CN110166203A - Determination, detection method and device, base station and the terminal of Physical Downlink Control Channel - Google Patents

Abstract

A kind of determination of Physical Downlink Control Channel, detection method and device, base station and terminal, base station determine the PDCCH candidate that should retain in the PDCCH candidate of configuration；The base station selects a PDCCH candidate as the PDCCH for sending Downlink Control Information to terminal from the PDCCH candidate of reservation.After terminal determines the PDCCH candidate retained in the PDCCH candidate configured, the terminal is attempted to receive the Downlink Control Information that PDCCH channel is carried in the running time-frequency resource position of the PDCCH candidate of the reservation.Present invention also provides corresponding device, base station and terminals.The application avoids the limit of power of UE in such a way that PDCCH candidate abandons.

Description

Method and device for determining and detecting physical downlink control channel, base station and terminal

Technical Field

The present application relates to a wireless communication network, and in particular, to a method and an apparatus for determining and detecting a physical downlink control channel, a base station, and a terminal.

Background

In Long Term Evolution (LTE) and New generation radio access technology (NR, New RAT), Downlink Control information is carried through a Physical Downlink Control Channel (PDCCH), and in general, a base station selects one PDCCH candidate among a plurality of PDCCH candidates as a final PDCCH Channel. The terminal does not know which PDCCH candidate (which may also be referred to as a candidate PDCCH) is finally selected by the base station among the plurality of PDCCH candidates as a final PDCCH channel. The terminal needs to try PDCCH demodulation and decoding one by one among multiple PDCCH candidates until a PDCCH channel can be successfully found.

The plurality of PDCCH candidates are typically distributed over a plurality of aggregation levels, each aggregation level typically containing a plurality of PDCCH candidates. The aggregation level refers to the number of Control Channel Elements (CCEs) included in one PDCCH candidate. For example, if the aggregation level is 4, each PDCCH candidate at that aggregation level consists of 4 CCEs. Taking NR (New RAT: New generation radio access technology) as an example, one CCE is composed of 6 Resource Element Groups (REGs), and each REG is composed of 12 Resource Elements (REs), but the present application is not limited thereto.

It can be seen that the larger the number of PDCCH candidates, the larger the number of PDCCH candidates that the terminal needs to blindly detect, and therefore, the larger the number of CCEs that need channel estimation.

The above has been presented with respect to some basic concepts of the PDCCH. In addition to this, the concept of Control Resource set (CORESET) and search space involved in some PDCCH is introduced. Where CORESET is a concept in NR, the search space has this concept in both LTE and NR.

Regarding the CORESET, the CORESET is mainly used for determining the frequency domain range of the PDCCH transmitted by the base station and the PDCCH detected by the terminal, and the number of symbols occupied by the PDCCH channel. CORESET may contain the following parameters:

a CORESET ID (control resource aggregation identification number)

Frequency-domain resources (Frequency domain resources)

Time-duration (1,2, or 3) (number of Time-domain symbols)

Regarding the search space, the search space is mainly used to determine which aggregation levels can be used by the PDCCH channel, and the number of PDCCH candidates at a specific aggregation level, and information such as PDCCH period and time domain position. The search space may contain the following parameters:

a CORESET ID (control resource aggregation identification number)

DCI format parameter; (Downlink control information format)

Monitoring period of slot(s)

Monitoring offset of slots(s) (0,1, …, N-1) for Monitoring periodicities of N) (physical downlink control channel Monitoring offset slot number)

Number of candidates for AL ═ 1(0,1,2,3,4,5,6,8) (aggregation level 1 Number of physical downlink channel candidates)

Number of candidates for AL ═ 2(0,1,2,3,4,5,6,8) (Number of physical downlink channel candidates for aggregation level 2)

Number of candidates for AL ═ 4(0,1,2,3,4,5,6,8) (aggregation level 4 Number of physical downlink channel candidates)

Number of candidates for AL ═ 8(0,1,2,3,4,5,6,8) (aggregation level 8 Number of physical downlink channel candidates)

Number of candidates for AL 16(0,1,2,3,4,5,6,8) (Number of physical downlink channel candidates for aggregation level 16)

The 3rd Generation Partnership Project (3 GPP) standards organization has determined that the maximum number of CORESET within a Bandwidth part (BWP) is 3, the maximum number of search spaces within a BWP is 10, and a search space corresponds to a CORESET.

According to the above, the periods in different search spaces may be different, and when multiple search spaces are located in the same time slot, especially when the search spaces are located in different CORESET, the total number of PDCCH candidates in the time slot will be significantly increased, so the number of blind detections in PDCCH, and the number of CCEs required to perform channel estimation will also be significantly increased. Thus, the number of PDCCH candidates and/or the number of CCEs required to perform channel estimation in each search space may exceed the capability supported by the User Equipment (UE), and fig. 1 shows an example of two search spaces, where a rectangular block represents 1 slot, where the number of CCEs required to perform channel estimation is overloaded, i.e. exceeds a set threshold. The above problem can be effectively attributed to the total number of PDCCH candidates configured by the base station exceeding the allowed PDCCH candidate value.

Another similar problem is that for a given search space configuration, a Downlink Control Information (DCI) format parameter (format parameter) may set multiple DCI formats for the search space. However, for a given Aggregation Level (AL), NR specifies that the number of PDCCH candidates for DCI format2-0 is at most 1 or 2. The search space parameter may configure a plurality of DCI formats, and the number of PDCCH candidates uniformly set for the aggregation level L is greater than 2, for example, configured to be 6. Then, for DCI format2-0, the number of PDCCH candidates configured by the base station is larger than its maximum supported number of PDCCH candidates. Consideration needs to be given to how to limit the number of PDCCH candidates for DCI format2-0 to within 2.

Disclosure of Invention

The embodiment of the invention provides a method for determining a Physical Downlink Control Channel (PDCCH), which comprises the following steps:

the base station determines PDCCH candidates which should be reserved among the configured PDCCH candidates;

and the base station selects one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

The embodiment of the invention also provides a method for determining the physical downlink control channel PDCCH, which comprises the following steps:

the base station respectively configures the PDCCH candidate number of each downlink control channel format on each aggregation level through a high-level signaling for each downlink control channel format in the search space;

and the base station selects one PDCCH candidate from the PDCCH candidates configured for the downlink control channel format as a PDCCH to send the downlink control information of the downlink control channel format to the terminal.

The embodiment of the invention also provides a method for determining the physical downlink control channel PDCCH, which comprises the following steps:

the base station selects W CCEs from a control resource set CORESET according to a set rule;

the base station determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

and the base station selects one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

The embodiment of the present invention further provides a device for determining a physical downlink control channel PDCCH, including:

a PDCCH candidate determining module, configured to determine PDCCH candidates to be reserved among the configured PDCCH candidates;

and the PDCCH selection module is used for selecting one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

The embodiment of the present invention further provides a device for determining a physical downlink control channel PDCCH, including:

the resource selection module is used for selecting W CCEs from a control resource set CORESET according to a set rule;

a PDCCH candidate determining module, configured to determine, for each aggregation level in each search space belonging to the CORESET, a time-frequency resource location of a configured PDCCH candidate within a range of the W CCEs;

and the PDCCH selection module is used for selecting one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending the downlink control information to the terminal.

An embodiment of the present invention further provides a base station, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the processing of the method described above.

Embodiments of the present invention also provide a computer storage medium for storing a computer program, where the computer program implements the processing of the method described above when executed by a processor.

The above embodiment scheme can avoid the number of PDCCH candidates on each search space and/or the number of CCEs required to perform channel estimation from exceeding the capability range of the UE by means of PDCCH candidate discarding.

The embodiment of the invention provides a method for detecting a Physical Downlink Control Channel (PDCCH), which comprises the following steps:

the terminal determines the reserved PDCCH candidates in the configured PDCCH candidates;

and the terminal tries to receive the downlink control information carried by the PDCCH at the reserved time-frequency resource position of the PDCCH candidate.

The embodiment of the invention also provides a method for detecting the physical downlink control channel PDCCH, which comprises the following steps:

the terminal selects W CCEs from a control resource set CORESET according to a set rule;

the terminal determines the time-frequency resource position of the PDCCH candidate to be detected in the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

and the terminal tries to receive the downlink control information carried by the PDCCH at the time-frequency resource position of the PDCCH candidate to be detected.

The embodiment of the present invention further provides a detection apparatus for a physical downlink control channel PDCCH, including:

a PDCCH candidate determination module for determining a reserved PDCCH candidate among the configured PDCCH candidates;

and the PDCCH detection module is used for trying to receive the downlink control information carried by the PDCCH in the reserved time-frequency resource position of the PDCCH candidate.

The embodiment of the present invention further provides a detection apparatus for a physical downlink control channel PDCCH, including:

the resource selection module is used for selecting W CCEs from a control resource set CORESET according to a set rule;

a PDCCH candidate determining module, configured to determine, within the range of the W CCEs, a time-frequency resource location of a PDCCH candidate to be detected for each aggregation level in each search space belonging to the CORESET;

and the PDCCH detection module is used for trying to receive the downlink control information carried by the PDCCH at the time-frequency resource position of the PDCCH candidate to be detected.

