, and the current status parameter of the PDCCH data transmission is ON, sets the status parameter to OFF, closes PDCCH data transmission from multiple TRPs, and switches to independent PDCCH data transmission, or does not perform any processing if the current status parameter of PDCCH data transmission is OFF.

In one embodiment, the determining device of the base station calculates the number of ACKs reported by the UE for PDCCH data transmission within a preconfigured duration, i.e. a second predetermined time period, e.g. N2 slots (slots), here denoted as N2N _ACK A PDCCH, a second threshold Thr2, and whether N is determined _ACK _PDCCH<Thr2, if N _ACK _PDCCH<Thr2, the base station triggers and executes PDCCH repeated data transmission from multiple TRPs, or else, if N is not the same _ACK And if the PDCCH is more than or equal to Thr2, the repeated data transmission of the PDCCH from the multiple TRPs is closed.

It is understood by those skilled in the art that the aforementioned second threshold is determined according to the number of ACKs received in a time duration, and the second threshold can be defined herein as the number of ACKs received in a unit time period, for example, whether (N) is determined _ACK _PDCCH)/N2<Thr2, if (N) _ACK _PDCCH)/N2<Thr2, the base station knows that the radio quality of the PDCCH is poor enough, and triggers the execution of repeated PDCCH data transmission from multiple TRPs, otherwise, if (N) _ACK And if the PDCCH)/N2 is more than or equal to Thr2, stopping the repeated data transmission of the PDCCH from the multiple TRPs. Both the two ways can be used to determine the number of ACKs reported by the UE for PDCCH data transmission, i.e. to determine the channel quality of the PDCCH, and thus determine whether to trigger execution of PDCCH repeated data transmission from multiple TRPs. And, the specific value of the second threshold value can be set according to the actual situation.

Preferably, the determining means of the base station is further configured to: and when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be larger than or equal to the sum of a second threshold value and an error tolerance value, the PDCCH repeated data transmission from the multiple TRPs is closed.

Specifically, when determining whether the counted number of ACKs for PDCCH data transmission received from the UE in the second predetermined period is greater than or equal to the second threshold, there may be an error tolerance value used for buffering, that is, the determining device of the base station does not immediately turn off PDCCH repeated data transmission from the plurality of TRPs once it is counted that the number of ACKs for PDCCH data transmission received from the UE in the second predetermined period is greater than or equal to the second threshold, but turns off PDCCH repeated data transmission from the plurality of TRPs only when it is counted that the number of ACKs for PDCCH data transmission received from the UE in the second predetermined period is greater than or equal to the sum of the second threshold and the error tolerance value.

The specific value of the error tolerance value can be set according to actual conditions. Here, the fault tolerance value is represented by Δ, when (N) _ACK When the continuous transmission rate of _ PDCCH)/N2 is more than or equal to Thr2+ delta, the base station knows that the radio quality of the PDCCH is good enough, namely, the base station can carry out single data transmission of the PDCCH, thereby closing repeated data transmission of the PDCCH from multiple TRPs.

In a specific embodiment, a scheduling device in a base station transmits a single modified DCI to schedule multiple PDSCHs, or to schedule different layers from the same PDSCH for data transmission. The base station sends an indication to the corresponding UE, and informs the UE to report ACK information for PDSCH data transmission to the base station accordingly, after the ACK information is received by a triggering device in the base station, the number of the ACKs for PDSCH data transmission received from the corresponding UE in a first preset time period is counted, when the number of the ACKs is smaller than a first threshold value, the fact that the PDSCH possibly has poor channel quality or is possibly that DCI issued by PDCCH dispatches wrong PDSCH, and because the base station cannot distinguish link errors, whether PDSCH or PDCCH causes PDSCH failure can not be distinguished, therefore, in order to solve the problem, when the number of the ACKs for PDSCH data transmission received from the corresponding UE in the first preset time period is counted to be smaller than the first threshold value, a PDCCH-ACK report is triggered, namely, an indication is sent to the corresponding UE, and the UE is informed of the ACK information for PDCCH data transmission. And the first reporting device in the corresponding UE reports the ACK information aiming at the PDCCH data transmission to the base station according to the indication. The determining device in the base station then counts the number of ACKs received from the UE for PDCCH data transmission in a second predetermined period according to the ACK information received from the UE for PDCCH data transmission, and if the number of ACKs is smaller than a second threshold, it indicates that the radio quality of the PDCCH is poor enough, and needs to trigger repeated data transmission of the PDCCH from multiple TRPs, and the performance loss caused by the channel problem is solved by enhancing the spatial domain through multiple TRPs. And if the determining device in the base station counts that the number of the ACKs received from the UE in the second predetermined period for the PDCCH data transmission is greater than or equal to the second threshold, the radio quality of the PDCCH is good enough, the PDCCH repeated data transmission from the multiple TRPs is not required, and only the PDCCH single data transmission is performed, so that the PDCCH repeated data transmission from the multiple TRPs is stopped. Moreover, the radio quality of the PDCCH is good enough to indicate that the PDSCH data transmission failure is not caused by the PDCCH, and other PDSCH enhancement schemes may be triggered, which is not described herein again. In addition, if the triggering device in the base station counts that the number of ACKs received from the corresponding UE for PDSCH data transmission in the first predetermined time period is greater than or equal to the first threshold, it indicates that PDSCH data transmission is good, and therefore, it is not necessary to determine the channel problem of the PDCCH, and it is not necessary to start the PDCCH-ACK report.