An embodiment of the present invention further provides a terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the processing of the method described above.

Embodiments of the present invention also provide a computer storage medium for storing a computer program, where the computer program implements the processing of the method described above when executed by a processor.

In the above embodiment, the terminal determines the PDCCH candidates that need to be detected by using a PDCCH candidate discarding mode, so as to avoid that the number of PDCCH candidates detected in each search space and/or the number of CCEs performing channel estimation exceeds the capability range of the UE.

Drawings

Fig. 1 is a diagram illustrating an example of the number of CCEs that a terminal needs to perform channel estimation exceeds the supported capability range;

FIG. 2 is a flowchart illustrating a PDCCH determination method according to an embodiment of the present invention;

FIG. 3 is a block diagram of a PDCCH determination apparatus according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating a PDCCH detection method according to an embodiment of the present invention;

FIG. 5 is a block diagram of a PDCCH detection apparatus according to an embodiment of the present invention;

FIG. 6 is a flowchart of a PDCCH determination method according to a second embodiment of the present invention;

FIG. 7 is a block diagram of a PDCCH determination apparatus according to a second embodiment of the present invention;

FIG. 8 is a flowchart of a PDCCH detection method according to a second embodiment of the present invention;

FIG. 9 is a block diagram of a PDCCH detection apparatus according to a second embodiment of the present invention;

FIGS. 10A-14B are diagrams of selecting PDCCH candidates in examples 1-6 of the present invention;

fig. 15 is a schematic diagram of CCEs contained in the CORESET bandwidth in the seventh example of the present invention;

fig. 16 is a diagram illustrating W CCEs selected in CORESET in the seventh exemplary embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The application provides a relevant scheme for solving the problem that the PDCCH candidate number and/or the CCE number required by the terminal to carry out channel estimation exceed the capability range of the UE. The maximum number of PDCCH candidates that the terminal can detect (blind detection) and the number of CCEs for channel estimation are defined by respective threshold values (also referred to as target thresholds), for example, the terminal detects 8 PDCCH candidates at most and performs channel estimation on 48 CCEs at most. The solution proposed by the application is that a base station selects a time-frequency resource subset according to a set rule in a given time-frequency resource set, selects time-frequency resources for one or more PDCCH candidates according to another set rule in the time-frequency resource subset, and then selects 1 PDCCH candidate as a PDCCH for sending downlink control information. The terminal selects a time frequency resource subset from a given time frequency resource set according to the same method, selects time frequency resources for one or more PDCCH candidates in the time frequency resource subset, and then tries to receive downlink control information carried by a PDCCH channel at the time frequency resource position corresponding to the one or more PDCCH candidates.

In one way of using PDCCH discard operations, a given set of time-frequency resources may be, for example, a certain bandwidth or a certain CORESET, a subset of time-frequency resources selected according to a set rule may be a set of time-frequency resources selected for configured PDCCH candidates, and a base station selects time-frequency resources for one or more PDCCH candidates according to another set rule, or may be time-frequency resources of PDCCH candidates that are reserved after discarding some PDCCH candidates from the configured PDCCH candidates. In another way of generating PDCCH candidates based on a selected CCE set, time-frequency resources (a part of the time-frequency resources in a time-frequency resource subset) selected by the base station for one or more PDCCH candidates according to another set rule may be used to determine time-frequency resource locations of the PDCCH candidates, and at this time, the PDCCH candidates may be directly used to determine the PDCCH without being discarded.

The present application will be described in detail with reference to examples.

Example one

The solution proposed in this embodiment is that, if the number of configured PDCCH candidates and/or the number of CCEs corresponding to the configured PDCCH candidates exceeds a corresponding threshold, the base station and the terminal discard some PDCCH candidates according to the same rule, so that the number of remaining PDCCH candidates and the corresponding number of CCEs do not exceed the corresponding threshold, that is, do not exceed the UE capability range.

In addition, the maximum number of PDCCH candidates set for DCI format2-0 in the relevant standard is 1 or 2, and a uniform allocation method is adopted for various DCI format, so that the number of allocated PDCCH candidates may exceed 2. Taking 2 choices as an example, 2 PDCCH candidates may be chosen from front to back according to a PDCCH candidate index, or 2 PDCCH candidates may be chosen at equal intervals, or 2 PDCCH candidates may be chosen according to a certain rule according to at least one information of a slot index, a C-RNTI and an SFI-RNTI.

The method for determining a physical downlink control channel PDCCH according to this embodiment is shown in fig. 2, and includes:

step 110, the base station determines PDCCH candidates which should be reserved among the configured PDCCH candidates;

and step 120, the base station selects one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

In this embodiment, the determining, by the base station, the PDCCH candidates to be reserved from the configured PDCCH candidates includes: the base station respectively executes PDCCH candidate discarding operation on each aggregation level in each search space, wherein the PDCCH candidate discarding operation comprises the following steps:

determining the number of PDCCH candidates to be reserved according to a first rule;

and selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule to serve as PDCCH candidates to be reserved, and discarding the rest of the configured PDCCH candidates.

In this embodiment, the base station respectively performs a PDCCH candidate discarding operation on each aggregation level in each search space, including: and sequentially executing PDCCH candidate discarding operations on each aggregation level in each search space from low to high. In the relevant standard, the number of the common search space is low (i.e., the number is small) and the number of the search space exclusive to the UE is high (i.e., the number is large), and in this embodiment, the PDCCH candidate discarding operations are sequentially performed on each aggregation level in each search space in the order from the low to the high of the search space number, so that it can be ensured that the important search space can preferentially reserve PDCCH candidates, and the situation that the PDCCH cannot be reserved for the aggregation level of the subsequent search space again after the number of the reserved PDCCH candidates reaches the corresponding threshold is avoided.

In this embodiment, the base station respectively performs a PDCCH candidate discarding operation on each aggregation level in each search space, including: in a search space, PDCCH candidate discarding operations are respectively performed on the aggregation levels in the order of the aggregation levels from top to bottom or the order of the aggregation levels from bottom to top.

A related approach to PDCCH candidate discard operation is: for aggregation level L belonging to a certain search space s, the number of PDCCH candidates reserved after PDCCH discard operation is recorded as M'_s,LThe number of PDCCH candidates before the PDCCH candidate discarding operation is M_s,LThen:

。

the base station and the terminal may respectively perform the processing of the above-described PDCCH determination method for each time slot in a period (e.g., a radio frame), where α is a certain number smaller than 1, for example, α is a ratio of a threshold value of a CCE channel estimation number of the terminal to a CCE number of the terminal that needs to perform channel estimation in a current time slot determined according to a configuration, and the current time slot refers to a time slot related to the currently performed PDCCH determination method and may also be denoted as a time slot k.

However, M 'was calculated as above'_s,LThere are some problems with the approach of (1): for example, with a rounding-down operation, for each search space s, there may be PDCCH candidates that are not available at some aggregation level L on that search space s, i.e., M'_s,LIs 0; in particular, it may result in no available number of PDCCH candidates at a certain aggregation level over an important search space (e.g., a common search space). For another example, after the PDCCH discarding operation is performed, the total number of PDCCH candidates in the time slot may be significantly smaller than the threshold value of the number of CCEs that the terminal can support, thereby resulting in a reduction in the number of available PDCCH candidates.

In this embodiment, the determining the number of PDCCH candidates to be reserved according to the first rule includes: for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0 and calculating the number M 'of PDCCH candidates to be reserved'_s,LWhen the value is equal to 0, thenLine of M'_s,L1. This may ensure that the search space s remains available for at least 1 PDCCH candidate. M'_s,L0 may be a formula as aboveTo calculate.

In another embodiment, the determining the number of PDCCH candidates that should be reserved according to the first rule comprises: informing terminals for calculating M 'through high-layer signaling'_s,LNumber n of_s，M'_s,LIs the number of PDCCH candidates that the aggregation level L within the search space s should reserve; and, according to the formulaCalculate M'_s,LWherein α equals n for the search space s on the current time slot_sDivided by n of other multiple search spaces on the current time slot_sThe quotient resulting from the sum of the values,indicating a rounding down. The value n of this further embodiment is configured by higher layer signaling_sSo that the base station can adjust the number of reserved PDCCH candidates as needed, for example, setting the value n based on the principle that at least 1 PDCCH candidate is reserved per search space or important search space_sAnd so on. The above search space s represents the relevant 1 search space, s is the number of the search space, and the aggregation level L represents the 1 aggregation level in the search space, L is the number of the aggregation level.

In another embodiment, the determining the number of PDCCH candidates that should be reserved according to the first rule comprises: for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0, the number of PDCCH candidates that should be reservedα is the threshold value of the number of CCE channel estimates for the terminal and the terminal in the current time slot determined according to the configurationThe ratio of the number of CCEs required to be channel estimated,indicating rounding up.