It should be noted that the present invention may be implemented in software and/or in a combination of software and hardware, for example, as an Application Specific Integrated Circuit (ASIC), a general purpose computer or any other similar hardware device. In one embodiment, the software program of the present invention may be executed by a processor to implement the steps or functions described above. Also, the software programs (including associated data structures) of the present invention can be stored in a computer readable recording medium, such as RAM memory, magnetic or optical drive or diskette and the like. Further, some of the steps or functions of the present invention may be implemented in hardware, for example, as circuitry that cooperates with the processor to perform various steps or functions.

In addition, some of the present invention can be applied as a computer program product, such as computer program instructions, which when executed by a computer, can invoke or provide the method and/or technical solution according to the present invention through the operation of the computer. Program instructions which invoke the methods of the present invention may be stored on a fixed or removable recording medium and/or transmitted via a data stream on a broadcast or other signal-bearing medium and/or stored within a working memory of a computer device operating in accordance with the program instructions. An embodiment according to the invention herein comprises an apparatus comprising a memory for storing computer program instructions and a processor for executing the program instructions, wherein the computer program instructions, when executed by the processor, trigger the apparatus to perform a method and/or solution according to embodiments of the invention as described above.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it will be obvious that the term "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means recited in the apparatus claims may also be implemented by one unit or means in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Claims

1. A method for determining PDCCH transmission in URLLC at a base station end, wherein the method comprises the following steps:

when the PDCCH-ACK report is executed, determining a PDCCH transmission mode based on the counted number of ACKs for PDCCH data transmission received from the UE in a second preset time period according to the PDCCH-ACK report;

wherein, the determining the PDCCH transmission mode comprises:

triggering repeated data transmission of the PDCCH from multiple TRPs when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value;

2. The method of claim 1, wherein turning off PDCCH repetition data transmission from multiple TRPs further comprises:

3. The method of claim 1 or 2, wherein triggering performance of PDCCH-ACK reporting comprises:

4. A method for determining PDCCH transmission in URLLC realized at UE end, wherein the method comprises:

5. The method of claim 4, wherein the method comprises:

reporting ACK information aiming at PDSCH data transmission to the base station according to the indication received from the base station, so that the base station judges whether to trigger execution of a PDCCH-ACK report based on the counted ACK number aiming at PDSCH data transmission received from the UE in a first preset time period;

when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value, the base station triggers the PDCCH repeated data transmission from the multiple TRPs;

otherwise, the base station closes the PDCCH repeated data transmission from the multiple TRPs.

6. A base station that enables determining PDCCH transmissions in URLLC, wherein the base station comprises:

the triggering device is used for triggering the execution of the PDCCH-ACK report when the number of the ACKs received from the corresponding UE in the first preset time period and aiming at the PDSCH data transmission is smaller than a first threshold value, or else, not executing the PDCCH-ACK report;

determining means for determining a PDCCH transmission mode based on a counted number of ACKs received from the UE for PDCCH data transmission within a second predetermined period of time when performing the PDCCH-ACK report;

wherein the determining means is further configured to: triggering repeated data transmission of the PDCCH from multiple TRPs when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value;

7. The base station of claim 6, wherein the determining means is further configured to:

8. The base station according to claim 6 or 7, wherein the triggering means is further configured to: and sending an indication to the UE to inform the UE to report ACK information aiming at PDCCH data transmission.

9. A UE that enables determining PDCCH transmissions in URLLC, wherein the UE comprises:

the first reporting device is used for reporting ACK information aiming at PDCCH data transmission to the base station according to an instruction received from a corresponding base station, so that the base station judges whether to trigger PDCCH repeated data transmission from multiple TRPs based on the counted ACK number aiming at PDCCH data transmission received from the UE in a second preset time period;

when the number of the ACKs received from the UE in a second preset time period and aiming at the PDCCH data transmission is counted to be smaller than a second threshold value, the base station triggers the PDCCH repeated data transmission from a plurality of TRPs;

10. The UE of claim 9, wherein the UE further comprises:

11. A system implementing determining PDCCH transmissions in URLLC, comprising a base station according to any of claims 6 to 8 and a UE according to claim 9 or 10.