In this embodiment, the selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to the second rule as PDCCH candidates to be reserved includes:

for the aggregation level L in the search space s, the configured M is arranged according to the descending order, ascending order or equal interval mode of the PDCCH candidate indexes_s,LM 'is selected in PDCCH (physical downlink control channel) candidate'_s,LPDCCH candidate, M ', which should be reserved'_s,LIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0。

Wherein, when the equal interval mode is adopted, the base station can perform aggregation level L in the search space s every otherIndividual PDCCH candidates, from configured M_i,jSelecting one PDCCH as a PDCCH candidate to be reserved in the PDCCH candidates until M 'is selected'_sLM 'to PDCCH candidates'_sLIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0，Indicating a rounding down.

It should be noted that, when the above embodiment is adopted, after the number of the reserved PDCCH candidates reaches the threshold value of the number of PDCCH candidates supported by the terminal, the process of determining the reserved PDCCH candidates may not be performed any more, and all the remaining PDCCHs in the configuration are discarded. In this way, the number of reserved PDCCH candidates may not exceed the corresponding threshold, and the search space, especially the important search space (e.g. common search space), may have available PDCCH candidates, without the reserved PDCCH candidates deviating too much from the corresponding threshold.

For the problem that the number of configured PDCCH candidates existing in DCI format2-0 exceeds the maximum number of PDCCH candidates allowed by DCI format2-0, the present embodiment proposes the following several solutions:

in a first mode

For a downlink control information format DCI format2-0 with aggregation level L in a search space s, according to the descending order of PDCCH candidate indexes, or the ascending order, or the equal interval mode, from the configured M_s,LPDCCH candidate selection M'_s,LPDCCH candidate, M ', that should be reserved'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

Mode two

For DCI format2-0 with aggregation level L in search space s, firstly, according to at least one information of cell radio network temporary identifier C-RNTI, time slot format indication cell radio network temporary identifier SFI-RNTI and time slot index, calculating configured M_s,LThe first PDCCH candidate which should be reserved is selected from the PDCCH candidates, and other M 'is selected based on the first PDCCH candidate'_s,L-1 PDCCH candidates, M ', that should be reserved'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

In this embodiment, the determining of other M 'based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved, comprising: starting from the first PDCCH candidate to be reserved, every otherSelecting a PDCCH candidate which should be reserved by the PDCCH candidates until M 'is selected again'_s,L-1 PDCCH candidates that should be reserved.

In another embodiment, the problem of the DCI format2-0 may be solved by separately configuring higher layer signaling, and in particular, the another embodiment provides a method for determining a physical downlink control channel PDCCH, including: the base station respectively configures the PDCCH candidate number of each downlink control channel format on each aggregation level through a high-level signaling for each downlink control channel format in the search space; and the base station selects one PDCCH candidate from the PDCCH candidates configured for the downlink control channel format as a PDCCH to send the downlink control information of the downlink control channel format to the terminal. Since the PDCCH candidates are configured separately for each downlink control channel format, there is no problem that the number of configured PDCCH candidates is larger than the maximum number supported by DCI format 2-0.

The present embodiment also provides a device for determining a physical downlink control channel PDCCH, as shown in fig. 3, including:

a PDCCH candidate determining module 10, configured to determine PDCCH candidates to be reserved among the configured PDCCH candidates;

and a PDCCH selecting module 20, configured to select one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

The specific processing in the method of this embodiment may be adopted when the PDCCH candidate determining module determines PDCCH candidates that should be reserved among the configured PDCCH candidates, and when the PDCCH selecting module selects one PDCCH candidate as a PDCCH for sending downlink control information to the terminal from the reserved PDCCH candidates, which is not described herein again.

The present embodiment also provides a base station, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the processing according to the method executed by the base station of the present embodiment.

Correspondingly, the present embodiment further provides a method for detecting a physical downlink control channel PDCCH, as shown in fig. 4, including:

step 210, the terminal determines the reserved PDCCH candidates among the configured PDCCH candidates;

step 220, the terminal tries to receive the downlink control information carried by the PDCCH channel at the time-frequency resource position of the reserved PDCCH candidate.

The method in which the terminal determines the configured PDCCH candidates to reserve PDCCH candidates is the same as the method in which the base station determines the configured PDCCH candidates to reserve PDCCH candidates.

In the present embodiment, the first and second electrodes are,

the determining, by the terminal, the PDCCH candidates to be reserved among the configured PDCCH candidates includes: the terminal respectively executes PDCCH candidate discarding operations on each aggregation level in each search space, wherein the PDCCH candidate discarding operations comprise:

determining the number of PDCCH candidates to be reserved according to a first rule;

and selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule to serve as PDCCH candidates to be reserved, and discarding the rest of the configured PDCCH candidates.

In the present embodiment, the first and second electrodes are,

the terminal respectively executes PDCCH candidate discarding operations on each aggregation level in each search space, and the operations comprise: and sequentially executing PDCCH candidate discarding operations on each aggregation level in each search space from low to high.

In the present embodiment, the first and second electrodes are,

the terminal determines the number of PDCCH candidates to be reserved according to a first rule, and the method comprises the following steps:

for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0 and calculating the number M 'of PDCCH candidates to be reserved'_s,LWhen being 0, then let M'_s,L1 is ═ 1; or

Informing terminals for calculating M 'through high-layer signaling'_s,LNumber n of_s，M'_s,LIs the aggregation level within the search space sL number of PDCCH candidates that should be reserved; according to the formulaCalculate M'_s,LWherein α equals n for the search space s on the current time slot_sDivided by n of other multiple search spaces on the current time slot_sThe quotient resulting from the sum of the values,represents rounding down; or

For aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0, the number of PDCCH candidates that should be reservedWherein α is the ratio of the threshold value of the number of CCE channel estimation of the terminal to the number of CCE needed to perform channel estimation of the terminal at the current time slot determined according to the configuration,indicating rounding up.

In the present embodiment, the first and second electrodes are,

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for the aggregation level L in the search space s, the configured M is selected according to the descending order or ascending order of PDCCH candidate indexes_s,LM 'is selected in PDCCH (physical downlink control channel) candidate'_s,LThe PDCCH candidates to be reserved; or

For aggregation level L in search space s, every otherIndividual PDCCH candidates, from configured M_i,jSelecting one PDCCH as a PDCCH candidate to be reserved in the PDCCH candidates until M 'is selected'_s,LThe PDCCH candidates are selected;

wherein, M'_s,LIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0，Indicating a rounding down.

In the present embodiment, the first and second electrodes are,

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for a downlink control information format DCI format2-0 with aggregation level L in a search space s, according to the descending order of PDCCH candidate indexes, or the ascending order, or the equal interval mode, from the configured M_s,LPDCCH candidate selection M'_s,LA PDCCH candidate that should be reserved; or

For DCI format2-0 with aggregation level L in search space s, firstly, according to at least one information of cell radio network temporary identifier C-RNTI, time slot format indication cell radio network temporary identifier SFI-RNTI and time slot index, calculating configured M_s,LThe first PDCCH candidate which should be reserved is selected from the PDCCH candidates, and other M 'is selected based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved;

wherein, M'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

In the present embodiment, the first and second electrodes are,

determining other M 'based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved, comprising: starting from the first PDCCH candidate to be reserved, every otherSelecting a PDCCH candidate to be reserved until reselectingM 'is taken out'_s,L-1 PDCCH candidates that should be reserved.

The present embodiment further provides a device for detecting a physical downlink control channel PDCCH, as shown in fig. 5, including:

a PDCCH candidate determination module 30 for determining a reserved PDCCH candidate among the configured PDCCH candidates;

and a PDCCH detecting module 40, configured to try to receive downlink control information carried by a PDCCH channel in the reserved time-frequency resource position of the PDCCH candidate.

The present embodiment also provides a terminal including a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor performs the processing according to the method performed by the terminal of the present embodiment.

Example two

In this embodiment, in one CORESET, a fixed number of CCEs is selected according to a certain rule (for example, 48, the CCE number capability supported by the UE is not exceeded); the base station and the terminal determine the time-frequency resource positions of the PDCCH candidates according to a certain rule, namely the positions and the number of CCEs corresponding to the PDCCH candidates. Since the PDCCH candidates are restricted to be fixed (e.g., within 48 CCEs), a threshold value for the number of CCEs for the terminal to perform channel estimation can be satisfied.

As shown in fig. 6, a method for determining a physical downlink control channel PDCCH provided in this embodiment includes:

step 310, the base station selects W CCEs from a control resource set CORESET according to a set rule;

w may be determined according to a threshold value of the number of CCEs for channel estimation by the terminal.

Step 320, the base station determines the time-frequency resource position of the configured PDCCH candidates within the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

in step 330, the base station selects one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

In the present embodiment, the first and second electrodes are,

the base station selects W CCEs from a control resource set CORESET according to a set rule, and the method comprises the following steps:

selecting W CCEs according to the sequence of CCE indexes from low to high; or

Selecting W CCEs according to the sequence of the CCE indexes from high to low; or

Each intervalOne CCE is selected by the CCEs until W CCEs, N, are selected_CCE,pIs the number of CCEs making up the CORESET,indicating a rounding down.

In the present embodiment, the first and second electrodes are,

the base station determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs, and the method comprises the following steps: for the aggregation level L in the search space s, the time-frequency resource location of the configured PDCCH candidate is determined as follows:

within the range of the W CCEs, determining M according to the sequence of CCE indexes from low to high_s,LTime-frequency resource position of each PDCCH candidate; or

Within the range of W CCEs, determining M according to the sequence of CCE indexes from high to low_s,LTime-frequency resource position of each PDCCH candidate; or

Determining M in an equally spaced manner within the range of W CCEs_s,LTime-frequency resource position of each PDCCH candidate;

wherein M is_s,LIs the number of PDCCH candidates configured by the base station for the aggregation level L within the search space s.

The embodiment also provides a device for determining a physical downlink control channel PDCCH on the base station side, as shown in fig. 7, including:

a resource selection module 50, configured to select W CCEs from a control resource set CORESET according to a set rule, where W may be determined according to a threshold of the number of CCEs for channel estimation by a terminal;

a PDCCH candidate determining module 60, configured to determine, for each aggregation level in each search space belonging to the CORESET, a time-frequency resource location of a configured PDCCH candidate within a range of the W CCEs;

and a PDCCH selecting module 70, configured to select one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

The specific implementation manner of the processing executed by each module is described in the method of this embodiment, and is not described herein again.

The present embodiment also provides a base station, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the processing according to the method executed by the base station of the present embodiment.

Correspondingly, the present embodiment further provides a method for detecting a physical downlink control channel PDCCH, as shown in fig. 8, including:

step 410, the terminal selects W CCEs from a control resource set CORESET according to a set rule;

w can be determined according to a threshold value of the number of CCEs for channel estimation of the terminal;

step 420, the terminal determines the time-frequency resource position of the PDCCH candidate to be detected in the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

step 430, the terminal tries to receive the downlink control information carried by the PDCCH channel at the time-frequency resource position of the PDCCH candidate to be detected.

In the present embodiment, the first and second electrodes are,

the terminal selects W CCEs from a control resource set CORESET according to a set rule, and the method comprises the following steps:

selecting W CCEs according to the sequence of CCE indexes from low to high; or

Selecting W CCEs according to the sequence of the CCE indexes from high to low; or

Each intervalOne CCE is selected by the CCEs until W CCEs, N, are selected_CCE,pIs the number of CCEs making up the CORESET,indicating a rounding down.

In the present embodiment, the first and second electrodes are,

the terminal determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs, and the determination comprises the following steps: for the aggregation level L in the search space s, the time-frequency resource location of the configured PDCCH candidate is determined as follows:

within the range of the W CCEs, determining M according to the sequence of CCE indexes from low to high_s,LTime-frequency resource position of each PDCCH candidate; or

Within the range of W CCEs, determining M according to the sequence of CCE indexes from high to low_s,LTime-frequency resource position of each PDCCH candidate; or

Determining M in an equally spaced manner within the range of W CCEs_s,LTime-frequency resource position of each PDCCH candidate;

wherein M is_s,LIs a base station for searchingThe number of PDCCH candidates configured for aggregation level L within the index space s.

The embodiment also provides a device for detecting a physical downlink control channel PDCCH at a terminal side, as shown in fig. 9, including:

a resource selection module 80, configured to select W CCEs from a control resource set CORESET according to a set rule, where W may be determined according to a threshold of the number of CCEs for channel estimation by a terminal;

a PDCCH candidate determining module 90, configured to determine, within the range of the W CCEs, a time-frequency resource location of a PDCCH candidate to be detected for each aggregation level in each search space belonging to the CORESET;

the PDCCH detecting module 100 is configured to try to receive downlink control information carried by a PDCCH channel at a time-frequency resource location of the PDCCH candidate to be detected.

The specific implementation manner of the processing executed by each module is described in the method of this embodiment, and is not described herein again.

The present embodiment also provides a terminal, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the processing according to the method executed by the terminal of the present embodiment.

Example 1

The example performs PDCCH candidate discard operations according to the rule of search space ID ordering + rounding down to 0 and then to 1.

In this example, for scheduling carrier n_CIFor aggregation level L in the search space s, the number of PDCCH candidates remaining after PDCCH discard operation is recorded as M'_s,LThe number of PDCCH candidates before PDCCH discard operation is recorded as M'_s,L。

Side of base station

The base station sequentially executes PDCCH candidate discarding operation according to the sequence of the search space numbers from low to high; for different aggregation levels in the same search space, performing PDCCH candidate discarding operations in the order of the aggregation levels from high to low;

for each aggregation level L in each search space s, a PDCCH discard operation is performed as follows:

for M_s,L>0, PDCCH number of candidates M 'reserved after PDCCH discard operation'_s,LThe calculation is as follows:if above calculated M'_s,LWhen being 0, then let M'_s,L＝1。

Number of PDCCH candidates M 'remaining after calculating PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LAnd (4) PDCCH candidate. The base station obtains the M'_s,LAfter PDCCH candidate, from M'_s,LOne of the PDCCH candidates is selected as an actual PDCCH channel.

For M'_s,LSelection of PDCCH candidates, base station from M_s,LSelecting M 'from PDCCH candidate indexes from low to high'_s,LA PDCCH candidate. E.g. for a certain aggregation level L, M in the search space s_s,L＝8，M’_s,LWhen 4, M before PDCCH candidate selection is performed_s,LThe individual PDCCH candidate positions are shown in fig. 10A. M 'after PDCCH candidate selection is performed'_s,LThe individual PDCCH candidate positions are shown in fig. 10B. Or

For M'_i,jSelection of PDCCH candidates, base station from M_s,LSelecting M 'from PDCCH candidate indexes in the order of high to low'_s,LA PDCCH candidate; e.g. for a certain aggregation level L, M in the search space s_s,L＝8，M’_s,LWhen 4, M before PDCCH candidate selection is performed_s,LThe individual PDCCH candidate positions are shown in fig. 11A. M 'after PDCCH candidate selection is performed'_s,LIndividual PDCCH candidate positionAs shown in fig. 11B. Or

For M'_s,LSelection of PDCCH candidates, every otherOne PDCCH candidate is selected as a reserved PDCCH candidate by the PDCCH candidates until M 'is selected'_s,LReserved PDCCH candidates. E.g. for a certain aggregation level L, M in the search space s_s,L＝8，M’_s,LWhen 4, M before PDCCH candidate selection is performed_s,LThe individual PDCCH candidate positions are shown in fig. 12A. M 'after PDCCH candidate selection is performed'_s,LThe individual PDCCH candidate positions are shown in fig. 12B.

For transmission of PDCCH using aggregation level L, the base station obtains M 'from the above'_s,LAnd selecting one PDCCH candidate position from the PDCCH candidates as a final PDCCH channel, and sending the downlink control information loaded on the PDCCH channel to the terminal by the base station through the PDCCH channel.

Terminal side

In this embodiment, the terminal side has the following operation characteristics: according to the sequence of the search space numbers from low to high, executing PDCCH candidate discarding operation; for different aggregation levels in the same search space, the PDCCH candidate discarding operations are performed in order of aggregation level from high to low.

For each aggregation level L in each search space s, a PDCCH discard operation is performed in the following manner; for M_s,L>0, PDCCH number of candidates M 'reserved after PDCCH discard operation'_s,LThe calculation is as follows:if above calculated M'_s,LWhen being 0, then let M'_s,L＝1；

Number of PDCCH candidates M 'remaining after calculating PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LPDCCH (physical Downlink control channel) waitingAnd (4) selecting. Base station is obtaining the M'_s,LAfter PDCCH candidate, in M'_s,LOne of the PDCCH candidates is selected as an actual PDCCH channel. For M'_s,LThe selection of the PDCCH candidates is performed in the same manner as the base station, and is not repeated here.

The terminal performs PDCCH blind detection on a plurality of aggregation levels, and for the PDCCH blind detection using the aggregation level L, the terminal tries to perform the detection on the M'_s,LEach PDCCH candidate location attempts detection of the PDCCH. If the terminal can successfully detect the PDCCH in a PDCCH candidate position on a certain aggregation level, the terminal uses the downlink control information carried by the PDCCH so as to receive the information carried by the corresponding PDSCH according to the indication of the DCI.

Example two

The present example employs a search space ID ordering + rounding up approach for PDCCH candidate discard operations.

In this example, for scheduling carrier n_CIFor aggregation level L in the search space s, the number of PDCCH candidates remaining after PDCCH discard operation is recorded as M'_s,LThe number of PDCCH candidates before PDCCH discard operation is recorded as M'_s,L。

Side of base station

In this example, the operation on the base station side differs from that of example one in that: for each aggregation level L in each search space s, a PDCCH discard operation is performed in the following manner;

for M_s,L>0, PDCCH number of candidates M 'reserved after PDCCH discard operation'_s,LThe calculation is as follows:wherein α is the ratio of the threshold value of the number of CCE channel estimation of the terminal to the number of CCE needed to perform channel estimation of the terminal at the current time slot determined according to the configuration,indicating rounding up.

Number of PDCCH candidates M 'remaining after calculating PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LA PDCCH candidate. Base station is obtaining the M'_s,LAfter PDCCH candidate, in M'_s,LOne of the PDCCH candidates is selected as an actual PDCCH channel.

For M'_s,LSelection of individual PDCCH candidates, the base station from M_s,LSelecting M 'from PDCCH candidate indexes from low to high'_s,LA PDCCH candidate;

or, for M'_s,LSelection of individual PDCCH candidates, the base station from M_s,LSelecting M 'from PDCCH candidate indexes in the order of high to low'_s,LA PDCCH candidate;

or, for M'_i,jSelection of individual PDCCH candidates, everyOne PDCCH candidate is selected as a reserved PDCCH candidate by the PDCCH candidates until M 'is selected'_s,LReserved PDCCH candidates.

For transmission of PDCCH using aggregation level L, the base station obtains M 'from the above'_s,LAnd selecting one PDCCH candidate position from the PDCCH candidates as a final PDCCH channel, and sending the downlink control information loaded on the PDCCH channel to the terminal by the base station through the PDCCH channel.

Terminal side

In this embodiment, the terminal side has the following operation characteristics: according to the sequence of the search space numbers from low to high, executing PDCCH candidate discarding operation; for different aggregation levels in the same search space, performing PDCCH candidate discarding operations in the order of the aggregation levels from high to low; for each aggregation in each search space sLevel L, performing PDCCH discard operation in the same manner as the base station, and calculating the PDCCH candidate number M 'reserved after the PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LAnd (4) PDCCH candidate. Terminal to M'_s,LThe PDCCH candidates are selected in the same manner as in the base station.

The terminal performs PDCCH blind detection on a plurality of aggregation levels, and for the PDCCH blind detection using the aggregation level L, the terminal tries to perform the detection on the M'_s,LEach PDCCH candidate location attempts detection of the PDCCH. If the terminal can successfully detect the PDCCH in a PDCCH candidate position on a certain aggregation level, the terminal uses the downlink control information carried by the PDCCH so as to receive the information carried by the corresponding PDSCH according to the indication of the DCI.

Example three

The present example performs the PDCCH candidate discard operation in a manner that the search space ID ordering + RRC notification value n is used for α calculation.

In this example, for scheduling carrier n_CIFor aggregation level L in the search space s, the number of PDCCH candidates remaining after PDCCH discard operation is recorded as M'_s,LThe number of PDCCH candidates before PDCCH discard operation is recorded as M'_s,L。

Side of base station

In this example, the operating characteristics of the base station side are as follows: the base station executes PDCCH candidate discarding operation according to the sequence of the search space numbers from low to high; for different aggregation levels in the same search space, performing PDCCH candidate discarding operations in the order of the aggregation levels from high to low; for each aggregation level L in each search space s, a PDCCH discard operation is performed in the following manner; for M_i,j>0, PDCCH number of candidates M 'reserved after PDCCH discard operation'_s,LThe calculation is as follows:

in this example, for scheduling carrier n_CIThe search space s and the number of PDCCH candidates configured in the aggregation level L are M_s,LPerforming PDCCH candidate discard operation M'_s,L。

The base station informs the value n used for calculation α for the search space s through high-level signaling_s. The base station configures one n for each search space s_sThe value is obtained. Base station according to n of search space s_sThe value determines the α value of the search space s, aggregation level L, over time slot k, for example:

α n of search space s_sN of all search spaces on value/slot k_sThe sum of the values.

Number of PDCCH candidates M 'remaining after calculating PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LA PDCCH candidate. Base station is obtaining the M'_s,LAfter PDCCH candidate, in M'_s,LOne of the PDCCH candidates is selected as an actual PDCCH channel.

For M'_s,LSelection of individual PDCCH candidates, the base station from M_s,LSelecting M 'from PDCCH candidate indexes from low to high'_s,LA PDCCH candidate; or, for M'_s,LSelection of PDCCH candidates, base station from M_s,LSelecting M 'from PDCCH candidate indexes in the order of high to low'_s,LA PDCCH candidate; or, for M'_s,LSelection of individual PDCCH candidates, everyOne PDCCH candidate is selected as a reserved PDCCH candidate by the PDCCH candidates until M 'is selected'_s,LOne reserved PDCCH candidate.

For transmission of PDCCH using aggregation level L, the base station obtains M 'from the above'_s,LIndividual PDCCH candidateIn the method, a PDCCH candidate position is selected as a final PDCCH channel, and the base station sends downlink control information loaded on the PDCCH channel to the terminal through the PDCCH channel.

Terminal side

In this embodiment, the terminal side has the following operation characteristics: the terminal executes PDCCH candidate discarding operation according to the sequence of the search space numbers from low to high; for different aggregation levels in the same search space, performing PDCCH candidate discarding operations in the order of the aggregation levels from high to low; for each aggregation level L in each search space s, a PDCCH dropping operation is performed as follows: for M_s,L>0, PDCCH number of candidates M 'reserved after PDCCH discard operation'_s,LThe calculation is as follows:

in this example, for scheduling carrier n_CIThe search space s and the number of PDCCH candidates configured in the aggregation level L are M_s,LThe number of PDCCH candidates after the PDCCH candidate discard operation is performed is M'_s,L。

The terminal configures a value n for each search space s according to the base station through high-level signaling and used for calculating α_sDetermine α values for search space s, aggregation level L, over time slot k, for example:

α n of search space s_sN of all search spaces on value/slot k_sThe sum of the values.

Number of PDCCH candidates M 'remaining after calculating PDCCH discard operation'_s,LThen, for the aggregation level L on the search space s, from M_s,LM 'is selected from PDCCH candidates'_s,LAnd (4) PDCCH candidate. Terminal is obtaining the above M'_s,LAfter PDCCH candidate, in M'_s,LOne of the PDCCH candidates is selected as an actual PDCCH channel. For M'_s,LFor selection of PDCCH candidates, the terminal uses the same approach as the base station.

The terminal performs PDCCH blind detection on a plurality of aggregation levels, and for the PDCCH blind detection using the aggregation level L, the terminal tries to perform the detection on the M'_s,LEach PDCCH candidate location attempts detection of the PDCCH. If the terminal can successfully detect the PDCCH in a PDCCH candidate position on a certain aggregation level, the terminal uses the downlink control information carried by the PDCCH so as to receive the information carried by the corresponding PDSCH according to the indication of the DCI.

Example four

The principle of the DCI format2-0 PDCCH candidate selection in this example is: the PDCCH candidate indices are in order from low to high.

For DCI format2-0 with aggregation level L in search space s, the base station aggregates M configured with aggregation level L in search space s_s,LIn the candidate positions, M 'is selected according to the descending order of the PDCCH candidate indexes'_s,LA PDCCH candidate; wherein, M'_s,LFor DCI format2-0 with aggregation level L in search space s, the number of PDCCH candidates remaining after performing PDCCH selection/discard operation.

Side of base station

In this example, for downlink control information format2-0, it is configured in search space s, and the number of PDCCH candidates that the base station configures for aggregation level L in search space s is M_s,LNumber of PDCCH candidates M 'for and for downlink control information formats 2-0'_s,LAnd (3) fixing to be 2. In this example, the base station needs M configured from the base station_s,LSelecting M 'from PDCCH candidates'_s,LA PDCCH candidate.

In this example, the base station generates M according to a certain rule_s,LA PDCCH candidate position; for downlink control format2-0 of aggregation level L over search space s, the base station derives from this M_s,LM 'is selected from the PDCCH candidates according to the descending order of PDCCH candidate indexes'_s,LA PDCCH candidate.

For example, for M_s,L＝8，M'_s,LFor search spaces of 2DCI format2-0 in s, for a certain aggregation level L, from M before PDCCH candidate selection is performed_s,LThe individual PDCCH candidate positions are shown in fig. 13A. M 'after PDCCH candidate selection is performed'_s,LThe individual PDCCH candidate positions are shown in fig. 13B.

For downlink control information format2-0 using aggregation level L, M 'obtained from above by P base station'_s,LAnd selecting one PDCCH candidate position from the PDCCH candidates as a final PDCCH channel, and sending the downlink control information with the format of 2-0 to the terminal by the base station through the PDCCH channel.

Terminal side

In this example, for downlink control information format2-0, it is configured in search space s, and the number of PDCCH candidates that the base station configures for aggregation level L in search space s is M_s,LNumber of PDCCH candidates M 'for and for downlink control information formats 2-0'_s,LAnd (3) fixing to be 2. In this example, the terminal needs M configured from the base station_s,LSelecting M 'from PDCCH candidates'_s,LA PDCCH candidate.

In this example, the terminal generates M according to certain rules_s,LA PDCCH candidate position; for the downlink control format2-0 of aggregation level L over the search space s, the terminal follows this M_s,LM 'is selected from the PDCCH candidates according to the descending order of PDCCH candidate indexes'_s,LA PDCCH candidate.

The terminal performs PDCCH blind detection on multiple aggregation levels, and for PDCCH blind detection using aggregation level L, the terminal attempts PDCCH detection. If the terminal can successfully detect the PDCCH in a certain PDCCH candidate position on a certain aggregation level, the terminal obtains the downlink control information carried by the PDCCH.

Example five

The selection principle of the DCI format2-0 PDCCH candidate in this example is: the PDCCH candidates are selected by slot index or the like.

For DCI form with aggregation level L in search space sat2-0, the base station aggregates M configured at level L from M configured for search space s_s,LIn the candidate positions, M 'is selected according to the descending order of the PDCCH candidate indexes'_s,LA PDCCH candidate; wherein, M'_s,LFor DCI format2-0 with aggregation level L in search space s, the number of PDCCH candidates remaining after performing PDCCH selection/discard operation.

Side of base station

In this example, for downlink control information format2-0, it is configured in search space s, and the number of PDCCH candidates that the base station configures for aggregation level L in search space s is M_s,LNumber of PDCCH candidates M 'for and for downlink control information formats 2-0'_s,LAnd (3) fixing to be 2. In this example, the base station needs M configured from the base station_s,LSelecting M 'from PDCCH candidates'_s,LA PDCCH candidate.

In this example, the base station generates M according to a certain rule_s,LA PDCCH candidate position; for downlink control format2-0 of aggregation level L over search space s, the base station derives from this M_s,LAccording to at least one of the following information, calculating the first PDCCH candidate position selected after PDCCH candidate selection is executed according to a certain calculation rule in each PDCCH candidate:

cell Radio Network Temporary identity (C-RNTI);

the time Slot format indicates a cell Radio network temporary Identifier (SFI-RNTI);

a time slot index;

for example, the first PDCCH candidate is at M_s,LThe index in each PDCCH candidate is mod (C-RNTI, M)_s,L). After calculating the first PDCCH candidate index, the base station continues to select other PDCCH candidate indexes according to the descending order and the set interval of the PDCCH candidate indexes from the PDCCH candidate index, and if the PDCCH candidate index selected to the highest is not selected for M'_s,LA PDCCH candidate, continuously selecting PDCCH candidate from PDCCH candidate index with lowest number, and selecting PDCCH candidate index with the sequence from low to high until M'_s,LOne PDCCH candidate. For example, for M_s,L＝8，M'_s,LFor DCI format2-0 in search space s, for a certain aggregation level L, from M before PDCCH candidate selection is performed_s,LThe individual PDCCH candidate positions are shown in fig. 14A. M 'after PDCCH candidate selection is performed'_s,LThe individual PDCCH candidate positions are shown in fig. 14B.

M 'obtained by the base station from the above for the downlink control information format2-0 using aggregation level L'_s,LAnd selecting one PDCCH candidate position from the PDCCH candidates as a final PDCCH channel, and sending the downlink control information with the format of 2-0 to the terminal by the base station through the PDCCH channel.

Terminal side

In this example, for downlink control information format2-0, it is configured in search space s, and the number of PDCCH candidates that the base station configures for aggregation level L in search space s is M_s,LNumber of PDCCH candidates M 'for and for downlink control information formats 2-0'_s,LAnd (3) fixing to be 2. In this example, the terminal needs M configured from the base station_s,LSelecting M 'from PDCCH candidates'_s,LA PDCCH candidate.

In this example, the terminal generates M according to the same rule as the base station_s,LIndividual PDCCH candidate position, i.e. determining M_s,LThe time frequency resource position of each PDCCH candidate. For example, the first PDCCH candidate is at M_s,LThe index in each PDCCH candidate is mod (C-RNTI, M)_s,L). After calculating the first PDCCH candidate index, the terminal continues to select other PDCCH candidate indexes according to the descending order and the set interval of the PDCCH candidate indexes from the PDCCH candidate index, and if the PDCCH candidate index selected to the highest is not enough M'_s,LContinuing to select PDCCH candidates from the PDCCH candidate index with the lowest number, and selecting the PDCCH candidate indexes from low to high in the PDCCH candidate index selection order until M'_s,LOne PDCCH candidate.

The terminal performs PDCCH blind detection on multiple aggregation levels, and for PDCCH blind detection using aggregation level L, the terminal attempts PDCCH detection. If the terminal can successfully detect the PDCCH in a PDCCH candidate position on a certain aggregation level, the terminal obtains the downlink control information carried by the PDCCH.

Example six

The DCI format2-0 PDCCH candidate selection principle of this example is: the number of PDCCH candidates is configured separately for DCI-format 2-0 in the index space.

Side of base station

In Downlink Control Information (DCI) format2-0 in the NR, the maximum number of allowed PDCCH candidates per aggregation level is 2. For the configuration of the search space, one search space may configure multiple downlink control information formats, however, only one PDCCH candidate number is configured for each aggregation level. In order to take care of other downlink control information formats except for downlink control information format2-0, the base station may configure a number of PDCCH candidates significantly greater than 2 for the aggregation level L in the search space s corresponding to format2-0, however, the number of PDCCH candidates in each aggregation level of downlink control information format2-0 cannot exceed 2. Therefore, the number of PDCCH candidates configured by the base station may be greater than the number of PDCCH candidates supported by downlink control information format 2-0.

To solve this problem, in this example, for each aggregation level in the same search space s, the base station configures, through higher layer signaling, one PDCCH candidate number for each downlink control information format in the search space s, for example, the base station configures M PDCCH candidate number for each aggregation level L in the search space s_s,LAnd M is_s,LNot greater than 2.

For downlink control information format2-0 using aggregation level L, the base station obtains M from above_s,LSelecting one PDCCH candidate position from the PDCCH candidates as a final PDCCH channel,and the base station sends the downlink control information with the format of 2-0 to the terminal through the PDCCH channel.

Example seven

The time-frequency resources of the PDCCH candidates of this example are located in W CCEs in the CORESET.

Side of base station

In this example, for scheduling carrier n_CIThe base station configures the number of PDCCH candidates for the aggregation level L in the search space s to be M_s,LIn this example, the base station selects W CCEs from one CORESET, and W is determined according to a threshold value of the CCE number for channel estimation by the terminal; selecting M within the W CCE according to a fixed rule_s,LThe individual PDCCH candidates serve as final PDCCH candidates for the aggregation level L in the search space s. Base station in M_s,LOne PDCCH candidate is selected from the PDCCH candidates to be used as a final PDCCH channel.

In this example, a CORESET bandwidth with number p configured by the base station is shown in fig. 15, and in fig. 15, the frequency domain bandwidth of CORESET p is N_CCE,p96 CCEs. For scheduling carrier n_CIThe base station configures the number of PDCCH candidates for the aggregation level L in the search space s to be M_s,LThe base station determines this M_s,LSpecific implementations of the individual PDCCH candidate locations are as follows.

For any search space s belonging to the CORESET and any aggregation level L, the base station generates M within the range of the W CCEs according to a certain rule_s,LIndividual PDCCH candidate (i.e., determining M)_s,LTime-frequency resource location of individual PDCCH candidates);

the base station selects W CCEs in CORESET according to one of the following rules, where W is 48 in this example:

in CORESET, selecting W CCEs according to the sequence of CCE indexes from low to high;

in CORESET, W CCEs are selected according to the sequence of CCE indexes from high to low;

in CORESET, in CORESET composed of Z CCEs, at equal intervalsSelecting one CCE by every CCE until selecting W which is 48 CCEs;

when W CCEs are selected at equal intervals, a schematic diagram of CCE candidates selected by the base station is shown in fig. 16.

After the base station selects W CCE locations, for all search spaces corresponding to the CORESET, PDCCH candidates at all aggregation levels are generated within the range of W ═ 48 CCEs.

In this example, for scheduling of a certain carrier, the base station configures the number of PDCCH candidates for aggregation level L in search space s to be M_s,LThe terminal selects M from the aforementioned W ═ 48 CCEs according to one of the following rules that are the same as those of the base station_s,LIndividual PDCCH candidates;

within the range of W CCEs, M is selected according to the sequence of CCE indexes from low to high_s,LOne PDCCH candidate, e.g. for aggregation level L-4, M_s,LThe CCE locations corresponding to the first PDCCH candidate among the PDCCH candidates are CCE indexes 0,2,4, and 6 in fig. 16, and the CCE indexes of the second PDCCH candidate are CCE indexes 8,10,12, and 14, and so on.

Within the range of W CCEs, M is selected according to the order of CCE indexes from high to low_s,LOne PDCCH candidate, e.g. for aggregation level L-4, M_s,LThe CCE locations corresponding to the last PDCCH candidate among the PDCCH candidates are CCE indexes 88,90,92, and 94 in fig. 16, and the CCE locations corresponding to the second last PDCCH candidate are CCE indexes 8,0,82, 84, and 86 in fig. 16, and so on.

In this example, for scheduling of a certain carrier, the base station configures the number of PDCCH candidates for aggregation level L in search space s to be M_s,LThe terminal selects M from the W-48 CCEs_s,LThe PDCCH candidate method of (3) may adopt the following methods in addition to the above two methods:

for carrier n_CIFor a search space s linked to said search space p, the aggregation level is LThe number of each PDCCH candidate in the above range of W-48 CCEs is:

wherein, the first and second guide rollers are arranged in a row,or formed of a single material,Yp,-₁＝nRNTI≠0,A₀＝39827,A₁＝39829,A₂＝39839,and D＝65537；

in the above formula, the first and second carbon atoms are, for a corresponding carrier n_CIThe number of PDCCH candidates corresponding to aggregation level L in the scheduled search space s.Is of all carriersMaximum value of (2). n is_RNTIThe RNTI is a radio network identification number, such as a cell radio network temporary identification number, a system information radio network temporary identification number, a slot format indication radio network temporary identification number, a paging radio network temporary identification number, and the like.

The base station determines M in 48 CCEs according to the rule_s,LAfter a PDCCH candidate position, the base station is in the M_s,LOne PDCCH candidate is selected from the PDCCH candidates to be used as a final PDCCH channel. And the base station sends downlink control information to the terminal through the PDCCH.

Terminal side

In this example, for scheduling carrier n_CIThe base station configures the number of PDCCH candidates for the aggregation level L in the search space s to be M_s,LThe terminal selects W CCEs from one CORESET, and then selects M within the W CCEs according to a fixed rule_s,LThe individual PDCCH candidates serve as final PDCCH candidates for the aggregation level L in the search space s.

In this example, a CORESET bandwidth with number p configured by the base station is shown in fig. 15, and in fig. 15, the frequency domain bandwidth of CORESET p is N_CCE,p96 CCEs. For scheduling carrier n_CIThe base station configures the number of PDCCH candidates for the aggregation level L in the search space s to be M_s,LThe terminal determines M_s,LThe specific manner of each PDCCH candidate location is the same as that of the base station.

For any search space s belonging to the CORESET and any aggregation level L, the terminal generates M within the range of the W CCEs according to a certain rule_s,LA PDCCH candidate;

the terminal selects W CCEs in CORESET according to one of the following rules, W being 48 in this example.

In CORESET, selecting W CCEs according to the sequence of CCE indexes from low to high;

in CORESET, W CCEs are selected according to the sequence of CCE indexes from high to low;

in CORESET, in CORESET composed of Z CCEs, at equal intervals

Selecting one CCE by every CCE until selecting W which is 48 CCEs;

when W CCEs are selected at equal intervals, a schematic diagram of CCE candidates selected by the base station is shown in fig. 16.

After the terminal selects W CCE locations, for all search spaces corresponding to the CORESET, PDCCH candidates at all aggregation levels are generated within the range of W ═ 48 CCEs.

In this example, for scheduling of a certain carrier, the base station configures the number of PDCCH candidates for aggregation level L in search space s to be M_s,LThe terminal selects M according to one of the following rules from the W-48 CCEs_s,LPDCCH candidates of (1);

within the range of W CCEs, M is selected according to the sequence of CCE indexes from low to high_s,LOne PDCCH candidate, e.g. for aggregation level L-4, M_s,LThe CCE locations corresponding to the first PDCCH candidate among the PDCCH candidates are CCE indexes 0,2,4, and 6 in fig. 16, and the CCE indexes of the second PDCCH candidate are CCE indexes 8,10,12, and 14, and so on.

Within the range of W CCEs, M is selected according to the order of CCE indexes from high to low_s,LOne PDCCH candidate, e.g. for aggregation level L-4, M_s,LThe CCE positions corresponding to the last PDCCH candidate among the PDCCH candidates are CCE indexes of 88,90,92 and 94 in FIG. 16, the CCE positions corresponding to the second last PDCCH candidate are CCE indexes of 8,0 and 82 in FIG. 16,84,86, and so on.

In this example, for scheduling of a certain carrier, the base station configures the number of PDCCH candidates for aggregation level L in search space s to be M_s,LThe terminal selects M from the W-48 CCEs_s,LThe PDCCH candidate method of (3) may adopt the following methods in addition to the above two methods:

for carrier n_CIFor a search space s linked to said search space p, the aggregation level is LThe number of each PDCCH candidate in the above range of W-48 CCEs is:

wherein, the first and second guide rollers are arranged in a row,or formed of a single material,Y_p，-1＝n_RNTI≠0，A₀＝39827,A₁＝39829,A₂＝39839,and D＝65537；

in the above formula, the first and second carbon atoms are, for a corresponding carrier n_CIThe number of PDCCH candidates corresponding to aggregation level L in the scheduled search space s.Is of all carriersMaximum value of (2). n is_RNTIThe RNTI is a radio network identification number, such as a cell radio network temporary identification number, a system information radio network temporary identification number, a slot format indication radio network temporary identification number, a paging radio network temporary identification number, and the like.

The terminal performs PDCCH blind detection on a plurality of aggregation levels, and for PDCCH blind detection using an aggregation level L, the terminal tries to perform PDCCH blind detection on the M_s,LEach PDCCH candidate location attempts detection of the PDCCH. If the terminal can successfully detect the PDCCH in a PDCCH candidate position on a certain aggregation level, the terminal uses the downlink control information carried by the PDCCH so as to receive the information carried by the corresponding PDSCH according to the indication of the DCI.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments. Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the embodiments of the present invention may be embodied in the form of a software product, which is stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (e.g., a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (32)

1. A method for determining a Physical Downlink Control Channel (PDCCH) comprises the following steps:

the base station determines PDCCH candidates which should be reserved among the configured PDCCH candidates;

and the base station selects one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

2. The method of claim 1, wherein:

the determining, by the base station, the PDCCH candidates to be reserved among the configured PDCCH candidates includes: the base station respectively executes PDCCH candidate discarding operation on each aggregation level in each search space, wherein the PDCCH candidate discarding operation comprises the following steps:

determining the number of PDCCH candidates to be reserved according to a first rule;

and selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule to serve as PDCCH candidates to be reserved, and discarding the rest of the configured PDCCH candidates.

3. The method of claim 2, wherein:

the base station respectively executes PDCCH candidate discarding operation on each aggregation level in each search space, and the operation comprises the following steps: and sequentially executing PDCCH candidate discarding operations on each aggregation level in each search space from low to high.

4. A method according to claim 2 or 3, characterized by:

the base station respectively executes PDCCH candidate discarding operation on each aggregation level in each search space, and the operation comprises the following steps: in a search space, PDCCH candidate discarding operations are respectively performed on the aggregation levels in the order of the aggregation levels from top to bottom or the order of the aggregation levels from bottom to top.

5. The method of claim 2, wherein:

the determining the number of PDCCH candidates to be reserved according to the first rule includes:

for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0 and calculating the number M 'of PDCCH candidates to be reserved'_s,LWhen being 0, then let M'_s,L＝1。

6. The method of claim 2, wherein:

the determining the number of PDCCH candidates to be reserved according to the first rule includes:

informing terminals for calculating M 'through high-layer signaling'_s,LNumber n of_s，M'_s,LIs the number of PDCCH candidates that the aggregation level L within the search space s should reserve;

according to the formulaCalculate M'_s,LWherein α equals n for the search space s on the current time slot_sDivided by n of other multiple search spaces on the current time slot_sThe quotient resulting from the sum of the values,indicating a rounding down.

7. The method of claim 2, wherein:

the determining the number of PDCCH candidates to be reserved according to the first rule includes:

for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0, the number of PDCCH candidates that should be reservedWherein α is the ratio of the threshold value of the number of CCE channel estimation of the terminal to the number of CCE needed to perform channel estimation of the terminal at the current time slot determined according to the configuration,indicating rounding up.

8. The method of claim 2, wherein:

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for aggregation level L in search space s, in order of PDCCH candidate index from low to high, orFrom high to low, or at equal intervals, from arranged M_s,LM 'is selected in PDCCH (physical downlink control channel) candidate'_s,LPDCCH candidate, M ', which should be reserved'_s,LIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0。

9. The method of claim 2, wherein:

the base station selects a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved, and the method comprises the following steps:

for aggregation level L in search space s, every otherIndividual PDCCH candidates, from configured M_s,LSelecting one PDCCH as a PDCCH candidate to be reserved in the PDCCH candidates until M 'is selected'_s,LM 'to PDCCH candidates'_s,LIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0，Indicating a rounding down.

10. The method of claim 2, wherein:

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for a downlink control information format DCI format2-0 with aggregation level L in a search space s, according to the descending order of PDCCH candidate indexes, or the ascending order, or the equal interval mode, from the configured M_s,LPDCCH candidate selection M'_s,LPDCCH candidate, M ', that should be reserved'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

11. The method of claim 2, wherein:

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for DCI format2-0 with aggregation level L in search space s, firstly, according to at least one information of cell radio network temporary identifier C-RNTI, time slot format indication cell radio network temporary identifier SFI-RNTI and time slot index, calculating configured M_s,LThe first PDCCH candidate which should be reserved is selected from the PDCCH candidates, and other M 'is selected based on the first PDCCH candidate'_s,L-1 PDCCH candidates, M ', that should be reserved'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

12. The method of claim 11, wherein:

the determining of other M 'based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved, comprising:

starting from the first PDCCH candidate to be reserved, every otherSelecting a PDCCH candidate which should be reserved by the PDCCH candidates until M 'is selected again'_s,L-1 PDCCH candidates that should be reserved.

13. A method for determining a Physical Downlink Control Channel (PDCCH) comprises the following steps:

the base station respectively configures the PDCCH candidate number of each downlink control channel format on each aggregation level through a high-level signaling for each downlink control channel format in the search space;

and the base station selects one PDCCH candidate from the PDCCH candidates configured for the downlink control channel format as a PDCCH to send the downlink control information of the downlink control channel format to the terminal.

14. A method for determining a Physical Downlink Control Channel (PDCCH) comprises the following steps:

the base station selects W CCEs from a control resource set CORESET according to a set rule;

the base station determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

and the base station selects one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

15. The method of claim 14, wherein:

the base station selects W CCEs from a control resource set CORESET according to a set rule, and the method comprises the following steps:

selecting W CCEs according to the sequence of CCE indexes from low to high; or

Selecting W CCEs according to the sequence of the CCE indexes from high to low; or

Each intervalOne CCE is selected by the CCEs until W CCEs, N, are selected_CCE,pIs the number of CCEs making up the CORESET,represents rounding down;

wherein, W is determined according to the threshold value of the number of CCEs for channel estimation by the terminal.

16. The method of claim 14 or 15, wherein:

the base station determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs, and the method comprises the following steps: for the aggregation level L in the search space s, the time-frequency resource location of the configured PDCCH candidate is determined as follows:

within the range of W CCEs, according toDetermining M in the sequence of CCE indexes from low to high_s,LTime-frequency resource position of each PDCCH candidate; or

Within the range of W CCEs, determining M according to the sequence of CCE indexes from high to low_s,LTime-frequency resource position of each PDCCH candidate; or

Determining M in an equally spaced manner within the range of W CCEs_s,LTime-frequency resource position of each PDCCH candidate;

wherein M is_s,LIs the number of PDCCH candidates configured by the base station for the aggregation level L within the search space s.

17. A method for detecting a Physical Downlink Control Channel (PDCCH) comprises the following steps:

the terminal determines the reserved PDCCH candidates in the configured PDCCH candidates;

and the terminal tries to receive the downlink control information carried by the PDCCH at the reserved time-frequency resource position of the PDCCH candidate.

18. The method of claim 17, wherein:

the determining, by the terminal, the PDCCH candidates to be reserved among the configured PDCCH candidates includes: the terminal respectively executes PDCCH candidate discarding operations on each aggregation level in each search space, wherein the PDCCH candidate discarding operations comprise:

determining the number of PDCCH candidates to be reserved according to a first rule;

and selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule to serve as PDCCH candidates to be reserved, and discarding the rest of the configured PDCCH candidates.

19. The method of claim 18, wherein:

the terminal respectively executes PDCCH candidate discarding operations on each aggregation level in each search space, and the operations comprise: and sequentially executing PDCCH candidate discarding operations on each aggregation level in each search space from low to high.

20. The method of claim 18, wherein:

the determining the number of PDCCH candidates to be reserved according to the first rule includes:

for aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0 and calculating the number M 'of PDCCH candidates to be reserved'_s,LWhen being 0, then let M'_s,L1 is ═ 1; or

Informing terminals for calculating M 'through high-layer signaling'_s,LNumber n of_s，M'_s,LIs the number of PDCCH candidates that the aggregation level L within the search space s should reserve; according to the formulaCalculate M'_s，LWherein α equals n for the search space s on the current time slot_sDivided by n of other multiple search spaces on the current time slot_sThe quotient resulting from the sum of the values,represents rounding down; or

For aggregation level L within search space s, the number M of PDCCH candidates if configured_s,L>0, the number of PDCCH candidates that should be reservedWherein α is the ratio of the threshold value of the number of CCE channel estimation of the terminal to the number of CCE needed to perform channel estimation of the terminal at the current time slot determined according to the configuration,indicating rounding up.

21. The method of claim 18, wherein:

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for the aggregation level L in the search space s, the configured M is selected according to the descending order or ascending order of PDCCH candidate indexes_s,LM 'is selected in PDCCH (physical downlink control channel) candidate'_s,LThe PDCCH candidates to be reserved; or

For aggregation level L in search space s, every otherIndividual PDCCH candidates, from configured M_s,LSelecting one PDCCH as a PDCCH candidate to be reserved in the PDCCH candidates until M 'is selected'_s,LThe PDCCH candidates are selected;

wherein, M'_s,LIs the number of PDCCH candidates to be reserved, M, determined according to said first rule_s,L>0，M'_s,L>0，Indicating a rounding down.

22. The method of claim 18, wherein:

selecting a corresponding number of PDCCH candidates from the configured PDCCH candidates according to a second rule as PDCCH candidates to be reserved includes:

for a downlink control information format DCI format2-0 with aggregation level L in a search space s, according to the descending order of PDCCH candidate indexes, or the ascending order, or the equal interval mode, from the configured M_s,LPDCCH candidate selection M'_s,LA PDCCH candidate that should be reserved; or

For DCI format2-0 with aggregation level L in search space s, firstly, according to at least one information of cell radio network temporary identifier C-RNTI, time slot format indication cell radio network temporary identifier SFI-RNTI and time slot index, calculating configured M_s,LThe first PDCCH candidate which should be reserved is selected from the PDCCH candidates, and other M 'is selected based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved;

wherein, M'_s,LIs the maximum number of PDCCH candidates allowed by DCI format2-0, M_s,L>0，M'_s,L>0。

23. The method of claim 22, wherein:

determining other M 'based on the first PDCCH candidate'_s,L-1 PDCCH candidates that should be reserved, comprising: starting from the first PDCCH candidate to be reserved, every otherSelecting a PDCCH candidate which should be reserved by the PDCCH candidates until M 'is selected again'_s,L-1 PDCCH candidates that should be reserved.

24. A method for detecting a Physical Downlink Control Channel (PDCCH) comprises the following steps:

the terminal selects W CCEs from a control resource set CORESET according to a set rule;

the terminal determines the time-frequency resource position of the PDCCH candidate to be detected in the range of the W CCEs for each aggregation level in each search space belonging to the CORESET;

and the terminal tries to receive the downlink control information carried by the PDCCH at the time-frequency resource position of the PDCCH candidate to be detected.

25. The method of claim 24, wherein:

the terminal selects W CCEs from a control resource set CORESET according to a set rule, and the method comprises the following steps:

selecting W CCEs according to the sequence of CCE indexes from low to high; or

Selecting W CCEs according to the sequence of the CCE indexes from high to low; or

Each intervalThe number of CCEs selects one CCE to be used,until W CCEs, N are selected_CCE,pIs the number of CCEs making up the CORESET,represents rounding down;

wherein, W is determined according to the threshold value of the number of CCEs for channel estimation by the terminal.

26. The method of claim 24 or 25, wherein:

the terminal determines the time-frequency resource position of the configured PDCCH candidates in the range of the W CCEs, and the determination comprises the following steps: for the aggregation level L in the search space s, the time-frequency resource location of the configured PDCCH candidate is determined as follows:

within the range of the W CCEs, determining M according to the sequence of CCE indexes from low to high_s,LTime-frequency resource position of each PDCCH candidate; or

Within the range of W CCEs, determining M according to the sequence of CCE indexes from high to low_s,LTime-frequency resource position of each PDCCH candidate; or

Determining M in an equally spaced manner within the range of W CCEs_s,LTime-frequency resource position of each PDCCH candidate;

wherein M is_s,LIs the number of PDCCH candidates configured by the base station for the aggregation level L within the search space s.

27. A device for determining a Physical Downlink Control Channel (PDCCH) comprises:

a PDCCH candidate determining module, configured to determine PDCCH candidates to be reserved among the configured PDCCH candidates;

and the PDCCH selection module is used for selecting one PDCCH candidate from the reserved PDCCH candidates as a PDCCH for sending downlink control information to the terminal.

28. A device for determining a Physical Downlink Control Channel (PDCCH) comprises:

the resource selection module is used for selecting W CCEs from a control resource set CORESET according to a set rule;

a PDCCH candidate determining module, configured to determine, for each aggregation level in each search space belonging to the CORESET, a time-frequency resource location of a configured PDCCH candidate within a range of the W CCEs;

and the PDCCH selection module is used for selecting one PDCCH candidate from the configured PDCCH candidates as a PDCCH for sending the downlink control information to the terminal.

29. A base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor performs the processing of the method according to claims 1-16.

30. A detection device for a Physical Downlink Control Channel (PDCCH) comprises the following components:

a PDCCH candidate determination module for determining a reserved PDCCH candidate among the configured PDCCH candidates;

and the PDCCH detection module is used for trying to receive the downlink control information carried by the PDCCH in the reserved time-frequency resource position of the PDCCH candidate.

31. A detection device for a Physical Downlink Control Channel (PDCCH) comprises the following components:

the resource selection module is used for selecting W CCEs from a control resource set CORESET according to a set rule;

a PDCCH candidate determining module, configured to determine, within the range of the W CCEs, a time-frequency resource location of a PDCCH candidate to be detected for each aggregation level in each search space belonging to the CORESET;

and the PDCCH detection module is used for trying to receive the downlink control information carried by the PDCCH at the time-frequency resource position of the PDCCH candidate to be detected.

32. A terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor performs the processing of the method according to claims 17-26.